New diagnostics for the spectrum of asymptomatic TB: from infection to subclinical disease

TB remains a leading cause of morbidity and mortality worldwide. However, most infected immunocompetent individuals are asymptomatic and only 5-10% of these will eventually develop active TB during their lifetime (typically within 2 years after exposure). Therefore, rapid diagnosis and efficient management of asymptomatic infected individuals who are at the highest risk of progression and transmission remain major clinical and public health challenges. In recent years, there has been important scientific progress in our understanding of the spectrum of asymptomatic Mycobacterium tuberculosis (Mtb) infections that not only includes the dynamic state of latent TB infection (LTBI), but also the preclinical state of incipient and subclinical TB. The latter is possibly as prevalent as symptomatically active TB and potentially contributes to global Mtb transmission in various settings. We summarize the latest developments and current challenges of the existing testing tools for LTBI and describe promising biomarkers and diagnostics for the spectrum of asymptomatic TB. Following the negative results of a recent clinical trial for a biomarker-guided preventive therapy approach, we also suggest some treatment options for incipient TB.

Factors associated with repeat visits among clients attending a clinic for sexually transmitted infections in Kisumu, Kenya

To identify factors associated with repeat visits among patients attending a clinic for sexually transmitted infections (STIs) in Kisumu, Kenya, we examined records of clinic visits from March 2009 to May 2010. Multivariable logistic regression identified factors associated with repeat visits occurring >30 days after the initial visit. Among 1473 clients (1296 single-visit individuals versus 177 individuals with repeat visits), the median age was 24 years, 67% were men and 8.6% self-reported being HIV-positive. In adjusted analyses, men with repeat visits were more likely to report ≥ 2 recent sexual partners (adjusted odds ratio [aOR] = 1.60) and being HIV-positive (aOR = 2.35). They were less likely to have been referred from other health facilities (aOR = 0.14) and more likely to have urethral discharge at their initial visit (aOR = 2.46). Among women, repeat visits were associated with vaginal discharge (aOR = 2.22), but attending the clinic with a partner was protective (aOR = 0.38). The association between sexual risk, HIV positivity and repeat visits among male clients highlights the need to focus intervention efforts on this group. For women, attending with a partner may reflect a decreased risk of re-infection if both partners are treated and counselled together.

Selenium concentrations in greater scaup and dreissenid mussels during winter on Western lake ontario

One hypothesis for the decline of the North American greater (Aythya marila) and lesser (A. affinis) scaup population is that contaminant burdens acquired on wintering or staging areas impair reproduction or cause lethal or sublethal health effects. Recent studies have found increased selenium (Se) concentrations in scaup but have focused on the fall and spring staging periods. From January to March 2006 and December to March 2006 and 2007, we analyzed liver tissues collected from greater scaup wintering in western Lake Ontario for 16 trace elements. We also measured Se concentrations in greater scaup blood and Dreissenid mussel tissue. Se was the only trace element that occurred at increased concentrations (>10 μg/g liver dry weight) in a substantial proportion (99%) of greater scaup livers. We also found that hepatic Se concentrations increased throughout winter and were increased in nearly all birds from January to March, suggesting that accumulation of this trace element occurred soon after their arrival in fall. Se concentrations were similar in male and female birds, but juvenile birds had higher concentrations than did adults. Blood Se concentrations were correlated to liver Se concentrations in 2006 only, suggesting that blood Se concentration is an unreliable predictor of liver concentration. Se in Dreissenid mussels generally decreased with mussel size and did not change throughout winter. Overall, our results suggest that greater scaup wintering on western Lake Ontario acquire sufficiently high Se concentrations to potentially impact their health. Thus, several indicators of health and survival should be examined in relation to Se concentrations in wintering scaup.

Herpes simplex virus type 2 antibody detection performance in Kisumu, Kenya, using the Herpeselect ELISA, Kalon ELISA, Western blot and inhibition testing

BACKGROUND

In certain parts of Africa, type-specific herpes simplex virus type 2 (HSV-2) ELISAs may have limited specificity. To date, no study has been conducted to validate HerpeSelect and Kalon type-specific HSV-2 ELISAs using both the Western blot and recombinant gG ELISA inhibition testing as reference standards.

METHODS

A total of 120 men who were HIV seronegative (aged 18-24 years) provided blood samples. HSV-2 IgG serum antibodies were detected using four different methods: HerpeSelect HSV-2 ELISA (n = 120), Kalon HSV-2 ELISA (n = 120), University of Washington Western blot (n = 101) and a recombinant inhibition test (n = 93).

RESULTS

HSV-2 seroprevalence differed significantly by HSV-2 detection method, ranging from 24.8% with the Western blot to 69.8% with the HerpeSelect ELISA. Using the Western blot as the reference standard, the HerpesSelect had the highest sensitivity for HSV-2 antibody detection (100%) yet lowest specificity (40%). Similar results were obtained using the inhibition test as the reference standard. The sensitivity and specificity of the Kalon test versus the Western blot were 92% and 79%, respectively, and 80% and 82% versus the inhibition test. Using the inhibition test as the reference standard, the sensitivity of the Western blot appeared low (49%).

CONCLUSIONS

In men in western Kenya who were HIV seronegative, the HerpeSelect and Kalon type-specific ELISAs had high sensitivities yet limited specificities using the Western blot as reference standard. Overall, the Kalon ELISA performed better than the HerpeSelect ELISA in these young men from Kisumu. Further understanding is needed for the interpretation of HSV-2 inhibition or ELISA test positive/ Western blot seronegative results. Before HSV-2 seropositivity may be reliably reported in selected areas of Africa, performance studies of HSV-2 serological assays in individual geographical areas are recommended.

Herpes simplex virus type 2 infection among young uncircumcised men in Kisumu, Kenya

OBJECTIVES

To identify factors associated with herpes simplex virus type 2 (HSV-2) infection among men aged 18-24 in Kisumu, Kenya.

METHODS

Baseline data from a randomised trial of male circumcision were analysed. Participants were interviewed for sociodemographic and behavioural risks. The outcome was HSV-2 by antibody status. Risk factors were considered singly and in combination through logistic regression models.

RESULTS

Among 2771 uncircumcised men, 766 (27.6%; 95% confidence interval (CI) 26.0% to 29.3%) tested antibody positive for HSV-2. The median age at first sex was 16 years, and the median number of lifetime sexual partners was four. HSV-2 seroprevalence increased from 19% among 18-year-olds to 43% among 24-year-olds (p<0.001). In multivariable analysis, statistically significant risks for infection were increasing age (adjusted odds ratio (AOR) = 1.22-2.58), being married or having a live-in female partner (AOR = 1.80; 95% CI 1.28 to 2.53), preferring "dry" sex (AOR = 1.39; 95% CI 1.14 to 1.69), reported penile cuts or abrasions during sex (AOR = 1.58; 95% CI 1.32 to 1.91), increasing lifetime sex partners (multiple response categories; AORs ranging from 1.65 to 1.97), and non-student occupation (multiple response categories; AORs ranging from 1.44 to 1.93). Risk decreased with reported condom used at last sex (AOR = 0.82; 95% CI 0.68 to 0.99).

CONCLUSION

Primary prevention efforts should be initiated at an early age. The same behavioural interventions used currently for HIV prevention-abstinence, reducing the number of sex partners and increasing condom use-should be effective for HSV-2 prevention.

Acceptability of male circumcision for prevention of HIV infection in Zambia

Numerous observational studies and three clinical trials have shown male circumcision (MC) to be partially protective against HIV acquisition in heterosexual men. This has led to consideration of introducing circumcision as an HIV prevention strategy in parts of sub-Saharan Africa. This study assesses the acceptability of male circumcision as an intervention to improve male genital hygiene and reduce sexually transmitted infections, including HIV-1 in Zambia. Thirty-four focus group discussions were conducted - 17 with men and 17 with women - in four districts chosen to represent urban and rural communities where circumcision is and is not traditionally practiced. In communities where circumcision is little practiced, the main facilitators for acceptance were improved genital hygiene, HIV/STI prevention, and low cost. The main barriers were cultural tradition, high cost, pain, and concerns for safety. If MC is proven to reduce risk for HIV and STIs, most participants reported that they would seek circumcision for themselves or their partners or their sons if it was free or at a minimal cost. Acceptability of male circumcision for STI and HIV prevention appears to be high in Zambia.

Acceptability of male circumcision for prevention of HIV/AIDS in sub-Saharan Africa: a review

Based on epidemiological, clinical and experimental evidence, male circumcision (MC) could have a significant impact on the HIV epidemic in selected areas. We reviewed studies of the acceptability of MC in sub-Saharan Africa to assess factors that will influence uptake of circumcision in traditionally non-circumcising populations. Thirteen studies from nine countries were identified. Across studies, the median proportion of uncircumcised men willing to become circumcised was 65% (range 29-87%). Sixty nine percent (47-79%) of women favored circumcision for their partners, and 71% (50-90%) of men and 81% (70-90%) of women were willing to circumcise their sons. Because the level of acceptability across the nine countries was quite consistent, additional acceptability studies that pose hypothetical questions to participants are unnecessary. We recommend pilot interventions making safe circumcision services available in conjunction with current HIV prevention strategies and evaluating the safety and acceptability of circumcision.

Acceptability of male circumcision and predictors of circumcision preference among men and women in Nyanza Province, Kenya

Numerous epidemiologic studies report significant associations between lack of male circumcision and HIV-1 infection, leading some to suggest that male circumcision be added to the limited armamentarium of HIV prevention strategies in areas where HIV prevalence is high and the mode of transmission is primarily heterosexual. This cross-sectional survey of 107 men and 110 women in Nyanza Province, Kenya, assesses the attitudes, beliefs, and predictors of circumcision preference among men and women in a traditionally non-circumcising region. Sixty per cent (n=64) of uncircumcised men and 69% (n=68) of women who had uncircumcised regular partners reported that they would prefer to be circumcised or their partners to be circumcised. Men's circumcision preference was associated with the belief that it is easier for uncircumcised men to get penile cancer, sexually transmitted diseases, and HIV/AIDS, and that circumcised men have more feeling in their penises, enjoy sex more, and confer more pleasure to their partners. Women with nine or more years of school were more likely to prefer circumcised partners. Men who preferred to remain uncircumcised were concerned about the pain and cost of the procedure, and pain was a significant deterrent for women to agree to circumcision for their sons. If clinical trials prove circumcision to be efficacious in reducing risk of HIV infection, it is likely that the procedure will be sought by a significant proportion of the population, especially if it is affordable and minimally painful.

Feasibility of medical male circumcision in Nyanza Province, Kenya

BACKGROUND

Over forty observational studies have reported a protective effect of male circumcision against HIV-I acquisition, leading some to suggest that male circumcision be added to the limited armamentarium of HIV prevention strategies.

OBJECTIVES

To evaluate the feasibility and requirements of implementing medical male circumcision in Nyanza Province of Kenya a quasi-experimental design was implemented to assess clinicians' knowledge of male circumcision and to assess the effectiveness of a one day educational intervention in one district. A cross sectional survey assessed the availability of necessary instruments and surgical supplies.

RESULTS

None of the participating ten health facilities had all the necessary instruments and supplies to safely perform male circumcisions. Though most clinicians reported training about circumcision, most lacked sufficient knowledge to perform the procedure, and few were familiar with the process of informed consent. We demonstrated that a didactic educational workshop significantly improved providers' knowledge of male circumcision.

CONCLUSIONS

Since increasing numbers of young men and parents are requesting male circumcision services in many parts of sub-Saharan Africa, health providers must undergo further training in the performance of the procedure and the process of informed consent. Many health facilities will have to be provided with the instruments and supplies necessary to perform male circumcision safely.

The acceptability of male circumcision to reduce HIV infections in Nyanza Province, Kenya

Compelling epidemiological evidence showing a significant association between lack of male circumcision and HIV infection has prompted calls for consideration of male circumcision interventions as a strategy for reducing HIV prevalence in highly affected areas where circumcision is little practiced and transmission is predominantly heterosexual. Little is known about whether male circumcision interventions would be acceptable or feasible in traditionally non-circumcisng areas of Africa. This study assesses the acceptability of male circumcision in the Luo, a large, traditionally non-circumcising ethnic group in western Kenya. Separate focused group discussions with adult Luo men and women and semi-structured interviews with clinicians were conducted in Nyanza Province, Kenya. The primary barriers to acceptance of male circumcision were cultural identification, fear of pain and excessive bleeding and cost. The main facilitators were association of male circumcision with better hygiene and reduced risk of infection. Both men and women were eager for promotion of genital hygiene and male circumcision, and they desired availability of circumcision clinical services in the Province's health facilities. Clinicians lacked the knowledge and resources to offer safe circumcision counselling and services. If results from this study are valid for other areas of sub-Saharan Africa, acceptability of male circumcision as a means to reduce STDs and HIV is higher than previously suspected. Further studies are needed in other regions to assess the feasibility of introducing acceptable male circumcision information and services to reduce HIV transmission.

Male circumcision and HIV prevention: current knowledge and future research directions

Over the past decade, numerous epidemiological studies have reported a significant association between lack of male circumcision and risk for HIV infection, leading to recommendations for male circumcision to be added to the armamentarium of effective HIV prevention strategies. We review the epidemiological data from studies that have investigated this association, including ecological, cross-sectional/case-control, and prospective studies. We discuss problematic issues in interpreting the epidemiological data, including the presence of other sexually transmitted infections, age of circumcision, and potential confounders such as religion, cultural practices, and genital hygiene. In addition, we review studies of biological mechanisms by which the presence of the foreskin may increase HIV susceptibility, data on risks associated with the circumcision procedure, and available data on the acceptability and feasibility of introducing male circumcision in societies where it is traditionally not practised. Although the evidence in support of male circumcision as an effective HIV prevention measure is compelling, residual confounding in observational studies cannot be excluded. Taken together with concerns over the potential disinhibiting effect of male circumcision on risk behaviour, and safety of the circumcision procedure, randomised trials of male circumcision to prevent HIV infection are recommended. An individual's choice to undergo male circumcision or a community's decision to promote the practice should be made in the light of the best available scientific evidence. More knowledge is required to assist individuals and communities in making those decisions. We conclude with recommendations for future research.

Eight hundred-year-old human remains from the Ituri tropical forest, Democratic Republic of Congo: the rock shelter site of Matangai Turu Northwest

Little is known about human prehistory in the central African lowland tropical forest due to a paucity of archaeological evidence. Here we report results from our archaeological investigations of a late Holocene site in the northeast Congo Basin, with emphasis on a single skeleton from the rock shelter site of Matangai Turu Northwest, in the Ituri Forest, Democratic Republic of Congo. The skeleton dates from approximately 810 BP (1235 calibrated AD) and is associated with Later Stone Age lithics, animal bone and shell remains from wild taxa, fruit endocarps from forest trees, phytoliths from tropical forest plants, Late Iron Age ceramics, and a single iron artifact. Phytolith analysis indicates that the habitat was dense tropical forest, without evidence of domesticated food.

Complications of tube thoracostomy in trauma

OBJECTIVE

To assess the complication rate of tube thoracostomy in trauma. To consider whether this rate is high enough to support a selective reduction in the indications for tube thoracostomy in trauma.

METHODS

A retrospective case series of all trauma patients who underwent tube thoracostomy during a 12 month period at a large UK teaching hospital with an accident and emergency (A&E) department seeing in excess of 125,000 new patients/year. These patients were identified using the hospital audit department computerised retrieval system supplemented by a hand search of both the data collected for the Major Trauma Outcome Study and the A&E admission unit log book. The notes were assessed with regard to the incidence of complications, which were divided into insertional, infective, and positional.

RESULTS

Fifty seven chest drains were placed in 47 patients over the 12 month period. Seven patients who died within 48 hours of drain insertion were excluded. The commonest indications for tube thoracostomy were pneumothorax (54%) and haemothorax (20%); 90% of tubes were placed as a result of blunt trauma. The overall complication rate of the procedure was 30%. There were no insertional complications and only one (2%) major complication, which was empyema thoracis.

CONCLUSION

This study reveals no persuasive evidence to support a selective reduction in the indications for tube thoracostomy in trauma. A larger study to confirm or refute these findings must be performed before any change in established safe practice.

Sexual behaviors and other HIV risk factors in circumcised and uncircumcised men in Uganda

OBJECTIVE

To study the differences in sexual practices, hygienic behaviors, and other HIV risk factors between circumcised and uncircumcised men.

DESIGN

A cross-sectional study of men >17 years of age selected by single stage cluster sampling in the Industrial Borough, Mbale, Uganda.

METHODS

Using a structured questionnaire, 188 circumcised and 177 uncircumcised consenting Ugandan men were interviewed in one of four native languages during April and May, 1997.

RESULTS

Among non-Muslims, circumcised men had a higher risk profile than uncircumcised men in that they were more likely to drink alcohol in conjunction with sex (odds ratio [OR], 1.86: 95% confidence interval [CI], 1.09-3.16), to have sexual contacts with women on the first day of meeting (OR, 2.37; 95% CI, 1.39-4.04), to have had sexual contacts in exchange for money or gifts (OR, 2.08; 95% CI, 1.21-3.09), to have experienced episodes of pain on urination or to have experienced penile discharge (OR, 1.68; 95% CI, 1.07-2.64), had an earlier age at sexual debut (15.7 versus 16.9 years), and had more extramarital sex partners in the last year (1.13 versus 0.62). Circumcised men also reported a preference for nonwet sex. Muslims generally had a lower risk profile than other circumcised men except they were less likely to have ever used a condom (OR, 0.34; 95% CI, 0.15-0.78) or to have used a condom during the last sex encounter (OR, 0.37; 95% CI, 0.14-0.87).

CONCLUSIONS

These results suggest that differences between circumcised and uncircumcised men in their sex practices and hygienic behaviors do not account for the higher risk of HIV infection found among uncircumcised men. Further consideration should be given to male circumcision as a prevention strategy in areas of high prevalence of HIV and other sexually transmitted diseases. Studies of the feasibility and acceptability of male circumcision in traditionally noncircumcising societies are warranted.

Growth of children according to maternal and child HIV, immunological and disease characteristics: a prospective cohort study in Kinshasa, Democratic Republic of Congo

BACKGROUND

Most HIV-infection in children occurs in sub-Saharan Africa where antiretroviral therapy is seldom available. This study compares the growth progression and retardation of HIV-infected and uninfected children in the Democratic Republic of Congo (formerly Zaire). It estimates the risk for child growth retardation according to child and maternal immunological factors, severity of maternal and child illness, and maternal socioeconomic and marital status.

METHODS

In a prospective cohort study of 258 children born to HIV seropositive mothers and 256 children of seronegative mothers in Kinshasa, Congo, the growth in length, weight, and weight-for-length of infected children (n = 68), uninfected children born to seropositive mothers (n = 190), and uninfected children born to uninfected mothers (n = 256) was compared. Serological, anthropometric and other clinical measures were collected monthly from 3-12 months and bi-monthly during the second year of life. Polymerase chain reaction for HIV was performed on bloods drawn at 2 days and 3 months post partum. Length-for-age, weight-for-age, and weight-for-length mean z-scores against National Center for Health Statistics (NCHS) reference data were calculated, and Cox proportional hazards models were used to estimate the risk of falling below -2.00 z-scores as a function of child and maternal immunological, clinical and sociodemographic variables.

RESULTS

There was no difference in mean length-for-age at birth between HIV-infected (Group 1) children, uninfected children of infected mothers (Group 2) or Control children, but by 3 months old, HIV-infected children were shorter than both Group 2 and Controls. In weight-for-age and weight-for-length, Group 1 infants were lighter and more wasted at birth and onwards. Group 2 newborns were lighter than Controls at birth, but by three months they had caught up to Controls in both length and weight and remained the same as Controls thereafter. The odds of falling below -2.00 z-scores by 20 months for length, weight, and weight-for-length for HIV-infected children compared to uninfected children were 2.10, 2.84, and 2.56 respectively. Both HIV-infection and associated illnesses were factors associated with child stunting, underweight and wasting. The mother's age, socioeconomic status, presence of father, stage of illness and immune status had no detectable effect on the child's growth in the first two years of life.

CONCLUSION

The HIV-infected children in Congo with no access to antiretroviral therapy were stunted, underweight, and wasted compared to same age uninfected children. Both HIV infection and HIV-associated signs and symptoms, not maternal immunological or socioeconomic circumstances, placed children at risk for growth retardation.

Women's strategies to alleviate nutritional stress in a rural African society

Many agricultural populations are subject to chronic or seasonal undernutrition, reproductive women and children often being most vulnerable. This paper presents quantitative and qualitative data on food consumption, food distribution practices, food taboos, garden sizes and work effort to show how Lese horticulturalist women living in the Ituri Forest of northeast Democratic Republic of Congo attempt to alleviate nutritional stress. The Lese experience an annual hunger season when approximately one quarter of the population suffer from energy deficiency. Nutritional intake is also compromised by a complex system of food taboos against meat from wild forest animals. Anthropometric data collected over several years suggest that Lese women suffer from nutritional stress more than men during the hunger season. They also have more food taboos particularly during pregnancy and lactation. Their low fertility is compounded by nutritional stress. Despite these inequities, Lese women use several strategies to improve their food intake. Since they are responsible for all household cooking, they manipulate food portions. During the hunger season, they snack frequently, and increase their consumption of palliative foods. Women with more food taboos plant larger gardens to supplement their diet with vegetable foods. Although this results in their consumption of more daily protein, they work harder compared to women with smaller gardens. Women cheat in their adherence to specific food taboos by actively discounting them, or by eating prophylactic plants that supposedly prevent the consequences (usually illness) of eating tabooed foods. In addition, women resort to subterfuge to access desirable resources. Lese women do not reduce work effort during the hunger season, but adapt physiologically by reducing resting metabolic rates during periods of weight loss. These results point to the ability of Lese women to minimize the ecological and cultural constraints on their nutrition. More data, however, are required to assess the long-term effectiveness of these strategies.

Upper pH tolerance limit of the zebra mussel (Dreissena polymorpha)

The upper pH tolerance limit of the zebra mussel (Dreissena polymorpha) has not been established experimentally. This study was designed to test the effect of elevated pH on the health and survivorship of zebra mussels. Dishes that contained 250 mL of pond water were assigned to four replicates of control, zebra mussel control, low-NaOH, medium-NaOH, and high-NaOH treatments. Except for the control replicates, two zebra mussels were added to each dish. Every other day, volumes of 1 M NaOH were added to low- (50 µL), medium- (100 µL), and high-NaOH (200 µL) treatments. All zebra mussels but one in the high-NaOH treatment died between days 17 and 31 at pH 9.3-9.5. On the last day of the study, day 31, three zebra mussels in the medium-NaOH treatment died at pH 9.5-9.6. The zebra mussels in the high-NaOH treatment moved and formed byssus attachments less often and had lower mean dry body mass than zebra mussels in other treatments. Dishes that contained zebra mussels had more algal genera than control dishes. In this experiment, the upper pH tolerance limit of zebra mussels was between 9.3 and 9.6 and may have been dependent on the rate of pH change.

Male circumcision: assessment of health benefits and risks

OBJECTIVES

Globally approximately 25% of men are circumcised for religious, cultural, medical, or parental choice reasons. However, controversy surrounds the procedure, and its benefits and risks to health. We review current knowledge of the health benefits and risks associated with male circumcision.

METHODS

We have used, where available, previously conducted reviews of the relation between male circumcision and specific outcomes as "benchmarks", and updated them by searching the Medline database for more recent information.

RESULTS

There is substantial evidence that circumcision protects males from HIV infection, penile carcinoma, urinary tract infections, and ulcerative sexually transmitted diseases. We could find little scientific evidence of adverse effects on sexual, psychological, or emotional health. Surgical risks associated with circumcision, particularly bleeding, penile injury, and local infection, as well as the consequences of the pain experienced with neonatal circumcision, are valid concerns that require appropriate responses.

CONCLUSION

Further analyses of the utility and cost effectiveness of male circumcision as a preventive health measure should, in the light of this information, be research and policy priorities. A decision as to whether to recommend male circumcision in a given society should be based upon an assessment of the risk for and occurrence of the diseases which are associated with the presence of the foreskin, versus the risk of the complications of the procedure. In order for individuals and their families to make an informed decision, they should be provided with the best available evidence regarding the known benefits and risks.

Development of tension pneumothorax after chest drain insertion

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Hereditarian scientific fallacies

Some have recently declared that a hereditarian or more balanced approach has triumphed over environmentalism as an explanatory tool for variation in the cognitive ability and behaviour of humans. However, the entire debate is constrained by several fallacies described here. Heritability of a trait, does not predict the effect of environmental or genetic changes on the trait (Fallacy #1), so knowing heritability does not assist in writing prescriptions for societal ills or budget cuts. Heritability estimates themselves are inaccurate, given the potential for gene-environment covariance and interaction, as well as other non-additive effects on behavior or cognitive ability (Fallacy #2). The 'revolution in molecular genetics' has provided more effective tools for describing the genome, but doesn't permit separation of gene and environmental effects on traits (Fallacy #3). If we were able to measure heritability accurately, it would give us absolutely no indication of whether or not group differences are genetically based (Fallacy #4). Finally, any proposed models of the evolutionary divergence of human groups must more adequately answer the basic questions of such a study, and are not supported by high heritability in present populations (Fallacy #5). Humans are not and should never be exposed to artificial selection and crossing experiments, so behavior geneticists will continue to be very limited in their ability to partition the effects of genes, the environment, and their covariance and interaction on human behavior and cognitive ability.

'Best clinical practice': assessment of processes of care and of outcomes in the US Military Health Services System

The National Quality Management Program of the Military Health Services System of the United States has undertaken a series of projects whose objective is the active, on-going monitoring and improvement of the effectiveness and efficiency of the care provided to a broad population that encompasses troops on active duty, retirees and dependents. The analytic activities consist of (1) identification by clinical panels of conditions and procedures of interest; (2) collection of data from electronic repositories and from charts to characterize the patients, how they are managed, the clinical outcomes they experience, the resource costs their care entails, and, from questionnaires, their functional status and level of satisfaction, and (3) generation of 'report cards' that inform organizational units down to the level of the hospital of the characteristics of their patients, their practices, and the risk-adjusted outcomes they achieve. The patterns of care employed by the hospitals that obtain the best risk-adjusted outcomes and resource utilization ('best clinical practice') are identified and made known. In addition, (4) a systematic process of developing outcomes-based practice guidelines has been devised. It intent is to serve as a decision-support tool for clinicians. Initial estimates have been obtained of the probable consequences of the application of this tool to operative interventions in childbirth. Use of the tool would result in a higher occurrence of elective Caesarean sections, a reduced rate of emergency Caesarean sections and much lower use of forceps, with an overall improvement in outcomes and lower resource costs. This program is currently in the early phases of implementation. The two principal requirements for the immediate future are (1) education of the clinical and administrative communities in the use of the data and the decision-support tools and (2) evaluation of the consequences of the use of the data by the clinical and administrative communities.

IGF-I does not mediate T-lymphoblast colony formation in response to estradiol, testosterone, 1,25(OH)2 vitamin D3, and triiodothyronine: studies in control and pygmy T-cell lines

The mechanism by which estradiol, testosterone, 1,25(OH)2 vitamin D3, and triiodothyronine promote tissue growth is unknown, although, in some tissues, a role for local IGF-I has been suggested. We previously showed that HTLV-II-transformed T-cell lines from healthy adults augmented basal colony formation in response to peptide (growth hormone, parathormone, and adrenocorticotrophin) and glycoprotein (thyroid-stimulating hormone) hormones through stimulation of local IGF-I. T-cell lines from African Efe Pygmies, however, were resistant to the direct growth-promoting action of IGF-I, as well as to the growth-promoting action of growth hormone, parathormone, adrenocorticotrophin, and thyroid-stimulating hormone. We, therefore, used these cell lines to determine the mechanism of T-cell growth in response to steroid and thyroid hormones. We quantified colony formation of American control T-cell lines in the presence and absence of alpha IR-3 antibody against the type 1 IGF receptor and Pygmy T-cell lines in response to estradiol (36.7-1835 pmol/ liter), testosterone (34.7-17,350 pmol/liter), 1,25(OH)2 vitamin D3 (2.4-24,000 pmol/liter), and triiodothyronine (1536-192,000 pmol/liter). There were no statistically significant differences by ANOVA in overall response curves for any of the four hormones comparing control clonal responses in the presence or absence of alpha IR-3 and no statistically significant difference in overall responsiveness between control and Pygmy T-cell lines. From these data, we conclude that (i) normal T-cell lines grow in response to estradiol, testosterone, 1,25(OH)2 vitamin D3, and triiodothyronine; (ii) these responses are not mediated through local IGF-I since they are not blocked by pretreatment with antibody to the type 1 IGF receptor; and (iii) Pygmy T-cell lines, which are genetically resistant to IGF-I, grow equivalently to control T-cell lines in response to estradiol, testosterone, 1,25(OH)2 vitamin D3, and triiodothyronine, further underscoring the IGF-I independence of this stimulation in our system.

Allometry and adaptation of body proportions and stature in African pygmies

We have analyzed the growth allometry of external body proportions in Efe pygmies from Zaire and combined these data with values from the literature for comparable dimensions in adult pygmies and nonpygmies. We sequentially tested the hypotheses that adult proportion differences between 1) male vs. female Efe, and 2) pygmies vs. nonpygmies result from ontogenetic scaling, or the differential extension of common patterns of growth allometry. Results indicate an almost complete concordance of allometric trajectories for male and female Efe. These preliminary analyses also strongly suggest that adult nonpygmy Africans generally differ from pygmies in their terminal size and correlated allometric consequences, rather than in more fundamental alterations of underlying patterns of growth. Biacromial diameter emerges as the measurement most likely to depart from this general pattern. These results provide further evidence that shifts in systemic growth hormones yielding differences in terminal overall body size may be accompanied by global and coordinated allometric transformations. Certain proportion differences previously interpreted by some as specific evidence of primitive retention in pygmies in fact reflect simple growth allometric correlates of the derive rapid size decrease in these groups. Selected divergent body proportions characterizing adult pygmies, previously interpreted by some as independent evidence of climatic adaptation, also reflect such allometric correlates of ontogenetic scaling. We critically assess arguments that the small overall body size of pygmies was specifically selected for reasons of thermoregulatory efficiency, and consider an alternative or complementary scenario, based on selection for small size in order to reduce caloric requirements.

IGF-I resistance in virus-transformed B-lymphocytes from African Efe Pygmies

To investigate IGF-I resistance in African Efe Pygmies, we examined clonal responsiveness to IGF-I in Epstein-Barr virus-transformed B-lymphocytes from three Efe Pygmies and three American control subjects. The Efe B-lymphoblasts did not increase clonal responsiveness when incubated with IGF-I (as high as 250 micrograms/liter) in contrast to the control B-lymphoblasts which showed a bimodal dose-response with a maximal stimulation of 50% above baseline. The proliferative response of Efe B-lymphoblasts was similar to that of control B-lymphoblasts when incubated with another growth factor, phorbol 12-myristate 13-acetate, which does not activate the IGF-I receptor. These findings indicate that Efe Pygmy B-lymphoblasts are resistant to IGF-I as measured by in vitro clonal proliferation assays. Coupled with our previous report of IGF-I unresponsiveness in Efe Pygmy HTLV-II-transformed T-lymphocytes, these data suggest that IGF-I resistance is generalized and may play a central role in the etiology of short stature in this population.

Decreased insulin-like growth factor I receptor expression and function in immortalized African Pygmy T cells

Efe Pygmies of northeast Zaire have the shortest mean adult stature of any population on earth. Although various alterations in the GH/insulin-like growth factor I (IGF-I) axis have been suggested, the basis for short stature in the Pygmy is unknown. We previously described IGF-I unresponsiveness in a T lymphoblast cell line derived from an Efe Pygmy, and studies in five additional lines have confirmed severe IGF-I resistance in these cells. We have now performed experiments to determine the molecular basis for the IGF-I resistance in these cells. We found markedly decreased cell surface expression of IGF-I receptors with normal ligand binding affinity. The Pygmy IGF-I receptors were not autophosphorylated and did not transmit a signal in response to physiological concentrations of IGF-I. There was a substantially decreased level of IGF-I receptor messenger ribonucleic acid in the Pygmy cells with a normal messenger ribonucleic acid half-life. The nucleotide sequence of the full-length IGF receptor complementary DNA in Pygmy 1 showed no significant variation. These results indicate decreased IGF-I receptor gene transcription and IGF-I receptor signaling as the primary variation in the Pygmy cell lines. The findings point to the IGF-I receptor as the locus governing short stature in the African Pygmy and suggest that human stature may be genetically controlled by expression of the IGF-I receptor.

Design and application of a low-temperature Peltier-cooling microscope stage

A light microscopy system has been designed for freezing and lyophilization studies of protein pharmaceuticals. The system consists of a cascade of four Peltier thermoelectric modules in the lyophilization cell to freeze samples to -60 degrees C, controllers to regulate temperature and pressure conditions, and a video camera to record the events under study. Specific demonstration of the system was conducted using recombinant CD4-IgG and human growth hormone (hGH) as model proteins. Observations of recrystallization during warming of frozen CD4-IgG solution and lyophilization of hGH solution are discussed. These examples demonstrate that the system is a useful tool for the fundamental understanding of freezing and lyophilization of protein pharmaceuticals.

Insulin-like growth factor I resistance in immortalized T cell lines from African Efe Pygmies

Previous investigations suggested that resistance to GH was the cause of short stature of African Pygmies. Because many of the actions of GH are mediated by insulin-like growth factor I (IGF-I), we sought to determine whether Pygmy tissue was responsive to IGF-I. An initial effort to obtain HTLV-II-transformed T lymphoblast cell lines resulted in a single cell line that showed complete resistance to both IGF-I and GH in a clonal proliferation assay as well as decreased IGF-I binding. In the current study, we examined T cell lines from seven Efe Pygmy subjects, three neighboring Lese farmers, and six American controls and quantified clonal responses to IGF-I, GH, and insulin. The T cell lines from the Efe Pygmies were all completely resistant to the growth-promoting actions of IGF-I concentrations less than 250 micrograms/L and GH concentrations less than 500 micrograms/L. The Lese population, with whom there is admixture with the Efe population, showed heights and clonal responses to IGF-I and GH intermediate between those of Pygmies and American controls. The Pygmy T cell lines showed reduced clonal proliferation in response to high insulin concentrations known to act through the IGF-I receptor. These findings indicate that genetic IGF-I resistance is present in the T cell lines of Efe Pygmies and suggest that unresponsiveness to IGF-I may be responsible for their short stature.

The level and tempo of children's physical activities: an observational study

We develop an observation system that quantifies the duration, intensity, and frequency of children's physical activities. We use this system to assess the level and tempo of energy expenditure under free-ranging, natural conditions experienced by 15 children aged 6-10 yr in southern California. Observations were recorded every 3 s during 4-h time blocks from 8:00 a.m.-8:00 p.m. Agreement among observers using the coding system was 91%. Using indirect calorimetry, calibration studies in the laboratory determined VO2 (ml.min-1.min-1) during each coded activity, and activities were categorized by intensity (low, medium, or high). Subjects were found to engage in activities of low intensity 77.1% of time and activities of high intensity 3.1% of time. The median duration of low and medium intensity activities was 6 s, of high intensity activities only 3 s with 95% lasting less than 15 s. Children engaged in very short bursts of intense physical activity interspersed with varying intervals of low and moderate intensity. These findings may be important for discovering how children's activity patterns under natural conditions influence physiological processes leading to growth and development. This study demonstrates the advantages of using an observational system that captures more than the intensity and frequency of children's activities to include duration and the length of intervals between activities of varying intensity.

Adequacy of national mortality data for internal hospital use: a case study

OBJECTIVE

The study investigated the value of using national or regional data bases to examine care in a specific hospital.

DATA SOURCES

The following data sources were included: (1) the results of the 1992 HCFA analysis of the index hospital for patients hospitalized in fiscal year 1990; (2) the 1989 Medicare Provider Analysis and Review (MEDPAR) file; and (3) clinical information from bypass surgery patients in Wisconsin and from the index hospital.

PRINCIPAL FINDINGS

The assessment of the mortality rates in the index hospital for all conditions combined and for CABG patients differed depending on what data base was used and how the data were analysed. The national data were most useful in establishing that the coding practices for all patients and the mortality rate for intra-aortic balloon patients differed between the index hospital and other hospitals. The regional clinical data base for bypass surgery patients was used to establish that the high mortality rates for intra-aortic balloon patients were due to patient selection.

CONCLUSIONS

National claims data must be analysed carefully before applying results to an individual hospital. Even a careful analysis is more for raising questions about care at a specific hospital rather than for reaching definitive conclusions.

Growth-promoting actions of parathyroid hormone, adrenocorticotrophic hormone, and thyroid-stimulating hormone: in vitro studies in normal and pygmy T-lymphoblast cell lines

We used an in vitro T-lymphoblast clonal proliferation assay to quantify human IGF-I (hIGF-I)-, human PTH (hPTH)-, human ACTH (hACTH)-, and human TSH (hTSH)-stimulated growth of human T-cell leukemia virus-II-transformed T-lymphoblast cell lines from normal individuals and to elucidate the role of IGF-I as the mediator of hPTH-, hACTH-, and hTSH-induced T-cell growth. Normal T-lymphoblast cell lines respond to hIGF-I in a bimodal fashion. The mean first peak response was 143 +/- 9.8% above baseline (defined as 100%) occurring at 8 micrograms/L, and the mean second peak response was 154 +/- 14.4% occurring at 100 micrograms/L. Both responses were completely blocked after incubation with alpha IR-3, an MAb to the IGF-I receptor (by analysis of variance, p = 0.015 between full response curves). After stimulation with hPTH, the mean peak clonal response of normal T-lymphoblast cell lines was 189 +/- 7.0%; after incubation with alpha IR-3, the mean peak clonal response was 108 +/- 7.9% (p = 0.0015 between full response curves). The mean peak clonal response of normal T-lymphoblast cell lines after hACTH stimulation was 192 +/- 8.6%; preincubation with alpha IR-3 reduced the mean peak clonal response to 94 +/- 1.2% (p < 0.0001 between full response curves). With hTSH stimulation, the mean peak clonal response of normal T-lymphoblast cell lines was 167 +/- 7.0%; after incubation with alpha IR-3, the mean peak clonal response was 94 +/- 8.2% (p = 0.003 between full response curves).(ABSTRACT TRUNCATED AT 250 WORDS)

Interpreting the Health Care Financing Administration's mortality statistics

In this article, the methodology used by the Health Care Financing Administration in the 1992 release of 1990 mortality statistics is described, and the performance of one outlier hospital is evaluated as a case study. The study hospital is compared to all other hospitals, and to a smaller cohort of 200-to-299-bed minor teaching hospitals, in terms of predicted and observed mortality rates and mortality model determinants. Proportionately more patients treated in the study hospital were women and had cerebrovascular degeneration or chronic renal disease; fewer patients had cardiovascular disease. Substantially more patients from this hospital were transfers from a skilled nursing facility. Fewer patients were admitted through the emergency department. Although patients tended to be more seriously ill overall compared with other hospitals in the country, observed mortality rates were still higher than predicted. Possible explanations for the discrepancy were coding inconsistencies, inability to control adequately for the severity of illness of transfers from skilled nursing facilities, or quality of care problems.

The systematic assessment of variations in medical practices and their outcomes

The Health Care Financing Administration of the Department of Health and Human Services has carried out for several years the systematic assessment of variations over time and among geographic locales in patterns of care and patterns of outcomes experienced by Medicare beneficiaries. This routine monitoring focuses principally on hospitalizations and their outcomes (death and readmission) and is based on the Medicare enrollment file and the claims file for inpatient care. The period 1985-88 has been marked by declining adjusted post-admission risks for mortality (down 4 percent) and readmission (down 6 percent) for Medicare beneficiaries. The downward trend in mortality risks is most evident following hospitalizations for acute myocardial infarction (down 8 percent) and stroke (down 12 percent). Hospital admission and population mortality rates, adjusted for differences in demographic and socioeconomic characteristics of the populations, vary substantially among areas as large as States and Metropolitan Statistical Areas, as do risk-adjusted post admission probabilities of death among those areas and among hospitals. Thus, if overall admission and mortality rates in the upper three quartiles of Metropolitan Statistical Areas were brought down to the average of the lowest quartile, there would be 20 percent fewer admissions and 12 percent fewer deaths within 180 days of admission for hospitalized patients. Although favorable trends in the effectiveness of the hospital care received by Medicare beneficiaries appear discernible, the existence of substantial variations suggests that further improvement may be possible.

Causal attribution and affective response as mediated by task performance and self-acceptance

Predictions derived from cognitive consistency theories, self-esteem theories, and ego-serving-bias theory concerning how students would make attributional and affective responses to their academic performance were investigated. 202 university students completed a measure of self-acceptance of their college ability and made attributional and affective responses to an hypothetical examination performance. Analyses showed that students receiving positive feedback perceived greater internal causality and responded with greater positive affect than students receiving negative feedback. Self-acceptance did not moderate the attributions or affective reactions. The results supported the ego-serving-bias theory and provided partial support for self-esteem theory. Findings did not support predictions from cognitive-consistency theory.

The relationship of hospital ownership and teaching status to 30- and 180-day adjusted mortality rates

Hospital characteristics have been shown previously to be associated with variations in the probability of death within 30 days of admission. In the current study, the authors extend the examination of the relationship between hospital type to both short-term and long-term adjusted mortality. Observed and predicted 1988 hospital mortality rates were obtained from the Health Care Financing Administration (HCFA). A total of 3,782 acute care hospitals were divided into six mutually exclusive groups on the basis of their status as osteopathic, private for-profit, public teaching, public nonteaching, private teaching, and private nonteaching hospitals. After adjusting for the HCFA predicted mortality, Medicaid admissions, and emergency visits, 30-day and 30-to-180-day patient mortality rates were compared for these hospital types. Separate comparisons also were performed after stratifying hospitals into three groups defined by community size. The risk-adjusted 30-day mortality per 1,000 patients was 91.5, ranging from 85.4 for private teaching hospitals to 95.3 for nonteaching public hospitals, and 97.4 for osteopathic hospitals. The adjusted 30-to-180-day mortality was 84.7, ranging from 82.6 for nonteaching public hospitals to 87.4 and 88.2, respectively for public teaching and osteopathic hospitals. Differences among hospital types were minimal for small communities and increased with community size. In the large communities, the types of hospitals with high 30-day mortality also had higher mortality after 30 days. There was a strong association of hospital type with adjusted 30-day mortality, which should depend on the quality of hospital care, and a much weaker association with post-30-day mortality, which may be more dependent on patient risk. There was no evidence that types of hospitals with low 30-day mortality were postponing rather than preventing mortality.

The Behavioral and Attitudinal Modification Project (BAM): a failed experiment using a classical experimental research design in a closed institutional setting for drug addicts

Failure in program implementation and related research within closed institutional settings has long been a source of discouragement for correctional administrators and correctional researchers. This paper describes an attempt to implement an innovative treatment program, The Experimental Behavioral and Attitudinal Modification Project, within a civil addict treatment facility to enhance treatment effectiveness. It documents the major obstacles to correctional program innovation and research which ultimately brought about disruption, complacent cooperation, and other implementation problems leading to a project shutdown. It also attempts to place in theoretical perspective the reasons behind implementation failures, particularly as they relate to innovations in treatment and the use of classical experimental designs in closed institutional settings. The article is adapted from the executive summary of the final report to the funding agency. Researchers working to facilitate the effective reintegration of drug-using offenders into society should take heed from this research project, originally implemented in 1970, as a study in FAILURE as apropos today as it was over two decades ago.

Growth hormone induces resistance to the mitogenic action of insulin through local IGF-I. Studies in normal and Pygmy T-cell lines

Growth hormone (GH) and insulin have both mitogenic and metabolic actions. The growth-promoting effects of GH in vivo are thought to be mediated by insulin-like growth factor-I (IGF-I), whereas the metabolic effects of GH are thought to be either direct or mediated by factors other than IGF-I. In previous studies using HTLV-II-transformed T-lymphoblast cell lines established from normal individuals, we have shown that GH preincubation induces resistance to the growth-promoting (mitogenic) action of insulin. In this study, using T-cell lines from 3 American control subjects, 1 African control subject, and 1 African Pygmy (the latter previously shown to be resistant to the growth-promoting actions of both IGF-I and GH), we examined the role of local IGF-I in the mediation of GH-induced resistance to the mitogenic action of insulin. In these studies, we quantified the stimulation of T-cell colony formation in response to insulin in the presence and absence of either GH or IGF-I.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-like growth factor-I unresponsiveness in an Efe Pygmy

The cause of short stature in African Pygmies is unknown, but some evidence suggests that they are GH resistant. Since IGF-I mediates many actions of GH, we sought to determine if Pygmy tissue is responsive to IGF-I. We established HTLV-II-transformed cell lines from 1 Efe Pygmy, 1 African control, and 3 American controls, and quantified in vitro colony formation in response to IGF-I, GH, and insulin, and assessed IGF-I receptor binding. The Pygmy T-cell line showed no clonal responsiveness following stimulation with physiologic concentrations of IGF-I or any concentration of GH, but responded normally to insulin. IGF-I binding studies showed no binding to the Pygmy T-cell line with normal binding to control cells. The primary abnormality in this Pygmy T-cell line is IGF-I resistance at the receptor level with secondary GH resistance.

Evaluation of the HCFA model for the analysis of mortality following hospitalization

From 1987 through 1990, the Health Care Financing Administration (HCFA) evaluated variations in the mortality rates experienced by patients admitted to hospitals participating in the Medicare program. This study was conducted to evaluate the adequacy of the model used for that purpose. Detailed clinical data were gathered on 42,773 patients admitted to 84 statistically selected hospitals. The effect of risk adjustment using the HCFA model, which is based on claims data, was compared to a risk-adjustment model based on physiologic and clinical data. Models that include claims data were markedly superior to those containing only demographic characteristics in predicting the probability of patient death, and the addition of clinical data resulted in further improvement. The correlation of ranks of hospitals based on a model that uses only the claims data and on one that uses, in addition, clinical data, was .91. As a screen for the identification of "high (mortality) outlier" hospitals, the claims model had moderate sensitivity (81 percent) and specificity (79 percent), a high negative predictive value (90 percent), and a low positive predictive value (64 percent) when compared to the clinical model. The two mortality models gave similar results when used to determine which structural characteristics of hospitals were related to mortality rates: hospitals with a higher proportion of registered nurses or board-certified physician specialists, or with a greater level of access to high-technology equipment had lower risk-adjusted mortality rates. These data suggest that the current claims-based risk-adjustment procedure may satisfactorily be used to characterize variations in mortality rates associated with hospitalization. The procedure could also be used as a basis for further epidemiological analyses of factors that affect the probability of patient death. However, it does not positively identify outlier hospitals as providers of problematic care.

The ecology of birth seasonality among agriculturalists in central Africa

The Lese are subsistence farmers living in the Ituri Forest of north-east Zaïre. They exhibit significant birth seasonality, with lowest frequencies of conception when food production is least, nutritional status is low and ovarian function, as measured by salivary steroid hormone levels, is reduced. Efe pygmy foragers, who live in the same geographical area but are less dependent on cultivated foods and have a more flexible life style, do not exhibit frequent fluctuations in nutritional status nor significant birth seasonality. These findings support a model of birth seasonality relating climatic variables to variation in fertility through a causal chain linking rainfall to food production to energy balance to ovarian function to fertility. The model, which emphasises an ecological approach to the study of human reproduction, should have broad applicability since seasonality of food production and energy balance is widespread geographically and across a wide variety of economies and cultures.