Prediction of substances of weak toxicity from chemical structures. An epidemiological approach

A global structure set of acute toxicity (LD50, mouse, i.v.) was constructed from databases. The common structural features of low toxicity substances were obtained from 1495 structure-toxicity data by applying the substructural balance method (SBM). This set contained 111 low toxicity (> ca. 1000 mg/kg) and 817 high toxicity substances (< ca. 30 mg/kg). The result was expressed by a control chart which is made to control the structural causes to obtain the desired effect (low toxicity). Within the control limits, 100% of low toxic and 20% of high toxic substances were found. The control chart was tested with another set of 81 structures of low toxicity selected among 718 structures retrieved from RTECS. Seventy-eight structures were found within the control limits and the predictability was 96.3% (78/81). SBM employs a new paradigm of descriptors, the ratios of numbers of substructures, which were selected through a descriptor-screening process. The results confirm that the new paradigm is applicable for structure-based toxicity prediction. This "epidemiological" approach suggests key structural criteria where no reliable mechanism of toxicity is available and serves to reduce the search space of organic structures. A theory supporting SBM was discussed.

Elucidation of adsorption mechanism of bone-staining agent alizarin red S on hydroxyapatite by FT-IR microspectroscopy

To elucidate adsorption mechanism of alizarin red S (ARS), which is often used for staining bones in histology, adsorption of ARS on hydroxyapatite, Ca10(PO4)6(OH)2 (HAP), was investigated by a batch method, compared with alizarin, phenols, and benzenesulfonates. We found that ionized 1-, 2-OH groups (1-, 2-O(-)) of ARS can be electrostatically bound to Ca2+ on HAP, but that the 3-SO3(-) group of ARS hardly participates in adsorption on HAP. ARS-adsorbed HAP (ARS-HAP) in dark reddish violet was also prepared and analyzed by FT-IR microspectroscopy to gain structural information on bonding between ARS and HAP. The obtained spectrum, which was converted to difference spectra, indicated a single band of nu(C=O) at 1627 cm(-1) and two types of symmetric C=O stretching bands of nu(s)(C=O) + nu(C=C) at 1345 cm(-1) and nu(s)(C=O) + delta(O-C=C) at 1272 cm(-1). These bands imply the existence of a salt form in ARS-HAP via 1-, 2-OH groups of ARS. As a result of the existence of a chelate form in ARS-HAP via 1-OH and 9-C=O groups of ARS, two bands of nu(C=C) + nu(C=O) at 1572 cm(-1) and nu(C=O) + nu(C=C) at 1537 cm(-1) were also observed. In addition, ARS was almost desorbed from colored ARS-HAP at 50 degrees C by using neutral phosphate buffer to recover slightly pale pinkish HAP, or De-ARS-HAP. The desorbed ARS belongs to ARS previously adsorbed on HAP by salt formation, while the remaining color on De-ARS-HAP indicates ARS still adsorbed on HAP by chelate formation. Consequently, we elucidated two adsorption mechanisms of ARS on HAP: The major adsorption is salt formation made up with 1-, 2-O(-) of ARS and Ca2+ on HAP, and the minor adsorption is chelate formation made up with 1-O(-) and 9-C=O of ARS and Ca2+ on HAP.

Sisters with atypical Fabry's disease with complete atrioventricular block

A 56 year old woman with severe right heart failure and complete atrioventricular block was referred to hospital for further examination. Symptoms and signs suggestive of Fabry's disease, such as corneal opacities, acroparaesthesias, hypohidrosis, and angiokeratoma, were not noted. Echocardiography showed a diffuse hypertrophic left ventricular wall and paradoxical movement of the interventricular septum. Cardiac catheterisation showed restrictive-type ventricular dysfunction. Left ventricular endomyocardial biopsy showed central vacuolar degeneration of myocytes with inclusion bodies, which had a concentric lamellar configuration under electron microscopy. This finding is specific for Fabry's disease. The patient's elder sister had experienced an almost identical clinical course and histological findings of myocardial cells on necropsy. In conclusion, two sisters were encountered displaying interesting cases of atypical Fabry's disease. Symptoms began with complete atrioventricular block and histological myocardial findings were specific for Fabry's disease.

The effects of body mass index on age at menopause

OBJECTIVE

We examined which of body mass index (BMI, kg/m(2)), serum cholesterol (mg/dl), or systolic blood pressure (SBP, mm Hg) affected age at natural menopause.

DESIGN

A population-based follow-up program.

METHODS

We determined the age at natural menopause in 1136 women followed biennially since their first examination in 1958-1959 through the 16th examination in 1988-1989. Four-hundred and ninety-three naturally menopausal women were classified into three groups by BMI, serum cholesterol and SBP measurement levels at age 40 or 41 y: the upper 25%, middle 50%, and lower 25%. We then studied whether there was a difference in age at menopause among the three groups thus classified. The 1136 natural menopausal women were also classified as early (n=454; 45-49 y at menopause (48.3+/-1.2 y)) or late (n=682; >or=50 y at menopause (52.3+/-1.6 y)) menopausal and compared for premenopausal trends in BMI, serum cholesterol and SBP in the early and late menopausal women by means of a longitudinal data analysis model.

RESULTS

When women were classified into the three groups based on a BMI that was measured at 40 or 41 y, age at menopause in the upper 25% (50.4+/-2.8 y) was significantly higher (P<0.05) than that in the lower 25% (49.7+/-2.8 y). The entire premenopausal trend in BMI in late menopausal women shifted upward compared to that in early menopausal women. On the other hand, the premenopausal trend more than 4 y before menopause in serum cholesterol and the entire premenopausal trend in SBP in late menopausal women were identical to those in early menopausal women.

CONCLUSION

Among the variables studied, only BMI is related to age at menopause, and the greater the BMI, the later the age at menopause.

Giant basal cell carcinoma affecting the lower abdominal, genital and bilateral inguinal regions

We describe a giant basal cell carcinoma, measuring 40 cm x 20 cm, of the lower abdominal, genital and bilateral inguinal regions. The rectus abdominis muscle and the adductor magnus muscle were exposed centrally, and the penis and scrotum were completely destroyed. Reconstruction was performed with a fillet thigh flap, and an excellent result was obtained 1 year after surgery.

[Synchronous tumors consisted of bronchial carcinoid and adenocarcinoma of the lung]

We report a case of synchronous tumors consisted of bronchial carcinoid and adenocarcinoma of the lung. A 58-year-old female was referred to our hospital after screening, because an abnormal shadow was noted in the right lung on her computed tomography (CT) of the chest. CT scans showed a peripheral pulmonary mass in the right middle lobe and a nodule around the right lower lobe bronchus. The nodular lesion like swollen lymph node was diagnosed as bronchial carcinoid originated in B6 by bronchoscopy. The pulmonary mass was diagnosed as adenocarcinoma by using core needle biopsy during operation. Right middle and lower bilobectomy and mediastinal lymph node dissection were performed. Coincidence of a bronchial carcinoid and an adenocarcinoma of the same side of the lung is a rare occurrence.

Changes in osteoprotegerin and markers of bone metabolism during glucocorticoid treatment in patients with chronic glomerulonephritis

It is well known that long-term glucocorticoid treatment causes osteoporosis, but the precise mechanism remains unclear. Recently, osteoprotegerin (OPG) has been identified as a cytokine that inhibits osteoclast differentiation. We have previously demonstrated that serum OPG is suppressed by glucocorticoids. Therefore, the present study was carried out to clarify the interrelationships between OPG and other markers of bone metabolism during glucocorticoid treatment. Thirteen patients (7 men, 6 women; 44.1 +/- 5.9 years old) with chronic glomerulonephritis who were to be treated with glucocorticoids for the first time were chosen for this study. Markers of bone metabolism, including serum OPG, osteocalcin (OC), bone-specific alkaline phosphatase activity (bAP), parathyroid hormone (PTH), tartrate-resistant acid phosphatase (TRAP), and bone mineral density (BMD), were measured before and during the treatment period. Glucocorticoids significantly reduced BMD of the lumbar spine in the 6 month treatment period (p < 0.01). Serum OPG was decreased significantly by glucocorticoids within 2 weeks (p < 0.001), and serum TRAP, a marker of bone resorption, was markedly increased (p < 0.001). On the other hand, there were no remarkable changes in serum PTH. Serum OC and bAP, markers of bone formation, were transiently reduced during the treatment period (p < 0.01). Furthermore, only serum OPG was positively and independently correlated with percentage BMD of age-matched reference (%AMR). These findings imply that glucocorticoid-induced bone loss develops rapidly via enhanced bone resorption and suppressed bone formation. Moreover, the increased bone resorption caused by glucocorticoids may be, at least in part, mediated by inhibition of OPG, not increment of PTH.

[Perioperative management of a patient with purpura fulminans syndrome due to protein C deficiency]

PURPOSE

Protein C is a vitamin K-dependent anticoagulant and homozygous protein C deficiency is a rare fatal thrombotic disease. This report describes the perioperative management of homozygous protein C deficiency in a patient who underwent a total of three surgical procedures under general anesthesia and the successful use of activated protein C concentrate.

CLINICAL FEATURES

A female baby, who developed disseminated intravascular coagulation and purpura fulminans shortly after birth, was diagnosed as purpura fulminans syndrome due to homozygous protein C deficiency. At one month of age, she suffered bilateral retinal detachment and glaucoma due to retinal hemorrhage. After marked improvement of her condition after administration of activated protein C concentrate, she underwent a left iridectomy and implantation of a Broviak catheter under general anesthesia. Her intraoperative course was uncomplicated but, on postoperative day four, she presented another episode of massive cutaneous necrosis and gangrene. Activated protein C concentrate was administered again, with good results. She underwent replacement of a Broviak catheter at four months of age, and right iridectomy for glaucoma at eight months. Both were uneventful.

CONCLUSION

The perioperative management of homozygous protein C deficiency and purpura fulminans requires appropriate measures for thromboembolic prophylaxis. Sufficient iv fluid administration is necessary. Attention should be paid to decrease the risk of tissue compression such as that associated with positioning, blood pressure cuff, and endotracheal intubation, which may cause necrosis over pressure points. Replacement therapy with activated protein C concentrate appears safe and effective. The anesthetic management is reviewed and discussed.

Effects of the quantity of water and milk ingested concomitantly with AS-924, a novel ester-type cephem antibiotic, on its pharmacokinetics

The effect of the quantity of water ingested concomitantly with drugs, on the absorption of AS-924, a novel prodrug-type cephem antibiotic, was studied in five healthy adult volunteers by a cross-over method, using cefteram-pivoxil (CTER-PI) as the control drug. In addition, the effect of milk on the absorption of AS-924 was also investigated. The absorption of CTER-PI was significantly reduced when administered together with 30 ml of water compared with its absorption when administered together with 150 ml of water, whereas no such reduction was found in the case of AS-924. Ingestion of milk did not significantly affect the absorption of AS-924. These results confirm that absorption of AS-924 after oral administration is not likely to be affected by the quantity of water taken concomitantly with the drug, nor by milk.

Effects of gastrointestinal stimulant and suppressant pretreatment on the pharmacokinetics of AS-924, a novel ester-type cephem antibiotic

The effects of pretreatment with the gastrointestinal stimulant domperidone and the suppressant scopolamine butylbromide on the absorption of AS-924, a novel prodrug-type cephem antibiotic, were investigated in six healthy adult male volunteers by a cross-over method. The T(max) of ceftizoxime (CTIZ), the active moiety of AS-924, was slightly prolonged by scopolamine butylbromide (T(max)=1.8 vs. 1.5 h for the group without pretreatment). However, there were no significant differences in pharmacokinetic parameters including T(max), cumulative urinary excretion rates of CTIZ and cumulative urinary excretion rates of pivaloylcarnitine for 12 h after the dosing between the pretreated and control groups. Domperidone did not affect the absorption of AS-924.

The right ventricular outflow tract as an unusual location for an implantable defibrillator electrode in a patient with arrhythmogenic right ventricular dysplasia

A 41-year-old woman with arrhythmogenic right ventricular dysplasia (ARVD) underwent the implantation of an implantable cardioverter-defibrillator (ICD), in which the defibrillator electrode was unusually located in the right ventricular (RV) outflow tract. Although fractionated electrograms were demonstrated in the RV apex, which is the usual site for ICD electrodes, normal electrograms were recorded in the RV outflow tract during an electrophysiologic study. An electrode with a screw-in tip was used to fix the implant in the RV outflow tract and obtain successful defibrillation. If normal electrograms are recorded in the RV outflow tract, the site may prove to be an alternative location for an ICD electrode even for ARVD patients.

Comparative results of coronary intervention in patients with variant angina versus those with non-variant angina

Coronary angioplasty is reported to be feasible and safe in patients with coronary spasm and fixed stenosis. However, the long-term results are not positive. We compared the results of coronary angioplasty in 20 patients with variant angina versus 17 patients with non-variant angina among 231 consecutive patients with vasospastic angina. Coronary angioplasty was performed successfully in all 37 patients without any complications. Stenting for coronary dissection or recoil was performed in 8 patients, directional coronary atherectomy was selected for ostial lesion of left anterior descending coronary artery stenosis in 2 patients, and standard balloon angioplasty was performed in 27 patients. There were no clinical differences between the two groups. The restensois rate in patients with variant angina was similar to that in patients with non-variant angina (30% vs 29%, ns). There was no relationship between the provoked spasm and restenosis. During the follow-up period, no major complications were observed in patients with variant angina or those with non-variant angina. In conclusion, full medication with calcium channel antagonists and isosorbide dinitrate, and treatment by coronary angioplasty including the use of new devices, were useful treatments for patients with coronary vasospasm and significant organic stenosis. There was no difference concerning the results of coronary intervention between the patients with variant angina and those with non-variant angina.

Immunological study on circulating murine osteoprotegerin/osteoclastogenesis inhibitory factor (OPG/OCIF): possible role of OPG/OCIF in the prevention of osteoporosis in pregnancy

Osteoprotegerin (OPG)/osteoclastogenesis inhibitory factor (OCIF) is a soluble member of the tumor necrosis factor receptor family and plays a crucial role in the negative regulation of osteoclastic bone resorption. We have immunized OPG/OCIF knockout mice with murine rOPG/rOCIF and established a panel of hybridomas producing monoclonal antibodies (mAbs) to murine rOPG/rOCIF. Utilizing the mAbs, we developed enzyme-linked immunosorbent assay (ELISA) systems: one detecting both homodimeric and monomeric forms of murine OPG/OCIF and the other detecting only dimeric form of murine OPG/OCIF. With the aid of these ELISA systems we showed that OPG/OCIF is present mainly as a monomer in murine blood. The concentration of OPG/OCIF in normal mouse sera was approximately 500 pg/ml and there was no statistical difference in the serum concentration of OPG/OCIF among genders, age, and strains. Interestingly, the concentration of circulating OPG/OCIF in mouse markedly increased during pregnancy. The result indicated that circulating OPG/OCIF plays an important role in the protection of bone from excess resorption during pregnancy in mammals.

Initial fermentation of sea sludge using aerobic and thermophilic microorganisms in a mangrove soil

As sea sludge has the potential to cause eutrophication and red tide resulting in the death of shellfish and offensive odors, an effective method to treat it is needed. It was found that adding soil taken from a mangrove swamp to sea sludge promoted an initial fermentation of the sludge constituents. The result suggested that certain microorganisms that were thought to inhabit the sub-tropical mangrove soil had the potential to play a significant role in the fermentation and that the use of the microorganisms in the mangrove soil might be useful for composting sea sludge.

Ankle-brachial blood pressure in elderly men and the risk of stroke: the Honolulu Heart Program

Although low ankle/brachial blood pressure index (ABI) is a marker of generalized atherosclerosis in the elderly, it has not been identified as a risk factor for stroke. The purpose of this report is to examine the relation between ABI and stroke in elderly men. ABI was measured from 1991 to 1993 in 2767 men aged 71 to 93 years in the Honolulu Heart Program without a history of stroke and coronary heart disease. Subjects were followed for 3 to 6 years for fatal and nonfatal thromboembolic and hemorrhagic stroke. During follow-up, there were 91 strokes. There was an age-adjusted 2-fold excess in men with an ABI < 0.9 (6.0%) versus men with an ABI > or = 0.9 (2.9%, P < 0.01). Thromboembolic events occurred in 4.6% of men with an ABI < 0.9 and in 2.0% in those with an ABI > or = 0.9 (P < 0.01). Hemorrhagic stroke was also more frequent in men with a low ABI (< 0.9) versus a higher ABI (1.9 vs. 0.8%, respectively). After adjusting for other factors, the risk of total and thromboembolic strokes increased with declining ABI (P = 0.019 and P = 0.004, respectively). The relation between ABI and stroke was similar and statistically significant in the presence and absence of diabetes and hypertension (P < 0.05). Findings suggest that ABI is inversely related to the incidence of stroke. Simple measurement of ABI in an outpatient setting could be an important tool for assessing the risk of stroke in the elderly.

The prevalence, incidence and prognostic value of the Brugada-type electrocardiogram: a population-based study of four decades

OBJECTIVES

We sought to demonstrate the prevalence, incidence and prognostic value of the Brugada-type electrocardiogram (ECG) in a general population.

BACKGROUND

The Brugada syndrome is characterized by evidence of right bundle branch block and ST segment elevation in the right precordial leads, as well as sudden death caused by ventricular fibrillation. However, the natural history of the Brugada-type ECG remains unclear.

METHODS

We investigated 4,788 subjects (1,956 men and 2,832 women) who were <50 years old in 1958 and had undergone biennial health examinations, including electrocardiography, through 1999. The Brugada-type ECG was defined as a terminal r' wave in lead V(1) and ST segment elevation > or =0.1 mV in leads V(1) and V(2). Unexpected death was defined as sudden death or unexplained accidental death.

RESULTS

There were a total of 32 Brugada-type ECG cases; the prevalence and incidence were 146.2 in 100,000 persons and 14.2 persons per 100,000 person-years, respectively. The incidence was nine times higher among men than women, and the average age at presentation was 45 +/- 10.5 years. The Brugada-type ECG appeared intermittently in most cases and was found in 26% of subjects who died unexpectedly. Cox survival analysis revealed that mortality from unexpected death was significantly higher in subjects with a Brugada-type ECG than in control subjects (p < 0.01). Unexpected deaths were more frequent among subjects with the Brugada-type ECG who had a history of syncope (p < 0.05).

CONCLUSIONS

The Brugada-type ECG is not a very rare condition in the adult Japanese population. Subjects with a Brugada-type ECG have an increased risk of unexpected death.

Isolation of a bacterium from mangrove soil for degradation of sea sludge

Sea sludge, which is sediment of fish excrement and sewage on the sea bottom, continues to be a serious environmental problem. It has the potential to cause eutrophication and red tide, resulting in the death of shellfish and leading to an offensive odor. Soil taken from a mangrove swamp was added to sea sludge, which promoted an initial fermentation of the sludge components. This article reports on the isolation of a bacterium from mangrove soil that is involved in that fermentation. Three bacteria were isolated on a marine agar plate after incubating for 12 h at 60 degrees C. One of these bacteria fermented sea sludge. 16S rDNA of this bacterium was sequenced, and it had a high homology with that of Bacillus fumarioli LMG17489 (AJ250056).

Glucagon-like peptide isolated from the eel intestine: effects on atrial beating

A new glucagon-like peptide was isolated from the intestine of the eel Anguilla japonica. The primary structure was determined by sequence analysis after cleavage with lysyl endopeptidase, quantitative amino acid analysis and fast atom bombardment mass spectrometry as HSQGTFTNDY10SKYLETRRAQ20DFVQWLMNSK30RSGGPT. Since its structure is similar to that of oxyntomodulins (OXMs) reported in various vertebrates, we named this peptide eel oxyntomodulin (eOXM). We found that eOXM enhanced the contractile force and the beating rate of the eel atrium in a dose-dependent manner. These effects of eOXM were not inhibited by betaxolol, a β1-adrenoceptor antagonist, indicating that the actions of eOXM were independent of those of adrenaline. eOXM enhanced the intracellular Ca2+ concentration of the myocardium. The contractility of the eel atrium was greatly reduced after omitting Ca2+ from the bathing medium or after treatment with verapamil, a Ca2+ channel blocker. After inhibiting Ca2+ entry under these conditions, the inotropic effect of eOXM was markedly reduced, but the chronotropic effect was not altered significantly. These results indicate that the inotropic effect of eOXM is via a stimulation of Ca2+ influx but that the chronotropic effect may be independent of extracellular Ca2+.