Characterization of the prostanoid receptors and of the contractile effects of prostaglandin F2a in human pial arteries

The contractile and relaxant effects of various prostanoids were studied on isolated human pial arteries. Contractions were elicited with the following order of potency: U46619?U44069>PGB₂>PGF_2a>PGE₂?PGD₂>PGF_1a≥TXB₂, indicating that prostanoid-induced contractions probably are mediated by a thromboxane-sensitive receptor. Relaxation of PGF_2a-contracted arteries was induced with the order of potency: PGE₂> PGE₁>PGD₂?PGD₁. Vessels contrated by K⁺ were relaxed only by PGE,. Since PGI₂ was previously found to be more potent than all the prostanoids tested in the present study, relaxant responses are probably mediated via a PGI₂-sensitive receptor. The roles of free extracellular and cellularly bound calcium for the contractile effects of PGF_2a and K⁺ were estimated by incubating the arteries for various times in calcium-free medium containing 10^-5 M EGTA. Incubation for 5–10 min abolished K⁺-induced contractions, whereas after 40 min of incubation PGF_2a still induced contractions that reached 70% of control. The PGF_2a-induced contraction was biphasic in 8 out of 10 preparations. The second phase could be eliminated by increasing the EGTA-concentration to 10^-4 M, as well as by nifedipine pretreatment. In calcium-free, high K⁺ medium calcium-induced contractions were elicited at lower concentrations in the presence of PGF_2a. The results suggest that PGF_2a-induced contractions in human pial arteries are relatively independent of free extracellular calcium. PGF_2a may promote trans-membrane influx of calcium, as well as release calcium from seemingly superficially located cellular stores.     

The human placental bed: histology, immunohistochemistry and pathology

There has been much interest recently on local intra-uterine materno-fetal interactions particularly in the placental bed where cellular relationships between mother and fetus are at their most intimate. While few histopathologists are expected to interpret formal placental bed biopsy specimens, confrontation with tissue from this site is common following abortion, post-partum haemorrhage or molar gestation. This review gives an account of recent advances in our knowledge of the histology, immunohistochemistry and pathology of the placental bed. It focuses particularly on extravillous trophoblast populations and their relationship to maternal cells and emphasizes the importance of vascular changes.     

Prognostic value of early somatosensory evoked potentials during carotid surgery: Relationship with electroencephalogram,stump pressure and clinical outcome

Summary The authors have reported on the prognostic value of continuous monitoring of somatosensory evoked potentials (SEP) in a survey of 25 patients who underwent carotid surgery. SEP recordings were correlated with the EEG, stump pressure (SP) values and clinical outcome. A non-cephalic reference was used for SEP recordings to allow the analysis of both subcortical and cortical components. During surgery the conduction time between SEP peaks relating to the subcortical components remained stable or showed minimum variations in all patients. During carotid clamping, SEP variations were observed in 9 out of 25 cases (36%). The application of an intraluminal shunt was accompanied by the return to normal values in 7 out of 9 patients. In the remaining two cases SEP abnormalities continued post-operatively and were accompanied by new neurological deficits. EEG changes during carotid clamping were associated with SEP modifications in 6 out of 7 cases, although they were not always correlated. Results confirm that SEP recordings provide useful data concerning the function of the CNS in anaesthetized patients and that, being sensitive to CBF changes, SEP monitoring acts as an indicator of cerebral ischaemia.Presented in part at the Third International Evoked Potentials Symposium, Berlin-West, September 28th–October 1st, 1986.     

Anterior displacement of the mandible for better exposure of the distal segment of the extracranial carotid artery

Summary Anterior displacement of the mandible (ADM) was performed in 34 patients undergoing surgery for malformations or atheromatous lesions of the distal segment of the extracranial internal carotid artery (ICA). This procedure greatly facilitates surgical access to the upper cervical region and has several advantages over mandibulotomy-mandibulectomy, namely: A shorter operating time, sparing of the inferior alveolar nerve and of the mandibular branch of cranial nerve VII, with no need for post-operative immobilization of the mandible. ADM permits the correction of ICA lesions extending as far as the first cervical vertebra. For lesions extending into the carotid canal ADM needs to be supplemented by various other procedures via the base of the skull.     

“Cross-over” duplication of middle cerebral artery,agenesis of internal carotid artery and saccular aneurysms

Summary The authors describe a patient with anomalous branches of the left internal carotid artery, cross-over duplication of its middle cerebral artery and agenesis of the contra-lateral internal carotid artery associated with two aneurysms successfully clipped. Pertinent literature is reviewed.     

Differential effects of α-β-methylene ATP on responses to nerve stimulation in SHR and WKY tail arteries

Summary The effects of ,-methylene-adenosine triphosphate, (,-methylene ATP, a P₂-receptor desensitising agent) have been evaluated on vasoconstrictor responses elicited by exogenous agonists or electrical field stimulation in isolated perfused SHR or WKY tail arteries and on tritium release elicited by electrical field stimulation in SHR-tail arteries pre-labeled with ³H-noradrenaline.Exposure to ,-methylene ATP (0.1 mol/l) significantly inhibited vasoconstrictor responses to electrical field stimulation in SHR tail arteries. These inhibitory effects were not further increased at a higher concentration of ,-methylene ATP (1 mol/l). In WKY tail arteries, ,-methylene ATP (1 mol/l) failed to significantly inhibit vasoconstrictor responses to electrical stimulation.In SHR tail arteries prelabelled with ³H-noradrenaline, ,-methyleneATP (1 mol/l) did not inhibit the stimulation evoked release of tritium. However, at this concentration, ,-methylene ATP significantly antagonized the vasoconstrictor responses of SHR tail arteries induced by exogenous ATP (1 mol/l), ,-methylene ATP (30 mol/l), a stable agonist at P₂-receptors, or 60 mmol/l KCl. These effects of ,-methylene ATP on contractile responses to KCl were not observed in WKY-tail arteries.In tail arteries obtained from reserpine pretreated SHR, despite a 85–95% decrease in endogenous noradrenaline tissue content, the vasoconstrictor responses induced by periarterial field stimulation were greatly diminished, but not abolished. These residual responses to periarterial field stimulation were not antagonized by prazosin (0.1 mol/l), but were practically abolished by the addition of ,-methylene ATP (1 mol/l).In tail arteries from WKY rats pretreated with reserpine, exposure to prazosin (0.1 mol/l) further reduced the residual responses elicited by electrical field stimulation. In these WKY-tail arteries, addition of ,-methylene ATP (1 mol/l) did not further inhibit the remaining vasoconstrictor response obtained in the presence of prazosin.While our results suggest a significantly greater cotransmitter role for ATP with noradrenaline in tail arteries of SHR compared with control normotensive WKY rats, additional effects of ,-methylene ATP not involving P₂ receptors cannot be entirely excluded.     

Review of 1,000 consecutive cases of severe head injury treated before the advent of CT scanning

Summary This is a review of 1,000 consecutive cases of severe head injury admitted to our Neurosurgical Department between January 1973 and August 1976, before the advent of CT scanning. All patients were comatose following head injury (GCS8) and were treated homogeneously by the same neurosurgical team by a protocol that included immediate resuscitation on arrival, diagnosis of intracranial lesions by angiography, early surgery when needed, mechanical ventilation, steroids, and mannitol. Extracranial lesions, even if preponderant, were treated by various specialists in the Neurosurgical Department, which for all practical purposes operated as an Emergency Department. Admission criteria were very broad with no preadmission selection. The overall mortality for this series was 45%. A little less than half the patients made good recoveries or remained moderately disabled (47%); 6% were severely disabled, and 2% survived in a persistent vegetative state. More than two-thirds of the patients were brought to our Neurosurgical Department after a short stay at a general hospital; 72% were admitted within 6 hours of injury; 71% were traffic accident victims; and 34% had significant associated extracranial injuries. Carotid angiography was performed in 78% of the patients and indicated the presence of an intracranial haematoma requiring surgery in 36% of the whole series. Mortality was significantly higher in operated than in unoperated patients (56% versus 39%); those treated surgically, however, were older, in worse clinical condition, and showed a higher incidence of acute subdural haematomas associated with brain contusion. Carotid angiography proved very effective in revealing the presence of an expansive lesion but failed to reflect the severity of brain damage, since the group with negative angiograms showed a high mortality (52%). Patients with a lucid interval had a higher percentage of surgical lesions than those with immediate coma (58% versus 26%); but fully 42% of them did not require surgery, and 25% had negative angiograms. From the prognostic point of view the clinical data elicited after initial resuscitation were highly predictive of the outcome: some individual neurological signs, such as mydriasis, posturing and eye movements, were not inferior to the GCS score in that respect. Age also proved a strong predictor, since elderly patients are more likely to have severe subdural and parenchymal lesions and their clinical severity is accordingly greater.Our series amounts to a data bank of cases both contemporary to and in good agreement with that collected by Jennett and his associates in their 1977 multinational study; and it affords a useful reference in the assessment of epidemiological variations and alternative management in relation to outcome.     

社区呼吸康复治疗在慢性呼吸系统 疾病患者干预管理中的应用*

摘 要： 目的：探究中老年人颈动脉斑块与血清25羟维生素D （25-OH-D） 的相关性。 方法：选取2019年1月—2020 年 12 月自愿参与该研究的上海市浦东新区北蔡社区常住居民 412 人为研究对象,测定及记录其一般临床资料及血清 25-OH-D 等实验室检测结果。依据血管 B 超结果将研究对象分为有斑块组 268 人和无斑块组 144 人,比较两组人群血清 25-OH-D水平差异,用Pearson相关性分析各变量的关系,采用logistic回归分析颈动脉斑块形成的危险因素。结果：有斑块 组血清 25-OH-D 为 （45.18±18.71） nmol/L,无斑块组为 （56.12±19.54） nmol/L,两组差异有统计学意义 （χ2=5.573,P＜ 0.05）。相关性分析显示颈动脉斑块与收缩压、HbA1c、年龄呈正相关 （r值分别为0.388、0.119和0.128,P值均＜0.05）;与 血清 25-OH-D 呈负相关 （r=-0.365,P＜0.01）。血清 25-OH-D 是颈动脉斑块形成的独立相关因素 （OR=0.973,95%CI： 0.960,0.985,P＜0.05）。结论：低水平血清25-OH-D是颈动脉斑块形成的独立危险因素。     

Kubelka-Munk模型下的兔血管对氦-氖激光的散射与吸收特性

测量了兔动脉和静脉对 He-Ne激光的反射和透射传输特性。实验采用两积分球系统及波长为632.8nm的He-Ne激光器,并根据测量数据及采用 Kubelka-Munk模型分析和计算了兔动脉和静脉组织对该长激光的吸收系数、散射系数及总的光强I（x）及前向散射通量i(x）和后向散射通量j(x）随厚度的变化情况。结果表明,兔动脉和静脉的漫反射率和透射率有明显差别,而且,动脉对激光的吸收系数明显较静脉的要小,而动脉对激光的散射系数却明显较静脉的要大,在动脉和静脉组织中总的光强I（x）及前向散射通量i(x）和后向散射通量j(x）随组织厚度的变化情况也有明显的区别。