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Biomedical subjects

L L Scott

Publications and source records attributed to L L Scott.

At least 19 recordsLinked to original sources
PubMed2005

Eradicating Listeria monocytogenes from fully cooked franks by using an integrated pasteurization-packaging system.

Surface pasteurization by applying steam or hot water before or after packaging of processed foods may be used to eliminate pathogens such as Listeria monocytogenes from ready-to-eat meat and poultry products. Surface pasteurization treatment with a mixture of pressurized steam and hot water was integrated into a continuous vacuum-packaging system to reduce L. monocytogenes from fully cooked franks. The franks (2.54 cm diameter by 15.24 cm length) were surface inoculated to contain up to 6 log CFU/cm2 L. monocytogenes. The inoculated franks were treated at 121 degrees C for 1.5 s in an arrangement of six franks per packaging chamber followed by immediate vacuum sealing of the top films of food packages in the same unit. A 3-log CFU/cm2 reduction of L. monocytogenes on fully cooked franks was obtained using the integrated pasteurization-packaging system. The pasteurization depth was 1.27 mm below the surfaces of the franks. This process provides a commercially applicable means of ensuring food safety by effectively eradicating L. monocytogenes from ready-to-eat meat and poultry products at the very last possible step of food packaging before reaching retail consumers.

Animals↗
PubMed2003

Physical properties of cream reformulated with fractionated milk fat and milk-derived components.

Emulsifying properties of milk-derived components influence the physical characteristics of reformulated creams. Fractionated butter oils with different melting ranges (low-melt: 10 to 25 degrees C; medium-melt: 25 to 35 degrees C) were recombined into fluid dairy systems using skim milk, or sweet buttermilk and butter-derived aqueous phase to manufacture 20% milk fat creams. Separation temperature (49 degrees C or 55 degrees C) in obtaining emulsifying components was examined for its effect on physical properties of pasteurized reformulated creams. Rate of creaming, viscosity, feathering, and sensory characteristics of reformulated and natural creams stored at 3.3 degrees C were evaluated over a 13-d period. Creaming rate of reformulated and natural creams was unaffected by formulation and was most influenced by duration of storage. Melting characteristics of butter oils influenced viscosity at some shear rates. With the exception of natural cream, all formulations were consistent in apparent viscosity during the 2-wk storage period. All creams feathered in a pH range of 4.70 to 5.20 and were classified as moderately stable to slightly unstable. All reformulated and natural creams met sensory quality specifications with the exception of creams formulated with skim milk and lower melting range butteroil. Creams formulated with buttermilk, butter-derived aqueous phase, and lower-melting range butter oil most closely mimicked natural creams with regard to sensory quality and viscosity.

Animals↗
PubMed2002

Acyclovir suppression to prevent recurrent genital herpes at delivery.

OBJECTIVE: To determine if suppressive acyclovir near term decreased the frequency of clinical recurrences at delivery in women with recurrent genital herpes simplex virus (HSV) infection. METHODS: We conducted a prospective, double-blind, randomized trial in 234 women with recurrent genital herpes. Women with genital infection of any frequency were enrolled. Patients received either suppressive oral acyclovir 400 mg three times daily or an identical placebo after 36 weeks' gestation. Clinical lesions were identified, and HSV cultures were obtained at delivery. The frequencies of clinical and subclinical HSV recurrences at delivery were evaluated. RESULTS: Six percent of patients treated with acyclovir, and 14% of patients treated with placebo had clinical HSV at delivery (p = 0.046). No patients in the acyclovir group had positive HSV cultures, compared with 6% of placebo-treated patients (p = 0.029). There was no significant difference in subclinical HSV shedding in the acyclovir group (0%) compared with the placebo-treated group (3%) (p = 0.102). CONCLUSIONS: Suppressive acyclovir therapy significantly decreased the incidence of clinical genital herpes and the overall incidence of HSV excretion at delivery in patients with previous herpes infection.

Acyclovir↗
PubMed2001

Relationship issues of women with breast cancer.

This in-depth, qualitative pilot study explored the impact of breast cancer on specific dimensions of the relationships and roles of women. It included interaction within the partner relationship as well as with family, friends, and colleagues. Data were obtained by individual and group interviews from 10 women with a diagnosis of breast cancer and 5 male partners. Both partnered and single women participated. There were four major findings seldom discussed in the literature, which have important implications for preventive intervention. First, partner relationships troubled before the diagnosis as well as those characterized by mutual caring faced challenges and negative changes. Second, in an effort to protect each other, communication within the partner dyad became less open, and there were changes in the usual manner of conflict resolution. Third, unpartnered women appeared to be more vulnerable to problems of negative adjustment, largely because of relationship issues. Fourth, participants confirmed the need for a comprehensive intervention to facilitate coping with issues relative to relationships, intimacy, and sexuality. Although the sample was small, in-depth data were obtained that provide a basis for specific areas in which further empirical investigation is needed, and they indicate that preventive intervention may well be warranted.

Adaptation, Psychological↗
PubMed2001

Acyclovir suppression to prevent clinical recurrences at delivery after first episode genital herpes in pregnancy: an open-label trial.

OBJECTIVE: To continue evaluation of the use of acyclovir suppression in late pregnancy after first episode genital herpes simplex virus (HSV) infection, using an open-label study design. METHODS: Ninety-six women diagnosed with genital herpes for the first time in the index pregnancy were prescribed suppressive acyclovir 400 mg orally three times daily from 36 weeks until delivery in an open-label fashion. Herpes cultures were obtained when patients presented for delivery. Vaginal delivery was permitted if no clinical recurrence was present; otherwise a Cesarean delivery was performed. Neonatal HSV cultures were obtained and infants were followed clinically. Rates of clinical and asymptomatic genital herpes recurrences and Cesarean delivery for genital herpes were measured, and 95% confidence intervals were calculated. RESULTS: In 82 patients (85%) compliant with therapy, only 1% had clinical HSV recurrences at delivery. In an intent to treat analysis of the entire cohort, 4% had clinical recurrences (compared with 18-37% in historical controls). Asymptomatic shedding occurred in 1% of women without lesions at delivery. Two of the four clinical recurrences were HSV-culture positive. No significant maternal or fetal side-effects were observed. CONCLUSIONS: In clinical practice the majority of patients are compliant with acyclovir suppression at term. The therapy appears to be effective at reducing clinical recurrences after a first episode of genital herpes complicating a pregnancy.

Acyclovir↗
PubMed2000

The relationship between rates of HVc neuron addition and vocal plasticity in adult songbirds.

In adulthood, songbird species vary considerably in the extent to which they rely on auditory feedback to maintain a stable song structure. The continued recruitment of new neurons into vocal motor circuitry may contribute to this lack of resiliency in song behavior insofar as new neurons that are not privy to auditory instruction could eventually corrupt established neural function. In a first step to explore this possibility, we used a comparative approach to determine if species differences in the rate of vocal change after deafening in adulthood correlate positively with the extent of HVc neuron addition. We confirmed previous reports that deafening in adulthood changes syllable phonology much more rapidly in bengalese finches than in zebra finches. Using [(3)H]thymidine autoradiography to identify neurons generated in adulthood, we found that the proportion of new neurons in the HVc one month after labeling was nearly twice as great in bengalese than in zebra finches. Moreover, among the subset of HVc vocal motor neurons that project to the robust nucleus of the archistriatum, the incidence of [(3)H]thymidine-labeled neurons was nearly three times as great in bengalese than in zebra finches. This correlation between the proportion of newly added neurons and the rate of song deterioration supports the hypothesis that HVc neuron addition may disrupt stable adult song production if new neurons cannot be "trained" via auditory feedback.

Animals↗
PubMed2000

Prospects for control of herpes simplex virus disease through immunization.

Herpes simplex viruses (HSVs) can cause a variety of infections, including genital herpes. Despite effective antiviral therapy, HSV infections remain a significant worldwide public health problem. Vaccines offer the best hope for controlling spread and limiting HSV disease. This article discusses the pathogenesis and immunobiology of mucocutaneous HSV infections, summarizes the spectrum of diseases caused by HSV, and provides a review of the field of HSV vaccine research. This article also discusses what might be realistically expected of a vaccine intended for control of genital herpes and explores the question of whether a vaccine that is effective in controlling genital HSV disease might also be effective in controlling nongenital HSV disease. The efficacy of such vaccines for the full spectrum of HSV disease will eventually determine the timing and targeting of immunization, ranging from selective immunization in preadolescence to universal childhood immunization as part of the routine childhood regimen.

Female↗
PubMed1999

Prevention of perinatal herpes: prophylactic antiviral therapy?

So what is the take-home message from these studies? The first question, about fetal and neonatal safety, appears to be answered positively. With more than 1,812 infants reported to have been exposed to varying amounts and duration of maternal acyclovir suppression, there has not been any apparent, short-term adverse fetal or neonatal effect. Use of acyclovir in infants, even in those that are premature, is very well tolerated, with a wide margin of safety. In addition, the pharmacokinetics studies by Frenkel et al and Kimberlin et al, as well as the animal studies, suggest that maternal use of acyclovir may actually provide a prophylactic and therapeutic benefit to an infant who is exposed to HSV. The second question, as to whether acyclovir suppression would simply change symptomatic outbreaks into asymptomatic ones, also appears to have some answers. The information provided by Wald et al indicated that acyclovir suppression actually decreases asymptomatic shedding, along with decreasing clinical recurrences. Because asymptomatic shedding seems to be similar in pregnant and nonpregnant patients, it would be reasonable to assume that asymptomatic shedding also would be decreased at delivery in pregnant women with HSV infection. This supposition is supported by the data from the randomized trials and cohort studies that demonstrated a lower than expected asymptomatic shedding rate. As yet, however, there has been no randomized trial in pregnant women that has had an adequate sample size to confirm this on a statistically significant basis. The third question, whether acyclovir suppression would lower the frequency of symptomatic recurrences at parturition, reducing the need for cesarean in these patients, has answers as well, although they may not be as clear cut as one would like. Women who experience their first genital herpes outbreak while they are pregnant seem to benefit from acyclovir suppression, with both a decrease in the risk of clinical recurrences at delivery and a decreased need for cesarean delivery. This is well documented by a randomized trial and other cohort studies. Acyclovir's efficacy in patients who have a history of genital herpes infections antedating their pregnancy is less clear. The data appear to indicate a clinically important decrease in the likelihood of symptomatic reactivations at the time of delivery, although the sample sizes in the randomized studies have been too small to draw a statistically significant conclusion one way or the other. Unfortunately, a definitive trial for this group of women may never be done. Assuming a 13% recurrence risk at the time of delivery and a 50% decrease in recurrences with the use of acyclovir, 652 women would have to complete the study to achieve a power of 80%. Conducting the study at the largest, single institution, prenatal center in the United States, Scott et al were only able to enroll 222 women during a period of 6 years. Likewise, Brocklehurst et al terminated their trial early because of recruitment difficulties. They enrolled only 63 women during a period of 4 years using two different sites in the United Kingdom. Unless a multicenter trial is conducted or a meta-analysis performed on the available data, we will probably have to be content with the data as it now stands. With valacyclovir and famciclovir now available, it is unlikely that any further work will be done with acyclovir. Information from the valacyclovir trials, however, may reach statistical significance because of changes in the study design that will allow smaller sample sizes to reach adequate power. Famciclovir treatment holds promise because of its longer intracellular half-life, but until concerns about potential mutagenicity are resolved and more information on its efficacy for suppressive therapy becomes available, it should not be considered for maternal suppressive therapy. Acyclovir appears to be effective, at least in some cohorts, and is probably safe for the fetus. (AB

Acyclovir↗
PubMed1999

Variation in food selection among lambs: effects of basal diet and foods offered in a meal.

In studies of behavior and nutrition, we typically determine nutritional needs and formulate diets for the average member of the herd, not for specific individuals within a herd. Nevertheless, variation among individuals could affect productivity of the group if the diet diverges too much from what individuals at the extremes prefer to eat. Thus, it is important to determine the degree to which individuals within a group vary in their food preferences when offered alternatives. Our first objective was to determine the degree to which lambs differed in preference for foods high in energy (barley) or protein (alfalfa) (Exp. 1). When we offered lambs barley and alfalfa for ad libitum consumption for 25 d, individuals varied in the amounts of barley (range: 221 to 991 g/d) and alfalfa (range: 51 to 558 g/d) they consumed (P < .0001). At one extreme, individuals preferred a diet of 6% alfalfa and 94% barley; at the other extreme, individuals preferred a diet of 70% alfalfa and 30% barley. Our second objective was to determine whether lambs from Exp. 1 compensated, when fed a basal diet that was lower in alfalfa than they preferred, by ingesting foods higher in alfalfa when offered a meal (Exp. 2). Lambs were ranked according to the percentage of alfalfa (range from 6 to 70%) and barley (range from 94 to 30%) they ate during Exp. 1 and then assigned alternately to two treatments: 1) basal diet with similar proportions of alfalfa and barley consumed ad libitum (preferred diet) or 2) basal diet with 10% less alfalfa than consumed ad libitum (low-alfalfa diet). We then conducted three trials in which lambs fed the different basal diets were offered a meal for 15 min/d for 2 d of two foods that differed in barley and alfalfa. During Trial 1, when we offered barley and alfalfa, lambs in both groups preferred barley (138 g) to alfalfa (46 g) (P < .05). During Trial 2, when the test foods (barley and alfalfa) were diluted with grape pomace (20%), lambs fed the preferred basal diet ate more barley (116 vs 64 g) and less alfalfa (48 vs 87 g) than lambs fed the low-alfalfa basal diet (P < .05). During Trial 3, when we offered a food high in barley (80% barley and 20% pomace) and a food high in alfalfa (70% alfalfa, 14% cornstarch, and 16% pomace), lambs fed the preferred basal diet ate more of the high-barley food (124 vs 73 g) and less of the high-alfalfa food (45 vs 98 g) than lambs fed the low-alfalfa basal diet (P < .05). Collectively, these results illustrate that lambs varied greatly in their preferences for foods that differ in energy (barley) and protein (alfalfa), and that when their preferred basal diet was altered, lambs compensated by ingesting food that complemented their basal diet during a daily meal. The addition of grape pomace in Trials 2 and 3 reduced the protein content of the high-barley and high-alfalfa foods such that the high-barley food was only marginally adequate to meet needs compared with the high-alfalfa food. Lambs fed the low-alfalfa basal diet compensated by eating more of the high-alfalfa food than lambs fed the preferred basal diet.

Animal Feed↗
PubMed1998

Prevention of herpes simplex virus infection and latency by prophylactic treatment with acyclovir in a weanling mouse model.

OBJECTIVE: Acyclovir is an antiviral agent that inhibits acute herpes simplex virus replication and decreases the frequency of reactivation, but it is not currently used to prevent primary disease or the establishment of latency. The purpose of this study was to reexamine the efficacy of acyclovir in preventing acute and latent herpes simplex virus infection. STUDY DESIGN: Mice were infected by footpad inoculation with 2 viral recombinants that express beta-galactosidase. Half of each group was treated prophylactically with intraperitoneal acyclovir and then given acyclovir in the drinking water. Four days after infection, the dorsal root ganglia were removed, fixed, and stained, and the number of cells expressing beta-galactosidase were counted. RESULTS: Compared with placebo, prophylactic acyclovir completely inhibited acute viral replication as evidenced by the absence of beta-galactosidase activity (P < .001) and significantly decreased the number of neurons harboring latent infection (P = .01). CONCLUSION: Acyclovir prophylaxis prevented acute and reduced latent ganglionic infection with herpes simplex virus in a weanling mouse model.

Acyclovir↗
PubMed1998

Cost-effectiveness of acyclovir suppression to prevent recurrent genital herpes in term pregnancy.

The objective of this paper is to determine whether acyclovir suppression provides a greater cost savings over no medical therapy in the management of recurrent genital herpes (HSV) in pregnancy. Estimates of the risk of HSV recurrence and cesarean delivery rates in acyclovir-treated and -untreated patients and frequency of neonatal acyclovir treatment were derived from literature reviews, prospective surveillance, and practices at our institution. Estimates of costs were derived from average hospital and outpatient clinic charges at our institution. Calculations were run separately for four different groups of patients: women whose first diagnosis of genital herpes occurred during the pregnancy, women whose diagnosis antedated pregnancy and who had infrequent recurrences, women whose diagnosis antedated pregnancy and had frequent recurrences, and all women with a history of genital herpes regardless of timing of diagnosis or frequency of recurrences. Suppressive acyclovir treatment of all term pregnant women with a history of genital herpes resulted in an estimated savings of $183.00 per patient or $36,600,000 per year. Women with their first episode of herpes diagnosed during pregnancy or with frequent recurrences benefitted even more, achieving a savings of $455.00 and $391.00 per patient, respectively. Assuming that prenatal acyclovir treatment is safe for the fetus, utilizing this management for all patients with recurrent HSV in pregnancy could immediately save $183 per patient. On a national level, this translates to $36,600,000 per year just in reduced obstetrical costs. If indirect costs associated with cesarean deliveries had been included in these calculations, the estimated savings would be even more substantial.

Acyclovir↗
PubMed1997

Postpartum endometritis caused by herpes simplex virus.

BACKGROUND: Herpes simplex virus (HSV) is rarely the causative agent of endometritis and is usually found in association with pelvic inflammatory disease. Only one case of postpartum HSV endometritis has been reported. CASES: We describe two cases of herpes simplex postpartum endometritis. Neither patient had genital HSV lesions noted at the time of delivery. The first case developed after a preterm cesarean delivery in an 18-year-old primipara. She had persistent puerperal fever despite broad-spectrum anti-microbial treatment. The second case was a 16-year-old primipara whose vaginal delivery was complicated by severe postpartum endometritis. Vulvar and endometrial cultures were positive for HSV alone in both patients. Both infants died from disseminated HSV infection. CONCLUSION: Herpes simplex virus can cause clinical postpartum endometritis.

Adolescent↗
PubMed1996

Acyclovir suppression to prevent cesarean delivery after first-episode genital herpes.

OBJECTIVE: To determine if suppressive acyclovir therapy given to term gravidas experiencing a first episode of genital herpes simplex virus (HSV)-infection during pregnancy decreases the need for cesarean delivery for that indication. METHODS: Forty-six pregnant women with first episodes of genital herpes during pregnancy were randomly assigned to receive oral acyclovir 400 mg or placebo, three times per day, from 36 weeks' gestation until delivery as part of a prospective, double-blind trial. Herpes simplex virus cultures were obtained when patients presented for delivery. Vaginal delivery was permitted if no clinical recurrence was present; otherwise, a cesarean was performed. Neonatal HSV cultures were obtained and infants were followed-up clinically. RESULTS: None of the 21 patients treated with acyclovir and nine of 25 (36%) treated with placebo had clinical evidence of recurrent genital herpes at delivery (odds ratio [OR] 0.04, 95% confidence interval [CI] 0.002-0.745; P = .002). No woman treated with acyclovir had a cesarean for herpes, compared with nine of 25 (36%) of those treated with placebo (OR 0.04, CI 0.002-0.745; P = .002). No patient in either treatment group experienced asymptomatic genital viral shedding at delivery. No neonate had evidence of herpes infection or adverse effects from acyclovir. CONCLUSION: Suppressive acyclovir therapy reduced the need for cesarean for recurrent herpes in women whose first clinical episode of genital HSV occurred during pregnancy. Suppressive acyclovir treatment did not increase asymptomatic viral shedding and was not harmful to the term fetus.

Acyclovir↗
PubMed1995

Erythropoietin use in pregnancy: two cases and a review of the literature.

End-stage renal disease complicates only a small percentage of pregnancies, but, of these, virtually all become anemic due to a deficiency in erythropoietin. Erythropoietin has been shown to correct anemia due to renal disease in nonpregnant patients. We report two cases of erythropoietin use during pregnancy complicated by severe anemia due to renal failure. No maternal or fetal side effects were noted. Our two cases exemplify that erythropoietin is an effective means of treating anemia due to renal disease in the gravid patient.

Adult↗
PubMed1992

Nutritive quality and palatability of switchgrass hays for sheep: effects of cultivar, nitrogen fertilization, and time of adaptation.

Feeding and palatability trials were conducted with four cultivars (cv) of switchgrass (Panicum virgatum L.), fertilized at three levels of N (0, 75, or 150 kg of N/ha) in 2 yr. Wether sheep had ad libitum access to chopped hays, and intake, apparent digestibility, particle passage rates, and concentrations of blood metabolites were determined. Palatability was measured with mature sheep in cafeteria trials. Nitrogen fertilization did not affect (P > .05) DM digestibility (DMD) or DMI, but there was a year x N interaction (P < .01) for NDF digestibility. Dry matter digestibility values for combined years and N levels were 56.9, 54.4, 56.6, and 57.9% (P < .01) for Pathfinder, New Jersey 50, Kentucky 1625, and Trailblazer cv, respectively; mean DMI values were 60.4, 60.8, 57.7, and 64.0 g/kg BW.75 (year x cv, P < .01). An apparently greater quality of Trailblazer was masked by weed invasion of N-fertilized stands of this cv in yr 2, with changes in hay composition. Lambs adapted to hay diets with time; mean DMI for cv and N levels combined increased (P < .001) from 50.5 to 71.4 g/kg BW.75 between wk 2 and 3 and wk 10 and 11, with no change in DMD. Intakes of NDF increased from 37.6 to 55.6 g/kg BW.75, an increase of 48%. Marker (Yb) measurements indicated little change in particle passage rates with treatment. There were no major differences in blood composition, apart from increases in blood urea N, as a result of N fertilization. Cafeteria trials showed preference by sheep for Trailblazer and KY 1625 compared with NJ 50 and Pathfinder, with a N x cv interaction (P < .01). Trailblazer was preferred to KY 1625 in a two-choice situation (P < .01). Results show relatively small effects of cv and N fertilization on quality of switchgrass and indicate the need for a lengthy period of adaptation by sheep to the feeding of a warm-season grass.

Animal Feed↗
PubMed1989

Cervical cytological services in the Orange Free State. Demographic characteristics.

In the Bloemfontein academic hospitals the incidence of infiltrating cervical cancer is four times that of severe cervical intra-epithelial neoplasia (CIN III). A cross-sectional survey was therefore conducted to identify the extent of cervical cytological services in the Orange Free State. From the four major laboratories dealing with the population of the OFS all cytological reports of one randomly chosen working day per month in 1985 were analysed for three demographic variables: age, race, and locality according to census district. As a control, similar demographic variables were identified from national census figures for 1980, limited to females aged 15-65 years. The follow-up of patients with CIN III diagnosed cytologically in the academic hospitals in Bloemfontein was determined. Results showed significant differences (P less than 0.001) in age, race and locality between the census population and that submitted to cytological screening. Acceptable figures were virtually limited to Bloemfontein, predominantly in white patients, while three-quarters of the population of the OFS is black. The peak frequency in the age distribution in the screened population was 25-35 years and 15-24 years for the census population. Follow-up for patients with CIN III was 65.5%. The conclusion is that the female population of the OFS is not representatively reached by existing cytological services.

Adolescent↗