Activin controls skin morphogenesis and wound repair predominantly via stromal cells and in a concentration-dependent manner via keratinocytes

The transforming growth factor-beta family member activin is a potent regulator of skin morphogenesis and repair. Transgenic mice overexpressing activin in keratinocytes display epidermal hyper-thickening and dermal fibrosis in normal skin and enhanced granulation tissue formation after wounding. Mice overexpressing the secreted activin antagonist follistatin, however, have the opposite wound-healing phenotype. To determine whether activin affects skin morphogenesis and repair via activation of keratinocytes and/or stromal cells, we generated transgenic mice expressing a dominant-negative activin receptor IB mutant (dnActRIB) in keratinocytes. The architecture of adult skin was unaltered in these mice, but delays were observed in postnatal pelage hair follicle morphogenesis and in the first catagen-telogen transformation of hair follicles. Although dnActRIB-transgenic mice showed slightly delayed wound re-epithelialization after skin injury, the strong inhibition of granulation tissue formation seen in follistatin-transgenic mice was not observed. Therefore, although endogenous activin appeared to affect skin morphogenesis and repair predominantly via stromal cells, overexpressed activin strongly affected the epidermis. The epidermal phenotype of activin-overexpressing mice was partially rescued by breeding these animals with dnActRIB-transgenic mice. These results demonstrate that activin affects both stromal cells and keratinocytes in normal and wounded skin and that the effect on keratinocytes is dose-dependent in vivo.     

Diversity of cell surface hematopoietic antigens on K-562 sublines identified with monoclonal antibodies

The surface antigen profile of 8 sublines of K-562 cells, the original line, and the clone RA6 was determined with a panel of 12 monoclonal antibodies reactive with hematopoietic cell differentiation antigens. Cells from all sublines expressed the precursor hematopoietic antigen reactive with RFB-1, the T-cell antigen reactive with OKT17, the B cell/granulocyte antigen reactive with BA-1, the My-1 antigen, and glycophorin A which reacted with R10. A low percentage of cells in some of the sublines expressed platelet/monocyte glycoprotein I binding AN51, monocyte antigen binding 63D3, and an erythroblast/monocyte/platelet antigen binding 5F1. The use of a panel of K-562 sublines demonstrates that K-562 cells do share several "common" antigens but express a marked diversity and variability of other hematopoietic antigens.     

The use of natural interferon alpha conjugated to a monoclonal antibody anti mammary epithelial mucin (Mc5) for the treatment of human breast cancer xenografts

Summary An immunoconjugate composed of natural interferon (nIFN) bound in a noncleavable fashion to a monoclonal antibody (MoAb) recognizing a breast epithelial membrane mucin (Mc5) was used to treat xenografts of a human mammary carcinoma cell line (MCF-7) growing in nude mice. The immunoconjugate (nIFN/Mc5) was administered as 20 intralesional (i.l.) injections to 1 of 2 xenografts in each animal. It was found that nIFN/Mc5 produced a significant enhancement of the growth inhibitory actions of nIFN on the injected tumors. Further enhancement was obtained when nIFN or nIFN together with Mc5 (at a dose 10 times larger than that present in nIFN/Mc5) were added to the immunoconjugate. Biodistribution experiments showed that the uptake of¹²⁵I-nIFN/Mc5 by the tumors was greater and its elimination slower than for¹²⁵I-nIFN alone or conjugated to irrelevant mouse IgG₁. In addition, the immunoconjugate up-regulated the antigenic expression of a breast epithelial membrane mucin by the carcinoma cells, an up-regulation which was not significantly different from that produced by nIFN alone. The contralateral noninjected tumors exposed to systemic levels of the immunoconjugate showed an enhancement of antitumor effects, but to a lesser extent than the injected tumors. These findings suggest that the enhancement of the growth inhibitory action of the immunoconjugate was related to the specific binding of Mc5 which targeted the IFN to the carcinoma cells and impeded its elimination. It is likely that the targeting was favored by the IFN-mediated up-regulation of antigenic expression by the carcinoma cells, thereby producing a cascade of interrelated effects. The results of this study point out the feasibility and potential usefulness of IFN treatment by means of immunoconjugates as well as the worth of pursuing and improving this form of therapy.     

EFFICACY OF SUCRALFATE IN PREVENTING GASTROINTESTINAL SIDE EFFECTS OF NSAIDs

To find out the efficacy of sucralfate in preventing gastrointestinal side effects of non-steroidal anti-inflammatory drugs (NSAIDs) a prospective, randomised single blind study was conducted from 1989 to 1992. Patients with osteoarthritis, rheumatoid arthritis and other long standing painful conditions, who were expected to receive NSAIDs for over three months, were recruited into the study. All medicines were discontinued for a period of 10–15 days prior to initial endoscopic assessment. NSAID therapy was started and the patients were randomised to receive either placebo (group A) or sucralfate (group B) in addition. Patient were reassessed clinically every week and an endoscopic examination was repeated after 6–8 weeks of follow-up. A total of 176 patients were studied in group A (n=91) and group B (n=85). At the end of 8 weeks gastrointestinal symptoms were present in 30.6% and 26.4% patients of group A and B respectively. Endoscopic assessment showed superficial lesions in 36.5% and 18.7% while endoscopic ulcer in 2.4% and 1.1% patients of groups A and B respectively. Thus in patients receiving chronic NSAID therapy, simultaneous administration of sucralfate reduces the incidence of superficial gastric lesions but has no significant effect on symptoms or ulcer formation.KEY WORDS: Gastropathy, Sucralfate, Nonsteroidal anti-inflammatory drugs     

Human peripheral blood leukocytes transplanted on CB17 scid-scid mice are transferred to their offspring.

Severe combined immunodeficient (scid) mice are deficient in functional T cells and B cells. Hence, scid mice reconstituted with human peripheral blood leukocytes (scid-huPBL) provide an excellent model for analysis of the human immune response under in vivo conditions. We have investigated this model further by analyzing human immune responses in the progeny of scid-huPBL (termed scid-humo). We find markedly elevated levels of human immunoglobulins (Ig) in the serum of scid-humo for more than 12 weeks indicating materno-fetal transfer of human B lymphocytes. Consistent with this finding we obtained evidence for the existence of human lymphocytes in scid-humo. Murine Ig levels in scid-humo were also elevated and surface Ig-expressing cells (probably B cells) were demonstrable. In this respect scid-humo resembled "leaky" scid. In contrast to "leaky" scid, scid-humo accepted transfer of human blood leukocytes. Not only leukocytes from autologous but also those from heterologous donors were accepted. Human Ig levels in scid-humo increased more rapidly as compared to normal scid mice. Thus, despite these increased B cell activities in scid-humo, transferred human leukocytes were not affected indicating that materno-fetal transfer of human cells had caused tolerization or conditioning. This is in contrast to scid mice in which elevated Ig levels correlate with increased failure rates of reconstitution with human blood leukocytes. We propose that scid-humo provide an improved model for studying the human immune responses in an in vivo setting.     

Expression pattern of the cell cycle promoter cyclin e in benign extravillous trophoblast and gestational trophoblastic lesions: correlation with expression of Ki-67.

In this study, a specific monoclonal antibody was used to immunohistochemically investigate correlated expression of the cell cycle promoter cyclin E and the proliferation marker Ki-67 in benign extravillous trophoblast and gestational trophoblastic lesions. Our data show that cyclin E is expressed in the normal extravillous trophoblast, with strongest levels of expression in the cell columns of anchoring villi. Differences could be observed in expression of Ki-67 in both normal extravillous trophoblast and gestational trophoblastic lesions. In the extravillous trophoblast of the cell columns, expression of cyclin E started more distal compared with Ki-67 and was maintained (with less intensity) into the deeper layers of interstitial trophoblast. In the benign trophoblastic lesions (exaggerated placental site [EPS] and placental site nodule [PSN]) and in the trophoblast proliferations on the surface of hydropic villi of hydatidiform moles (HM), the percentage of cells expressing cyclin E was higher than of those expressing Ki-67. The same observation could be made for a case of placental site trophoblastic tumor (PSTT). In contrast, choriocarcinomas (N=8), which are definitely malignant tumors, showed an opposite pattern, with a much higher percentage of strongly Ki-67-positive cells compared with cyclin E-positive cells. We conclude that cyclin E is expressed in benign extravillous trophoblast and gestational trophoblastic lesions, where a ratio cyclin E/Ki-67<1 characterizes choriocarcinomas, whereas PSTT and the benign lesions (HM, EPS, PSN) show expression of cyclin E in a higher percentage of cells than Ki-67 (cyclin E/Ki-67 ratio >1).     

Pain and pain management in newborn infants: a survey of physicians and nurses

BACKGROUND: Despite an increased awareness among clinicians regarding pain and pain management for infants undergoing surgery, pain associated with procedures performed outside the operating room may not be adequately managed. PURPOSE: To examine the beliefs and self-described behavior of physicians and nurses regarding the management of procedural pain in newborn infants. METHODS: A survey was distributed to 467 clinicians (nurses and physicians) working in 11 level II and 4 level III nurseries in a large metropolitan area. Respondents were asked to rate the painfulness of 12 common bedside nursery procedures and how often pharmacologic and nonpharmacologic (comfort) measures are currently used and should be used for those procedures. Demographic data were also collected. RESULTS: Surveys were completed by 374 clinicians (80% response rate). Physicians and nurses believe infants feel as much pain as adults and that 9 of the 12 listed procedures are moderately to very painful. Neither pharmacologic nor comfort measures are believed to be used frequently, even for the most painful procedures. Physicians and nurses believe both pharmacologic and comfort measures should be used more frequently, but nurses believe comfort measures should be used more frequently than do physicians. Beliefs about infant pain and procedural pain were related to pain management preferences. Physicians' but not nurses' ratings were associated with significant personal pain. CONCLUSIONS: Despite their beliefs that infants experience significant procedure-related pain, clinicians believe pain management for infants remains below optimal levels. Barriers to more consistent and effective pain management need to be identified and surmounted.