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Biomedical subjects

S Willis

Publications and source records attributed to S Willis.

At least 73 records · Page 4Linked to original sources
PubMed1996

[Progressive pneumoperitoneum in treatment of inguinal and scar hernias. Results of animal experiments and clinical applications].

Preoperative progressive pneumoperitoneum is a well-known, but sporadically used procedure in preparing patients with giant inguinal or incisional hernias for the operation. The technique requires frequent insufflation of air into the abdominal cavity in order to create space to accommodate herniated viscera and facilitate fascial repair with minimal tension. This article demonstrates the histological findings, technique, complications, advantages and long-term results of the preoperative progressive pneumoperitoneum in hernia repair.

Abdominal Muscles↗
PubMed1996

Effects of transforming growth factor-beta 1 on nitric oxide synthesis by C2C12 skeletal myocytes.

The production of nitric oxide (NO) via the inducible form of NO synthase (iNOS) is regulated by a complex network of cytokines and endogenous hormones. Among these, transforming growth factor-beta (TGF-beta 1) is known to suppress iNOS expression and NO production by many cell types. To determine the effect of TGF-beta 1 on NO production by skeletal muscle cells, we stimulated C2C12 myocytes with interferon-gamma (IFN) and interleukin-1 (IL-1) in the presence or absence of TGF-beta 1. In contrast to findings in macrophages, TGF-beta 1 markedly enhanced NO production by skeletal muscle cells. Increases in NO production reflected significant increases in iNOS immunoreactive protein and iNOS mRNA. Elevated iNOS mRNA levels associated with TGF-beta 1 treatment were not due to an alteration in mRNA stability, but rather reflected a significantly increased transcriptional rate of the iNOS gene. These findings indicate that TGF-beta 1 enhances iNOS expression in skeletal muscle cells and suggest that the regulation of NO production by TGF-beta 1 may depend on the cell type studied.

Animals↗
PubMed1996

Small intestinal myoelectrical activity and bacterial flora after Roux-en-Y reconstruction.

Small bowel myoelectrical activity and intestinal microflora were examined after partial gastrectomy and Roux-en-Y reconstruction in six dogs. Bacteriological analysis revealed a predominance of faecal bacteria. The basal electrical rhythm of the Roux limb was significantly decreased, while the frequency of phase III was increased (P < 0.05). In the bypassed duodenum, activity fronts occurred in only 25 per cent of experiments. Food intake led to an increase in the mean(s.e.m.) motility index in the Roux limb (from 46.1(9.4) to 75.0(21.5), P < 0.05), but not in the bypassed intestine (from 27.0(3.6) to 27.8(4.1), P not significant). Stimulation of the hypomotile bypassed intestine with cisapride induced an increase in the motility index from 27.0(3.6) to 111.2(16.5) (P < 0.001).

Anastomosis, Roux-en-Y↗
PubMed1996

[Palliative therapy of inoperable malignant occlusive jaundice--stent implantation or biliodigestive anastomosis].

For therapy of malignant jaundice different methods are possible: The palliative operative bypass and the monoperative stent implantation by endoscopic or transhepatic procedure. The primary success rate of both methods is similarly high (> 90%). The rate of early complication and the lethality of the stent implantation compared to the operative procedure are lower. The rate of occlusion and incidence of later cholangitis by operative bypass are lower. Postoperative lethality is related to the ASA classification. The preoperative diagnosis of resectability by CT, NMR, angiography and diagnostic laparoscopy has a success rate of maximally 95%. The choice of therapeutic method is therefore related to the general condition of the patient (ASA, staging, duodenal stenosis, expected survival time).

Anastomosis, Surgical↗
PubMed1995

The impact of knowledge of human immunodeficiency virus serostatus on contraceptive choice and repeat pregnancy.

OBJECTIVE: To examine relationships among human immunodeficiency virus (HIV) serostatus, postpartum contraceptive choice, and the rate of repeat pregnancy within a short interval. METHODS: This retrospective cohort study was performed in 83 seropositive and 218 seronegative women identified from an inner-city prenatal population undergoing routine voluntary HIV antibody screening from July 1987 through June 1989. Postpartum contraceptive choices and rate of repeat pregnancies were compared based on HIV serostatus. RESULTS: Seropositive women were significantly more likely than seronegative women to undergo tubal sterilization (27 versus 15%; odds ratio [OR] 2.9, 95% confidence interval [CI] 1.5-5.9). This relationship persisted after controlling for age, race, marital status, and parity by logistic regression modeling (adjusted OR 2.9, 95% CI 1.4-5.9). Seropositive women were significantly less likely than seronegative women to select oral contraceptives (34 versus 68%; OR 0.2, 95% CI 0.1-0.4), a relationship that persisted after controlling for age, race, marital status, parity, and foam and condom use (adjusted OR 0.2, 95% CI 0.1-0.5). Seropositive women were significantly more likely than seronegative women to select foam and condoms as their primary method of contraception (30 versus 15%; OR 2.4, 95% CI 1.2-4.5), a relationship that did not persist after controlling for age, race, marital status, and parity (adjusted OR 0.7, 95% CI 0.4-1.3). The risk of repeat pregnancy was slightly lower in seropositive versus seronegative women (34 versus 44%; OR 0.7, 95% CI 0.4-1.3). Most repeat pregnancies among seropositive and seronegative women were unplanned (90 and 82%, respectively). CONCLUSION: There was a relationship between the method of postpartum contraception and HIV serostatus, but no significant difference in repeat pregnancy rates associated with choice of method.

Adolescent↗
PubMed1994

Teaching health promotion: motivating students through collaboration.

The collaborative model provided a number of benefits. Personalizing general health risks enabled the students to translate health promotion knowledge to individuals and groups in the community. The presence of the community health nurse permitted confidential dialogue with students regarding their personal appraisals. In the clinical setting the community health nurse served as a role model and demonstrated use of the tool among a variety of groups. Nurses are expected to identify populations at risk for various health problems and to promote healthful outcomes. This model was useful in assisting students to apply and synthesize health promotion concepts in an active and creative manner. Collaboration with an effective nurse role model was critical to the project.

Alabama↗
PubMed1994

Double blind placebo controlled study on the effect of the nitric oxide donor molsidomin and the 5-HT3 antagonist ondansetron on human esophageal motility.

The aim of the present study was to investigate the effects of acute administration of the NO-donor molsidomin (2 mg) and the 5-HT3 antagonist ondansetron (8 mg) on esophageal motility and lower esophageal sphincter pressure (LESP) in 10 healthy volunteers by stationary side hole manometry in a double-blind placebo controlled study design. LESP, contraction amplitudes (5, 10, 15 cm above the LES) and propagation velocity (10-15 cm above the LES) for dry and wet swallows were analysed and additional blood samples were taken for determination of plasma levels of VIP and gastrin. Molsidomin significantly decreased basal LESP from 16.8 +/- 1.6 mmHg to 11.4 +/- 1.0 mmHg, while ondansetron had no influence. Molsidomin also reduced contraction amplitudes of dry swallows (saline 61.9 +/- 7.2 mmHg, molsidomin 40.1 +/- 8.1 mmHg), while it did not influence contraction amplitudes of wet swallows. Ondansetron had no effect on contraction amplitudes. Both substances did not influence propagation velocity of wet swallows, while they reduced propagation velocity of dry swallows significantly (saline 3.9 +/- 0.4 cmls, ondansetron 3.1 +/- 0.2 cm/s, molsidomin 3.1 +/- 0.2 cmls). There were no effects on plasma levels of gastrin or VIP. These data strongly suggest a possible therapeutic role of molsidomin in the treatment of esophageal motility disorders. Effects of ondansetron have to be further evaluated in patients with disturbed esophageal motility.

Adult↗
PubMed1993

The risk of sexually transmitted diseases in human immunodeficiency virus-infected parturients.

OBJECTIVE: We assessed the prevalence of and defined the relationship between other sexually transmitted diseases and human immunodeficiency virus infection. STUDY DESIGN: We performed a case-control study among 121 human immunodeficiency virus-infected and 222 randomly selected seronegative parturient women. These women were identified from a prenatal population undergoing routine voluntary antibody screening in a large urban hospital in the southeastern United States. RESULTS: During the 24-month study period, 16,868 women consented to human immunodeficiency virus antibody screening; 121 (7.2/1000) were infected with human immunodeficiency virus. Cases were significantly more likely than controls to be infected with at least one sexually transmitted disease during pregnancy (48% vs 21%; odds ratio 3.4, 95% confidence interval 2.1 to 5.7). The prevalence of Chlamydia trachomatis and hepatitis B infection did not differ significantly among the groups. Cases were significantly more likely than controls to be infected with Treponema pallidum (29% vs 4%; odds ratio 9.6, 95% confidence interval 4.2 to 22.4). This relationship persisted after we controlled for confounding risk factors (odds ratio 9.2, 95% confidence interval 2.1 to 13.3). In addition, cases were significantly more likely than controls to be infected with Neisseria gonorrhoeae (17.2% vs 4%; odds ratio 5.2, 95% confidence interval 2.1 to 13.3). This relationship also persisted after we controlled for confounders (odds ratio 3.7, 95% confidence interval 1.4 to 10.0). CONCLUSION: Human immunodeficiency virus-infected parturient women in our center are at substantial risk of having other sexually transmitted diseases.

Adult↗
PubMed1993

Differential effects of selective neurokinin agonists on phasic and tonic activity in rat ileal longitudinal muscle.

To test the hypothesis that different neurokinin receptors might be involved in the generation of either phasic or tonic muscular activity, selective ligands for the 6 neurokinin-1-receptor, [Sar9, Met(O2)]-SP, the neurokinin-2-receptor, [Nle10]-NKA4-10, and the neurokinin-3 receptor, [beta Asp4,MePhe7]-NKB4-10, were used to evaluate the excitatory effects of these agonists in the longitudinal rat ileal muscle in vitro. The excitatory effect was analyzed as total response (area under the curve) and as tonic or phasic (area under or within the peaks) activity. Substance P (SP, relative amount of phasic activity in comparison to total activity: 3 x 10(-8) M 87%, 3 x 10(-6) M 30%) and the neurokinin-2-receptor selective agonist [Nle10]-NKA4-10 (N-NKA: 3 x 10(-8) M 67%, 3 x 10(-6) M 59%) caused both tonic and phasic responses, with the percentage of phasic responses decreasing at higher concentrations. The neurokinin-1-receptor selective agonist [beta Ala4, Sar9, Met(O2)]-SP4-11 caused a predominantly tonic response with only a small phasic component (10(-8) M 27.1% 10(-6) M 13.8%). The selective neurokinin-3 receptor agonist [beta Asp4, MePhe7]-NKB4-10 caused a predominantly phasic motor response (SM-SP: 3 x 10(-8) M 98%, 3 x 10(-6) M 87%). Tetrodotoxin (TTX 10(-6) M), omega-conotoxin (CTX 10(-7) M) and atropine (10(-6) M) had no significant influence on the contractile responses to all four peptides, indicating a direct action on the smooth muscle cell.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Human immunodeficiency virus infection among inner-city adolescent parturients undergoing routine voluntary screening, July 1987 to March 1991.

OBJECTIVE: The objective of our study was to describe the human immunodeficiency virus epidemic among pregnant adolescents undergoing follow-up in a large inner-city hospital. STUDY DESIGN: We conducted a case-control study comparing demographic and risk behaviors of seropositive and seronegative adolescents (aged 13 to 20) identified from a population undergoing routine voluntary antibody screening at Grady Memorial Hospital in Atlanta, Georgia, between July 1987 and March 1991. RESULTS: Of 10,794 pregnant adolescents screened, 51 (4.7/1000) were infected with human immunodeficiency virus. More than one fourth of case patients were < or = 17 years old. Significantly more case patients than controls reported a history of crack cocaine use (10 [19.6%] vs 23 [8.2%] p < 0.05). A majority (58.8%) of case patients reported no risk factors for infection, and the remainder (41.2%) were presumably infected by heterosexual contact. Thirty-nine controls (13.8%) had self-identified risk factors for infection. CONCLUSIONS: Pregnant adolescents in our center are at risk for human immunodeficiency virus infection and should be targeted for human immunodeficiency virus education and risk reduction counseling.

Adolescent↗
PubMed1992

Crack cocaine: a risk factor for human immunodeficiency virus infection type 1 among inner-city parturients.

OBJECTIVE: To define the relationship between crack cocaine use and human immunodeficiency virus (HIV) infection while controlling for other HIV risk factors. METHODS: We performed a case-control study among inner-city pregnant women who were followed at a large urban hospital in Atlanta, Georgia; 79 of the women were HIV-1-infected and 525 were seronegative. We identified the women from a prenatal population undergoing routine voluntary HIV-1 antibody screening. RESULTS: From July 1, 1989 to December 31, 1990, we screened 13,469 pregnant women; 80 (5.9 per 1000) were HIV-1-infected. One seropositive woman who did not complete a risk-behavior questionnaire was excluded from the study. Seropositivity was associated with a history of crack cocaine use (odds ratio 2.3, 95% confidence interval [CI] 1.1-4.8), intravenous drug use (odds ratio 14.5, 95% CI 4.5-46.3), and a history of sexually transmitted diseases (odds ratio 2.6, 95% CI 1.5-4.5). We found a significant interaction (P = .01) between a history of crack cocaine use and employment status: Unemployed women who used crack cocaine were 3.5 times more likely to be HIV-1-infected than were employed women who used crack cocaine. CONCLUSIONS: Crack cocaine use was found to be a risk factor associated with HIV-1 infection among pregnant women, particularly those who were unemployed. This finding suggests that the impact of crack cocaine use on HIV transmission may be related to economic factors and possibly to either trading sex for money to buy cocaine or trading sex for the drug.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Nursing perspectives in the management of infants and children requiring thoracic surgery.

Nurses who care for infants and children undergoing thoracic surgery must function and make decisions which take into account a multiplicity of complex data. This necessitates a background of knowledge, skill and intuition which guides their nursing practice. The principles of holistic care in which the total needs of the infant and child are met within the context of the family are seen as an important approach to patient care. Selected perspectives in the care of infants with congenital and acquired thoracic anomalies are discussed, in particular infants with congenital diaphragmatic hernia and oesophageal atresia. The preparation of children for chest surgery and the postoperative nursing management are outlined and include aspects of pain management, physiotherapy and chest drain care.

Chest Tubes↗
PubMed1991

Incidence and prevalence of human immunodeficiency virus infection in a prenatal population undergoing routine voluntary human immunodeficiency virus screening, July 1987 to June 1990.

To characterize the epidemiologic characteristics of human immunodeficiency virus type 1 infection in an urban prenatal population in the southeastern United States, we conducted serial routine voluntary antenatal human immunodeficiency virus antibody testing and obtained self-reported human immunodeficiency virus risk behavior profiles on women registering for prenatal care. From July 1987 to June 1990, 23,432 women registered for prenatal care. The majority of women (95%) consented to human immunodeficiency virus antibody testing and completed risk behavior profiles. The cumulative incidence of human immunodeficiency virus infection increased from 3.5 per 1000 in 1987 and 1988 to 5.3 per 1000 in 1989 and 1990. A history of "crack" cocaine use emerged as a significant risk factor for infection (p less than 0.01). The majority (70%) of human immunodeficiency virus-infected women did not self-acknowledge risk factors for infection and would not have been identified if screening had been targeted. The increasing incidence of human immunodeficiency virus type 1 infection in our prenatal population reinforces the need for our continued routine voluntary antenatal human immunodeficiency virus screening and risk behavior assessment.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Modulatory effect of insulin on rat small intestinal motility and peptide release in vitro.

Intact segments of rat ileum were stimulated in vitro by either electrical field stimulation (EFS) or cholinergic stimulation with carbachol, in the presence of absence of varying insulin concentrations (50, 100 and 200 microU/ml), and the contraction in the longitudinal axis was recorded. Insulin had no significant influence on the carbachol contractile dose-response curve nor did it affect the cholinergically mediated 'on-contraction' at onset of the electrical stimulus. The 'off-contraction' occurring at cessation of the electrical stimulus was partly mediated by a cholinergic and partly by a noncholinergic and nonadrenergic mechanism, and decreased over time with repeated stimulation. This decay with time was significantly attenuated by insulin. In the presence of insulin, release of bombesin-like immunoreactivity induced by carbachol or EFS significantly increased. On the other hand, the release of somatostatin-like immunoreactivity was suppressed by 50-70% in the presence of insulin. These results demonstrate that in vitro insulin can modify both the motility responses of isolated segments of rat ileum and the neuropeptide release from such segments.

Animals↗
PubMed1991

Routine human immunodeficiency virus infection screening in unregistered and registered inner-city parturients.

Women who receive little or no prenatal care are at increased risk of adverse pregnancy outcome. Although many of these women are disadvantaged and presumably at increased risk for human immunodeficiency virus (HIV) infection, few data are available to describe risk behaviors and infection prevalence in this population. To better characterize HIV infection in unregistered inner-city parturients in Atlanta, we offered routine voluntary screening for HIV antibody and requested HIV risk-behavior profiles on all unregistered and registered parturients seen at Grady Memorial Hospital from July 1, 1987 to June 30, 1988. Of the 834 unregistered and 7356 registered parturients screened, significantly more unregistered parturients were seropositive on enzyme-linked immunosorbent assay and Western blot testing, 12 (1.4%) versus 26 (0.4%) (odds ratio 4.06; 95% confidence interval 1.93-8.43). Five unregistered and 15 registered parturients were seropositive by repeat enzyme-linked immunosorbent assay testing but were Western blot-negative. Significantly more unregistered parturients reported both a history of intravenous drug use, 4.4 versus 1.5% (odds ratio 3.09; 95% confidence interval 2.10-4.54), and crack cocaine use, 3 versus 0.8% (odds ratio 3.96; 95% confidence interval 2.42-6.44). Significantly more unregistered parturients acknowledged risk factors for HIV infection, 14.3 versus 9.9% (odds ratio 1.46; 95% confidence interval 1.19-1.80). Nearly all registered and 86% of unregistered parturients consented to HIV testing. Nearly all parturients completed HIV risk-behavior questionnaires. These data suggest that unregistered inner-city parturients in Atlanta are at greater risk of being HIV-infected and are more likely to report risk behaviors for infection.

Adolescent↗
PubMed1990

Acute urinary retention in a child with appendiceal abscess: diagnostic dilemma.

Rarely do children with appendiceal abscess present with acute urinary retention as the only sign or symptom. This presentation may delay diagnosis and definitive therapy, thereby causing additional morbidity and possible mortality. We report the eighth case of acute urinary retention in a child associated with an appendiceal abscess.

Abscess↗
PubMed1990

Routine human immunodeficiency virus infection screening of women requesting induced first-trimester abortion in an inner-city population.

Infection with the human immunodeficiency virus (HIV) among reproductive-age women occurs disproportionately among inner-city minority populations. These women are at risk because of intravenous drug abuse and heterosexual transmission from partners infected through drug abuse. From July 1, 1988 to December 31, 1988, we conducted routine voluntary screening for HIV antibody among 923 women who requested induced first-trimester abortion at Grady Memorial Hospital. Eight (8.7 per 1000) women were seropositive on repeat enzyme-linked immunosorbent assay and Western blot testing. Two infected women had had heterosexual contact with a person at risk for HIV infection, two others reported "crack" cocaine use, and four acknowledged no risk factors. Thirteen percent of seronegative women reported risk factors for HIV infection. Nearly all women consented to HIV testing, and most completed the risk-behavior questionnaire. These data suggest that women seeking first-trimester abortion at our hospital are at risk for HIV infection.

Abortion Applicants↗