Search PubMed⌕ Search

Biomedical subjects

P Roberts

Publications and source records attributed to P Roberts.

At least 181 records · Page 10Linked to original sources
PubMed1987

Levinsonian studies of women's adult development.

We reviewed four unpublished dissertations that used Levinson's theory to study women's adult development. The 39 biographies presented in these studies suggested that the women progressed through the same developmental periods as had men in Levinson's study and at roughly the same ages. Although the timing of the periods and the nature of the developmental tasks appeared to be similar, the ways of working on these tasks as well as the outcomes achieved were different. These differences are understood in part as consequences of the greater complexity of women's dreams and the problems encountered in living them out.

Adult↗
PubMed1987

The effect of sorbitol and activated charcoal on serum theophylline concentrations after slow-release theophylline.

The effect of the addition of sorbitol to an oral regimen of multiple doses of activated charcoal on serum theophylline concentrations was studied after the ingestion of slow-release theophylline in nine healthy male volunteers. At 6, 7, 8, 10, and 12 hours after Theo-24 (1200 mg/70 kg) ingestion, each subject received, in a randomized crossover design, either 300 ml water, 20 gm activated charcoal in water, or 20 gm activated charcoal in water plus 75 ml 70% sorbitol at 6 and 8 hours only. The serum AUCs from 6 to 30 hours after Theo-24 ingestion during the water, charcoal, and charcoal plus sorbitol phases were 305 +/- 16, 113 +/- 6, and 85 +/- 10 mg-hr/L (mean +/- SE), respectively. We conclude that the addition of sorbitol to an oral regimen of multiple doses of activated charcoal decreased the serum theophylline concentrations after therapeutic doses of slow-release theophylline to a significantly greater extent than did the activated charcoal regimen alone.

Adult↗
PubMed1986

AIDS virus infection in Nairobi prostitutes. Spread of the epidemic to East Africa.

The acquired immunodeficiency syndrome (AIDS) is epidemic in Central Africa. To determine the prevalence of AIDS virus infection in East Africa, we studied 90 female prostitutes, 40 men treated at a clinic for sexually transmitted diseases, and 42 medical personnel in Nairobi, Kenya. Antibody to human T-cell lymphotropic virus Type III (HTLV-III) was detected in the serum of 66 percent of prostitutes of low socioeconomic status, 31 percent of prostitutes of higher socioeconomic status, 8 percent of the clinic patients, and 2 percent of the medical personnel. The presence of the antibody was associated with both immunologic and clinical abnormalities. The mean T-cell helper/suppressor ratio was 0.92 in seropositive prostitutes and 1.82 in seronegative prostitutes (P less than 0.0001). Generalized lymphadenopathy was present in 54 percent of seropositive prostitutes and 10 percent of seronegative prostitutes (P less than 0.0001). No constitutional symptoms, opportunistic infections, or cases of Kaposi's sarcoma were present. Our results indicate that the epidemic of AIDS virus infection has, unfortunately, spread extensively among urban prostitutes in Nairobi, Kenya. Sexual exposure to men from Central Africa was significantly associated with HTLV-III antibody among prostitutes, suggesting transcontinental spread of the epidemic.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Association between diaphragm use and urinary tract infection.

We conducted independent case-control and retrospective cohort investigations to assess the relationship between diaphragm use and urinary tract infection (UTI). In the former, we compared diaphragm use and vaginal flora among 114 women with acute UTI and 85 women with acute urinary tract symptoms and no UTI. In the latter study, we ascertained the incidence of UTI in 192 diaphragm users and 182 women taking oral contraceptives during a mean follow-up of 9.4 months. Both studies demonstrated a significantly increased risk of UTI in diaphragm users: relative odds were 2.0 in the case-control study and the relative risk was 2.5 in the retrospective cohort study. Vaginal colonization with Escherichia coli was significantly greater in diaphragm users. The incidence of UTI in the cohort study was 26.6 per 1,000 patient-months for diaphragm users and 8.9 per 1,000 patient-months for women taking oral contraceptives. The increased risk of UTI in diaphragm users could not be attributed to differences in age, parity, sexual activity, or previous UTI.

Adolescent↗
PubMed1985

Loss of epidermal growth factor receptors and release of transforming growth factors do not correlate with sarcoma virus-transformation in clonally-related NIH/3T3-derived cell lines.

Transformation of NIH/3T3 cells by Kirsten murine sarcoma virus (MSV) caused a dramatic reduction in the number of cell-surface receptors for epidermal growth factor (EGF). However, the number of EGF receptors remained at a very low level in a non-tumourigenic revertant cell line isolated from the virus-transformed cells, indicating that an increase in EGF receptors is not a requirement for the phenotypic reversion of Kirsten MSV-transformed 3T3 cells. Serum-free conditioned medium from normal and virus-transformed cell lines contained similar amounts of cell growth-promoting activity as assayed by the ability to stimulate DNA synthesis in quiescent Swiss 3T3 cell cultures. However, the concentrated conditioned medium from these cell lines showed no evidence of beta-transforming growth factor (TGF) activity as assayed by promotion of anchorage-independent growth of untransformed normal rat kidney (NRK) fibroblasts in agarose. The cellular release of alpha-TGF activity was assayed by measuring the ability of concentrated conditioned medium to inhibit the binding of 125I-EGF to Swiss 3T3 cells. Conditioned medium protein from the virus-transformed cell line inhibited 125I-EGF binding but only to the same extent as conditioned medium protein prepared from the untransformed cell line. The alpha-TGF secretion by these cell lines was estimated to be 30-45-fold lower than the level of alpha-TGF released by a well-characterized alpha-TGF-producing cell line (3B11). These results suggest that the induction of TGF release is not a necessary event in the transformation of NIH/3T3 cells by Kirsten MSV.

Animals↗
PubMed1985

The effects of activated charcoal on digoxin and digitoxin clearance.

The effect of multiple oral doses of activated charcoal on digitalis glycoside kinetics was studied to determine whether an activated charcoal regimen might have utility in treating patients with digitalis toxicity. Normal subjects were given intravenous infusions of digoxin 0.75 mg/70 kg or digitoxin 1 mg/70 kg iv followed by either water alone or water with activated charcoal in divided doses in a randomized crossover design. A subject with chronic renal failure was also given digoxin 0.5 mg/70 kg iv followed by water alone or water with activated charcoal. In six normal subjects, treatment with activated charcoal did not increase digoxin clearance (Cl) significantly (16.79 +/- 1.70 vs. 22.68 +/- 3.51 L/h). However, digitoxin Cl did increase significantly, from 0.24 +/- 0.01 to 0.47 +/- 0.04 L/h. In the renal failure subject, digoxin Cl increased from 3.6 L/h to 10.1 L/h. We conclude that the activated charcoal regimen is probably useful in patients with digitoxin toxicity. Although similar benefit is limited in patients with normal renal function who develop digoxin toxicity, it is possible that activated charcoal will be useful in patients with prolonged digoxin elimination due to renal dysfunction.

Adult↗
PubMed1984

Activated polymorphonuclear leucocytes consume vitamin C.

Polymorphonuclear leucocytes (PMN) are known to produce superoxide and other oxygen derivatives upon activation as part of their microbicidal armory. Here we report that extracellular ascorbate is effectively oxidised by activated but not by resting human PMN in vitro. The oxidation of ascorbate is mainly caused by the superoxide that is generated by the activated cells, as shown by its effective inhibition by superoxide dismutase. However, myeloperoxidase, which may generate hypochlorite, also contributes to a significant extent. Ascorbate reduces superoxide to peroxide, as indicated by measurements of the stoichiometry of ascorbate and oxygen consumption. These results support the notion that extracellular ascorbate may serve as an important physiological protecting agent against oxygen radical damage in inflammation.

Ascorbic Acid↗
PubMed1984

Measurement of esophageal reflux by scintigraphy.

Gastroesophageal reflux and clearance of the refluxed material can be measured by plotting a time-activity curve from an esophageal area of interest after 1 mCi of 99mTc sulfur colloid is placed in the stomach. Control subjects do not have peaks exceeding a value twice that of the baseline count levels. Reflux patients exceed this value, either spontaneously or after Valsalva maneuvers. This technique has a sensitivity which is greater than that of barium and equal to the sensitivity of a pH probe in patients with both moderate and severe reflux. Scintigraphic reflux was shown in 62% of moderate refluxes and 85% of those with severe reflux as defined clinically. Clearing of the refluxed material occurs rapidly in most patients if measured by this scintigraphic technique. This test can be performed rapidly with minimal radiation exposure and is noninvasive.

Adult↗
PubMed1984

Comparison of CA 19-9 and carcinoembryonic antigen (CEA) levels in the serum of patients with colorectal diseases.

The serum levels of CA 19-9 and carcinoembryonic antigen (CEA) were determined in 37 patients with benign colorectal diseases and in 111 patients with newly discovered colorectal carcinomas or clinically verified relapses. In cancer patients, the CA 19-9 level ranged from normal (0-37 U ml-1) to 77,500 U ml-1 whereas all samples but one from patients with benign colorectal diseases had a normal value. CA 19-9 was increased in 46% and 45% of patients with an advanced (Dukes C or D) carcinoma or a verified recidive, respectively. Only one out of 26 patients (4%) with a localized (Dukes A or B) carcinoma displayed an elevated CA 19-9 level (greater than 37 U ml-1). No clear correlation was found between the CA 19-9 and CEA levels. The sensitivity of the CA 19-9 test (36%) was poorer than that of the CEA assay (69%), but the new test was markedly more specific (97% vs 70%) than the CEA assay.

Antigens, Neoplasm↗
PubMed1984

Comparison of a new tumour marker, CA 19-9, with alpha-fetoprotein and carcinoembryonic antigen in patients with upper gastrointestinal diseases.

Serum CA 19-9 antigen concentrations were measured in 246 patients with benign and histologically confirmed malignant gastrointestinal diseases. The CA 19-9 concentration was above the upper limit of the normal range (0-37 U/ml) in 76% of patients with pancreatic carcinoma, 73% of patients with cholangiocarcinoma, 42% of patients with gastric carcinoma, and 22% of patients with hepatoma. High CA 19-9 concentrations were found mainly in patients with a metastasised cancer, whereas 71% of patients with a localised carcinoma had normal CA 19-9 concentrations. All of the patients with benign gastric diseases had normal CA 19-9 values. Moderately increased concentrations were found in 15-36% of the patients with benign pancreatic, liver, and biliary tract diseases. alpha-fetoprotein was a better marker for hepatomas than CA 19-9. CA 19-9 was better than carcinoembryonic antigen in differentiating malignant from benign diseases. The results indicate that the CA 19-9 assay is not completely specific for cancer but serves as a valuable adjunct, especially in the diagnosis of pancreatic carcinoma.

Antigens, Neoplasm↗
PubMed1983

Belief discrepancy reasoning in the elderly.

The development of belief discrepancy reasoning, or how people evaluate disagreeing others, was examined with forty-four college and elderly respondents. Dogmatism and IQ measures were also administered. The results showed that the elderly were significantly lower in belief discrepancy reasoning and higher in dogmatism than the college sample, despite statistically greater IQ for the former sample and controls for education. For belief discrepancy, the elderly sample did not evidence intolerance, but rather relativism and open-mindedness toward disagreeing others. Implications for the construct validation of belief discrepancy and senescent intolerance are discussed.

Aged↗