Biomedical subjects
Publications and source records attributed to D K Brown.
This paper describes a newborn infant in whom an intrahepatic biliary cyst was successfully demonstrated by antenatal ultrasound. Postnatally, percutaneous cyst aspiration and computed tomography enhanced with intravenous cholangiographic contrast proved extremely helpful in the selection of surgical procedure. The lesion was completely removed at 12 weeks of age without complications.
One hundred and ninety-nine patients with a history of intravenous drug abuse, and enrolled on the St Luke's-Roosevelt Hospital Center Methadone Program, had baseline evaluations performed from September 1984 to April 1987. The study was designed to examine immunologic parameters associated with HIV seropositivity and those predictive of progression to AIDS-related complex (ARC) and AIDS. Sixty-four patients (32%) had antibodies to HIV by enzyme-linked immunosorbent assay (ELISA), with confirmation by Western blot and none of these patients had ARC or AIDS at the time of initial evaluation. The mean values for white blood-cell count, absolute lymphocyte count, proportion and absolute CD4, and CD4/CD8 ratio were decreased significantly in the HIV-seropositive group compared with the HIV-seronegative group. On the other hand, levels of circulating beta 2-microglobulin, SCD8, SIL-2R, and HIV p24 antigen were significantly elevated in the HIV-seropositive group compared with the HIV-seronegative group.
The effectiveness of the Dial-A-Phone (D-A-P) instructional package plus a least intrusive prompt hierarchy was compared to a least intrusive prompt hierarchy alone for teaching adults with moderate developmental disabilities to match digits of personal phone numbers with digits on a rotary dial telephone. Instructional programs were administered in the context of an alternating treatments design. The dependent variable was the percentage of digits matched independently per session (21 digits per session). Results suggest that although a least intrusive prompt hierarchy alone produced findings similar to the D-A-P plus prompts procedure for one subject, the D-A-P plus prompts package was the most effective in helping both subjects to match digits independently. Strategies for individualizing the D-A-P program were discussed.
Behavioral momentum refers to the tendency for behavior to persist following a change in environmental conditions. The greater the rate of reinforcement, the greater the behavioral momentum. The intervention for noncompliance consisted of issuing a sequence of commands with which the subject was very likely to comply (i.e., high-probability commands) immediately prior to issuing a low-probability command. In each of five experiments, the high-probability command sequence resulted in a "momentum" of compliant responding that persisted when a low-probability request was issued. Results showed the antecedent high-probability command sequence increased compliance and decreased compliance latency and task duration. "Momentum-like" effects were shown to be distinct from experimenter attention and to depend on the contiguity between the high-probability command sequence and the low-probability command.
Squamous cell carcinoma of the anus (SCCA), an aggressive and often fatal malignancy, has traditionally been treated with surgery. In recent years, however, nonoperative therapy has emerged as an alternative to operation. Twenty five years of experience with SCCA at this institution were reviewed to examine the presentation and outcome of a population treated primarily with surgery. Forty two patients, including 26 women and 16 men, had a mean age of 56 years. SCCA was usually heralded by a mass, bleeding, or pain and was associated with chronic perianal disease in 25.8%. Symptoms were present for an average of 11 months. Among the patients in this review, 92.3 per cent underwent radical surgery, while 11.9 per cent had radiation as their primary therapy following palliative surgery or local excisions for biopsy. Actuarial 5-year-survival for the entire group was 45.5 percent; all patients with nodal or disseminated disease at diagnosis have died. Patients with perianal lesions fared no better than those with anal tumors, probably due to the unusually large perianal tumors in this series. To diagnose SCCA at its earliest stage, a high index of suspicion must be maintained when dealing with anal and perianal lesions, especially if the abnormality is chronic. When compared with reported advances in combined therapy, it is likely that in most cases surgery alone no longer offers optimal treatment for SCCA.
A ten-year (1974 to 1984) retrospective chart review was conducted to find all patients with peptic ulcer perforation associated with steroid treatment. During this period, 151 peptic ulcer perforations occurred, 25 (17%) associated with steroid use. Twenty patients had the diagnosis confirmed at operation, five at autopsy. The most common operative procedure was oversewing of the perforation with an omental patch (ten cases). Postoperative complications occurred in 16 patients and were multiple in 11. Underlying malignant neoplasms were the most common concurrent disease (11 patients), five patients having brain metastasis. Of 25 patients, 15 died--five preoperatively and ten postoperatively. Patients older than age 50 years had an overall mortality of 85%; those younger than age 50 years, 17%. A recurring pattern in 21 patients was perforation occurring after a major increase in steroid dose (pulse). Ulcer perforations associated with steroid use constitute a significant portion of all ulcer perforations, are lethal in most patients older than age 50 years, and are often associated with a steroid pulse before perforation.
The nucleotide sequences of the spike precursor genes of infectious bronchitis virus strains M41 and 6/82 have been determined and compared with that of the Beaudette strain which we have previously sequenced. The two Massachusetts strains, M41 and Beaudette, were found to be remarkably similar, having only 3.7% of the amino acids different. The situation with 6/82, one of the new field isolates, is quite different and this strain had 13.8% of its amino acids different from Beaudette. The differences identified are discussed in terms of the structural features of the spike protein.
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