Treatment of infectious arthritis and osteomyelitis.

Infectious arthritis and osteomyelitis are commonly encountered diseases of the skeletal system that can result in premature loss of an affected animal from the herd. Selection of the best possible treatment approach for an individual animal requires a solid understanding of the pathophysiologic processes involved in the infection of bone or joint; recognition of the unique aspects of the anatomy, physiology, behavior, management, and economics of the species involved; and a broad grasp of the availability and role of various therapeutic options. By recognizing the importance of all three of these areas, a clinician not only will be able to make realistic and effective judgments about care of commonly encountered cases today but also will have a sufficient basis for rational variations in therapy as pharmacologic options expand and environmental or economic pressures change.

Changes in lung tissue fibronectin content and synthesis during postnatal lung growth.

We studied changes in lung tissue fibronectin content and synthesis during postnatal lung growth in rats. We reasoned that fibronectin, which is important in cell differentiation, migration, and adhesion, and in the organization of the extracellular matrix, might play a role in the rapid cell proliferation and alveolar septal formation that occurs postnatally in mammalian lungs. Newborn rats were sacrificed at 4, 7, 11, 14, and 21 days after birth. The lungs were perfused and lavaged, tissue fibronectin was extracted using urea and heparin (Bray et al, Science 1981; 214:793) and the extracted fibronectin was measured by enzyme-linked immunoassay. Tissue fibronectin synthesis was measured by the in vivo incorporation of 35S-methionine into fibronectin that was extracted from lung tissue and immunoprecipitated. Lavage fibronectin and albumin content and lung tissue collagen (hydroxyproline) content were also determined. Lung tissue fibronectin content per g dry lung almost doubled between days 4 and 7 after birth, was slightly higher at day 14 than at day 7, and decreased sharply between days 14 and 21. Lung tissue fibronectin synthesis per g dry lung increased steadily between days 4 and 14 to reach a peak value of about 2.5 times the 4-day value; it then decreased sharply between days 14 and 21. The period of increased fibronectin content and synthesis (4 to 14 days) coincided with the period during which lung cell proliferation and secondary alveolar septa formation are known to be the most active, and the sharp decrease in fibronectin content and synthesis (between 14 and 21 days) coincided with the period during which lung growth and remodeling markedly decrease.(ABSTRACT TRUNCATED AT 250 WORDS)

Availability of personal counseling in medical schools.

The deans of student affairs at 114 medical schools were surveyed about the availability of counseling services for medical students. There were 85 respondents (75 percent), all of whom indicated that some counseling services were available at their schools. One-third felt the services were not adequate. In addition, student representatives at these 114 schools were surveyed on the same topic, 53 responded (46 percent), and most said there was underutilization due to poor communication, problems resulting from initial contacts through the administration, and concern about confidentiality. Recommendations are made to help increase the utilization of counseling resources.

T-lymphocyte and B-lymphocyte subpopulations infiltrating human mammary carcinomas.

Both T- and B-lymphocytes were found in human primary mammary carcinomas and were distributed in widely varying amounts, but in most tumors, T-lymphocytes predominated. A small percentage of the T-lymphocytes expressed receptors for the Fc portion of IgG (Fc gamma R), but very few had receptors for C3 (C3+) (comparable to the findings in blood). A prominent subset of lymphocytes had Fc gamma R and were C3+, and most of these were surface immunoglobulin (slg)-bearing cells. The majority of lymphocytes from this subset were Fc+ C3+, and only a small percentage were Fc+ C3- (in contrast to the findings in blood). IgD and IgM were the predominant classes of findings in blood). IgD and IgM were the predominant classes of immunoglobulin found on the B-lymphocytes. The different preparative techniques did not result in a selective loss of lymphocyte subsets, but collagenase digestion did lead to a loss of expression of the C3 receptor on the lymphocyte surface, which was recoverable when lymphocytes were reincubated at 37 degrees C. No evidence was found for blocking of the C3 receptor by immune complexes with activated complement.

Natural cytotoxicity in the guinea-pig: the natural killer (NK) cell activity of the Kurloff cell.

Natural killer (NK) cell activity was found in the various lymphoid compartments of the normal guinea-pig, prominent in the spleen and absent in the thymus. Oestrogen treatment, which increased the Kurloff cell population in blood, spleen and thymus, did not alter NK cell activity in blood and spleen but markedly augmented the lytic capacity of the thymus. Rosetting reactions and selective depletion studies in normal and oestrogen-treated animals revealed the NK cells to belong to a small population of E+ Kurloff cells, some of which were Fc+ and others apparently Fc-. Some of these natural killer cells in the spleen also had receptors for C3 and carried Ig (probably cytophilic). In the lymph nodes, however, the NK cells were found to be E+ lymphocytes, again some of which were Fc+ and others Fc-.

Human regional tumour lymph nodes: alterations of micro-architecture and lymphocyte subpopulations.

Axillary lymph nodes draining mammary carcinoma showed an alteration of both micro-architectue and lymphocyte subpopulations. Lymph nodes with a normal or increased T and/or B lymphocyte compartment (assessed by histology) had a low incidence of nodal tumour spread, whilst hypocellularity of the T- or B-lymphocyte-dependent areas was associated with a significant increase in metastatic invasion. Tumour-draining lymph nodes, in particular the more proximal ones, were often enlarged, spherical and tense due to an increased cellular content, predominatly B lymphocytes and their various subsets. The increased number and percentage of B lymphocytes was associated with follicular hyperplasia and prominent germinal centres. Lymph nodes with a prominent paracortex tended to have a higher ratio of T to B lymphocytes than nodes with a hypocellular paracortical area, but in many instances both the T- and B-lymphocyte-dependent areas were increased. There was no correlation between a particular axillary-node lymphocyte subpopulation pattern (assessed by surface markers) and the size, degree of necrosis, inflammatory infiltrate or histologic type of breast carcinoma, or the presence of metastatic node invasion.

Characterization of the human natural killer (NK) cell in blood and lymphoid organs.

The human natural killer (NK) cell in peripheral blood is a non-thymus-dependent, (Fc+ C3-), Ig-bearing lymphocyte and is probably identical to the human K cell, although not requiring the Fc receptor, in contrast to the K cell, for the lytic process. The human NK cell in tonsil and lymph node, on the other hand, is a non-Ig- bearing T lymphocyte, lacking both Fc and C3 receptors.

Antibody-dependent cellular cytotoxicity and natural cytotoxicity: effect of pre-treatment of human lymphocytes with deionised water and ammonium chloride.

Deionised water is an efficient red blood cell lytic agent with no demonstrable deleterious effects on ADCC and natural cytotoxicity (blood and tonsil). Treatment with isotonic ammonium chloride, however, produces a significant reduction of both ADCC and natural cytotoxicity. This reduction is less pronounced if the treatment is carried out at 4 degrees C and is temporary, recovery occurring over a 24 h period of incubation at 37 degrees C.

Surface characteristics of the human K (killer) lymphocyte.

The human non-allergized K (killer) lymphocyte has been characterized using selective depletion and isolation procedures based on surface markers. It was found to be a non-thymus-dependent, Fc-receptor-bearing cell. In an area which is controversial, our findings also indicate that the cell has immunoglobulin on its surface but lacks the receptor for the C3 component of complement (mouse). This would suggest it to be an (Fc + C3-) B lymphocyte.

T and B lymphocyte populations in human normal lymph node, regional tumour lymph node and inflammatory lymph node.

We have determined the T and B lymphocyte subpopulations in normal human lymph nodes. The lymphocyte profile was the same irrespective of the anatomical distribution and was similar to that found in peripheral blood with identical T and B cell values but with a lower Fc and a higher C3-receptor-bearing lymphocyte subpopulation. This pattern showed a marked change in the regional nodes of patients with mammary carcinoma and nodes draining a variety of other solid tumours, with a fall in T and pronounced elevation of B, Fc and C3 cells but with a persistence of C3 predominance. The lymphocyte profile found in tonsils and nodes draining inflammatory foci was a similar but further exaggeration of the tumour node pattern, with reversal of T and B cell ratios. The T and B lymphocyte percentages in the peripheral blood of patients with clinically localized breast cancer are identical to those of the healthy controls. Different Fc/C3 subsets exist in peripheral blood and lymphoid structures and probably represent a differential functional heterogeneity. Proximity of tumour to the draining node modified this profile.