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Biomedical subjects

S Pearson

Publications and source records attributed to S Pearson.

At least 73 records · Page 4Linked to original sources
PubMed1987

The effects of cheese snacks on caries in desalivated rats.

Rats that had had their submandibular/sublingual glands removed surgically, and their parotid ducts tied, developed fewer and less severe caries lesions on coronal and root surfaces when fed cheese snacks in addition to a cariogenic diet than when fed additional cariogenic snacks or no additional snacks. The effects of cheese snacks were particularly dramatic on root-surface caries. These observations may be relevant for elderly humans who are most likely to develop root surface caries. Populations of Streptococcus mutans did not differ among the groups. Actinomyces viscosus was not detected at the end of the experiment in any of the groups. The results of this study demonstrate that cheese exerts a protective effect against coronal and root-surface caries in rats with a severely limited salivary function.

Animals↗
PubMed1985

Comparative toxicities of alpha- and beta-N-oxalyl-L-alpha, beta-diaminopropionic acids to rat spinal cord.

alpha- and beta-N-oxalyl-L-alpha, beta-diaminopropionic acids, isolated from Lathyrus sativus seed, which is implicated in the pathogenesis of human neurolathyrism, were injected into rat lumbar cerebrospinal fluid. The alpha-isomer was neither acutely nor chronically toxic, whereas the beta-isomer was both an acute and a chronic neurotoxin in this test system. These results are relevant to the aetiology of neurolathyrism and suggest that the conversion of the beta- to the alpha-isomer that occurs during boiling of the seed prior to human consumption reduces the neurotoxicity of the seed.

Amino Acids, Diamino↗
PubMed1985

A clinical appraisal and comparison of double pump single needle dialysis systems.

Six recently developed double pump tidal flow single needle systems have been assessed clinically and the magnitude of recirculation, efficiency of dialysis determined and compared with the classical system (Bellco BL 760). Results indicate that the problems of designing twin pump systems with instantaneous response, occlusive rollers capable of generating clinically acceptable blood flow rates has been largely overcome and such systems offer a high degree of patient acceptance, flexibility, safety and an efficiency of dialysis comparable with that obtained using two needle access.

Blood Flow Velocity↗
PubMed1984

The prevalence of sexually stressful events among females in the general population.

Five hundred sixteen adult females were administered a questionnaire inquiring into the nature of sexually stressful events in their lives. There were 500 responses, and, of those, 298 (59.9%) had experienced an event of this type. A total of 416 different incidents were reported. They were categorized by the authors as either noninvasive (harassment, obscene calls, exposures, "peepers") or invasive (fondling, attempted rape, rape). The invasive incidents were most often initiated by a friend, acquaintance, or relative. The noninvasive events were almost always perpetrated by strangers. The subjects were asked to report the emotional impact of the events. All were reported to be stressful, with rape being the most stressful event. Regardless of whether formal therapy was sought, all victims reported lowered stress levels over time. There were 98 incidents reported when the subjects were 13 years of age or younger. There were 45 invasive events, including 9 rapes. All the rapes were committed by acquaintances or relatives. Only one victim of childhood rape received professional attention. Of the 41 women who were raped, nearly 75% were raped by acquaintances or relatives. This does not parallel existing emergency room data, suggesting that the group of patients who report to medical authorities may be a skewed sample of rape victims. Only four victims reported their rapes to either legal or medical authorities.

Adolescent↗
PubMed1984

Measurement of plasma caffeine concentrations by substrate labelled fluoroimmunoassay.

Abuse or misuse of caffeine has been implicated in the pathogenesis of a variety of clinical disorders and measurement of its plasma concentration is likely to become important in clinical laboratories in the future. A rapid, sensitive and easily performed method for the measurement of caffeine in biological fluids by the technique of fluoroimmunoassay is described. The results produced are precise and agree well with those obtained by radioimmunoassay or HPLC. Cross-reactivity of the antiserum with other substituted xanthines and uric acids is negligible for the major metabolites of caffeine but there is significant cross-reactivity with theophylline at concentrations likely to be found when this drug is being administered therapeutically. The measurement of caffeine by fluoroimmunoassay has a place in the clinical laboratory particularly where small batches of samples are to be analysed.

Binding Sites, Antibody↗
PubMed1983

Evaluation of a one-parameter flow analysis of cervical samples for gynecology cancer screening.

A total of 246 endocervical samples were collected for Papanicolaou staining and one-parameter flow cytometric DNA analysis (FCDA) using 4',6-diamidino-2-phenylindole as a DNA stain. Typical histograms derived from FCDA analysis were designated class I, II, III, and V. Two groups of patients were studied: 135 women referred for colposcopy (COLPO), and 79 women exposed to diethylstilbestrol (DES). The remaining 32 samples were evaluated and found unsatisfactory. In the colposcopy group FCDA assigned 38 patients normal, 62 mild to moderate dysplasia, 33 moderate to severe dysplasia, and 2 carcinoma in situ and invasive carcinoma. Agreement of Pap smear and FCDA occurred in 56, 59, 72, and 100%, respectively. In the diethylstilbestrol group 57 patients were normal and 12 had mild to moderate dysplasia according to Pap diagnosis. Agreement between FCDA and Pap diagnosis were 45 and 58%, respectively. However, FCDA did not falsely assign severe dysplasia or carcinoma in situ to any DES patient. This preliminary study based on FCDA appears to clearly differentiate patients with normal Pap smears from those patients with invasive cancer.

Carcinoma in Situ↗
PubMed1983

The nurse practitioner's role in complex patient management: hypertension.

The importance of hypertension as a risk factor and the size of the hypertensive population have created a demand for care of this problem. Nurse practitioners are effective managers of simple hypertension; however, high blood pressure often coexists with other chronic illnesses. Data are not yet available to support the role of the nurse practitioner in the management of more complex patients. The authors have examined the characteristics of patients and the processes and outcomes of care in a hypertension clinic in which physicians and nurse practitioners share responsibilities for patient care. The results show that the nurses are managing patients as complex as those seeing only physicians and are achieving better blood pressure control. The nurses successfully identify important problems and refer appropriately. Thus, nurse practitioners, with physician support, can serve as primary managers for even complex patients. Use of this model will significantly increase the resources available for care of hypertension.

Evaluation Studies as Topic↗
PubMed1981

The neurolathyrogen, beta-N-oxalyl-L-alpha,beta-diaminopropionic acid, is a potent agonist at 'glutamate preferring' receptors in the frog spinal cord.

A neurotoxic amino acid, beta-N-oxalyl-L-alpha,beta-diaminopropionate (beta-ODAP), found in seeds of Lathyrus sativus and a possible causative agent of neurolathyrism, was equipotent with kainate as a depolarizing agent of frog spinal cord ventral roots. beta-ODAP and kainate appeared to act on a common receptor, as their actions could not be differentiated pharmacologically. These results could explain some of the symptoms of neurolathyrism.

Amino Acids, Diamino↗
PubMed1981

Immunological control of hepatotoxicity and parasite egg excretion in Schistosoma mansoni infections: stage specificity of the reactivity of immune serum in T-cell deprived mice.

Within seven weeks of infection with 200 Schistosoma mansoni cercariae, T-cell deprived mice have been shown to suffer from extensive microvesicular damage to hepatocytes, and an inability to excrete parasite eggs at the same rate as comparably infected, immunologically intact controls. Administration of serum (CIS) from chronically infected, immunologically intact donors prevented the development of microvesicular cell damage and partially restored egg excretion rates in infected deprived mice. Serum pools obtained from mice injected either with intact S. mansoni eggs or with a homogenate of eggs emulsified in Freund's complete adjuvant (FCA) were as effective as CIS in preventing hepatotoxicity and restoring the rate of egg excretion in infected deprived recipients. The degree of protection of liver tissue afforded by immune sera could be monitored either by histopathological examination of liver sections or by estimation of serum transaminase concentrations, the results from both assays being generally in agreement. Sera from donor mice injected with cercarial or worm antigens in FCA were relatively inactive either in protecting against S. mansoni-induced liver damage or in reconstituting egg excretion rates in infected deprived mice. Serum from donor mice infected with 25 cercariae became hepato-protective between 49 and 53 days after infection of the donors, and the degree of hepatoprotective activity and egg excretion reconstituting capacity in the serum of 25 cercariae-infected donors was shown to increase between 8 and 16 weeks after infection. Increasing the size of infection of the serum donors to 100 cercariae gave only a marginal increase of hepatoprotective activity at 7 weeks when compared with serum donors infected with 25 cercariae for 7 weeks. Liver parenchymal cells of very heavily infected, immunologically intact mice were found to show microvesicular damage similar to that in livers of infected deprived mice, and administration of CIS to these normal mice was histopathologically protective. However, the elevated serum transaminase concentrations obtaining in the infected normal mice were not reduced to any extent by CIS. The results obtained from serum-reconstituted deprived mice are discussed in terms of the contribution they may make to a better understanding of the host-parasite relationship in immunologically intact mice.

Animals↗
PubMed1981

Identification and partial purification of an antigen (omega 1) from Schistosoma mansoni eggs which is putatively hepatotoxic in T-cell deprived mice.

T-cell deprived mice heavily infected with Schistosoma mansoni suffer from severe microvesicular damage to hepatocytes within seven weeks of infection. The damage can be prevented by administration of serum (CIS) obtained from mice chronically infected with S. mansoni or from mice immunized with intact or homogenized S. mansoni eggs. Reaction of serum samples from individual chronically infected mice in immunoelectrophoresis with S. mansoni egg homogenate has enabled the identification of at least 12 distinct immuno precipitation reactions. Precipitating antibody against one S. mansoni egg antigen, omega 1, has been detected in all mice with patent chronic infections, and anti-omega 1 antibody is the most concentrated of the precipitating anti-egg antibody species in pooled CIS. Pooled serum obtained from infected intact mice reacting predominantly against omega 1 was found partially to prevent the hepatotoxicity reaction on transfer to infected deprived mice. Serum samples from mice injected with egg homogenate fractionated either by preparative electrophoresis or by cation exchange chromatography, and containing antibodies reactive with antigen omega 1 in immunoprecipitation, were fully protective against liver cell damage induced by S. mansoni in deprived mice. Sera from mice immunized with other S. mansoni egg fractions, and which did not contain antibodies reactive with omega 1, were not hepatoprotective. Antigen omega 1 is compared and contrasted with other S. mansoni egg antigens that have been described.

Animals↗
PubMed1980

Comparative trial of sulphadiazine-trimethoprim (co-trimazine), co-trimoxazole and sulphamethizole in the treatment of uncomplicated urinary tract infections.

A combination of sulphadiazine and trimethoprim (co-trimazine) has been developed specifically for the management of urinary tract infections. The pharmacokinetics of co-trimazine make it possible to use lower doses of both the sulphonamide and trimethoprim than in co-trimoxazole, while maintaining clinical efficacy. One hundred and twenty women with a urinary tract infection were randomly allocated to a five-day course of treatment with either co-trimazine (sulphadiazine 410 mg and trimethoprim 90 mg 12-hourly), co-trimoxazole (sulphamethoxazole 800 mg and trimethoprim 160 mg 12-hourly) or sulphamethizole (1 g 8-hourly). The respective cure rates were 95, 98 and 90 percent. No serious side effects of therapy were encountered. Co-trimazine proved to be an effective antibacterial combination for the treatment of uncomplicated urinary tract infections.

Adult↗
PubMed1979

Clinical use of cefamandole: a new cephalosporin.

Cefamandole, a new cephalosporin derivative, has been used in treatment of six patients who had diminished renal function and respiratory infections, and of 14 patients with urinary tract infections (UTI). Infection was eliminated in all patients with respiratory infections, and in seven of the patients with UTI. No serious side effects were encountered and, even in patients with pre-existing renal dysfunction, no reduction in renal function occurred.

Adolescent↗