Biomedical subjects

Rachel Brown

Publications and source records attributed to Rachel Brown.

9 recordsLinked to original sources

PubMed2006

The glycemic load estimated from the glycemic index does not differ greatly from that measured using a standard curve in healthy volunteers.

Glycemic load (GL) is calculated indirectly as glycemic index (GI) times the weight of available carbohydrate. Alternatively, GL may be measured directly using a standard glucose curve. The purpose of this study was to test the agreement between GL values obtained using direct and indirect methods of measurement in 20 healthy volunteers. A standard curve in which glucose dose was plotted against blood glucose incremental area under the curve (iAUC) was generated using beverages containing 0, 12.5, 25, 50, and 75 g glucose. The GI and available carbohydrate content of 5 foods were measured. The foods (white bread, fruit bread, granola bar, instant potato, and chickpeas) were consumed in 3 portion sizes, yielding 15 food/portion size combinations. GL was determined directly by relating the iAUC of a test food to the glucose standard curve. For 12 of 15 food/portion size combinations, GL determined using GI x available carbohydrate did not differ from GL measured from the standard curve (P > 0.05). For 3 of the test products (100 g white bread, and 100- and 150-g granola bars), GI x available carbohydrate was higher than the direct measure. Benefits of the direct measure are that the method does not require testing for available carbohydrate and it allows portion sizes to be tested. For practical purposes, GI x available carbohydrate provided a good estimate of GL, at least under circumstances in which available carbohydrate was measured, and GI and GL were tested in the same group of people.

Blood Glucose↗

PubMed2006

Multiple antenatally diagnosed foregut duplication cysts excised and the value of thoracoscopy in diagnosing small concurrent cysts.

A case report of a female neonate referred with antenatally diagnosed cystic lesions within the right hemithorax and under the left hemidiaphragm is presented to highlight the ease with which these lesions can be resected in an asymptomatic post-natal infant with minimally invasive surgery. The diagnostic and cosmetic benefits of minimally invasive surgery are also demonstrated. While excising the documented thoracic cyst, another small cyst was identified adherent to the right main bronchus. An elective laparoscopic excision of the abdominal cyst was also successful. A brief review of the complications and treatment of foregut duplication cysts is detailed.

Cysts↗

PubMed2005

Using children as simulated patients in communication training for residents and medical students: a pilot program.

Medical schools are charged with the challenge of teaching effective communication skills, a core competency for residents and medical students. Especially challenging is the task of developing effective methods for training residents and students to communicate with children with mental health issues. The authors describe a pilot program at Mercer University School of Medicine that used pediatric standardized patients (SPs), ages 9-19, to aid in training residents and medical students in complex interviewing skills addressing mental health issues. New curriculum components for four pediatric problems, anorexia nervosa, depression, separation anxiety, and attention deficit hyperactivity disorder (ADHD), were designed and implemented by the authors in 2002-04. The training sessions were evaluated by the participating SPs as well as the residents and medical students in training. The components of the training were a lecture and subsequent practice using pediatric SPs and adults acting as their mothers. Evaluation included the qualitative analysis of SPs' reactions to participation in the training as described during a posttraining-session focus-group, as well as questionnaire responses by residents and medical students. The children role-playing the scenario of a difficult-to-manage situation and their adult "parent" actors voiced strongly positive reactions to participating in training residents and medical students. The reactions of physicians in training were also positive. The authors thus conclude that child and adolescent actors can be effectively used as SPs to train residents and students in complex interviewing skills, even in cases involving children with challenging mental health issues.

Adolescent↗

PubMed2004

Avenues to prestige among adolescents in public and religiously affiliated high schools.

We used data from 1,733 college students to explore whether adolescents' avenues to prestige differ in public and private high schools. Students attending seven large universities during the 1997--98 academic year provided information on the ways in which adolescents in their high schools had gained prestige with peers. The analyses revealed no differences by high school type for girls, with the exception of greater emphasis on clothes in public schools as compared with private schools. For boys, the differences were more pronounced. Boys who attended private schools were less likely than those who attended public schools to accrue prestige through clothes and car ownership and more likely to gain prestige through general sociability and having a good reputation. However, boys who attended private schools were more likely to gain prestige through being the class clown. Taken together, the findings show few differences between avenues to prestige for girls in private and public high schools, and differences for boys that are not uniformly in the direction that parents and private school advocates would predict or desire.

Adolescent↗

PubMed2003

Cutaneous vasculitis - a case for laparotomy?

The diagnosis of gut vasculitis infers a poor prognosis necessitating aggressive therapy. We describe a case with predominant features of a skin-limited vasculitis but atypical debilitating abdominal symptoms. Although endoscopic biopsies were unremarkable, full thickness biopsy taken at laparotomy revealed a necrotizing vasculitis. After treatment with cyclophosphamide, the previously resistant abdominal symptoms resolved. This case illustrates the need to tailor treatment to disease severity, rather than determine it by the type of vasculitis with which the patient has been labelled. In view of the importance of gastrointestinal involvement to therapy decisions, laparotomy may be necessary to establish the presence of vasculitis.

Cyclophosphamide↗

PubMed2002

SERRS dyes. Part I. Synthesis of benzotriazole monoazo dyes as model analytes for surface enhanced resonance Raman scattering.

The synthesis of seven monoazo benzotriazole dyes for use in surface enhanced resonance Raman scattering, SERRS, is reported. The dyes are all capable of complexing to the silver surface used to provide the surface enhancement found in SERRS and hence act as 'model' analytes. One dye was examined in detail and showed a quantitative relationship between concentration and signal intensity.

Journal Article↗

PubMed2002

Evaluation of type 1 immune response in naïve and vaccinated animals following challenge with Leptospira borgpetersenii serovar Hardjo: involvement of WC1(+) gammadelta and CD4 T cells.

Organisms within the Hardjo serovar of Leptospira species are harbored in cattle throughout the world, causing abortion in pregnant animals as well as being shed in the urine, thereby providing sources of zoonotic infection for humans. We recently showed that sterile immunity in vaccinated cattle is associated with induction of a type 1 (Th1) cell-mediated immune response. Here naïve and previously vaccinated pregnant cattle were challenged with a virulent strain of serovar Hardjo and subsequently evaluated for expression of a type 1 immune response. Lymphocytes that responded in a recall response to antigen by undergoing blast transformation were evident in cultures of peripheral blood mononuclear cells (PBMC) from vaccinated cattle throughout the postchallenge test period while those from naïve cattle were evident at one time point only. Nevertheless, beginning at 2 weeks after challenge, gamma interferon (IFN-gamma) was measured in supernatants of antigen-stimulated PBMC cultures from nonvaccinated animals although the amount produced was always less than that in cultures of PBMC from vaccinated animals. IFN-gamma(+) cells were also evident in antigen-stimulated cultures of PBMC from vaccinated but not from nonvaccinated animals throughout the postchallenge period. The IFN-gamma(+) cells included CD4(+) and WC1(+) gammadelta T cells, and a similar proportion of these two subpopulations were found among the dividing cells in antigen-stimulated cultures as ascertained by carboxyfluorescein succinimidyl ester loading. Finally, while naïve and vaccinated animals had similar levels of antigen-specific immunoglobulin G1 (IgG1) following challenge, vaccinated animals had twofold-more IgG2. In conclusion, while infection may induce a type 1 response we suggest that it is too weak to prevent establishment of chronic infection.

Animals↗

PubMedDate not supplied

Peripheral primitive neuroectodermal tumor with postchemotherapy neuroblastoma-like differentiation.

We report the case of an 11-year-old girl with a retroperitoneal tumor in the left upper quadrant. The girl was admitted to hospital with weight loss and a painless abdominal mass that on biopsy was diagnosed as a peripheral primitive neuroectodermal tumor/Ewing sarcoma (pPNET/EWS) of the soft tissue. The patient underwent chemotherapy followed by surgical resection of the tumor 5 months after diagnosis. The posttreatment residual viable tumor showed a morphologic appearance resembling a neuroblastoma. Interphase and metaphase fluorescent in situ hybridization (FISH) studies performed on the pretreatment and posttreatment samples showed the presence of a t(11;22) rearrangement resulting in EWSR1/FLI1 gene fusion consistent with pPNET/EWS in both specimens. This case is unusual in the sense of showing the typical gene fusion for pPNET/EWS both in the pretherapy sample with the typical morphological appearance of this tumor and in the posttherapy specimen showing neural differentiation suggestive of a neuroblastoma.

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

Cancer-related overexpression of the peripheral-type benzodiazepine receptor and cytostatic anticancer effects of Ginkgo biloba extract (EGb 761).

The peripheral-type benzodiazepine receptor (PBR) is an 18-kDa high affinity drug- and cholesterol-binding protein that is involved in various cell functions, including cell proliferation and apoptosis. PBR was shown to be overexpressed in certain types of malignant human tumors and cancer cell lines, correlating with enhanced tumorigenicity and cell proliferation rates. The present study was conducted in order to further define the role of PBR in cancer and to extend our recent findings regarding the possible anticancer effects of the standardized Ginkgo biloba extract EGb 761. Treatment with EGb 761 decreased PBR mRNA levels and inhibited the proliferation of breast, glioma and hepatocarcinoma cell lines, further corroborating our previous contention that its mechanism of action is through the modification of PBR expression. In vivo treatment with Ginkgo biloba extract led to dose-dependent decreases in xenograft growth of both MDA-MB-231 breast cancer and U-87 glioma cell lines in nude mice, although the effects were not maintained after 50 days of treatment in the latter. The results obtained in MDA-MB-231 xenografts indicated pronounced inhibition of tumor growth, verified by MRI imaging. These results were obtained using a modified experimental protocol where the animals were treated with the extract before cell inoculation. Although an exact role for PBR in relation to the initiation and progression of various types of cancer remains to be defined, our results indicate that PBR overexpression in certain cancer cells is related to an aggressive phenotype. Since EGb 761 treatment opposes this aggressive phenotype by decreasing PBR overexpression, it could be useful in preventing or treating cancer invasiveness and metastasis.

Animals↗