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Biomedical subjects

D Willis

Publications and source records attributed to D Willis.

At least 55 records · Page 3Linked to original sources
PubMed1995

Insulin action in human granulosa cells from normal and polycystic ovaries is mediated by the insulin receptor and not the type-I insulin-like growth factor receptor.

In order to account for the effects of insulin on the polycystic ovary (PCO), despite peripheral insulin resistance in women with polycystic ovary syndrome (PCOS), it has been suggested that insulin may act through the type-I insulin-like growth factor (IGF) receptor and not the insulin receptor. We have tested this hypothesis by investigating the effect of anti-insulin receptor and anti-type-I IGF receptor antibodies on insulin-stimulated steroidogenesis in human granulosa cells in vitro from normal (N) and PCO. Insulin-stimulated estradiol and progesterone production was inhibited by an anti-insulin receptor antibody. In contrast, anti-type-I IGF receptor antibodies had no effect on insulin-stimulated steroidogenesis in granulosa cell cultures from N or PCO. Hence insulin acts via its own receptor in human granulosa cells from both N and PCO.

Adult↗
PubMed1995

Is tolerance induction a possible mode of action of OM-89?

Neonatal Wistar rats were injected intraperitoneally with either 20 mu g OM-89 at birth and on day 3 after birth or 2 mg three times weekly until 200 g body weight. At this weight, groups were either implanted subcutaneously with a cotton pellet to induce granuloma, or had avridine polyarthritis or pleurisy induced. Both OM-89 treatment regimes significantly reduced granuloma weight (p < 0.05 and < 0.01), paw volume (p < 0.001) and pleural exudates (p < 0.01). The results suggest that OM-89 could work via tolerance induction.

Adjuvants, Immunologic↗
PubMed1994

Cyclo-oxygenase and nitric oxide synthase isoforms in rat carrageenin-induced pleurisy.

1. The profiles of cyclo-oxygenase (COX) and nitric oxide synthase (NOS) isoforms were determined in the rat carrageenin-induced pleurisy model of acute inflammation. 2. The enzymes were assessed in peripheral blood leucocyte (PBL) cell pellets taken from untreated animals and at 2, 6 and 24 h after injection of the irritant in pleural exudate cell pellets and lung homogenates. 3. COX activity was assessed by the generation of prostacyclin (PGI2, measured as the stable metabolite, 6-keto prostaglandin F1 alpha) and prostaglandin E2 (PGE2). Western blot analysis and immunohistochemistry were also carried out. 4. NOS activity was based on the conversion of [3H]-L-arginine to [3H]-L-citrulline in the presence (total NOS activity) or absence of Ca2+ (inducible NOS; iNOS). 5. Peripheral blood leucocyte samples contained low levels of COX activity. In pleural exudate cell pellets, COX activity peaked at 2 to 6 h after injection of the carrageenin. At 24 h, COX activity was significantly reduced. 6. Western blot analysis demonstrated that the inducible isoform of COX (COX-2), was the predominant enzyme at all time points. Low levels of COX-2 were seen in PBLs. In pleural exudate cell pellets maximal COX-2 protein levels were seen at 2 h. 7. Immunohistochemistry confirmed the findings of Western blot studies. Approximately 10% of polymorphonuclear neutrophils (PMNs) in PBLs from untreated animals were immunopositive for COX-2. In cell pellet smears from carrageenin-induced pleurisy taken 2 h after injection of the irritant, PMNs were also the major source of COX-2 immunoreactivity. A small proportion of macrophages and mesothelial cells were also immunolabelled for COX-2.8. Low levels of NOS activity were seen in PBLs. In pleural exudates NOS activity was maximum at 6 h and greatly reduced by 24 h. This activity was solely attributable to iNOS.9. The present results illustrated a similar profile of COX and NOS activity in the carrageenin-induced pleurisy model of acute inflammation. It was demonstrated that COX-2 and iNOS were the predominant isoforms of their respective enzymes.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

The relationship of insulin insensitivity to menstrual pattern in women with hyperandrogenism and polycystic ovaries.

OBJECTIVE: Insulin insensitivity is a recognized feature of polycystic ovary syndrome (PCOS) but previous studies have suggested that circulating insulin concentrations are normal in hyperandrogenaemic women with regular cycles. The aim of this study was to examine the relationship between insulin sensitivity and menstrual pattern in women with PCO. DESIGN: A cross-sectional study of insulin sensitivity in a cohort of PCO subjects with oligomenorrhoea compared to women with PCO and regular menstrual cycles and a group of normal control subjects. SUBJECTS: Seventy-two women with polycystic ovaries on ultrasonography were studied. PCO subjects had clinical and/or biochemical evidence of hyperandrogenism; 53 had oligo/amenorrhoea (olig) and 19 had regular menses (reg). Results were compared with 31 control subjects. The groups were matched for age, weight and ethnic origin. METHODS: Glucose and insulin responses to 75 g oral glucose were measured. Insulin sensitivity was assessed by the decline in plasma glucose following intravenous insulin (0.05 U/kg). RESULTS: Glucose area (mean +/- SEM) after oral glucose was increased slightly in both PCO groups compared with controls (olig 37.6 +/- 1.4, reg 36.0 +/- 1.8, control 33.7 +/- 0.9 mmol/l h, both P < 0.01). Insulin area median (interquartile range) in response to glucose was significantly greater in the oligomenorrhoeic group (346 (239-734) mU/l h), compared with both PCO with regular cycles (246 (148-355), P < 0.01) and controls (221 (147-277), P < 0.01). Insulin sensitivity was reduced (P < 0.01) in the oligomenorrhoeic group (147 +/- 9.2 mumol/l min) compared to controls (185 +/- 7.4) but was normal in PCO with regular cycles (182 +/- 12.5). Insulin sensitivity did not correlate significantly with plasma testosterone or with SHBG levels, but plasma insulin concentrations correlated negatively with SHBG levels (fasting insulin vs SHBG, r = -0.47, P < 0.01; insulin area vs SHBG, r = -0.41, P < 0.01). CONCLUSIONS: Insulin insensitivity in polycystic ovary syndrome occurs when there is oligo/amenorrhoea but not when the menstrual cycle is regular. This is consistent with PCO and insulin insensitivity being separate abnormalities which when combined are associated with anovulation.

Adult↗
PubMed1992

Cervicovaginal cytology in carcinosarcoma [malignant mixed mullerian (mesodermal) tumor] of the uterus.

We examined the cervicovaginal cytology (PAP) findings in a series of 21 endometrial and 2 cervical carcinosarcomas (CS) [malignant mixed mullerian (mesodermal) tumors] (MMMT). Initial cytology diagnosis was positive for cancer in 14 of 23 cases (sensitivity of 61%); however, CS was correctly identified only 2 times. The remaining 12 cancer diagnoses were carcinomas: 10 adenocarcinomas (4 endometrial, 1 cervical, and 5 adenocarcinomas not otherwise specified), 1 squamous carcinoma, and 1 poorly differentiated carcinoma. Seventeen smears were available for review, all 8 false negative, one unsatisfactory, and 8 of 14 true positive smears. One false negative smear showed rare clusters diagnostic of adenocarcinoma. The remaining 7 false negative smears showed 3 high grade squamous dysplasias (two with additional findings: one showed atypical spindle cells and the other showed endometrial stromal cells), 2 extensive repair changes, and 2 negatives. The unsatisfactory smear showed atypical spindle cells. Review of the 8 true positive smears confirmed malignant spindle cells in the two cases originally identified as CS by cytology and in 3 other cases originally identified as adenocarcinoma. Of 9 smears positive for cancer available for review, 4 showed only carcinoma cells. PAP positive for cancer was associated with high stage at presentation (P less than .025) and recurrent disease (P less than .001) (even among stage I or II patients, P less than .025). PAP positive for cancer showed no association with depth of myometrial invasion, size, grade, or histologic type of carcinosarcoma. The results of this study demonstrate the importance of consultative cytology reporting in which recommendations for appropriate biopsy are included in the report.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Inhibitory effects of insulin-like growth factor-binding proteins on steroidogenesis by human granulosa cells in culture.

The effects of insulin-like growth factor-binding proteins (IGFBPs) 1 and 3 on steroidogenesis by human granulosa cells has been examined. Both IGFBP-1 and IGFBP-3 produced a dose-related inhibition of IGF-I-stimulated oestradiol accumulation in granulosa cell-conditioned medium with complete reversal of the effects of IGF-I in the presence of a molar excess of binding protein. IGFBPs 1 and 3 also exerted a small (25-40%) but significant and consistent inhibition of oestradiol secretion in response to follicle-stimulating hormone (FSH) alone. The progesterone response to IGF-I was inhibited by IGFBPs 1 and 3 but there was no effect on FSH-stimulated progesterone production. These data support the concept of a physiologically important intraovarian IGF system in the human ovary and demonstrate an unequivocally inhibitory effect of IGFBPs 1 and 3 on IGF-I-stimulated granulosa cell steroidogenesis.

Carrier Proteins↗
PubMed1992

Prostaglandin E2 gel induction of patients with a prior low transverse cesarean section.

To determine safety and efficacy of induction with prostaglandin E2 gel, we compared the outcome of 25 patients (study group) with an unfavorable cervix, a medical indication for delivery, and one prior low cervical transverse cesarean section to 56 patients (comparison group) with one prior low cervical transverse cesarean section and spontaneous labor. We placed 1 mg of prostaglandin E2 in gel intracervically in the 25 study patients. Common indications for delivery were: diabetes, post dates, and preeclampsia. Although most labor and delivery variables were similar, the study group had a longer mean latent phase (14.2 +/- 13.8 versus 7.3 +/- 3.7 hours: p less than 0.002), but had a shorter mean length of active phase (4.0 +/- 3.5 versus 5.7 +/- 3.0 hours; p less than 0.02). None of the patients in either group had a dehiscence of the uterine scar, nor rupture of the uterus. Both groups had a similar cesarean section rate. Since from the few reported, nonrandomized studies it appears that prostaglandin E2 gel use in patients with a prior low cervical transverse cesarean section may be useful and relatively safe, it may be time to attempt randomized trials of prostaglandin E2 gel versus oxytocin for induction of patients with a prior low cervical transverse cesarean section, unfavorable cervix, and a medical indication for delivery.

Adult↗
PubMed1991

Patient attitudes toward testing for maternal serum alpha-fetoprotein values when results are false-positive or true-negative.

We investigated the attitudes toward the maternal serum alpha-fetoprotein (MSAFP) test of patients whose results from MSAFP testing were either false-positive or true-negative. Forty-six women who had previous false-positive results from MSAFP testing and 46 who had previous true-negative values participated. Patients were matched for age and socioeconomic status, and all were delivered of normal neonates. A significantly larger number of patients in the group with false-positive results believed they had not understood the MSAFP test than in the group with true-negative results (19.6% vs 0%). Significantly more women in the "false-positive" group felt that the test caused anxiety than in the "true-negative" group (65.2% vs 17.4%). Fewer women in the false-positive group than in the true-negative group said they would have MSAFP testing in a subsequent pregnancy (58.7% vs 91.3%). Further, the women in the false-positive group were less likely than those in the true-negative group to recommend MSAFP testing to a friend (52.1% vs 80.4%). In patients whose results were false-positive, there was a significant relationship between the patient's perception of understanding the MSAFP test and her attitude toward MSAFP testing.

Adult↗
PubMed1991

Intracranial astrocytoma: pathology, diagnosis and clinical presentation.

Approximately 15,000 deaths a year occur in the United States from brain tumors. Astrocytomas, the most common primary tumor of the central nervous system, develop from astrocytes, the neuroglial support cell. Normal astrocytes can undergo anaplasia for unknown reasons and form brain tumors. Astrocytomas are graded from I to IV. As normal brain tissue is displaced by tumor cells, varying signs and symptoms develop, depending on tumor site and size. The goal of surgery, radiation, chemotherapy or a combination of these treatments is to decrease tumor size and improve quality of life and survival time. This article addresses astrocyte cell development, classification of astrocytomas, theories of tumor development, signs and symptoms of astrocytoma, diagnosis and treatment of the astrocytoma. The role of the nurse is explored and two case histories are presented.

Adult↗
PubMed1991

Lyme disease.

Lyme disease, also known as Lyme borreliosis, is at present the most common arthropod-borne infectious disease in Europe and the United States. It is caused by the bacterial spirochete Borrelia burgdorferi and transmitted to the human primarily in the spring, summer and early fall by the tick Ixodes dammini or deer tick. Signs and symptoms of infection are many and misdiagnosis often occurs. If not treated with antibiotics in early stages neurological complications can occur. Health care providers must have a thorough knowledge of the disease so they are able to recognize signs and symptoms. Health care personnel are the key to education of the public and their peers regarding prevention, recognition and treatment of Lyme disease.

Education, Nursing, Continuing↗
PubMed1990

Transcatheter arterial embolization of cerebral arteriovenous malformations.

An arteriovenous malformation (AVM) is a tangled mass of arteries and veins. These abnormal dilated vessels shunt blood away from normal brain tissue, resulting in adjacent tissue damage. In the past surgical removal of an AVM was often complicated by hemorrhage. In some cases the location or size of an AVM made it unresectable. The risks of surgical removal have led to the development of alternative approaches for the treatment of AVMs, such as transcatheter arterial embolization therapy. A variety of substances can be introduced via a catheter to occlude the abnormal vessels and obliterate the AVM or to decrease size to ease surgical management. This article discusses patient selection for embolization therapy, the materials and methods used and related nursing care and patient education. A case history is presented.

Embolization, Therapeutic↗
PubMed1990

The effect of gestational age at birth on somatosensory-evoked potentials performed at term.

Multimodality-evoked potentials are widely used in newborns to assess the maturation and integrity of the sensory pathways. Reliable normative data are needed to maximize the utility of this technique as a diagnostic and research tool. Several electrophysiologic studies on the maturational changes of the auditory brain-stem response have demonstrated that latency measurements decrease as a function of increasing conceptional age. However, maturational studies of the somatosensory-evoked potential, particularly in low-risk premature infants, are limited. The existing evoked potential literature in healthy newborns proposes that maturation of the central nervous system occurs at a predictable rate, irrespective of a given gestational age at birth. Behavioral studies of premature infants suggest that neurologic development may be altered by early extrauterine exposure. The purpose of this study was to determine whether brain-stem auditory- or somatosensory-evoked potential conduction times were comparable in premature and full-term infants matched for conceptional age. The results of this study suggest that myelination is determined by conceptional age, independent of premature birth.

Brain Stem↗
PubMed1990

Linear basal cell nevus.

We report a case of linear basal cell nervus occurring on the thigh of a forty-five-year-old woman. In this lesion, the characteristic comedones were absent. Linear basal cell nevus is a rare, benign condition that must be differentiated from both basal cell nevus syndrome and linear basal cell carcinoma, either of which can be locally aggressive.

Basal Cell Nevus Syndrome↗
PubMed1989

A fatal attraction: cocaine related subarachnoid hemorrhage.

An alarming number of people use cocaine, a drug surrounded with myths and misconceptions. Cocaine use is associated with many medical and psychiatric problems. It is now believed cocaine use may lead to subarachnoid hemorrhage. Cocaine stimulates the release of various neurotransmitters in the brain as well as blocks their uptake, causing a temporary surge in systolic blood pressure. The constant assault on the vessels from continuous cocaine use weakens them causing hemorrhage or possibly creates an aneurysm. This article explains how cocaine affects the blood vessels and neurotransmitters of the brain, reviews two case histories in which cocaine may have contributed to aneurysmal formation and subarachnoid hemorrhage and discusses nursing implications of cocaine related subarachnoid hemorrhage.

Adult↗