Neurophysiological methods in occupational and environmental health: methodology and recent findings

Neurophysiological measurement, a promising technique for assessment of the subclinical effects of occupational and environmental factors, is rapidly progressing following development of computer technology. The methods include measurement of evoked and event-related potentials, nerve conduction velocity, distribution of nerve conduction velocities, electrocardiographic R-R interval variability, and computerized static posturography. This paper provides an overview of these methods, except for evoked and event-related potentials, which have been reviewed previously by the authors, to evaluate the effects of occupational and environmental factors on the peripheral, autonomic, and cerebellar nervous systems. The available data indicate that these methods are sensitive, reliable, and easily applied in a field study. When conducting these measurements, controlling for confounding factors such as age, sex, height, skin temperature, alcohol ingestion, and neurologic diseases is necessary.

[Evaluation of nutritional status of patients on continuous ambulatory peritoneal dialysis (CAPD) by dual photon energy X-ray absorptiometry (DEXA)]

Malnutrition is a serious complication in patients on long-term CAPD treatment. Accordingly, quantitative evaluation of nutritional status is a critical issue. This study aimed to assess nutritional status by dual photon energy x-ray absorptiometry (DEXA) in CAPD patients. Total lean body mass (D-TBM), right arm lean mass (D-RAM) and body fat percent (D-% FAT) measured by DEXA were compared with mid-arm muscle circumference (MAMC) and body fat percent (AP-% FAT) measured by anthropometrics (AP) in 51 CAPD patients. The subjects were stratified into groups by gender, age, duration on CAPD, and diabetes mellitus or non-diabetes. There was significant correlation between D-TBM, D-RAM and MAMC (r = 0.519, p = 0.001, r = 0.545, p = 0.001) or D-% FAT and AP-% FAT (r = 0.763, p = 0.0001). However, in the groups of females with over 50 years and over 48 months of dialysis duration, there was no correlation between D-TBM, D-RAM and MAMC. The DEXA method is useful in the quantitative evaluation of nutritional status of dialysis patients serially.

[Spinal anesthesia with 2% plain lidocaine for ultrasonically guided vaginal oocyte retrieval]

Spinal anesthesia with 3 ml of 2% plain lidocaine was administered to 10 women for ultrasonically guided vaginal oocyte retrieval. Spread of anesthesia was assessed by skin vasodilatation, change of skin texture, loss of goose flesh reflex, and loss of cold as well as pin-prick sensation, and we studied time to complete motor block, time to two-segment regression, time to full motor and sensory recovery, ambulation time, haemodynamic parameters, and postoperative complications. The highest sensory block assessed by pin-prick was up to Th 8.3 +/- 3.4 10 min following spinal anesthesia. All patients had complete motor block and this was achieved at 9.0 +/- 1.7 min. Times to two-segment regression, full motor and sensory recovery, and ambulation were 84.5 +/- 31.0, 147.5 +/- 24.7, 176.5 +/- 23.2, and 203.3 +/- 50.0 min, respectively. No serious side effects were observed during the operation and postoperatively. We concluded that 3 ml of 2% plain lidocaine provided adequate spinal anesthesia for ultrasonically guided vaginal oocyte retrieval.

Low prevalence of activated protein C resistance and coagulation factor V Arg506 to Gln mutation among Japanese patients with various forms of thrombosis, and normal individuals

Resistance to activated protein C (APC), recently reported to be the most prevalent inherited cause of thrombosis among Caucasians, is associated with a single point mutation in the coagulation factor V gene. We investigated the prevalence of APC resistance and the factor V gene mutation (R506Q) in 34 consecutive Japanese patients with venous thrombosis or pulmonary thromboembolism and 63 control subjects. Three of the 33 patients examined (9%) had an APC ratio below the 5th percentile of control values (2.27), but all were above 2.0. The factor V mutation (R506Q) was not detected in the 29 patients studied, including the 3 patients whose APC ratios were below 2.27, or in 53 controls. In a tissue factor-based factor V assay to detect APC resistance recently described by Le et al. (Blood 1995;85:1704-1711), all patients studied were found to be normal including the three with a low APC ratio. We conclude that APC resistance and factor V gene mutation are less prevalent in Japan than in several European countries.

[Effectiveness of the radioactive strontium (89Sr) chloride agent, SMS.2P for pain palliation in patients with metastatic bone tumor in phase III multicenter clinical trial]

The phase III clinical trial of strontium-89 chloride agent (SMS.2P) was performed in 90 patients with painful bone metastases secondary to prostate (53), breast (18) and other types of cancer (19). Some patients experienced a transient increase in pain or nausea and vomiting. However both symptoms subsided and serious side effects were not observed in any of the patients. As reported, we confirmed some abnormal changes in peripheral blood picture. A decrease in the number of white blood cells and platelets was considered to be partly a result of bone marrow suppression due to 89Sr irradiation. Pain was substantially improved after 89Sr therapy in 58% of the patients and there was some alleviation in 12%. The release from pain was accompanied by an improved quality of life for these patients including sleep patterns and morbidity. Some patients were able to resume their former life styles. Most of the improved patients experienced pain relief from days to one week following 89Sr therapy and in half cases, this remained effective for 2 or 3 months. There were even cases in which the pain relief continued over an observation period of time of clinical study.

Oestrogen producing adrenocortical adenoma: clinical, biochemical and immunohistochemical studies

Oestrogen producing adrenocortical tumours are extremely rare. We report a 65-year-old woman who presented with abnormal vaginal bleeding, with no significant abnormalities in her uterus or ovaries, who was found to have a right adrenal mass by radiological examination. Excessive secretion of oestrogens from the tumour was demonstrated by adrenal venous sampling. Basal levels of corticosteroids were within normal limits. Adrenalectomy was performed and pathological examination revealed an adrenocortical adenoma measuring 5.5 cm in its greatest dimension, in which both clear and compact tumour cells were observed. Oestrogen levels normalized following the removal of the adrenal mass. Tissue concentrations of oestrone and oestradiol in the tumour were 6.9 (69.5 pmol/g wet tissue weight) and 34.6 (93.6 pmol/g wet tissue weight)-fold greater respectively than those of adjacent non-neoplastic adrenal cortex. Aromatase activity in the tumour tissue determined by the 3H-water method was 118.6 pmol/h/mg protein, equivalent to that of a full-term human placenta. Immunohistochemical analysis of aromatase demonstrated immunoreactivity in the tumour cells, especially in compact cells, but not in adjacent non-neoplastic adrenal cells. This is the first reported case of an oestrogen producing adrenocortical adenoma in which aromatase in the tumour cells was documented.

Mechanism of induction of prostaglandin E2 production by endothelin 1 in cultured rat mesangial cells

The phospholipase A2 inhibitors mepacrine, ONO-RS-082, and AACOCF3 completely inhibited prostaglandin E2 production induced by endothelin 1 in cultured rat mesangial cells, suggesting that phospholipase A2 is a critical enzyme in this process. TMB-8, an inhibitor of calcium mobilization from intracellular stores, abolished its production, while neither nicardipine nor chelation of extracellular calcium by EGTA did. The protein kinase C inhibitors, H-7 and staurosporine, and downregulation of protein kinase C could not inhibit prostaglandin E2 production, while W-7, a calmodulin inhibitor, abolished it. Pertussis toxin never influenced its production. Thus, endothelin 1 evokes prostaglandin E2 production in mesangial cells mainly through the activation of phospholipase A2, dependent on intracellular calcium and calmodulin and independent of extracellular calcium, protein kinase C, and pertussis toxin sensitive guanosine 5'-triphosphate binding proteins.

Inhaled nitric oxide improved the outcome of severe right ventricular failure caused by lipopolysaccharide administration

OBJECTIVE

To evaluate the efficacy of nitric oxide (NO) inhalation against endotoxin-induced lung injury.

DESIGN

Randomized prospective short-term study.

SETTING

University school of Medicine Laboratory.

INTERVENTIONS

Animal experiment (using 16 Japanese white rabbits). The animals inhaled NO at a concentration of 10 ppm.

MEASUREMENTS AND RESULTS

The rabbits were randomly divided into the NO inhaling group (n = 7) and the control group (n = 9). Both groups received continuous infusion of 1200 mcg lipopolysaccharide (LPS) and the NO group inhaled 10 ppm NO during the LPS administration. In the control group, severe right ventricular (RV) failure was observed at 30-90 min of LPS infusion, and 4 of 9 animals died within 90 min of LPS infusion. In the NO group, none of the animals died and the early phase hemodynamic deterioration was milder than in the control group. But pulmonary gas exchange was not significantly different between the two groups throughout the study. At the end of the study there were no significant differences in any parameters of the surviving animals between the two groups.

CONCLUSION

Although an improvement of pulmonary gas exchange was not demonstrated, NO inhalation (10 ppm) improved the outcome of severe RV failure caused by LPS infusion.

Distribution of glucocorticoid receptor immunoreactivity and mRNA in the rat brain: an immunohistochemical and in situ hybridization study

The localization of glucocorticoid receptor (GR) immunoreactivity and mRNA in the adult rat brain was examined by light microscopic and electron microscopic immunohistochemistries, and in situ hybridization. For the purpose of detailed investigation of the distribution and comparison of GR immunoreactivities and mRNAs, specific polyclonal antibodies against a part of the transcription modulation (TR) domain of rat GR were used in the immunohistochemistry, whereas fluorescein-labeled RNA probes, complementary to the TR domain in the GR cDNA were used in the in situ hybridization. In the rat brain, GR immunoreactivity was predominantly localized in the cell nucleus, and the expression of GR mRNA was detected in the cytoplasm. GR-immunoreactive and GR mRNA-containing cells were widely distributed from the olfactory bulb of the forebrain to the gracile-cuneate nuclei of the medulla oblongata. The highest densities of GR-immunoreactive and mRNA-containing cells were observed in the subfields of cerebral cortex, olfactory cortex, hippocampal formation, amygdala, septal region, dorsal thalamus, hypothalamus, trapezoid body, cerebellar cortex, locus coeruleus and dorsal nucleus raphe. The distributional pattern of GR immunoreactivity in many regions was well-correlated with that of GR mRNA, but in the CA3 and CA4 pyramidal layers of the hippocampus, different localization was noted. The present study provides the groundwork for elucidating the role of GRs in brain function.

[Diagnosis of pleural dissemination lung cancer by thin-section CT--a prospective study]

In this prospective study, thin-section CT was used to diagnose pleural dissemination in patients with pulmonary adenocarcinomas in which the primary lesion was found to be adjacent to the pleural surface by conventional CT. The subjects were 32 patients (25) who had undergone resection and 7 who had not with pulmonary adenocarcinoma without pleural effusion from among the 136 patients with pulmonary adenocarcinoma examined at our institution over 3 years. Thin-section CT images of three regions were obtained, and these included the pleural surface adjacent to the lesion, the minor fissure, and the diaphragmatic dome. Histopathological examination revealed pleural dissemination in 12 patients (5 who had undergone resection and who had not), in 2 of whom a diagnosis could not be made preoperatively. Pleural dissemination was diagnosed by CT in 12 patients; there were 2 false positives. In 6 patients who did not undergo resection, cancerous cells were found in fluid obtained by percutaneous pleural lavage, and mediastinal lymph node metastases or distant metastases were also detected. The diagnostic rate of CT was as follows interlobar space. 100% (7/7); mediastinum, 75% (3/4); diaphragm, 71% (5/7); and chest wall, 57% (4/7). In the patients who underwent resection, sensitivity was 100% for the interlobar space, but it was 0% to 33% for other pleural surfaces.

Rat whole-limb viability after cold immersion using University of Wisconsin and Euro-Collins solutions

The purpose of this study was to compare University of Wisconsin (UW) solution with Euro-Collins (EC) solution in their cold preservation effects on rat limbs. Thirty-six Lewis rat limbs were preserved in EC solution (n=18) or UW solution (n=18) at 4 degrees C for 72 hr, and grafted orthotopically to a syngeneic rat using microsurgical techniques. The surgeon was blinded to the solution used. We evaluated the vascular patency rate and death rate of both groups at day 7 after surgery and performed histological evaluations of bone, muscle, growth plate, and articular cartilage for each specimen of successful grafts in both groups. The vascular patency rates of the EC and UW groups were 27.7% (5/18) and 11% (2/18), respectively, and showed no significant difference. The death rates of the EC and UW groups were 50% (9/18) and 60% (10/18), which were not significantly different. There were no clear differences in histological viability between both groups, in all tissues exclusive of bone marrow and muscle tissue. Our results showed that in comparing EC and UW solutions, one was not significantly superior to the other as a cold immersion storage medium after a 72 hr ischemia-induced reperfusion injury.

Cloning, expression and characterization of plasma platelet-activating factor-acetylhydrolase from guinea pig

In a previous study, we purified PAF-acetylhydrolase, which converts PAF to an inactive metabolite, lysoPAF, from peritoneal fluid of guinea pigs subjected to experimental endotoxin shock and found that this purified enzyme had similar biochemical properties to the plasma enzyme [Karasawa, K., Yato, M., Setaka, M., and Nojima, S. (1994) J. Biochem. 116, 374-379]. In this study, we isolated a homogeneous enzyme preparation from guinea pig plasma using a similar procedure. The molecular mass of this purified enzyme, as determined by SDS-PAGE was 58-63 kDa, larger than that (43 kDa) of the human enzyme. To elucidate the molecular structure of this enzyme and clarify its relationships with PAF-acetylhydrolases of other species, we isolated and sequenced a cDNA encoding this enzyme. Its cDNA contains an open reading frame encoding 436 amino acids and its predicted molecular mass (49 kDa) is lower than that of the native enzyme, suggesting that guinea pig plasma PAF-acetylhydrolase, unlike the human enzyme, is modified post-translationally, perhaps by glycosylation.

Open knee dislocation associated with vascular injury successfully salvaged by primary arthrodesis in an elderly patient: a case report

Treatment by primary arthrodesis of the knee joint after temporary intraluminal shunt placement in a 70-year-old man with open knee dislocation involving the popliteal vessels is reported. After temporary shunting, the definitive vascular reconstruction of both the popliteal artery and vein was established by end-to-end anastomoses because of the shortening effect of the arthrodesis. Two skin coverage procedures were performed on day 0 and day 18. The patient recovered activity to a level near his pretrauma status. Primary arthrodesis for open knee dislocation associated with vascular injury in an elderly patient may be an efficacious procedure, depending on the patient's age, occupation, and level of activity.

An alpha-chain TCR CDR3 peptide can enhance EAE induced by myelin basic protein or proteolipid protein

Regulation of experimental autoimmune encephalomyelitis (EAE) can be induced by anti-idiotype immunity against T cell receptor (TCR) fragments associated with major histocompatibility complex (MHC) molecules. However, we have recently found that preimmunization with an alpha-chain TCR CDR3 peptide (LYFCAARSNYQL) derived from myelin basic protein (MBP)-specific clones did not suppress but rather augmented the severity of EAE induced by MBP-specific T cells in SJL/J mice. To test whether CDR3 vaccination could control only a highly restricted T cell population, we studied the effect of the peptide against EAE induced by T cells specific for different Ag/MHC ligands and autoimmune diseases affecting non-neural tissues. In contrast to expectations, the peptide was found to augment not only EAE induced by MBP-specific T cells, but also proteolipid protein (PLP)-specific T cell- or PLP peptide-induced EAE in SJL/J mice, and MBP-induced EAE and adjuvant arthritis (AA) in rats. The CDR3 peptide was neither inhibitory nor supportive for Ag-induced activation of an encephalitogenic clone in vitro. In addition, the peptide treatment neither inhibited the induction of Ag-specific T cells nor altered the APC function of spleen cells. These findings, on the one hand, confirm previous results showing TCR peptide-induced enhancement of the disease and, on the other hand, indicate that the TCR CDR3 peptide may control T cells with broader Ag/MHC specificities than could be expected. Structural similarity among TCR idiotypes of autoimmune T cells may partly account for these results.

[Clinical experience of the Er: YAG laser for apicoectomy]

Recently, the Er: YAG laser has attracted attention because of its possibility of cutting hard tissue with extremely small thermal injuries. In this paper, eight cases (thirteen teeth) of apicoectomy using Er: YAG laser are reported. All procedures were performed without using air turbin or electric drill. The advantages of Er: YAG laser application include: absence of uncomfortable vibration: less chance for contamination of the surgical site: and reduced risk of trauma of adjacent tissue compared with ordinary methods.

Application of non-radioactive europium (Eu3+) release assay to a measurement of human natural killer activity of healthy and patient populations

Europium (Eu3+) release assay is a non-radioactive method for a measurement of cytotoxicity of lymphocytes and has several advantages compared with a conventional 51Cr release assay. However, the Eu3+ release assay has not been applied to a natural killer (NK) activity measurement of a large number of the human population mainly due to a lack of comparability with the 51Cr release assay. With some modifications of the procedures and careful manipulation of cells, constant and reproducible results were obtained by the Eu3+ release assay. NK activity of several individuals was measured by the Eu3+ release assay and was compared with data obtained by 51Cr release assay performed simultaneously. The obtained values by the two methods were almost identical. We applied the Eu3+ method to measure NK activity of a large number of individuals, including 68 apparently healthy donors and 36 autoimmune and 21 cancer patients. Some of these diseases are known to show abnormal NK activity. The obtained cytotoxicities were mostly consistent with the previously reported data obtained by the 51Cr release assay. These results indicated that the Eu3+ release assay could be used as an alternative method for a measurement of human NK activity of mass population including patients.

[Study on the positive rate of infectious diseases in in-patients at the department of oral surgery]

The positive rate of infectious diseases (syphilis, hepatitis B and C) in in-patients at the department of oral surgery was investigated for five years. Each positive rate of them was 2.4% for STS, (1.3% for TPHA), 0.6% for HBs antigen, 3.2% for HCV antibody, respectively. These results suggest that it is important to perform universal precaution in the treatment room.

[Serum levels of remnant-like particles-cholesterol (RLP-C) in patients on hemodialysis]

Serum remnant-like particles-cholesterol (RLP-C), an atherosclerosis risk factor that strongly reflects disorders of chyromicron and VLDL metabolism and contains high levels of TG, was measured in patients on hemodialysis and CAPD. The purpose of this study was to determine the serum levels of RLP-C in 30 outpatients on hemodialysis (18 males, 12 females) and 84 patients on CAPD (53 males, 31 females). The serum RLP-C level was 8.1 +/- 13 mg/dl in CAPD patients and 2.7 +/- 0.2 mg/dl in hemodialysis patients (p < 0.001). Patients who used dialysate containing over 150 g of glucose per day, showed higher levels of serum RLP-C than CAPD patients whose glucose consumption was under 150 g (10.4 +/- 2.4 mg/dl vs. 5.5 +/- 0.6 mg/dl, p < 0.01). There was no statistical relationship between age, sex, dialysis duration and serum RLP-C in CAPD and hemodialysis patients. Serum level of RLP-C was positively correlated with serum triglyceride, total cholesterol, apolipoprotein B and VLDL, and was negatively correlated with apoA-I/apoB in the dialysis patients. It appears that RLP-C, which is one of the risk factors of atherosclerosis, might reflect a disorder of triglyceride metabolism in patients on dialysis, especially on CAPD.

Case reports of epulis treated by CO2 laser without anesthesia

This study reports seven cases of epulis excised by the CO2 laser without anesthesia. The laser was used in a continuous wave mode at power setting of 2-4 W. All lesions were excised completely, and no patients felt pain during laser irradiation. The operation was successful without using surgical packs, and there was no postoperative discomfort. There has been no evidence of recurrence after operation.

Adjustment of creatinine-adjusted values in urine to urinary flow rate: a study of eleven heavy metals and organic substances

The use of urinary monitoring in medical surveillance programs in industry requires development of an accurate and unbiased index of urinary concentrations of occupational toxins. To examine the effects of urinary flow (UF) rate on the standard creatinine (Cn)-adjusted value and the UF- and Cn-adjusted values according to Greenberg and Levine and to Araki et al. for 11 heavy metals and organic substances, 19 metal-foundry workers aged 34-59 years (mean 48), who had been exposed to lead, zinc, and copper for 2-17 (mean 10) years, were studied during four periods of the day under water-free, water-restrictive and water-loading conditions for 6 days. The blood lead concentrations of the 19 workers ranged from 22 to 59 (mean 38) micrograms/dl. The results indicated that there was no significant UF effect on the UF- and Cn-adjusted values of Araki et al. for all urinary substances except mercury and coproporphyrin. On the other hand, the UF- and Cn-adjusted value of Greenberg and Levine was positively correlated with UF rate for all urinary substances, and the standard Cn-adjusted value was either positively or inversely correlated with UF rate for many urinary substances. Therefore, the UF- and Cn-adjusted value of Araki et al. is considered to be applicable to the measurement of most urinary substances under conditions of wide variation in UF rate.