Hydration assessment using the cardiovascular response to standing

The cardiovascular response to standing (sit-to-stand change in heart rate; SSΔHR) is commonly employed as a screening tool to detect hypohydration (body water deficit). No study has systematically evaluated SSΔHR cut points using different magnitudes or different types of controlled hypohydration. The objective of this study was to determine the diagnostic accuracy of the often proposed 20?b/min SSΔHR cut point using both hypertonic and isotonic models of hypohydration. Thirteen healthy young adults (8M, 5F) underwent three bouts of controlled hypohydration. The first bout used sweating to elicit large losses of body water (mass) (>3?% sweat). The second two bouts were matched to elicit 3?% body mass losses (3?% diuretic; 3?% sweat). A euhydration control trial (EUH) was paired with each hypohydration trial for a total of six trials. Heart rate was assessed after 3-min sitting and after 1-min standing during all trials. SSΔHR was compared among trials, and receiver operator characteristic curve analysis was used to determine diagnostic accuracy of the 20?b/min SSΔHR cut point. Volunteers lost 4.5?±?1.1, 3.0?±?0.6, and 3.2?±?0.6?% body mass during >3?% sweat, 3?% diuretic, and 3?% sweat trials, respectively. SSΔHR (b/min) was 9?±?8 (EUH), 20?±?12 (>3?% sweat; P?<?0.05 vs. EUH), 17?±?7 (3?% diuretic; P?<?0.05 vs. EUH), and 13?±?11 (3?% sweat). The 20 beats/min cut point had high specificity (90?%) but low sensitivity (44?%) and overall diagnostic accuracy of 67?%. SSΔHR increased significantly in response to severe hypertonic hypohydration and moderate isotonic hypohydration, but not moderate hypertonic hypohydration. However, the 20 beats/min cut point afforded only marginal diagnostic accuracy.     

Role of TNF block genetic variants in HIV-associated sensory neuropathy in black Southern Africans

HIV-associated sensory neuropathy (HIV-SN) is a common neurological complication of HIV infection. The TNF block is a region within the central MHC that contains many immunoregulatory genes. Polymorphisms and haplotypes of the TNF block have been associated with increased risk of HIV-SN in Asians and whites. Here we investigated genetic associations with HIV-SN in 342 black Southern Africans (190 cases and 152 neuropathy-free controls) using single nucleotide polymorphisms (SNPs) spanning the TNF block and a set of haplotypes defined by 31 SNPs in Asian and white populations (denoted FVa). We included population-appropriate tagSNPs derived from an African population (Yoruban, YRI, HapMap) and derived extended haplotypes comprising 61 SNPs (denoted FVa_ext b). We found no association between HIV-SN and carriage of two SNPs (TNF-1031/rs1799964*C and BAT1 (intron10)/rs9281523*C) associated with HIV-SN in whites and Asians. Additionally, a haplotype containing TNF-1031/rs1799964*C associated with increased risk of HIV-SN in Asians, but was not present in this African population. However, alleles of seven SNPs associated with reduced risk of HIV-SN (corrected for age, height and multiple comparisons). These were rs11796*A, rs3130059*G, rs2071594*C, NFKBIL1-62/rs2071592*A, rs2071591*A, LTA+252/rs909253*G, rs1041981*C. One haplotype (FV18_ext1), not containing these alleles, was associated with increased risk of HIV-SN after correction for age, height and multiple comparisons. Our results confirm the involvement of genes in the TNF block in altering risk for HIV-SN, but genotypes critical in this African population differed from those affecting HIV-SN in whites and Asians. These differences support the need for genetic association studies in diverse populations.     

Knowledge and attitudes of infection prevention and control among health sciences students at University of Namibia

Background

Health Sciences students are exposed early to hospitals and to activities which increase their risk of acquiring infections. Infection control practices are geared towards reduction of occurrence and transmission of infectious diseases.

Objective

To evaluate knowledge and attitudes of infection prevention and control among Health Science students at University of Namibia.

Methods

To assess students'' knowledge and attitudes regarding infection prevention and control and their sources of information, a self-administered questionnaire was used to look at standard precautions especially hands hygiene.

Results

One hundred sixty two students participated in this study of which 31 were medical, 17 were radiography and 114 were nursing students. Medical students had better overall scores (73%) compared to nursing students (66%) and radiology students (61%). There was no significant difference in scores between sexes or location of the high school being either in rural or urban setting.

Conclusion

Serious efforts are needed to improve or review curriculum so that health sciences students'' knowledge on infection prevention and control is imparted early before they are introduced to the wards.     

Impact of a protective vest and spacer garment on exercise-heat strain

Protective vests worn by global security personnel, and weighted vests worn by athletes, may increase physiological strain due to added load, increased clothing insulation and vapor resistance. The impact of protective vest clothing properties on physiological strain, and the potential of a spacer garment to reduce physiological strain, was examined. Eleven men performed 3 trials of intermittent treadmill walking over 4 h in a hot, dry environment (35°C, 30% rh). Volunteers wore the US Army battledress uniform (trial B), B + protective vest (trial P), and B + P + spacer garment (trial S). Biophysical clothing properties were determined and found similar to many law enforcement, industry, and sports ensembles. Physiological measurements included core (T _c), mean skin (T _sk) and chest (T _chest) temperatures, heart rate (HR), and sweating rate (SR). The independent impact of clothing was determined by equating metabolic rate in all trials. In trial P, HR was +7 b/min higher after 1 h of exercise and +19 b/min by the fourth hour compared to B (P < 0.05). T _c (+0.30°C), T _sk (+1.0°C) and Physiological Strain Index were all higher in P than B (P < 0.05). S did not abate these effects except to reduce T _sk (P > S) via a lower T _chest (−0.40°C) (P < 0.05). SR was higher (P < 0.05) in P and S versus B, but the magnitude of differences was small. A protective vest increases physiological strain independent of added load, while a spacer garment does not alter this outcome.     

Gene polymorphisms,tobacco exposure and oral cancer susceptibility: a study from Gujarat,West India

Polymorphic variability in the enzymes involved in biotransformation of tobacco‐related pro‐carcinogens plays an important role in modulating oral cancer susceptibility. CYP1A1*2A, CYP1A1*2C, GSTM1 and GSTT1 polymorphisms were determined in 122 oral carcinoma cases and 127 controls from Gujarat, West India using PCR‐based methods. The results revealed that the polymorphic variants of CYP1A1 gene did not show association towards oral cancer risk. The GSTM1 and GSTT1 null genotypes were found to be over‐represented in patients than controls, suggesting a moderate increase in risk of oral cancer. The oral cancer risk was significantly increased in the patients having either alone or concurrent deletion of GSTM1 and GSTT1. The results also suggested significant association between tobacco habits, especially chewing, variant genotypes of CYP1A1, GSTM1 and GSTT1 and oral cancer risk. Our data have provided evidence that GST polymorphism modified the susceptibility to oral cancer and individuals with variant genotypes of the three genes with tobacco habits are at significant risk of developing oral cancer.     

先天性无肛直肠舟状窝瘘手术186例

1临床资料1988-06/2003-12我院共186例,均为女性,无肛门,其中0～6月龄21例,0.5～1岁96例,1～3岁53例,3～8岁15例,13岁1例.以大便从会阴部舟状窝瘘口处排出而就诊,患儿有不同程度的排便困难,严重时伴腹胀呕吐,多数患儿有营养不良性贫血.瘘口直径0.3～0.6 cm,直肠盲端到肛穴皮肤之间的距离1.0～2.5 cm,属于中、低位肛门直肠畸形.本组有3例合并先天性心脏病-室间隔缺损,2例合并骶前囊肿,1例合并脐疝.     

抗痫灵在大鼠肝脏中代谢的研究

用离体大鼠肝脏灌流法,研究了抗痫灵在肝脏灌流过程中的代谢规律。用高效液相色谱法由灌流液中分离、制备得到了两种代谢物,经紫外吸收光谱与质谱鉴定,确定代谢物的结构为3,4-次甲基二氧桂皮酰羟基哌啶及阿魏酰哌啶,后者经化学合成得到了进一步的确证。本文还研究了肝循环过程中抗痫灵的代谢动力学,揭示了大部份抗痫灵以原形结合贮存于肝脏中。