Does Age Influence Gastrointestinal Status Responses to Exertional-heat Stress?

This meta-data exploration aimed to determine the impact of exertional-heat stress (EHS) on gastrointestinal status of masters age and young adult endurance athletes. Sixteen MASTERS (mean: 44y) and twenty-one YOUNG (26y) recreational endurance athletes completed 2 h of running at 60% ˙V O2max in 35˚C ambient conditions. Blood samples were collected pre-, immediately and 1 h post-EHS, and analyzed for markers of exercise-induced gastrointestinal syndrome (EIGS). Thermo-physiological measures and gastrointestinal symptoms (GIS) were recorded every 10-20 min during EHS. Peak Δ pre- to post-EHS did not substantially differ (p>0.05) between MASTERS and YOUNG for intestinal epithelial injury [I-FABP: 1652pg/ml vs. 1524pg/ml, respectively], bacterial endotoxic translocation [sCD14: -0.09µg/mL vs. 0.84µg/mL, respectively], lipopolysaccharide-binding protein [LBP: 0.26µg/mL vs. 1.76µg/mL, respectively], and systemic inflammatory response profile (SIR-Profile: 92.0arb.unit vs. 154arb.unit, respectively). A significantly higher peak Δ pre- to post-EHS in endogenous endotoxin anti-body IgM (p=0.042), and pro-inflammatory cytokine IL-1β (p=0.038), was observed in YOUNG compared to MASTERS. No difference was observed between incidence (81% and 80%, respectively) and severity (summative accumulation: 21 and 30, respectively) of reported GIS during EHS between MASTERS and YOUNG. Pathophysiology of EIGS in response to EHS does not substantially differ with age progression, since masters and younger adult endurance athletes responded comparably.

Exertional Stress-induced Pathogenic Luminal Content Translocation - Friend or Foe?

The incidence of perturbed gastrointestinal integrity, as well as resulting systemic immune responses and gastrointestinal symptoms, otherwise known as exercised-induced gastrointestinal syndrome (EIGS), is common among individuals who partake in prolonged exercise. EIGS may cause the translocation of pathogenic material, including whole bacteria and bacterial endotoxins, from the lumen into circulation, which may progress into clinical consequences such as sepsis, and potentially subsequent fatality. However, further investigation is warranted to assess the possibility of food allergen and/or digestive enzyme luminal to circulatory translocation in response to exercise, and the clinical consequences. Findings from this narrative literature review demonstrate evidence that whole bacteria and bacterial endotoxins translocation from the gastrointestinal lumen to systemic circulation occurs in response to exercise stress, with a greater propensity of translocation occurring with accompanying heat exposure. It has also been demonstrated that food allergens can translocate from the lumen to systemic circulation in response to exercise stress and initiate anaphylaxis. To date, no research investigating the effect of exercise on the translocation of digestive enzymes from the lumen into systemic circulation exists. It is evident that EIGS and consequential pathogenic translocation presents life-threatening clinical implications, warranting the development and implementation of effective management strategies in at-risk populations.

The Impact of a 24-h Low and High Fermentable Oligo- Di- Mono-Saccharides and Polyol (FODMAP) Diet on Plasma Bacterial Profile in Response to Exertional-Heat Stress

Exertional-heat stress (EHS) compromises intestinal epithelial integrity, potentially leading to the translocation of pathogenic agents into circulation. This study aimed to explore the impact of EHS on the systemic circulatory bacterial profile and to determine the impact of a short-term low (LFOD) and high (HFOD) fermentable oligo- di- mono-saccharide and polyol dietary intervention before EHS on this profile. Using a double-blind randomized cross-over design, thirteen endurance runners (n = 8 males, n = 5 females), with a history of exercise-associated gastrointestinal symptoms (Ex-GIS), consumed a 24 h LFOD and HFOD before 2 h running at 60% V.O2max in 35.6 °C. Blood and fecal samples were collected pre-EHS to determine plasma microbial DNA concentration, and sample bacteria and short chain fatty acid (SCFA) profiles by fluorometer quantification, 16S rRNA amplicon gene sequencing, and gas chromatography, respectively. Blood samples were also collected post-EHS to determine changes in plasma bacteria. EHS increased plasma microbial DNA similarly in both FODMAP trials (0.019 ng·μL-1 to 0.082 ng·μL-1) (p < 0.01). Similar pre- to post-EHS increases in plasma Proteobacteria (+1.6%) and Firmicutes (+0.6%) phyla relative abundance were observed in both FODMAP trials. This included increases in several Proteobacteria genus (Delftia and Serratia) groups. LFOD presented higher fecal Firmicutes (74%) and lower Bacteroidota (10%) relative abundance pre-EHS, as a result of an increase in Ruminococcaceae and Lachnospiraceae family and respective genus groups, compared with HFOD (64% and 25%, respectively). Pre-EHS plasma total SCFA (p = 0.040) and acetate (p = 0.036) concentrations were higher for HFOD (188 and 178 μmol·L-1, respectively) vs. LFOD (163 and 153 μmol·L-1, respectively). Pre-EHS total fecal SCFA concentration (119 and 74 μmol·g-1; p < 0.001), including acetate (74 and 45 μmol·g-1; p = 0.001), butyrate (22 and 13 μmol·g-1; p = 0.002), and propionate (20 and 13 μmol·g-1; p = 0.011), were higher on HFOD vs LFOD, respectively. EHS causes the translocation of whole bacteria into systemic circulation and alterations to the plasma bacterial profile, but the FODMAP content of a 24 h diet beforehand does not alter this outcome.

Amino Acid-Based Beverage Interventions Ameliorate Exercise-Induced Gastrointestinal Syndrome in Response to Exertional-Heat Stress: The Heat Exertion Amino Acid Technology (HEAAT) Study

The study aimed to determine the effects of two differing amino acid beverage interventions on biomarkers of intestinal epithelial integrity and systemic inflammation in response to an exertional-heat stress challenge. One week after the initial assessment, participants (n = 20) were randomly allocated to complete two exertional-heat stress trials, with at least 1 week washout. Trials included a water control trial (CON), and one of two possible amino acid beverage intervention trials (VS001 or VS006). On VS001 (4.5 g/L) and VS006 (6.4 g/L), participants were asked to consume two 237-ml prefabricated doses daily for 7 days before the exertional-heat stress, and one 237-ml dose immediately before, and every 20 min during 2-hr running at 60% maximal oxygen uptake in 35 °C ambient conditions. A water volume equivalent was provided on CON. Whole blood samples were collected pre-, immediately post-, 1 and 2 hr postexercise, and analyzed for plasma concentrations of cortisol, intestinal fatty acid protein, soluble CD14, and immunoglobulin M (IgM) by ELISA, and systemic inflammatory cytokines by multiplex. Preexercise resting biomarker concentrations for all variables did not significantly differ between trials (p > .05). A lower response magnitude for intestinal fatty acid protein (mean [95% CI]: 249 [60, 437] pg/ml, 900 [464, 1,336] pg/ml), soluble CD14 (-93 [-458, 272] ng/ml, 12 [-174, 197] ng/ml), and IgM (-6.5 [-23.0, 9.9] MMU/ml, -10.4 [-16.2, 4.7] MMU/ml) were observed on VS001 and V006 compared with CON (p < .05), respectively. Systemic inflammatory response profile was lower on VS001, but not VS006, versus CON (p < .05). Total gastrointestinal symptoms did not significantly differ between trials. Amino acid beverages' consumption (i.e., 4.5-6.4 g/L), twice daily for 7 days, immediately before, and during exertional-heat stress ameliorated intestinal epithelial integrity and systemic inflammatory perturbations associated with exercising in the heat, but without exacerbating gastrointestinal symptoms.

The increase in core body temperature in response to exertional-heat stress can predict exercise-induced gastrointestinal syndrome

Utilizing metadata from existing exertional and exertional-heat stress studies, the study aimed to determine if the exercise-associated increase in core body temperature can predict the change in exercise-induced gastrointestinal syndrome (EIGS) biomarkers and exercise-associated gastrointestinal symptoms (Ex-GIS). Endurance-trained individuals completed 2 h of running exercise in temperate (21.2-30.0°C) to hot (35.0-37.2°C) ambient conditions (n = 132 trials). Blood samples were collected pre- and post-exercise to determine the change in gastrointestinal integrity biomarkers and systemic inflammatory cytokines. Physiological and thermoregulatory strain variables were assessed every 10-15 min during exercise. The strength of the linear relationship between maximal (M-Tre) and change (Δ Tre) in rectal temperature and EIGS variables was determined via Spearman's rank correlation coefficients. While the strength of prediction was determined via simple and multiple linear regression analyses dependent on screened EIGS and Ex-GIS confounding factors. Significant positive correlations between Tre maximum (M-Tre) and change (Δ Tre) with I-FABP (rs = 0.434, p < 0.001; and rs = 0.305, p < 0.001; respectively), sCD14 (rs = 0.358, p < 0.001; and rs = 0.362, p < 0.001), systemic inflammatory response profile (SIR-Profile) (p < 0.001), and total Ex-GIS (p < 0.05) were observed. M-Tre and Δ Tre significantly predicted (adjusted R2) magnitude of change in I-FABP (R2(2,123)=0.164, p < 0.001; and R2(2,119)=0.058, p = 0.011; respectively), sCD14 (R2(2,81)=0.249, p < 0.001; and R2(2,77)=0.214, p < 0.001), SIR-Profile (p < 0.001), and total Ex-GIS (p < 0.05). Strong to weak correlations were observed between M-Tre and Δ Tre with plasma concentrations of I-FABP, sCD14, SIR-Profile, and Ex-GIS in response to exercise. M-Tre and Δ Tre can predict the magnitude of these EIGS variables and Ex-GIS in response to exercise.

Relationship between natriuretic peptides and left atrial mechanics and their relation to recurrence of atrial fibrillation following catheter ablation

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): The Danish Heart Foundation (grant no.: 09-04-R72-A2408-22545, 10-04-R78-A2929-22588, 11-04-R84-A3230-22650, and 18-R125-A8534-22083), and the Heart Centre Research Committee at Rigshospitalet, Copenhagen.

Background

The relationship between natriuretic peptides and atrial distension is not completely understood. Furthermore, how they can be used together clinically has not been fully explored.

Purpose

We sought to examine their interrelationship and how they relate to atrial fibrillation (AF) recurrence following catheter ablation.

Methods

Patients scheduled for catheter ablation as part of a randomized controlled clinical trial were included. Patients who underwent pre-operative echocardiography and had natriuretic peptide measurements performed, specifically mid-regional proANP (MR-proANP) and N-terminal proBNP (NT-proBNP), were included in this analysis. Echocardiography included assessment of atrial distension by left atrial strain.

The outcome was AF recurrence at 6 months after a 3-month blanking period. Logistic regression was performed to assess the association between log-transformed natriuretic peptides and AF. Multivariable adjustments were made for age, gender, randomization, and LVEF.

Results

Out of 99 patients 44 developed AF. No differences in natriuretic peptides nor echocardiographic measures were observed between the outcome groups.

Neither MR-proANP nor NT-proBNP were univariable predictors of AF recurrence (MR-proANP: OR = 1.06 (0.99-1.14), p = 0.09, per 10% increase; NT-proBNP: OR = 1.01 (0.98-1.05), p = 0.38, per 10% increase). These findings were unchanged after multivariable adjustments. However, atrial strain significantly modified the association between MR-proANP and AF (p for interaction = 0.009) such that MR-proANP was a significant predictor of AF in patients with high atrial strain values (OR = 1.24 (1.06-1.46), p = 0.008, per 10% increase) but not in patients with low atrial strain values. Among patients with high atrial strain values, an MR-proANP &gt; 116pmol/L was associated with a 10-fold increased risk of AF (OR = 9.78 (2.21-43.33), p = 0.003). figure.

Conclusion

Atrial natriuretic peptide predicts AF recurrence in patients with preserved atrial distension. Assessing atrial distension by echocardiography may assist the clinical interpretation of atrial natriuretic peptide concentration.

Abstract Figure.

Association between natriuretic peptides and left atrial structural and functional properties in atrial fibrillation following catheter ablation

Background

Atrial natriuretic peptides (ANP) and brain natriuretic peptides (BNP) are acutely released from the atrial myocytes upon increased mechanical distension of the atria. The relationship between imaging measures of left atrial (LA) structure and function and natriuretic peptides following catheter ablation (CA) have not been clearly delineated.

Purpose

To characterize the relationship between LA structure and function and natriuretic peptides.

Methods

We performed an echocardiographic substudy of a randomized trial of AF patients scheduled for CA. Echocardiographic measurements included: LA volume at end-systole (LAVi), at end-diastole (LAEDVi), emptying fraction (LAEF), LA reservoir strain (LAs), and global longitudinal strain (GLS). Patients were stratified by tertiles of mid-regional proANP (MR-proANP) concentrations in circulation (&lt;92 pmol/l, 92–146 pmol/l, &gt;146 pmol/l), and NT-proBNP (&lt;10pmol/l, 10–38 pmol/l, &gt;38 pmol/l). Linear regressions were performed to compare baseline echocardiographic measures to natriuretic peptide concentrations at baseline, 1 month, 3 months and 6 months of follow-up. MR-proANP and NT-proBNP were logarithm transformed in these analyses. Multivariable adjustments were made for: age, gender, AF subtype, AF burden, rhythm during echocardiogram, rhythm at study visit for blood sampling, time known with AF, beta-blocker use, and CHA-2DS2-VASc score.

Results

We included 101 patients with AF. The mean age was 58 years, 82% were men, 46% had persistent AF. Increasing tertiles of MR-proANP at baseline were associated with abnormal LA size and function (3rd vs 1st tertile: LAVi: 42mL/m2 vs 32mL/m2; LAEDVi: 31mL/m2 vs 20mL/m2; LAEF: 38% vs 26%; LAs: 27% vs 19%; GLS: −18% vs −14%) whereas both LA and left ventricular measures were associated with increasing NT-proBNP concentrations at baseline. After multivariable adjustments, only LA volumes and LAEF remained significantly associated with MR-proANP, whereas only LA volumes and GLS remained significantly associated with NT-proBNP. At follow-up, impaired LA function associated with persistently elevated concentrations, which was not the case for LAVi (figure).

Conclusion

MR-proANP reflects LA dysfunction better than NT-proBNP. Measures of LA function rather than LAVi associates with persistently elevated natriuretic peptide concentrationsw, which may indicate that functional measures are more closely associated with evidence of LA myocardial stretch than LAVi.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The Danish Heart Foundation

Electroconvulsive stimulation reverses anhedonia and cognitive impairments in rats exposed to chronic mild stress

Electroconvulsive therapy remains the most effective treatment for depression including a fast onset of action. However, this therapeutic approach suffers from some potential drawbacks. In the acute phase this includes amnesia. Electroconvulsive stimulation (ECS) has previously been shown to reverse a depression-like state in the chronic mild stress model of depression (CMS), but the effect of ECS on cognition has not previously been investigated. In this study the CMS model was used to induce a depressive-like condition in rats. The study was designed to investigate the acute effect of ECS treatment on working memory and the chronic effect of repeated ECS treatments on depression-like behavior and working memory. The results indicated that, in the acute phase, ECS treatment induced a working memory deficit in healthy controls unexposed to stress, while repeated treatments reversed stress-induced decline in working memory, as well as recovering rats submitted to the CMS paradigm from the anhedonic-like state. Like in the clinical setting, a single ECS exposure was ineffective in inducing remission from a depression-like state.

No fallacies in the formulation of the paternity index

In a recent publication, Li and Chakravarti claim to have shown that the paternity index is not a likelihood ratio. They present a method of estimating the prior probability of paternity from a sample of previous court cases on the basis of exclusions and nonexclusions. They propose calculating the posterior probability on the basis of this estimated prior and the test result expressed as exclusion/nonexclusion. Their claim is wrong--the paternity index is a likelihood-ratio, that is, the ratio of the likelihood of the observation conditional on the two mutually exclusive hypotheses. Their proposed method of estimating the prior has been long known, has been applied to several samples, and is inferior (in terms of variance of the estimate) to maximum likelihood estimation based on all the phenotypic information available. Their proposed "new method" of calculating a posterior probability is based on the use of a less informative likelihood ratio 1/(1-PE) instead of Gürtler's fully informative paternity index X/Y (Acta Med Leg Soc Liege 9:83-93, 1956), but is otherwise identical to the Bayesian approach originally introduced by Essen-Möller in 1938.

Atopic dermatitis. A genetic-epidemiologic study in a population-based twin sample

Atopic dermatitis is a multifactorial disease that seems both to rise in frequency and to be dependent on a genetic predisposition. In order to clarify these issues we encircled a representative twin series with atopic dermatitis from a total twin population of 592 like-sexed twin pairs. We found that the cumulative incidence rate (0-7 years) of atopic dermatitis in Denmark has increased significantly from 0.03 for the birth cohort 1960-1964 to 0.10 for the birth cohort 1970-1974, that monozygotic twin pairs are more often concordant for atopic dermatitis than dizygotic twin pairs, that monozygotic twins run a risk of 0.86 of having atopic dermatitis if the twin partner has the disease, whereas the disease risk of 0.21 run by dizygotic partners does not differ from the frequency seen in ordinary brothers and sisters. The results indicate that genetic factors play a decisive role in the development of atopic dermatitis and that widespread environmental factors are operating in genetically susceptible individuals.

Familial cranial diabetes insipidus: a report of five families. Genetic, diagnostic and therapeutic aspects

Five families were studied in which cranial diabetes insipidus occurred. In the pedigrees presented, the disease clearly followed an autosomal dominant mode of inheritance. Linkage analysis was performed in one large family by calculating lod scores for linkage between loci for cranial diabetes insipidus and 18 polymorphic markers and chromosome heteromorphisms. No significant genetic linkage was found and only one of the polymorphic markers gave a positive hint of linkage. A water deprivation test was performed in nine patients from three of the families and in healthy control subjects. The plasma concentration of arginine vasopressin was very low or undetectable in the patients, and unlike the control subjects did not increase significantly during water deprivation. Arginine vasopressin and serum osmolality (Sosm) were significantly positively correlated in the controls, but not in the patients. The results indicated that an arginine vasopressin-level lower than 2 pg/ml strongly suggests a diagnosis of cranial diabetes insipidus if at the same time Sosm is higher than 295 mosmol/kg. Studies with different intranasal dosages of 1-deamino-D-arginine-vasopressin (DDAVP) given once or twice a day showed that 20 micrograms effectively reduced urinary output and that administration once a day could be sufficient.

Linkage and chromosome study of multiple endocrine neoplasia IIa

A linkage and chromosome investigation of a large family with multiple endocrine neoplasia (MEN) IIa (medullary thyroid carcinoma, pheochromocytoma, and occasionally hyperparathyroidism) was undertaken. No significantly positive lodscores were obtained between MEN IIa and 25 different genetic markers. Conventional metaphase chromosome analysis showed normal karyotypes and no heterochromatin markers linked to the MEN IIa locus were found. High-resolution chromosome analysis in five MEN IIa carriers revealed no deletion within band 20p12.2. The present investigation could thus neither demonstrate linkage of the MEN IIa locus to genetic or chromosome markers nor identify chromosome abnormalities in MEN IIa carriers.

Partial deletion of the short arm of chromosome 3

A case of deletion of the short arm of chromosome 3 (46,XY,del(3)(p253) is described. The patient is a youth of 18 years in an institution for the mentally retarded. Phenotypically, he presents congenital heart disease, hypertelorism, ptosis, epicanthus, blepharophimosis, strabismus, nystagmus, synophrys, low-set ears, frequent infections, epilepsy (abnormal EEG and grand mal seizures), "rocker bottom" feet, flat occiput and muscular hypotonia. The parents are healthy and with normal karyotypes. A silent allele in the GPT system was found in the mother, the propositus and 4 of the 5 siblings.

A study of the linkage relations of epidermolysis bullosa dystrophica

Two large families from the Faroe Islands presenting epidermolysis bullosa of the dystrophic type were subjected to extensive linkage analyses with 22 serological markers. No significant evidence in support of linkage with any of these loci was provided. It was found to be very unlikely that the gene or genes causing the present types of epidermolysis bullosa belong to the EBS1 locus known to be closely linked to the GPT locus.

Successful nonsibling bone marrow transplantation in severe combined immunodeficiency

Severe combined immunodeficiency (SCID) was diagnosed in a girl immediately after birth; her older brother had SCID and was successfully reconstituted by bone marrow transplantation from his uncle. She was isolated in a laminar air flow bench and decontaminated. The father differed by one HLA-A antigen but was HLA-Dw2 homozygous like the patient; his lymphocytes showed a slight response to the patient's cells in mixed lymphocyte culture (MLC). At the age of 2 1/2 months and again at 5 months, she was given a bone marrow transplant from the father. During the entire course the patient had no infections, and apart from a transient eosinophilia she had no signs of graft-versus-host reaction. Immunological reconstitution was nearly complete at 9 months of age, when she was recontaminated. One year later plasma immunoglobulin concentrations are in the low normal range (IgG and IgM) or decreased (IgA); tests of cell-mediated immunity are normal. Apart from slight upper respiratory infections, the patient has been healthy. Physical and psychological development have been normal.

Metacarpal morphometry in monozygotic dizygotic elderly twins

The relative importance of genetic factors in the pathogenesis of age related bone loss has been investigated in a study involving 17 monozygotic (MZ) and 8 dizygotic (DZ) pairs of twins aged 64 to 75 years. Radiographic morphometry was performed at the midpoints of the 2nd, 3rd and 4th metacarpals of both hands and the mean total and cortical widths were evaluated. The heritability, h2, was calculated as the difference between the intrapair variances in same sexed DZ and MZ pairs divided by the intrapair variance in DZ pairs. The mean intrapair variance of both total and cortical width was found to be four to five times higher in DZ than in MZ pairs. The differences are highly significant with an h2 value between 0.7 and 0.8, indicating a predominant genetic influence. It is stressed that this result applies only to the population from which the twin sample was drawn.

Fluorescent Y-chromosomes in hairs and blood stains

Y-chromosome detection by way of fluorescence microscopy in biological materials has made sex determination possible in various areas of investigation. The present report describes the results of sex determination on hairs and blood stains. Significant differences were found between the Y-body count for female and male materials. In blind trials it was demonstrated that a reliable sex determination of hairs was possible for at least 27 weeks and of blood stains on cotton cloth and glass for 6 weeks. There were no false positive findings, but there was one male with a "female" blood smear count, who revealed an abnormally small fluorescent region on his Y-chromosome. The existence of such variants calls for caution when evaluating a low count.

Possible localization of Gc-System on chromosome 4. Loss of long arm 4 material associated with father-child incompatibility within the Gc-System

A mentally retarded girl with a sporadically occurring B/F translocation was reexamined with new banding techniques. Chromosome material from the long arm of chromosome 4 was inserted into the long arm of chromosome 20. The segment 4q11 leads to q13 was lost. The formerly reported abnormal segregation of the Gc-system was verified. The localization of the Gc-locus on the lost segment cannot be ruled out.

Data on the HL-A linkage group

Lod scores from a study in 229 families of the linkage relations of HL-A-PGM3 to 19 marker loci and cystic fibrosis are reported. The data exclude that ADA belongs to this linkage group while they give weak support for the inclusion of P. There is weak evidence for linkage of cystic fibrosis to PGM3, but none for linkage to HL-A. No new suggestive linkages appeared.

Haptoglobin type Hp-Jo and hypohaptoglobinaemia in a Danish family. Preliminary report

The occurrence of the rare Hp 2-Jo type in a Danish family is reported. By subtyping procedure the 2alphaJ polypeptide chain was demonstrated for the first time in an HP 2-Jo sample. Apparently independent of the transmission of the HpJo gene hypohaptoglobinaemia was found in a rather high proportion of the members of the kindred.

Amylo-1,60glucosidase deficiency (glycogenosis type III) in the Faroe Islands

Seven cases of glycogenosis type III (amylo-1,6-glucosidase deficiency) in two probably related families from the Faroe Islands are presented. The group of patients comprised two pairs of sibs. In a total of 78 members of the two families case histories were obtained and clinical examinations, analyses of amylo-1,6-glycosidase activity in erythrocytes and leucocytes, determinations of red cell, serum and enzyme groups as well as HL-A types were performed. In addition, all patients were subjected to studies of liver function. The distribution patients in these families supports the assumption of autosomal recessive inheritance. Heterozygotes could not be diagnosed with certainty by the methods of enzyme activity analysis employed. The incidence of glycogenosis type III with amylo-1,6-glucosidase deficiency was found to be high in the Faroe Islands.

Sex-linked hereditary thrombocytopenia with immunological defects

14 cases of severe thrombocytopenia in one family are presented. Case histories, clinical examination, analyses of platelets, haemoglobin, reticulocytes, leucocytes, eosinophilocytes, differential counts of leucocytes, serum immunoglobulin IgA, IgM, IgG, IgE concentrations, complement fixing platelet antibodies, isohaemagglutinins, colour perception, determination of red cell and serum groups as well as HL-A types were obtained from a total of 59 members of the family. The in vitro blast transformation response of blood lymphocytes was studied in 6 patients and 45 relatives. The pattern of transmission of the disease was in full agreement with X-linked recessive inheritance. Investigation of the immune system revealed impaired responses to microbial antigens in the 6 patients so studied. All relatives examined had normal haematological status, whereas approximately half showed a subnormal response to one microbial extract. The low responders were evenly distributed within the family, and it was not possible to correlate low response and presumed carrier state.

A group-C ring chromosome in a mentally deficient male

Images