Effect of L-arginine on arginase activity in male accessory sex glands of alloxan-treated rats

Arginase activity has been identified in the prostate, and may be important in the synthesis of polyamines in accessory sex glands in the male. Polyamines in turn may mediate the action of androgens. Diabetic patients have disordered androgen synthesis. The purpose of this work was to evaluate the effect of L-arginine on arginase activity in accessory sex glands of male rats under normal and diabetic conditions (alloxan 120 mg/kg, i.p.). Normal and diabetic male rats were untreated or were treated with insulin or L-arginine for 96 h, and sacrificed. Arginase activity was measured in serum and in accessory sex glands. Arginase activity in accessory glands did not change significantly with induction of diabetes. Arginase activity was increased in diabetic insulin-treated rats, but there was no arginase response to L-arginine administration in diabetic animals. These findings stand in contrast to beneficial effects of L-arginine previously observed when this amino acid was administered for a long time (at least 10 days). We suspect that altered arginase activity in accessory sex glands may play a role in the reproductive dysfunction caused by diabetes, inasmuch as arginase activity can be increased in experimentally diabetic rats by the administration of insulin.     

Minimally invasive parathyroidectomy

Efforts to minimize the incision, extent of exploration, length of hospital stay, and cost associated with parathyroidectomy have resulted in the development of a number of new surgical techniques, including minimally invasive, "concise," radio-guided, and endoscopic parathyroid exploration. With minimally invasive parathyroidectomy, a small incision is used in combination with a cervical block and sedation to perform a unilateral neck exploration. In so doing, risks of bilateral neck exploration are avoided, and the procedure can be done on an outpatient basis. This minimally invasive strategy has been shown to maintain the outstanding success of conventional bilateral neck exploration. All of the new surgical techniques necessitate pre-operative localization, which allows for unilateral neck exploration, and are facilitated by use of the intra-operative parathyroid hormone assay, which provides surgeons with feedback in the operating room regarding whether the patient has undergone adequate resection.     

Long-term followup of primary intestinal lymphangiectasia in the child. Six case reports]

Primary intestinal lymphangiectasia induce symptoms of protein-losing gastroenteropathy. Only very few studies evaluate the long term follow up of such patients. We reviewed six children diagnosed at 17 +/- 12 months and followed for 11 +/- 4.9 years. CASE REPORTS: As soon as the diagnosis was made the patients were submitted to a strict low fat diet with added medium chain triglycerides and intermittent liposoluble vitamins perfusions. The diet allowed the disappearance of symptoms for all the patients but laboratory findings indicated continuing chyle leak for most of the children. Only one child who had normal biological parameters tolerates a normal diet since four years. Relaxation of the diet by two patients who had moderate hypoalbuminemia and lymphopenia led to severe clinical relapses 14 and 17 years after the diagnosis period with therapeutic difficulties. Three patients with long term strict low fat diet remain asymptomatic. CONCLUSION: In most asymptomatic patients, the underlying lymphatic defect remains with permanent biological abnormalities. Clinical relapses may be severe and difficult to treat; thus the need for dietary treatment appears to be permanent.     

Catheter Ablation of the Left Ventricular Outflow Tract Tachycardia from the Left Atrium

RF ablation of idiopathic left ventricular outflow tract ventricular tachycardia (LOT-VT) may imply in significant risk of damaging the proximal left main if RF pulses are being delivered from the left sinus of Valsalva or from inside an epicardial coronary vein. This report describes a new approach to control LOT-VT by means of RF catheter ablation.     

Bone mass, bone turnover, vitamin D, and estrogen receptor gene polymorphisms in male to female transsexuals: effects of estrogenic treatment on bone metabolism of the male.

The effect of chronic administration of estrogens on bone and mineral metabolism in men is not known. We have studied the effect of chronic administration of estrogens on bone mineral metabolism in a group of transsexual (TS) Canarian men, who were taking estrogens for a minimum of 3 years. This is a cross-sectional study of cases and controls and we studied biochemical markers of bone remodeling, bone mineral density (BMD), and selected biochemical and hormonal features. TS subjects had shorter stature than controls, and after adjusting for height and weight, we found that they had lower values for serum-free testosterone and higher values for BMD, both in the lumbar spine and in femoral neck. Biochemistry, bone remodeling markers, and calcitropic hormone values were similar in both groups. Finally, the distributions of vitamin D receptor (BsmI) and estrogen receptor (ER-Pvu and ER-Xba) polymorphisms were also similar in both groups. We conclude that the chronic administration of estrogens in men may produce an increase in serum estradiol, a decrease in free testosterone levels, and an increase in BMD-both in lumbar spine and in femoral neck. We found no association between the transsexual phenotype and the distribution of vitamin D receptor (BsmI) and estrogen receptor (ER-Pvu and ER-Xba).     

Racial and socioeconomic disparities in lung cancer screening in the United States: A systematic review

Nonsmall cell lung cancer (NSCLC) is the leading cause of cancer deaths. Lung cancer screening (LCS) reduces NSCLC mortality; however, a lack of diversity in LCS studies may limit the generalizability of the results to marginalized groups who face higher risk for and worse outcomes from NSCLC. Identifying sources of inequity in the LCS pipeline is essential to reduce disparities in NSCLC outcomes. The authors searched 3 major databases for studies published from January 1, 2010 to February 27, 2020 that met the following criteria: 1) included screenees between ages 45 and 80 years who were current or former smokers, 2) written in English, 3) conducted in the United States, and 4) discussed socioeconomic and race-based LCS outcomes. Eligible studies were assessed for risk of bias. Of 3721 studies screened, 21 were eligible. Eligible studies were evaluated, and their findings were categorized into 3 themes related to LCS disparities faced by Black and socioeconomically disadvantaged individuals: 1) eligibility; 2) utilization, perception, and utility; and 3) postscreening behavior and care. Disparities in LCS exist along racial and socioeconomic lines. There are several steps along the LCS pipeline in which Black and socioeconomically disadvantaged individuals miss the potential benefits of LCS, resulting in increased mortality. This study identified potential sources of inequity that require further investigation. The authors recommend the implementation of prospective trials that evaluate eligibility criteria for underserved groups and the creation of interventions focused on improving utilization and follow-up care to decrease LCS disparities.     

Morphological characterization of six subpopulations of adult human DRG neurons at the light microscopic level

Dorsal root ganglion (DRG) neurons are composed of physiologically distinct subpopulations, each responding to a different sensory stimulus. One can morphologically discriminate between two broad populations of adult rat and frog DRG neurons by their appearance under the light microscope. These groups are called large clear and small dark. However, additional subpopulations have not been identified by visual observation. Such identification requires application of immunochemistry or biophysical techniques. Although these are useful techniques, they do not allow the rapid discrimination of different neuron subpopulations, which would be useful for pharmacological studies on unique neuron subpopulations. Such experiments would be greatly facilitated if viable DRG neuron subpopulations could be identified based on their morphology at the light microscopic level. Just as for adult frog and rat DRG neurons, when adult human DRG neurons are observed under phase optics, two subpopulations can be seen, small dark and large light. However, under bright-field illumination, six distinct subpopulations can be distinguished based solely on morphological features. Five subpopulations contain rusty-colored cytoplasmic inclusions with different sized granules and differences in the size and density of the granule clusters, while one is granule-free. Analysis of the soma diameter distribution shows each of the six granule-containing and the non-granule-containing (clear) neuron subpopulations has a statistically significant difference in size distribution. We propose that neurons with different morphologies correspond to unique physiological subpopulations of DRG neurons. Experiments are underway using immunochemical techniques to determine whether neurons with the unique morphologies correspond with unique physiological functions.