Pseudopodia of capillary endothelium in ocular tissues

The frequencies of pseudopodia projecting from capillaries of various parts of the eye were observed in 16 human eyes with a transmission electron microscope. The pseudopodia were found mainly projecting from the choriocapillaris and rarely seen in the retina, iris or ciliary body. The frequencies of pseudopodia from the choriocapillaris were not correlated with the localization in the fundus (macular area or peripheral fundus), age, sex, time elapsed between death or enucleation and fixation. The significance of pseudopodia from the choriocapillaris is unknown. However, there is the possibility that pseudopodia are related to choroidal neovascularization or have other physiological functions.     

Pharyngeal Patency in Response to Advancement of the Mandible in Obese Anesthetized Persons

Background: During anesthesia in humans, anterior displacement of the mandible is often helpful to relieve airway obstruction. However, it appears to be less useful in obese patients. The authors tested the possibility that obesity limits the effectiveness of the maneuver.

Methods: Total muscle paralysis was induced under general anesthesia in a group of obese persons (n = 9; body mass index, 32 +/- 3 kg sup -2) and in a group of nonobese persons (n = 9; body mas index, 21 +/- 2 kg sup -2). Nocturnal oximetry confirmed that none of them had sleep-disordered breathing. The cross-sectional area of the pharynx was measured endoscopically at different static airway pressures. A static pressure-area plot allowed assessment of the mechanical properties of the pharynx. The influence of mandibular advancement on airway patency was assessed by comparing the static pressure-area relation with and without the maneuver in obese and nonobese persons.

Results: Mandibular advancement increased the retroglossal area at a given pharyngeal pressure, and mandibular advancement increased the retropalatal area in nonobese but not in obese persons at a given pharyngeal pressure.     

Gadolinium-enhanced breath-hold three-dimensional time-of-flight MR angiography of the abdominal and pelvic vessels: The value of ultrafast MP-RAGE sequences

MR angiography (MRA) was performed in 50 consecutive subjects (mean age, 59 years), who had been referred for abdominal MRA, on a 1.5-T superconductive unit that used a body phased-array coil. Three breath-hold three-dimensional sequences were evaluated both in phantom and clinical studies: (a) standard fast three-dimensional gradient-echo sequence (TR = 15, TE = 6; imaging time, 32 seconds), (b) ultrafast three-dimensional gradient-echo sequence (TR = 8.2, TE = 3; imaging time, 18 seconds), and (c) ultrafast magnetization-prepared (MP) rapid acquisition gradient echo (RAGE) (TR = 5.8, TE = 2.9, inversion time [TI] = 20; imaging time, 15 seconds). The initial 30 patients were randomized into three groups by three separate sequences. For the remaining 20 patients, ultrafast-gradient-echo and ultrafast MP-RAGE sequences were performed. Conventional angiography was performed on 36 patients. Signal measurements of the phantom and clinical images of the aorta, visceral branches of the aorta, iliac arteries, inferior vena cavae, and portal veins were performed. The overall image quality and background fatty tissue contrast of the vessels were rated subjectively. Comparison of images between MRA and conventional angiography also was performed. The contrast between the vessels and background fatty tissue was significantly higher in the ultrafast MP-RAGE sequence in both quantitative and qualitative analysis, and image-quality ultrafast MP-RAGE was superior to the other two sequences (P < .01). The aorta and iliac arteries could be visualized in all pulse sequences, and abnormalities of these vessels were diagnosed correctly. The renal artery was visualized more clearly with the two ultrafast sequences.     

Cerebrovascular reserve capacity in ischemia due to occlusion of a major arterial trunk: studies by Xe-CT and the acetazolamide test.

Classifications based on clinical and radiographic criteria have proved to be inadequate predictors of the course of cerebral ischemia or its response to therapy. In this study the cerebrovascular reserve capacity (CRC) of 46 patients with symptomatic cerebrovascular ischemia was studied by stable xenon-enhanced CT (Xe-CT) combined with the acetazolamide test. Fifteen patients had internal carotid artery (ICA) occlusion, 10 had ICA stenosis, 10 had middle cerebral artery (MCA) occlusion, and 11 had MCA stenosis. In the patients with chronic cerebral ischemia due to occlusive lesions of the ICA and MCA, the CRC was reduced most in those with MCA occlusion, followed, in descending order, by those with ICA stenosis, MCA stenosis, and ICA occlusion. Our results indicate that measurement of the CRC elucidates cerebral hemodynamic factors that cannot be detected by angiography in patients with chronic cerebral ischemia and that Xe-CT combined with the acetazolamide test is useful for this purpose.     

Effects of beta-adrenoceptor-related agents on hypoxic pulmonary vasoconstriction and relation with cyclic AMP and prostaglandins]

Effects of a beta-agonist (isoproterenol) and beta-antagonists (propranolol and pindolol) on hypoxic pulmonary vasoconstriction (HPV) and on changes in some chemical mediators were compared between HPV-responsive lobes and non-responsive lobes in which HPV was induced by aspirin DL-lysine (ASA groups). Hypoxic ventilation (4 min) was repeated in 56 of isolated, blood-perfused dog lung lobes. Each drug was administrated in a bolus dose of 0.2 mg in the intermittent period between hypoxia. In HPV-responsive lobes, the first hypoxia increased pulmonary vascular resistance by 33% or more in all groups. Both isoproterenol and pindolol inhibited the elicitation of HPV completely, but propranolol induced almost the same degree of HPV as control. In ASA groups, HPV was completely inhibited by isoproterenol, but was not influenced by propranolol. However, pindolol's inhibitory effect on HPV was less than that in HPV-responsive lobes. Isoproterenol significantly increased cyclic AMP from 17.0 to 76.7 pmol/ml in HPV-responsive lobes (n = 7). Pindolol increased prostaglandin E2 from 87.0 to 1015.4 pg/ml in HPV-responsive lobes (n = 7), and from 93.4 to 361.3 pg/ml when ASA was treated. Propranolol did not show the different results from the control group whether ASA was present or not. The different mechanisms among beta-adrenoceptor-related agents in HPV and pulmonary circulation were investigated.     

Carinal resection and reconstruction for recurrent lung cancer

A patient with a recurrent tumor in the trachea adjacent to the right main bronchus was treated by surgical resection 19 months after undergoing surgery for the primary cancer. The patient had previously undergone right upper lobectomy for T1N0M0 stage I squamous cell carcinoma. A carinal resection was performed which included 4 rings of the trachea, 2 rings of the righ main bronchus, and 1 ring of the left main bronchus. Reconstruction consisted of an end-to-end anastomosis of the trachea and left main bronchus, and an end-to-side anastomosis of the right and left main bronchi. The postoperative course was uneventful, and at present the patient is healthy 12 months following reoperation.     

Virtual endoscopic images by 3D FASE cisternography for neurovascular compression.

Three-dimensional fast asymmetric spin echo (3D FASE) cisternography provides high spatial resolution and excellent contrast as a water image acquisition technique. It is also useful for the evaluation of various anatomical regions. This study investigated the usefulness and limitations of virtual endoscopic images obtained by 3D FASE MR cisternography in the preoperative evaluation of patients with neurovascular compression. The study included 12 patients with neurovascular compression: 10 with hemifacial spasm and two with trigeminal neuralgia. The diagnosis was surgically confirmed in all patients. The virtual endoscopic images obtained were judged to be of acceptable quality for interpretation in all cases. The areas of compression identified in preoperative diagnosis with virtual endoscopic images showed good agreement with those observed from surgery, except in one case in which the common trunk of the anterior inferior cerebellar artery and posterior inferior cerebellar artery (AICA-PICA) bifurcated near the root exit zone of the facial nerve. The veins are displayed in some cases but not in others. The main advantage of generating virtual endoscopic images is that such images can be used for surgical simulation, allowing the neurosurgeon to perform surgical procedures with greater confidence.     

Antihypertensive effect of bopindolol on stroke-prone spontaneously hypertensive rats (SHRSP)

The antihypertensive effect of bopindolol, a long-acting beta-adrenoceptor blocking agent, was investigated in stroke-prone spontaneously hypertensive rats (SHRSP). One group received tap water during the period of 8 to 32 weeks of age. The average dose of bopindolol administered was calculated from water intake to be approximately 1.4 mg/kg/day. The lowering effect in blood pressure of bopindolol was apparent at the age of 14 weeks, and this continued up to the end of the experiment. Bopindolol significantly reduced the heart rate. Plasma levels of urea nitrogen (BUN), triglyceride, and phospholipid of SHRSP treated with bopindolol were lower than those of the control SHRSP. One of the 8 control SHRSP died, and no rats treated with bopindolol died during the experiment. The histopathological study revealed that three of the control SHRSP had cerebral apoplexy, whereas there was no evidence of cerebral apoplexy in the treated SHRSP. Chronic treatment of bopindolol clearly alleviated myocardial fibrosis and hypertrophic changes in the left ventricular wall of the heart. Decreases in the incidence of proliferative arteritis and malignant nephrosclerosis in the kidney and necrotizing arteritis of the mesenteric arteries were observed in SHRSP treated with bopindolol. The data presented indicate that bopindolol is a powerful antihypertensive agent.