MEDIAN NERVE INJURY AND THE TRANSVERSE WRIST CREASE INCISION IN OPEN CARPAL TUNNEL RELEASE

The author has recently had referred to him three patients with median nerve injuries who have had open carpal tunnel decompression via a small transverse wrist incision. Despite previous adverse reports, some surgeons persist with this technique.     

Immunohistochemical localization of glutathione-S-transferase and glutathione peroxidase in adult Syrian hamster tissues and during kidney development.

Tissues from adult Syrian hamsters were studied with immunoperoxidase techniques using polyclonal antibodies to glutathione-S-transferase (rat liver and human placental enzymes) and human erythrocyte glutathione peroxidase. Most tissues immunostained similarly with these antibodies. Most notable was the cytoplasmic staining of mesenchyme tissues, especially smooth muscle, by all three antibodies. Epithelial cells stained distinctively, but usually less intensely than mesenchyme. Epithelial cells from all levels of the gastrointestinal tract, respiratory epithelium, transitional epithelium, and epidermis all showed strong staining with these antibodies. Other epithelial cell types were usually positive but showed less dramatic staining. Most epithelial tissues showed both nuclear and cytoplasmic staining; some also showed cell-surface (eg, cilia) staining. The role of these enzymes in cell differentiation of a stable organ was studied by immunostaining the kidney during its development. Early stroma (13- and 15-day fetuses) of the kidney (metanephric mesenchyme) showed strong cell-surface staining for glutathione transferases and moderate staining for glutathione peroxidase; renal tubules (which are epithelial cells) at this stage were negative for these markers. As renal tubules differentiated, first cytoplasm and then nuclei stained moderately, suggesting that glutathione-S-transferases and glutathione peroxidase are markers of both mesenchymal cells, including embryonic mesenchyme, and terminal differentiation of at least some epithelial cells.     

Differentiation of Brucella ovis from Brucella abortus by gas-liquid chromatographic analysis of cellular fatty acids

The cellular fatty acid composition of Brucella ovis and Brucella abortus strains was determined by gas-liquid chromatography. Both species were characterized by the presence of fatty acids 16:0, 17:0, 17:0 cyclopropane, 18:0, 18:1, and 19:0 cyclopropane; B. ovis also contained some 15:0. There were differences in the relative proportions of the fatty acids present, and it was possible to differentiate B. ovis from B. abortus on the basis of the absence of 15:0, lower concentrations of 17:0 and 18:1, and higher concentrations of 19:0 cyclopropane in B. abortus. The data indicate that analysis of cellular fatty acid composition by gas-liquid chromatography can be used for the identification of B. ovis and its differentiation from B. abortus.     

Twice weekly prophylactic therapy in haemophilia A.

Factor VIII-containing materials were administered to four severely affected haemophiliacs twice weekly in doses calculated to raise the factor VIII level to either 15% or 30% of average normal. The pooled results from those patients with statistically similar baseline bleeding frequencies showed a significant reduction in bleeding frequency on both doses in the first 48 hours. The 30% dose produced a more significant reduction than the 15% dose in the first 24 hours, but there was no significant difference between the two doses in the second 24 hours. It appears that to reduce the bleeding frequency of severely affected haemophiliacs by 60% would require a two-and-a-half-fold increase in therapeutic materials. A 90% reduction would need nine times the amount of material currently in use.     

A simple method to improve the accuracy of non-invasive ultrasound in selecting TIA patients for cerebral angiography.

A prospective study is reported of the ability of B mode ultrasound imaging and continuous wave Doppler flow studies to detect different degrees of stenosis of the extracranial internal carotid artery (ICA) in 186 arteries in 99 patients with transient ischaemic attacks (TIA) and minor ischaemic stroke. A simple mathematical equation has been developed which combines the image and flow data to provide a single predictor of the degree of angiographic stenosis which has advantages over either ultrasonic modality used alone. The sensitivity and specificity of the predictive model in the detection of stenosis greater than or equal to 25% was 73% and 98%, of stenosis greater than or equal to 50% was 90% and 93%, of stenosis greater than or equal to 75%, 65% and 99% and occlusion 100% and 94% respectively. The principal clinical value of ultrasound screening is to spare patients with "non-significant" stenosis the risk of unnecessary angiography. Thus a simple measure of the Duplex screening tests' performance is the proportion of all strokes occurring as a complication of angiography that are avoided by changing the investigation policy from "angiograms for all carotid TIA and minor ischaemic stroke patients" to "angiograms for all patients with abnormal ultrasound results". If Duplex scanning were used to select patients most likely to have a significant abnormality on angiography, depending on the degree of stenosis to be detected, 52-85% of angiographic strokes might be avoided. If the predictive equation were used 62-88% of angiographic strokes might be avoided.     

Plant foods and colon cancer: an assessment of specific foods and their related nutrients (United States)

Plant foods have been associated inversely with colon cancer. Since amajor focus of this study was to identify components of plant foods whichmay account for their association with colon cancer, nutrients which arecommonly found in plant foods also were evaluated. A population-basedcase-control study was conducted in Northern California, Utah, and the TwinCities area of Minnesota (United States). Complete data were available frominterviewer-administered questionnaires on 1,993 cases and 2,410 controls.Higher intakes of vegetables (for highest relative to lowest quintile ofintake) were associated inversely with colon cancer risk: the odds ratio(OR) was 0.7 for both men (95 percent [CI] confidence interval = 0.5-0.9)and women (CI = 0.5-1.0). Associations were stronger among those withproximal tumors. Total fruit intake was not associated with colon cancerrisk although, among men, higher levels of whole grain intake wereassociated with a decreased risk (OR = 0.6, CI = 0.4-0.9 for older men);high intakes of refined grains were associated with an increased risk (OR =1.5, CI = 1.1-2.1). Dietary fiber intake was associated with a decreasedrisk of colon cancer: OR = 0.5 (CI = 0.3-0.9) for older men; OR = 0.7 (CI =0.4-1.2) for older women; OR = 0.6 (CI = 0.4-1.0) for men with proximaltumors; OR = 0.5 (CI = 0.3-0.9) for women with proximal tumors. Othernutrients, for which plant foods were the major contributor - such asvitamin B6, thiamin, and niacin (women only) - also were associatedinversely with colon cancer. Neither beta-carotene nor vitamin C wasprotective for colon cancer. Adjustment of plant foods for nutrients foundin plant foods or for supplement use did not appreciably alter the observedassociations between plant foods and colon cancer.     

MTHFR C677T and A1298C polymorphisms: diet, estrogen, and risk of colon cancer.

5,10-methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism, diverting metabolites toward methylation reactions or nucleotide synthesis. Using data from an incident case-control study (1608 cases and 1972 controls) we investigated two polymorphisms in the MTHFR gene, C677T and A1298C, and their associations with risk of colon cancer. All of the combined genotypes were evaluated separately, and the 1298AA/677CC (wild-type/wild-type) group was considered the reference group. Among both men and women, the 677TT/1298AA (variant/wild-type) genotype was associated with a small reduction in risk [men: odds ratio (OR), 0.7, 95% confidence interval (CI), 0.5-1.0; women: OR, 0.8, 95% CI, 0.5-1.2]. However, the 677CC/1298CC (wild-type/variant) genotype was associated with a statistically significant lower risk among women (OR, 0.6; 95% CI, 0.4-0.9) but not men. When the polymorphisms were considered individually, for A1298C a significant risk reduction associated with the homozygous variant CC genotype was seen among women only (OR, 0.6; 95% CI, 0.5-0.9), and nonstatistically significant reduced risks were observed for the variant 677 TT genotypes among both men and women. Stratification by nutrient intakes showed inverse associations with higher intakes of folate, vitamin B(2), B(6), B(12), and methionine among women with the MTHFR 677CC/1298AA genotypes, but not those with 677TT/1298AA. We observed opposite risk trends for both MTHFR variants, depending on whether women used hormone-replacement therapy or not (P for interaction = <.01). In summary, this study supports recent findings that the MTHFR A1298C polymorphism may be a predictor of colon cancer risk and have functional relevance. The possible interaction with hormone-replacement therapy warrants additional investigation.     

Aspirin, NSAIDs, and colorectal cancer: possible involvement in an insulin-related pathway.

INTRODUCTION: Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce risk of colorectal cancer. Although inhibition of cyclooxygenase (COX)-2 is generally thought to be the relevant mechanism, aspirin-like drugs apparently are involved in other pathways and mechanisms. We explore the associations between aspirin/NSAIDs, the insulin-related pathway, and the risk of colorectal cancer. METHODS: Genetic polymorphisms of five genes identified as being involved in an insulin-related pathway were genotyped using data collected in a case-control study of 1346 incident colon cancer cases and 1544 population-based controls and 952 incident rectal cancer cases and 1205 controls. Genotypes assessed were the 3' untranslated region poly(A) and the intron 8 BsmI polymorphisms of the VDR gene, a CA repeat polymorphism of the IGF1 gene, the A/C polymorphism at nucleotide -202 of the IGFBP3, the Gly972Arg polymorphism of the IRS1 gene, and the Gly1057Asp polymorphism of the IRS2 gene. RESULTS: Use of aspirin and NSAIDs was associated with a decreased risk of colorectal cancer, with slightly greater protection from NSAIDs than aspirin for rectal cancer. We observed a significant interaction between IRS1 genotype and aspirin/NSAIDs use and risk of colorectal cancer. Relative to the GR/RR IRS1 genotype, a protective effect from the GG IRS1 genotype was seen in those who did not use NSAIDs; use of NSAIDs was protective for all genotypes. These associations were especially strong for those diagnosed prior to age 65 (P interaction = 0.0006). We also observed a significant interaction between aspirin/NSAIDs use and the VDR gene. Having the SS or BB VDR genotypes reduced risk of colorectal cancer among non-aspirin/NSAID users; however, aspirin/NSAIDs reduced risk for all VDR genotypes. CONCLUSIONS: These data support the protective effect of aspirin and NSAIDs on colorectal cancer risk. In addition, the observed interactions for aspirin/NSAIDs and IRS1 and VDR genotypes suggest that mechanisms other than COX-2 inhibition may be contributing to the protective effect of aspirin and NSAIDs on colorectal cancer risk.     

The relationship between dietary fat intake and risk of colorectal cancer: evidence from the combined analysis of 13 case-control studies

The objective of this study was to examine the effects of the intakeof dietary fat upon colorectal cancer risk in a combined analysis of datafrom 13 case-control studies previously conducted in populations withdiffering colorectal cancer rates and dietary practices. Original datarecords for 5,287 cases of colorectal cancer and 10,470 controls werecombined. Logistic regression analysis was used to estimate odds ratios (OR)for intakes of total energy, total fat and its components, and cholesterol.Positive associations with energy intake were observed for 11 of the 13studies. However, there was little, if any, evidence of anyenergy-independent effect of either total fat with ORs of 1.00, 0.95, 1.01,1.02, and 0.92 for quintiles of residuals of total fat intake (P trend =0.67) or for saturated fat with ORs of 1.00, 1.08, 1.06, 1.21, and 1.06 (Ptrend = 0.39). The analysis suggests that, among these case-control studies,there is no energy-independent association between dietary fat intake andrisk of colorectal cancer. It also suggests that simple substitution of fatby other sources of calories is unlikely to reduce meaningfully the risk ofcolorectal cancer.     

The evolution of surgical approaches for posterior fossa meningiomas.

OBJECTIVE: To evaluate surgical outcomes for the treatment of posterior fossa meningiomas at the House Ear Clinic from 1987 to 2001. We review our current treatment algorithm and present our postoperative outcomes with attention to facial and auditory neural preservation. STUDY DESIGN: Retrospective review. SETTING: Tertiary care center. PATIENTS: Medical records of 71 patients who underwent posterior fossa meningioma surgery at the House Ear Clinic were reviewed. INTERVENTION: All patients had surgical removal of their meningioma via translabyrinthine, transcochlear, retrosigmoid, extended middle fossa, or combined petrosal approaches by House Ear Clinic neurotologists and neurosurgeons. MAIN OUTCOME MEASURES: Preoperative and postoperative auditory and facial nerve function data were collected. Patient and tumor characteristics including presenting symptoms, completion of tumor resection, and complications secondary to surgery were also recorded. RESULTS: The most common presenting symptoms in this series were otologic, with hearing loss (61%), tinnitus (58%), and imbalance (58%) as the three most common. Gross total resection was achieved in 67 (94%) patients. Hearing-preservation surgery was attempted in 37 (52%) patients (68% via extended middle fossa or combined approach). Twenty-one patients with preoperative Class A hearing had follow-up audiometric data and 18 (86%) had serviceable hearing preserved. Excluding transcochlear craniotomies, 85% of patients had normal facial nerve function postoperatively. Cerebrospinal fluid leak (6%) was the most common complication. CONCLUSIONS: Advances in microsurgical techniques have greatly changed our management of patients with posterior fossa meningiomas. These changes have reduced postoperative morbidity. Specifically, use of the anterior and posterior petrosal approaches has facilitated facial and auditory neural preservation while not compromising the extent of tumor excision.