Burden of stigma among tuberculosis patients in a pastoralist community in Kenya: A mixed methods study.

BACKGROUND: Tuberculosis (TB) stigma remains a barrier to early diagnosis and treatment completion. Increased understanding of stigma is necessary for improved interventions to minimise TB stigma and its effects. The purpose of this study is to quantitatively measure TB stigma and to explore qualitatively its manifestation among TB patients in a rural Kenyan community. METHODS: This hospital based study using explanatory sequential mixed methods approach was conducted in 2016. In the quantitative part of the study, a questionnaire containing socio-demographic characteristics and scales measuring perceived TB stigma and experienced TB stigma, was administered to 208 adult pulmonary TB patients receiving treatment in West Pokot County. Respondents with high stigma were purposively selected to take part in in-depth interviews and focus group discussions. The qualitative data were collected through 15 in-depth interviews and 6 focus group discussions with TB patients. Descriptive and bivariate analysis was done for the quantitative data while the thematic analysis was done for qualitative data. RESULTS: The internal consistency reliability coefficients were satisfactory with Cronbach alphas of 0.87 and 0.86 for the 11-item and 12-item stigma measurement scale. The investigation revealed that TB stigma was high. The key drivers of TB stigma were the association of TB with HIV/AIDS and the fear of TB transmission. TB stigma was exemplified through patients being isolated by others, self-isolation, fear to disclose TB diagnosis, association of TB with human immunodeficiency virus (HIV) and lack of social support. Being a woman was significantly associated with high levels of both experienced stigma (p = 0.007) and perceived stigma (p = 0.005) while age, marital status, occupation and the patient's religion were not. CONCLUSION: There is a need to implement stigma reduction interventions in order to improve TB program outcomes.

Anopheles gambiae and Anopheles arabiensis population densities and infectivity in Kopere village, Western Kenya.

INTRODUCTION: This study was conducted in a sugar belt region of western Kenya interfacing epidemic and endemic malaria transmission. We investigated Anopheles gambiae sensu stricto (ss) and Anopheles arabiensis species compositions and densities, human host choice, and infectivity. METHODOLOGY: Mosquitoes were captured using pyrethrum spray catch technique and first identified based on morphology; species were confirmed by PCR. Blood meal preference and sporozoite rates were determined by ELISA. Parity rates and entomological inoculation rates (EIR) were determined. Seasonal densities were compared against environmental temperatures, relative humidity and rainfall. RESULTS: In total 2,426 An. gambiae were collected.  Out of 1,687 female blood-fed mosquitoes, 272 were randomly selected for entomological tests. An. gambiae ss and An. arabiensis comprised 75% (205/272) and 25% (68/272) of the selection, respectively. An. gambiae ss had higher preference for human blood (97%; n=263/272) compared with An. arabiensis, which mostly fed on bovines (88%; n=239/272).  The sporozoite and parity rates were 6% (16/272) and 66% (179/272) for An. gambiae ss and 2% (4/272) and 53% (144/272) for An. arabiensis respectively, while EIR was 0.78 infective bites/person/night.  Climate (ANOVA; F=14.2; DF=23) and temperature alone (r=0.626; t=3.75; p=0.001) were significantly correlated with vector densities. CONCLUSION: An. gambiae ss are the most efficient malaria vector mosquito species in Kopere village. Because An. gambiae ss largely rests and feeds indoors, use of indoor residual spray and insecticide-treated nets is likely the most suitable approach to malaria vector control in Kopere village and other parts of Kenya where this species is abundant. 

Effects of breakfast meal composition on second meal metabolic responses in adults with Type 2 diabetes mellitus.

OBJECTIVE: We tested the relative importance of a low-glycemic response versus a high glycemic response breakfast meal on postprandial serum glucose, insulin and free fatty acid (FFA) responses after consumption of a standardized mid-day meal in adult individuals with Type 2 diabetes mellitus (DM). DESIGN: Following an overnight fast of 8-10 h, a randomized crossover intervention using control and test meals was conducted over a 3-week-period. A fasting baseline measurement and postprandial measurements at various time intervals after the breakfast and mid-day meal were taken. SUBJECTS: Forty-five Type 2 DM subjects completed the requirements and were included in the study results. INTERVENTIONS: Two different breakfast meals were administered during the intervention: (A) a high glycemic load breakfast meal consisting of farina (kJ 1833; carbohydrate (CHO) 78 g and psylium soluble fiber 0 g), (B) a low-glycemic load breakfast meal consisting of a fiber-loop cereal (kJ 1515; CHO 62 g and psyllium soluble fiber 6.6 g). A standardized lunch was provided approximately 4 h after breakfast. Blood plasma concentrations and area under the curve (AUC) values for glucose, insulin and FFA were measured in response to the breakfast and mid-day lunch. Statistical analyses were performed using SAS software (8.02). Comparisons between diets were based on adjusted Bonferroni t-tests. RESULTS: In post-breakfast analyses, Breakfast B had significantly lower area under the curve (AUC) values for plasma glucose and insulin compared to Breakfast A (P<0.05) (95% confidence level). The AUC values for FFA were higher for Breakfast B than for Breakfast A (P<0.05) (95% confidence level). Post-lunch analyses indicated similar glucose responses for the two breakfast types. Insulin AUC values for Breakfasts B were significantly lower than Breakfast A (P<0.05) (95% confidence level). The AUC values for FFA were unaffected by breakfast type. CONCLUSIONS: These data indicate that ingesting a low-glycemic load meal containing psyllium soluble fiber at breakfast significantly improves the breakfast postprandial glycemic, insulinemic and FFA responses in adults with Type 2 DM. These data revealed no residual postprandial effect of the psyllium soluble fiber breakfast meal beyond the second meal consumed. Thus, there was no evidence of an improvement postprandially in the glycemic, insulinemic and FFA responses after the consumption of the lunch meal.

Increased poly-(R)-3-hydroxybutyrate concentrations in streptozotocin (STZ) diabetic rats.

Poly-(R)-3-hydroxybutyrate, a linear polymer of the ketone body, R-3-hydroxybutyric acid, is an amphiphilic, water-insoluble, salt-solvating polymer. In humans, shortchain, complexed polyhydroxybutyrate has been found in a wide variety of tissues and in atherosclerotic plaques. In the circulation, plasma polyhydroxybutyrate concentrations correlate strongly with atherogenic lipid profiles. We compared polyhydroxybutyrate levels in plasma, kidney, eye, sciatic nerve, aorta, and brain of streptozotocin-diabetic and healthy control Sprague-Dawley rats, three weeks after injection. With the exception of brain, which showed only a marginal increase (1.3-fold), polyhydroxybutyrate levels were 3- to 8-fold greater in tissues from diabetic vs. control rats. Increases in polyhydroxybutyrate levels between normal and diabetic rat tissues were in order: sciatic nerve (9.0-fold), kidney (7.2-fold), plasma (6.0-fold), aorta (4.4-fold), and whole eye (2.9-fold). These data indicate a significant increase in polyhydroxybutyrate levels in organs affected by complications of diabetes, and further suggest that plasma polyhydroxybutyrate levels may serve as a marker for the disease.

Glucose-specific regulation of aldose reductase in human retinal pigment epithelial cells in vitro.

PURPOSE: To test the hypothesis that pathophysiological levels of glucose regulate aldose reductase (AR2) gene expression, protein production, and activity in human retinal pigment epithelial (RPE) cells in vitro. METHODS: Primary cultures of human RPE cells were grown for up to 72 hours in media supplemented with various concentrations of glucose (5, 20, or 75 mM), or in 5 mM glucose containing media supplemented with one of the following: galactose, the transported but nonmetabolized glucose analogue 3-O-methylglucose (3-OMG), or the impermeant hexitol mannitol-so that the final hexose concentrations were equimolar to those of the various glucose concentrations used. Changes in the transcript levels for AR2 mRNA, AR2 protein content, and AR2 enzyme activity were determined. RPE glucose utilization and lactate production were determined in media containing 5 and 20 mM glucose. RESULTS: Glucose utilization and lactate production increased 4.8-fold and 4.4-fold, respectively, when RPE cells were grown in media containing 20 mM versus 5 mM glucose. Glucose was more effective than any other hexose in the induction of AR2 mRNA or increased AR2 protein expression. When RPE cells were grown in media containing 20 mM mannitol, 3-OMG, or galactose they had lower levels of AR2 mRNA expression than when cells were grown in medium containing 5 mM glucose. RPE cells grown in medium supplemented with 20 or 75 mM galactose did not show a greater increase in AR2 protein expression than cells grown in medium containing 5 mM glucose. Hyperosmotic induction of AR2 mRNA was the same in medium containing 75 mM glucose or 75 mM mannitol, but was at least 50% lower when RPE cells were grown in 75 mM galactose or 3-OMG. CONCLUSIONS. These data indicate that elevations in ambient glucose result in greater metabolism of glucose through glycolysis and polyol metabolism. Induction of AR2 was greatest when RPE cells were grown in pathophysiological concentrations of glucose. Hyperosmolar stress is not a necessary determinant of AR2 mRNA, AR2 protein, or AR2 protein activity in cells that form the outer blood-retinal barrier. Increased facilitative glucose transport or glucose metabolism appears to be requisite for glucose-specific and nonosmotic regulation of AR2 in the RPE cell in vitro.

Glucose transporters control gene expression of aldose reductase, PKCalpha, and GLUT1 in mesangial cells in vitro.

The process linking increased glucose utilization and activation of metabolic pathways leading to end-organ damage from diabetes is not known. We have previously described rat mesangial cells that were transduced to constitutively express the facilitative glucose transporter 1 (GLUT1, MCGT1 cells) or bacterial beta-galactosidase (MCLacZ, control cells). Glucose transport was rate limiting for extracellular matrix production in the MCGT1 cells. In the present work, we investigated the effect of GLUT1 overexpression in mesangial cells on aldose reductase (AR), protein kinase Calpha (PKCalpha), and native GLUT1 transcript levels, to determine whether changes in GLUT1 alone could regulate their expression in the absence of high extracellular glucose concentrations. MCGT1 cells grown in normal (8 mM) or elevated (20 mM) glucose had elevated abundance of AR, PKCalpha, and the native GLUT1 transcripts compared with control cells. AR protein levels, AR activity, sorbitol production, and PKCalpha protein content were also greater in the MCGT1 cells than in control cells grown in the same media. This is the first report of the concomitant activation of AR, PKCalpha, and GLUT1 genes by enhanced GLUT1 expression. We conclude that increased GLUT1 expression leads to a positive feedback of greater GLUT1 expression, increased AR expression and activity with polyol accumulation, and increased total and active PKCalpha protein levels, which leads to detrimental stimulation of matrix protein synthesis by diabetic mesangial cells.

Human Na(+)-myo-inositol cotransporter gene: alternate splicing generates diverse transcripts.

Na(+)-myo-inositol cotransport activity generally maintains millimolar intracellular concentrations of myo-inositol and specifically promotes transepithelial myo-inositol transport in kidney, intestine, retina, and choroid plexus. Glucose-induced, tissue-specific myo-inositol depletion and impaired Na(+)-myo-inositol cotransport activity are implicated in the pathogenesis of diabetic complications, a process modeled in vitro in cultured human retinal pigment epithelium (RPE) cells. To explore this process at the molecular level, a human RPE cDNA library was screened with a canine Na(+)-dependent myo-inositol cotransporter (SMIT) cDNA. Overlapping cDNAs spanning 3569 nt were cloned. The resulting cDNA sequence contained a 2154-nt open reading frame, 97% identical to the canine SMIT amino acid sequence. Genomic clones containing SMIT exons suggested that the cDNA is derived from at least five exons. Hypertonic stress induced a time-dependent increase, initially in a 16-kb transcript and subsequently in 11.5-, 9.8-, 8.5-, 3.8-, and approximately 1.2-kb SMIT transcripts, that was ascribed to alternate exon splicing using exon-specific probes and direct cDNA sequencing. The human SMIT gene is a complex multiexon transcriptional unit that by alternate exon splicing generates multiple SMIT transcripts that accumulate differentially in response to hypertonic stress.

Glucose-specific regulation of aldose reductase in capan-1 human pancreatic duct cells In vitro.

Impaired pancreatic duct secretion is frequently observed in insulin-dependent diabetes mellitus (IDDM), although the cellular mechanism(s) of dysfunction remains unknown. Studies in other tissues have suggested that a hyperglycemia-induced decrease in Na, K-ATPase activity could contribute to the metabolic complications of IDDM and that increased polyol metabolism is involved in this response. The present studies examined the effects of glucose on Na, K-ATPase activity and on expression and activity of aldose reductase (AR), a primary enzyme of polyol metabolism, in Capan-1 human pancreatic duct cells. Increasing medium glucose from 5.5 to 22 mM caused a 29% decrease in Na,K-ATPase activity. The decrease was corrected by 100 microM sorbinil, a specific AR inhibitor. Increasing glucose from 5.5 to 110 mM also resulted in concentration-dependent increases in AR mRNA and enzyme activity that could be resolved into two components, one that was glucose specific and observed at pathophysiological concentrations (< 55 mM) and a second that was osmotically induced at high concentrations (> 55 mM) and which was not glucose specific. The present study demonstrates that pathophysiological levels of glucose specifically activate polyol metabolism with a consequent decrease in Na,K-ATPase activity in pancreatic duct epithelial cells, and that this response to hyperglycemia could contribute to decreased pancreatic secretion observed in IDDM. This is the first report of AR regulation in the pancreatic duct epithelium.

Glucose transporters of the glomerulus and the implications for diabetic nephropathy.

Several glucose transporters have recently been identified in glomeruli, and in cultured glomerular cells. These include the facilitative glucose transporter isoforms GLUTs 1, 3 and 4, and sodium-glucose cotransport activity with characteristics of SGLT1. GLUTs 1, 3 and 4 are all high affinity, low capacity, facilitative glucose transporters which typically would be saturated at or near physiologic glucose concentrations. The SGLT transporter of mesangial cells is also a high affinity transporter which similarly could be saturated under normal glucose conditions. This suggests that in order for mesangial cells to take up excessive quantities of glucose in diabetes, changes in glucose transporter expression, translocation or activity may be required. Accordingly, recent investigations discovered positive-feedback regulation of the mesangial cell GLUT1 transporter by glucose, and a regulatory role for GLUT1 in glucose metabolism and extracellular matrix synthesis. Future investigations of glucose transporters in the pathogenesis of diabetic renal disease will now likely proceed in multiple directions, including but not limited to: (1) examination of their regulation by growth factors implicated in diabetic nephropathy, and the resultant effects on ECM synthesis; (2) determination of the mechanisms by which GLUT1 regulates the expression of aldose reductase, PKC, GLUT1, and other genes in the mesangial cell; and (3) Suppression of glucose transporters in attempts to prevent high glucose-induced diabetic glomerulosclerosis.

Aldose reductase gene expression and osmotic dysregulation in cultured human retinal pigment epithelial cells.

A "compatible osmolyte hypothesis" proposes that intracellular nonionic organic osmolytes such as sorbitol, myo-inositol, taurine, betaine, and glycerophosphorylcholine respond coordinately to changes in external osmolality, thereby maintaining the intracellular ionic milieu. Osmoregulation may be the primary physiological function of aldose reductase, which catalyzes the conversion of glucose to sorbitol. Glucose-induced sorbitol accumulation in isosmotic hyperglycemic states is associated with compensatory depletion of myo-inositol and taurine. Because such depletion may predispose to chronic diabetic complications, the relationship between osmolyte shifts and aldose reductase gene expression was studied in two human retinal pigment epithelial cell lines, one exhibiting osmoregulated and the other high basal aldose reductase gene expression. High basal expression of the aldose reductase gene was associated with rapid sorbitol accumulation and myo-inositol depletion in response to hyperglycemic (20 mM) concentrations of glucose. Myo-inositol and sorbitol behaved as compensating intracellular osmolytes by accumulating markedly in response to hyperosmolality (300 mM mannitol). Thus the pattern of response of myo-inositol to hyperglycemic and hyperosmotic levels of glucose and mannitol was related to the degree of basal aldose reductase gene expression, which may therefore influence the development of diabetic complications.

Altered aldose reductase gene regulation in cultured human retinal pigment epithelial cells.

Aldose reductase (AR2), a putative "hypertonicity stress protein" whose gene is induced by hyperosmolarity, protects renal medullary cells against the interstitial hyperosmolarity of antidiuresis by catalyzing the synthesis of millimolar concentrations of intracellular sorbitol from glucose. Although AR2 gene induction has been noted in a variety of renal and nonrenal cells subjected to hypertonic stress in vitro, the functional significance of AR2 gene expression in cells not normally exposed to a hyperosmolar milieu is not fully understood. The physiological impact of basal AR2 expression in such cells may be limited to hyperglycemic states in which AR2 promotes pathological polyol accumulation, a mechanism invoked in the pathogenesis of diabetic complications. Since AR2 overexpression in the retinal pigment epithelium has been associated with diabetic retinopathy, the regulation of AR2 gene expression and associated changes in sorbitol and myo-inositol were studied in human retinal pigment epithelial cells in culture. The relative abundance of aldehyde reductase (AR1) and AR2 mRNA was quantitated by filter hybridization of RNA from several human retinal pigment epithelial cell lines exposed to hyperglycemic and hyperosmolar conditions in vitro. AR2 but not AR1 mRNA was significantly increased some 11- to 18-fold by hyperosmolarity in several retinal pigment epithelial cell lines. A single cell line with a 15-fold higher basal level of AR2 mRNA than other cell lines tested demonstrated no significant increase in AR2 mRNA in response to hypertonic stress. This cell line demonstrated accelerated and exaggerated production of sorbitol and depletion of myo-inositol upon exposure to 20 mM glucose. Therefore, abnormal AR2 expression may enhance the sensitivity of cells to the biochemical consequences of hyperglycemia potentiating the development of diabetic complications.

Spinal anesthesia reduces the hazard of apnea in high-risk infants.

General anesthesia in premature babies is associated with a significant risk of life-threatening apnea. Spinal anesthesia in the high-risk infant is simple, safe, and effective, but the incidence of apnea with its use has not been previously determined. The total absence of apnea in 84 high-risk infants suggests that surgery below the umbilicus under spinal anesthesia can safely be performed on an outpatient basis in preterm infants or babies with a history of apnea. Ketamine as an adjunctive agent adds no apparent risk. The technique is relatively easy, surgery is not compromised, and parental acceptance is high.