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S Shepherd

Publications and source records attributed to S Shepherd.

52 records · Page 3Linked to original sources
PubMed1989

Searching for pattern and mutation in the Drosophila genome with a P-lacZ vector.

A P-element vector has been constructed and used to generate lines of flies with single autosomal P-element insertions. The lines were analyzed in two ways: (1) the identification of cis-acting patterning information within the Drosophila genome, as revealed by a lacZ reporter gene within the P element, and (2) the isolation of lethal mutations. We examined 3768 independent lines for the expression of lacZ in embryos and looked among these lines for lethal mutations affecting embryonic neurogenesis. This type of screen appears to be an effective way to find new loci that may play a role in the development of the Drosophila nervous system.

Animals↗
PubMed1989

Separate effects of gravity and venous pressure on regional and capillary blood flows in the human finger.

The objective of this study was to determine if and to what extent a veno-arteriolar reflex is responsible for the adjustments in regional and capillary blood flows that occur in response to gravitational stress in the human finger. Nine male subjects 20 to 40 years of age consented to have regional cutaneous blood flow measured in the index finger via a laser Doppler flowmeter (LDF) and blood cell velocity (CBV) measured in individual nailfold capillaries via video microscopy while placing the hand 20 then 40 cm below the heart and while a pneumatic cuff placed around the wrist was inflated to pressures of 20, 40 than 60 mm Hg. Both lowering the hand and selective elevation of venous pressure elicited significant decreases in LDF and CBV (P less than 0.03). The flow reductions that occurred with lowering the hand 20 cm below the heart were significantly greater (P less than 0.05) for both LDF and CBV when compared to cuff pressure elevation of 27 cm H2O (20 mm Hg), and significantly greater (P less than 0.095) for LDF in matching the 40 cm below the heart position to data obtained at a cuff pressure of 57 cm H2O (40 mm Hg). Analyzing the flow responses relative to precapillary perfusion pressure (arterial pressure - estimated capillary pressure) indicated the reductions in LDF and CBV that occurred in response to cuff pressure elevation were a passive effect of the increase in venous pressure itself. These results indicate that the reductions in regional and capillary blood flow that occur in response to gravitational stress in the fingers are due to myogenic vasoconstriction of arterioles secondary to a rise in arterial pressure and that a veno-arteriolar reflex mechanism is not operative in this region of the cutaneous circulation.

Adult↗
PubMed1989

In vivo evaluation of the effects of altered cyclosporine metabolism on its immunosuppressive potency.

The dose-response and plasma concentration-response relationships of cyclosporine after both inducing and inhibiting its metabolism were studied in a mouse heart transplant model. The metabolism of cyclosporine was altered by coadministering phenobarbital and cimetidine as metabolism inducing and inhibiting agents, respectively. We found that phenobarbital depressed the immunosuppressive potency of cyclosporine by enhancing its metabolism resulting in lower cyclosporine blood levels. On the other hand, when cimetidine was administered concurrently with cyclosporine, the immunosuppressive effect was enhanced due to inhibition of the metabolism of cyclosporine which produced higher cyclosporine blood levels. When graft survival was evaluated relative to blood cyclosporine concentrations, however, it appeared that cimetidine had a direct negative effect on the survival of transplanted organs independent and contrary to its effect on the accumulation of cyclosporine. The immunosuppression produced by cyclosporine at these elevated blood levels was less than expected. The accrued data support the conclusion that cyclosporine and not its metabolites are primarily responsible for its immunosuppressive activity in the mouse.

Animals↗
PubMed1989

Infectious and toxic syndromes from fish and shellfish consumption. A review.

Primary care physicians care for large numbers of patients presenting with "food poisoning" or gastroenteritis. When a patient who presents with acute gastrointestinal illness, especially in conjunction with neurologic or cutaneous symptoms, is evaluated, the history should focus on past seafood consumption (particularly raw or undercooked seafood). The infectious syndromes are generally self-limited and respond to supportive care; exceptions are those caused by Vibrio cholerae and Vibrio vulnificus, which may be fatal in severe cases. The toxic syndromes are uncommon and fall into two categories: the histaminelike syndrome of scombroid poisoning and the neurotoxic syndromes, including ciguatera, paralytic shellfish poisoning, and puffer fish poisoning. Recognition of these clinical entities may lead to more appropriate management and preventive measures.

Animals↗
PubMed1988

Radiotherapy and the management of metastatic bone pain.

A pilot study was carried out to investigate the ease with which pain could be quantitatively assessed before and after treatment. The results obtained showed the methods used to be suitable and convenient for quantifying pain both before and after radiotherapy, given as either a single or a multiple fraction regimen. The protocol could be used to produce data for statistical analysis in a long-term, prospective, randomised trial to determine the optimum single dose of radiation necessary for maximum pain relief with minimal side effects.

Aged↗
PubMed1988

Ampicillin, tetracycline, and chloramphenicol resistant Haemophilus influenzae in adults with chronic lung disease. Relationship of resistance to prior antimicrobial therapy.

Antibiotic resistance in 1,003 sputum isolates of Haemophilus influenzae from adults with chronic lung disease was assessed from January 1983 through June 1986. The incidence of resistance was 3.2% for tetracycline, 0.6% for chloramphenicol, and 12.5% for ampicillin. Resistance to ampicillin or tetracycline usually occurred alone, while 100% of chloramphenicol resistant isolates were co-resistant to tetracycline or ampicillin. More than 90% of antibiotic resistant isolates were nontypable and belonged to biotypes II, III, or V. Chart reviews of 331 patients revealed that patients with ampicillin resistant isolates were more likely than control subjects to have received ampicillin in the prior 6 wk (33% versus 6%, p less than 0.0001), whereas patients with isolates resistant to tetracycline or chloramphenicol plus tetracycline were more likely to have received tetracycline than control subjects (24% and 50%, respectively, versus 5%, p less than 0.005). The incidence of ampicillin resistance and the reluctance of physicians caring for adults to use chloramphenicol suggests that a newer cephalosporin such as cefotaxime may be the initial therapy of choice for severe H. influenzae disease in our patient population.

Adult↗
PubMed1988

Evaluation of the role of skin temperature in the response of cutaneous capillary blood flow to indirect heat.

The purpose of this study was to test the hypothesis that the rise in cutaneous capillary blood flow that occurs while heating a remote region of the body; i.e., indirect heating, is mediated by an increase in local heat flux secondary to the opening of larger vessels; e.g. AVAs. Twelve unanesthetized rats were placed in a chamber and exposed to a 35 degree C environment while their tail remained unheated. Measurements of regional skin blood flow in the tail were obtained by a laser Doppler flowmeter (LDF) while measurements of blood cell velocity in individual capillaries (CBV) within the subepidermal vascular plexus were made by videodensitometry before and during body heating under two procedures: A control procedure in which skin temperature of the tail (TS) was allowed to increase as LDF increased, then under an experimental procedure during which TS was "clamped" at 25 degree C during body heating. During the control procedure TS increased from 24.5 to 33.2 degrees C while LDF increased by 404% and CBV increased by 89%. During the experimental heating procedure in which TS was clamped, respective increments in LDF and CBV were 414% and 72%. Respective changes in LDF and CBV between the control and experimental procedures were not significantly different. These results argue against local heat flux as a major mechanism for an increase in cutaneous capillary blood flow during indirect heating.

Animals↗
PubMed1988

Alternative or additional medicine? A new dilemma for the doctor.

The growth of alternative medicine poses particular problems for general practitioners working in the National Health Service. This paper reviews the subject and presents preliminary results of a two-stage study of the prevalence of use of alternative medicine in a south London practice. Extended interviews with users explored motivations for choice of treatment and attitudes towards orthodox and alternative health care. The study suggests that many patients are making use of alternative medicine in addition to their NHS consultations without the knowledge of their general practitioners. The clinical and ethical implications of this pattern of illness behaviour are discussed.

Adult↗
PubMed1982

Some health problems of the Maldives.

It is difficult to quantify the major health scourges from which the Maldivians suffer because of the scattered nature of their settlements and their conservative attitudes to health and hygiene-related matters. Projects to improve the quality of the health and disease data have been instituted by the World Health Organization (WHO) and the Maldivian Ministry of Health. The paper analyses information that has since become available on three major ill-health conditions in the Maldives, namely infant deaths, malaria and leprosy.

Adolescent↗
PubMedDate not supplied

Induction of molecular remission by donor peripheral blood leukocyte therapy in patients relapsing with extramedullary blastic phase chronic myeloid leukemia after allogeneic bone marrow transplantation.

Two patients with chronic myeloid leukemia (CML) who relapsed in blastic transformation after allogeneic bone marrow transplantation (BMT) were treated with infusions of leukapheresed peripheral blood mononuclear cells from their original donor. At relapse, their disease was characterized by symptomatic extramedullary deposits of leukemia with minimal (PCR positive, cytologically negative) involvement of bone marrow. Treatment with donor cell infusions was associated with clinical remission, return of full donor chimerism and loss of the BCR-ABL transcript detectable in bone marrow before donor leukocyte infusion (molecular remission). Donor leukocyte infusions should be considered for therapy of relapsed blastic phase CML after allogeneic BMT, especially when the relapse is primarily extramedullary and responsive to local and systemic cytoreductive therapy. However, severe GVHD and CNS relapse remain obstacles to achieving a successful long-term outcome.

Adult↗