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Biomedical subjects

C Brown

Publications and source records attributed to C Brown.

At least 217 records · Page 12Linked to original sources

103Pd brachytherapy and external beam irradiation for clinically localized, high-risk prostatic carcinoma.

PURPOSE: To summarize biochemical failure rates and morbidity of external beam irradiation (EBRT) combined with palladium (103Pd) boost for clinically localized high-risk prostate carcinoma. METHODS AND MATERIALS: Seventy-three consecutive patients with stage T2a-T3 prostatic carcinoma were treated from 1991 through 1994. Each patient had at least one of the following risk factors for extracapsular disease extension: Stage T2b or greater (71 patients), Gleason score 7-10 (40 patients), prostate specific antigen (PSA) > 15 (32 patients), or elevated prostatic acid phosphatase (PAP) (17 patients). Patients received 41 Gy EBRT to a limited pelvic field, followed 4 weeks later by a 103Pd boost (prescription dose: 80 Gy). Biochemical failure was defined as a PSA greater than 1.0 ng/ml (normal < 4.0 ng/ml). Patients whose PSA was still decreasing at the last follow-up were censored at that time. Patients whose PSA plateaued at a value greater than 1.0 were scored as failures at the time the PSA first plateaued. RESULTS: The overall, actuarial freedom from biochemical failure at 3 years after treatment was 79%. In Cox proportional hazard multivariate analysis, the strongest predictor of failure was elevated acid phosphatase (p = 0.04), followed by PSA (p = 0.17), Stage (p = 0.23), and Gleason score (p = 0.6). Treatment-related morbidity was usually limited to temporary, RTOG Grade 1-2 urinary symptoms. One patient, who had both a transurethral incision of the prostate (TUIP) and a transurethral resection of the prostate (TURP), developed low-volume urinary incontinence. The actuarial potency rate at 3 years after implantation was 77% for 46 patients who were sexually potent prior to implant. CONCLUSION: Biochemical freedom from failure rates following combined EBRT and 103Pd brachytherapy for clinically localized, high-risk prostate cancer compare favorably with that reported after conventional dose EBRT alone. Morbidity has been acceptable.

Aged↗

Absorption of sulindac from a novel (Pro-SorbTM) liquid formulation.

The absorption of sulindac from two different 200 mg oral dosage forms, Pro-SorbTM liquid and Clinoril tablets, was compared following administration to eight healthy human volunteers. Subjects received both formulations according to a randomized crossover design and blood samples were collected at selected times during 24 h. Concentrations of both sulindac and its active sulphide metabolite were determined by HPLC and individual serum concentration versus time profiles were constructed. Maximal serum concentrations (Cmax) and area under the curve values (AUClast and AUC0-infinity) were compared for both sulindac and sulindac sulphide. The results indicate that the rate and extent of absorption of sulindac from Pro-SorbTM liquid are significantly greater than those from Clinoril tablets, a finding consistent with the observation that the liquid form produces less gastric irritation following oral administration.

Absorption↗

Phenomenology and severity of major depression and comorbid lifetime anxiety disorders in primary medical care practice.

The psychiatric history and presenting clinical characteristics of 276 depressed primary care patients with and without a lifetime comorbid anxiety disorder were studied in a randomized control trial of treatments for major depression. Our findings indicate that distinctive patterns of depressive symptoms and severity, functional impairment, comorbidity of other DSM-III-R Axis I and Axis II disorders, and treatment participation are associated with lifetime histories of panic and generalized anxiety disorder. The most consistent differences are evident between patients with major depression alone and those with major depression and a lifetime panic disorder. The latter presented with greater depressive severity, greater impairment in physical and psychosocial functioning, and were more likely to have a history of alcohol dependence, somatization disorder, and avoidant personality disorder. Discriminant function analysis indicated that 66% of depressed patients with lifetime panic disorder could be correctly distinguished from those without such comorbidity on the basis of the severity of somatic and affective symptoms but not cognitive symptoms of depression. Further, depressed patients with lifetime panic disorder were more likely to prematurely terminate both pharmacotherapy and psychotherapy during each treatment's acute phase. Implications for the diagnosis and treatment of major depression with comorbid anxiety disorder in primary care patients are discussed.

Adolescent↗

A comparative analysis of somatolactin-related immunoreactivity in the pituitaries of four neopterygian fishes and one chondrostean fish: an immunohistochemical study.

An antiserum to cod somatolactin (SL) was used for immunohistochemical screening for the pars intermedia of two teleosts (Oreochromis mossambicus and Gymothorax meleagris), two holostean fishes (Lepisosteus osseus and Amia calva), and a chondrostean fish (Acipenser fulvescens) for SL-immunopositive (SL-IR) cells. As expected, a subset of the epithelial cells in the pars intermedia of O. mossambicus (tilapia) was immunopositive for SL, and the remainder of the epithelial cells was immunopositive for alpha-MSH-specific antiserum (alpha-MSH-IR). SL-IR was not detected in any of the epithelial cells in the pars intermedia of the moray eel G. meleagris. To determine whether SL-IR could be detected in nonteleost fishes, immunohistochemical analyses were done on the pituitaries of two holostean fishes and one chondrostean fish. In the pars intermedia of the gar, L. osseus, a subset of cells was immunopositive for alpha-MSH only. However, in the pars intermedia of the bowfin, A. calva, all of the epithelial cells indicated the presence of both SL and alpha-MSH. Finally, no SL-positive cells were detected in the pars intermedia of the sturgeon, A. fulvescens.

Animals↗

The postmodernist hoax and its effects on nursing.

Nursing literature has not been immune to the influences of postmodernist thought. It has been argued that postmodernism is relevant and important to the development of the occupation and the discipline of nursing. This paper attempts to demonstrate that there are serious weaknesses in such claims.

Existentialism↗

Future directions for resuscitation research. III. External cardiopulmonary resuscitation advanced life support.

This discussion about advanced cardiac life support (ACLS) reflects disappointment with the over 50% of out-of-hospital cardiopulmonary resuscitation (CPR) attempts that fail to achieve restoration of spontaneous circulation (ROSC). Hospital discharge rates are equally poor for in-hospital CPR attempts outside special care units. Early bystander CPR and early defibrillation (manual, semi-automatic or automatic) are the most effective methods for achieving ROSC from ventricular fibrillation (VF). Automated external defibrillation (AED), which is effective in the hands of first responders in the out-of-hospital setting, should also be used and evaluated in hospitals, inside and outside of special care units. The first countershock is most important. Biphasic waveforms seem to have advantages over monophasic ones. Tracheal intubation has obvious efficacy when the airway is threatened. Scientific documentation of specific types, doses, and timing of drug treatments (epinephrine, bicarbonate, lidocaine, bretylium) are weak. Clinical trials have failed so far to document anything statistically but a breakthrough effect. Interactions between catecholamines and buffers need further exploration. A major cause of unsuccessful attempts at ROSC is the underlying disease, which present ACLS guidelines do not consider adequately. Early thrombolysis and early coronary revascularization procedures should also be considered for selected victims of sudden cardiac death. Emergency cardiopulmonary bypass (CPB) could be a breakthrough measure, but cannot be initiated rapidly enough in the field due to technical limitations. Open-chest CPR by ambulance physicians deserves further trials. In searches for causes of VF, neurocardiology gives clues for new directions. Fibrillation and defibrillation thresholds are influenced by the peripheral sympathetic and parasympathetic nervous systems and impulses from the frontal cerebral cortex. CPR for cardiac arrest of the mother in advanced pregnancy requires modifications and outcome data. Until more recognizable critical factors for ROSC are identified, titrated sequencing of ACLS measures, based on physiologic rationale and sound judgement, rather than rigid standards, gives the best chance for achieving survival with good cerebral function.

Animals↗

Surgical treatment of patients with open tibial fractures.

Open tibial fractures are true surgical emergencies because of the risk of extensive infection to bone and devitalized soft tissue. The most serious consequence of open tibial fractures is osteomyelitis, which usually can be prevented by prompt surgical intervention within six to eight hours after injuries occur. Open tibial fractures often are the result of trauma from motor vehicle collisions, farm accidents, falls from heights, or gunshot wounds. Initial management of patients with multiple trauma injuries focuses on their life-threatening injuries before or during orthopedic surgical intervention for open tibial fractures. Orthopedic surgeons often work in collaboration with general, vascular, and plastic surgeons and perform multiple surgical procedures (eg, fasciotomy procedures for compartment syndromes, irrigation and debridement of wounds, application of external fixation devices, placement of intramedullary nails, possible limb amputations). The type and extent of open tibial fractures and soft tissue injuries determine the best treatment options for patients. Perioperative nurses should help patients focus on treatment choices for their open tibial fractures that ensure optimal surgical outcomes and maintain their quality of life.

Accidents↗

An immunohistochemical study of the pathogenesis of virulent viscerotropic Newcastle disease in chickens.

Ten specific pathogen-free cockerels aged 8-12 months were infected by ocular instillation of 2 x 10(7) embryo-lethal doses 50% of a virulent viscerotropic strain of Newcastle disease virus (Fontana 1083 strain). The birds were killed at 24-h intervals after infection and tissues were collected for histological and immunohistochemical evaluation. The infection ran an acute course, severe clinical disease occurring within 72 h of infection. By gross and histological examination, the most severe damage detected was found to occur in lymphoid areas in a number of tissues. The greatest amounts of viral antigen detected occurred in the proventriculus, small intestine, spleen, thymus and eyelid. Immunohistochemical labelling was confined to large mononuclear cells.

Animals↗

Future directions for resuscitation research. IV. Innovative advanced life support pharmacology.

The topics discussed in this session include a partial review of laboratory and clinical studies examining the effects of adrenergic agonists on restoration of spontaneous circulation after cardiac arrest, the effects of varying doses of epinephrine, and the effects of novel vasopressors, buffer agents (NaHCO3, THAM, 'Carbicarb') and anti-arrhythmics (lidocaine, bretylium, amiodarone) in refractory ventricular fibrillation. Novel therapeutic approaches include titrating electric countershocks against electrocardiographic power spectra and of preceding the first countershocks with single or multiple drug treatments. These approaches need to be investigated further in controlled animal and patient studies. Epidemiologic data from randomized clinical outcome studies can give clues, but cannot document pharmacologic mechanisms in the dynamically changing events during attempts to achieve restoration of spontaneous circulation from prolonged cardiac arrest. Also, rapid drug administration by the intraosseous route was compared with intratracheal and intravenous (i.v.) drug administration. Many studies on the above treatments have yielded conflicting results because of differences between healthy hearts of animals and sick hearts of patients, differences in arrest (no-flow) times and cardiopulmonary resuscitation (CPR) (low-flow) times, different pharmacokinetics, different dose/response requirements, and different timing of drug administration during low-flow CPR versus during spontaneous circulation. The need to stabilize normotension and prevent rearrest by titrated novel drug administration, once spontaneous circulation has been restored, requires research. Most of the above topics require some re-evaluation in clinically realistic animal models and in cardiac arrest patients, especially by titration of old and new drug treatments against variables that can be monitored continuously during resuscitation.

Adrenergic Agonists↗

A head impact model of early axonal injury in the sheep.

Axonal injury (AI), one of the principal determinants of clinical outcome after head injury, may evolve over several hours after injury, raising the future possibility of therapeutic intervention during this period. A new head impact model of AI in sheep was developed to examine pathological and physiological changes in the brain resulting from a graded traumatic insult. In this preliminary study 10 anesthetized and ventilated Merino ewes were used. Head injury was produced by impact from a humane stunner to the temporal region of an unrestrained head. Eight sheep were studied for 1, 2, 4, or 6 h after impact. Two sham animals (no impact, 6 h survival) were also examined. Arterial blood pressure, intracranial pressure, and cerebral blood flow were monitored continuously. A physiological index of injury severity was calculated by weighting the percentage shift from preinjury values for each monitored parameter over the first hour after injury. Immunostaining with amyloid precursor protein (APP) was used as a marker of axonal damage and the distribution of APP positive axons was recorded according to a sector scoring method (APPS). Widespread AI was identified in 7 of the 8 impacted animals, around cerebral contusions and in hemispheric white matter, central gray matter, brain stem, and cerebellum, and was detected as early as 1 h after injury. The degree of axonal injury (APPS) correlated well with an index of physiological response to injury (r = 0.83, p = 0.005).

Amyloid beta-Protein Precursor↗

Relation of energy, fat, and fiber intakes to plasma concentrations of estrogens and androgens in premenopausal women.

To evaluate whether diet may influence the incidence of hormone-dependent cancers through an effect on blood estrogen and androgen concentrations, we analyzed diet-blood hormone relations in a cross-sectional study. Dietary energy, fat, and fiber intakes were estimated from 7-d food records completed by 90 premenopausal women on days 14-20 of their menstrual cycles. Fasting blood specimens were collected on days 5-7, 12-15, and 21-23 of each participant's cycle and pooled to create follicular-, midcycle-, and luteal-phase samples, respectively, for analysis. Energy intake was associated inversely with plasma androstenedione and dehydroepiandrosterone sulfate (DHEAS), averaged across the three menstrual cycle phases, and directly with the probability of a luteal-phase rise in progesterone. For each additional 1 MJ (239 kcal) consumed, androstenedione decreased by 6.0% (95% CI: -8.4%, -3.6%), DHEAS decreased by 5.1% (95% CI: -9.6%, -0.4%), and the probability of a progesterone rise increased by 60% (95% CI: 5%, 145%). After energy intake was adjusted for, the ratio of polyunsaturated to saturated fat (P:S) in the diet was significantly inversely associated with plasma estradiol and estrone during the luteal phase of the menstrual cycle. For each 0.1 increment in the P:S, there was a 7.6% (95% CI: -14.3%, -0.5%) decrease in estradiol and a 6.8% (95% CI: -12.7%, -0.6%) decrease in estrone. Results of this cross-sectional study support a relation between both energy and fat ingestion and plasma sex hormone concentrations in premenopausal women.

Adult↗

Effects of dietary fat and fiber on plasma and urine androgens and estrogens in men: a controlled feeding study.

We conducted a controlled feeding study to evaluate the effects of fat and fiber consumption on plasma and urine sex hormones in men. The study had a crossover design and included 43 healthy men aged 19-56 y. Men were initially randomly assigned to either a low-fat, high-fiber or high-fat, low-fiber diet for 10 wk and after a 2-wk washout period crossed over to the other diet. The energy content of diets was varied to maintain constant body weight but averaged approximately 13.3 MJ (3170 kcal)/d on both diets. The low-fat diet provided 18.8% of energy from fat with a ratio of polyunsaturated to saturated fat (P:S) of 1.3, whereas the high-fat diet provided 41.0% of energy from fat with a P:S of 0.6. Total dietary fiber consumption from the low- and high-fat diets averaged 4.6 and 2.0 g.MJ-1.d-1, respectively. Mean plasma concentrations of total and sex-hormone-binding-globulin (SHBG)-bound testosterone were 13% and 15% higher, respectively, on the high-fat, low-fiber diet and the difference from the low-fat, high-fiber diet was significant for the SHBG-bound fraction (P = 0.04). Men's daily urinary excretion of testosterone also was 13% higher with the high-fat, low-fiber diet than with the low-fat, high-fiber diet (P = 0.01). Conversely, their urinary excretion of estradiol and estrone and their 2-hydroxy metabolites were 12-28% lower with the high-fat, low-fiber diet (P < or = 0.01). Results of this study suggest that diet may alter endogenous sex hormone metabolism in men.

Adult↗

Type-specific prevalence of human papillomavirus DNA among Jamaican colposcopy patients.

Human papillomavirus (HPV) types differ in their association with cervical cancer. Therefore, the types of HPV in precancerous lesions are important. In many regions with high cancer incidence, the HPV types in precancerous lesions have not been well studied. In Jamaica, a country that has high cervical cancer incidence, 174 colposcopy patients were tested for HPV DNA using polymerase chain reaction. HPV DNA detection was strongly related to presence and grade of cervical neoplasia (P<.001). Furthermore, severe neoplastic change was most highly associated with HPV DNA types also considered high-risk for severe neoplasia in other populations. HPV-45 DNA, a high-risk type uncommon in most previously tested countries, was detected in 12% of patients who had neoplasia. Thus, cervical neoplasia in Jamaica, as elsewhere, is linked to HPV. The high prevalence of HPV-45 was notable, and its relation to high cervical cancer incidence in Jamaica must be assessed.

Adult↗

Estimating the timing of mother-to-child transmission of human immunodeficiency virus in a breast-feeding population in Kinshasa, Zaire.

Breast-fed infants born to human immunodeficiency virus (HIV)-infected mothers in Kinshasa, Zaire, were monitored a mean of 18 months. HIV infection in infants was determined by polymerase chain reaction (PCR), HIV culture, or ELISA. PCR test results for HIV DNA on venous blood drawn from children ages 0-2 days and 3-5 months were used to estimate proportions of mother-to-child transmission and transmission risks during the intrauterine, intrapartum/early postpartum, and late postpartum periods. Among 69 HIV-infected children (26% of the cohort), 23% (95% confidence interval [CI], 14%-35%) were estimated to have had intrauterine, 65% (CI, 53%-76%) intrapartum/early postpartum, and 12% (CI, 5%-22%) late postpartum transmission. The estimated risks for intrauterine, intrapartum/early postpartum, and late postpartum infection, respectively, were 6% (16/261; CI, 4%-10%), 18% (45/245; CI, 14%-24%), and 4% (8/189; CI, 2%-8%). These results support earlier studies indicating that most transmission occurs during labor and delivery or in the early postpartum period and that the risk of HIV transmission through breast-feeding during the postpartum period is substantial.

Breast Feeding↗

Prevalence of and potential risk factors for symptoms associated with insecticide use among animal groomers.

Pet groomers make numerous insecticide applications during the flea season, but few studies have examined their health complaints. The Pesticide Control Program of the New Jersey Department of Environmental Protection conducted a health and safety survey of this population. All licensed pet applicators in New Jersey were contacted, as were New Jersey veterinarians listed as pet-animal practitioners by the American Veterinary Medical Association. Approximately 36% of the respondents indicated that during the 1994 flea season, they had experience at least one of the 17 symptoms associated with insecticide application. Central nervous system symptoms (headache, dizziness, or confusion) and skin symptoms (skin rash or numbness/tingling) were reported most frequently. Logistic regression results suggest that applications per season, years as an applicator, certain hygiene variables, certain classes of products, and status of applicator (veterinary vs veterinary) are potentially important risk factors.

Adolescent↗