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Biomedical subjects

K Fox

Publications and source records attributed to K Fox.

At least 109 records · Page 6Linked to original sources
PubMed1996

Vertical Banded Gastroplasty and Distal Gastric Bypass as Primary Procedures: A Comparison.

BACKGROUND: Comparing primary vertical banded gastroplasty (VBG) and distal gastric bypass (DGBP) patients might assist decision-making based on patient profiles and desired outcomes. METHODS: A prospective study of 81 vertical banded gastroplasty and 60 distal gastric bypass patients. Technical aspects, complications, weight loss, post-op compliance and satisfaction are reported. Length of follow-up is 48 months (VBG) and 36 (DGBP). Lost-to-follow-up 41% (VBG) and 22% (DGBP). Ten per cent of VBGs were revised, with 1% takedown. Three percent DGBPs were converted to proximal GBPs. Demographics are comparable. RESULTS: Operative time was 40 min VBG and 88 DGBP; blood loss 187 cc vs 335 cc; and hospital stay 3 versus 4 days. Exclusive VBG complications include: 1% staple-line leak, 4% intra-abdominal abscess, 1% respiratory failure, 5% pneumonia, 1% intra-abdominal bleed, 1% small bowel obstruction, 2% infected incision, 2% fistula, 2% stenotic or obstructed obstructed stoma, and 1% bezoar. Exclusive DGBP complications include: 2% GI bleed, 12% marginal ulcer, 5% reflux esophagitis, 13% hypocalcemia, 23% hypovitaminosis A and D (12% requiring B12 therapy). Shared complications include hypoproteinemia 6% VBG versus 40% DGBP; excess vomiting (>6 months post-op), 7% versus 10%, excess diarrhea 2% versus 20%, dehydration 1% versus 8%, re-hospitalization 4% versus 15% (hyperalimentation), post-op cholecystectomy 1% versus 5%, weight regain 48% versus 1%. VBG experienced an average of 64% excess weight loss at 36 months versus DGBP 89% excess weight loss. VBG follow-up compliance is generally poor but good for DGBP. Compliance with diet and supplements is equivalent (50%). Satisfaction is 85% and 93% respectively. CONCLUSION: The DGBP provides better long-term weight loss, but nutritional deficiencies occur more often and require close follow-up. The surgery is more complex, but as a primary procedure there are few major complications.

Journal Article↗
PubMed1996

Relationship between donor/recipient lung size mismatch and functional outcome in single lung transplantation for COPD.

Single lung transplantation is an effective treatment for patients with severe chronic obstructive pulmonary disease. Pulmonary hyperinflation, which is seen in most patients with severe chronic obstructive pulmonary disease, makes the task of appropriately matching the donor and recipient difficult. It seems that the optimal matching strategy remains undefined. No correlation between donor/recipient size match (actual and predicted) and the degree of functional improvement after single lung transplantation was found. There were no significant differences noted when comparing the functional outcomes of right and left lung transplant recipients. It was concluded that the chronic hyperinflation associated with severe chronic obstructive pulmonary disease allows for the use of significantly larger donors. The use of expanded donor/recipient size match criteria in patients with severe chronic obstructive pulmonary disease may shorten the waiting period prior to single lung transplantation and provide better utilization of donor organs.

Aged↗
PubMed1996

Assessing a murmur, saving a life: current trends in the management of hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy, formerly called idiopathic hypertrophic subaortic stenosis (IHSS), is the leading cause of sudden cardiac death in young people. Hypertrophic cardiomyopathy is a non-dilated cardiomyopathy primarily affecting the left ventricle, left atria, intraventricular septum, and mitral valve. It is an autosomal dominant genetic disorder that impairs diastolic and systolic function. Diagnosis is complex due to the heterogeneity of the disease. Symptoms and morphology are not always related and clinical signs may be absent or limited to a soft systolic murmur. The first symptom of hypertrophic cardiomyopathy is frequently sudden cardiac death. Echocardiogram is an accurate diagnostic tool. Asymptomatic patients are generally not treated. Treatment for symptomatic patients begins with beta or calcium channel blockers. Antiarrhythmics may be added to protect against sudden cardiac death. Surgical intervention is done if other treatments fall and involves removal of a portion of the obstructive septum. Operative mortality is 5% with a 60% reduction in symptoms. A promising alternative to surgery is dual-chamber pacemakers. Patient and family teaching is the emphasis of long-term management.

Adolescent↗
PubMed1995

From antianginal drugs to myocardial cytoprotective agents.

The existing major classes of antianginal drugs improve quality of life in patients with coronary artery disease, but mortality in these patients remains unacceptably high. In order to limit the complications of the disease, it is vital to limit myocyte loss. Potentially, this can be achieved not only by prophylaxis, but also by protection, against ischemia. Any therapy that increases myocardial resistance to ischemia will protect against cell death and prolong the life of the myocyte, and possibly the patient. The mechanisms of cell damage during ischemia, and possible therapeutic interventions, are discussed.

Heart↗
PubMed1995

Effect of vibrissae deprivation on follicle innervation, neuropeptide synthesis in the trigeminal ganglion, and S1 barrel cortex plasticity.

Deprivation of vibrissae from an early age causes plasticity in S1 barrel cortex. This method of deprivation is most likely to induce plasticity by altering the balance of primary afferent activity from the deprived and spared vibrissae. To study whether or not induction or expression of this type of plasticity might be affected by follicle nerve injury caused by the deprivation technique, three different methods of detecting nerve injury were used: counting axon numbers in the distal follicle nerve, quantifying morphological changes in axons, and measuring neuropeptide expression in the trigeminal ganglion cells. First, nerves innervating follicles chronically deprived of vibrissae from birth had the same number of myelinated and unmyelinated axons as nerves from normally reared animals. Second, axons innervating deprived follicles showed no morphological changes in myelination or mitochondria characteristic of damaged nerves. Third, the corresponding nerve cell bodies in the trigeminal ganglion did not show upregulation of galanin or neuropeptide Y expression. In contrast, animals receiving mild injury of the follicle nerve endings (by cauterization of the follicle) showed profound changes in axonal myelination and mitochondria and increases in neuropeptide expression. These results imply that vibrissae deprivation does not act by inducing injury of the follicular nerve, suggesting that changes in the balance of follicle nerve activity are the cause of cortical plasticity. Consistent with this notion, a fourth experiment demonstrated that trimming the vibrissae induces cortical plasticity comparable to that induced by complete vibrissae removal.

Afferent Pathways↗
PubMed1995

The vicious circle of ischemic left ventricular dysfunction.

Myocardial ischemia tends to be self-propagating, and minor events such as plaque rupture can lead to the catastrophic sequelae of myocardial infarction and death. The biology of the endothelium and the cardiac myocyte is crucial to the development of these vicious circles. The abnormal responses of the endothelial cell in atherosclerosis tend to provoke and propagate ischemia, and because of the limited metabolic reserve of the myocyte, even short periods of ischemia can lead to left ventricular dysfunction and arrhythmias. This article examines the clinical implications of the disordered biology of the endothelial cell and the myocyte that is the basis for ischemic left ventricular dysfunction.

Coronary Vessels↗
PubMed1995

Plasticity in the development of neocortical areas.

Heterotopic transplantation analysis suggests that individual areas of the developing neocortex have the capacity to differentiate many of the architectural and connectional features normally characteristic of other neocortical areas. Many studies indicate a pivotal role for thalamocortical afferents in the differentiation of the area-specific features that distinguish neocortical areas. Both activity-dependent and activity-independent mechanisms contribute to the patterning of thalamocortical afferent terminations. The available evidence suggests that positional information is established in the cortical subplate and that this information controls the precise targeting of developing thalamocortical axons. In this way appropriate thalamocortical relationships can be established that allow these afferents to promote the differentiation of the functionally specialized and anatomically distinct areas of the adult neocortex.

Animals↗
PubMed1995

Potassium channel openers: clinical applications in ischemic heart disease--overview of clinical efficacy of nicorandil.

Nicorandil is a balanced arterial and venodilator that may also possess cardioprotective properties via its activation of ATP-sensitive potassium channels. It has a number of beneficial hemodynamic effects and has been shown to be effective in treating angina with similar efficacy as the currently available antianginal agents. In addition, it may have useful effects in unstable and variant angina. In this review we examine the hemodynamic effects of nicorandil and discuss the currently available data on its clinical efficacy, both in isolation and in comparison with other agents.

Angina Pectoris↗
PubMed1995

Detection of ambulatory ischaemia is not of practical clinical value in the routine management of patients with stable angina. A long-term follow-up study.

It has been reported that medically treated patients with stable angina and positive exercise test for ischaemia have an adverse 1-2 year outlook if they are shown also to have transient, and predominantly silent, ischaemic episodes detected by ambulatory ST segment monitoring during their daily activities: it has been suggested that this investigation could be used to identify patients more likely to benefit from early investigation and treatment. We assessed the long-term (up to 65 months) prognostic significance of transient ischaemic episodes during daily activities in 172 patients routinely attending cardiac outpatients with medically treated stable angina who had undergone exercise testing and 48 h of ambulatory ST segment monitoring between February 1988 and August 1989 for this purpose. A positive exercise test for ischaemia was not a prerequisite for inclusion. One hundred and four patients (60.5%) had a positive exercise test for ischaemia and 72 (42%) had transient ischaemia during daily activities (63 had both tests positive). Over a median 50-month follow-up period 54 patients suffered at least one cardiac event (primary event: cardiac death n = 7; non-fatal myocardial infarction n = 11; unstable angina n = 18; elective CABG/PTCA n = 18). Two further patients suffered non-cardiac death. Cardiac events, either objective (cardiac death or non-fatal myocardial infarction) or subjective (unstable angina or revascularisation) were no more likely to occur in those with transient ischaemia during daily life when compared with those without, at follow-up times up to 65 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

A comparison of the efficacy and tolerability of moclobemide given as a single daily dose or in three divided doses per day for the treatment of patients with a major depressive episode (DSM-III-R)

This was a prospective, double-blind, randomized, multicenter trial comparing moclobemide once daily (OD) with three times daily (TDS) dosing. The duration of the study was 6 weeks with the initial dose of moclobemide being 450 mg/day (either 450 mg in the morning or 150 mg three times daily). Placebo tablets were used to ensure that the study was double blind. After 2 weeks, the dose could be increased to 600 mg/day if tolerability was acceptable and efficacy was judged insufficient by the investigator. Patients were assessed at baseline and at days 3, 7, 14, 21, 28, and 42. Efficacy was primarily judged on the Hamilton Rating Scale for Depression (HAM-D) (17item). Patients had to score at least 17 to enter the study. Safety and tolerability were judged on reported adverse events, safety parameters, premature withdrawals, and a physicians' global tolerability rating. There were also three secondary efficacy parameters--the Hamilton Rating Scale for Anxiety, Visual Analogue Scales for pain and irritability, and physicians' Clinical Global Impression (CGI). A total of 130 evaluable patients were required to detect a difference of more than 20% (alpha = 0.05 and beta = 0.8) between groups. A total of 189 patients entered the study, and the standard analysis comprised 145 patients. The efficacies between the two dosing regimens as determined by the HAM-D score and from the CGI were found not to differ significantly. For the standard analysis population, there was a reduction in mean HAM-D of 73.8 and 72.9% for the OD and TDS groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Estimating the costs of substance abuse to the Medicaid hospital care program.

OBJECTIVES: The purpose of this study was to develop a model, using the epidemiologic tool of attributable risk, for estimating the cost of substance abuse to Medicaid. METHODS: Based on prior substance-use and morbidity research, population attributable risks for substance abuse-related diseases were calculated. (These risks measure the proportion of total disease cases attributable to smoking, drinking, and drug use.) The risks for each disease were applied to Medicaid hospital discharges and days on the 1991 National Hospital Discharge Survey that had these diseases as primary diagnoses. The cost of these substance abuse-related days were added to Medicaid hospital costs for direct treatment of substance abuse. RESULTS: More than 60 medical conditions involving 1100 diagnoses were identified, at least in part, as attributable to substance abuse. Factoring these substance abuse-related conditions into hospital costs, 1 out of 5 Medicaid hospital days, or 4 million days, were spent on substance abuse-related care in 1991. In 1994, this would account for almost $8 billion in Medicaid expenditures. CONCLUSIONS: The use of tobacco, alcohol, and drugs contributes significantly to hospital costs. To address rising costs, substance abuse treatment and prevention should be an integral part of any health care reform effort.

Alcoholism↗
PubMed1994

Electrospray tandem mass spectrometry for analysis of native muramic acid in whole bacterial cell hydrolysates.

Muramic acid is an amino sugar found in eubacterial cell walls and not elsewhere in nature. This study explored the use of electrospray tandem mass spectrometry (ESI MS/MS) in analysis of underivatized muramic acid in bacterial hydrolysates. Fungal hydrolysates were used as negative controls. The only processing used was hydrolysis in sulfuric acid followed by extraction with an organic base (N,N-dioctylmethylamine) to remove the acid prior to ESI MS/MS analysis. Compared with pure muramic acid, bacterial hydrolysates produced more complex ESI mass spectra, such that the protonated molecular ion at m/z 252 was barely detectable. In contrast, product ion spectra of m/z 252 were identical among pure muramic acid, Gram positive bacteria, and Gram negative bacteria. However, no characteristic product ion spectrum was manifested from m/z 252 in fungal samples. This allowed ready, visual differentiation of bacteria and fungi. Multiple reaction monitoring (MRM) following muramic acid fragmentations (m/z 252-->144 and m/z 252-->126) increased sensitivity and allowed quantitative differentiation when compared with the MRM of the internal standard N-methyl-D-glucamine (m/z 196-->44). ESI MS/MS required minimal sample preparation and allowed rapid sample throughput for analysis of muramic acid in whole bacterial cell hydrolysates.

Cell Wall↗
PubMed1994

The influence of young age on outcome in early stage breast cancer.

PURPOSE: To assess the impact of young age on outcome in women with early stage breast cancer undergoing conservative surgery and radiation. METHODS AND MATERIALS: Between 1981 and 1991, 980 patients with Stage I and II breast cancer underwent excisional biopsy, axillary dissection, and radiation. The median follow-up was 4.6 years, with a range of 1 month to 11 years. The patients were divided into three groups, based on age at the time of diagnosis: (a) age < or = 35 years--64 patients, (b) age 36-50 years--363 patients, and (c) age > 50 years--553 patients. The comparability of the groups was assessed in terms of clinical factors (tumor size and race), histopathologic factors (histologic subtype, final resection margin, estrogen and progesterone receptor status, pathologic nodal status), and treatment related factors (reexcision, median total dose to the primary, region(s) treated with radiation, and the use of adjuvant systemic chemotherapy and/or tamoxifen). Outcome was evaluated for overall, relapse-free, and cause-specific survival and patterns of first failure (breast, regional nodes, and distant metastasis). RESULTS: There were no significant differences among the three groups in terms of race, clinical tumor size, pathology of the primary tumor, pathologic nodal status, final margin of resection, progesterone receptor status, median total dose to the primary tumor, or the regions treated. However, younger women were significantly more likely to have estrogen receptor negative tumors, undergo reexcision, and receive adjuvant systemic chemotherapy without tamoxifen. Younger women were found to have a statistically significantly decreased 8-year actuarial relapse-free survival (53% vs. 67% vs. 74%, p = 0.009), cause-specific survival (73% vs. 84% vs. 90%, p = 0.02), freedom from distant metastasis (76% vs. 75% vs. 83%, p = 0.02), and a significantly increased risk of breast recurrence (24% vs. 14% vs. 12%, p = 0.001), and regional node recurrence (7% vs. 1% vs. 1%, p = 0.0002). The patients were further divided on the basis of their pathologic nodal status. There were no statistically significant differences among the three age groups for axillary node-positive patients for overall survival (75% vs. 80% vs. 74%), relapse-free survival (73% vs. 73% vs. 62%), cause-specific survival (76% vs. 85% vs. 80%), and freedom from distant metastasis (75% vs. 75% vs. 72%), or breast recurrence (0% vs. 9% vs. 6%). The findings were identical when the analysis was restricted to node-positive patients who received chemotherapy. However, for axillary node-negative women, young age was associated with a statistically significant decreased overall survival (71% vs. 83% vs. 92%), relapse-free survival (51% vs. 65% vs. 76%), cause-specific survival (71% vs. 86% vs. 93%), freedom from distant metastasis (77% vs. 76% vs. 88%), and a statistically significant increased risk of breast recurrence (40% vs. 16% vs. 13%), and regional node recurrence (3% vs. 1% vs. 0%). The risk of a breast recurrence in axillary node-negative young women was decreased by the addition of adjuvant systemic chemotherapy but not by the use of reexcision. CONCLUSIONS: The present analysis demonstrates that young women with early stage breast cancer do significantly worse when compared to older women in terms of relapse-free survival, cause-specific survival, distant metastasis and breast and regional node recurrence. However, the adverse effect of young age on outcome appears to be limited to the node-negative patients. These findings suggest that node-negative early stage breast cancer in young women is a more aggressive disease, with an increased risk for all patterns of failure and a decreased survival.

Adult↗
PubMed1994

Kinetics of bioconcentration and clearance of 28 polychlorinated biphenyl congeners in zebrafish (Brachydanio rerio).

Bioconcentration experiments were performed on 28 polychlorinated biphenyl (PCB) congeners with NCl = 2 to NCl = 10, evaluating them simultaneously. Bioconcentration factors (BCFs) were calculated from the uptake rate constant (k1) and the clearance rate constant (k2) as BCF = k1/k2. BCFs on a wet weight basis ranged from 7710 to 940,000. They were correlated with octanol-water partition coefficients (P). The curvilinear relationship between log BCF and log P based upon data covering the log P range 5.06 to 8.18. About a log P of 7.38, a range of "optimal lipophilicity," results in highest BCFs for PCBs, above which the degree of bioconcentration decreases.

Animals↗