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Biomedical subjects

C M Brown

Publications and source records attributed to C M Brown.

276 records · Page 16Linked to original sources
PubMedDate not supplied

Ionized calcium buffering in the transfused anhepatic patient: Ab initio calculations of calcium ion concentrations.

Homeostatic control of ionized calcium can be volatile during liver transplantation, particularly during the anhepatic stage. Recently, an opportunity arose to evaluate an 11-year-old girl who developed persistent ionic hypocalcemia during a prolonged anhepatic period subsequent to the failure and removal of the graft. The patient was remarkable for having survived a 34-hour anhepatic interval before a second and successful orthotopic liver transplant. Ionic hypocalcemia (ionized calcium less than 1 mmol per L) coexisted with significant hypercalcemia (total calcium greater than 5 mmol per L) during this anhepatic interval. The discrepancy was due to high concentrations of citrate, which accumulated from the multiple transfusions of citrated blood, and the inability to metabolize citrate in the anhepatic state. Using a mathematical model to solve for free calcium ion concentration in the presence of multiple ligands, it is demonstrated that prolonged hypercitricemia markedly alters the calcium ion buffering properties of blood, and these changes must be recognized in order to prevent adverse clinical consequences of ionic hypocalcemia.

Blood Transfusion↗
PubMedDate not supplied

Forms of human milk folacin and variation patterns.

The pattern of folacin in 180 human milk samples collected from 16 women was studied before and after pteroylglutamic hydroxylase (conjugase) treatment. The differential response of Lactobacillus casei versus Streptococcus faecalis distinguishes N-5-methyltetrahydrofolate from other forms. Growth of Pediococcus cerevisiae differentiates the reduced monoglutamates, other than the N-5-methylated derivative, from oxidized folacins. Mean folacin activity with L. casei was 85.3 ng/ml. Prior to conjugase treatment of samples, mean activity was 46.9 ng/ml with this organism. The responses of S. faecalis and P. cerevisiae were 48% and 7.6%, respectively, of the total L. casei active folacins. The total L. casei active folacins increased from 76.5 ng/ml at 6 weeks of lactation to 97.1 ng/ml at 12 weeks of lactation. Increases were also observed with time of day: from morning (65.7 ng/ml), to afternoon (80.0 ng/ml), and to evening (114.7 ng/ml). Hindmilk had greater total L. casei activity (100.0 ng/ml) than foremilk (73.8 ng/ml). Although folacins active for S. faecalis and P. cerevisiae were not affected by duration of lactation, increases in folacin activity with time of day and from fore- to hindmilk were observed using both of these organisms. Values for the folacin content of human milk are therefore dependent on sampling procedures. Pteroylpolyglutamates of greater than or equal to 3 glutamic acid residues and N-5-methyltetrahydrofolate are the predominant forms of human milk folacin based on differential growth responses of L. casei, S. faecalis, and P. cerevisiae to these forms.

Bacteriological Techniques↗
PubMedDate not supplied

Synergized pyrethrin mousse, a new approach to head lice eradication: efficacy in field and laboratory studies.

The purpose of this study was to evaluate the pediculicidal and ovicidal efficacy of a new, single-application formulation of synergized natural pyrethrins (presented in an aerosol mousse form) compared with an established, effective formulation based on permethrin (in a creme rinse form). The trial was a single-blind, comparative, randomized, parallel-group study. Children between the ages 7 and 15 years and adults with active head lice infections, identified by the presence of live lice, were enrolled from a school and a children's home in Dhaka, Bangladesh. Prevalence of infection ranged from 75% to 100% in the two study centers. The field study confirmed laboratory findings showing pyrethrin mousse to be effective at killing both lice and their eggs with a single 10-minute application. Of 52 patients identified with lice, 42 were treated with pyrethrin mousse and 10 with permethrin creme rinse. In each case, a sample of viable louse eggs was taken from the patients' hair before and after treatment. The eggs were then incubated to assess ovicidal activity. After treatment, the patients were examined for lice on alternate days until day 8 and then again on day 14. None of the patients in either group was found to have lice up to 2 days after treatment. One patient was found to have two moribund hatchlings on day 4. By day 6, when any eggs still present on the scalp would be expected to hatch, 19 pyrethrin mousse-treated patients were available for assessment. Two patients had been reinfected from contacts.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMedDate not supplied

Non-radiological investigation of pancreatic disease.

Pancreatic exocrine insufficiency is investigated by long established techniques: either by duodenal intubation studies, or by indirect functional methods. Serum markers and specific gastrointestinal hormones are available for the diagnosis of pancreatic inflammation, carcinoma, and rare pancreatic endocrine tumours. The clinical utility of these diagnostic tests is discussed in this article.

Amylases↗
PubMedDate not supplied

Asthma. The states' challenge.

At the national level, asthma is increasingly being recognized as an important public health problem. Because of the significant role of environmental exposure in asthma morbidity, public health agencies have a critical role to play in the surveillance and prevention of the disease. In April 1996, the Council of State and Territorial Epidemiologists, with assistance from the Centers for Disease Control and Prevention, surveyed state and territorial public health departments to determine the status of their asthma surveillance and intervention programs. Of the 51 health departments that responded, only eight reported that they had implemented an asthma control program within the previous 10 years. Reasons cited for not having programs included lack of funds, shortage of personnel, and asthma not being a priority. Most states were unable to assess the burden of asthma because they lack data or face barriers to using existing data. Removing barriers to the use of data is a first step toward defining the scope of the asthma problem.

Adolescent↗