Biotin deficiency in protein-energy malnutrition

Several of the clinical and biochemical manifestations of biotin deficiency also occur in severe protein-energy malnutrition (PEM). Average plasma biotin concentrations were lower in 16 malnourished children (10 with marasmus, 3 with kwashiorkor and 3 with marasmic kwashiorkor) than in 31 controls. Lymphocyte mitochondrial carboxylase activities were studied in 11 controls and in 10 patients with PEM; on the average, they were lower in the patients. Their activation indices (the ratio of enzyme activity in cells incubated with biotin to activity in cells incubated without the vitamin) were higher in PEM. All these differences were statistically significant. None of these parameters were age-dependent in a range between 3 and 72 months. Carboxylase activities and plasma biotin levels increased to normal during nutritional recovery in two malnourished patients who were further studied. These results suggest that there is biotin deficiency in severe PEM. Urinary biotin concentrations, expressed per g of creatinine, were higher in the patients than in the controls; this may have been caused by increased renal clearance or by the reduced creatinine excretion which occurs in malnourished individuals. It will be important in future studies to determine the relative contribution of biotin deficiency to the malnourished phenotype.     

Lymphocyte Populations and Cellular Immune Reactions in Juvenile Rheumatoid Arthritis

Ten patients with juvenile rheumatoid arthritis and age- and sex-matched healthy controls were investigated in pairs. The patients were found to have both normal proportions and normal absolute numbers of T lymphocytes, B lymphocytes, and the Fc-receptor-bearing lymphoid cells in peripheral blood. No abnormality of mitogen-induced lymphocyte transformation was observed. Lymphocyte-mediated cytotoxicity induced by phytohemagglutinin (PHA) or anti-target cell antibodies was also found to be normal. As in an earlier study, impaired delayed hyper-sensitivity by skin testing was observed in the patient group, thus indicating a dissociation between in vivo and in vitro parameters of lympboid cell function.     

Inhibition of Antibody-Dependent Human Lymphocyte-Mediated Cytotoxicity by Immunoglobulin Classes, IgG Subclasses, and IgG Fragments

The cytotoxicity of human peripheral blood lymphocytes against chicken erythrocytes sensitized by rabbit antibodies was inhibited by human immunoglobulin and immunoglobulin fragments. Myeloma proteins isolated in dimeric state or aggregated by heat treatment inhibited better than the corresponding monomeric proteins. Strong inhibition was observed with IgG1 and IgG3, and with IgG₂ after aggregation, while IgG₄ inhibited very little. No inhibition was found with IgM, IgA. IgD and IgE. The F(ab')₂. and Fab fragments of IgG inhibited poorly or not at all. While- considerable inhibition was observed with the Fc fragment, the pFc' fragment, which roughly corresponds to the C-terminal half of the Fc portion, showed little inhibitory capacity. A fragment isolated from IgG3, containing an extension of the N-terminal part of Fc (the Fch fragment), was an even better inhibitor than tin Fc fragment. The inhibitory capacity of the Fch and Fc fragments was greatly diminished following partial reduction and alkylation On the basis of the inhibitory pattern of IgG fragments, it is suggested that the region on the immunoglobulin molecule involved in binding to the Fc receptor of the effector lymphocytic cell may be located within the CH2 domain.     

Striated intramural gallbladder lucencies on US studies: predictors of acute cholecystitis

Ultrasound scans of 51 consecutive patients with gallbladder wall thickening were reviewed, and specific sonographic features were correlated with surgical and clinical follow-up. Two patterns of thickening were identified as specific indicators of the presence or absence of acute cholecystitis. "Striated" wall thickening, consisting of several alternating, irregular, discontinuous, lucent and echogenic bands, was seen in eight of 13 patients (62%) with acute cholecystitis. This pattern was not encountered in any of the patients who did not have acute cholecystitis. Conversely, "three-layer" thickening, consisting of a single circumferential lucent zone between two relatively uniform echogenic layers, was seen in only one of 13 patients (8%) with acute cholecystitis but in 11 of 38 patients (29%) with other diagnoses. Other abnormalities, including the presence of intramural echogenic foci and wall irregularities, were more frequently seen in patients with acute cholecystitis but were not as helpful. Use of these features may suggest or help exclude a diagnosis of acute cholecystitis in those patients in whom the cause of gallbladder wall thickening is otherwise not apparent.     

The changing face of reoperative parathyroidectomy: a single-centre comparison of 147 parathyroid reoperations

IntroductionReoperative parathyroidectomy for persistent and recurrent primary hyperparathyroidism is dependent on radiology. This study aimed to compare outcomes in reoperative parathyroidectomy at a single centre using a combination of traditional and newer imaging studies.Materials and methodsRetrospective case note review of all reoperative parathyroidectomies for persistent and recurrent primary hyperparathyroidism over five years (June 2014 to June 2019; group A). Imaging modalities used and their positive predictive value, complications and cure rates were compared with a published dataset spanning the preceding nine years (group B).ResultsFrom over 2000 parathyroidectomies, 147 were reoperations (101 in group A and 46 in group B). Age and sex ratios were similar (56 vs 62 years; 77% vs 72% female). Ultrasound use remains high and shows better positive predictive value (76% vs 57 %). 99mTc-sestamibi use has declined (79% vs 91%) but the positive predictive value has improved (74% vs 53%). 4DCT use has almost doubled (61% vs 37%) with better positive predictive value (88% vs 75%). 18F-fluorocholine positron emission tomography-computed tomography and ultrasound-guided fine-needle aspiration for parathyroid hormone are novel modalities only available for group A. Both carried a positive predictive value of 100%. Venous sampling with or without angiography use has decreased (35% vs 39%) but maintains a high positive predictive value (86% vs 91%). Cure rates were similar (96% vs 100%). Group A had 5% permanent hypoparathyroidism, 1% permanent vocal cord palsy and 1% haematoma requiring reoperation. No complications for group B.ConclusionOptimal imaging is key to good cure rates in reoperative parathyroidectomy. High-quality, non-interventional imaging techniques have produced a shift in the preoperative algorithm without compromising outcomes.     

HIV-1 and hepatitis B virus infections in adolescents lodged in security institutes of Buenos Aires

The goal of this study was to determine the prevalence of human immunodeficiency virus type 1 (HIV-1) and hepatitis B virus (HBV) infections in street youth lodged in security institutes, from February 1992 to March 1995, to correlate these infections with nontherapeutic drug use, and to compare these results with a previous study done in a similar population. A total of 1460 white adolescents, 276 females and 1184 males, were enrolled (mean age 16.6 years). Prevalence of HIV-1 was 4.58% and of HBV was 6.78%. The prevalence of dual HIV-1/HBV infection was 1.91%; the prevalence of HBV infection was significantly higher in HIV-positive subjects (p < 0.0000000, chi 2 = 136.17, OR = 13.37) than in those not infected with HIV-1. Prevalences were higher in males. Intravenous drug addiction proved to be a significant risk factor for both viruses (HIV-1, p < 0.0000000, chi 2 = 171.34, OR = 16.84; HBV, p = 0.000044, chi 2 = 16.67, OR = 3.17); 6.43% of the total population were intravenous drug users. Comparison of the current results with our previous study (1989-1992) showed that the prevalence of HIV-1, HBV, and concurrent HIV/HBV as well as intravenous drug addiction has decreased significantly in our current cohort (chi 2 = 134.85, p < 0.0000000; chi 2 = 126.62, p < 0.0000000; chi 2 = 110.05, p < 0.0000000; and chi 2 = 158.3, p < 0.0000000) respectively. Progress appears to have been made in the fight against acquired immunodeficiency syndrome (AIDS), and promising results have been obtained. However, if further viral spread is to be avoided, the emphasis on prevention should be energetically maintained.     

Short-term efficacy of topical capsaicin therapy in severely affected fibromyalgia patients

The purpose of this study was to evaluate the short-term efficacy of topical capsaicin treatment in patients severely affected by fibromyalgia. One hundred and thirty fibromyalgia patients were randomly divided into two groups. The control group, 56 women and 4 men who continued their medical treatment, and the capsaicin group, 70 women who apart from continuing their medical treatment, also underwent topical capsaicin 0.075 % 3 times daily for 6 weeks. At the beginning of the program, there were no significant differences between the two groups in any of the analyzed parameters. At the end of the treatment, there were significant improvements in the capsaicin group in the myalgic score (5.21 vs 3.8, p = 0.02) and global subjective improvement (22.8 vs 5 %, p = 0.001). Six weeks after the end of the treatment, the experimental group showed significant differences in Visual Analogue Scale of depression (5.63 vs 7.35, p = 0.02), Fibromyalgia Impact Questionnaire (67.89 vs 77.7, p = 0.02), role limitations due to emotional problems (36.17 vs 17.2, p = 0.05), Fatigue Severity Scale (6.2 vs 6.6, p = 0.04), myalgic score (3.94 vs 2.66, p = 0.02) and pressure pain threshold (79.25 vs 56.71, p = 0.004). In conclusion, patients severely affected by fibromyalgia can obtain short-term improvements following topical capsaicin 0.075 % treatment three times daily for 6 weeks.     

Acute administration of corticoids: a new and peculiar stimulus of growth hormone secretion in man

It is widely accepted that chronic administration of corticoids in man inhibits the GH response to all of the stimuli tested so far. To study the action of corticoids administered acutely, several dexamethasone challenge tests were performed, after which GH levels were measured for 7 h. In eight volunteers, administration of 4 mg dexamethasone (Dex), iv, induced a clear-cut GH release compared with saline administration. The secretion followed an unusual pattern; basal GH levels (1.5 +/- 0.1 micrograms/L) started rising 2 h after Dex injection, reaching a peak of 17.5 +/- 4.4 micrograms/L after 3 or 3.5 h. Peak levels were maintained until 5 h post-Dex and decreased thereafter. Similar data were obtained when Dex was administered to five volunteers at the dose of 8 mg, orally, with a 30-min delay of the GH peak (19.6 +/- 7.9 micrograms/L). To study whether there was a cholinergic input responsible for the Dex action, another group of eight volunteers underwent three Dex tests (4 mg, iv) on three occasions, followed 90 min later by the administration of placebo (control), atropine (0.5 mg, iv), or pyridostigmine (120 mg, orally). The Dex-induced GH peak (20.8 +/- 5.2 micrograms/L) was not significantly increased by pyridostigmine (cholinergic agonist) treatment (24.2 +/- 4.0 micrograms/L). The blockade of muscarinic receptors by atropine induced a delay in the Dex-induced secretory peak, which appeared at 5 h. However, the Dex-atropine GH peak (14.9 +/- 4.1 micrograms/L) was not different from the Dex-placebo one. In conclusion, Dex alone is able to induce a clear-cut GH secretion in man. The stimulus followed a peculiar time pattern, with peaks levels attained 3 h after either iv or oral administration.     

Depending on the time of administration, dexamethasone potentiates or blocks growth hormone-releasing hormone-induced growth hormone release in man

In humans, corticoids suppress growth hormone (GH) secretion elicited by a variety of stimuli, while in vitro they potentiate GH release. To further study this problem, the effect of two doses of dexamethasone on GH secretion elicited by GH-releasing hormone (GHRH) in 6 normal volunteers was studied. Each subject underwent three tests, on 3 separate days with GHRH 1-29 (1 microgram/kg i.v. at 12.00 h). On the control day, only GHRH was given, on the second day dexamethasone 4 mg i.v. was administered at 09.00 h (3 h before GHRH) and on the third day dexamethasone 8 mg p.o. was given 12 h before GHRH (at 00.00 h). The GHRH-induced GH peak was 9.9 +/- 2.0 ng/ml, while 4 mg dexamethasone significantly (p less than 0.05) potentiated GH secretion elicited by GHRH (29.2 +/- 5.7 ng/ml). When dexamethasone 8 mg was given 12 h before, GHRH-induced GH secretion was completely blocked (3.0 +/- 1.1 ng/ml) (p less than 0.05). These results indicate that corticoids have two different actions: an acute potentiating activity on GHRH, and a delayed blocking action on GHRH-induced GH secretion.