[Clinical features and prognosis of facial palsy and hearing loss in patients with Ramsay Hunt syndrome]

Clinical studies were performed on 325 patients with Ramsay Hunt syndrome who were treated in the Facial Nerve Clinic at Ehime University Hospital between 1976 and 1995. The clinical manifestations of Ramsay Hunt syndrome were various. Three major symptoms, auricular vesicles, facial paralysis and vestibulo-cochlear dysfunction, were found in 57.6% of the patients although these symptoms did not always appear simultaneously. Auricular vesicles appeared before (19.3%), during (46.5%), or after (34.2%) the onset of facial paralysis. Hearing loss was observed subjectively in only 20% but objectively in 48.2% of the patients. Hearing loss appeared before (34.3%), during (34.3%), or after (31.3%) the onset of facial paralysis. Complete recovery from facial paralysis was achieved in 52.4% of the patients. Good recovery of the facial nerve function was achieved in patients who had zoster vesicles or vestibulo-cochlear dysfunction preceding the development of facial paralysis. Complete recovery of hearing was also achieved in 45.4% of the patients, and the recovery was better in patients having light hearing loss, less than 35dB. The patients younger than 16 years old showed better recovery from both facial paralysis and hearing loss than the patients older than 60 years. Glossopharyngeal nerve or vagal nerve paralysis concomitant with facial paralysis was found in 8 (2.5%) patients. The outcome of glossopharyngeal nerve paralysis was good but that of the vagal nerve was poor.

[Atherosclerosis and clinical examination: epidemiology of stroke and ischemic heart disease]

We discussed the risk factors for stroke and ischemic heart disease (IHD) as a main atherosclerotic disease. We showed that hypertension was the most principal risk factor for both cerebral hemorrhage and cerebral infarction, and the increase of total cholesterol (TCH) was inversely related with the incidence of cerebral hemorrhage. Many of the cerebral infarctions occurred where a large number of the cerebral hemorrhages did. We indicated that the mechanism of occurrence was different between stroke and IHD. In Japan, TCH has been recognized as a risk factor for IHD as same as western countries, but there are not many IHD. The mean of TCH was lower before one or two decade. But, it has increased in the last decade, and recently is nearing the level of American people in the thirties and forties. Death statistics of IHD became more accurate in Japan by reason for revision of the death certificate form from ICD-9 to ICD-10. The recognition of IHD death statistics will be changed. Incidence of stroke has been decreasing because of the decrease of hypertension. However, we will have to reconsider a preventive measure of IHD.

Induction of Fas-dependent apoptosis in synovial infiltrating cells in rheumatoid arthritis

Apoptosis is a feature of the synovium of rheumatoid arthritis (RA). We have recently shown that RA synoviocytes were susceptible to anti-Fas mAb and undergo apoptosis in vitro. To investigate whether infiltrating mononuclear cells also undergo Fas-dependent apoptosis, double-labeling techniques combined with immunohistochemical examination with anti-CD3 mAb and the TdT-mediated dUTP-blotin nick end labeling (TUNEL) method to detect apoptotic cells, or in situ RT assay to detect Fas mRNA, were performed using frozen tissue sections. We also examined the in vitro induction of Fas-dependent apoptosis in freshly isolated synovium infiltrating mononuclear cells (SIM), synovial stromal cells (SSC) and peripheral blood lymphocytes (PBL) using tissues from nine patients with RA and three with osteoarthritis (OA). The results showed expression of Fas antigen and apoptotic cells in a number of CD3-bearing cells in RA synovial tissues. In vitro treatment with anti-Fas mAb produced a significant apoptosis of RA SIM and SSC, while none of PBL, and neither SIM nor SSC from OA exhibited apoptosis. Moreover, approximately 50% of CD4+, CD3+ and CD45RO+ cells, and > 90% of Fas-expressing cells of RA SIM underwent apoptosis in response to anti-Fas mAb, as detected by flow cytometry. Our results suggest that RA synovial infiltrating lymphocytes acquire high susceptibility to anti-Fas mAb and undergo apoptosis. Such a phenomenon of infiltrating T cells in RA synovium may play an important pathophysiological role and suggest a possible therapeutic effect for anti-Fas mAb in RA.

Novel mechanisms of selective apoptosis in synovial T cells of patients with rheumatoid arthritis

OBJECTIVE

To analyze whether T cells infiltrating the synovium of patients with rheumatoid arthritis (RA) express functional Fas antigen.

METHODS

Mononuclear T cells, mainly from synovial tissues, synovial fluids (SF), and peripheral blood mononuclear cells (PBMC) from 14 patients with RA and 5 with osteoarthritis (OA), were treated with anti-Fas monoclonal antibody (Mab) (CH11) for 24 h in vitro. Cell viability and DNA fragmentation were examined. The expression of Fas antigen, Fas ligand, and T cell subpopulations was examined using flow cytometry and reverse transcription polymerase chain reaction.

RESULTS

More than 50% of T cells from synovial tissue and SF of patients with RA underwent apoptosis, whereas no effect was observed in PBMC from RA or PBMC and synovial T cells from OA, suggesting that functional Fas antigens are specifically expressed on synovial T cells. Flow cytometric analysis demonstrated higher expression of Fas antigen in T cells from RA synovium than from PBMC. The T cell subpopulations susceptible to anti-Fas Mab were mainly CD45RO+ and CD4 or CD8 single positive T cells, indicating that activated mature T cells express functional Fas antigen. Fas ligand was overexpressed only in synovial nonadherent cells in RA at the level of mRNA, whereas T cells account for more than 60% of the total, but not in OA.

CONCLUSION

These findings suggest the majority of activated T cells infiltrating the synovium express functional Fas antigen and Fas ligand specifically in patients with RA but not OA. This phenomenon may provide a clue to understanding the pathogenesis of RA.

Therapeutic effect of the anti-Fas antibody on arthritis in HTLV-1 tax transgenic mice

We have recently demonstrated Fas-mediated apoptosis in the synovium, of patients with rheumatoid arthritis (RA) and suggested that it may be one factor responsible for the regression of RA. To examine whether the induction of apoptosis caused by anti-Fas mAb may play a potential role as a new therapeutic strategy for RA, we investigated the effect of anti-Fas mAb (RK-8) on synovitis in an animal model of RA, the human T cell leukemia virus type I (HTLV-1) tax transgenic mice. We report here that administration of anti-Fas mAb into mice intra-articularly improved the paw swelling and arthritis within 48 h. Immunohistochemical study and in vitro culture studies showed that 35% of synovial fibroblasts, 75% of mononuclear cells, and some of polymorphonuclear leukocytes infiltrating in synovium underwent apoptosis by anti-Fas mAb. In situ nick end labeling analysis and electron microscope analysis clearly showed that many cells in synovium were induced apoptosis by anti-Fas mAb administration. However, local administration of anti-Fas mAb did not produce systemic side effects. Results demonstrated that administration of anti-Fas mAb in arthritic joints of the HTLV-1 tax transgenic mice produced improvement of arthritis. These findings suggest that local administration of anti-Fas mAb may represent a useful therapeutic strategy for proliferative synovitis such as RA.

[Accurate placement of central venous catheters using right atrial electrocardiography]

We have evaluated the effectiveness of central venous catheter placement using right atrial electrocardiography (RAECG). Consecutive patients under general anesthesia (n = 42) who required a central venous catheter underwent RAECG-guided catheter insertion procedure via right internal jugular vein. Catheter tip position was verified by post procedure portable chest radiography. Forty of 42 catheter tips were placed above the superior vena cava-right atrial junction, and none of them had its associated complications. The average insertion depth of catheters was 16.4 cm. We also attempted to predict the optimal catheter insertion depth for each patient from the previous measurements of external landmarks, but it was found to be difficult to predict reliably. In this point of view, we should use RAECG technique to make sure the proper positioning of the catheter tip.

Activation of transcription factor NF-kappa B in human synovial cells in response to tumor necrosis factor alpha

OBJECTIVE

To examine whether nuclear factor kappaB (NF-kappaB) is activated in cultured synovial cells in response to tumor necrosis factor alpha (TNFalpha) and to investigate the correlation between NF-kappaB activation and synovial cell proliferation.

METHODS

Activation of NF-kappaB was detected by electrophoretic mobility shift assay. The transcription of several NF-kappaB-dependent genes was evaluated by reverse transcriptase polymerase chain reaction and transient expression assay using human immunodeficiency virus-long terminal repeat chloramphenicol acetyltransferase. Proliferative activity was determined by measurement of 3H-thymidine incorporation.

RESULTS

Stimulation of synovial cells with TNFalpha activated NF-kappaB and subsequent transcription of several genes. Treatment of synovial cells with N-acetyl-L-cysteine (NAC), an antioxidant agent, inhibited TNFalpha-induced NF-kappaB activation and transcription. Moreover, NAC also inhibited synovial cell proliferation induced by TNFalpha.

CONCLUSION

Our results suggest that NF-kappaB plays a pivotal role in synovial cell activation by TNFalpha. Thus, suppression of NF-kappaB could be a potential therapeutic modality for synovitis such as that of rheumatoid arthritis.

Direct suppression of human synovial cell proliferation in vitro by salazosulfapyridine and bucillamine

OBJECTIVE

The mechanism of disease modifying antirheumatic drugs (DMARD) is incompletely understood. We investigated in vitro the effect of DMARD such as bucillamine (Buc), salazosulfapyridine (SASP), and D-penicillamine (D-Pen) on the proliferation of human synovial cells in patients with rheumatoid arthritis (RA).

METHODS

We evaluated the inhibitory effect of DMARD on [3H]-thymidine incorporation and cytokine production in synovial cells from patients with RA. Moreover, the expression of cytokine and protooncogene mRNA in synovial cells was determined by reverse transcription polymerase chain reaction methods.

RESULTS

The proliferation of synovial cells and interleukin 1 beta (IL-1 beta) and interleukin 6 (IL-6) production of synovial cells were significantly inhibited by Buc and SASP in the concentration range of 1 to 100 microM in a dose dependent manner. In contrast D-Pen had no apparent effect at the same concentrations. Subsequently, the inhibitory effects of these compounds on transcriptional regulation of IL-1 beta, IL-6, and c-fos, which are well known to play an important role in synovial cell proliferation, were clarified. Overexpression of c-fos mRNA was inhibited by Buc and SASP. Moreover, the combination of low dose Buc and SASP inhibited synovial cell growth and transcriptional regulation of these mRNA.

CONCLUSION

DMARD may have a direct inhibitory effect on rheumatoid synovial cell proliferation without the involvement of other cellular factors, which may be a mechanism of clinical remission induced by DMARD in patients with RA.

[Usefulness of rapid detection of plasma insulin levels during resection of insulinoma]

Insulinoma is one of the causes of hypoglycemia and can be cured by surgery. Using the enzyme immunoassay kit (ERUMOTEC INSULIN, Mochida Pharmacy Co.), immunoreactive insulin (IRI) can be measured within one hour. Curative operation was confirmed by normalized IRI level. A 58-year-old man had an episode of loss of consciousness. His blood glucose was below, and his IRI was above, normal. These and other examinations revealed that he was suffering from insulinoma. Tumor resection under general anesthesia was scheduled. Glucose was continuously administered intravenously to prevent hypoglycemia until the end of tumor resection. Frequent blood glucose measurement showed that he had no hypoglycemic episodes. Using the enzyme immunoassay kit, IRI was found to be 704 microU.ml-1 during manipulation of the tumor. At 30 minutes after the tumor resection, it decreased to 9.8 microU.ml-1 (within normal ranges). These data suggested that the operation was curative and that no further hypoglycemic attacks by remnant insulinomas would be anticipated.

Apoptosis and functional Fas antigen in rheumatoid arthritis synoviocytes

OBJECTIVE

To determine whether apoptosis occurs in rheumatoid arthritis (RA) synoviocytes, and if this phenomenon is dependent on the Fas/Apo-1 pathway.

METHODS

Apoptotic change in vivo was examined in RA synovial cells by several standard methods. The ability of cells to undergo Fas-induced apoptosis was determined in vitro.

RESULTS

Typical apoptotic change was demonstrated in RA synovial cells by each method. Anti-Fas antibody induced apoptotic synovial cell death in vitro.

CONCLUSION

This is the first reported study to demonstrate apoptosis in RA synovial cells. The findings indicate that rheumatoid synoviocytes undergo Fas-mediated apoptosis.

Oligoclonal proliferation of human T-cell leukemia virus type I infected lymphocytes in lesions of virus-induced arthropathy

To investigate the pathogenesis of human T-cell leukemia virus type I associated arthropathy, the mode of proviral integration in the pathological lesions was analyzed using ligation-mediated polymerase chain reaction. Peripheral blood mononuclear cells (PBMC) of these patients possessed multiple dominant clones of the virus-infected cells. On the other hand, synovial fluid cells of the affected joints exhibited fewer dominant clones even though the copy numbers of the provirus were comparable to those of PBMC. Thus, restricted HTLV-I infected T cell clones may proliferate and expand in the lesions.

Toxicity study of the angiotensin converting enzyme inhibitor rentiapril in rats

A three-months toxicity study of an angiotensin converting enzyme (ACE) inhibitor, rentiapril (CAS 80830-42-8), was performed in Sprague-Dawley rats by oral administration. The dose levels of 0, 30, 125, 500 and 1000 mg/kg were tested in both sexes, in which each experimental group comprised 10 rats. Another ACE inhibitor, captopril, was used as a reference compound. Rentiapril at the highest dose of 1000 mg/kg caused low food consumption and death of some animals with signs of bloody feces and anemia. In males and females receiving 500 and 1000 mg/kg, there were low body weight gain, increases in water intake, urine volume and serum BUN level, and decreases in levels of various erythrocytic parameters. Kidney weight was increased dose-dependently in both sexes. Histopathologically, renal changes in the 500 and 1000 mg/kg groups consisted of proximal tubular degeneration, juxtaglomerular cell hyperplasia and interstitial cell infiltration. Similar, but mild, changes in proximal tubules were present in the female 125 mg/kg group. Dead animals from the highest dose groups further showed gastrointestinal hemorrhagic erosion and/or ulcer, decreased bone marrow erythropoiesis and hepatocytic vacuolar degeneration. There was no pathological alteration in rats from other rentiapril-treated groups, as well as in controls. These results indicate that the no-effect dose of rentiapril in rats by three months oral administration is 30 mg/kg in female and 125 mg/kg in male, and suggest that, like other ACE-inhibitors, this compound also has a toxic potential to affect renal tissues.

[Perioperative management of a patient with myotonic dystrophy developing the cardiac symptoms initially prior to the neuromuscular symptoms]

The authors anesthetized a 48-year-old woman with endometrial cancer and a large ovarian cyst. She developed cardiac failure initially followed by the sick sinus syndrome and A-V block from hypertrophic cardiomyopathy, prior to neuromuscular symptoms. Epidural anesthesia assisted by general anesthesia was carried out safely without intravenous administration of any muscle relaxants. From this experience, it is considered that epidural anesthesia assisted with some other proper methods is suitable for surgery of lower abdomen.

Establishment and characterization of synovial cell clones with integrated human T-cell leukemia virus type-I

Human T cell leukemia virus type-I (HTLV-I)-integrated synovial cell clones (SCCs) were established from four HTLV-I-infected patients with chronic proliferative arthropathy. Extracted DNAs of these SCCs were examined for the existence of HTLV-I proviral DNA. Electron microscopic analysis and immunohistochemical staining were also performed to examine the nature of the HTLV-I integrated SCCs. SCCs derived from all four patients consisted of either HTLV-I integrated or nonintegrated cells. HTLV-I integrated SCCs also produced viral messenger RNA which was detected by reverse transcriptase-polymerase chain reaction as well as viral protein which was detected by immunohistochemical staining. Phenotypically, these SCCs containing HTLV-I proviral DNA were shown to be all cell types as observed by electron microscopic analysis and immunohistochemical analysis. Moreover, expression of HTLV-I glycoprotein was greater in SCCs with a monocyte marker. These findings suggest that SCCs harboring HTLV-I have an important role in synovial hyperplasia.

Cytolysis of hemocytes induced by serum and plasma in three crustaceans, Panulirus japonicus, Penaeus japonicus, and Homarus americanus

The effects of serum and/or plasma of three crustacean species on cellular morphology of homologous and heterologous hemocytes were observed using an in vitro short-term culture system. When hemocytes of the spiny lobster, Panulirus japonicus, isolated from hemolymph were mixed with serum of the same species, rapid cytolysis occurred in hyaline and semigranular cells. Plasma of Panulirus japonicus dialyzed against artificial sea water (dialyzed plasma) had the same cytolytic effect on hyaline and semigranular cells. Although the granular cells are not lysed, exposure to serum and plasma does produce changes in morphology and behavior (adhesion and spreading). Dialyzed plasma of the shrimp (Penaeus japonicus) and the lobster (Homarus americanus) also showed the same phenomena on homologous hemocytes. Dialyzed plasma of these three species had a less pronounced cytolytic effect on heterologous hemocytes. The cytolytic activity of the dialyzed plasma was weakened by heat treatment and inactivated by protease treatment. These results suggest that a protein factor(s) that specifically induces bursting of hyaline and semigranular cells exists in plasma of crustaceans.

Overgrowth of human synovial cells driven by the human T cell leukemia virus type I tax gene

One of the salient pathological features of rheumatoid arthritis is synovial cell proliferation with bone erosion. Despite extensive investigation, the factors essential for synovial cell proliferation remain to be identified. Recent studies suggest that human T cell leukemia virus type I (HTLV-I) may play an important role in synovial overgrowth observed in patients with one type of chronic inflammatory synovitis. In order to confirm and extend these observations, we have established synovial cell clones (SCCs) from three HTLV-I carriers who demonstrated synovial overgrowth but were otherwise asymptomatic. HTLV-I proviral DNA randomly integrated into the cellular genome was present in 20-30% of SCCs. The SCCs carrying HTLV-I proviral DNA and expressing the tax gene exhibited high levels of proliferative potential. HTLV-I was found to function as a transcriptional trans-activator in these SCCs. Moreover, transfection of the tax expression plasmid into SCCs resulted in the same phenotype of increased proliferation and cytokine expression as exhibited by HTLV-I provirus-carrying and tax-expressing SCCs. These data suggest that tax plays a critical role not only in leukemogenesis but also in synovial overgrowth in humans.

Radial and median nerve conduction velocities in workers exposed to lead, copper, and zinc: a follow-up study for 2 years

To evaluate the interactive effects of lead, zinc, and copper on the peripheral nervous system in man, we measured maximal motor and sensory conduction velocities (MCV and SCV) in the distal radial and median nerves in 19 gun metal foundry workers with asymptomatic increased absorption of these metals twice at a 12-month interval. The workers' initial blood lead (BPb) concentrations ranged from 16 to 64 (mean, 42) micrograms/dl. The principal findings in the present study indicated that (1) radial and median nerve conduction velocities were significantly slowed in the gun metal foundry workers; (2) indicators of lead absorption were inversely related to radial nerve conduction velocities, whereas indicators of copper and zinc absorption were positively correlated with the radial and median nerve conduction velocities; and (3) yearly changes in MCV in the radial nerve and in SCV in the median nerve were positively correlated with the changes in indicators of copper and zinc absorption. These findings suggest that zinc and copper antagonize the subclinical neurologic effects of lead. Also, the radial and median nerve conduction velocities provide important indicators of subclinical lead toxicity.

[The CO2 absorption capacity and color indication of a newly developed soda lime (Wakolime)]

The CO2 absorption capacity and the color change of ethyl violet (color indicator) of Wakolime A (newer type). Wakolime (older type), and Sorb 800 were studied under the clinical anesthetic condition. A two chamber canister was filled with soda lime and anesthetic gas flowed upward through the canister at the rate of 4 ml.min-1. The wall temperature of each chamber was measured with surface temperature sensing device. After 30 hours of use, the colored soda lime in the first chamber was examined with a color analyzer. The change of wall temperature indicated that the CO2 absorption capacity of Sorb 800 was the largest and that of Wakolime was the smallest among the three. The indicator color of both Wakolime A and Sorb 800 was clearer and of more vivid violet than that of Wakolime, which was dull and grayish. These results indicated that Wakolime A is superior in the CO2 absorption capacity and color indication to Wakolime.

Central and peripheral nervous system effects of hand-arm vibrating tool operation. A study of brainstem auditory-evoked potential and peripheral nerve conduction

To examine the effects of hand-arm vibrating tool operation on the central and peripheral nervous system, the brainstem auditory-evoked potential (BAEP), median nerve conduction velocity and hearing level were measured in twelve chain saw operators (6 operators had a history of white finger attack) and in eight brush saw operators (none had a history of the attack). Control subjects, matched to each chain saw and brush saw operator by sex and age, were selected randomly from healthy adults without otitis, deafness and tinnitus. The I-V interpeak latency (conduction from cochlear nerve to brainstem) and V peak latency of BAEP were significantly prolonged in chain saw operators; the I-V interpeak latency was significantly correlated with working years in brush saw operators. The median nerve conduction velocity was significantly slowed in both chain saw and brush saw operators. Moderate hearing loss was observed in the two groups. It is suggested that vibrating tool operation, i.e. the combined stressors of local vibration, noise, climate and heavy work, affected not only the peripheral nervous system but also the brainstem portion of the auditory pathway; the brainstem effect, if any, is less advanced than the peripheral nervous system effect of local vibration.

Agonist activity of a novel compound, 1-[3-(3,4-methylenedioxyphenoxy)propyl]-4-phenyl piperazine (BP-554), at central 5-HT1A receptors

We used an in vitro radioligand receptor binding assay with rat cerebral cortex, hippocampus and striatum membrane preparations to show that 1-[3-(3,4-methylenedioxyphenoxy)propyl]-4-phenyl piperazine (BP-554) had much higher affinity for 5-HT1A recognition sites than for 5-HT1-non-A, 5-HT2, benzodiazepine, dopamine D-2 and alpha 2-adrenergic recognition sites. The compound inhibited the activity of forskolin-stimulated adenylate cyclase in rat hippocampal membranes. Intraperitoneal injection of BP-554 to mice decreased the concentration of only 5-hydroxy-indoleacetic acid of the amines and their metabolites in the brain and decreased the accumulation of 5-hydroxytryptophan in the brain after decarboxylase inhibition by 3-hydroxybenzylhydrazine. Furthermore, the administration of BP-554 caused hypothermia and increased serum corticosterone levels in mice. The observed effects of BP-554 were similar to those of 8-hydroxy-2-(di-n-propylamino)tetralin. These results suggest that BP-554 acts as a selective 5-HT1A receptor agonist in vivo.

Effects of water restriction and water loading on daily urinary excretion of heavy metals and organic substances in metal workers

The effects of urinary volume on daily urinary excretion of seven heavy metals and four organic substances were examined in relation to the changes in their plasma and erythrocyte concentrations and urinary creatinine excretion in 19 metal workers. The examination was conducted under the conditions of water restriction and loading for six days. The major findings were as follows: (1) urinary excretion of all heavy metals and organic substances except mercury, together with creatinine excretion, significantly decreased under the water restrictive condition whereas under the water loading condition their excretion significantly increased and (2) daily variations in urinary excretion of lead, cadmium, chromium, copper, hippuric acid, delta-aminolaevulinic acid, and coproporphyrin did not differ significantly from the variation in urinary excretion of creatinine (profile analysis, p greater than 0.05). It is suggested that glomerular filtration is the major factor determining renal excretory mechanisms of the four heavy metals and three organic substances examined.

Retinoic acid promotes proliferation and chondrogenesis in the distal mesodermal cells of chick limb bud

Distal and proximal mesoderm of chick limb bud was respectively dissociated and cultured in the medium containing various concentrations of retinoic acid (RA). At low concentrations (5-50 ng/ml), RA promoted proliferation and chondrogenesis in the distal mesodermal cells. The distal cells of stage 20-24 limb buds were responsive to RA, although those of stages 25-27 were unresponsive. Both the cells of anterior and posterior regions of the distal mesoderm were responsive to RA, while the cells of proximal mesoderm were unresponsive. At higher concentrations, the growth-promoting effect of RA was reduced and chondrogenesis in the distal cells was rather inhibited. These results were discussed in relation to the role of RA as the morphogen in normal limb development and experimental duplicate formation.

A gradient of responsiveness to the growth-promoting activity of ZPA (zone of polarizing activity) in the chick limb bud

Limb bud mesoderm of stage 22-23 embryos was dissected into four pieces along the anteroposterior axis and dissociated cells of each region were separately cultured under various conditions. When the cells were cultured in medium containing 0.1% fetal calf serum (serum-poor medium) only a slight increase in cell number occurred in the cultures of all four regions. However, when the cells were cultured in medium containing 10% FCS, only cells of two central regions proliferated rapidly, and no growth promotion was observed in cells in the most anterior and posterior regions. Using the serum-poor medium, we examined the growth-promoting effects of cocultured limb bud fragments and of some growth factors on the cells of four regions. Anterior, distal, and proximal fragments promoted cell proliferation and their promotive effect on the cells of each region was equal. On the other hand, posterior fragments (containing ZPA) showed stronger promotive effects on preaxial cells than on postaxial cells. For comparison with the growth-promotive effect of the posterior fragment, fibroblast growth factor (FGF), epidermal growth factor (EGF), insulin, and retinoic acid were tested in cell culture. FGF showed position-dependent growth promotion, while EGF and insulin promoted growth in the cells of all four regions to a similar degree. Retinoic acid showed no effect on cell growth at low concentrations, and was rather toxic at high concentrations. These results suggest that the cells of the posterior region secrete an FGF-like growth factor(s), which controls normal limb development and experimental duplicate formation.

Determination of the distribution of nerve conduction velocities in chain saw operators

By measuring the distribution of conduction velocities (DCV) in sensory fibres of the median nerve, the effects of local vibration on all faster and slower large myelinated nerve fibres were examined in 10 male chain saw operators (three operators had frequent attacks of white finger; the attacks were only occasional in four and negative in three). All parameters of DCV, and conventional sensory nerve conduction velocity were significantly slowed in the chain saw operators. It is suggested that local vibration affects the faster and slower nerve fibres; parameters of the DCV are sensitive indicators of both the neurological and vascular effects.

Circadian rhythms in the urinary excretion of heavy metals and organic substances in metal workers in relation to renal excretory mechanism: profile analysis

Circadian rhythms in the urinary excretion of eleven heavy metals and organic substances were examined under free, water-restrictive and water-loading conditions for 6 d (2 d for each of the three conditions) in twenty metal workers exposed to lead, zinc and copper. Circadian rhythms were found for all heavy metals and organic substances as well as for urinary flow (UF) rate, creatinine (Cn) and total urinary solutes (TUS). The Cn rhythm was significantly unparallel to the UF rhythm under the water-loading condition, indicating that the two rhythms were essentially different from each other. Circadian rhythms of the eleven urinary substances were then related to the Cn and UF rhythms, using profile analysis. The results indicated that the rhythms in the manganese, chromium, copper and beta-2-microglobulin excretion depend on the Cn rhythm, i.e. the rhythm of glomerular filtration; the rhythms in the hippuric acid, delta-aminolevulinic acid and TUS excretion are on the UF rhythm, i.e. the rhythm of reabsorption by the distal tubule and collecting duct. On the other hand, the rhythms in the lead, inorganic mercury, cadmium, zinc and coproporphyrin excretion were considered as reflecting complex renal excretory mechanisms.

Central and peripheral nervous system dysfunction in workers exposed to lead, zinc and copper. A follow-up study of visual and somatosensory evoked potentials

To evaluate the effects of lead, zinc and copper in the causation of physiological changes in the central and peripheral nervous systems, we measured the latencies of pattern-reversal, visually-evoked potential (VEP) and of short-latency, somatosensory-evoked potential (SSEP) twice at a 12-month interval in nineteen gun metal founders exposed to lead, zinc and copper. The workers' initial blood-lead (BPb) concentrations ranged from 16 to 64 (mean 42) micrograms/dl. BPb and plasma zinc and copper concentrations decreased significantly during the study period owing to the improvement in working environments. In the first examinations, we found that the N2 latency of VEP (conduction time from the retina to the visual cortex) and the N9-N13 latency of SSEP (conduction from the brachial plexus to the medulla oblongata) were both significantly prolonged in exposed workers. In the second examination, the N2 latency had returned to the "normal" level. These changes were correlated positively with changes in the indicators of lead absorption and inversely with changes in the indices of zinc and copper absorption. In the first examination, the N9 latency of SSEP (median nerve conduction) was also found to be significantly prolonged. This change also returned to normal over the study period in proportion to the reduction in BPb and the increase in intra-erythrocytic enzyme delta-aminolevulinic acid dehydratase activity. On the other hand, no significant prolongation of the N13-N20 latency of SSEP (central nerve conduction) was found in either of the two examinations; this latency and alteration over the study period were inversely correlated with the indicators of zinc and copper absorption. These data suggest that lead interferes with both peripheral and central nerve conduction. zinc and copper appear to antagonize strongly the lead-induced conduction delay in the upper central nervous system, but only weakly in the lower central and peripheral nervous systems.

Effects of lead, zinc and copper absorption on peripheral nerve conduction in metal workers

To examine the antagonistic effects of lead, zinc and copper on the nervous system in man, we measured maximal motor and sensory conduction velocities (MCV and SCV, respectively) in the distal radial and median nerves in 20 gun metal founders with asymptomatically increased absorption of these metals [blood lead concentrations ranged from 16 to 64 micrograms/dl (mean 42)]; and analyzed metal effects on nerve conduction by multiple regression analysis. The MCVs in the radial and median nerves and the SCV in the forearm segment of the median nerve were significantly slowed; indicators of lead absorption (urinary delta-aminolevulinic acid and coproporphyrin) were inversely correlated with the SCV in the radial nerve. The SCVs in the radial nerve and in the hand segment of the median nerve, which were not significantly slowed, were positively related to indicators of copper absorption (plasma or erythrocyte copper). The SCV in the radial nerve was also positively related to the indicator of zinc absorption (plasma zinc); similarly, the MCVs in the radial and median nerves were positively related to the indicators of zinc absorption (erythrocyte or urinary zinc). These findings suggest that copper and zinc antagonize the subclinical effects of lead on peripheral nerve conduction velocities; the conduction velocity in the distal radial nerve is sensitive not only to asymptomatic lead absorption but also to zinc and copper absorption.

Assessment of central and peripheral nerve functions in chain-saw operators: a study of short-latency somatosensory evoked potential and peripheral nerve conduction

In order to clarify the effects of local vibration on the peripheral and central nervous system, peripheral (median) nerve conduction velocities and short-latency somatosensory evoked potentials (SSEP) following stimulation of the median nerve at the wrist were measured in 15 male forest workers in 1986. They had engaged in chain-saw operation for 16-34 (mean 22) years; their working days in 1985 averaged 124 days with a range of 50-203 days. The results indicated significant delays in maximal motor and sensory nerve conduction velocities followed by prolongation of all 4 peak latencies of SSEP up to the sensory cortex of the brain (N9, N13, N20 and P23 latencies) in chain-saw operators; their N9 and P23 latencies were significantly correlated with total working days per year. On the other hand, no significant prolongation of the interpeak latencies of SSEP (i.e., cervico-spinobulbar and central conduction times) was found in the workers. It is concluded that local vibration predominantly affects peripheral nerve conduction; cervico-spinobulbar and central nerve conduction may not be significantly affected.

Seasonal variation in suicide rates by cause and sex

Seasonal variations in cause- and age-specific suicide rates in males and females were analysed in Osaka, Japan, for the years 1974–83, using profile analysis. Significant cause differences were found in males: (1) the rate for poisoning by domestic, car-exhaust or other gases was high in winter and spring and low in summer and autumn; (2) the rate for hanging, strangulation and suffocation was low in winter; (3) the rate for a variety of violent methods (chemicals, firearms, drowning, etc.) was high in summer. Similarly, there were sex differences in the variation for causes (2) and (3) and for ages 40–54. No significant age difference was found in either sex. Seasonal differences in the ease of suicidal methods and sex- and season-specific psychosocial factors were thought to be the major determinant of the seasonal variation.

Mobilisation of heavy metals into the urine by CaEDTA: relation to erythrocyte and plasma concentrations and exposure indicators

To investigate the effects of calcium disodium ethylenediamine tetra-acetate (CaEDTA) on the urinary excretion, erythrocyte, and plasma concentrations and exposure indicators of seven heavy metals, CaEDTA was administered by intravenous infusion to 20 workers exposed to lead, zinc, and copper. The workers' blood lead concentrations ranged from 22 to 59 micrograms/dl (mean 38 micrograms/dl (1.8 mumol/l]. The 24 hour urinary excretion of metals after CaEDTA administration (mobilisation yield) was on average 13 times the background excretion for lead, 11 times for zinc, 3.8 times for manganese, 3.4 times for cadmium, 1.3 times for copper, and 1.1 times for chromium; no significant increase was found for mercury. The mobilisation yield of lead (MPb) was significantly correlated with whole blood and erythrocyte concentrations and the urinary excretion of lead but not with its plasma concentration; similarly, the mobilisation yield of cadmium was significantly correlated with its erythrocyte concentration. In addition, MPb was significantly correlated with intra-erythrocytic enzyme delta-aminolaevulinic acid dehydratase activity and urinary coproporphyrin excretion. The relation between the mobilisation yield of heavy metals and their body burden (and toxic signs) is discussed in the light of these findings.

Comparison of the effects of urinary flow on adjusted and non-adjusted excretion of heavy metals and organic substances in 'healthy' men

The effect of variation in urinary flow rate (ml urine min-1, UF) on adjusted and non-adjusted urinary excretion of metals and organic substances was examined in ten 'healthy' men. The effect of UF was found to be eliminated when urinary concentrations of lead (Pb), hippuric acid (HA), delta-aminolevulinic acid (ALA) and coproporphyrin (CP) were adjusted to urinary specific gravity and to UF. Similarly, the effect of UF on inorganic mercury (Hg) was eliminated when the concentration was adjusted to timed excretion and to UF. The effect on zinc (Zn) and copper (Cu) was eliminated when adjusted to urinary creatinine (Cn) and to UF. The difference in the effect of UF on the adjusted urinary excretion was explained by the effect of UF on timed excretion of substance, which was ranked in the following order: Pb, HA, total urinary solutes, ALA and CP; Zn; Cu; Cn; and Hg. It was concluded that 'UF-adjusted concentration' is applicable to measurement of all substances in urine as a method of minimizing UF effects, while the other three adjustment methods have only limited uses.

Filterable plasma concentration, glomerular filtration, tubular balance, and renal clearance of heavy metals and organic substances in metal workers

To estimate "filterable" plasma concentration (FPx), glomerular filtration, tubular balance, and renal clearance of heavy metals and organic substances, the authors examined the regressions of the 24-hr urinary excretion on glomerular filtration rate [GFR, 24-hr endogenous creatinine (Cn) clearance] in 19 gun-metal foundry workers with blood lead (Pb) concentrations of 25-59 micrograms/dl. It was estimated that the proportion of FPx to total plasma concentration was on average 15, 7, 3, 0.6, 0.06, and 0.008% for Pb, cadmium (Cd), manganese (Mn), zinc (Zn), chromium (Cr), and copper (Cu), respectively. The estimated FPx value was 2.8 X 10(2), 4, 0.08, and 2.8 X 10(4) micrograms/dl for hippuric acid (HA), delta-aminolevulinic acid (ALA), coproporphyrin (CP), and total urinary solutes (TUS), respectively. The estimated glomerular filtration was significantly greater than the zero level for all substances but inorganic mercury (Hg). Similarly, the estimated net tubular secretion was significantly greater than the zero level for Cr, Cu, and TUS; the net tubular reabsorption was significantly greater than the zero level for Pb, ALA, and CP. The renal clearance of "filterable" plasma substance was significantly greater than GFR for Cr, Cu, and TUS and was significantly smaller for Pb, ALA, and CP. Thus the renal excretory mechanisms of substances were classified into four major categories: glomerular filtration for Cd, Mn, Zn, HA, and Cn; glomerular filtration and net tubular secretion for Cr, Cu, and TUS; glomerular filtration and net tubular reabsorption for Pb, ALA, and CP; and no glomerular filtration, i.e., suspected tubular secretion, for Hg.

Adjustment of urinary concentration to urinary volume in relation to erythrocyte and plasma concentrations: an evaluation of urinary heavy metals and organic substances

The effects of urinary volume on adjusted and nonadjusted urinary excretion of 11 heavy metals and organic substances were examined in relation to plasma and erythrocyte concentrations in 19 metal workers under conditions of water restriction and loading. Blood lead concentrations in these workers ranged from 25 to 59 micrograms/dl. The results indicated that: urinary volume significantly affects not only nonadjusted urinary concentration for all substances, but also affects timed excretion and concentrations adjusted to urinary specific gravity and to urinary creatinine for most substances; the concentration adjusted to urinary volume is, on the other hand, independent of urinary volume; and urinary excretion of lead and mercury is related more closely to erythrocyte concentration than to plasma concentration. This last finding reflects complex renal excretory mechanisms for these heavy metals.

Determination of the distribution of conduction velocities in workers exposed to lead, zinc, and copper

By measuring the distribution of conduction velocities (DCV) in sensory fibres of the median nerve, the effects of asymptomatic increased lead, zinc, and copper absorption on the conduction velocities of slower and faster nerve fibres were examined in 29 gun metal founders with blood lead (BPb) concentrations of 22-59 (mean 39) micrograms/dl (1.1-2.8 (mean 1.9) mumol/l). The results indicated that the conduction velocities of slower fibres were inversely affected by lead absorption, resulting in a significant reduction in the velocities at the BPb level of 40-59 micrograms/dl; on the other hand, the conduction velocities of faster fibres and the conventional sensory nerve conduction velocity were presumably positively affected by zinc absorption without a significant reduction in the velocities of faster fibres. It is suggested that assessment of the possible antagonistic effect of zinc is essential when conduction velocities are not decreased in lead exposed workers.

Psychological performance in relation to central and peripheral nerve conduction in workers exposed to lead, zinc, and copper

Psychological performance was examined in relation to central and peripheral nerve conduction by means of the Wechsler Adult Intelligence Scale test, short-latency somatosensory-evoked potential (SSEP), and median nerve conduction velocity in 19 male gun-metal foundry workers exposed to lead, zinc, and copper. (Their blood lead concentrations--ie, 16-64 micrograms/dl with a mean of 42--and plasma zinc and copper concentrations were significantly higher than those of control subjects). In these workers, the score of picture completion (psychological performance) was significantly low; indicators of lead absorption, but no indicators of zinc and copper absorption, were significantly correlated with this score. The score of picture completion was significantly correlated with the N11-N13 latency of SSEP (conduction time in the spinobulbar region) in the workers; their N11-N13 latency, together with the N9 and N9-N11 latencies, was significantly prolonged and was significantly correlated with indicators of lead absorption. Furthermore, their maximal motor and sensory conduction velocities of the median nerve were significantly slowed. It is concluded that both psychological performance and central and peripheral nerve conduction may be impaired in lead-exposed workers with BPb's below approximately 60 micrograms/dl.

Subclinical cervico-spino-bulbar effects of lead: a study of short-latency somatosensory evoked potentials in workers exposed to lead, zinc, and copper

Subclinical central and peripheral nervous system dysfunction among lead-exposed workers was studied by measuring short-latency somatosensory evoked potentials (SSEP) and maximal motor and sensory nerve conduction velocities (MCV and SCV) following stimulation of the median nerve at the wrist. The examinations were conducted in 20 gun-metal foundry workers exposed to lead, zinc, copper, and tin, with blood lead (BPb) concentrations of 16 to 64 micrograms/dl (mean, 42 micrograms/dl). The interpeak latency of SSEP in the cervico-spino-bulbar region [N9(Erb)-N13 latency] was significantly prolonged, and the MCV and SCV in the forearm were significantly slowed. Multiple regression analysis revealed that the yield of urinary lead following challenge with calcium disodium ethylenediamine tetraacetate (CaEDTA) and packed red blood cell volume were the major factors associated with the prolongation of SSEP latency in the cervico-spino-bulbar region. Similarly, the interpeak latency in the upper central nervous system (N13-N20 latency) was inversely related to the zinc concentration in erythrocytes; latency up to the Erb's point [N9(Erb) latency], which reflects conduction time in a long pathway of the sensory median nerve, was inversely related to urinary zinc level; the MCV and SCV in the palm were positively related to erythrocyte zinc concentration and plasma copper concentration, respectively. These findings suggest that the subclinical neurophysiological effects of lead occur not only in peripheral nerves but also in the central nervous system. It appears that zinc antagonizes the central and peripheral neurologic dysfunction caused by lead; similarly, copper antagonizes the peripheral sensory nerve dysfunction.

The effects of CaEDTA injection on lead, zinc, copper and ALAD in erythrocyte, plasma and urine in lead-exposed workers: a 24-h observation

To evaluate the effects of calcium disodium ethylenediamine tetraacetate (CaEDTA) on the concentrations of lead, zinc and copper in plasma, erythrocyte and urine, and the delta-aminolevulinic acid dehydratase (ALAD) activity in erythrocyte, we administered CaEDTA in 1-h intravenous infusion to ten male gun metal founders with blood-lead concentration of 39 to 64 micrograms/dl (mean 49 micrograms/dl). We found that the plasma concentration of lead, following a rapid rise within the first 3 h, fell temporarily to the level significantly lower than the initial level 19 h after start of the infusion. The plasma concentration of zinc fell to the minimal level 5 h after the infusion; and the erythrocyte concentration of zinc and the ALAD activity concurrently rose to the maximal level 5 h after the infusion. By contrast, no significant alteration was observed in the concentrations of copper in plasma and erythrocyte. The maximal level of urinary metal excretion was attained during the period between 1 and 2 h after start of CaEDTA infusion for lead; within 2 h for zinc; and between 2 and 4 h for copper. The urinary metal excretion returned to the initial level 14 to 24 h after infusion for zinc and copper; but lead excretion was still higher than the initial level during this period. The difference in the kinetics of the three metals following CaEDTA injection is discussed in the light of these findings.

Behavior of lead and zinc in plasma, erythrocytes, and urine and ALAD in erythrocytes following intravenous infusion of CaEDTA in lead workers

To evaluate the effect of calcium disodium ethylenediamine tetraacetate (CaEDTA) on concentrations of lead and zinc in plasma, erythrocytes, whole blood, and urine, we administered CaEDTA by intravenous infusion for 1 hr to seven lead workers with blood lead concentrations of 46-67 micrograms/100 g (mean 54 micrograms/100 g). The plasma lead concentration (PPb) and the mobilization yield of lead in urine by CaEDTA were highest during the period between 1 and 2 hr after the infusion was started. In contrast, the lead concentration in erythrocytes (EPb) and in whole blood (BPb) remained unchanged during the 24 hr following infusion. Plasma zinc concentration (PZn) also fell rapidly following CaEDTA infusion; the decline was followed by a gradual rise in the zinc concentration in erythrocytes (EZn) without alteration in the zinc in whole blood. The mobilization yield of zinc in urine by CaEDTA (MZn) reached its highest level within 1 hr after the start of the infusion. Delta-aminolevulinic acid dehydratase (ALAD) activity in erythrocytes gradually increased for 5 hr following CaEDTA infusion. These observations suggest that (1) PPb concentration is a more sensitive indicator of the body burden of chelatable lead than is either BPb or EPb; (2) MZn is mobilized mostly from plasma during the first several hours following the start of CaEDTA infusion, and the fall in PZn concentration following infusion is compensated first by a rise in EZn concentration and then by an immediate redistribution of zinc in other organs to the blood; and (3) Pb-inhibited ALAD activity is reactivated by the increased EZn during and shortly after CaEDTA infusion.

A comparison of the diminution rates of lead in blood and lead mobilized by CaEDTA after termination of occupational exposure: a long-term observation in two lead workers

CaEDTA 20 mg/kg was administered weekly for 3.5 years after termination of occupational exposure to two lead workers. The diminution half-lives for lead in blood and urine lead mobilized by CaEDTA were 4.8 and 3.3 years respectively for subject 1 following 28 years exposure and 3.3 and 2.0 years respectively for subject 2 following 26 years exposure. The difference in the diminution rate between lead in blood and lead mobilized by CaEDTA was significant in subject 2 (p less than 0.05).

Evolutionary significance of the system utilizing D-amino acid enantiomers

The evolutionary significance of the system utilizing D-amino acid enantiomers in living organisms is discussed, based on an experiment in which the mutant from Escherichia coli K--12 4627 grown on D-tryptophan was used. The mutant shows the ability of D-tryptophan is degraded to indol which can be utilized for the synthesis of L-tryptophan in the presence of serine.

Effect of mutation to streptomycin resistance on amber suppressor genes

Three classes of nonidentical streptomycin-resistant mutations were distinguished in Escherichia coli by their effect on the efficiency of suppression by an amber suppressor gene, sup E. The first class of mutation caused a strong restriction in efficiency of suppression of an amber codon in various cistrons of phage lambda and in an alkaline phosphatase structural gene of E. coli. The second class caused weak restriction, and the third class caused no restriction. The restrictive effect of the streptomycin resistance mutation of the first class on the sup E gene was reduced by addition of streptomycin. This mutation had little effect on efficiencies of suppression by amber suppressor genes sup D and sup F. Analyses on the alkaline phosphatase formed in the suppressor strain indicated that mutation to restrictive streptomycin resistance causes a reduction in translation of the amber codon in the alkaline phosphatase structural gene.