Plant cardiac glycosides and digoxin Fab antibody

The potential application of the Digoxin Fab antibody (Wellcome Digibind) in the clinical management of plant poisoning was investigated. The cardiac glycoside contents of various Australian plants were studied using immunoassay techniques. The cross-reactions of the Fab antibody and two digoxin assay antibodies against extracts of these plants were also studied. Results obtained indicated that the Digibind antibody cross-reacted with a wide range of glycosides contained in Australian plants and therefore could be of use in the treatment of life-threatening plant poisoning.     

Failure of intravenous infusions in neonates

The median life expectancy (survival) of 286 peripheral intravenous infusion sites in 105 babies in a children's intensive care unit was 36 h. Unadjusted univariate survival analysis revealed that dextrose infusions and the initial infusions received by a baby had longer survival than total parenteral nutrition (TPN) infusions and later infusions respectively. Also infusions with cloxacillin and penicillin survived for longer than average while infusions with phenytoin had reduced survival. Gestational age, weight, infusion site, other drugs, co-infusion of Intralipid with TPN solutions and neutralization of TPN did not influence survival of infusions. Multivariate survival analysis confirmed the findings for TPN and penicillin but not for cloxacillin, phenytoin or later infusions. Multivariate analysis also suggested that survival was improved with ampicillin and aminophylline and worse for leg sites, for older babies and for infusions in which the fluids were given at greater rates. It also indicated that neutralization of TPN improved survival.     

Stem Cell Migration and Proliferation During Severe Anemia

The pluripotential stem cell (CFU) compartment of marrow and spleen wasevaluated in mice subjected to an intense erythroid stimulus associated withphenylhydrazine-induced anemia. Erythroid hyperplasia occurred in both marrow and spleen. CFU in the marrowgradually declined to approximately 50per cent of control levels (day 5) whiletheir numbers in the spleen increased(fourfold) by day 3 and were maintainedat this level for several days. Thesechanges in numbers of marrow andsplenic CFU were not associated withCFU proliferation. Thereafter, CFU inthe marrow, but not in the spleen, entered active cell cycle. The data suggestthat CFU migrate from marrow to spleenduring the demands of severe anemia.The induction of marrow CFU into cyclefurther suggests a negative feedback,which, perhaps through cell-cell interaction, maintains stem cells at a criticalcompartment size. The failure of splenicCFU to cycle may reflect the converseeffect, i.e. an inhibition on stem cell proliferation in the wake of an expandedstem cell pool.

Submitted on March 17, 1970 Revised on May 14, 1970 Accepted on June 9, 1970     

The Renin–Angiotensin System Mediates the Effects of Stretch on Conduction Velocity,Connexin43 Expression,and Redistribution in Intact Ventricle

Effect of Stretch on Conduction and Cx43 . Introduction: In disease states such as heart failure, myocardial infarction, and hypertrophy, changes in the expression and location of Connexin43 (Cx43) occur (Cx43 remodeling), and may predispose to arrhythmias. Stretch may be an important stimulus to Cx43 remodeling; however, it has only been investigated in neonatal cell cultures, which have different physiological properties than adult myocytes. We hypothesized that localized stretch in vivo causes Cx43 remodeling, with associated changes in conduction, mediated by the renin–angiotensin system (RAS). Methods and Results: In an open‐chest canine model, a device was used to stretch part of the right ventricle (RV) by 22% for 6 hours. Activation mapping using a 312‐electrode array was performed before and after stretch. Regional stretch did not change longitudinal conduction velocity (post‐stretch vs baseline: 51.5 ± 5.2 vs 55.3 ± 8.1 cm/s, P = 0.24, n = 11), but significantly reduced transverse conduction velocity (28.7 ± 2.5 vs 35.4 ± 5.4 cm/s, P < 0.01). It also reduced total Cx43 expression, by Western blotting, compared with nonstretched RV of the same animal (86.1 ± 32.2 vs 100 ± 19.4%, P < 0.02, n = 11). Cx43 labeling redistributed to the lateral cell borders. Stretch caused a small but significant increase in the proportion of the dephosphorylated form of Cx43 (stretch 9.95 ± 1.4% vs control 8.74 ± 1.2%, P < 0.05). Olmesartan, an angiotensin II blocker, prevented the stretch‐induced changes in Cx43 levels, localization, and conduction. Conclusion: Myocardial stretch in vivo has opposite effects to that in neonatal myocytes in vitro. Stretch in vivo causes conduction changes associated with Cx43 remodeling that are likely caused by local stretch‐induced activation of the RAS. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1276‐1283, November 2010)     

DFP Labeling of Platelets During Recovery from Thrombocytopenia

Rat platelets were labeled with tritiated diisopropylfluorophosphate(³H-DFP) during recovery from acute thrombocytopenia. The results indicated that there was significant labeling of megakaryocytes by ³H-DFPwhich, in the presence of an increased rate of platelet production, resulted inmaintenance of relatively constant values for platelet-bound radioactivity during the period of maximum platelet production and reactive thrombocytosis.Significant random loss of platelets was apparent, and, when a cohort ofyoung platelets was transfused to normal recipients, they were destroyed at anormal rate.

     

Risk factors for suicide and undetermined death among in-patient alcoholics in Scotland

Approximately 32 000 patients, representing all those discharged alive from inpatient psychiatric care for alcoholism in Scottish hospitals between 1974 and 1983, were traced for up to 10 years by means of a national record-linkage study in order to ascertain the frequency of suicide and undetermined deaths. The cumulative mortality from these causes was 1.17% at 5 years and 2.01% at 10 years. Several risk factors were investigated, using survival analysis techniques. Sex, age, social class (mates only) and marital status were not found to be useful predictors, but the different secondary diagnoses recorded at discharge were associated with major variations in outcome. Attention is drawn to the prognostic importance of a secondary diagnosis of both affective disorders and personality disorders, and some implications of the findings are noted concerning attempts to construct population models linking alcoholism, demographic characteristics and suicide.     

The pathology of hysterectomy specimens following trans-cervical resection of the endometrium

The pathological findings in 29 hysterectomy specimens from a series of 175 patients undergoing trans-cervical resection of the endometrium are presented. In all but one case endometrium was present. Although all phases of the normal menstrual cycle were represented, in nine (28%) cases the endometrium appeared inactive, sometimes showing appearances similar to those in Asherman's syndrome. Adenomyosis was present in five (17%) cases and simple hyperplasia in one case. Haematocolpos was present in two cases. Inflammation was uncommon, usually mild in degree and present in the superficial myometrium. Four (14%) cases contained epithelioid or foreign body granulomas in the superficial myometrium. Deposits of haemosiderin and amorphous brown and/or particulate black pigment were seen in a total of 20 (69%) cases. A combination of transmission electronmicroscopy and energy dispersive analysis of X-rays showed these pigments to be a combination of charred organic material and metals, the latter corresponding to the composition of the diathermy cutting loop and electrocautery rollerball used in the ablative surgery.