[Results of annual health examination for the aged provided by the law that are predictive of increased mortality risk]

Possible risk factors associated with mortality were studied in a community using data derived from annual mass health examinations for the aged mandated by law. A total of 1,804 adults (685 men and 1,119 women) aged 40 or older in A-town, located on Tsushima Island, Nagasaki Prefecture, Japan who had participated in annual health examinations at least once between 1984 and 1990, were followed for a mean period of 4.9 years. After adjustment for age using Cox proportional hazards models, in men liver dysfunction (aspartate aminotransferase > 40 U/l or alanine aminotransferase > 35 U/l), fasting blood glucose > or = 110 mg/dl and glucosuria, and in women serum creatinine > or = 1.2 mg/dl, fasting blood glucose > or = 110 mg/dl and proteinuria were found to be associated with a significantly increased risk of total mortality. In multivariate analysis using all independent variables that were significantly associated with mortality in age-adjusted bivariate analysis, in men liver dysfunction and hyperglycemia, and in women hypercreatininemia and hyperglycemia, were significant predictors of mortality. These independent variables remained significant or marginally significant predictors of total mortality even after excluding the effects of 3 pancreatic cancer cases with liver dysfunction or hyperglycemia or 12 deaths within the first year of follow-up, being associated with at least two-fold increased hazard rate ratios. From these results, it is recommended that persons with these risk factors be followed intensively and counseled by public health personnel to modify risk factors.

[Clinical studies on the time-difference combination therapy with netilmicin and minocycline in methicillin-resistant Staphylococcus aureus infections]

Twenty-eight patients with methicillin-resistant Staphylococcus aureus (MRSA) infections were clinically studied for the effectiveness of the time-difference combination use of netilmicin (NTL) and minocycline (MINO). The patients were treated with NTL 100 mg and two hours later, with MINO 100 mg intravenously, twice daily, in the morning and evening for 14 days. Of 26 patients, MRSA was eradicated in 16 (61.5%), decreased in one, and unchanged in nine. Superinfections occurred with Serratia marcescens and Pseudomonas aeruginosa in two patients. The clinical efficacies were assessed in two patients with septicemia, 16 with pneumonia, and eight with chronic bronchitis. The obtained results were excellent in four patients, good in 15, fair in six, and poor in one patient. The rate of effectiveness was 73.1% (19/26). The overall clinical effectiveness judged by the committee was good in 19, fair in five, and poor in two patients. The efficacy rate was also 73.1% (19/26). Coagulase type II of MRSA was found in 23 patients, and coagulase type III in three patients, with overall clinical efficacy rates of 73.9% (17/23) and 66.7% (2/3), respectively. A side effect of eruption was observed in one patient, and its incidence was 3.6% (1/28). Abnormal laboratory test results were observed in 16 patients (57.1%), including abnormal liver function in 14 patients, abnormal kidney function in three, and increased eosinophils in three. Laboratory abnormalities occurred twelve of 16 bedridden patients, and this rate was higher than that in non bedridden patients. However, these abnormalities were all mild, transient, and immediately recovered after the treatment. In conclusion, the time-difference combination therapy using NTL and MINO was effective in the treatment of MRSA infections.

Analysis of intra- and intercellular calcium signaling in a mouse malignant glioma cell line

Intra- and intercellular calcium signaling in glioma cells was examined by mechanical stimulation of a monolayer cell line of methylcholanthrene-induced mouse ependymoblastoma, 203-glioma, with a fine round-tip glass needle. A fura-2 fluorescence image of the glioma revealed a four- to eightfold increase in the cytosolic calcium ion concentration in directly stimulated signal cells. The increased calcium spread to surrounding cells at a speed of 20 microns/sec for a distance of up to 200 microns. Calcium was transmitted between adjacent cells and even in cells up to 200 microns distant from the initially stimulated cell. Microinjection of Lucifer yellow dye showed no gap junctional communication between cells. Depletion of extracellular calcium ion inhibited both cytosolic calcium elevation and propagation to neighboring cells by mechanical stimulus. An intracellular calcium blocker, TMB-8, eliminated the cytosolic calcium mobilization in a mechanically stimulated cell, but had no effect on calcium diffusion to surrounding cells. Nifedipine and verapamil, antagonists of voltage-dependent calcium channels, did not act on the mechanically induced calcium response. This suggests that some stimulating factor may trigger transmission of calcium, which may be ejected directly from single stimulated cells and mediated via a membrane receptor but not through a gap junction. The calcium signaling in a mechanically stimulated cell may be related to both an influx and a redistribution of intracellular calcium from internal stores, while calcium propagation to neighboring cells may involve calcium influx alone.

Hyperresponsiveness of cardiac muscles to histamine in reserpine-treated guinea pigs

The hyperresponsiveness of cardiac tissue to histamine following treatment with reserpine was pharmacologically characterized. Guinea pig hearts were isolated 24 hours after intraperitoneal administration of 5 mg/kg reserpine. This treatment resulted in a complete depletion of tissue norepinephrine. Reserpine treatment potentiated the positive inotropic response of isolated perfused hearts to histamine at doses ranging from 0.3 to 3 micrograms (23 to 57% increase for reserpine-treated animals vs. 14 to 32% increase for control animals). Isolated left ventricular papillary muscle of reserpine-treated guinea pig hearts also showed hyperresponsiveness to histamine at concentrations of 0.1 microM or greater. The hyperresponsiveness of the papillary muscle contraction of the reserpine-treated animals to histamine was abolished in the presence of 1 microM cimetidine, but not attenuated in the presence of 1 microM diphenhydramine. This hyperresponsiveness was not modified by 1 microM bunazosin or 1 microM propranolol. The results suggest that H2-receptor mediated action plays a role in the hyperresponsiveness of cardiac muscles to histamine.

In-vitro effects of antimicrobial agents on Pseudomonas aeruginosa biofilm formation

The in-vitro effects of ten antimicrobial agents on the biofilm formation of Pseudomonas aeruginosa were investigated. The production of alginic acid by mucoid P. aeruginosa cells cultured in agar media with sub-MICs of antimicrobial agents was quantified by high-performance liquid chromatography. Alginic acid production was inhibited by 1/4 MIC of minocycline (P < 0.002) and tobramycin (P < 0.02), and by 1/256-1/1/64 MIC of macrolides (erythromycin, clarithromycin, roxithromycin, and rokitamycin) and clindamycin (P < 0.02), compared with drug-free controls. Piperacillin, ceftazidime, and ofloxacin did not inhibit alginic acid production. The production of exopolysaccharide by non-mucoid P. aeruginosa cells grown on silicone plates in sub-MICs of antimicrobial agents was determined by quantitative tryptophan assay. Exopolysaccharide production was inhibited by 1/16 MIC of macrolides and clindamycin, but not by other antimicrobial agents. Electron microscopy showed that biofilm formation by mucoid and non-mucoid type P. aeruginosa strains was inhibited by sub-MICs of erythromycin and correlated with the in-vitro production of alginic acid and exopolysaccharide. These results suggest that sub-MICs of macrolides and clindamycin suppress biofilm formation by P. aeruginosa and that intractable chronic respiratory tract infections due to P. aeruginosa might be prevented.

Impression of smoothness of a sound stream in relation to legato in musical performance

Physically continuous sounds do not always produce the subjective impression of legato. In the present study, the effect of temporal factors on the impression of smoothness of a sound stream was systematically investigated in relation to the dynamic characteristics of hearing. The results showed that decaying sounds, successively presented, were perceived as being marginally connected when the sounds physically overlapped, while steady-state sounds were perceived as being marginally connected when they were physically separated. It was also shown that judgments by the subjects agreed quite well with the effect intended by the pianist when the passage was given in different temporal interpretations.

[A case of malignant hemangiopericytoma arising from the mediastinum accompanied by hepatocellular carcinoma]

A 65-year-old man was admitted to Oita Medical University Hospital with complaints of right back pain, diplopia and vertigo. A tumor, 33 x 25 mm, was found on the right lateral chest wall on admission. Chest X-ray film and chest CT scan showed a tumor, 50 x 30 mm, in the right posterior mediastinum. The chest wall tumor was diagnosed as malignant hemangiopericytoma by biopsy, and the same diagnosis was made for the mediastinal lesion by aspiration cytology. Brain MRI showed a mass at the skull base, which was found to be a metastatic bone tumor from the mediastinal malignant hemangiopericytoma. Abdominal CT scan showed a massive tumor, 65 x 60 mm, in the right lobe of the liver. The liver tumor was diagnosed as hepatocellular carcinoma by biopsy. Combination chemotherapy, employing cyclophosphamide, vincristine, pirarubicin and dacarbazine (DYVADIC), in conjunction with radiation therapy, produced no response. The patient died 5 months after admission. Malignant hemangiopericytoma arising from the mediastinum is uncommon. Thus, the clinical features of our case, as well as those of previously reported cases in Japan, are discussed herein.

Direct contractile response of isolated gallbladder smooth muscle cells to cholecystokinin in patients with gallstones

To examine whether the contractile response of gallbladder smooth muscle cells to cholecystokinin is reduced in patients with gallstones, smooth muscle cells were isolated from the gallbladders of patients either with or without gallstones and their direct contractile responses to cholecystokinin-octapeptide (CCK-8) were examined at physiological concentrations. The basal cell lengths were similar in patients with cholesterol gallstones (43 +/- 1.2 micron (SEM)), in patients with black pigment stones (42 +/- 1.1), and in the gallstone-free group (42 +/- 1.3). The contractile responses to CCK-8 at physiological concentrations ranging from 10(-13) to 10(-11) M were significantly greater in the gallstone patients compared with those in the gallstone-free patients, while the responses were similar at 10(-10) and 10(-9) M. No difference in contractile response to CCK-8 was found between the patients with cholesterol gallstones and those with black pigment stones. The effective dose of 50% was 1.6 x 10(-13) M in cholesterol gallstone patients, 3.2 x 10(-14) M in black pigment stone patients, and 1.0 x 10(-12) M in gallstone-free patients. The current in vitro study showed that the contractile responses of isolated smooth muscle cells of the gallbladder to CCK-8 are not impaired in patients with gallstones.

[Effects of nilvadipine on membrane potential in cultured neuroblastoma-glioma hybrid NG108-15 cells]

Examination was made of the effects of nilvadipine on membrane potential in cultured neuroblastoma-glioma hybrid NG108-15 cells using the current clamp method. The NG108-15 cells line differentiates into neuronal cells following the addition of 1mM dibutyryl cAMP to the culture medium. This agent (nilvadipine) was found to inhibit both sodium and calcium current on the cell membranes of differentiated NG108-15 cells. The inhibitory effect was reversible in a dose-dependent manner between 10 and 100 microM. A substantial washing-time with normal saline, over 20 minutes, was needed for complete recovery from inhibition. The higher the concentration of nilvadipine, the more suppressive was the action on the membrane potential. A higher dose of nilvadipine, 100 microM, caused the disappearance of the peak membrane potential. This effect appeared irreversible, when cells were incubated in the presence of 100 microM nilvadipine for a longer time. Nilvadipine may thus exert inhibitory effect on the electrophysiological activity of neuronal cells, especially the calcium current of the membrane.

Intratumoral administration of tumor necrosis factor-alpha for malignant gliomas--two case reports

Two patients with histologically verified glioblastoma multiforme and anaplastic astrocytoma were treated with four courses of intratumoral administration of human natural tumor necrosis factor-alpha (TNF) (specific activity 2.0 x 10(6) Japan reference unit [JRU]/mg protein) at intervals of 3-5 months. Each consisted of eight to 10 serial injections, ranging from 5 x 10(3) to 10(4) JRU/injection, at intervals of 3-5 days. There was no simultaneous administration of steroids. Serial neurological examinations and neuroimaging studies with computed tomography and magnetic resonance imaging demonstrated partial responses ranging from 28 and 36 months in duration. No significant TNF-related brain edema, intracerebral bleeding, or neurotoxicity occurred. Local immunotherapy with TNF may be used safely to contribute to therapeutic efficacy.

[Mental health and its related factors among middle-aged male workers: an eighteen-month follow-up study]

Based on a longitudinal questionnaire survey of 11,121 subjects (males aged 30-59, engaged in various occupations and firms), this study examined the relationships of the baseline psychosocial work environment and personal health practices to mental disorders which occurred during an 18-month follow-up period. The onset of mental disorders during the follow-up period was assumed to be the time when the subject reported to have received medical treatment for the first time due to mental disorder. The psychosocial factors of the work environment were conceptually constructed from two aspects of working conditions and occupational stress. Working conditions were assessed by actual working hours, frequencies of late night work (10 p.m.-5 a.m.), and role in the organization. Occupational stress was measured by psychological work overload and job characteristics (job demands, decision latitude). Various factors associated with positive health behavior were examined through an index based on six variables, that is, supper time, exercise, smoking, alcohol consumption, sleep and weight. Multiple logistic analysis showed that both psychological work overload and late night work have a significant independent effect on the onset of mental disorders after controlling for other variables.

Mortality among inhabitants of an HTLV-I endemic area in Japan

A community-based cohort study was conducted to clarify the risk of human T-cell leukemia virus type I (HTLV-I) infection for cause-specific deaths. A total of 1,997 individuals (751 men and 1,246 women) aged 30 or older in A-Island, Nagasaki Prefecture, Japan who had voluntarily attended annual mass health examinations, including serum HTLV-I antibody test, were followed up for a mean period of 5.3 years. In a Cox proportional hazards analysis adjusted for age at baseline, the HTLV-I seropositivity was found to be associated with mortality from all causes in men (hazard ratio (HR) 1.89; 95% confidence interval (CI) 1.01-3.54) and women (HR 1.94; 95% CI 1.16-3.22). When the effects of 2 deaths (1 man and 1 woman) from adult T-cell leukemia/lymphoma (ATL) were excluded, the mortality risk decreased slightly but was still significantly or marginally significantly greater than 1 in both men (HR 1.77; 95% CI 0.93-3.37) and women (HR 1.87; 95% CI 1.12-3.12). Further analysis of cause-specific deaths revealed a significant increase in the risk for non-neoplastic diseases but not for neoplasms excluding ATL. These findings suggest that long-term HTLV-I infection represents a health hazard greater than just that for the development of ATL. It was difficult, however, to draw a conclusion regarding the association between HTLV-I infection and cancer risk, because the number of cancer deaths was small and the incidence of cancer was not investigated.

Intraoperative use of Doppler ultrasound and endoscopic monitoring in the stereotactic biopsy of malignant brain tumors. Technical note

An intraoperative monitoring tool is described that prevents mechanical injury to intracerebral vessels during stereotactic surgery. The method, which combines pulse Doppler ultrasonography and fiberendoscopy, allowed stereotactic biopsy to be performed without serious intracerebral bleeding in 25 patients with hypervascular malignant brain tumors, 13 with glioblastoma multiforme, five with anaplastic astrocytoma, five with metastatic tumor, and two with malignant lymphoma. The ultrasound apparatus has a built-in fast-Fourier transformation system analyzer and an improved filtering system that provide real-time measurement of blood flow velocity. The source of flow (arterial or venous) could be identified by both real-time sonography and acoustic signal frequencies. It was possible to measure the size and distance of a vessel by adjusting the Doppler signal gain dial from initially waxing to waning sounds, because the acoustic signal was adjusted to the axial flow of each vessel in 0.1-mm steps. Each of three Doppler probes (1 mm, 2 mm, and 3 mm in diameter) fit through the outer cannula of the biopsy needle. Vessels located within 7 mm from the tip of these probes could be detected easily and rapidly, so the biopsy needle could be advanced safely to the desired target in 7-mm steps. If sonograms revealed blood flow, indicating the presence of larger vessels in the intended stereotactic trajectory, the angle of the needle was changed slightly to avoid vascular injury. Because the fiberendoscope was connected to a video processor, the vessel could be visualized at a higher magnification on the video display, unless there was active bleeding. This technically simple and reliable system enhances operative safety while maintaining accuracy.

Nefiracetam enhances acetylcholine outflow from the frontal cortex: in vivo microdialysis study in the rat

The effects of nefiracetam [DM-9384; N-(2, 6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide], a cognitive enhancer, on extracellular acetylcholine and glutamic acid in the frontal cortex were studied using brain microdialysis in freely moving rats. Nefiracetam administration (1 mg/kg, p.o.) doubled the amount of acetylcholine in the dialysate. When tetrodotoxin was added to the perfusion solution, the basal level of acetylcholine decreased and nefiracetam caused no increase in acetylcholine outflow. The amount of glutamic acid in the dialysates was not affected by nefiracetam. These results suggest that nefiracetam increases the amount of acetylcholine within the cholinergic synaptic clefts.

Direct contractile effect of motilin on isolated smooth muscle cells from human gallbladder

To test the hypothesis that motilin receptors are present on smooth muscle cells of the human gallbladder, smooth muscle cells were isolated from the gallbladder and their direct contractile responses to motilin were examined. Motilin elicited a dose-dependent contraction of human gallbladder smooth muscle cells. Maximal contraction rate as defined by the percentage decrease in cell length was 23.7 +/- 0.7% at 10(-7) M for motilin and was similar to that for cholecystokinin octapeptide (CCK-OP) (24.2 +/- 1.5%) observed at 10(-10) M. The contractile sensitivity of gallbladder muscle cells to motilin (ED50 = 6 pM) was two orders of magnitude less than that to CCK-OP (ED50 = 0.07 pM). The motilin-induced contraction was inhibited in a dose-dependent manner by addition of 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride, an inhibitor of intracellular Ca2+ release. These results indicate that distinct motilin receptors are likely to be present on human gallbladder smooth muscle cells, as evidenced by their direct contractile responses, and suggest that Ca2+ release from intracellular calcium stores is important in the contractile response to motilin.

Sevoflurane anaesthesia for one-lung ventilation with PEEP to the dependent lung in sheep: effects on right ventricular function and oxygenation

This study was undertaken to examine the effect of sevoflurane on right ventricular function, the safety of sevoflurane for one-lung ventilation and the effects of PEEP (positive end-expiratory pressure) to the dependent lung in this model using 12 open-chest sheep. Haemodynamic variables, including cardiac output, mean arterial blood pressure, right ventricular pressure and pulmonary arterial pressure, and right ventricular segment shortening (sonomicrometry) were measured. First, animals received 2.0, 3.0 or 4.0% sevoflurane for 20 min each, respectively, during two-lung ventilation to measure the dose-dependent haemodynamic effects of sevoflurane. Then one-lung ventilation was performed with a randomized sequence of 0 (ZEEP), 5 and 10 cm H2O PEEP to the dependent lung under 2.0% sevoflurane anaesthesia after one-hour stabilization. A decrease in systolic segment shortening along with increases in both the end-diastolic and end-systolic lengths of the right ventricle were observed at 3.0 and 4.0% sevoflurane, while global right ventricular function remained substantially unchanged during two-lung ventilation. During one-lung ventilation the PaO2 was greater with 5 cm H2O PEEP 198 mmHg (+/- 25 SEM) than with ZEEP 138 mmHg (+/- 22) or with 10 cm H2O PEEP 153 mmHg (+/- 23) (P < 0.05). No differences in haemodynamic variables or segment shortening between ZEEP and PEEPs during one-lung ventilation were observed. We conclude that although sevoflurane causes a dose-dependent depression of right ventricular function, sevoflurane anaesthesia can be safely applied to one-lung ventilation, and that 5 cm H2O PEEP to the dependent lung can improve arterial oxygenation without causing changes in right ventricular function.

Dopamine D2 and serotonin S2 receptors in susceptibility to methamphetamine psychosis detected by positron emission tomography

Positron emission tomography (PET) was used to assess the role of dopamine D2 receptors in the striatum and serotonin S2 receptors in the frontal cortex in the susceptibility to methamphetamine-induced psychosis. Subjects were six men who had previously experienced methamphetamine psychosis (methamphetamine subjects) and 10 age- and sex-matched control subjects. The radiotracer used was 11C-N-methylspiperone. Although binding availability, assessed by dynamic analysis, in the two regions did not differ between the two groups, the ratio of binding availability in the striatum to that in the frontal cortex significantly decreased in the methamphetamine subjects as compared with the control subjects. These findings suggest that an imbalance in the activity of these two receptors may be related to the susceptibility to methamphetamine psychosis.

[Effect of enalaprilat, an angiotensin converting enzyme inhibitor, on the membrane potential of cultured neuroblastoma-glioma hybrid NG108-15 cells]

The effect of enalaprilat on the membrane potential of cultured neuroblastoma-glioma hybrid NG108-15 cells was investigated using the current clamp method. The NG108-15 cell line characteristically differentiates into neurons after addition of 1 mM dibutyryl cAMP to the culture medium. First it was found that enalaprilat inhibits both sodium and calcium currents in the cell membrane of differentiated NG108-15 cells. At concentrations between 10 and 100 microM, this inhibitory effect was reversible and transient, and occurred in a dose-dependent manner. Prolonged washing with normal saline (> 20 min) was needed to completely reverse the inhibitory effect of enalaprilat. The higher the concentration of enalaprilat, the greater its suppressant action on the membrane potential, and at high concentrations (100 microM), enalaprilat caused the peak membrane potential to disappear. When cells were incubated with enalaprilat, 100 microM, for longer periods, however, this inhibitory effect appeared to become irreversible. These findings suggest that enalaprilat has an inhibitory effect on the electrophysiological activity of neurons especially on membrane calcium currents.

[A case of cytomegalovirus pneumonia and Pneumocystis carinii pneumonia with lung cancer--diagnosis by the polymerase chain reaction]

A 64-year-old male was admitted to Oita Medical University Hospital because of primary lung cancer. After the anticancer chemotherapy, the patient developed a high fever. His chest X-ray showed diffuse reticular shadows bilaterally, which were considered to be a drug induced pneumonia, then pulse therapy with corticosteroid was performed. With this treatment, the diffuse reticular shadows disappeared. One month later, however, a severe interstitial pneumonia developed, and the patient died of respiratory failure. Autopsy findings demonstrated cytomegalovirus (CMV) and Pneumocystis carinni pneumonia. The polymerase chain reaction (PCR) for CMV in mononuclear cells in the blood was positive through out his hospitalization. In the sera, however, it was negative at the time of admission, then became positive 10 days before the onset of pneumonia. In addition, the PCR for P. carinni on the swab became positive as well. These results imply that PCR can be used for diagnosis of CMV and P. carinii infections from sera or swabs.

Chemotherapeutic effects of intra-arterial administration of ACNU in primary intracerebral non-Hodgkin's lymphoma

The authors report five patients with primary intracerebral non-Hodgkin's lymphoma who were treated with several cycles of intra-arterial injection of 1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) at doses of 80 to 100 mg/m2/injection at several monthly intervals. There was no simultaneous use of steroids, and no patients had concomitant immunosuppression; no patient was human immunodeficiency virus positive. This therapy was initially used in four patients with advanced recurrent lymphoma. These patients experienced tumor progression despite our institutional standard therapy comprising cranial irradiation followed by repeated courses of systemic multi-agent chemotherapy (cyclophosphamide, vincristine, adriamycin, and prednisolone) more than 3 months previously. Based upon brain computed tomography scans and clinical neurologic examinations, three of the four cases showed partial responses ranging from 10 to 12 months in duration, whereas the other patient remained stable without worsening for 8 months. A fifth case was particularly noteworthy; this patient had no prior therapy and intra-arterial chemotherapy alone induced an 18-month, disease-free remission. No significant therapy-related complications nor neurotoxicity were seen. These results suggest that intra-arterial administration of ACNU may be a potential candidate for intracerebral lymphoma therapy.

[Empty sella syndrome]

An empty sella is defined as a sella which, regardless of its size, is completely or partly filled with cerebrospinal fluid (CSF). Empty sella is occasionally found as a normal anatomical variation, which is referred to as primary empty sella. On the other hand, empty sella is also seen after surgery, irradiation or medical treatment of pituitary adenoma, which is called secondary empty sella. Magnetic resonance imaging (MRI) is useful in diagnosing empty sella. Primary empty sella is usually free from clinical symptoms but sometimes associated with headache, obesity, visual disturbance, non-traumatic CSF rhinorrhea and pituitary insufficiency. These associated findings constitute the empty sella syndrome. CSF rhinorrhea, visual disturbance and severe increased intracranial pressure are the indications for surgical treatment. Non-symptomatic cases require no treatment but periodical follow up is necessary.

[Disseminated Trichosporon beigelii infection: report of nine cases and review]

Trichosporon beigelii (formerly called Trichosporon cutaneum) is an emerging pathogen of disseminated trichosporonosis in immunocompromised patients. We conducted postmortem microbiological examinations of lung aspirates and blood in the heart. T. beigelii was isolated from the samples of 7 (2.24%) of 313 patients. Five of 7 patients isolated were diagnosed as having trichosporonosis based on histochemical and clinical findings. The other two were considered as colonization. Immunohistochemical study using Cryptococcus neoformans-absorbed antiserum to T. beigelii was carried out on the sections of autopsied tissues with deep mycoses. The sections from seven patients were positively stained, which were formerly diagnosed as candidiasis and/or aspergillosis. Consequently, 9 patients had disseminated trichosporonosis caused by T. beigelii. In Japan, 43 patients including the present 9, 31 males and 12 females, aged 51 (range, 2-84), were reported in the literature. Thirty-seven (86%) patients had hematologic malignancy, and the majority of them revealed profound neutropenia due to cytotoxic chemotherapy. Thirty-eight (88%) patients died despite the anti-fungal chemotherapy including amphotericin B. New strategies for refractory disseminated trichosporonosis in immunocompromised patients is needed.

Inhibition of dexamethasone-induced cytochrome P450-mediated mutagenicity and metabolism of aflatoxin B1 by Chinese medicinal herbs

Oldenlandia diffusa (OD) and Scutellaria barbata (SB) have been used in traditional Chinese medicine for treating liver, lung and rectal tumours. We previously showed that they inhibited mutagenesis, DNA binding and metabolism of aflatoxin B1 (AFB1) and benzo(a)pyrene (BaP) bioactivated by Aroclor 1254-induced rat S9. The purpose of this study was to investigate the effects of OD and SB on the mutagenicity of AFB1 in Salmonella typhimurium TA100 using dexamethasone (DXM)-induced rat hepatic S9, on cytochrome P450-linked aminopyrine N-demethylase (APND) activity in DXM-induced hepatic microsomes and on the metabolism of AFB1 by DXM-induced S9 using high-performance liquid chromatography (HPLC). The experimental results showed that OD and SB consistently inhibited the mutagenicity of AFB1 bioactivated by either non-induced or DXM-induced S9. These effects correlated with the inhibition of cytochrome P450-linked APND activity in DXM-induced microsomes and with an inhibition of DXM-induced S9 mediated metabolism of [3H]AFB1 as determined by HPLC. Since DXM treatment has been associated with an induction of the CYP3 enzyme family, these results suggest that OD and SB may possess antimutagenic and antitumorigenic activity towards AFB1 through an inhibition of CYP3-mediated metabolism of AFB1.