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Biomedical subjects

H Yamaguchi

Publications and source records attributed to H Yamaguchi.

At least 253 records · Page 14Linked to original sources
PubMed2000

[Prophylactic efficacy of a basidiomycetes preparation AHCC against lethal opportunistic infections in mice].

The prophylactic effects of a Basidiomycetes preparation, AHCC, against experimental opportunistic infections were investigated in leukopenic mice. In cyclophosphamide-induced leukopenic mice, oral or intraperitoneal administration of the AHCC at doses of 1000 or 50 mg/kg/day, respectively, for 4 consecutive days prior to Candida albicans infection significantly prolonged the survival periods of the infected mice, and decreased the viable counts of C. albicans cells recovered from their kidneys. Similarly, the oral treatment with AHCC protected mice from lethal infection with Pseudomonas aeruginosa and intraperitoneal one also protected mice from infection with methicillin-resistant Staphylococcus aureus (MRSA). These results suggest a potential usefulness of the AHCC as a prophylactic agent for the management of patients with opportunistic infections.

Animals↗
PubMed2000

Ampulla cardiomyopathy ('Takotusbo' cardiomyopathy)--reversible left ventricular dysfunction: with ST segment elevation.

The clinicopathologic findings of reversible ampulla-like ventriculogram of the left ventricle were studied in 8 elderly women and one middle-aged man. Their coronary arteriograms were normal, even in the 7 patients who had ST elevation on electrocardiogram. Coronary spasm was positive in only 2 of the 7 patients who received provocation tests. Biopsy specimens revealed focal myocyte injury. Normal coronary arteriograms during ST elevation and the presence of pathologic myocardial lesions were not consistent with a concept of stunned myocardium. The presence of myocardial lesions suggested that focal and disseminated myocardial damage had occurred.

Aged↗
PubMed2000

Arrhythmogenic right ventricular cardiomyopathy with an initial manifestation of severe left ventricular impairment and normal contraction of the right ventricle.

A case of arrhythmogenic right ventricular cardiomyopathy (ARVC) with an initial manifestation of severe impairment of the left ventricle (LV) and normal contraction of the right ventricle (RV) is presented. A 43-year-old man was admitted to hospital because of congestive heart failure following a common cold. The LV function was diffusely and severely hypokinetic. Coronary arteriogram revealed normal vessels. An endomyocardial biopsy specimen obtained from the RV septum revealed mild infiltration of lymphocytes with focal myocytes necrosis and so healing myocarditis was suspected. The specimen did not include any fatty replacement of myocytes. Since then, the patient suffered from recurrent congestive heart failure as well as nonsustained ventricular tachycardia and required frequent hospitalization. Progressive impairment, dilation, and thinning of both ventricles were observed on serial echocardiographic examinations. Although the RV gradually enlarged and became impaired, severe dilatation and impairment of the LV has always been predominant in the patient's clinical course. After medical follow-up for 10 years, he died suddenly of ventricular fibrillation and pump failure. The autopsy revealed extensive fibrofatty replacement of myocytes in both the ventricles, extending from the outer layer to the inner layer of myocardium in the RV and to the middle layer in the LV. These features were compatible with arrhythmogenic right ventricular cardiomyopathy or perimyocarditis, although only the rightsided bundle of the interventricular septum was completely replaced by fatty tissue, which can not be explained as a sequel of perimyocarditis. Moreover, apoptosis was present in the myocyte nuclei of the myocardial layers bordering the area of fatty replacement. Therefore, myocarditis may have triggered or accelerated the process of apoptosis leading to ARVC.

Adult↗
PubMed2000

Stereocontrolled reduction of alpha- and beta-keto esters with micro green algae, Chlorella strains.

The stereocontrolled reduction of alpha- and beta-keto esters using micro green algae was accomplished by a combination of the cultivation method and the introduction of an additive. The reduction of ethyl pyruvate and ethyl benzoylformate by the photoautotrophically cultivated Chlorella sorokiniana gave the corresponding alcohol in high e.e. (>99% e.e. (S) and >99% e.e. (R), respectively). In the presence of glucose as an additive, the reduction of ethyl 3-methyl-2-oxobutanoate by the heterotrophically cultivated C. sorokiniana afforded the corresponding (R)-alcohol. On the other hand, the reduction in the presence of ethyl propionate gave the (S)-alcohol. Ethyl 2-methyl-3-oxobutanoate was reduced in the presence of glycerol by the photoautotrophically cultivated C. sorokiniana or the heterotrophically cultivated C. sorokiniana to the corresponding syn-(2R,3S)-hydroxy ester with high diastereo- and enantiomeric excess (e.e.). Some additives altered the stereochemical course in the reduction of alpha- and beta-keto esters.

Chlorella↗
PubMed2000

Blockade of angiotensin receptors in the anterior hypothalamic preoptic area lowers blood pressure in DOCA-salt hypertensive rats.

It has been established that deoxycorticosterone acetate (DOCA)-salt hypertensive rats have an overactive brain angiotensin-system. The purpose of the present study was to identify the brain sites showing enhanced angiotensin-system activity responsible for the pathogenesis of hypertension in DOCA-salt hypertensive rats. The angiotensin receptor antagonist, losartan, was injected into brain ventricles or into tissues around the rostral parts of the third ventricle in conscious DOCA-salt hypertensive rats. Losartan (1 microg) injection into the lateral ventricle or into the rostral parts of the third ventricle produced a depressor response, whereas the agent did not affect blood pressure when injected into the caudal parts of the third ventricle or into the fourth ventricle. Losartan (0.1 microg) injection into the anterior hypothalamic preoptic area, anterior (AHA) produced a depressor response. Angiotensin II (0.1-1 ng) injection into the AHA produced a pressor response in sham-operated and DOCA-salt hypertensive rats, and the pressor response to angiotensin II (1 ng) was greater in DOCA-salt hypertensive rats than that in sham-operated rats. Release of angiotensin peptides in the AHA was greater in DOCA-salt hypertensive rats than that in sham-operated rats. These findings suggest that the angiotensin-system in the AHA is enhanced, and that this enhancement is involved in the maintenance of hypertension in DOCA-salt hypertensive rats. Both increased pressor reactivity to angiotensin II and increased release of angiotensin peptides in the AHA appear to be related to this enhancement of the angiotensin-system in DOCA-salt hypertensive rats.

Angiotensin II↗
PubMed2000

An encephalopathy with argyrophilic inclusions in a Holstein-Friesian cow.

The brain of a 6-year-old Holstein cow, which showed progressive neurologic symptoms during several months, was examined by histopathologic methods. Many round or oval-shaped cytoplasmic inclusions were observed, mainly in neurons of the temporal lobe and the hippocampus. Those inclusions were faintly eosinophilic with hematoxylin and eosin and positive with Bielschowsky's silver stain. Immunohistochemically, the inclusions were recognized by antiubiquitin and antiphosphorylated tau antibodies. Ultrastructurally, the inclusions were globular and well demarcated from the rest of the cytoplasm, lacked limiting membranes, and were mainly composed of straight fibrils about 15 nm in width. The structure of the inclusions was similar to that of Pick bodies in Pick's disease of humans. The pathogenesis of this bovine condition is not known.

Animals↗
PubMed2000

Atrial function during cardiac arrest caused by ventricular fibrillation.

OBJECTIVES: To report observations on preserved regular atrial electrical and mechanical systole during ventricular fibrillation (VF) and to quantitate blood flow generated by atrial contractions in this setting. METHODS: In 10 rats, right atrial pressure pulses were continuously recorded before and for an interval of 8 min after inducing VF. In 3 isolated, perfused rat hearts, epicardial right atrial electrograms were recorded after inducing VF. In 15 pigs, transesophageal echo-Doppler measurements were obtained with pulsed and color-Doppler visualization of flow across the mitral valve after onset of VF. RESULTS: In each rat, regular right atrial pressure pulses were documented during VF. These persisted over an average interval of 7.5 min. In isolated, perfused hearts, right atrial contractions were accompanied by regular atrial depolarizations. In pigs, regular atrial contractions generated atrial stroke volumes of approximately 12 mL, or 25% of prearrest values during the first minute after onset of VF, but those declined to approximately 6 mL after 10 min of untreated cardiac arrest. Blood flow from the left atrium into the left ventricle failed to advance significantly into the systemic circuit. During atrial diastole, we observed reversal of flow into the left atrium. CONCLUSIONS: Atrial contractions are preserved during the initial 8 min or more after cardiac arrest due to VF. Substantial forward flow into the left ventricle failed to advance through the outflow tract but regurgitated into the atrium during atrial diastole.

Animals↗
PubMed2000

Analysis of possible silencer elements of ovine interferon-tau gene.

During the peri-implantation period significant production of ovine interferon-tau (olFNtau) by the trophectoderm is detected in day 13-16 conceptuses, but its level rapidly declines thereafter. To understand molecular mechanisms by which oIFNtau gene expression is down-regulated, a variety of deletion constructs were prepared from upstream sequences of the oIFNtau gene and examined for possible silencer regions by using transient transfection into human choriocarcinoma, JEG3, cells. Two regions between -700 to -654 bases (distal region) and from -503 to -453 bases (proximal region) were found to be the possible negative regulatory regions. With probes prepared from these regions, gel mobility shift assay (GMSA) was then conducted. DNA-protein complexes were observed, but the gel shift pattern was different between nuclear extracts from days 14 (active oIFNtau production) and 20 (minute oIFNtau production) ovine trophoblasts. Day 20 nuclear extracts exhibited more band patterns than those of day 14; most notably the distal region between -692 and -668 bases exhibited the distinct band with nuclear extracts from day 20, but not from day 14 trophoblasts. In addition, the band patterns from day 20 trophoblast nuclear proteins were similar to those detected with JEG3 and HeLa cell nuclear extracts. Taken together, these observations suggest that the upstream sequences identified could serve as negative regulatory regions to which various nuclear factors bind, resulting in reduction of oIFNtau gene transcription.

Animals↗
PubMed2000

Increase in serum ceruloplasmin with aging is not observed in type 2 diabetes.

Changes of serum ceruloplasmin (Cp) levels have been reported in many conditions including diabetes mellitus (DM), in which the serum Cp levels were increased. In this study, we have examined the influence of aging on serum Cp levels in normal individuals and in individuals with DM. Serum Cp levels were measured in 85 outpatients with type 2 diabetes (type 2 DM group) as well as in 71 healthy individuals (control group). All patients recruited for this study were negative for the glutamic acid decarboxylase (GAD) antibody. The subjects were sub-grouped based on their ages (<55 and 55 < or =). The serum Cp levels in the control group increased significantly with aging (r=0.325, p<0.0055), while levels in the type 2 DM group did not (r=0.091, p=0.4079). The levels in the type 2 DM group (<55) were significantly higher than those in the control group (<55) (p = 0.0029), while the Cp levels in the type 2 DM group (55 < or =) were not different from those in the control group (55 < or =) (p=0.4187). An age-related increase of serum Cp levels was observed in normal individuals, but this change was not observed in type 2 DM patients since serum Cp levels in type 2 DM patients of all ages were similar to the levels in normal elderly individuals.

Adult↗
PubMed2000

Marked and prompt hemodynamic improvement by carperitide in refractory congestive heart failure due to dilated cardiomyopathy.

A 16-year-old Japanese male diagnosed with congestive heart failure (CHF) due to dilated cardiomyopathy was treated by conventional intensive treatment such as intravenous infusion of diuretics, catecholamines, and phosphodiesterase inhibitors with vasodilators. However, he developed a low output syndrome with appearances of hyponatremia and hypochloremia. As a consequence, intravenous infusion of carperitide (synthetic atrial natriuretic peptide) was added to the therapy. Thereafter his symptoms and hemodynamic parameters promptly and dramatically improved without significant diuresis, and this amelioration persisted for more than 20 days without drug intolerance. This outcome suggests that use of carperitide may be a safe and efficacious means to reduce cardiac preload without hypotension and tachycardia in patients with refractory CHF in whom intensive treatment has already been performed.

Adolescent↗
PubMed2000

A novel mutation of the ceruloplasmin gene in a patient with heteroallelic ceruloplasmin gene mutation (HypoCPGM).

We found a novel missense mutation in the ceruloplasmin (Cp) gene in a patient with the heteroallelic Cp gene mutation (HypoCPGM). The patient was a 72-year-old woman who came to our hospital with a 1-year history of postural tremor of the hands. The diagnosis was made based on serum Cp and copper readings which were about half the normal levels, as well as MRI tests of her brain which showed characteristics for hereditary ceruloplasmin deficiency (HCD), known to be caused by the homoallelic Cp gene mutation. Polymerase chain reaction (PCR)-direct sequencing analysis of the Cp gene of the patient revealed a novel point mutation, A to T, at nucleotide position 82 in Exon 1. This mutation changes the Ile28 codon (ATT) to a Phe codon (TTT) (missense mutation). PCR-restriction analysis with restriction enzyme Tsp EI for the mutation revealed that both the patient and her son were heterozygotes for the mutation.

Aged↗
PubMed2000

Effective arterial elastance of irregular beats during atrial fibrillation in canine left ventricle.

Effective arterial elastance (E(a)) was originally defined as the end-systolic pressure (ESP)/stroke volume (SV) ratio of the left ventricle (LV). E(a) combined with LV contractility (E(max)), E(a)/E(max), proved to be powerful in analyzing the ventriculo-arterial coupling of normal and failing hearts in regular beats. However, E(a) sensitively changes with LV E(max), preload, and afterload widely changing among irregular beats. This has discouraged the use of E(a) during arrhythmia. However, we hypothesized that E(a) could serve as the effective afterload (not always arterial) elastance against ventricular ejection under arrhythmia. We tested this hypothesis by analyzing beat-to-beat changes in E(a) of irregular beats during electrically induced atrial fibrillation (AF) in normal canine in situ hearts. We newly found that during AF in each heart: 1) E(a) changed widely among irregular beats and became markedly high in weak beats with small SVs; 2) E(a) and E(a)/E(max) distributed non-normally with large skewness but 1/E(a) distributed more normally; 3) 1/E(a) correlated closely with end-diastolic volume, E(max) and preceding beat intervals; and 4) the reciprocal of mean 1/E(a) closely correlated with mean ESP/mean SV. These results support our hypothesis that E(a) can serve as the effective afterload elastance against ventricular ejection on a per-beat basis during AF. E(a)/E(max) can also quantify the ventriculo-afterload (not arterial) coupling on a per-beat basis. This study, however, warns that mean E(a) and mean E(a)/E(max) of irregular beats cannot necessarily represent their averages during AF.

Animals↗
PubMed2000

Characteristics of coronary heart disease in Japanese taxi drivers as determined by coronary angiographic analyses.

Several epidemiological studies have shown that the prevalence of ischemic heart disease is higher in occupational drivers than in people with other occupations. Although occupation categories can be surrogate measures for coronary risk factors, the relationships between taxi driving and severity of coronary heart disease (CHD) has not been investigated. Even more important, the contribution of risk factors to the severity of CHD in taxi drivers remains unclear. Our study tested the hypothesis that taxi driving could be associated with the severity of CHD. We also examined the relation between this occupation and risk factors and social lifestyle. We analyzed the coronary angiograms of 57 consecutive male taxi driver patients and compared them with those of 215 age-adjusted male non-taxi-driver patients. The number of diseased vessels and risk factors were compared between two groups. The prevalence of myocardial infarction and multi-vessel disease was higher in the taxi-driver patients than in the non-taxi-driver patients. The taxi-driver patients had higher prevalence of body mass index (BMI), diabetes, and smoking, higher levels of low-density lipoprotein cholesterol (LDL-C), and lower levels of apolipoprotein AI (ApoAI). Multiple logistic regression analysis showed that multi-vessel disease was associated with BMI and diabetes mellitus in taxi-driver patients. The taxi-driver patients were characterized by more extensive coronary atherosclerosis associated with higher prevalence of diabetes mellitus and obesity. These characteristics may be explained by in part their working environment.

Automobile Driving↗
PubMed2000

[Protective effect of oral administration of several traditional Kampo-medicines on lethal Candida infection in immunosuppressed mice].

The protective effects of a "hozai" type of Kampo medicine, Juzen-taiho-to (Shi-quan-da-bu-tang, TJ-48), Hochu-ekki-to (Bu-zhong-yi-qi-tang, TJ-41) or Ninjin-yoei-to (Ren-shen-yang-rong-tang, TJ-108) on experimental candidiasis in immunosuppressed mice were investigated. ICR mice, which were immunosuppressed by injection of cyclophosphamide or prednisolone, were given these medicines orally andchallenged intravenously with Candida albicans (day 0). Treatments with a daily dose of 1 g/kg/day of TJ-48 or that of 1 or 2 g/kg/day of TJ-108 for 4 consecutive days from day-4 significantly prolonged the survival time of the Candida-infected mice pretreated with cyclophosphamide. Treatments with a daily dose of 1 g/kg/day of TJ-48 for 4 consecutive days from day 0, but not from day -4, significantly prolonged the life span of the Candida-infected mice pretreated with prednisolone. On the basis of these results and previous findings, characteristics of these kampo medicines as therapeutic agents against candidiasis in immunosuppressed hosts were discussed.

Animals↗
PubMed2000

[New developments in therapy of deep mycoses].

Over the past two decades the incidence of deep mycoses caused by several major groups of fungal pathogens such as Candida spp., aspergilli, Cryptococcus neoformans and zygomycetes has risen steadily. Moreover, opportunistic fungal infections due to Fusarium spp., Trichosporon spp., Pseudallescheria boydii and other emerging pathogens, as well as fluconazole-resistant Candida albicans, all of which are often resistant to existing antifungal drugs, are also encountered more and more frequently. This makes it more difficult for the clinician to achieve successful treatment. Thus there is an urgent need to develop new antifungal agents or formulations with advantages over and/or complimentary to existing drugs. This review focuses on current approaches to antifungal chemotherapy with special reference to the clinical development of new drugs, including (ii) lipid formulations of amphotericin B, (i) second-generation azoles and (iii) antifungal lipopeptides.

Amphotericin B↗
PubMed2000

[Host defense mechanisms against fungal infections].

Recent advances in the research on host defense mechanisms against infections with Candida and Aspergillus were reviewed. Modes of the defense mechanisms were divided into three phases by thedifferent physiological circumstances surrounding the fungi: 1, the exocrine fluid in which fungi exist on the mucosal membranes; 2, the tissues invaded by fungi with the circulating blood; and 3, the limited lesions where fungi continue to be alive with a restricted blood flow. In each defense mechanism, theroles of the endogenous antifungal substances such as lactoferrin, defensins and calprotectin and leukocytes were discussed.

Aspergillosis↗
PubMed2000

[Suppressive effects of lanoconazole on arthus phenomenon in vivo and on production and functions of TNF in vitro].

The anti-inflammatory effect of lanoconazole (LCZ) was investigated in vivo and in vitro. The effect of LCZ was evaluated on the inflammatory reactions elicited by intradermal injection of ovalbumin to ovalbumin-immunized rabbits, as an Arthus phenomenon. A one or two % cream preparation of LCZ was topically applied on the lesion daily after challenging injection until the inflamation had diminished. By macroscopic observation and measuring the diameter of edema, erythema, hemorrhage and necrosis, the effects of LCZ on the reactions were compared with the reactions of the sites administered withcream vehicle as reference agent. Two % LCZ showed an anti-hemorrhagic effect. The in vitro effect of LCZ on production and functions of an inflammatory cytokine, TNF was also examined. LCZ suppressed the production of TNF by murine peritoneal macrophages at 20 micro g/ml and the adhesion of neutrophils at 100 micro g/ml. Moreover, LCZ significantly suppressed the growth inhibitory activity of TNF against L929 fibroblasts at 0.5 micro g/ml. A very low concentration of LCZ might protect the fibroblasts from immunological cytotoxicity in vivo. These findings suggest that LCZ has a suppressive activity to inflammatory responses and this suppressive action may be due to its protective activity to cells like fibroblasts.

Animals↗