Electrophysiological characterization of RACTK1 K+ channel in stable cell line

RACTK1 is a pH-sensitive K+ channel cloned from rabbit renal collecting tubule cells. To characterize the function of this K+ channel in more detail, RACTK1 was transfected to an established cell line and the patch-clamp study was performed. cDNA of RACTK1 was inserted in the pMAM vector and transfected to Chinese hamster ovary cells. In one of 36 cell lines, the channel protein as expressed by the dexamethasone-induced mRNA and was detected by the specific antibody. The RACTK1 K+ channel with 80 pS was consistently observed. In inside-out patch, Ca2+ at concentrations higher than 500 nM activated the channel. Open probability was decreased by protein kinase A (from 45 to 4.2%, n+6) but not by protein kinase C. Whole cell currents of the transformed cells represented K+ conductance that was not blocked by an addition of charybdotoxin but by apamin. RACTK1 K+ channel has similar, though not identical, characteristics to the Ca2+ -activated K+ channel. RACTK1 might therefore encode a subunit of the intermediate conductance Ca2+ -activated K+ channel observed in the apical membrane of the rabbit renal collecting duct.

[Mononeuritis multiplex associated with measles virus infection]

We describe a 19-year-old patient who developed mononeuritis multiplex associated with measles virus infection. On April 30th, 1995, he suffered from fever and skin eruption, which disappeared ten days later. Thirteen days later, he noticed weakness of the fingers of both hands and forearms, and pain on both elbow joints. He was admitted to our hospital on June 12th, 1995. Neurologic examination revealed weakness and sensory disturbance, confined to the distal aspects of the right radial nerve and left median nerve. The electrodiagnostic findings confirmed those of axonal neuropathy in the right radial and left median nerves. Routine laboratory studies were normal. The cerebrospinal fluid test and EEG were normal. The IgG and IgM antibody titers against measles virus continued to be elevated in serum over four months after the onset, while they were not elevated in the cerebrospinal fluid. The corticosteroid therapy was mildly effective. Although the pathogenesis of this case is unclear, we speculate that the mononeuritis multiplex was caused by vasculitis related to the persistent measles virus infection in both elbow areas.

Cyclosporine-related encephalopathy following allogeneic bone marrow transplantation

A 46-year-old man with chronic myelogenous leukemia received allogeneic bone marrow transplantation (BMT) from a partially human leukocyte antigen (HLA)-mismatched sibling. Cyclosporine (CYA)-related encephalopathy developed on days 10 and 21 following BMT, and CYA-related thrombotic thrombocytopenic purpura (TTP) developed on day 45 following BMT. We measured serum concentrations of thrombomodulin (TM) as a marker of endothelial injury. The concentrations of TM were increased during the encephalopathy or TTP and decreased following recovery. Since CYA can cause endothelial injury, we suggest that CYA-induced endothelial injury is common to the pathogenesis of both the encephalopathy and the TTP. CYA therapy should be reinstituted with extreme caution in patients with a past history of CYA-related encephalopathy, since readministration of a low-dose CYA can evoke the immediate return of the encephalopathy.

Studies on fatigue of night duty workers at a newspaper office

Fatigue of night duty workers in different divisions of a newspaper office was investigated by physiological methods such as the Blinker, Flicker and grip methods. The relationship between fatigue and hematological parameters such as hemoglobin (Hb), the hematocrit (Ht), serum-free amino acid levels, and indices of liver function such as the GOT and GPT levels were also examined. The composing and press room workers mainly complained of the subjective symptom of muscle fatigue, while workers in the photo-engraving and editorial departments mainly complained of mental fatigue. The overall rate of fatigue in the newspaper office was about 38.1%, but varied from one division to another, being especially high in the photo-engraving and editorial departments. The subjects with fatigue had low levels of serum GOT and GPT and high levels of serum-gluconeogenic amino acids, such as aspartic acid, glutamic acid, prolin, glycine, and alanine. These altered levels of serum-free amino acids and GOT and GPT seemed to be due to increased secretion of adrenal corticoid hormone caused by the stress of fatigue.

Reassessment of second look operation for epithelial ovarian cancer

We retrospectively reviewed 91 patients with epithelial ovarian cancer who underwent second-look operation (SLO). SLO identified a persistent tumor in 18 (19.8%) of 91 patients. Of these 18 patients, 13 (72.2%) showed disease progression after SLO. Patients with a positive SLO in which the identification of the persistent disease was only possible by washing cytological study showed better prognosis than patients with macroscopic lesions. Of the 73 patients with a negative SLO, 12 (16.4%) developed recurrence after cessation of treatment. These 12 patients were from stage 1c to 3 with Grade 2 and 3 tumors. The SLO findings were more sensitive than the serum tumor marker in identifying persistent disease. Also we reviewed 55 patients having no SLO. Among 57 cases in stage 1 and 2 with Grade 1 tumor, there were no cases of recurrence, regardless of whether they had SLO or not. Our results suggest that SLO findings correlate well with the patient's prognosis. SLO may not be needed for patients in stage 1 and 2 with Grade 1 tumor. Patients with advanced stage disease with Grade 2 and 3 tumors have high-risk for recurrence after negative SLO. While SLO is still of benefit in management of ovarian cancer, refinements are needed to determine its indication and scheduling.

Specific deficit of the ON response in visual transmission by targeted disruption of the mGluR6 gene

Taking advantage of the restricted expression of metabotropic glutamate receptor subtype 6 (mGluR6) in retinal ON bipolar cells, we generated knockout mice lacking mGluR6 expression. The homozygous mutant mice showed a loss of ON responses but unchanged OFF responses to light. The mutant mice displayed no obvious changes in retinal cell organization nor in the projection of optic fibers to the brain. Furthermore, the mGluR6-deficient mice showed visual behavioral responses to light stimulation as examined by shuttle box avoidance behavior experiments using light exposure as a conditioned stimulus. The results demonstrate that mGluR6 is essential in synaptic transmission to the ON bipolar cell and that the OFF response provides an important means for transmitting visual information.

Epidemiological studies on regional differences in suicide mortality and its correlation with socioeconomic factors

To investigate regional differences in suicide mortality and its correlation with socioeconomic factors during the 1975-1990 period, we analyzed annual change in suicide mortality and 18 socioeconomic indicators among each prefectures in Japan. Annual course of age-adjusted mortality from suicide during the 1975-1985 period differed between males (increasing) and females (decreasing), because of rapidly increase in suicide mortality for middle-aged males. During the 1986-1990 period, suicide mortality decreased in both males and females. A census characteristic that suicide mortality was higher in rural districts than in urban districts intensified annually until 1985 and weakened thereafter. The factor analysis of socioeconomic indicators revealed that 1st factor was recognized as the industrial and economic activity. A high inverse correlation was observed between age-adjusted mortality from suicide and the 1st factor for males and females. In males this tendency continued until the end of the 1980s. On the whole, correlation coefficients between age-adjusted mortality from suicide and the socioeconomic indicators in males were much higher than that in females. The indicators whose annual change differed remarkably between the prefectures with an increase and a decrease in suicide mortality for males were amount of savings and frequency of bankruptcy. Therefore they were considered to be closely related to suicide mortality.

Characterization of region Ic in site I on human serum albumin. Microenvironmental analysis using fluorescence spectroscopy

Characteristics of region Ic among at least three overlapping binding regions (regions Ia, Ib and Ic) in site I on human serum albumin (HSA) were analysed using n-alkyl p-aminobenzoates (n-alkyl p-ABEs), all of which are specific fluorescent probes for region Ic. In the interaction processes between n-alkyl p-ABEs and HSA, hydrophobic interaction, van der Waals interaction and local structural changes in region Ic were found to be involved based on the results obtained by analyses of the fluorescence spectra, structure-activity relationships and thermodynamic parameters. In addition, comparison of the fluorescence spectra of n-alkyl p-ABEs in HSA and detergents indicated that the possibility of a hydrophobic region Ic around which an amino acid with cationic charge locates could not be denied because of the similarity of fluorescence spectra between n-alkyl p-ABEs in HSA and in neutral and cationic detergents. The deviation of n-alkyl p-ABEs with long alkyl chains (C9-C12) in the relationships between association constants and physicochemical properties of a series of n-alkyl p-ABEs (C1-C12) suggested that region Ic possess an optimal depth. A conformational change of HSA with increasing pH (pH 6-9) generated an increase in hydrophobicity and adaptability of the binding region and made interaction easy, with an increase in adaptability of the binding region Ic; consequently, it enhanced the binding of n-alkyl p-ABEs to HSA.

Epidemiological study on relationship between breast cancer mortality and dietary factors

To elucidate the effects of nutritional factors on regional differences in breast cancer mortality in Japan, the statistical analysis was made using the results of the national nutrition surveys in 12 districts from 1966 to 1980 and age-adjusted mortality from breast cancer from 1966 to 1990. The correlation analysis between food or nutrient intake and breast cancer mortality was performed with a fixed time lag of 10 years. Dietary factors such as wheat, milk, meats, animal fat, animal protein, total fat, saturated fatty acid (SF) and monounsaturated fatty acid (MUF) were correlated highly positively with breast cancer mortality. The correlation analysis between increase rates in age-adjusted mortality from breast cancer and increase rates in food or nutrient intake was also examined. Highly positive correlations were obtained between breast cancer mortality and following dietary factors; oils and fats, fruits, milk, total fat, vegetable fat, SF, MUF and n-6 polyunsaturated fatty acid. Factor analysis using fat intake by 12 districts revealed the factor representing the intake of fat component resulting from ingestion of animal fat. This factor showed a positive correlation with age-adjusted mortality from breast cancer. The findings suggested that the dietary factors due to intake of Westernized meals, especially SF had the effect on breast cancer mortality in Japan.

Relationship between physical exercise and health of the elderly people in a rural community

The significance of life style and regular physical exercise for health of elderly people in a rural community was evaluated by questionnaires. The subjects studied were a group who had been playing gate ball (such as croquet) for more than three years (N = 86) and a group who had not (N = 255). Significantly more males in the group playing gate ball (GB group) than in the group not playing gate ball (n-GB group) reported feeling healthier than three years before. The average overall score for life style which indicates a healthier life style was analyzed. The score for life style of males was significantly lower in the GB group than in the n-GB group. Significantly more males in the GB group did not take snacks or smoke than those in the n-GB group. Regarding regular physical exercise, significantly fewer females in the GB group went for a daily walk than those in the n-GB group. The average score for integrated regular physical exercise was significantly higher in the GB group than in the n-GB group. The scores for regular physical exercise of females in the GB group, even in spite of disability or hypertension, were significantly higher than those in the n-GB group. From this survey it appears that regular physical exercise including gate ball may be beneficial for health of elderly people in a rural community.

Tumor blood flow measured using dynamic computed tomography

RATIONALE AND OBJECTIVES

A method for measuring the tumor blood flow (TBF) by means of dynamic computed tomography (DCT) was devised and investigated.

METHODS

Twenty-seven patients with superficial tumors underwent measurement of TBF by the new DCT method. For all of the 27 patients, the thermal clearance method was employed to measure the relative tumor blood flow (RTBF). For 16 patients, TBF was measured by oxygen-15-gas positron-emission tomography (PET). The TBF values measured by DCT were compared with the RTBF by the thermal clearance method and the TBF by PET.

RESULTS

The results demonstrated a linear relationship.

CONCLUSIONS

The newly devised DCT method yields reliable data in measuring TBF.

Neonatal group B streptococcal sepsis during 2 years of a universal screening program

OBJECTIVE

To assess the feasibility and efficacy of a protocol for universal screening for group B streptococci combined with selective intrapartum prophylaxis at a teaching hospital.

METHODS

This is a descriptive study of experience with a standardized protocol in which patients were screened at 26-28 weeks with a rectal and genital culture placed directly in selective media. As risk factors, we used clinical chorioamnionitis, preterm birth, and rupture of the membranes greater than 12 hours. Participants were all women receiving prenatal care at our hospital. Major outcomes were compliance and neonatal sepsis due to group B streptococci.

RESULTS

The prevalence of rectal and genital group B streptococci was 18.5% of 3721 screened women. Of culture-positive women, 35% developed risk factors (9% chorioamnionitis, 13% preterm birth, and 13% membrane rupture greater than 12 hours at term). With strict application of criteria, the compliance rate in administering indicated prophylaxis was 80.3%. Of women receiving prophylaxis, 42% had the first dose for 4 hours or less before delivery. There were five cases of group B streptococcal neonatal sepsis, resulting from either protocol violations, protocol failures, or both. Compared to the historic rate of group B streptococcal sepsis of 1.5 per 1000 births at our hospital, the rate in these 2 years was 1.0 per 1000 (1.6 per 1000 in the first year and 0.5 per 1000 in the second).

CONCLUSIONS

It is feasible to conduct such a protocol, but compliance is only moderately good because the algorithm is complex. The protocol is not foolproof in preventing neonatal group B streptococcal sepsis, as there are protocol failures and violations.

[A case of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with bilateral recurrent nerve palsy and primary alveolar hypoventilation--comparative studies of the histological findings of the two sural nerve biopsies with 9 years interval]

A 27-year-old man noticed a tingling sensation in his fingers and toes in early 1982, at the age of 18 years, and his symptom gradually progressed in the following several months. In December 1982, based on neurological and laboratory examinations including the first sural nerve biopsy on the right side, a diagnosis of axonal sensory neuropathy of unknown etiology was made. During the following years, muscle weakness in the distal limbs and hoarseness developed and progressed, and the sensory impairments became gradually evident. On the second neurological examination in July 1991, he showed soft palate palsy and bilateral recurrent nerve palsy. The intrinsic muscles of hands and feet were atrophic, and pes cavus was noted bilaterally. There was mild to moderate weakness in the distal muscles of both limbs. Ankle jerk was absent and other tendon reflexes were decreased in both limbs. A mild to moderate decrease of both superficial and deep sensations with mild paresthesia was noted in both hands and feet. Routine laboratory findings were unremarkable. In blood gas analysis, hypercapnea and respiratory acidosis were found. Spirometry showed an increase of residual volume, and alveolar CO2-pulmonary ventilation response test suggested the presence of primary alveolar hypoventilation caused by hypofunction of the medullary respiratory center. In nerve conduction studies, motor nerve conduction velocities were moderately reduced in bilateral median and ulnar nerves. Distal latencies of M-waves were prolonged in bilateral median nerves. Temporal dispersion of M-wave was found in the left tibial nerve. The amplitudes of sensory action potentials were moderately reduced in bilateral median and sural nerves.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on in vitro paraquat and diquat removal by activated carbon

The adsorption characteristics of paraquat and diquat onto activated carbon in vitro were discussed for the primary treatment of acute poisoning by accidental, suicidal or homicidal ingestion of paraquat containing herbicides. Paraquat was adsorbed onto activated carbon more abundantly and more rapidly in physiological saline solution than that in artificial gastric juice and distilled water. Most suitable solvent for paraquat removal by activated carbon was physiological saline solution (0.9% sodium chloride solution). No significant correlation was observed between the ability of paraquat removal and the properties of adsorbent. Paraquat was preferentially adsorbed onto activated carbon in the mixed solution. The adsorption abilities by activated carbon (the removal ratio, the amount adsorbed and the adsorption rate) for paraquat were larger than those for diquat, and it was enhanced by added sodium chloride and added magnesium sulfate. Enhancing effect for adsorption removal was proportional to the saline concentration. As addition of salts into carbon suspension enhanced the adsorption ability, it will contribute to the effective treatment of acute poisoning.

Evaluation of the effects of various factors on the serum triglyceride level in young adults

The life style of young adults has been receiving attention with a view to its improvement to preventing coronary heart diseases (CHD) in later life. In this study, for determining the influence of different life styles on the serum triglyceride level, we carried out surveys and laboratory studies on the relationships of the nutritional intake, physical activity, and cigarette smoking and alcohol consumption of young adults with their serum triglyceride levels. The nutritional survey indicated a significant correlation between the serum triglyceride level and carbohydrate intake (p < 0.01). In the survey of physical activity, a significant inverse correlation was found between the energy expenditure per kg body weight and the serum triglyceride level (p < 0.05). No significant relationship was found of smoking or drinking with the serum triglyceride level. The body mass index was found to have effects on both the serum triglyceride and total cholesterol levels. Of the factors examined, carbohydrate intake and energy expenditure per kg body weight had the greatest effects on the serum triglyceride level. Considering the trend for young people to consume large quantities of carbonated drinks, in which most of carbohydrate is sucrose, we tested the affect of a high carbohydrate diet on one group of subjects and found that it caused a significant increase in the serum triglyceride level (p < 0.05). Another group for whom a mild exercise regimen was prescribed showed slight, but not significant decrease in the serum triglyceride level. These results suggest that at least optimal nutrition and physical activity including weight control during adolescence are important for preventing CHD.

The survival of rat cerebral cortical neurons in the presence of trophic APP peptides

One function of Alzheimer amyloid protein precursor (APP) is the regulation of growth and differentiation in several types of cells, including fibroblasts, PC12 cells, and neurons. This activity is represented by a small stretch of amino acids in the center of the molecule around RERMS. The APP 17-mer peptide containing the RERMS domain supported survival and neurite extension of rat cortical neurons in a dose-dependent and sequence-specific manner. The APP fragment synthesized in Escherichia coli supported the survival and neurite extension of rat cortical neurons, whereas the mutant APP fragment lacking the 30 amino acids around the RERMS domain had drastically reduced activity to support the survival and neurite extension. The current study established APP as a neuron survival factor and determined that the sequence around RERMS is important for this function.

[Tumor blood flow measured by dynamic CT]

A method of measuring tumor blood flow by dynamic CT (DCT) was devised, and the reliability of data obtained by the new method was investigated. The subjects were 16 patients with superficial tumors who underwent measurement of tumor blood flow by both the new DCT-based method and 15O gas positron emission tomography (PET). The results showed that tumor blood flow as measured by the new DCT-based method was about 1.2 times greater than that measured by PET, and both data yielded a straight line passing almost through the origin (proportional relationships); the correlation coefficient was 0.836. On the basis of these studies, it was concluded that the newly devised DCT-based method yields reliable data in the measurement of tumor blood flow.

Evaluation of serum lactate dehydrogenase activity for estimation of energy expenditure in human subjects

We investigated the relationship between serum lactate dehydrogenase (LDH) activity and energy expenditure in young adults, evaluating their serum LDH activities in order to develop an index of energy expenditure. The results obtained were as follows. (1) There were significant correlations between the serum LDH activity and energy expenditure/day, energy expenditure/body weight/day and daily activity index in men. (2) There were significant correlations between the serum LDH activity and energy expenditure/day and daily activity index in women. (3) A group of men who 'rarely' exercised had lower levels of serum LDH activity than those who exercised 'sometimes' or 'usually', but little difference was noted between similar groups of women.

Assessment of the mechanical properties of peripheral arteries in chain saw operators using a photosensor

In order to evaluate the severity of peripheral vascular disorders, and to detect changes in the digital arteries of workers who use chain saws, the mechanical properties of the digital arteries of 22 such workers were examined using a photosensor. The elastic properties and the nonlinearity of digital arteries were assessed through observation of the changes in the vascular volume ratio (V/Vo) against the volume (Vo) at mean blood pressure (Pm). A significant negative correlation was found between age and V/Vo at a transmural pressure of 30 mmHg (V30/Vo), which suggested that V30/Vo tended to decrease with aging. Although it was impossible to calculate V30/Vo for chain saw operators because of the vague changes in the volume pulse wave, this nonlinearity was more clearly observed through changes in the relative vascular volume (V/V40) along with a reduction in cuff pressure (Pc) to 40 mmHg below systolic blood pressure. A group of similarly aged healthy controls and three groups of workers with a different severity of vibration-induced white finger (VWF), i.e., no symptoms of VWF, mild VWF and severe VWF, were classified according to the changes in their V/V40 and the reduction in Pc. The results obtained in the present study suggest that the peripheral vascular disorders in workers using chain saws are due to the opening disturbance of the arteries with nonlinear changes in the peripheral artery, which is related to functional and organic abnormality of the arteries.

A carcinoma in situ arising in an endocervical polyp--a case report

A rare case of a carcinoma in situ arising from an endocervical polyp is described. The covering epithelium of the polyp transformed gradually into a carcinoma in situ via squamous metaplasia and dysplasia, spreading horizontally with glandular involvement, and colliding with the surface columnar cells. The lack of tumor tissue in the pedicle and adjacent cervical region confirms the case was a carcinoma in situ originating from the surface epithelium of the endocervical polyp.