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Biomedical subjects

M Baba

Publications and source records attributed to M Baba.

At least 595 records · Page 33Linked to original sources
PubMed1990

Effect of ornithine decarboxylase inhibitor on tetragastrin treatment of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of combined administration of tetragastrin and the ornithine decarboxylase inhibitor 1,3-diaminopropane (DAP) on the incidence and number of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and the BUdR labelling indices of the fundic and antral mucosae, were investigated in inbred Wistar rats. Rats were given drinking water containing 2.5 g/l of DAP ad libitum and received alternate-day injections of 1 mg/kg body weight of tetragastrin in depot form after 25 weeks of oral treatment with MNNG. At week 52, prolonged administration of tetragastrin alone resulted in a significant reduction in the incidence and number of gastric cancers and a significant increase or decrease in the labelling indices of the fundic and antral mucosae, respectively. Concomitant administration of tetragastrin and DAP had no effect on the inhibition by tetragastrin of gastric carcinogenesis. With this treatment, the labelling index was significantly reduced in the fundic mucosa but not in the antral mucosa. These results suggest that ODC inhibitor does not attenuate tetragastrin inhibition of gastric carcinogenesis, and that anti-trophic action of tetragastrin on antral mucosa may be related to tetragastrin inhibition of gastric carcinogenesis.

Animals↗
PubMed1990

Tumor necrosis factor antagonizes inhibitory effect of azidothymidine on human immunodeficiency virus (HIV) replication in vitro.

Tumor necrosis factor alpha (TNF-alpha) completely reverses the activity of azidothymidine (AZT) against human immunodeficiency virus type 1 (HIV-1) in MOLT-4 cell cultures. The 50% effective concentration of AZT, required to protect MOLT-4 cells against the cytopathic effect of HIV-1, increased from 5.8 nM in the absence of TNF-alpha to greater than 125 microM in the presence of TNF-alpha (100 U/ml). TNF-alpha also antagonized the anti-HIV-1 activity of dideoxycytidine but did not markedly affect the anti-HIV-1 activity of dextran sulfate. The intracellular phosphorylation pattern of AZT was not changed upon the presence of TNF-alpha.

Biotransformation↗
PubMed1990

Antimetastatic effect of defibrinogenation with batroxobin depends on the natural killer activity of host in mice.

Using batroxobin, a thrombin-like enzyme found in snake venom, the effects of defibrinogenation on artificial lung metastasis in mice were studied. The role of natural killer (NK) cells in the inhibitory effects of defibrinogenation on metastasis was also investigated. Artificial lung metastasis experiments were performed by inoculating either B16-F10 cells or B16-BL/6 cells, highly metastatic strains of B16 melanoma cells, into C57BL/6 mice via the tail vein. The administration of batroxobin significantly inhibited lung metastasis, as did NK activity augmented by poly (I).poly (C) were administered, lung metastasis was more markedly inhibited. When NK activity was suppressed by administration of anti-(asialo GM1) antibody, lung metastasis was markedly increased. When batroxobin was administered with anti-(asialo GM1) antibody, no inhibitory effects on lung metastasis, such as those seen with batroxobin alone, were observed. The administration of batroxobin had no effect at all on spleen lymphocyte NK activity. These results indicated that defibrinogenation due to batroxobin inhibits lung metastasis, and these effects depend on NK activity of the host.

Animals↗
PubMed1990

Fatal aneurysmal rupture: a survey of 60 grade-5 cases.

The purpose of the present study was to describe the clinical course of patients with Grade-5 ruptured aneurysms (WFNS grading). Among 250 consecutive cases of ruptured aneurysms, 60 Grade-5 patients were reviewed retrospectively, consisting of 24 males and 36 females with an average age of 58 years. Thirty-two patients were directly transferred to our clinic, while the remaining 28 were referred from other clinics. Duration from rupture to arrival at our clinic was within 1 hour in 25 cases and within 2 hours in 43 cases. Systolic blood pressure on admission was 186 mmHg on average. Obvious misdiagnoses by primary physicians were made in 7 cases. Ventricular drainage and clipping/trapping of the aneurysms were performed in 7 and 25 cases, respectively. Forty-nine patients died and the remaining 11 survived. One made a good recovery, 1 was moderately disabled, 8 severely disabled, and 1 in a vegetative state. The prognosis for Grade-5 patients is well known as being extremely poor, which also was the case in our series. Early referral and early surgical intervention have not changed this poor prognosis. Possible improvement of the outcome of this group might be expected by 1) public health and primary physician education on aneurysmal subarachnoid haemorrhage, and 2) control of blood pressure during referral.

Adult↗
PubMed1990

Endoscopic Nd:YAG laser surgery on malignant and benign lesions of the trachea and carina.

A total of 47 patients with malignant and benign lesions in the trachea and carina were used to demonstrate the effectiveness of endoscopic Nd:YAG laser surgery. The histology consisted of 37 malignant and 10 benign lesions, and 23 of the patients had severe symptoms with laser surgery being performed as a lifesaving emergency. Endoscopic Nd:YAG laser treatment was able to dilate the tracheal calibers from 2.6 +/- 0.9 mm to 6.1 +/- 1.4 mm in the emergency cases with a remarkable effect and brought relief from wheezing and dyspnea, with an objective improvement of more than 25 per cent in peak expiratory flow rate being demonstrated. Furthermore, the tracheal diameters were able to be dilated from about 7 mm to 10 mm in the non-emergency cases. A remarkable effect was achieved in patients with intraluminal or mixed types of tumors among both the emergency and non-emergency cases. The survival rates of the emergency patients in whom a remarkable effect was achieved were definitely better than those in whom only fair or poor effects were achieved and, in the non-emergency cases, similar results were demonstrated. In conclusion, the application of endoscopic Nd:YAG laser surgery to tracheal stenotic diseases has an instantaneous and definite effect on luminal dilatation and shows significance as a lifesaving procedure. Moreover, the resultant improvement in the patients' general condition could make it possible for them to undergo other combined therapy and prolong their life span. Endoscopic Nd:YAG laser surgery is thus considered to be a very effective and established procedure for the treatment of tracheal stenotic lesions.

Bronchoscopy↗
PubMed1990

Total removal of an arteriovenous malformation embedded in the brain stem.

The removal of brain stem arteriovenous malformations is one of the most challenging problems in neurosurgery. The authors report a successful total removal of an arteriovenous malformation situated in the middle cerebellar peduncle, which was embedded in the floor of the fourth ventricle. The importance of dissection "flush" with coils of an arteriovenous malformation is stressed.

Adult↗
PubMed1990

Indirect carotid-cavernous sinus fistula: transvenous embolization from the external jugular vein using a superior ophthalmic vein approach. A case report.

A case of indirect carotid-cavernous sinus fistula treated by combined transarterial and transvenous embolization is described. A 49-year-old woman with a right indirect carotid-cavernous sinus fistula draining solely to the right superior ophthalmic vein was treated first by transarterial embolization with polyvinyl alcohol particles. Then, by approaching through the superior ophthalmic vein from the right external jugular vein, the cavernous sinus was embolized with platinum wire using a tracker microcatheter, which resulted in marked clinical improvement. Transvenous embolization by approaching from the external jugular vein through the superior ophthalmic vein represents a promising alternative when shunted blood drains anteriorly to the superior ophthalmic vein.

Arteriovenous Fistula↗
PubMed1990

Effect of ketotifen on antigen-induced interleukin 2 (IL-2) responsiveness in lymphocytes from patients with atopic dermatitis and/or bronchial asthma.

We tested the effect of Ketotifen (4-(1-methyl-4-piperidylidene)-4H- benzo[4,5] cyclohepta[1,2-b]thiophen-10(9H)-one hydrogen (fumarate) on the induction of allergen-induced IL-2 responsiveness in lymphocytes from patients with atopic dermatitis and/or bronchial asthma. Ovalbumin (OVA)- and/or Dermatophagoides farinae(Df)-induced IL-2 responsiveness was increased in almost all patients (1-15 years old) before Ketotifen treatment. Two to 12 months administration of Ketotifen (0.06 mg/kg/day) decreased activity of the response in 7 out of 9 cases corresponding to improvement of clinical symptoms. In in-vitro studies, antigen presenting cells (adherent cells) from the patient pretreated with 5, 50 and 500 ng/ml doses of Ketotifen for 12 h failed to present OVA or Df antigen to T-cells for induction of IL-2 responsiveness. Antigen-pulsed adherent cells also failed to induce the response of the T-cells pretreated with 50 and 500 ng/ml doses of Ketotifen but not with a 5 ng/ml dose. A 50 ng/ml dose of Ketotifen did not affect T-cells for induction of the response. In contrast, the treated adherent cells are capable of presenting PPD antigen or Con A for the induced response. The combined data indicate that induction of IL-2 responsiveness of peripheral blood lymphocytes on stimulation with nominal antigen may reflect an immune response to allergen in patients with allergy and a weak immunosuppressive effect of Ketotifen seems to block the response in the pathogenic process of allergic diseases.

Adolescent↗
PubMed1990

Protection by oral phenylalanine against gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effect of oral administration of L-phenylalanine on the incidence and histology of gastric adenocarcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine was investigated in inbred Wistar rats. Oral administration of 6% phenylalanine after 25 weeks of treatment with the carcinogen significantly reduced the incidence and number of adenocarcinomas of the glandular stomach at experimental week 52. Oral administration of high dose phenylalanine significantly increased the basal serum gastrin level and significantly decreased the norepinephrine concentration in the antral portion of the gastric wall, as well as the labelling indices of antral mucosa. These findings indicate that orally administered phenylalanine inhibits the development of gastric cancers.

Adenocarcinoma↗
PubMed1990

Enhancement by neurotensin of experimental carcinogenesis induced in rat colon by azoxymethane.

The effects of neurotensin on the incidence, number, size, and histology of colon tumours induced by azoxymethane (AOM) were investigated in Wistar rats. Rats were given 10 weekly injections of AOM (7.4 mg kg-1 body weight) and were also given 200 micrograms kg-1 of neurotensin in depot form every other day until the end of the experiment. In week 40, prolonged alternate-day administration of neurotensin resulted in significant increases in the number and size of colon tumours and the incidence of adenocarcinomas penetrating muscle layer and deeper. However, neurotensin did not influence the incidence of tumour-bearing rats and the histological appearance of colon tumours. Administration of neurotensin caused a significant increase in the labelling index of the colon cancers but not that of colon mucosa. These findings indicate that neurotensin enhanced the growth of colon tumours, possibly related to its effect in increasing proliferation of colon cancer cells.

Adenocarcinoma↗
PubMed1990

Comparative morphological and biological studies on the itraconazole- and ketoconazole-resistant mutants of Cryptococcus neoformans.

Studies were carried out on the resistance in vitro of Cryptococcus neoformans to the oral antifungal drugs itraconazole and ketoconazole. None of the six sensitive strains tested developed resistance to itraconazole or ketoconazole by serial transfer on Sabouraud's glucose agar plates containing increasing concentrations of either drug. One mutant resistant to itraconazole, and one mutant resistant to ketoconazole, were isolated from the progenies of yeast cells surviving after treatment with a mutagenic substance, N-methyl-N'-nitro-N-nitroso-guanidine. These mutants were capable of growing in the presence of high concentrations of the drugs to which they were resistant. The itraconazole- and ketoconazole-resistant mutants obtained by mutagenesis were compared morphologically and biologically. The itraconazole-resistant mutant was characterized by the formation of very rough colonies which varied in size and shape, production of a large number of cell clusters, complete loss of capsule formation, and major degenerative changes in the cells, while in the ketoconazole-resistant mutant these changes were less pronounced and no cell clusters were formed. The acquisition of resistance was more stable in the itraconazole-resistant mutant than in the ketoconazole-resistant mutant. Both mutants showed partial cross-resistance and complete loss of virulence for mice.

Animals↗
PubMed1990

Novel sulfated polysaccharides: dissociation of anti-human immunodeficiency virus activity from antithrombin activity.

Novel sulfated polysaccharides, sulfated bacterial glycosaminoglycan (Org 31581) and chemically degraded heparin (Org 31733), have proved to be potent and selective inhibitors of human immunodeficiency virus (HIV) in vitro. Their 50% inhibitory concentrations for HIV type 1 (HIV-1) in MT-4 cells were 0.67 and 0.52 micrograms/ml, respectively. These values are comparable to those obtained for dextran sulfate and standard heparin (0.39 and 0.89 micrograms/ml, respectively). Org 31581 and Org 31733 showed much less antithrombin activity than did dextran sulfate and standard heparin. These results indicate that the anti-HIV activity of sulfated polysaccharides can be dissociated from their antithrombin activity. Org 31581 and Org 31733 were equally inhibitory to HIV-2 and HIV-1 and were also inhibitory to the replication of human cytomegalovirus. Syncytium formation, induced by cocultivation of MOLT-4 (clone 8) cells with chronically HIV-1-infected HuT 78 cells, was also inhibited by Org 31581. As previously demonstrated with dextran sulfate and heparin, both Org 31581 and Org 31733 blocked virus adsorption to the host cells. These compounds offer great promise as candidate drugs for the chemotherapy of HIV infections.

Blood Coagulation↗
PubMed1990

Neonate blood IgE levels on filter paper as indicators of atopic disease.

Measurements of IgE levels in the blood of neonates were investigated using filter paper for blood collection in mass screening of congenital metabolic disorders. Time-resolved fluoroimmunometric assay system for the measurement of filter paper blood IgE levels was also studied. In an analysis of the present results, IgE values of at least 0.015U/ml, the measurement limit, were considered as high. High IgE levels in filter paper blood were seen in 28 (7.2%) of the 389 cases. When the relation with serum IgE levels at 18 months of age was investigated in 134 of 389 subjects, high serum IgE levels were also found in about 86.7% of the subjects with high IgE levels in filter paper blood. In addition, when the relation between family history of atopic disease and presence of atopic disease in the first 18 months of age was investigated in 203 of the 389 subjects, about 90% of the subjects with a family history of atopic disease and high IgE levels in filter paper blood developed atopic disease. Since filter paper blood is routinely collected in Japan, IgE levels in this blood should be widely checked for the prediction of onset of atopic disease in infants.

Female↗
PubMed1990

Death from asthma in children.

We have recorded 29 cases of death from asthma in children who had visited the Department of Pediatrics of Doai Memorial Hospital between 1965 and 1987. These cases have been analyzed. They were 18 males and 11 females. The mean age at death was 12.4 years and we found that in later childhood and adolescence the age at death had been increasing since 1973. The duration from final attack to death was very short: less than 1 hour: 21% and less than 2 hours: 50%. About half of the cases could not reach the hospital. Ten cases died within one year after cessation of long-term systemic use of steroid. Severe attacks of asthma were particularly likely to occur during the reducing period or following cessation of these drugs. The importance of adequate and vigorous initial therapy in severe asthmatic attacks should be emphasized. The causes of death are as follows: asphyxia: 23 cases (one complicated by aspiration, one withdrawal syndrome of steroid, one subendocardial haemorrhage and two pneumothorax cases), anaphylactic shock to ACTH: 1 case, shock to stimulant: 1 case, following emergency operation: 1 case and unknown: 3 cases. Asthma death in children in Japan is reviewed.

Adolescent↗
PubMed1990

[Effects of immunoglobulin preparations on the opsonic activities against various pathogens].

We evaluated the opsonic activities of human intravenous immunoglobulin (IVIG) preparations against pathogenic organisms by measuring the luminol-enhanced chemiluminescence (CL) from human polymorphonuclear leukocytes (PMN) during the phagocytosis of these organisms. Polyethylenglycol-treated IVIG significantly increased the CL of PMN by opsonization against various bacteria and Candida albicans (p less than 0.01). The high CL induced by IVIG with intact Fc-fragment showed no significant differences among lots or preparations made by different treatments. In both PMN-CL in the absence of human serum and whole blood CL at low concentration of serum complement, the CL response was not affected by pepsin-treated IVIG. In the severely burned patients' blood with a very low concentration of serum immunoglobulin, IVIG with intact Fc-fragment significantly increased CL (p less than 0.01). It is suggested that administration of IVIG is useful against infections in these patients. The measurement of whole blood CL in vitro may be useful for evaluating the opsonic activity of IVIG against target pathogens in vivo.

Bacteria↗
PubMed1990

Novel sulfated polymers as highly potent and selective inhibitors of human immunodeficiency virus replication and giant cell formation.

Novel synthetic sulfated polymers, namely, sulfated polyvinyl alcohol (PVAS) and sulfated copolymers of acrylic acid with vinyl alcohol (PAVAS), proved to be potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) and HIV-2 in vitro. The compounds completely inhibited HIV-1-induced cytopathogenicity in MT-4 cells and HIV-1 antigen expression in CEM cells at a concentration of 0.8 micrograms/ml. They were equally effective against HIV-2 replication. In addition, and in contrast to azidothymidine, PAVAS and PVAS suppressed HIV-1-induced giant cell (syncytium) formation, a process that may account for the depletion of T4 lymphocytes in patients with acquired immunodeficiency syndrome. PAVAS and PVAS completely blocked giant cell formation at a concentration of 4 micrograms/ml, whereas for dextran sulfate a concentration of 100 micrograms/ml was required to achieve complete inhibition of giant cell formation. As has been demonstrated previously for the sulfated polysaccharides, the mechanism of action of PAVAS and PVAS resides in the inhibition of virus adsorption to the cells.

Acrylic Resins↗
PubMed1990

Anti-human immunodeficiency virus type 1 activities and pharmacokinetics of novel 6-substituted acyclouridine derivatives.

The novel 6-substituted acyclouridine derivatives 1-[(2-hydroxyethoxy)methyl]-6-phenylthiothymine (HEPT), 1-[(2-hydroxyethoxy)methyl]-6-(3-methylphenylthio)thymine (HEPT-M), 6-cyclohexylthio-1-[(2-hydroxyethoxy) methyl]thymine (HEPT-H), and 1-[(2-hydroxyethoxy)methyl]-6-phenylthio-2- thiothymine (HEPT-S) have proved to be potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) replication in a variety of cell systems, including peripheral blood lymphocytes. They are not inhibitory to the replication of HIV-2. HEPT-S emerged as the most active congener, with a 50% inhibitory concentration of 1.6 microM for HIV-1 (human T-cell lymphotropic virus type IIIB) in MT-4 cells. We also examined the pharmacokinetics of the compounds following oral administration to rats. The pharmacokinetic profile varied considerably from one compound to another. The highest concentration in plasma (7.4 micrograms/ml, or 22.8 microM) was achieved by HEPT-S within 30 min after administration of an oral dose of 20 mg/kg of body weight. HEPT-S can be considered a promising candidate for the treatment of HIV-1 infections.

Animals↗