Deficiencies in education and experience in the management of acute kidney injury among Malawian healthcare workers.

BACKGROUND: Acute kidney injury (AKI) is a common but under-recognised disease process, which carries a high risk of mortality or chronic complications, such as chronic kidney disease and other organ dysfunction. Management of AKI, however, is suboptimal, both in developed settings and in Malawi. This is partly because of deficiencies in AKI education and training. AIM: To establish current levels of AKI education in a range of healthcare workers in Malawi. METHODS: An AKI symposium was held in Blantyre in March 2015. Delegates were asked to complete a survey at the start of the symposium to assess their clinical experience and education in the management of AKI. RESULTS: From 100 delegates, 89 nurses, clinical officers, and physicians, originating from 11 different districts, responded to the survey. Twenty-two percent of healthcare workers (including 28% of district workers of the various cadres and 31% of nurses) had never received teaching on any aspect of renal disease, and 50% (including 63% of district workers and 61% of nurses) had never received teaching specifically on AKI. Forty-four percent did not feel confident managing AKI, and 98% wanted more support managing patients with renal disease. Thirty-four percent (including 55% of district workers) were unaware that haemodialysis was available at Queen Elizabeth Central Hospital (QECH) for the treatment of AKI and 53% (74% of district workers) were unaware that peritoneal dialysis was available for the treatment of AKI in children. Only 33% had ever referred a patient with AKI to QECH. CONCLUSIONS: There are deficiencies in education about, and clinical experience in, the management of AKI among Malawian healthcare workers, in addition to limited awareness of the renal service available at QECH. Urgent action is required to address these issues in order to prevent morbidity and mortality from AKI in Malawi.

Applying research in nutrition education planning: a dietary intervention for Bangladeshi chronic kidney disease patients.

BACKGROUND: Effective nutrition health interventions are theory-based, as well as being drawn from practice and research, aiming to successfully accomplish dietary behavioural changes. However, the integration of theory, research and practice to develop community dietary educational programmes is a challenge that many interventionists feel ill equipped to achieve. METHODS: In the present study, a community-based education programme was designed for Bangladeshi patients with chronic kidney disease and hypertension. The goal of this programme was to reduce dietary salt intake in this population group, with a view to reducing their blood pressure and slowing kidney disease progression. RESULTS: The present study sets out the first four steps of a six-step model for creating a behaviour change programme. CONCLUSIONS: These four steps were concerned with the translation of theory and evidence into intervention objectives, and illustrate how a practical, community-based intervention was developed from behavioural theory, relevant research, knowledge of practice and the target patient group. Steps 5 and 6, which are concerned with implementation and evaluation, will be reported separately.

Barriers and facilitators of dietary sodium restriction amongst Bangladeshi chronic kidney disease patients.

BACKGROUND: People of Bangladeshi origin have the highest mortality ratio from coronary heart disease of any minority ethnic group in UK and their rate of kidney disease is three- to five-fold higher than that of the European UK population. However, there is little information regarding their dietary customs or knowledge, beliefs and attitudes towards health and nutrition. This multi-method qualitative study aimed to identify: (i) barriers and facilitators to dietary sodium restriction; (ii) traditional and current diet in the UK; and (iii) beliefs and attitudes towards development of hypertension, and the role of sodium. METHODS: Methods included focus group discussions, vignettes and food diaries. Twenty female chronic kidney disease patients attended four focus group discussions and maintained food diaries; ten responded to vignettes during telephone interviews. Triangulation of the results obtained from the three methods identified categories and themes from qualitative thematic analysis. RESULTS: Identified barriers to sodium restriction were deeply-rooted dietary beliefs, attitudes and a culturally-established taste for salt. Facilitators of change included acceptable strategies for cooking with less salt without affecting palatability. Dietary practices were culturally determined but modified by participants' prosperity in the UK relative to their previous impoverished agrarian lifestyles in Bangladesh. CONCLUSIONS: Cultural background and orientation were strong determinants of the group's dietary practices and influenced their reception and response to health communication messages. Efforts to understand their cultural mores, interpret and convey health-promotion messages in culturally-appropriate ways met with a positive response.

Belatacept as maintenance immunosuppression for postrenal transplant de novo drug-induced thrombotic microangiopathy.

De novo posttransplant thrombotic microangiopathy (TMA) is a complication of solid organ transplantation, which remains difficult to treat. In many cases, immunosuppressants and particularly calcineurin inhibitors, trigger TMA. Although withdrawing the offending drug may lead to resolution of TMA, graft and patient outcomes are poor. Specific treatments, including plasma exchange, have not gained widespread acceptance in those with fulminant disease and new approaches to the condition are urgently needed. We report a case of posttransplant de novo TMA presenting serially in association with ciclosporin, tacrolimus and sirolimus in a young recipient of a living donor kidney transplant. We describe a patient treated with belatacept, a novel CTLA4 Ig fusion protein, as ongoing maintenance immunosuppression to allow avoidance of conventional agents once associated with TMA. We report excellent early graft outcome, with no adverse events using this strategy. We suggest that belatacept may have a role in this traditionally difficult-to-treat group of patients.

Detection of bloodstream pathogens in a bacille Calmette-Guérin (BCG)-vaccinated pediatric population in Malawi: a pilot study.

Children in Malawi receive bacille Calmette-Guérin (BCG) vaccination within the first 3 days of life. Thus, we hypothesized that Malawian children infected with the human immunodeficiency type 1 virus (HIV-1) might be particularly vulnerable to dissemination of the BCG Mycobacterium bovis strain with which they were vaccinated. Following informed consent by parents, we studied children admitted to a Malawi general hospital during the 1998 wet and dry seasons. Blood from cohorts of acutely ill children was cultured for bacteria, including mycobacteria, and fungi, and tested for anti-HIV-1 antibodies. It was shown that non-typhi Salmonella and Escherichia coli were the predominant bloodstream pathogens during the wet and dry seasons, and that bloodstream dissemination of the BCG M. bovis strain is uncommon in HIV-1-infected children who receive the BCG vaccine.

Age-related differences in cell-specific cytokine production by acutely ill Malawian patients.

Age-related changes in human cell-specific cytokine responses to acute illness have not been well examined. We therefore evaluated age-related differences in T, B and natural killer (NK) peripheral blood lymphocyte cytokine responses of 309 acutely ill hospitalized people in Malawi, Africa, < 1 month-61 years of age. We used four-colour flow cytometry and performed Wilcoxon rank sum and Kruskal-Wallis tests, Pearson (rp) and Spearman (rs) correlations, and linear and logistic regression analyses to control for human immunodeficiency virus infection (HIV) status, the percentages of lymphocytes expressing CD4, and the nature of the acute infection. The percentages of CD8- and CD8+ T cells producing induced IL-8 decreased with age (rs = -0.44 and -0.53). The percentages of T cells producing TNF-alpha were higher, and the percentages producing IL-10 were lower, in those > or =13 than those < 13 years old (medians: 17.7 versus 10.5 and 1.4 versus 3.0, respectively). The percentages of CD8- T cells producing IFN-gamma were higher and stable in those > or =1 year old compared to infants (medians: 23.5 versus 10.4); the percentages of NK producing IFN-gamma were higher post-infancy and then declined to relatively low levels with increasing age. The percentages of T cells producing IL-2 were highest in those 5- <31 years old (median 5.6) and lowest in those > or =31 years old (median 1.9). The ratios of the percentages of T cells producing IL-4 to those producing IL-8 and to those producing IL-10 both increased with age. These data suggest that innate immunity, represented by NK IFN-gamma production, dominates in early life. A number of shifts occur after infancy and before adolescence, including a proinflammatory shift from IL-8 to TNF-gamma and a type 2 shift from IL-10 to IL-4 dominance. These findings suggest distinct age-related differences in the human response to acute illness and may be useful in directing future efforts at immunomodulatory therapies.

The effects of iron deficiency on lymphocyte cytokine production and activation: preservation of hepatic iron but not at all cost.

Worldwide, over 40% of children have iron deficiency anaemia, frequently associated with infections. Certain cytokines are involved in both immune activation/response to infection and iron transport/metabolism. We therefore assessed the relations among iron deficiency, cytokine production and lymphocyte activation markers in 142 hospitalized Malawian children. We examined peripheral blood lymphocyte antigens/cytokine production using four- colour flow cytometry and serum transferrin receptor (TfR) levels, an inverse measure of iron status unaffected by acute illness or infection, with an enzyme-linked immunosorbent assay. Wilcoxon rank sum tests and logistic regression analyses (LRA) were performed. Iron deficiency (TfR > or = 10 microg/ml) versus TfR < 10 microg/ml, was associated with higher percentages of lymphocytes producing: (a) induced or spontaneous IL-6 (medians: induced, 15.9% for iron-deficient children versus 8.8% for iron-replete children, P = 0.002; spontaneous, 24.4% versus 13.0%, P < 0.001) and (b) induced IFN-gamma (medians:18.4% versus 12.4%, P = 0.006). The percentages of CD8(+) T cells spontaneously producing IL-6 and of all lymphocytes producing induced TNF-alpha and IFN-gamma in the same cell had the strongest relationships to iron deficiency (b = + 0.0211, P = 0.005 and b = + 0.1158, P = 0.012, respectively, LRA) and were also positively related to the co-expression of the T cell activation markers HLA DR and CD38. Severe iron deficiency (TfR > or = 30 microg/ml) was associated with the percentage of lymphocytes producing induced IL-4 (medians: 0.5% versus 1.6%, P < 0.010). The cytokine patterns associated with iron deficiency in our study would preserve iron stores but also preferentially retain the activation capabilities of T cells, albeit not necessarily other immune cells, until a critical level of iron depletion is reached.

Comparison of serum and cell-specific cytokines in humans.

Cytokines function at the cellular, microenvironmental level, but human cytokine assessment is most commonly done at the macro level, by measuring serum cytokines. The relationships between serum and cellular cytokines, if there are any, are undefined. In a study of hospitalized patients in Malawi, we compared cytometrically assessed, cell-specific cytokine data to serum interleukin 2 (IL-2), IL-4, IL-6, IL-8, IL-10, gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha) levels in 16 children and 71 (IL-2, -4, -6, -10) or 159 (IL-8, IFN-gamma, and TNF-alpha) adults, using Wilcoxon rank sum tests and Pearson's (r(p)) and Spearman's (r(s)) rank correlations. For the entire study group, correlations between identical serum and cellular cytokines mainly involved IL-8 and IFN-gamma, were few, and were weakly positive (r < 0.40). Blood culture-positive persons had the most and strongest correlations, including those between serum IL-2 levels and the percentages of lymphocytes spontaneously making IL-2 (r(s) = +0.74), serum IL-8 levels and the percentages of lymphocytes spontaneously making IL-8 (r(p) = +0.66), and serum IL-10 levels and the percentages of CD8(+) T cells making TNF-alpha (r(p) = +0.89). Human immunodeficiency virus (HIV)-positive persons had the next largest number of correlations, including several serum IL-8 level correlations, correlation of serum IL-10 levels with the percentages of lymphocytes producing induced IL-10 (r(s) = +0.36), and correlation of serum IFN-gamma levels and the percentages of lymphocytes spontaneously making both IL-6 and IFN-gamma in the same cell (r(p) = +0.59). HIV-negative, malaria smear-positive, and pediatric patients had few significant correlations; for the second and third of these subgroups, serum IL-8 level was correlated with the percentage of CD8(-) T cells producing induced IL-8 (r(s) = +0.40 and r(s) = +0.56, respectively). Thus, the strength of associations between serum and cellular cytokines varied with the presence or absence of bloodstream infection, HIV status, and perhaps other factors we did not assess. These results strongly suggest that serum cytokines at best only weakly reflect peripheral blood cell cytokine production and balances.

Cytokines and malaria parasitemia.

The balance between pro- and antiinflammatory cytokines may be important in malaria presentation and outcome. Malaria tends to be more severe in children than in adults, presumably because partial immunity develops with age. However, the full nature of, and age-related differences in, anti-malarial immunity are unknown. We compared: (1) serum and cell-specific cytokines of patients with acute malaria to those of patients with other acute illnesses and to those of healthy adults and (2) the cytokine responses of parasitemic children and parasitemic adults. Flow cytometry was done on the peripheral blood mononuclear cells of 148 hospitalized children, 161 febrile hospitalized adults, and 20 healthy adults in Malawi, Africa, a malaria-endemic country. Serum cytokines were also assessed for 80 of these patients. Thirty-eight participants were parasitemic with Plasmodium falciparum. Serum interleukin (IL)-10 (an antiinflammatory, immunoregulatory, and type 2 cytokine) levels were higher in malaria patients than in other patients (medians 502 pg/mL vs 16 pg/mL, P = 0.002), and the percentages of various lymphocyte populations making IL-6 (a proinflammatory, type 2 cytokine regulating iron distribution) were lower in malaria patients than in other patients (e.g., for spontaneous production by children's CD8(+) T cells: medians 1.4% vs 33.1%, P = 0.004). For adult patients, the percentages of lymphocytes spontaneously making IL-4 (a type 2 cytokine) were significantly lower in those with malaria than in those without malaria (medians 0.9% vs 2.1%, P = 0.005). The percentages of monocytes spontaneously making IL-8 (a chemotactic, proinflammatory chemokine) were higher in parasitemic children than in parasitemic adults (medians 5.8% vs 1.7%, P = 0.003). A number of cellular proinflammatory, type 1 parameters were significantly higher in all children (with or without malaria) than in all adults; these included the percentages of various lymphocyte populations making IL-6, both IL-6 and interferon-gamma, or IL-8. These data support the importance of IL-10 in malaria parasitemia. Given the lack of an IL-4 (type 2) response, IL-10's primary role may be immunoregulatory rather than type 2 in nature. In this study, the immune response to malaria was more proinflammatory in children than in adults. This difference, if corroborated by other studies, could be related to malaria's greater severity in children.

Seasonal variation in the etiology of bloodstream infections in a febrile inpatient population in a developing country.

OBJECTIVES: Published data suggest that Streptococcus pneumoniae, non-typhi Salmonella species, and Mycobacterium tuberculosis are the predominant causes of bloodstream infection (BSI) in hospitalized populations in sub-Saharan Africa. This study was conducted during the wet season to ascertain the etiology and prevalence of BSI among febrile inpatients in a hospital where the dry season BSI profile in a similar study population had already been documented. METHODS: In the period from March to May 1998, consecutive febrile (> or = 37.5 degrees C) adult (> or = 14 y) patients presenting to a Malawi hospital were enrolled after providing informed consent. Following clinical evaluation, blood was drawn for culture (bacteria, mycobacteria, and fungi), human immunodeficiency virus (HIV) testing, and malaria smears. RESULTS: Of 238 enrolled patients, 173 (73%) were HIV-positive and 67 (28%) had BSI. The predominant wet season BSI pathogens were non-typhi Salmonella species (41%), M. tuberculosis (19%), and Cryptococcus neoformans (9%) (cf. the predominant dry season pathogen was S. pneumoniae). Mycobacteremia was more likely in HIV-positive than in HIV-negative patients (13/173 vs. 0/65; P < 0.05). A logistic regression model yielded clinical predictors of BSI that included chronic fever, oral candidiasis, or acute diarrhea. CONCLUSION: Pathogens causing BSI in febrile inpatients in a Malawi teaching hospital vary by season. Season- and country-specific studies, such as this one, provide data that may facilitate empirical therapy of febrile illnesses whose etiologies vary by season.

Utility of paired BACTEC MYCO/F LYTIC blood culture vials for detection of bacteremia, mycobacteremia, and fungemia.

In previous bloodstream infection studies in Malawi, we inoculated blood from a single venesection into a single BACTEC MYCO/F LYTIC (MFL) vial. Inoculation of one vial, however, would be expected to reduce the sensitivity of bloodstream pathogen detection with MFL vials. To ascertain the degree of this loss of sensitivity, blood was drawn from each of 228 febrile, adult inpatients in Malawi and 5 ml of each blood sample was inoculated into each of two MFL vials. Of 228 paired vials, 51 (22%) were both positive, 172 (75%) were both negative, and 5 (3%) had discordant results. Bloodstream infection would have been detected in 11 (92%) of 12 patients with mycobacteremia and 38 (92%) of 41 patients with bacteremia had only one MFL vial been inoculated. Our study shows that a second MFL vial does not significantly increase diagnostic sensitivity.

Comparison of BACTEC MYCO/F LYTIC and WAMPOLE ISOLATOR 10 (lysis-centrifugation) systems for detection of bacteremia, mycobacteremia, and fungemia in a developing country.

In less-developed countries, studies of bloodstream infections (BSI) have been hindered because of the difficulty and costs of culturing blood for bacteria, mycobacteria, and fungi. During two study periods (study period I [1997] and study period II [1998]), we cultured blood from patients in Malawi by using the BACTEC MYCO/F LYTIC (MFL), ISOLATOR 10 (Isolator), Septi-Chek AFB (SC-AFB), and Septi-Chek bacterial (SC-B) systems. During study period I, blood was inoculated at 5 ml into an MFL bottle, 10 ml into an Isolator tube for lysis and centrifugation, and 10 ml into an SC-B bottle. Next, 0.5-ml aliquots of Isolator concentrate were inoculated into an SC-AFB bottle and onto Middlebrook 7H11 agar slants, chocolate agar slants, and Inhibitory Mold Agar (IMA) slants. During study period II, the SC-B and chocolate agar cultures were discontinued. MFL growth was detected by fluorescence caused by shining UV light (lambda = 365 nm) onto the indicator on the bottom of the bottle. During study period I, 251 blood cultures yielded 44 bacterial isolates. For bacteremia, the MFL was similar to the Isolator concentrate on chocolate agar (34 of 44 versus 27 of 44; P, not significant [NS]), but more sensitive than the SC-B bottle (34 of 44 versus 24 of 44; P = 0.05). For both study periods combined, 486 blood cultures yielded 37 mycobacterial and 13 fungal isolates. For mycobacteremia, the sensitivities of the MFL and Isolator concentrate in the SC-AFB bottle were similar (30 of 37 versus 29 of 37; P, NS); the MFL bottle was more sensitive than the concentrate on Middlebrook agar (30 of 37 versus 15 of 37; P = 0.002). For fungemia, the MFL bottle was as sensitive as the SC-B bottle or Isolator concentrate on chocolate agar or IMA slants. We conclude that the MFL bottle, inoculated with just 5 ml of blood and examined under UV light, provides a sensitive and uncomplicated method for comprehensive detection of BSI in less-developed countries.

Natural T, gammadelta, and NK cells in mycobacterial, Salmonella, and human immunodeficiency virus infections.

NK cells, gammadelta T cell antigen receptor chain-positive cells, and CD3(+)CD16/56(+) (natural T [NT]) cells are involved in innate immunity and immunoregulation; however, their role in clinical infection is not well defined. Cytofluorometric analysis was used to examine peripheral blood from bacteremic, nonbacteremic, and healthy human immunodeficiency virus (HIV)-positive and -negative persons in Malawi, Africa. Mycobacteremia was associated with a higher proportion of CD3(+)CD8(-) gammadelta cells (median, 16.6% vs. 0.7% for all other cells; P<.001), and Salmonella bacteremia was associated with a higher proportion of NT cells (4.3% vs. 2.2%; P=. 002). HIV plasma RNA levels were weakly positively correlated with NT cells (rs=.39; P=.002), NK cells (rs=.38; P=.003), and gammadelta cells (rs=.43; P<.001). Compared with patients who survived, patients who died had a higher percentage of NT cells (3.7% vs. 1. 9%; P=.017) and a higher percentage of NT cells that spontaneously produced interferon-gamma (2.4% vs. 1.2%; P=.035). The data support the clinical relevance of gammadelta and NT cells in mycobacterial, Salmonella, and HIV infections and of NT cells in mortality.

A hospital-based prevalence survey of bloodstream infections in febrile patients in Malawi: implications for diagnosis and therapy.

The etiology of bloodstream infections (BSIs) in febrile (> or =37.5 degrees C) adults (> or =18 years old) in one Malawi hospital were determined during August and September 1997. After clinical evaluation, blood was drawn for comprehensive culture, human immunodeficiency virus (HIV) type 1 testing, and malaria smear. Of 233 patients, 173 (74%) were HIV-1 infected, and 70 (30%) had BSI. BSI pathogens included 25 (33%) Streptococcus pneumoniae and 21 (28%) Mycobacterium tuberculosis. Nine patients (4%) had malaria parasitemia. BSIs were more likely in HIV-1-positive than in -negative patients (62/173 vs. 8/60, P<.01). Clinical predictors of BSI included HIV-1 infection and altered mental status. Mortality among inpatients with BSI was higher than among those without BSI (P<.001). In conclusion, S. pneumoniae and M. tuberculosis are frequent causes of BSI in febrile adults. Similar surveys, performed periodically in developing countries, may assist in the identification of clinical predictors of BSI and in planning appropriate therapy.

Unrecognised Mycobacterium tuberculosis bacteraemia among hospital inpatients in less developed countries.

BACKGROUND: Nosocomial transmission of Mycobacterium tuberculosis is a global public-health concern. Although early clinical recognition of M. tuberculosis in hospital inpatients is critical for effective infection control, such recognition may be difficult in patients with HIV infection. To find out whether M. tuberculosis bacteraemia frequently goes unrecognised, we did a prospective blood-culture survey in an infectious-diseases hospital in Thailand and a general hospital in Malawi. METHODS: Consecutive febrile (> or = 37.5 degrees C axillary or > or = 38.0 degrees C orally) hospital inpatients (aged > or = 18 years) were enrolled; blood was obtained for mycobacterial culture and HIV testing. Simple diagnostic tests, such as chest radiographs and sputum smears, were ordered by clinicians as deemed necessary, and were carried out with existing local resources. FINDINGS: Of 344 patients enrolled, 255 (74%) were HIV infected, the median age was 33 years (range 18-87), and 208 (61%) were male. 34 (10%) patients had M. tuberculosis bacteraemia; five of these patients were already on antituberculosis therapy. Only HIV-infected patients had M. tuberculosis bacteraemia. Of the 29 patients with M. tuberculosis bacteraemia who were not already receiving antituberculosis therapy, 13 (45%) had an abnormal chest radiograph or a positive sputum smear. 16 (55%) patients had no additional diagnostic test results to indicate M. tuberculosis infection; 18 (81%) of these had a cough. INTERPRETATION: In less developed countries where both M. tuberculosis and HIV infections are prevalent, M. tuberculosis bacteraemia may frequently go unrecognised among febrile hospital inpatients.

PIP: A blood-culture survey was conducted in Thailand and Malawi to measure the prevalence of Mycobacterium tuberculosis bacteremia among adult inpatients. A total of 344 febrile patients, aged 18 years or older, were recruited. Blood samples were taken for mycobacterial culture and HIV testing. Simple diagnostic tests, such as chest radiographs and sputum smears, were also carried out. Findings revealed that 255 (74%) patients were infected with HIV, and 34 (10%) patients had M. tuberculosis bacteremia. All patients who had M. tuberculosis bacteria were HIV-infected. Out of the 29 patients with M. tuberculosis bacteria who were not receiving antituberculosis therapy, 13 (45%) had an abnormal chest radiograph or a positive sputum smear; 16 (55%) patients did not manifest M. tuberculosis infection in their test results and were defined to have an unrecognized active disease. Moreover, oral thrush, chronic cough, fever or weight loss remained significantly associated with tuberculosis bacteremia. The findings suggest that tuberculosis-control efforts should also include the improvement of availability and use of chest radiographs and sputum smears to diagnose active disease, especially in developing countries where it is most needed.

Pregnancy-related factors and diseases influencing surfactant.

Obstetric complications have been associated with accelerated fetal lung maturity. In a prospective study involving 189 babies born before 36 weeks no specific obstetric complication was observed to have a significant influence on neonatal respiratory function. In addition fetal stress factors did not seem to contribute to eventual outcome.

Phosphatidylglycerol and neonatal mortality and morbidity.

In spite of major improvements in neonatal intensive care, mortality and morbidity remain a problem for the very preterm baby. In a study of 168 babies born before 36 weeks the presence of phosphatidylglycerol (PG) as a marker of fetal lung maturity in amniotic fluid or pharyngeal aspirate was associated with a lower requirement for ventilatory support and a reduced incidence of intraventricular haemorrhage and patent ductus arteriosus. It is suggested that the value of the antenatal assessment of fetal lung maturity should Perhaps be reviewed since babies in whom PG is absent appear to be at a high risk of sustaining considerable morbidity.

Amniotic fluid phospholipid profile in multiple pregnancy and the effect of zygosity.

Because respiratory distress syndrome (RDS) may occur in one twin but not the other it may be misleading to assess fetal lung maturity using amniotic fluid from only one sac. We compared the amniotic fluid lecithin/sphingomyelin (L/S), phosphatidyl glycerol/sphingomyelin (PG/S) and phosphatidyl inositol/sphingomyelin (PI/S) ratios between co-twins and co-triplets in 32 sets of twins and three set of triplets. In the twin pregnancies we found a weak correlation for L/S ratio but a much improved one for PG/S and PI/S. The concordance between sacs for all three ratios was better in monozygotic than in dizygotic twins. The efficacy of amniotic fluid PG in the determination of fetal lung maturity was demonstrated and the discrepancies between the sacs was much less for PG than for the L/S ratios. Employing the L/S ratio combined with the presence or absence of PG should reduce false results to a minimum.

Presence and activity of LH-RH in the mid-term human fetus.

Immunoreactive LH-RH was present in all the hypothalamic and cortical extracts of mid-term human fetuses studied and in the cortical tissue removed from the two youngest fetuses. Gonadotrophin-releasing activity of hypothalamic and cortical extracts was demonstrated by the significant rises of circulating LH after infusion into oestrogen and progesterone-primed ovariectomized rats.

Radioimmunoassay and chromatographic similarity of circulating endogenous gonadotropin releasing hormone and hypothalamic extracts in man.

A highly sensitive radioimmunoassay for the gonadotropin releasing hormone has been developed in order to study its physiological importance in man. In view of the expected low concentrations in peripheral blood, large volumes of human plasma were extracted by two different methods and characteristics of the radioimmunoassayable material compared with those of synthetic decapeptide and extracts of human hypothalami. The results indicate that radioimmunoassayable gonadotropin releasing hormone is present in some human plasmas but the plasma concentration are less than 2.5 pg/ml. Peripheral levels were more consistently measurable in women at midcycle and after the menopause. The hormone was undetectable in the plasma of normel men, human cerebrospinal fluid, and fetal cerebral tissue, but was present in fetal hypothalami.