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Biomedical subjects

K Kitazawa

Publications and source records attributed to K Kitazawa.

At least 37 records · Page 2Linked to original sources

The relationship of adhesion molecules and leukocyte infiltration in chronic tubulointerstitial nephritis induced by puromycin aminonucleoside in Wistar rats.

We studied the expression of adhesion molecules on infiltrating leukocytes and tubular cells in chronic tubulointerstitial nephritis associated with puromycin aminonucleoside (PA) nephrosis. Rats received injections of PA (2 mg/100 g body wt) weekly for the first 3 weeks and every other week thereafter. Rats were killed at 0, 3, 5, 8, and 12 weeks after the start of injections. From the third to the fifth week, the initial infiltrating cells in interstitial tissue were mainly CD4+ T lymphocytes. At the fifth week, ICAM-1, CD44, and hyaluronate were expressed on infiltrating cells in interstitial tissue. At the eighth week, the number of infiltrating cells reached a peak and consisted of T lymphocytes (CD4, CD8) and macrophages (ED1, MHC class II, CD11b, and CD18). The severity of interstitial infiltration was correlated with the degree of proteinuria and with ICAM-1 expression. Our results suggest that CD4+ T lymphocytes may contribute to the production of initial tubular injury. Expression of ICAM-1 helps mononuclear cells migrate to the interstitium. In addition, expression of CD44 and hyaluronate may play important roles in the chronicity of tubulointerstitial nephritis.

Animals↗

Infantile subdural fluid collection: diagnosis and postoperative course.

The authors reviewed 47 cases of infantile subdural fluid collection with regard to diagnosis and postoperative course after placement of a subdural-peritoneal shunt. CT scan with contrast enhancement proved to be an important diagnostic modality, showing vessels in the subarachnoid space as high-density spots. Utilizing this technique, we were able to differentiate the following varieties of fluid collection: (1) subdural fluid collection, in which enhancing vessels were seen on the brain surface, (2) subarachnoid fluid collection, in which vessels were on the inner table of the cranium, and (3) coexistence of subdural and subarachnoid fluid collections, in which vessels were between the inner table of the cranium and the brain surface. The postoperative course of subdural fluid collection was characterized as follows: (1) the subdural fluid collection decreased first, with increased subarachnoid fluid collection; (2) the subarachnoid fluid collection remained after the disappearance of subdural fluid collection; and (3) the brain expanded again later. Subdural fluid collection disappeared about 1 month after the shunt operation, which could lead occlusion of the shunt system. Postoperative enlargement of the subarachnoid space was an early indicator of the efficacy of the subdural-peritoneal shunt.

Cerebral Angiography↗

[Guillain-Barré syndrome associated with external ophthalmoplegia, consciousness disturbance, and extensor plantar responses: an overlap between Guillain-Barré syndrome and Bickerstaff's brainstem encephalitis].

A 14-year-old girl developed diplopia and ataxic gait following upper respiratory tract infection. On day 3, she became lethergic, but was easily roused on stimulation. Neurologic examinations showed external ophthalmoplegia, tetraplegia, tendon areflexia, and extensor plantar responses. CSF protein was 93 mg/dl with normal cellurality on day 25. Serum in the acute phase of her illness had autoantibodies to gangliosides GQ1b and Ga1NAc-GD1a. An EEG showed bilateral theta activity. Results of ABR, SEP and blink reflexes suggested the presence of intramedullary brainstem lesion. She received plasmapheresis on days 4, 5 and 6. Neurological signs immediately improved. Five months after onset of neurological symptoms, she had no neurological abnormalities except for tendon areflexia. Electrophysiologic studies returned to normal concurrently with her clinical improvement. This patient demonstrates an overlap between Guillain-Barré syndrome and Bickerstaff's brainstem encephalitis.

Adolescent↗

[Fulmonant group A streptococcal infection accompanied by massive pulmonary hemorrhage and subsequent asphyxia: a case report].

A case of fulminant group A streptococcal infection occurring in a 6-year-old Japanese child is reported. She was accompanied by massive pulmonary hemorrhage and subsequent asphyxia. She initially had pharyngalgia with fever. The cephalosporin antibiotic was given orally for 3 days. Three days after that recurrence of fever and pharyngalgia was noted. Twelve hours later tachypnea and a sudden onset of hemoptysis was noted. She manifested DOA (dead on arrival) and died in the emergency room. Autopsy revealed the presence of numerous cocci in the vessels and massive pulmonary hemorrhage. Streptococcus pyogenes was isolated from the blood. The serotype of this group A streptococcal organism was typed as M4, T4, which produces exotoxin type B and C, which was sensitive to the penicillins.

Asphyxia↗

Elevation of transforming growth factor-beta 1 level in cerebrospinal fluid of patients with communicating hydrocephalus after subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Transforming growth factor-beta 1 (TGF-beta 1) is a multifunctional polypeptide that controls the production of extracellular matrix protein. Platelets store a large quantity of TGF-beta 1, which is released at hemorrhage. We recently reported that human recombinant TGF-beta 1 induced communicating hydrocephalus in mice. The aim of this study was to determine whether TGF-beta 1 is related to the development of communicating hydrocephalus after subarachnoid hemorrhage (SAH). METHODS: TGF-beta 1 in the cerebrospinal fluid of 24 patients with SAH was measured with enzyme-linked immunosorbent assay. The levels were compared between hydrocephalic and nonhydrocephalic groups. Western blot analysis was performed to determine active TGF-beta 1 in the cerebrospinal fluid. RESULTS: TGF-beta 1 rapidly decreased from the onset of SAH. The level of TGF-beta 1 of 13 patients showing ventricular dilatation with periventricular low density on computed tomographic scan was 1.07 +/- 0.37 ng/mL on days 12 through 14, which was significantly higher than 0.52 +/- 0.21 ng/mL in patients without ventricular dilatation (P < .02). Furthermore, the TGF-beta 1 level of patients who had undergone ventriculoperitoneal shunt (n = 11) was 1.11 +/- 0.09 ng/mL on days 12 through 14, which was also higher than the level of the nonshunt group (n = 13) (0.56 +/- 0.22 ng/mL; P < .01). A 25-kD band was demonstrated by Western blot analysis in the cerebrospinal fluid of a patient with SAH. CONCLUSIONS: Our results strongly suggest that TGF-beta 1 plays an important role in generating communicating hydrocephalus after SAH.

Adult↗

[Studies on cell-mediated immunity (CMI) in the glomeruli: immunization with GBM antigen from Masugi nephritis in Wistar-Kyoto rats].

The role of cell-mediated immunity in glomerular injury has been extensively studied, but the precise mechanism remains obscure. This study was undertaken to determine whether the homologous glomerular basement membrane (GBM) combined heterogeneous anti-GBM antibody would induce cell-mediated immunity. Wistar-Kyoto rats were divided into three groups; group I rats were immunized with homologous GBM antigen that was derived from Masugi nephritis and emulsified in complete Freund's adjuvant (CFA); group II rats were immunized with homologous GBM antigen that was derived from normal rats and emulsified in CFA; group III rats were immunized with CFA only. Group I rats demonstrated proteinuria on days 7 and 10 after immunization. Histologically, mesangial cell proliferation and cell infiltration were observed in the glomeruli. No changes in tubulointerstitial tissue. CD4-positive cells, CD8-positive cells and macrophages were found in the glomeruli, and mononuclear cells were found in the glomerular capillary lumen. Group II and Group III rats demonstrated no proteinuria and no histological changes. These findings indicated that the altered GBM obtained antigenicity and induced cell-mediated immunity in the glomeruli.

Animals↗

[Clinicopathological significance of immune complex (IC) along the tubular basement membrane (TBM) in lupus nephritis].

This paper reports on the clinicopathological significance of IC along the TBM in lupus nephritis. Renal biopsies were performed on 60 patients with SLE. All of the patients demonstrated immunoglobulin deposits in the glomeruli, and 16 of them also showed immune deposits along the TBM. The IgG in the glomeruli or along the TBM completely disappeared after incubation with human IgG, IgG Fc fragments, but not with human F(ab')2, rabbit or rat IgG. These results suggest that IgG along the TBM are similar in nature to IC in the glomeruli and that the IC are composed of IgG rheumatoid factor. The square of tubulointerstitial lesions was more severe in the group with IgG along the TBM than in the group with no IgG along the TBM (5.85 +/- 9.88% vs 1.29 +/- 3.72%). In addition of this, the group with IgG deposits along the TBM frequently demonstrated type IV lupus nephritis. Although the renal function was not significantly different in the both groups, the serum complement level was lower in the cases with IC deposits in the TBM. From these results, it is suggested that IC deposits along the TBM as one of the important inflammatory agents lead to the severe forms of tubulointerstitial injury and show the active stage of the disease in SLE patients.

Antigen-Antibody Complex↗

[CT guided transsphenoidal surgery: report of nine cases].

We have developed a Computed Tomography system for use in the operating room and applied this CT system to intraoperative monitoring during transsphenoidal surgery. This system includes Toshiba TCT-300 CT system, mobile CT scanner gantry, digitally controlled operating table and head fixation system. Between June 1989 and Dec. 1989, CT guided transsphenoidal surgery was carried out in 9 cases in our department. The suprasellar masses were visualized directly during transphenoidal surgery and were removed safely and efficiently. Under this CT monitoring system the surgeon can obtain accurate information about the location and volume of residual tumor as well as about the important surrounding deeper structure. Another advantage of this system is that the digitally controlled operating table makes it possible to keep the patient in a head-up position, which lessens oozing from the parasellar region during transsphenoidal surgery. We believe the best application of this method is that for pituitary tumor with moderate suprasellar extension. Nine cases were reported in this paper which were operated on using this system. To our knowledge, this is the first report of use of intraoperative CT monitoring during transsphenoidal surgery.

Adenoma↗