Elevated fasting cholecystokinin levels in pancreatic exocrine impairment: evidence to support feedback regulation

Previous studies have suggested that intraduodenal protease suppression of pancreatic exocrine secretion may be mediated through cholecystokinin (CCK) release. Our study compares basal plasma immunoreactive CCK concentrations in normal human subjects with those obtained in patients with chronic pancreatitis. Fasting plasma samples were collected from 18 normal subjects and from 18 patients with chronic pancreatitis. Eight patients had mild to moderate pancreatic exocrine impairment, and 10 had severe exocrine insufficiency. Venous plasma immunoreactive CCK concentrations were measured with two distinct peptide region-specific antibodies. Basal plasma CCK concentration in controls was 14.3 +/- 1.3 fmol/ml (mean +/- SEM), a value significantly less than that obtained in all patients with chronic pancreatitis, 30.1 +/- 4.0 fmol/ml (p less than 0.001). Patients with mild to moderate impairment had a fasting plasma CCK concentration of 32.8 +/- 7.9 fmol/ml (vs. control p less than 0.01), and those with severe disease 27.9 +/- 3.6 fmol/ml (vs. control p less than 0.001). In five patients with mild to moderate impairment of exocrine function and pancreatic extract-responsive abdominal pain, there was a 39 +/- 11% decrease in basal CCK levels during extract therapy (p less than 0.05). Results of this study indicate that pancreatic exocrine impairment is associated with elevated basal CCK levels, which may reflect a failure to provide feedback downmodulation of CCK release.     

Diastolic Potentials Recorded by Surface Electrocardiographic Signal Averaging During Sustained Ventricular Tachycardia: Possible Origin From the Reentrant Circuit

ECG signal averaging can detect low amplitude diastolic potentials in sinus rhythm. We, therefore, recorded signal-averaged ECGs during eight episodes of inducible uniform sustained VT with coincident atrial pacing to look for continuous diastolic electrical activity. Simultaneous AV pacing in seven patients served as controls. The number of QRS complexes averaged (187 +/- 47 vs 183 +/- 63), the noise level (1.26 +/- 0.88 vs 1.39 +/- 0.47) and cycle length (385 +/- 52 vs 404 +/- 40) did not differ between VT and paced recordings. In each lead the difference in onset between the unfiltered surface recording and the filtered data (40 Hz bidirectional) was significantly greater in VT than the paced recordings (25 +/- 16 vs 11 +/- 8 msec, P = 0.0012). These late diastolic (pre-QRS) potentials were greater than 15 msec duration in 65% of the leads in VT versus 20% of paced recording (P = 0.021). The maximum value was greater than 20 msec in six VT (75%) versus one (14%) paced recording (P = 0.019). The earliest filtered onset in any lead preceeded the earliest surface activity by greater than 12 msec, in 6 VT versus one paced recording (P = 0.019). Early diastolic (post-QRS) potentials were also longer in VT than pacing (49 +/- 40 versus 5 +/- 20, P = 0.001) and exceeded 38 msec in seven of the VTs but none of the paced recordings (P = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

P wave dispersion on 12-lead electrocardiography in patients with paroxysmal atrial fibrillation

The prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses have been shown in patients with atrial fibrillation. Recently P wave dispersion (PWD), which is believed to reflect inhomogeneous atrial conduction, has been proposed as being useful for the prediction of paroxysmal atrial fibrillation (PAF). Ninety consecutive patients (46 men, 44 women; aged 55 +/- 13 years) with a history of idiopathic PAF and 70 healthy subjects (42 men, 28 women; mean age 53 +/- 14 years) were studied. The P wave duration was calculated in all 12 leads of the surface ECG. The difference between the maximum and minimum P wave duration was calculated and this difference was defined as P wave dispersion (PWD = Pmax-Pmin). All patients and controls were also evaluated by echocardiography to measure the left atrial diameter and left ventricular ejection fraction (LVEF). There was no difference between patients and controls in gender (P = 0.26), age (P = 0.12), LVEF (66 +/- 4% vs 67 +/- 5%, P = 0.8) and left atrial diameter (36 +/- 4 mm vs 34 +/- 6 mm, P = 0.13). P maximum duration was found to be significantly higher in patients with a history of PAF (116 +/- 17 ms) than controls (101 +/- 11 ms, P < 0.001). P wave dispersion was also significantly higher in patients than in controls (44 +/- 15 ms vs 27 +/- 10 ms, P < 0.001). There was a weak correlation between age and P wave dispersion (r = 0.27, P < 0.001). A P maximum value of 106 ms separated patients with PAF from control subjects with a sensitivity of 83%, a specificity of 72%, and a positive predictive accuracy of 79%. A P wave dispersion value of 36 ms separated patients from control subjects with a sensitivity of 77%, a specificity of 82%, and a positive predictive accuracy of 85%. In conclusion, P maximum duration and P wave dispersion calculated on a standard surface ECG are simple ECG markers that could be used to identify the patients with idiopathic paroxysmal atrial fibrillation.     

Plasma trypsin in chronic pancreatitis and pancreatic adenocarcinoma.

We have used a simple and precise radioimmunoassay to measure trypsin in human plasma. Fasting plasma trypsin concentrations were extremely low in patients with chronic pancreatitis with steatorrhoea (5 +/- 2 ng/ml) when compared to healthy controls (86 +/- 7 ng/ml, p less than 0.001). In patients with chronic pancreatitis but no steatorrhoea basal plasma trypsin levels were similar to those of the normal controls (99 +/- 25 ng/ml). A small but significant postprandial rise in plasma trypsin concentrations was observed in normal subjects (mean increment 15 +/- 4%, p less than 0.005, paired t test) but was absent in patients with chronic pancreatitis with steatorrhoea. In contrast to exocrine deficient chronic pancreatitis, other malabsorptive conditions associated with steatorrhoea (active coeliac disease and acute tropical sprue) demonstrated mean fasting trypsin concentrations similar to controls. Patients with adenocarcinoma of the pancreas had basal trypsin concentrations similar to healthy subjects as did patients with adenocarcinoma of the stomach, colon, rectum, brochus, and breast. In some cases measurement of plasma trypsin may be of help in the differential diagnosis of steatorrhoea.     

Endoscopic ultrasonography (EUS) and fine-needle aspiration (FNA) cytology for diagnosis of chronic pancreatitis

BACKGROUND AND STUDY AIMS: Previous studies have shown that endoscopic ultrasonography (EUS) sensitively detects morphologic abnormalities due to chronic pancreatitis. However, morphologic EUS findings have limited specificity, particularly at the early stages of chronic pancreatitis. Our aims were to study pancreatic morphology and inflammation in patients with chronic pancreatitis, using EUS and fine-needle aspiration cytology (EUS-FNA), and to compare the results with those of endoscopic retrograde cholangiopancreatography (ERCP) and pancreatic function tests. PATIENTS AND METHODS: 37 patients (48 +/- 13 years) with clinical symptoms and laboratory test findings suggestive of chronic pancreatitis were prospectively studied. Patients with malignancy or major concomitant disorders were excluded. Clinical evaluation included indirect pancreatic function tests. Morphologic criteria for chronic pancreatitis included echo-intense septae/echo-reduced foci (i. e. pseudolobularity), ductal irregularities, and calcifications. EUS-FNA was performed in 27/37 patients, by means of the Hitachi FG34-UX echo endoscope and a 22-gauge needle, and tissue specimens were submitted for standard cytological evaluation. ERCP served as reference in all patients, using the Cambridge classification. RESULTS: 31 patients had chronic pancreatitis while six had normal findings at ERCP. EUS showed morphologic abnormalities of the pancreas in 33 patients. Morphologic abnormalities alone reached a sensitivity of 97 % for chronic pancreatitis with a specificity of only 60 %, while the positive predictive value (PPV) was 94 %, and the negative predictive value (NPV) was 75 %. EUS-FNA increased the negative predictive value to 100 % and the specificity to 67 %. On average, 2.3 needle passes were necessary to obtain sufficient amounts of tissue. The correlation of EUS findings with pancreatic function tests was poor. EUS results were in agreement with regard to the severity of chronic pancreatitis in 5/8 patients with grade I disease, in 11/13 patients with grade II, and in 10/10 patients with grade III disease. Minor complications occurred in two patients (7 %). CONCLUSIONS: EUS is as sensitive and effective as ERCP in the detection of chronic pancreatitis, particularly when only mild disease is present. However, EUS findings have limited specificity, particularly in patients with mild disease. EUS-FNA with cytology is safe and improves the negative predictive value. Negative EUS-FNA findings rule out chronic pancreatitis, but cytological investigation alone does not improve the specificity of EUS findings, suggesting that further improvements in tissue sampling and analysis are necessary to support routine use of FNA in patients with chronic pancreatitis.     

Depletion of OX-8 lymphocytes from the blood and airways using monoclonal antibodies enhances the late airway response in rats.

Recent evidence supports a role for T lymphocytes in allergic airway responses. We hypothesized that reducing blood T suppressor cells (Ts) might increase the late airway response (LR). Sprague-Dawley (SD) rats were sensitized with ovalbumin (OA). On days 8, 10, and 12, post-sensitization test SD (n = 14) received monoclonal antibody intravenously (OX-8; 1 mg) specific to rat Ts. Controls received saline (n = 7) or mouse ascites IgG (n = 7). On day 14, animals were challenged with OA aerosol (5% wt/vol) for 5 min, lung resistance was recorded for 8 h (n = 18) and bronchoalveolar lavage was performed. The LR was determined from the area under the lung resistance vs time curve from 75 to 480 min after challenge. In the remaining 10 rats, airway lymphocyte subsets were measured 8 h after OA aerosol challenge in minced and digested lungs. A decrease in percentage of blood and airway Ts, respectively, in test animals was observed vs controls (blood: 6.27 +/- 0.84 vs 32.95 +/- 1.94, P < 0.001); (airway: 5.05 +/- 0.66 vs 24.5 +/- 3.05, P < 0.02). Blood and airway helper T lymphocytes did not differ between test and control animals. The LR was significantly increased in test (22.89 +/- 3.92) vs controls (4.22 +/- 2.18, P < 0.001). Bronchoalveolar lavage macrophages, neutrophils and lymphocytes, and serum OA-specific IgE were also significantly elevated (P < 0.05) in test animals. We conclude that Ts play an important role in attenuating the LR in SD rats.     

Magnesium deficiency in patients with chronic pancreatitis identified by an intravenous loading test

Magnesium deficiency is a common clinical condition that may exist despite a normal serum magnesium concentration. Patients with chronic pancreatitis could develop magnesium deficiency due to either malabsorption, diabetes mellitus, or chronic alcoholism. Since serum levels of magnesium are a poor indicator of magnesium deficiency, the retention of a low-dose intravenous magnesium load (0.1 mmol/kg body weight) was determined in 13 patients with chronic pancreatitis (10 due to alcoholism) and eight healthy controls. Percentage magnesium retention was greater in patients with chronic pancreatitis than controls (59.8+/-37.3% S.D. versus 22.0+/-38.2% S. D.: P=0.038), and 10 of 13 patients showed evidence of magnesium deficiency. Routine evaluation of magnesium status could allow appropriate supplementation and conceivably symptomatic improvement in patients with severe chronic pancreatitis.     

Distinct clinical features in the recipients of the implantable cardioverter defibrillator in Taiwan: a multicenter registry study

Little information about the ICD is available from the Asian Pacific region. The purpose of this study was to characterize the clinical features in ICD patients in Taiwan and to compare these features with those in patients in the Western populations, mainly the Canadian Implantable Defibrillator Study (CIDS), the Antiarrhythmics versus Implantable Defibrillator (AVID) trial, and the Cardiac Arrest Study Hamburg (CASH) trial. From February 1995 to October 2001, 101 ICDs were implanted in 92 patients (78 [84%] men) in 12 hospitals. Clinical presentations included sudden cardiac death due to VF/VT in 35 (38%) patients, syncopal VT in 25 (27%), drug refractory nonsyncopal VT in 27 (29%), and unexplained syncope with inducible sustained VT/VF in 5 (6%). The mean age was significantly younger than that in CIDS or AVID (59 +/- 16 vs 63 +/- 9 years in CIDS, P = 0.02; vs 65 +/- 11 years in AVID, P < 0.001), but was comparable to that in CASH (59 +/- 16 vs 58 +/- 11 years in CASH, P = 0.75). The mean LVEF was significantly higher than that in CIDS or AVID (48 +/- 19% vs 34 +/- 15% in CIDS, P < 0.001; vs 32 +/- 13% in AVID, P < 0.001), but was comparable to that in CASH (48 +/- 19 vs 46 +/- 19% in CIDS, P = 0.83). The ICD patients in the current study also showed a higher incidence of normal heart (23 vs 4% in CIDS, P < 0.001; vs 3% in AVID, P < 0.001; vs 9% in CASH, P < 0.001) and cardiomyopathy (41% vs 10% in CIDS, P < 0.001; vs 15% in AVID, P < 0.001; vs 11% in CASH, P < 0.001), but a lower incidence of coronary artery disease (29% vs 83% in CIDS, P < 0.001; vs 82% in AVID, P < 0.001; vs 73% in CASH, P < 0.001). During a mean follow-up of 28 +/- 24 months, 13 (14%) patients died. Older age was the only factor associated with poorer survival after ICD implantation. Forty-seven (51%) patients received appropriate ICD discharges during follow-up. History of prior myocardial infarction was the only factor associated with an earlier first appropriate ICD discharge and LVEF < 0.35 the only factor associated with subsequent poorer survival after the first ICD discharge. In conclusion, this study demonstrated many distinct clinical features in our ICD population that were different from those in the Western populations.     

Severe aortic valve stenosis with preserved and reduced systolic left ventricular function: diagnostic usefulness of the Tei index.

BACKGROUND: In patients with severe aortic valve stenosis (AS), the onset of heart failure is associated with increased mortality and higher operative risk. Heart failure may result from either systolic, diastolic, or "overall" left ventricular dysfunction. The index "isovolumic contraction time and isovolumic relaxation time divided by ejection time" was shown to be a sensitive indicator of "overall" cardiac dysfunction in patients with dilated cardiomyopathy and cardiac amyloidosis. We sought to define the role of the Tei index in patients with severe AS and to validate this index against conventional measures of systolic and diastolic LV function. PATIENTS AND METHODS: Fifty-three participants underwent left heart catheterization for invasive measurement of LV end-diastolic pressure as a marker of diastolic function: 10 AS patients (valve orifice 0.6 +/- 0.2 qcm) with depressed systolic LV function (defined by LV ejection fraction < or = 45% [mean 32% +/- 8%], 7 male/3 female, 72 +/- 10 years old, DAS group), 22 AS patients (valve orifice 0.7 +/- 0.2 qcm) with preserved systolic LV function (ejection fraction > 45% [mean 55% +/- 6%], 13 male/9 female, 71 +/- 11 years old, PAS group) and 21 asymptomatic control participants (ejection fraction > 45% [mean 62% +/- 8%], 14 male/7 female, 66 +/- 8 years old, CON group). Within 24 hours from catheterization, conventional 2-dimensional and Doppler echocardiographic examination including measurement of the Tei index was performed. RESULTS: LV end-diastolic pressure was elevated in the DAS and in the PAS group in comparison with control participants (32 +/- 6 mm Hg and 22 +/- 7 mm Hg vs 11 +/- 4 mm Hg, respectively, P <.01 for both comparisons). DAS patients were in a higher New York Heart Association functional class than PAS patients (3.2 +/- 0.4 vs 2.2 +/- 0.4, P <.001) The Tei index was easily and reproducibly obtained in all study participants. In the DAS group, isovolumic contraction time was prolonged and ejection time was shortened in comparison with the CON group (102 +/- 20 ms vs 52 +/- 15 ms, P <.01; and 235 +/- 44 ms vs 316 +/- 45 ms, P <.01), resulting in a significantly increased Tei index (0.78 +/- 0.28 vs 0.40 +/- 0.11, P <.01). In the PAS group, isovolumic relaxation time was shortened (62 +/- 18 ms vs 81 +/- 26 ms for the CON group, P <.01) and ejection time was prolonged (335 +/- 34 ms vs 316 +/- 45 ms for the CON group, P <.05), resulting in a decreased Tei index (0.29 +/- 0.12 vs 0.40 +/- 0.11, P <.05). Receiver operating characteristic curve analysis for the Tei index yielded an area under the curve of 0.98 +/- 0.03 for separating DAS and PAS patients. Using a Tei index greater than 0.42 as a cutoff, DAS patients were identified with a sensitivity of 100% and a specificity of 91%. CONCLUSION: The Tei index is significantly increased in patients with severe AS and depressed overall cardiac LV function. In AS patients with predominant diastolic dysfunction, in whom systolic function is preserved, the index is decreased in comparison with control patients. The index differentiates between symptomatic AS patients with depressed and less symptomatic AS patients with preserved systolic LV function, and may thus provide relevant information in the work-up and care of such patients.     

The glucoregulatory and antilipolytic actions of insulin in abdominal obesity with normal or impaired glucose tolerance: an in vivo and in vitro study

To evaluate the effects of obesity and impaired glucose tolerance on insulin sensitivity, we performed a euglycaemic-hyperinsulinemic clamp at about 350 pmol l-1, combined with 3H-glucose infusion, in 14 obese patients, BMI 36.5 +/- 1.2 and in 12 matched controls, BMI 23.9 +/- 0.4. Six obese patients had normal glucose tolerance (oNGT), and eight had impaired glucose tolerance (oIGT). The ability of insulin to inhibit lipolysis in isolated adipocytes was also studied. Insulin-mediated glucose utilization was more severely impaired in oIGT than in oNGT with respect to the controls (621 +/- 51 vs. 897 +/- 83 vs. 1298 +/- 55 mumol m-2 min-1, P < 0.001). Plasma glycerol was higher in oIGT than in oNGT and in the controls, both fasting (238 +/- 12 vs. 179 +/- 14 vs. 112 +/- 8 mumol l-1, P < 0.001) and during the clamp (175 +/- 21 vs. 120 +/- 12 vs. 36 +/- 6 mumol l-1, P < 0.001). The correlation between glucose utilization and the percent reduction of plasma glycerol during the clamp was significant in the study group as a whole (r = 0.809, P = 0.0001), and in each of the groups separately (oIGT: r = 0.929, P = 0.002; oNGT: r = 0.943, P = 0.036; controls: r = 0.902, P = 0.0001). Inhibition by insulin of noradrenaline-stimulated lipolysis in isolated adipocytes was more severely impaired in oIGT than in oNGT compared with the controls (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Electrophysiologic characteristics of atria in patients without heart disease

BACKGROUND: The significance of atrial fibrillation or tachycardia (AF) induction remains debatable. Some believe that the presence of heart disease (HD) increases the sensitivity and decreases the specificity of programmed atrial stimulation (PAS). There are few data in patients without HD. The purpose of the study was to evaluate the results of PAS in asymptomatic patients without HD and in those with documented spontaneous AF, but without HD, to know the diagnosis value of the technique. METHODS: A total of 4,900 PAS were consecutively performed. The control group (I, N=67) was defined by the absence of preexcitation syndrome, dizziness/syncope, hypertension, history of tachycardia, or other documented HD together with a normal 2D echocardiogram and 24-hour Holter monitoring. They were compared to a group (II) of 54 patients with documented paroxysmal AF and without HD. PAS used one and two extrastimuli, delivered during sinus rhythm and two drive rates (600, 400 ms). Atrial-effective refractory periods (ARP), their adaptation to cycle length, and conduction times were noted. AF induction was defined as the induction of AF lasting more than 1 minute. RESULTS: Group I patients (1.4% of 4,900) were younger than group II (51 +/- 17 vs 65 +/- 11 years, P < 0.001). A single extrastimulus never induced sustained AF in group I, but did so in 11 group II patients (20%); sustained AF was induced by two extrastimuli in 15 group I patients (22%) and in 31 group II patients (57%) (P < 0.001). There were no ARP and conduction time differences in group I patients with and without inducible AF, but there was a longer sinus cycle length in patients with inducible AF (977 +/- 164 vs 838 +/- 141 ms, P < 0.02). There were no electrophysiological differences in group II patients with and without inducible AF. No group I patient developed spontaneous AF (follow-up 4 +/- 2 years). The sensitivity of PAS with one extrastimulus was 20% and the specificity 100%; the sensitivity of PAS with two extrastimuli was 57% and the specificity 78%. CONCLUSION: Sustained AF was not induced by one extrastimulus in control patients without symptoms, nor heart disease, but sustained AF was induced by two extrastimuli in 22% of these patients. The induction of a sustained AF by two extrastimuli should be interpreted cautiously, particularly in patients with a relative sinus bradycardia. However, the sensitivity of PAS with one extrastimulus was very low and two extrastimuli were required in patients with spontaneous AF to induce the tachycardia. Other electrophysiological parameters were not useful to differentiate patients with and without inducible AF.     

Cardiac autonomic dysfunction in obese subjects

1. The prevalence of cardiac autonomic alterations was evaluated in 23 obese subjects with body mass index 37.2 +/- 3.03 kg/m2 (mean +/- SD), compared with 78 controls with body mass index 22.5 +/- 2.6 kg/m2 (P less than 0.001). 2. Cardiac autonomic function was assessed by four standard tests (heart rate response to deep breathing and to the Valsalva manoeuvre, systolic blood pressure fall after standing and diastolic pressure rise during handgrip) and by the cross-correlation test, a new method of computerized analysis of respiratory sinus arrhythmia based on spectral analysis of electrocardiographic and respiratory signal. 3. Considering tests indicative of parasympathetic function, only the heart rate response to the deep breathing and the cross-correlation test were significantly lower in the obese than in the control group [deep breathing = 13.95 +/- 8.65 beats/min (mean +/- SD) vs 24.5 +/- 7.65, P less than 0.001; cross-correlation 4.28 +/- 0.74 units vs 5.14 +/- 0.63, P less than 0.001]. Deep breathing and/or cross-correlation were abnormal in 10 (43.5%) obese subjects (deep breathing: seven subjects, cross-correlation: eight subjects). No significant difference between groups was found for the response to the Valsalva manoeuvre: the Valsalva ratio was 1.69 +/- 0.45 in obese subjects and 1.88 +/- 0.33 in controls (P = NS). The Valsalva ratio was abnormal in three obese subjects. 4. No significant differences were found between groups for tests indicative of sympathetic function.(ABSTRACT TRUNCATED AT 250 WORDS)     

Using the initial vector from surface electrocardiogram to distinguish the site of outflow tract tachycardia

BACKGROUND: The purpose of this study is to determine whether initial vector force might best distinguish tachycardias arising from the right ventricular (RV) outflow tract (OT) versus aortic sinus cusps (ASCs). METHODS: Among 45 patients with OT tachycardia, we measured the time from the earliest QRS onset in any lead to local onset and to the first QRS peak/nadir in each surface leads during VT. We compared the earliest phase differences among patients with foci in RVOT (n = 32) and in ASCs (n = 13) (determined by ablation), using unpaired t-tests. We determined the optimum cut-points by analyzing the receiver-operator characteristics curves, and derived an algorithm to discriminate ASC from RVOT foci. RESULTS: Compared with an RVOT focus, origin in the ASC was associated with lower likelihood that the earliest lead of QRS activation was V2 (4/13 [12%] vs 29/32 [88%], P = 0.0001), later initial peak/nadir in III (110 +/- 19 vs 93 +/- 16 ms, P = 0.0026) and V2 (75 +/- 26 vs 42 +/- 19 ms, P < 0.0001). After determining the optimum cut-points for each, we found that the presence of any one of these findings discriminated well between RVOT and ASC foci (sensitivity 92%, specificity 88%, positive predictive value 75%, and negative predictive value 97%). The sensitivity and specificity using standard ECG criteria were inferior to the vector approach. CONCLUSIONS: The ECG phase differences during VT can distinguish the origin of OT-VT. Earliest onset or first peak/nadir in V2 and early initial peak/nadir in the inferior leads suggest a RVOT focus.     

基于深度学习的肝外伤超声图像自动识别模型

目的建立基于深度学习的卷积神经网络肝损伤模型（CNLDM）,并评估其对肝实质挫裂伤的诊断价值。 方法通过动物实验获得2009张含有肝实质挫裂伤超声图像及1302张正常肝超声图像,作为模型的训练集和验证集。回顾性收集2015年1月至2021年4月解放军总医院第一医学中心确诊存在肝实质挫裂伤的超声图像153张,以及81张不含肝实质挫裂伤的肝超声图像,作为模型的外部测试集。6名不同年资医师分别对测试集图像数据进行判读。使用受试者操作特征（ROC）曲线及决策曲线分析（DCA）检验模型效能,比较不同年资医师与CNLDM模型预测肝实质挫裂伤的敏感度、特异度、准确性、阴性预测值及阳性预测值。 结果CNLDM模型诊断效能（敏感度为80%,特异度为77%,阳性预测值为87%,阴性预测值为66%）优于低年资医师组（敏感度为61%,特异度为75%,阳性预测值为82%,阴性预测值为51%）,略差于高年资医师组（敏感度为84%,特异度为86%,阳性预测值为92%,阴性预测值为75%）,差异具有统计学意义（H=15.306,P＜0.001;H=3.289,P＜0.001）,而模型效能与中年资医师组接近,差异无统计学意义（P＞0.05）。DCA显示模型在阈值0.4~0.6之间有较好的测试集收益。 结论基于超声的人工智能模型可以较为准确地区分正常肝与含有肝实质挫裂伤的异常肝,对进一步指导临床诊治工作具有重要的意义。     

Safety and efficacy of radiofrequency ablation of common atrial flutter in elderly patients: a single center prospective study

Little data is available concerning the invasive treatment of atrial flutter (AFL) in elderly patients. The purpose of this prospective study was to evaluate the risks, safety, and follow-up of radiofrequency (RF) catheter ablation of common AFL in patients >75 years old (n = 61) (Group I) compared to patients younger than 75 years (n = 187) (Group II). The study population consisted of 248 patients (81% men/19% women), 21 to 96 years old (mean 66.3 +/- 12 years) with AFL, referred for RF from June 1999 to June 2001. RF endpoint was the assessment of the bidirectional block. The cumulative risk of atrial fibrillation (AF) was analyzed by the Kaplan-Meier method and log-rank test. The mean follow-up was 12.4 +/- 9 months. No complication occurred. Group I (80.1 +/- 4.5 years) did not differ significantly from Group II (61 +/- 11 years) regarding: AF history before ablation (34.4% vs 39.8%), structural heart disease (54% vs 42%), LVEF (57%+/- 12% vs 58%+/- 12%), left atrial size (43.8 +/- 7 vs 42.5 +/- 7), cava-tricuspid isthmus dimension (40 +/- 10 vs 39 +/- 4 mm), bidirectional block (100% vs 96.2%), RF application (12.5 +/- 10 vs 13.5 +/- 12 minutes), AFL recurrence (3.3% vs 5.3%), antiarrhythmic agents at hospital discharge (34.4% vs 38.9%), mean follow-up (12 +/- 9 vs 13 +/- 9 months) and AF occurrence (29.5% vs 20.3%; P = 0.2). Of these, the incidence of AF in patients without prior history (n = 150) was 7 (18%) of 39 for Group I and 11 (10%) of 111 for Group II (P = 0.1) after follow-up. Catheter ablation of AFL in very elderly patients appears to be a reasonable approach regarding feasibility, effectiveness, and low procedural risk.     

Fully automated processing of buffy-coat-derived pooled platelet concentrates

BACKGROUND: The OrbiSac device, which was developed to automate the manufacture of buffy-coat PLT concentrates (BC-PCs), was evaluated. STUDY DESIGN AND METHODS: In-vitro characteristics of BC-PC preparations using the OrbiSac device were compared with manually prepared BC-PCs. For standard processing (Std-PC, n = 20), four BC-PCs were pooled using 300 mL of PLT AS (PAS) followed by soft-spin centrifugation and WBC filtration. The OrbiSac preparation (OS-PC, n = 20) was performed by automated pooling of four BC-PCs with 300 mL PAS followed by centrifugation and inline WBC filtration. All PCs were stored at 22 degrees C. Samples were withdrawn on Day 1, 5, and 7 evaluating PTL count, blood gas analysis, glucose, lactate, LDH, beta-thromboglobulin, hypotonic shock response, and CD62p expression. RESULTS: A PLT content of 3.1 +/- 0.4 x 10(11) (OS-PCs) versus 2.7 +/- 0.5 x 10(11) (Std-PCs, p < 0.05) was found. A CV of 19 percent (Std-PC) versus 14 percent (OS-PC) suggests more standardization in the OS group. At Day 7, the Std-PCs versus OS-PCs showed a glucose consumption of 1.03 +/- 0.32 micro mol per 10(9) PLT versus 0.75 +/- 0.25 micro mol per 10(9) PLT (p < 0.001), and a lactate production of 1.50 +/- 0.86 micro mol per 10(9) versus 1.11 +/- 0.61 micro mol per 10(9) (p < 0.001). The pH (7.00 +/- 0.19 vs. 7.23 +/- 0.06; p < 0.001), pO(2) (45.3 +/- 18 vs. 31.3 +/- 10.4 mmHg; p < 0.01), and HCO(3) levels (4.91 +/- 1.49 vs. 7.14 +/- 0.95 mmol/L; p < 0.001) suggest a slightly better aerobic metabolism within the OS group. Only small differences in CD62p expression was observed (37.3 +/- 12.9% Std-PC vs. 44.8 +/- 6.6% OS-PC; p < 0.05). CONCLUSION: The OrbiSac device allows an improved PLT yield without affecting PLT in-vitro characteristics and may enable an improved consistency in product volume and yield.     

Copper, zinc and copper/zinc ratio in chronic pancreatitis and pancreatic cancer

Serum copper and zinc levels and their ratio were evaluated in 48 control subjects, 29 patients with pancreatic cancer, 46 with chronic pancreatitis and 32 with extra-pancreatic diseases, with the purpose of ascertaining modifications in chronic pancreatic disease. Hepatic involvement and age were also investigated as possible factors influencing results. Cu/Zn ratio was found to be significantly increased in pancreatic cancer (2.66 +/- 0.16, mean +/- SE) as compared to controls (1.39 +/- 0.06, p less than 0.001), chronic pancreatitis (1.82 +/- 0.09. p less than 0.001) and extra-pancreatic diseases (1.81 +/- 0.18, p less than 0.001), but without practical clinical value. Serum zinc levels appear to decrease with age, while copper and Cu/Zn ratio increase. However, covariance analysis demonstrated that age does not play an important role in influencing copper and Cu/Zn ratio. A decreased liver synthetic function, at least in part age-related, seems to be an additional factor in decreasing serum zinc values.     

Optical spectroscopy demonstrates elevated intracellular oxygenation in an endotoxic model of sepsis in the perfused heart

Recent clinical studies of patients with sepsis have shown that the delivery of adequate oxygen alone does not necessarily result in improved organ function or survival. This study was undertaken to determine if optical spectroscopy could detect higher intracellular oxygenations in isolated, perfused guinea pig hearts that have been treated with endotoxin (lipopolysaccharide [LPS]) than in controls. Four hours after intraperitoneal injection with LPS, adult guinea pigs were anesthetized, and hearts were excised and perfused in the Langendorff manner. Six control and eight LPS-exposed guinea pigs were studied. Myoglobin oxygen saturation was determined from analysis of optical reflectance spectra acquired from the left ventricular free wall. Myoglobin saturation was significantly higher at baseline with LPS than in controls (96.0% +/- 0.8% vs. 89.4% +/- 1.7%, P < 0.001). At the end of 30 s of ischemia, myoglobin saturation decreased to 15% +/- 1% in controls, but to only 60% +/- 7% in the LPS group. Myocardial performance was determined by measured left ventricular developed pressure, which was significantly depressed in the LPS-exposed hearts relative to controls (30 +/- 4 mmHg vs. 67 +/- 9 mmHg, P < 0.001). Myocardial oxygen consumption, calculated from measurements of arterial and venous PO2 and coronary flow, was lower in LPS hearts relative to controls (0.199 +/- 0.021 mL oxygen x min(-1) x g(-1) vs. 0.157 +/- 0.006 mL oxygen x min(-1) x g(-1)). In this model of sepsis in the perfused guinea pig heart, intracellular oxygenation was higher and oxygen consumption was lower than in controls. Cellular dysfunction seen in sepsis may be caused by compromised oxygen use rather than insufficient oxygen delivery. Optical spectroscopy has the potential to noninvasively monitor patients and their responses to therapy.     

Gastropathy and diarrhea in diabetic patients: the presence of helicobacteriosis and PAS-positive vascular deposits in gastric and duodenal mucosa

AIM: To determine the presence of vascular periodic acid-Schiff's reagent (PAS) positive deposits in the gastric and duodenal mucosa of diabetic patients and controls. METHODS: Forty-six poorly controlled diabetic patients with digestive symptoms, aged 23 to 63 years (32 type I patients on insulin therapy with a mean diabetes duration of 14.2 +/- 3.1 years (mean +/- SE) and 13 type II patients with a mean diabetes duration of 7.2 +/- 2.3 years) were included. Of these, 17 had mainly gastropathic symptoms while 13 had diarrhea, and the remaining 16 patients had nonspecific symptoms. Forty control individuals of similar age and gender were included. Biopsy specimens were taken from areas of grossly normal gastric and duodenal mucosa. RESULTS: Gastric mucosa samples were pathological in 38 of 46 diabetic patients (18 cases of chronic active H. pylori antral gastritis, 13 cases of chronic active H. pylori pangastritis and 7 cases of nonspecific chronic gastritis). Duodenal mucosa samples were pathological in 32/46 diabetic patients. In the control group, 21 of 40 gastric samples (5 cases of chronic active H. pylori antral gastritis, 3 cases of chronic active H. pylori pangastritis and 13 cases of H. pylori-negative chronic gastritis) and 12/40 duodenal samples were pathological. Both helicobacteriosis and gastric and duodenal mucosa pathologies were significantly (p < 0.01) more common in diabetic patients than in controls. No significant associations were found between histological findings of gastric mucosa and of duodenal mucosa in diabetics and the control group. PAS-positive material in the vascular wall of gastric (16/46 vs. 2/40 in controls) and duodenal mucosa specimens (25/46 vs. 5/40 in controls) was significantly more common among diabetics (p = 0.001 for gastric and p < 0.001 for duodenal mucosa). No significant association was found between the presence of gastropathy or diarrhea compared to the presence of neuropathy, retinopathy, nephropathy or the type of diabetes. CONCLUSION: Endoscopic specimens from the gastroduodenum of diabetic patients revealed a large quantity of PAS positive vascular deposits, probably reflecting the condition of the mucosal vessels in our patients.     

Sustained pulmonary hypertension and right ventricular hypertrophy after chronic hypoxia in mice with congenital deficiency of nitric oxide synthase 3.

Chronic hypoxia induces pulmonary hypertension and right ventricular (RV) hypertrophy. Nitric oxide (NO) has been proposed to modulate the pulmonary vascular response to hypoxia. We investigated the effects of congenital deficiency of endothelial NO synthase (NOS3) on the pulmonary vascular responses to breathing 11% oxygen for 3-6 wk. After 3 wk of hypoxia, RV systolic pressure was greater in NOS3-deficient than in wild-type mice (35+/-2 vs 28+/-1 mmHg, x+/-SE, P < 0.001). Pulmonary artery pressure (PPA) and incremental total pulmonary vascular resistance (RPI) were greater in NOS3-deficient than in wild-type mice (PPA 22+/-1 vs 19+/-1 mmHg, P < 0.05 and RPI 92+/-11 vs 55+/-5 mmHg.min.gram.ml-1, P < 0.05). Morphometry revealed that the proportion of muscularized small pulmonary vessels was almost fourfold greater in NOS3-deficient mice than in wild-type mice. After 6 wk of hypoxia, the increase of RV free wall thickness, measured by transesophageal echocardiography, and of RV weight/body weight ratio were more marked in NOS3-deficient mice than in wild-type mice (RV wall thickness 0.67+/-0.05 vs 0.48+/-0.02 mm, P < 0.01 and RV weight/body weight ratio 2.1+/-0.2 vs 1.6+/-0.1 mg. gram-1, P < 0.05). RV hypertrophy produced by chronic hypoxia was prevented by breathing 20 parts per million NO in both genotypes of mice. These results suggest that congenital NOS3 deficiency enhances hypoxic pulmonary vascular remodeling and hypertension, and RV hypertrophy, and that NO production by NOS3 is vital to counterbalance pulmonary vasoconstriction caused by chronic hypoxic stress.