Entonox for casualties at 1000 m: use of nitrous oxide analgesia in Nigeria at moderate altihnle

Analgesia with nitrous oxide and oxygen (Entonox) has been found to give adequate pain relief for 90 minor casualty procedures in over 90% of cases at moderate altitude. It was self administered except in six patients. Children between 6 and 10 years of age comprised 14% of patients, and the majority of the remainder were young adults. Additional analgesia was required in 11 patients, with no increase in complications. Complications were few; drowsiness occurred in 9%, dizziness was troublesome in one patient, but there was no nausea or vomiting and no one became unconscious. In situations where trained personnel are scarce, and where supervision can only be given at the time of the procedure and even at moderate altitudes Entonox is a clinically effective safe analgesic.     

Characterization of breast tumors using machine learning based upon multiparametric magnetic resonance imaging features

Magnetic resonance imaging (MRI) is playing an important role in the classification of breast tumors. MRI can be used to obtain multiparametric (mp) information, such as structural, hemodynamic, and physiological information. Quantitative analysis of mp-MRI data has shown potential in improving the accuracy of breast tumor classification. In general, a large set of quantitative and texture features can be generated depending upon the type of methodology used. A suitable combination of selected quantitative and texture features can further improve the accuracy of tumor classification. Machine learning (ML) classifiers based upon features derived from MRI data have shown potential in tumor classification. There is a need for further research studies on selecting an appropriate combination of features and evaluating the performance of different ML classifiers for accurate classification of breast tumors. The objective of the current study was to develop and optimize an ML framework based upon mp-MRI features for the characterization of breast tumors (malignant vs. benign and low- vs. high-grade). This study included the breast mp-MRI data of 60 female patients with histopathology results. A total of 128 features were extracted from the mp-MRI tumor data followed by features selection. Five ML classifiers were evaluated for tumor classification using 10-fold crossvalidation with 10 repetitions. The support vector machine (SVM) classifier based on optimum features selected using a wrapper method with an adaptive boosting (AdaBoost) technique provided the highest sensitivity (0.96 ± 0.03), specificity (0.92 ± 0.09), and accuracy (94% ± 2.91%) in the classification of malignant versus benign tumors. This method also provided the highest sensitivity (0.94 ± 0.07), specificity (0.80 ± 0.05), and accuracy (90% ± 5.48%) in the classification of low- versus high-grade tumors. These findings suggest that the SVM classifier outperformed other ML methods in the binary classification of breast tumors.     

Effects of mercuric chloride on renal plasma membrane function after depletion or elevation of renal glutathione

The role of renal nonprotein sulfhydryls (NPSH) in mercuric chloride-induced nephrotoxicity has been studied in various laboratories. Similarly, the importance of NPSH for mercuric ion accumulation by renal tissue also has been studied. In this study the potential role of NPSH was examined with respect to mercuric ion effects on membrane transport utilizing isolated membrane vesicles prepared from Sprague-Dawley rat kidneys. Sodium gradient-driven p-aminohippurate (PAH) transport in basolateral vesicles and glucose transport in brush border vesicles were studied. Depletion of NPSH, primarily glutathione (GSH), appeared to alter PAH but not glucose transport. HgCl2 (1 mg/kg) had no effect on either transport system in vesicles isolated from kidneys with normal GSH content, but it markedly disrupted both PAH and glucose transport in vesicles isolated from GSH-depleted rats. The most consistent effects were observed after GSH depletion with diethyl maleate plus buthionine sulfoximine. Elevation of renal GSH by administration of glutathione monoethyl ester blocked the effect of mercuric chloride (4 mg/kg) on glucose transport reported earlier. These data indicate that renal sulfhydryls not only modulate the effects of mercuric chloride, but they also may be important for normal physiological functioning of the PAH transport system.     

Characterization of breast lesion using T1-perfusion magnetic resonance imaging: Qualitative vs. quantitative analysis

Objectives

The objective of this study was to quantify the hemodynamic parameters using first pass analysis of T₁-perfusion magnetic resonance imaging (MRI) data of human breast and to compare these parameters with the existing tracer kinetic parameters, semi-quantitative and qualitative T₁-perfusion analysis in terms of lesion characterization.

Metallothionein induction in rat hippocampal neurons in primary culture

Primary cultures of hippocampal neurons are important for the study of trace elements in epileptogenesis. We developed a model system for culturing hippocampal neurons on poly-L-lysine in Iscove's modification of Dulbecco's MEM (IMDM) supplemented with K+, D-glucose, glutamine, insulin, p-amino benzoic acid, transferrin, BSA, beta-estradiol, gentamycin, and fungizone. Neurons were identified by histochemical staining for cholinesterase. Zinc at concentrations of 10(-9) to 10(-6) M induced metallothionein in hippocampal neuronal cultures. Maximum metallothionein induction occurred after 48 hrs incubation with zinc.     

Loop diuretic derivative L-644, 711 inhibits K+-stimulated cellular injury in neonatal guinea pig cortical astrocytes

An early pathological rise in extracellular K⁺ following acute hypoxia results in Cl^? uptake into astrocytes through the Cl^?/HCO ₃ ^? exchanger with an osmotic equivalent of water. This study addressed effects of the anion transport inhibitor, L-644,711, (5,6,-dichloro-2,3,9,9a-tetrahydro-3-oxo-9a-propyl-1H-fluroen-7-yl)oxyacetic acid. Confluent primary cultures from neonatal guinea pigs, characterized as >95% astrocytes with antiserum to glial fibrillary acidic protein, were manipulated by incubation in either basal buffer (BB) with the ionic composition of Dulbecco’s minimum essential media (DMEM) or one with high extracellular K⁺ (HiK). Incubation in 27 or 60 mM Hik significantly reduced cell viability and precipitated a time-dose dependent increase in lactate dehydrogenase (LDH) efflux (30 min to 4h). L-644,711 was not cytotoxic, and significantly inhibited HiK-stimulated LDH efflux. The optimal effective dose of L-644,711 for preventing injury in guinea pig astrocytes was 10^?11 M when administered simultaneously with the HiK paradigm or in reversing injury when administered 30 min after exposing cells to HiK. These findings indicate the potential usefulness of agents which modify ion transport processes in hypoxic-ischemic cerebral injury.     

The effects of mercuric chloride on transport by brush border and basolateral membrane vesicles isolated from rat kidney

Both brush border and basolateral membrane vesicles were prepared from rat kidney by Percoll gradient centrifugation. The addition of mercuric chloride (100 nM) to vesicles prepared from healthy, male, Sprague-Dawley rats reduced p-aminohippurate (PAH) transport by basolateral vesicles. No effect was observed on glucose transport by brush border vesicles even at mercuric chloride concentrations as high as 10 microM. However, when the metal salt was added in the presence of 5% bovine serum albumin, basolateral PAH transport was unaffected. Transport studies also were done with vesicles isolated from rats pretreated with mercuric chloride (4 mg/kg, sc). Transport of PAH was unaffected at all times studied. Glucose transport was unaffected at 1 and 3 hr, but at 16 hr was reduced significantly. By 48 hr, brush border glucose transport had recovered. These data demonstrate that mercuric chloride can alter renal membrane function, and that the effects depend on the membrane vesicle population used. With pretreatment studies, the time after treatment also influences whether or not an effect is seen.