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Biomedical subjects

S Davidson

Publications and source records attributed to S Davidson.

At least 235 records · Page 13Linked to original sources
PubMedDate not supplied

Role of mitogenicity in pathogenicity of mycoplasmas for murine hosts.

The mitogenicity and pathogenicity of Mycoplasma pulmonis were compared in two rat strains. Both the mitogenic and the pathologic effects induced by M. pulmonis membranes were more severe in Lewis rats than in Hooded rats, and were dependent on the mitogen doses used. It was concluded that the severity of lung lesions induced by M. pulmonis membranes correlated with the degree of mitogenic responses of the different rat strains to this organism. The roles of T- and B-cell mitogens in induction of pneumonia were studied in Hooded rats treated intranasally with either the T-cell mitogen concanavalin A or with M. neurolyticum membranes which stimulate the B-cell populations, or with both concanavalin A and M. neurolyticum. Results clearly showed that the individual B- and T-cell mitogens affected the lungs of treated animals. Nevertheless, the mitogenic co-stimulation of both B and T lymphocytes in rat lungs was necessary to obtain maximal development of interstitial lymphocytic pneumonia.

Animals↗
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Sacral nevus flammeus simplex: the role of imaging.

Neonates with midline lumbar, thoracic, or occipital cutaneous lesions should be suspected of having spinal dysraphism and should undergo an imaging study. The aim of the present study was to evaluate whether sacral nevus flammeus simplex (SNFS) in neonates is associated with spinal dysraphism. During a period of 6 months, we prospectively examined all neonates in our center for the presence of SNFS. Those affected were evaluated for associated anomalies by physical and neurologic examination and ultrasound imaging of the lumbosacral area. Twenty-eight of 3623 neonates (0.77%) were diagnosed as having SNFS. In 64% of the SNFS patients, nevus flammeus simplex (NFS) was noted as well. Physical and neurologic examinations were unremarkable. Ultrasound imaging of the lumbosacral area was performed in 25 patients (89%) and revealed diastematomyelia in one. The results show that SNFS may constitute the only cutaneous sign of spinal dysraphism. In conclusion, we recommend that neonates with SNFS be investigated for occult spinal dysraphism.

Female↗
PubMedDate not supplied

Corynebacterium diphtheriae endocarditis.

Two patients with Corynebacterium diphtheriae endocarditis have been observed in the past ten years. Both cases occurred sporadically. In one case toxigenic C. diphtheriae caused endocarditis in an immunized child with congenital heart disease. The second patient developed rapidly progressive valve destruction caused by a nontoxigenic strain of C. diphtheriae. These cases illustrate that C. diphtheriae may produce endocarditis in addition to its previously described diseases spectrum.

Child, Preschool↗
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The Americans with Disabilities Act and essential functions in nursing programs.

With the recent passage of the Americans with Disabilities Act, the author conducted a study to determine what percentage of BSN nursing programs had a list of essential functions that students must be capable of performing while enrolled. Results showed that the majority of programs have not developed lists and currently do not request information, during the admissions process, related to the applicant's ability to complete the essential functions of the programs, with or without reasonable accomodation. Almost half of the programs surveyed plan to request this information during the admissions process in the future.

Clinical Competence↗
PubMedDate not supplied

HER-2 and cancer antigen 125 evaluation in ovarian borderline tumors by immunohistochemistry and fluorescence in situ hybridization.

The study determined the expression of cancer antigen (CA) 125 and HER-2 in 45 borderline ovarian tumors (BOTs) and investigated the correlation of these biologic markers with histologic type, clinical stage, and outcome. The level of CA 125 protein was assessed using DAKO's M-11 clone antibody in immunohistochemistry (IHC) assays (Carpinteria, CA). The HER-2 protein expression was assessed in IHC assays using the HercepTest (DAKO), and the HER-2 gene copy number per cell was investigated through fluorescence in situ hybridization (FISH) assays using VYSIS' PathVysion DNA Probe (Downers Grove, IL). Expression of the CA 125 protein was detected in 49% of the samples (22 out of 45 tumors) and significantly associated with the serous histologic type. However, CA 125 expression did not associate with clinical stage or outcome. Protein overexpression or gene amplification of HER-2 was not found. However, abnormal FISH results were detected in 16% (seven out of 45 patients) of specimens comprising extranumerary copies of HER-2 and/or chromosome 17 per cell. Abnormal FISH results were found to be independent of CA 125 expression and histologic type whereas they positively associate with advanced clinical stage. Our data show that HER-2 is not altered in BOTs, and the presence of aneusomy for chromosome 17 and HER-2 may predict tumor progression.

Adenocarcinoma, Mucinous↗
PubMedDate not supplied

Managed competition in practice: 'value purchasing' by fourteen employers.

Many large U.S. companies have transformed their procurement of health benefits in the 1990s by combining the principles of managed competition with other business tactics to create a business-savvy hybrid of the private sector's own design, often referred to as "value purchasing." Until recently, few policymakers or health care observers believed that large firms would be a force in health system reform. Yet to implement value purchasing, the large companies in this study created new organizational forms, provided employees with financial incentives to select low-cost health plans, and used business tactics such as competitive bidding to negotiate more favorable rates and to improve quality among health plans. The financial results were impressive for the companies studied. In addition, the companies' demands on the health care delivery system are multiplying as the interface between business firms and health care organizations changes. These demands will only increase as the practices we found become more widespread.

Community Participation↗
PubMedDate not supplied

Chaos, perfectionism, and sabotage: personality disorders in the workplace.

Psychiatric nurses work in a variety of settings as supervisors, administrators, and consultants. They understand that success or failure of organizational activities depends in large measure on the staff's productivity, commitment, and cooperation. When these qualities are absent, major problems can ensue. This paper uses a case study approach to examine the impact that employees with borderline, obsessive-compulsive, and passive-aggressive personality disorders have an organizations. Specific disruptive behaviors that can challenge co-workers and negatively affect the effectiveness of the work group are presented. Therapeutic strategies are identified that have been adapted for use in the workplace. These strategies are used to help employees perform in a more effective manner while minimizing maladaptive responses to guidance and supervision.

Adaptation, Psychological↗
PubMedDate not supplied

Retinopathy of prematurity and surfactant treatment.

PURPOSE: Surfactant therapy in premature infants has reduced the severity of respiratory distress syndrome (RDS), thus leading to a reduction in mortality. However, the anticipated effect of surfactant therapy on the incidence and severity of retinopathy of prematurity (ROP) is ambiguous. The acute rise in PaO2 and the increased survival of low-birth-weight infants may augment the risk of ROP, whereas their improved health and respiratory status may lower it. METHODS: We reviewed the findings of sequential ophthalmologic examinations performed in our neonatal intensive care unit. Premature infants of gestational age under 32 weeks and weighing less than 1500 g at birth who received surfactant treatment were compared with a group of historical controls consisting of premature infants of the same mean birth weight and gestational age who did not get this supplement. RESULTS: ROP was present in 13 (65%) of the 20 surfactant-treated babies, and threshold disease was noted in six (30%). In the historical control group, 20 (77%) of 25 infants had ROP, of whom 10 (40%) were treated for threshold disease. These differences were not statistically significant. CONCLUSION: Surfactant therapy was not associated with an increased incidence of ROP in our series.

Age of Onset↗