Suppurative corneal ulceration in Bangladesh

Suppurative keratitis is an important preventable cause of blindness, particularly in the developing world. This study analyses 142 cases of suppurative keratitis referred to Chittagong Eye Infirmary, Bangladesh. Some 53.5% of cases were bacterial and 35.9% were fungal. The five most common pathogens were: Pseudomonas sp. 24%, Streptococcus pneumoniae 17%, Aspergillus sp. 13%, Fusarium sp. 7% and Curvularia sp. 6%. Gram stain and culture results were consistent in 62.6% of cases. Previous antibiotic treatment was a significant factor for failure of culture isolation and less so for Gram stain failure. On Gram stain, 55.9% of pseudomonal cases were missed, but only 2% of fungal cases were missed. Over all, Gram stain had a sensitivity of 62% and positive predictive value of 84% for bacterial cases, and 98% and 94% for fungal cases, respectively. Fungal ulcers were typically filamentous, but an antecedent history of trauma was not common. The most frequent injury was due to rice grains, but the inoculum appeared to be introduced during eye washing with contaminated water. Pseudomonal ulcers occurred most frequently in the monsoon season, and Fusarium cases were seen only in the hot, dry season.     

Psychiatric mental health nursing: challenge and change

. We invited Dr Peplau to provide a personal reflection on the recent history of psychiatric nursing and her thoughts on immediate challenges facing the profession. The paper is an individual scholar's commentary on the way that psychiatry has waxed and waned over the years, in relation to nursing. This historical review discovers and reports a challenge to current practice. Dr Peplau describes a professional shift that is pulling nurses toward the subordinate role observed earlier this century. The paper draws attention to how contemporary practice can be positively influenced, e.g., by giving a structure to the allocation and conduct of nurse–patient time.     

A novel 37-Kd adhesive membrane protein from cloned murine bone marrow stromal cells and cloned murine hematopoietic progenitor cells

The adhesion of hematopoietic progenitor cells to bone marrow stromal cells is critical to hematopoiesis and involves multiple effector molecules. Stromal cell molecules that participate in this interaction were sought by analyzing the detergent-soluble membrane proteins of GBI/6 stromal cells that could be adsorbed by intact FDCP-1 progenitor cells. A single-chain protein from GBI/6 cells having an apparent molecular weight of 37 Kd was selectively adsorbed by FDCP-1 cells. This protein, designated p37, could be surface-radiolabeled and thus appeared to be exposed on the cell membrane. An apparently identical 37- Kd protein was expressed by three stromal cell lines, by Swiss 3T3 fibroblastic cells, and by FDCP-1 and FDCP-2 progenitor cells. p37 was selectively adsorbed from membrane lysates by a variety of murine hematopoietic cells, including erythrocytes, but not by human erythrocytes. Binding of p37 to cells was calcium-dependent, and was not affected by inhibitors of the hematopoietic homing receptor or the cell-binding or heparin-binding functions of fibronectin. It is proposed that p37 may be a novel adhesive molecule expressed on the surface of a variety of hematopoietic cells that could participate in both homotypic and heterotypic interactions of stromal and progenitor cells.     

Atrial natriuretic factor in the pleural fluid of congestive heart failure patients

To investigate the possibility that atrial natriuretic factor might be secreted into the pleural fluid of patients with congestive heart failure who are known to have high concentrations of this new peptide hormone circulating in their plasma, six patients with class 2 New York Heart Association classified congestive heart failure had simultaneos measurement of plasma and pleural fluid atrial natriuretic factor concentrations. Atrial natriuretic factor was found in high concentrations in the pleural fluid of all of these patients. The concentration of atrial natriuretic factor in pleural fluid was nearly equal to the concentration in plasma of these patients. Their plasma levels were double the plasma concentration of this peptide hormone in 54 persons without congestive heart failure. These preliminary findings demonstrate that atrial natriuretic factor is present in pleural fluid of patients with congestive heart failure, but whether or not this secretion of atrial natriuretic factor into the pleural fluid helps the lung clear the fluid present in the lung in congestive heart failure cannot be determined from the present investigation.     

Ultraviolet light-induced modification of crosslinked hyaluronan gels

Hyaluronan (HA) gels (hylans) crosslinked with divinyl sulfone (DVS) are highly biocompatible and can be structurally modified to obtain desired mechanical properties that are attractive for their use as tissue-engineering scaffolds. However, unmodified hylan gels are not good substrates for cell attachment or infiltration, likely as a result of their smooth surface and the highly anionic nature of HA. This study investigated whether the cell-adhering characteristics of hylan gels could be enhanced by irradiation with ultraviolet (UV) light, with or without prior dehydration. The attachment and proliferation of neonatal rat smooth muscle cells atop these gels was compared with that on unmodified (control; C) or dehydrated (D) gels. UV-induced changes to gel structure and chemistry were characterized by confocal and electron microscopy, and fluorphore-assisted carbohydrate electrophoresis (FACE). Cell attachment was sparse on both unmodified (C) and dehydrated (D) gels. Significantly higher levels of cell attachment were observed on the surface of irradiated (UV) and dehydrated-irradiated (DUV) gels, likely because of texturing of the gel surface by UV light. In addition, dehydration of gels before UV irradiation created irregular pore-like structures through which cells appeared to migrate into the interior. FACE assays demonstrated that UV-irradiation alters the chemistry of HA, causing limited breakdown of HA chains and DVS crosslinks within gel and possibly creating new crosslinks that have not yet been identified. Because the hylan gels are altered structurally and chemically, binding of cells to the material is likely to be more permanent than possible by other approaches, such as coating of cell-adhesive matrix factors on the gel surface, described previously. The significance of this work is that we have developed a technique for the modification of DVS-crosslinked HA (hylans) to enhance their performance as a cellular scaffold for tissue-engineering applications.