Melanin-concentrating hormone in peripheral circulation in the human

Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide with a well-characterised role in energy homeostasis and emergent roles in diverse physiologic functions such as arousal, mood and reproduction. Work to date has predominantly focused on its hypothalamic functions using animal models; however, little attention has been paid to its role in circulation in humans. The aims of this study were to (a) develop a radioimmunoassay for the detection of MCH in human plasma; (b) establish reference ranges for circulating MCH and (c) characterise the pattern of expression of circulating MCH in humans. A sensitive and specific RIA was developed and cross-validated by RP-HPLC and MS. The effective range was 19.5-1248 pg MCH/mL. Blood samples from 231 subjects were taken to establish a reference range of 19.5-55.4 pg/mL for fasting MCH concentrations. There were no significant differences between male and female fasting MCH concentrations; however, there were correlations between MCH concentrations and BMI in males and females with excess fat (P < 0.001 and P = 0.020) and between MCH concentrations and fat mass in females with excess fat (P = 0.038). Plasma MCH concentrations rose significantly after feeding in a group of older individuals (n = 50, males P = 0.006, females P = 0.023). There were no robust significant correlations between fasting or post-prandial MCH and resting metabolic rate, plasma glucose, insulin or leptin concentrations although there were correlations between circulating MCH and leptin concentrations in older individuals (P = 0.029). These results indicate that the role of circulating MCH may not be reflective of its regulatory hypothalamic role.

Pulmonary edema: pathophysiology and diagnosis

Healthy human lungs are normally the sites of fluid and solute filtration across the pulmonary capillary endothelium. Unlike other organs, the filtrate in the lungs is confined anatomically within adjacent interstitial spaces, through which it moves by a built-in pressure gradient from its site of formation to its site of removal through pulmonary lymphatic channels. The quantity of fluid filtered and its protein content depend on the transvascular hydrostatic and protein osmotic (colloid) pressure differences, and the leakiness of the endothelial barrier to water and protein. Lymphatic drainage can increase several-fold, which means that pulmonary edema-defined as an increase in extravascular water content of the lungs-cannot occur until the rate of fluid filtration exceeds the rate of lymphatic removal. Two main types of pulmonary edema are recognized: first, cardiogenic (or hydrostatic) pulmonary edema from, as the name implies, an elevated pulmonary capillary pressure from left-sided heart failure; second, noncardiogenic (increased permeability) pulmonary edema from injury to the endothelial and (usually) epithelial barriers. Owing to their fundamental differences, each occurs in distinct clinical conditions, requires separate therapy, and has a different prognosis.

Benefit of amoxicillin in differentiating between TB suspects whose initial AFB sputum smears are negative

SETTING

Out-patient dispensary in Conakry, Guinea, West Africa.

OBJECTIVE

To differentiate between pulmonary tuberculosis (PTB) and non-PTB diseases among 204 acid-fast bacilli (AFB) smear-negative adult TB suspects.

DESIGN

We derived scores from clinical, serological and radiological findings among PTB suspects aged > or = 15 years who, after having had three AFB-negative smears, were treated for 10 days with amoxicillin (AMX, 1.5 g/day).

RESULTS

At the selected cut-off score from model 1 (clinical), sensitivity for PTB was 95%, specificity 40%, negative predictive value (NPV) 84%, and positive predictive value (PPV) 69%. Comparable values from model 2 (clinical + serological + radiological) were: sensitivity 99%, specificity 45%, NPV 97%, and PPV 71%. Results from AMX were better: sensitivity 92%, specificity 93%, NPV 94%, and PPV 91%. Of the 117 suspects who failed to respond clinically and radiographically to AMX and remained AFB smear-negative, 110 (94%) had PTB, confirmed either by positive culture (73 patients) or response to anti-tuberculosis treatment (37 patients).

CONCLUSION

The clinical and radiographic response to AMX is better than derived scores at differentiating between PTB and non-PTB in TB suspects presenting to a dispensary in Guinea, a low HIV-seroprevalence country.

Evidence for a stimulatory action of melanin-concentrating hormone on luteinising hormone release involving MCH1 and melanocortin-5 receptors

The present series of studies aimed to further our understanding of the role of melanin-concentrating hormone (MCH) neurones in the central regulation of luteinising hormone (LH) release in the female rat. LH release was stimulated when MCH was injected bilaterally into the rostral preoptic area (rPOA) or medial preoptic area (mPOA), but not when injected into the zona incerta (ZI), of oestrogen-primed ovariectomised rats. In rats that were steroid-primed to generate a surge-like release of LH, MCH administration into the ZI blocked this rise in LH release: no such effect occurred when MCH was injected into the rPOA or mPOA. In vitro, MCH stimulated gonadotrophin-releasing hormone (GnRH) release from hypothalamic explants. Double-label immunohistochemistry showed GnRH-immunoreactive neurones in the vicinity of and intermingled with immunoreactive MCH processes. MCH is the endogenous ligand of the MCH type 1 receptor (MCH1-R). Previously, we have shown a role for melanocortin-5 receptors (MC5-R) in the stimulatory action of MCH, so we next investigated the involvement of both MCH1-R and/or MC5-R in mediating the actions of MCH on GnRH and hence LH release. The stimulatory action of MCH in the rPOA was inhibited by administration of antagonists for either MCH1-R or MC5-R. However, in the mPOA, the action of MCH was blocked only by the MC5-R antagonist. LH release was stimulated by an agonist for MC5-R injected into the rPOA or mPOA; this was blocked by the MC5-R antagonist but not the MCH1-R antagonist. These results indicate that both MCH1-R and MC5-R are involved in the central control of LH release by MCH.

Effects of maternal undernutrition during early pregnancy on apoptosis regulators in the ovine fetal ovary

This study aimed to determine whether reduced fetal ovary folliculogenesis in ewes undernourished during early/midpregnancy is associated with altered ovarian cell proliferation and/or the expression of apoptosis-regulating genes. Groups of ewes (n= 11–19) were fed either 100% (high; H) or 50% (low; L) of metabolisable energy requirements for live-weight maintenance during selected windows of gestation. All animals were killed at days 50, 65 or 110 of gestation. Between mating and slaughter, control animals were fed the H ration, while animals of other subgroups were fed the L ration from (a) mating to slaughter at 50, 65 or 110 days; (b) 0 to 30 days; (c) 31 to 50 or 65 days; or (d), in the day 110 slaughter group only, from 66 to 110 days. Bouin’s-fixed fetal ovaries were examined for (a) Ki67 immunoexpression (proliferation) and (b) Bax and Mcl-1 (apoptosis-regulating genes) expression byin situhybridisation (day 110) and immunohistochemistry (days 50, 65 and 110). At day 50, maternal nutrition had no effect on Ki67, predominant in germ cells, or Bax and Mcl-1, predominant in the oocytes. Restricted maternal food intake from 0 to 30 days significantly reduced staining for Ki67 in germ cells at day 65 (P< 0.05) but increased staining in granulosa cells at day 110 (P< 0.05). In animals fed the L ration for 110 days, primordial follicle Bax and Mcl-1 were significantly increased (Bax:P< 0.01; Mcl-1:P< 0.05). Granulosa cell Bax was also increased (P< 0.05). When the L ration was fed from 66 to 110 days, granulosa cell Bax (P< 0.05) and primordial follicle Mcl-1 (P< 0.01) were also significantly increased. In the fetal ovarian vasculature, animals underfed for 0–110 days had significantly elevated perivascular Mcl-1 (P< 0.001) and endothelial Bax expression (P< 0.05). Moreover, at day 110, endothelial Mcl-1 was increased by underfeeding from 0 to 30 days (P< 0.05). These data indicate that maternal undernutrition alters proliferation and the expression of apoptosis-regulating genes in the developing fetal ovary. The precise mechanism depends on the window of maternal food restriction.

Pulmonary complications of HIV-1 infection among adults living in Sub-Saharan Africa

Sub-Saharan Africa, which has just over 10% of the world's population, is home to more than 25 million people living with HIV/AIDS-two thirds of the global total. Opportunistic pulmonary infections are major causes of morbidity and mortality among HIV-infected adults in the subcontinent. Of these diseases, tuberculosis (TB) is by far the most prevalent and serious, and in some countries it causes one third or more of all AIDS-related deaths. Because it is so frequent and a major public health problem, TB tops the list of differential diagnoses of people-with or without coexisting HIV infection-who present to the health care system with chronic cough and other pulmonary symptoms. As HIV-induced immunosuppression worsens, the clinical and radiographic manifestations of TB become increasingly atypical. Second among HIV/AIDS-associated pulmonary complications is community-acquired pneumonia, most commonly caused by Streptococcus pneumoniae, which usually responds to standard beta-lactam antimicrobial agents. The prevalence of Pneumocystis jirovecii pneumonia is increasing, due to both improved recognition of its characteristic clinical and radiographic features and aggressive diagnostic interventions. Treatment outcome in most countries, however, has been poor. Combined infections, usually including TB, are common. Pulmonary nocardiosis, cryptococcosis, Kaposi's sarcoma, and (possibly) histoplasmosis appear to be infrequent, but probably underdiagnosed. Improved diagnosis, treatment, and prevention of all these diseases are urgently needed, but a greatly expanded antiretroviral treatment program will help most of all.

Leptin expression in the fetus and placenta during mouse pregnancy

During pregnancy, leptin concentrations in the maternal circulation are elevated in both humans and rodents but decrease to pre-pregnancy levels at birth, suggesting a role for leptin in the maintenance of pregnancy. Synthesis of leptin by the human placenta is established but whether the murine placenta synthesizes leptin remains controversial. The aims of this study were to determine (a) if the mouse wild-type placenta expresses the ob gene using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and (b) whether the mouse fetus and placenta contribute to the significant increase of leptin in the maternal circulation during pregnancy. The mouse placenta did not express the ob gene at a level that could be readily detected using RT-PCR. Moreover, both maternal gain in weight and undetectable concentrations of leptin in sera in leptin-deficient ob/ob mothers bearing heterozygote (ob/+) fetuses suggested that the mouse fetus and placenta do not make a significant contribution to the dramatic increase in maternal plasma concentrations of leptin during late gestation. It is therefore concluded that neither fetal- nor placental-derived leptin modulates maternal weight gain during pregnancy.

Neonatal 5HT activity antagonizes the masculinizing effect of testosterone on the luteinizing hormone release response to gonadal steroids and on brain structures in rats

Hypothalamic 5HT concentrations are transiently lower in male compared to female Wistar rats in the second week post partum (pp) and our previous findings have shown that pharmacologically potentiating 5HT activity over this period feminizes certain aspects of sexually differentiated behaviours in adult males and androgenized females. In order to investigate whether neonatal testosterone and 5HT interact to influence physiological and morphological brain sexual differences, females, androgenized females and males were treated with the 5HT2 agonist (-) [2,5 dimethoxy-4-iodophenyl]-2-amino propane HCl [(-) DOI], over days 8-16 pp. In androgenized females (250 microg testosterone proprionate, day 2 pp) (-) DOI prevented the delay in vaginal opening, but did not prevent the androgen-induced constant oestrus in females treated with 100 microg TP, day 2 pp. (-) DOI overcame the neonatal androgen effect in suppressing the positive feedback of ovarian steroids in a few males and androgenized females. (-) DOI had a feminizing effect on the volume of the anteroventral periventricular nucleus (normally smaller in males), by significantly increasing its volume in male and androgenized females. It also had a significant antagonistic effect on the testosterone-induced increase in the volume of the sexually dimorphic nucleus of the preoptic area in males and androgenized females. These findings support the view that raised 5HT activity in the second week of life antagonizes the masculinizing effect of neonatal testosterone.

Clinical and radiological presentation of 340 adults with smear-positive tuberculosis in The Gambia

SETTING

Four clinics in The Gambia.

OBJECTIVE

To document clinical and radiographic presentations of sputum smear-positive tuberculosis in adults.

DESIGN

Newly diagnosed acid-fast bacilli (AFB) smear, culture-positive tuberculosis patients aged > or = 15 years were interviewed and examined, and underwent tuberculin skin testing, HIV testing and chest X-ray reviewed by a chest physician using set criteria.

RESULTS

Of 340 patients enrolled (median age 29 years; males 73%), 8.3% were HIV-positive. One-third reported haemoptysis, > 90% reported weight loss and fever, and wasting was the most common sign (69%). Crepitations were the most frequent auscultatory finding (41%). The most common radiological lesion was a patchy infiltrate (> 90%). Cavitation was present in 206 patients (60.6%), most frequently occurred in the upper lung fields, was associated with increasing bacterial load in the sputum, and was less prevalent in HIV-positive patients (45% vs. 62%; P = 0.07). Auscultatory and chest X-ray findings matched only one-third of the time.

CONCLUSION

In our setting, wasting is the most common clinical sign of sputum smear-positive tuberculosis. Auscultatory findings correlate poorly with radiological abnormalities. Cavitation is associated with increasing bacterial load in the sputum, and is therefore a strong indicator for early treatment.

Central orexin A has site-specific effects on luteinizing hormone release in female rats

Orexin A stimulates GnRH release from hypothalamic explants in vitro. The sites of action of orexin A in the regulation of LH release have been investigated in vivo in ovariectomized rats that were given vehicle or estradiol benzoate (EB), with or without an injection of progesterone 48 h later. Orexin A was administered intrahypothalamically under Saffan anesthesia, 50 h after the EB or vehicle; its effects on plasma LH levels were monitored in sequential blood samples. Orexin A (1.0 microg/side) injected into the rostral preoptic area (rPOA) at the level of the organum vasculosum of the lamina terminalis had a stimulatory effect on LH release in EB-treated ovariectomized rats. When orexin A was injected into the medial POA (mPOA) or the arcuate/median eminence, it had an inhibitory effect on the LH surge that occurs in ovariectomized rats primed with EB plus progesterone. Orexin A injected into the mPOA also reduced LH levels in ovariectomized rats untreated with ovarian steroids. Both the stimulatory and inhibitory effects of orexin A were antagonized by SB334867A, a selective orexin 1 receptor antagonist. Furthermore, when given alone into the rPOA, this antagonist attenuated the LH surge induced by EB plus progesterone. Thus, orexin appears to have a dual effect on LH release, being stimulatory in the rPOA and inhibitory in the mPOA or arcuate/median eminence. Both effects may be mediated, at least in part, by the orexin 1 receptor. Double label immunohistochemistry revealed close appositions between orexin A immunoreactive varicosities and a small proportion of GnRH cell bodies in the rPOA. It is suggested that the stimulatory effect of orexin A on LH release may involve direct actions on GnRH neurons.

Useful clues to the presence of smear-negative pulmonary tuberculosis in a West African city

OBJECTIVE

Tuberculosis suspects with negative sputum smears for acid-fast bacilli (AFB) may have either pulmonary tuberculosis (PTB) or some other pulmonary disease (non-PTB). The aim of this study was to improve the differentiation between PTB and non-PTB.

DESIGN

We enrolled 396 tuberculosis suspects 15 years of age or older who had cough of 21 days or longer and three negative AFB smears. Non-PTB was diagnosed by clinical and radiographic responses to amoxicillin; smear-negative PTB was diagnosed by positive culture for Mycobacterium tuberculosis or response to antituberculosis chemotherapy.

RESULTS

Multivariate analysis, without X-ray variables, of 79 patients with a final diagnosis of non-PTB and 110 patients with smear-negative PTB indicated that age less than 37 years, family contact with TB, never having been married, loss of weight, lack of expectoration, human immunodeficiency virus (HIV) seropositivity, and tuberculin reactivity were significantly associated with PTB. When the initial X-ray findings were included, age younger than 37 years, lack of expectoration, HIV seropositivity, and tuberculin reactivity remained in the model, and cavitation and patchy densities were significantly associated.

CONCLUSION

The response to 10 days of amoxicillin and certain demographic, clinical and radiographic characteristics are useful in separating non-PTB from PTB in tuberculosis suspects with negative AFB smears.

Leptin requirement for conception, implantation, and gestation in the mouse

The ob/ob mouse has a complete absence of circulating leptin, resulting in obesity and infertility. Using the minimum daily dose of leptin required to maintain normal body weight and sexual maturation (5 mg/kg, ip), leptin-treated ob/ob females were mated with either wild-type (+/+) or leptin-treated ob/ob males. The leptin treatment continued throughout pregnancy until weaning or was withdrawn at 0.5, 3.5, 6.5, or 14.5 d post coitum (dpc). Normal pregnancy and parturition with pups of normal weight resulted when ob/ob females were mated with +/+ males and leptin treatment was continued throughout pregnancy (6 of 8 pregnancies), to 14.5 dpc (6 of 8 pregnancies), or to 6.5 dpc (9 of 12 pregnancies). Pregnancy did not result when treatment was stopped at 3.5 dpc (1 of 7 pregnancies) or 0.5 dpc (0 of 6 pregnancies). Similar results were obtained when leptin-treated ob/ob females were mated with leptin-treated ob/ob males. The newborn pups failed to survive after birth in groups treated with leptin up to 14.5 and 6.5 dpc despite reinstating leptin at birth. This appeared to be due to a lack of development of the mammary glands. In conclusion, we have shown that leptin is essential for normal preimplantation and/or implantation processes. It is also essential for normal development of the mammary glands, but is not required for pregnancy and parturition once implantation is established.

Cardiac troponin T and creatine kinase MB are not increased in exterior oblique muscle of patients with renal failure

BACKGROUND

Serum cardiac troponin T (cTnT) concentrations may be increased in patients with renal dysfunction without evidence of cardiac damage, as assessed by conventional methods. It has been suggested that these positive measurements result from the expression in skeletal muscle of fetal isoforms of cTnT, which are detected by the cTnT immunoassay.

METHODS

Skeletal muscle (exterior oblique) biopsies were taken from healthy living kidney donors (n = 5) and transplant recipients (n = 19). The amounts of cTnT and creatine kinase (CK) isoenzymes in skeletal muscle of healthy controls were compared with those in patients with renal failure (Wilcoxon-Mann-Whitney test). cTnT was measured quantitatively by a second-generation assay, with a limit of detection of 1 microg/g of protein, and qualitatively by immunohistochemistry and immunoblotting. CK-MB was measured by quantitative electrophoresis.

RESULTS

Minute quantities of cTnT were detected in 2 of the 5 (40%) control samples and 9 of the 19 (47%) renal failure samples, respectively, at mean concentrations of <5 microg/g of protein for both subject groups. This was <1/6000th that found in heart muscle. There was no significant difference in cTnT or CK-MB content in skeletal muscle between healthy controls and patients with renal failure. Increased serum cTnT did not predict detectable cTnT in skeletal muscle. cTnT was not detected qualitatively by immunoblotting or immunohistochemistry in any skeletal muscle samples.

CONCLUSIONS

Uremia does not affect the content of cTnT or CK-MB in exterior oblique muscle, suggesting that cTnT detected in serum from patients with renal failure does not originate from skeletal muscle.

Indirect cost of ischemic heart disease to employers

BACKGROUND

The management of healthcare programs by employers requires accurate information about the indirect and direct costs of important chronic diseases.

OBJECTIVE

To determine the indirect costs of ischemic heart disease from the perspective of the employer in private industry in the United States.

DESIGN

Indirect cost of illness analysis using the human capital approach, taking the perspective of the employer rather than that of society.

METHODS

Ischemic heart disease was identified in a proprietary claims database of 3.1 million insured persons using an algorithm based on administrative codes. Economic data were derived from the Bureau of Labor Statistics, the Employment Management Association, and published sources. Work-loss data were taken from the National Center for Health Statistics' Health Interview Survey. The indirect cost was calculated as the sum of the costs due to morbidity and mortality. From the perspective of the employer, morbidity costs come from lost productivity, idle assets, and nonwage factors resulting from absenteeism and mortality costs are expenditures for replacing and retraining workers. This differs from calculations from the societal perspective, in which indirect costs are the value of an individual's lost income--both current and potential.

RESULTS

The total indirect cost of ischemic heart disease to employers in private industry was $182.74 per enrollee. Ninety-five percent of the indirect cost was the consequence of work loss due to morbidity rather than of mortality costs.

CONCLUSION

From the perspective of the employer, the indirect cost of ischemic heart disease is overwhelmingly due to morbidity costs.

Alternative valuations of work loss and productivity

In this article, we examine the indirect costs (i.e., work loss and productivity costs) of employee illness from the employer's perspective. We provide a conceptual framework to help employers consider alternative views with regard to assessing indirect costs and valuing the health care they purchase. First, we discuss the matter of perspective and how an employer should view and assess indirect costs. We briefly review current models of measuring indirect costs, and we critique these models. Then we introduce a simple, conceptual framework based on the ideas of health capital and labor productivity, and we lay out the effects of health investment on indirect costs while considering what employees desire and employers can provide. Finally, we offer an agenda for further research.

Serotonin inhibits luteinizing hormone release via 5-HT1A receptors in the zona incerta of ovariectomised, anaesthetised rats primed with steroids

The zona incerta (ZI), an area in the dorsal hypothalamus, contains neuronal systems that appear to control gonadotropin release. Previous findings show that there is an inverse relationship between serotonin (5-HT) activity in the ZI and plasma luteinizing hormone (LH) levels, indicating that the 5-HT system in this area has an inhibitory effect on LH release. Employing anaesthetised, ovariectomised rats primed with 5 microg oestradiol benzoate followed at 48 h by 0.5 mg progesterone, we have shown that 2 microg/side 5-HT in the ZI inhibits the LH surge that normally occurs 4 h after the progesterone treatment. This effect was mimicked by 2 microg/side 8-OH-DPAT, a 5-HT1A agonist, but not by DOI, a 5-HT2 agonist, BMY7378, a presynaptic 5-HT1A agonist or MCPP, a 2B & 2C agonist. The inhibitory effect of 5-HT and 8-OH-DPAT was prevented by pretreatment, 1 h before, with either 2 mg/kg i.p. WAY100135, a 5-HT1A antagonist or 0.25 mg/kg i.p. ritanserin, a 5-HT2 antagonist. These results indicate that 5-HT in the ZI exerts its inhibitory effect on LH release via 5-HT1A receptors but that another 5-HT subtype may also be involved.

The effect of leptin on luteinizing hormone release is exerted in the zona incerta and mediated by melanin-concentrating hormone

The adipose hormone, leptin, not only restrains appetite, but also influences energy expenditure. One such influence is to promote sexual maturation and fertility. The neuromodulatory circuits that mediate this effect are not well known but the present study suggests that one mediator could be melanin-concentrating hormone (MCH). We show that the long-form receptor (Ob-Rb) is expressed in the zona incerta of the rat and that administration of leptin (both 0.5 microg and 1.0 microg/side) into this area of ovariectomized, oestrogen-primed rats stimulated the release of luteinizing hormone (LH) within 1 h, the effect enduring for a further 1 h. Injections of leptin into the arcuate nucleus induced a smaller, transient rise in LH while injections into the paraventricular and ventromedial nuclei were without effect. MCH neurones are present in the zona incerta and administration of this hormone into the medial preoptic area (mPOA) stimulates LH release, therefore we investigated the possibility that MCH might mediate this effect of leptin. An injection of MCH antiserum into mPOA prevented the rise in LH normally induced by leptin injected into the zona incerta. In addition, melanocortin receptor antagonists ([D-Arg8]ACTH(4-10) and [Ala6]ACTH(4-10)), previously shown to inhibit the stimulatory effect of MCH on LH release, also inhibited the effect of leptin. We propose that one route by which leptin may promote reproductive activity is by enhancing MCH release from fibres within the mPOA. Speculative mechanisms for the action of MCH include the following possibilities: MCH may be acting on the specific MCH receptor which in turn interacts with a melanocortin or melanocortin-like receptor; MCH may bind directly to one of the melanocortin receptors; or melanocortin antagonists may interact with the MCH receptor.

Tuberculosis-associated severe CD4+ T-lymphocytopenia in HIV-seronegative patients from Dakar. SIDAK Research Group

OBJECTIVES

To determine the frequency and associated features of severe CD4+ T-lymphocytopenia (<300 cells/mm(3)) in HIV-seronegative patients with tuberculosis.

METHODS

Statistical analysis of 430 consecutively enrolled HIV-seronegative inpatients with tuberculosis in two teaching hospitals in Dakar, Senegal.

RESULTS

The mean CD4 + cell count was 602+/-318.3 cells/mm(3). CD4 + cell counts were below 300 cells/mm(3)in 62 patients (14.4%). Patients with fewer than 300 CD4+ cells/mm(3)differed from those with higher counts in being less likely to have a positive smear for acid-fast bacilli; in having a higher frequency of extrapulmonary involvement (pleural effusion, adenopathy and miliary disease) and oral candidiasis; and in having smaller tuberculin reactions, lower haemoglobin levels, less cavitation and less patchy infiltration. After adjustment for gender and age, all differences remained except miliary disease.

CONCLUSIONS

A substantial percentage (14.4%) of HIV-seronegative hospitalized patients for tuberculosis in a West African country presented with severe CD4 + T-lymphocyte depletion and had clinical and radiographic features indicative of more advanced disease and accompanying immunodepression. These results and those already published suggest that tuberculosis should be regarded as one of the diseases associated with a subgroup of patients with "idiopathic CD4 + T-lymphocytopenia".

Tuberculosis and HIV infection: a global perspective

The incidence of HIV-associated tuberculosis has been increasing worldwide since the beginning of the AIDS epidemic, and is expected to increase even further during the foreseeable future, especially in developing countries. There is no doubt now that, in the presence of HIV infection, new-onset tuberculous infection progresses rapidly to clinically significant disease and the likelihood that latent tuberculous infection progresses rapidly to clinically significant disease and the likelihood that latent tuberculous infection will reactivate is enormously increased. The accelerating and amplifying influence of HIV infection is contributing to the increasing incidence of disease caused by multidrug-resistant strains of Mycobacterium tuberculosis. Neither clinical features nor radiographic abnormalities reliably distinguish the majority of patients with HIV-associated tuberculosis from those without HIV infection. Some persons with HIV infection, however, present with atypical manifestations of tuberculosis and these patients may be difficult to diagnose. Six months of daily or thrice weekly chemotherapy with the usual regimen of 4 then 2 antituberculosis drugs cures most patients, but many die during or after treatment of other AIDS-related complications.

Melanin-concentrating hormone, melanocortin receptors and regulation of luteinizing hormone release

Melanin-concentrating hormone (MCH) is a neuropeptide, identified by its ability to either mimic or antagonize the melanin-dispersing action of alpha-melanocyte stimulating hormone (alphaMSH) on skin melanophores. MCH and alphaMSH also have antagonistic actions in the brain affecting feeding behaviour, aggression, anxiety, arousal and reproductive function through the release of luteinizing hormone (LH). It is not clear, however, how they exert their opposite effects in the central nervous system (CNS). One possibility is that they act via a common receptor. In this study we have examined the effect of a number of MC receptor antagonists, with relative selectivity for the MC3, 4 and 5 subtypes, on the actions of MCH on LH release. We confirmed that bilateral administration of MCH (100 and 200 ng/side) into the medial preoptic area of oestrogen-primed (oestradiol benzoate 5 microgram) ovariectomized anaesthetized rats, stimulated the release of LH. This effect was blocked by the concomitant administration into the medial preoptic area of the MC4/5 antagonist ([D-Arg8]ACTH(4-10) and the MC3/5 antagonist ([Ala6]ACTH(4-10)-both at 500 ng/side-but not by the MC3/4 antagonist, SHU9119 (200 ng/side). Furthermore, the MC3 agonist [Nle3]-gamma2 MSH failed to affect LH release. These results indicate that the MC3 and MC4 receptors are not involved in mediating the action of MCH but are consistent with an action via the MC5 subtype. Preputial glands, which express MC5 receptors, were also stimulated by MCH which is in keeping with this idea. In HEK293 cells transfected with the MC5 receptor MCH increased the production of IP3. However, it was much less potent than alphaMSH and unlike alphaMSH, had no effect on the production of cAMP. MCH (10-10 to 10-5 M) also failed to displace I125NDP-MSH from cells transfected with MC5 receptors indicating that it was not acting as a competitive antagonist and its binding site was distinct from that of alphaMSH. Thus while MCH may function as an agonist at the MC5 receptor, its stimulation of LH release is more likely to be mediated via a specific MCH receptor that has common properties with the MC5 receptor.

[How is it with tuberculosis in the world?]

Tuberculosis is well entrenched in the world and the number of cases is projected to continue to rise, especially in low-income countries. Eradication of the disease will be difficult in poor countries where, for the most part, the population is increasing, HIV infection is spreading, and control measures are inadequate or lacking. The problem is worsened by the increasing prevalence in many countries of strains of drug-resistant Mycobacterium tuberculosis.

The influence of gonadal steroids on pre-pro melanin-concentrating hormone mRNA in female rats

Melanin-concentrating hormone (MCH) may have a regulatory role in the control of luteinizing hormone (LH) release. We have investigated if gonadal steroids induce changes in the expression of pre-pro MCH (ppMCH) that are associated with changes in the pattern of LH release. Using quantitative in-situ hybridization histochemistry we have determined the effect of administration of either oestradiol benzoate (5 microg/rat) or oestradiol benzoate followed 44 or 48 h later by progesterone (0.5 mg/rat) to ovariectomized rats on the expression of ppMCH in the medial and lateral zona incerta and the lateral hypothalamus. The prevalence of ppMCH transcripts in the intact female rat at 12.00 and 19.00 h on proestrus and the first day of dioestrus was also examined. Oestrogen reduced the intensity of hybridization signal for ppMCH mRNA and this was associated with both a decrease in the number of cells in which the message was detected in the medial zona incerta and a negative feedback effect on LH release in ovariectomized rats. Progesterone administration to oestradiol benzoate-primed rats did not alter the reduced expression in the medial zona incerta in spite of its positive feedback effect on LH release. We suggest that progesterone may act only on post-translational events. Expression in the MCH cell bodies of the lateral zona incerta were not affected but there was a transient decrease 4 h after progesterone treatment in the oestradiol benzoate-primed rats in expression in the lateral hypothalamus. No changes in ppMCH mRNA were seen in intact animals on proestrus or the first day of dioestrus indicating that gonadal steroids are not important in the modulation of ppMCH gene expression during the oestrous cycle. In other steroid-dependent physiological situations, however, oestrogen may influence the expression of ppMCH in a subpopulation of cell bodies in the medial zona incerta.

The cost-effectiveness of losartan versus captopril in patients with symptomatic heart failure

The Losartan Heart Failure ELITE Study recently found that in patients with symptomatic heart failure and a left ventricular ejection fraction of </=0.40, losartan compared to captopril improved survival with better tolerability. The objective of this study was to perform an economic evaluation of losartan versus captopril based on the results of the Losartan Heart Failure ELITE Study. The Losartan Heart Failure ELITE Study was a multinational, double-blind, randomized 48-week study comparing the safety and efficacy of losartan to captopril in angiotensin-converting enzyme-inhibitor-naive patients >/=65 years with symptomatic heart failure. Data on health care resource utilization were collected as part of the trial. We conducted a cost-effectiveness analysis to estimate the lifetime benefits of treatment and the associated costs. We observed no differences between treatments in the number of hospitalizations, hospital days, and emergency room visits per patient over the trial period. We estimated the total cost of losartan to be USD 54 (95% CI: USD -1,717, USD 1,755) less per patient than captopril over this time frame. We also estimated that over the projected remaining lifetime of the study population, losartan compared to captopril would increase survival by 0.20 years (undiscounted) at an average cost of USD 769 (discounted) more per patient. This cost increase translated into a cost-effectiveness ratio of USD 4,047 per year of life gained for losartan relative to captopril. In patients with symptomatic heart failure, losartan compared to captopril increased survival with better tolerability at a cost well within the range accepted as cost-effective.

The effects of exogenous growth hormone on follicular steroid secretion and ovulation rate in sheep

Growth hormone (GH) has diverse actions in many tissues, including the follicle. This paper summarizes three experiments that examined the effects of GH and insulin-like growth factor (IGF)-I on the ovary. Ewes given oGH and pregnant mane serum gonadotrophin were compared with control and pregnant mane serum gonadotrophin-treated ewes. Ewes, with synchronized cycles, were given varying doses of pregnant mane serum gonadotrophin and/or oGH to determine if oGH is able to augment ovulation rate (Experiment 1). Experiments 2 and 3 used the ovarian autotransplant model. Ewes were infused via the ovarian artery with oGH (Experiment 2) or insulin-like growth factor I (IGF-I) (Experiment 3). Both were administered for 12 hr on Day 10. In Experiment 2, ewes were given intravenous gonadotropin releasing hormone (150 ng i.v.) at -2.5 and 10.5 hr relative to infusion. Ovarian and jugular venous blood was collected every 15 min from -30 to 150 min relative to gonadotropin releasing hormone. In Experiment 3, luteolysis was induced at the end of infusion. Ovarian and jugular venous blood was collected every 3 hr from before and until 84 hr after the infusion. Estradiol and androstenedione were assayed in ovarian venous plasma and GH in jugular venous plasma. In Experiment 1, treatment with oGH increased the jugular venous concentration of GH. However, in Experiment 2 treatment with oGH via the ovarian artery did not increase jugular venous GH but did increase ovarian venous GH. Treatment with oGH had no effect on ovulation rate (Experiment 1) or the secretion of androstenedione and estradiol (Experiment 2). Infusion of IGF-I (Experiment 3) increased the secretion of estradiol during the follicular phase. These data show that short-term treatment of sheep with GH had no in vivo effects on the follicle and that IGF-I was a potent stimulator of follicular steroidogenesis in vivo.

Effects of preconceptual caffeine exposure on pregnancy and progeny viability

OBJECTIVE

A previous study demonstrated for the first time that a drug such as caffeine, administered prior to ovulation and genomic activation, causes a quantitative difference in growth-promoting energy utilization in a proportion of 5-day-old blastocysts. The objective of the present study was to investigate whether developmental changes induced by caffeine administered throughout the estrus cycle prior to fertilization are sustained throughout pregnancy and after birth.

METHODS

Caffeine was administered to rats throughout the estrus cycle prior to fertilization, with control and experimental groups subdivided into preimplantation and postimplantation categories. Preimplantation fertilization rate was assessed on day 4 of pregnancy by a pregnancy-induced elevation in maternal plasma progesterone concentration, or by flushing each uterine horn on day 5 of pregnancy to determine the presence or absence of a litter. Postimplantation fetuses were collected on gestational day 12 or allowed to go to term.

RESULTS

Preconceptual caffeine exposure significantly reduced maternal fertility by the failure of a proportion of the litters to implant, rather than curtailing preimplantation development or postimplantation losses. Postnatal mortality between weeks 0 and 1 was elevated and the weekly incremental growth rate of the pups from week 3 through week 7 was significantly reduced in the preconceptually caffeine-treated offspring. Experimental females reached puberty at the same age as the controls but at a significantly lower body weight. Gestation length, hirthweight, litter size, sex ratio, and anogenital distance (a measure of prenatal androgenization) were not affected by preconceptual caffeine treatment.

CONCLUSIONS

It was concluded that the reduced fertility rate in preconceptually caffeine-exposed rats was due to the failure of litters to implant rather than to a reduced fertilization rate, which was normal. It was further concluded that the growth rate over the neonatal and prepubertal periods of surviving pups in the caffeine-treated group was subnormal.

Risk factors for negative sputum acid-fast bacilli smears in pulmonary tuberculosis: results from Dakar, Senegal, a city with low HIV seroprevalence

SETTING

Two teaching hospitals in Dakar, Senegal, a West African country with a low prevalence of human immunodeficiency virus (HIV) infection.

OBJECTIVE

To determine whether patients with HIV-associated pulmonary tuberculosis have fewer acid-fast bacilli (AFB) in their sputum as assessed by routine microscopy, and to correlate the findings with systematically obtained clinical, radiographic and laboratory variables.

DESIGN

Prospective study from November 1995 to October 1996 of 450 consecutive patients diagnosed with pulmonary tuberculosis.

RESULTS

Tuberculosis was diagnosed in 380 patients (84.4%) by positive bacteriology, in 61 (13.6%) by a favorable response to anti-tuberculosis chemotherapy, and in nine (2.0%) by the presence of a miliary radiographic pattern. Forty (8.9%) patients were HIV-seropositive. AFB-negative smears were found in 14/40 (35.0%) of the HIV-seropositive patients with pulmonary tuberculosis compared with 71/410 (17.3%) of the seronegative patients (risk ratio [RR] = 2.02, 95% confidence interval [CI] 1.26-3.24, P = 0.01). Multivariate analysis revealed that AFB smear negativity was associated with absence of cavitation (P = 0.002), lack of cough (P = 0.005), the presence of HIV seropositivity (P = 0.02), a CD4+ cell count above 200/mm3 (P = 0.02), and age over 40 years (P = 0.03).

CONCLUSIONS

Compared with HIV-seronegative patients with pulmonary tuberculosis, seropositive patients in Dakar, Senegal, are more likely to have negative sputum-AFB smears. This phenomenon has now been observed in seven of eight sub-Saharan African countries with varying HIV seroprevalence from which reports are available.

Dissecting cost-effectiveness analysis for preventive interventions: a guide for decision makers

BACKGROUND

Decision makers usually limit their use of economic evaluations of preventive interventions to the cost-effectiveness ratio.

OBJECTIVE

To show decision makers how economic evaluations can be used to understand the cost-effectiveness of different options for altering health intervention strategies.

OBSERVATIONS

Cost-effectiveness analysis provides insights into many factors that contribute to the overall benefits, hazards, and costs of interventions. This article reviews how epidemiologic and intervention characteristics, costs, natural history, targeting, and current interventions influence the value of prevention strategies.

CONCLUSION

Understanding the factors that contribute to the overall costs and effectiveness of interventions should allow decision makers to better adapt interventions to their needs.

Tuberculosis and HIV infection: global perspectives

This paper reviews the epidemiological and clinical aspects of the interaction between Mycobacterium tuberculosis and HIV infection. The incidence of HIV-associated tuberculosis is increasing worldwide and is expected to increase further, especially in Africa and parts of Asia. HIV infection appears to increase the likelihood that tuberculous infection will occur after tubercle bacilli are inhaled into the lungs. Moreover, there is persuasive evidence that in the presence of HIV infection, new-onset tuberculous infection will progress rapidly to clinically significant disease and the probability that latent tuberculous infection will reactivate is enormously increased. The accelerating and amplifying influence of HIV infection is also contributing to the increasing incidence of disease caused by multidrug-resistant strains of M. tuberculosis. Neither clinical nor radiographic features reliably distinguish the majority of patients with HIV-associated tuberculosis from those who are non-HIV-infected. Some HIV-infected patients, however, have atypical manifestations and are difficult to diagnose. Chemotherapy for 6 months with conventional antituberculosis drugs cures most patients, but many died during or after treatment of other AIDS-related complications. HIV is contributing heavily to the worldwide increase in tuberculosis. There is also mounting evidence that tuberculosis accelerates the course of co-existing HIV disease.

Methods for diagnosing tuberculosis among in-patients in eastern Africa whose sputum smears are negative

SETTING

Two University hospitals in Eastern African capital cities where large prospective studies had been carried out on hospitalized patients to determine the cause of their respiratory diseases.

OBJECTIVE

To identify features that differentiated between tuberculosis (TB) and non-tuberculous respiratory disease (non-TB) in hospitalized patients from Bujumbura, Burundi (n = 111) and Dar es Salaam, Tanzania (n = 71) whose sputum smears were negative on microscopic examination for acid-fast bacilli (AFB).

DESIGN

Review of clinical findings, radiologic abnormalities, and laboratory test results from 182 patients, first by univariate and then by multivariate (stepwise logistic regression) analysis to assess the contribution of each factor to the final diagnosis.

RESULTS

Of the 182 patients with two or more negative AFB smears, 41 had TB and 141 had non-TB. Stepwise regression analysis revealed four easily ascertained symptoms were associated with TB: 1) cough > 21 days; 2) chest pain > 15 days; 3) absence of expectoration; and 4) absence of shortness of breath. Any two of the four diagnosed TB with 85% sensitivity and 67% specificity; any three of the four with 49% sensitivity and 86% specificity. Multivariate analysis showed that adding lymphadenopathy and hematocrit < 30% improved discrimination.

CONCLUSION

This methodological approach provides a means for diagnosing TB among all AFB smear-negative hospitalized patients. In this setting, simple clinical symptoms alone are helpful. Similar studies are needed to develop a system for out-patient TB suspects.

USQA Health Profile Database as a tool for health plan quality improvement

Managed care organizations are in a unique position to evaluate and improve the quality of care delivered to their defined memberships. Traditionally, health services delivery has been claims-focused. We describe a potentially richer, patient-centered approach, whereby patients with certain chronic diseases are first identified and then used as the unit of analysis. U.S. Quality Algorithms (USQA), a subsidiary of U.S. Healthcare (USHC) based in Blue Bell, Pennsylvania, has developed selection criteria for 36 different chronic diseases and a new database, the USQA Health Profile Database (HPD), to identify and archive patients with those diseases. Examples of how this approach and database can be used as a quality tool are demonstrated.

Bridging the gap between managed care and academic medicine: an innovative fellowship

Numerous challenges face academic medicine in the era of managed care. This environment is stimulating the development of innovative educational programs that can adapt to changes in the healthcare system. The U.S. Quality Algorithms Managed Care Fellowship at Jefferson Medical College is one response to these challenges. Two postresidency physicians are chosen as fellows each year. The 1-year curriculum is organized into four 3-month modules covering such subjects as biostatistics and epidemiology, medical informatics, the theory and practice of managed care, managed care finance, integrated healthcare systems, quality assessment and improvement, clinical parameters and guidelines, utilization management, and risk management. The fellowship may serve as a possible prototype for future post-graduate education.

Pulmonary complications of HIV infection in Dar es Salaam, Tanzania. Role of bronchoscopy and bronchoalveolar lavage

To determine the pulmonary complications in HIV-1-infected patients in Dar es Salaam, Tanzania, and to evaluate the diagnostic utility of bronchoscopy and bronchoalveolar lavage, we carried out a prospective study of 237 patients with acute respiratory disease who were hospitalized at Muhimbili Medical Center (MMC). Diagnoses were made using well-defined criteria. Of the total, 127 (54%) were HIV-1-seropositive and 110 (46%) were seronegative. Tuberculosis was the most common diagnosis occurring in 95 (75%) HIV-1-seropositive and 87 (79%) seronegative patients. Bacterial pneumonia was the next most common diagnosis occurring in 18 (14%) HIV-1-seropositive and 17 (15%) seronegative patients. Pneumocystis carinii pneumonia was diagnosed in one and Kaposi's sarcoma was seen in only two HIV-1-seropositive patients. Bronchoscopy with bronchoalveolar lavage was the sole source of a diagnosis in nine (8%) seropositive and six (5%) seronegative patients. We conclude that the HIV seroprevalence rate among patients hospitalized for acute respiratory disease at MMC is extremely high. Tuberculosis was the most common cause of pulmonary disease, regardless of HIV serostatus, and other HIV-associated opportunistic pulmonary infections were unusual. Bronchoscopy with bronchoalveolar lavage added little to the diagnosis and thus should not be high-priority procedures for the routine workup in resource-poor areas where tuberculosis is endemic.

[Current clinical manifestations of tuberculosis]

Tuberculosis is an enormously serious and growing global disease that is becoming increasingly concentrated in the so-called "developing" nations of the world, where the epidemic is fuelled by the rapid expansion of the population, the presence of extreme poverty, and the coexistence of HIV infection. Most persons who become infected with M. tuberculosis do not develop the disease tuberculosis. In those who do, two types are recognised: 1) early progression of the primary pulmonary lesion or its lymph node component, or a complication from hematogenous dissemination, and 2) late reactivation of one or more previously latent sites, of which upper lobe pulmonary disease is the most common; extrapulmonary disease may also occur. Progressive immunosuppression from HIV infection exaggerates and accelerates the evolution of virtually all aspects of tuberculosis.

Pulmonary complications of HIV infection

Pulmonary disease is a major source of morbidity and mortality in HIV-infected persons. Pneumocystis carinii pneumonia has decreased substantially during the last eight years, but in the United States it remains the most common disorder that announces the onset of AIDS. In contrast, tuberculosis is by far the most important AIDS-associated indicator disease in developing countries. Community-acquired acute bacterial pneumonia is a common HIV-linked complication throughout the world; pneumonia occurs at all levels of immune suppression but increases in frequency as CD4 counts decrease. Fungal infections mainly afflict persons who live or have lived in the various endemic areas. AIDS-related Kaposi's sarcoma and lymphoma generally do not involve the lungs until the malignancies are advanced. The increasing use of successful chemoprophylaxis against many important HIV-associated infections is increasing the incidence of other end-stage complications such as cytomegalovirus and disseminated MAC disease.

Tuberculosis and HIV infection worldwide

The incidence of HIV-associated tuberculosis is increasing worldwide and will continue to increase during the foreseeable future, especially in developing countries. HIV infection appears to increase the opportunity for M. tuberculosis to succeed in causing infection after inhalation into the lungs. Moreover, there is persuasive evidence that in the presence of HIV infection, new-onset tuberculous infection will progress rapidly to clinically significant disease and the likelihood that latent tuberculous infection will reactivate is enormously increased. The accelerating and amplifying influence of HIV infection is contributing to the increasing incidence of disease caused by multidrug-resistant strains of M. tuberculosis. Neither clinical or radiographic features reliably distinguish the majority of patients with HIV-associated tuberculosis from those who are non-HIV-infected. The remainder, however, may have atypical manifestations and be difficult to diagnose. Six months of chemotherapy with conventional antituberculosis drugs cures most patients, but many die during or after treatment of other AIDS-related complications.

Using comparative clinical and economic outcome information to profile physician performance

This paper presents strategies and empirical examples of comparative physician profiling under conditions of limited patient sample sizes and varying patient severity. A method by which clinical and cost outcomes may be evaluated simultaneously is also presented. Physician economic and clinical performance are compared using data abstracted from nine hospitals into the MedisGroups clinical information management system for inpatients treated from July, 1990 through June, 1992. The main outcome measures are comparative total and ancillary adjusted charges, and morbidity status. Results suggest that objective comparative outcome data provide useful information to assist in evaluating physician performance. A simultaneous comparison of clinical outcomes and adjusted charges identifies physicians who experience favorable outcomes at lower charges, as well as those who have higher charges and/or poorer outcomes. Strategies outlined in this paper may be of value to clinicians, governing boards, and third party payors. These strategies may be used to assist with privileging and other peer review activities when pursued proactively within a Continuous Quality Improvement framework to improve care.

Radiographic abnormalities in tuberculosis and risk of coexisting human immunodeficiency virus infection. Methods and preliminary results from Bujumbura, Burundi

We evaluated the age profile and chest radiographic abnormalities in 158 patients from Bujumbura, Burundi, with new-onset intrathoracic tuberculosis (pulmonary, pleural, or hilar/mediastinal adenopathy), to identify features that were associated with and would allow prediction of HIV seropositivity or seronegativity. Using agreed-upon criteria and prepared reporting forms, initial chest radiographs were reviewed by three readers, first independently and then at a consensus conference. Of the 158 patients, 105 (66%) were HIV seropositive and 53 patients were seronegative. Seropositive subjects (mean age, 35.8 yr) were older (p = 0.001) than seronegative subjects (mean age, 29.4 yr). Significant or borderline differences between HIV-seropositive and -seronegative patients included the frequency of small nodular lesions (p = 0.03), upper lobe cavitation (p = 0.05), and lymphadenopathy (p = 0.12), and the location of parenchymal abnormalities (p = 0.0006). Stepwise logistic regression revealed four important variables: age, small lesions, location, and lymphadenopathy; these were then used to derive an equation to calculate the probability that a given tuberculosis patient was HIV seropositive. Our mathematical model fit the observed data and the equation predicted serologic findings reasonably well. We conclude that it is possible to determine with useful probability a Burundian tuberculosis patient's HIV serologic status.

Radiographic abnormalities in tuberculosis and risk of coexisting human immunodeficiency virus infection. Results from Dar-es-Salaam, Tanzania, and scoring system

First, we evaluated the age profile and chest radiographic abnormalities in 146 patients from Dar-es-Salaam, Tanzania, with new-onset intrathoracic tuberculosis (pulmonary, pleural, or hilar/mediastinal adenopathy), to identify features that were associated with human immunodeficiency virus (HIV) seropositivity or seronegativity; then, we combined these data with those from a companion investigation in Burundi to develop a simple scoring system to predict HIV serologic status. Using agreed-upon criteria and simplified reporting forms, initial chest radiographs were reviewed by three readers, first independently and then at a consensus conference. Of the 146 patients, 80 (55%) were HIV seropositive and 66 were seronegative. More seropositive than seronegative subjects were 31 to 40 yr old (p = 0.03). Because the radiographic characteristics of the two serologic groups were similar in Tanzania and Burundi, we combined the data for stepwise logistic regression that revealed four highly significant variables: age, small lesions, location, and lymphadenopathy. From these, we obtained an equation to calculate the probability that a given tuberculosis patients was HIV seropositive and then we derived a scoring system that in its simplest form (threshold) predicted serologic status correctly in 68.1% of patients; a graded scale was even more accurate in the high (89.1%) and low (82.6%) ranges. This scoring system should be useful when serologic testing is unavailable or refused.

A glossary of medical decision-making terms

Many of the terms used in medical decision making are foreign to clinicians. This problem creates a barrier that can prevent physicians from acquiring these new clinical tools. This glossary contains definitions of the most common terms as well as examples of their usage by using Down syndrome as the illustrative condition.

Using data from epidemiologic studies to revise probabilities

Information about the relationship between risk factors and the probability of disease is often reported by an odds ratio, although its use for revising the probability of disease in a clinical setting is not intuitive and requires complex computations. A somewhat better approach is Bayesian probability revision. The authors present a method where likelihood ratios can be obtained from odds ratios, and they present simple computational methods for implementing all of the techniques described.

The International Union Against Tuberculosis and Lung Disease: its contribution to world lung health

Most readers of the American Journal of Respiratory and Critical Care Medicine probably know that beginning in 1986 the number of reported cases of tuberculosis in the United States, which had been declining at a steady rate of 5%-6% per year, increased for the first time in 33 yr; moreover, since then the number of reported cases has continued to increase nearly every year until 1993. Similar increases in tuberculosis have been observed in other countries, such as Denmark, Italy, the Netherlands, Spain, Switzerland, France, and the United Kingdom. Unfortunately, there has been a global resurgence of tuberculosis and, as is predictable from the prevailing geographic distribution of persons with the disease, the great majority of the "extra" cases, almost 90%, do not live in the rich industrialized nations of North America and Europe or in Japan or Australia; they live in the impoverished countries of Asia, Africa, and South America (1). Among the journal's sophisticated audience, probably only a few know that the health organization with the longest and by far the best track record in actually doing something about the immense problem of tuberculosis in developing nations is the International Union Against Tuberculosis and Lung Disease or, as it is customarily known, the IUATLD. This article recounts the origins of the IUATLD and describes what it has done to combat tuberculosis and other perils to lung health in some of the poorest countries of the world.

Changes in progesterone secretion following treatment with transforming growth factor alpha (TGF-alpha) during the follicular phase of the sheep oestrous cycle

The effects of transforming growth factor alpha (TGF-alpha) on ovarian steroid secretion were investigated. Three crossbred ewes synchronized for oestrus with ovarian autotransplants were infused with TGF-alpha (30 micrograms in 12 h) via the ovarian artery for 12 h before withdrawal of progestagen pessary. Three ewes were used as controls. Jugular and ovarian venous blood samples were taken at intervals of 10 min at two stages during the follicular phase (21-27 h and 38-42 h after pessary withdrawal) and every 2 h from 44 to 86 h. Plasma LH and FSH concentrations, and ovarian secretion rates of inhibin, androstenedione, oestradiol and progesterone were determined using radioimmunoassays. LH pulse amplitude increased in ewes treated with TGF-alpha in the early follicular phase (0.92 +/- 0.25 micrograms l-1 in controls versus 3.10 +/- 0.35 micrograms l-1 in TGF-alpha treated ewes; P < 0.05) and remained high in the late follicular phase. Plasma FSH concentrations were high during the follicular phase in ewes treated with TGF-alpha (P < 0.05). The infusion of TGF-alpha had no significant effect on the ovarian rate of secretion of androstenedione and, although the secretion rates of oestradiol and inhibin were consistently lower in TGF-alpha-infused ewes, the differences were not significant. The ratio of secretion of androstenedione to oestradiol was greater during the follicular phase in TGF-alpha-treated ewes (P < 0.05), suggesting that the efficiency of aromatization had been impaired.(ABSTRACT TRUNCATED AT 250 WORDS)

The Rorschach and diagnosis of neurotic conditions in children and adolescents: a case study

The diagnosis of neurotic disturbance in children and adolescents can be an exceedingly complex decision given the impact of developmental and situational factors on aspects of personality organization and personality style. The potential for rapid regression, rapid development, and incomplete structuralization of personality organization and style complicates our understanding of the meaning of particular symptoms or behavior. The Rorschach offers help in sorting through these issues because it can uniquely assess aspects of personality organization, personality style, and the impact of developmental or situational factors.