Keratinocyte growth factor administered before conditioning ameliorates graft-versus-host disease after allogeneic bone marrow transplantation in mice

Keratinocyte growth factor (KGF) is important in tissue repair and wound healing and its administration can abrogate chemical- and radiation-induced tissue damage in rodents. We investigated KGF as a therapeutic agent for the prevention of graft-versus-host disease (GVHD)-induced tissue damage, morbidity, and mortality in an established murine allogeneic bone marrow transplantation (BMT) model. B10.BR (H2(k)) recipient mice were lethally irradiated and transplanted with C57BL/6 (H2(b)) bone marrow (BM) with spleen cells (BMS) as a source of GVHD-causing T cells. KGF-treated mice (5 mg/kg/d subcutaneously days -6, -5, and -4 pre-BMT) receiving BMS exhibited better survival than those not receiving KGF (P =.0027). Cyclophosphamide (Cy), a common component of total body irradiation (TBI)-containing regimens, was administered to other cohorts of mice at a dose of 120 mg/kg/d intraperitoneally on days -3 and -2 before BMT. KGF-treated mice again exhibited a better survival rate than those not receiving KGF (P =.00086). However, KGF-treated recipients receiving TBI or Cy/TBI BMS were not GVHD-free, as shown by lower body weights compared with BM groups. GVHD target tissues were assessed histologically during a 38-day post-BMT observation period. KGF ameliorated GVHD-induced tissue damage in the liver, skin, and lung (completely in some recipients) and moderately so in the spleen, colon, and ileum, even with Cy conditioning. These studies demonstrate that KGF administration, completed before conditioning, has potential as an anti-GVHD therapeutic agent.     

Extemporaneous prescribing module 3

Australian Family Physician is pleased to be able to present a home course in extemporaneous prescribing, an interesting area that is poorly understood by many practitioners, especially recent graduates. Dr Bernard Kelly has been teaching this discipline to Family Medicine Trainees in New South Wales for many years and has written a series of modules to be placed in the journal during 1993. A question is included at the end of each module.     

CB1 receptor antagonist precipitates withdrawal in mice exposed to Delta9-tetrahydrocannabinol

Although tolerance to cannabinoids has been well established, the question of cannabinoid dependence had been very controversial until the discovery of a cannabinoid antagonist, SR141716A. The objective of this study was to develop and characterize a mouse model of precipitated withdrawal indicative of cannabinoid dependence. Using a dosing regimen known to produce pharmacological and behavioral tolerance, mice were treated with Delta9-tetrahydrocannabinol (Delta9-THC) twice a day for 1 wk. SR141716A administration after the last Delta9-THC injection promptly precipitated a profound withdrawal syndrome. Typical withdrawal behavior was an increase in paw tremors and head shakes that was accompanied with a decrease in normal behavior such as grooming and scratching. Of the three Delta9-THC regimens tested, daily Delta9-THC injections of 10 and 30 mg/kg produced the greatest number of paw tremors and head shakes and the least number of grooms after challenge with SR141716A. Precipitated withdrawal was apparent after 2, 3, 7 and 14 days of treatment based on an increase in paw tremors in Delta9-THC-treated mice as compared with vehicle-treated mice. These findings are consistent with SR141716A-precipitated withdrawal in rats. Moreover, these results suggest that mice are a viable model for investigating dependence to cannabinoids.     

A computational model of cholinergic disruption of septohippocampal activity in classical eyeblink conditioning

Aspartate-like immunoreactivity was visualized in the neostriatum of rats using indirect immunofluorescence techniques and antibodies raised against aspartate conjugated to keyhole limpet hemocyanine. In normal rats only a few aspartate-positive cell bodies with limited processes were observed. A moderate increase was seen after treatment with (+)methamphetamine and haloperidol. A dramatic increase in the number and fluorescence intensity was observed in the unilaterally 6-hydroxy-dopamine lesioned rats after multiple injections of the D1-dopamine receptor agonist SKF 38393. In these rats strongly fluorescent processes as well as extensive terminal varicose fibre networks were observed. This increase could partly be blocked by the D1-dopamine receptor antagonist SCH 23390. Using a modified technique the aspartate-positive cell bodies and processes were observed even when the antiserum was diluted 1:80,000. Positive cell bodies and fibres were also seen on the ipsilateral side outside the neostriatum, for example in the islet of Calleja and in the piriform cortex. The aspartate-positive cells were negative for dopamine- and cyclic AMP-regulated phosphoprotein-32, a marker for neurons bearing dopamine D1-receptor subtype. A proportion of the aspartate-positive neurons (20%) contained neuropeptide tyrosine-like immunoreactivity. On adjacent sections there was a marked up-regulation of preprodynorphin-like immunoreactivity. The up-regulation of dynorphin and aspartate was only observed when there was an almost complete denervation of the neostriatum as visualized with antiserum to tyrosine hydroxylase, a marker for dopamine fibres. The present results raise the possibility that aspartate may act as a neurotransmitter released from interneurons in the neostriatum.     

Localization of a gene for a glutamate binding subunit of a NMDA receptor (GRINA) to 8q24

De novo acute leukaemia presenting with a mixed lymphoid and myeloid leukaemic population has rarely been described. We have used the consensus Ig heavy chain primers and DNA isolated from these two distinct populations of cells in polymerase chain reactions. We demonstrated that both populations of cells exhibited Ig heavy chain gene rearrangements. Cloning and subsequent DNA sequencing of the amplified products showed a common V-D-J junctional nucleotide sequence. This work therefore provides the first evidence that the leukaemic cells in de novo acute leukaemia with a mixed lymphoid and myeloid population are derived from a common progenitor clone and may offer an explanation for the poor prognosis in these patients.     

Anorectal physiological testing in defecatory disorders: a prospective study

A prospective study of anorectal physiological testing in 26 patients with obstructed defecation and 20 patients with faecal incontinence was performed. There were overlaps in individual test parameters between the two groups of patients. However, patients with severely blunted rectal sensation (maximum tolerated volume > 300 mL) and anismus were more likely to have obstructed defecation. Patients with very low anal canal pressures, a short (< 2.0 cm) anal canal, bilaterally prolonged (> 2.1 ms) pudendal nerve terminal motor latency and a grossly distorted and canal (vector symmetry index < or = to 0.75) were more likely to have faecal incontinence. Thus, patterns of anorectal physiological test results together with clinical evaluation, rather than individual test measurements, are more valuable in defining the underlying defecatory disorders and providing guidance on therapy.     

Randomized event-related experimental designs allow for extremely rapid presentation rates using functional MRI

Previous studies have shown that hemodynamic response overlap severely limits the maximum presentation rate with event-related functional MRI (fMRI) using fixed intertrial experimental designs. Here we demonstrate that the use of randomized experimental designs can largely overcome this limitation, thereby allowing for event-related fMRI experiments with extremely rapid presentation rates. In the first experiment, fMRI time courses were simulated using a fixed intertrial interval design with intervals of 16, 3, and 1 s, and using a randomized design having the same mean intertrial intervals. We found that using fixed intertrial interval designs the transient information decreased with decreasing intertrial intervals, whereas using randomized designs the transient information increased with decreasing mean intertrial intervals. In a second experiment, fMRI data were collected from two subjects using a randomized paradigm with visual hemifield stimuli presented randomly every 500 ms. Robust event-related activation maps and hemodynamic response estimates were obtained. These results demonstrate the feasibility of performing event-related fMRI experiments with rapid, randomized paradigms identical to those used in electrophysiological and behavioral studies, thereby expanding the applicability of event-related fMRI to a whole new range of cognitive neurosciences questions and paradigms.     

Determination of neutrophil antigen gene frequencies in five ethnic groups by polymerase chain reaction with sequence-specific primers

BACKGROUND: The granulocyte antigens NA1 and NA2 are the two recognized allelic forms of Fc gamma receptor IIIB. These antigens are clinically relevant, because they are the most frequent targets of neutrophil antibodies in alloimmune neonatal neutropenia, transfusion-related acute lung injury, and chronic benign autoimmune neutropenia of infancy. STUDY DESIGN AND METHODS: A genotyping assay for NA1 and NA2 using polymerase chain reaction with sequence-specific forward and reverse oligonucleotide primers has been developed and validated. Genomic DNA was isolated from the peripheral blood of 478 unrelated individuals of five ethnic groups and used as template for NA genotyping. RESULTS: A validation study of 22 serologically typed samples (2 NA1/NA1, 10 NA1/NA2, and 10 NA2/NA2) was performed. A concordance rate of 100 percent (22/22 samples) was observed between the genotyping assay and serologic typing. In the genotyping study conducted, the NA1 and NA2 gene frequencies observed were 0.31 and 0.69 for African Americans, 0.30 and 0.70 for Asian Indians, 0.37 and 0.63 for whites, 0.53 and 0.47 for Hispanics, and 0.55 and 0.45 for Native Americans, respectively. CONCLUSION: Polymerase chain reaction with sequence-specific primers provides a simple and rapid alternative to neutrophil antigen typing by serologic tests. The NA1 and NA2 gene frequencies observed in Asian Indians and African American populations are similar to those observed in white populations, while those observed in Native American and Hispanic populations are more similar to those previously reported for Asian populations.     

Muscle rigidity due to fentanyl infusion in the pediatric patient

Two cases of fentanyl-induced muscle rigidity are presented. Significant features of these cases include the unusual pattern of rigidity and the use of fentanyl doses lower than those usually associated with muscle rigidity.     

Comparison of two devices for wound measurement

Sixty leg ulcers were measured with two techniques, a common paper tape measure and a new technique, a plastic grid device. The plastic grid proved to be a reliable, valid, and feasible method to quickly assess wounds in a busy outpatient setting. The grid was superior to the tape measure in assessing large and/or irregular ulcers.