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Biomedical subjects

S Kawamura

Publications and source records attributed to S Kawamura.

At least 361 records · Page 20Linked to original sources
PubMed1988

The ventral lateral geniculate nucleus in the cat: thalamic and commissural connections revealed by the use of WGA-HRP transport.

The present investigation was carried out to clarify the topographical details of both the origin and terminal site of the thalamic projections and the commissural connections of the ventral lateral geniculate nucleus (LGNv) in the cat by using bidirectional transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP). Thalamic projections: Unilateral injections of WGA-HRP into the LGNv produced orthograde labeling in the intralaminar nuclei bilaterally and in the lateralis posterior (LP) and the pulvinar (Pul) nucleus ipsilaterally. In the intralaminar nuclei the rostral part of the nucleus centralis lateralis (CL) was most densely labeled by orthogradely transported material, particularly in its dorsal and lateral large-celled portion. Other intralaminar nuclei--such as the nucleus paracentralis, centralis medialis, and centralis dorsalis--also were labeled bilaterally with ipsilateral predominance, but no labeling was detected in the caudal portion of the CL and the centromedian and parafascicular nuclei. In the Pul, labeling of terminal ramifications was found to be concentrated in a region just medial to the so-called retinorecipient zone of the Pul as a slim band of labeling inclining dorsoventrally. In the LP, fine labeled fibers were located in the lateral portion of the LP. Commissural connections: Commissural fibers crossed in the dorsal part of the posterior commissure and reached the most caudal part of the contralateral LGNv. Labeling in the contralateral LGNv was concentrated in the dorsomedial part of the medial zone that extends medially to the middle portion of the cerebral peduncle. Origins of the commissural connections arose mostly from the medial zone that roughly corresponds to the commissural terminal zone and partly from aberrant cells dispersed among optic tract fibers. From these results, together with the previous studies, it is concluded that although the cat's LGNv has connections with diverse structures in the central nervous system, the origin and terminal site of the connections are partially segregated within the nucleus, which suggests that the LGNv may contain functional subsystems.

Animals↗
PubMed1988

Comparison of the antinociceptive effects of new [D-Arg2]-dermorphin tetrapeptide analogs and morphine in mice.

The antinociceptive effects of synthetic dermorphin tetrapeptide analogs containing D-Arg in position 2, H-Tyr-D-Arg-Phe-Gly-NH2 and H-Tyr-D-Arg-Phe-beta-Ala-OH, were measured in mice by the tail-pressure test. The antinociceptive effect produced by intracerebroventricular (ICV), intrathecal (IT) and subcutaneous (SC) administration of either peptide was greater than that produced by morphine. Oral (PO) administration of the peptides showed approximately the same antinociceptive potency as morphine. In addition, the antinociceptive effect produced by SC and PO administration of either peptide was of longer duration than morphine. Pretreatment with naloxone resulted in nearly complete antagonism of the antinociceptive effects produced by ICV and IT administration of either peptide or morphine. Dose ratios (ICV/IT) of H-Tyr-D-Arg-Phe-Gly-NH2 and H-Tyr-D-Arg-Phe-beta-Ala-OH, which were calculated from the AD50 (Antinociceptive Dose = 50% MPE) values, were 5.8 and 6.2, respectively, whereas that of morphine was only 1.46. These results suggest that the mechanisms of the antinociceptive effects of [D-Arg2]-dermorphin tetrapeptide analogs differ from morphine, and that these peptides may possess higher affinities than does morphine for opioid receptors in the spinal cord.

Analgesics, Opioid↗
PubMed1988

Ultrastructure of kidney from three patients with HBeAg-associated nephropathy with special reference to virus-like particles in the glomerular tufts.

The biopsied kidneys from three patients with hepatitis Be antigen (HBeAg)-associated nephropathy were observed by light microscopy, immunohistochemistry and electron microscopy. By an indirect technique utilizing horseradish peroxidase-conjugated antisera, HBeAg was found to be deposited in a diffuse granular fashion along the glomerular capillary wall. No deposition of hepatitis Bs or hepatitis Bc antigen was detected. The three cases were diagnosed as HBeAg-associated nephropathy. Ultrastructurally, there were finely granular electron-dense deposits in the subendothelial area, basement membrane, mesangial area and subepithelial area of the glomerular tufts. In all three cases, virus-like particles between 30 and 70 nm in diameter were also found in such areas of the glomerular tufts, and rarely in the glomerular capillary lumen and space of Bowman. They occasionally formed clusters in the phagosomes of mesangial cells. In addition, tubulo-reticular structures were noted in the cytoplasm of endothelial cells in the glomerular capillaries. The presence of HBeAg both in the serum and in the kidney and of virus-like particles in the glomerular tufts suggests that HBeAg is causally related to the development of HBeAg-associated nephropathy.

Adult↗
PubMed1988

Antinociception and physical dependence produced by [D-Arg2] dermorphin tetrapeptide analogues and morphine in rats.

1. The antinociceptive effects of [D-Arg2] dermorphin tetrapeptide analogues, H-Tyr-D-Arg-Phe-Gly-NH2 and H-Tyr-D-Arg-Phe-beta-Ala-OH when administered subcutaneously (s.c.) in rats were measured by the tail-flick test. In addition, the appearance of typical withdrawal signs upon cessation of administration or on subsequent treatment with naloxone were measured after chronic administration of either peptide or morphine. 2. The dose of peptides and of morphine in the physical dependence test was determined from the AD50 to inhibit the tail-flick test in rats. Doses from 4 to 64 times the AD50 doses were employed in the s.c. administration schedules. 3. The intensity of the antinociception induced by either peptide was greater than that produced by morphine. Moreover, the antinociception induced by the peptides was of much longer duration than that produced by morphine. 4. Abrupt withdrawal after chronic administration of either peptide produced only slight loss of body weight. In contrast, morphine withdrawal produced sharp loss of body weight. 5. Naloxone precipitated withdrawal signs after chronic administration of either peptide were less intense than those after chronic morphine. 6. These results suggest that the antinociception produced by these peptides is more intense and of longer duration than that produced by morphine. It is also interesting to note that the physical dependence produced by these peptides is less marked than that produced by morphine.

Analgesics↗
PubMed1988

The Effect of Diminazene Aceturate on Spienectomized Dogs with Babesia gibsoni Infection.

The effect of diminazene aceturate on splenectomized and nonspienectomized dogs with Babesia gibsoni (B. gibsoni) infection was investigated. In splenectomized dogs, the fissional and multiplicational stages of B. gibsoni were observed in peripheral blood films, and hemoglobinuria was frequently observed. These findings were different from previous reports and were not changed by administration of diminazene aceturate. It is clear that the intramuscular administration of diminazene aceturate at the dose of 3 mg/kg body weight for 3 days is not effective against B. gibsoni infection in splenectomized dogs.

Journal Article↗
PubMed1988

Ureteral obstruction secondary to sigmoid diverticulitis.

A case of ureteral obstruction secondary to diverticulitis is described. The patient had a 2-month history of lower left quadrant pain before an operation. As an intravenous pyelogram showed persistent hydronephrosis, an operation was performed. At the operation, a fibrotic mass which encased the left ureter and sigmoid colon was found. Ureterolysis and segmental sigmoidectomy were carried out. The pathological specimen showed two diverticula and subserosal cicatrization.

Adult↗
PubMed1988

[Effect of cysteamine on vocalization responses by arterial algogenics in guinea pigs].

Effects of cysteamine (2-mercaptoethylamine) on vocalization responses, a parameter of nociceptive response, was studied in conscious guinea pigs. Intra-arterial injection of bradykinin (3 micrograms), acetylcholine (300 micrograms), capsaicin (3 micrograms) and vanillyl n-nonoylamide (3 micrograms, VNA) induced severe vocalization responses. Three hours after an administration of cysteamine (300 mg/kg, s.c.), a significant suppressive effect was observed for bradykinin and acetylcholine-evoked vocalization. A weak suppressive effect appeared in capsaicin and VNA-evoked vocalization, but there were not statistically significant changes on vocalization counts when compared with the value of the saline-treated animals. However, consecutive pretreatment of guinea pigs with VNA led to a complete suppression of capsaicinoids-evoked vocalization only. Cysteamine completely suppressed bradykinin, acetylcholine, capsaicin and VNA-evoked vocalization responses in VNA desensitized guinea pigs. These findings suggest that the mechanisms of bradykinin and acetylcholine-evoked vocalization response differ from that of capsaicinoids.

Acetylcholine↗
PubMed1988

[Prostatic tissue levels of cefpiramide (CPM)].

The concentration of CPM in prostatic tissue and serum in 12 patients with benign prostatic hypertrophy was measured. One gram of CPM was injected intravenously prior to prostatectomy. One, 2, 3 and 5 hours following the administration of CPM, the mean serum level of CPM was 142, 88.2, 87.4 and 61.2 micrograms/ml, respectively, while the mean level in the prostatic tissue was 48.3, 15.1, 15.6 and 8.3 micrograms/g, respectively. The prostatic tissue level of CPM was thought to be enough to eradicate gram-negative and gram-positive bacteria in the prostate. It is presumed from our study that clinical effectiveness of CPM might be expected in the case of acute or chronic bacterial prostatitis.

Cephalosporins↗
PubMed1988

[A study of 6-day subrenal capsule assay with cyclophosphamide pretreatment--histological evaluation of clinical samples].

In order to suppress the host immune reaction in subrenal capsule assay (SRCA), effect of cyclophosphamide (CPM) was evaluated histologically in 25 fresh clinical samples. In 21 out of 25 clinical samples, the extent of lymphocyte infiltration was minimal, and in all samples the host reaction was suppressed significantly by CPM pretreatment. However, tumor cells were well preserved in only 10 out of 20 samples obtained from esophageal cancer patients. With the samples obtained from gastric and colorectal cancer patients, there were no tumor cells in the subrenal space on day 6. Persistence of tumor cells was well recognized in the samples having rich tumor and less stromal cells. The xenografts with moderately to well-preserved cancer cells showed an increase of the tumor size as expressed by delta TS. Though many xenografts showed a positive delta TS, preservation of tumor cells was poor. In each of the drug treated groups, a decrease of the tumor size and the histological effects were well correlated. It is suggested that 6-day SRCA with CPM pretreatment is useful as a chemosensitivity test, especially for the esophageal cancer whose tumor cells were well preserved.

Colonic Neoplasms↗