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Biomedical subjects

N Baba

Publications and source records attributed to N Baba.

At least 73 records · Page 4Linked to original sources
PubMed1993

Evidence for 5-HT2 receptor involvement in the stimulation of preovulatory LH and prolactin release and ovulation in normal cycling rats.

The participation of serotonin (5-HT) in the control of LH secretion and ovulation has been reported in numerous pharmacological experiments, although the results have been contradictory. In this study to determine the physiological involvement of 5-HT2 receptors in the control of preovulatory LH and prolactin (PRL) release and ovulation, ketanserin (KET), a selective 5-HT2 receptor antagonist, was administered to normal cycling rats. Oral administration of KET at 10 mg/kg BW between 0900h and 1300h on the day of proestrus completely blocked ovulation, while the administration after 1500h did not. The ovulation was confirmed 2 days after treatment with KET. There was no consistent effect on the number of ova ovulated. Co-administration of KET with 5-methoxy-N,N-dimethyltryptamine (5-MeDMT), a 5-HT agonist, at a dose of 2 mg/kg BW ip reversed KET-induced inhibition of ovulation. The highest rate (89%) of reversal was obtained by co-administration at 1500h. KET administered at 1100h completely blocked the preovulatory surge of LH and PRL observed in control animals at 1800h. The present study suggests that 5-HT stimulates preovulatory LH and PRL surge and ovulation via 5-HT2 receptor under physiological conditions and that the effect of 5-HT depends on the critical period and the 24-hour periodicity.

Animals↗
PubMed1993

Serotonin stimulates steroidogenesis in rat preovulatory follicles: involvement of 5-HT2 receptor.

The role of serotonin (5-HT) in the regulation of steroidogenesis in the ovary via 5-HT2 receptor was studied in normal cycling rats and their preovulatory follicles. Oral administration of ketanserin (KET), a selective 5-HT2 antagonist, at 10 mg/kg BW at 1100h on the day of proestrus resulted in a marked decrease in serum estradiol levels immediately after the administration. 5-HT stimulated estradiol secretion by preovulatory follicles incubated for 5 hrs in Krebs-Ringer bicarbonate buffer. 5-HT (2.5 microM) -enhanced estradiol secretion was inhibited by KET (1-100 microM) in a dose-dependent manner. Secretion of progesterone and testosterone was also inhibited by about the same order of magnitude as estradiol. Addition of pregnenolone (1 microgram/ml) prevented the KET-inhibited progesterone production. Both testosterone and estradiol increased at the same ratio by the addition of progesterone (1 microgram/ml). The inhibition of secretion of these hormones was overcome by dbcAMP (0.1 mM). The present study suggests that 5-HT stimulates steroidogenesis in the metabolic pathway prior to pregnenolone in rat preovulatory follicles and the action of 5-HT could possibly be mediated by a 5-HT2 receptor.

Animals↗
PubMed1993

Successful treatment of adult T-cell leukemia/lymphoma with MACOP-B, M-FEPA and VEPP-B combination chemotherapy.

A 45-year-old man was referred to our department in March of 1989. Physical examination showed erythroderma, palmo-plantar hyperkeratosis, generalized lymphadenopathy, hepatosplenomegaly, and leukemic manifestation. The lymphocyte count in the peripheral blood before treatment was 1.7 x 10(4) cells/mm3. Atypical lymphocytes such as flower cells and lobulated cells were seen in the peripheral blood. A sample excised from a lymph node showed immunoblastic, pleomorphic T cells by a modified classification scheme of the Working Formulation. A high level of serum LDH was detected (2.1 times the upper normal limit). Anti HTLV-1 antibody was also detected in the serum. The atypical lymphocytes were positive for CD3, CD4, CD5, CD7 and HLA-DR, and negative for CD8. Thus, the clinical, pathologic and immunologic features were those of typical acute-type ATL. The patient was treated with VEPA-M for three months starting in March of 1989. Because of poor response, the patient was then treated with MACOP-B, M-FEPA, and VEPP-B for about one year from June of 1989 and has been free of disease up to the time of writing, March of 1993.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

A case of cutaneous B-cell lymphoma with a storiform stromal reaction.

A case of cutaneous B-cell lymphoma is described. The patient was treated only by surgical excision of the skin tumors five times during a period of about two years from February of 1984 to October of 1986. After the last surgical excision, a continuous disease-free period was achieved. Biopsy samples showed dense lymphocytic infiltrations with discrete masses in the dermis and subcutis; one of them showed a storiform pattern. At the time, the infiltrating cells were composed of medium and large lymphoid cells and spindle-shaped cells. The medium and large lymphoid cells were positive for CD20, CD22 and HLA-DR and negative for CD3, CD4, CD5, CD8, CD43, and kappa and lambda light chain. The spindle-shaped cells were negative for CD20, CD43, kappa and lambda light chain, lysozyme, and S-100 protein.

Adult↗
PubMed1993

A case of cutaneous B-cell lymphoma treated successfully with MACOP-B.

A case of cutaneous B-cell lymphoma successfully treated by MACOP-B therapy is described. The patient was a 43-year-old man with reddish tumors measuring 3 to 7 cm in diameter on the right cheek and the post-auricles. Histopathologically, massive infiltrations of medium-sized atypical lymphoid cells were found in the reticular dermis and subcutis. A clear zone beneath the epidermis was also detected. The atypical lymphoid cells were positive for CD19, CD20, CD22 and HLA-DR but negative for CD3, CD4, CD5, CD10, CD43, CD45RO and CDw75. The patient was treated successfully with the MACOP-B protocol from March of 1990 to May of 1990. Since April of 1990, he has been free of disease.

Adult↗
PubMed1993

Cutaneous B-cell lymphoma--a clinical, pathological and immunohistochemical study.

Eleven cases of cutaneous B-cell lymphoma (CBCL) were studied. The ages at presentation ranged from 34 to 79 years (mean = 59.9 years). Six patients were female and five male. Five of the 11 patients had a solitary tumour and the other six had multiple tumours at initial presentation. According to Burg's classification, six cases were at stage I, two stage II, two stage III and one was at stage IV at initial presentation. Abnormalities in laboratory data were rare, except for serum lactic dehydrogenase values. Epidermotropism was not detected, and the area mainly affected by neoplastic cells was the reticular dermis (seven cases) and subcutis (four cases). Biopsy specimens from the patients analysed by immunohistochemical techniques on paraffin or cryostat sections showed CD20 and/or CD22 positivity. Biopsy specimens from two patients which showed CD10 positivity were diffuse large cell types by the working formulation and presented as pre-B-cell lymphoma. At least two groups of CBCL were demonstrable on the basis of prognosis. One was a benign low-grade lymphoma presenting with solitary tumours, mature B-cell markers and intermediate-grade pathology, and the other was a high-grade lymphoma with multiple tumours, pre-B-cell or mature B-cell markers and a poor prognosis.

Adult↗
PubMed1993

Effects of antihypertensive drugs on the progress of renal failure in hyperlipidemic Imai rats.

Hyperlipidemic Imai rats spontaneously develop hypercholesterolemia, proteinuria and glomerulosclerosis. The aim of the present study was to clarify whether two different antihypertensive regimens (enalapril and a combination of reserpine, hydralazine and hydrochlorothiazide) would offer similar degrees of protection against glomerular injury in male hyperlipidemic Imai rats. Group 1 (n = 4) received no specific therapy. Group 2 (n = 4) was treated with enalapril at a dose of 50 mg/l in drinking water starting at 6 weeks of age. Group 3 (n = 5) was treated with the triple drug regimen (reserpine 5 mg/l, hydralazine 80 mg/l and hydrochlorothiazide 25 mg/l in drinking water). Body weight, blood pressure, urinary protein, serum albumin, cholesterol, BUN and serum creatinine were checked and compared among groups. Although enalapril and triple drug therapy were almost equally effective in controlling systemic hypertension, there were striking differences between the two treated groups in proteinuria, hypercholesterolemia and glomerular injury. Enalapril treatment significantly reduced proteinuria (731 +/- 23 vs. 256 +/- 144 mg/kg/day at 36 week; p < 0.005) and hypercholesterolemia (264 +/- 17 vs. 104 +/- 17 mg/dl at 38 weeks; p < 0.001). Triple drug therapy failed to prevent the development of proteinuria (909 +/- 75 mg/kg/day at 38 weeks) and hypercholesterolemia (330 +/- 61 mg/dl at 38 weeks). The glomerulosclerosis index was significantly higher in untreated control rats (229 +/- 65) and in triple drug-treated rats (218 +/- 59) than in the enalapril-treated group (24 +/- 12; p < 0.05, and p < 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Castration attenuates proteinuria and glomerular injury in hyperlipidemic male Imai rats.

Hyperlipidemic Imai rats spontaneously develop proteinuria and glomerulosclerosis, especially in males. We investigated the effect of castration on spontaneous proteinuria and progressive renal injury in male Imai ats. Male Imai rats (n = 16) were castrated at 5 weeks of age. Body weight, blood pressure, urinary protein excretion and serum constituents were checked and compared with sham-operated control rats (n = 16) up to 24 weeks. Sham-operated group 1 (n = 5) and castrated group 2 (n = 6) underwent morphological study after 16 weeks of observation and sham-operated group 3 (n = 11) and castrated group 4 (n = 10) were followed for an additional 8 weeks and used for morphological study. Growth rate was significantly stunted in castrated rats as compared with the controls. Castration significantly reduced proteinuria almost throughout the experiment (167 +/- 84 vs. 46 +/- 24 mg/kg/day, p < 0.001, at 8 weeks and 688 +/- 211 vs. 458 +/- 97, p < 0.01, at 20 weeks). The glomerulosclerosis index was significantly higher in sham-operated control rats than in castrated rats (28.8 +/- 18.0 vs. 7.3 +/- 3.1, p < 0.01, at 16 weeks, and 92.1 +/- 35.5 vs. 39.5 +/- 8.9, p < 0.001, at 24 weeks). There were no significant differences in blood pressure, serum cholesterol, plasma renin activity, plasma somatomedin C levels between the two groups. These results raise the possibility that sex hormones may partly contribute to spontaneous proteinuria and progressive renal injury in male Imai rats.

Animals↗
PubMed1993

Effects of an angiotensin II receptor antagonist on the progression of renal failure in hyperlipidemic Imai rats.

This study was undertaken to determine the role of angiotensin II (AII) in the development of glomerulosclerosis, using an AII receptor antagonist in an animal model of hyperlipidemia. Hyperlipidemic Imai rats were employed because they spontaneously develop glomerulosclerosis; this is especially true in males. Group 1 (n = 5) received no specific therapy. Group 2 (n = 5) was treated with enalapril at a dosage of 50 mg/l in drinking water starting at 6 weeks of age. Group 3 (n = 5) and group 4 (n = 6) were treated with the AII receptor antagonist DuP 753 at a respective dosage of 15 mg/l (low-dose DuP) and 150 mg/l (high-dose DuP) in drinking water. Body weight, blood pressure, urinary protein, serum albumin, cholesterol, BUN and serum creatinine were measured and compared among the groups from 12 to 24 weeks of age. Enalapril and high-dose DuP were almost equally effective in controlling systemic hypertension. Each treatment significantly reduced proteinuria (172 +/- 112 and 152 +/- 72 mg/kg/day at 24 weeks) as compared with that in the controls (421 +/- 147 mg/kg/day; p < 0.05 and p < 0.01, respectively). Hypercholesterolemia also decreased (82 +/- 4 and 89 +/- 6 mg/dl) as compared with that of the controls (141 +/- 48 mg/dl; both p < 0.05). Glomerulosclerosis index (SI) was significantly higher in the untreated control rats (55 +/- 26) than in the enalapril-treated rats (2 +/- 3; p < 0.005) and the high-dose-DuP-treated rats (6 +/- 6, p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin Receptor Antagonists↗
PubMed1993

[Lymphomas of the skin].

Malignant lymphoma of the skin is a type of extranodal lymphoma, in which the main organ involved is the skin, and 80-90% of cases in Japan show a T-cell phenotype. Mycosis fungoides (MF) and Sézary syndrome (SS) are common T-cell lymphomas of the skin with a benign prognosis. Therefore, various forms of topical therapy, such as topical steroid, photochemotherapy (PUVA) and interferons, have been indicated for the low-risk group (stages I A, I B and II A), whereas electron-beam irradiation, retinoid plus interferon (IFN), photopheresis and deoxycoformycin (DCF) plus IFN have been indicated for intermediate-risk group (stages II B and III). The cutaneous involvement of B-cell lymphoma has been considered an unmistakable sign of progression and dissemination of lymphoid disease, and is thus associated with a poor prognosis. However, some primary cutaneous B-cell lymphomas (CBCLs) show a benign prognosis, and electron-beam irradiation has been indicated for early-stage CBCL (stages I and II). However, the prognosis of high-risk group CTCL (stage IV) and cutaneous B-cell lymphoma (CBCL) (stages III and IV) is poor. Therefore, an effective multiagent combination chemotherapy, such as MACOP-B, M-BACOD or ProMACE-Cyta BOM is required for patients with advanced-stage CTCL and CBCL. With regard to age at the time of the first medical examination, patients with CTCL or CBCL at an advanced stage have a tendency to be older. Therefore, a mild but effective therapy, such as DCF plus IFN is recommendable.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Castration attenuates proteinuria and glomerular injury in unilaterally nephrectomized male Sprague-Dawley rats.

BACKGROUND: To clarify the pathogenesis of focal and segmental glomerulosclerosis, we investigated the effect of castration on the development of proteinuria and glomerulosclerosis in unilaterally nephrectomized male Sprague-Dawley (SD) rats. EXPERIMENTAL DESIGN: At 5 weeks of age, group 3 was castrated, whereas groups 1 and 2 were sham-operated. At 6 weeks of age, groups 2 and 3 received unilateral right nephrectomy and group 1 received sham-operation. Body weight, blood pressure, urinary protein, serum albumin, cholesterol, blood urea nitrogen and serum creatinine were checked every 2 months from 2 through 12 months after right nephrectomy. Control group 1, Nx (nephrectomized) group 2 and castrated (nephrectomized + castrated) group 3 underwent morphologic study 6 months after nephrectomy. In an additional experiment, control group 4, Nx group 5, and castrated group 6 were followed for an additional 6 months and used for morphologic study. RESULTS: Growth was significantly stunted in the castrated rats as compared with control and Nx rats. Nx rats became proteinuric with age. Castration significantly reduced the proteinuria after 2 months of nephrectomy throughout the experiment. The proteinuria in castrated rats tended to decrease as compared with the controls. The glomerulosclerosis index was significantly higher in Nx rats than in either the controls or the castrated rats. The three groups showed no significant differences in blood pressure, plasma renin, activity and plasma aldosterone concentration. CONCLUSIONS: These observations suggest that sex hormones may contribute to the development of proteinuria and glomerulosclerosis in unilaterally nephrectomized male SD rats.

Animals↗
PubMed1993

The crystal structure of specific granules in human eosinophils studied by thin sectioning and deep-etching with the aid of Fourier transformation.

The crystal structures of specific granules in human eosinophils were studied by thin sectioning and deep-etching with the aid of Fourier transformation. The crystal, thought to be a simple cubic by previous studies by thin sectioning, was demonstrated as the body-centered cubic (the cesium chloride type) consisting of two kinds of particles. The crystal parameters obtained by deep-etching were slightly larger (a = b = c = 4.1-4.4 nm) than by thin sectioning (4.0 nm). By deep-etching, the crystal also showed the stacking folds suggesting the piled-up plates. Although it is known that the patients with hypereosinophilic syndrome have more hypodense eosinophils compared with normal persons, no morphological differences could be detected in the crystals between these eosinophils.

Crystallization↗
PubMed1993

Structure-activity relationship for D-ring derivatives of grayanotoxin in the squid giant axon.

Grayanotoxin (GTX) binds specifically to the voltage-dependent sodium channel and induces a persistent increase in the membrane permeability to sodium ion. By studying the structure-activity relation of the GTX action, we attempt to elucidate the molecular moiety of the sodium channel facing around the carbon atoms C-15 beta, C-16 beta and C-14S in the D-ring of GTX in exerting the biological activity. A dose-response curve for each GTX analog was constructed using membrane depolarization as an index and assuming a one-to-one stoichiometry. Addition of alpha-OH, carbonyl and beta-OH groups to either C-15 or C-16 sequentially reduces the toxin potency, suggesting that the domain of the Na channel facing C-15 and C-16 contains a positive charge. Substitution of a hydroxymethyl group to the beta side of C-16 reduces GTX activity 10 times more than a similar substitution in the alpha side, indicating that this positive charge is located close to the beta side. Introduction of a hydrophilic hydroxy group into C-14S reduced GTX activity by a factor of 20, whereas introduction of an electronegative amino group totally eliminated it. We infer that hydrophobic bonds are a predominant factor on the alpha surface of the GTX molecule. In summary, 3 beta-OH, 5 beta-OH and 6 beta-OH of the GTX molecule make contact with the Na channel by hydrogen bonding and with most of remainder by hydrophobic bond in binding to the Na channel.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Pharmacokinetics of intratumoral RK-28, a new hypoxic radiosensitizer.

RK-28 is one of the new hypoxic cell radiosensitizers being developed in Japan and has been tested clinically. To reduce its toxicity and increase its sensitizing activity, intratumoral injection of RK-28 was performed during intraoperative radiation therapy for pancreatic cancer. This report presents the results of pharmacokinetic studies performed in 10 of the 17 patients who were administrated intravenous or intratumoral RK-28 during intraoperative radiation therapy. No adverse effects were noted following intravenous or intratumoral injection of the drug. Pharmacokinetic studies demonstrated several metabolites of RK-28 in both serum and tumor tissues. After intratumoral injection, the tumor drug concentration ranged from 123 micrograms/g to 9,292 micrograms/g just after intraoperative radiation therapy (30-50 min after injection of the compound), while the serum concentration ranged from 4.1 to 9.8 micrograms/ml. The tumor drug concentration was 23.3 micrograms/g at 45 min after intravenous injection of RK-28. Thus, intratumoral injection of RK-28 was superior to intravenous administration in this pharmacokinetic study. The combination of intraoperative radiation therapy and intratumoral injection of RK-28 appears to be a feasible treatment method.

Adult↗
PubMed1992

Histopathological study of focal dermal hypoplasia (Goltz syndrome).

We report a case of focal dermal hypoplasia, or Golz syndrome in a 13-year-old girl. The patient presented with a variety of cutaneous defects, including atrophy-like depressions, striations, a verrucous papilloma, and lipomas. Histopathological examination showed deposits of fat cells or adipose tissue in the dermis, which were subepidermal, mid-dermal, perivascular, or involved the whole dermis. These findings indicate that the adipose tissue in the dermis is a result of dermal dysplasia and not hypoplasia.

Adolescent↗
PubMed1992

Adult T-cell leukemia/lymphoma (ATL)--clinical, histopathological, immunological and immunohistochemical characteristics.

Twenty-one patients with ATL were assessed. The predominant physical findings were lymph node and bone marrow involvement, skin involvement, hepatosplenomegaly and leukemic manifestations. The predominant histopathological findings in both skin and lymph node specimens were the diffuse medium-sized cell type and the diffuse mixed cell type. Some phenotypic discrepancy was found between the neoplastic cells in the peripheral blood, lymph nodes and skin of patients with ATL with respect to CD45RA and CD45RO, and CD7, CD29, CD25 and HLA-DR. That is, the predominant neoplastic cell phenotype was the helper T-cell, which was CD3+, CD4+, CD7+, CD25+, CD45RA+ and HLA-DR+, and CD29- and CD45RO- in peripheral blood and lymph nodes, and CD3+, CD4+, CD7+, CD29+, CD45RO+ and HLA-DR+, and CD45RA- in the skin. In other words, we have described the phenotypic heterogeneity of ATL cells and demonstrated the heterogeneity of CD45R isoform expression on ATL cells in different organs--the skin, peripheral blood and lymph nodes--of the same patient.

Adult↗
PubMed1992

Angiotensin-converting enzyme inhibition attenuates hypercholesterolemia and glomerular injury in hyperlipidemic Imai rats.

Hyperlipidemic Imai rats spontaneously develop hypercholesterolemia, proteinuria and glomerulosclerosis. We investigated the effect of enalapril, an angiotensin-converting enzyme (ACE) inhibitor, on spontaneous hypercholesterolemia and the progressive renal injury in this rat strain. Male Imai rats (n = 7) were treated with enalapril at a dose of 50 mg/l in drinking water starting at 6 weeks of age. Body weight, blood pressure, urinary protein excretion and serum constituents were checked and compared with untreated controls (n = 5) up to 38 weeks of age. Enalapril treatment significantly reduced hypercholesterolemia (247 +/- 41 vs. 102 +/- 13 mg/dl, p < 0.01, at 38 weeks) and proteinuria (766 +/- 290 vs. 206 +/- 119 mg/kg/day, p < 0.01, at 38 weeks). The glomerulosclerosis index (SI) was significantly higher in untreated control rats than in the enalapril-treated group (227 +/- 57 vs. 27 +/- 9, p < 0.01). Although we could not clarify whether hypercholesterolemia is a primary event or secondary to the nephrotic syndrome, these results indicate that the ACE inhibitor has the property to protect remnant glomeruli from glomerulosclerosis in male Imai rats as well as in other animal models in which focal and segmental glomerulosclerosis is believed to represent a common pathologic pattern. This rat strain represents a unique model of a spontaneous proteinuria which can provide an important information on the pathogenesis of human focal and segmental glomerulosclerosis.

Angiotensin-Converting Enzyme Inhibitors↗