Nagoya Journal of Medical Science

Dialysis-induced hypotension, the sharp decrease in blood pressure occurring during hemodialysis, remains one of the most difficult problems associated with hemodialysis even today. However, there is yet no established theory to explain the mechanism triggering dialysis-induced hypotension. This review attempts to offer a consistent and cohesive source of information on the hemodynamics during dialysis-induced hypotension, and then analyzes etiologic factors in such hypotension reported by various investigators. Finally, three hypotheses concerning the mechanism of dialysis-induced hypotension including our own are introduced.

During infection with L.monocytogenes, a facultative intracellular bacteria, TcR γ/δ T cells specific for 65 kd hsp precede TcR α/β T cells specific for the listerial antigens in appearance. The γ/δ T cells provide a first line of defense against the infection by recognizing exogenous and endogenous 65 kd hsp on infected cells and producing cytokines such as γIFN. The hsp-specific T cells respond quickly to antigenically diverse pathogens before antigen-specific T cells expand clonally, and they playa role in covering the gap between the phagocytic system and highly evolved immune response. 65 kd hsp-specific T cells play important roles not only in host defense mechanism against infection with various pathogens but also in induction of autoimmune disease. Both 65 kd hsp-specific γδ T cells and 65 kd hsp-specific αβ T cells abrogate the unresponsiveness of the self-reactive αβ T cells and/or B cells by producing IL-2 and contribute to induction of autoimmune disease.

Observations of the disease course mainly by X-ray were made in 52 patients (85 joints) with avascular necrosis of the femoral head to determine the prognosis and to decide on treatment. The progression of the necrotic area is related to the activity of the original disease, to the size of the necrotic area in the early stages of the disease, and to whether or not the patient received steroid treatment. On the basis of the size and location of the necrotic area, the disease process is divided into four stages, I to IV. The affected heads are also classified into six types according to their site and extent, the degree of flatness of their weightbearing surface, and the presence of cystic lesion. Preventive treatment and conservative observation or transtrochanteric anterior rotational osteotomy and vascularized pedicle bone graft are applicable to cases in Stages I and II. Total hip joint arthroplasties and salvage procedures are performed in Stages III and IV. The usefulness of 99mTc bone scintigraphy was unexpectedly disappointing for diagnosis of the stages of the disease. However, MRI was sensitive for the diagnosis in the early stages of the disease.

Morphologically and functionally intact mitochondria were isolated from the porcine pancreas using a conventional, differential centrifugation method. The homogenate of the porcine pancreas made in a medium containing 0.25 M sucrose, 10 mM Tris-CI, pH 7.4, 0.5% bovine serum albumin and 1 mM EDTA, in the presence or in the absence of dibucaine and trypsin inhibitor, was centrifuged for 10 min at 700xg. The supernatant was centrifuged for 10 min at 7000xg, and the pellet was washed three times. Trypsin activity of mitochondria isolated in the absence of dibucaine and trypsin inhibitor was as low as that of mitochondria isolated in the presence of dibucaine and trypsin inhibitor, and a major part of the activity remained inactivated. Phospholipase A₂ activity of the former mitochondria was as low as that of the latter, and remained unchanged up to 8-10 hr at 4°C. The presence of bovine serum albumin and EDTA in the respiration medium was absolutely required to obtain good respiratory controls of those mitochondria. These data suggest that well-coupled mitochondria can be obtained from the pancreas by a conventional isolation procedure without activating the major part of trypsin.

This study was designed to investigate the potential of the Gianturco-Rosch Z stent in the alimentary canal, using the rabbit esophagus as the animal model. Single stents were implanted in four animals, which were followed up for predetermined periods, lasting from 48 hours to 6 weeks. All the stents remained in place. A florid tissue reaction was noticed, initially manifesting primarily as submucosal cellular infiltration, and mucosal erosion. Over the ensuing six weeks, the acute changes gave way to mucosal regeneration, and the appearance of granulation tissue in the submucosa. The stented segments remained patent, and feeding difficulties were limited to the immediate post-procedure period. These preliminary results suggest that peristaltic activity is no contraindication to the use of Z stents, though measures to limit the tissue response need to be identified.

The effect of hypophysectomy on transepithelial movement of ³H-androgen in the rat epididymis was examined by using in vivo micropcrifusion of ³H-tcstosterone followed by in vivo micropuncture to obtain peritubular and intraluminal fluids. Experiments were performed on aminals without hypophysectomy or on aminals 5-6 days after hypophysectomy and 9-10 days after hypophysectomy. Tubules were perifused with Minimum Essential Medium containing ³H-testosterone. ¹⁴C-polyethyleneglycol was included in the perifusion fluid as a marker for contamination of the intraluminal fluid by peritubular fluid. Radioactivity of isotopes in the interstitial and intraluminal fluid was determined at 1 and 2 hours after perifusion and the percentage of peritubular isotopes appearing in the intraluminal fluid was determined. A sperm concentration microassay was performed on micropuncture samples from the epididymal tubules to assess testicular contribution to the lumen content. Proluminal movement of ³H-androgen and intratubular sperm concentrations in the caput epididymal tubules of rats 9-10 days after hypophysectomy were significantly decreased. Pruluminal movement of ³H-androgen and intratubular sperm concentrations in the cauda epididymal tubules of rats 9-10 days after hypophysectomy were significantly increased. These results suggest that proluminal androgen movement is controlled by the presence of some testicular product in the epididymal lumen.

Intrahepatic venous collaterals develop in Budd-Chiari syndrome, hepatomas, and other tumors if the hepatic veins are obstructed. In portal hypertension hepatic vein-to-vein anastomoses develop without obstruction of the hepatic veins. In a 53-year-old woman with giant cavernous hemangioma of the liver, hepatic venography demonstrated remarkable hepatic vein-to-vein anastomoses in the periphery of the heaptic veins without venous obstruction, accompanied with low wedged hepatic vein pressure. The hemodynamic change of the liver may cause this abnormality because of the large blood space of the hemangioma. Pathological examination of the resected liver apart from the tumor confirmed numerous deformations and dilatations of the central veins not found in the normal liver, in the area of hepatic vein-to-vein anastomoses shown by venography. Clinically, atypical hepatic resection is possible by maintaining a drainage vein to preserve as much of the normal liver as possible. Hepatic venography, as well as hepatic angiography, gives important information about the liver.

Movement studies of the neck have shown that certain patients with cervical spondylotic myelopathy (CSM) demonstrate instability in the vertebral joint immediately above the posterior osteophytic bar. While Cloward's anterior cervical decompression with fusion eliminates the cord or root compressive element, it adds to the hypermobility of the adjoining vertebral segment. In an attempt to reduce the hypermobility or subluxation, anterior cervical decompression without fusion was carried out on a selected group of twentythree patients with spondylotic cervical myelopathy in whom the cord compression was mainly at a single level. Follow-up cineradiographic studies of these cases demonstrated the continued preservation of the range of movement of the adjoining vertebral segments and in 30%, a return of normal functional mobility to the affected cervical intervertebral joint. The findings and results of anterior cervical decompression surgery to a single level are reported.