The effect of experimental alterations in urine concentration on nephron filtration rate

Summary Experiments were performed to clarify the cause of the dependency of juxtamedullary nephron filtration rate (JN-GFR) on the diuretic state of the animal. Using the ferrocyanide technique of de Rouffignacet. al. [5] the distribution of nephron filtration rates was determined during selective modification of final urine osmolarity by papillary superfusion with concentrated or isotonic solutions. Papillary superfusion with a 2000 mosmolar solution led to a mean urine osmolarity of 1848±78 mOsm/l. JN-GFR displayed a mean increase of 66.6% over the superficial nephron filtration rate (SN-GFR). When the superfusion fluid was isotonic urine osmolarity averaged 754±53 mOsm/l and JN-GFR increased by a mean of only 26.3% over the SN-GFR. Using the micropuncture technique it was shown that SN-GFR in a given animal was not altered when the superfusion fluid was interchanged. We conclude therefore that the change in the percentage increase in GFR from superficial to juxtamedullary nephrons is caused by a change of juxtamedullary nephron filtration rate. Since plasma ADH concentration was not altered this effect appears to be elicited by the changed medullary solute concentration rather than by a vasomotor action of the antidiuretic hormone.This work was supported by the Deutsche Forschungsgemeinschaft.     

Effects of intravascular laser phototherapy on delayed neurological sequelae after carbon monoxide intoxication as evaluated by brain perfusion imaging: A case report and review of the literature

BACKGROUNDDelayed neurological sequelae (DNS) caused by carbon monoxide (CO) intoxication poses considerable treatment challenges for clinical practitioners. In this report, we used nuclear medicine imaging and the Mini-Mental State Examination (MMSE) to evaluate the effectiveness of intravascular laser irradiation of blood (ILIB) therapy for the management of DNS.CASE SUMMARYA 51-year-old woman presented to our medical center experiencing progressive bradykinesia, rigidity of limbs, gait disturbance, and cognitive impairment. Based on her neurological deficits, laboratory tests and imaging findings, the patient was diagnosed with delayed neurological sequelae of CO intoxication. She received intensive rehabilitation and ILIB therapy during 30 sessions over 2 mo after diagnosis. Brain single-photon emission computed tomography was performed both prior to and after ILIB therapy. The original hypoperfusion area in bilateral striata, bilateral frontal lobe, right parietal lobe, and bilateral cerebellum showed considerable improvement after completion of therapy. The patient’s MMSE score also increased markedly from 6/30 to 25/30. Symptoms of DNS became barely detectable, and the woman was able to carry out her daily living activities independently.CONCLUSIONILIB therapy could facilitate recovery from delayed neurological sequelae in patients with CO intoxication, as demonstrated by improved cerebral blood flow and functional outcomes in our patient.     

Changes in blood-flow distribution during acute emotional stress in dogs

Summary The changes in mesenteric, renal and hindlimb circulations during natural emotional stress have been investigated in dogs. Arterial pressure showed a moderate and generally byphasic rise. Heart rate rose markedly in most experiments, but tended to return towards control values more rapidly than blood pressure. Both mesenteric and renal vascular resistance were increased. In the kidney, however, the vasoconstriction was less constant and in most instances less pronounced than in splanchnic viscera. This suggested a relatively high threshold of the central neuron pools controlling the renal vessels. Also, the reduction of blood flow was less sustained in the renal than in meseteric vessels, probably because of the action of autoregulatory mechanisms in the kidney. In hindlimb skeletal muscles, emotional stress produced a vasodilatation which appeared to be independent of the blood pressure rise and, at least to a large extent, of muscle activity. Most likely, the effect was due to sympathetic vasodilator fiber activation, though there was some indication that vasoconstrictor fibers to skeletal muscles were also activated. The observation that muscle vasodilatation invariably occurred in response to very different emotional stimuli suggests that it is a component of most, if not all, emotional reaction patterns in dogs. Muscle vasodilatation was the primary vascular reaction to changes from resting condition to alertness, the mesenteric and renal vessels being only slightly constricted or unaffected.Supported by a grant from the Consiglio Nazionale delle Ricerche, Roma.     

Redistributive effects in public health care financing

This article focuses on the redistributive effects of different measures to finance public health insurance. We analyse the implications of different financing options for public health insurance on the redistribution of income from good to bad health risks and from high-income to low-income individuals. The financing options considered are either income-related (namely income taxes, payroll taxes, and indirect taxes), health-related (co-insurance, deductibles, and no-claim), or neither (flat fee). We show that governments who treat access to health care as a basic right for everyone should consider redistributive effects when reforming health care financing.

Books received

The problems for poor people generated by ‘disorganised health care markets’ in the developing world have grave consequences for their health. In many countries, processes of liberalisation and commercialisation have generated a number of dilemmas for policy-makers, non-governmental organisations and individuals seeking health care. Complex markets for health care provision and financing exist, regulation is lacking and rates of exclusion are high due to the effects of prices and a lack of concerted efforts to make health systems more accessible to the poor. Analysis of health systems and the problems they create for the poor should lead to responses that protect and enhance the rights of poor people to health.     

倾斜试验鉴别运动试验结果阴性患者运动后晕厥

目的为了探讨直立倾斜试验（TTT）对活动平板运动试验结果阴性患者运动后晕厥的鉴别诊断价值以及运动后晕厥的临床意义。方法 活动平板运动试验结果阴性的运动后晕厥患者,均进行TTT。结果186例运动后晕厥患者有141例在TTT中出现阳性,阳性率75.81％,且以男性（102／141）、血管抑制性晕厥（106／141）患者占大多数;其中出现在基础倾斜试验（BTTT）中22例,阳性率11．83％;出现在异丙基肾上腺素倾斜试验（ITTT）中119例,阳性率63．98％。结论运动后晕厥多属血管迷走性,TTT是鉴别活动平板运动试验结果阴性患者运动后晕厥的首选方案。     

Evaluation of the significance of “redistribution” in I-123 IMP SPECT in cerebrovascular disorders—a comparative study with PET

We evaluated the significance of redistribution in¹²³I-IMP SPECT study using PET. Twelve lesions in ten patients were selected. These lesions were classified into the following three groups; ischemia, infarction of subacute phase and infarction of chronic phase. All lesions with ischemia or subacute infarction showed good or moderate redistribution. Three of four lesions with chronic infarction showed no redistribution. The mean values of rCBF and rCMRO₂ were highest in the lesions with good redistribution, but there was no differences in rOEF with the degree of redistribution. In conclusion, the tissue with good redistribution is not always viable and it was impossible to predict a region with increased rOEF by redistribution alone.This article was presented at the 1st EEC workshop on accuracy determination in PET, January 19–20th. 1989 Pisa, Italy (COMAC-BME Concerted Project Characterization and Standardization of PET Instrumentation)     

Skeletal differences in bone mineral area and content before and after cure of endogenous Cushing’s syndrome

SUMMARY: We examined bone densitometric data in a four-year follow-up period before and after the cure of CS. Plasma cortisol concentrations were similar, but the duration of estimated glucocorticoid excess was longer in patients with prevalent bone fractures compared to those without fractures. After therapy of CS, bone area, BMC and BMD increased significantly at the LS and femur during follow-up, but they decreased at the forearm, suggesting redistribution of bone minerals from the peripheral to the axial skeleton. INTRODUCTION: Only a few studies report the changes in bone mineral density (BMD) after the cure of Cushing's syndrome (CS). METHODS: Forty-one patients with Cushing's disease, 21 patients with adrenal CS and 6 patients with ectopic CS were prospectively enrolled. BMD, bone mineral content (BMC) and bone area were measured by DXA. RESULTS: No significant correlations were found between serum cortisol concentrations and baseline bone densitometric data. After successful therapy of CS, bone area and BMD increased significantly at the lumbar spine (LS) and femur during follow-up, but they decreased at the forearm. The progressive increase in BMC at the LS had a significant negative correlation with the change of the BMC of radius in the first and second follow-up years. The change in the body mass index was an independent predictor for changes in BMC both at the LS and at the forearm at the second year of remission. CONCLUSIONS: The regional differences and the time-dependent changes of BMC suggest that the source of marked increase in axial BMC after the cure of CS is, at least partly, due to the redistribution of bone minerals from the peripheral to the axial skeleton.     

Cerebral venous blood flow in growth restricted fetuses with an abnormal blood flow in the umbilical artery before 32 weeks of gestation

Objective

To evaluate the brain venous circulation in fetuses with severe intrauterine growth restriction (IUGR) before 32 weeks of gestation.

Study design

Fifty fetuses with severe IUGR diagnosed between 27 and 32 weeks of gestation and 50 appropriate-for-gestational age (AGA) fetuses matched by gestational age were evaluated. IUGR fetuses were classified according to their hemodynamic deterioration pattern in relation to the Doppler examination of the umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV). The fetal venous brain blood flow was evaluated in the vein of Galen (VG), superior sagittal (SS), straight and transverse venous sinuses.

Results

Only the transverse sinus (TS) showed a significant reduction in the pulsatility index (PI) values in IUGR fetuses. All other veins showed similar PI values between IUGR and AGA fetuses. All cerebral veins of IUGR fetuses showed significantly increased maximum and mean velocities. All these findings did not change in relation to the hemodynamic IUGR deterioration. In nearly all normal and all IUGR fetuses, a pulsatile blood flow pattern was observed in the straight and transverse sinuses, whereas an increased pulsatile pattern in the VG and in the SS was noted in IUGR fetuses.

Conclusion

Brain venous blood flow in IUGR fetuses shows an increment in the maximum and mean velocities of all veins and a reduction in the PI in the transverse sinus.     

吸食鸦片类毒物死者体内吗啡的免疫组化检测

用免疫组化ＰＡＰ法对４例吸食鸦片类毒物死亡尸体各组织器官中的吗啡进行定位观察。结果发现：吗啡广泛分布于中枢神经系统大脑皮质、海马、基底节、丘脑和脑干内的部分神经细胞及小脑浦肯野氏细胞胞浆内，部分神经纤维及部分血管壁组织亦有吗啡分布。此外，吗啡还分布于心、肝、脾、肺、肾、肾上腺、胰腺、胸腺、甲状腺和睾丸等脏器被膜及间质结缔组织内。该研究结果进一步证实吗啡在中枢神经系统中的死后再分布不明显，而在外周各组织器官中存在死后再分布现象。作者认为，用免疫组化ＰＡＰ法检测组织器官中的吗啡可作为吸食鸦片类毒物死亡的诊断依据之一。