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Biomedical subjects

K Welch

Publications and source records attributed to K Welch.

At least 109 records · Page 6Linked to original sources
PubMed1971

The permeation of several materials into the fluids of the rabbit's brain.

1. (24)Na, (36)Cl and (35)S thiourea were infused I.V. in rabbits according to schedules designed to yield approximately level activity in plasma for periods up to 5 hr. Cerebrospinal fluid was sampled before ending the experiment by decapitation and the radioactivities in cerebrospinal fluid and in homogenized brain were compared in each case to a time weighted mean value for plasma.2. The results are considered in terms of a simplified model which specifically acknowledges the continuity of the extracellular and cerebrospinal fluids and thus the coupling between processes which occur at the interfaces bordering those fluids.3. From the rate constants for exchange across the blood-brain interface that were necessary for simulation of the observed behaviours, permeability coefficients for that interface were estimated for the materials studied and, from experiments of others, for (42)K.

Animals↗
PubMedDate not supplied

Characterization of two novel pre-B-cell lines (LK63 and LiLa-1): potential models of pre-B-cell differentiation.

In this report we describe two newly isolated pre-B acute lymphoblastic leukaemia cell lines. Both cell lines lack EBV as detected by the EBNA-1 gene probed Southern-blots. Neither cell line expressed the B-cell-specific CD20 antigen on the cell membrane. However surface expression of CD20 was induced by phorbol ester (TPA) on both LiLa-1 and LK63 cell lines. Other pre-B and B-cell lines, such as Reh, Nalm-1, and BALL-1 did not exhibit these changes in phenotype. Previous immunoprecipitation studies have noted that a broad 50-55 kD band co-precipitates with the characteristic 33-37 kD CD20 protein. We demonstrate that, while the 33-37 kD CD20 species was undetectable on resting LiLa-1 and LK63 cells, in each case a 50-55 kD protein was immunoprecipitated by the CD20 antibody. However, the failure to detect any cell surface CD20-associated antigen on the control cells by immunophenotyping indicated that the CD20 epitope of the 50-55 kD molecule was not expressed on the cell surface. Following exposure to TPA the 50-55 kD species was reduced over 48-72 h while the level of the p33-37 CD20 protein was increased. Northern-blot analysis showed that the 50-55 kD protein was not a cryptic form of CD20 as the uninduced cells contained no detectable CD20 mRNA. The decrease of the 50-55 kD protein and the acquisition of the mature CD20 molecule were paralleled by a decline in proliferative activity in both cell lines. As expression of CD20 by normal pre-B cells also coincides with the cessation of cell division and maturation towards a mature B-cell phenotype, these cell lines appear to represent models for a discrete stage of B-cell differentiation which may be valuable in defining the signals regulating pre-B-cell proliferation.

Antigens, CD↗
PubMedDate not supplied

Women's health and low-income housing.

The inequities in health care and housing access experienced by low-income women in the United States are a continuing concern. This article addresses the interrelationships between housing and health as experienced by low-income clients so that health care practitioners can begin to build active and effective health-promoting partnerships with clients, their families, and their communities. A case study is presented that describes the actual experience of a woman living in a low-income housing development and its effect on her health and access to health care. The importance of the role of midwives in addressing the health care and advocacy needs of women in substandard housing is highlighted.

Female↗
PubMedDate not supplied

Recommendations and illustrations for combining hypnosis and EMDR in the treatment of psychological trauma.

Three experienced therapists, trained in hypnosis and EMDR, distilled some tentative hypotheses about the use of hypnosis in EMDR from fifteen cases, two presented here. When a therapist uses hypnosis with EMDR, it seems that the client is having difficulty or the therapist anticipates that the client will have difficulty managing the experiences processed with EMDR. Hypnosis initiated either during the introduction to EMDR or within a therapy session prior to the initiation of EMDR seems to have served two functions. The first function is to activate inner work that prepares the client to use EMDR successfully, and the second function is to facilitate overtly the processing of the traumatic experience. Clients might have two kinds of difficulties in managing affect or distress: (1) they may have a long-standing, irrational and strongly held belief that interferes with managing affect or distress, and (2) they may never have developed the capacity to tolerate intense affect, distress or pain. Should a therapist use hypnosis during the closing down phase of a session without preparing the client with hypnosis during the introduction to EMDR, the therapist should seriously reconsider the pace and focus of EMDR and the client's resources to manage affect and distress.

Adolescent↗
PubMedDate not supplied

Arsenic exposure, smoking, and respiratory cancer in copper smelter workers.

A report by Lee and Fraumeni in 1969 linked exposure to arsenic and other contaminants to a threefold excess of respiratory cancer among 8,047 employees at the Anaconda copper smelter. We established vital status through December 1977 for a sample of 1,800 men from the original cohort. Average arsenic concentrations were estimated for each smelter department based on industrial hygiene measurements made from 1943 to 1965. Departments with similar concentrations were combined into four categories of exposure: 1) low (less than 100 micrograms/m3), 2) medium (100-499 micrograms/m3), 3) high (500-4,999 micrograms/m3) and 4) very high (greater than or equal to 5,000 micrograms/m3). Three indices of individual arsenic exposure were developed: time-weighted average, 30-day ceiling, and cumulative. Exposures to sulfur dioxide and asbestos were also examined. Smoking habits were obtained by questionnaire. Mortality was compared to that of men in the State of Montana using the modified lifetable method. A clear dose-response relationship between arsenic exposure and respiratory cancer was demonstrated. Men in the highest exposure category had a sevenfold excess. Those in the low and medium categories had a risk close to that expected. Ceiling arsenic exposure appeared to be more important than did time-weighted average exposure. Sulfur dioxide and asbestos did not appear to be important in the excess of respiratory cancer, although sulfur dioxide and arsenic exposures could not be separated completely. Smoking did not appear to be as important as arsenic exposure. Our findings suggest that had men worked only in departments with low or medium arsenic exposures (i.e., less than 500 micrograms/m3) there would have been little excess respiratory cancer. Since the estimates of arsenic exposure were based on department averages rather than on concentrations for individual jobs, these results must be interpreted with caution.

Aged↗