Sterilisation of intellectually disabled women

Objective

To point out the proportion of intellectually disabled women (IDW) who are sterilised, and the medical and social factors associated with an increased probability to be sterilised.

Study design

A population-based study among 97% of IDW aged 18–46, attending government-accredited institutions in the region of Brussels-Capital and the province of Walloon Brabant (Belgium).

Results

Among the IDW included in this study, 22.2% are sterilised, which is superior to the 7% in the general Belgian population. Factors associated with an increased probability to be sterilised are: living in an institution, having a higher intellectual quotient (IQ), being enrolled in an institution where sexual intercourse is authorised and attending an institution where contraception is required. The last three factors are significant only among women living in institutions and the last two, only in women with severe disability. Among IDW using contraception, no factor was associated with a greater probability to be sterilised.

Conclusion

The prevalence of sterilisation among IDW is three times higher than that in the Belgian population and it is mainly correlated with factors related to the institution where these women live, especially the severely disabled.

Perforated Duodenal Ulcer and Cigarette Smoking

Whilst the association between smoking and peptic ulceration has been reported previously, the relationship between smoking and the complications of ulcers, such as perforation, bleeding or acute painful exacerbation, has not been examined. In a retrospective study comparing 275 emergency admissions for peptic ulcer with 275 controls, cigarette smoking was significantly more common only in those with a perforated duodenal ulcer. Of 128 patients with perforated duodenal ulcers, 110 (86%) were cigarette smokers compared with 65 (51%) of the 128 matched controls (χ2, P<0.01). Cigarette smoking in patients with bleeding or acutely exacerbated ulcers was not significantly more common than in controls. These findings strongly suggest a particular association between smoking and perforated duodenal ulcer.

High-dose interleukin2 - a 10-year single-site experience in the treatment of metastatic renal cell carcinoma: careful selection of patients gives an excellent outcome

Background

VEGF-targeted therapy has become the mainstay of treatment for majority of mRCC patients. For most patients, benefit is short-lived and therefore treatment remains palliative in intent. HD IL2 is an effective immunotherapy treatment capable of durable remission in some patients but its unselected use has been difficult due to its modest response rate and considerable adverse effects. Using set pathology criteria as a selection tool in clinical practice, we have been able to show improved outcomes in our previous report. Here, we present an updated and extended report of this treatment and seek to explore any pathological, clinical and treatment variables likely to predict better outcomes.

Methods

This is an extension of a previously reported clinical audit, which includes mRCC cases treated with HD IL2 between 2003 and 2013. Since 2006, tumour specimens of potential candidates were routinely reviewed prospectively and stratified into Favourable or Other categories based on constitution of histological growth pattern, namely alveolar or solid versus papillary and/or sarcomatoid architecture; clear cell versus granular cell cytoplasmic morphology. HD IL2 was preferentially offered to patients with Favourable pathology. Outcome evaluation includes response rates, survival, and treatment tolerance. Multivariate analysis was performed to explore potential prognostic and predictive factors.

Results

Among prospectively selected patients with Favourable pathology (n = 106), overall response rate was 48.1 % (51/106) with CR rate of 21.6 % (23/106). Median OS was 58.1 months. Factors associated with significantly better response and/or survival includes favourable pathology pattern, higher cycle 1 tolerance and lower number of metastatic organ sites (<3). CAIX (Carbonic anhydrase 9) has prognostic value but is not predictive of response. Toxicities were those expected of IL2 but were manageable on general medical wards, with no treatment-related death. Importantly most complete responses were durable with 76 % (23/30) cases remained relapse-free (median 39 months follow up) and 2 of the seven who relapsed had had long-term disease free survival after resection of oligometastatic relapse.

Conclusions

Our experience shows that HD IL2 remains an effective and safe treatment in well-selected cases of mRCC. The result in this single-institution patient series confirms similar outcomes to our previously reported retrospective series. Given the prospect of long-term remission, fit patients with Favourable histology and low disease burden should be considered for HD IL2 in an experienced centre. Better understanding has been gained from this in-depth analysis especially the examination of possible response predictors and strategies that can improve treatment outcome.

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-016-0174-5) contains supplementary material, which is available to authorized users.

Interventions that cause weight loss and the impact on cardiovascular risk factors: a systematic review and meta-analysis

Overweight and obesity increase the risks of diabetes and cardiovascular disease (CVD). This has been shown to be reversed with weight loss. A systematic review and meta-analysis were performed to determine the effect of weight loss in the primary prevention of CVD. PubMed, Embase and the Cochrane Library databases were searched electronically through to May 2013. Randomized controlled trials assessing weight loss and cardiovascular risk factors and outcomes were included. A random effects meta-analysis, with sub-group analyses for degree of weight loss, and age were performed. Because few studies reported clinical outcomes of CVD, analyses were limited to cardiovascular risk factors (83 studies). Interventions that caused any weight loss significantly reduced systolic blood pressure (-2.68 mmHg, 95% CI -3.37, -2.11), diastolic blood pressure (-1.34 mmHg, 95% CI -1.71, -0.97), low-density lipoprotein cholesterol (-0.20 mmol L(-1) , 95% CI -0.29, -0.10), triglycerides (-0.13 mmol L(-1) , 95% CI -0.22, -0.03), fasting plasma glucose (-0.32 mmol L(-1) , 95% CI -0.43, -0.22) and haemoglobin A1c(-0.40%, 95% CI -0.52, -0.28) over 6-12 months. Significant changes remained after 2 years for several risk factors. Similar results were seen in sub-group analyses. Interventions that cause weight loss are effective at improving cardiovascular risk factors at least for 2 years. © 2016 World Obesity.

Facial trauma

Facial trauma. Patients with facial trauma must be assessed in a systematic way so as to avoid missing any injury. Severe and disfiguring facial injuries can be distracting. However, clinicians must first focus on the basics of trauma care, following the Advanced Trauma Life Support (ATLS) system of care. Maxillofacial trauma occurs in a significant number of severely injured patients. Life- and sight-threatening injuries must be excluded during the primary and secondary surveys. Special attention must be paid to sight-threatening injuries in stabilized patients through early referral to an appropriate specialist or the early initiation of emergency care treatment. The gold standard for the radiographic evaluation of facial injuries is computed tomography (CT) imaging. Nasal fractures are the most frequent isolated facial fractures. Isolated nasal fractures are principally diagnosed through history and clinical examination. Closed reduction is the most frequently performed treatment for isolated nasal fractures, with a fractured nasal septum as a predictor of failure. Ear, nose and throat surgeons, maxillofacial surgeons and ophthalmologists must all develop an adequate treatment plan for patients with complex maxillofacial trauma.

Complex intubation, cricothyrotomy and tracheotomy

Complex intubation, cricothyrotomy and tracheotomy. Successful management of a difficult airway begins with recognizing the potential problem. When the patient cannot breathe spontaneously, oxygenation and ventilation should start first with bag-valve ventilation, with or without an airway adjunct such as a Mayo cannula, followed by an orotrache4l intubation attempt, performed by an experienced emergency doctor. If orotracheal intubation fails, a quick decision must be made regarding surgical options. In a "cannot intubate, cannot ventilate" situation, a surgical cricothyrotomy should be considered. When orotracheal intubation is impossible, but bag-valve or laryngeal mask ventilation is possible, an urgent surgical tracheostomy should be performed. In the long run, patients in need of longterm artificial ventilation will need a percutaneous or open tracheostomy. This review provides an update of all aspects of immediate and long-term airway management.

Face and neck: airway and sensorial capacities

Face and neck: airway and sensorial capacities. For the assessment and the management of face and neck trauma knowledge of the neuro-anatomy and physiology of the ear, nose, throat (ENT) and head and neck (HN) region and structures is essential, as this area is particularly vulnerable to injury. Indeed, the complex anatomy and physiology in this specific area supports important basic functions. In addition, this review elaborates on upper airway and sensorial capacities. Upper airway dimensions are influenced by bony and soft tissues. Age is of fundamental importance in the upper airway assessment, as significant differences in size and proportions apply in children and adults. The cranial nerves (CN) supply motor, sensory ad special sensory fibres to the upper airway. Injury of the CN is a frequent complication of trauma.

The change in differing leukocyte populations during vaccination to bovine respiratory disease and their correlations with lung scores, health records, and average daily gain

Bovine respiratory disease (BRD) is the most economically important disease in U.S. feedlots. Infection can result in morbidity, mortality, and reduced average daily gain. Cheap and reliable genetic methods of prediction and protection from BRD would be highly advantageous to the industry. The immune response may correlate with BRD incidence. Cattle (n = 2,182) were vaccinated against common viral and bacterial pathogens of BRD. Two blood samples were collected, one during booster vaccination and one 21d later, enabling 3 phenotypes for each trait [prebooster (pre), postbooster (post), and delta (post minus pre)]. From the blood samples innate and adaptive responses [counts of white blood cells (WBC), neutrophils, lymphocytes, monocytes, eosinophils, and basophils] were measured. In addition, feedlot ADG and binary traits [health records (HR; 0 = healthy, 1 = ill) and lung scores (LS; collected at harvest; 0 = no lesions, 1 = lesions)] were also recorded. Traits ADG, HR, and LS have all been significantly correlated with infection to BRD. In this investigation we aimed to find correlations between the immune response and ADG, HR, and LS to find an easily measurable trait that would be a good predictor of BRD resistance after vaccination. The results showed an average positive delta for the innate immune response (eosinophils, basophils, neutrophils), whereas the adaptive immune response had an average negative delta (lymphocytes). Overall, we discovered that the immune responses had moderately high heritabilities (h(2); lowest: delta monocytes, 0.21 ± 0.05; greatest: pre lymphocytes: 0.5 ± 0.05), with lymphocytes having the greatest h(2) throughout the study (h(2) ≥ 0.41). All genetic correlations were calculated using bivariate REML models. Although LS did not significantly correlate with any of the immune phenotypes, both ADG (post lymphocytes, -0.24 ± 0.12) and HR (pre eosinophils, -0.67 ± 0.29; delta WBC, -0.5 ± 0.24, and delta lymphocytes, -0.67 ± 0.21) did. All the significant genetic correlations with HR were negative; resistance to BRD appears to be a function of greater delta lymphocytes and WBC. The increase in eosinophils may potentially link its role in decreasing lymphocytes. These results may enable producers to predict if revaccination, quarantine, and breeding of animals is required to reduce the incidence of BRD postvaccination. In addition, immunological phenotypes maybe used to aid genomic selection indices to select animals with greater rates of protection after BRD vaccination.

TGFB-induced factor (TGIF): a candidate gene for psychosis on chromosome 18p

Schizophrenia (SC) and bipolar disorder (BP) share many clinical features, among them psychosis. We previously identified a putative gene locus for psychosis on chromosome 18p in a sample from the Central Valley of Costa Rica (CVCR) population. The present study replicated the association to a specific allele of microsatellite marker D18S63 on 18p11.3, using a newly collected sample from the CVCR. A combined analysis of both samples, plus additional subjects, showed that this specific allele on D18S63, which lies within an intron on the TGFB-induced factor (TGIF) gene, is strongly associated (P-value=0.0005) with psychosis. Eleven additional SNP markers, spanning five genes in the region, were analyzed in the combined sample from the CVCR. Only the four SNPs within the TGIF gene were in strong linkage disequilibrium with D18S63 (D'=1.00). A specific haplotype for all five markers within the TGIF gene showed evidence of association (P-value=0.011) to psychosis. A second, distinct haplotype, containing a newly identified nonsynonymous polymorphism in exon 5 of the TGIF gene, showed a nonsignificant trend towards association to psychosis (P-value=0.077). TGIF is involved in neurodevelopment, neuron survival and controls the expression of dopamine receptors. Altogether, our results point to the possible involvement of TGIF in the pathophysiology of psychotic disorders in the CVCR population.

Evaluation of tight junction protein 1 encoding zona occludens 1 as a candidate gene for albuminuria in a Mexican American population

Albuminuria, a hallmark of diabetic nephropathy, has been shown to be significantly heritable in multiple studies. Therefore, the identification of genes that affect susceptibility to albuminuria may lead to novel avenues of intervention. Current evidence suggests that the podocyte and slit diaphragm play a key role in controlling the selective sieve of the glomerular filtration barrier, and podocyte-specific genes have been identified that are necessary for maintaining its integrity. We therefore investigated the role of gene variants of tight junction protein (TJP1) which encodes another slit diaphragm-associated protein zona occludens 1 as risk factors for albuminuria in the San Antonio Family Diabetes/Gallbladder Study (SAFDGS), which consists of extended Mexican-American families with a high prevalence of type 2 diabetes. Albuminuria, defined as an albumin (mg/dl) to creatinine (mg/dl) ratio (ACR) of 0.03, which is approximately equivalent to a urinary albumin excretion (UAE) >30 mg/day, was present in a total of 14.9% of participants, and 31% had type 2 diabetes. The TJP1 exons, flanking intronic sequence, and putative proximal promoter regions were investigated in this population. Twentynine polymorphisms, including 7 nonsynonymous SNPs, were identified and genotyped in all subjects of this study for association analysis. Three sets of correlated SNPs, which include 3 exonic SNPs, were nominally associated with ACR (p value range 0.007-0.049); however, the association with the discrete trait albuminuria was not significant (p value range 0.094-0.338). We conclude that these variants in TJP1 do not appear to be major determinants for albuminuria in the SAFDGS; however, they may play a minor role in its severity in this Mexican-American population. Further examination of the TJP1 gene region in this and other cohorts will be useful to determine whether ZO-1 plays a significant role in glomerular permselectivity.

Obesity and the Metabolic Syndrome: The Stress on Society

The problem of obesity was only accepted by the World Health Organization as of major public health importance in 1997 when the criteria for the specification of the metabolic syndrome were also being sought. Then the risk factor analyses of the determinants of global ill health at the start of the millennium showed that an excessive body mass index (BMI) above the optimum of 21 was one of the top 10 contributors. No analyses could be related to abdominal obesity because of the absence of systematic representative surveys of waist circumferences but the ill health attributable to excess weight included the risk factors specified in the metabolic syndrome and showed that the co-morbidities in Asia were far greater than those predicted from simply an excess weight. The recent proposed definition of the metabolic syndrome includes these different criteria specified on an ethnic basis but there is now a need to recognize that abdominal obesity is more common on the developing world and linked to childhood stunting and early deprivation. The importance of intrauterine and postnatal epigenetic and altered organ function needs to be recognized. Thus the co-morbidities associated with weight gain and the development of the metabolic syndrome dominate in the developing world where the majority of the population is proving more susceptible to the effects of weight gain than Caucasians now living in affluent societies. This therefore presents a major challenge in both research and public policy terms.

PHC3, a component of the hPRC-H complex, associates with E2F6 during G0 and is lost in osteosarcoma tumors

Polyhomeotic-like 3 (PHC3) is a ubiquitously expressed member of the polycomb gene family and part of the human polycomb complex hPRC-H. We found that in normal cells PHC3 associated with both hPRC-H complex components and with the transcription factor E2F6. In differentiating and confluent cells, PHC3 and E2F6 showed nuclear colocalization in a punctate pattern that resembled the binding of polycomb bodies to heterochromatin. This punctate pattern was not seen in proliferating cells suggesting that PHC3 may be part of an E2F6-polycomb complex that has been shown to occupy and silence target promoters in G(0). Previous loss of heterozygosity (LoH) analyses had shown that the region containing PHC3 underwent frequent LoH in primary human osteosarcoma tumors. When we examined normal bone and human osteosarcoma tumors, we found loss of PHC3 expression in 36 of 56 osteosarcoma tumors. Sequence analysis revealed that PHC3 was mutated in nine of 15 primary osteosarcoma tumors. These findings suggest that loss of PHC3 may favor tumorigenesis by potentially disrupting the ability of cells to remain in G(0).

Golli-MBP copy number analysis by FISH, QMPSF and MAPH in 195 patients with hypomyelinating leukodystrophies

The inherited disorders of CNS myelin formation represent a heterogeneous group of leukodystrophies. The proteolipoprotein (PLP1) gene has been implicated in two X-linked forms, Pelizaeus-Merzbacher disease (PMD) and spastic paraplegia type 2, and the gap junction protein alpha12 (GJA12) gene in a recessive form of PMD. The myelin basic protein (MBP) gene, which encodes the second most abundant CNS myelin protein after PLP1, presents rearrangements in hypomyelinating murine mutants and is always included in the minimal region deleted in 18q- patients with an abnormal hypomyelination pattern on cerebral MRI. In this study, we looked at the genomic copy number at the Golli-MBP locus in 195 patients with cerebral MRI suggesting a myelin defect, who do not have PLP1 mutation. Although preliminary results obtained by FISH suggested the duplication of Golli-MBP in 3 out of 10 patients, no abnormal gene quantification was found using Quantitative Multiplex PCR of Short Fluorescent fragments (QMPSF), Multiplex Amplifiable Probe Hybridization (MAPH), or another FISH protocol using directly-labelled probes. Pitfalls and interest in these different techniques to detect duplication events are emphasised. Finally, the study of this large cohort of patients suggests that Golli-MBP deletion or duplication is rarely involved in inherited defects of myelin formation.

Association analyses of the neuregulin 1 gene with schizophrenia and manic psychosis in a Hispanic population

OBJECTIVE

This study used the population of the Central Valley of Costa Rica (CVCR) and phenotyping strategies alternative to DSMIV classifications to investigate the association of neuregulin 1 with schizophrenia.

METHOD

Using 134 family trios with a history of psychosis, we genotyped six of the seven markers originally identified to be associated with schizophrenia in Iceland.

RESULTS

The neuregulin Icelandic haplotype was not associated with schizophrenia in the CVCR population. However, a novel haplotype was found to be overrepresented in subjects with functional psychosis (global P-value > 0.05). Stratification of the sample by history of mania suggests that this haplotype may be preferentially over-transmitted to persons with a history of manic psychosis.

CONCLUSION

These results suggest that the neuregulin 1 gene is unlikely to play a major role in predisposing to schizophrenia in the CVCR. Further studies in the CVCR and other Latin American populations should be performed in order to corroborate these findings.

FGF Ligand Family mRNA Expression Profile for Mouse Preimplantation Embryos, Early Gestation Human Placenta, and Mouse Trophoblast Stem Cells

Signaling by fibroblast growth factor (FGF) is essential is for trophoblast stem (TS) cells and preimplantation embryos. FGF4 provides essential signaling, but the expression of the complete set of 23 FGF family members has not been analyzed. Here, semi-quantitative RT-PCR and microarray analyses were used to define expression of all FGF ligand mRNA. RT-PCR was done for developmentally important FGF subfamilies, FGF10/FGF22 and FGF8/FGF17/FGF18 as well as FGF11. FGF4 and FGF18 are detected at highest levels by RT-PCR and microarrays. FGF10 was detected at low levels in both assays. FGF11 was detected at moderate levels by microarray, but not by RT-PCR. FGF17 was detected at low levels by array and moderate levels by RT-PCR. FGF8 and FGF22 were detected by RT-PCR, but not by microarrays during late cleavage divisions. FGF8, FGF5, and FGF9 were detected in the oocyte by microarray. FGF2, FGF3, and FGF7 were not detected by RT-PCR or microarrays and FGF13, FGF14, and FGF23 were not detected by microarray. Since a major role of FGF is to maintain TS cells, we tested human and mouse placental cell lines and early gestation human placenta for expression of FGF ligands. Expression in mouse TS cells was compared with preimplantation embryos, and human placental cell line expression was compared with human placenta, to infer which ligands are expressed in placental lineage vs. other cell lineages. The data suggest that human and mouse placenta share FGF18 and its high expression suggests preimplantation and early placental function.

Promise and challenge: Markers of prostate cancer detection, diagnosis and prognosis

Approximately 1 man in 6 will be diagnosed with prostate cancer during his life lifetime, and over 200,000 men in the U.S. are diagnosed with prostate cancer annually. Since the widespread adoption of PSA testing, about 60–70% of men at risk in the U.S. have had a blood test for prostate cancer. With this, prostate cancer death rates have decreased, yet only slightly. Thirty thousand men still die each year from this disease. PSA testing fails to identify a small but significant proportion of aggressive cancers, and only about 30% of men with a “positive” PSA have a positive biopsy. Additionally, of men who are treated for prostate cancer, about 25% require additional treatment, presumably due to disease recurrence. Also of concern is the growing evidence that there are some prostate cancers for which treatment may not be necessary. Very long-term studies from the U.S. and Europe, following men with prostate cancer have found that some tumors do not progress over time. In these individuals, prostate cancer treatment is unnecessary and harmful as these men do not benefit from treatment but will be at risk of treatment-related side effects and complications. They suggest a fundamental problem with prostate cancer: it is not possible, at this time, to predict the natural history of the disease. It is for these reasons that the most important challenge in prostate cancer today is the inability to predict the behavior of an individual tumor in an individual patient. Here we review issues related to performance and validation of biomarkers with a focus on “doing no harm”, and bearing in mind that it is the ultimate goal of early detection to save lives. Improved diagnostic and prognostic biomarkers are needed for prostate cancer, and the use of these markers should ultimately translate into increased life span and quality of life. The ultimate goal would be to not only have accurate biomarkers suitable for early diagnosis, but also biomarkers that identify men at greatest risk of developing aggressive disease. Technology has been brought to bear on this problem, and the major approaches are genomics, expression analysis, and proteomics. Proteomics and DNA methylation assays may soon be used in sensitive and specific diagnostic testing of serum and tissues for cancer. Expression arrays may be used to establish both a more specific diagnosis and prognosis for a particular tumor. The proteome is only beginning to be understood, and alternative splicing and post-translational modifications of proteins such as glycosylation and phosphorylation are challenging areas of study. Finally, risk assessment and prognosis are being pursued through analysis of genomic polymorphisms (single nucleotide polymorphisms, SNPs). This huge task is only beginning, and requires the combined expertise of molecular epidemiologists, oncologists, surgeons, pathologists, and basic scientists.

Chromosome 18 suppresses prostate cancer metastases

Loss of heterozygosity and allelic imbalance data has shown that there are two distinct regions of loss on chromosome 18q associated with the progression of prostate cancer (CaP). To investigate the functional significance of chromosome 18q loci in CaP, we utilized the technique of microcell-mediated chromosome transfer to introduce an intact chromosome 18 into the human prostate cancer cell line, PC-3. Three of the resulting hybrid lines were compared to the PC-3 cells in vitro and in vivo. The hybrid cell lines, containing an intact copy of the introduced chromosome 18, exhibited a substantial reduction in anchorage-dependent and independent growth in vitro. These hybrid cell lines also made smaller tumors in nude mice following subcutaneous injection compared to PC-3 cells. Because tumor growth was not completely eliminated by introduction of chromosome 18, we assessed the ability of the hybrids to metastasize to bone after intra-cardiac inoculation in a nude mouse model. Mice inoculated with PC-3 hybrids containing intact copies of chromosome 18 had significantly fewer bone metastases and dramatically improved survival compared to PC-3 cells. In addition, the introduction of chromosome 18 significantly reduced tumor burden in extraskeletal sites. This was not because of differences in growth rates because mice bearing hybrids were monitored for metastases over twice as long as mice bearing PC-3 cells. Taken together, these data suggest that chromosome 18 has a functional role in CaP to suppress growth and metastases. Identification of the responsible gene(s) may lead to molecular targets for drug discovery.

Regions of allelic imbalance in the distal portion of chromosome 12q in gastric cancer

AIMS

To define regions of loss on the distal portion of chromosome 12q in gastric adenocarcinoma.

METHODS

Microsatellite analysis on chromosome 12 was performed on 19 human gastric cancer cell lines using 77 markers, 71 of which were within or distal to 12q21; some portions of this region showed extended regions of homozygosity (ERHs) in 10 of 19 gastric cancer cell lines. In addition, microdissected tumour cells from 76 primary gastric adenocarcinomas were examined using 13 markers of interest implicated by the cell line data; 70% of these showed allelic imbalance (AI) at one or more markers in or distal to 12q21.

RESULTS

Mapping ERHs in the cell lines and sites of AI in the tumours identified three regions that contain putative tumour suppressor genes: region A is located within 2.8 Mb between markers D12S1667 and D12S88; region B, within 1.9 Mb between markers D12S1607 and D12S78; and region C, in 0.74 Mb between markers D12S342 and D12S324. Fluorescence in situ hybridisation (FISH) analysis in two cell lines confirmed that two of the ERHs reflected deletions, not amplifications, of D12S81 in region A and D12S340 in region C. FISH analysis of marker D12S1075 within an ERH containing region B in one cell line showed neither amplification nor deletion. AI on 12q was not associated with prognosis, but was associated with ethnicity of the patient.

CONCLUSIONS

These results identify regions on chromosome 12 that appear to contain tumour suppressor genes important in the development of gastric cancer.

Effects of ACh and adenosine mediated by Kir3.1 and Kir3.4 on ferret ventricular cells

The inotropic effects of ACh and adenosine on ferret ventricular cells were investigated with the action potential-clamp technique. Under current clamp, both agonists resulted in action potential shortening and a decrease in contraction. Under action potential clamp, both agonists failed to decrease contraction substantially. In the absence of agonist, application of the short action potential waveform (recorded previously in the presence of agonist) also resulted in a decrease in contraction. Under action potential clamp, application of ACh resulted in a Ba(2+)-sensitive outward current with the characteristics of muscarinic K+ current (I(K,ACh)); the presence of the muscarinic K+ channel was confirmed by PCR and immunocytochemistry. In the absence of agonist, on application of the short ACh action potential waveform, the decrease in contraction was accompanied by loss of the inward Na(+)/Ca(2+) exchange current (I(NaCa)). ACh also inhibited the background inward K+ current (I(K,1)). It is concluded that ACh activates I(K,ACh), inhibits I(K,1), and indirectly inhibits I(NaCa); this results in action potential shortening, decrease in contraction, and, as a result of the inhibition of I(K,1), minimum decrease in excitability.

Contraception of women with intellectual disability: prevalence and determinants

The contraception of women with intellectual disability (ID) is a major concern for caregivers. However, the prevalence of contraception and the frequency of use of different methods (e.g. sterilization) remain generally unknown. Moreover, indications specific to women with ID are controversial. The present authors conducted a population-based study among 97% of the women with ID aged between 18 and 46 years attending government-funded facilities in Brussels and the nearby province of Walloon Brabant in Belgium. Out of 397 subjects, 40.8% did not use any contraceptive method, 22.2% were sterilized, 18.4% used an oral contraceptive agent, 17.6% used depotmedroxyprogesterone acetate and 1% used an intrauterine device. These figures differ widely from those of the general Belgian population. Binary logistic regression for 'contraceptive utilization' showed the strong influence of institutional factors such as sleeping environment (i.e. institutional or parental), sexual relationship policy and contraception policy. Having or having had a boyfriend is also correlated with a stronger probability of contraceptive use. Other factors have a smaller influence (e.g. a milder level of ID). Very few factors, none of which are medical, are correlated with an increased use of a specific method. The present results are discussed in the light of the general medical application of contraception and the commonly assumed specific indications for women with ID.

The worldwide obesity epidemic

The recent World Health Organization (WHO) agreement on the standardized classification of overweight and obese, based on body mass index (BMI), allows a comparable analysis of prevalence rates worldwide for the first time. In Asia, however, there is a demand for a more limited range for normal BMIs (i.e., 18.5 to 22.9 kg/m(2) rather than 18.5 to 24.9 kg/m(2)) because of the high prevalence of comorbidities, particularly diabetes and hypertension. In children, the International Obesity Task-Force age-, sex-, and BMI-specific cutoff points are increasingly being used. We are currently evaluating BMI data globally as part of a new millennium analysis of the Global Burden of Disease. WHO is analyzing data in terms of 20 or more principal risk factors contributing to the primary causes of disability and lost lives in the 191 countries within the WHO. The prevalence rates for overweight and obese people are different in each region, with the Middle East, Central and Eastern Europe, and North America having higher prevalence rates. In most countries, women show a greater BMI distribution with higher obesity rates than do men. Obesity is usually now associated with poverty, even in developing countries. Relatively new data suggest that abdominal obesity in adults, with its associated enhanced morbidity, occurs particularly in those who had lower birth weights and early childhood stunting. Waist measurements in nationally representative studies are scarce but will now be needed to estimate the full impact of the worldwide obesity epidemic.

Genetic mapping of a novel X-linked recessive colobomatous microphthalmia

Colobomatous microphthalmia is a common ocular malformation with a heterogeneous phenotype. The majority of cases without associated systemic abnormalities have an autosomal dominant inheritance pattern [McKusick, 1990: Mendelian inheritance in man]. A few isolated cases with autosomal recessive transmission have been described [Zlotogora et al., 1994: Am J Med Genet 49:261--262]. To our knowledge, no cases of X-linked colobomatous microphthalmia that are not a part of a syndrome or a multisystem disorder have been reported. In this study, we describe a genetic and clinical evaluation of a large pedigree in which colobomatous microphthalmia is segregating in an X-linked recessive fashion. Based on recombination breakpoint analysis, we have determined that the critical interval exists between markers DXS989 and DXS441, placing the disease locus on the proximal short arm or the proximal long arm of the X chromosome. Using linkage analysis, we obtained two-point lod scores of 2.71 at zero recombination with markers DXS1058, DXS6810, DXS1199, and DXS7132. Overlapping multipoint analysis established a broad maximum from marker DXS1068 to marker DXS7132, a region spanning approximately 28 cM. This study provides evidence for the presence of a new locus for colobomatous microphthalmia.

A novel human amino acid transporter, hNAT3: cDNA cloning, chromosomal mapping, genomic structure, expression, and functional characterization

Amino acid transporters are proteins that transport amino acids across the membrane. We report here the isolation and characterization of a novel human cDNA clone encoding a protein of 547 amino acids. This protein shares approximately 50% amino acid sequence homology with the amino acid transporters mouse mNAT and its orthologs, rat SN1 and human g17, and mouse GlnT/ATA1 and ATA2. Expression of this cRNA in Xenopus oocytes revealed that the strongest transport activities were specific for l-alanine. In addition, hNAT3 is a Na(+)- and pH-dependent, low-affinity transporter and partially tolerates substitution of Na(+) by Li(+). Since this protein has sequence and functional similarities to the previously identified system N amino acid transporters, we named this protein hNAT3. The genomic DNA sequence encoding the transcript of hNAT3 spans over 14 kb with 16 exons and 15 introns. Using fluorescence in situ hybridization, we mapped the hNAT3 gene to human chromosome 12q12-q13. By RT-PCR of embryonic and adult human tissues, hNAT3 was detected to be predominantly expressed in the liver and to a much lesser extent in the muscle, kidney, and pancreas. The data obtained in this study are likely to offer critical clues for identification of amino acid transporter-associated diseases.

A major locus for fasting insulin concentrations and insulin resistance on chromosome 6q with strong pleiotropic effects on obesity-related phenotypes in nondiabetic Mexican Americans

Insulin resistance and hyperinsulinemia are strong correlates of obesity and type 2 diabetes, but little is known about their genetic determinants. Using data on nondiabetics from Mexican American families and a multipoint linkage approach, we scanned the genome and identified a major locus near marker D6S403 for fasting "true" insulin levels (LOD score 4.1, empirical P<.0001), which do not crossreact with insulin precursors. Insulin resistance, as assessed by the homeostasis model using fasting glucose and specific insulin (FSI) values, was also strongly linked (LOD score 3.5, empirical P<.0001) with this region. Two other regions across the genome were found to be suggestively linked to FSI: a location on chromosome 2q, near marker D2S141, and another location on chromosome 6q, near marker D6S264. Since several insulin-resistance syndrome (IRS)-related phenotypes were mapped independently to the regions on chromosome 6q, we conducted bivariate multipoint linkage analyses to map the correlated IRS phenotypes. These analyses implicated the same chromosomal region near marker D6S403 (6q22-q23) as harboring a major gene with strong pleiotropic effects on obesity and on lipid measures, including leptin concentrations (e.g., LOD(eq) for traits-specific insulin and leptin was 4.7). A positional candidate gene for insulin resistance in this chromosomal region is the plasma cell-membrane glycoprotein PC-1 (6q22-q23). The genetic location on chromosome 6q, near marker D6S264 (6q25.2-q26), was also identified by the bivariate analysis as exerting significant pleiotropic influences on IRS-related phenotypes (e.g., LOD(eq) for traits-specific insulin and leptin was 4.1). This chromosomal region harbors positional candidate genes, such as the insulin-like growth factor 2 receptor (IGF2R, 6q26) and acetyl-CoA acetyltransferase 2 (ACAT2, 6q25.3-q26). In sum, we found substantial evidence for susceptibility loci on chromosome 6q that influence insulin concentrations and other IRS-related phenotypes in Mexican Americans.

Chromosome 18 suppresses the tumorigenicity of prostate cancer cells

Microcell-mediated chromosome transfer allows for the introduction of normal chromosomes into tumor cells in an effort to identify putative tumor suppressor genes. We have used this approach to introduce an intact copy of chromosome 18 into the prostate cancer cell line DU145, and independently to introduce human chromosomes 8 and 18 into the prostate cancer cell line TSU-PR1. Introduction of an extra copy of human chromosome 8 had no effect on the growth properties in vitro or the tumorigenicity in vivo of TSU-PR1 cells. However, microcell hybrids containing an introduced copy of human chromosome 18 exhibited a longer population doubling time, retarded growth in soft agar, and slowed tumor growth in athymic nude mice. These experiments provide functional evidence for the presence of one or more tumor suppressor genes on human chromosome 18 that are involved in prostate cancer.

Isolation of vascular smooth muscle cells from a single murine aorta

The vascular smooth muscle cell plays a significant role in many important cardiovascular disorders, and smooth muscle biology is therefore important to cardiovascular research. The mouse is critical to basic cardiovascular research, largely because techniques for genetic manipulation are more fully developed in the mouse than in any other mammalian species. We describe here a technique for isolating smooth muscle cells from a single mouse aorta. This technique is particularly useful when material is limiting, as is frequently the case when genetically modified animals are being characterized.

The spectrum of growth abnormalities in children with 18q deletions

The objective of this study was to assess the spectrum of growth abnormalities in children with 18q deletions. The growth axis of 50 individuals with a cytogenetically and molecularly confirmed 18q deletion was investigated by determining height, growth velocity, insulin-like growth factor I (IGF-I), IGF-binding protein-3, bone maturation, and response to pituitary stimulants of GH. Children with 18q deletions are short; 64% have a height more than -2 SD below the mean. Affected children also grow slowly; 68% have a growth velocity more than -1 SD below the mean. Half of the individuals have delayed bone maturation. Growth factors are skewed downward; 72% of the IGF-I values and 83% of the IGF-binding protein-3 values are below the mean for chronological age. Similarly, 72% of the children had a reduced or absent response to either of the GH stimulants, arginine and clonidine. In the total group of 50 children only 2 were normal for all parameters evaluated. Short stature and poor growth are common features of individuals with 18q deletions. GH deficiency is common in this cohort of patients and probably plays a role in the short stature seen in many of the affected individuals.

Residues and mechanisms for slow activation and Ba2+ block of the cardiac muscarinic K+ channel, Kir3.1/Kir3.4

Mechanisms and residues responsible for slow activation and Ba(2+) block of the cardiac muscarinic K(+) channel, Kir3.1/Kir3.4, were investigated using site-directed mutagenesis. Mutagenesis of negatively charged residues located throughout the pore of the channel (in H5, M2, and proximal C terminus) reduced or abolished slow activation. The strongest effects resulted from mutagenesis of residues in H5 close to the selectivity filter; mutagenesis of residues in M2 and proximal C terminus equivalent to those identified as important determinants of the activation kinetics of Kir2.1 was less effective. In giant patches, slow activation was present in cell-attached patches, lost on excision of the patch, and restored on perfusion with polyamine. Mutagenesis of residues in H5 and M2 close to the selectivity filter also decreased Ba(2+) block of the channel. A critical residue for Ba(2+) block was identified in Kir3.4. Mutagenesis of the equivalent residue in Kir3.1 failed to have as pronounced an effect on Ba(2+) block, suggesting an asymmetry of the channel pore. It is concluded that slow activation is principally the result of unbinding of polyamines from negatively charged residues close to the selectivity filter of the channel and not an intrinsic gating mechanism. Ba(2+) block involves an interaction with the same residues.

Cs+ block of the cardiac muscarinic K+ channel, GIRK1/GIRK4, is not dependent on the aspartate residue at position 173

Cs+ block of GIRK1/GIRK4 expressed in Xenopus oocytes has been investigated. It has been reported that a negatively charged aspartate residue at position 172 in IRK1 is responsible for Cs+ block of the channel. IRK1, a homotetramer, has four aspartate residues at this position. GIRK1/GIRK4 is a heterotetramer and has two aspartate residues at the equivalent position (GIRK1-D173) and, consequently, it should be less sensitive to Cs+. Cs+ caused voltage-dependent block of GIRK1/GIRK4 current (measured with the two-microelectrode voltage-clamp technique). The apparent fraction of the electrical field through which Cs+ moves in order to reach its site of block (delta approximately equals 1.66) is comparable to that in IRK1, suggesting that Cs+ binds to a similar site in the two channels. GIRK1/GIRK4 was less sensitive than IRK1 to Cs+ -the Kd was 3.0-8.5 times greater and at potentials more negative than approximately or = to 130 mV there was voltage-dependent relief of block of GIRK1/GIRK4 (not the case with IRK1). However, the mutations GIRK1-D173A and GIRK1-D173Q increased the sensitivity of the channel to Cs+, while adding a negatively charged aspartate residue to GIRK4 at the equivalent position (GIRK4-N 79D) decreased Cs+ sensitivity. GIRK1-D173 cannot be the site of Cs+ block of GIRK1/GIRK4.

Inhibition of the K+ channel kv1.4 by acidosis: protonation of an extracellular histidine slows the recovery from N-type inactivation

1. Acidosis alters the transient outward current, ito, in the heart. We have studied the mechanism underlying the effect of acidosis on one of the K+ channels, Kv1.4 (heterologously expressed in Xenopus laevis oocytes), known to underlie ito. 2. At pH 6.5, wild-type Kv1.4 current was inhibited during repetitive pulsing, in part as a result of a slowing of recovery from N-type inactivation. 3. Acidosis still caused slowing of recovery after deletion of just one (either the first or second) of the N-terminal inactivation ball domains. However, deletion of both the N-terminal inactivation ball domains greatly reduced the inhibition. 4. As well as the N-terminus, other parts of the channel are also required for the effect of acidosis, because, whereas the transfer of the N-terminus of Kv1.4 to Kv1.2 conferred N-type inactivation, it did not confer acidosis sensitivity. 5. Replacement of an extracellular histidine with a glutamine residue (H508Q) abolished the slowing of recovery by acidosis. Reduction of C-type inactivation by raising the bathing K+ concentration or by the mutation K532Y also abolished the slowing. 6. It is concluded that binding of protons to H508 enhances C-type inactivation and this causes a slowing of recovery from N-type inactivation and, thus, an inhibition of current during repetitive pulsing.