The glucoregulatory response to intravenous glucose infusion in normal man: Roles of insulin and glucose

In order to differentiate the roles of hyperinsulinemia and hyperglycemia per se in the homeostatic response to i.v. glucose administration, two groups of normal subjects were given either glucose alone (3.5 mg kg^?1 min^?1) or glucose (3 mg kg^?1 min^?1) in conjunction with somatostatin (500 μg hr^?1), insulin (0.15 mU kg^?1 min^?1) and glucagon (1 ng kg^?1 min^?1). Glucose kinetics were measured by the primed-constant infusion of 3-³H-glucose. During the infusion of glucose alone, plasma glucose stabilized at levels 45–50 mg/dl above the fasting values. Endogenous glucose output was markedly suppressed by 85%–90% while glucose uptake rose to values very close to the infusion rate of exogenous glucose. Glucose clearance remained unchanged. Plasma insulin rose three-fourfold while plasma glucagon fell by 25%–30%. When glucose was infused with somatostatin, insulin, and glucagon, plasma insulin was maintained at levels 50% above baseline while glucagon remained at preinfusion levels. Under these conditions, the infusion of exogenous glucose resulted in a progressive increase of plasma glucose which did not stabilize until the end of the study period (190 mg/dl at 120 min). Endogenous glucose production was consistently suppressed (52%) but significantly less than observed with the infusion of glucose alone (p < 0.01). Glucose uptake increased to the same extent as with glucose alone, despite the more pronounced hyperglycemia. Thus, glucose clearance fell significantly below baseline (25%–30%; p < 0.01). These data demonstrate that hyperglycemia per se (fixed, near basal levels of insulin and glucagon) certainly contributes to the glucoregulatory response to i.v. glucose administration by both inhibiting endogenous glucose output and increasing tissue glucose uptake. However, the extra-insulin evoked by hyperglycemia is necessary for the glucoregulatory system to respond to the glucose load with maximal effectiveness.     

Characteristics of superficial mycoses in Malta

BACKGROUND: A study was conducted to determine the chief agents of superficial mycoses in Malta. Data were collected over a 5-year period from mycologic investigations carried out on all dermatologic specimens sent to the Mycology Laboratory at St. Luke's Hospital in Malta. METHODS: In the period between January 1995 and December 1999, a total of 1271 specimens from skin, nails, or hair were collected from 1200 clinically suspected cases of dermatomycoses. RESULTS: The fungi cultivated included dermatophytes (n = 371), yeasts (n = 33), and nondermatophyte filamentous fungi (n = 12). Trichophyton rubrum (n = 121) was the most prevalent, followed by Microsporum canis (n = 109), T. mentagrophytes (n = 80), M. gypseum (n = 27), Epidermophyton floccosum (n = 17), T. soudanense (n = 10), T. tonsurans (n = 2), T. verrucosum (n = 2), M. persicolor (n = 1), and T. violaceum (n = 1). Candida species were also cultivated, with C. parapsilosis (n = 14) being the most common, followed by C. albicans (n = 12) and C. tropicalis (n = 6). Nondermatophyte filamentous fungi were isolated from nail specimens only. CONCLUSIONS: In this study, superficial fungal infections were reported more commonly in female (n = 207) than in male (n = 182) patients. M. canis was the chief agent of tinea capitis and tinea corporis, whilst T. rubrum was the main causative agent of tinea pedis, tinea manuum, and tinea unguium. Onychomycosis due to Candida species was more common in female than in male patients.     

Cystic lesions associated with meningiomas

Three cases of meningiomas associated with large cysts are reported, and 58 other cases from the literature are reviewed. The etiology of these cysts is analyzed on the basis of surgical and pathological findings. The preoperative diagnosis of large computed tomographic hypodensities associated with meningiomas and the differential features from other cystic tumors are discussed. The surgical aspect of the solid tumor and particularly the absence of a capsule separating the tumor from the cyst are usually decisive in confirming the intratumoral nature of the cyst. In questionable cases a histologic evaluation of the cyst walls may be necessary.     

Variability of the mesolimbic neuronal activity in a rat model of depression

The Flinders Sensitive Line of rats is a widely accepted and validated model of depression. These rats demonstrate abnormalities in limbic dopamine neurotransmission, suggesting disturbed neuronal activity in the ventral tegmental area. Interspike interval time series were recorded from the ventral tegmental area of the control Sprague-Dawley and Flinders Sensitive Line rats. These data were analyzed for the variance of interspike interval for each group of animals. We found that FSL rats show a significant decrease in the variance of 0.25-0.5-s-long interspike intervals. Moreover, these abnormalities were normalized following 14-day treatment with desipramine. We suggest that the interspike intervals at this range may have an important role in the information encoding of mesolimbic dopaminergic activity. Impaired variance of the length of interspike intervals in this area may correspond to the pathophysiology of depression, and hence be a possible marker for the analysis of the efficiency of antidepressant treatment.     

Rapid Serological Tests for SARS-CoV-2: Diagnostic Performance of 4 Commercial Assays

ObjectiveTo assess the diagnostic performance of lateral flow immunochromatographic assays (LFAs) of 4 different manufacturers to identify SARS-CoV-2 antibodies (IgM, IgG, or total), comparing them with the nucleic acid amplification test (NAAT) or the clinical defined test (definite or probable SARS-CoV-2 infection, respectively).MethodsOne hundred nineteen serum samples were randomly selected by convenience and distributed in the following groups: (1) group with SARS-CoV-2 infection (n = 82; RT-qPCR positive [definite, n = 70] and probable [n = 12]); (2) other diseases (n = 27; other viruses identified [n = 8] and SARS of other etiologies [n = 19]); and (3) healthy control group (n = 10). LFAs of 4 manufacturers were compared: MedTest Coronavirus (COVID-19) IgG/IgM (MedLevensohn, Brazil); COVID-19 IgG/IgM ECO Test (Ecodiagnóstica, Brazil); Camtech COVID-19 IgM/IgG Rapid Test Kit (Camtech Diagnostics Pte Ltd, Singapore); and 1-Step COVID-19 Test for total antibodies (Guangzhou Wondfo Biotech Co., China).ResultsThe 4 tests studied showed high diagnostic performance characteristics for the diagnoses of definite or probable SARS-CoV-2 infection. The best measures were for the Wondfo test: sensitivity (86.59%; 95% CI: 77.26–93.11%), specificity (100%; 90.51–100%), DOR (257; 60–1,008), LR+ (33.43; 4.82–231.85), LR− (0.13; 0.08–0.23), accuracy (90.76%; 84.06–95.29%), and Matthews correlation coefficient (MCC) 0.82. Although considering only the probable SARS-CoV-2 infection (PCR−) cases, all the kits studied showed limited values.ConclusionOur data demonstrate the excellent performance of LFA for the diagnoses of definite or probable SARS-CoV-2 infection. There was substantial heterogeneity in sensitivities of IgM and IgG antibodies among the different kits. LFA tests cannot replace molecular diagnostics but should be used as an additional screening tool.     

Malignant evolution of monoclonal gammopathy of undetermined significance: analysis of 633 consecutive cases with a long term follow-up

In 633 consecutive patients with monoclonal gammopathy of undetermined significance (MGUS) the probability of malignant evolution was 9, 17 and 51 % at 5, 10 and 15 years, respectively, after diagnosis. The values of monoclonal component, Bence-Jones proteinuria and erythrocyte sedimentation rate were associated with malignant transformation.