A Mycobacterium tuberculosis fingerprint in human breath allows tuberculosis detection

An estimated one-third of tuberculosis (TB) cases go undiagnosed or unreported. Sputum samples, widely used for TB diagnosis, are inefficient at detecting infection in children and paucibacillary patients. Indeed, developing point-of-care biomarker-based diagnostics that are not sputum-based is a major priority for the WHO. Here, in a proof-of-concept study, we tested whether pulmonary TB can be detected by analyzing patient exhaled breath condensate (EBC) samples. We find that the presence of Mycobacterium tuberculosis (Mtb)-specific lipids, lipoarabinomannan lipoglycan, and proteins in EBCs can efficiently differentiate baseline TB patients from controls. We used EBCs to track the longitudinal effects of antibiotic treatment in pediatric TB patients. In addition, Mtb lipoarabinomannan and lipids were structurally distinct in EBCs compared to ex vivo cultured bacteria, revealing specific metabolic and biochemical states of Mtb in the human lung. This provides essential information for the rational development or improvement of diagnostic antibodies, vaccines and therapeutic drugs. Our data collectively indicate that EBC analysis can potentially facilitate clinical diagnosis of TB across patient populations and monitor treatment efficacy. This affordable, rapid and non-invasive approach seems superior to sputum assays and has the potential to be implemented at point-of-care.

Bioinspired Threonine-Based Polymers with Potent Ice Recrystallization Inhibition Activity

Ice growth mitigation is a pervasive challenge for multiple industries. In nature, ice-binding proteins (IBPs) demonstrate potent ice growth prevention through ice recrystallization inhibition (IRI). However, IBPs are expensive, difficult to produce in large quantities, and exhibit minimal resilience to nonphysiological environmental stressors, such as pH. For these reasons, researchers have turned to bioinspired polymeric materials that mimic IBP behavior. To date, however, no synthetic polymer has rivaled the ability of native IBPs to display IRI activity at ultralow nanomolar concentrations. In this work, we study the IRI activity of peptides and polypeptides inspired by common ice-binding residues of IBPs to inform the synthesis and characterization of a potent bioinspired polymer that mimics IBP behavior. We show first that the threonine polypeptide (pThr) displays the best IRI activity in phosphate-buffered saline (PBS). Second, we use pThr as a molecular model to synthesize and test a bioinspired polymer, poly(2-hydroxypropyl methacrylamide) (pHPMA). We show that pHPMA exhibits potent IRI activity in neutral PBS at ultralow concentrations (0.01 mg/mL). pHPMA demonstrates potent IRI activity at low molecular weights (2.3 kDa), with improved activity at higher molecular weights (32.8 kDa). These results substantiate that pHPMA is a robust molecule that mitigates ice crystal growth at concentrations similar to native IBPs.

Borderline, where are you? A psychometric approach to the personality domains in the International Classification of Diseases, 11th Revision (ICD-11)

The inclusion of the borderline pattern in the International Classification of Diseases, 11th Revision (ICD-11) dimensional classification of personality disorders (PDs) has caused controversy. Unease about leaving out these clinically challenging patients seems to conflict with the need of an evidence-based and credible diagnostic system. However, the accommodation of borderline within the new diagnostic system has not yet been studied in depth. To this end, we examine in a sample of 1799 general population and clinical subjects the joint structure of the five initial ICD-11 domains and the borderline pattern. Regression and item-level factor analyses reveal that borderline criteria do not form a separate construct and are indissociable from negative affectivity. Furthermore, borderline adds nothing to the remaining domains when it comes to predict PD severity. The borderline pattern appears as largely superfluous and even misguiding, unless their criteria are properly integrated within the structure of personality pathology. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Decision-Making and the Alternative Five Factor Personality Model: Exploring the Role of Personality Traits, Age, Sex and Social Position

This study explores the relationship between decision-making style, as measured by the Melbourne Decision Making Questionnaire, and personality based on alternative five-factor model along with effect of age, sex and social position on such styles. A large sample of community and undergraduate students (n = 1,562; M_age = 40.03, SD = 18.43) was analyzed. The results showed that Neuroticism and Extraversion were significantly related to the non-vigilant styles Hypervigilance, Buck-passing and Procrastination. Women scored significantly lower in Vigilance and higher in Hypervigilance, Buck-passing and Procrastinations than men. Age was significantly related to decision-making style in a U-shaped fashion. The Social Position Index was significantly related to all decision-making styles. The most predictive personality domains regarding decision-making scales were Aggressiveness (negatively) and Activity for Vigilance, and Neuroticism for Hypervigilance, Buck-passing and Procrastination. Age, sex and social position had a small/medium overall effect on the four dimensions of Melbourne Decision Making Questionnaire (p < 0.001) with a η² of 0.038, 0.068, 0.050, and 0.031 for Vigilance, Hypervigilance, Buck-passing and Procrastination, respectively. Based on scores on a single factor dimension of the MDMQ, the profile of participants with higher scores was characterized by lower age, more likely to be females, lower social position, higher levels of Aggressiveness, less Activity, less Extraversion, and higher Neuroticism.

Silk physico-chemical variability and mechanical robustness facilitates intercontinental invasibility of a spider

There are substantive problems associated with invasive species, including threats to endemic organisms and biodiversity. Understanding the mechanisms driving invasions is thus critical. Variable extended phenotypes may enable animals to invade into novel environments. We explored here the proposition that silk variability is a facilitator of invasive success for the highly invasive Australian house spider, Badumna longinqua. We compared the physico-chemical and mechanical properties and underlying gene expressions of its major ampullate (MA) silk between a native Sydney population and an invasive counterpart from Montevideo, Uruguay. We found that while differential gene expressions might explain the differences in silk amino acid compositions and protein nanostructures, we did not find any significant differences in silk mechanical properties across the populations. Our results accordingly suggest that B. longinqua’s silk remains functionally robust despite underlying physico-chemical and genetic variability as the spider expands its range across continents. They also imply that a combination of silk physico-chemical plasticity combined with mechanical robustness might contribute more broadly to spider invasibilities.

Differential role of CD28 and CD27 in human CD4 T cells primary and secondary responses to bacterial antigens

Although CD28 is considered the main T cell costimulatory molecule, CD27 has also costimulatory activity; nevertheless, it is not well established whether they play overlapping or complementary roles during CD4 T cell activation. Both molecules are co-expressed on a large percentage of CD4 T cells, mainly in naive and central memory T cells; but their ligands, CD80/CD86 and CD70 respectively, are differentially expressed on antigen presenting cells.

To further differentiate the costimulatory role of CD28 and CD27 in the human CD4 T cell responses, circulating T cells from healthy donors were stimulated with Mycobacterium tuberculosis Purified Protein Derivative (PPD) under conditions of selective blockade of CD80 and CD86 or CD70 binding. The costimulatory activities of CD28 and CD27 in CD4 T cells memory responses were compared by stimulating PBMC, from tuberculin positive (TST+) donors, with PPD in the presence of either anti-CD80 plus anti-CD86 or anti-CD70 and then measuring CD4 T cells proliferation, IFN-gamma production and CD30 expression by flow cytometry. Treatment with anti-CD80 plus anti-86 inhibited all CD4+ T cell responses, but anti-CD70 had no effect. To study their role in the CD4+ T cell primary responses, myeloid dendritic cells, from TST negative donors, were pulsed with PPD and cocultured with autologous T cells under the blockade conditions described above. Anti-CD80 plus anti-CD86 as well as anti-CD70 inhibited CD4+ T cell proliferation and CD30 expression. These results support that CD28-CD80/CD86 signals are needed for both primary and memory CD4 T cell responses, whereas CD27-CD70 signals are required mainly for the primary anti-PPD responses. (Supported by Colciencias, Colombia, contract 0275-2014).

Ancestral association between HLA and HFE H63D and C282Y gene mutations from northwest Colombia

A significant association between HFE gene mutations and the HLA-A*03-B*07 and HLA-A*29-B*44 haplotypes has been reported in the Spanish population. It has been proposed that these mutations are probably connected with Celtic and North African ancestry, respectively. We aimed to find the possible ancestral association between HLA alleles and haplotypes associated with the HFE gene (C282Y and H63D) mutations in 214 subjects from Antioquia, Colombia. These were 18 individuals with presumed hereditary hemochromatosis (“HH”) and 196 controls. The HLA-B*07 allele was in linkage disequilibrium (LD) with C282Y, while HLA-A*23, A*29, HLA-B*44, and B*49 were in LD with H63D. Altogether, our results show that, although the H63D mutation is more common in the Antioquia population, it is not associated with any particular HLA haplotype, whereas the C282Y mutation is associated with HLA-A*03-B*07, this supporting a northern Spaniard ancestry.

Blockade of the NFκB pathway drives differentiating glioblastoma-initiating cells into senescence both in vitro and in vivo

Glioblastoma multiforme is one of the most devastating cancers and presents unique challenges to therapy because of its aggressive behavior. Cancer-initiating or progenitor cells have been described to be the only cell population with tumorigenic capacity in glioblastoma. Therefore, effective therapeutic strategies targeting these cells or the early precursors may be beneficial. We have established different cultures of glioblastoma-initiating cells (GICs) derived from surgical specimens and found that, after induction of differentiation, the NFκB transcriptional pathway was activated, as determined by analyzing key proteins such as p65 and IκB and the upregulation of a number of target genes. We also showed that blockade of nuclear factor (NF)κB signaling in differentiating GICs by different genetic strategies or treatment with small-molecule inhibitors, promoted replication arrest and senescence. This effect was partly mediated by reduced levels of the NFκB target gene cyclin D1, because its downregulation by RNA interference reproduced a similar phenotype. Furthermore, these results were confirmed in a xenograft model. Intravenous treatment of immunodeficient mice bearing human GIC-derived tumors with a novel small-molecule inhibitor of the NFκB pathway induced senescence of tumor cells but no ultrastructural alterations of the brain parenchyma were detected. These findings reveal that activation of NFκB may keep differentiating GICs from acquiring a mature postmitotic phenotype, thus allowing cell proliferation, and support the rationale for therapeutic strategies aimed to promote premature senescence of differentiating GICs by blocking key factors within the NFκB pathway.

Incremental effect for antisocial personality disorder genetic risk combining 5-HTTLPR and 5-HTTVNTR polymorphisms

As the serotonin transporter gene (SLC6A4 or 5-HTT) is a key regulator of central serotonergic activity, several association studies between Antisocial Personality Disorder (APD) and the SLC6A4 polymorphisms have been conducted in the last decade. In the present study, the role of both 5-HTTLPR and 5-HTTVNTR polymorphisms of the SLC6A4 gene in APD is investigated. A sample of 147 male inmates was analyzed. APD was assessed by Aluja's Antisocial Personality Disorder Scale, a measure that correlates 0.73 with the dimensional score of DSM-IV APD and 0.62 with factor II of the Psychopathy Checklist-Revised. Inmates presenting both 5-HTTLPR S/S+S/L and 5-HTTVNTR 12/12 had a higher risk of being classified in the APD group (Odds ratio=3.48). The results also showed that the genotype and haplotype distribution was more dissimilar when extreme groups were compared with odds ratios up to 6.50. Our results supported that, in addition to the widely investigated 5-HTTLPR polymorphism, the 5-HTTVNTR polymorphism might be an interesting candidate for association studies with APD. Results also suggested that previous failures to replicate the association between serotonin transporter gene polymorphisms and APD, or similar phenotypes, could have been due to an under-representation of extremely high APD subjects in the samples analyzed.

Impulsive-disinhibited personality and serotonin transporter gene polymorphisms: association study in an inmate's sample

The association between different impulsive-disinhibited personality traits with 5-HTTLPR and 5-HTTVNTR genetic polymorphisms was examined in an imprisoned male sample. Higher scores of the impulsive-disinhibited personality traits tended to be associated with carrying one or two copies of the 5-HTTPLR S allele (S/S homozygous and S/L heterozygous), and carrying two copies of the 5-HTTVNTR 12 allele (12/12 homozygous). Genotype, allele, haplotype and extended genotype distribution between low and high impulsive-disinhibited groups confirmed this association. Allele S and genotypes S/S+S/L at the 5-HTTLPR locus and allele 12 and genotype 12/12 at the 5-HTTVNTR locus were overrepresented in the high scoring group. Accordingly, allele S and allele 12 conferred a trend for risk to be in the high scoring group with an odds ratio (OR) of 1.8 (p < 0.035) and 1.7 (p < 0.014), respectively. In addition, extended genotype distribution shows that those S allele carriers (S/S homozygote and S/L heterozygote) that were also 12/12 homozygote, were overrepresented in the high scoring group (OR = 3.2; p < 0.004). The main risk of being in the high scoring group was assigned to those carrying two copies of the S-12 haplotype (OR = 5.7; p < 0.0007). We discuss the possible relationship between the two genetic serotonin polymorphisms and the personality impulsive-disinhibited traits investigated.

Decreased expression of CD3zeta and nuclear transcription factor kappa B in patients with pulmonary tuberculosis: potential mechanisms and reversibility with treatment

BACKGROUND

The protective immune response against Mycobacterium tuberculosis relies both on antigen-presenting cells and on T lymphocytes. In patients with different forms of tuberculosis, varying degrees of T cell function--ranging from positive delayed-type hypersensitivity, in asymptomatic infected healthy individuals, to the absence of the response, in patients with miliary or pulmonary tuberculosis (PTB)--have been reported. The decreased expression of CD3zeta reported in T cells from patients with either cancer or leprosy has provided possible explanations for the altered immune response observed in these diseases.

METHODS

The present study aimed to compare the expression of CD3zeta , nuclear transcription factor- kappa B (NF- kappa B), arginase activity, and cytokine production in 20 patients with PTB, in 20 tuberculin-positive asymptomatic subjects, and in 14 tuberculin-negative control subjects.

RESULTS

Compared with those in tuberculin (purified protein derivative)-negative control subjects, peripheral-blood T lymphocytes from patients with active PTB had significantly (P < .001) decreased expression of CD3zeta and absence of the p65/p50 heterodimer of NF- kappa B. These alterations were reversed only in patients who responded to treatment. Also reported here for the first time is that the presence of arginase activity in peripheral-blood mononuclear-cell lysates of patients with PTB parallels high production of interleukin-10.

CONCLUSIONS

The presence of arginase could, in part, explain the decreased expression of CD3zeta . These findings provide a novel mechanism that may explain the T cell dysfunction observed in patients with PTB.

The 16PF5 and the NEO-PI-R in Spanish and Swiss Samples: A Cross-Cultural Comparison

Abstract. This study compared the Spanish (Castilian) and French versions of the 16PF5 and of the NEO-PI-R in Spanish and Swiss samples. The five-factor solution for the 16PF5 only seems clear for the Castilian version, but not for the French version. Indeed, the congruence coefficients for the Tough-Mindedness and the Self-Control dimensions are low. On the other hand, the five-factor solutions are highly similar for both countries concerning the NEO-PI-R, and the congruence coefficients are above .95 for all five dimensions. The low cross-cultural replicability for the 16PF5 makes it difficult to analyze the differences at the mean level for this inventory. For the NEO-PI-R, the differences are generally very small and globally account for 2.6% of the total variance. Spaniards seem to have slightly lower scores on Actions and slightly higher scores on Dutifulness. These differences could either be due to translation problems, sample selection, or cultural differences.

Kidney Transplant Patients with Long-Term Graft Survival Have Altered Expression of Molecules Associated with T-Cell Activation

BACKGROUND

Patients with long-term functioning organ allografts may have developed different mechanisms that explain the lack of graft rejection. However, it is not known how these mechanisms interplay or whether one of them predominates in such situations.

METHODS

The authors analyzed the expression of T-cell surface molecules involved in alloantigen recognition, signal transduction, co-stimulation, and activation markers on circulating T cells from patients with normal kidney function 10 or more years after transplantation, short-term survival (1-4 years), and chronic rejection and from healthy adults. The percentage and the median fluorescent intensity of each marker were determined by flow cytometry. Proliferative response against specific and third-party donors and mitogenic stimulation were also determined.

RESULTS

Peripheral blood lymphocytes from patients with long-term surviving kidneys had decreased expression of T-cell receptor (TCR)-alphabeta (P < 0.01), CD3epsilon (P < 0.05), and CD3 zeta-chains (P < 0.001); diminished percentages of CD4(+)CD28(+) (P < 0.001) cells; and increased expression of CTLA-4(+) (P < 0.01) on CD3(+) cells. CD4(+)CD25(+)CD69(+) cells were also increased in long-term surviving patients. Long-term surviving patients had decreased donor-specific proliferative responses.

CONCLUSIONS

The decreased expression of TCR-alphabeta and epsilon- and zeta-chains on circulating T cells of long-term surviving patients suggests that these cells may have defects in alloantigen recognition or signal transduction that may result in decreased numbers of T cells expressing co-stimulatory molecules and activation markers as well as a decreased specific proliferative response. The decrease in the percentage of CD28(+) cells and the increase in CD4(+)CD25(+)CD69(+) cells suggest that regulatory mechanisms of the immune response are still active in such patients.

Modulation of macrophage apoptosis by antimycobacterial therapy: physiological role of apoptosis in the control of Mycobacterium tuberculosis

Apoptosis is a form of cell death that avoids inflammatory responses. We had previously reported that Mycobacterium tuberculosis (Mtb) and Purified Protein Derivative (PPD) induce apoptosis in murine macrophages. The production of TNFalpha and IL-10 in response to Mtb infection modulates apoptosis by controlling nitric oxide production and caspase activation. Furthermore, Mtb triggers calcium influx responsible for mitochondrial alterations, an early pathway of apoptosis, independently of TNFalpha and IL-10. In tuberculosis patients apoptotic macrophages are found in granulomas and bronchoalveolar lavages, suggesting that apoptosis may participate in the control of Mtb. To further explore the role of macrophage apoptosis in tuberculosis, we studied the capacity of standard antimycobacterial drugs to modulate different events associated with the induction of apoptosis. The B10R murine macrophage line was infected or not with Mtb (5:1 bacteria to macrophage ratio) or exposed to PPD (10 microg/ml), in the presence or absence of varying concentrations (1-20 microg/ml) of anti mycobacterial drugs (isoniazid, rifampin, thiacetazone, streptomycin, and ethambutol). Inhibition of the intracellular growth of M. tuberculosis by all drugs studied/correlated with inhibition of permeability transition (PT) alterations; TNFalpha, IL-10, and nitric oxide production, and caspase-1 activation. However, these drugs did not affect PPD-induced apoptosis or its associated events, suggesting that the ability of antimycobacterial drugs to block macrophage apoptosis could be explained by their effects on the metabolic activities of Mtb. All drugs, except isoniazid, at higher concentrations, induced PT alterations in noninfected macrophages in a way that appears to be dependent of calcium, since a calcium chelator prevented it. The results presented herein suggest that the pharmacological manipulation of pathways associated with macrophage apoptosis may affect the intracellular growth of Mtb.

Absence of association between mannose-binding lectin gene polymorphisms and HIV-1 infection in a Colombian population

Mannose-binding lectin (MBL) is a calcium-dependent lectin shown to play an important role in innate immunity to infection by activating the classical complement pathway and phagocytosis. In vitro studies have shown that MBL is able to bind to the gp120 HIV-1 surface antigen, and variants of the gene are associated with increased risk of HIV infection among Scandinavians. We investigated the association of genetic MBL variants and HIV-1 infection in 278 Colombian HIV-infected and control individuals. MBL genotype frequencies were similar for both groups, and no association was detected between MBL alleles B, C, and D and susceptibility to HIV-1 infection ( P=1.0). Since there is a well-documented link between the tested MBL alleles and very low MBL serum concentration, these results do not support the hypothesis that MBL levels are a risk factor for HIV-1 infection in Colombia.

A randomized, blinded, comparative trial of one pepsin-digested and two whole IgG antivenoms for Bothrops snake bites in Uraba, Colombia. The Regional Group on Antivenom Therapy Research (REGATHER)

The therapeutic efficacy and the incidence of early antivenom reactions (EARs) were compared in a clinical trial performed in 79 patients bitten by Bothrops sp. in Urabá, Colombia. Patients were randomized into three groups according to the antivenom administered: A (n = 30, Butantan polyspecific, pepsin-digested Bothrops antivenom); B (n = 27, Butantan polyspecific, whole IgG Bothrops antivenom); and C (n = 22, Colombian commercial, monovalent, whole IgG Bothrops antivenom). The groups were comparable in all clinical and epidemiologic aspects; 33 patients had mild, 22 moderate, and 24 severe envenoming. At the doses used (two, four, and six vials [10 ml/vial] for mild, moderate, and severe envenomings, respectively) there were no differences between the antivenoms in restoring normal hemostatic parameters within 24 hr. The evolution of local envenoming was comparable in the three groups. Serum venom/antivenom kinetics determined by ELISA showed a complete clearance of venom levels 1 hr after treatment in mild/moderate envenomings. In severe cases, venom levels remained detectable up to 24 hr and recurrence of antigenemia was observed in some cases. Antivenom concentrations remained at high levels up to 24 hr of treatment. The incidence of EARs was significantly different in the groups: A (36.7%), B (11.1.%), and C (81.8%). There were no life-threatening anaphylactic reactions. We conclude that the efficacy of the three antivenoms was similar in neutralizing human Bothrops envenomings and that the production of whole IgG antivenoms by caprylic acid fractionation is a good alternative for reducing the incidence of EARs.

Differential induction of apoptosis by virulent Mycobacterium tuberculosis in resistant and susceptible murine macrophages: role of nitric oxide and mycobacterial products

Resistance and susceptibility of macrophages to mycobacteria are under the control of the Bcg/Nramp1 gene, which also controls the NO- production in response to macrophage activators. There is recent evidence indicating that mycobacteria induces apoptosis in infected macrophages. Using murine macrophage lines, congenic at the Bcg/Nramp1 gene, this report shows that B10R are more prone than B10S macrophages to undergo apoptosis after exposure to live virulent Mycobacterium tuberculosis H37Rv (Mtb) or PPD, as determined by cell viability, DNA fragmentation, hypoploidy, and the terminal deoxynucleotide transferase dUTP-biotin nick-end labeling assay. Induction of apoptosis correlated with NO- production. Aminoguanidine and anti-TNF-alpha inhibited NO- production and apoptosis. B10R and B10S macrophages were equally affected by sodium nitroprusside, a donor of NO-, but its effect, mainly in B10R cells, was enhanced by the presence of Mtb. Nonvirulent mycobacteria induced lower levels of NO- and did not cause cell death. Killed Mtb, mannose-capped lipoarabinomannan (ManLAM), and LPS rescued macrophages from apoptosis albeit induce NO-. These findings suggest the existence of opposite pathways: metabolically active mycobacteria promotes apoptosis whereas their structural components inhibit it. Apoptosis may be a critical mechanism by which Nramp1 gene controls the macrophage infection with virulent mycobacteria.

Differential induction of apoptosis by virulent Mycobacterium tuberculosis in resistant and susceptible murine macrophages: role of nitric oxide and mycobacterial products

Resistance and susceptibility of macrophages to mycobacteria are under the control of the Bcg/Nramp1 gene, which also controls the NO- production in response to macrophage activators. There is recent evidence indicating that mycobacteria induces apoptosis in infected macrophages. Using murine macrophage lines, congenic at the Bcg/Nramp1 gene, this report shows that B10R are more prone than B10S macrophages to undergo apoptosis after exposure to live virulent Mycobacterium tuberculosis H37Rv (Mtb) or PPD, as determined by cell viability, DNA fragmentation, hypoploidy, and the terminal deoxynucleotide transferase dUTP-biotin nick-end labeling assay. Induction of apoptosis correlated with NO- production. Aminoguanidine and anti-TNF-alpha inhibited NO- production and apoptosis. B10R and B10S macrophages were equally affected by sodium nitroprusside, a donor of NO-, but its effect, mainly in B10R cells, was enhanced by the presence of Mtb. Nonvirulent mycobacteria induced lower levels of NO- and did not cause cell death. Killed Mtb, mannose-capped lipoarabinomannan (ManLAM), and LPS rescued macrophages from apoptosis albeit induce NO-. These findings suggest the existence of opposite pathways: metabolically active mycobacteria promotes apoptosis whereas their structural components inhibit it. Apoptosis may be a critical mechanism by which Nramp1 gene controls the macrophage infection with virulent mycobacteria.

Involvement of programmed cell death in morphogenesis of the vertebrate inner ear

An outstanding challenge in developmental biology is to reveal the mechanisms underlying the morphogenesis of complex organs. A striking example is the developing inner ear of the vertebrate, which acquires a precise three-dimensional arrangement of its constituent epithelial cells to form three semicircular canals, a central vestibule and a coiled cochlea (in mammals). In generating a semicircular canal, epithelial cells seem to ‘disappear’ from the center of each canal. This phenomenon has been variously explained as (i) transdifferentiation of epithelium into mesenchyme, (ii) absorption of cells into the expanding canal or (iii) programmed cell death. In this study, an in situ DNA-end labeling technique (the TUNEL protocol) was used to map regions of cell death during inner ear morphogenesis in the chicken embryo from embryonic days 3.5-10. Regions of cell death previously identified in vertebrate ears have been confirmed, including the ventromedial otic vesicle, the base of the endolymphatic duct and the fusion plates of the semicircular canals. New regions of cell death are also described in and around the sensory organs. Reducing normal death using retrovirus-mediated overexpression of human bcl-2 causes abnormalities in ear morphogenesis: hollowing of the center of each canal is either delayed or fails entirely. These data provide new evidence to explain the role of cell death in morphogenesis of the semicircular canals.

Natural killer cell activity in patients with pulmonary tuberculosis and in healthy controls

Natural killer (NK) cell activity of freshly isolated peripheral blood mononuclear cells (MNC) or cells stimulated for 72 h with 10 micrograms/ml of a sonicate antigen of Mycobacterium tuberculosis H37Rv were studied in healthy responder and non-responder controls, as detected by lymphocyte proliferation with specific antigen, and in patients with pulmonary tuberculosis. K-652 cells were used as targets in a 4 h 51Cr release assay. MNC from patients exhibited a significant decrease in NK function as compared with responder controls (p less than 0.02). NK activity in responder individuals was highest 72 h after incubation with antigen. Non-stimulated cells were not cytotoxic. MNC from healthy responder and non-responder subjects incubated for 72 h with antigen yielded a significant increase in the percentage NK cytotoxicity at all effector/target ratios studied (p less than 0.01) as well as in the number of lytic units per culture (p less than 0.004). However, this increase was higher in responder individuals as compared to non-responder subjects (p = 0.02). The response to antigen was not significant in the group of patients although a net increase was also observed in the whole group. Only 4 of 9 patients exhibited significant increased responses after antigenic stimulation, 3 showed moderate responses, 1 did not respond and in a further patient a decrease was observed. The decreased NK activity could be secondary to abnormalities in the production of lymphokines by tuberculous patients. Although the role of non-specific cytotoxic cells in tuberculosis is unknown, their alterations could contribute to the pathogenesis of the disease.

Blood transfusions and HLA compatibility in first cadaveric kidney transplants treated with cyclosporine A

One-year graft survival of 54 first cadaveric kidney transplants that received immunosuppressive treatment with CsA was analyzed with respect to the number of random pretransplant blood transfusions and the HLA class 1 and class 2 matching. Overall graft survival at 1 year was 80.7%. Patients with 3 to 20 pretransplant transfusions had a survival of 93.7% compared with 66.7% in those with less than three or more than 20 transfusions. All kidneys transplanted with two or less HLA-A + B mismatches survived at 1 year. With three mismatched antigens survival was of 88.9%. This value was reduced to 66.7% for four incompatibilities. A similar situation was found for HLA-DR matching since all kidneys with full compatibility survived at 1 year compared with 90.9% and 66.7% for one and two mismatches, respectively. HLA-B and HLA-DR exhibited an additive effect since again all grafts with two or less mismatches survived, whereas in the group with three different antigens this figure was 90% and only 1 of the three kidneys with completely different antigens survived.