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J Reeves

Publications and source records attributed to J Reeves.

At least 37 records · Page 2Linked to original sources
PubMed1995

C-erbB-2 gene amplification: a molecular marker in recurrent bladder tumors?

C-erbB-2 gene amplification and protein overexpression have been implicated as prognostic markers for patients with recurrent progressive bladder tumors. This event has been investigated as a potential diagnostic indicator in archival samples of transitional cell carcinoma of the bladder. Two hundred thirty-six bladder tumors from 89 patients with recurrent disease (mean follow-up, 4 years), 20 tumors from patients with no evidence of bladder tumor recurrence (mean follow-up, 7 years) and 10 normal bladder controls (patients with no history of transitional cell carcinoma) were studied. A differential PCR was used to provide a semiquantitative estimate of C-erbB-2 gene amplification. Protein overexpression was assessed immunohistochemically. Sixteen of 89 patients with recurrent disease had evidence of C-erbB-2 gene amplification. No C-erbB-2 gene amplification was seen in the nonrecurrent tumors or normal bladder controls. Of the 89 patients with recurrent bladder tumors, 43 had evidence of progressive disease, and of these, 14 patients exhibited C-erbB-2 gene amplification, indicating a strong association with gene amplification and progressive disease (P < 0.0005). Gene amplification in these patients was seen only after disease progression had occurred. Protein overexpression was seen in 50% of patients with recurrent and 45% of patients with nonrecurrent disease. No protein overexpression was seen in normal controls. Protein overexpression could not be linked to disease progression. C-erbB-2 gene amplification and protein overexpression were of predictive value in multivariate analysis for overall bladder cancer death; however stage and grade remained the most important independent prognostic variables. C-erbB-2 gene amplification and protein overexpression were of no value as independent markers for the prediction of disease recurrence or progression. It appears from these results that the role of C-erbB-2 as a diagnostic marker may far outweigh its usefulness as a prognostic indicator.

Aged↗
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↗
PubMed1994

Tumor incidence in a chemical carcinogenesis study of nonhuman primates.

This report covers a 32-year period of an ongoing chemical carcinogenesis study in nonhuman primates, which was initiated by the National Cancer Institute in 1961. Autopsy records of 373 breeders and normal controls showed very low incidence of spontaneous malignant tumors in cynomolgus (1.5%) and rhesus (2.8%) monkeys, but considerably higher incidence in African green monkeys (8%). A large number of substances including a variety of food additives, food components, environmental contaminants, N-nitroso compounds, "classical" rodent carcinogens, antineoplastic agents, and immunosuppressive agents have been evaluated for long-term carcinogenic activity. Food components tested which are probably most relevant to human exposure are the artificial sweeteners, cyclamate and saccharin. After 22 years of continuous dosing, neither cyclamate nor saccharin have shown any evidence of carcinogenic effects. Similarly, the tumorigenic potential of arsenic and DDT was negligible after dosing for 15-22 years. In contrast, the fungal food contaminants, aflatoxin B1 (AFB1) and sterigmatocystin (SMT), were found to be potent hepatocarcinogens. AFB1 also induced adenocarcinomas of the pancreas, osteosarcomas, and other tumors. Also, the aglycone of cycasin, MAM acetate, induced a variety of tumors, but primarily hepatocellular and renal cell carcinomas. The compounds most recently introduced into the colony include three heterocyclic amines present in cooked meat. One of these compounds, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) has proven to be one of the most potent hepatocarcinogens in the history of the monkey project, inducing malignant liver tumors in 65% of animals over a 7-year period of exposure. Of the classical rodent carcinogens studied, urethane was the only one which produced malignant tumors in the monkeys. Conversely, all except two of the N-nitroso compounds were carcinogenic. Diethylnitrosamine (DENA) was the most potent and predictable hepatocarcinogen in cynomolgus, rhesus, and African green monkeys. However, when administered intraperitoneally to galagos (a prosimian), DENA induced primarily mucoepidermoid carcinoma of the nasal cavity. N-Methyl-N-nitrosourea (MNU) was the only carcinogen persistently producing tumors in the digestive tract, mostly squamous cell carcinomas of the esophagus. Among the antineoplastic and immunosuppressive agents, procarbazine (MIH) was the only unequivocal carcinogen, with a 33% tumor incidence, causing acute nonlymphocytic leukemia in most of the cases.

Animals↗
PubMed1994

Epidermal growth factor receptor expression by human squamous cell carcinomas of the head and neck, cell lines and xenografts.

Epidermal growth factor receptor (EGFR) overexpression has been associated frequently with squamous cell carcinomas (SCC) and SCC cell lines. In most cases the level of EGFR on the tumours from which the cell lines were derived has not been determined, nor have EGFR levels been determined for xenograft tumours from the cell lines. In this study we determined EGFR expression on a new series of head and neck SCC (SCCHN)-derived cell lines, which were obtained from tumours representing a spectrum of malignant progression, and two cell strains derived from erythroplakia premalignant lesions. The level of EGFR on cell lines was determined by [125I]EGF competitive binding assays. EGFR levels on some of the original tumours and xenografts of the cell lines were determined on cryosections by a competitive binding assay based on [125I]EGFR1, an EGFR-specific monoclonal antibody. EGFR expression on the tumour cryosections was compared with expression on cryosections of skin and buccal mucosa. Eight of the ten tumour cell lines had elevated EGFR. Two of the tumour-derived cell lines and the two erythroplakia-derived cell strains expressed EGFR at levels similar to that detected on normal keratinocytes in tissue culture. Only two of the tumours overexpressed EGFR when compared with normal tissue. The other tumours had levels similar to that detected on the basal layers of skin or buccal mucosa. The xenografts expressed EGFR, as did the original tumours, even though they were derived from cell lines that displayed significant overexpression of EGFR. This study suggests that most tumours have a latent potential to overexpress EGFR which is realised in tissue culture.

Animals↗
PubMed1990

The electrocardiogram at rest and exercise during a simulated ascent of Mt. Everest (Operation Everest II).

To evaluate the effect of extreme altitude on cardiac function in normal young men, electrocardiograms were recorded at rest and during maximal exercise at several simulated altitudes up to the equivalent of the summit of Mt. Everest (240 torr or 8,848 m). The subjects spent 40 days in a hypobaric chamber as the pressure was gradually reduced to simulate an ascent. Changes in the resting electrocardiogram were evident at 483 torr (3,660 m) and were more marked at 282 torr (7,620 m) and 240 torr (8,848 m). They consisted of an increase in resting heart rate from 63 +/- 5 to a maximum of 89 +/- 8 beats/min; increase in P-wave amplitude in inferior leads; right-axis shift in the frontal plane; increased S/R ratio in the left precordial leads; and increased T negativity in V1 and V2. No significant arrhythmias or conduction defects were observed. Most changes reverted to normal within 12 hours of return to sea level, with the exception of the frontal-plane axis and T-wave alterations. Maximal cycle ergometer exercise at 282 torr (7,620 m) and 240 torr (8,848 m) resulted in a heart rate of 138 +/- 7 and 119 +/- 6 beats/min at the 2 altitudes, respectively. No ST depression or T-wave changes suggestive of ischemia occurred despite a mean arterial oxygen saturation of 49% and a mean pH of 8 during peak exercise. Occasional ventricular premature beats were observed during exercise in 2 subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Carcinogenicity of 2-amino-3-methylimidazo[4,5-f]quinoline in nonhuman primates: induction of tumors in three macaques.

The carcinogenic potential of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) was evaluated in cynomolgus monkeys. Monkeys received IQ, beginning at the age of one year, at doses of 10 or 20 mg/kg by gavage. Thus far, IQ has induced hepatocellular carcinoma in three monkeys with a latent period of 27 to 37 months. Metastases to the lung occurred in two of the three monkeys. Microscopically, the hepatocellular carcinoma in all three cases demonstrated a trabecular pattern. These data demonstrate that IQ is a potent carcinogen in nonhuman primates and support the idea that it is a potential carcinogen for humans.

Animals↗
PubMed1989

[Application of the negotiated process method to primary health care for women].

Since 1984 the University of Illinois School of Public Health in Chicago has been offering the course "Women's Health: A Primary Health Care Method." The objectives of the course are to develop a model to meet the health needs of urban women in industrialized countries and to teach post-graduate students from various health-related programs to work as members of interdisciplinary teams with groups of women in communities. This activity involves the use of the negotiated process method, the purpose of which is to train students and the community group to work together and separately on solutions to identified health problems. During the course given in 1985 this method was applied to analyzing the problem of battered women in a Latin American community. Although the results were satisfactory, other similar experiments should be conducted to determine its usefulness more precisely.

Community Health Services↗
PubMed1989

Automated quantitation of cell density distribution and hyperdense cell fraction in RBC disorders.

An altered state of cell hydration is a hallmark of a number of RBC disorders. The two parameters most often used to characterize the state of cell hydration are (a) the complete cell density distribution profile, and (b) the fraction of cells with densities greater than a defined value. Buoyant density cell fractionation with a variety of polymers has long been the preferred method for obtaining data on cell density distribution. Although this method provides accurate and quantitative information on the state of RBC hydration, its applicability has been limited due to the time-consuming experimental procedure involved in generating the data. A recently developed light-scattering method has been used in the present study to quantitate RBC density distribution. This new method accurately quantitates both the cell density distribution profile and the fraction of dense, dehydrated cells in various RBC disorders. The ability of the automated method to generate this information rapidly makes possible objective testing of different hypotheses concerning the contributions of cell hydration and dehydration to the pathophysiology of various RBC disorders.

Anemia, Sickle Cell↗
PubMed1988

Antioxidants, enzyme induction, and chronic pancreatitis: a reappraisal following studies in patients on anticonvulsants.

Our published dietary and pharmakokinetic studies in 15 patients with idiopathic chronic pancreatitis and 15 age- and sex-matched controls suggested that a combination of subnormal antioxidant intakes and chronic induction of the cytochromes P450 facilitates the pancreatic problem. We have now attempted to determine the relative importance of these two factors by studying a group of 15 institutionalized patients with epilepsy (EP), but without abdominal pain, who were on long-term treatment with anticonvulsant inducers of cytochromes P450 so that their clearance of theophylline (which reflects cytochromes P450 activities, and thereby provides an index of antioxidant demand) was as high as in the patients with chronic pancreatitis (CP) (mean +/- s.d., 123 +/- 59 ml/kg/h versus 120 +/- 62 respectively), and significantly higher than in controls (74 +/- 16 ml/kg/h, P less than 0.02). Canonical variate analysis of the drug kinetic and dietary data provided two functions with which to separate the three groups. The first function, heavily weighted on selenium, separated the controls from the other two groups whose values were lower; the second function, equally weighted on methionine and vitamin C, separated the EP group from the CP group whose values were generally lower. The results suggest that enzyme induction per se is not the critical factor in the development of CP. Instead, suboptimal availability of antioxidants in the face of increased demand--in particular of those substances that protect cells against non-biological free radicals--may be the key consideration, a deduction reinforced by observations in patients with epilepsy who went on to develop chronic pancreatitis.

Adult↗
PubMed1987

Reaction of methylated urates with 1,1-diphenyl-2-picrylhydrazyl.

The kinetics of the reaction between the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and methylated urates was studied. Urates that had methyl groups on the 1,3,9, or on the 1 and 3 or 1 and 9 nitrogens reacted with DPPH 15 to 77% faster than uric acid. Urates substituted with methyl groups on the 7 nitrogen or on both the 3 and 9 nitrogens reacted with DPPH at rates that were less than 0.1 that of uric acid. 3,7,9-Trimethyluric acid and 1,3,7,9-tetramethyluric acid reacted with DPPH at barely detectable rates. DPPH reacted with uric acid, the monomethylated urates, and some of the dimethylated urates in a ratio of 2:1. DPPH reacted with other dimethylated and trimethylated urates in a ratio of 1:1. Semiempirical MNDO calculations indicate that the most stable radical of uric acid is formed by hydrogen abstraction from the 3, 7 or 9 position. The most stable species resulting from loss of a second hydrogen lack hydrogens at the 3 and 7 positions or the 7 and 9 positions. For maximum reactivity with DPPH, methylated uric acid derivatives must have a hydrogen at nitrogen 7 and one of the hydrogens at either the 3 or 9 position.

Biphenyl Compounds↗
PubMed1986

Uric acid protects membranes and linolenic acid from ozone-induced oxidation.

Aqueous preparations of linolenic acid, bovine serum albumin, and bovine erythrocyte membrane fragments were bubbled with ozone in the presence or absence of uric acid. Ozonation of the membrane fragments or the bovine serum albumin did not result in protein degradation. After 15 min of ozonation, the absorbance of the thiobarbituric acid-reactive material increased by 0.34 in the linolenic acid preparation and by 0.08 in the suspension of membrane fragments. In the presence of uric acid, these changes in absorbance were reduced to 0.14 for the fatty acid and to 0.01 for the membrane fragments. This result indicates that uric acid protects lipids from ozone-induced oxidation.

Animals↗