Naked DNA vaccination of Atlantic salmon Salmo salar against IHNV

A naked plasmid DNA encoding the glycoprotein (pCMV4-G) of a 1976 isolate of infectious hematopoietic necrosis virus (IHNV) obtained from steelhead Oncorhynchus mykiss was used to vaccinate Atlantic salmon Salmo salar against IHNV. Eight weeks post-vaccination the fish were challenged with a strain of IHNV originally isolated from farmed Atlantic salmon undergoing an epizootic. Fish injected with the glycoprotein-encoding plasmid were significantly (p < 0.05) protected against IHNV by both immersion and cohabitation challenge. Survivors of the first challenges were pooled and re-challenged by immersion 12 wk after the initial challenge. Significant (p < 0.05) protection was observed in all of the previously challenged groups including those receiving the complete vaccine. Fish injected with the glycoprotein-encoding plasmid produced low levels of virus-neutralizing antibodies prior to the first challenge. Neutralizing antibodies increased in all groups after exposure to the IHNV. Passive transfer of pooled sera from pCMV4-G vaccinates and IHN survivors provided relative survivals of 40 to 100% compared to fish injected with sera collected from fish immunized with control vaccines or left unhandled. In this study, DNA vaccination effectively protected Atlantic salmon smolts against challenges with IHNV.

Loss of STAT1 expression confers resistance to IFN-gamma-induced apoptosis in ME180 cells

Interferon gamma (IFN-gamma) induces apoptosis in many tumor cell lines and sensitizes tumor cells to apoptosis by tumor necrosis factor family members. IFN-gamma induces the expression of many early response genes such as interferon regulatory factor-1 (IRF-1) by activation of signal transducer and activator of transcription (STAT) factor proteins. We found that ME180 cells became resistant to IFN-gamma-induced cell death after 4-5 passages in culture. These resistant cells were characterized by a loss of STAT1 expression and a loss of inducible IRF-1 expression. We describe for the first time the emergence of a STAT1-deficient ME180 cell line.

Characterization of the dimer interface of transcription factor NFkappaB p50 homodimer

Dimers of the Rel/NFkappaB transcription factor family form with differential stabilities through the combinatorial association of five polypeptides: p50, p52, p65, cRel, and RelB. Here, we have characterized the nature of the monomer-dimer equilibrium of the p50 homodimer. Sedimentation equilibrium studies show that the equilibrium constant for p50 dimer dissociation is in the low micromolar range. Using the X-ray crystal structure of the p50 homodimer as a guide, we have created site-directed alanine mutations at ten dimer-forming residues in p50 and measured their effects on p50 homodimerization. Characterization of these alanine mutants by a series of chemical crosslinking, size-exclusion chromatography, and sedimentation equilibrium experiments shows that the most critical residue in stabilizing the p50 dimer interface is Y267. Sedimentation equilibrium experiments show that an alanine substitution at position 267 destabilizes the dimer interface by 2.0 kcal/mol. Alanine substitutions at two other positions, L269 and V310, significantly destabilize the p50 dimer interface. These two residues are observed to mediate critical interactions in the crystal structure. Together, these three residues constitute the "hot-spot" of protein-protein interaction in p50 dimerization. Of the four charged residues in the dimer interface, R252, D254, E265, and D302, only D302 contributes significantly to p50 dimer stability. D254 appears to slightly destabilize the subunit interface. Although residues H304, R305, and F307 occupy positions at the hydrophobic core of the interface and appear to be involved in multiple interactions in the X-ray crystal structure, alanine substitutions at these positions do not significantly reduce the affinity for p50 dimerization. Upon evaluating the roles of these amino acid residues at the p50 dimer interface, we propose that differential contributions of a few key residues dictate the selectivity of dimer formation within the Rel/NFkappaB family.

Fasting hyperinsulinemia and changes in regional body composition in human immunodeficiency virus-infected women

A novel lipodystrophy syndrome (characterized by insulin resistance, hypertriglyceridemia, and fat redistribution) has recently been described in human immunodeficiency virus (HIV)-infected patients. However, investigation of the lipodystrophy syndrome has generally been limited to men; and a comprehensive evaluation of insulin, lipids, and regional body composition has not been performed in the expanding population of HIV-infected women. In this study, we assessed fasting insulin, lipid levels, virologic parameters, and regional body composition, using dual-energy x-ray absorptiometry, in a cohort of 75 HIV-infected women (age, 25-46 yr), in comparison with 30 healthy weight-matched premenopausal control subjects. HIV-infected women demonstrated significant truncal adiposity (38.5 +/- 0.9 vs. 34.9 +/- 1.3%, P < 0.05) hyperinsulinemia (15.9 +/- 1.5 vs. 7.5 +/- 0.6 microU/mL, P < 0.001) and an increased insulin-to-glucose ratio (0.2 +/- 0.02 vs. 0.1 +/- 0.03, P < 0.001), compared with control subjects. Insulin and the insulin-to-glucose ratio were increased, even among HIV-infected patients with low body weight (<90% of ideal body weight) (insulin, 13.3 +/- 2.8 microU/mL, P < 0.01 vs. control; insulin/glucose, 0.2 +/- 0.04, P < 0.01 vs. control). Insulin and the insulin-to-glucose ratio were most significantly elevated among patients with increased truncal adiposity (insulin, 28.2 +/- 3.2 microU/mL, P < 0.001 vs. control; insulin/ glucose, 0.32 +/- 0.04, P < 0.001 vs. control). In contrast, no differences in insulin were seen in relation to protease inhibitor (PI) use. Similarly, HIV-infected women also demonstrated significant hypertriglyceridemia (144 +/- 15 vs. 66 +/- 23 mg/dL, P < 0.01 vs. controls), which was present even among low-weight patients (148 +/- 32 mg/dL, P < 0.001 vs. control) but was not related to truncal adiposity or PI usage. These data demonstrate significant hyperinsulinemia and truncal adiposity in HIV-infected women. Our data suggest that these metabolic abnormalities occur at baseline in HIV-infected women, independent of PI use. However, these data do not rule out a direct effect of PI therapy on fat metabolism or indirect effects of PI therapy to further worsen glucose and lipid homeostasis in association with weight gain and disease recovery.

Sustained anabolic effects of long-term androgen administration in men with AIDS wasting

Fifty-one human immunodeficiency virus-positive men with hypogonadism and wasting were randomized to receive testosterone enanthate, 300 mg i.m. every 3 weeks, or placebo for 6 months, followed by open-label testosterone administration for 6 months. Subjects initially randomized to placebo gained lean body mass (LBM) only after crossover to testosterone administration (mean change +/- standard error of the mean, -0.6 +/- 0.7 kg [months 0-6] vs. 1.9 +/- 0.7 kg [months 6-12]; P = .03). In contrast, subjects initially randomized to testosterone continued to gain LBM during open-label administration (2.0 +/- 0.7 kg [months 0-6] vs. 1.6 +/- 0.6 kg [months 6-12]; P = .62) and had gained more LBM at 1 year than did subjects receiving testosterone for only the final 6 months of the study (3.7 +/- 0.8 kg vs. 1.0 +/- 1.0 kg; P = .05). Testosterone administration results in sustained increases in LBM during 1 year of therapy in hypogonadal men with AIDS wasting.

Coping with epilepsy: do illness representations play a role?

OBJECTIVES

To determine the relative contributions of neuroepilepsy, coping and illness representation variables to psychological adjustment in epilepsy.

DESIGN

The study was a cross-sectional design, contrasting the adjustment of recently diagnosed and chronic patients. Neuroepilepsy, illness representation, coping and adjustment variable were all measured.

METHOD

A total of 94 patients were studied comprising three groups: recently diagnosed patients, chronic patients cared for in hospital clinics, and chronic patients cared for by their GP. A measure was developed to assess each patient's illness representations of epilepsy.

RESULTS

Overall, the epilepsy patients showed significant adjustment problems relative to a normative group. There were, however, significant differences between epilepsy subgroups: recently diagnosed and chronic (clinic) patients exhibited problems, but chronic (GP) patients were relatively well adjusted. After controlling for the effects of group membership and neuroepilepsy variables, coping and illness representations, each explained significant additional variance on measures of psychological adjustment. Patients presenting with adjustment difficulties were characterized by high seizure frequency, avoidance father than problem-focused coping, doubt about their diagnostic label and belief in poor containment.

CONCLUSIONS

We conclude that the illness representations paradigm has value in understanding psychosocial adjustment to epilepsy. This approach offers the potential to identify the critical factors in patients' adaptation to illness. Such insights into the coping process may contribute to the development of effective clinical interventions.

The primary use of endocrine therapies

Primary endocrine therapy is potentially superior to primary chemotherapy in patients with ER-positive tumors. The ability to give endocrine therapy perioperatively may be a better test than chemotherapy of the hypothesis that the events accompanying surgery affect prognosis. However, a major problem in all studies of primary endocrine therapy is that there has been no clear experimental test of preoperative versus postoperative therapy. This is because the major thrust of treatment has been in the elderly with the purpose of determining whether surgery can be avoided altogether. The fact that in ER-positive tumors primary endocrine therapy is associated with similar response rates to chemotherapy make it an attractive therapy for older women. This is the group where adjuvant chemotherapy has not been adequately tested (> or = 70 years of age). In contradistinction, adjuvant endocrine therapy shows marked survival benefits in patients with ER-positive tumors in these age groups (Table 1). It appears likely that primary endocrine therapy will allow breast conservation and prognostic information as is seen with chemotherapy. A major question which requires answering is whether primary endocrine therapy will improve survival more than adjuvant therapy alone. Although ER status is a good marker of responsiveness, its specificity, in particular, is not optimal. The ability to assess the dynamic effects of primary endocrine therapy by sequential biopsy and measurement of biological responses to oestrogen deprivation may allow us to predict precisely the patients likely to benefit from treatment. This clinical scenario allows us to use other potentially useful assessments such as the non-invasive estimation of angiogenesis using quantitative imaging techniques of blood flow. The newer anti-estrogens and aromatase inhibitors appear ideally suited to primary therapy since they have rapid and profound inhibitory activities, few or no agonist effects, and low side effect profiles. A preoperative trial of Faslodex is planned by the EORTC and another with Arimidex is under consideration by the ATAC (Arimidex, tamoxifen and combined) Trialist Group (Fig. 7). The precise design of these studies will require considerable thought.

Differential distribution of inositol trisphosphate receptor isoforms in mouse oocytes

In mammalian fertilization, inositol 1,4,5-trisphosphate receptor (IP3R)-dependent Ca2+ release is a crucial signaling event that originates from the vicinity of sperm-egg interaction and spreads as a wave throughout the egg cytoplasm. While it is known that Ca2+ is released by the type 1 IP3R in the egg cortex, the potential involvement of other isoform types responsible for the Ca2+ rise in the mouse egg (interior) and their spatial distribution are not known. In addition, the biochemical basis has not been definitively established for the development of increased sensitivity to inositol 1,4,5-trisphosphate (IP3) during meiotic maturation. Using specific antibodies to the type 1, 2, and 3 IP3R, we tested the hypotheses that different IP3R isoforms are responsible for the internal Ca2+ elevation and that they contribute to the maturation-associated acquisition of IP3 sensitivity. In both preovulatory oocytes and ovulated eggs of CF-1 mice, immunofluorescence revealed that types 1 and 2 isoforms were present in the cell cortex and interior. Type 1 was observed throughout the cytoplasm, and Western analysis indicated a 1.9-fold maturation-associated increase. In contrast, the signals detected for the type 2 (high-affinity) isoform and type 3 were present to a lesser extent, with type 2 restricted to isolated islands (similar to aggregates of vesicles detected by electron microscopy), which, in the cortex, may amplify early sperm-egg signaling events. The cortical-to-perinuclear localization of the receptor and cortical vesicle aggregates imply an efficient mechanism for propagating Ca2+ release from the cortex into the interior of the egg to activate development, and the isoform localization analysis indicates a clear spatial and biochemical heterogeneity. Types 1 and 2 isoforms were also present in granulosa cells.

Guidelines for follow-up of women at high risk for inherited breast cancer: consensus statement from the Biomed 2 Demonstration Programme on Inherited Breast Cancer

Protocols for activity aiming at early diagnosis and treatment of inherited breast or breast-ovarian cancer have been reported. Available reports on outcome of such programmes are considered here. It is concluded that the ongoing activities should continue with minor modifications. Direct evidence of a survival benefit from breast and ovarian screening is not yet available. On the basis of expert opinion and preliminary results from intervention programmes indicating good detection rates for early breast cancers and 5-year survival concordant with early diagnosis, we propose that women at high risk for inherited breast cancer be offered genetic counselling, education in ‘breast awareness’ and annual mammography and clinical expert examination from around 30 years of age. Mammography every second year may be sufficient from 60 years on. BRCA1 mutation carriers may benefit from more frequent examinations and cancer risk may be reduced by oophorectomy before 40–50 years of age. We strongly advocate that all activities should be organized as multicentre studies subjected to continuous evaluation to measure the effects of the interventions on long-term mortality, to match management options more precisely to individual risks and to prepare the ground for studies on chemoprevention.

Epithelial stem cells in the mammary gland: casting light into dark corners

The epithelial structures of the human breast or the mouse mammary gland are derived from a relatively small number of multipotent, tissue-specific stem cells, of which we are surprisingly ignorant. We do not know how many are required to produce a complete mammary gland, how many times they divide during the process, where they are situated in the gland, or even what they look like. We want to know the answers to these questions, not just to satisfy intellectual curiosity, but also because the answers may shed light on the evolution of breast cancer. Now, studies carried out by Kordon and Smith at the National Cancer Institute have pointed the way toward a new understanding of mammary stem cells and their progeny.

Efficacy of early diagnosis and treatment in women with a family history of breast cancer. European Familial Breast Cancer Collaborative Group

BACKGROUND

Surveillance programmes for women at increased genetic risk of breast cancer are being established worldwide but little is known of their efficacy in early detection of cancers and hence reduction in mortality.

METHODS

Data were contributed from seven centres participating in the EU Demonstration Programme on Clinical Services for Familial Breast Cancer. All breast tumours (n = 161) detected prospectively, from the time of enrolment of women in a screening programme, were recorded. Analysis took account of age at diagnosis, whether tumours were screen-detected or not, their pathological stage and outcome by Kaplan-Meier survival plots.

RESULTS

Mean age at diagnosis was 48.6 years. Overall, 75% of tumours were detected in the course of planned examinations. For women under age 50 at diagnosis, this figure was 68%. Eighteen percent were mammographically negative, (23% in patients under age 50). At first ("prevalence") round and at follow-up screening, 16% and 22% of tumours respectively were carcinoma in situ (CIS) while 27% and 22% respectively had evidence of nodal or distant spread (CaN+). Comparison of screen-detected and other tumours showed that the latter were more frequently mammogram-negative and CaN+. Overall five-year survival was 89% and five-year event-free survival 86%. Five-year event-free survival was 100% for CIS, 88% for invasive cancer without nodal or distant spread and 67% for CaN+.

CONCLUSIONS

The majority of cancers arising in women at increased genetic risk of breast cancer can be detected by planned screening, even in those under age 50. Surveillance should include regular expert clinical examination and teaching of "breast awareness" as well as mammography. Attention to the logistics of screening programmes may improve still further the proportion of tumours that are screen-detected. The trend towards earlier pathological stage in tumours detected during follow-up rounds and the preliminary findings on survival analysis suggest that this approach will prove to be of long-term benefit for breast cancer families.

Utilisation of prophylactic mastectomy in 10 European centres

Increasingly women at high risk of breast cancer are opting for prophylactic surgery to reduce their risks. Data from 10 European centres that offer a risk counselling and screening service to women at risk show different approaches to the option of preventive surgery, although most centres adhere to a protocol including at least two risk counselling sessions and a psychological assessment. Thus far the combined centres have data on 174 women who have undergone prophylactic mastectomy with in excess of 400 women years of follow up. Operations were carried out on women with lifetime risks of 25-80%, with an average annual expected incidence rate of 1% per women. No breast cancers have occurred in this cohort. Long term follow up on an extended group of women will be necessary to truly address the risk of subsequent breast cancer and the psychological sequelae.

Determinants of increased energy expenditure in HIV-infected women

BACKGROUND

Little is known about sex-specific effects of HIV infection on energy expenditure.

OBJECTIVE

We investigated the determinants of energy expenditure in HIV-infected women.

DESIGN

Resting energy expenditure (REE), body composition, and hormonal and nutritional indexes were compared in 33 ambulatory, premenopausal HIV-infected women and 26 weight-matched, healthy premenopausal control subjects. REE was determined by indirect calorimetry and body composition by dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis, and skinfold-thickness analysis. Hormonal indexes included leptin, testosterone, estradiol, and insulin-like growth factor I.

RESULTS

HIV-infected subjects had a higher REE than control subjects [6794 +/- 1374 compared with 6011 +/- 607 kJ/d (1624 +/- 329 compared with 1437 +/- 145 kcal/d), P = 0.0096]. On average, REE was 119 +/- 23% of Harris-Benedict predictions in HIV-infected subjects compared with 102 +/- 9% for control subjects (P = 0.0007). In HIV-infected subjects, REE was highly correlated with fat-free mass (FFM) by DXA (R = 0.641, P < 0.001), but not with weight or disease status. The slope of the regression equation for REE and FFM was significantly greater (P = 0.027, analysis of covariance) for HIV-infected subjects [REE (kJ/d) = 203.5 (kg FFM) - 1237] than for control subjects [REE (kJ/d) = 77.4 (kg FFM) + 2923]. In a stepwise regression analysis, FFM was the most significant variable (P = 0.005), followed by free testosterone (P = 0.029), which together explained 49% of the variation in REE. The final equation was REE (kJ/d) = 230.8 (kg FFM) + 395.9 (free testosterone, pmol/L) - 3304.

CONCLUSIONS

Energy expenditure was higher in HIV-infected women than in control women. FFM is the primary determinant of REE in HIV-infected women, but energy expenditure is greater per kg FFM in HIV-infected subjects than in control subjects, which may contribute to the wasting syndrome.

Characterization of Ke 6, a new 17beta-hydroxysteroid dehydrogenase, and its expression in gonadal tissues

The abnormal regulation of the Ke 6 gene has been linked to the development of recessive polycystic kidney disease in the mouse. In this report, we have shown that Ke 6 is a 17beta-hydroxysteroid dehydrogenase and can regulate the concentration of biologically active estrogens and androgens. The Ke 6 enzyme is preferentially an oxidative enzyme and inactivates estradiol, testosterone, and dihydrotestosterone. However, the enzyme has some reductive activity and can synthesize estradiol from estrone. We find that the Ke 6 gene is expressed within the ovaries and testes. The presence of Ke 6 protein within the cumulus cells surrounding the oocyte places it in a strategic location to control the level of steroids to which the egg is exposed. Previously, it had been shown that glucocorticoids can induce renal cysts in the neonatal rodent, only when given at a narrow time window of postnatal kidney development. We propose that the reduction in the level of Ke 6 enzyme, which occurs in the cpk, jck, and pcy mice, may lead to abnormal elevations in local level of sex steroids, which either directly or indirectly via abnormal glucocorticoid metabolism result in recessive renal cystic disease, a developmental disorder of the kidney.

A statewide survey of immunization rates in Minnesota school age children: implications for targeted assessment and prevention strategies

BACKGROUND

A retrospective statewide immunization survey of the 69115 Minnesota children who entered kindergarten in 1992 was conducted.

METHODS

Information was collected from school immunization records on date of birth, dates of vaccination for each dose of vaccine, address of residence and race/ethnicity (when available). Immunization rates were assessed retrospectively for each month of a child's life from 2 to 48 months of age. Age-appropriate immunization was defined as receipt of all scheduled vaccines within 30 days of the recommended age.

RESULTS

Immunization levels varied by vaccine, age of the child and race/ethnicity. For example at 19 months of age, 73% of students had received measles, mumps, rubella vaccine; however, only 39% had received their fourth dose of diphtheria, tetanus and pertussis vaccine. White, non-Hispanic students consistently had higher vaccination rates than children of other racial/ ethnic groups. For example 45% of white, non-Hispanic students were age-appropriately vaccinated at 16 months of age compared with 25% of Blacks, 30% of American Indians, 30% of white Hispanics and 28% of Asian-Pacific Islanders (Mantel-Haenzel chi square, P < 0.001 for each comparison). Furthermore coverage rates frequently varied significantly by neighborhood, thereby identifying pockets of underimmunization within communities.

CONCLUSION

Our data demonstrate that vaccination rates can vary substantially by age, race/ ethnicity and neighborhood. Detailed immunization assessment is necessary so that effective targeted interventions can be developed.

Transdermal testosterone administration in women with acquired immunodeficiency syndrome wasting: a pilot study

Although human immunodeficiency virus (HIV) disease is increasing rapidly among women, no prior studies have investigated gender-based therapeutic strategies for the treatment of acquired immunodeficiency syndrome (AIDS) and its complications in this population. Markedly decreased serum androgen levels have been demonstrated in women with AIDS and may be a contributing factor to the wasting syndrome in this population. To assess the effects of androgen replacement therapy in women with AIDS wasting, we conducted a randomized, placebo-controlled, pilot study of transdermal testosterone administration. The primary aim of the study was to determine efficacy in terms of the change in serum testosterone levels, safety parameters and tolerability. A secondary aim of the study was to investigate testosterone effects on weight, body composition, quality of life, and functional indexes. Fifty-three ambulatory women with the AIDS wasting syndrome defined as weight less than 90% of ideal body weight or weight loss of more than 10% of the preillness maximum, free of new opportunistic infection within 6 weeks of study initiation, and with screening serum levels of free testosterone less than the mean of the normal reference range (< 3 pg/mL) were enrolled in the study. Subjects were age 37 +/- 1 yr old (mean +/- SEM), weighed 92 +/- 2% of ideal body weight, and had lost 17 +/- 1% of their maximum weight. CD4 count was 324 +/- 36 cells/mm3, and viral burden was 102,382 +/- 28,580 copies. Subjects were randomized into three treatment groups, in which two placebo patches (PP), one active/one placebo patch (AP group), or two active patches (AA group) were applied twice weekly to the abdomen for 12 weeks. The expected nominal delivery rates of testosterone were 150 and 300 microg/day, respectively, for the AP and AA groups. Forty-five subjects completed the study (PP group, n = 13; AP group, n = 14; AA group, n = 18). Two additional subjects from the PP group and two from the AP group were included in the intent to treat analysis. Serum free testosterone levels increased significantly from 1.2 +/- 0.2 to 5.9 +/- 0.8 pg/mL (AP) and from 1.9 +/- 0.4 to 12.4 +/- 1.6 pg/mL (AA) in response to testosterone administration (P < 0.0001 for comparison of AA vs. PP and AP vs. PP; normal range, 1.3-6.8 pg/mL). Testosterone administration was generally well tolerated locally and systemically, with no adverse trends in hirsutism scores, lipid profiles, or liver function tests. Weight increased significantly in the AP group (1.9 +/- 0.7 kg) vs. the PP group (0.6 +/- 0.8 kg; P = 0.043), but did not increase significantly in the AA group (0.9 +/- 0.4 kg; P = 0.263 vs. PP, by mixed effects model assessing the interaction of time and treatment on all available data, one-tailed test). Improved social functioning (P = 0.024, by one-tailed test) and a trend toward improved pain score (P = 0.059) were observed in the AP vs. the PP-treated patients (RAND 36-Item Health Survey questionnaire). Five of six previously amenorrheic patients in the AP group had spontaneous resumption of menses compared to only one of four amenorrheic patients in the AA group (P = 0.045 for comparison of actual number of periods during the study). This study is the first investigation of testosterone administration in women with AIDS wasting. We demonstrate a novel method to augment testosterone levels in such patients that is safe and well tolerated during short term administration. At the lower of the two doses administered in this study, testosterone therapy was associated with positive trends in weight gain and quality of life. Higher, more supraphysiological, dosing was not associated with positive trends in weight or overall well-being. These data suggest that testosterone administration may improve the status of women with AIDS wasting. Further studies are needed to assess the effects of testosterone on weight in HIV-infected women and to define the optimal therapeutic window for test

Glucocorticoid pretreatment reduces the cytotoxic effects of a variety of DNA-damaging agents on rat tibial growth-plate chondrocytes in vitro

It is apparent that cytotoxic chemotherapy used to treat childhood malignancies has a major impact on subsequent growth. Our initial studies have demonstrated a direct adverse effect of individual glucocorticoids and cytotoxic agents on the proliferative capacity of rat tibial growth-plate chondrocytes in vitro. In the present study we investigated the interaction between these classes of agents using in vitro cultures of chondrocytes and examined the potential of these cells to recover from the adverse effects of the drugs as applied either alone or in combination. The glucocorticoids prednisolone and dexamethasone significantly reduced the growth rate of chondrocytes when present in cultures for 3 days. The growth rate increased following the removal of prednisolone and dexamethasone from cultures and reached 83.9+/-0.8% and 62.4+/-4.0%, respectively, of the control values after 11 days of culture. In contrast, cell numbers were significantly reduced when the DNA-damaging agents cisplatin, carboplatin, etoposide or actinomycin-D were present in cultures for 3 days. Very little recovery of cell growth was observed after removal of the drugs from cultures, with cell loss occurring in the cisplatin- and actinomycin-D-treated cultures. However, pretreatment of chondrocytes with either of the glucocorticoids completely ameliorated the cytotoxic effects of etoposide and carboplatin and significantly reduced those of cisplatin and actinomycin-D. Recovery of the cells treated with a combination of glucocorticoid and DNA-damaging agent was demonstrated by a significant increase in their ability to form colonies in suspension culture. Colony numbers were increased by a factor of between 5 and 80 as compared with the cells receiving medium alone followed by DNA-damaging agent. The glucocorticoids offer a protective effect in terms of the reduced cytotoxicity of DNA-damaging agents and improve the subsequent clonogenicity and recovery of growth-plate chondrocytes. This has important implications for treatment schedules involving both cytotoxic agents and glucocorticoids in childhood malignancies.

Effects of androgen administration in men with the AIDS wasting syndrome. A randomized, double-blind, placebo-controlled trial

BACKGROUND

Development of successful anabolic strategies to reverse the loss of lean body mass is of critical importance to increase survival in men with the AIDS wasting syndrome. Hypogonadism, an acquired endocrine deficiency state characterized by loss of testosterone, occurs in more than half of all men with advanced HIV disease. It is unknown whether testosterone deficiency contributes to the profound catabolic state and loss of lean body mass associated with the AIDS wasting syndrome.

OBJECTIVE

To investigate the effects of physiologic testosterone administration on body composition, exercise functional capacity, and quality of life in androgen-deficient men with the AIDS wasting syndrome.

DESIGN

Randomized, double-blind, placebo-controlled study.

SETTING

University medical center.

PATIENTS

51 HIV-positive men (age 42 +/- 8 years) with wasting (body weight < 90% of ideal body weight or weight loss > 10% of baseline weight) and a free testosterone level less than 42 pmol/L (normal range for men 18 to 49 years of age, 42 to 121 pmol/L [12.0 to 35.0 pg/mL]).

INTERVENTION

Patients were randomly assigned to receive testosterone enanthate, 300 mg, or placebo intramuscularly every 3 weeks for 6 months.

MEASUREMENTS

Change in fat-free mass was the primary end point. Secondary clinical end points were weight, lean body mass, muscle mass, exercise functional capacity, and change in perceived quality of life. Virologic variables were assessed by CD4 count and viral load.

RESULTS

Compared with patients who received placebo, testosterone-treated patients gained fat-free mass (-0.6 kg and 2.0 kg; P = 0.036), lean body mass (0.0 kg and 1.9 kg; P = 0.041), and muscle mass (-0.8 kg and 2.4 kg; P = 0.005). The changes in weight, fat mass, total-body water content, and exercise functional capacity did not significantly differ between the groups. Patients who received testosterone reported benefit from the treatment (P = 0.036), feeling better (P = 0.033), improved quality of life (P = 0.040), and improved appearance (P = 0.021). Testosterone was well tolerated in all patients.

CONCLUSIONS

Physiologic testosterone administration increases lean body mass and improves quality of life among androgen-deficient men with the AIDS wasting syndrome.

Decreased leptin levels in normal weight women with hypothalamic amenorrhea: the effects of body composition and nutritional intake

Leptin is a protein encoded by the ob gene and expressed in adipocytes. A sensitive marker of nutritional status, leptin is known to correlate with fat mass and to respond to changes in caloric intake. Leptin may also be an important mediator of reproductive function, as suggested by the effects of leptin infusions to restore ovulatory function in an animal model of starvation. We hypothesized that leptin levels are decreased in women with hypothalamic amenorrhea and that leptin may be a sensitive marker of overall nutritional status in this population. We, therefore, measured leptin levels and caloric intake in 21 women with hypothalamic amenorrhea (HA) and 30 age-, weight-, and body fat-matched eumenorrheic controls. Age (24 +/- 5 vs. 24 +/- 3 yr), body mass index (20.6 +/- 1.3 vs. 21.1 +/- 1.5 kg/m2), percent ideal body weight (94.9 +/- 5% vs. 96.3 +/- 6.3%), and fat mass (14.2 +/- 3.6 vs. 15.5 +/- 2.9 kg, determined by dual energy x-ray absortiometry) did not differ between the groups. Leptin levels were significantly lower in the HA subjects compared with those in the controls (7.1 +/- 3.0 vs. 10.6 +/- 4.9 micrograms/L; P = 0.005). Total caloric intake (1768 +/- 335 vs. 2215 +/- 571 cal/day; P = 0.003), fat intake (333 +/- 144 vs. 639 +/- 261 cal/day; P < 0.0001), and insulin levels (5.6 +/- 1.2 vs. 7.4 +/- 3.2 microU/mL; P = 0.015) were lower in the women with HA than in the eumenorrheic controls. The difference in leptin levels remained significant after controlling for insulin (P = 0.023). These data are the first to demonstrate hypoleptinemia, independent of fat mass, in women with HA. The hypoleptinemia may reflect inadequate calorie intake, fat intake, and/or other subclinical nutritional disturbances in women with HA. The mechanism and reproductive consequences of low leptin in this large population of women remain unknown.

The pathogenesis of African swine fever in the resistant bushpig

Bushpigs and warthogs are natural reservoir hosts of African swine fever virus (ASFV) in the wild, showing no clinical signs of disease when infected with the same highly virulent isolates of ASFV that induce rapid, haemorrhagic death in domestic pigs. In contrast to domestic pigs, infection of bushpigs with Malawi isolate results in low levels of virus replication and lymphocyte apoptosis within the spleen, and a relatively low spread of virus to other lymphoid tissues. However, at 10 days post-infection, a high degree of apoptosis was seen in B lymphocytes of the B cell follicles in bushpig lymph nodes. Virus infected cells were present amongst the apoptotic B cells of these follicles, suggesting that indirect factors released from ASFV infected macrophages signal surrounding lymphocytes to enter apoptosis. The susceptibility/resistance of domestic pigs/bushpigs to ASFV may serve as a unique veterinary model for the recently emerging haemorrhagic disease of man.

Imaging soft X-ray microscope at Rits Synchrotron Radiation Center

An imaging soft X-ray microscope with zone plates has been installed at Rits SR Center (Ritsumeikan University, Kusatsu, Japan). With this microscope, specimens were set in air, which made it possible to investigate the specimens without breaking the vacuum of the microscope. The specimens can be prefocused with an optical microscope. Dry and wet biospecimens in air were observed. A new optical system was designed to improve the resolution.

Chemotherapeutic agents used in the treatment of childhood malignancies have direct effects on growth plate chondrocyte proliferation

Short stature is one of the most well recorded long term sequelae for adult survivors of childhood malignancies. It has become increasingly apparent that cytotoxic chemotherapy, as well as craniospinal irradiation, has a major impact on growth, but there are virtually no studies which explore the mechanisms by which these cytotoxic drugs affect growth. We have used an in vitro system to investigate the direct effects of a range of chemotherapeutic agents on the proliferative responses of rat tibial growth plate chondrocytes, both in suspension and monolayer culture. The glucocorticoids and purine anti-metabolites reduced chondrocyte proliferation both in monolayer and suspension cultures and this resulted from an increase in cell doubling times with a concomittant reduction in the numbers of S phase cells. DNA damaging agents (e.g. actinomycin-D) were also able to reduce chondrocyte proliferation, both in monolayer and suspension culture. This, however, was the result of a cell cycle arrest and subsequent cell death. In our studies, methotrexate had no significant effect on the proliferative responses of the chondrocytes either in monolayer or suspension culture. These results indicate direct effects of a range of chemotherapeutic agents on the proliferative responses of growth plate chondrocytes. Both cytostatic and cytotoxic effects were observed although the impact of either the potential loss of cells from the proliferative pool during chondrocyte differentiation, or the reduction in the rate of chondrocyte turnover on long bone growth remains to be elucidated.

Effect of Cheyne-Stokes respiration on muscle sympathetic nerve activity in severe congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy

Severe congestive heart failure (CHF) is associated with Cheyne-Stokes (C-S) respiration, which may be an index of poorer prognosis. The mechanisms linking C-S respiration to poorer functional status and prognosis in patients with CHF are unknown. We tested the hypothesis that C-S respiration increases muscle sympathetic nerve activity (MSNA) in 9 patients with CHF. Oxygen saturation was 96 +/- 1% during normal breathing and 91 +/- 1% after the apneic episodes (p < 0.05). Mean blood pressure was 79 +/- 8 mm Hg during normal breathing and 85 +/- 8 mm Hg during C-S respiration (p = 0.001). C-S respiration increased MSNA burst frequency (from 45 +/- 5 bursts/min during normal breathing to 50 +/- 5 bursts/min during C-S respiration; p < 0.05) and total integrated nerve activity (to 117 +/- 7%; p < 0.05). We also studied an additional 5 patients in whom C-S breathing was constant, without any periods of spontaneous normal breathing. In these patients, MSNA was higher (65 +/- 5 bursts/min) than MSNA in patients in whom C-S breathing was only intermittent (45 +/- 5 bursts/min; p < 0.05). In all 14 patients, the effects of different phases of C-S respiration were examined. MSNA was highest during the second half of each apnea (increasing to 152 +/- 14%; p < 0.01) and blood pressure was highest during mild hyperventilation occurring after termination of apnea (p < 0.0001). We conclude that C-S respiration decreases oxygen saturation, increases MSNA, and induces transient elevations in blood pressure in patients with CHF.

Multidrug resistance gene expression correlates with progesterone production in dehydroepiandrosterone-induced polycystic and equine chorionic gonadotropin-stimulated ovaries of prepubertal rats

Polycystic ovaries (PCO) can be induced in prepubertal rats by daily injection of dehydroepiandrosterone (DHEA). There are high levels of progesterone, androgens, and estrogens in the cystic fluid of DHEA-treated rat ovaries. The purpose of this study was to investigate whether high levels of steroids in the PCO correlate with the expression of multidrug resistance gene product P-glycoprotein (Pgp). Using C219, a monoclonal antibody that recognizes the 170-kDa ATP-dependent transmembrane pump, we localized Pgp on the plasma membrane of granulosa cells in cystic follicles but not of oocytes or thecal/interstitial cells. In normal prepubertal rats, Pgp was localized in progesterone-producing granulosa cells of the preovulatory follicles and in cells of the corpora lutea after eCG/hCG stimulation, but not in growing follicles, oocytes, or thecal/interstitial cells. Northern analysis of these tissues indicated strong expression of Pgp mRNA in the preovulatory follicles, cystic follicles, and corpora lutea. From these findings it seems that progesterone produced by the granulosa cells may act in an autocrine manner to induce the expression of Pgp. It may be possible that progesterone interacts with the Pgp of these granulosa cells to modulate steroid efflux.