PubMed Health⌕ Search

Biomedical subjects

C Singer

Publications and source records attributed to C Singer.

At least 19 recordsLinked to original sources
PubMed1992

Insulin-like growth factor expression in breast cancer epithelium and stroma.

The insulin-like growth factors (IGFs) are mitogens for many cancer cell types. In breast cancer cells, IGF-I and IGF-II have both been shown to stimulate cell proliferation. However, IGF-I mRNA has not been found in human breast cancer cell lines, making it unlikely that IGF-I is commonly expressed as an autocrine growth factor for breast cancer cells. Nevertheless, IGF-I mRNA can be detected in breast cancer tissue samples, and in situ hybridization studies have shown that the message originates from the stromal cells adjacent to normal lobules. IGF-II, on the other hand, has been detected in some breast cancer cell lines. In the estrogen receptor positive cell line T47-D, IGF-II mRNA was induced by estradiol. Furthermore, transfection of an IGF-II expression vector into a previously estrogen-dependent cell line resulted in hormone independent growth. Thus, IGF-II can be expressed as an autocrine growth factor in some breast cancers and its expression may, in part, result in hormone independence. Finally, stromal cells obtained from breast tissues showed that IGF-I was commonly expressed in fibroblasts derived from non-malignant biopsy specimens, while IGF-II mRNA was detected in fibroblasts adjacent to malignant tissue. These studies suggest that IGF-II expression may be important in both autocrine and paracrine regulation of breast cancer cell growth.

Breast↗
PubMed1992

Clinical significance of Staphylococcus warneri bacteremia.

Twenty-seven episodes of bacteremia caused by Staphylococcus warneri were identified at Long Island Jewish Medical Center in New York between 1984 and 1989. Fourteen of these were thought to represent true bacteremias and 13 to represent contaminants. Of the 14 true bacteremias, 5 were in pediatric and 9 were in adult patients. Eight of 14 patients (57%) had catheter-related bacteremia and 5 of 14 had bacteremia of unknown source. There was one case of fulminant native valve S. warneri endocarditis. All cases of catheter-related bacteremia, except one, were nosocomially acquired, and 75% of these patients had an underlying immunosuppressive condition. Only 40% of patients with bacteremias of unknown source were immunocompromised, and S. warneri appeared to be noninvasive in this group. Interestingly, all five of the pediatric isolates were oxacillin susceptible, although four of five were resistant to penicillin, despite the fact these patients were hospitalized an average of 29 days. In contrast, seven of nine adult isolates were resistant to both oxacillin and penicillin. The only case of native valve S. warneri endocarditis occurred in a patient who had no known underlying valvular heart disease, but had an underlying immunosuppressive condition. Identification to species level of coagulase-negative staphylococci may lead to appreciation of the importance of bacteria such as S. warneri as human pathogens.

Adolescent↗
PubMed1992

Autonomic dysfunction in men with Parkinson's disease.

Forty-eight men with Parkinson's disease (PD) were interviewed utilizing a questionnaire which evaluated autonomic function. The study population included PD patients (mean age: 65.8 years, mean duration of PD: 8 years) and 32 elderly healthy nonparkinsonian males (mean age: 70.4 years). We found a significantly higher prevalence of the following symptoms of autonomic dysfunction in the parkinsonian patients: erectile dysfunction (60.4 vs. 37.5%), sensation of incomplete bladder emptying (41.6 vs. 15.6%), urgency (45.8 vs. 3.125%), constipation (43.9 vs. 6.25%), dysphagia (22.9 vs. 6.25%) and orthostatic dizziness (21.95 vs. 0%). Eighty-nine percent of parkinsonian patients had at least one of these autonomic symptoms, compared to 43% of control subjects (p less than 0.05). This study is the first comprehensive survey of autonomic symptomatology in PD compared to elderly healthy controls and confirms that autonomic nervous system dysfunction is a pervasive problem in PD. Erectile dysfunction is a significant problem in this patient group and contributes to deterioration in the quality of life.

Aged↗
PubMed1992

Sexually transmitted viruses other than HIV and papillomavirus.

This review has focused on a select group of viruses that can be sexually transmitted. The viruses include the herpesviruses, hepatitis A virus, hepatitis B virus, delta virus, non-A, non-B hepatitis virus(es), and molluscum contagiosum. Their impact on the population alone or in association with HIV disease necessitates a clear understanding of their ability to cause infection and of the manifestations of these infections. Characterization of these particular pathogens and treatment have been discussed with respect to the most current data available. Despite the growing sophistication in the field, we are still limited in our endeavors to identify and manage many viral infections. Therefore, measures to prevent transmission are continually being evaluated in an attempt to minimize exposure to these pathogens.

Cytomegalovirus Infections↗
PubMed1991

Visuospatial impairment in Parkinson's disease.

We explored the nature of the visuospatial deficit in Parkinson's disease (PD) and its progression as a function of disease duration. We compared the performance of 183 patients with idiopathic PD and 90 control subjects matched for age and education on six visuospatial measures. We divided patients into three groups according to the disease duration: early (1 to 4 years), middle (5 to 10 years), and advanced (greater than 10 years). Performance deteriorated in five of the six visuospatial measures, as a function of disease duration. However, the pattern of visuospatial decline depended on whether dementia was present. The results were not influenced by age or anticholinergic medication. These findings support the presence of visuospatial deficits in PD patients, with a changing pattern of impairment related to dementia and progression of the disease.

Aging↗
PubMed1991

Problems in the use of serologic tests for the diagnosis of Lyme disease.

Lyme disease can be reliably diagnosed in the presence of erythema migrans. When erythema migrans is absent, serologic tests are often used to confirm the diagnosis. To choose a test for our Lyme disease diagnostic center, serum samples were obtained from 34 patients and tested for antibodies to Borrelia burgdorferi. We evaluated five enzyme-linked immunosorbent assays from Stony Brook (NY) University Hospital, Cambridge Bioscience (Worcester, Mass), Hillcrest Biologicals (Cypress, Calif), Sigma Diagnostics (St Louis, Mo), and Zeus-Wampole Scientific Inc (Raritan, NJ) and two fluorescent antibody tests (3M [Diagnostic Systems Inc, Santa Clara, Calif] and FIAX [Whittaker M.A. Bioproducts Inc, Walkersville, Md]). A positive sample by any test was further analyzed by Western blot. Using the Centers for Disease Control (Atlanta, Ga) epidemiologic case definitions, patients were classified into those with clinical Lyme disease, patients not meeting the Centers for Disease Control definitions, and asymptomatic patients. Sensitivities of Lyme serologies varied from 13% to 73%, with Hillcrest showing the highest value and Sigma the lowest value. False-positive test results were found in 0% to 27% of patients. Western blot analysis was positive in six of 15 patients with clinical Lyme disease. These results emphasize the need for better serologic testing for Lyme disease and underline their usefulness only as adjuncts in the clinical diagnosis of Lyme disease.

Blotting, Western↗
PubMed1990

Levodopa-responsive parkinsonism in a patient with Down's syndrome.

We report a patient with Down's syndrome (DS) who developed progressive parkinsonian symptomatology at the age of 43 years. His parkinsonism was responsive to levodopa/carbidopa, but he developed end of dose wearing off. We discuss basal ganglia and dopamine abnormalities in DS and suggest that DS may be associated with parkinsonism.

Activities of Daily Living↗
PubMed1989

A case of post-traumatic tic disorder.

We present the case of a 27-year-old man who developed multiple motor tics following closed head trauma with loss of consciousness. Age of onset, lack of family history of tics, and atypical progression of tic severity and location make it unlikely that the patient had Gilles de la Tourette syndrome. Previous reports of post-traumatic tic syndrome are discussed.

Adult↗
PubMed1989

Quantitation of poliovirus antigens in inactivated viral vaccines by enzyme-linked immunosorbent assay using animal sera and monoclonal antibodies.

Recent advances in methods for the manufacture of inactivated poliovirus vaccines have resulted in increased vaccine immunogenicity. In conjunction with this capability it is important to have available highly sensitive and quantitative potency assays. The potential suitability of enzyme-linked immunoassay (ELISA) was evaluated using animal sera with neutralizing antibodies or neutralizing monoclonal antibodies for antigen detection in potency tests. The monoclonal antibodies developed, which bound D antigen but not C antigen, were neutralizing unless relatively weakly reactive. Those that bound C antigen only were non-neutralizing. Those that bound both C and D antigens were sometimes neutralizing. D-specific and D/C-specific neutralizing monoclonal antibodies against type-2 poliovirus protected mice on passive immunization against paralytic disease and death from the MEF strain virus. Potency measurements by ELISA using either D-specific neutralizing monoclonal antibodies or type-specific goat sera for antigen detection were sensitive and precise. Tests using C-specific monoclonal antibodies for antigen detection indicated that increased C antigen content may result in falsely elevated reactivities of animal sera with some vaccines. Monoclonal antibodies may be useful ELISA reagents for IPV potency testing.

Animals↗
PubMed1989

Analysis of emergency department management of suspected bacterial meningitis.

Previous studies of emergency department management of bacterial meningitis have indicated that there are often long delays before initiation of antibiotics. The purpose of our study was to determine whether these delays were related to specific aspects of patient management. From 1981 through 1988, we retrospectively reviewed the medical records of 122 patients primarily evaluated in the ED and admitted for suspected bacterial meningitis at a university (55) and a community (67) hospital. The median time (interquartile range) from ED registration until initiation of antibiotics (time to antibiotics) was 3.0 hours (1.6 and 4.3 hours, respectively) (total range, 0.5 to 18 hours). The time to antibiotics was not significantly related to the time of ED registration. Ninety percent of the total time to antibiotics occurred after the initial physician encounter. Time to antibiotics was significantly (P less than .00005) longer for patients in whom computed tomography scan and/or laboratory analysis of cerebrospinal fluid preceded initiation of antibiotics compared with patients in whom antibiotic administration was not contingent on the results of these procedures (4.3 [3.2 and 6.0] versus 1.9 [1.2 and 3.4] hours, respectively). Also, time to antibiotics was significantly (P less than .00005) longer for patients in whom antibiotics were initiated on the ward as compared with in the ED (4.5 [3.5 and 6.8] versus 2.2 [1.4 and 3.5] hours, respectively). We conclude that long delays exist in the ED before initiation of antibiotics for cases of suspected bacterial meningitis, and that in general these delays appear to be physician generated and to a great extent potentially avoidable.

Adolescent↗
PubMed1989

Single-source outbreak of Candida tropicalis complicating coronary bypass surgery.

Candida tropicalis was isolated from the sternal wounds of eight coronary bypass patients from 18 to 89 days postoperatively; infections were limited to soft tissue in five patients but involved the sternum in three patients. Analysis of surgery records implicated one individual as the potential source of the yeast; this was confirmed by microbiological studies of fingertips and nasopharynx cultures of all personnel in contact with these patients. Only the suspect nurse, then acting as a scrub nurse and not as a circulator, infected the eight patients. Her removal from the cardiac team terminated the cluster outbreak.

Candida↗
PubMed1989

Psychogenic tremors.

We diagnosed 24 patients, 9 men and 15 women ranging in age from 15 to 78 years, with clinically established or documented psychogenic tremors. Clinical presentations were unique, with complex tremors (often resting, postural, and kinetic), unusual temporal profiles (abrupt onset with a variable course), absence of other neurologic signs, inconsistent and incongruous symptomatology, selective disability with ability to perform some functions despite severe tremors, distractibility that lessens or abolishes tremor, atypical tremorgraphic recordings with changing amplitude and frequency, unusual handwriting and drawing specimens, presence of multiple undiagnosed somatizations, unresponsiveness to all treatments, absence of documented disease by laboratory or radiographic tests, presence of psychiatric disease, spontaneous remissions, or recovery with psychotherapy. We present criteria for the diagnosis of psychogenic tremor.

Adolescent↗