Search PubMed⌕ Search

Biomedical subjects

M Baba

Publications and source records attributed to M Baba.

At least 343 records · Page 19Linked to original sources
PubMed1996

Follicular dendritic cells in vitro are not susceptible to infection by HIV-1.

OBJECTIVES: To investigate whether follicular dendritic cells (FDC) are target cells for HIV-1 infection. DESIGN: Based on the principle that if FDC are true target cells, HIV-1 particles will bind to the surface of FDC and then invade their cytoplasm and nuclei. METHODS: Freshly isolated tonsilar FDC were exposed to two strains (HE and JR-FL) of HIV-1 and cultured. They were then examined for HIV-1 replication, using p24 antigen-capture enzyme-linked immunosorbent assay, immunolabelling, and polymerase chain reaction (PCR) amplification. We used FDC clusters as the FDC source, since the culture system for FDC clusters has various advantages over other methods for the successful long-term culture of FDC. RESULTS: After 2 h incubation, particles of both HIV-1 strains bound to the surfaces of FDC, as well as to CD4+ T cells, although FDC do not have CD4 receptors. The FDC gradually released the particles into the culture supernatant. More HIV-1 particles were bound to fresh FDC than to dedifferentiated FDC or to control fibroblasts. However, HIV-1 particles bound to the FDC did not seem to enter the cells. We found no evidence of HIV-1 proviral DNA synthesis in FDC. CONCLUSIONS: Our results suggest that FDC are not readily infected with HIV-1 in situ, although we found that FDC in vitro were not infected by HIV-1.

Cells, Cultured↗
PubMed1996

Different properties of wild type and drug-resistant mutants of human immunodeficiency virus type 1 reverse transcriptase in vitro.

Drug-resistant mutants of human immunodeficiency virus type 1 (HIV-1) emerge during treatment with various reverse transcriptase (RT) inhibitors in vitro and in vivo. However, the virological nature and pathogenic importance of these mutants have not been fully elucidated. In this study, we have examined HIV-1 mutants resistant to 3'-azido-3'-deoxythymidine (AZT) and nonnucleoside RT inhibitors (NNRTIs) for their infectivity, RT activity, and replication in MT-4 cells. Although the infectivity of AZT- and NNRTI-resistant mutants was similar, the RT activity of AZT-resistant mutants was much higher than that of NNRTI-resistant mutants and their wild types. Furthermore, the RT activity of NNRTI-resistant mutants was significantly lower than that of the wild types. In contrast, the replication of NNRTI-resistant mutants was found to be greater than that of AZT-resistant mutants and the wild types. When HIV-1 proviral DNA (cDNA) synthesis was examined by PCR in MT-4 cells infected with the wild type, AZT-resistant mutant, or NNRTI-resistant mutant, the PCR signal of the NNRTI-resistant mutant was found to be much higher than those of the wild type and AZT-resistant mutant. These results suggest that the drug-resistant mutants differ from their corresponding wild types not only in drug sensitivity but also in other virological properties.

Antiviral Agents↗
PubMed1996

Triamterene suppresses bombesin-enhanced peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane.

The effects of combined administration of bombesin and the diuretic triamterene on the incidence of peritoneal metastasis of intestinal cancers induced by azoxymethane (AOM) and the labeling index of intestinal cancers were investigated in male inbred Wistar rats. From the start of the experiment, rats were given weekly s.c. injections of AOM (7.4 mg/kg body weight) for 10 weeks and s.c. injections of bombesin (40 micrograms/kg body weight) every other day, and from week 16, s.c. injections of triamterene (10 and 20 mg/kg body weight) every other day until the end of the experiment in week 45. Bombesin significantly increased the incidence of intestinal tumors and cancer metastasis to the peritoneum in week 45. It also significantly increased the labeling index of intestinal cancers. Although administration of both doses of triamterene with bombesin had little or no influence on the enhancement of intestinal carcinogenesis by bombesin, or the location, histologic type, depth of invasion, or labeling index of intestinal cancers, it significantly reduced the incidence of cancer metastasis. These findings indicate that triamterene suppresses cancer metastasis through a mechanism that does not affect the proliferation of intestinal cancers.

Adenocarcinoma↗
PubMed1996

Survey of family history on allergy in 1-year-old and 6-year-old children.

A retrospective survey of a family history of allergy employing a special questionnaire for children was performed. The survey included 1-year-old (n = 267) and 6-year-old children (n = 410) with allergies as well as 1-year-old (n = 313) and 6-year-old children (n = 329) without allergies. An 'Allergy Risk Score' (ARS) for each subject was calculated according to the history of allergy in three family members: father, mother and a sibling. Each family member was scored as 2.0 (overt history of allergies), 1.0 (provable), 0.5 (possible) or 0 (absent), and the ARS of the subjects was calculated as the total of the family members' scores. The ARS of children in the allergy groups was statistically higher than that of the control groups in both age groups. The ARS increased with an increase in the odds ratio (an approximate value of the risk), especially in 6-year-old children. An ARS calculated on the basis of family history could be a useful and practical index for estimating the risk of allergy development in children, and may be helpful in predicting and preventing allergies in infants and children.

Child↗
PubMed1996

[Assay of specific anti-Chlamydia pneumoniae antibodies by ELISA method. 2. studies on clinical usefulness and serological diagnostic standards].

We measured anti-Chlamydia pneumoniae (C. pneumoniae) specific antibody titers by means of a newly-developed enzyme-linked immunosorbent assay (ELISA) method using an anti-C. pneumoniae specific antibody detection reagent. The clinical usefulness of this method was hereby evaluated. The IgG, IgA and IgM titers in 418 serum specimens obtained from patients with respiratory tract infections were measured by this new ELISA method, and the results were compared with the titers determined for the same specimens with the micro immunofluorescence (Micro-IF) method. The results showed good correlation coefficients for IgG, IgA and IgM. The two assay methods showed high agreement rates for positivity and for negativity. Specimens which did not yield the same results with the ELISA method and the Micro-IF method were subjected to analysis by the Western blot method, and the rates of agreement with the ELISA results were high. In addition, the child (0 approximately 15 yrs old; n = 122) and adult (16 approximately 90 yrs old; n = 133) cases were classified on the basis of being antigen-positive or antigen-negative at the initial examination, and their antibody-positive rates were determined. The adults showed no statistically significant differences in the antibody-positive rates for either IgG or IgA antibodies as a function of the pretreatment antigen status. However, the children showed statistically significant (p < 0.001) differences in the antibody-positive rates for both IgG and IgA antibodies as a function of the antigen status in the antigen-positive group compared with the rates in the antigen-negative group. Furthermore, the IgM-positive rates for the children were high in the antigen-positive group compared with the rates in the antigen-negative group, and the difference was statistically significant (p < 0.001). The IgM-positive rates in the adults were also significantly (p < 0.05) different between the antigen-positive group and the antigen-negative group. The Micro-IF method was applied to 34 specimens from antigen-positive patients, and 22 specimens were found to show an IgG titer of > or = 512 or an IgM titer of > or = 16. The diagnoses of these patients were acute respiratory disease in sixteen, pneumonia in four. Application of the ELISA-method to those 22 specimens showed all of them to exhibit IgG absorbance of > or = 0.6 and IgA absorbance of 0.2. The results described above indicate the clinical usefulness of our new ELISA method for the detection of antibodies specific for C. pneumoniae. The significance of this ELISA method for serological diagnosis of C. pneumoniae infections and the criteria for diagnosis of acute infections were also discussed.

Adolescent↗
PubMed1996

Mechanism of selective inhibition of human immunodeficiency virus by ingenol triacetate.

Ingenol 3,5,20-triacetate (ITA), one of the ingenol derivatives, is a selective inhibitor of human immunodeficiency virus (HIV) replication in vitro. ITA inhibited the replication of HIV strains in MT-4 cells at concentrations of 0.051 to 0.65 microM. This concentration was approximately 10(3)-fold lower than its cytotoxic threshold. The mechanism of action of ITA is primarily attributed to the inhibition of viral adsorption to the host cells, but it is distinct from the mechanism of inhibition by other adsorption inhibitors.

Antiviral Agents↗
PubMed1996

T cell mediation of abnormally low production of ovalbumin-specific immunoglobulin A in patients allergic to eggs.

Cells producing IgA specific to ovalbumin (OVA) were detected with an assay of plaque-forming cells (PFC). Non-T cells were separated on a polystyrene resin column and were further depleted of B cells that bound sheep erythrocytes (SRBC) by SRBC-rosette sedimentation. The cells were recombined with T cells separated on a polystyrene resin column, stimulated with OVA antigen, and then cultured for 5 d. The number of OVA-specific IgA-PFC from the lymphocytes of infants allergic to hen's eggs (7 +/- 5 per 7 x 10(4) non-T cells, n = 9) was significantly less than that of PFC from lymphocytes of age-matched controls (110 +/- 18 per 7 x 10(4) non-T cells, n = 7) and from those of children with atopic dermatitis who were not allergic to hen's eggs (90 +/- 30 per 7 x 10(4) non-T cells, n = 4). Patients' B cells added to the culture supernatant from OVA-stimulated normal T cells (82 +/- 18 per 7 x 10(4) non-T cells, n = 4) were able to produce the specific IgA to levels comparable to those of normal B cells (92 +/- 9 per 7 x 10(4) non-T cells, n = 6), but the patients' T cells did not cause normal B cells to produce the antibody (8 +/- 2 per 7 x 10(4) non-T cells, n = 4). This indicates that the patients' T cells were less able than were normal T cells to promote the production of OVA-specific IgA-PFC. Until the age of 6 y, the ability of the patients' lymphocytes to produce specific IgA was abnormally low; from that age on, it was normal. At the stage of allergen entry, this transiently low production of OVA-specific IgA may contribute to the onset of allergy to hen's eggs.

Cells, Cultured↗
PubMed1996

N30 in PD.

Explore the source record for details and available documents.

Brain↗
PubMed1996

Central conduction in somatosensory evoked potentials: comparison of ulnar and median data and evaluation of onset versus peak methods.

To compare central conduction in ulnar and median nerve somatosensory evoked potentials (SEPs), we recorded SEPs from the neck and scalp elicited by median and ulnar nerve stimulation in 46 normal young adults. We determined the central conduction time (CCT) in each subject from peak-to-peak and onset-to-onset measurements. The mean value of the onset CCT for the ulnar nerve SEP was 6.2 +/- 0.3 msec, and for the median nerve SEP, 5.9 +/- 0.3 msec. Onset CCT was significantly longer for the ulnar nerve SEP, and there was a significant correlation between onset CCT in both median and ulnar nerve SEPs and subject height. In contrast, the mean value of the "conventional" peak CCT for the ulnar nerve SEP was 5.6 +/- 0.6 msec, and for the median nerve SEP, 5.8 +/- 0.5 msec, with no significant difference between them. In addition, the peak CCT was not correlated with subject height in the ulnar or median nerve SEPs. Our findings suggest that onset CCT measurement is superior to the conventional peak CCT measurement for ulnar as well as median nerve SEPs, and confirm that the central conduction pathway for the ulnar nerve SEP is slightly longer than that for the median nerve SEP.

Adolescent↗
PubMed1996

Galactosemic neuropathy in transgenic mice for human aldose reductase.

We studied the functional consequences of an enhanced polyol pathway activity, elicited with galactose feeding, on the peripheral nerve of transgenic mice expressing human aldose reductase. Nontransgenic littermate mice were used as controls. With a quantitative immunoassay, the expression level of human aldose reductase in the sciatic nerve was 791 +/- 44 ng/mg protein (mean +/- SE), about 25% of that in human sural nerve. When the transgenic mice were fed food containing 30% galactose, significant levels of galactitol accumulated in the sciatic nerve. Galactose feeding of nontransgenic littermate mice led to a 10-fold lower accumulation of galactitol. Galactose feeding for 16 weeks caused a significant and progressive decrease in motor nerve conduction velocity in transgenic mice to 80% of the level of galactose-fed littermate mice, which was not significantly different from that of galactose-free littermate mice. A morphometric analysis of sciatic nerve detected > 10% reduction of mean myelinated fiber size but no alterations of myelinated fiber density in galactose-fed transgenic mice compared with other groups. The functional and structural changes that develop in galactose-fed transgenic mice are similar to those previously reported in diabetic animals. The results of these studies suggest that transgenic mice expressing human aldose reductase may be a useful model not only for defining the role of the polyol pathway in diabetic neuropathy but also for identifying and characterizing effective inhibitors specific for human aldose reductase.

Aldehyde Reductase↗
PubMed1996

[Thrombotic complication in the course of aplastic anemia-paroxysmal nocturnal hemoglobinuria syndrome; possible involvement of dysplasminogenemia (plasminogen Tochigi) in the pathogenesis of thrombosis].

A 44-year-old Japanese man having aplastic anemia (AA)-paroxyamal nocturnal hemoglobinuria (PNH) syndrome was referred to our hospital because of purpuras due to thrombocytopenia in July 1994. He suffered from pneumonia after admission, complicated with cerebral, splenic, and left renal infarction. Pulmonary infaction was also confirmed by perfusion lung scan. He had a plasma plasminogen (PLG) functional activity of 54.4% with a normal level of PLG antigen. The gel isoelectrofocusing pattern of the plasminogen derived from the patient showed 10 normal bands and 10 additional doublet bands with slightly higher isoelectric points than the normal components. Abnormal PLG is converted by urokinase to an inactive two-chain plasmin molecule. These findings were similar to those of a case with dysplasminogenemia (PLG Tochigi) reported by Aoki et al. He was given warfarin for the prevention of thrombosis in December 1994. As of October 1995, these was no recurrence of thrombosis. The cause of thrombosis in the present case have been the association with PNH, predisposition to PLG Tochigi, or the complication of pneumonia. This is the first report of AA/PNH syndrome associated with dysplasminogenemia.

Adult↗
PubMed1996

[Inhibitory effect of Kanpo-medicines: saiboku-to, syouseryu-to, sairei-to on Dermatophagoides farinae antigen-induced IL2 responsiveness in lymphocytes from patients with bronchial asthma and their comparison].

We had previously reported that antigen-induced IL2 responsiveness by lymphocytes can be used to identify etiological allergens and to monitor the clinical activity in atopic diseases. The effect of Kanpo-Medicines; Saiboku-to, Syoseiryu-to, Sairei-to, antiallergic agents, on Dermatophagoides farinae (Df) antigen-induced interleukin 2 (IL2) responsiveness from patients with bronchial asthma was studied and compared among 3 Kanpo-medicines. Allergen-sensitized patient mononuclear cells pretreated with 30-30,000 ng/ml doses of Saiboku-to for 16 hours failed to induce responsiveness to IL2 on stimulation with Df antigen in 8 patients out of 11 (73%). The cells treated with 30 micrograms/ml of Syoseiryu-to also failed to introduce the response in 6 out of 10 (60%) with less frequency compared with Saiboku-to. Sairei-to also suppressed the response on stimulation with a 10 micrograms/ml dose alone in 1 x 10(-3)-1 x 10(-4)ng/ml doses examined in 6 patients out of 17 (35%) with much less frequency and % inhibition. Also Saiboku-to and Sairei-to not Syoseiryu-to inhibited purified protein derivatives (PPD)-induced IL2 responsiveness. However. These agents failed to suppress the Con A-induced IL2 responsiveness. Antigen-presenting adherent cells were more susceptible to any Kanpo-medicines studied rather than IL2-responding T cells except Sairei-to. These results indicated that Kanpo-medicines studied have a weak immuno-suppressive property resulting in inhibiting antigen-induced IL2-responsiveness. Suppressive effects of each Kanpo-medicine seemed to depend on combinations and doses of their elements (Syouyaku). Decreased suppressive effect of higher doses of any Kanpo-medicine was likely to be mitogenic effects of each element on T cells.

Adolescent↗
PubMed1996

[Evaluation of tissue oxygenation utilizing a tonometer in the stomach tube or colon used in substitutive esophagus after surgery for esophageal cancer].

We measured serial changes in mucosal pH (pHi) as an index of blood flow of the stomach tube or the colon in a substitutive esophagus using a tonometer in 18 patients following surgery for esophageal cancer. The pHi showed the lowest level at the postoperative 1 hr (PO 1 hr) and increased significantly at PO 6 hr. At PO 12 hr, pHi showed the level of more than pHi 7.3 which increased significantly compared with PO 6 hr. The oxygen delivery and oxygen consumption increased significantly from PO 1 hr at PO 6 hr but not changed between 6 and 12 hr. It was suggested that the blood flow was inadequate in the stomach tube or the colon as a substitutive esophagus within PO 12 hr following operation despite of adequate oxygen delivery systemically. In this series, the decreased pHi were shown in 2 patients with minor leakage of anastomosis and in one patients with the perforation of stomach tube. The correlation between pHi and modified respiratory index was recognized at PO 12 hr and 24 hr suggesting that pHi was associated with the pulmonary dysfunction. Therefore, it was suggested that the value and change of pHi is an useful predicting index of occurrence of anastomotic leakage or respiratory failure which may be a fatal postoperative complication after surgery for esophageal cancer.

Aged↗
PubMed1996

[Malignant mediastinal schwannoma associated with von Recklinghausen's disease--a resected case].

A case of malignant mediastinal schwannoma associated with von Recklinghausen's disease is reported. A 44-year-old woman was admitted to Chiba University Hospital because of an abnormal shadow on chest X-ray film. CT scan showed a cystic tumor in upper mediastinum and then tumor extirpation was performed. This cystic tumor was related to the sympathetic trunk and 60 x 35 x 33 mm in diameter. Its cut surface showed a thick irregular capsule and multilocular. Microscopic examination disclosed malignant cells with mitosis associated with neurofibroma. An immunohistochemical staining of these malignant cells with anti S-100 protein showed positive reaction. From these findings this tumor was diagnosed as malignant schwannoma. There is no evidence of recurrence two year after the operation. This is the first case of malignant schwannoma with cystic formation in Japan.

Adult↗
PubMed1996

Diagnosis of pancreatic cancer by K-ras point mutation and cytology of pancreatic juice.

OBJECTIVES: Recently, it was reported that detection of K-ras point mutation at codon 12 in pancreatic juice is an objective method for the diagnosis of pancreatic cancer, but a few reports have suggested that this might represent an early event in pancreatic oncogenesis. In the present study we examined, in various patients, the occurrence of K-ras codon 12 point mutation in pancreatic juice and compared it with pancreatic juice cytology, which is also a reliable diagnostic method. METHODS: Pancreatic juice was obtained endoscopically from patients with various pancreatic disorders and those without definite diseases, and was examined cytologically and for the occurrence of K-ras codon 12 point mutation. The K-ras gene was amplified by polymerase chain reaction (PCR) and the mutation at codon 12 (GGT-->GAT) was examined by slot blot hybridization analysis. RESULTS: K-ras point mutation at codon 12 was detected in seven of 14 (50%) pancreatic cancers, in four of 10 (40%) mucin-producing tumors, in four of 13 (31%) chronic pancreatitis, and in two of 10 (20%) pancreas without definite disorders. K-ras point mutation was detected in nine of 18 (50%) pancreatic juice samples containing cancer cells, in eight of 18 (44%) pancreatic juice samples containing atypical cells, but in none of such samples containing only normal cells. CONCLUSION: Cancer cells were detected from pancreatic cancer exclusively, but K-ras point mutation at codon 12 was detected in pancreatic juice, not only from pancreatic cancer, but also from other diseases.

Aged↗