Release of cytokines during generation of lymphokine-activated killer (LAK) cells by IL-2.

Supernatants of IL-2-activated mononuclear cells (MNC) that displayed an optimal lymphokine-activated killer (LAK) cell activity at 48-72 hr in culture were found to contain increased levels of tumour necrosis factor alpha (TNF alpha), interleukin-1 alpha (IL-1 alpha) and interferon-gamma (IFN-gamma) when compared with supernatants from mononuclear cells cultured in the absence of IL-2. The concentration of TNF alpha and IL-1 alpha produced by MNC at 24 hr was either increased or maintained by extending the cultures to 96 hr. In contrast, TNF beta was only detected at very low levels after 72-96 hr culture, irrespective of whether IL-2 was present or absent. Optimal concentrations of IL-2 needed to induce maximum release of TNF alpha, IL-1 alpha and IFN-gamma by MNC varied among different individuals. Enriched populations of lymphocytes secreted higher levels of all measured cytokines upon activation with IL-2 in contrast to untreated cells. Supernatants from purified monocyte preparations contained high concentrations of TNF alpha and IL-1 alpha regardless of the presence of IL-2 in the cell cultures. This work suggests that in addition to the generation of LAK cell activity, by promoting the release of other cytokines with potential anti-tumoricidal activity, IL-2 may be amplifying cell-mediated cytotoxicity, which is associated with protection against neoplastic disease.     

Expression of BCL-2 and p53 in oncocytic (Hürthle cell) tumors of the thyroid: An immunohistochemical study

Previous studies have established that thyroid follicular neoplasms of higher malignant potential show a high p53 and low bc1-2 expression. This however has not been well studied in Oncocytic (Hürthle cell) neoplasms, the management of which remains controversial. We therefore studied the expression of p53 and bc1-2 in 18 Hürthle cell adenomas (HCA) and 8 Hürthle cell carcinomas (HCC) and compared them with their benign and malignant counterparts, respectively, including 16 follicular adenomas (FA) and 68 papillary carcinomas (PC). All 16 FA were bc1-2 positive, 4 were 2+, and 12 were 3+. On the other hand, 14/18 (78%) HCA showed bc1-2 expression, 5 were 1+, 6 were 2+, and only 3 were 3_. Similarly, HCC showed a weaker bc1-2 staining pattern compared to PC. Only 1 FA showed grade 1, p53 staining, the remaining 15 were negative, and 15/18 HCA showed p53 expression of varying grades. This difference in p53 staining was statistically significant (p=0.005). A significant p53 overexpression was also seen in HCC compared to PC (p=0.005). In conclusion, there appears to be an inverse relationship between p53 and bc1-2 expression in thyroid follicular neoplasms. A higher expression of p53 and lower levels bc1-2 in Hürthle cell neoplasms may have biological and clinical implications. This may support a more aggressive surgical treatment for HCA compared to FA.     

Calbindin immunoreactivity in the developing and adult human cerebellum

Calbindin (CALB), a calcium-binding protein, is known to be expressed in the embryonic nervous system. In this study, we have examined its distribution in the cerebellum of human fetuses (11–25 weeks of gestation) and adult by immunohistochemistry. At the gestational age of 11–12 weeks, CALB immunoreactivity was present in granule and Purkinje cells throughout the cerebellum. By 16–21 weeks of gestation, immunoreactive Purkinje cells were well-differentiated in the vermis and flocculus, and their axons ran towards the deep cerebellar nuclei area, while the axon collaterals were seen to be distributed into adjacent folia. At the gestational period of 24–25 weeks, most Purkinje cells of the flocculus and vermis were arranged in one to two rows, while those of the hemispheres were still undifferentiated. A few Golgi cells of the vermis showed immunoreactivity. The neurons of the deep nuclei were immunonegative right from the gestational age of 11 weeks although a fine stippled staining of fibers was present throughout the body of all nuclei. The fibers lying close to the hilum of the dentate nucleus were strongly CALB-positive. The vestibulocerebellar fibers, being traced at the level of lower pons and upper medulla oblongata were stained as early as 11 weeks of gestation, whereas the olivocerebellar fibers were stained from 16 weeks onward. In the adult cerebellum, Purkinje cells were moderately immunopositive while granule cells were faintly stained; no other cells, including those of the deep nuclei were stained. In the medulla oblongata, the inferior olivary nucleus and olivocerebellar fibers were strongly CALB-positive. Our results indicate that CALB is expressed in early migratory Purkinje cells, and their maturation occurs in a vermal-to-hemisphere gradient. It is likely that CALB plays a significant role in the regulation of Ca²⁺-dependent activities in the developing cerebellum.     

Estimation of the minimum number of test specimens for fatigue testing of acrylic bone cement

In the literature on fatigue testing of acrylic bone cements, data sets of various sizes have been used in different test series for the same cement formulation. There are two important consequences of this situation. First, it means that some test series last much longer than others, with all the implications for the cost of testing. Second, it makes drawing conclusions about the fatigue performance of a cement, based on the results of different literature series, a problematic issue. Clearly then, a recommendation as to what should be the minimum number of test specimens to use that would allow for confidence in the results of the statistical treatment of the test results (Gmin) would be desirable. In the present work, a method that could be used to culminate in such a recommendation is described. This method involves (i) obtaining experimental fatigue test results and (ii) analyzing those results using the Weibull probability distribution function and other statistical methods. This methodology is illustrated using fatigue life results obtained from uniaxial tension-compression fatigue tests on specimens fabricated from the polymerizing dough of one commercially available acrylic bone cement. For a tolerable error of 5%, we estimated Gmin to be either 7 (if the fatigue life results are treated using the two-parameter Weibull distribution function) or 11 (if the fatigue life results are treated using the three-parameter Weibull distribution function). To be on the conservative side, we therefore recommend that Gmin be 11. Three key limitations of the methodology presented here are discussed.     

Increased IL-2, IL-4 and interferon-gamma (IFN-gamma) in steroid-sensitive nephrotic syndrome.

We investigated the production of cytokines by peripheral blood mononuclear cells (PBMC) and serum cytokine concentrations in children with steroid-sensitive idiopathic nephrotic syndrome (SSNS). PBMC from patients off treatment were collected during remission and relapse and cultured in medium alone or stimulated with calcium ionophore plus phorbol myristate acetate. Control PBMC were taken from healthy age-matched children. IL-2 was measured by bioassay, IL-4 by immunoradiometric assay, and IL-8 and IFN-gamma by ELISA. After 24 h culture without stimulation, IL-2, IL-4 and IFN-gamma were not detectable in the supernatant in any of the children. After stimulation, the supernatant concentrations of IL-2 (median 172 U/ml at 24 h) and IL-4 (160 pg/ml at 24 h; 210 pg/ml at 72 h) were significantly increased in relapse compared with remission (IL-2 37 U/ml; IL-4 65 pg/ml and 60 pg/ml) and controls (IL-2 69 U/ml; IL-4 40 pg/ml and 40 pg/ml) (P < 0.05). The concentration of IFN-gamma was not significantly increased in relapse compared with remission and controls (600, 325, and 145 U/ml, respectively, at 72 h). IL-8 concentrations were similar in relapse, remission and controls with stimulation (median 32, 40 and 40 ng/ml, respectively) and without (30, 17 and 10 ng/ml). IL-2 was not detectable in serum, but IL-4, IL-8 and IFN-gamma were measurable in about half the patients, both in relapse and remission, though were virtually undetectable in controls. We conclude that relapse of SSNS in children is associated with T lymphocyte activation with release of IL-2, IL-4 and IFN-gamma.     

Potential role of intermittent fasting on decreasing cardiovascular disease in human immunodeficiency virus patients receiving antiretroviral therapy

Cardiovascular disease (CVD) has become one of the commonest causes of comorbidity and mortality among People living with human immunodeficiency virus (HIV) (PLWH) on antiretroviral therapy (ART). Nearly 50% of PLWH are likely to have an increased risk of developing CVD, including coronary heart disease, cerebrovascular disease, peripheral artery disease and aortic atherosclerosis. Aside from the common risk factors, HIV infection itself and side effects of antiretroviral therapy contribute to the pathophysiology of this entity. Potential non-pharmacological therapies are currently being tested worldwide for this purpose, including eating patterns such as Intermittent fasting (IF). IF is a widespread practice gaining high level of interest in the scientific community due to its potential benefits such as improvement in serum lipids and lipoproteins, blood pressure (BP), platelet-derived growth factor AB, systemic inflammation, and carotid artery intima-media thickness among others cardiovascular benefits. This review will focus on exploring the potential role of intermittent fasting as a non-pharmacological and cost-effective strategy in decreasing the burden of cardiovascular diseases among HIV patients on ART due to its intrinsic properties improving the main cardiovascular risk factors and modulating inflammatory pathways related to endothelial dysfunction, lipid peroxidation and aging. Intermittent fasting regimens need to be tested in clinical trials as an important, cost-effective, and revolutionary coadjutant of ART in the fight against the increased prevalence of cardiovascular disease in PLWH.     

Primary Obstructive Megaureter in Adults: Need for an Aggressive Management Strategy

Purpose: Primary obstructive megaureter (POM) is an uncommon disease in adults. We reviewed our experience with this disease to determine the clinical profile, management and prognosis of this disease in adults. Methods: We studied 37 adults with POM who presented from January 1989 to December 1998. Their clinical presentation, renal function, radiologic data, complications, treatment as well as the results and follow-up were studied. Results: The patients' age ranged from 13 to 52 years. Male : female ratio was 27 : 10. Seven patients had bilateral disease. All patients were symptomatic excepting 2. Complications at presentation were loin pain (26 cases), urinary infection (15 cases), calculus disease (17 cases), azotaemia (5 cases), and obstructive jaundice (1 case). Associated congenital anomalies included contralateral renal agenesis (2 cases), posterior urethral valve (1 case) and exstrophy of bladder (1 case). Thirty-four patients required surgical intervention. Of these, 26 patients underwent ureteroneocystostomy (UNC) with ureteral tailoring in 18 patients; 4 patients were treated endoscopically by ureteric meatotomy and stenting, 2 patients with nonfunctioning kidney by nephroureterectomy, 2 patients in advanced renal failure by percutaneous nephrostomy alone. In 4 out of 5 patients uraemia did not improve despite adequate drainage. Conclusion: The majority of adults with POM are symptomatic, have complications and require surgical correction. Complications of stone formation (46%) and renal failure (13.5%) are unusually common in adults. Once renal failure is advanced, intervention appears futile, therefore, it is imperative to treat these patients as soon as possible. Surgical correction by ureteric reimplantation is effective and has low morbidity.