APOE loss-of-function variants: Compatible with longevity and associated with resistance to Alzheimer's disease pathology

The ε4 allele of apolipoprotein E (APOE) is the strongest genetic risk factor for sporadic Alzheimer's disease (AD). Knockdown of ε4 may provide a therapeutic strategy for AD, but the effect of APOE loss of function (LoF) on AD pathogenesis is unknown. We searched for APOE LoF variants in a large cohort of controls and patients with AD and identified seven heterozygote carriers of APOE LoF variants. Five carriers were controls (aged 71-90 years), one carrier was affected by progressive supranuclear palsy, and one carrier was affected by AD with an unremarkable age at onset of 75 years. Two APOE ε3/ε4 controls carried a stop-gain affecting ε4: one was cognitively normal at 90 years and had no neuritic plaques at autopsy; the other was cognitively healthy at 79 years, and lumbar puncture at 76 years showed normal levels of amyloid. These results suggest that ε4 drives AD risk through the gain of abnormal function and support ε4 knockdown as a viable therapeutic option.

APOE loss-of-function variants: Compatible with longevity and associated with resistance to Alzheimer's Disease pathology

The ε4 allele of apolipoprotein E (APOE) is the strongest genetic risk factor for sporadic Alzheimer's Disease (AD). Knockdown of this allele may provide a therapeutic strategy for AD, but the effect of APOE loss-of-function (LoF) on AD pathogenesis is unknown. We searched for APOE LoF variants in a large cohort of older controls and patients with AD and identified six heterozygote carriers of APOE LoF variants. Five carriers were controls (ages 71-90) and one was an AD case with an unremarkable age-at-onset between 75-79. Two APOE ε3/ε4 controls (Subjects 1 and 2) carried a stop-gain affecting the ε4 allele. Subject 1 was cognitively normal at 90+ and had no neuritic plaques at autopsy. Subject 2 was cognitively healthy within the age range 75-79 and underwent lumbar puncture at between ages 75-79 with normal levels of amyloid. The results provide the strongest human genetics evidence yet available suggesting that ε4 drives AD risk through a gain of abnormal function and support knockdown of APOE ε4 or its protein product as a viable therapeutic option.

APOE Locus-Associated Mitochondrial Function and Its Implication in Alzheimer's Disease and Aging

The Apolipoprotein E (APOE) locus has garnered significant clinical interest because of its association with Alzheimer's disease (AD) and longevity. This genetic association appears across multiple genes in the APOE locus. Despite the apparent differences between AD and longevity, both conditions share a commonality of aging-related changes in mitochondrial function. This commonality is likely due to accumulative biological effects partly exerted by the APOE locus. In this study, we investigated changes in mitochondrial structure/function-related markers using oxidative stress-induced human cellular models and postmortem brains (PMBs) from individuals with AD and normal controls. Our results reveal a range of expressional alterations, either upregulated or downregulated, in these genes in response to oxidative stress. In contrast, we consistently observed an upregulation of multiple APOE locus genes in all cellular models and AD PMBs. Additionally, the effects of AD status on mitochondrial DNA copy number (mtDNA CN) varied depending on APOE genotype. Our findings imply a potential coregulation of APOE locus genes possibly occurring within the same topologically associating domain (TAD) of the 3D chromosome conformation. The coordinated expression of APOE locus genes could impact mitochondrial function, contributing to the development of AD or longevity. Our study underscores the significant role of the APOE locus in modulating mitochondrial function and provides valuable insights into the underlying mechanisms of AD and aging, emphasizing the importance of this locus in clinical research.

Redefining transcriptional regulation of the APOE gene and its association with Alzheimer's disease

The apolipoprotein E gene (APOE) is the strongest genetic risk factor for late-onset Alzheimer's disease (AD), yet the expression of APOE is not clearly understood. For example, it is unclear whether AD patients have elevated or decreased APOE expression or why the correlation levels of APOE RNA and the ApoE protein differ across studies. Likewise, APOE has a single CpG island (CGI) that overlaps with its 3'-exon, and this CGI's effect is unknown. We previously reported that the APOE CGI is highly methylated in human postmortem brain (PMB) and that this methylation is altered in AD frontal lobe. In this study, we comprehensively characterized APOE RNA transcripts and correlated levels of RNA expression with DNA methylation levels across the APOE CGI. We discovered the presence of APOE circular RNA (circRNA) and found that circRNA and full-length mRNA each constitute approximately one third of the total APOE RNA, with truncated mRNAs likely constituting some of the missing fraction. All APOE RNA species demonstrated significantly higher expression in AD frontal lobe than in control frontal lobe. Furthermore, we observed a negative correlation between the levels of total APOE RNA and DNA methylation at the APOE CGI in the frontal lobe. When stratified by disease status, this correlation was strengthened in controls but not in AD. Our findings suggest a possible modified mechanism of gene action for APOE in AD that involves not only the protein isoforms but also an epigenetically regulated transcriptional program driven by DNA methylation in the APOE CGI.

Abstract P4-06-12: Different patterns of risk reducing decisions in affected or unaffected BRCA mutation carriers

BACKGROUND

Risk-reducing (RR) management decreases the risk of breast cancer and BRCA related gynecologic cancer. However, there are fewer reports on the RR management in Asia compared to Western countries.The aim of this study is to identify risk reducing management patterns with BRCA1 or BRCA2 mutation carriers.

METHODS

The study group consisted of all consecutive 1104 breast cancer, ovarian patients and their families of high-risk patients who underwent BRCA gene testing in National Cancer Center, Korea from 2008 to 2016. A total 220 BRCA mutations (19.9%) were detected with 125(11.3%) of BRCA1 gene and 95 (8.6%) of BRCA2 gene.

RESULTS

Out of 220 BRCA mutations carriers, they were consisted of 83 breast cancers, 10 ovarian cancers, 7 both cancers, and 120 unaffected carriers. Among them, 42 were men and 178 were women. About 90 % (198/ 220) had the familial history of breast, ovarian or both malignancies (113 in BRCA1 and 85 in BRCA2 mutation (p=0.821)).

All 42 men chose surveillance. Among 178 female BRCA mutation carriers, 98(55.1%) underwent risk reducing management including 18(10.1%) of chemoprevention, and 80(49.9%) had risk-reducing surgeries (RRSs) (1 case of risk-reducing mastectomy, 76 of risk reducing bilateral salphingo-oophorectomy (RRSO), and 3 of both) and 80 (54.9%) chose only intensive surveillance for both of breast and ovary cancer.

In affected carriers with breast cancer, 59 (71.1%) underwent RR management (1 case of risk reducing mastectomy, 53 of RRSO, 3 of both surgery, and 2 of chemoprevention). There was no risk reducing management in affected carrier with ovarian cancer patients. In 78 unaffected women carriers, 39(50.0%) women received RR management (23(29.5%) cases of RRSO and 16(20.5%) cases of chemoprevention). The rates of RRSs have increased annually since the 2013 year, (prior to 2013 vs. since 2013, RRSs 28.6% (6 cases/21 carriers) vs. 37.2% (74/199), p<0.01).

CONCLUSION

This study was conducted on the largest numbers of BRCA mutation carriers in Asian countries. RRSO is the more preferred management for affected carriers with breast cancer or unaffected carriers. The results might be explained by the severity of the illness and that RRSO was only reimbursed RR strategy from the Korean Government Insurance. Tailored genetic counseling and insurance policy may enhance overall levels of RR management.

Citation Format: Lee EG, Kang H, Park SJ, Han JH, Jung S-Y, Lee S, Kang H-S, Park B, Kong S-Y, Lim MC, Park S-Y, Lee ES. Different patterns of risk reducing decisions in affected or unaffected BRCA mutation carriers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-06-12.

Mutations in the amino terminus of foamy virus Gag disrupt morphology and infectivity but do not target assembly

Foamy viruses (FVs) assemble using pathways distinct from those of orthoretroviruses. FV capsid assembly takes place near the host microtubule-organizing center (MTOC). Assembled capsids then migrate by an unknown mechanism to the trans-Golgi network to colocalize with the FV glycoprotein, Env. Interaction with Env is required for FV capsid egress from cells; the amino terminus of FV Gag contains a cytoplasmic targeting/retention signal that is responsible for targeting assembly to the MTOC. A mutant Gag was constructed by addition of a myristylation (M) signal in an attempt to target assembly to the plasma membrane and potentially overcome the dependence upon Env for budding (S. W. Eastman and M. L. Linial, J. Virol. 75:6857-6864, 2001). Using this and additional mutants, we now show that assembly is not redirected to the plasma membrane. Addition of an M signal leads to gross morphological defects. The aberrant particles still assemble near the MTOC but do not produce infectious virus. Although extracellular Gag can be detected in a pelletable form in the absence of Env, the mutant particles contain very little genomic RNA and are less dense. Our analyses indicate that the amino terminus of Gag contains an Env interaction domain that is critical for bona fide egress of assembled capsids.

The clinical and immunogenetic characteristics of adult-onset type 1 diabetes mellitus in Korea

Although the HLA class II alleles and immunological abnormalities are associated with type 1 diabetes mellitus (T1DM) in all racial groups, there are considerable variations in the genotypes and the prevalence of autoantibodies. In order to investigate the characteristics of the immunogenetic patterns and to use these as an early diagnostic tool and guideline for a therapeutic plan, we examined the clinical characteristics and the patterns of anti-GAD antibody (GADA), IA-2 antibody (IA-2A), HLA-DR and HLA-DQ in Korean adult-onset T1DM patients. Adult-onset patients had higher serum C-peptide levels than child-onset patients. In adult-onset patients, the prevalence of GADA and IA-2A were 59.5% and 15.3% respectively, and increased frequencies of HLADR4 and-DR9 were found. The frequencies of HLADQA1,-DQB1 and-DQ heterodimers were similar to those of the control, but child-onset patients had high frequencies of the HLA-DR3,-DR4,-DR9, DQA1*0301, DQA1*0501 and DQB1*0201 genotypes. In conclusion, Korean adult-onset T1DM patients had a lower prevalence of GADA, which was comparable to that found in Caucasian patients. The detection of GADA might help to predict the insulin dependency of adult-onset diabetes. Difference in the frequencies of diabetes associated with HLA type suggests that there might be a heterogeneity in the pathogenesis of diabetes according to the age of onset.

A heterologous prime-boost vaccination regime using DNA and a vaccinia virus, both expressing GRA4, induced protective immunity against Toxoplasma gondii infection in mice

SUMMARYThe dense granule antigen 4 (GRA4) is known as an immundominant antigen of Toxoplasma gondii and, therefore, is considered as a vaccine candidate. For further evaluation of its vaccine effect, a recombinant plasmid and vaccinia virus, both expressing GRA4, were constructed, and a heterologous prime-boost vaccination regime was performed in a mouse model. The mice immunized with the heterologous prime-boost vaccination regime showed a high level of specific antibody response against GRA4 and a significantly high level of gamma interferon (IFN-gamma) production and survived completely against a subsequent challenge infection with a lethal dose of T. gondii. In addition, the formation of cysts was inhibited in the mice vaccinated with the heterologous prime-boost vaccination regime. These results demonstrate that the heterologous prime-boost vaccination regime using DNA and a vaccinia virus, both expressing GRA4, could induce both humoral and cellular immune responses and provide effective protection against lethal acute and chronic T. gondii infections in mice.

An Internet-based surveillance system for tuberculosis in Korea

SETTING

The Korea Tuberculosis Surveillance (KTBS) network includes 248 health centres throughout the country, as well as other public and private health institutions.

OBJECTIVE

To develop a web-based surveillance system for tuberculosis (TB) and to monitor implementation of the National TB Control Programme (NTP) on an ongoing basis.

DESIGN

A TB notification form was developed with new case definitions, and standardised to obtain uniform essential information of the cases with ease and speed. Data collection, compilation, analysis and feedback were made available at every level of the health authority via the Internet without restrictions of time and space.

RESULTS

The Internet-based surveillance system was successfully implemented across the country, providing real-time national figures of TB using different variables-patient, time, area, site and type of disease--and facilitating on-line evaluation of NTP implementation.

CONCLUSION

The web-based surveillance system has been well established within the existing health infrastructure, providing real-time figures on the TB burden. However, it requires continued improvement of the quality of information and of case reporting activities.

Deletion of a Cys-His motif from the Alpharetrovirus nucleocapsid domain reveals late domain mutant-like budding defects

The Rous sarcoma virus (RSV) Gag polyprotein is the only protein required for virus assembly and release. We previously found that deletion of either one of the two Cys-His (CH) motifs in the RSV nucleocapsid (NC) protein did not abrogate Gag-Gag interactions, RNA binding, or packaging but greatly reduced virus production (E-G. Lee, A. Alidina et al., J. Virol. 77: 2010-2020, 2003). In this report, we have further investigated the effects of mutations in the CH motifs on virus assembly and release. Precise deletion of either CH motif, without affecting surrounding basic residues, reduced virus production by approximately 10-fold, similar to levels seen for late (L) domain mutants. Strikingly, transmission electron microscopy revealed that virions of both DeltaCH1 and DeltaCH2 mutants were assembled normally at the plasma membrane but were arrested in budding. Virus particles remained tethered to the membrane or to each other, reminiscent of L domain mutants, although the release defect appears to be independent of the L domain functions. Therefore, two CH motifs are likely to be required for budding independent of a requirement for either Gag-Gag interactions or RNA packaging.

Basic residues of the retroviral nucleocapsid play different roles in gag-gag and Gag-Psi RNA interactions

The Orthoretrovirus Gag interaction (I) domain maps to the nucleocapsid (NC) domain in the Gag polyprotein. We used the yeast two-hybrid system to analyze the role of Alpharetrovirus NC in Gag-Gag interactions and also examined the efficiency of viral assembly and release in vivo. We could delete either or both of the two Cys-His (CH) boxes without abrogating Gag-Gag interactions. We found that as few as eight clustered basic residues, attached to the C terminus of the spacer peptide separating the capsid (CA) and NC domains in the absence of NC, was sufficient for Gag-Gag interactions. Our results support the idea that a sufficient number of basic residues, rather than the CH boxes, play the important role in Gag multimerization. We also examined the requirement for basic residues in Gag for packaging of specific packaging signal (Psi)-containing RNA. Using a yeast three-hybrid RNA-protein interaction assay, second-site suppressors of a packaging-defective Gag mutant were isolated, which restored Psi RNA binding. These suppressors mapped to the p10 or CA domains in Gag and resulted in either introduction of a positively charged residue or elimination of a negatively charged one. These results imply that the structural interactions of NC with other domains of Gag are necessary for Psi RNA binding. Taken together, our results show that while Gag assembly only requires a certain number of positively charged amino acids, Gag binding to genomic RNA for packaging requires more complex interactions inherent in the protein tertiary structure.

Ambulatory treatment of multidrug-resistant pulmonary tuberculosis patients at a chest clinic

SETTING

Retrospective cohort analysis of multidrug-resistant tuberculosis (MDR-TB) patients treated at a Korean National Tuberculosis Association out-patient chest clinic.

OBJECTIVE

To evaluate treatment outcomes and contributing factors.

DESIGN

A review of clinical records of 1011 pulmonary MDR-TB patients retreated with individualised regimens selected on the basis of previous chemotherapy and drug susceptibility testing from 1988 to 1996.

RESULTS

The patients (mean age 38.6 years) had resistant organisms to an average of 3.7 drugs and were retreated with an average of 4.2 drugs which they had previously not taken and to which they were susceptible. Treatment outcomes were as follows: 487 cases (48.2%) cured, 82 (8.1%) failed, 394 (39.0%) defaulted, 45 (4.5%) transferred out, and three (0.3%) died. The treatment efficacy among those who completed chemotherapy was 85.6%. In a multivariate analysis favourable response was significantly associated with a greater number of newly prescribed drugs in the regimen to which they were susceptible (odds ratio [OR] 3.6; 95% confidence interval [CI] 1.3-9.5), younger age (OR 2.0; 95%CI 1.1-3.9), and a lower number of drugs to which they were resistant (OR 1.8; 95%CI 1.1-3.1). The case fatality rate, including the follow-up period, was 1.7% (17 cases).

CONCLUSION

The cure rate of MDR-TB patients treated at an out-patient clinic was 48.2% due to a high defaulter rate (39.0%). However, 85.6% of those who completed treatment were cured.

Twenty-year trend of chronic excretors of tubercle bacilli based on the nationwide tuberculosis prevalence surveys in Korea, 1975-1995

SETTING

A study of chronic excretors of tubercle bacilli (chronic cases) based on the nationwide random sample surveys of tuberculosis prevalence conducted in Korea from 1975 through 1995.

OBJECTIVE

To investigate the temporal trend of the prevalence of chronic cases, and to match these with treatment outcomes and drug resistance rates.

DESIGN

Bacillary cases were classified by history of chemotherapy into new (those who denied a history of chemotherapy), non-chronic (those who had taken chemotherapy for less than 2 years) and chronic cases (those who had taken chemotherapy for more than 2 years).

RESULTS

Chronic cases decreased from 107 to 12 per 100000 population (annual rate of reduction [ARR] 11.89%) over the 20-year period. The ARR of chronic cases was significantly greater than that of new cases, and accelerated from 1985 (ARR 15.83%), after the application of short course chemotherapy. Rates of overall drug resistance rates increased up to 1980, and those of multidrug resistance up to 1985, followed by a decrease thereafter. A reduction in chronic cases was observed even during the period of increase in drug resistance (including multidrug resistance).

CONCLUSION

The prevalence of chronic tuberculosis cases has decreased due to improvements in overall treatment outcome.

Yeast three-hybrid screening of rous sarcoma virus mutants with randomly mutagenized minimal packaging signals reveals regions important for gag interactions

We previously showed that the yeast three-hybrid system provides a genetic assay of both RNA and protein components for avian retroviral RNA encapsidation. In the current study, we used this assay to precisely define cis-acting determinants involved in avian leukosis sarcoma virus packaging RNA binding to Gag protein. In vivo screening of Rous sarcoma virus mutants was performed with randomly mutated minimal packaging sequences (MPsi) made using PCR amplification after cotransformation with GagDeltaPR protein into yeast cells. Colonies with low beta-galactosidase activity were analyzed to locate mutations in MPsi sequences affecting binding to Gag proteins. This genetic assay delineated secondary structural elements that are important for efficient RNA binding, including a single-stranded small bulge containing the initiation codon for uORF3, as well as adjacent stem structures. This implies a possible tertiary structure favoring the high-affinity binding sites for Gag. In most cases, results from the three-hybrid assay were well correlated with those from the viral RNA packaging assays. The results from random mutagenesis using the rapid three-hybrid binding assay are consistent with those from site-directed mutagenesis using in vivo packaging assays.

Recovery of poly(3-hydroxybutyrate) from coagulated Ralstonia eutropha using a chemical digestion method

For economic recovery of poly(3-hydroxybutyrate) (PHB) from culture broths of Ralstonia eutropha containing PHB, Al-based and Fe-based coagulants were used in the pretreatment step. The coagulated cells were then separated by centrifugation, and PHB was extracted by chemical digestion with a sodium hypochlorite/chloroform dispersion solution. The practical upper limits of dosage were found to be 1, 500 mg-Al/L and 1,000 mg-Fe/L, respectively, for Al- and Fe-based coagulants. When the harvested cells were treated with a 50% sodium hypochlorite/chloroform dispersion solution, PHB recovery and purity were 90-94% and 98-99%, respectively. The influence of the use of coagulants on the PHB recovery process was found to be insignificant. Despite the residual Al and Fe in the recovered PHB (less than 450 mg-Al/kg-PHB and 750 mg-Fe/kg-PHB, respectively), no detectable amounts of Al and Fe were leached from films made of the recovered PHB under acidic conditions. The use of Fe-based coagulants is less recommended because the Fe impurity can cause an unwanted colorization problem in the final product.

Separation of Alcaligenes eutrophus cells containing Poly(3-hydroxybutyrate) from fermentation broth with pretreatment using Al- and Fe-based coagulants

Alcaligenes eutrophus containing intracellular poly(3-hydroxybutyrate) was recovered from fermentation broth by centrifugation and filtration after pretreatment with Al- and Fe-based coagulants. Coagulation efficiency was largely affected by pH, and the optimum pH's for cell recovery were about 4.6-5.6 for the Al-based coagulants and about 5-8 for the Fe-based coagulants. Ammonium ions that combined with metals to form complex compounds increased the coagulant requirement, and the additional requirement of coagulant was found to be proportional to the ammonium concentration. In addition, various ligands in addition to ammonium ions contained in the culture medium interfered with the coagulation reaction and increased the coagulant requirement also. The coagulant requirement increased with the cell concentration regardless of coagulant type. The polymeric coagulants such as PACS, Hi-PAX, and Ferix-3 were more effective than nonpolymeric coagulants of aluminum sulfate and ferrous sulfate. The optimum dosages of the coagulants tested were determined over a broad range of cell concentration of 20.5-210 g/L. It was observed that the energy requirement for centrifugation could be greatly reduced with cell coagulation.

Relationship between moderate intensity endurance training volume and natural killer cell cytolytic activity

BACKGROUND

This study was designed to examine the relationship between endurance training volume and natural killer cell (NK) cytolytic activity. We hypothesized that a dose dependent relationship exists between forced treadmill training volume and training induced increases in NK cell cytolytic activity.

METHODS

EXPERIMENTAL DESIGN

female, Swiss Webster mice were assigned to treadmill control (TC) or treadmill trained groups (n = 10 per group). Trained mice ran at 12 m per min. (8 degrees grade) for: 15 (EX15), 30 (EX30), or 60 minutes (EX60) per day, five days per week for 11 weeks. Splenic NK cell activity was expressed as median lytic unit (LU), median LU per asialo GM1 (AsGM1+) cell, and median LU per spleen.

RESULTS

Median NK activity was not significantly increased by training volume. A trend toward greater median LU per AsGM1+ cell was observed in EX30 group versus TC (p = 0.1). Training volumes less than or greater than this level produced smaller increases in NK cytolytic activity.

CONCLUSIONS

These data provide preliminary evidence indicating that training induced increases in splenic NK cell cytolytic activity do not exhibit a dose dependent relationship with treadmill training volume.

CD40 ligand-activated human monocytes amplify glomerular inflammatory responses through soluble and cell-to-cell contact-dependent mechanisms

Monocytes/macrophages play a critical role in the initiation and progression of a variety of glomerulonephritides. We sought to define the interactions between physiologically activated human monocytes and glomerular mesangial cells (MC) by employing a cell culture system that permits the accurate assessment of the contribution of soluble factors and cell-to-cell contact. Human peripheral blood monocytes, primed with IFN-gamma and GM-CSF, were activated with CD40 ligand (CD40L) or TNF-alpha and cocultured with MC. CD40L-activated monocytes induced higher levels of IL-6, monocyte chemoattractant protein-1 (MCP-1) and ICAM-1 synthesis by MC. Separation of CD40L-activated monocytes from MC by a porous membrane decreased the mesangial synthesis of IL-6 by 80% and ICAM-1 by 45%, but had no effect on MCP-1. Neutralizing Abs against the beta 2 integrins, LFA-1 and Mac-1, decreased IL-6 production by 40 and 50%, respectively. Ligation of mesangial surface ICAM-1 directly enhanced IL-6, but not MCP-1, production. Simultaneous neutralization of soluble TNF-alpha and IL-1 beta decreased MCP-1 production by 55% in membrane-separated cocultures of MC/CD40L-activated monocytes. Paraformaldehyde-fixed CD40L-activated monocytes (to preserve membrane integrity but prevent secretory activity), cocultured with MC at various ratios, induced IL-6, MCP-1, and ICAM-1 synthesis by MC. Plasma membrane preparations from activated monocytes also induced mesangial IL-6 and MCP-1 synthesis. The addition of plasma membrane enhanced TNF-alpha-induced mesangial IL-6 production by approximately 4-fold. Together, these data suggest that the CD40/CD40L is essential for optimal effector function of monocytes, that CD40L-activated monocytes stimulate MC through both soluble factors and cell-to-cell contact mediated pathways, and that both pathways are essential for maximum stimulation of MC.

Treatment of bacillary pulmonary tuberculosis at the chest clinics in the private sector in Korea, 1993

SETTING

Cohort study of bacillary pulmonary tuberculosis patients treated at private sector chest clinics in Korea.

OBJECTIVE

To assess the treatment behaviour of physicians in private chest clinics and the treatment outcomes of their patients.

DESIGN

1) A retrospective analysis of a cohort of patients admitted from July through October in 1993, and 2) comparison with results from health centres under the National Tuberculosis Programme (NTP).

RESULTS

Nine hundred and sixty bacillary patients (507 newly diagnosed--'new', and 453 retreatment--'old') were admitted to the study. Initial smears and cultures were not performed in 7% and 21%, and follow-up smears and cultures not done in 19% and 28%, respectively. The regimens prescribed were variable: 23 in 'new' and 72 in 'old' patients, 86 in total. Six-month short-course treatment using HRZE was prescribed for 26.2% of 'new' patients. In many instances, the planned treatment duration was excessive. The success rates (cured plus completed) for 'new' and 'old' patients were 74% and 51%, respectively. The failure rates were less than 1% in 'new' and 9% in 'old' patients.

CONCLUSION

Prescribed regimens were variable in terms of drug combinations and treatment duration. Overall treatment outcome was inferior to that of the health centres under the NTP.

FTIR Emission Spectra, Molecular Constants, and Potential Curve of Ground State GeO

Extensive new high-temperature, high-resolution FTIR emission spectroscopy measurements for the five common isotopomers of GeO are combined with previous diode laser and microwave measurements in combined isotopomer analyses. New Dunham expansion parameters and an accurate analytical potential energy function are determined for the ground X1Sigma+ state. Copyright 1999 Academic Press.

Cellular interactions in the pathogenesis of lupus nephritis: the role of T cells and macrophages in the amplification of the inflammatory process in the kidney

A significant number of T cells and macrophages infiltrate the kidneys of patients with lupus nephritis. Chemotactic factors, especially monocyte chemoattractant factor-1 (MCP-1) and adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1), cooperatively facilitate recruitment of mononuclear cells into inflamed tissue. Increased expression of class II MHC molecules and CD40 on renal tubular epithelial cells coupled with upregulation of CD40 ligand (CD40L) and interleukin-2 receptor on infiltrating T cells suggest ongoing cellular immune responses. Recent studies employing knockout mice suggest that the T(H)-1 cytokine interferon-gamma is an important cytokine in amplifying the local immune response of lupus nephritis. Infiltrating mononuclear cells exert their effects on resident renal cells through secretion of soluble factors and/or direct cell to cell contact. These interactions, among others, involve molecules such as CD40/CD40L and adhesion molecules. Studies to better define these molecules are in progress and may provide additional targets for therapeutic intervention. Thus, while autoantibody production and complement activation are the major players in initiating the inflammatory response in lupus nephritis, cellular immune mechanisms mediated through infiltrating mononuclear cells have an important role in its amplification and the progression of renal injury.

Modulation of NK cell cytolytic activity by macrophages in chronically exercise-stressed mice

This study was designed to investigate the effects of moderate-intensity endurance training on basal natural killer (NK) cell cytolytic activity in murine splenocytes that were enriched for 1) NK1.1+ cells or 2) macrophages and NK1.1+ cells. Mice were assigned to sedentary (Sed), treadmill control (TM), or treadmill-trained (Trn) groups. Splenocyte number, the percentages of NK1.1+, large granular lymphocytes (NK1.1+, LGL-1+), and other subpopulations did not change in Trn mice. Approximately 70% of cells enriched for NK1.1+ expressed this surface antigen. Lytic units (LU) expressed per LGL-1+ cell were significantly lower in Trn [83.9 +/- 3.2 (SE)] compared with Sed (109.5 +/- 7.5) and TM (101.3 +/- 6.4) groups. When macrophages remained in the in vitro assay, LU per LGL-1(+) cell did not differ across groups. The results indicate that highly enriched NK1.1+ cells from Trn mice had lower NK cell activity compared with Sed mice. No differences in NK cell activity were observed when cells were enriched for NK1.1+ cells and macrophages. These findings support the hypothesis that macrophage modulation of NK cells may be one mechanism contributing to augmented basal NK cell activity in endurance-trained individuals.

Incidence of pulmonary tuberculosis in Korean civil servants

SETTING

Longitudinal epidemiological study based on civil servants in Korea.

OBJECTIVE

To estimate the incidence of pulmonary tuberculosis (PTB) for the general population from a reliable sample.

DESIGN

New active PTB developing between 1988 and 1990 in civil servants has been determined from (1) the findings of biennial medical examinations and (2) perusal of the medical records of those claiming health insurance for tuberculosis (TB).

RESULTS

A total of 790,204 subjects was available for investigation. Active PTB was diagnosed in 5107 patients over the 2 years of the study. Bacteriological examination of 3847 patients yielded 575 (14.9%) positive smears and 350 (9.1%) smear-negative positive cultures from them. Applying these rates to the 1260 whose sputum was not examined, 702 were smear-positive, and 431 were culture-positive. Overall PTB incidence was 393 per 10(5), with 84 and 53 per 10(5) smear- and culture-positive. Incidence was high in males, and in the age group 20-29 years in both sexes.

CONCLUSION

Such high PTB incidence, particularly in the age group 20-29, clearly indicates that TB in Korea remains a serious health problem.

Incidence of pulmonary tuberculosis among diabetics

SETTING

Longitudinal epidemiological study based on diabetic and non-diabetic civil servants in Korea.

OBJECTIVE

To determine a comparative incidence of pulmonary tuberculosis (PTB) between diabetic and non-diabetic subjects.

DESIGN

Investigation of newly developed PTB among diabetics and non-diabetics between 1988 and 1990, on the basis of biennial medical examination and the medical records of those who claimed health insurance for tuberculosis.

RESULTS

The 1990 medical examination and investigation of medical records of the health insurance claimants revealed that PTB had developed in 170 patients (including 37 smear and eight culture positives) among 8015 diabetics, and in 4935 patients (including 538 smear and 342 culture positives) among 806,698 control subjects. Estimated annual incidence rates of PTB of (1) all types, (2) smear and/or culture positive versus (3) smear positive cases were 1061, 281 and 231 per 10(5) respectively among diabetics and 306, 55 and 33 per 10(5) among non-diabetic controls. PTB developed in 167 of 7695 male diabetics and in 3 of 320 female diabetics. The greater the age, the more diabetics were found.

CONCLUSION

Relative risks (RR) of developing PTB of all types and bacteriologically confirmed cases were 3.47 times and 5.15 times higher in the diabetics than in the matched controls. A greater RR was observed on those at the age of 30-49 than in those of 50 years or more.

Mechanistic differences in NK cell cytolytic activity in treadmill-trained and chronic ethanol-consuming mice

The present study was undertaken to investigate mechanisms contributing to differences in natural killer (NK) cell activity in moderately endurance-trained and ethanol-consuming mice. Independent of ethanol exposure, NK cell activity in nylon wool-nonadherent (NWNA) splenocytes is lower in trained than in sedentary control mice (Blank et al. J. Appl. Physiol. 72: 8-14, 1992). Reduced activity may result from a generalized loss of cytolytically active cells, redistribution of NK cells from the spleen to other body compartments, or disruption of paracrine regulation of NK cells after removal of nylon wool-adherent cells. To examine these possibilities, NK cell cytolytic activity was determined in nonenriched splenocytes from treadmill-trained and ethanol-consuming mice. Lymphocyte subpopulations in nonenriched splenocytes and NWNA splenocytes were also compared. Peripheral blood lymphocyte subpopulations were determined to examine combined effects of training and ethanol intake on regional distribution of lymphocytes in blood and spleen. NK cell activity in nonenriched splenocytes from trained water-drinking mice was not reduced compared with that in sedentary mice; rather, cytolytic activity was moderately enhanced (17% increase in lytic units, P < 0.05). Training did not change percentages of T-cells, B-cells, and NK [NK1.1+ and large granular lymphocytes (LGL-1+)] cells or the LGL/NK ratio in the spleen and blood. NK cell cytolytic activity was significantly reduced in nonenriched splenocytes from ethanol-consuming mice, independent of training. These findings support the hypothesis that moderate-intensity endurance training influences splenic NK cell function by modulating paracrine regulation of NK cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Pancreatic plasma membranes: promiscuous partners in membrane fusion

We have developed a system in which the fusion of pancreatic plasma membranes with zymogen granules can be studied in vitro. We show here that pancreatic plasma membranes fuse not only with pancreatic zymogen granules but also with parotid secretory granules. In contrast, parotid membranes fuse only with parotid granules and not with pancreatic granules. The extent of fusion is insensitive to Ca2+ for all combinations of plasma membranes and granules. Guanosine 5'-[gamma-thio]triphosphate (GTP[S]), on the other hand, stimulates fusion of pancreatic membranes with both pancreatic granules and parotid granules, but inhibits fusion between parotid membranes and parotid granules.

Plasma corticosterone response to chronic ethanol consumption and exercise stress

Acute exposure to ethanol induces a stress response in mice that is manifested by increased plasma corticosterone (PC) concentration. However, during chronic intake of 7.5% w/v ethanol, diurnal fluctuation of PC is dampened. Whether chronic consumption of 20% w/v ethanol alters normal diurnal fluctuation of plasma glucocorticoids is not known. Investigating the PC response in 20% w/v ethanol-consuming mice is of interest because glucocorticoids are known suppressants of natural killer (NK) cell activity and increased concentration or altered diurnal fluctuation of PC may have a modulatory role on NK cells in these mice. Mice given 20% w/v ethanol for at least 7 days and for as long as 10 weeks have suppressed splenic NK cell cytolytic activity. Thus, the purpose of this study was to examine whether mice given 20% w/v ethanol exhibited normal concentrations and diurnal variation of PC. To further define the glucocorticoid response in chronic ethanol-consuming mice, PC concentration was evaluated in response to a secondary stress of physical exercise. After 1 week, ethanol-consuming mice exhibited abnormal diurnal PC periodicity that was progressively dampened during the remaining 9 weeks. Acute physical exercise during Week 1 induced a 2-fold increase in PC concentration compared with pre-exercise values, a response that was independent of ethanol intake. After 6 and 10 weeks, the postexercise PC concentration was attenuated in ethanol-consuming compared with water-drinking mice. It was concluded that suppressed NK cell activity typically observed with this model of chronic ethanol intake is not directly associated with dampened diurnal fluctuation in PC.

Genetic activity in Saccharomyces cerevisiae of compounds found in effluents of pulp and paper mills

20 compounds identified in pulp mill effluents were screened for genetic activity in growing cells using Saccharomyces cerevisiae strains D7 and XV185-14C without and with S9. Nine compounds were positive in one or the other yeast strain (7 in D7; 2 in XV185-14C). One additional compound showed weak effects and two others showed elevated frequencies/survivor without absolute increases of mutants. The presence of S9 enabled detection of one positive and two weak effects, it enhanced the genetic activity of one compound in each strain, and it reduced the mutagenic effects of 4 others in strain D7. 7 of the 20 chemicals tested have been shown previously to be mutagenic in the Salmonella/mammalian-microsome assay. Of the 7 bacterial mutagens, 6 were positive and 1 had a weak effect in yeast.

Sigmoid volvulus: new thoughts on the epidemiology

Sigmoid volvulus usually affects the elderly, but it is being increasingly described in a younger age group. In these patients the diagnosis is often delayed, due to a prolonged and intermittent history. Three patients, of 31,36, and 67 years, are described here, and they demonstrate an increased incidence within families, which has not been previously recognized. Awareness of this possibility may allow earlier diagnosis when investigating young patients with intermittent abdominal symptoms, whose relatives are known to be affected.

Mutagenicity of constituents of pulp and paper mill effluent in growing cells of Saccharomyces cerevisiae

42 compounds identified in pulp mill effluent were screened for genetic activity in growing yeast cells using strains D7 and XV185-14C without S9. In addition to 3 of these compounds that had been shown previously to be mutagenic in Salmonella. 5 more were mutagenic in strain XV185-14C. All 8 induced 2-5-fold increases in reversion frequencies over background at the trp5 locus--5 of these induced 1.5-3-fold increases at the hom3 locus and 1 induced a doubling at his1. None of the compounds induced absolute increases of gene convertants per plate in strain D7, although 3 showed increased convertant frequencies as survival decreased.

Mutagenicity of constituents identified in pulp and paper mill effluents using the Salmonella/mammalian-microsome assay

About 300 compounds have been reported in the literature as constituents of pulp-mill effluent. Previously, in our screening program, 10 resin acids identified in effluent were examined for potential mutagenicity in the Salmonella/mammalian-microsome assay. Neoabietic acid was the only resin acid which was found to be mutagenic. Now, a program to screen for mutagenicity of 48 additional compounds, belonging to chemical classes of chlorinated aliphatic and aromatic hydrocarbons, phenols, aldehydes, quinones, and carboxylic acids, has been completed. Only 2 of these compounds, tetrachloropropene and pentachloropropene, were found to be mutagenic, showing dose-related increases in His+ reversion mutations, in the standard Salmonella test. Metabolic activation with a preparation of Aroclor 1254-induced liver homogenate (S9) greatly reduced the mutagenic responses of these 2 compounds. Modifications of the Salmonella test for volatile mutagens enabled the detection of the mutagenicity of 3 additional chlorinated aliphatic hydrocarbons dichloromethane, dichloroethane and trichloroethane.

Mutagenicity of resin acids identified in pulp and paper mill effluents using the Salmonella/mammalian-microsome assay

Ten resin acids which have been identified as constituents of pulp and paper mill effluents have been examined for potential mutagenicity in the Salmonella/mammalian-microsome assay. Only neoabietic acid has been found to be mutagenic. Neoabietic acid showed dose-related increases in mutagenicity in strains TA1535, TA100, TA1538, and TA98, but not in strain TA1537. Metabolic activation with a preparation of Aroclor 1254-induced liver homogenate (S9) slightly reduced the mutagenic responses. Negative responses were found for abietic acid, dehydroabietic acid, levopimaric acid, 7-oxodehydroabietic acid, monochlorodehydroabietic acid, dichlorodehydroabietic acid, pimaric acid, isopimaric acid, and sandaracopimaric acid.

Further experience in the treatment of severe attacks of ulcerative colitis

One hundred courses of an intensive intravenous regimen have been used in 87 patients with severe attacks of ulcerative colitis during the past 5 years, 11 of the patients having been treated more than once during separate admissions to hospital. 60% of the attacks responded swiftly to the regimen, and the patients were symptom-free at the end of the 5-day course. In 15% there was improvement but the patients were not entirely symptom-free. In 25% failure to respond resulted in emergency colectomy, the usual operation being proctocolectomy as a single-stage procedure. There were no deaths directly due to ulcerative colitis or to surgical treatment in these patients during the period of the study, the mean period of follow-up being 25 months; but 4 elderly patients died from unrelated causes. These favourable results are better than most published figures. The advantages of the intensive medical regimen are that: (i) many patients quickly go into clinical remission, which is frequently sustained; and (ii) failure to improve can be regarded as a clear-cut indication for emergency surgery.

Psychiatric problems in the first year after mastectomy

The psychiatric morbidity associated with mastectomy was assessed in 75 women by following them up from the time they presented with suspected breast cancer to one year after the operation. Fifty women with benign breast disease served as controls. Throughout the follow-up period the incidence of psychiatric problems was higher among the women who had undergone mastectomy. One year after surgery 19 (25%) of these women compared with only 5 (10%) of the controls needed treatment for anxiety or depression or both, and 16 (33%) compared with 3 (8%) respectively had moderate or severe sexual difficulties. Altogether 29 patients in the mastectomy group (39%) and six of the controls (12%) had serious anxiety, depression, or sexual difficulties. Of the eight women in the mastectomy group who sought help for their problems, only two felt that the help given had been appropriate. The inability to recognise and treat these emotional disturbances is a common and serious problem. Monitoring by specially trained nurses and social workers might help to identify them earlier and even reduce them.

A quantitative assessment of the structural changes the rat's liver following obstruction of the common bile duct

A study has been made of sequential changes in the rat's liver from 1 to 40 days after obstruction of the common bile duct. The qualitative changes have been described and illustrated. The volume proportions of hepatocytes, bile duct epithelium and biliary stroma have been quantified by histological analysis using a point counting technique. The proliferation of hepatocytes and bile duct cells have been measured by labelling with tritiated thymidine. The absolute quantity of hepatocytes in each liver has been estimated and expressed as a percentage of body weight. Over 40 days there is a relative fall in the volume proportion of hepatocytes and an increase in bile duct cells and biliary stroma. These changes in volume proportions are related directly to the period of jaundice. Biliary stroma increases in support of new bile duct tissue and there is no excessive fibrosis. Hepatocytes proliferate at a greater rate than normal after obstruction of the common bile duct and the degree of proliferation reaches a maximum of 24 times that of normal 4 days after obstruction. Similarly, the proliferation of bile duct epithelium is increased in obstructive jaundice but in this instance it reaches a maximum of 50 times that of normal 24 h after ligation of the common bile duct. The absolute quantity of hepatocytes in the liver probably falls during the period of jaundice. However, the fall is less than anticipated from the volume proportion of hepatocytes because of the overall increase in liver size.

Biosynthesis of pyocyanine by a paraffin hydrocarbon-oxidizing strain of Pseudomonas aeruginosa

A paraffin-oxidizing bacterium, designated as Pseudomonas aeruginosa ATS-14, was isolated from soil samples obtained from the Athabasca "tar sands." This strain utilized kerosene as the only carbon source of energy and produced a high concentration of pyocyanine in the culture medium. Aromatic carbons were not attacked, but C(10) to C(17)n-alkanes were readily oxidized by the pseudomonad and formed pyocyanine. The highest yield of the pigment was obtained from hexadecane and heptadecane.