Demystified. Human endogenous retroviruses.

Human endogenous retroviruses (HERVs) are a family of viruses within our genome with similarities to present day exogenous retroviruses. HERVs have been inherited by successive generations and it is possible that some have conferred biological benefits. However, several HERVs have been implicated in certain cancers and autoimmune diseases. This article demystifies these retroviruses by providing an insight into HERVs, their means of classification, and a synopsis of HERVs implicated in cancer and autoimmunity. Furthermore, the biological roles of HERVs are explored.     

The repopulation of lymph nodes of dogs after 1200 R whole-body x-irradiation and intravenous administration of mononuclear blood leukocytes.

Fresh and cryopreserved autologous or allogeneic mononuclear blood cells (MBCs) intravenously injected in 1200 R total-body x-irradiated dogs repopulated lymph nodes within 10 days after tranfusion. Several parameters of the lymphopoietic regeneration were correlated with the number of cells transfused and with the number of colony-forming units contained in the cell suspension when they were cultured in agar (CFUc). Values within the normal or close to normal range were reached in the mesenteric nodes of most of the animals transfused with 10 X 10(9) MBC or more. These values were obtained when 5 X 10(5) CFUc or more were transfused. Axillary nodes showed lower values than mesenteric nodes. They were mostly under the normal range but well over those of the irradiated controls. Frozen and thawed MBCs seem to be as effective as fresh cells for lymphopoietic restoration. The mesenteric nodes of dogs transfused with allogeneic MBCs showed higher cellularity and larger cortical-paracortical areas than those of dogs tranfused with approximately the same number of autologous cells. The repopulation of lymph nodes parallels that of the marrow.     

A multi-modal treatment program for childhood trauma recovery:Women Recovering from Abuse Program (WRAP).

This article describes the Women Recovering from Abuse Program (WRAP), an outpatient day-hospital program for women suffering from the sequelae of childhood abuse. WRAP was conceived in 1998 by clinicians who advocated for its development based on a growing need to provide women who had experienced childhood trauma an alternative to an inpatient program. WRAP draws from a Stage 1 treatment approach to address chronic interpersonal trauma and dissociation by incorporating psychopharmacology, individual and group psychotherapy. The program is structured into two phases: a preparatory Building Resources Group (BRG) and an intensive multimodal segment comprised of seven types of group therapy. Each group is described in terms of the treatment rationale and its structure and process. Two research studies to date support the effectiveness of WRAP.     

Does feeding regime affect physiologic and thermal responses during exposure to 8, 20, and 27° C?

Summary When the loss of body heat is accelerated by exposure to low environmental temperatures, additional substrates must be oxidized to provide energy to sustain temperature homeostasis. Therefore, the present investigation examined the relation between feeding regime [pre-experimental carbohydrate feeding (FED) vs a fast (FAST)], during 120 min of exposure to 8, 20, and 27° C in well-nourished men. The following were examined: tissue insulation (I; °C · m² · W^–1), rectal temperature (T _re; °C), and oxygen consumption ( O₂; ml · kg^–1 · min^–1). O₂, T _re, and I revealed no significant differences between treatments (FED vs FAST) at any temperature. At 27° C, I was less (P < 0.05) than at 20 and 8° C, and decreased (P < 0.05) as exposure time increased. At 8° C, O₂was higher (P < 0.5) than at 20 or 27°C, and O₂increased as time increased (P < 0.05). T _re decreased (P < 0.05) as time increased for all conditions. Respiratory exchange ratio (R) differed (P < 0.05) between treatments (FED vs FAST), temperature (8 vs 20° C), and across time. Values for R suggests that carbohydrate accounted for 56% and 33% of caloric utilization during the FED vs FAST conditions, respectively. At 8 vs 20° C, R represented 54% vs 30% of cabohydrate utilization. Across time, R demonstrated that in both conditions (FED vs FAST) there was a decreased reliance on carbohydrate utilization for energy provision. From these data it appears that while substrate utilization differed between dietary treatment and across time this did not differentially affect O₂or T _re during protracted exposure to 8, 20, and 27° C. The higher R in the 8° C condition for both dietary treatments demonstrates that carbohydrate utilization is increased in shivering cold-exposed humans. However, the reduction in R across time suggests that fat oxidation is also involved in metabolic heat production and core temperature maintenance during shivering in the cold.     

Filamentous phage DNA cloning vectors: a noninfective mutant with a nonpolar deletion in gene III

A filamentous phage derivative, fKN16, has been constructed from the tetracyclineresistance transducing phage fd-tet by deleting a 507-base-pair (bp) segment of phage gene III. In accord with the importance of the gene III protein in infection, the infectivity of fKN16 phage is less than 10^?8 that of fd-tet phage. In contrast to most gene III amber mutants, which are polar on the downstream phage genes VI and I, fKN16 should be a nonpolar mutant since its 507-bp deletion spans an integral number of coding triplets. And indeed, two phage traits that may depend on gene VI and I function—the level of phage production and packaging into unit-length virions—appear to be normal in fKN16. High phage production coupled with very low infectivity make fKN16 suitable as a vector for DNA cloning experiments requiring a high level of biological containment. The characteristics of fKN16 as a vector were investigated in detail, using HindIII fragments of phage λ DNA as model foreign DNA. fKN16 may also be useful in studying the role of the gene III protein in the filamentous phage life cycle.     

Eosinophil granule lysis in vitro induced by soluble antigen antibody complexes

A simple test system is described, for the demonstration of antigen—antibody reactions capable of causing eosinophil granule lysis in vitro. The antigen preparations used were extracts of the nematode Amplicaecum robertsi and body fluid of Ascaris suum. Antisera were obtained from rats infested with Amplicaecum. Eosinophils were obtained from the peritoneal cavity of normal rats. Centrifugation of the cells to form a cell button was an essential step in the procedure. Lysis of eosinophils occurred with antiserum obtained from the animals between the 12th and 32nd days of infestation with Amplicaecum, and was accompanied by vacuole formation in macrophages and mast cell disruption. The reaction was most pronounced during the 3rd week. Serum from adrenalectomized infested animals caused the most marked changes in eosinophils. Serum from cortisonetreated infested animals failed to cause eosinophil changes.

Attempts at purification of the antigen in Ascaris body fluid resulted in two fractions with marked activity in the test system. The same two fractions were found to form precipitin lines on agarose gel diffusion against rat antiserum.

It is postulated that antigen—antibody complexes soluble in low concentration were responsible for the changes observed in the eosinophils, macrophages and mast cells. One or more labile factors in the serum were found to be necessary for eosinophil granule lysis. The evidence, though incomplete, would favour the suggestion that both labile antibody and complement were necessary.

     

Trophoblast interaction with fibrin matrix. Epithelialization of perivillous fibrin deposits as a mechanism for villous repair in the human placenta.

The authors have used morphometric, immunocytochemical, and electron optical techniques to study fibrin deposits associated with villi from 14 normal term placentas, and have examined the response of cultured cellular trophoblast to fibrin matrix in vitro. Morphometric analysis of 3477 villous profiles showed that 5.5% of villi examined had fibrin deposition at sites of syncytial denudation and that fibrin deposition was highly associated with villous epithelial denudation, as evidenced by loss of cytokeratin staining. The perivillous fibrin deposits were strongly immunoreactive for the B beta chain of fibrin II, consistent with local thrombolytic cleavage of fibrinogen to fibrin. Deposits were frequently surfaced by a discontinuous layer of cytokeratin-positive trophoblastic cells that showed type IV basement membrane collagen immunoreactivity at the interface between trophoblast and fibrin. Ultrastructurally, damage to the syncytial trophoblast was apparent at the edge of some deposits, where syncytial denudation was accompanied by a fibrin coating of residual cellular trophoblast and the trophoblastic basal lamina. Other deposits were surfaced by syncytial trophoblast with underlying cellular trophoblast and a new basal lamina external to the basal lamina of the villous core. Cultured cellular trophoblast grown on a fibrin matrix, but not on uncoated plastic, showed morphologic differentiation into a trophoblast layer like that on term villi. The authors suggest that epithelialization of perivillous fibrin deposits is a form of villous repair and that trophoblast-fibrin interactions can modulate trophoblastic differentiation.