Contraction of developing avian heart muscle

26 patients with at least one clinical symptom that could indicate a tear of the scapho-lunate interosseous ligament but normal static and dynamic radiographs were examined by arthroscopy. We found that a diagnosis of scapho-lunate instability could be established by dynamic manoeuvres during radio-carpal and mid-carpal arthroscopy. Five patients were found to have true scapholunate instability. Six tears of the interosseous ligament without instability were also detected but it was doubtful if the tear was the origin of the painful symptomatology. This experience suggests that dynamic manoeuvres during arthroscopy are superior to other methods in diagnosing scapholunate instabilities at the pre-radiographic stage.     

Biosynthesis of progesterone derived neurosteroids by developing avian CNS: in vitro effects on the GABAA receptor complex

Although enthusiasm for measuring health-related quality of life (HRQL) in clinical trials exists, information is limited on the meaning of scores. We examined the relation between scores from the 34-item Medical Outcomes Study HIV Health Survey (MOS-HIV) and the more detailed HIV Overview of Problems-Evaluation System (HOPES) using the responses of 318 HIV-infected outpatients being treated in Los Angeles and Baltimore. With the HOPES problem statements as independent variables, statistically significant predictors of the variation in MOS-HIV scores for the Physical Function, Mental Health, and Energy/Fatigue scales were identified using stepwise regression. Approximately 60% to 70% of the variation in each of the scores was explained by five to seven different HOPES problem statements, with a single item explaining 47% to 59% of the variation. We created illustrative profiles for each of the three MOS-HIV scales using the HOPES items identified in the regressions. Independent of the scale, persons scoring in the top MOS-HIV quartile tended to report few if any problems, whereas a decline in score to the next quartile was characterized by functional difficulties (e.g., "HIV interferes with work"). The onset of specific problems might trigger further evaluation and potential intervention from health care providers to help maintain patient functioning.     

Loss of glucose transport in developing avian red cells

OBJECTIVE: This study aimed to examine the characteristics of intraretinal changes associated with macular holes and epiretinal membranes by scanning retinal thickness analysis. STUDY DESIGN: The study design was a nonconsecutive case series. PATIENTS: Fifty-six eyes of patients who had either a suspected or clinically diagnosed macular hole or epiretinal membrane were recruited. INTERVENTIONS: A commercial prototype of the scanning retinal thickness analyzer (RTA) was used. It projected a laser slit beam onto the retina and scanned it, in 200 or 400 msec, across a 2- x 2-mm area, yielding multiple optical cross sections that were recorded digitally. RESULTS: Epiretinal membranes were detected, and sites of attachment could be identified. Full-thickness holes corresponded to intraretinal cavities in which the inner retinal surface was broken, usually at the center. The majority of eyes with full-thickness macular holes showed increased retinal thickness surrounding the hole. The so-called "cuff of subretinal fluid," however, often was not present by retinal thickness analysis, despite clinical diagnosis to the contrary, even though retinal thickness analysis is capable of detecting such fluid. In 20 (42%) of 47 eyes diagnosed or suspected of having macular holes, scanning retinal thickness analysis showed findings different from those reported by retinal specialists. CONCLUSIONS: Examination of macular holes with the scanning RTA provides useful information in the diagnosis of macular holes in addition to that obtained through conventional techniques. The findings support the idea that many macular holes develop in association with intraretinal cystic changes. The precise chronology of the events remains to be determined.     

Phytohemagglutinin-induced leukocyte blastogenesis in normal and avian leukosis virus-infected chickens

Tbc has not yet been eradicated in Western Europe. Among 311 human/bovin-tuberculin tested cases out of 500 patients with uveitis (1971-1974), 37-50% (average age 40-45 years) reacted highly positive. Chorioretinitis disseminata and periphlebitis retinae (Eales' disease): 90% positive. The criteria for a long term tuberculostatic treatment are exposed. 20% of all cases of uveitis and 90% of Jensen Retinochorioditis have been interpreted as caused by toxoplasmosis. 75% are relapses. The gigantic toxoplasmotic lesions of the eyeground is stressed. As a rule low Sabin Feldmann titers are found. Quantitative serology is valuable. In the closing discussion the immunologically well known adjuvans-effect of Koch's bacillus-extract is supposed to be of importance in highly tuberculin positive uveitis.     

Differential distribution of agrin isoforms in the developing and adult avian retina

At the developing and regenerating neuromuscular junction, agrin is responsible for the formation of aggregates containing the acetylcholine receptor (AChR) and other molecules. Multiple isoforms of agrin are generated by alternative splicing, and the presence of an 8, 11, or 19 (8 + 11) amino acid insert at splice site B is required for agrin's AChR aggregation activity. An antiserum was generated against the 19 amino acid peptide which reacted specifically with the B11 and B19 agrin isoforms. The antiserum blocked the formation of agrin-induced AChR aggregates on myotubes, but the peptide itself had no aggregation activity, suggesting that agrin's active site is close to the splice site, but not the peptide itself. In the embryonic and adult retina anti-peptide immunoreactivity was concentrated in the synapse-containing layers. In contrast, the inner limiting membrane and radial cells, which express strong immunoreactivity with a pan-specific anti-agrin antiserum, were not stained by the anti-peptide antiserum, showing that agrin isoforms are differentially distributed in the retina. In addition, agrin B11 and B19 isoforms were associated with ganglion cell axons, particular at early developmental stages before synapse formation, indicating additional functions for these isoforms in the developing CNS.     

The effects of nephrectomy on the developing fetus

Bilateral renal pathologies such as renal agenesis and renal dysplasia and lower urinary tract obstruction have been reported to result in pulmonary hypoplasia. Although oligohydramnios and resultant thoracic compression was suggested to be the cause of pulmonary hypoplasia, the exact mechanism is still unknown. Additionally the effect of absence of renal tissue on the development of the fetus has not been previously studied in detail. Therefore an experimental study was planned to investigate the effects of fetal nephrectomy on development. The fetuses from 27 New Zealand white rabbits were studied on the 23rd day of gestation. Right ovarian-end fetuses underwent bilateral nephrectomy or sham operations. Rabbits underwent hysterectomy on gestational day 30, and live fetuses were studied. Fetal body, lung, heart and liver weights, and lung, heart and thorax volumes were determined, organ weight/body weight ratios were calculated. Additionally, lungs were evaluated by histological examination. Although fetal nephrectomy resulted in decreased body weight (BW), lung, heart, liver weights and heart weight/BW ratio (p < 0.05), lung weight/BW and liver weight/BW ratios did not differ. Additionally, heart and thorax volumes were significantly decreased in the nephrectomy group (p < 0.05). However lung volume and thorax volume/BW ratio did not differ between groups. The histological evaluation of lungs revealed exfoliated cells but normal lung development. Bilateral fetal nephrectomy results in small-for-gestational age (SGA) status during birth without affecting the development of organic systems. Since SGA status may be associated with decreased placentofetal blood flow, bilateral nephrectomy may act through decreasing placentofetal blood flow and/or through the lack of kidney-related growth factors.     

Differential effects of methimazole and dexamethasone in avian muscular dystrophy

We showed previously that thyroid antagonists and glucocorticoids partially alleviated the impaired righting ability and abnormally high levels of plasma creatine kinase activity in genetically dystrophic chicks. The goals of the present study were: (1) to ascertain whether the beneficial effects of methimazole (MMI; thyroid antagonist) on muscle function and plasma creatine kinase (CK) activity in dystrophic chickens are correlated with significant reduction in plasma triiodothyronine (T3) and thyroxine (T4); (2) to assess whether the MMI-induced thyroid changes are accompanied by increased plasma corticosterone level and/or changes in muscle glucocorticoid receptors which might account partially for the beneficial effects of MMI; and (3) to determine if plasma T3 and T4 are reduced in dexamethasone (DEX) treated dystrophic chickens which might account at least partially for the beneficial effects of DEX (a potent glucocorticoid) on avian dystrophy. The data show that beneficial effects of MMI are associated with reduced plasma levels of thyroid hormones and increased circulating levels of corticosterone. In addition, DEX actually increases plasma T3 levels. These differential effects indicate that reduced plasma thyroid hormone levels do not represent a common mechanism of beneficial drug effects in avian muscular dystrophy. On the other hand, elevated plasma glucocorticoid levels accompany the beneficial effects of both severe hypothyroidism and DEX treatment. The data also show that MMI induces down-regulation of muscle cytosolic glucocorticoid receptors which are higher than normal in dystrophic muscles.     

Paneth cell differentiation in the developing intestine of normal and transgenic mice

Paneth cells represent one of the four major epithelial lineages in the mouse small intestine. It is the only lineage that migrates downward from the stem-cell zone located in the lower portion of the crypt of Lieberkühn to the crypt base. Mature Paneth cells release growth factors, digestive enzymes, and antimicrobial peptides from their apical secretory granules. Some of these factors may affect the crypt stem cell, its transit-cell descendants, differentiating villus-associated epithelial lineages, and/or the gut microflora. We used single and multilabel immunocytochemical methods to study Paneth cell differentiation during and after completion of gut morphogenesis in normal, gnotobiotic, and transgenic mice as well as in intestinal isografts. This lineage emerges coincident with cytodifferentiation of the fetal small intestinal endoderm, formation of crypts from an intervillus epithelium, and establishment of a stem-cell hierarchy. The initial differentiation program involves sequential expression of cryptdins, a phospholipase A2 (enhancing factor), and lysozyme. A dramatic increase in Paneth cell number per crypt occurs during postnatal days 14-28, when crypts proliferate by fission. Accumulation of fucosylated and sialylated glycoconjugates during this period represents the final evolution of the lineage's differentiation program. Establishment of this lineage is not dependent upon instructive interactions from the microflora. Transgenic mice containing nucleotides -6500 to +34 of the Paneth cell-specific mouse cryptdin 2 gene linked to the human growth hormone gene beginning at its nucleotide +3 inappropriately express human growth hormone in a large population of proliferating and nonproliferating cells in the intervillus epithelium up to postnatal day 5. Transgene expression subsequently becomes restricted to the Paneth cell lineage in the developing crypt. Cryptdin 2 nucleotides -6500 to +34 should be a useful marker of crypt morphogenesis and a valuable tool for conducting gain-of-function or loss-of-function experiments in Paneth cells.     

The effects of hyperbaric oxygen on normal and ischemic colon anastomoses

A pregnant woman with transient gastric obstruction was fed by enteral nutrition alone for 11 wk and 6 d. Her body mass index of 23.2 kg/m2 before pregnancy declined to 21.8 kg/m2 after delivery. Although she did not gain weight during enteral nutrition, fetal growth, estimated by ultrasonography, was normal, and she delivered a 3030-g female infant at 38 wk gestation. The blood laboratory data during pregnancy and the breast milk after pregnancy were also normal. The results suggest that factors other than maternal weight gain alone should be considered in the evaluation of nutritional status for the pregnant woman.     

Evidence for a distinct gap-junctional phenotype in ventricular conduction tissues of the developing and mature avian heart

The gap-junctional proteins connexin43 and connexin42 have been shown to be expressed in the developing and mature avian heart, but their respective spatiotemporal distributions are unknown. In the present study, we have immunolocalized connexin42 in the conduction tissues of the adult avian heart (nonbranching bundle, bundle branches, and Purkinje fibers) and vascular endothelial cells. Connexin43 immunolabeling was confined to vascular smooth muscle. A novel microwave-based method was used to label connexin42 and connexin43 in the same tissue section. Neither connexin42 nor connexin43 was immunolocalized in working myocardium, atrioventricular node, and atrioventricular ring tissue of the bird heart. Although connexin42 first appeared in periarterial conduction myocytes and vascular endothelium at 9-10 embryonic days, the central conduction tissues, including the nonbranching bundle and proximal branches, remained immunonegative for connexin42 up until hatching (approximately 20 embryonic days). During the early postnatal period (1-14 days), connexin42 immunolabeling progressively spread up the bundle branches toward the nonbranching bundle. Connexin42 appeared uniformly distributed along the left bundle branch by 14 postnatal days. The distribution and spread of connexin42 immunoreactivity suggest that the emergence of specialized junctional contacts along ventricular fascicles occurs relatively late in heart development and coincides with the emergence of the chick from incubation within the egg.     

The effects of GM-CSF on myeloperoxidase release in normal and myelodysplastic neutrophils

When purified control neutrophils were primed with GM-CSF, a significant increase in FMLP-induced MPO release was observed (mean +/- S.E.M., 3.4 +/- 0.8 mU/10(7) unprimed cells compared to 6.5 +/- 1.1 mU/10(7) primed cells, p < 0.001). This MPO release was greatly augmented by Cytochalasin B (Cy B), but after the addition of Cy B the priming effects of GM-CSF became less obvious. Exposure to GM-CSF without FMLP did not enhance MPO release. Within whole blood, FMLP produced negligible MPO release, but priming with GM-CSF prior to FMLP always resulted in a significant increase in MPO release. Myelodysplastic neutrophils released similar amounts of MPO in response to FMLP, compared with control cells (3.4 +/- 0.8 mU/10(7) control cells compared to 2.7 +/- 0.3 mU/10(7) MDS cells, p > 0.05). Priming with GM-CSF produced an increase in FMLP-stimulated MPO release comparable with control cells. In terms of total MPO content, although some MDS patients exhibited low levels, as a group there was no significant difference from controls (169 +/- 21 mU/10(7) control cells compared with 157 +/- 19 mU/10(7) MDS cells). These findings suggest that MPO activity is not a universal defect in MDS and cannot account for the defects in respiratory burst activity in these neutrophils.     

Comparative effects of rapid and normal smoking on heart rate and carboxyhemoglobin.

Compared a rapid smoking procedure closely approximating that found in clinical and research practice to normal smoking and a rapid breathing/sham-smoking control. Ss were 3 male and 3 female undergraduates who had smoked for an average of 4.4 yrs with a mean baseline of 24.2 cigarettes/day. Nicotine concentration of cigarettes was systematically varied. Major dependent variables included heart rate (HR) and estimates of blood carboxyhemoglobin (COHb) based on expired respiratory air carbon monoxide. Results show rapid smoking produced significantly greater rise in HR than normal smoking. No carbon monoxide differences were found across the smoking conditions. Individual data indicated that no S exceeded estimated danger levels of COHb or HR increases. Although replication and extension of these findings are necessary, results indicate that rapid smoking is not unduly hazardous to nonsymptomatic young adults. A suggested screening procedure for rapid smoking is presented. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lack of melatonin effects on insulin action in normal rats

Despite a large number of studies, the role of melatonin on glucose metabolism is still controversial. The aim of the present work was to further characterize the effect of melatonin on insulin action during: i) intravenous insulin tolerance test performed at different times of the day using melatonin, a melatonin agonist (S-20304), a melatonin antagonist (S-20928) or in pinealectomized rats. ii) euglycemic-hyperinsulinemic clamp performed in melatonin agonist-treated as well as in pinealectomized rats. The fall in glycemia after the insulin injection was not significantly affected by melatonin and melatonin agonist (S-20304) at ZT6, nor by the melatonin antagonist (S-20928) at ZT13 nor in pinealectomized animals at ZT6 in comparison to their respective control. Acute treatment with S-20304 or chronic suppression of melatonin by pinealectomy did not significantly alter basal plasma glucose and insulin levels or hepatic glucose production and whole body or individual tissue glucose utilization. These data do not give support to a crucial role of melatonin on insulin action in normal rats.