Effects of B vitamins on glutamate-induced neurotoxicity in retinal cultures

The effects of B vitamins on glutamate-induced neurotoxicity were examined using primary cultures obtained from the rat retina. Cell viability was markedly reduced by a brief exposure to glutamate followed by incubation with glutamate-free media for 1 h. Glutamate cytotoxicity was reduced in the cultures that had been maintained in thiamine-, pyridoxine- or nicotinamide-containing medium before the exposure to glutamate. Glutamate cytotoxicity was also reduced by chronic application of thiamine pyrophosphate and pyridoxal phosphate, which are active coenzyme forms of thiamine and pyridoxine, respectively. By contrast, chronic application of riboflavin, pantothenate, biotin, folic acid and inositol did not affect glutamate cytotoxicity. None of the B vitamins tested had any effect on glutamate cytotoxicity when added only during the exposure to glutamate. These findings suggest that chronically applied thiamine, pyridoxine and nicotinamide protect retinal neurons against glutamate cytotoxicity.

Pharmacokinetic study on acetaminophen: interaction with a Chinese medicine

To know the influences of a Chinese traditional medicine (KAKKONTO) on the metabolism of acetaminophen (APAP), we have carried out pharmacokinetic studies on APAP under KAKKONTO coadministration in humans and rats. In humans, the pharmacokinetic parameters were calculated from the blood APAP concentration-time curves of each volunteer. The parameters did not show any significant differences between the KAKKONTO-coadministration group (group K) and the APAP-administration group (group A). KAKKONTO, when given at two different doses, did not show any significant effects on blood APAP level. In rats, the blood APAP level was significantly higher than that of group A (p < 0.01) only in the 100 mg/kg of group K at 0.25 h after APAP administration. There were no other significant differences.

Mycobacterium tuberculosis enhances human immunodeficiency virus-1 replication in the lung

We investigated the in vivo effect of coinfection of Mycobacterium tuberculosis on human immunodeficiency virus type 1 (HIV-1) replication using bronchoalveolar lavage (BAL) of 11 HIV-1-infected patients with pulmonary tuberculosis and 10 patients with no lung disease. Lung segments involved with pulmonary tuberculosis had significantly elevated HIV-1 branched DNA (bDNA) levels and p24 in BAL compared with lung segments uninvolved with tuberculosis or with BAL from patients with no lung disease. The BAL viral burden was higher than plasma HIV-1 in tuberculosis patients, indicating local production of virus. BAL HIV-1 bDNA declined over the course of treatment for tuberculosis in three patients who underwent serial bronchoscopies. Tumor necrosis factor-alpha (TNF-alpha) and HIV-1 bDNA particles were strongly correlated (r2 = 0.9, p < 0.01) in lung segments involved with tuberculosis. The deduced amino acid sequence of HIV-1 gp120 V3 region from involved segments of three patients with pulmonary tuberculosis showed basic substitutions associated with altered viral phenotype. Phylogenetic analysis of V3 sequences demonstrated that BAL HIV-1 RNA had diverged from plasma. These data support the conclusion that pulmonary tuberculosis enhances local HIV-1 replication in vivo.

Osteogenic protein-1 stimulates mRNA levels of BMP-6 and decreases mRNA levels of BMP-2 and -4 in human osteosarcoma cells

Bone morphogenetic proteins (BMPs) are novel growth and differentiation factors that act on mesenchymal stem cells to initiate new bone formation in vivo and promote the growth and differentiation of cells in the osteoblastic lineage. In the present study, we examined the effects of recombinant human osteogenic protein-1 (also known as BMP-7) on the expression of related members of the BMP family using SaOS-2 and U2-OS, two human osteosarcoma cell strains. Evaluation of BMP-2, -4, and -6 mRNA expression indicates that OP-1 stimulated the mRNA levels of BMP-6 in both SaOS-2 cells (threefold) and U2-OS cells (fivefold) after 24 hours of treatment, while decreasing the mRNA levels of BMP-4 in SaOS-2 cells (80%) and BMP-2 and BMP-4 in U2-OS cells by 50% and 72%, respectively. BMP-2 mRNA expression, as examined by Northern blot analysis, was below detectable limits in SaOS-2 cultures. These results demonstrate that OP-1 modulates the mRNA expression of related members of the BMP family, suggesting a possible mode of action of OP-1 on the growth and differentiation of cells in the osteoblastic lineage in vitro.

Contribution of peripheral chemoreceptor drive in exercise hyperpnea in humans

The peripheral chemoreceptors play a dominant role in the respiratory compensation of lactic acidosis during heavy exercise of humans. Our object was to determine the contribution of peripheral chemoreceptors to exercise hyperpnea during mild to moderate and heavy exercise above the anaerobic threshold. We used a hyperoxic suppression test in six normal male subjects. Inspired gas was abruptly changed without the subject's knowledge from air to pure oxygen for 5 to 6 breaths. The maximal ventilatory depression after O2 breathing was 5.5 +/- 1.7 L/min (BTPS) at mild exercise, and the depression increased with increasing exercise intensity up to 12.8 +/- 4.1 L/min (BTPS). The relative contribution of the peripheral chemoreceptors to ventilation in terms of percentage of the maximal ventilatory depression was maintained, being 20% throughout the entire work ranges studied. The contribution of the peripheral chemoreceptors to total ventilation is hardly altered by lactic acidosis caused by heavy exercise above the anaerobic threshold according to our data. These results suggested that the peripheral chemoreceptors may not be solely responsible for excessive hyperventilation, or residual activities of peripheral chemoreceptors still exist after O2 breathing especially during heavy exercise above the anaerobic threshold.

Recurrence of spontaneous intracranial hypotension with subdural hematomas

A 59-year-old man developed postural headache associated with a low CSF pressure. A CT scan revealed no abnormal findings and the orthostatic symptoms resolved without treatment 6 weeks after onset. He was diagnosed as having spontaneous intracranial hypotension (SIH) and remained symptom-free until he experienced recurrence of postural headache 9 months later. A lumbar puncture demonstrated low CSF pressure, and a CT scan revealed slit-like ventricles with narrowing of the sulci, Sylvian fissures, and infratentorial cisterns, in addition to bilateral subdural masses. After draining the hematomas, his symptoms resolved completely, and a follow-up CT scan was normal. We hypothesize that recurrent SIH in this case was due to small recurrent tears of a root sleeve. This case emphasizes the importance of follow-up of SIH for at least 9 months after resolution of symptoms.

Expression of neurotrophic factors in cultured human retinal pigment epithelial cells

PURPOSE

To see if cultured human retinal pigment epithelial (RPE) cells have the capacity to synthesize neurotrophins, including nerve growth factor (NGF), brain-derived growth factor (BDNF), and neurotrophin-3 (NT-3).

METHODS

Expression of mRNAs for the neurotrophins was studied by the reverse transcription polymerase chain reaction (PCR) method. Quantitative analysis of the gene expression was done by using a semiquantitative PCR method. Secretion of NGF-like immunoreactivity (NGF-LI) into the culture medium was analyzed by enzyme immunoassay (EIA).

RESULTS

Cultured human RPE cells were found to express mRNAs for NGF, BDNF and NT-3. In the conditioned culture medium of the human RPE, 9.44 +/- 0.62 pg/ml (mean +/- SEM, n = 6) NGF-LI was found. Pretreatment of human RPE cells with interleukin-l (IL-1) (20 ng/ml), phorbol myristate acetate (PMA) (100 ng/ml) or tumor necrosis factor-alpha (TNF-alpha) (40 ng/ml) was found to increase the mRNA expression of neurotrophins and also to increase secretion of NGF-LI into the culture medium.

CONCLUSIONS

Our data demonstrate that cultured human RPE cells have the capacity to synthesize neurotrophins, and that various stimulations can up-regulate gene and protein expression of NGF by these cells.

Effects of exposure to hypobaric-hypoxia on body weight, muscular and hematological characteristics, and work performance in rats

The metabolic activities of skeletal muscles were studied in male rats exposed to hypobaric-hypoxia at about 550 Torr for 8 h per day for 2 weeks. Rats were divided into three groups; control (normoxic control), diurnal hypoxic (DH) exposure, and nocturnal hypoxic (NH) exposure groups. The changes in body weight and daily diet intake of the NH group were lower than the other groups (p < 0.01). The weights of fat in the abdominal cavity of both NH and DH groups were less than that of the control group. The red blood cell count, hemoglobin concentration, and hematocrit values were significantly increased in the hypoxic groups. The plasma glucose level in the NH group was significantly less than the control group (p < 0.05). The lactate dehydrogenase/citrate synthase (LDH/CS) activity ratios in the skeletal muscle tended to be lower in both hypoxic groups than in the control group. The swimming times to exhaustion at mild and high intensities that were measured after 2 weeks, loaded with a weight equivalent to 2.5% of the body weight, improved in the DH group. There were insignificant differences in the metabolic activity of skeletal muscles and blood characteristics between the NH and DH groups, but endurance swimming times in the DH group tended to be improved as compared to the NH group. We conclude that the DH group became competent in endurance work, which is believed to be driven from the combined effects of increased O2 transport capacity of the blood and enhanced O2 utilization capability by mitochondrial enzyme activity.

Impact of curve distortion errors on intravascular ultrasound measurements and three-dimensional reconstructions

Intravascular ultrasound distortion errors and longitudinal reconstructions are primarily determined by the angle of curvature. The error in commonly encountered angles is relatively small.

Acute left ventricular dysfunction and left ventricular thrombus in a patient with cerebral hemorrhage

A 66-year-old woman was admitted to the hospital with a cerebral hemorrhage. An echocardiogram showed severe left ventricular hypokinesis and a left ventricular thrombus. An electrocardiogram showed ST segment elevation in the precordial leads. The patient's creatine kinase level was elevated. A follow-up echocardiogram performed 1 month after admission showed normalization of left ventricular wall motion and disappearance of the thrombus. The results of thallium myocardial scintigraphy, coronary arteriography, and left ventriculography performed 1 month after admission were normal, and the patient was discharged without clinical sequelae. The cause of the patient's left ventricular dysfunction was believed to be not myocardial infarction or myocarditis, but a massive adrenergic discharge due to the cerebral hemorrhage.

Multicenter genetic study of retinitis pigmentosa in Japan: I. Genetic heterogeneity in typical retinitis pigmentosa

A nationwide, multicenter study of typical retinitis pigmentosa (RP) was carried out in collaboration with 18 hospitals throughout Japan to obtain current information for genetic counseling. We analyzed the genetic heterogeneity of RP based on the parental consanguinity of 434 probands registered during a 6-month period in 1990. A gradual decline in the frequency of consanguineous marriage was recognized among the normal parents of RP patients. The relative frequencies of inheritance patterns were estimated as: autosomal recessive, 25.2%; autosomal dominant, 16.9%; X-linked, 1.6%; and simplex, 56.3%. A comparison of these results with previous reports in Japan revealed a decline in the relative frequency of autosomal recessive cases and an increase in simplex cases. This suggests a decrease in the incidence of autosomal recessive retinitis pigmentosa in Japan, as well as the necessity for exhaustive investigations aimed at identifying inheritance patterns for RP patients seeking genetic counseling.

Analysis of localization of adult T-cell leukemia-derived factor in the transient ischemic rat retina after treatment with OP-1206 alpha-CD, a prostaglandin E1 analogue

Prostaglandin E1 (PGE1) is commonly used in therapy for obstructive diseases, including ischemic retinopathy, in which pathogenetic reactive oxygen intermediates are responsible. However, the mechanism(s) of PGE1 in reducing tissue damage is still unclear. Adult T-cell leukemia-derived factor/human thioredoxin (ADF) is induced by oxidative stresses and has protective activity against oxidative cellular injury. To evaluate the possible involvement of ADF in the tissue-protective effect of PGE1, we analyzed ADF expression immunohistochemically using a rat transient retinal ischemia model. Rats were treated orally with 300 micrograms/kg/day OP-1206 alpha-cyclodextrin clathrate (OP-1206), a stable PGE1 analogue, for 14 days after photodynamic retinal vascular thrombosis by rose Bengal. Rats without any OP-1206 treatment were used as controls. In the OP-1206-treated rats, minimal retinal atrophy due to ischemia/reperfusion was observed histologically up to 14 days, whereas in the non-treated rats the inner layer of the retina became markedly atrophic. In parallel with the histological change, after 14 days following thrombosis ADF immunoreactivity was preserved on retinal pigment epithelial cells in the OP-1206-treated rats, whereas it was diminished in the non-treated rats. These findings suggest an important role for ADF in the OP-1206-dependent suppression of retinal tissue damage caused by oxidative insult.

Multicenter genetic study of retinitis pigmentosa in Japan: II. Prevalence of autosomal recessive retinitis pigmentosa

Retinitis pigmentosa (RP) is a group of genetically heterogeneous diseases with autosomal recessive (AR), autosomal dominant, and X-linked modes of inheritance. Autosomal recessive retinitis pigmentosa (ARRP) is the most common form in Japan. A genetic analysis was done to determine the prevalence of ARRP indirectly, to provide an estimation of changing trends in the overall prevalence of RP. Data on the frequency of consanguinity and marriage year of normal parents of 59 ARRP patients were obtained from a nationwide multicenter survey of typical retinitis pigmentosa conducted in 1990. The gene frequency of ARRP was 0.01145 (Dahlberg's formula). In 1990, the number of young symptomatic ARRP patients decreased, while the number of patients aged 40 years and older increased. The total number of symptomatic ARRP patients in 1990 was nearly 21% higher than in 1970. Despite a dramatic decline in consanguinity in recent decades in Japan, the number of ARRP patients has increased. This increase is attributed to greater longevity and overall population growth. Our results suggest that the total number of RP patients has not decreased, and may even have increased.

Morphologic and histochemical evaluation of muscle in patients with chronic pulmonary emphysema manifesting generalized emaciation

Twelve severely emaciated patients with emphysema and 4 control patients with mild emaciation were studied. Arterial blood gas analysis, pulmonary function tests, and muscle biopsy were performed. According to the percentage of ideal body weight (%IBW), patients were divided into two groups of 6 patients each; one with %IBW values greater than 70.0 (group 1) and the other with %IBW values less than 70.0 (group 2), and 4 control patients with emphysema whose %IBW values were greater than 85.5. %FEV1.0, PaO2 and Hugh-Jones scores in group 2 patients were consistent with significantly greater deterioration as compared with those in group 1 patients and controls. In the muscle fibers of 11 patients and 4 controls, nicotinamide and adenosine dinucleotide tetrazolium reductase activity was studded with spots. Nemalin rods were detected in 3 specimens in group 2 and in 1 specimen each in both group 1 and controls. These changes probably result from chronic hypoxemia. Fiber type grouping accompanied by type II dominant fiber atrophy was demonstrated in 5 patients of group 2, whereas type II fiber atrophy was shown in 2 specimens from patients of group 1. Diameters of both types I and II fibers in group 2 were smaller than those in group 1 and controls. Significant correlations were observed between fiber diameters and %IBW, %FEV1.0 and %IBW, and PaO2 and %IBW. Neurogenic and disuse muscular atrophy due to both hypoxic axonal disorder and disuse is likely to be the cause of the emaciation, and a 'vicious circle' between muscular atrophy, respiratory function and hypoxemia probably exists in group 2. Since mild or moderate emaciation was observed in controls and group 1 in spite of the lack of fiber atrophy, involvement of fat and connective tissue should also be taken into consideration to determine the cause of emaciation.

Monoclonal antibody #5-2-26 recognizes the phosphatase-sensitive epitope of rabies virus nucleoprotein

We prepared monoclonal antibodies (MAbs) against the rabies virus N protein, among which one antibody (MAb 5-2-26) was shown to lack reactivity with the phosphatase-treated N protein. The MAb was able to recognize the sodium dodecyl sulfate (SDS)-denatured N protein. The MAb did not recognize the N-protein analogues produced in Escherichia coli (E. coli), indicating that the N-gene products were not normally processed in E. coli after translation. On the other hand, the MAb reacted normally with N-gene products produced in COS-7 cells, but not with those produced in the presence of K-252a (a protein kinase inhibitor of a broad spectrum). The MAb displayed weak cross-reactivity with the Triton-insoluble network structures composed of several components, while another phosphoprotein (M1) of the virus was not recognized at all. These results suggest that MAb 5-2-26 preferentially recognizes a phosphatase-sensitive linear epitope of N protein, which may enable further investigations to be conducted on the mechanism of N-protein phosphorylation and its role(s) in virus replication.

Heterocyclic analogues of quinone methide: preparation and cytotoxicity of 3-oxo-3H-pyrazolo[1,5-a]indole derivatives

A series of 3-oxo-3H-pyrazolo[1,5-a]indole derivatives was prepared and characterized as heterocyclic analogues of quinone methide. These compounds showed some cytotoxicity to cancer cells, but were ineffective in an in vivo test against murine leukemia L1210.

Detached retina affects morphologic and biochemical changes in the retina adjacent to bullous retinal detachment in rabbits

PURPOSE

Long-term results, more than 10 years after successful retinal detachment surgery, have shown gradually decreasing visual acuity in some cases. It is unclear if reduced functional recovery postoperatively is caused by anatomic changes or biochemical disorders. To determine the etiology of the reduced visual acuity, we cytochemically examined the changes in the cellular responses of the edges of retinal detachments.

METHODS

We histochemically studied the glucose-6-phosphatase (G6P) and 5'-nucleotidase (5'-Nase) activity in the rabbit retina. Experimental rhegmatogenous retinal detachment was produced in a rabbit model after partial vitrectomy, followed by retinal tear formation.

RESULTS

Although 5'-Nase activity gradually decreased during the period of detachment, activity was still detectable after 24 weeks. G6P activity increased in the region of the detached neural retina. Around the border of the detached retina, the decrease in 5'-Nase activity extended approximately 140 micrometers into the adjacent attached retina at 2 weeks after detachment and 270 micrometers at 24 weeks.

CONCLUSIONS

These observations suggest that some anatomical and biochemical damages may occur in the retina adjacent to bullous retinal detachment and may explain the reduction in postoperative vision in some clinical cases.

Hypovitaminosis D and decreased bone mineral density in amyotrophic lateral sclerosis

To assess the bone health of patients with amyotrophic lateral sclerosis (ALS), we evaluated the bone density and serum biochemical indices of bone metabolism in 11 ALS patients. The serum concentration of 25-hydroxyvitamin D (25-OHD) was significantly lower in patients (14.0 +/- 3.7 ng/ml) than in controls (25.2 +/- 4.0 ng/ml), at deficient levels (< 10 ng/ml) in 2, and at insufficient levels (10-20 ng/ml) in 9 patients. Serum levels of parathyroid hormone (PTH) and ionized calcium were elevated in 8 and 6 patients, respectively. Dietary intake of vitamin D was below the recommended level (100 IU) in 10 patients, and 10 patients were in a sunlight-deprived state. The metacarpal bone density (MBD) and the metacarpal index (MCI) of the second metacarpal bone were measured by computed X-ray densitometry. Z scores of the MBD and the MCI were negative in 7 and 6 patients, respectively. The serum concentration of 25-OHD was positively correlated with the Z score of the MBD (p < 0.05, r = 0.727) and negatively with the PTH level (p < 0.05, r = -0.410). The degree of dysfunction of hand grip also correlated with the Z score of the MBD (p < 0.05, r = 0.749). These data underscore the importance of hypovitaminosis D and compensatory hyperparathyroidism in the development of osteopenia in patients with ALS.

The anti-inflammatory effects of ketoprofen in animal experiments

The authors investigated the anti-inflammatory actions of ketoprofen using a battery of tests: in the rat paw oedema test induced by five different inciters, in the capillary permeability test, and in measuring the interleukin-8 (IL-8) production and superoxide dismutase (SOD) activity. The findings in these studies show that ketoprofen inhibits rat paw oedema, suppresses capillary permeability, reduces IL-8 production and increases SOD activity in the acetic-acid-induced inflammatory state. These results would seem to provide a clear rationale for exploring the usefulness of ketoprofen in the treatment of acute and chronic inflammatory diseases.

Rupture of lens cataract: a novel hereditary recessive cataract model in the mouse

The RLC is a new mouse model of hereditary cataract. In this mutant, opacity of lens developed spontaneously at 35-60 days of age. The initial histological change was irregular swelling, condensation, degeneration and fragmentation of lens fibers in the deep cortex, leading to rupture of the lens capsule at the posterior pole at 45-100 days of age. Following rupture, the lens nucleus dislocated behind the lens or occasionally in the anterior chamber. Both eyes were affected. Genetic analysis indicated that the mutation was dictated by a single autosomal recessive gene with complete penetrance. Homozygotes of either sex developed cataract with rupture of lens capsule. We named the responsible gene as rupture of lens cataract (rlc) and the mouse strain as RLC. Neither allelism nor linkage was found between rlc and nct, another recessive gene in Nakano cataract mice. The rlc mutation is now fixed in a inbred background since the RLC has been maintained over 20 inbred generations in the laboratory. Although no direct homologous disease of this unusual cataract is found in human, this mutant will provide a valuable tool to investigate the mechanism involved in maintainance of lens.

Effects of obesity, current smoking status, and alcohol consumption on heart rate variability in male white-collar workers

In order to examine the effects of mild to moderate obesity, moderate to heavy smoking, and moderate alcohol consumption on cardiac parasympathetic activities and systemic sympathetic activities, a cross-sectional survey was carried out in 282 healthy Japanese male white-collar workers. Their autonomic activities were assessed as amplitudes of spectral components of heart rate variability (HRV) which was measured in the annual physical examination at their work sites. Taking the effects of aging on HRV into account, the cardiac parasympathetic activity at supine rest and its response to a change in posture were reduced in mildly to moderately obese subjects with a body mass index of 21-36, whereas the sympathetic activity was not. The effects of smoking and alcohol consumption on HRV were not confirmed. The above results means that we should consider obesity as a covariate when we examine possible relationships between cardiac parasympathetic activity and other environmental factors. There is a need for further studies on the relationships among obesity, change in parasympathetic activity, and development of health problems. The dose-effect relationships between long-term smoking or alcohol consumption and chronic changes in autonomic activities also remain to be determined.