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Biomedical subjects

L Clark

Publications and source records attributed to L Clark.

At least 19 recordsLinked to original sources
PubMed1998

Impact of HIV on families of HIV-infected women who have recently given birth, Bangkok, Thailand.

The objective of this study was to assess changes in the family situation of HIV-infected women who have recently given birth. As part of a prospective perinatal HIV transmission study, interviews were conducted with a subset of HIV-infected women at 18 to 24 months postpartum, and answers were compared with baseline information obtained during pregnancy. Standardized scales were used to assess levels of psychosocial functioning. A convenience sample of 129 HIV-infected women enrolled during pregnancy was interviewed at 18 to 24 months postpartum. At delivery, the women were young (median age, 22 years), primiparous (57%), and asymptomatic (93%). When baseline and follow-up data were compared, more women were living alone (1% versus 6%; p = 0.03), fewer women were living with their partners (98% versus 73%; p < 0.001), and 30% of families had reduced incomes. At follow-up, 10% of partners had died, and more partners than wives had become ill or died (21% versus 4%; p = 0.02). Most children (78%) were living with their mothers, but only 57% of the HIV-infected women were the primary caretakers. Fewer women had disclosed their HIV status to others (e.g., family, friends) than to their partners (34% versus 84%; p < 0.001), largely because of fear of disclosure. The women appeared to have high levels of depression and worry. The women's greatest worries were about their children's health and the family's future. Within 2 years after childbirth, substantial change within the families of HIV-infected women was evident. These were manifest by partner illness or death, family separation, reduced family income, shifting responsibilities for child care, and signs of depression and isolation. Providing family support is a major challenge in Thailand as the perinatal HIV epidemic progresses.

Adult↗
PubMed1998

Bird repellents: interaction of chemical agents in mixtures.

Numerous studies characterize the concentration-behavioral response for odorants, tastants, and irritants. However, to achieve ecological validity, interaction of agents in mixtures must be considered. Equiresponse and equimolar molar models of interactions have been proposed, and methods for testing whether agents in mixture interact independently have been evaluated. Yet these averaging models cannot a priori predict whether agents will interact antagonistically, independently, or synergistically. I studied the bird repellent properties of several structurally similar and well-described trigeminally mediated avian irritants, singly and in mixture. Compounds within a chemical class, in which the electron withdrawing groups were similar, interacted independently to produce their repellent effects, e.g., 2-amino methyl benzoate v methyl-2-methoxy benzoate, and o-aminoacetophenone v 2-methoxy acetophenone. The response to mixtures drawn from compounds of dissimilar chemical class, e.g., 2-amino methyl benzoate v o-aminoacetophenone, interacted antagonistically at concentrations below 10 mM, suggesting meditation by a different mechanism within the trigeminally mediated sensory modality. At 10 mM and near saturation of the solutions, there was no evidence of interaction between agents, suggesting responses became saturated. These observations underscore our previous findings for the importance of the molecular properties of the carbonyl group for aromatic bird repellents and suggests the possible existence of multiple receptor mechanisms for avian trigeminal repellents. These data also underscore the importance of attending to interactions of agents in mixtures when designing repellents as tools for the management of wildlife and resolution of conflicts between humans and wildlife.

Algorithms↗
PubMed1998

The Family Health Project: psychosocial adjustment of children whose mothers are HIV infected.

The psychosocial adjustment of 87 inner-city African American children 6-11 years old whose mothers were HIV infected was compared with that of 149 children from a similar sociodemographic background whose mothers did not report being HIV infected. Children were not identified as being HIV infected. Mother reports, child reports, and standardized reading achievement scores were used to assess 4 domains of adjustment: externalizing problems, internalizing problems, cognitive competence, and prosocial competence. The results indicated that, on average, children from both groups had elevated levels of behavior problem scores and low reading achievement scores when compared with national averages. Relative to children whose mothers were not infected, those whose mothers were HIV infected were reported to have more difficulties in all domains of psychosocial adjustment. Potential family processes that may explain the findings are discussed.

Achievement↗
PubMed1998

Failure to collect oocytes in assisted reproductive technology: a retrospective.

While there is much information and discussion on pregnancy failure after assisted reproductive technologies, less emphasis is placed on the failure to collect oocytes after apparently successful ovarian stimulation. This retrospective survey reviewed 4973 treatment cycles in order to obtain information about the likelihood of this event. Overall 42 women (43 treatment cycles) failed to have oocytes collected [0.86% of treatments started and 0.92% of women given human chorionic gonadotrophin (HCG)]. However, in only six cases was this failure unexpected (0.1%) with no obvious potential clinical reason (i.e. all six cases had: HCG administered; more than two follicles >15 mm in diameter; oestradiol values >2000 pmol/l; <38 years old; normal body mass index). Indifference concerning uncommon events is fraught with peril, as although rare, the particular outcome may be devastating to the individual, both economically and psychologically. Eighteen of the 42 women did not return for on-going treatment suggesting increased contact by clinic staff may be required when oocyte retrieval is not achieved. These data suggest that the failure to collect oocytes after apparently successful ovarian stimulation is rare and random. The information has proved useful in allaying the fears of couples contemplating assisted reproductive technologies.

Adult↗
PubMed1998

Increasing breastfeeding rates to reduce infant illness at the community level.

OBJECTIVE: Although breastfeeding is associated with lower rates of a variety of infant illnesses, skeptics have suggested that much of the association is attributable to confounding, even after appropriate statistical adjustment. This article utilizes a novel design to investigate changes in infant illness at the community level after a successful breastfeeding promotion program. METHODS: In this population-based cohort study, the medical records of all infants born in one Navajo community the year before a breastfeeding promotion program (n = 977) and the year during the intervention (n = 858) were reviewed. Outcomes assessed include changes after the intervention in: proportion breastfeeding and/or breastfeeding exclusively; incidence of common infant illnesses in the first year of life; and feeding-group specific incidence of illness. RESULTS: The proportion of women breastfeeding exclusively for any period of time increased from 16.4% to 54.6% after the intervention. The percent of children having pneumonia and gastroenteritis declined 32. 2% and 14.6%, respectively, after the intervention. Feeding-group specific rates of these illnesses were unchanged, indicating that the decline observed was attributable to the increased proportion of infants breastfeeding. In contrast, rates of croup and bronchiolitis increased after the intervention among those fed formula from birth, suggesting a viral epidemic which was limited to those never exclusively breastfed. Finally, sepsis declined in both formula-fed and breastfed infants after the intervention, suggesting that other factors affected this illness outcome after the intervention. CONCLUSIONS: Increasing the proportion of exclusively breastfed infants seems to be an effective means of reducing infant illness at the community level. The experimental design suggests that the increased incidence of illness among minimally breastfed infants is causally related to lack of breast milk, rather than being attributable to confounding.

Breast Feeding↗
PubMed1998

Diagnosis of pancreatic carcinoma: role of FDG PET.

OBJECTIVE: The purpose of this study was to investigate the role of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in differentiating benign from malignant disease in patients with possible pancreatic malignancy. SUBJECTS AND METHODS: All patients with a possible diagnosis of pancreatic carcinoma based on CT or ERCP findings were eligible for inclusion in this prospective study. PET imaging of the abdomen was performed in 37 patients and was interpreted as positive if FDG activity in the pancreas exceeded background activity and as negative if activity was less than or equal to background activity. Semiquantitative analysis was performed by calculating a standardized uptake ratio. Studies were reviewed independently by two radiologists, and results were correlated with biopsy results and with CT and ERCP findings. Sensitivity and specificity of FDG PET for revealing pancreatic malignancy was determined. RESULTS: FDG activity in the pancreas was increased in 24 patients, and adenocarcinoma was diagnosed in 22 of these patients (92%). Two patients (8%) with increased activity had benign disease, including one patient with chronic pancreatitis who showed no evidence of tumor at laparotomy and one patient with a mucinous cystic tumor who showed no malignant features at laparotomy. FDG uptake was low or normal in 13 patients, 10 of whom (77%) had benign disease. FDG uptake was also low in three patients with adenocarcinoma, whose tumor size ranged from 2 to 4 cm in diameter. The mean standardized uptake ratio value for malignant disease was 5.1 (range, 1.0-10.1) and for benign disease was 1.9 (range, 0.0-5.8) (p < .001). The sensitivity of FDG PET for revealing malignant disease in the pancreas was 88% and the specificity was 83%. CONCLUSION: FDG PET is a sensitive and specific noninvasive technique for the diagnosis of pancreatic malignancy.

Adenocarcinoma↗
PubMed1998

Quality care for cardiology patients.

To evaluate outcome measures in a cardiology unit, patient satisfaction was measured. Patients consistently related problems in two areas: pain management and the waiting period before their procedure. After a major system change, patient satisfaction increased 16% and 29% respectively.

Heart Diseases↗
PubMed1998

Noninvasive detection of allograft rejection in heart transplant recipients by use of Doppler tissue imaging.

BACKGROUND: Allograft rejection in heart transplant recipients is associated with lymphocytic extracellular infiltration and edema resulting in increased myocardial stiffness and abnormal relaxation. We hypothesize that these abnormalities will result in reduced myocardial relaxation velocities. Doppler tissue imaging is a novel noninvasive imaging modality that is capable of quantifying myocardial tissue velocities and may therefore be useful to identify allograft rejection. METHODS: In this observational study, 121 heart transplant recipients underwent pulsed-wave Doppler tissue imaging at the time of their surveillance endomyocardial biopsies. Peak relaxation and systolic velocities were measured from the inferior wall blinded to clinical biopsy. Biopsy results were classified as rejecting (3a, 3b, 4) or nonrejecting (0, 1a, 1b). RESULTS: The peak relaxation velocity in nonrejecting allograft recipients (n = 98) was 0.21 m/sec +/- 0.01. During moderate allograft rejection (n = 16), peak relaxation velocities decreased to 0.14 m/sec +/- 0.01 (p < 0.0001), and subsequently increased to 0.23 m/sec +/- 0.0 after successful treatment (p = 0.0001). Peak systolic velocities did not change during rejection, 0.08 m/sec +/- 0.02 when compared with nonrejecting recipients 0.09 +/- 0.02 (p = NS). With a cutoff value of less than 0.16 m/sec, the sensitivity of peak myocardial relaxation velocities for detection of rejection was 76%. The specificity and negative predictive values were 88% and 92%, respectively. CONCLUSION: Moderate allograft rejection results in reduced myocardial relaxation velocities, which can be detected noninvasively with pulsed-wave Doppler tissue imaging. Hence, Doppler tissue imaging is a useful noninvasive tool to exclude allograft rejection.

Adult↗
PubMed1997

Risperidone dose and blood level variability: accumulation effects and interindividual and intraindividual variability in the nonresponder patient in the clinical practice setting.

Risperidone blood levels were measured every 2 weeks after initiation of therapy in 24 refractory chronic schizophrenic patients referred to a locked, skilled nursing facility for long-term treatment. Blood levels were assessed on 285 occasions over a 1- to 16-month treatment program. Drug plasma level increases peaked by 2 months for risperidone at 334% and by 6 months for 9-hydroxy-risperidone at 104% over the baseline levels. Total blood levels (risperidone plus 9-hydroxy-risperidone) peaked at 111% increase at 6 months and then declined 8% per month to 12 months, stabilizing at a value 31% higher than the initial value. Significant dose to blood level interindividual variation was noted. Considerable blood level variation was evident in single blood level sample determinations. The results suggest the value of risperidone blood levels, consideration of reduction of initial recommended starting dosages, and a need to optimize risperidone dosage approaches individually to patients.

Adult↗
PubMed1997

The effect of wheat bran fiber and calcium supplementation on rectal mucosal proliferation rates in patients with resected adenomatous colorectal polyps.

Colorectal cancers continue as the second most common cause of death from cancer in the United States. Only a few prospective, randomized clinical trials have been performed to evaluate the potential preventive effects of dietary fiber or calcium in patients with an increased risk for the development or recurrence of colorectal cancer. We designed and conducted a double-blinded, placebo-controlled randomized trial involving supplementation of fiber and calcium intake and measurements of [3H]thymidine labeling index (LI) percentages in rectal mucosal biopsies obtained from patients with resected colorectal adenomas to examine the potential mechanisms by which dietary interventions might reduce colorectal cancer risk. We performed a randomized, double-blinded, Phase II study, using a factorial design to measure the effects of supplemental dietary wheat bran fiber (2.0 or 13.5 g/day) and calcium carbonate (250 or 1500 mg/day elemental calcium) supplementation on [3H]thymidine LI percentages in rectal mucosal crypts and 24-h in vitro outgrowth cultures. Measurements were made at baseline randomization (i.e., after a 3-month placebo run-in period using 2.0 g of wheat bran fiber plus 250 mg of calcium carbonate) and after 3 and 9 months on treatment in 100 randomized participants who had a history of colon adenoma resection. Neither the wheat bran fiber nor the calcium carbonate supplements significantly reduced [3H]thymidine LI percentages in rectal mucosal crypts (total or compartmental analysis) or 24-h in vitro outgrowth cultures at either 3 or 9 months of daily supplementation in the 93 evaluable participants. We conclude that 9 months of high-dose wheat bran fiber and calcium carbonate supplementation in study participants with a history of recently resected colorectal adenomas does not have a significant effect on cellular proliferation rates in rectal mucosal biopsies, comparing 3- and 9-month results to baseline results. Ultimately, there is great need for the evaluation of these two different nutrient interventions in the setting of Phase III studies wherein adenomatous polyp recurrence, rather than a rectal mucosal biomarker, serves as the primary end point.

Adenomatous Polyps↗
PubMed1996

Corneal infection with herpes simplex virus type 1 leads to autoimmune responses in rats.

Lewis rats were infected by corneal scarification with HSV type 1 type strain F virus. The animals showed symptoms of infection and inflammatory infiltrates of the eye but little mortality. After one month, immune responses to viral and autoantigens were examined. It was shown that lymph node cells proliferated to the myelin antigen, proteolipoprotein, and the HSV antigen, glycoprotein D, but showed depressed responses to antigens of the eye, specifically corneal and retinal antigens. Splenic cells showed small but significant responses to antigens of the eye, indicating immune deviation similar to that previously demonstrated in ACAID, where antigen had been injected into the anterior chamber of the eye.

Animals↗
PubMed1996

Randomized, double-blinded, placebo-controlled study of effect of wheat bran fiber and calcium on fecal bile acids in patients with resected adenomatous colon polyps.

BACKGROUND: Ongoing epidemiologic and nutritional studies suggest that colorectal carcinogenesis is consistent with complex interactions between genetic susceptibility and environmental and dietary factors. Among the dietary components found to reduce colon cancer risk are high intakes of dietary fiber and calcium. PURPOSE: We designed and conducted a randomized, double-blinded, placebo-controlled trial involving supplementation of the customary dietary intake with fiber and calcium and measurements of fecal bile acids to examine the potential mechanisms by which added dietary interventions might reduce colorectal cancer risk. METHODS: In a randomized, double-blinded, phase II study, we used a factorial design to measure the effects of dietary wheat bran fiber (2.0 or 13.5 g/day) in the form of cereal and supplemental calcium carbonate (250 or 1500 mg/day elemental calcium) taken as a tablet on fecal bile acid concentrations and excretion rates. Measurements were made at base-line randomization (i.e., after a 3-month placebo run-in period using 2.0 g wheat bran fiber plus 250 mg calcium carbonate) and after 3 and 9 months on treatment in a randomly selected 52-patient subsample of the 95 fully assessable study participants who had a history of colon adenoma resection. Concentrations of fecal bile acids, total, primary (i.e., chenodeoxycholic and cholic), and secondary (i.e., deoxycholic, lithocholic, and ursodeoxycholic), were measured in 72-hour stool samples by gas-liquid chromatography. All P values resulted from two-sided tests. RESULTS: All geometric mean fecal bile acid concentrations and excretion rates were lower at 9 months than at 0 months or 3 months on treatment in the high-dose fiber, high-dose calcium, and high-dose fiber/high-dose calcium treatment groups. The high-dose fiber effect at 9 months of supplementation was statistically significant with respect to virtually all geometric mean fecal bile acid concentrations and excretion rates. For example at 9 months versus 0 months, high-dose fiber supplementation caused a reduction in fecal concentrations of total bile acids (52% reduction; P = .001) and deoxycholic acid (48% reduction; P = .003). High-dose calcium supplementation also had a significant, but lower, effect at 9 months versus 0 months on the geometric mean total bile acid (35% reduction; P = .044) and deoxycholic fecal bile acid (36% reduction; P = .052) concentrations. CONCLUSIONS: High-dose wheat bran fiber and calcium carbonate supplements given for 9 months are associated with statistically significant reductions in both total and secondary fecal bile acid concentrations and excretion rates in patients with resected colon adenomas. This study supports the hypothesis that one of the important ways in which a high intake of wheat bran fiber and calcium may reduce the risk of colorectal neoplasia and cancer is by reduction of the concentrations of fecal bile acids. IMPLICATION: Phase III studies of these agents in the prevention of adenoma recurrence are necessary to confirm this hypothesis and have now been initiated at multiple institutions.

Adenomatous Polyposis Coli↗
PubMed1996

Postoperative use of pediatric pain scales: children's self-report versus nurse assessment of pain intensity and affect.

The purpose was to examine nurses' use of pediatric pain scales and to compare their estimate of the child's pain intensity and affect with the child's self-report. The Analog Chromatic Continuous Scale (ACCS) was used for pain intensity and the McGrath Affective Faces Scale (MAFS) for pain affect. Self-report of pain was obtained from 124 hospitalized postoperative children aged 5 to 17 years and compared with estimates of 44 pediatric nurses randomly assigned to either an experimental or control group. Experimental nurses used the ACCS and MAFS to obtain pain ratings whereas control nurses made estimates according to their customary method of assessment. Findings revealed that only 36% of the nurses had at any time used a pediatric pain scale. Correlations between the experimental nurses' ratings and the child's self-report were significantly higher than the control nurses' estimates and the child's self-report. The correlation between the child's self-report of pain intensity on the ACCS and of affect on the MAFS was r = .612, suggesting that nurses' use of both an intensity and affect pediatric pain scale would more accurately reflect the child's pain experience.

Affect↗
PubMed1996

Learning from patients: a discharge planning improvement project.

BACKGROUND: In 1991 Beth Israel Hospital (Boston) joined nine other hospitals in using the Picker/Commonwealth survey instrument to tap patients perceptions of their hospitalization experience. Beth Israel focused on one of the nine dimensions of the instrument-continuity and transition (discharge planning). FOUR WORK TEAMS: In 1992 four multidisciplinary work teams were formed-for cardiac surgical patients, stroke patients, patients on a medical unit, and patients on a medical and surgical unit. Each team conducted a patient/family discussion group, during which recently discharged patients and their families were asked about their preparation for discharge and asked for input on how to improve the process. INTERVENTIONS: Each work team developed interventions on the basis of information specific to their patients. The cardiac work team, for example, developed interdisciplinary practice guidelines for patient care management for the entire postoperative period; the guidelines include a patient education component on what patients and families can expect during hospitalization. OUTCOMES: Clinicians practice differently, inviting more patient feedback and other involvement in care, as a results of their involvement in the project. On the first annual patient survey, administered in 1994, only 6% of 1,179 randomly selected patients (versus 20% of the 100 patients first surveyed in 1993) indicated that they did not receive the information they needed to help themselves recover. CURRENT PROGRESS AND FUTURE DIRECTIONS: A standardized teaching packet containing material developed during the discharge planning improvement project is now distributed. In May 1995 the nursing department launched a patient and family learning center to better meet the health education needs of patients.

Aftercare↗
PubMed1996

Transfer of gametes into the fallopian tubes--is choice of side important?

The aim of this study was to define pregnancy rates for gamete intra-Fallopian transfer (GIFT) with respect to the ovary from which most oocytes were collected (i.e. a gross index of ovarian stimulation) and the Fallopian tube (ipsilateral or contralateral) into which gametes were replaced. The only inclusion criterion was the ability to transfer gametes into the Fallopian tubes at GIFT. No other factors that could influence outcome were considered. In this retrospective review of the clinic's database, no relationship was found between pregnancy rate and placement of gametes into the Fallopian tube coincident with the ovary from which most oocytes were collected. Thus when performing unilateral tubal transfer at GIFT gametes may be returned to the side most convenient to the operating surgeon without fear of compromising pregnancy potential.

Adult↗
PubMed1996

Changes in health after elective percutaneous coronary revascularization. A comparison of generic and specific measures.

OBJECTIVES: This study determines changes in health-related quality of life after elective percutaneous transluminal coronary angioplasty and compares generic and specific measures. METHODS: Changes in health-related quality of life were measured in consecutive, symptomatic patients undergoing elective percutaneous coronary revascularization using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), the Specific Activity Scale (SAS), and the Canadian Cardiovascular Society Classification (CCSC). The patients were interviewed as outpatients before admission and at least 6 months later. RESULTS: There were significant changes in the following SF-36 measures: physical functioning (postscore minus prescore = 19.1 +/- 24.1), role limitations due to physical-health problems (40.4 +/- 47.2), bodily pain (19.9 +/- 29.3), vitality (12.9 +/- 25.1), social functioning (20.0 +/- 33.1), role limitations due to emotional-health problems (26.7 +/- 49.0), and general mental health (7.1 +/- 21.2). General health perceptions did not change significantly. Internal-consistency reliability coefficients for these measures ranged from 0.73 to 0.91. There also was significant improvement in the CCSC class, but the SAS class did not change significantly. Overall, the SF-36 role-physical scale was the most responsive to changes after elective percutaneous coronary revascularization, followed by the CCSC and the SF-36 physical functioning scale. CONCLUSIONS: Although this study cannot determine the causal role of elective percutaneous coronary revascularization in these changes, it provides support for the usefulness of these measures in future evaluations of this intervention.

Activities of Daily Living↗