Hemostatic profiles in 39 dogs with congenital portosystemic shunts

OBJECTIVES

To determine if there were significant changes in prothrombin time (PT), partial thromboplastin time (PTT), and fibrinogen levels in dogs with naturally occurring congenital portosystemic shunts (CPSS) and to determine if there was any association between these values, serum albumin concentration, and the ability to attenuate the shunt vessel.

STUDY DESIGN

Retrospective clinical study.

ANIMALS

Thirty-nine client-owned dogs.

METHODS

Medical records of 60 dogs with confirmed CPSS were retrospectively evaluated. Hemostatic profiles had been performed before surgery in 39 cases.

RESULTS

Dogs with CPSS had significantly higher values for PTT (P < .001) when compared with normal dogs. Of the total number of dogs, 64.1% had a PTT greater than 16 seconds (25/39). PTT was prolonged by 25% or more in 51.3% of dogs (20/39). PT tended to be higher in dogs with CPSS (P = .036), although only 7.7% (3/39) of dogs had a PT greater than 12 seconds (the maximum reference value). Dogs with CPSS had significantly lower values for albumin and fibrinogen (P < .001). Platelet numbers were within the normal range in 87.2% of cases (34/39). Of the 5 dogs with platelet numbers outside the normal range, 3 were mildly thrombocytopenic. Fibrin degradation product concentrations were not elevated in any dogs tested (N = 22). There was no significant difference in any of the measured variables between dogs with extrahepatic shunts and those with intrahepatic shunts (P > .1). For PT, PTT, albumin, and fibrinogen, there was no significant difference between dogs that underwent total, partial, or no attenuation (P > .3).

CONCLUSIONS

Dogs with CPSS have a tendency to have a prolonged PTT. There was no significant difference in hemostatic profile results between dogs with intrahepatic shunts versus extrahepatic shunts. Preoperative hemostatic profile abnormalities were not useful as predictors of ability to attenuate CPSS.

CLINICAL RELEVANCE

Prolonged PTT was not associated with bleeding tendencies in any of the dogs. Assays of individual clotting factors may help to further characterize the abnormalities present in animals with CPSS and may identify specific factor deficiencies. This might enable identification of a noninvasive diagnostic or prognostic indicator.

Butyrate alters the expression and activity of cell cycle components in anaplastic thyroid carcinoma cells

Anaplastic thyroid carcinoma (ATC) is the most malignant and aggressive form of thyroid cancer. Most patients die within months of diagnosis, primarily due to the absence of effective chemotherapeutic strategies. Identifying alternative therapies is necessary to increase long-term survival. Butyrate elicits a number of responses from cancer cells both in vitro and in vivo including growth repression, cell cycle arrest, differentiation, and apoptosis. Even though many types of cancer cells have been studied, little is known of the response of ATC cells to this drug. In this study, we report that butyrate induces differential cell cycle arrest (arrest in G1 and G2/M phases) in an ATC cell line that correlates with changes in the expression, phosphorylation, and activity of key components of the cell cycle machinery. Exposure to butyrate increases the expression of the cyclin-dependent kinase inhibitors, p21/Cip1 and p27/Kip1, decreases the expression of cyclin A and cyclin B, inhibits the phosphorylation of the retinoblastoma protein (pRb), and decreases the activity of cdk1 and cdk2-associated kinases. These results suggest that butyrate may be useful in the clinical treatment of ATC.

Are infants with autism socially engaged? A study of recent retrospective parental reports

The purpose of this study was to identify the specific aspects of social engagement that distinguish infants with autism from infants of similar age and developmental level who do not have autism. Ten parents of preschoolers with autism and 10 parents of matched children without autism were given a semistructured interview, the Detection of Autism by Infant Sociability Interview (DAISI), which elicits reports on whether 19 aspects of social engagement characteristic of typically developing infants were present at some time during the child's first 24 months. The reports of infants with autism differed from those of the control group on 16 items. Findings suggest that infants with autism have marked limitation in both person-to-person and person-person-object social engagement, in keeping with the theory that autism involves impairments in primary as well as secondary intersubjectivity (Hobson, 1993a).

Reproducibility of nerve fiber layer thickness measurements by use of optical coherence tomography

OBJECTIVE

To evaluate the reproducibility of optical coherence tomograph (OCT) retinal nerve fiber layer (RNFL) measurements in normal and glaucomatous eyes by means of the commercially available OCT 2000 instrument (Humphrey Systems, Dublin, CA).

DESIGN

Prospective instrument validation study.

PARTICIPANTS

One eye each from 10 normal subjects and 10 glaucoma patients.

METHODS

Twenty subjects underwent a total of eight scanning sessions during two independent visits. In each session, five circular scans centered on the optic nerve head were performed. The first two sessions were performed by two experienced technicians. Followed by a 30-minute break, a third and a fourth session was completed by the same technicians. This sequence was duplicated on a second visit. Intrasession, intersession, intervisit, and interoperator reproducibility of quadrant and global RNFL measurements were calculated by use of a components of variance model.

MAIN OUTCOME MEASURES

RNFL thickness.

RESULTS

The coefficient of variation for the mean RNFL thickness was significantly smaller (P = 0.02) in normal eyes (6.9%) than in glaucoma eyes (11.8%). The estimated root mean squared error based on the statistical model using three scans per patient was 5.8 and 8.0 micrometer for normal and glaucoma eyes, respectively. A components of variance model showed most of the variance (79%) to be due to differences between patients. Only a modest contribution to variability was found for session (1%), visit (5%), and operator (2%).

CONCLUSION

With the commercially available OCT, our results indicate that the RNFL measurements are reproducible for both normal and glaucomatous eyes.

Role of nitric oxide in a toxin-induced model of haemolytic uraemic syndrome

The role of nitric oxide in the pathogenesis of glomerular thrombotic microangiopathy was explored using an established rat model in which ricin with or without lipopolysaccharide induced glomerular thrombosis. Ricin alone caused a small rise in the plasma concentration of nitric oxide (control 9.2+/-0.7 microM, ricin 23.3+/-6.3 microM at 7 h). This increase occurred after the development of glomerular thrombosis. Nitric oxide synthase (NOS) activity in the kidney showed no significant change from control values (control 5.66+/-2.7 pmol/min per ml homogenate, ricin 7.52+/-1.8 pmol/min per ml homogenate, total activity). When ricin and lipopolysaccharide were administered together, calcium-independent NOS activity increased whereas calcium-dependent activity decreased (1.22+/-2.6 pmol/min per ml homogenate). The increase in calcium-independent NOS activity correlated with a high plasma concentration of interleukin-1beta in the ricin plus lipopolysaccharide group (4,036.83+/-1,001.5 pg/ml). These data indicate that thrombus formation in a rat model of haemolytic uraemic syndrome is independent of the effects of nitric oxide.

Spindle cell lipoma of the foot and the application of CD34 immunohistochemistry to atypical lipomatous tumors in unusual locations

Spindle cell lipoma demonstrates a distinctive histologic appearance and characteristic clinical presentation. We recently observed two cases of solitary subcutaneous neoplasm of the foot with histologic features of spindle cell lipoma that in one case includes a minor component of the overlapping tumor, pleomorphic lipoma. Because the foot is an unusual location for these neoplasms, immunoperoxidase and cytogenetic studies were performed. In both cases, staining was strongly positive for CD34 and negative for smooth muscle actin. Cytogenetic studies from the tumor with a pleomorphic component revealed features consistent with a lipomatous neoplasm, but are otherwise diagnostically nonspecific. An analysis of the literature reveals that although CD34 immunoreactivity is characteristic of spindle cell lipoma and helps exclude nonlipomatous neoplasms, it does not clearly eliminate other well-differentiated lipomatous tumors. Accordingly, without the aid of classic tumor location, the diagnosis of the spindle cell/pleomorphic lipoma group relies primarily on histologic features, with supportive but not definitive information provided by immunoperoxidase and cytogenetic studies. Obscuring this issue, however, are the imprecise histologic distinction between these tumors and those of the atypical lipoma/atypical lipomatous tumor/ well-differentiated liposarcoma group and the nomenclature controversy that surrounds the latter group of neoplasms. Despite these obstacles, both groups of well-differentiated lipomatous tumors are clinically benign when subcutaneously located.

Tyrosine phosphorylation-dependent inhibition of hippocampal synaptic plasticity

We examined the effects of two protein tyrosine phosphatase inhibitors on the induction of synaptic plasticity in CA1 slices of rat hippocampus. Field potential recordings were made in stratum radiatum in response to stimulation of the Schaffer collateral afferents. Bath application of the tyrosine phosphatase inhibitors sodium orthovanadate or phenylarsine oxide for 30 min had little effect on basal synaptic transmission but blocked the induction of both long-term potentiation (LTP) and homosynaptic long-term depression (LTD). LTP could be partially recovered, and LTD fully recovered, when conditioning stimulation was given in conditions of reduced synaptic inhibition. The block of both forms of synaptic plasticity by the phosphatase inhibitors correlated with a concurrent depression of the N-methyl-D-aspartate (NMDA) receptor-mediated potential, as measured both extracellularly and intracellularly. This depression, which was also induced by peroxyvanadate, required synaptic stimulation to be induced, and was tyrosine kinase-dependent. Our results suggest that tyrosine phosphorylation of as yet unidentified proteins is responsible for a novel activity-dependent depression of NMDA receptor function that inhibits synaptic plasticity.

CD40 ligand, Bcl-2, and Bcl-xL spare group I Burkitt lymphoma cells from CD77-directed killing via Verotoxin-1 B chain but fail to protect against the holotoxin

Owing to its lineage and differentiation stage-restricted expression, CD77 has been mooted as a therapeutic target in Burkitt lymphoma (BL). The recognition that the globotriaosyl moiety of this neutral glycosphingolipid is a receptor for Escherichia coli-derived Verotoxin-1 (Shiga-Like Toxin-1) offers a potential delivery system for the attack. Here we show that CD77-expressing Group I BL cells which are normally susceptible to activation-induced death on binding Verotoxin-1 B chain are protected in the presence of CD40 ligand. Ectopic expression of either bcl-2 or bcl-xL also afforded resistance to the actions of the B chain. In total contrast, neither of the survival genes nor a CD40 signal - even when acting in concert - protected against killing mediated by the holotoxin. These findings indicate that while therapeutic modalities for CD77-expressing B cell tumors (which include follicular lymphoma) based on the use of Verotoxin-1 B chain might be compromised by the activation of endogenous or exogenous survival pathways, those exploiting the holotoxin should be left unscathed.

Prevention of relapse/recurrence in major depression by mindfulness-based cognitive therapy

This study evaluated mindfulness-based cognitive therapy (MBCT), a group intervention designed to train recovered recurrently depressed patients to disengage from dysphoria-activated depressogenic thinking that may mediate relapse/recurrence. Recovered recurrently depressed patients (n = 145) were randomized to continue with treatment as usual or, in addition, to receive MBCT. Relapse/recurrence to major depression was assessed over a 60-week study period. For patients with 3 or more previous episodes of depression (77% of the sample), MBCT significantly reduced risk of relapse/recurrence. For patients with only 2 previous episodes, MBCT did not reduce relapse/recurrence. MBCT offers a promising cost-efficient psychological approach to preventing relapse/recurrence in recovered recurrently depressed patients.

Sequential increase in Egr-1 and AP-1 DNA binding activity in the dentate gyrus following the induction of long-term potentiation

Establishment of long-term potentiation (LTP) at perforant path synapses is highly correlated with increased expression of Egr and AP-1 transcription factors in rat dentate gyrus granule cells. We have investigated whether increased transcription factor levels are reflected in increased transcription factor activity by assessing Egr and AP-1 DNA binding activity using gel shift assays. LTP produced an increase in binding to the Egr element, which was NMDA receptor-dependent and correlated closely with our previously reported increase in Egr-1 (zif/268) protein levels. Supershift analysis confirmed involvement of Egr-1, but not Egr-2 in the DNA binding activity. AP-1 DNA binding was also rapidly elevated in parallel with protein levels, however, the peak increase in activity was delayed until 4 h, a time point when we have previously shown that only jun-D protein was elevated. These data indicate that binding of Egr-1 and AP-1 to their response elements is increased in two phases. This may result in activation of distinct banks of target genes which contribute to the establishment of persistent LTP.

Mindfulness-based cognitive therapy reduces overgeneral autobiographical memory in formerly depressed patients

Previous research on depressed and suicidal patients and those with posttraumatic stress disorder has shown that patients' memory for the past is overgeneral (i.e., patients retrieve generic summaries of past events rather than specific events). This study investigated whether autobiographical memory could be affected by psychological treatment. Recovered depressed patients were randomly allocated to receive either treatment as usual or treatment designed to reduce risk of relapse. Whereas control patients showed no change in specificity of memories recalled in response to cue words, the treatment group showed a significantly reduced number of generic memories. Although such a memory deficit may arise from long-standing tendencies to encode and retrieve events generically, such a style is open to modification.

Septohippocampal pathway as a site for the memory-impairing effects of ethanol

Ethanol affects behavior by interacting with synaptic sites at many levels of the nervous system. However, it targets most readily and at the lowest concentrations those sites mediating higher cognitive functions such as attention and memory. The memory-impairing effects of ethanol are thought to involve the hippocampus, a structure particularly vulnerable to the effects ethanol at low concentrations and early in the rising phase of the blood ethanol concentration curve. One of the early, low-dose effects of ethanol is an interruption of the normal physiological regulation of the hippocampus by the ascending septohippocampal pathway originating in the medial septal area (MSA). Ethanol enhances GABAergic transmission in the MSA, thereby reducing the regularity and vigor with which rhythmically bursting neurons of the MSA drive the hippocampal theta rhythm. Disruption of septohippocampal activity also has consequences on the response of the hippocampus to cortical inputs. Ethanol produces a loss of hippocampal responsivity that reduces the ability of the hippocampus to encode and retrieve relevant stimulus information necessary for accurate memory. This paper examines the behavioral and neural evidence for hippocampal vulnerability to ethanol and explores the hypothesis that these effects are due to ethanol disrupting septohippocampal modulation of the hippocampus, resulting in impairments of memory.

Myocardial revascularization in the elderly using beating heart coronary artery bypass surgery

BACKGROUND

Beating heart or "off-pump" coronary artery bypass (OP-CAB) has become an accepted method of myocardial revascularization by reducing the perioperative morbidity related to cardiopulmonary bypass (CPB). However, the efficacy of OP-CAB has not been well established in the elderly patient population.

METHODS

OP-CABs were performed in 53 patients aged 75 years and older, at Pitt County Memorial Hospital from January 1996 to October 1999, either through a median sternotomy or an anterior thoracotomy. These results were compared with 220 patients who underwent standard coronary artery bypass graft (CABG) operation using CPB during the same time period.

RESULTS

Mean patient age for both groups was 79+/-0.5 years and preoperative risk factors were similar. There were no differences in postoperative myocardial infarction, atrial fibrillation, bleeding, neurologic complications, or renal failure. There were no deaths after OP-CAB, compared with the 7.6% operative mortality rate after CABG (p<0.05). The OP-CAB group had a significantly shorter postoperative length of stay (4.4+/-0.4 days vs. 8.4+/-0.6 days) and lower transfusion requirements (0.4+/-0.1 units packed red blood cells vs 1.9+/-0.2 units packed red blood cells) than the CABG group.

CONCLUSIONS

Our data demonstrate that OP-CAB is a safe and efficacious method of myocardial revascularization in the elderly, and may actually be preferential in these patients when applicable.

Mindfulness-based cognitive therapy reduces overgeneral autobiographical memory in formerly depressed patients

Previous research on depressed and suicidal patients and those with posttraumatic stress disorder has shown that patients' memory for the past is overgeneral (i.e., patients retrieve generic summaries of past events rather than specific events). This study investigated whether autobiographical memory could be affected by psychological treatment. Recovered depressed patients were randomly allocated to receive either treatment as usual or treatment designed to reduce risk of relapse. Whereas control patients showed no change in specificity of memories recalled in response to cue words, the treatment group showed a significantly reduced number of generic memories. Although such a memory deficit may arise from long-standing tendencies to encode and retrieve events generically, such a style is open to modification.

The retinal nerve fiber layer thickness in ocular hypertensive, normal, and glaucomatous eyes with optical coherence tomography

OBJECTIVE

To quantitatively assess and compare the thickness of the retinal nerve fiber layer (RNFL) in ocular hypertensive eyes with normal and glaucomatous eyes using the Optical Coherence Tomograph (OCT 2000, software version A4X1; Humphrey Instruments, San Leandro, Calif).

METHODS

The mean RNFL thickness of ocular hypertensive (n = 28) eyes was compared with age-matched normal (n = 30) and glaucomatous (n = 29) eyes. Subject eyes were classified into diagnostic groups based on intraocular pressure, stereoscopic disc photographs, and standard automated perimetry. Three circular scans were obtained for each eye at a diameter of 3.4 mm around the optic disc. In each eye, average RNFL thickness measurements were obtained in temporal, superior, nasal, and inferior quadrants. A single index of average RNFL thickness throughout 360 degrees also was obtained.

RESULTS

Mean (95% confidence interval) RNFL was significantly thinner in ocular hypertensive eyes than in normal eyes, 72.8 microm (66.4-78.1 microm) and 85.8 microm (80.2-91.7 microm), respectively. More specifically, RNFL was significantly thinner in ocular hypertensive eyes than in normal eyes in the inferior quadrant, 84.8 microm (75.6-94.0 microm) vs 107.6 microm (99.3-115.9 microm); and in the nasal quadrant, 44.1 microm (37.5-51.7 microm) vs 61.8 microm (53.0-65.6 microm). Retinal nerve fiber layer was significantly thinner in glaucomatous eyes than in ocular hypertensive and normal eyes throughout 360 degrees and in all quadrants.

CONCLUSION

These findings suggest that quantitative differences in RNFL thickness exist between age-matched ocular hypertensive, normal, and glaucomatous eyes.

Health promotion practices of emergency physicians

In this article we describe health promotion practices of emergency physicians (EPs). A survey was mailed to members of the West Virginia American College of Emergency Physicians. Main outcomes included the EP's beliefs regarding health promotion, perceived roles in health promotion, and perceived effectiveness in modifying the behavior of patients. Over 90% of respondents routinely asked about cigarette smoking and half about alcohol use. A minority routinely asked about illicit drug use, diet, exercise, domestic violence, or stress. The majority stated they were the main person responsible for patient health education in their emergency department (ED). Most felt prepared to counsel patients about smoking (68%) and alcohol (59%), although very few described themselves as successful in helping patients change their behavior. Although EPs feel responsible for promoting the health of their patients, only a minority reported routinely screening and counseling patients about prevention and most were not confident in their ability to help patients change their health-related behaviors.

Platinum-catalysed allylic alkylation: reactivity, enantioselectivity, and regioselectivity

The use of platinum complexes as catalysts for allylic substitution has been studied. A variety of different complexes catalyse the reaction, and several substrates have been tested. In the alkylation of mono(alkyl)-substituted allylic acetates, regioselectivity is highly dependent on ligand choice. By using tricyclohexylphosphine as the ligand, almost complete formation of branched products is observed. The development of a highly enantioselective (ca. 80-90% ee) reaction that makes use of chiral diphenylphosphinooxazoline ligands (abbreviated as (S)-PN) is also described. The enantioselectivity is highly dependent on the ratio of ligand to platinum (when the ratio ligand/Pt is greater than 1:1, the ee drops off dramatically). This is in contrast to palladium and is interpreted in terms of differing coordination chemistry for the two metals ((S)-PN is hemilabile when complexed to platinum) and should be of significance to future systems that utilise heterobidentate ligands. The crystal structures of two isoelectronic platinum and palladium complexes [[(S)-PN]MCl2] are also described.

Hyaluronan suppresses fibronectin fragment-mediated damage to human cartilage explant cultures by enhancing proteoglycan synthesis

Hyaluronic acid, recently renamed hyaluronan, has been used as a therapeutic intervention in the treatment of osteoarthritis. We have reported that high-molecular-weight (800 kDa) hyaluronan is effective in blocking the catabolic action of fibronectin fragments in explant cultures of bovine cartilage and in an experimental in vivo model of damage to the rabbit knee joint. The fibronectin fragments induce catabolic cytokines in human cartilage, which, in turn, suppress proteoglycan synthesis and induce matrix metalloproteinases to decrease the proteoglycan content. Since the clinical target of high-molecular-weight hyaluronan is human cartilage, which may differ in certain ways from bovine cartilage, we tested the effect on human knee cartilage. We found that 1 mg/ml hyaluronan completely blocked fibronectin fragment-mediated decreases in proteoglycan content in five of five specimens of cartilage from the human knee. This was associated with binding of exogenous hyaluronan to the superficial surface, suppressed penetration of the fibronectin fragment into the cartilage, decreased expression for the first week in culture of one of the matrix metalloproteinases involved in cartilage degradation, matrix metalloproteinase-3, and proteoglycan synthesis rates that increased to supernormal levels. However, the appearance of the NITEGE and VDIPEN neoepitopes, indices of cartilage degradation, was not blocked but was delayed by 1 week. The addition of hyaluronan to cartilage previously damaged by the fibronectin fragments or to osteoarthritic cartilage fully restored the proteoglycan content to control levels. We conclude that hyaluronan blocked damage at least partly by blocking penetration of the fibronectin fragments and slowing matrix metalloproteinase expression. However, the major effect on blocking damage and promoting repair may be through enhanced proteoglycan synthesis, a mechanism that requires further study. Nonetheless, these data clearly demonstrate that hyaluronan completely protected human cartilage in explant culture and facilitated a full restoration of proteoglycan in damaged cartilage.

Autobiographical memory and dissociation in borderline personality disorder

BACKGROUND

This study investigated whether individuals with borderline personality disorder (BPD) tend to be overgeneral in their autobiographical recall and whether the extent of their overgeneral recall covaries with their susceptibilities to dissociative experiences, as expected on theoretical grounds.

METHODS

Twenty-three patients with BPD and 23 matched controls completed the Autobiographical Memory Test (AMT) and self-report measures of depression, anxiety, trait anger and dissociative experiences.

RESULTS

Participants with BPD scored significantly higher than the control group on the measures of depression, anxiety, trait anger, and dissociative experiences and also retrieved significantly more general memories on the AMT. The number of general memories retrieved by the BPD group correlated significantly with their dissociation scores but not with their scores on mood measures.

CONCLUSIONS

Patients with BPD have difficulties in recalling specific autobiographical memories. These difficulties are related to their tendency to dissociate and may help them to avoid episodic information that would evoke acutely negative affect.

Spatial relationship of motion automated perimetry and optic disc topography in patients with glaucomatous optic neuropathy

PURPOSE

To compare the spatial relationship of focal motion automated perimetry (MAP) visual field defect with focal defect in optic disc topography.

METHODS

Patients (n = 12) with focal MAP visual field loss and focal change in optic disc topography were studied. The MAP visual field was divided into 12 field zones representing retinal nerve fiber layer arcuate bundles. Zones of MAP loss were related to rim area ratio (RAR), which was obtained by dividing the rim area, measured by the Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Heidelberg, Germany), into 36 10 degrees sectors and then dividing the area of each sector by the total rim area for each subject. Rim area ratio was compared to a normative database (n = 76) to quantify change in optic disc topography. In these same patients, the spatial relationship between standard automated perimetry (SAP) and short-wavelength perimetry (SWAP) and optic disc topography was also assessed.

RESULTS

Motion automated perimetry superior visual field zones 14 through 19 were most often associated with a reduction in RAR for inferior sectors 24 through 29, and inferior visual field zones 4 through 7 were most often associated with a reduction in RAR for superior temporal sectors 11 through 16. Similar spatial relationships were found between SWAP and SAP and the RAR.

CONCLUSION

Focal MAP visual field loss and focal changes in optic disc topography are spatially related. This relationship is similar to that found between SWAP and SAP with optic disc topography. Focal thinning or notching detected by RAR analysis might be independent of the specific functional test employed.

The extrafollicular-to-follicular transition of human B lymphocytes: induction of functional globotriaosylceramide (CD77) on high threshold occupancy of CD40

Amongst lymphocytes, expression of CD77 (globotriaosylceramide, Gb3) is exclusive to B cells of the germinal center (GC). Its acquisition by extrafollicular B cells may thus herald their commitment to a follicular response. Here we show that high threshold occupancy of CD40 by its cognate ligand (CD40L) promotes rapid induction of CD77 expression in non-GC (CD38(lo)) B cells. The kinetics of CD77 acquisition mirrored those of GC-related markers CD95 and CD86 but contrasted with the more delayed increase in CD38 expression. Induction of CD77 was not a simple consequence of cell cycle entry: other conditions of stimulation equally capable of driving proliferation failed to promote CD77 expression. CD77 was functional in that cells were now sensitive to Verotoxin-1, an Escherichia coli-derived ligand of Gb3. These data indicate that acquisition by extrafollicular B cells of CD77 results from high threshold occupancy of CD40, a situation that should be reached physiologically only once a critical level of T cell priming has been achieved.

Athletic injury, psychosocial factors and perceptual changes during stress

In this study, we measured changes in state anxiety, visual perception and reaction time during stress among 196 collegiate athletes participating in 10 sports. The athletes also completed measures of life events and social support at the beginning of their seasons. Measures of life events stress, social support, perceptual changes and changes in reaction time during stress were used as predictors of the number of injuries. For the entire sample, the only significant predictor of injury was negative life events stress (R = 0.45, P < 0.001). Following the suggestions of Smith et al., simple correlations were performed for those with least social support (bottom 33%, n = 65). Among this group, those individuals with more negative life events and greater peripheral narrowing during stress incurred more injuries than those with the opposite profile. Our findings are in line with the model of Andersen and Williams, in that those individuals who were low in a variable that buffers stress responsivity (i.e. social support), their negative life events and peripheral narrowing under stress (large and medium effect sizes, respectively) were substantially related to their number of injuries.

Impact of diaphragmatic paralysis after cardiothoracic surgery in children

OBJECTIVES

We sought to determine the prevalence and clinical impact of diaphragmatic paralysis caused by phrenic nerve injury after cardiothoracic surgery in children.

METHODS

A search of cardiology, radiology, and hospital databases identified 170 episodes of diaphragmatic paralysis after cardiothoracic surgery in 168 children operated on from 1985 to 1997. Medical records were reviewed to determine demographics, details of the operation and postoperative course, diagnostic features and management of diaphragmatic paralysis, and follow-up status.

RESULTS

The prevalence of diaphragmatic paralysis was 1.6% (95% confidence interval 1.4%-1.8%). Median age at operation was 6 months (range <1 day-14.4 years). Median time from the operation to the initial investigation was 5 days (range <1 day-61 days), with 57% of patients receiving mechanical ventilation at diagnosis. Diaphragmatic plication was performed in 40% of the patients at a median interval from the initial investigation of 15 days (range 3 days-11.1 months). Significant independent factors associated with increased postoperative hospital stay were lower patient weight at operation, previous cardiothoracic operations, bilateral diaphragmatic paralysis, increased interval from operation to investigation, mechanical ventilation at the time of investigation, and diaphragmatic plication. Confirmed recovery of diaphragmatic function was noted before hospital discharge in only 15 episodes.

CONCLUSIONS

Diaphragmatic paralysis complicating cardiothoracic surgery continues to occur in the current era, with a significant impact on morbidity. Smaller patients with bilateral hemidiaphragmatic paralysis, requiring mechanical ventilation, may represent a higher risk subgroup to target for increased diagnostic suspicion and more aggressive management; early spontaneous recovery is rare.

Effects of hyaluronic acid on cartilage degradation

Based on the published literature available so far, it appears that naturally derived hyaluronic acid (HA) and newer formulations available on the market belong to the pharmacologic class of slow-acting drugs for the treatment of osteoarthritis. These compounds seem to have the potential to modulate the painful symptoms of osteoarthritis as well as to improve the function of the osteoarthritis joint. Positive clinical consequences are based on direct and indirect effects of viscosupplementation associated with a normalization of the rheologic properties of the osteoarthritic synovial fluid, decreased inflammation, and end-coating of the pain receptors in the osteoarthritis joint. Few in vivo data exist in humans to support the concept that HA formulations could have a structure-modifying effect on human osteoarthritis cartilage. Animal-based studies have demonstrated positive effects of exogenous HA on pain in the joint, heat shock proteins, and in models of osteoarthritis. Although many promising effects of exogenous HA have been reported, there remains uncertainty as to the effectiveness of reversing cartilage injury and other manifestations of joint diseases with exogenous HA because of difficulties in interpreting and unifying results of these studies. This is due largely to differences of cartilage source in models of joint/cartilage injury, multiple end points, the controls employed, analytical techniques, and the molecular weight of exogenous HA used. There exists a need for uniform agreement as to the choice of injury model, time points of the study, evaluation tools, and source and molecular weight of the HA used if we are to determine whether exogenous application of HA has a truly beneficial role in the reversal of cartilage injury.

The effect of imageability and predicability of cues in autobiographical memory

Four experiments investigated the role of imagery in the recollection of autobiographical memories. The first two experiments examined the effects of word imageability and word frequency on the retrieval of personal memories in a cued autobiographical memory task. They showed that the imageability of cues (but not frequency) mediates specificity in the recall of personal memories. Experiment 2 explored how different imagery modalities (visual, olfactory, tactile, auditory, and motor) influence autobiographical retrieval. Consistent with research on imagery modalities in verbal learning paradigms, visual imageability emerged as the most significant predictor of specificity. Experiments 3 and 4 examined how far a knowledge-based account of imagery effects might account for these effects, using predicability as a measure of semantic richness of a cue. Results found that visual imageability of cues accounted for more variance in specificity of recall than did predicability. The results are explained in terms of the way images represent the most efficient form of summarizing the information that can be used at each stage of the recollection process: setting the retrieval plan, strategic search, and evaluation of candidate episodes.

New technologies for diagnosing and monitoring glaucomatous optic neuropathy

BACKGROUND

Recently, instruments have been developed to provide real-time, quantitative measurements of the optic disc and retinal nerve fiber layer (RNFL) for use in glaucoma management. Our objective is to (1) provide an overview of two of these instruments, the confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph, HRT) and scanning laser polarimeter (Nerve Fiber Analyzer, NFA) and (2) compare measurements obtained with these instruments to clinical features used in the diagnosis of glaucoma.

METHODS

Twenty glaucoma patients, 4 normal subjects and 20 glaucoma subjects were included. All subjects had images obtained with the HRT and NFA, and RNFL and optic disc photography completed within 5 weeks of each other. The HRT results were compared with qualitative evaluation of stereophotographs of the optic disc, and NFA results were compared against a semi-quantitative RNFL photograph severity score.

RESULTS

Twenty-five (57%) subjects had thinning of the neuroretinal rim identified by evaluation of stereoscopic optic disc photographs. Despite overlap, HRT measurements of rim volume, rim area, and rim/disc ratio were significantly smaller in eyes with evidence of rim thinning than in eyes with no evidence of rim thinning. Moderate to severe RNFL damage was detected by evaluation of photographs in 25 (57%) of subjects. NFA RNFL thickness measures were smaller in eyes with moderate to severe RNFL damage than in relatively healthy eyes.

CONCLUSIONS

Previous studies have documented the reproducibility of these instruments and suggested analytic techniques for improving their ability to differentiate between normal and glaucoma eyes. Our results indicate that despite overlap in values, these instruments provide measurements that reflect clinically relevant features of the optic disc and RNFL. Whether these technologies can improve our ability to detect glaucomatous progression over time needs to be determined with well-designed longitudinal studies and comparison with established diagnostic techniques for evaluating glaucomatous optic neuropathy.

Factors associated with outcomes of persistent truncus arteriosus

OBJECTIVES

The purpose of this study was to identify trends and factors associated with outcomes of persistent truncus arteriosus (PTA).

BACKGROUND

Although there have been significant improvements, PTA continues to be associated with significant morbidity and mortality.

METHODS

We undertook a review of all consecutive cases of PTA (n = 205) presenting at our institution from 1953 to 1997. Data were collected regarding demographics, anatomy, management (surgical palliation and repair) and outcomes (mortality and reoperation).

RESULTS

Significant trends (p < or = 0.001) related to groups defined by year of birth were as follows: number of cases (1953-1967, n = 13; 1968-1977, n = 42; 1978-1987, n = 69; 1988-1997, n = 81), median age at first assessment (8 months, 42 days, 7 days and 2 days, respectively), proportion who did not have any surgery (58%, 27%, 22% and 11%), proportion who had an initial palliative procedure (25%, 37%, 6% and 2%), proportion who underwent PTA repair (31%, 59%, 72% and 88%), median age at PTA repair (11.2 years, 1.1 years, 1.6 months and 12 days) and proportion dying before hospital discharge after repair (50%, 63%, 56% and 41%). Since 1995, mortality before hospital discharge after repair has further decreased to 2/11 (18%). Increasing time to initial conduit replacement in hospital survivors was significantly related to larger sized conduit at repair (p = 0.02) and use of pulmonary homografts (vs. aortic homografts or xenografts; p = 0.002). Interventional catheterization to address conduit obstructions significantly increased conduit longevity.

CONCLUSIONS

Significant improvements in PTA outcomes are evident with trends toward earlier age at assessment and complete repair.

Status of women in academic medicine at West Virginia University School of Medicine

The committee on Women in Academic Medicine at West Virginia University conducted a study to compare the status of women in academic medicine at West Virginia University with national averages. We obtained data on gender distributions, ranks, degrees, and administrative titles of full-time women faculty members. Our data showed that 26% of WVUSOM faculty are women. This fell short of the national average within some departments and exceeded the national average in others. Our data also indicated that among women faculty, 15% are full professors (10% nationally), 27% are associate professors (19% nationally), 51% are assistant professors (50% nationally), and 7% are instructors (17% nationally). No clinical departments, and only two basic science departments, are chaired by women. We conclude that the proportion of women faculty and differences in rank distributions at WVUSOM mirror national trends with few exceptions. There is a lack of women in senior positions including full professors, departmental chairs, division chiefs, and academic deans at WVUSOM.

Boxer's fracture: an indicator of intentional and recurrent injury

The objective was to describe the population of patients presenting with a boxer's fracture (BF), to determine how often BF is an intentional injury, to determine if it is a predictor of recurrent injury, and to compare the rates of intentional injury and injury recidivism between patients with BF and those with other injuries. An emergency department (ED)-based injury surveillance system (EDBISS) in a university-affiliated ED (census of 35,000) provided data on injured patients presenting between January 1, 1995 and December 31, 1996. Chart review was performed. Descriptive analyses were performed. The results showed 22,728 of 69,438 (33%) ED visits during a 2-year period were attributable to injuries. Sixty-two patients presented with BF. Mean age of BF patients was 22.1 versus 28.6 for all injured (P < .005). Ninety-two percent (57/62) of BF patients were men compared with 58% of all injured (P < .0001). Thirty-eight of 62 (61%) BF injuries were sustained after intentional punches of an object/person. Seventeen of 62 (27%) BF patients were injury recidivists. Previous studies in this same ED population showed that 6% had intentional injuries and 12% were injury recidivists. BF is usually an intentional injury and these patients are at increased risk for recurrent injury. Clinicians should focus prevention efforts on this high-risk population.

Effects of extreme heat on teeth with implications for histologic processing

This pilot study examined teeth subjected to extreme heat under laboratory conditions, and the subsequent effect of decalcification and histologic processing. Physical and microscopic findings were evaluated in relation to temperature and duration of thermal insult. Microscopic examination following decalcification and histologic processing revealed changes including severe tissue fragmentation, vapor bubbles within dentinal tubules, altered histologic staining, charring and tissue shrinkage. Dentin appeared to be the most reliable microscopic identifier of incinerated dental tissues. Temperatures above 600 degrees C strongly predicted tooth disintegration following decalcification. This finding has implications in incineration cases where histologic evidence must be maintained and examined intact.

Treatment with calcitonin suppresses the responses of bone, cartilage, and synovium in the early stages of canine experimental osteoarthritis and significantly reduces the severity of the cartilage lesions

OBJECTIVE

To relate the rate of bone resorption to serum levels of both hyaluronan (HA) and antigenic keratan sulfate (KS) in canine experimental osteoarthritis (OA) and to evaluate the effects of calcitonin on these parameters and the OA lesions of the unstable knee.

METHODS

Twenty-two dogs underwent anterior cruciate ligament transection (ACLT) and 6 dogs underwent sham operation. Urinary pyridinium crosslinks were quantified by high-performance liquid chromatography. Immunoassays quantified hyaluronan (HA) and antigenic KS. Macroscopic and histologic OA lesions were scored. Calcitonin treatment was started on day 14 postsurgery and stopped on either day 49 or day 104 postsurgery. Control dogs and all treated dogs were killed on day 105.

RESULTS

All ACLT joints developed OA. In contrast to sham-operated animals, all operated dogs exhibited an early and sustained rise in the levels of their urinary and serum markers. Calcitonin markedly reduced the levels of these markers and the severity of OA lesions. Furthermore, the longer the period of calcitonin therapy, the lower the score of the OA lesions.

CONCLUSION

Bone, synovium, and articular cartilage all appear to be involved in the state of hypermetabolism that develops in unstable joints. Furthermore, the rate of bone resorption increases markedly in the early stages of this OA model and is likely to contribute to cartilage breakdown. Since calcitonin reduced the severity of OA changes, this form of therapy may have benefits for humans who have recently experienced a traumatic knee injury.

Genitourinary dysplasia in a cat

A six-month-old kitten had congenital urethral sphincter mechanism incompetence due to urethral hypoplasia and associated uterine hypoplasia and vaginal aplasia. Diagnosis was based on radiographic examination, surgical exploration and histological examination of the lower urinary tract. Surgical correction resulted in a marked clinical improvement. The cat became fully continent following treatment with phenylpropanolamine.

Fetal cell identifiers: results of microscope slide-based immunocytochemical studies as a function of gestational age and abnormality

OBJECTIVE

We evaluated monoclonal antibodies to 3 cell surface and 3 intracellular antigens for their relative usefulness as markers to identify fetal cells in maternal blood.

STUDY DESIGN

With indirect immunocytochemical labeling techniques, antigen expression was studied in 52 fetal blood samples as a function of gestational age, fetal karyotype, the presence of multiple anomalies detectable on ultrasonography, and anemia.

RESULTS

A decline in the expression of these antigens as gestational age advanced was demonstrated. Samples from karyotypically abnormal fetuses, fetuses with multiple anomalies, and anemic fetuses showed an antigenic distribution that was immature for gestational age. In normal fetuses zeta globin and epsilon globin expression decreased after 12 to 14 weeks, potentially limiting the utility of these proteins as fetal cell markers in the isolation of fetal cells from maternal blood.

CONCLUSIONS

The results of this study demonstrate a fetal developmental hematologic profile that varies with gestational age and also with pathologic condition. Antibodies to the gamma chain of fetal hemoglobin and the transferrin receptor (CD71) are the most useful fetal cell-identifying reagents.

A laboratory model of toxin-induced hemolytic uremic syndrome

BACKGROUND

Verocytotoxin-producing (Shiga-like toxin-producing) Escherichia coli infection is the principal cause of hemolytic uremic syndrome (HUS). The pathogenesis is unclear, and there is a need for animal models. These are impeded by the different distribution of verocytotoxin receptors between species. We have circumvented this restriction using ricin, which gains entry into cells via various galactose receptors. Like verocytotoxin, ricin specifically cleaves a single adenine from ribosomal RNA.

METHODS

Rats were given ricin at a dose of 6.7 micrograms/100 g body wt, with or without lipopolysaccharide at 10 micrograms/100 g body wt. Lipopolysaccharide alone or saline were used as controls. Changes in glomerular filtration rate, hematological parameters, histology, and plasma cytokine concentrations were measured.

RESULTS

Extensive glomerular thrombosis, pyknotic nuclei, and an infiltration of ED1-positive cells into glomeruli were observed eight hours after an injection of ricin. Other vascular beds were unaffected. Histologic changes were preceded by oliguric renal failure, hemolysis, and thrombocytopenia. Ricin produced a rise in plasma concentrations of monocyte chemotactic protein-1, > tumor necrosis factor-alpha, > interleukin-1 beta, > interleukin-6. Interferon-gamma showed a small increase at the end of the experiment.

CONCLUSIONS

Ricin induces glomerular thrombotic microangiopathy, closely resembling that which occurs in verocytotoxin-producing E. coli-induced HUS. As in HUS, high concentrations of proinflammatory cytokines are present, which are probably a result of cytokine superinduction by the toxin.

A comparison of the effects of verocytotoxin-1 on primary human renal cell cultures

Infection with verocytotoxin-producing Escherichia coli causes haemolytic uraemic syndrome (HUS). Verocytotoxin-1 (VT1) is cytopathic to renal microvascular endothelial cells in culture, supporting the hypothesis that the vasculopathy of HUS is caused directly by the toxic action of VT1 on cells. We provide evidence that VT1 inhibits protein synthesis in primary cultures of glomerular epithelial cells (GE), cortical tubular epithelial cells (CTE) and mesangial cells (MC). Using 100 pg/ml of VT1 we saw a decrease in protein synthesis to 14.3+/-1.9% in vero cells (a primate cell line), 1.7+/-0.3% in GE, 0.9+/-0.4% in CTE and 74.8+/-1.3% in MC at 24 h. The human renal epithelial cells are at least as sensitive as vero cells to the protein synthesis inhibitory effects of VT1 if not more so. Cell viability decreased in all cultures as measured by MTT reduction, neutral red incorporation and lactate dehydrogenase release and followed the same pattern of susceptibility as for protein synthesis inhibition. However, unlike vero cells, death occurred without DNA fragmentation. Cell sensitivity was greatest in cells which bound more VT1.

A reporter gene assay to assess the molecular mechanisms of xenobiotic-dependent induction of the human CYP3A4 gene in vitro

1. A plasmid containing 1 kb of the CYP3A4 regulatory (promoter) region coupled to a reporter gene for secretary placental alkaline phosphatase (SPAP) was transfected into HepG2 cells. Transfected cells were dosed with several known inducers of CYP3A4 and the levels of SPAP were measured. The effect of co-transfecting a plasmid encoding the human glucocorticoid receptor on reporter gene activity was also examined. 2. Dexamethasone induced CYP3A4-dependent reporter gene expression in a concentration-dependent manner and induction was approximately doubled in the presence of the glucocorticoid receptor. Dexamethasone-dependent induction was blocked by RU-486 (a glucocorticoid receptor antagonist), in the presence of the co-transfected glucocorticoid receptor. 3. Induction of CYP3A4-dependent reporter gene expression and enhancement of the induction by the glucocorticoid receptor was also observed with pregnenolone-16alpha-carbonitrile (PCN), rifampicin, phenytoin, carbamazepine, phenylbutazone and phenobarbitone, all known in vivo inducers of CYP3A4 in man. 4. Metyrapone and sulfinpyrazone induced CYP3A4-dependent reporter gene expression, but induction was not enhanced by the glucocorticoid receptor. 5. Clotrimazole, erythromycin and triacetyloleandomycin (TAO) did not induce CYP3A4-dependent reporter gene expression, consistent with the observation that these inducers act through post-transcriptional mechanisms. 6. These results highlight differences in the molecular mechanisms of induction of CYP3A4 by the xenobiotics studied and indicate that the glucocorticoid receptor is involved in the induction of the CYP3A4 gene by some, but not all, CYP3A4 inducers. 7. We propose that the approach described here provides a useful in vitro approach for the identification of transcriptional regulators of the CYP3A4 gene.

Ferritin mutants of Escherichia coli are iron deficient and growth impaired, and fur mutants are iron deficient

Escherichia coli contains at least two iron storage proteins, a ferritin (FtnA) and a bacterioferritin (Bfr). To investigate their specific functions, the corresponding genes (ftnA and bfr) were inactivated by replacing the chromosomal ftnA and bfr genes with disrupted derivatives containing antibiotic resistance cassettes in place of internal segments of the corresponding coding regions. Single mutants (ftnA::spc and bfr::kan) and a double mutant (ftnA::spc bfr::kan) were generated and confirmed by Western and Southern blot analyses. The iron contents of the parental strain (W3110) and the bfr mutant increased by 1.5- to 2-fold during the transition from logarithmic to stationary phase in iron-rich media, whereas the iron contents of the ftnA and ftnA bfr mutants remained unchanged. The ftnA and ftnA bfr mutants were growth impaired in iron-deficient media, but this was apparent only after the mutant and parental strains had been precultured in iron-rich media. Surprisingly, ferric iron uptake regulation (fur) mutants also had very low iron contents (2.5-fold less iron than Fur+ strains) despite constitutive expression of the iron acquisition systems. The iron deficiencies of the ftnA and fur mutants were confirmed by Mössbauer spectroscopy, which further showed that the low iron contents of ftnA mutants are due to a lack of magnetically ordered ferric iron clusters likely to correspond to FtnA iron cores. In combination with the fur mutation, ftnA and bfr mutations produced an enhanced sensitivity to hydroperoxides, presumably due to an increase in production of "reactive ferrous iron." It is concluded that FtnA acts as an iron store accommodating up to 50% of the cellular iron during postexponential growth in iron-rich media and providing a source of iron that partially compensates for iron deficiency during iron-restricted growth. In addition to repressing the iron acquisition systems, Fur appears to regulate the demand for iron, probably by controlling the expression of iron-containing proteins. The role of Bfr remains unclear.

Perineal hernia with bladder retroflexion in a female cocker spaniel

Perineal herniation in the bitch is rare and its complication by bladder retroflexion in the bitch has not been previously reported in the literature. This case report describes a multigravid, five-year-old female cocker spaniel with bilateral perineal hernias, complicated by marked rectal sacculation and ventral bladder retroflexion. The case was managed initially by cystopexy and colopexy, followed seven days later by bilateral perineal herniorrhaphy. There was no recurrence of the problem by 12 months postsurgery.

Dynamic kinetic resolution

The use of transition-metal-enzyme combinations to effect tandem in situ racemisation and resolutions has extended the scope of dynamic kinetic resolutions. This methodology has signalled a more proactive stance to the racemisation process, which has traditionally relied on more fortuitous approaches, namely the exploitation of labile substrates. The development and application of specific racemising enzymes such as mandelate racemase offers potential for future multienzyme dynamic kinetic resolutions.

Pubertal timing and self-reported delinquency among male adolescents

Pubertal timing has consequences for adolescent adaptation, and Moffitt has theorized that puberty is a motivating factor for delinquency. Pubertal timing and self-reported delinquency were examined in a questionnaire-based survey of 14-year-old boys (n=99). The questionnaire was completed anonymously, under test conditions, in the school classroom. The results showed that offtime maturers (those early or late) reported a wider range of delinquency, including higher levels of crime and school opposition behaviours. Offtimers also reported a greater frequency of particular delinquent acts over a 12-month period. Overall, the results lend support to the "deviance hypothesis" of pubertal timing.

Problem solving and suicidal behavior

Research on suicidal behavior falls into two main areas: studies that aim to identify demographic and social risk factors, and studies that aim to investigate the psychological processes mediating suicidal behavior. Within the latter approach, impaired problem-solving ability has been found to be an important variable. This paper reviews recent research focusing on problem-solving deficits and their relation to suicidal behavior and considers some of the methodological problems that arise. These findings are discussed in terms of active versus passive problem solving, state or trait factors, and the psychological processes underlying problem solving. Suggestions for further research are made, focusing on the links between suicidal behavior, problem solving, and autobiographical memory.

A role for ATR in the DNA damage-induced phosphorylation of p53

Phosphorylation at Ser-15 may be a critical event in the up-regulation and functional activation of p53 during cellular stress. In this report we provide evidence that the ATM-Rad3-related protein ATR regulates phosphorylation of Ser-15 in DNA-damaged cells. Overexpression of catalytically inactive ATR (ATRki) in human fibroblasts inhibited Ser-15 phosphorylation in response to gamma-irradiation and UV light. In gamma-irradiated cells, ATRki expression selectively interfered with late-phase Ser-15 phosphorylation, whereas ATRki blocked UV-induced Ser-15 phosphorylation in a time-independent manner. ATR phosphorylated p53 at Ser-15 and Ser-37 in vitro, suggesting that p53 is a target for phosphorylation by ATR in DNA-damaged cells.

Use of omentum as a physiologic drain for treatment of chylothorax in a dog

OBJECTIVES

To describe a novel technique for the surgical treatment of idiopathic chylothorax in a dog.

ANIMALS

A 6-year-old, male Rhodesian Ridgeback, which presented with a history of reduced exercise tolerance and dyspnea.

METHODS

Idiopathic chylothorax was diagnosed. Intermittent pleural drainage failed to resolve the problem. During surgery, extensive pleural fibrosis made it impossible to identify the thoracic duct. A dorsal omental pedicle was advanced through an incision in the diaphragm and into the cranial thoracic cavity to act as a physiological drain.

RESULTS

The dog recovered well and has remained free from clinical signs of recurrence of the effusion (16 months at the time of writing).

CONCLUSIONS

The disease-free interval achieved in this dog indicates that this novel technique is worthy of further consideration in the management of idiopathic chylothorax.