西宁地区健康小儿窦房结功能测定的初步探讨

应用食道心房调博缩测定健康小儿窦房结功能，以了解西宁地区正常数值与平原地区进行对比。选择２７例健康小儿，将Ｆ６二级电极导管从鼻腔送入，定位地食道心电图最大正负双相Ｐ波处，采用苏州东方电子仪器厂生产的ＤＦ－３Ａ型心脏电生理治疗仪进行检查，从而作出诊断。     

Abnormal Digital Pressure Measurements in Diabetic Neuropathic Foot Ulceration

The diabetic neuropathic ulcer is typically slow to heal and recurrent. Macrovascular insufficiency is usually excluded as foot pulses are present and ankle:brachial pressure ratios are not decreased. These assessments cannot however exclude more distal vascular disease. Digital pressure measurements enable a reliable assessment of the distal peripheral vascular status to be made. The aim of this study was therefore to use toe pressures to assess the contribution of distal ischaemia in the pathogenesis of the neuropathic ulcer. Sixteen diabetic patients with recurrent neuropathic foot ulceration had their toe pressures compared to 10 neuropathic patients without a history of foot ulceration, 10 diabetic control subjects, and 11 normal subjects. Four non-diabetic patients with neuropathy and foot ulceration were also assessed. All subjects had ankle:brachial pressure indices ≧ 1. Toe pressure was assessed using laser Doppler flowmetry to record the return of skin blood flow. The toe:brachial pressure index (TBI) was then calculated. The diabetic patients with a history of recurrent neuropathic ulceration, had the lowest mean TBI, 0.63 ± 0.14 (SD), compared to the non-ulcerated diabetic neuropathy patients, the diabetic control subjects, and the normal subjects. 0.84 ± 0.11, 0.82 ± 0.1, and 0.81 ± 0.07, p < 0.01, respectively. Three of the four non-diabetic patients with neuropathic foot ulceration also had an abnormally low TBI. Reduced toe pressure measurements are thus found to be associated with neuropathic foot ulceration. The contribution of distal ischaemia in the pathogenesis of the diabetic neuropathic foot ulcer needs to be evaluated. One hundred and eight non-insulin-dependent diabetic patients who had been tested for autonomic dysfunction in 1984/85 were re-evaluated 5 years later. Autonomic function was assessed by means of four cardiovascular tests (heart rate variation during deep breathing and standing, and blood pressure variation after standing and sustained handgrip). Eighteen subjects were lost to follow-up; in the 90 patients who completed the study, both the deep breathing and the handgrip test significantly worsened (respectively from 13.7 ± 7.8 to 11.6 ± 6.3 beats min^?1 p < 0.01, and from 16.9 ± 8.2 to 12.7 ± 7.1 mmHg, p < 0.001), whereas both the 30:15 ratio and the variation of blood pressure on standing did not change. The impairment of a comprehensive evaluation score (from 2.5 ± 1.7 to 3.0 ± 1.5; p < 0.05) also confirmed the gradual deterioration of autonomic function over the study period.     

丝裂霉素C与5—Fu用于抗青光眼滤过性手术的对比研究

采用随机、双讯，前瞻对照的方法比较了丝裂霉素Ｃ（ＭＭＣ）和５－氟尿嘧啶对难治性青光眼小梁切除手术的安全性和有效性。３９例病人随机分成二组，一组使用ＭＭＣ，另一组使用５－Ｆｕ。结果提示：（１）ＭＭＣ组手术成功率高于５－Ｆｕ组；（２）ＭＭＣ组角膜上皮缺损发生率，结膜创口渗漏率明显低于５－Ｆｕ组。     

A New Low Threshold Platinized Epicardial Pacing Electrode: Comparative Evaluation in Immature Canines

A prospective comparison of pacing and sensing capabilities between the conventional Medtronic Model 4951 platinum-iridium epicardial pacing electrode and a new modified "platinized" version of the same electrode was performed in immature canines to determine if the new electrode design improves pacing in the immature myocardium. The conventional electrode was modified by electroplating platinum black particles onto the surface to increase the effective or true microscopic surface area, yet essentially maintain the same overall geometric electrode size. Both epicardial electrodes were inserted into the right ventricular myocardium with the lead pad sutured to the epicardium, and externalized to the scruff in five puppies (age 3 months). An additional left ventricular lead was implanted to permit chronic pacing following epicardially-induced atrioventricular block. Acute and chronic sensing and pacing capabilities of each externalized electrode were performed at implant and weekly up to 4 months. Histologic examination of each electrode implant site was performed at the end of the study period. At implant, both electrodes exhibited comparable values for sensed R waves, lead impedances, and pacing thresholds. During the study, the platinized electrode exhibited lower pacing thresholds. Analysis of all postimplant data demonstrated this threshold difference to be significantly lower (P less than .01) for the platinized version. Lead impedance and sensing capabilities remained comparable between the two designs. Histologic study demonstrated less fibrotic infiltration at the platinized electrode site. This preliminary evaluation indicates that for the duration of the postimplant study period, the platinized epicardial electrode design was associated with significantly lower thresholds and less fibrosis as a function of time compared to the conventional smooth electrode surface design. The new platinized electrode limits exit block in the developing immature myocardium and permits safe pacing at lower pulse widths and voltages to increase battery life.     

“Occult” hydrocephalus in children

The authors describe 32 children between 2 and 15 years of age who had hydrocephalus that was only clinically manifest late in life. The clinical picture of these children did not suggest an obvious increase in intracranial pressure; instead, the presenting signs were rather nonspecific and included macrocrania, mild psychomotor retardation, unsteady gait, increased muscle tone and deep tendon reflexes in the lower limbs, impaired ocular movement, epilepsy, and endocrine dysfunction. Their histories suggest the possible causes of the ventricular dilation in about one third of the cases were: perinatal hemorrhage, leptomeningitis, neurofibromatosis, and untreated aneurysm of the great vein of Galen. In 20 patients, however, no positive anamnestic findings were reported. CT scan revealed triventricular dilation in more than half of the cases; tetraventricular dilation was present in 6 patients, and biventricular dilation in the remaining subjects. All children underwent CSF shunting, which resulted in complete recovery in all but 2 cases. The most frequently recorded surgical complication was postoperative subdural effusion (7 subjects), which required surgical treatment in only 2 cases.Presented at the 15th Annual Scientific Meeting of the International Society for Pediatric Neurosurgery, New York, 1987     

Heart rate and body temperature sensitive diaphragm pacing

Two ways of rate control for diaphragm pacing are proposed. One is rate control using only the patients' body temperature (method I). The other is rate control by both the patients' heart rate and body temperature (method II). To test the effectiveness of these methods, a diaphragm pacemaker which can be controlled by both heart rate and body temperature has been developed. It was applied to nine mongrel dogs. The pacing rate is controlled by atrial blood temperature (method I) or by both heart rate and temperature (method II). The animal's metabolism was elevated by the administration of a pyrogenic drug. It was found that method I is not suited to rapid changes in metabolism; however, it is useful in extreme metabolic elevation. An animal's metabolism was supported by using method II in all ranges of metabolism. This method proved more effective than method I for rate-responsive diaphragm pacing.     

Minimising stimulator artefacts in electromagnetic flow signals

Simultaneous electrical stimulation of tissue with the measurement of blood flow using an electromagnetic flowmeter system almost invariably results in large flow measurement inaccuracies. These inaccuracies are because the electrical energy from stimulating artefacts is amplified along with the flow signals. The paper describes the building and use of an inexpensive circuit to remove stimulation artefacts from electromagnetic flow measurements.     

Antibodies against the extracellular enveloped virus B5R protein are mainly responsible for the EEV neutralizing capacity of vaccinia immune globulin

In the event of smallpox bioterrorism, widespread vaccination may be required. Vaccinia immune globulin (VIG) has been used to treat complications from the smallpox vaccine. While the potency of VIG was defined by its ability to neutralize intracellular mature virus, a second form of vaccinia called the extracellular enveloped virus (EEV) is critical for virus spread in the host. The B5R-protein is one of many EEV-specific proteins. Immunoprecipitation and ELISA revealed that VIG recognizes the B5R-protein. An EEV plaque-reduction assay using a recombinant vaccinia that lacks the majority of the extracellular domain of B5R showed that the ability of VIG to neutralize EEV is principally directed at B5R. In addition, absorbing out the anti-B5R antibody present in VIG through the addition of recombinant B5R protein abrogated VIG's ability to significantly neutralize wild-type EEV. This work demonstrates the prominent role of B5R as a target of EEV-neutralizing activity of human antibodies.     

妊高征患者淋巴细胞β_2－肾上腺素能受体结合量改变及与新生儿体重关系的研究

应用放射配体结合分析，测定４０例正常晚期妊娠妇女及４０例妊高征妇女外周血淋巴细胞β_２－肾上腺素能受体（β_２－ＡＲ）结合量，并测定两组妇女分娩的新生儿体重。结果为：１．正常晚期妊娠妇女外周淋巴细胞β_２－ＡＲ结合量明显降低，妊高征妇女β_２－ＡＲ结合量降低更显著；２．妊高征孕妇组的新生儿出生体重明显低于正常妊娠组的新生儿体重；３．孕妇β_２－ＡＲ结合量与新生儿出生体重呈明显正相关，提示好高征与机体β_２－ＡＲ结合量下降有关，β_２－ＡＲ改变影响胎儿生长发育。     

Determinants of pulmonary blood volume. Effects of acute changes in pulmonary vascular pressures and flow

To examine the effects of pulmonary vascular pressures and flow on pulmonary blood volume (PBV), experiments were performed at constant heart rate and zone 3 conditions (mean left atrial pressure (LAP) above airway pressure) in six anesthetized, open-chest dogs. PBV was calculated as the product of electromagnetic aortic flow and pulmonary mean transit time for ascorbate, obtained without blood withdrawal by polarographic recording of aortic ascorbate changes. In three series of experiments LAP was raised similarly in three steps, from 4.5 to 14.8 mmHg: by mitral constriction which reduced pulmonary blood flow, by blood volume expansion which more than doubled pulmonary blood flow, or by a combination of the two procedures which kept pulmonary blood flow constant. In all three series, LAP and mean pulmonary arterial pressure (PAP) rose in proportion, but PBV was better correlated to PAP (r=0.87±0.02) than to LAP (r=0.66±0.09). These experiments suggest that PAP is the most important factor in determining PBV under zone 3 conditions, whether PAP is raised by increasing pulmonary blood flow or by mitral constriction.