Differential response of hypertrophied rat hearts to various α1-adrenoceptor agonists

Summary— With respect to the heart, the prolonged existence of hypertension, both in man and in experimental animals is predominantly characterized by an increase in left ventricular myocardial mass. In this process, the autonomic nervous system plays an important role. Although endogenous catecholamine stimulation of the heart is mainly exerted via the β-adrenoceptors, in several mammalian species, the stimulation of cardiac α-adrenoceptors also mediates positive inotropic actions. We investigated the functional responses of isolated hypertrophied hearts taken from spontaneously hypertensive rats (SHR) and rats with an induced aortic stenosis (ASR) to various α₁-adrenoceptor agonists and compared them with those from age matched Wistar Kyoto (WKY) and "sham" operated controls. Accordingly, we studied the functional response to: methoxamine (α₁), cirazoline (α₁) and phenylephrine (α₁ > β₁). The inotropic response to the α₁-adrenoceptor agonists cirazoline and methoxamine proved to be significantly weaker in hypertrophied hearts from SHR and ASR than in non-hypertrophied hearts from WHY and "sham" operated controls ( p < 0.05). The inotropic response to phenylephrine remained intact in hypertrophied myocardial tissue. However, it was significantly reduced when the hearts were pre-treated with the intracellular Ca²⁺-antagonists ryanodine and TMB-8. These findings show that the mechanism of sarcolemmal Ca²⁺ release, activated by phenylephrine, is still intact in the hypertrophied myocardial cell. In conclusion, these data show that cardiac hypertrophy, be it of genetical or mechanical origin, leads to a reduced response of the isolated heart to α₁-adrenoceptor stimulation.     

Clinical Assessment of Gestational Age

There is disagreement among authors as to what criteria are most reliable in assessing postnatal fetal age. A comparison–for objectivity, accuracy, and frequency of use– of specific criteria was made using three independent examiners at different educational levels: a second-year medical student, a perinatal nurse practitioner, and a pediatrics resident. It was shown that trained examiners develop favorite criteria which differ among examiners and thus sacrifice accuracy; however, accurate assessment of fetal age can be accomplished by an examiner with minimum clinical knowledge.     

Development of an improved multi-pressure-sensor probe for recording muscle contraction in human intestine

We have developed an improved semiconductor recording probe for monitoring motility of the upper small intestine in humans. The probe consists of six ultraminiature silicon pressure sensors spaced 10 cm apart and encased in a flexible polyurethane sheath. The probe is small [2.67 mm (8F) diameter], is easily passed transnasally, and is tolerated by patients for prolonged recording periods (24–36 hr) with a minimum of discomfort. The initial semiconductor and catheter material were those designed for use in the cardiovascular system, but they proved to be easily damaged by gastric acid and enzymes. After improvement of this probe, we now have recordings from more than 100 patients for an approximate total of 6000 hr of recording time. The improved probe is a durable recording device that facilitates the investigation of motility of the small intestine in humans in health and disease.This study was supported by funds from the Medical Research Service of the Veterans Administration and by National Institutes of Health Clinical Research Center grant RR-82.     

Angiosarcoma of the of scalp with calvarium involvement in a 50-year-old African-American man

BACKGROUND: Angiosarcoma of the scalp is a rare, aggressive, and deadly cancer that affects mainly elderly Caucasian men. OBJECTIVES: The insidious and masquerading presentation of angiosarcoma poses enormous diagnostic challenges for primary care providers. PATIENTS/METHODS: We present a case of a 50-year-old black man referred for evaluation of a 3.7-cm-x-5.4-cm ulcerated, fluctuant scalp lesion that had failed to respond to different antibiotics and proper wound care. RESULTS: Surgical excision and subsequent histopathology revealed angiosarcoma. CONCLUSIONS: This case report highlights the importance of high index of suspicion for early diagnosis of cancerous lesions in wounds and stresses the need to include angiosarcoma in the differential diagnosis for all face and scalp lesions, as early detection may save lives. A comprehensive literature review is also presented.     

Infection by Dipylidium caninum in an infant

Dipylidium caninum, the dog tapeworm, is a cosmopolitan parasite of dogs and cats and occasionally causes human infection in the United States. Diagnosis is made by observing the characteristic rice grain-like proglottids in stool specimens and the pathognomonic egg packets in the gravid uterus in histologic sections of the parasite. There have been few reported cases of human infection with this parasite, and very little information on the pathology of this zoonotic disease is available in the English language. This report of a case of D caninum infection in a 6-month-old infant highlights the diagnostic features of this disease. To our knowledge, this is the first case to be reported in the American pathology literature during the last 36 years (MEDLINE database, 1966-2002).     

Pulmonary hypertension in sickle cell hemoglobinopathy: a clinicopathologic study of 20 cases

Pulmonary hypertension is one of the major causes of morbidity and mortality of patients with sickle cell hemoglobinopathy (SCH). Although a clinically recognized complication of sickle cell disease (SCD), there are few published pathologic studies of pulmonary findings in these patients. The aim of this study was to define the pulmonary pathologic changes and to investigate correlation between the pathologic changes, the antemortem diagnosis of pulmonary hypertension, and the severity of SCH. Cases of SCH were identified from the autopsy database using Snomed codes. Clinical and echocardiograph data were collected for correlation with the pathologic data. A total of 20 adult patients (12 males and 8 females) were identified. Hemoglobin electrophoresis results were available for 16 patients, with hemoglobin S fraction percentages ranging from 23% to 97.8%. Eleven patients had SCD, 5 patients had sickle cell trait (SCT), and the remaining 4 patients without hemoglobin electrophoresis were included in the SCT group. The mean age of the SCT group was higher than that of the SCD group (P = 0.03). Histologically, all 20 patients demonstrated changes in pulmonary vasculature considered diagnostic of pulmonary hypertension grade I to grade IV, associated with plexiform lesions in 60% of patients. Medial hypertrophy and intimal hyperplasia/fibrosis, considered potentially reversible lesions, were seen in all patients. A weak association was found between SCD and plexiform lesions. Fibroelastic degeneration of small arteries, arterioles, and venules was identified in almost all (95%) cases. Clinically, tricuspid regurgitation was detected by echocardiogram in 10 of 20 (50%) patients; 6 of these 10 had significant regurgitation to allow estimation of systolic pressure. Sudden death occurred in 8 patients, with males having a significantly higher incidence. Cardiomegaly was present in 95% of patients, however, autosplenectomy and hepatic cirrhosis/hemochromatosis were observed almost exclusively in patients with SCD. Cirrhosis was found to have a strong positive association with SCD. This study demonstrates pulmonary hypertensive changes in all 20 autopsied patients who had SCH but died from various causes. We conclude that a high prevalence of pulmonary hypertension is associated with SCH with consequent high mortality. Therefore, patients with SCH would benefit from a regular periodic assessment for pulmonary hypertension regardless of age, sex, and severity of hemoglobinopathy.     

Revision of Failed Gastric Bypass to Distal Roux-en-Y Gastric Bypass: A Review of 65 Cases

Background: No bariatric operation has been documented to effect adequate weight loss in all patients. Patients with inadequate weight loss or significant weight regain with an anatomically intact short-limb gastric bypass, of which the Fobi pouch operation (FPO) for obesity is a modification, are usually revised to a distal Roux-en-Y gastric bypass (DRYGBP) to enhance weight loss. Method: A retrospective review of the charts of all patients who had a revision to a DRYGBP at our Center during an 8-year period was carried out and the findings analyzed. Results: 65 patients who had the FPO had a revision to the DRYGBP.Most were super obese patients who, even though they had lost significant weight, were still morbidly obese. Some were patients who had not lost adequate weight or <40% excess weight, and a small number were patients who requested more weight loss even though they had a BMI of < 35. 15 patients developed protein malnutrition requiring supplemental feeding. 6 required rerevision to short-limb gastric bypass. Conclusion: Revision of short-limb gastric bypass to DRYGBP usually enhances weight loss but at a cost of an increased incidence of protein malnutrition.     

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目的探讨瘦素质量浓度与早期静脉营养及生长发育的关系。方法新疆医科大学第一附属医院新生儿科于2005-01—2006-02,将收治的86例早产适于胎龄儿用随机数字表法分为观察组(早期微量喂养同时辅助胃肠外营养组)45例和对照组(单纯早期微量喂养组)47例,分别测定脐血及第7天血清瘦素质量浓度,同时监测营养状况和生长发育指标,并作对比分析。结果(1)观察组与对照组脐血瘦素质量浓度分别为(4.6±3.7)ng/mL、(4.8±2.2)ng/mL,生后第7天两组瘦素质量浓度分别为(4.3±2.2)ng/mL、(3.1±1.7)ng/mL。对照组第7天血清瘦素质量浓度明显低于脐血(P<0.05),而观察组其差异无统计学意义(P>0.05)。(2)脐血瘦素质量浓度与出生体重、胎龄成正相关(r=0.56、r=0.67)。(3)观察组第7天热卡及蛋白质摄入量、血清瘦素质量浓度、皮褶厚度变化值与对照组相比,差异有统计学意义(P<0.05)。结论对早产儿应尽早喂养,同时需要胃肠外营养作为肠内营养的补充。瘦素可作为新生儿营养效果判定的实验室指标之一。     

Intraventricular haemorrhage in the preterm infant without hyaline membrane disease

The clinicopathological associations of 33 singleton infants who died with intraventricular haemorrhage (IVH) without hyaline membrane disease (HMD) ('IVH only') were compared with those of 39 infants who died with IVH+HMD over the same gestation range in order to determine what factors other than those related to HMD may contribute to the pathogenesis of IVH. The incidence of 'IVH only' was inversely related to gestational age in the Hammersmith birth population, whereas the incidence of IVH+HMD rose to a peak at 28-29 weeks' gestation. Infants with 'IVH only' lived longer on average than those with IVH+HMD despite a lower birthweight and shorter gestation. Infants who died in the first 12 hours from 'IVH only' had suffered severe birth asphyxia but in those who died later the main symptom was recurrent apnoea. Fewer infants with asphyxia but in those who died later the main symptom was.recurrent apnoea. Fewer infants with 'IVH only' were given alkali therapy or were connected to the ventilator as compared to those with IVH+HMD, but there were no differences in alkali therapy in those who lived for 12 hours or more. In the 'IVH only' group there was a high incidence of haemorrhage from other sites and of bacterial infections. It is suggested that, in the absence of HMD, extreme immaturity is the main factor determining the occurrence of IVH. Birth asphyxia, apnoeic attacks, haemorrhage, and infections may play subsidiary roles, possibly through development of metabolic acidosis.