Biomedical subjects

L Kemp

Publications and source records attributed to L Kemp.

9 recordsLinked to original sources

PubMed2000

Vacuum-assisted stereotactic breast biopsy: histologic underestimation of malignant lesions.

HYPOTHESIS: The histopathologic correlation between stereotactic core needle biopsy and subsequent surgical excision of mammographically detected nonpalpable breast abnormalities is improved with a larger-core (11-gauge) device. DESIGN: Retrospective medical record and histopathologic review. SETTING: University-based academic practice setting. PATIENTS: Two hundred one patients who underwent surgical excision of mammographic abnormalities that had undergone biopsy with an 11-gauge vacuum-assisted stereotactic core biopsy device. MAIN OUTCOME MEASURE: Correlation between stereotactic biopsy histologic results and the histologic results of subsequent surgical specimens. RESULTS: Results of stereotactic biopsy performed on 851 patients revealed atypical hyperplasia in 46 lesions, ductal carcinoma in situ (DCIS) in 89 lesions, and invasive cancer in 73 mammographic abnormalities. Subsequent surgical excision of the 46 atypical lesions revealed 2 cases of DCIS (4.3%) and 4 cases of invasive carcinoma (8.7%). Lesions diagnosed as DCIS on stereotactic biopsy proved to be invasive carcinoma in 10 (11.2%) of 89 patients on subsequent excision. Stereotactic biopsy completely removed 21 (23.6%) of 89 DCIS lesions and 20 (27.4%) of 73 invasive carcinomas. CONCLUSIONS: In summary, 11-gauge vacuum-assisted core breast biopsy accurately predicts the degree of disease in the majority of malignant lesions; however, understaging still occurs in 11% to 13% of lesions showing atypical hyperplasia or DCIS.

Biopsy↗

PubMed1999

New modification of hot-water irrigation in the treatment of posterior epistaxis.

BACKGROUND: Tamponade treatment for epistaxis is painful and traumatic to the nasal mucosa, and may necessitate hospitalization for several days. Hot-water irrigation (HWI) was introduced as a treatment of epistaxis more than 100 years ago. In a previous study the treatment proved to be effective, less painful, and less traumatic, and required a shorter hospital stay than tamponade treatment. However, HWI has the risk of aspiration during treatment. To minimize this risk, a special catheter has been designed. OBJECTIVES: To evaluate the modified HWI and to compare the results with tamponade treatment, with respect to patient compliance, effectiveness, recurrence of bleeding, pain, complications, and length of hospital stay. PATIENTS: A total of 122 patients, hospitalized for posterior epistaxis, were randomized to receive either HWI or tamponade treatment. RESULTS: In the HWI group, 31 (55%) of the patients could be discharged from the hospital after the initial treatment only, compared with 29 (44%) of the patients treated with tamponade. Using a 10-cm visual analog scale, the mean pain score during treatment was 4.7 in the HWI group compared with 7.5 in the tamponade group. The mean hospital stay was 2.9 days for the HWI group vs. 4.0 days for the tamponade group. After discharge from the hospital, necrosis or synechia was found on rhinoscopy in 12 patients (40%) in the tamponade group compared with none in the HWI group. CONCLUSIONS: Compared with tamponade treatment, HWI is as effective, requires a significantly shorter hospital stay, is less traumatic to the nose, and is significantly less painful.

Adult↗

PubMed1998

Characterization of Brx, a novel Dbl family member that modulates estrogen receptor action.

Regulation of gene activation by the estrogen receptor (ER) is complex and involves co-regulatory proteins, oncoproteins (such as Fos and Jun), and phosphorylation signaling pathways. Here we report the cloning and initial characterization of a novel protein, Brx, that contains a region of identity to the oncogenic Rho-guanine nucleotide exchange (Rho-GEF) protein Lbc, and a unique region capable of binding to nuclear hormone receptors, including the ER. Western and immunohistochemistry studies showed Brx to be expressed in estrogen-responsive reproductive tissues, including breast ductal epithelium. Brx bound specifically to the ER via an interaction that required distinct regions of ER and Brx. Furthermore, overexpression of Brx in transfection experiments using an estrogen-responsive reporter revealed that Brx augmented gene activation by the ER in an element-specific and ligand-dependent manner. Moreover, activation of ER by Brx could be specifically inhibited by a dominant-negative mutant of Cdc42Hs, but not by dominant negative mutants of RhoA or Rac1. Taken together, these data suggest that Brx represents a novel modular protein that may integrate cytoplasmic signaling pathways involving Rho family GTPases and nuclear hormone receptors.

A Kinase Anchor Proteins↗

PubMed1997

Retinoid X receptor and peroxisome proliferator-activated receptor activate an estrogen responsive gene independent of the estrogen receptor.

Estrogen receptors regulate transcription of genes essential for sexual development and reproductive function. Since the retinoid X receptor (RXR) is able to modulate estrogen responsive genes and both 9-cis RA and fatty acids influenced development of estrogen responsive tumors, we hypothesized that estrogen responsive genes might be modulated by RXR and the fatty acid receptor (peroxisome proliferator-activated receptor, PPAR). To test this hypothesis, transfection assays in CV-1 cells were performed with an estrogen response element (ERE) coupled to a luciferase reporter construct. Addition of expression vectors for RXR and PPAR resulted in an 11-fold increase in luciferase activity in the presence of 9-cis RA. Furthermore, mobility shift assays demonstrated binding of RXR and PPAR to the vitellogenin A2-ERE and an ERE in the oxytocin promoter. Methylation interference assays demonstrated that specific guanine residues required for RXR/PPAR binding to the ERE were similar to residues required for ER binding. Moreover, RXR domain-deleted constructs in transfection assays showed that activation required RXR since an RXR delta AF-2 mutant completely abrogated reporter activity. Oligoprecipitation binding studies with biotinylated ERE and (35)S-labeled in vitro translated RXR constructs confirmed binding of delta AF-2 RXR mutant to the ERE in the presence of baculovirus-expressed PPAR. Finally, in situ hybridization confirmed RXR and PPAR mRNA expression in estrogen responsive tissues. Collectively, these data suggest that RXR and PPAR are present in reproductive tissues, are capable of activating estrogen responsive genes and suggest that the mechanism of activation may involve direct binding of the receptors to estrogen response elements.

Cell Culture Techniques↗

PubMed1995

Increasing attendance at immunisation clinics: lessons from a trial program that failed.

Previous studies suggested that the use of a baby-enrolment and reminder system for early childhood immunisation increased public immunisation clinic attendance. It was decided to run a trial to assess the effects of introducing a baby-enrolment program on attendances at local government immunisation clinics. Enrolment leaflets were distributed to each mother of a new child in six areas of greater Sydney while the mother was in the postnatal ward of the local hospital. Clinic attendance figures were monitored, interviews were conducted with mothers as well as professionals involved in early childhood health services, and the conduct of clinics was observed. The trial failed to increase attendance at public clinics. Mothers' reasons for choice of service, particularly their desire for what they believed to be a more personalised service, and the attitude of the professionals (particularly community nurses) with whom they came in contact were considered to be more influential in determining their use (or lack of use) of public immunisation services. Baby enrolment may be effective in increasing attendance at public immunisation clinics only where there is willing cooperation of all stakeholders in supporting public immunisation services.

Adult↗

PubMed1995

Femoral catheters increase risk of infection in total parenteral nutrition patients.

Central venous access for the administration of total parenteral nutrition is usually achieved via the subclavian or internal jugular veins. Although a high incidence of complications has been reported with the use of femoral catheters for central venous access, this route has been used when traditional central venous access is contraindicated. We retrospectively reviewed 171 patients who received total parenteral nutrition via a central venous triple-lumen catheter and compared the rates of infections in femoral vs nonfemoral access. A literature review was performed to identify associated complications of and appropriate indications for femoral catheter use. In the 171 patients studied, 355 triple-lumen catheters were placed; these included 331 nonfemoral catheters and 24 femoral catheters. Femoral catheters were placed in nine patients. Femoral catheters had a greater incidence of positive tips (42% vs 6.9%, p < .001) and related bacteremia (16.7% vs 1.8%, p = .002) than did nonfemoral catheters. The organisms most commonly isolated from the blood and catheter tips of both catheter access sites were methicillin-resistant Staphylococcus epidermidis and Candida. The use of femoral catheters for central venous access for total parenteral nutrition administration results in an increased risk of infectious complications.

Adult↗

PubMed1994

Etiology of acute diarrhea among United States Embassy personnel and dependents in Cairo, Egypt.

The purpose of this study was to identify the enteropathogens causing acute diarrheal disease in Americans living in the North Africa/Middle East region during a 34-month period from February 12, 1985 to December 30, 1987 to guide preventive and therapeutic measures. Stool specimens were examined and an epidemiologic questionnaire was administered to patients with acute diarrhea at the Outpatient Health Unit of the United States Embassy in Cairo, Egypt. The subjects consisted of 126 American employees and dependents of the U. S. Embassy in Cairo, Egypt with diarrhea of less than two-weeks duration. Subjects received routine medical care administered by the U.S. Embassy Medical staff. A possible etiologic agent was detected in 41% of the subjects. Enteroadherent Escherichia coli was the most commonly isolated enteropathogen. A high degree of antimicrobial resistance was noted among the bacterial isolates, but all were susceptible to the quinolone antibiotics. Episodes of acute diarrhea occurring among American expatriates in Cairo, Egypt were primarily of bacterial etiology, but only a small portion were caused by the bacterial pathogens routinely identified in a standard clinical bacteriology laboratory. Most of the diarrheal episodes were due to noninvasive enteroadherent E. coli that may cause prolonged disease requiring antimicrobial therapy.

Acute Disease↗

PubMed1987

Immunohistochemical demonstration of cytochrome P-450 monooxygenase in Clara cells throughout the tracheobronchial airways of the rabbit.

The nonciliated bronchiolar epithelial (or Clara) cell is considered the primary pulmonary site of cytochrome P-450-dependent monooxygenase activity. Despite the general conception that Clara cells are restricted to bronchioles, we have previously shown that a nonciliated cell with the cytological features of the Clara cell predominates throughout rabbit tracheobronchial airways. The present study was designed to determine if the cytochrome P-450 monooxygenase system has the same distribution. Trachea, terminal bronchioles and 3 generations of bronchi were selected by microdissection from fixed lungs of adult specific-pathogen-free rabbits. Serial sections of paraffin-embedded tissue were stained with either Alcian blue/periodic acid Schiff's (AB/PAS) or with antisera to one of the following: cytochrome P-450 form 2, form 5, or NADPH-dependent cytochrome P-450 reductase. The majority of nonciliated epithelial cells lining all 5 airway generations were PAS+ and AB-. Nonciliated cells in all 5 airway generations reacted positively with all three antisera. The primary deposition site was the apical portion of nonciliated cells. Other sites included ciliated surfaces and vascular endothelium. Reaction products from all three antisera had the same localization pattern. We conclude that (1) the cytochrome P-450 monooxygenase system is distributed throughout the tracheobronchial airways of the rabbit and (2) the Clara cells of the trachea and bronchi are functionally, as well as structurally, similar to those of the bronchioles.

Animals↗

PubMedDate not supplied

The effect of catheter type and site on infection rates in total parenteral nutrition patients.

Infections pose a major problem in patients receiving total parenteral nutrition. Controversy continues concerning the effect of catheter type (triple-, double-, single-lumen, or pulmonary artery), insertion site (subclavian, internal jugular, or femoral vein), and the incidence of catheter-related infections. We retrospectively studied multi-lumen catheter use for total parenteral nutrition over a 6-month period in 192 patients, a total of 3334 catheter days. Nonintensive care unit catheters were inserted by the Nutrition Support Service, and intensive care unit catheters were inserted by the intensive care unit staff. All catheters were cared for using Nutrition Support Service protocols, with multi-lumen catheters changed every 7 to 10 days and pulmonary artery catheters changed every 4 days. Infections were determined by semiquantitative cultures (> 15 colonies/plate). The incidence of infections for triple-lumen catheters was 5 (subclavian), 17 (internal jugular), and 36% (femoral) respectively; total infection rate for triple-lumen catheters was 10%. Infection rates for pulmonary artery catheters were 4 (subclavian), and 6% internal (jugular site), respectively, the overall infection rate was 5%. There were no differences in infection rates at any site based on catheter type; however, when triple-lumen catheter sites were compared, the differences were significant (p < .001 vs subclavian, chi 2). Catheter duration was 7.8 days (subclavian),, 7.3 days (internal jugular), and 4.6 (femoral) days. These data suggest that the use of multi-lumen catheters for total parenteral nutrition is safe, that there is a benefit associated with the subclavian route, and that the femoral site should be avoided.

Catheterization↗