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Biomedical subjects

S W Davis

Publications and source records attributed to S W Davis.

At least 19 recordsLinked to original sources
PubMed2001

A randomized trial of a brief intervention to increase fruit and vegetable intake: a replication study among callers to the CIS.

BACKGROUND: Results are reported from a large randomized trial designed to increase fruit and vegetable consumption among callers to the National Cancer Institute's Cancer Information Service (CIS) (n = 1,717). METHODS: CIS callers assigned to the intervention group (n = 861) received a brief proactive educational intervention over the telephone at the end of usual service, with two follow-up mailouts. Key educational messages and print material derived from the NCI 5 A Day for Better Health program were provided to intervention participants. Participants were interviewed by telephone at 4 weeks (n = 1,307), 4 months (n = 1,180), and 12 months for follow-up (n = 1,016). RESULTS: Results obtained from a single-item measure of fruit and vegetable consumption indicate a significant intervention effect of 0.88 servings per day at 4 weeks follow-up (P < 0.001), 0.63 servings per day at 4 months follow-up (P < 0.001), and 0.43 servings per day at 12 months follow-up (P < 0.001). Using a 7-item food frequency measure, an intervention effect of 0.63 servings per day was obtained at 4 weeks follow-up (P < 0.001), compared with 0.39 servings per day at 4 months follow-up (P = 0.002) and 0.44 servings per day at 12 months follow-up (P = 0.002). A 24-h recall assessment included in the 4-month interviews also yielded a significant intervention effect of 0.67 servings per day (P = 0.015). The vast majority of callers (90%) endorsed the strategy of providing 5 A Day information proactively within the CIS. CONCLUSIONS: This brief educational intervention was associated with higher levels of self-reported fruit and vegetable intake at both short- and long-term follow-up. Additional research is recommended to test this or a similar intervention in diverse populations.

Adult↗
PubMed1999

Isolation of developmental mutants of the ascidian Ciona savignyi.

Ascidians have been used extensively as model animals for experimental embryology. We report here the results of a pilot study with the aim of developing genetic methods for the ascidian Ciona savignyi. The chemical mutagen N-ethyl-N-nitrosourea (ENU) was used to induce point mutations. F1 animals, produced by using sperm from ENU-treated animals to fertilize untreated eggs, were grown to reproductive age. Sperm and eggs collected from the hermaphrodite F1 adults were used to generate self-fertilized F2 broods, which were then screened for recessive, zygotically acting mutations. Animals carrying potential mutations were outcrossed to wild type to test for the heritability of the phenotypes. We report on a number of mutants isolated using this method, including several with abnormalities in tail and notochord development.

Animals↗
PubMed1998

Building effective partnerships: a national evaluation of the Cancer Information Service outreach program. Part 2.

The Cancer Information Service's (CIS) nationally coordinated, regionally focused outreach program establishes partnerships with government, nonprofit, and private organizations to reach underserved and minority populations. A national random sample telephone survey, conducted with 867 partner organizations who had contact with the CIS in early 1996, assessed the types of CIS assistance used, satisfaction with and usefulness of these services, organizational characteristics, and the overall impact on partners' cancer-related programs. CIS partners provide programs for the medically underserved (79%) and specific racial and ethnic groups (72%) and address a range of cancer control issues. Partners use and highly value an array of CIS assistance. Over 90% are satisfied with the CIS services. Diffusion of accurate and science-based information, materials and resources is a key element of the outreach assistance. Two out of three partners are receiving late-breaking news and scientific information from the CIS and 86% are disseminating it to their constituents. The majority of those partners surveyed reported that they rely on the CIS to assist with their most important cancer programs. Sixty-eight percent of the partners rated the CIS assistance as important or very important to their cancer-related programs. These survey results indicate that the CIS outreach program provides key support to partners' cancer programs and has an impact on their efforts. The results support the effectiveness of a regionally based outreach program working in partnership with existing organizations at the state, county, and local level who are addressing the needs of underserved populations.

Community-Institutional Relations↗
PubMed1998

Treatment and clinical trials decisionmaking: the impact of the Cancer Information Service. Part 5.

The Cancer Information Service (CIS) provides accurate, up-to-date information to cancer patients, their families, the general public, and health professionals. In 1996, the CIS telephone service received 208,971 calls from people with questions about cancer treatments and clinical trials (total calls = 500,000). Cancer information specialists are trained and certified to access the PDQ database of treatment options and clinical trials, to translate medical information into understandable terms in order to help callers make treatment decisions, and to discuss clinical trials proactively. A telephone service user survey was conducted to assess the satisfaction and impact of the assistance and information provided to CIS callers. Almost half of the callers (46% of those calling for treatment information, 50% calling for clinical trial information) discussed the CIS information with a physician. Over half (55% treatment, 54% clinical trial) said the information helped them make a treatment decision. Twenty-four percent of treatment and 64% of clinical trial callers had enrolled in or had considered a clinical trial. Almost all (95%) were satisfied with information received from the CIS. The authors find that the CIS is fulfilling its role in disseminating information on cancer treatment and clinical trials through its telephone service. The CIS proactively educates treatment callers about clinical trials. However, the CIS needs to apply other strategies to reach medically underserved populations. Although most callers were able to understand the information, clinical trial callers found the information more difficult than did treatment callers. The CIS is working to simplify written clinical trial information.

Adolescent↗
PubMed1998

Promoting cancer prevention and screening: the impact of the Cancer Information Service. Part 7.

Cancer Information Service (CIS) inquiries about cancer prevention and screening are an important opportunity to educate callers about primary or secondary cancer prevention, facilitate their decision-making, and, where appropriate, encourage action. An evaluation was conducted to assess whether these callers' information needs are being satisfied and to determine if the information provided facilitates decisionmaking and subsequent risk reduction actions. A random sample of 2,489 callers was surveyed during a 5-week period, 3 to 6 weeks after their initial call to CIS; prevention or screening was stated as the main reason for calling by 331 respondents. A series of questions was asked regarding level of satisfaction with CIS's performance and how helpful the information provided was in terms of feeling more knowledgeable, making decisions, and taking action. The vast majority of respondents were satisfied with the information received, found it to be helpful, felt more knowledgeable as a result, and would call CIS again with subsequent questions. Although demand characteristics are a possible source of bias, nearly three-quarters of the respondents reported subsequently discussing the information provided with someone else, and almost half sought additional information recommended by CIS. Nearly two-thirds of primary prevention respondents and about half of secondary prevention respondents indicated that they had taken some risk-reducing action subsequent to their interaction with CIS. The CIS is effectively satisfying the information needs of prevention and screening callers; information it is providing is effectively facilitating decisionmaking and stimulating callers to take action.

Adolescent↗
PubMed1996

P2u purinoceptor regulation of mucin secretion in SPOC1 cells, a goblet cell line from the airways.

The SPOC1 cell, a novel goblet cell line derived from rat trachea, was tested for its ability to exhibit regulated mucin secretion in response to purinergic (P2) agonists. High-molecular mass glycoconjugates (HMMGs) purified by CsCl-density-gradient centrifugation had a buoyant density of 1.45 g/ml. The purified HMMG material exhibited a single major band with an apparent molecular mass of greater than 1000 kDa in SDS/ polyacrylamide gels stained with silver or blotted and stained with soya-bean agglutinin. [3H]HMMG was resistant to proteoglycan-degrading enzymes, but was susceptible to neuraminidase. The HMMG was approx. 91% carbohydrate by weight, and the glycosides were O-linked. The HMMG amino acid composition was enriched in Ser and Thr (sum 27%). Thus SPOC1-cell HMMG possess the characteristics of mucin. Mucin secretion by SPOC1 cells, grown on permeable supports and perfused luminally, was stimulated by ATP, UTP and adenosine 5'-[gamma-thio]triphosphate (100 microM) 4-5-fold over a baseline of 4 ng/min. The three dose-effect relations were nearly identical (K0.5 approximately 4 microM). SPOC1 cells grown on plastic and rat tracheal epithelial primary cells responded similarly to ATP and/or UTP. SPOC1 cells failed to respond to other purinergic agonists, either luminally or serosally, and consequently seem to possess an apical membrane P2u purinoceptor. SPOC1-cell total RNA was probed for P2u purinoceptor mRNA. Using conserved primers for both reverse transcriptase and PCR, a single band of the predicted size was observed, which had a nucleotide base sequence identical with the rat P2u purinoceptor mRNA. Thus SPOC1 cells secrete mucin under the control of a P2u purinoceptor; they should prove useful in dissecting the associated cellular regulatory pathways.

Adenosine Triphosphate↗
PubMed1996

Selective kallikrein-kinin system activation in inbred rats differentially susceptible to granulomatous enterocolitis.

BACKGROUND & AIMS: Crohn's disease is characterized by unrestrained inflammation with a genetic component. Genetic susceptibility and activation of the kalli-krein-kinin (contact) system were investigated in experimental enterocolitis and extraintestinal inflammation induced by bacterial polymers. METHODS: Kinetics of inflammation in inbred Lewis and Buffalo rats injected subserosally with peptidoglycan-polysaccharide polymers were correlated with in vivo and in vitro activation of the contact system. RESULTS: Lewis rats had a biphasic course of enterocolitis. Acute inflammation peaked 1 day after injection, gradually decreasing until day 14 when intestinal inflammation spontaneously reactivated and persisted for 16 weeks, accompanied by arthritis, granulomatous hepatitis, anemia, and leukocytosis. Self-limited acute enterocolitis in Buffalo rats resolved by 24 days without extraintestinal involvement. Consumption of the precursor proteins prekalli-krein and high-molecular-weight kininogen indicated activation of the plasma contact system in Lewis rats and closely correlated with chronic intestinal inflammation. Contact system activation did not occur in Buffalo rats, even during acute inflammation. In vitro studies showed a decreased rate of kininogen cleavage in Buffalo plasma. CONCLUSIONS: Selective in vivo and in vitro activation of the contact system in susceptible Lewis rats suggests that this pathway is one determinant of genetic susceptibility to granulomatous enterocolitis and systemic complications.

Acute-Phase Proteins↗
PubMed1995

Morbidity, mortality, and charges for hospital care of the elderly: a comparison of internists' and family physicians' admissions.

BACKGROUND: In an atmosphere of cost containment, an important question is whether there are differences in quality or cost of medical care provided by physicians with different specialty training. METHODS: This study is an analysis of Pennsylvania hospital admissions from the 1989 MedisGroups Comparative Database, consisting of 31,321 hospital admissions by internists and family physicians. It encompasses the top 10 admission diagnostic-related groups in patients 65 years and older. Outcome measures of morbidity, mortality, length of stay, and hospital charges were compared between patients of internists and family physicians while controlling for patient variables, such as age, sex, Medicaid insurance payment, admission from nursing home, and admission severity scores, and hospital characteristics, such as number of beds, teaching status, and available technologies and procedures. RESULTS: Admission diagnoses were similar for patients of family physicians and internists. After adjusting for relevant patient and hospital characteristics, there were no differences in mortality or hospital charges; however, the patients of internists experienced slightly higher morbidity (odds ratio = 1.07, 95% confidence interval, 1.017 to 1.123) and longer mean length of stay (10.80 vs 10.54 days, P < .05). The mean age of patients and the proportion of Medicaid patients was similar in the two specialty groups. Family physicians' patients were more likely to be female (60% vs 57%, P < .01), were less likely to be admitted from nursing homes (4% vs 5%, P < .01), and had a lower mean admission severity score (1.940 vs 1.964 on a scale of 0 [least seriously ill] to 4 [most seriously ill], P < .01). Internists were more likely to work in teaching hospitals and hospitals with sophisticated technology (P < .01). CONCLUSIONS: It makes little difference in medical outcomes or hospital charges whether family physicians or internists manage the hospital care of elderly patients for common medical problems. Previously documented lower costs of care by family physicians may be due to outpatient rather than inpatient care.

Aged↗
PubMed1995

Mediation of immunity to Toxoplasma gondii oocyst shedding in cats.

Immunity to Toxoplasma gondii, as measured by oocyst shedding, was studied in cats. In 3 trials, 12 3-mo-old T. gondii-free cats were fed tissue cysts of the ME-49 strain of T. gondii. All cats shed T. gondii oocysts for approximately 1 wk starting 3-5 days after ingesting tissue cysts. One cat became ill because of toxoplasmic pneumonia and was killed 17 days after inoculation. The remaining cats remained clinically normal. Approximately 3 mo after primary infection, these 11 cats (immune) and 11 age-matched or littermate uninfected cats (nonimmune) were challenged orally with tissue cysts of the ME-49 strain. In trials 1 and 3, 1 immune and 1 nonimmune cat were killed at 36 hr, 60 hr, 5 days, and 12 days after challenge and the development of T. gondii in intestines was studied histologically; in trial 2, cats were killed at 36 hr, 60 hr, and 5 days only. None of the "immune" cats shed oocysts after challenge. Asexual T. gondii types were found at 36 and 60 hr and at 5 days, indicating partial development of T. gondii in the intestine of immune cats. There were no significant differences in lymphocyte CD4+/CD8+ from spleen, popliteal, and mesenteric lymph nodes of immune cats compared to nonimmune cats.

Animals↗
PubMed1995

Flow-sensitive magnetic resonance imaging in the evaluation of cerebrospinal fluid leaks.

Cerebrospinal fluid (CSF) leaks involving the skull base are associated with considerable morbidity and mortality, and often present a diagnostic challenge. Current diagnostic methods are invasive and cumbersome and involve substantial radiation exposure of the patient. The authors identified seven patients with clinically suspected CSF leaks and evaluated them with a flow-sensitive magnetic resonance imaging (MRI) sequence in addition to more conventional studies. In cases with active CSF leakage, flow characteristics were documented with slow-flow and diffusion-weighted MRI. Unlike current approaches, MRI offers the advantages of rapidity, non-invasiveness, and absence of ionizing radiation. Preliminary results suggest that flow-sensitive MRI may have a role in the evaluation of CSF leaks involving the skull base and temporal bone.

Adult↗
PubMed1994

Ectopic gastric mucosa in the upper esophagus: detection and radiographic findings.

PURPOSE: To detect and characterize the appearance of islands of ectopic gastric mucosa in the upper esophagus at routine examination of the upper gastrointestinal (GI) tract. MATERIALS AND METHODS: Well-distended upper esophagus was documented with spot radiographs obtained with routine double-contrast examination performed after administration of high-density barium in nine patients. Detected lesions were confirmed by means of endoscopy and biopsy. RESULTS: Twelve lesions were detected. Radiographic findings were characterized by either a discrete, shallow depression surrounded by a subtle, rimlike elevation on double-contrast images or by a pair of small indentations on the same wall on full-column, single-contrast images at the level of the thoracic inlet. Endoscopic examination revealed well-circumscribed areas of reddish mucosa located 15-26 cm from the incisors. CONCLUSION: Ectopic gastric mucosa in the upper esophagus is easily demonstrated at routine examination of the upper GI tract. Diagnosis can be based on location and characteristic radiographic appearance.

Adult↗
PubMed1994

Persistence of immunity to toxoplasmosis in pigs vaccinated with a nonpersistent strain of Toxoplasma gondii.

Persistence of the vaccine RH strain of Toxoplasma gondii was studied by bioassay and histologically in 14 pigs. Pigs were euthanatized 2, 4, 7, 8, 14, 15, 21, 29, 36, 42, 52, 57, and 76 days after IM inoculation with 100,000 T gondii tachyzoites. Viable T gondii tachyzoites derived from the RH strain were isolated by bioassay in mice inoculated with tissues of pigs euthanatized up to 14 days after vaccination. Except for fever, pigs vaccinated IM with the RH strain remained clinically normal. Two other pigs inoculated IV with 100,000 T gondii tachyzoites of the RH strain became ill, and 1 pig was comatose by 4 days after inoculation. These findings indicate that route of inoculation may influence the response of pigs to T gondii. To evaluate protective immunity in pigs vaccinated with the RH strain, 16 age-matched pigs were allotted to 4 groups (A-D) of 4 pigs each. Eight pigs (groups A and C) were vaccinated IM with 100,000 RH strain tachyzoites and 8 pigs (groups B and D) were nonvaccinated controls. Pigs of groups A and C were challenge-inoculated orally with a lethal dose of T gondii oocysts (100,000 oocysts) 81 days after vaccination, pigs of groups B and D were inoculated similarly 220 days after vaccination. The concentration of T gondii at 3 days after challenge inoculation of pigs vaccinated 81 days earlier was reduced 100,000-fold in mesenteric lymph nodes, compared with that in a nonvaccinated pig euthanatized at 3 days after challenge inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Absence of sex differences in the evaluation of patients hospitalized for transient ischemic attacks.

BACKGROUND: Sex has been shown to affect the extent of evaluation and treatment of patients with coronary artery disease. This study investigates potential differences in the evaluation of hospitalized men and women with transient ischemic attacks to determine whether a similar bias exists. METHODS: The 1989 MedisGroups comparative database was used to analyze a convenience sample consisting of all family and internal medicine patients with the primary admission diagnosis-related group (DRG) of "transient ischemic attack." RESULTS: Women comprised 1933 of the 3165 admissions. The mean age for women was 1.88 years older than for men (P < .01). Women were three times more likely to reside in a nursing home before admission (P < .01), but had a lower prevalence of dementia (P < .05). The 1232 men had a higher severity of illness score at admission (P < .05), and were 5.3% more likely to be admitted to a teaching hospital than women (P < .01). Men were also more likely than women to be admitted to large hospitals (P < .01). There were no differences between sexes in the use of cranial computed tomography, carotid or cardiac Doppler, or carotid arteriography. Adjusted means for hospital charges, morbidity, and mortality did not differ between sexes, but length of stay was longer by 1.5 days for women compared with men (P < .01). CONCLUSIONS: In-hospital evaluation of elderly patients with transient ischemic attacks did not differ significantly between men and women. This finding does not exclude the possibility of a difference in workup for men as compared with women in the ambulatory management of this condition.

Aged↗
PubMed1993

Sacral meningeal cysts: evaluation with MR imaging.

It is often difficult for the radiologist to determine if a given sacral meningeal cyst is causing symptoms. Radiographic criteria for identifying cysts likely to be symptomatic are needed. Using conventional magnetic resonance (MR) imaging along with a specifically designed flow-sensitive sequence, the authors characterized 24 cysts (19 patients) with respect to diameter and communication with the subarachnoid space. They found no significant difference in size between symptomatic and asymptomatic cysts (P > .05) but did observe a clear-cut disparity in the context of communication: Five of five asymptomatic cysts were shown to communicate on MR flow studies, while seven of seven symptomatic cysts were not shown to communicate. The authors propose that flow-sensitive MR imaging is useful in differentiating communicating from noncommunicating sacral meningeal cysts and that this information may be of value in classifying these lesions as more or less likely to be symptomatic.

Adult↗
PubMed1993

Equine protozoal myeloencephalitis: antigen analysis of cultured Sarcocystis neurona merozoites.

Antigens of cultured Sarcocystis neurona merozoites were examined using immunoblot analysis. Blotted proteins were probed with S. cruzi, S. muris, and S. neurona antisera produced in rabbits, S. fayeri (pre- and post-infection) and S. neurona (pre- and post-inoculation) sera produced in horses, immune sera from 7 histologically confirmed cases of equine protozoal myeloencephalitis (EPM), and pre-suckle serum from a newborn foal. Eight proteins, 70, 24, 23.5, 22.5, 13, 11, 10.5, and 10 Kd, were detected only by S. neurona antiserum and/or immune serum from EPM-affected horses. Equine sera were titered by the indirect immunofluorescent antibody (IFA) method using air-dried, cultured S. neurona merozoites. Anti-Sarcocystis IFA titers were found in horses with or without EPM. Serum titers did not correspond to the number of specific bands recognized on immunoblots.

Animals↗