Defective antigen processing associated with familial disseminated mycobacteriosis

To gain insights into a possible immune defect predisposing to disseminated mycobacteria infection, we studied three of six surviving children with disseminated Mycobacterium avium complex infection, who had no recognized form of immunodeficiency. We used mycobacteria isolated from the patients and diphtheria, tetanus and pertussis vaccine (DTP) to study antigen-specific T lymphocyte responses. We observed that interferon-gamma (IFN-gamma) production by T cells in response to antigens (both mycobacteria and DTP) in these patients with disseminated infection was greatly impaired. This defect did not seem to be the result of T cell unresponsiveness, as phytohaemagglutinin (PHA) stimulation was able to induce high levels of IFN-gamma comparable to those seen in control patients with localized infection. Further experiments showed that peripheral blood mononuclear cells (PBMC) from patients with disseminated infection were able to present influenza haemagglutinin (HA) peptides to specific T cell clones. However, this ability was lost when the whole HA protein was used as source of antigen. Taken together, these observations support the notion that the primary immune defect in these patients with disseminated mycobacterial infection rests in the antigen-processing functions of their antigen-presenting cells (APC). These findings may provide clues to the wider problem of susceptibility to mycobacteria and other intracellular pathogens and have implications in designing therapy for these patients.

Differential susceptibility of human CNS-derived cell populations to TNF-dependent and independent immune-mediated injury

We examined whether oligodendrocytes, neurons, and astroglia derived from the human central nervous system differ in susceptibility to injury mediated by tumor necrosis factor (TNF)-alpha and by activated CD4+ T cells acting via a TNF-independent mechanism. Injury was assessed either as cell membrane-directed (lysis), measured by 51chromium (Cr) or lactate dehydrogenase (LDH) release, or nucleus-directed (apoptosis), measured by morphologic features based on propidium iodide (PI) staining and by DNA fragmentation measured by a terminal transferase (TdT)-mediated dUTP biotin nick end labeling technique (TUNEL). TNF did not induce 51Cr or LDH release in any cell targets, but did induce nuclear (66 +/- 2% of cells) and DNA (68 +/- 2% of cells) fragmentation selectively in the oligodendrocytes over 96 hr. At this time, there was no significant loss of oligodendrocyte cell number. Nuclear injury could be induced in neurons by serum deprivation and in malignant astrocytes by the combination of TNF and low serum. CD4+ T cells activated with phytohemagglutin (pha) or anti-CD3 plus interleukin-2 induced significant 51Cr and LDH release in all target cells tested; only pha-activated CD4+ T-cell cocultures showed reduced target cell numbers. Significant nuclear fragmentation was observed only for glioma cells (22 +/- 1% of cells). Differences in susceptibility to different immune effector mechanisms and in the nature of the injury response to the same effector mediator among human CNS-derived neural cells will need to be considered in design of therapeutic strategies aimed at protecting or limiting target cell injury consequent to disease or trauma.

Effect of tumor necrosis factor alpha and beta on human oligodendrocytes and neurons in culture

Cytokines produced by infiltrating hematogenous cells or by glial cells activated during the course of central nervous system disease or trauma are implicated as mediators of tissue injury. In this study, we have assessed the extent and mechanism of injury of human-derived CNS oligodendrocytes and neurons in vitro mediated by the cytokines tumor necrosis factor alpha and beta and compared these with the tumor necrosis factor independent effects mediated by activated CD4+ T-cells. We found that activated CD4+ T-cells, but not tumor necrosis factor alpha or beta, could induce significant release of lactate dehydrogenase, a measure of cell membrane lysis, from oligodendrocytes within 24 hr. Neither induced DNA fragmentation as measured using a fluorescence nick-end labelling technique. After a more prolonged time period (96 hr), tumor necrosis factor alpha did induce nuclear fragmentation changes in a significant proportion of oligodendrocytes without increased lactate dehydrogenase release. The extent of DNA fragmentation was comparable to that induced by serum deprivation. Tumor necrosis factor beta effects were even more pronounced. In contrast to oligodendrocytes, the extent of DNA fragmentation, assessed by propidium iodide staining, induced in neurons by tumor necrosis factor alpha was less than that induced by serum deprivation. In-situ hybridization studies of human adult glial cells in culture indicated that astrocytes, as well as microglia, can express tumor necrosis factor alpha mRNA.

Severe asthenozoospermia: a structural and functional study

Ejaculates from 25 patients with severe asthenozoospermia (all spermatozoa immotile or only non-progressively motile) were studied to identify individually the cause of impaired motility. Multiple tests were performed, viz. light and electron microscopic studies and sperm function tests. An objective scoring was applied to both the routine and the functional analyses. Three categories of samples were identified: (1) necrozoospermia (n = 9), where sperm viability was very poor; (2) structural tail abnormality as seen by light microscopy (n = 4); and (3) ultrastructural abnormality (n = 12). In the last category, one case showed absence of dynein arms; this was associated with mitochondrial abnormalities. Mitochondrial abnormality with normal tail components was observed in the majority (n = 7) and accessory fibre abnormality in four cases. The scoring system revealed that, functionally, all samples were abnormal whereas routine analysis showed 15 samples to be subnormal and 10 to be abnormal, which indicates the need for functional analysis. Because of the multiple defects seen in these samples, there is a need for a battery of sperm function tests. This study indicates that mitochondrial defects are one of the causes that may account for the loss of sperm motility in the patient population.

Effects of antisense c-myb oligonucleotides on vascular smooth muscle cell proliferation and response to vessel wall injury

The process of restenosis after arterial balloon dilatation has been demonstrated to involve smooth muscle cell hyperplasia. Initial reports with antisense oligonucleotides directed against the proto-oncogene c-myb suggest marked in vitro specificity and in vivo efficacy. In the present study, we sought to confirm and extend the hypothesis that antisense to c-myb results in a specific antiproliferative effect with a comprehensive assessment by using different oligonucleotide preparations, different species, and tissue and cellular uptake experiments. Phosphorothioate-protected oligonucleotides representing the appropriate sequence for antisense to c-myb and multiple controls were used to inhibit proliferation of platelet-derived growth factor- and fetal bovine serum-stimulated rat, dog, and human aortic smooth muscle cells in vitro and neointimal proliferation in the rat carotid injury model. In vitro experiments using identical culture conditions in rat, dog, and human aortic smooth muscle cells failed to show specificity as well as consistency in growth inhibitory effects that could be attributed to an antisense mechanism. Proliferation of smooth muscle cell growth in culture was consistently inhibited with oligomers containing a contiguous 4-guanosine residue motif. In vivo, the rat carotid injury neointimal hyperplasia was similar for antisense c-myb (0.095 +/- 0.009 mm2) and sense c-myb (0.090 +/- 0.009 mm2). Fluorescent-labeled oligonucleotides were present in tissue after local delivery via pluronic gel, and their activity rapidly declined over a 72-hour period. Our findings point to the potential nonspecificity and lack of consistency of the antisense oligonucleotide to c-myb in vitro and in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Phenotypic and cell cycle properties of human oligodendrocytes in vitro

The remyelination, albeit limited, which occurs at the lesion sites in the central nervous in multiple sclerosis has been attributed to both myelin production by previously myelinating cells and to precursor cells which mature into myelin-producing cells. Oligodendrocyte (OL) number may be increased at the periphery of the lesions. In this study, we assessed the state of maturation and cell cycle-dependent properties of OLs derived from surgically resected adult human cerebral cortex specimens. In 6-day-old OL cultures, a small proportion of cells (14.1 +/- 3.5%: range 4-24%) expressed an immature phenotype, defined as A007+:myelin basic protein (MBP)-negative. Using lack of statin expression as an index of cells exiting the G0 phase of the cell cycle, we observed that 4.6 +/- 1.6% of A007+ cells, but only rare MBP+ cells (0.4 +/- 1.8%) were non-reactive with the anti-statin antibody, S44. The proportion of non-statin-reactive cells was not affected by treatment with basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) or insulin-like growth factor (IGF). The oligodendrocytes did not incorporate BrdU during a 48-h pulse and did not immunoreact with Ki-67 antibody. In 4-week-old cultures, we found that all A007+ cells were also MBP+ and that 99.5 +/- 0.7% were statin-positive. Exposing 4-week-old OLs to conditions of serum deprivation or to 1,000 units/ml of recombinant human TNF-beta for 4 days induced nuclear fragmentation in a high proportion (> 70%) of cells, as measured by a TUNEL technique; in these cultures, a similarly high proportion of cells were non-immunoreactive with anti-statin antibody. Our results suggest that a small number of phenotypic 'pre-oligodendrocytes' can be derived from the adult human CNS and that a proportion of these cells have exited the G0 phase of the cell cycle. Attempt at cell cycling, however, could reflect abortive mitosis and activation of programmed cell death.

Familial disseminated atypical mycobacterial infection in childhood: a human mycobacterial susceptibility gene?

Inherited defects in specific components of the immune system have provided many clues to the immunological mechanisms underlying resistance to microbial infection. We report a familial immune defect predisposing to disseminated atypical mycobacterial infection in childhood. 6 children with disseminated atypical mycobacterial infection and no recognised form of immunodeficency were identified. Four, including two brothers, come from a village in Malta, and two are brothers of Greek Cypriot origin. They presented with fever, weight loss, lymphadenopathy, and hepatosplenomegaly. They had anaemia and an acute phase response. A range of different mycobacteria (Mycobacterium fortuitum, M chelonei, and four strains of M avium intracellulare complex) were isolated. Treatment with multiple antibiotics failed to eradicate the infection, although treatment with gamma interferon was associated with improvement. Three have died and the surviving children have chronic infection. Tumour necrosis factor-alpha production in response to endotoxin and gamma-interferon was found to be defective in affected patients and their parents. T-cell proliferative responses to mycobacterial and recall antigens were reduced in parents of affected children and gamma-interferon production was diminished in the affected patients and their parents. Clinical and immunological features suggest that these patients are phenotypically similar to Lsh/Ity/Bcg susceptible mice. Understanding of this defect may provide insights into the mechanisms responsible for susceptibility to mycobacteria.

Antigen-dependent in vitro culture of protective T cells from BCG-primed mice

Induction of protective immunity against pathogenic mycobacteria depends on vaccination with live organisms such as Bacille Calmette-Guérin (BCG). However, it is not known how many and which antigens are involved in the protective host response. In this study, we developed a system of antigen-dependent in vitro culture which is suitable for the analysis of protective subunits, presented in a soluble form. Spleen cells from Mycobacterium bovis BCG-immune mice, enriched for T cells and depleted of adherent cells on a column of G-10 Sephadex, were cultured for periods varying between 3 and 14 days before transfer and challenge with M. tuberculosis in irradiated hosts. Following 10 days in culture, immune T cells sustained their capacity to transfer protection to tuberculous infection when incubated in the presence of either live BCG or a soluble extract from M. tuberculosis, but lost this ability when cultured in the absence of antigen, or in the presence of the polyclonal mitogen concanavalin A. One immunodominant antigen, represented by the recombinant 38-kD antigen, failed to sustain the adoptive protection, despite pronounced stimulation of lymphoproliferation in culture. Antigenic in vitro stimulation of protective T cells was accompanied by enhanced responsiveness to exogenous IL-2. The experimental system described may be generally suitable to test in vitro the protective potentials of soluble molecular subunits of mycobacteria.

The development of ultradian and circadian rhythms in premature babies maintained in constant conditions

Twenty very premature babies, born at 24-29 weeks gestation, have been studied while they were maintained in intensive care with continuous intravenous feeding and constant ambient lighting and temperature. Hourly records of insulated skin temperature and heart rate were made for a continuous period of 6-17 weeks, always starting the recording within 24 h of birth. The development of rhythms within the ultradian, circadian and infradian domains was sought by methods including maximum entropy spectral analysis and autocorrelation. Circadian and ultradian rhythms were present, but not regularly so; rather they appeared and disappeared erratically in successive weeks. As a consequence, the group as a whole did not show an increasing rhythmicity with chronological age. In some cases, babies were later placed in a ward in which the lighting was dimmed at night, and feeding by mouth at regular intervals was instituted. There was some evidence for increases in circadian and ultradian rhythmicity after these changes. These results enable inferences to be drawn as to the origin of fetal rhythms in the third trimester of pregnancy, as well as speculation to be made on the ontogeny of ultradian and circadian rhythms in the neonate.

Analysis of gene-dosage effects on the expression of CD18 by trisomy 21 lymphoblastoid cell-lines using a statistical model to fit flow cytometry profiles

It is not clear whether Down syndrome, the phenotypic expression of constitutional trisomy for chromosome 21 (T21), is the result of generalised disruption of homeostasis resulting from genetic imbalance, or the over-expression of specific genes on chromosome 21. In order to understand the effect of gene dosage more clearly, we have analysed the predicted and actual levels of expression of the leucocyte integrin beta subunit CD 18 on the surface of T21 leucocytes. Previous studies showed that CD18 expression by T21 lymphoid cell lines (LCL) is greater than on normal LCL. We have now developed a computer model that compares the observed and predicted CD18 flow cytometric profiles for trisomy 21 LCL. Three parameters (alpha, beta and gamma) have been defined that measure different aspects of gene dosage. Using the computer model to calculate these parameters, we have carried out a series of paired comparisons between normal and T21 LCL. The results show that, in some T21 LCL, increased CD18 expression is proportional to the existing gene dosage, in another set the effect is additive, whereas in others there is a combination of proportional and additive effects. The results suggest that gene regulation can exert pleiotropic effects on gene-dosage, and is consistent with a model in which gene dosage itself is the cause of disrupted homeostasis.

Birth intervals and childhood mortality in rural Bangladesh

This study investigates the relationship between birth intervals and childhood mortality, using longitudinal data from rural Bangladesh known to be of exceptional accuracy and completeness. Results demonstrate significant but very distinctive effects of the previous and subsequent birth intervals on mortality, with the former concentrated in the neonatal period and the latter during early childhood. The impact of short birth intervals on mortality, however, is substantially less than that found in many previous studies of this issue, particularly for the previous birth interval. The findings are discussed in terms of the potential for family planning programs to contribute to improved child survival in settings such as Bangladesh.

Sequential flow cytometric analysis of cell-cycle related changes in LFA-1 (CD18/CD11a) expression by trisomy 21 (Down's syndrome) lymphoblastoid cells

Lymphocyte function associated antigen 1 (LFA-1) is a heterodimeric leucocyte adhesion molecule comprising non-covalently associated 95 kD, CD18 and 180 kD, CD11a subunits. Lymphoblastoid cell-lines (LCL) derived from persons with Down's syndrome (Trisomy 21) exhibit increased expression of LFA-1 compared with normal LCL. Although this is probably due to a gene-dosage related increase in the synthesis of CD18, cell-cycle differences between Trisomy 21 (T21) and normal LCL could also influence LFA-1 expression. We have therefore analysed expression of CD18 on G1 and G2M cells using sequential flow cytometry. T21 and normal LCL were co-stained with the DNA-binding vital dye HO342 (Hoechst 33342), and with a CD18 monoclonal antibody. The LCL were first sorted on the basis of HO342 staining into G1 and G2M populations, and these fractions then analysed for CD18 expression. Irrespective of the stage of the cell-cycle, expression of CD18 was increased on T21 compared with normal LCL. Although more CD18 was detected on both T21 and normal G2M compared with G1 cells, the relative density of CD18 in G2M was less than in G1 because G2M cells were larger.

Measles case fatality among the under-fives: a multivariate analysis of risk factors in a rural area of Bangladesh

This study investigated the relationship of measles case fatality among the under-fives with age, case type, complications, sex, mother's education, and household economic condition in a rural area of Bangladesh. A total of 3465 measles cases were detected during 1980 and 61 of them died of measles associated complications within 45 days of rash onset. Case type, sex, mother's education and household economic condition were found to have statistically significant impact on case fatality. Risk of death among the secondary cases was 1.87 times higher than in the primary cases, girls had 2.73 times higher risk of death than boys. Children of mothers without any formal schooling and those from the poorest households experienced 1.83 and 2.18 times higher risk of death than their counterparts whose mothers had at least one year of schooling and from economically better off households respectively.

Human recombinant transforming growth factor alpha stimulates bone resorption and inhibits formation in vitro

Human recombinant transforming growth factor alpha (TGF alpha), which binds to the epidermal growth factor (EGF) receptor and causes several biological effects similar to those caused by EGF, was compared with murine EGF for its effects on a number of parameters of bone cell metabolism. TGF alpha stimulated bone resorption in two organ culture systems, the fetal rat long bone and neonatal mouse calvarial systems. TGF alpha stimulated bone resorption at concentrations as low as 0.1 ng/ml. TGF alpha effects on bone resorption in mouse calvariae were inhibited by indomethacin, suggesting that, like EGF, its effects were mediated by prostaglandin synthesis. TGF alpha had a different time course of action on bone resorption from that of EGF, causing more rapid release of previously incorporated 45Ca from bone cultures, suggesting that TGF alpha does not function on bone as a simple EGF analogue. TGF alpha also caused effects on osteoblast function resembling those of EGF. It inhibited alkaline phosphatase activity in cultured rat osteosarcoma cells with the osteoblast phenotype and inhibited collagen synthesis in fetal rat calvaria at concentrations of 1.0 ng/ml. The lowest concentration of TGF alpha (expressed as nanogram equivalents of EGF per ml) required to produce a response in all of the systems tested was about 1/10th of that needed for EGF to produce a similar effect. These results indicate that TGF alpha is a potent stimulator of bone resorption and inhibitor of bone formation as assessed by inhibition of collagen synthesis and alkaline phosphatase activity and are consistent with the hypothesis that TGF alpha may be responsible, at least in part, for the bone resorption associated with some tumors.

Sex differences in childhood mortality in rural Bangladesh

The issue of higher female than male mortality during childhood in developing countries has recently generated considerable interest. This paper presents additional evidence on this subject, based upon an analysis of longitudinal data from children in rural Bangladesh. Initially, the basis for higher female than male mortality in patriarchal societies is explored, and more specifically, the rationale for the differential valuation of male and female offspring. The pattern, timing and magnitude of sex differentials in mortality during infancy and early childhood is subsequently examined for children in our study. The paper concludes with a review of possible behavioral mechanisms which may contribute to higher female than male mortality during childhood.

Autoradiographic characterization of beta adrenergic receptors in coronary blood vessels and myocytes in normal and ischemic myocardium of the canine heart

This light microscopic autoradiographic study was performed to test the hypotheses that (a) the density of beta adrenergic receptors (BAR) may differ in various components of the heart and (b) BAR in certain components of the heart may exhibit a selective response to pharmacologic and pathological stimuli. Blocks of canine left ventricle were frozen and tissue sections cut and incubated in (-)[3H]dihydroalprenolol (DHA) to label the BAR. For total and nonspecific binding, serial sections were incubated with and without 10(-5) M (+/-)propranolol. Scintillation spectrometry of sections demonstrated rapid binding, saturability, stereospecificity, a dissociation constant (KD) of 3.2 +/- 0.5 nM (SD) (n = 3), and a maximal binding of 31.3 +/- 3.1 fmol/mg of tissue protein. Isoproterenol was 12.5 times more effective than norepinephrine in displacing DHA. Sections incubated with 10(-5) - 10(-8) M metoprolol, a beta one selective antagonist, demonstrated a KD of 0.7 X 10(-6) M. For autoradiography, emulsion-coated coverslips were attached to the slides. After exposure, the slides were developed and stained, and grain density quantified. Specific BAR binding (n = 4 dogs) was 1,047 +/- 131 (SEM) grains/10(-2) mm2 for myocardial arterioles, 219 +/- 30 for myocardial arteries, 31 +/- 12 for the proximal left anterior descending coronary artery (LAD), and 231 +/- 34 for cardiac myocytes. Specific binding in the presence of 10(-5) M metoprolol was reduced approximately 75% for both arterioles and myocytes. However, at 10(-6) M metoprolol, the percent reduction in specific DHA binding was greater for myocytes (50%) than for arterioles (0%), and at 10(-7) M metoprolol, the percent reduction in specific DHA binding was 17% for myocytes with no reduction over arterioles. After 1 h of LAD occlusion, a selective increase (18%) in BAR density occurred over cardiac myocytes, but not over blood vessels in the ischemic myocardium. Thus, (a) specific BAR binding was five times greater in arterioles than in small arteries and myocardium and 34 times greater than in the proximal LAD; (b) BAR of myocytes were more sensitive than those of arterioles to displacement by the beta one selective antagonist, metoprolol; and (c) a selective increase in BAR occurs in cardiac myocytes but not in blood vessels after 1 h of ischemia in this experimental model.

Affinity chromatography in the separation of human alpha 1-antitrypsin (alpha 1-AT) and antithrombin-III (AT-III)

The two antiproteases alpha 1-antitrypsin (alpha 1-AT) and antithrombin-III (AT-III) have been purified simultaneously from human plasma. Purification procedure consisted of gel filtration on Sephadex G-200 after initial processing of plasma, followed by ion exchange chromatography on DEAE-Sephadex A50 and DEAE-Cellulose, at a pH of 9.0 and pH 8.3 respectively. The two proteins could not be separated by any of these procedures including a lower pH (7.4) in ion exchange chromatography. Affinity chromatography on heparin-Sepharose separated the proteins since alpha 1-AT did not bind to the matrix. Alpha 1-AT unbound to the heparin-Sepharose was subsequently purified through con A-Sepharose affinity column. The final yield of both the proteins was about 20%. The molecular weight estimated on SDS electrophoresis for AT-III and alpha 1-AT was 63,000 and 50,000, respectively.

Some aspects of the occurrence of new mutations in haemophilia

Using the data available on a group of carriers of haemophilia, the mutation rate in the male germ line was compared with that of the female germ line. The mutation rate among the male germ line was about 1-2 times that in the female germ line. An assessment of grandparental ages as a factor in the production of new mutations of haemophilia was also investigated.

Effect of phospholipases on factor-VIII activity

The effect of the enzymes phospholipases C and D on Factor VIII were investigated. Phospholipase D was found to activate the partially purified intact Factor-VIII molecule maximally at a final concentration of 0.6 U/ml. Neither the dissociated small molecular weight component nor the high molecular weight component were activated. Phospholipase C, on the other hand, inactivated both the intact and the dissociated Factor-VIII molecule. Phospholipase D, however, had no effect on the haemophilic cryoprecipitate or the partially purified haemophilic Factor VIII. The implications of these results for the genetic control of the Factor-VIII molecule are discussed. In this connection, haemophilia A is hypothesized to be caused by an X-linked enzyme effect that impairs phospholipid assembly of the Factor-VIII protein, whereas von Willebrand's disease might be due to a structural defect of the Factor-VIII protein.

Studies on the altered electrophoretic type of the factor VIII related antigen

A distinct sub-group of von Willebrand's disease is characterized by an electrophoretically faster mobility of the factor VIII related antigen. Some of the physico-chemical properties of this variant antigen were investigated in this communication. The effect of temperature was tested by heating aliquots (0.5 ml) for 20 minutes at 45 degrees C, 56 degrees C and 65 degrees C. The variant was found to be denatured at 56 degrees C while the control was denatured at 65 degrees C. The effect of pH was tested by assessing the quantity (Laurell technique) and electrophoretic mobility (two dimensional immunoelectrophoresis) of the antigen in a variety of buffers ranging in pH from 7.0 to 9.5. The quantity of antigen was variable both among variants and controls and the electrophoretic mobility of the variant antigen was faster at all pH's. Molecular weight differences between the variant and controls were not detected since the chromatographic profile of the variant was similar to that of the controls in Sepharose 6 B using a 0.02 M Tris-NaCL buffer at pH 7.0. The affinity of the antigen for human antibody was heterogeneous although the variant exhibited less affinity for one of the human antibodies but not the other. The inhibitory effect was more pronounced in serum than in plasma. Purified IGG, however, did not show any inhibition, as the residual antigen assayed by the Laurell technique, was similar to the expected values. This would imply that non-IgG plasmatic factors could also play a part in the observed inhibition.

Family studies of patients with reduced ristocetin aggregation and abnormalities of factor VIII and/or platelet function

Factor VIII procoagulant activity (VIIIc), antigen (vWa), mobility of the antigen on two dimensional immunoelectrophoresis and platelet function were studied in 9 families with reduced ristocetin induced platelet aggregation rate (RIPA) and/or deficiency of plasma factor(s) required for ristocetin aggregation of washed normal platelets (vWf). the families could be subdivided into 4 groups. Group I showed dominant inheritance and reduced levels of VIIIc and vWa characteristic of typical von Willebrand's disease. All patients had reduced vWf and in 7 of 10 RIPA was reduced. Group II showed normal levels of VIIIc but reduced vWa. All showed reduced vWf but RIPA was reduced in one patient only. There was a good correlation between vWf and vWa and VIIIc in both groups. The bleeding time correlated with vWf in group I but not group II. Group III showed normal or nearly normal VIIIc and vWa but there was an increased mobility of vWa compared to normals and to groups I and II. RIPA was markedly reduced as was the vWf in one patient. Group IV is represented by one child with a strong family history of bleeding, who had reduced RIPA and defective platelet release reaction. The vWf in this child was normal and the ratio between VIIIc and vWa was similar to that seen in carriers of haemophilia. This spectrum of abnormalities of ristocetin aggregation justifies the use of the term 'von Willebrand's syndrome'.

Cholera transmission near a cholera hospital

A review of the incidence of cholera from 1964 through 1974 in Matlab, Bangladesh, revealed that among the villages several had very high incidence-rates. Investigation indicated that high cholera-rates in two of these villages were probably related to water contamination from a nearby cholera hospital established in 1963. The data imply that heavy contamination can overcome any immunity resulting from repeated exposure.

Failure of sanitary wells to protect against cholera and other diarrhoeas in Bangladesh

Within an area of Bangladesh in which the incidence of cholera was high, use of sanitary pipe wells did not protect against cholera or related non-cholera diarrhoeas because well users also used contaminated water sources regularly enough to maintain high infection-rates. Protection was found to correlate with education and wealth.

Assessment of the value of factor VIII procoagulant and antigen ratio in the diagnosis of carriers of haemophilia

The detection rate of carriers of haemophilia was evaluated using the ratio of factor VIII procoagulant activity (VIIIc) to factor VIII antigen (VIIIag). In normals the corelation coefficient of VIIIc to VIIIag was 0.82. In 15 obligatory carriers of haemophilia whose VIIIc and VIIIag levels were studied in the authors' labotatory there was no correlation between VIIIc and VIIIag and the ratio of VIIIc to VIIIag was below the lowest normal value in 12 (80%). In all five obligatory carriers whose VIIIc levels were estimated in the referring institution and VIIIag levels in the authors' laborary the ratio was below the lowest normal value. In 17 sisters of haemophiliacs studied here or referred for estimation of VIIIag only, an abnormal ratio was found in seven. Of 25 mothers of haemophilic children without a family history of haemophilia carriers is close to that expected on theoretical grounds but the interpretation of the results is complicated by the small numbers of patients all of whose studies were performed entirely in the authors' laboratory. In two normal individuals, one of who was on a contraceptive pill, there were no fluctuations of the ratio of VIIIc to VIIIag during the menstrual cycle. In one obligatory carrier with a normal ratio there was also no fluctuation. It is concluded here that a measurement of the ratio of VIIIc to VIIIag is a valuable adjuvant in genetic counselling in haemophilia.

Platelet release abnormality associated with a variant of von Willebrand's disease

A family with a platelet release abnormality (PRA) is described. The only son also showed a reduced rate of platelet aggregation in response to ristocetin, markedly reduced levels of von Willebrand's factor (vWf, ristocetin cofactor), and increased mobility of factor VIII-like antigen, features which were suggestive of von Willebrand's disease (vWd). No inhibition of vWf was found in his plasma. Family studies showed no evidence of vWd in the mother. The father's investigations showed a low rate of ristocetin aggregation on one of the two occasions when it was tested and low vWf on two of four occasions. Despite repeated testing, the findings in the father did not conclusively rule out the possibility of mild vWd, and it was impossible to determine whether the vWd in the son was inherited or arose as a mutation. The findings in this family suggest a possible relationship between abnormalities of the factor VIII complex and defective platelet function.

Ristocetin in the diagnosis of von willebrand's disease: a comparison of rate and percent of aggregation with levels of the plasma factor(s) necessary for ristocetin aggregation

Percent aggregation and the aggregation rate of platelet rich plasma (PRP) in response to ristocetin (1.75 mg/ml) were measured in 20 normals and 16 patients with von Willebrand's disease (v Wd), with and without the addition of acetylsalicylic acid (ASA). Percent aggregation did not clearly distinguish between normals and patients with vWd. Aggregation rate was normal in only 2 of 16 patients, and after incubation of PRP with ASA 1 of these 2 remained normal. The corrective effect of dilutions of platelet poor plasma (PPP) on the ristocetin response of washed platelets (von Willebrand's factor, vWf) was measured in 21 normals and 12 patients with vWd. All patients with vWd had abnormal levels. There was a significant correlation between aggregation rate and vWf in patients with vWd but not in normals. Both tests appear to measure closely related defects, and the aggregation rate is as specific as the vWf level for the diagnosis of clinically affected patients.