Lower adiponectin is associated with higher anthropometry and insulin resistance but not with low cardiorespiratory fitness in adolescents

PURPOSE

The aim of this study was to analyze the relationship between adiposity, cardiometabolic risk and cardiorespiratory fitness (CRF) according to different groups of adiponectin concentration.

METHODS

255 adolescents of both sexes, aged 11-17 years old, participated. Anthropometric and biochemical parameters such as body mass, height, abdominal circumference (AC), waist circumference (WC), fat mass, fat-free mass, total cholesterol (TC), high-density lipoprotein (HDL-c), low-density lipoprotein (LDL-c), triglycerides (TG), glucose, insulin, adiponectin, blood pressure, peak oxygen consumption (VO2peak) were measured. Body mass index (BMI), z-score BMI (BMI-z), triponderal mass index (TMI), waist-to-height ratio (WHtR), homeostasis model to assessment insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) were calculated. Adiponectin was categorized: low adiponectin concentration (LAC  ≤ 5.18 µg/mL-1), intermediate (IAC = 5.18 and 7.63 µg/mL-1) and high (HAC ≥ 7.63 µg/ml-1).

RESULTS

LAC showed higher BMI, BMI-z and TMI than the other groups (p < 0.05) and higher AC, WC and WHtR that the HAC (p < 0.05). IAC showed lower values of TC, LDL-c and TG, and the LAC presented the highest values of insulin, HOMA-IR and QUICKI (p < 0.05) to the IAC and HAC. HAC presented the lower VO2peak than the other groups (p < 0.01). BMI, TMI, glucose, insulin, HOMA-IR showed inverse, and QUICKI a direct and weak correlation with adiponectin (p < 0.05). No significant association was found between adiponectin and VO2peak (p > 0.05).

CONCLUSION

The LAC group had higher means in the anthropometric variables and the worst results related to insulin resistance and sensitivity. Thus, adiponectin may play an important role in obesity and reduced concentration may be a factor in the development of obesity-associated morbidities.

Morphophysiological changes of Acca sellowiana (Myrtaceae: Myrtoideae) saplings under shade gradient

Understanding morphological and physiological changes under different light conditions in native fruit species in juveniles' stage is important, as it indicate the appropriate environment to achieve vigorous saplings. We aimed to verify growth and morphophysiological changes under shade gradient in feijoa (Acca sellowiana (O. Berg) Burret) to achieve good quality saplings adequate to improve cultivation in orchards. The saplings were grown for twenty-one-month under four shading treatments (0%, 30%, 50%, and 80%). Growth, photosynthetic pigments, gas exchanges, chlorophyll fluorescence, and leaf anatomy parameters were evaluated. Saplings under full sun and 30% shade had higher height and diameter growth and dry mass accumulation due to higher photosynthesis rate. As main acclimatization mechanisms in feijoa saplings under 80% shade were developed larger leaf area, reduced leaf blade thickness, and enhanced quantum yield of photosystem II. Even so, the net CO2 assimilation and the electron transport rate was lower and, consequently, there was a restriction on the growth and dry mass in saplings under deep shade. Therefore, to obtain higher quality feijoa saplings, we recommend that it be carried out in full sun or up to 30% shade, to maximize the sapling vigor in nurseries and, later, this light environment can also be used in orchards for favor growth and fruit production.

Culex quinquefasciatus predominance during integrated mosquito surveillance in an urban area of the Brazilian Amazon

Abstract The presence and establishment of Culicidae in urban areas increase the transmissibility of tropical diseases, since some species can participate as vectors of pathogens. Thus, this study aimed to evaluate the indoor and outdoor abundance of immature and adult populations of Culicidae at the urban area of Porto Velho, Rondônia. Mosquitoes were captured using electric aspirators and ovitraps in September and December 2018 in 27 households spread over nine neighborhoods. A total of 2,342 specimens were collected, distributed among five species, of which Culex quinquefasciatus (Say, 1823), Aedes aegypti (Linnaeus, 1762) and Aedes albopictus (Skuse, 1894) were the most abundant. Considering the sum total obtained by both techniques, more mosquitoes were captured indoors than outdoors. However, the GLM estimates for the ovitrap technique showed that immature Ae. aegypti, Ae. albopictus and Cx. quinquefasciatus were significantly more abundant in the outdoors, on average. The opposite result was observed for electrical aspiration, in which Ae. aegypti and Cx. quinquefasciatus adults were more abundant indoors. The average number of winged Ae. albopictus showed no significant difference between indoors and outdoors. Our findings corroborate the data on the abundance and incidence of these three species in other regions of Brazil, highlighting the need for continuous surveillance due to their importance in disease transmission to humans. We also demonstrated that the ovitrap is a sensitive device to monitor Cx. quinquefasciatus larvae and wild species that occasionally frequent urban areas, and thus can be used for surveillance, especially when there are budgetary constraints. Therefore, we emphasize that the combination of techniques, in addition to identifying which species and which stage of development are more frequent inside and outside households, also allows for the implementation of specific and integrated control measures.

Development and evaluation of a low-density single-nucleotide polymorphism chip specific to Bos indicus cattle

Context Genomic selection has been of increasing interest in the genetic improvement of Zebu cattle, particularly for quantitative traits that are difficult or expensive to measure, such as carcass traits and meat tenderness. The success of genomic selection depends on several factors, and at its core is the availability of single-nucleotide polymorphism (SNP) chips that are appropriately designed for Bos indicus cattle. However, the currently available commercial bovine SNP chips are mostly designed for Bos taurus cattle. There are two commercial Bos indicus SNP chips; namely, GeneSeek genomic profiler high-density Bos indicus (GGP-HDi) SNP chip and a low-density (LD) Bos indicus SNP chip (Z chip), but these two Bos indicus SNP chips were built with mixed contents of SNPs for Bos indicus and Bos taurus cattle, due to limited availability of genotype data from Bos indicus cattle. Aims To develop a new GGP indicus 35000 SNP chip specifically for Bos indicus cattle, which has a low cost, but high accuracy of imputation to Illumina BovineHD chips. Methods The design of the chip consisted of 34000 optimally selected SNPs, plus 1000 SNPs pre-reserved for those on the Y chromosome, ‘causative’ mutations for a variety of economically relevant traits, genetic health conditions and International Society for Animal Genetics globally recognised parentage markers for those breeds of cattle. Key results The present results showed that this new indicus LD SNP chip had considerably increased minor allele frequencies in indicus breeds than the previous Z-chip. It demonstrated with high imputation accuracy to HD SNP genotypes in five indicus breeds, and with considerable predictability on 14 growth and reproduction traits in Nellore cattle. Conclusions This new indicus LD chip represented a successful effort to leverage existing knowledge and genotype resources towards the public release of a cost-effective LD SNP chip specifically for Bos indicus cattle, which is expected to replace the previous GGP indicus LD chip and to supplement the existing GGP-HDi 80000 SNP chip. Implications A new SNP chip specifically designed for Bos indicus, with high power of imputation to Illumina BovineHD technology and with excellent coverage of the whole genome, is now available on the market for Bos indicus cattle, and Bos indicus and Bos taurus crosses.

Abstract P1-15-16: Pathological complete response rates with the addition of carboplatin to standard neoadjuvant chemotherapy in a cohort of real–world patients with triple negative breast cancer

Objectives: Addition of carboplatin to standard neoadjuvant chemotherapy (NACT) for triple negative breast cancer (TNBC) remains controversial. There are several randomized trials showing that carboplatin increases the likelihood of achieving pathological complete response (pCR) in TNBC. Patients with TNBC who achieve pCR has been shown to have better disease-free and overall survival. The aim of this study was to asses the impact of adding carboplatin to standard NACT in TNBC in terms of pCR rates and toxicity. Methods:In this cross-sectional study, 252 consecutive patients with primary TNBC who were submitted to neoadjuvant chemotherapy between 2013 and 2018, in a single center, were selected. Patients with biopsy-confirmed TNBC, previously untreated, with clinical stages I-III were included (n=179). Clinical pathological features, pathological response, treatment protocol, and toxicities were analyzed and considered for statistical analysis. Eighty patients treated from 2013 to 2015 received doxorubicin plus cyclophosphamide once every 3 weeks (AC) for four cycles, followed by 12 weeks (wP) or every 3 weeks (P) paclitaxel(AC-T group). Ninety-nine patients, treated from 2015 to 2018 had four cycles of AC followed by wP plus weekly carboplatin (Cb) area under curve (AUC) 1.5-2.0 (AC-TCb group). Pathologic response was determined locally, and pCR was defined as the absence of residual invasive disease with or without ductal carcinoma in situ in the breast and axilla. Results: Data from 179 patients were included in the analysis (AC-T: n=80; AC-TCb: n=99). Patients in AC-TCb group had a median age of 51.7 years vs. 47.4 years in AC-T group, p=0.01. In AC-TCb group 61.6% of patients were postmenopausal vs 43.7% in AC-T group, p=0.03. The distribution of clinical stage in groups AC-TCb and AC-T were as follows: stage I 6.0% vs 0%; stage II 42.4% vs 43.7%; stage III 51.6% vs 56.3%, respectively (p=0.02). In AC-TCbgroup, 34 patients (35.0%) had pCR in comparison to 20 patients (25.0%) on AC-T group (p=0.22). Pathological stage distribution in groups AC-TCb and AC-T were: stage I 24.7% vs 33.7%; stage II 23.7% vs 26.3%; stage III 16.4% vs 15%, respectively (p=0.42). More than 85.0% of patients in AC-TCb group received at least 9 weeks of carboplatin and less than 20.0% required dose reduction due to toxicity.Conclusions: An improved pathological complete response for TNBC patients submitted to standard NACT plus carboplatin was observed. The results are in accordance with previous studies demonstrating that the addition of carboplatin to NACT improves pCR rate in TNBC with a favorable risk to benefit profile. Therefore carboplatin might be a potential component of NACT and should be considered in this context.

Distribution of patients with TNBC submitted to NACT with AC-T and AC-TCb according clinical–pathological characteristicsClinical pathological characteristicsAC-T n= 80AC-TCb n=99pMenopausal  0.03yes3561 no4538 Clinical stage  0.02I06 II3542 III4551 Histologic type  0.25IDC8096 others03 Histologic grade  0.86101 22932 35164 Pathological stage  0.42O2034 I2724 II2123 III1216 pCR  0.22yes2034 no6063 

Citation Format: Ramalho S, Natal RdA, Cardoso Filho C, Xavier MB, da Silva AER, Silva LR, Vasconcelos V, Reinert T, Coelho GP, Silva GRdP, dos Santos CC. Pathological complete response rates with the addition of carboplatin to standard neoadjuvant chemotherapy in a cohort of real–world patients with triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-15-16.

Molecular bloodmeal analyses reveal that Trypanosoma cruzi-infected, native triatomine bugs often feed on humans in houses in central Brazil

The identification of bloodmeal sources in triatomine bugs (Hemiptera: Reduviidae) is important in understanding vector-host associations and in measuring the risk for Chagas' disease transmission. The bloodmeal sources of triatomines infected with Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae) caught in houses in central Brazil (Goiás State and the Federal District) were investigated during 2012-2014. Mitochondrial cytochrome b amplicons were used to identify bloodmeals through high-resolution melting and DNA sequencing. Most bugs were found to have fed on either humans (45.7%) or chickens (43.1%). Human blood was detected in Triatoma sordida (n = 22/50 bugs), Triatoma pseudomaculata (n = 7/11 bugs), Panstrongylus megistus (n = 10/24 bugs), Panstrongylus geniculatus (n = 1/3 bugs) and Rhodnius neglectus (n = 18/28 bugs) (all: Hemiptera: Reduviidae). Sequencing identified Necromys (Rodentia: Cricetidae) mouse blood in P. geniculatus and Tropidurus (Squamata: Tropiduridae) lizard blood in T. pseudomaculata and T. sordida. These findings reveal new vector-host associations. The present results suggest frequent contact between humans and T. cruzi-infected triatomines in central Brazil and indicate that Chagas' disease transmission by native vectors is an ongoing threat.

Dydrogesterone vs progesterone for luteal-phase support: systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To compare the effects of dydrogesterone and progesterone for luteal-phase support (LPS) in women undergoing assisted reproductive techniques (ART).

METHODS

We performed a systematic review to identify relevant randomized controlled trials (RCTs) by searching the following electronic databases: Cochrane CENTRAL, PubMed, Scopus, Web of Science, ClinicalTrials.gov, ISRCTN Registry and WHO ICTRP.

RESULTS

The last search was performed in October 2015. Eight RCTs were considered eligible and were included in the review and meta-analyses. There was no relevant difference between oral dydrogesterone and vaginal progesterone for LPS with respect to rate of ongoing pregnancy (risk ratio (RR), 1.04 (95% CI, 0.92-1.18); I(2) , 0%; seven RCTs, 3134 women), clinical pregnancy (RR, 1.07 (95% CI, 0.93-1.23); I(2) , 34%; eight RCTs, 3809 women) or miscarriage (RR, 0.77 (95% CI, 0.53-1.10); I(2) , 0%; seven RCTs, 906 clinical pregnancies). Two of the three studies reporting on dissatisfaction of treatment identified lower levels of dissatisfaction among women using oral dydrogesterone than among women using vaginal progesterone (oral dydrogesterone vs vaginal progesterone capsules: 2/79 (2.5%) vs 90/351 (25.6%), respectively; oral dydrogesterone vs vaginal progesterone gel: 19/411 (4.6%) vs 74/411 (18.0%), respectively). The third study showed no difference in dissatisfaction rate (oral dydrogesterone vs vaginal progesterone capsules: 8/96 (8.3%) vs 8/114 (7.0%), respectively).

CONCLUSIONS

Oral dydrogesterone seems to be as effective as vaginal progesterone for LPS in ART cycles, and appears to be better tolerated . Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

A serological study of Cryptosporidium transmission in a periurban area of a Brazilian Northeastern city

OBJECTIVES

To study the prevalence of Cryptosporidium infection by measuring the levels of anti-Cryptosporidium IgG antibodies among people inhabiting three neighbourhoods of a periurban area of Salvador, Northeast of Brazil; and to investigate the effects of environmental sanitation measures, hygienic habits and household water supply, storage and handling on the frequency of these antibodies in sera of the studied population.

METHODS

Cryptosporidium inter-household transmission was studied by comparing the frequency of anti-Cryptosporidium IgG antibodies among people inhabiting areas with or without different environmental sanitation measures and intra-household transmission by comparing the presence of these antibodies in families with or without cases of diarrhoea, associated with the presence of Cryptosporidium oocysts in their stools. Children or family members with diarrhoeal episodes were evaluated parasitologically for Cryptosporidium infection by testing stool specimens with the Ritchie-modified formol-ether concentration and the acid-fast staining methods. All groups were serologically evaluated for parasite exposure by an indirect enzyme-linked immunosorbent assay.

RESULTS

A statistically significant difference was detected in the prevalence of Cryptosporidium infection between area 1 which had no environmental sanitation measures and area 3 which had improved environmental sanitation measures (P = 0.044). Most of the hygienic habits investigated did not correlate with the presence of anti-Cryptosporidium antibody in sera of the population studied. However, positive associations were found between both poor household water supply (OD = 0.17; 90% CI = 0.09-0.32; P = 0.0001) and drinking unboiled/unfiltered water (OD = 0.40; 90% CI = 0.24-0.67; P = 0.0002) with high levels of anti-Cryptosporidium antibodies in sera.

CONCLUSIONS

These data suggest that although uncorrected household water supply, storage and handling play an important role on Cryptosporidium transmission in periurban areas of developing country cities, like Salvador, Brazil, inadequate environmental conditions may also contribute to the spread of this parasite.

Glutamine and alanyl-glutamine accelerate the recovery from 5-fluorouracil-induced experimental oral mucositis in hamster

INTRODUCTION

Mucositis induced by anti-neoplastic drugs is an important, dose-limiting and costly side effect of cancer therapy.

AIM

To evaluate the effect of oral glutamine and alanyl-glutamine, a more stable glutamine derivative, on 5-FU-induced oral mucositis in hamsters.

MATERIALS AND METHODS

Oral mucositis was induced by two intraperitoneal (i.p) administrations of 5-FU on the first and second days of the experiment (60 and 40 mg/kg, respectively) followed by mechanical trauma on the fourth day in male hamsters. Animals received saline, glutamine or alanyl-glutamine suspension (100 mM) 1 h before the injections of 5-FU and daily until sacrifice, on the 10th or 14th day. Macroscopic and histopathological analyses were evaluated and graded. Tissues from the cheek pouches were harvested for measurement of myeloperoxidase activity and glutathione stores. For investigation of serum concentration of glutamine, blood was obtained by heart puncture from anesthetized animals before sacrifice, on day 10.

RESULTS

Treatment with glutamine and alanyl-glutamine reduced macroscopic and histological parameters of oral mucositis, and reduced the myeloperoxidase activity on day 14, but not on day 10. The 5-FU-induced oral mucositis significantly decreased the serum glutamine levels as well as the cheek pouch glutathione stores observed on day 10. Glutamine or alanyl-glutamine administration reversed the 5-FU effects, restoring serum glutamine levels and cheek pouch glutathione stores, observed on day 10, but did not prevent oral mucositis on the tenth day.

CONCLUSION

Glutamine or alanyl-glutamine accelerated the mucosal recovery increasing mucosal tissue glutathione stores, reducing inflammatory parameters and speeding reepithelization.

Role of nitric oxide on pathogenesis of 5-fluorouracil induced experimental oral mucositis in hamster

INTRODUCTION

Mucositis induced by antineoplastic drugs is an important, dose-limiting, and costly side effect of cancer therapy.

AIM

To investigate the role of nitric oxide (NO) on the pathogenesis of 5-fluorouracil (5-FU)-induced oral mucositis.

MATERIALS AND METHODS

Oral mucositis was induced by two intraperitoneal (i.p) administrations of 5-FU on the first and second days of the experiment (60 and 40 mg/kg, respectively) in male hamsters. Animals were treated subcutaneously with saline (0.4 ml), 1,400 W (1 mg/kg), aminoguanidine (5 or 10 mg/kg) or Nphi-Nitro-L-Arginine Methyl Ester (L-NAME) (5, 10, or 20 mg/kg) 1 h before the injections of 5-FU and daily until sacrifice, on the tenth day. Macroscopic and histopathological analyses were evaluated and graded. Tissues from the cheek pouches were harvested for measurement of myeloperoxidase (MPO) activity, nitrite level, and immunohistochemistry for induced nitric oxide synthase (iNOS).

RESULTS

Treatment with 1,400 W or aminoguanidine reduced macroscopic and histological parameters of oral mucositis, and reduced the inflammatory cell infiltration as detected by histopathology and by MPO activity. In contrast, the administration of L-NAME did not significantly reverse the inflammatory alterations induced by experimental mucositis. Increased NOS activity, nitrite level and immunostaining for iNOS were detected on the check pouch tissue of animals submitted to 5-FU-induced oral mucositis on the tenth day.

CONCLUSION

These results suggest an important role of NO produced by iNOS in the pathogenesis of oral mucositis induced by 5-FU.

A novel heterodimeric antimicrobial peptide from the tree-frog Phyllomedusa distincta

We present here the purification and the analysis of the structural and functional properties of distinctin, a 5.4 kDa heterodimeric peptide with antimicrobial activity from the tree-frog Phyllomedusa distincta. This peptide was isolated from the crude extract of skin granular glands by different chromatographic steps. Its minimal inhibitory concentration was determined against pathogenic Escherichia coli, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa strains. Amino acid sequencing and mass spectrometric investigations demonstrated that distinctin is constituted of two different polypeptide chains connected by an intermolecular disulphide bridge. Circular dichroism and Fourier-transformed infrared spectroscopy studies showed that this molecule adopts, in water, a structure containing a significant percentage of anti-parallel beta-sheet. A conformational variation was observed under experimental conditions mimicking a membrane-like environment. Database searches did not show sequence similarities with any known antimicrobial peptides. In the light of these results, we can consider distinctin as the first example of a new class of antimicrobial heterodimeric peptides from frog skin.

[Deflazacort and colonic anastomotic healing. An experimental study in rats]

BACKGROUND

Deflazacort, a new corticosteroid is claimed to induce less collateral effects than other corticoids. The aim of this study was to investigate the effect of this drug on the healing of colonic anastomosis.

MATERIAL AND METHOD

75 Wistar rats were randomized to receive daily by gavage, one of the following treatments: control group (N=24) - 1 ml of saline; deflazacort (N=25) - 1 ml of this drug containing 0.15mg/ml (0,1 mg/kg/day), and dexamethasone (N=26) - 1 ml containing 0.03 mg/ml of this drug (0.5 mg/kg/day). After 6 days of treatment, the animals underwent laparotomy followed by section and immediate colonic anastomoses in a point 2 cm above peritoneal reflexion. Treatment in each group was carried out until the animals were killed on the third of a six postoperative day. At necroscopy, signs of peritonitis and anastomotic dehiscence were registered. Anastomotic site was tested for tensile rupture and biopsies containing all layers were sent for hydroxyproline and protein measurements.

RESULTS

There was no difference in the peritonitis and anastomotic dehiscence rates among the groups. Bowel rupture pressure was similar at day 3 but significantly higher in controls (180 [150-230] mmHg) than in deflazacort (150 [120-180] mmHg) and dexamethasone groups (140 [100-180] mmHg) at day 6. No difference occurred in the hydroxyproline concentration. Protein content was higher in dexamethasone group than in controls on the third postoperative day.

CONCLUSIONS

Corticosteroids may impair colonic anastomotic resistance and deflazacort may have similar deleterious effects of dexamethasone in anastomotic healing.

Survival after acute myocardial infarction in patients with end-stage renal disease: results from the cooperative cardiovascular project

Cardiovascular disease (CVD) is the most common cause of death in patients with end-stage renal disease (ESRD). The optimal management strategy in this population is unknown. We studied 640 patients with ESRD and acute myocardial infarction during 1994 to 1995 as part of the Health Care Financing Administration's Cooperative Cardiovascular Project. The majority of patients were treated with medical therapy alone, 46 patients (7%) were treated with percutaneous transluminal coronary angioplasty (PTCA), and 29 patients (5%) underwent coronary artery bypass grafting (CABG). Patient characteristics and comorbid conditions were similar among the three groups. The overall 1-year mortality rate was 53%. Advanced age, low or high body mass index, history of peripheral vascular disease or stroke, the inability to walk independently, and several indicators of cardiac dysfunction were associated with an increased relative risk (RR) for death. Survival curves differed significantly by treatment modality, with 1-year survival rates of 45%, 54%, and 69% in the medical therapy alone, PTCA, and CABG groups, respectively (P = 0.03). After adjustment for confounding variables, the RR for death was less (but not significantly so) in the CABG group (RR, 0.6; 95% confidence interval, 0.3 to 1.1). There are no randomized clinical trial data to guide therapy of CVD in patients with ESRD. On the basis of these and other available data, CABG may be the optimal therapy for CVD in ESRD. In light of the exceptionally poor outcomes observed for patients treated with medical therapy alone, it may be premature to dismiss PTCA as a therapeutic option in this population.

[The patient's perspective. Reflections on past, present, and future in the chronic illness experience]

The illness experience is a relevant issue in current research and academic discussions. A growing number of research initiatives have undertaken to account for the subject's perspective and subjectivity in the health field. This paper discusses our research team's approach and results in studying the experience of people living with chronic illness. Our perspective is based upon the production in this relatively new field as well as health-related discussions in Latin America. The illness experience calls for an understanding of it as a subjective and existential phenomenon, entailing the phenomenological arena, immersed in the process where ill people "produce" and "reproduce" themselves. The unfolding and course of the illness as well as treatment management are some salient dimensions we evoke. Some lines of future work are presented in order to create a research agenda, highlighting its implications for existing proposals pertaining to health reform in our Latin American countries.

Omega-conotoxin sensitivity and presynaptic inhibition of glutamatergic sensory neurotransmission in vitro

Synaptic transmission between embryonic chick dorsal root ganglion (DRG) neurons and spinal cord neurons was studied in dissociated cell culture. Stimulation of DRG neurons evoked monosynaptic and polysynaptic excitatory responses in the spinal neurons. These responses could be reversibly blocked by application of 6-cyano-7-nitroquinoxaline-2,3-dione (a selective non-NMDA receptor antagonist) and irreversibly eliminated through the presynaptic action of omega-conotoxin GVIA (a selective N-type calcium channel antagonist). As N-type calcium channels in DRG neuron somata are targets for modulation via GABAB receptors, we tested the role of these receptors as regulators of synaptic transmission. Baclofen (a selective GABAB receptor agonist) reversibly inhibited synaptic transmission via a presynaptic, pertussis toxin-sensitive mechanism; CGP 35348 (a selective GABAB receptor antagonist) blocked the actions of baclofen. Taken together, these results demonstrate that N-type calcium channels play a dominant role in glutamatergic sensory neurotransmission. They suggest, in addition, that modulation of N-channel activity may underlie, at least in part, presynaptic inhibition of synaptic transmission between DRG neurons and their targets in the intact spinal cord.

Mitral valvuloplasty with a new prosthetic ring. Analysis of the first 105 cases

From October 1987 to March 1993, 105 patients were studied who have undergone valvuloplasty with an open ring. They ranged from 5 to 79 years (mean 30); 33 (31.4%) were under 16. All patients had mitral insufficiency, alone in 62 (59.0%) and associated with mitral stenosis (double mitral lesion) in 43 (41.0%). In the majority of the cases, the aetiology was rheumatic (78.1%); active in 10 (9.5%) patients. Three patients (2.9%) were in class II, 42 (40.0%) in class III, 57 (54.3%) in class IV and 3 (2.9%) in class V. Ten patients (9.5%) had isolated ring implantation while the remaining underwent associated procedures on the leaflets, chordae and papillary muscles. There were two (1.9%) hospital deaths, and six patients (5.7%) had to be reoperated. On the 30th (mean) postoperative day, 75 (71.4%) patients were reevaluated by catheterization, echo Doppler or both to confirm the effectiveness of the techniques employed. The mitral valve was functioning normally or with mitral regurgitation + in 63 (84.0%) patients, mitral regurgitation + + in 2 (2.7%), mitral regurgitation + + + in 5 (6.7%), mitral stenosis + in 4 (5.3%), and mitral stenosis + + in 1 (1.3%) patient. The results were therefore considered excellent in 63 (84.0%) patients with either normal mitral valve or mitral regurgitation +, good in 6 (8.0%) patients with mitral regurgitation + + and/or mitral stenosis +, and poor in 6 (8.0%) patients with mitral regurgitation + + + and/or mitral stenosis + +. Two deaths (1.9%) occurred within the first 7 months of follow-up. Patients were evaluated clinically 1-67 months postoperatively (mean 27):90 (85.7%) were in class I, 4 (3.8%) in class II, 4 (3.8%) in class III and 1 (1.0%) in class IV.(ABSTRACT TRUNCATED AT 250 WORDS)

Laminar distribution of neuronal membrane properties in neocortex of normal and reeler mouse

1. Reeler is an autosomal recessive mutation of mice that alters neuronal migration during development, yielding a general inversion of the laminae in the neocortex. We recorded in vitro from slices of normal and reeler neocortex to study the influence of neuron position and shape on membrane properties and synaptic responses. 2. The intrinsic firing patterns, action-potential shapes, resting membrane potentials, input resistances, and evoked excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) did not differ between reelers and controls when data were grouped. 3. The depth distribution of intrinsic firing patterns was inverted in the reeler: intrinsically bursting (IB) neurons were found only in layer 5 in the normal mouse, but they were found exclusively in supragranular layers of the reeler cortex. 4. The spatial distribution of synaptic responses in the reeler was also inverted: very prominent IPSPs were characteristic of upper layer neurons in the normal mouse, but in the reeler similar inhibitory responses were observed predominantly in deep infragranular layers. 5. Dye injections in reeler pyramidal neurons revealed atypical morphologies, including distorted apical dendrites and cell inversion. 6. The data imply that cortical neurons develop the membrane and synaptic properties appropriate to their function, despite being malformed and mispositioned.

Intrinsic oscillations of neocortex generated by layer 5 pyramidal neurons

Rhythmic activity in the neocortex varies with different behavioral and pathological states and in some cases may encode sensory information. However, the neural mechanisms of these oscillations are largely unknown. Many pyramidal neurons in layer 5 of the neocortex showed prolonged, 5- to 12-hertz rhythmic firing patterns at threshold. Rhythmic firing was due to intrinsic membrane properties, sodium conductances were essential for rhythmicity, and calcium-dependent conductances strongly modified rhythmicity. Isolated slices of neocortex generated epochs of 4- to 10-hertz synchronized activity when N-methyl-D-aspartate receptor-mediated channels were facilitated. Layer 5 was both necessary and sufficient to produce these synchronized oscillations. Thus, synaptic networks of intrinsically rhythmic neurons in layer 5 may generate or promote certain synchronized oscillations of the neocortex.

Two inhibitory postsynaptic potentials, and GABAA and GABAB receptor-mediated responses in neocortex of rat and cat

1. Pyramidal neurones from layers II and III of the rat primary somatosensory cortex and cat primary visual cortex were studied in vitro. Inhibitory postsynaptic potentials (IPSPs) and responses to exogenously applied gamma-aminobutyric acid (GABA) and its analogue baclofen were characterized. The results from rats and cats were very similar. 2. Single electrical stimuli to deep cortical layers evoked a sequence of PSPs in the resting neurone: (a) an initial, brief excitation (EPSP), (b) a short-latency, fast inhibition (the f-IPSP) and (c) a long-latency, more prolonged inhibition (the l-IPSP). The f-IPSP was accompanied by a large conductance increase (about 70-90 nS) and reversed polarity at -75 mV; the l-IPSP displayed a relatively small conductance increase (about 10-20 nS) and reversed at greater than -90 mV. 3. Focal application of GABA near the soma evoked a triphasic response when measured near the threshold voltage for action potentials: (a) the GABAhf (hyperpolarizing, fast) phase was very brief and was generated by a large conductance increase with a reversal potential of -78 mV, (b) the GABAd (depolarizing) phase also had a high conductance but reversed at -51 mV, (c) the GABAhl (hyperpolarizing, long-lasting) phase had a relatively low conductance and reversed at -70 mV. The GABAhf response was specifically localized to the soma, whereas the apical or basilar dendrites generated predominantly GABAd responses. 4. Baclofen, a selective GABAB receptor agonist, caused a small (about 2 mV), slow hyperpolarization of the resting potential, which reversed at -90 mV. Saturating baclofen doses increased membrane conductance by a maximum of about 12 nS. Baclofen depressed the amplitude and conductance of PSPs; when baclofen was focally applied near the soma. IPSPs were selectively depressed. 5. The GABAA receptor antagonists bicuculline methiodide or picrotoxin (10 microM) greatly depressed f-IPSPs, but either enhanced or did not affect l-IPSPs. Concomitantly, GABAhf and GABAd responses were antagonized, leaving a more prominent GABAhl response that reversed polarity at a more negative level of -87 mV. Baclofen responses were unaffected by bicuculline and picrotoxin. Extracellular barium abolished the baclofen response, and shifted the reversal potentials of the GABAd and GABAhl responses in the positive direction; the GABAhf response was unaffected. 6. Both focal GABA and f-IPSPs strongly depressed the intrinsic excitability of pyramidal neurones. Each greatly increased spike threshold and abolished or vastly reduced the capacity of the cells to fire repetitively during intense stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

Cherubism, gingival fibromatosis, epilepsy, and mental deficiency (Ramon syndrome) with juvenile rheumatoid arthritis

This is a report on four persons in one family with a condition similar to that described by Ramon et al [Oral Surg 24:436-48, 1967] in two sibs born to a consanguineous couple. Our patients also had mental deficiency, epilepsy, cherubism due to fibrous dysplasia of the maxillae, gingival fibromatosis, hypertrichosis, and stunted growth. This appears to be an autosomal recessive trait in both families. Our patients are the second set reported with this syndrome; they also have juvenile rheumatoid arthritis, which was not described in the family reported by Ramon et al [Oral Surg 24:436-48, 1967]. We conclude that the Ramon syndrome should also include juvenile rheumatoid arthritis.

An investigation of the factors affecting development of frontal cortex self-stimulation

Intracranial self-stimulation (ICSS) of the medial prefrontal cortex (MFC) is acquired gradually, taking 4 or more days to establish. One explanation for this finding is that the stimulation becomes more rewarding with repetition. Four experiments were conducted to test this hypotheses. In Experiment 1, the MFC ICSS frequency thresholds remained constant over the first 3 weeks of testing while the rate of lever pressing response increased. In Experiment 2, it was found that acquisition of MFC ICSS was much more rapid when a motorically simpler response (nose-poking) was employed. Similarly, Experiments 3 and 4 further demonstrated that response factors such as task complexity may ultimately determine the rate of development of frontal cortex ICSS. Overall, these data suggest that independent of the rewarding effects of MFC stimulation there are other effects that initially interfere with learning of complex operant responses.