When is now? Perception of simultaneity

We address the following question: Is there a difference (D) between the amount of time for auditory and visual stimuli to be perceived? On each of 1000 trials, observers were presented with a light-sound pair, separated by a stimulus onset asynchrony (SOA) between -250 ms (sound first) and +250 ms. Observers indicated if the light-sound pair came on simultaneously by pressing one of two (yes or no) keys. The SOA most likely to yield affirmative responses was defined as the point of subjective simultaneity (PSS). PSS values were between -21 ms (i.e. sound 21 ms before light) and +150 ms. Evidence is presented that each PSS is observer specific. In a second experiment, each observer was tested using two observer-stimulus distances. The resultant PSS values are highly correlated (r = 0.954, p = 0.003), suggesting that each observer's PSS is stable. PSS values were significantly affected by observer-stimulus distance, suggesting that observers do not take account of changes in distance on the resultant difference in arrival times of light and sound. The difference RTd in simple reaction time to single visual and auditory stimuli was also estimated; no evidence that RTd is observer specific or stable was found. The implications of these findings for the perception of multisensory stimuli are discussed.

A novel series of 4-piperidinopyridine and 4-piperidinopyrimidine inhibitors of 2,3-oxidosqualene cyclase-lanosterol synthase

A novel series of 4-piperidinopyridines and 4-piperidinopyrimidines showed potent and selective inhibition of rat 2,3-oxidosqualene cyclase-lanosterol synthase (OSC) (e.g. 26 IC(50) rat = 398 +/- 25 nM, human = 112 +/- 25 nM) and gave selective oral inhibition of rat cholesterol biosynthesis (26 ED(80) = 1.2 +/- 0.3 mg/kg, n = 5; HMGCoA reductase inhibitor simvastatin ED(80) = 1.2 +/- 0.3 mg/kg, n = 5). The piperidinopyrimidine OSC inhibitors have a significantly lower pK(a) than the corresponding pyridine or the previously reported quinuclidine OSC inhibitor series. This indicates that other novel OSC inhibitors may be found in analogues of this series across a broader pK(a) range (6.0-9.0). These series may yield novel hypocholesterolemic agents for the treatment of cardiovascular disease.

Distribution of growth factors and immune cells are altered in the lacrimal gland during pregnancy and lactation

We have undertaken a series of studies to elucidate the roles of growth factors (FGF-2, EGF, TGF-beta1) and prolactin (PRL) in lacrimal gland function during pregnancy and lactation, and to better understand the status of the immune system within the lacrimal gland during those physiological states. In this initial study, lacrimal glands of pregnant (d15, d29), lactating (9d, 22d), and adult female control rabbits, were evaluated by immunohistochemistry, Western blotting and image analysis. In control rabbits EGF, TGF-beta1, and PRL, were immunolocalized primarily in the apical cytoplasm of intralobular ductal epithelial cells, and acini demonstrated a basement membrane-associated immunopositivity for TGF-beta1. FGF-2 immunolocalized in myoepithelial cells in the basal ductal epithelium and complexed to the basement membrane enclosing ducts and acini. Cells immunopositive for immune cell markers (RTLA and CD18) were apparent primarily around interlobular ducts. In d29 pregnant rabbits immunopositivity for EGF and TGF-beta1 was increased within intralobular ducts, both apically and basally, and within some interlobular ductal epithelial cells. Immunopositivity for PRL was strongest in d29 pregnant rabbits within the apical and basal cytoplasm of intralobular ductal epithelial cells. Immunopositivity for FGF-2 in myoepithelial cells was strong in d15 and d29 pregnant rabbits, although basement membrane-associated immunopositivity around acini was often decreased. Immunostaining for EGF and TGF-beta1 in lactating rabbits was similar to that in d29 pregnant rabbits, although basement membrane-associated immunopositivity around acini was more comparable to controls. By 22d lactation immunopositivity for FGF-2 closely resembled that in controls. Image analysis of pregnant and lactating rabbits demonstrated that cells immunopositive for RTLA and CD18 were less abundant around ducts and more abundant between acini, although in 22d lactating rabbits the size of periductal foci was increased to nearly that of controls. Western blots correlated well with the immunohistochemistry. Our findings demonstrate that pregnancy and lactation are accompanied by a shift in the distributions of growth factors and PRL, suggestive of increased release both apically into the lacrimal fluid and basally into the interstitium. Additional shifts in the distributions of cells of the immune system from periductal foci to interacinar sites suggest that there is a recruitment of immune cells away from ducts and toward the connective tissue interstitium surrounding the acini, possibly as part of a heightened state of immune readiness during pregnancy and lactation.

Corneal insult affects the production and distribution of FGF-2 within the lacrimal gland

The purpose of this study was to determine the distribution of FGF-2 within rabbit lacrimal glands and to determine whether corneal insult affects that distribution. The scarified corneas of experimental animals were inoculated either with adenovirus type 5 or buffer. Control animals were either untreated, or animals whose corneas were scarified. Twenty-one days later all animals were killed and the lacrimal glands were studied by immunocytochemistry and Western blotting to detect FGF-2. In untreated control animals, FGF-2 was immunolocalized predominantly within a population of elongated cells in the basal epithelium of ducts, and to a lesser degree in the basal epithelium of the acini. The elongated immunopositive cells appear to be myoepithelial cells known to be present at these sites. Interstitial cells around ducts and acini, and the basement membranes of the ducts and acini, were also immunopositive for FGF-2. Twenty-one days after adenovirus inoculation and scarification of the cornea, immunopositivity for FGF-2 was dramatically decreased in basement membranes, but increased within myoepithelial cells of the duct epithelium. These myoepithelial cells were frequently enlarged, bulging toward the duct lumen. In animals whose corneas were inoculated with buffer and scarified, or animals whose corneas were simply scarified, the changes in the lacrimal gland were similar, but somewhat less pronounced, to those of adenovirus-inoculated animals. Western blots confirmed the presence of FGF-2 immunoreactivity in all groups. The major band in untreated controls was at 24 kD, whereas all animals with corneal scarification had major bands at 38 kD. Densitometry of Western blots demonstrated that the amount of 24 kD FGF-2 present within the lacrimal gland after corneal scarification was at least 50% less than in untreated controls, whereas 38 kD FGF-2 was at least ten-fold greater. Our findings indicate that corneal scarification results in an altered distribution of FGF-2 within the lacrimal gland, which involves a decrease in low molecular weight FGF-2 and a dramatic increase in a higher molecular weight isoform of FGF-2. FGF-2 may be released from myoepithelial cells apically (exocrine) into the tear fluid and basally (autocrine/paracrine) into the connective tissue, as well as from extracellular complexes within basal laminae.

Diagnosing HIV-associated tuberculosis: reducing costs and diagnostic delay

SETTING

University-affiliated hospital in South Africa.

OBJECTIVE

To assess the time to diagnosis and the yield and laboratory cost of diagnostic procedures in human immunodeficiency virus (HIV) associated tuberculosis.

DESIGN

Cohort study.

PATIENTS

Adult HIV-infected patients with newly-diagnosed tuberculosis admitted over a 2-year period.

RESULTS

A total of 141 admissions fulfilled the case definition. Sputum smear yield (43% overall) correlated strongly with chest radiograph appearance but not with CD4+ lymphocyte count. Sputum smear yield was approximately 40% per sample sent, resulting in a high cumulative yield when > or = three samples were sent. Smear of sputum or wide needle lymph node aspirates were the most cost-effective diagnostic methods. Significant diagnostic delay occurred in sputum smear-negative patients. Most patients with sputum smear-negative tuberculosis had either pleural effusions or lymphadenopathy. Lymph node biopsy had a high diagnostic yield even in patients with symmetrical nodes, but was under-utilised in this group. There was unnecessary expenditure on cultures, with many patients having several positive cultures.

CONCLUSION

Repeated sputum smear examination produces a high cumulative yield in HIV-associated tuberculosis. Considerable savings in laboratory utilisation and bed occupancy would have been made if a streamlined diagnostic approach with greater use of lymph node aspirate and early pleural or lymph node biopsy had been followed.

Relationship of (known) control values to (unknown) test values in proficiency studies of pesticide residues

Proficiency studies have been suggested as an alternative source of information for evaluating method performance characteristics when results from interlaboratory method performance studies conforming to internationally recognized protocols are not available. To explore this possibility, results were examined from ongoing proficiency studies of pesticide residue analyses in celery, carrot, and grape purees, and in wine. Statistical performance parameters were calculated from 18 data sets analyzed as unknowns by about 60 analysts for 12 analytes in the 25-1,000 microg/kg range, and from presumably parallel control (spike) analyses conducted by about half of the participants. A surprising finding was that recovery of known, independent control additions by the participant did not correlate with the recoveries determined as unknowns in the exercise. The data suggest that censoring or truncating of control data has occurred. The question of substitution of proficiency data for method performance data cannot be answered until the problem of unbiased reporting of control data is resolved.

Risk factors for developing tuberculosis in HIV-1-infected adults from communities with a low or very high incidence of tuberculosis

OBJECTIVE

To estimate the incidence rate of tuberculosis in HIV-1-infected adults resident in a region with a high tuberculosis prevalence and to identify clinical and laboratory parameters associated with increased risk of developing tuberculosis.

METHODS

Adult patients going to the University of Cape Town HIV clinics between January 1986 and May 1996. The following variables were assessed for the risk of developing tuberculosis: ethnicity, employment and education status, World Health Organization (WHO) clinical stage, erythrocyte sedimentation rate (ESR), CD4+ count, and total lymphocyte count. Tuberculin skin test data were not available.

RESULTS

There were 198 prevalent and 144 incident cases of tuberculosis in the cohort of 1206 patients. The incidence rate of tuberculosis risk was 10.4/100 person years. WHO clinical stages 3 and 4 (risk ratio [RR], 3.4; 95% confidence interval [CI], 1.8-6.4), ESR >75 mm/hour (RR, 3.5; CI, 1.8-6.5) and being a member of a high-prevalence tuberculosis community (RR, 2.5; CI, 1.2-5.1) were independently associated with the risk of developing tuberculosis.

CONCLUSIONS

HIV-infected adults in Cape Town are at high risk of developing tuberculosis irrespective of tuberculin skin testing. The risk increases markedly with HIV disease progression. Patients at extremely high risk can be identified on the basis of demographic and clinical features. Such individuals would be suitable for targeted tuberculosis prophylaxis.

Lipids of the pawpaw fruit: Asimina triloba

The fatty acid composition and structure of pawpaw fruit (Asimina triloba) triglycerides were examined and found to contain fatty acids ranging from C6 to C20. Octanoate represented 20% of the fatty acids while other medium-chain fatty acids were present in low amounts. Analysis of the intact triglycerides by high-temperature gas-liquid chromatography gave an unusual three-cycle carbon number distribution. Analysis of triglyceride fractions separated according to degree of unsaturation suggested that one octanoate was paired with diglyceride species containing long-chain fatty acids. Determination of the double-bond positions of monoene fatty acids revealed cis delta9 and cis delta11 hexadecenoate and cis delta9, cis delta11, and cis delta13 octadecenoate isomers were present in significant quantities. Octanoate and positional monoene fatty acid isomers were found only in the fruit lipids and not in the seed lipids. Phenacyl esters of fatty acids were found to be useful derivatives for structure determination using multiple types of analyses.

Measuring aspects of women's life and work for the study of variations in health

BACKGROUND

Studies of occupation and health commonly examine only men. This paper draws on reviews of inequalities in health carried out by the Office for National Statistics in London which in recent years have focused more on women.

METHODS

Many sources of official statistics such as censuses, surveys, vital registration and health service records are used to explore different ways of measuring and monitoring economic activity, education, socio-economic, and family status and their impact on fertility and health among women.

RESULTS

Taking a life cycle approach we first look at fertility and family formation, the time around childbirth, age 15-49, and finally 50+. Some relevant health issues are used to illustrate how we use available data to describe and monitor inequalities in health.

CONCLUSIONS

In Britain, there is a wealth of information and linked data sources which enable us to analyze patterns and trends in fertility, morbidity, and mortality. Nevertheless, none of the traditional data sources or methods of analysis are suitable for all purposes nor for keeping up with changes in society. Sources of official statistics and ways of linking and analyzing need then to be continuously developed.

Rubella infection in pregnancy

It is over 50 years since a syndrome of congenital abnormalities following maternal rubella infection was first recognised. Despite the potentially devastating effects of the congenital rubella syndrome, immunisation rates are not optimal and infections in pregnancy still occur. Four cases of rubella infection occurring in pregnancy are presented. Laboratory diagnosis of primary infection and reinfection is discussed, and the need for full immunisation in childhood, and of women of child-bearing age is reiterated.

Quinuclidine inhibitors of 2,3-oxidosqualene cyclase-lanosterol synthase: optimization from lipid profiles

Novel 3-substituted quinuclidine inhibitors of cholesterol biosynthesis are reported. Compounds were optimized against oxidosqualene cyclase-lanosterol synthase (OSC) inhibition in vivo, rather than by the conventional optimization of structure-activity relationship information based on in vitro OSC inhibition. Thus, examination of HPLC lipid profiles from orally dosed rats showed cholesterol biosynthetic intermediates and whether cholesterol levels were reduced. A new substituted quinuclidine pharmacophore 18a-c was rapidly found for the inhibition of OSC, and the most promising inhibitors were validated by the confirmation of potent OSC inhibition. Compound 16 gave an IC50 value of 83 +/- 11 nM for human and an IC50 value of 124 +/- 14 nM, for rat, coupled with oral and selective inhibition of cholesterol biosynthesis derived from OSC inhibition (rat, ED50 = 1.3 +/- 0.7 mg/kg, n = 5; marmoset, 15 mg/kg dose, n = 3, caused complete inhibition). These 3-substituted quinuclidines, which were derived from a quinuclidine series previously known to inhibit cholesterol biosynthesis at the squalene synthase step, may afford a novel series of hypocholesterolemic agents acting by the inhibition of OSC.

Restriction fragment length polymorphism analysis for rapid gag subtype determination of human immunodeficiency virus type 1 in South Africa

A rapid method for identification of human immunodeficiency virus Type 1 (HIV-1) gag subtypes was developed based on restriction fragment length polymorphism (RFLP) analysis of 400 or 650 bp long polymerase chain reaction (PCR) fragments encompassing the start of the p17 (400 bp) and part of the p24 (650bp) regions. The consensus sequences of subtypes A-D, the only subtypes identified in South Africa, were analyzed to detect restriction endonucleases which generate unique patterns for each subtype. Four restriction endonucleases were identified: AluI, AccI, SwaI and XmnI. Digestion of a 400 bp fragment with AluI allowed identification of subtype C. Samples not identified were then reamplified, and a 650 bp fragment digested with AccI to identify subtype B, followed by SwaI and XmnI to distinguish between subtypes A and D. This strategy was applied to 87 samples previously subtyped by either sequence analysis of the gag p17 region (n = 33); or heteroduplex mobility assay (HMA) based on the env gene (n = 75); or both (n = 21). Out of the 87 samples, RFLP identified two samples as subtype A, 28 as subtype B, 56 as subtype C and one as a subtype D virus. No discrepancies were found between RFLP gag subtypes and gag sequence subtypes demonstrating the reliability of this method. There was also no discordance between gag RFLP subtypes and env HMA subtypes, suggesting that there were no recombinant viruses detected relating to the genomic regions analyzed. RFLP is an effective technique for the rapid screening in an HIV epidemic of limited diversity, such as in South Africa.

Birth statistics: recent trends in England and Wales

This article summarises recent trends in birth statistics in England and Wales. Particular attention is given to the characteristics of conceptions in 1996 and births in 1997, the latest years for which figures are available. The article examines changes in the number of births outside marriage, the age women become mothers and the number of women expected to remain childless throughout their lives. It also analyses differences in the timing of childbearing between women from different social classes or living in different regions of the UK. Finally it describes changes in the overall and underage conception rates between 1995 and 1996.

Teenage mothers and the health of their children

Teenage mothers continue to present challenges to social policy and remain of topical interest to the media. This article discusses trends in teenage conception rates, their outcomes and long term consequences. In 1996, 7 per cent of all births were to girls aged under 20. On average children born to teenage girls have lower birthweights, increased risk of infant mortality and an increased risk of some congenital anomalies. They are less likely to be breastfed and more likely to live in deprived circumstances. These factors in turn influence their health and long term opportunities.

GM-CSF, IL-5 and RANTES immunoreactivity and mRNA expression in chronic hyperplastic sinusitis with nasal polyposis (NP)

BACKGROUND

Eosinophils are a prominent feature of chronic hyperplastic sinusitis with nasal polyposis (CHS/NP). Our previous studies showed that their presence was associated with the expression of GM-CSF and RANTES mRNA. In allergic NP, increased expression of IL-5 was also found.

OBJECTIVE

We wished to examine cytokine immunoreactivity for IL-5, GM-CSF and RANTES mRNA in allergic and non-allergic NP and compare immunoreactivity with expression of cytokine mRNA by in situ hybridization. Methods NP were obtained from five allergic and eight non-allergic subjects with CHS/ NP. Middle turbinate tissue from eight normal subjects were used as controls. Cell-associated cytokine mRNA was detected by in situ hybridization (ISH). Cytokine immunoreactive cells were enumerated by immunostaining. Colocalization immunostaining was also performed to identify specific cell types producing IL-5.

RESULTS

Immunostaining for GM-CSF, IL-5 and RANTES protein was increased in both allergic and non-allergic NP compared with control middle turbinates. Allergic polyps contained greater numbers of IL-5 immunoreactive cells (P = 0.01), whereas non-allergic polyps contained greater numbers of GM-CSF immunoreactive cells (P = 0.04). Immunostaining was primarily associated with inflammatory cells, but immunostaining for RANTES and, to a lesser extent GM-CSF, was also seen in the epithelium. The density of immunoreactive cells was variably correlated with cytokine mRNA+ cells (GM-CSF: R=0.56, P=0.05; IL-5: R=0.76, P=0.003; and RANTES: R=0.89, P=0.0005). Colocalization immunostaining revealed that the majority of IL-5 immunoreactive cells in both allergic and non-allergic NP were T lymphocytes. However, allergic NP contained greater numbers of IL-5+/CD3+ T lymphocytes and IL-5+ mast cells, whereas non-allergic NP contained greater numbers of IL-5+ eosinophils.

CONCLUSION

We conclude that GM-CSF, IL-5 and RANTES are produced in increased amounts in both allergic and non-allergic NP. Distinguishing features of non-allergic NP include fewer numbers of CD3 T lymphocytes, fewer IL-5+/CD3+ T lymphocytes and greater numbers of IL-5+ eosinophils. These differences may suggest different mechanisms of eosinophil accumulation and activation in allergic vs non-allergic NP.

A picture of locational--occupational diversity: an analysis of the needs of rural and remote healthcare workers when writing RHSET applications. Rural Health Support Education and Training

Methods for meeting the research needs of rural/remote health workers have been assessed on the assumption that these workers form a seemingly homogeneous group. This paper provides a picture of locational-occupational diversity not previously considered when addressing the needs of rural health workers writing research and project grant submissions. Rural/remote health workers and researchers were surveyed about their needs when seeking assistance with the development, implementation and evaluation of funded project/program proposals. New South Wales respondents were differentiated according to five geographical locations and 10 occupational categories. The results suggest that geographical location and occupational category are major factors in determining research requirements for rural/remote health workers and researchers, and should be considered when identifying barriers to the development and implementation of research projects in rural/remote health care issues. Those health workers most isolated required access to resource information and research and grant writing skills development, while researchers in metropolitan areas were more inclined to seek funding information and general assistance. Those in occupational categories who do not generally receive research and grant writing skills training are less likely to attract funding than their more 'academic' counterparts.

Presurgical columellar elongation and primary retrograde nasal reconstruction in one-stage bilateral cleft lip and nose repair

We present a new combined approach to primary bilateral cleft lip, nose, and alveolus repair using presurgical nasoalveolar molding combined with a one-stage lip, nose, and alveolus repair. Presurgical alveolar molding is used to bring the protruding premaxilla back into proper alignment with the lateral segments in the maxillary arch. Presurgical nasal molding produces tissue expansion of the short columella and nasal lining. A coordinated surgical approach involves a one-stage repair of the lip, nose, and alveolus. The nasal repair uses a retrograde approach in which the prolabial flap and columella are reflected over the nasal dorsum by continuing the dissection behind the prolabium up the membranous septum and over the septal angle. Tissues are dissected out from between the tip cartilages, and the domes are sutured together in the midline. This method joins a new class of bilateral cleft repairs that place the primary emphasis on correction of the deformity of the nasal tip cartilages.

Human immunodeficiency virus-related abdominal pain in South Africa. Aetiology, diagnosis and survival

BACKGROUND

Abdominal pain in acquired immunodeficiency syndrome (AIDS) patients is often a marker of an underlying opportunistic pathologic condition. There are no data on HIV-related abdominal pain in Africa.

METHODS

Forty-four consecutive Cape Town patients with advanced human immunodeficiency virus (HIV) infection (CD4 < 200) and abdominal pain were studied prospectively to determine aetiology and survival.

RESULTS

A probable cause of pain was identified in 37 (84%): disseminated Mycobacterium tuberculosis infection in 11, cryptosporidiosis in 6, cytomegalovirus infection in 6, and atypical mycobacterial infection in 2. Gastrointestinal lymphoma and pancreatitis were not seen. Fever, hepatomegaly, respiratory symptoms, abnormal chest radiograph, and adenopathy, ascites, or abscesses on ultrasound had predictive diagnostic value for disseminated M. tuberculosis. Fifty-one per cent of abdominal pain patients survived 6 months, compared with 73% of all AIDS patients (P < 0.001).

CONCLUSIONS

The aetiology of HIV-related abdominal pain in Cape Town reflects the high local prevalence of tuberculosis. Clinical and ultrasound features facilitate diagnosis. Abdominal pain is associated with poor survival.

The health beliefs and behaviors of three groups of complementary medicine and a general practice group of patients

Patients (n = 256), consulting either a general practitioner (GP) or one of three complementary practitioners (osteopath, homeopath, or acupuncturist), completed a seven-part questionnaire that looked at demographic data, medical history, familiarization with complementary therapies, health beliefs and life-style, health locus of control, scientific health beliefs, and their perceptions of the consultation style of general and complementary practitioners. The four subject groups did not differ significantly on the demographic variables of sex, years of schooling, whether or not they had a degree, marital status, or income, but did differ on age and number of children. The effects of both the significant demographic variables and some aspects of patients medical history were controlled for in subsequent analyses. Acupuncture patients stood out as having the most different chronic medical history. They were also least satisfied with their GP, had least confidence in prescribed drugs, and were most concerned with leading a healthy life-style. The acupuncture patients were most skeptical about orthodox medicine. The main finding was that patients of complementary practitioners are not a homogeneous group, but do differ in their views on satisfaction with GPs, healthy life-style, global environmental issues, confidence in prescribed drugs, faith in medical science, importance of a "healthy mind," harmful effects of medical science, and scientific methodology. The results imply that patients consult different practitioners, general or alternative, on the basis of a combination of their level of skepticism about orthodox medicine, their life-style, and other health beliefs. To talk of patients of complementary practitioners as a homogeneous group is fundamentally wrong.

Trends in conceptions before and after the 1995 pill scare

On 18 October 1995, the Committee on Safety of Medicines issued a warning that seven brands of the contraceptive pill (containing 'new generation' progestogens) carried a relatively higher risk of thrombosis (the formation of a blood clot in a vein). This warning received much attention from the media. Family planning services and others working in public health raised concerns that the pill scare would result in an increase in unplanned pregnancies. This article uses national conception statistics to show trends before and after October 1995.

Determination of lead in wine by graphite furnace atomic absorption spectrophotometry: interlaboratory study

An interlaboratory study of a graphite furnace atomic absorption spectrophotometry (GFAAS) method for the determination of lead in wine was conducted. Seventeen laboratories from France, United States, and the United Kingdom, using a variety of GFAAS instruments, took part in the study. The method incorporated a novel matrix-matching procedure to minimize matrix effects between standards and samples. Six wine test materials were prepared and sent to participants as 12 blind duplicate or split level samples. There was good agreement between results obtained from participants and target values (24-279 micrograms/L) obtained with an inductively coupled plasma-mass spectrometry method. The precision of the GFAAS method was well within the range predicted by the Horwitz equation for the 6 test materials analyzed. Repeatability standard deviations ranged from 3 to 17%. Reproducibility standard deviations were in the range of 10 to 30%. The method is recommended for use for official purposes.

Independent epidemics of heterosexual and homosexual HIV infection in South Africa--survival differences

Survival with HIV infection is shorter in sub-Saharan Africa than in developed countries. The pattern of HIV transmission in our region has changed from homosexual to heterosexual, with viral subtypes similar to those in North America/Europe and Central Africa, respectively. We compared survival for the two transmission patterns after AIDS, and after the first CD4+ lymphocyte counts < 200/microliter and < 50/microliter, for adults presenting 1988-1993. Antiretroviral therapy was excluded. There were 180 homosexuals (63% White, 56% employed) and 314 heterosexuals (67% Black, 34% employed). Extrapulmonary tuberculosis was the AIDS-defining diagnosis in 36/90 heterosexuals and 5/58 homosexuals (p < 0.0001). Survival after AIDS was longer in heterosexuals (p = 0.0015), but AIDS occurred earlier as shown by their higher CD4+ count at AIDS onset (median 98/microliter vs. 40/microliter; p = 0.036). Survival was similar in the two groups after first CD4+ count < 200/microliter and < 50/microliter. Race, socioeconomic status and morbidity are markedly different in the two transmission groups. AIDS occurs with less severe immune suppression in heterosexuals, with correspondingly longer survival. Survival after defined CD4+ counts, however, is remarkably similar.

Management of the infected median sternotomy wound with muscle flaps. The Emory 20-year experience

OBJECTIVE

The purpose of the study is to define those patient variables that contribute to morbidity and mortality of median sternotomy wound infection and the results of treatment by debridement and closure by muscle flaps.

BACKGROUND

Infection of the median sternotomy wound after open heart surgery is a devastating complication associated with significant mortality. Twenty years ago, these wounds were treated with either open packing or antibiotic irrigation, with a mortality approaching 50% in some series. In 1975, the authors began treating these wounds with radical sternal debridement followed by closure using muscle or omental flaps. The mortality of sternal wound infection has dropped to < 10%.

METHODS

The authors' total experience with 409 patients treated over 20 years is described in relation to flap choices, hospital days after sternal wound closure, and incidence rates of morbidity and mortality. One hundred eighty-six patients treated since January 1988 were studied to determine which patient variables had impact on rates of flap closure complications, recurrent sternal wound infection, or death. Variables included obesity, history of smoking, hypertension, diabetes, poststernotomy septicemia, internal mammary artery harvest, use of intra-aortic balloon pump, and perioperative myocardial infarction and were analyzed using chi square tests. Fisher's exact tests, and multivariable logistic regression analysis.

RESULTS

The mortality rate over 20 years was 8.1% (33/49). Additional procedures for recurrent sternal wound infection were necessary in 5.1% of patients. Thirty-one patients (7.6%) required treatment for hematoma, and 11 patients (2.7%) required hernia repair. Among patients treated since 1988, variables strongly associated with mortality were septicemia (p < 0.00001), perioperative myocardial infarction (p = 0.006), and intra-aortic balloon pump (p = 0.0168). Factors associated with wound closure complications were intra-aortic balloon pump (p = 0.0287), hypertension (p = 0.0335), and history of smoking (p = 0.0741). Factors associated with recurrent infection were history of sternotomy (p = 0.008) and patients treated for sternal wound infection from 1988 to 1992 (p = 0.024). Mean hospital stay after sternal wound reconstruction declined from 18.6 days (1988-1992) to 12.4 days (1993-1996) (p = 0.005). To clarify management decisions of these difficult cases, a classification of sternal wound infection is presented.

CONCLUSIONS

Using the principles of sternal wound debridement and early flap coverage, the authors have achieved a significant reduction in mortality after sternal wound infection and have reduced the mean hospital stay after sternal wound closure of these critically ill patients. Further reductions in mortality will depend on earlier detection of mediastinitis, before onset of septicemia, and ongoing improvements in the critical care of patients with multisystem organ failure.

Association of polymorphisms of dopamine D2 receptor (DRD2), and dopamine transporter (DAT1) genes with schizoid/avoidant behaviors (SAB)

The dopaminergic system, and in particular the dopamine D2 receptor, has been implicated in reward mechanisms in the brain. Dysfunction of the D2 dopamine receptors leads to aberrant substance-seeking behaviors (ethanol, drugs, tobacco, and food) and other related behaviors (pathological gambling, Tourette's disorder, attention-deficit/hyperactivity disorder). This is the first study supporting a strong association between the dopamine D2 receptor Taq A1 allele with schizoid/avoidant behavior (SAB). Additionally, an albeit weaker association between the 480-bp VNTR 10/10 allele of the dopamine transporter (DAT1) gene with SAB was similarly found.

Intergroup comparisons of oral lesions in HIV-positive South Africans

OBJECTIVE

To determine whether there are any differences in the oral manifestations of sub-groups of persons with HIV. These data could provide information for planning of oral health promotion and prevention programmes.

DESIGN

A comparative inter-group cross-sectional investigation of the oral manifestations of HIV. Ethnic, gender and sexual orientation differences were taken into consideration.

SETTING

Three large general hospitals that offer comprehensive medical investigations and care to persons with HIV.

SUBJECTS AND METHODS

A total of 485 HIV-positive adults participated. Clinical examination and, where necessary, swabs or smears of lesions for microbiology, biopsies for histology.

MAIN OUTCOME MEASURES

Presence of lesions, associated signs, incidence and type of micro-organisms.

RESULTS

A total of 485 HIV-positive persons were examined over a period of 3 years consisting of 225 Blacks, 191 Coloureds (persons of 'mixed' descent) and 69 Whites. Data were analysed using, where relevant, the chi 2 test or Fisher's exact test. Heterosexual males revealed a higher prevalence of all oral lesions combined when compared with heterosexual females. A similar finding was evident when HIV-associated periodontal diseases was compared in these two groups. Homosexual males had a higher prevalence of candidal infections than heterosexual males. Coloured heterosexuals had a higher prevalence of oral lesions combined than black heterosexuals. All these results showed statistical significance.

CONCLUSIONS

The study tends to show that different patterns of prevalence emerge when inter-group comparisons are made of oral soft tissue diseases evident in HIV-infected South Africans.

Analytical quality assurance for the WHO GEMS/Food-EURO programme--results of 1993/94 laboratory proficiency testing

As a means of assessing the performance of European laboratories who contribute analytical data on food contamination to the World Health Organization (WHO) Global Environmental Monitoring Scheme (GEMS), a series of five proficiency testing exercises were carried out during 1993 and 1994. In total 136 laboratories from 21 different countries took part in one or more of the exercises which covered the analysis of trace elements (lead, cadmium and mercury) in milk powder, pesticides (organochlorine, organophosphorus and pyrethroid) in spinach powder, nitrate in spinach powder, aflatoxins in nut-based animal feed and patulin in apple juices. The proficiency testing was carried out according to the ISO/IUPAC/AOAC INTERNATIONAL Harmonized Protocol and laboratories were awarded z-scores signifying their analytical capability based on their reported results for each of the respective exercises. Overall 60% of laboratories were satisfactory for accuracy for trace element analysis, 41% for pesticides, 43% for nitrate, 88% for aflatoxins and 53% for patulin. These results gave an overall poorer performance (68%) than the average for other similar schemes (79%), indicating the need for care in collating data for such programmes as GEMS and the need for remedial measures to assist in improving performance.