A subpopulation of small pre-B cells in rabbit bone marrow expresses x light chains and exhibits allelic exclusion of b locus allotypes

The expression of immunoglobulin heavy and light chains by pre-B cells and B lymphocytes was examined by two-color immunofluorescence in heterozygous b⁵b⁹ rabbits. Allelic exclusion of b5 and b9 x light chain allotypes was observed for both surface immunoglobulin-negative pre-B cells and surface immunoglobulin-positive B lymphocytes. In newborn bone marrow, pre-B cells and immature B lymphocytes expressing b9 were as numerous as those expressing b5. In contrast, circulating B cells and bone marrow plasma cells expressing the b5 marker outnumber b9⁺ cells by 2 to 1 in adult b⁵b⁹ animals. Whereas most B lymphocytes expressed x light chain b allotypes, approximately 80% of the μ heavy chain-positive pre-B cells did not. The pre-B cells that expressed detectable light chains were relatively small lymphocytes. A model is presented which includes a “transitional” pre-B cell that expresses both p chains and x chains.     

Escherichia coli and Staphylococcus aureus elicit differential innate immune responses following intramammary infection

Staphylococcus aureus and Escherichia coli are among the most prevalent species of gram-positive and gram-negative bacteria, respectively, that induce clinical mastitis. The innate immune system comprises the immediate host defense mechanisms to protect against infection and contributes to the initial detection of and proinflammatory response to infectious pathogens. The objective of the present study was to characterize the different innate immune responses to experimental intramammary infection with E. coli and S. aureus during clinical mastitis. The cytokine response and changes in the levels of soluble CD14 (sCD14) and lipopolysaccharide-binding protein (LBP), two proteins that contribute to host recognition of bacterial cell wall products, were studied. Intramammary infection with either E. coli or S. aureus elicited systemic changes, including decreased milk output, a febrile response, and induction of the acute-phase synthesis of LBP. Infection with either bacterium resulted in increased levels of interleukin 1beta (IL-1beta), gamma interferon, IL-12, sCD14, and LBP in milk. High levels of the complement cleavage product C5a and the anti-inflammatory cytokine IL-10 were detected at several time points following E. coli infection, whereas S. aureus infection elicited a slight but detectable increase in these mediators at a single time point. Increases in IL-8 and tumor necrosis factor alpha were observed only in quarters infected with E. coli. Together, these data demonstrate the variability of the host innate immune response to E. coli and S. aureus and suggest that the limited cytokine response to S. aureus may contribute to the well-known ability of the bacterium to establish chronic intramammary infection.     

Predominance of Ehrlichia ewingii in Missouri dogs

To investigate the species distribution of Ehrlichia present in Missouri dogs, we tested 78 dogs suspected of having acute ehrlichiosis and 10 healthy dogs. Blood from each dog was screened with a broad-range 16S rRNA gene PCR assay that detects known pathogenic species of Ehrlichia and ANAPLASMA: The species was determined by using species-specific PCR assays and nucleotide sequencing. Ehrlichia antibody testing was performed by using an indirect immunofluorescence assay with Ehrlichia chaffeensis as the antigenic substrate. The broad-range assay detected Ehrlichia or Anaplasma DNA in 20 (26%) of the symptomatic dogs and 2 (20%) of the asymptomatic dogs. E. ewingii accounted for 20 (91%), and E. chaffeensis accounted for 1 (5%) of the positives. Anaplasma phagocytophilum DNA was detected in one dog, and the sequences of regions of the 16S rRNA gene and the groESL operon amplified from the blood of this dog matched the published sequences of this organism. Antibodies reactive with E. chaffeensis were detected in 14 (67%) of the 21 PCR-positive dogs and in 12 (19%) of the 64 PCR-negative dogs. Combining the results of PCR and serology indicated that 33 (39%) of 85 evaluable dogs had evidence of past or current Ehrlichia infection. We conclude that E. ewingii is the predominant etiologic agent of canine ehrlichiosis in the areas of Missouri included in this survey. E. canis, a widely recognized agent of canine ehrlichiosis, was not detected in any animal. The finding of E. ewingii in asymptomatic dogs suggests that dogs could be a reservoir for this Ehrlichia species.     

Additive cytotoxicity of adriamycin and a naturally occurring growth inhibitor extracted from bovine aorta

A factor of nominal molecular weight 6K–10K Daltons, isolated from bovine aorta, has previously been shown to inhibit neovascularization and tumor growth in vivo and the growth of some tumor cells as well as endothelial cells in culture. This factor, termed A-10, was tested alone and in combination with Adriamycin against TA3Ha mammary adenocarcinoma cells in tissue culture. It was found to have cytotoxicity additive to that of Adriamycin in inhibiting the growth of these cells. In vitro and animal studies show that the sequence of Adriamycin A-10 is superior to either agent alone in delaying the appearance of palpable tumors after subcutaneous injection of 10⁵ pre-treated tumor cells in the tail of strain A mice. While the growth rate of the primary tumor was not affected by such treatment, survival was prolonged to a greater degree by the this sequence than by either of these agents used alone. A-10 treatment reduced the number of metastases to the adrenal gland but not to lung, liver, or lymph nodes. It did, however, reduce the size of metastases to para-aortic lymph nodes.     

Convulsive Therapy: Fifty Years of Progress

The origins of convulsive therapy, its early developments, present practice, central elements of the treatment, and neurohumoral and neuroendocrine theories of its antidepressant action are reviewed on the 50th anniversary of its introduction.     

Serial Dexamethasone Suppression Tests and Clinical Outcome in ECT

Serial dexamethasone suppression tests (DST), obtained during a course of electroconvulsive therapy in 43 severely depressed patients, did not exhibit relationships between the initial DST, final DST, or the change in DST with clinical outcome measures at the time of discharge. In 37 patients reviewed six months after discharge, no relationship with the continuation of improvement, rehospitalization, or suicide was found. We are unable to confirm a clinical application for the DST in the management of patients during a course of convulsive therapy.     

On the Occurrence of Kaempferol-4'-O-beta-D-glucopyranoside in Filipendula ulmaria and Allium cepa

In addition to the main flavonol glycoside spiraeoside in bulbs of ALLIUM CEPA L., kaempferol-4'-glucoside ( 1) has been found in smaller amounts. Traces of other flavonoids could be detected also.     

Emergency department thoracotomy (EDT). A 26-month experience using an "agonal" protocol

EDT can be successfully performed with the proper system in place. This includes an established thoracotomy protocol, a well-integrated EMS system, and an in-house team. Time seems to be critical, and the time between injury and EDT may be the single most important factor affecting survival other than the mechanism of injury. Cardiac penetrations, especially stab wounds, were found to have a 93 per cent survival while subdiaphragmatic penetrations had only one survivor from a group of 18 patients (5.5%). The high rate of salvage in the heart wound group probably reflects the speed of prehospital transport, though all other major series have found this group to gain the maximum benefit. No patient was successfully resuscitated from blunt injury with EDT. Three additional patients had "signs of life" restored (one pediatric blunt; two subdiaphragmatic gunshot wounds) but died of coagulopathies shortly thereafter. The experience with air ambulance patients was far too small to allow any conclusions or observations. It is felt that as the use and application of helicopters to EMS situations becomes widespread, more patients will be arriving at trauma centers with no vital signs and massive blunt injury but only moments from the accident. This special group of "dying" patients will require intense scrutiny and possibly new and inventive approaches for any hopeful salvage. Emergency thoracotomy will, no doubt, have a place as part of this. The development of a simple working protocol is of extreme importance. The protocol should be one that will allow maximum selection of patients who can benefit and elimination of those patients where EDT would be useless. The primary benefactor for EDT remains the patient sustaining a stab wound to the heart who arrives at the center shortly after injury. In other areas, such as abdominal exsanguination or severe blunt injury, further study is needed to determine what factors, prehospital and resuscitative, will improve outcome.