Lymphocyte Subpopulations in Man: No Selective Loss during Isolation from Defibrinated Blood

Human lymphocytes isolated from defibrinated blood are characterized especially in relation to the total yield of lymphocytes and their subpopulations identified by membrane markers. The defibrination per se gives a significant loss of monocytes and granulocytes but no loss of lymphocytes, indicating that no selective loss of lymphocytes occurs. In a comparison of heparin-stabilized and defibrinated blood no difference in yield is found during every single step of the isolation procedure. Quantitation of E-RFC and Smlg-positive lymphocytes gives no differences in comparing the respective isolated suspensions of mononuclear cells. The observed difference in EA- and EAC-RFC can freely be ascribed to the difference in monocyte contamination. Further, no correlation is found between total lymphocyte yield and the relative number of the subpopulations identified, i. e. E-RFC, Smlg-positive, Fc-receptor- and complement-receptor-bearing lymphocytes. Hence it is concluded that defibrinated blood is optimal as blood source for the isolation of mononuclear cells when lymphocyte subpopulations are studied and enumerated.     

Reduced arterial O2 saturation during supine exercise in highly trained cyclists

Performance of intense dynamic exercise in highly trained athletes is associated with a reduced arterial haemoglobin saturation for O₂ (SaO ₂) and lower arterial PO ₂ (PaO ₂). We hypothesized that compared with upright exercise, supine exercise would be accompanied by a smaller reduction in SaO ₂ because of a lower maximal O₂ uptake (VPO _2max) and/or a more even ventilation–perfusion distribution. Eight elite bicyclists completed progressive cycle ergometry to exhaustion in both positions with concomitant determinations of ventilatory data, arterial blood gases and pH. During upright cycling VPO _2max averaged 75±1.6 mL O₂ min^-1 kg^-1 (±SEM) and it was 10.6±1.7% lower during supine cycling (P<0.001). Also the maximal pulmonary and alveolar ventilation were lower during supine cycling (by 15±2% and 21±3%, respectively; P< 0.001) which related to a 0.8±0.1 L lower tidal volume (P<0.001). In all subjects and independent of work posture PaO ₂ and SaO ₂ decreased from rest to exhaustion (from 99±3 to 82±2 Torr and 98.1±0.2 to 95.2±0.4%, respectively; P<0.001); alveolar–arterial PO ₂ difference increased from 6±2 to 37±3 Torr in both body positions. At exhaustion arterial PCO ₂ was lower in upright than in supine (33.4±0.6 vs. 35.9±0.9 Torr; P<0.01), suggesting a greater relative hyperventilation in upright. Arterial pH was similar in upright and supine at rest (both 7.41±0.01) and at exhaustion (7.31±0.01 vs. 7.32±0.01, respectively). We conclude that despite a lower VPO _2max and supposedly an improved ventilation–perfusion distribution, altering body position from upright to supine does not influence arterial O₂ desaturation during intense exercise.     

Contribution of pH,diprotonated phosphate and potassium for the reflex increase in blood pressure during handgrip

The relative importance of pH, diprotonated phosphate (H₂PO₄^?) and potassium (K⁺) for the reflex increase in mean arterial pressure (MAP) during exercise was evaluated in seven subjects during rhythmic handgrip at 15 and 30% maximal voluntary contraction (MVC), followed by post-exercise muscle ischaemia (PEMI). During 15% MVC, MAP rose from 92 ± 1 to 103 ± 2 mmHg, [K⁺] from 4.1 ± 0.1 to 5.1 ± 0.1 mmol L^?1, while the intracellular (7.00 ± 0.01 to 6.80 ± 0.06) and venous pH fell (7.39 ± 0.01 to 7.30 ± 0.01) (P < 0.05). The intracellular [H₂PO₄^?] increased 8.4 ± 2 mmol kg^?1 and the venous [H₂PO₄^?] from 0.14 ± 0.01 to 0.16 ± 0.01 mmol L^?1 (P < 0.05). During PEMI, MAP remained elevated along with the intracellular [H₂PO₄^?] as well as a low intracellular and venous pH. However, venous [K⁺] and [H₂PO₄^?] returned to the level at rest. During 30% MVC handgrip, MAP rose to 130 ± 3 mmHg, [K⁺] to 5.8 ± 0.2 mmol L^?1, the intracellular and extracellular [H₂PO₄^?] by 20 ± 5 mmol kg^?1 and to 0.20 ± 0.02 mmol L^?1, respectively, while the intracellular (6.33 ± 0.06) and venous pH fell (7.23 ± 0.02) (P < 0.05). During post-exercise muscle ischaemia all variables remained close to the exercise levels. Analysis of each variable as a predictor of blood pressure indicated that only the intracellular pH and diprotonated phosphate were linked to the reflex elevation of blood pressure during handgrip.     

Local forearm and whole-body respiratory quotient in humans after an oral glucose load: methodological problems

The effects of an oral glucose load of 75 g on the local forearm and whole-body energy thermogenesis were measured in normal subjects during the 4 h after the glucose intake. Simultaneous assessment of substrate metabolism in the forearm was performed. Energy expenditure (EE) increased after the glucose load and had not returned to baseline level at the end of the experiment. Whole-body respiratory quotient (RQ) was, on average, 0.80 (SD 0.05) in the baseline condition and increased to a maximum of 0.91 (0.03) and then decreased to baseline level at the end of the experiment. The local forearm oxygen uptake increased 30 min after the glucose intake and remained elevated during the rest of the experiment. The carbon dioxide output from the forearm did not increase before 90 min after the glucose load. Consequently the local forearm RQ decreased significantly from a baseline value of 0.86 (0.17) to 0.63 (0.17) 30 min after the glucose load (P < 0.05). Ninety min after the glucose load RQ increased to a maximum level at 0.95 (0.22) and decreased then gradually to baseline level. The experiments emphasize several methodological problems in the measurement of local forearm RQ The whole-body RQ and local forearm RQ are not significantly different in the fasting state. The finding of a decrease in local forearm RQ below 0.70 30 min after the glucose load probably indicates a non-steady state in the carbon dioxide exchange. Thus, indirect calorimetry cannot be applied locally during short time periods.     

STIMULATION OF CHONDROCYTE DNA SYNTHESIS BY INTERLEUKIN-1

Interleukin-1 (IL-l)-containing conditioned media (CM) fromactivated guinea-pig peritoneal macro-phages were found to stimulatethe DNA synthesis of rat epiphyseal chondrocytes in vitro. SephadexG 150 chromatography revealed that the chondrocyte-stimulatingactivity was molecularly heterogeneous, with apparent molecularratios of 16 000-21 000 (16-21K), 45-50K, 80-90K, and more than100K. The IL-1 activity, as estimated by a murine thymocyteactivation assay, co-eluted with the 16-21K chondrocyte-stimulatingpeak, indicating that IL-1 might stimulate the DNA synthesisof chondrocytes in vitro. This assumption was verified in experimentsdemonstrating a dose-dependent stimulation of chondrocyte DNAsynthesis by recombinant human IL-1 a. CM from resting and proliferatingchondrocytes lacked detectable IL-1 activity, speaking againstan autocrine role of IL-1 in epiphyseal cartilage growth. Theresults suggest that IL-1, in addition to its other effectsin inflammatory responses, also acts as a chondrocyte growthfactor. This might be one mechanism behind the reactive formationof cartilage in inflamed joints and the increased longitudinalbone growth often seen in affected limbs of children with arthritis. KEY WORDS: Interleukin-1, Cartilage, Chondrocytes, Growth factor, Arthritis     

Radiofrequency Catheter Ablation for Wolff-Parkinson-White Syndrome Associated with a Coronary Sinus Diverticulum

The case of a patient with Wolff-Parkinson-White syndrome undergoing attempted radiofrequency catheter ablation of a left posterior paraseptal accessory pathway is described. Coronary sinus venography revealed the presence of a large diverticulum attaching near the os. The electrogram recorded from a catheter placed in the narrow neck of the diverticulum revealed a very short atrioventricular time during sinus rhythm. The pathway was easily ablated using radiofrequency energy applied in the neck of the diverticulum, after multiple failed attempts at catheter ablation from the endocardial surface of the mitral annulus. Our report emphasizes the importance of searching for a coronary sinus diverticulum in all patients with posterior accessory pathways undergoing catheter ablation.     

《国际功能、残疾和健康分类》:对物理和康复医学进行统一概念描述的模式

需要发展一个当代为国际上广泛接受的物理和康复医学（PRM）的概念描述。建立这种新的概念依赖于统一的概念模型和《国际功能、残疾和健康分类》（ICF）的分类体系。这种基于ICF的康复概念描述是将康复作为一种健康策略。欧盟医学专家委员会（UEMS）的康复专家正在致力于将ICF作为物理和康复医学的统一概念的模型，并依据此建立基于ICF的概念描述并给PRM下定义。根据此项目标，作者通过与欧盟物理和康复医学专业实践委员会成员的合作，对于属于医学专业的PRM作丁一个简明的定义。物理和康复医学是荩于功能评估的医学专业，包含健康状况的诊断和治疗，实旌、应用生物医学并结合其它更为广泛的干预方法，使残疾人或者可能经历残疾的人达到功能最佳化的目标。     

Efficacy of inferior vena cava filters in anticoagulated patients

BACKGROUND AND OBJECTIVES: The benefit of an inferior vena cava (IVC) filter in addition to standard anticoagulation regimens is unknown. METHODS: We examined data for patients who received IVC filters with anticoagulation (AC-Filter) after an episode of venous thromboembolism (VTE) and compared them with data for those who received anticoagulation only (AC-Only). Outcome measures were new pulmonary embolism (PE), recurrent deep vein thrombosis (DVT), and mortality at 90 days and at 5 years. Demographic data included age, gender, and ethnicity/race, prior thromboembolic history, cancer, serum albumin, and time in therapeutic range. In addition, subsets matched for age, gender and race/ethnicity were examined in detail. RESULTS: AC-Filter patients (n = 251), when compared to AC-Only patients (n = 1377), did not differ significantly with regard to gender or cancer status, but white males in general had better outcomes. AC-Filter patients were more likely to have had a previous history of PE or VTE (P < 0.001). In comparison to AC-Only patients, AC-Filter patients had lower mean serum albumin levels (3.1 +/- 0.8 vs. 3.6 +/-0.8 mg dL(-1), P < 0.001) and were older (65 +/- 16.1 years vs. 60 +/- 17.5 years, P < 0.001). After stratification according to previous history of PE or VTE prior to the index VTE event, no differences in the outcome measures of new PE, recurrent DVT or mortality were identified between groups, but patients with a prior history of PE from either group were more likely to have a new PE (hazard ratio 1.9, P < 0.001). CONCLUSIONS: These data suggest that IVC filters may not provide any substantial additional benefit for patients who can tolerate anticoagulant therapy.     

Histologic Findings of the Heart and the Conduction System in the First Patient Who Underwent Catheter Ablation

This is a detailed pathological examination of the heart including the conduction system (CS) from a 64-year-old male who had catheter ablation of the atrioventricular (AV) junction for intractable atrial fibrillation. This is the world's first human who had this procedure, and who survived 3 years and 8 months, and later died of congestive heart failure. Pathologically, the heart was hypertrophied and enlarged. Histologically, there were chronic inflammatory cells, marked fatty metamorphosis with fibrosis of the atria, the approaches to the AV node, and the AV node, with almost isolation of the node from the atria, and considerable fibrosis of the bundle and bundle branches. In addition, there was fibrosis of the summit of the ventricular septum with chronic inflammatory cells. These represent the sequelae of the ablation procedures. It is not known how much of the pathological findings contributed to the cardiac hypertrophy and impairment of cardiac function.