Biomedical subjects
B Montgomery
Publications and source records attributed to B Montgomery.
Localization of transfused neutrophils to site of infection during treatment with recombinant human granulocyte-macrophage colony-stimulating factor and pentoxifylline.
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Beta-blocking agents inhibit Na+K+ATPase in cultured corneal endothelial and epithelial cells.
An effort was made to determine whether the beta-blocking agents: timolol maleate and betaxolol hydrochloride could affect the activity of the plasma membrane, transport ATPases of corneal endothelial and epithelial cells grown in culture. It was found that both agents were able to inhibit the activity of Na+K+ATPase in endothelial cells in the concentration range from 10(-12) to 10(-4) M (47-77% inhibition with timolol and 24-78% inhibition with betaxolol). In concentrations of 10(-9) M or greater (for betaxolol) and 10(-12) M or greater (for timolol) the inhibition was highly significant (p less than .001). Timolol maleate also inhibited the activity of Na+K+ATPase in epithelial cells in the concentration range from 10(-12) to 10(-4) M (16-68%). The inhibition was significant to the p = .002 level at concentrations greater than 10(-11) M. Although the data suggested that both drugs caused inhibition of Mg+2ATPase through the same concentration ranges, none of the values were statistically different compared to the controls. This study may point to a minor inhibition of the deturgescent pump with the use of these agents. It may also indicate caution for usage in patients with metabolically stressed corneas.
Age as a function of ATPase activity in cultured corneal endothelial cells.
As cells grown in tissue culture age, they typically become altered when compared to their in vivo counterparts. Bovine corneal endothelial cells were grown in culture for periods up to 60 days (primary = 10 days; secondary = 50 days). The plasma membrane enzymes: Na+K+ ATPase and Mg2+ ATPase were assayed for specific activity at selected intervals throughout the growth periods. In primary cultures, it was found that Na+K+ ATPase was quite low at 5 days (0.05 units), but increased fourfold at 10 days (0.22 units). By contrast, Mg2+ ATPase changed little over the same period. Tissue cultures grown secondarily had Na+K+ ATPase activity fall 0.3 units (0.52 to 0.22) for 35 days after a single trypsinization. After five trypsinizations over a 50-day period, the activity fell 0.23 units (0.33 to 0.10). The alterations in Mg2+ ATPase activity were more complex in secondary cultures. In the instance in which a single trypsinization was used, the activity fell 0.15 units at day 20, rose 0.12 units (above the starting value) at day 25, then returned to the initial level by day 35. When multiple trypsinizations were used, the activity fell 0.06 units by day 30, then remained stable for the duration. The data may be indicative of mechanisms such as receptor alteration, feedback inhibition and genetic instability when these cells are grown in culture.
The acidification response of normal subjects to ammonium chloride using a 3-day loading test.
The acidification response to NH4 Cl loading (0.1 g/kg bw/day) was tested in 16 normal healthy subjects in the basal fasting state on Day 4, the subjects having taken the salt daily for the 3 previous days. The response was measured in terms of blood pH and in urine, creatinine, phosphate, pH, titratable acidity, ammonium, net acidity and creatinine clearance. To minimise inter-subject variation the urine values were adjusted to a standard body surface area of 1.73 m2. A normal range for the blood pH of the mean value +/- 2 SD, encompassed the observed range of values. However, to fit the observed range of acid-base values in urine into the 2 SD range required a logarithmic transformation of the data. Statistical analysis confirmed a significant correlation between blood [H+] net acid secretion, urine titratable acidity and ammonium. Urine net acid secretion was positively correlated with urinary phosphate, titratable acidity and ammonium.
The treatment of secondary orgasmic dysfunction II.
This study investigated the impact of group treatment on women with secondary orgasmic dysfunction and their partners. Eleven couples received 4 hours of basic sex education, after which seven of the couples received a Combination treatment format consisting of communication skills followed by sexual skills, while four of the couples received the opposite sequence. No significant differences were found between the two sequences. When compared with similarly recruited control couples in a previous study, a significantly greater number of treated women reached or exceeded the 50% criterion for coital orgasmic functioning after treatment. Couples who reported a better relationship adjustment prior to treatment reported a significantly greater gain in total sexual harmony than did less adjusted couples. Across the treatment conditions, women who had reached coital orgasm prior to treatment reported a significantly greater increase in relationship adjustment between the post-sex education and 6-month follow-up testing periods than women who had never reached coital orgasm. Some discrepancies in outcome were found in comparison with our earlier study, suggesting that subject heterogeneity may influence differential outcomes.
Sodium and potassium saturation kinetics of Na+K+-ATPase in plasma membranes from corneal endothelium: fresh tissue vs. tissue culture.
The maximal velocity (Vmax) and the apparent dissociation constant (K0.5) of Na+K+-ATPase have each been estimated with respect to sodium and potassium ion activation. These estimations were made from the enzymatic activity of plasma membrane preparations derived from bovine corneal endothelial cells. The determinations were made on cells obtained from fresh tissue and from secondary tissue cultures. Two methods were used to obtain the estimates: the first used a combination of Eadie-Hofstee and Hill plots; the second used Eisenthal-Cornish-Bowden plots. The Vmax for sodium was 5.58-5.60 mumol Pi/mg protein/30 min for fresh tissue vs. 2.00-1.80 mumoles Pi/mg protein/30 min for tissue cultures. The corresponding K0.5 values were 62-57 mM (fresh tissue) vs. 7.9-6.7 mM (tissue culture). Vmax for potassium was 4.28-4.00 mumoles Pi/mg protein/30 min for fresh tissue vs. 1.37-1.34 mumoles Pi/mg protein/30 min for tissue cultures. The corresponding K0.5 values were 3.3-3.1 mM (fresh tissue) and 1.7-1.7 mM (tissue culture). The results indicate a lowered activity and change in affinity of the enzyme for the two ions in tissue cultures compared to fresh tissues. The detergent Lubrol W-X increased activity in both tissue sources. Sonication had no significant effect on the activity. Variations in pH (7-9) indicated that the highest activity was obtained at pH 7.8 for the enzyme in tissue culture while activity was highest at pH 8.0 for the enzyme in fresh tissues. These differences in kinetic activity suggest a response to changes in the ion requirements of these cells due to their environment, developmental stage or some other parameter.
A retrospective study of patients with cancer in their terminal year.
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Treatment of secondary orgasmic dysfunction: an outcome study.
This study investigated the differential effectiveness of various treatment formats for 55 couples in which the woman reported secondary orgasmic dysfunction (defined as the inability of the woman to reach orgasm during intercourse, with or without clitoral stimulation, more than 50% of the time for the last 5 months). Couples received two 2-hr sessions of sexual reeducation and were then assigned into one of four treatment conditions (a communication skills format, a sexual skills format, one of two combination formats) or into one of two control conditions (an attention-comparison control condition which consisted of didactic presentations, or a waiting-list control condition). Treatment was conducted by one of two female clinical psychologists in groups of between four to six couples. No significant differences were found between the different treatment conditions at the posttest or at the 6-month follow-up. Statistical comparisons conducted between the combined treatment and combined control conditions showed that the couples who received treatment reported significantly less overall sexual dissatisfaction and significantly greater sexual harmony at the posttest; however, these differences became nonsignificant at the follow-up. In comparison with the women in the control conditions, a significantly greater number of women who received treatment reached or exceeded the project's 50% criterion for coital orgasmic functioning at the posttest; however, these differences became nonsignificant at the follow-up. Couples who reported less relationship adjustment prior to treatment showed greater overall gains in coital orgasmic frequency than couples who reported better relationship adjustment.
Immunobiology of the feto-maternal interface.
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Polyurethane in the management of ulcerating lesions of the lower extremities.
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Ontogeny of the MHC antigens on human trophoblast cells during the first trimester of pregnancy.
The presence and the ontogeny of class I and class II major histocompatibility (MHC) antigens were investigated on human trophoblast cells in single cell suspensions of collagenase dispersed placentae during the first trimester of pregnancy by using a highly sensitive radioautographic approach. Cells were treated with monoclonal anti-HLA-A,B,C or anti-HLA-DR (or anti-human Ia) antibodies followed by 125I-labeled protein A, normal mouse serum, or medium alone used as negative controls, and monoclonal antibodies against trophoblast specific antigenic markers (anti-Trop 2, NDOG-1, and NDOG-2) used as positive controls for specificity of trophoblast labeling. Tissue controls were provided by Ficoll-paque-separated adult human peripheral blood lymphocytes (PBL), and placental lymphocytes were used as additional internal controls. Results revealed variable but specific labeling of cytotrophoblast cells for class I but not class II MHC antigens at all gestational stages during the first trimester. The incidence of HLA-A,B,C antigen-bearing cytotrophoblast cells in early gestational (5 to 8 wk) placentae was high (75 to 91%) in the minority, but was low to medium (35 to 66%) in placentae at later gestational intervals (9 to 12 wk). The initial antigen density on the labeled cytotrophoblast cells as reflected by the median silver grain counts per unit area was approximately 75% of that noted on adult PBL or placental lymphocytes at 5 to 7 wk. The density then dropped to 50% of the initial level by the eighth week of gestation with no further change up to 12 wk. Syncytiotrophoblast cells revealed no appreciable labeling for either antigen class. This could not be explained by antigen stripping due to the collagenase dispersion procedure; specific labeling was not detectable on the syncytiotrophoblast cell layer in situ in histologic sections after intact chorionic villi had been directly exposed to 125I-labeled monoclonal anti-class I antibody. These results are qualitatively similar to our findings in the mouse in revealing the presence of class I MHC antigens on a major population of trophoblast cells.
Concerns of some semiprofessionals working in professionally directed programs.
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Caregiver education: feminist or male model?
Most nurses have become aware that they work in patriarchal organizations and understand how oppressive and destructive this is to their career and their work. Few nurses recognize that this same male model dominates many nursing education programs, even those designed, delivered, and controlled by nurses. A study was undertaken to determine the learning needs of critical care nurses in Atlantic Canada and identify obstacles that prevented them from meeting their needs. The findings and the subsequent development of an education program are described. The findings are related to feminist values and feminist-based models of education that seem to be congruent with women's needs.
Adjunctive interventions for burn pain control: comparison of hypnosis and ativan: the 1993 Clinical Research Award.
Thirty-two patients hospitalized for the care of major burns were randomly assigned to groups that received hypnosis, lorazepam, hypnosis with lorazepam, or placebo controls as adjuncts to opioids for the control of pain during dressing changes. Analysis of scores on the Visual Analogue Scale indicated that although pain during dressing changes decreased over consecutive days, assignment to the various treatment groups did not have a differential effect. This finding was in contrast to those of earlier studies and is likely attributable to the low baseline pain scores of subjects who participated. A larger number of subjects with low baseline pain ratings will likely be necessary to replicate earlier findings. The results are argued to support the analgesic advantages of early, aggressive opioid use via PCA or through careful staff monitoring and titration of pain drugs.
Allo-antigenicity of trophoblast cells.
Trophoblast cells of the placenta represent the frontier of the conceptus at the feto-maternal interface, exposed to the maternal immune system. The presence or the absence of major histocompatibility (MHC) antigens on trophoblast cells, thus, is a key determinant of immune interactions between the mother and the allogeneic fetus during pregnancy. This article critically reviews the studies of the alloantigenic status of murine and human trophoblast cells, including the published data in the mouse and unpublished data in the human in the authors' own laboratory. It is shown that, in both these species, a significant proportion of trophoblast cells express Class 1 but not Class 2 MHC antigens in a manner directly accessible to the maternal immune system. However, the lack of immunogenicity of semiallogeneic trophoblast cells can not solely be explained on the basis of the absence of Class 2 molecules, despite the presence of Class 1 molecules. It is proposed either that the Class 1 MHC antigens on the trophoblast cells are presented in a nonimmunogenic manner to the maternal T cells or else that certain cells at the feto-maternal interface (eg, fetally derived trophoblast cells, maternally derived lymphoid cells, or decidual cells) elaborate potent immunosuppressor molecules capable of abrogating T cell alloreactivity.