The effects of high glucose concentration on angiotensin II- or transforming growth factor-beta-induced DNA synthesis, hypertrophy and collagen synthesis in cultured rat mesangial cells

Hyperglycemia is a principal characteristic of diabetes, and has an influence on many cellular functions. In order to investigate whether the intracellular signaling pathways inducing proliferation, hypertrophy and matrix synthesis of mesangial cells are altered in a diabetic environment, we evaluated the effects of a high concentration of extracellular glucose(25 mM; 450 mg/dl) on [3H]thymidine uptake, hypertrophy, and [3H]proline incorporation into a collagenase-sensitive protein, induced by angiotensin II(Ang II) or transforming growth factor(TGF)-beta, in cultured rat mesangial cells. The exposure to a high glucose concentration for 7 days significantly inhibited Ang II(10(-6) M)-induced [3H]thymidine uptake, compared to normal glucose concentration (5 mM)(M +/- SD., 1050 +/- 100 cpm/well vs 550 +/- 97, p < 0.05), and markedly prevented the inhibition of [3H]thymidine uptake by TGF-beta(1 ng/ml)(132 +/- 10 vs 340 +/- 67, p < 0.05). The administration of H-7(50 microM), a protein kinase C(PKC) inhibitor, did not reverse these effects of high glucose on [3H]thymidine uptake. On flow cytometric analysis of cell size, the mean cell size was significantly greater for the cells exposed to high glucose or treated with Ang II or TGF-beta, compared to that for the untreated cells. But the addition of Ang II or TGF-beta to the cells exposed to high glucose did not show further enlargement in size. The exposure to high glucose and the treatment with Ang II or TGF-beta significantly increased collagen synthesis, measured by [3H]proline incorporation. The Ang II -or TGF-beta-induced increase of [3H]proline incorporation did not show changes under high glucose culture condition, compared to normal glucose concentration(Ang II, 27880 +/- 3560 cpm vs 26978 +/- 2284, TGF-beta, 26559 +/- 3700 vs 25800 +/- 1660, p > 0.05). In conclusion, although the signaling pathway for DNA synthesis by Ang II or TGF-beta are influenced, possibly mediated by PKC-independent mechanism(s), the pathway inducing hypertrophy or collagen synthesis by both agents appears to be unchanged under the high extracellular glucose concentration in cultured rat mesangial cells.

Studies on bone markers and bone mineral density in patients with chronic renal failure

Renal osteodystrophy has become a frequent complication in patients with chronic renal failure (CRF), and various histologic forms such as high turnover, low turnover and mixed bone disease have been demonstrated. The only reliable method for distinguishing patients with high turnover from those with low turnover bone disease is bone histomorphometric study, but its clinical utility is restricted. Because of its invasive nature, efforts have been made to predict indirectly the type and severity of this metabolic bone disease by serum assays. In this cross-sectional study, we measured total and regional (head, arms, trunk, ribs, legs, spine and pelvis) bone mineral densities (BMD) by dual X-ray absorptiometry (DXA) in patients with variable degrees of CRF and correlated them with various bone markers. Decreased BMDs were detected in various skeletal sites (trunk and pelvis) in the patients' group. Total BMD Z score was lower in predialysis CRF patients than in the control subjects. Decreased BMD Z scores on weight-bearing bone were pronounced at L1 lumbar vertebra, femur trochanter, femur neck and Ward's triangle. Positive linear correlations were found between creatinine clearance and trunk, ribs, pelvis, and spine BMDs. There were inverse linear correlations between total BMD and total BMD Z score and alkaline phosphatase (AP), urine deoxypyridinoline (U-DPD) in the patients' group. There were no correlations between regional and total BMD, total BMD Z score and serum calcium, ionized calcium, and serum phosphate. There were inverse linear correlations between BUN, creatinine and bone-specific alkaline phosphatase in the predialysis CRF group. We evaluated the correlations between intact parathyroid hormone (i-PTH) and biochemical and other bone markers. There was statistically significant linear correlation between i-PTH and AP. Other bone markers have no significant correlations with i-PTH. Our results demonstrated that there is significant bone loss in patients with CRF before the start of dialysis and also regional variations of BMDs in predialysis CRF patients. DXA is a useful method for evaluating regional and total BMDs and provides information about diverse regional skeletal changes. AP, i-PTH and U-DPD can predict BMD of predialysis CRF patients.

Regulation of the activity of M-phase promoting factor through protein kinase A-mediated pathway in LP1-1 cells

Treatment of cAMP analogs, dibutyryl cAMP and 8-bromo-cAMP, was found to inhibit the proliferation of mouse fibroblast LP1-1 cells and the p34cdc2 kinase activity of M-phase promoting factor (MPF). However, it showed relatively little effect on expression of the cyclin B1 and cdc2 genes. On the other hand, when the nuclear extracts obtained from the cells at early G2 phase were treated with cAMP analogs, the kinase activity was significantly decreased as compared to the untreated control. Furthermore, the inhibitory effect of cAMP analogs could be reversed upon treating with okadaic acid even in the presence of the cAMP analogs, implying that cdc25 remains in an active form. In addition, the treatment of okadaic acid stimulated the cell progression. These results suggest that down-regulation of MPF activity through protein kinase A-mediated pathway is under post-translational control and cdc25 activation pathway involving okadaic acid-sensitive phosphatase play a role in the regulation of MPF activity.

Cognitive and emotional assessments of perceived risk for HIV among unmarried heterosexuals

We examined perceived risk of contracting HIV using assessments of likelihood and worry in a probability sample of unmarried heterosexuals. Perceptions of the likelihood of contracting HIV and worry about HIV were only modestly correlated (r = .23), suggesting that they are different constructs. Far more respondents expressed worry (43%) than expressed the belief that they were at risk for HIV (9%). A significant proportion of the sample reported experiences that may have placed them at risk for HIV transmission. Demographic and psychosocial correlates of perceived likelihood and worry were examined in separate multivariate logistic analyses. Misconceptions about HIV transmission, a history of injection-drug-using sexual partners, and less education were associated with higher perceived likelihood of contracting HIV. Misconceptions, having multiple sexual partners in the past year, and a history of sexually transmitted diseases (STDs) were associated with high worry about HIV. Implications of the findings for correcting HIV-related misconceptions are discussed.

Thiopurine methyltransferase activity in a Korean population sample of children

Thiopurine methyltransferase (TPMT) is a cytoplasmic enzyme that catalyzes the S-methylation of the cytotoxic drugs 6-mercaptopurine and azathioprine. Red blood cell (RBC) TPMT activity is subject to genetic polymorphism, and we have previously demonstrated an interethnic difference in TPMT activity. To investigate whether there was a race-related difference in RBC TPMT activity, TPMT was measured in a Korean population sample of 309 healthy children. Mean TPMT activity in healthy Korean children was 12.4 +/- 2.4 units/ml RBC, which is similar to the earlier reported TPMT activities in white populations. In contrast to the bimodal or trimodal frequency distributions of RBC TPMT activity in most other population samples, the frequency distribution histogram, the probit plot, and the Shapiro-Wilk test supported a normal distribution of TPMT activity in this Korean population sample of healthy children. Mean RBC TPMT activity showed a tendency to decrease with age, but it was not statistically significant. No gender-related difference in RBC TPMT activity was found.

Induction of E. coli oh8Gua endonuclease by oxidative stress: its significance in aerobic life

The induction of 8-hydroxyguanine (oh8Gua) endonuclease, a DNA repair enzyme for an oxidatively modified guanine, oh8Gua was studied in various growth conditions in Escherichia coli (AB1157). Anaerobically grown E. coli were found to have a very low activity of this enzyme while aerobically grown cells showed activity about 20 times that of the anaerobic level. Under the same condition, superoxide dismutase (SOD) showed about 6-fold increase in activity. A shift in growth conditions from anaerobic to aerobic resulted in rapid induction of this enzyme, and this induction was blocked (but not completely) by chloramphenicol. It is indicated that molecular oxygen is an effective stimulator to the induction of this enzyme and its induction depends partly on protein synthesis. Superoxide-producing compounds such as paraquat and menadione also increased the activity of endonuclease as well as SOD, but H2O2 showed no effect. Thus, superoxides are also implied as a stimulator. In contrast, hyperoxia induced only SOD not the endonuclease. This induction of the endonuclease by hyperoxia was only observed in a SOD-deficient strain (QC774). The aerobic activity of the endonuclease in QC774 was the same as that of wild types (AB1157, GC4468). It is implied that the responsiveness of oh8Gua endonuclease to superoxides is less sensitive than that of SOD. The endonuclease was also induced by a temperature shift from 30 to 43 degrees C and treatment with nalidixic acid. Among the stimuli used, molecular oxygen seems to be most effective for its induction. The inducible nature of this enzyme will serve as an important mechanism for the protection of oxidative DNA damage in the aerobic environment.

Poly(ADP-ribosyl)ation of histone H1 correlates with internucleosomal DNA fragmentation during apoptosis

The biochemical role of poly(ADP-ribosyl)ation on internucleosomal DNA fragmentation associated with apoptosis was investigated in HL 60 human premyelocytic leukemia cells. It was found that UV light and chemotherapeutic drugs including adriamycin, mitomycin C, and cisplatin increased poly(ADP-ribosyl)ation of nuclear proteins, particularly histone H1. A poly(ADP-ribose) polymerase inhibitor, 3-aminobenzamide, prevented both internucleosomal DNA fragmentation and histone H1 poly(ADP-ribosyl)ation in cells treated with the apoptosis inducers. When nuclear chromatin was made accessible to the exogenous nuclease in a permeabilized cell system, chromatin of UV-treated cells was more susceptible to micrococcal nuclease than the chromatin of control cells. Suppression of histone H1 poly(ADP-ribosyl)ation by 3-aminobenzamide reduced the micrococcal nuclease digestibility of internucleosomal chromatin in UV-treated cells. These results suggest that the poly(ADP-ribosyl)ation of histone H1 correlates with the internucleosomal DNA fragmentation during apoptosis mediated by DNA damaging agents. This suggestion is supported by the finding that xeroderma pigmentosum cells which are defective in introducing incision at the site of DNA damage, failed to induce DNA fragmentation as well as histone H1 poly(ADP-ribosyl)ation after UV irradiation. We propose that poly(ADP-ribosyl)ation of histone H1 protein in the early stage of apoptosis facilitates internucleosomal DNA fragmentation by increasing the susceptibility of chromatin to cellular endonuclease.

Changes in multiple sexual partnerships, HIV testing, and condom use among US heterosexuals 18 to 49 years of age, 1990 and 1992

We compared data from two independent, representative samples of the US population to determine whether heterosexual adults 18 to 49 years of age modified their human immunodeficiency virus (HIV) risk behaviors between 1990/91 and 1992. We found little change in multiple sexual partnerships, having a risky partner, and HIV test seeking in the heterosexual population. Overall, consistent condom use significantly increased from 11% in 1990/91 to 20% in 1992, but this increase was limited to selected demographic groups. These results suggest a continuing need for HIV education among heterosexual adults.

Factors affecting low values of serum albumin in CAPD patients

To investigate the factors affecting low values of serum albumin (SA) in continuous ambulatory peritoneal dialysis (CAPD) patients, we undertook a cross-sectional study of 106 CAPD patients, with a mean age of 49.0 years and dialysis duration of 43.4 months, with respect to demographic, clinical, and biochemical parameters. In group I (n = 28, SA < or = 3.5 g/dL), diabetics were more common, patients were significantly older, and more patients were malnourished, according to the subjective global assessment (SGA), compared to group II (n = 78, SA > 3.5 g/dL). Serum C-reactive protein (CRP), lipoprotein (a), and 24-hour dialysate-to-plasma creatinine concentration ratio (D/P) were significantly higher, and 24-hour dialysate albumin was greater in group I. Compared to group II, group I had significantly lower serum creatinine and urea nitrogen appearance (UNA). Blood urea nitrogen (BUN), lean body mass (LBM), % of body weight (%BW), and normalized protein equivalent of nitrogen appearance (nPNA) tended to be lower in the low SA group, without statistical significance. There were no differences in the duration of CAPD, peritonitis rate, serum insulin-like growth factor-I (IGF-I), anthropometric data, dietary assessment, dialysis adequacy, and residual renal function (RRF) between the two groups. SA was positively correlated with serum creatinine, IGF-I, LBM, UNA, BUN, nPNA, and CAPD duration, and was negatively correlated with 24-hour D/P, 24-hour dialysate albumin, age, CRP, and bicarbonate (HCO3-). By stepwise multiple logistic regression analysis, 24-hour D/P, age, CRP, and SGA were independent risk factors for low SA level. In conclusion, SA seems to be influenced not only by nutritional factors but also by nonnutritional factors such as peritoneal membrane transport characteristics, age, and presence of acute phase protein response manifested by CRP elevation.

Idiopathic transverse myelitis: MR characteristics

PURPOSE

To describe the MR characteristics that can distinguish idiopathic transverse myelitis from other intramedullary lesions.

METHODS

A total of 32 initial and follow-up MR studies in 17 patients with clinically proved transverse myelitis were reviewed retrospectively. The location, size, pattern, and segmental length of areas of hyperintensity were estimated on T2-weighted axial and sagittal images. In 15 of the patients, whose neurologic abnormalities were limited to the spinal cord, the location and pattern of intramedullary contrast enhancement were evaluated on sagittal and axial T1-weighted images. Follow-up MR studies were available for 10 patients. The statistical significance of cord enhancement between the groups with and without cord expansion was calculated.

RESULTS

Common MR findings of idiopathic transverse myelitis included a centrally located hyperintensity occupying more than two thirds of the cross-sectional area of the cord (88%); a length of 3 to 4 vertebral segments (53%), with variable presence of cord expansion (47%); a small central area of intensity, isointense with normal cord, in the core of hyperintensity (47%); focal, peripheral cord enhancement (53%), particularly in patients with cord expansion; and a slow regression of T2 hyperintensity with an enhancing nodule. Although no linear correspondence was observed between MR findings and neurologic signs and symptoms, all but 4 patients improved clinically as MR findings improved or remained stable.

CONCLUSIONS

MR findings are helpful in detecting transverse myelitis and in differentiating this entity from multiple sclerosis and cord tumors, but clinical assessment and observation of MR changes over time are essential in making the diagnosis.

The efficacy of brief group counseling in HIV risk reduction among homosexual Asian and Pacific Islander men

OBJECTIVES

The incidence of AIDS is increasing at a higher rate among homosexual Asian and Pacific Islanders (API) than white homosexual men in the United States. The number of homosexual API men engaging in unsafe sex is increasing at an alarming rate. HIV risk reduction is urgently needed in this population.

SUBJECTS AND METHODS

We developed and evaluated culturally appropriate brief group counseling with 329 self-identified homosexual API recruited in San Francisco between 1992 and 1994. Participants were randomized into a single, 3-h skills training group or a wait-list control group. The intervention consisted of four components: (1) development of positive self-identity and social support, (2) safer sex education, (3) eroticizing safer sex, and (4) negotiating safer sex. Data were collected at baseline and 3 months after the intervention.

RESULTS

Significant reductions in number of sexual partners were observed among all treatment subjects, regardless of ethnicity (P = 0.003). Treatment decreased the number of partners reported at 3-month follow-up by 46% [95% confidence interval (CI), 28-77]. Chinese and Filipino men further benefited from the intervention: treatment subjects from these two ethnic groups reduced unprotected anal intercourse at follow-up by more than half when compared to their counterparts (odds ratio = 0.41; 95% CI, 0.19-0.89; P = 0.024).

CONCLUSIONS

We demonstrated the efficacy of brief group counseling in reducing HIV risk among homosexual API. Cities with significant API populations should adopt culturally tailored skills training as part of HIV prevention strategies for this group of homosexual men.

Hypoxia induces changes in phospholipase A2 in rat proximal tubules: evidence for multiple forms

Increased free fatty release during hypoxia is believed to contribute to cell injury. This phenomenon is likely to be mediated through activation of specific isoforms of phospholipase A2 (PLA2). In this study, PLA2 enzymatic activity was measured in cell-free extracts prepared from rat renal proximal tubules. Both soluble and membrane-associated PLA2 activity were detected. All PLA2 activity detected during normoxia was Ca2+ dependent. Fractionation of cytosolic extracts by gel filtration revealed three peaks of PLA2 activity. Exposure of tubules to hypoxia resulted in stable activation of soluble PLA2 activity, which correlated with disappearance of the highest molecular mass form (> 100 kDa) and appearance of a low-molecular-mass form (approximately 15 kDa) of PLA2. Hypoxia also resulted in release of a low-molecular-mass form of PLA2 into the extracellular medium. Pretreatment of tubules with glycine before hypoxia blocked this release of PLA2 but not activation of soluble PLA2 activity. These studies provide direct evidence for PLA2 activation during hypoxia and suggest that multiple mechanisms regulate free fatty acid release associated with hypoxia injury.

Risk factors for HIV and other sexually transmitted diseases and prevention practices among US heterosexual adults: changes from 1990 to 1992

OBJECTIVES

The National AIDS Behavioral Survey (1990-1992) of heterosexual adults (18-49 years) measured human immunodeficiency virus (HIV) risk factors, condom use, and HIV antibody testing, with a focus on major "high-risk" cities.

METHODS

A longitudinal survey was conducted.

RESULTS

There was little reduction in the overall prevalence of HIV risk factors in the national or high-risk cities cohorts over time. Despite this picture of stability, approximately 39% of the population at risk for HIV because of multiple sexual partners turns over annually. There was little change in HIV test-seeking or in consistent condom use with primary sexual partners. Although the majority of at-risk respondents used condoms sporadically or not at all (65%), a significant increase in condom use was found among those reporting multiple sexual partners in both waves, particularly among Black heterosexuals. Data from other surveys and condom sales nationally support the findings.

CONCLUSIONS

There is a need for a series of surveys in this area to assess the reliability of the present findings and to monitor the general US population's response to prevention programs.

Neuronal dysfunction in patients with closed head injury evaluated by in vivo 1H magnetic resonance spectroscopy

RATIONALE AND OBJECTIVES

With the use of localized, water-suppressed in vivo 1H magnetic resonance spectroscopy (MRS), the proton metabolic alterations of white matter in patients with closed head injury (CHI) and healthy controls are evaluated, and metabolic alterations with Glasgow Outcome Scale (GOS) scores are compared.

METHODS

Patients with CHI (n = 10) and healthy control subjects (n = 10) underwent MRS examinations using a stimulated-echo acquisition mode pulse sequence that provided 2 x 2 x 2 cm3 volume of interest in the left frontoparietal white matter. Proton metabolite ratios relative to creatine were obtained using a Marquart algorithm.

RESULTS

The specific feature in patients with CHI was significant decrease of N-acetylaspartate (NAA)/creatine ratio compared with normal controls. No clear correlation of other metabolite ratios such as choline/creatine and inositols creatine was established. The level of NAA/creatine ratio was significantly correlated with GOS.

CONCLUSIONS

Results of this preliminary study suggest that the reduction of NAA/creatine ratio may indicate neuronal loss in patients with CHI. The NAA/creatine ratio may serve as a metabolic criterion to predict the GOS of patients with CHI. Thus, in vivo 1H MRS may be a useful modality in the clinical evaluation of patients with CHI based on the proton metabolite concentrations of cerebral white matter.

The effect of lovastatin on proliferation of cultured rat mesangial and aortic smooth muscle cells

In order to investigate the anti-proliferative effect of 3-hydroxy-3-methylglutaryl coenzyme. A reductase inhibitor, we evaluated the effects of lovastatin on DNA replication and the proliferation of rat mesangial and aortic smooth muscle cells, both of which were mesenchymal origin cells. Proliferations were determined by measuring [3H]thymidine uptake, and counting the number of cells. Growth-arrested mesangial and aortic smooth muscle cells were exposed to platelet-derived growth factor (PDGF), endothelin (ET) and angiotensin II (Ang II) to stimulate mitogenesis. All agents exhibited dose-dependent stimulation of [3H] thymidine uptake. PDGF was more potent than the others. Ang II increased [3H] thymidine uptake without demonstrable mitogenic activity. Lovastatin inhibited PDGF (10 ng/ml in mesangial cell, 25 ng/ml in smooth muscle cell)-, ET (10(-7)M)- and Ang II (10(-7)M)-induced [3H] thymidine uptake significantly in a dose-dependent manner in both cells. The increase of cell number in response to PDGF and ET treatment were also inhibited at 10 microM of lovastatin. The inhibitory effect of lovastatin was largely overcome in the presence of exogenous mevalonate at 200 microM, with 75.5% restoration from lovastatin-induced inhibition on PDGF-induced [3H] thymidine uptake in mesangial cells (77.8% in aortic smooth muscle cells). However, the addition of cholesterol did not prevent inhibition by lovastatin. In conclusion, lovastatin had an inhibitory effect on mesangial and aortic smooth muscle cell proliferation, and mevalonate was essential for DNA replication in both types of cells. Lovastatin may reduce glomerular and atherosclerotic injury through an anti-proliferative effect on mesangial and vascular smooth muscle cells, in addition to lowering circulating lipids.

Colorimetric assay using XTT for assessing virulence of avian Pasteurella multocida strains

A colorimetric assay using sodium 3,3'-[1[(phenylamino)carbonyl]3,4- tetrazolium]-bis(4-methoxy-6-nitro) benzene sulfonic acid hydrate (XTT) was adapted to quantitate bactericidal activity of chicken macrophage HD 11 cell line against five Pasteurella multocida strains and an avirulent transposon insertion mutant. The strains used were virulent P1059, and D92, and four avirulent strains including a streptomycin resistant mutant of P1059 (P1059 SmR), two live vaccine strains namely, the Clemson University (CU) and M9, and a transposon insertion mutant PmTn-294. Percentage of bacteria killed by chicken macrophage (HD 11) cells was determined by extrapolation from a standard formazan curve derived by incubating XTT with known bacterial cell numbers of each strain. The amount of formazan as measured by absorption at 450 nm was directly related to the number of viable bacterial cells. The percentages of P1059 SmR, CU, M9 and PmTn-294 killed by HD 11 cells were approximately 50%, 61%, 25% and 34%, respectively. By contrast, the virulent P1059 and D92 strains were resistant to killing, and were able to replicate inside the HD 11 cells. Association of virulence with resistance to phagocytic killing by HD 11 cells as assessed by the colorimetric bactericidal assay, was validated with resistance to complement (C')-mediated killing and a turkey mortality test. Strains P1059 and D92 were resistant to C'-mediated killing, whereas strains P1059 SmR, CU, M9 and PmTn-294 strains were susceptible. All turkeys challenged with P1059 or D92 were dead within 18 hrs. Mortality did not occur in turkeys challenged with strains of P1059 SmR, M9 and PmTn-294. The mortality among CU challenged turkeys ranged from 0 to 40%. The results suggest that the colorimetric bactericidal assay using XTT can be used to quantitate chicken macrophage phagocytic killing of P. multocida strains, and may be a valuable assay to differentiate virulent from avirulent strains of avian P. multocida.

Female partners of AIDS patients in Uganda: reported knowledge, perceptions and plans

OBJECTIVE

To assess reported knowledge of a partner's AIDS diagnosis, perceived risk of HIV infection, need for HIV testing and future support plans among women partners of male Ugandan AIDS patients.

SUBJECTS AND METHODS

A cross-sectional descriptive survey was conducted at New Mulago Hospital, Kampala, Uganda. The subjects were women partners of consecutive male AIDS patients admitted to medical wards.

RESULTS

Only 12% reported their partner's AIDS diagnosis; women who reported knowing were less likely to be financially dependent on the partner. Most women (76%) reported being at risk of HIV; in general, these women were older, in a newer relationship, had less children and were in customary rather than civil or cohabiting marriages. More than half (56%) of the women reported a need for HIV testing, though few (5%) had been tested. Those who stated the need for HIV testing were in a newer relationship, had less children and were more financially independent of their husbands; women in a cohabiting type marriage were less likely to report their need for testing than those in a civil or customary marriage. About half (56%) reported plans for future support if their husbands did not recover; these women were more likely to be in an older relationship and to have more children.

CONCLUSIONS

Most women partners of AIDS patients in New Mulago Hospital reported no knowledge of their husbands' diagnosis. Over half perceived a need to be tested but very few reported having been tested, and only half reported having planned for the future of their families. Interventions are urgently needed to address barriers to knowledge and to acknowledgement of a partner's AIDS diagnosis, to HIV testing and to planning for the future.

Prognostic factors and renal survival rates in IgA nephropathy

A retrospective study of 223 patients with IgA nephropathy (IgAN) was performed to clarify the prognostic factors and the renal survival rates of the disease. One hundred twenty-two patients were followed-up for more than 6 months after their renal biopsy (mean follow-up duration: 43.0 months), and 20 of them (16.4%) had progressed to end-stage renal disease (ESRD). Using univariate analysis, 8 risk factors (2 clinical and 6 histopathological findings) for developing ESRD were identified: renal insufficiency at initial presentation (serum creatinine > or = 1.5 mg/dl); heavy proteinuria (> or = 3.5 gm/day); moderate to severe histopathologic findings such as class IV/V lesions by W.H.O. classification, mesangial hypercellularity, glomerular sclerosis, interstitial infiltration, interstitial fibrosis, and tubular atrophy. In multivariate regression analysis, class IV/V lesions and renal insufficiency at initial presentation were the independent prognostic factors of IgAN. The renal survival rates were 100% at 1 year, 97.0% at 3 years, and 78.9% at 5 years. In conclusion, it seems that about 20% of IgAN patients have a risk to progress to ESRD within 5 years, and a careful follow-up is recommended especially in patients who have either renal insufficiency at the time of presentation or severe renal pathology (class IV/V lesions).

Extramarital sex and HIV risk behavior among US adults: results from the National AIDS Behavioral Survey

Data from the National AIDS Behavioral Survey were used to examine the social distribution of extramarital sex and risk for human immunodeficiency virus (HIV) infection among married individuals in the United States. Of 1686 married respondents living across the United States, 2.2% reported extramarital sex; of 3827 married respondents living in 23 urban areas with large Hispanic or African-American populations, 2.5% reported having sexual partners outside marriage. The data indicate that the correlates of extramarital sex varied by race/ethnicity. Low levels of condom use were found among people reporting extramarital sex (8% to 19% consistent users).

Injecting drug use and HIV infection in southwest China

OBJECTIVES

To determine the prevalence of drug injection among drug users, the seroprevalence of HIV and risk factors for HIV infection among injecting drug users (IDU), and to determine heterosexual transmission of HIV among IDU and their spouses in southwest China.

METHODS

Using a cross-sectional design, we conducted an HIV seroprevalence and behavioral survey in three rural counties of Yunnan province, Ruili, Longchuan and Luxi in southwest China, bordering Myanmar (Burma). A total of 860 drug users were recruited in randomly selected communities at the three study sites (response rate, 97%). In addition, a random sample of 62 wives of HIV-infected IDU were assembled from 460 known HIV-positive IDU in Ruili and Longchuan (response rate, 81%).

RESULTS

In the sample of 860 drug users, 33% reported injecting drugs. Among the 282 subjects who injected drugs, 82% began intravenous drug use after 1988; 64% injected drugs at least once every day. All subjects shared needles but none cleaned the injection equipment with alcohol or bleach. Overall, 49% tested HIV-positive. HIV seropositivity was independently correlated with a longer history of drug injecting, daily injecting, frequent needle-sharing, being younger, and living in Ruili county. Among the 62 wives of HIV-positive IDU, none used condoms during sex and 10% tested HIV-positive.

CONCLUSIONS

We conclude that the introduction of HIV into drug-using communities and the rapid increase in heroin injecting in this population appear to have triggered an explosive HIV epidemic among IDU in southwest China. We recommend that AIDS prevention efforts should begin immediately and focus on discouraging the shift from opium smoking to heroin injecting, needle-sharing, and unprotected sex among drug users and their partners.

Posterior lumbar apophyseal ring fractures: a report of 20 cases

Posterior apophyseal ring fracture (PARF) of the lumbar spine is an uncommon injury thought usually to occur in adolescence. We analysed CT findings in 20 cases (19 patients), whose age ranged from 16 to 45 years (average 30 years). The PARF could be divided into two distinct groups on the basis of the shape and location of the fracture and the defect of the vertebral rim. In group 1 (2 cases), PARF involved the central aspect of the inferior vertebral rim and bone fragments were large and broad-based. In group 2, PARF were located at the posterolateral margin of the superior vertebral rim and bone fragments were small and focal. The great majority of previously reported cases belonged to our group 1. A pathogenesis for each group is suggested.

Formation of a hairpin structure by telomere 3' overhang

The telomeres of most eukaryotes contain tandemly-repeated DNA sequences, with a cluster of G residues on one strand. Recent studies showed that the Oxytricha telomeric DNA oligonucleotide, d(G4T4G4), dimerizes to form a quadruplex in the presence of Na+ or K+. We have observed that the oligonucleotide d(G4T4G4) does not dimerize in the presence of Li+ ion at low sample concentrations. In the monomeric state, this molecule forms a simple foldback hairpin structure containing G x G reverse Hoogsteen basepairs in the stem region. This hairpin structure has a thermal stability which is well reconciled with telomere functions in vivo.

Spontaneous evolution of posttraumatic subdural hygroma into chronic subdural haematoma

Thirteen of 145 patients with post-traumatic subdural hygroma (SDHy) developed chronic subdural haematoma (CSDH) at the involved site over a period of 6 years. CSDHs were found at the site of SDHys with no history of further head injury at a mean interval of 56 days. It appeared that these 13 patients did not have any distinguishing clinical features early on. Old age and brain atrophy on CT scans do not seem to be reasonable causative factors in the evolution of SDHy into CSDH. Initial enlargement of subdural accumulations at an early stage of SDHy and a subsequent increase in density at a later stage may point to the development of CSDH from SDHy in some instances. Ten of these 13 CSDH cases underwent surgical drainage, and the remaining 3 cases received no specific management. All resolved completely. The prognosis was good in all patients. The possible mechanism for the evolution of SDHy into CSDH is discussed.

Comparative study of hepatitis C virus antibody between hemodialysis and continuous ambulatory peritoneal dialysis patients

We have done cross sectional and prospective studies to determine the prevalence and the clinical significance of antibodies to the hepatitis C virus (Anti-HCV) in 54 hemodialysis (HD) patients and 227 continuous ambulatory peritoneal dialysis (CAPD) patients. Fifteen patients (27.8%) were anti-HCV (+) among the HD group, and twelve patients (5.3%) were anti-HCV (+) among the CAPD group. In the HD group, the positivity of anti-HCV correlated with the duration of HD, but there was no significant correlation with the history of transfusion, the amount of transfusion and abnormal alanine aminotransferase (ALT). At the follow-up study in 164 cases (HD 50 cases, CAPD 114 cases) after 6 months, one of 14 anti-HCV (+) CAPD patients was converted to anti-HCV (-) and two of 35 anti-HCV (-) HD patients were converted to anti-HCV (+). In conclusion, the prevalence of anti-HCV was significantly higher in HD patients compared to CAPD patients, and the positivity for anti-HCV in HD patients correlated with the duration of HD. A regular follow-up of anti-HCV and isolation of anti-HCV (+) HD patients with a separate machine may be needed to prevent the transmission of the hepatitis C virus during hemodialysis.

Psychosocial predictors of needle sharing among intravenous drug users

This study examined the relationship between health beliefs and needle sharing in a sample of 226 heroin detoxification clients. Zero-order correlations revealed that needle sharing was positively associated with perceived susceptibility and AIDS anxiety, and negatively associated with self-efficacy and communication skill in negotiating safe needle practices. Logistic regression analysis showed that demographic and situational factors also play a role in needle sharing. White race and injection of drugs in shooting galleries or other public places increase the odds of sharing a "dirty" needle, while that probability decreases sharply as a function of drug users' self-efficacy. This last finding suggests that preventive clinical interventions such as counseling or psychoeducational groups maybe needed to help drug users develop confidence in resisting needle sharing.

Studies on IL-2 production and T-cell colony forming unit in patients with chronic renal failure

To elucidate the nature of altered cellular immunity seen in patients with chronic renal failure, the values of interleukin-2 (IL-2), a kind of lymphokine, and T-cell colony forming units were measured in controls (N = 10), predialysis uremic patients (N = 14), patients undergoing chronic hemodialysis (HD, N = 11) and patients on continuous ambulatory peritoneal dialysis (CAPD, N = 9). Dialytic patients were selected as relatively stable cases receiving dialysis for more than 3 months. The duration of dialysis was 25.5 +/- 5.5 months in HD and 14.7 +/- 3.0 months in CAPD groups. The mean age was 30.3 years in the control, 36.1 years in the predialysis, 32.9 years in the HD and 41.1 years in the CAPD groups; all 4 groups showed male predominance. The serum creatinine concentration of each group was 1.2 +/- 0.1 mg/dl in the control, 14.1 +/- 0.9 mg/dl in predialysis, 13.5 +/- 1.3 mg/dl in HD and 14.7 +/- 0.9 mg/dl in CAPD groups. The level of IL-2 in the predialysis group was markedly lower compared to the control, HD and CAPD groups (as 3.1 +/- 0.8 unit vs. 8.8 +/- 2.2 unit, 11.8 +/- 3.0 unit and 14.9 +/- 3.4 unit, respectively, p < 0.05); the difference between the control and dialytic groups was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

A partial blockade of catecholaminergic neurotransmission with 6-hydroxydopamine decreases mRNA level of gonadotropin releasing hormone in the male rat hypothalamus

Central catecholamines (CA) are known to be involved in the regulation of synthesis and secretion of gonadotropin releasing hormone (GnRH) from the hypothalamus. However, no attempt has been yet made to determine whether CA affects GnRH gene expression. To this end, the effect of 6-hydroxydopamine (6-OHDA), a catecholaminergic neurotoxin, on GnRH mRNA level was examined. Hypothalamic tissues obtained from adult male rats were incubated with medium containing 6-OHDA. To ensure the effect of 6-OHDA on CA depleting action, CA levels in media and in postincubation tissues were determined. Increasing concentrations of 6-OHDA resulted in decrease in norepinephrine (NE) and dopamine (DA) contents in a dose dependent manner. Treatment with 6-OHDA (5 x 10(-4) M produced a time-dependent decrease in NE but not DA, when CA levels in media were determined at 30 min intervals during the incubation period. To determine changes in GnRH mRNA level in response to 6-OHDA treatment in vitro, for 2.5 h total cytoplasmic RNA fractions were isolated from postincubation hypothalamic tissues and used for RNA-blot hybridization with 32P-labeled GnRH riboprobe. A blockade of CA neurotransmission with 6-OHDA (5 x 10(-4) M) significantly reduced GnRH mRNA level by half over its control and internal control (actin mRNA) groups. Northern blot analysis revealed that addition of NE (1 x 10(-6) M) reversed the decreased GnRH mRNA level by 6-OHDA.(ABSTRACT TRUNCATED AT 250 WORDS)

Coping with death anxiety: help-seeking and social support among gay men with various HIV diagnoses

OBJECTIVE, DESIGN AND PARTICIPANTS: We examined sources of help-seeking related to worries or concerns about death and dying and the effects of social support on death anxiety in a longitudinal sample of gay men (n = 52).

RESULTS

Friends and primary sexual partners were the most frequent sources sought in dealing with death concerns for all groups of respondents (HIV-negative, HIV-positive asymptomatic, and HIV-positive symptomatic). Men experiencing HIV symptoms were more likely than HIV-negative and asymptomatic men to use formal sources of support (medical, psychological). Although HIV-positive symptomatic men did not differ from HIV-negative men in terms of help-seeking from family sources, they were significantly more likely to seek the help of family members than HIV-positive asymptomatic men. All three HIV groups showed significantly different mean levels of death anxiety, with HIV-negative men reporting the lowest level and HIV-positive symptomatic men the highest. Among HIV-negative men, only mental health sources of support (psychologists and clergy) were significantly related to death anxiety, measured 1 year later (beta = -0.35). These sources of support were also associated with death anxiety among HIV-positive asymptomatic men, but in the opposite direction (beta = 0.26). Contrary to expectations, men experiencing HIV symptoms benefited most from family support (beta = -0.31), although peer (beta = -0.19) and medical (beta = -0.28) support sources were also prominent.

CONCLUSIONS

Thus, while earlier research found peers to be the most common and effective source of support among gay men, this study suggests that obtaining support from family may become particularly important as one approaches death. The effectiveness of social support in reducing death anxiety appears to vary over the course of the disease from asymptomatic to symptomatic. HIV-symptomatic men obtain support from a wide range of helpers, including medical and peer supports and family.

Effect of captopril on heavy proteinuria in patients with various glomerular diseases

The effect of captopril on proteinuria was evaluated in twenty patients with various glomerular diseases excreting heavy proteinuria (> 3.0 g/day). Captopril in a daily dose of 37.5 mg was administered orally three times a day to all patients and they were followed for eight weeks. Twenty-four hour urinary excretion of protein, creatinine, sodium, selective protein index (SPI), and blood chemistry including serum electrolytes were measured every two weeks. Twenty-four hour urinary protein excretion per gram creatinine started to fall within two weeks of captopril administration and became nearly stable after four weeks of therapy (p < 0.05). Mean 24-hour urinary protein excretion decreased significantly from a pretreatment value of 9.0 +/- 6.0 gm/gm of cr. to 4.4 +/- 3.5 gm/gm of cr. after eight weeks of captopril treatment. The serum albumin level increased progressively at six and eight weeks after the captopril treatment period and was significantly higher than the pretreatment value (p < 0.05). The decrease in proteinuria did not coincide with a fall in blood pressure or any changes in creatinine clearance. We conclude that captopril does have a significant antiproteinuric effect in patients excreting heavy proteinuria with various glomerular diseases. However, the long term therapeutic efficacy and any renal protective effect of this drug remain to be proven.

Induction of protease La under stress and its effect on intracellular proteolysis in Escherichia coli

Induction of protease La was found to increase to higher extent in E. coli that had been treated with canavanine for longer period. However, hydrolysis of canavanine-containing proteins occurred rapidly but at nearly an identical rate regardless of the period of canavanine-treatment. Exposure of E. coli to heat also raised the level of protease La but showed little effect on overall rate of proteolysis. These results suggest that induction of protease La under stress occurs as a part of heat shock response but not necessarily for elimination of denatured or abnormal proteins.

Comparison of enzyme-linked immunosorbent assay with dot immunobinding assay for detection of antibodies against Pasteurella multocida in turkeys

A dot immunobinding assay (DIA) was developed to detect antibodies against Pasteurella multocida in turkey serum. Five coating antigens, namely, whole-cell (WC) antigen, sonicated cell lysate (SCL), crude capsular extract (CE), formalin extract (FE), and heat-stable antigen (HSA), were compared by enzyme-linked immunosorbent assay (ELISA) and DIA using reference antisera against P. multocida organisms. WC and SCL antigens showed higher sensitivity, whereas FE and HSA antigens were more specific coating antigens in both assays. The specificity of DIA was greater than ELISA by comparing the P/N ratios of HSA against serum prepared from heterologous serotype of P. multocida. The DIA had also several distinct advantages over the ELISA, which included reduction of the manipulation time and more uniform binding of coating antigens onto the nitrocellulose membranes compared with binding of coating antigens to microtiter plates for ELISA.

Hepatitis C infection in hemodialysis units

We performed an epidemiological study of the hepatitis C infection on 112 patients of 3 urban hemodialysis units using a recently developed anti-HCV recombinant based assay. Eleven patients (9.8%) were positive for anti-HCV. Among them, 8 (72.7%) were positive for anti-HBc, one of whom was HBsAg positive and 6 of whom were also anti-HBs positive. Surprisingly, all of the anti-HCV (+) patients were normal alanine aminotransferase. The mean age of the anti-HCV (+) patients was 50.7 +/- 3.3 (mean +/- SE) and that of the anti-HCV (-) was 47.6 +/- 1.3. The mean duration (month) of hemodialysis of the anti-HCV (+) and anti-HCV (-)groups were 52.7 +/- 7.2 (mean +/- SE) and 60.9 +/- 9.7, respectively. The prevalence of anti-HCV among anti-HBc positive subjects was 9.5% and that among anti-HBc negative subjects was 17.6%. This didn't have any statistical significance according to the criteria of the study (p = 0.308). The prevalence of anti-HCV among the transfusion positive group was 11.0% and that of the transfusion negative group was 7.7%. This data showed the tendency for a higher prevalence of anti-HCV among the transfusion positive group, but this also didn't reach statistical significance (p = 0.424). Of the 40 normal controls, none were anti-HCV positive. The prevalence of HBsAg in our hemodialysis units was 12.5%. This rate was not so much higher than the average population in Korea. The prevalence of anti-HCV and previous hepatitis B virus infection also had no significant relationship.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of nutritional status on CAPD peritonitis

To investigate the effect of nutritional status of continuous ambulatory peritoneal dialysis (CAPD) patients on the development of peritonitis, a cross-sectional study of the nutritional status of 79 CAPD patients and a retrospective study on the incidence of peritonitis in these patients were done. The incidences of peritonitis were compared according to the nutritional status of these patients on CAPD. Protein-caloric malnutrition assessed by a score system based on triceps skinfold thickness, mid-arm circumference, serum albumin level and relative body weight was demonstrated in 27 patients (34%) among 79 total CAPD patients. The incidence of peritonitis was significantly higher in poor nutritional status patients, with 1.09 +/- 0.86/patient-year, than that in normal nutritional status patients with 0.64 +/- 0.72/patient-year (p less than 0.05). In patients with the same nutritional status, patients using Dianeal solution had a trend of a lower incidence of peritonitis than those using Peritosol solution. In conclusion, the nutritional status and possibly the type of CAPD solution may influence CAPD peritonitis as risk factors.

Effect of adenine arabinoside and alpha-interferon in patients with HBeAg-positive chronic active hepatitis

To evaluate and compare the therapeutic efficacy of adenine arabinoside (Ara-A) and alpha-interferon (alpha-INF), 40 patients with biopsy proven chronic active hepatitis B were chosen at random to receive Ara-A (15 mg/Kg, iv, for 10 day) or alpha-INF (3 million unit, sc, every other day for 12 wks) and followed up to 12 months after completion of the therapy. All patients were HBeAg positive. The clinical effects of Ara-A and alpha-INF on seroconversion of HBeAg positive. The clinical effects of Ara-A AND alpha-INF on seroconversion of HBeAg and the levels of serum aminotransferase (ALT) were closely matched and compared with those of the untreated control group (20 cases). Eighteen out of 20 patients received Ara-A, 19 patients received alpha-INF, and 19 out of 20 control cases were evaluated at 12 months after completion of treatment. Seroconversion of HBeAg in the alpha-INF treated group (19 cases) was observed in seven cases (36.8%), showing a higher seroconversion rate as compared to Ara-A-treated (2/18 cases, 11.1%) and to the control patients (1/19 cases, 5.3%). There were no effects of Ara-A on serum ALT levels in the treated patients compared with the untreated control patients. However there was a remarkable drop in serum ALT levels in the INF-treated patients (p less than 0.005, ALT levels at 12 months after treatment; 87.4 +/- 98.8 IU/L) compared to the pretreatment levels (256.7 +/- 175.8 IU/L).(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of outer membrane protein-enriched extracts from Pasteurella multocida isolated from turkeys

Outer membrane protein (OMP)-enriched extracts of avian strains of Pasteurella multocida were examined by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Culture medium did not have a significant effect on the OMP profiles of strains of P multocida examined; however, in vivo propagation had an appreciable effect on the OMP profile composition of the reference strain P-1059. Such bacteria, expressed several additional OMP in the 27-kD, 48-kD, 56-kD, 60-kD, 80-kD, and 94-kD molecular mass regions. These OMP were not detected in the electrophorogram of strain P-1059 grown in vitro. The OMP profiles of reference strains of the 16 serotypes of P multocida did not identify any serotype-specific protein markers. Field strains of serotype A:3 had variation in OMP profiles and did not express OMP that all were identical to that expressed by the reference strain P-1059. The live attenuated CU and M9 bacterial vaccine strains expressed strain-specific OMP markers of 48-kD and 45-kD molecular masses, respectively. These strain-specific OMP markers may be used to differentiate these strains from virulent field strains that are of the same serotype and isolated from turkeys that have succumbed to pasteurellosis as a result of vaccine-related reactions or breakdown in immunity.

Autonomously replicating episomes contain mdr1 genes in a multidrug-resistant human cell line

Gene amplification in human tumor cells is frequently mediated by extrachromosomal elements (e.g., double minute chromosomes [DMs]). Recent experiments have shown that DMs can be formed from smaller, submicroscopic circular precursors referred to as episomes (S. M. Carroll, M. L. DeRose, P. Gaudray, C. M. Moore, D. R. Needham-Vandevanter, D. D. Von Hoff and G. M. Wahl, Mol. Biol. 8:1525-1533, 1988). To investigate whether episomes are generally involved as intermediates in gene amplification, we determined whether they mediate the amplification of the mdr1 gene, which when overexpressed engenders cross resistance to multiple lipophilic drugs. A variety of methods including electrophoresis of undigested DNAs in high-voltage gradients, NotI digestion, and production of double-strand breaks by gamma irradiation were used to distinguish between mdr1 sequences amplified on submicroscopic circular molecules and those amplified within DMs or chromosomal DNA. The gamma-irradiation procedure provides a new method for detecting and determining the size of circular molecules from 50 kilobases (kb) to greater than 1,000 kb. These methods revealed that some of the amplified mdr1 genes in vinblastine-resistant KB-V1 cells are contained in supercoiled circular molecules of approximately 600 and approximately 750 kb. Analysis of the replication of these molecules by a Meselson-Stahl density shift experiment demonstrated that they replicate approximately once in a cell cycle. The data lend further support to a model for gene amplification in which DMs are generally formed from smaller, autonomously replicating precursors.