Treatment of subchondral lucencies in the medial proximal radius with a bone screw in 8 horses.

OBJECTIVE: To describe the results of screw placement through subchondral lucencies (SCL) of the proximal radius in 8 horses. STUDY DESIGN: Retrospective clinical study. ANIMALS: Horses with cubital SCL causing lameness (n=8). METHODS: Medical record review and clinical follow-up. RESULTS: Eight horses with SCL in the proximal radius causing lameness were treated with a screw placed across the lucency. The horses range in age from 1 to 20 years. In 4 of 8 horses, the lameness had been intermittently severe (apparent at the walk). Lameness was isolated to the cubital joint by intra-articular anesthesia in 5 horses and diagnosed radiographically in all 8. All horses had a 4.5 mm cortical bone screw placed from medial to lateral (6 lag, 2 neutral) across the SCL using fluoroscopic or radiographic control. Postoperative care included stall confinement with hand walking for 30-60 days, followed by an additional 30-60 days of pasture turnout. Radiographic SCL healing (reduction in SCL size) was demonstrated at 3-4 months after surgery in all horses, and 7/8 horses (87.5%) were used as intended (4 performance, 3 pasture turn-out) within 6 months. Lameness in the remaining horse improved initially (dressage) but returned. CONCLUSIONS: A screw placed through the SCL of the proximal-medial radius was effective in reducing or resolving lameness associated with the elbow joint in 7/8 horses (88%). Screw placement in the proximal radius should be considered for horses with lameness caused by an SCL when a quick return to exercise is desired or conservative therapy is ineffective.

Range verification in heavy-ion therapy using a hadron tumour marker.

Objective.A new method to estimate the range of an ion beam in a patient during heavy-ion therapy was investigated, which was previously verified for application in proton therapy.Approach.The method consists of placing a hadron tumour marker (HTM) close to the tumour. As the treatment beam impinges on the HTM, the marker undergoes nuclear reactions. When the HTM material is carefully chosen, the activation results in the emission of several delayed, characteristicγrays, whose intensities are correlated with the remaining range inside the patient. When not just one but two reaction channels are investigated, the ratio between these twoγray emissions can be measured, and the ratio is independent of any beam delivery uncertainties.Main results.A proof-of-principle experiment with an16O ion beam and Ag foils as HTM was successfully executed. The107Ag(16O,x)112Sb and the107Ag(16O,x)114Sb reaction channels were identified as suitable for the HTM technique. When only oneγ-ray emission is measured, the resulting range-uncertainty estimation is at the 0.5 mm scale. When both channels are considered, a theoretical limit on the range uncertainty of a clinical fiducal marker was found to be ±290µm.Significance.Range uncertainty of a heavy-ion beam limits the prescribed treatment plan for cancer patients, especially the direction of the ion beam in relation to any organ at risk. An easy to implement range-verification technique which can be utilized during clinical treatment would allow treatment plans to take full advantage of the sharp fall-off of the Bragg peak without the risk of depositing excessive dose into healthy tissue.

Compressor optimization with compressor-based multiphoton intrapulse interference phase scan (MIIPS).

The multiphoton intrapulse interference phase scan (MIIPS) technique is modified to optimize the compressor settings of a chirped pulse amplification (CPA) laser system. Here, we use the compressor itself to perform the phase scan inherent in MIIPS measurement . A frequency-resolved optical gating measurement shows that the pulse duration of the compressor optimized using the modified MIIPS technique is 33.8 fs with a 2.24 rad temporal phase variation above 2% intensity. The measured time-bandwidth product is 0.60, which is close to that of transform-limited Gaussian pulse (0.44).

Transfixation cast technique for arthrodesis of the distal interphalangeal joint of horses.

Surgical arthrodesis of the distal interphalangeal (DIP) joint by transfixation casting was used to salvage a three-year-old filly and a yearling filly that were chronically lame because of infection of the DIP joint for breeding. Unlike previously described techniques for arthrodesis of the DIP joint, the technique used did not require insertion of implants across the joint, which may have contributed to the successful outcome.

Fluorescence measurements of environmental relaxation at the lipid-water interface region of bilayer membranes.

Nanosecond time-resolved emission spectroscopy is used to characterize the complex fluorescence behavior of the probe 2-p-toluidinonaphthalene 6-sulfonate (2,6 p-TNS) when adsorbed to several bilayer membrane system. These include egg phosphatidylcholine vesicles with and without added cholesterol as well as erythrocyte ghost membranes. In each case a nanosecond time-dependent shift of the fluorescence emission to lower energy follows pulsed photoexcitation. The properties of the time-resolved surfaces obtained are consistent with a non-exponential decay law which describes a continuous interaction process of 2,6 p-TNS with its local environment in the membrane. This environment consists in part of polar residues (water plus polar head region) undergoing nanosecond motions. The pure phosphatidylcholine bilayer system was studied at four temperatures and electronic and spectral relaxation contributions to the total fluorescence decay were separated. Temperature coefficients for empirical rate parameters derived for the separated processes were obtained. It appears that a treatment of the fluorescence behavior of amphiphilic probes such as 2,6 p-TNS adsorbed to bilayer membranes at temperatures near ambient in which a single lifetime and radiative decay channel have been assumed is inappropriate.

Molecular diagnostics for polychlorinated biphenyl degradation in contaminated soils.

Molecular diagnostic methods using DNA hybridization with specific gene probes are being developed for the monitoring of microbial populations capable of polychlorinated biphenyl (PCB) degradation in contaminated soils. Evaluation of composite samples from contaminated electrical substation soil by gas chromatography (GC) indicated that the PCBs present in the soil (approximately 200 ppm) resulted from contamination with Aroclor 1248. The PCBs have been weathered or degraded so that the lower molecular weight PCB congeners are no longer present. Microbiological and molecular site characterizations are in progress to determine the abundance of PCB degradative organisms and catabolic genes present. Cloned DNA fragments for the bphC gene (2,3-dihydroxybiphenyl dioxygenase) from the biphenyl/chlorobiphenyl degradative pathways of different organisms were used as gene probes to identify indigenous microorganisms with bphC gene sequences. In colony hybridization experiments, positive signals with the pDA251 gene probe were detected in cultures from both contaminated and uncontaminated soils. The degradative abilities of indigenous microorganisms and an added PCB-degradative bacterial strain were also monitored with [14C]4-chlorobiphenyl mineralization assays and gas chromatography of PCB residues extracted from the soils. Enrichment of the contaminated soil with biphenyl and chlorobiphenyls did not stimulate the indigenous microorganisms to degrade the soil PCB. Nevertheless, enrichment of the contaminated soil with biphenyl and chlorobiphenyl and addition of the PCB-degrading strain Alcaligenes eutrophus GG4202 did result in additional degradation of the soil PCB. The results obtained from these experiments should assist in developing and monitoring a remediation plan for these PCB-contaminated soils.

Immunological abnormalities in patients with untreated retinal vasculitis.

Peripheral blood immunological features were assessed in 21 patients with clinical and angiographic evidence of retinal vasculitis (RV). Abnormalities of humoral and cellular immunity were frequent in this group of patients. Lymphopenia was the most common immunological abnormality, being present in 76% of patients at presentation (p less than 0.05). Peripheral blood T and B cells were decreased with a normal helper (OKT4) to suppressor (OKT8) T cell ratio in 11 patients tested (five with Behçet's syndrome and six with idiopathic RV). Significantly increased concentrations of serum immune complexes were present in 55% of patients (p less than 0.05). Results of the present study indicate the frequent association of peripheral blood immunological abnormalities in patients with active RV and indicate the possible role of immunological mechanisms in its pathogenesis.

Alpha 1 antitrypsin serum levels and phenotypes in patients with retinal vasculitis.

alpha 1 antitrypsin is an important immunoregulatory protein, the serum level of which is genetically determined. Deficient phenotypes of this ubiquitous protease inhibitor are associated with a variety of inflammatory diseases including anterior uveitis. In order to investigate the role of this protease inhibitor in the pathogenesis of retinal vasculitis (RV) 25 patients were investigated. Diseases associated with RV included Behcet's syndrome (8), SLE (2), and sarcoidosis (1). Deficient phenotypes of alpha 1 antitrypsin were not associated with RV. However, the serum alpha 1 antitrypsin level was significantly increased in patients with active RV and paralleled disease activity in patients studied prospectively.

In vitro evaluation of a novel prosthesis for laryngoplasty of horses with recurrent laryngeal neuropathy.

A prosthesis, composed of a steel cable and stress-reducing washers, was developed to prevent failure of laryngoplasty, a common treatment for horses affected by recurrent laryngeal neuropathy. Laryngoplasties were performed on 15 cadaveric larynges using a polyester suture on one side and the cable prosthesis on the other. Each prosthesis was distracted at a displacement rate of 20 mm/s using a servohydraulic materials testing machine until laryngoplasty failed. Distraction force and actuator displacement were recorded and analysed. All 15 laryngoplasties performed with a suture failed at the muscular process at a mean +/- s.d. force of 55.8 +/- 13.1 N. Six laryngoplasties performed with the cable prosthesis failed at the muscular process at mean force 219.6 +/- 125.0 N. In the other 9, the arytenoid cartilage was avulsed from the larynx at mean force 206.4 +/- 75.3 N, and the cable then tore through the muscular process at mean force 357.0 +/- 32.0 N. The difference in force required to cause failure of laryngoplasty was significant (P<0.0001). Although the prosthesis resisted substantially higher forces than did the suture, the effects of the prosthesis in vivo must be evaluated.

Effects of postoperative peritoneal lavage on pharmacokinetics of gentamicin in horses after celiotomy.

OBJECTIVE: To evaluate the effect of peritoneal lavage on pharmacokinetics of gentamicin sulfate in healthy horses after experimental celiotomy. ANIMALS: 13 clinically normal horses. PROCEDURE: Horses were randomly assigned to control or experimental groups. All horses received gentamicin (6.6 mg/kg of body weight, IV, q 24 h) before surgery, underwent experimental abdominal surgery, and had abdominal drains placed percutaneously. Horses of the experimental group received postoperative peritoneal lavage; horses of the control group did not receive peritoneal lavage. The day after surgery, 24 hours after the preoperative dose of gentamicin, a second dose of gentamicin was administered. Three and 15 hours after this second dose of gentamicin, horses of the experimental group received peritoneal lavage. Venous blood was obtained, for determination of concentration of gentamicin, immediately before and at specified intervals during the 24-hour period after the second dose of gentamicin. RESULTS: There were no differences in any of the pharmacokinetic values of gentamicin between horses of the control and experimental groups. CONCLUSIONS: Peritoneal lavage had no effect on pharmacokinetics of gentamicin in healthy horses after abdominal surgery, in which localized nonseptic peritonitis was induced. CLINICAL RELEVANCE: Peritoneal lavage in horses with localized nonseptic peritonitis or for the prevention of intra-abdominal adhesions should not necessitate alteration of the dosage of gentamicin to maintain predictable serum concentrations.

Facility planning for small and rural hospitals.

As changes in health care delivery move faster than ever, small or rural hospitals are struggling in a catch-up mode. In order to reverse this trend, these facilities need to reassess their position in the marketplace and develop a flexible plan for responding to the needs. This document provides a model to help achieve the vision of the physical plant in its supporting role to the strategic vision for the hospital, as well as options in the business of caring in a variety of alternative caregiving and treatment environments.

The chromosome partitioning protein, ParB, is required for cytokinesis in Caulobacter crescentus.

In Caulobacter crescentus, the genes encoding the chromosome partitioning proteins, ParA and ParB, are essential. Depletion of ParB resulted in smooth filamentous cells in which DNA replication continued. Immunofluorescence microscopy revealed that the formation of FtsZ rings at the mid-cell, the earliest molecular event in the initiation of bacterial cell division, was blocked in cells lacking ParB. ParB binds sequences near the C. crescentus origin of replication. Cell cycle experiments show that the formation of bipolarly localized ParB foci, and presumably localization of the origin of replication to the cell poles, preceded the formation of FtsZ rings at the mid-cell by 20 min. These results suggest that one major function of ParA and ParB may be to regulate the initiation of cytokinesis in C. crescentus.

Nanosecond time-resolved emission spectroscopy of a fluorescence probe adsorbed to L-alpha-egg lecithin vesicles.

Nanosecond time-resolved emission spectra (TRES) are fluorescence emission spectra obtained at discrete times during the fluorescence decay. The complete data-set obtainable is a surface representing the intensity at all wavelengths and times during the emission decay time. When 2-p-toluidinonaphthalene-6-sulfonate (2,6 p-TNS) is adsorbed to egg lecithin vesicles, an excited-state reaction associated with energetic changes of the emitting species occurs on the nanosecond time scale. Convolution of the fluorescence decay with the excitation response introduces an artifact in the time-dependent spectra. A precedure is described by which this artifact can be eliminated. The data for the generation of time-resolved emission spectra are obtained with a computer-interfaced instrument based on the single-photon counting method.

Immunological features of HLA-B27 anterior uveitis.

Analysis of the immunological features of anterior uveitis (AU) revealed a dichotomy of abnormalities defined in terms of the HLA-B27 status of the patient. HLA-B27-positive AU was characterised by the occurrence of iris autoantibodies and an absolute T cell lymphopenia during active disease which returned to normal with recovery. This phenomenon was not observed in HLA-B27-negative AU or in controls and could not be attributed to antilymphocyte antibodies as these were not detected. Furthermore, there were no changes in T-cell subsets (helper and suppressor T lymphocytes). Compared with HLA-B27-positive AU patients, the HLA-B27-negative group demonstrated elevated IgE levels and increased prevalence of smooth muscle autoantibodies.

Chemiluminescent response to pathogenic organisms: normal human polymorphonuclear leukocytes.

Chemiluminescence (CL) is a sensitive indicator of phagocytosis and intracellular killing; however, little is known of the normal CL response by human polymorphonuclear leukocytes to different pathogenic microorganisms. We investigated the luminol-enhanced CL response of normal polymorphonuclear leukocytes to a number of common bacterial pathogens and two yeasts. We analyzed the CL response to viable and heat-killed microorganisms at 25 and 37 degrees C. The CL response to all microorganisms was greater and more rapid at 37 degrees C. Variable responses were observed with viable and heat-killed microorganisms; some were unaffected, whereas other demonstrated reduced CL. Each microorganism caused a reproducible response pattern, which could be placed into two general categories. In the first category were those which caused a rapid exponential rise and decay in CL: Enterobacter cloacae, Salmonella typhimurium, Shigella flexneri, Staphylococcus aureus, Candida albicans, and zymosan. In the second category were those which rose slowly over a longer time course to a poorly defined peak: Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Streptococcus pyogenes. The CL response also reflected serum opsonic activity. The effect of inactivated complement, factor B, and removal of specific antibody were investigated. Increasing the concentration of zymosan gave a proportional rise in peak CL; however, a strain of E. coli caused a variation in peak time rather than peak height. Different CL kinetics were shown for three strains of K. pneumoniae, possibly a result of each having different membrane or cell wall characteristics. This study defines the nature and factors affecting the normal CL response to a variety of common pathogenic microorganisms.

The chemiluminescence response of normal human leukocytes to chlamydia trachomatis.

The aim of the present study was to investigate the phagocytic response of normal human polymorphonuclear leukocytes (PMN) and monocytes (MN) to eight serotypes of C trachomatis (B,C,D,E,F,I,J, and L2) using a chemiluminescence (CL) assay, with luminal and lucigenin as amplifiers. The magnitude of the phagocytic cell CL response was proportional to the phagocyte-to-chlamydiae ratio, with a poor CL response detected at a ratio of 1:125 and progressively larger CL responses up to ratios of 1:50,000. The durations of the CL responses to all chlamydiae serotypes tested were considerably longer than that for zymosan. The PMN demonstrated a relatively greater CL response to all chlamydiae serotypes tested when compared with MN. The PMN and MN CL responses to "genital serotypes" (D,E,F,I, and J) (as well as lymphogranuloma venereum serotype L2) were greater than that for "ocular" serotypes (B and C). Inactivation of serum complement and specific chlamydial antibody absorption reduced the CL responses of both PMN and MN. This is the first study to characterize the CL responses of normal human PMN and MN cells to C trachomatis, and it indicates the important role of oxygen dependent antimicrobial systems in the phagocytosis of this common human pathogen.

Decreased chemiluminescent associated phagocytic response of peripheral blood mononuclear cells to Chlamydia trachomatis in patients with HLA-B27+ anterior uveitis.

The chemiluminescent (CL) associated phagocytic response of peripheral blood monocytes to two serovars of Chlamydia trachomatis, Shigella flexneri and zymosan was assessed in a group of 26 patients with anterior uveitis (AU). HLA-B27+ patients with AU, when compared to HLA-B27- patients with AU and appropriate controls, had a significantly decreased CL response to C. trachomatis but no difference between groups in the response to S. flexneri and zymosan. The decreased chemiluminescent (phagocytic) response of mononuclear phagocytes to Chlamydiae may indicate an important abnormality in the pathogenesis of HLA-B27+ AU.

Failure of Klebsiella pneumoniae antibodies to cross-react with peripheral blood mononuclear cells from patients with ankylosing spondylitis.

Cross-reactivity between antibodies to 2 strains of Klebsiella pneumoniae (K43 and F77) and the peripheral blood lymphocytes of patients with ankylosing spondylitis (AS) was examined in 3 separate antibody binding and cytotoxicity assays. Using K pneumoniae antisera in a chromium release cytotoxicity assay, we found no difference in the reactions of cells from AS patients and those from control subjects. This result contrasts with the results of previous studies. Similarly, using an enzyme-linked immunosorbent assay, we detected no significant increase in antibody binding to peripheral blood mononuclear cells (PBMC) in HLA-B27 positive patients with AS. Low levels of antibody binding were detected by a fluoresceinated antibody binding assay; however, normal rabbit serum, which was used as a control, was shown to have a binding affinity for PBMC that was significantly greater than that of specific K pneumoniae antisera. The results of our present study do not support the concept of a specific cross-reactivity between antibodies to K pneumoniae and the PBMC of patients with AS who are HLA-B27 positive.