Spontaneous regression of lymphoproliferative disorders in patients treated with methotrexate for rheumatoid arthritis and other rheumatic diseases

PURPOSE

To determine the clinicopathologic features of lymphoproliferative disorders (LPD) that occur in the setting of methotrexate (MTX) therapy for rheumatic diseases (RD) and to define the relationship between the presence of Epstein-Barr virus (EBV) in tumor cells and the response of LPD to MTX withdrawal.

PATIENTS AND METHODS

In addition to nine new cases, we analyzed 28 cases previously reported in the literature of LPD in patients receiving MTX for RD. In addition to MTX, immunosuppressive therapy included corticosteroids in 19 patients, azathioprine in three, and cyclosporine in one. Extranodal disease was identified in 16 patients, but none had CNS involvement. Pathologic findings included five cases of Hodgkin's disease and seven low-grade lymphomas. The remaining patients had intermediate or aggressive lymphomas. In situ hybridization studies (ISHS) for EBV-RNA transcripts were positive in 12 of 27 patients (44%).

RESULTS

Among 37 patients, 16 were initially observed after MTX withdrawal without additional antitumor therapy. Six achieved a spontaneous complete remission (CR), three had a partial response (PR), one had a minimal response, and six had no response to MTX withdrawal. Of 10 responding patients, EBV was detected by ISHS (n = 6) or polymerase chain reaction (PCR) (n = 2); one patient had a CR despite the absence of EBV by PCR and one had a CR but did not have viral assays performed. Only one of six patients with negative EBV by ISHS or PCR responded to MTX withdrawal.

CONCLUSION

MTX withdrawal and observation for a short period should be considered in the initial management of patients who develop LPD while on MTX therapy. Responses were consistently observed, but not limited to patients in whom EBV was detected by ISHS or PCR. Further studies are required to confirm these findings and to evaluate the role for EBV in LPD that occur in patients receiving MTX.

The Trauma Symptom Checklist for Young Children (TSCYC): reliability and association with abuse exposure in a multi-site study

OBJECTIVE

The Trauma Symptom Checklist for Young Children (TSCYC) is a 90-item caretaker-report measure of children's trauma- and abuse-related symptomatology. It contains two reporter validity scales and eight clinical scales [Post-traumatic Stress-Intrusion (PTS-I), Post-traumatic Stress-Avoidance (PTS-AV), Post-traumatic Stress-Arousal (PTS-AR), Post-traumatic Stress-Total (PTS-TOT), Sexual Concerns (SC), Dissociation (DIS), Anxiety (ANX), Depression (DEP), and Anger/Aggression (ANG)], as well as an item assessing hours per week of caretaker contact with the child. This paper introduces the TSCYC and describes its psychometric properties in a multisite validity study.

METHOD

A total of 219 TSCYCs administered by six clinician/researchers across the United States were analyzed for scale reliability and association with several types of childhood maltreatment.

RESULTS

The TSCYC clinical scales have good reliability and are associated with exposure to childhood sexual abuse, physical abuse, and witnessing domestic violence. The PTS-I, PTS-AV, PTS-AR, and PTS-TOT scales were most predictive, followed by SC in the case of sexual abuse and DIS in the case of physical abuse. There were a small number of age, sex, and race effects on TSCYC scores.

CONCLUSIONS

The TSCYC appears to have reasonable psychometric characteristics, and correlates as expected with various types of trauma exposure. Subject to continued validation and the development of general population norms, its use as a clinical measure is supported.

Predictors of outcome following severe head trauma: follow-up data from the Traumatic Coma Data Bank

Outcome as a function of employment status or return to school was evaluated in severely head-injured patients. A priori we selected the most salient demographic, physiological, neuropsychological and psychosocial outcome predictors with the aim of identifying which of there variables captured at baseline or 6 months would best predict employability at 6 or 12 months. Based on the patients evaluated at 6 months, 18% of former workers had returned to gainful employment and 62% of former students had returned to school. For those not back to work or school at 6 months, 31% of the former workers and 66% of the former students had returned by 12 months. Age, length of coma, speed for both attending and motor movements, spatial integration, and intact vocabulary were all significantly related to returning to work or school. The three most potent predictors for returning to work or school were intactness of the patient's verbal intellectual power, speed of information processing and age.

Reduced incidence of Epstein-Barr virus-associated posttransplant lymphoproliferative disorder using preemptive antiviral therapy

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) has been observed with increasing frequency consequent to the availability of more effective and potent immunosuppression. Prior work suggested that a peripheral blood monitoring strategy detecting peripheral B lymphoproliferation was effective in the early diagnosis of PTLD among 7 of 179 (3.9%) consecutive transplant recipients. Each of those seven patients received at least one course of antithymocyte globulin, Minnesota antilymphocyte globulin, or OKT3 before developing PTLD.

METHODS

To determine whether antiviral prophylaxis might reduce the incidence of PTLD, a subsequent group of 198 consecutive recipients received either ganciclovir or acyclovir during antilymphocyte antibody administration. When the donor or recipient were cytomegalovirus-seropositive, ganciclovir was given; acyclovir was used when both were cytomegalovirus-seronegative. Baseline and protocol posttransplant cell surface profiles were obtained using immunofluorescence and flow cytometry to detect T cells, lymphocyte activation markers, and the CD19 B cell antigen.

RESULTS

Demographic factors, including the incidence of recipients more than 50 years of age, non-Caucasians, previous transplantation, and diabetes mellitus, were similar in both groups. Additionally, the number of patients receiving antilymphocyte preparations was similar. However, only one patient (0.5%) from the latter group who received preemptive antiviral therapy developed PTLD. Although elevations in CD19+ B cells preceded clinical PTLD among each of the seven earlier patients, evidence of peripheral B cell proliferation was not demonstrated for the sole patient from the latter group, which suggests a possible effect of antiviral therapy.

CONCLUSIONS

Prophylactic antiviral therapy may reduce the sensitivity of peripheral monitoring for B lymphoproliferation, but the dramatic reduction in PTLD incidence strongly supports its use among transplant recipients at risk.

Tract-based spatial statistics of diffusion tensor imaging in adults with dyslexia

BACKGROUND AND PURPOSE

Diffusion tensor imaging is a tool that can be used to study white matter microstructure in dyslexia. We tested the hypothesis that dyslexics have a white matter structural change (as measured by directional diffusion of water, which can be affected by disruption in white matter tracts) between brain regions that previous functional connectivity studies showed were associated with phonologic processing.

MATERIALS AND METHODS

Diffusion tensor imaging (DTI) scans were acquired from 7 healthy adult normal readers and from 14 adults with dyslexia on a 1.5T scanner. Voxelwise statistical analysis of the fractional anisotropy data were carried out by using Tract-Based Spatial Statistics to compare dyslexic subjects versus control subjects in white matter tracts.

RESULTS

Significant group difference map clusters (comparing adults with and without dyslexia) occurred in specific bilateral white matter tracts within the frontal lobe, temporal lobe, occipital lobe, and parietal lobe.

CONCLUSION

The DTI fractional anisotropy results in the bilateral white matter showing higher fractional anisotropy in adult control subjects compared with adults with dyslexia (relating to white matter fiber tract integrity) are consistent with our previous functional connectivity results from seed points in the bilateral inferior frontal gyrus.

Intracranial pressure waveform indices in transient and refractory intracranial hypertension

Analysis of data obtained by continuous computerized monitoring of intracranial pressure (ICP) in 109 adult patients with severe head trauma was performed to examine the pattern of change in indices of the ICP waveform. Indices derived from direct measurement of the ICP wave and obtained from a Fast Fourier Transform (FFT) were examined. Concurrent physiologic measurements were made. Two types of intracranial hypertension (ICH) were defined for comparison. 'Transient intracranial hypertension' occurred when an abrupt rise in ICP was followed by a return to below 25 mm Hg (n = 63). Increases in ICP that were progressive and led to neurologic deterioration and death were termed 'refractory intracranial hypertension' (n = 18). During transient ICH heart rate, arterial pressure, end-tidal carbon dioxide and jugular venous oxygen saturation all increased, while these measures either were unchanged or decreased during refractory ICH. The pulse amplitude of the ICP wave increased in both types of ICHtn. Other changes in the waveform indices were consistent with this change in pulse amplitude. HFC responded differently to the two types of changes, with an increase during the transient changes and a decrease during the refractory changes. The differences in changes in physiologic measurements as ICH occurred in the 2 groups suggest that in refractory ICH cerebral blood flow is maintained against the mounting ICP, while in transient ICH the hypertension is caused by an increase in cerebral blood flow. The waveform indices do not discriminate between the two types of changes.

Platelet PlA2 polymorphism enhances risk of neurocognitive decline after cardiopulmonary bypass. Multicenter Study of Perioperative Ischemia (McSPI) Research Group

BACKGROUND

Neurocognitive decline, often produced by atherosclerotic plaque embolization, remains a frequent complication of cardiopulmonary bypass. Plaque fragments may initiate local thrombosis, which, in turn, aggravates the embolic insult. Prothrombotic genetic factors may exacerbate this process. We investigated whether the PlA2 polymorphism of platelet GPIIIa, a prothrombotic risk factor in other cardiovascular settings, is associated with early neurocognitive decline after cardiopulmonary bypass.

METHODS

Neurocognitive changes were evaluated by the Mini-Mental State Examination administered preoperatively and on postoperative day 4 and the PlA genotype determined in 70 patients undergoing cardiopulmonary bypass.

RESULTS

Forty-nine patients were PlA1/A1, and 21 were PlA1/A2 or PlA2/A2. Fifty-two patients (74%) demonstrated post-cardiopulmonary bypass neurocognitive decline, of which 34 were PlA1/A1 and 18 were PlA1/A2 or PlA2/A2 Multivariate analysis revealed that the PlA2 genotype and baseline Mini-Mental State Examination were significantly associated with greater neurocognitive decline (decreased Mini-Mental State Examination scores, p = 0.036 and 0.024, respectively).

CONCLUSIONS

This study demonstrates a link between the PlA2 allele of platelet GPIIIa and more severe neurocognitive decline after cardiopulmonary bypass. Although the mechanism is unknown, it could represent exacerbation of platelet-dependent thrombotic processes associated with plaque embolism.

The role of psychological factors in the report of building-related symptoms in sick building syndrome

Sick building syndrome (SBS) is an increasingly common problem, although continued skepticism exists regarding its validity. Because of this, the attribution of complaints to psychogenic causes or mas hysteria persists. In this study (N = 111), self-report measures of psychopathology (Minnesota Multiphasic Personality Inventory [Hathaway & McKinley, 1983] and SCL-90-R [Derogatis, 1983]) and physical symptom reports failed to discriminate symptomatic from nonsymptomatic workers in an affected building but could more generally differentiate workers in the target building from control subjects. These results suggest that SBS cannot be justifiably attributed to psychological factors alone, although working in a contaminated environment appeared to have deleterious psychological consequences for some workers. Smoking history (in pack/years [packs per day x number of years smoked]) was reliably associated with the development of symptoms in exposed workers. Issues related to the assessment of psychological complaints in SBS are discussed.

Endocarditis caused by culture-negative organisms visible by Brown and Brenn staining: utility of PCR and DNA sequencing for diagnosis

Two cases of culture-negative endocarditis with cocci seen in valve vegetations are presented. The organisms were identified by molecular analysis using broad-range PCR primers complementary to the 16S rRNA gene, sequencing, and database search using BLAST software. The results and utility of this method are discussed.

New microsatellite markers for pigeonpea (cajanus cajan (L.) millsp.)

Background

Pigeonpea is a nutritious tropical legume with several desirable characteristics but has been relatively neglected in terms of research. More efficient improvement can be achieved in this crop through molecular breeding but adequate molecular markers are lacking and no linkage map has been developed so far. Microsatellites remain the markers of choice due to their high polymorphism and their transferability from closely related genera. The overall objective of this study was to develop microsatellite markers from an enriched library of pigeonpea as well as testing the transferability of soybean microsatellites in pigeonpea.

Results

Primers were designed for 113 pigeonpea genomic SSRs, 73 of which amplified interpretable bands. Thirty-five of the primers revealed polymorphism among 24 pigeonpea breeding lines. The number of alleles detected ranged from 2 to 6 with a total of 110 alleles and an average of 3.1 alleles per locus. GT/CA and GAA class of repeats were the most abundant di-nucleotide and tri-nucleotide repeats respectively. Additionally, 220 soybean primers were tested in pigeonpea, 39 of which amplified interpretable bands.

Conclusion

Despite the observed morphological diversity, there is little genetic diversity within cultivated pigeonpea as revealed by the developed microsatellites. Although some of the tested soybean microsatellites may be transferable to pigeonpea, lack of useful polymorphism may hinder their full use. A robust set of markers will still have to be developed for pigeonpea genome if molecular breeding is to be achieved.

Comparison of four real-time ultrasound systems that predict intramuscular fat in beef cattle

Eighty-one crossbred steers were used to evaluate four commercially available ultrasound systems that predict intramuscular fat. The software systems represented included Animal Ultrasound Services, Inc., Ithaca, NY; CPEC, Oakley, KS; Critical Vision, Inc., Atlanta, GA (CVIS); and Classic Ultrasound Equipment, Tequesta, FL. Systems were evaluated using marbling scores and percentage ether extractable fat of the longissimus muscle. Before statistical analyses, system predictions were corrected for the respective system's average deviation between the prediction and carcass measurement. The absolute difference between system prediction and percentage ether extract (EEADIFF) or marbling score (MADIFF) converted to ether extract by regression was analyzed with a model accounting for effects of system, technician within system, animal, and animal x system. Steers with USDA marbling scores less than Small00 were assigned to a low marbling class, and all others were assigned to a second class. Data were then analyzed with a subsequent model including marbling class. For EEADIFF in the first model, system, animal, and system x animal were significant (P < .001). For MADIFF, technician within system (P < .05) and all other effects (P < .001) were significant. In the second model, system x marbling class was significant (P < .05) for EEADIFF and approached significance for MADIFF (P = .17). Least squares means for EEADIFF indicated that the systems were more precise measuring animals in the low marbling class. Finally, the CPEC and CVIS systems were the most precise for predicting intramuscular fat.

Evaporative Tunnel Cooling of Dairy Cows in the Southeast. II: Impact on Lactation Performance

Heat stress has a dramatic impact on the dairy industry, reducing production and profitability throughout the southeastern United States. In many regions, management techniques can be used to mitigate the effects of heat stress, but available cooling technologies are often overwhelmed by the conditions of chronic heat stress present in southeastern United States. Although combining tunnel ventilation and evaporative cooling (evaporative tunnel cooling) seems to provide superior cooling for dairy cows, there is a dearth of reports on the impact of this technology on milk production. A model evaporative tunnel cooling facility in northern Mississippi was studied using 2 groups of 10 lactating Holstein cows housed in the tunnel barn and 2 groups of 10 matched herdmates housed in an adjacent naturally ventilated free-stall barn. Two 10-wk trials were performed in 2 yr beginning June 25, 2001, and May 26, 2003, in which cows housed outside were cooled by traditional fans and shade alone (2003) or with sprinklers (2001). In both years, the use of evaporative tunnel cooling decreased exposure to conditions of moderate heat stress by 84%. Cows cooled by evaporative tunnel ventilation increased feed intake by 12 and 11% over cows housed outside in 2001 and 2003, respectively. Evaporative tunnel cooling had no effect on milk composition, but increased milk yield over the 10-wk trial by 2.6 +/- 0.27 and 2.8 +/- 0.19 kg/cow per day in 2001 and 2003, respectively. In addition, somatic cell count was decreased 27 to 49% by evaporative tunnel cooling. Thus, under the range of environmental conditions present, evaporative tunnel cooling reliably reduced exposure to conditions of heat stress and improved milk production of lactating dairy cows during the summer season.

Pilot study of current factors influencing the choice of psychiatry as a specialty

OBJECTIVE

This is a time of major shifts in the perception of medical specialties. The authors have attempted to assess current attitudes of potential applicants for a residency in psychiatry.

METHOD

Pilot interviews with fourth-year medical students at the University of California, San Francisco, led to the development of a questionnaire on factors influencing the choice of psychiatry as a specialty. The questionnaire was then sent to 113 fourth-year students with an identified psychiatric interest at nine schools.

RESULTS

There was a response rate of 50.4%. The 54 students with a clear career decision had 22 of 38 item responses that significantly distinguished between those who matched in psychiatry and those who chose other specialties.

CONCLUSIONS

Focused recruitment strategies are suggested based on answers to the questionnaire items.

Pediatric AIDS-associated lymphocytic interstitial pneumonia and pulmonary arterio-occlusive disease: role of VCAM-1/VLA-4 adhesion pathway and human herpesviruses

Because the mechanisms of lymphocyte accumulation in the lungs of children with AIDS-associated lymphocytic interstitial pneumonia (LIP) are unknown, we studied the relative contributions of known adhesion pathways in mediating lymphocyte adherence to endothelium and the potential role of human herpesviruses in the expansion of these lesions. LIP was characterized by lymphoid hyperplasia of the bronchus-associated lymphoid tissue (BALT) and infiltration of the pulmonary interstitium with CD8(+) T lymphocytes. In some individuals there was expansion of the alveolar septae with dense aggregates of B lymphocytes, many containing the Epstein-Barr viral (EBV) genome. Patients with concurrent EBV infection also demonstrated large-vessel arteriopathy characterized by thickening of the intimae with collagen and smooth muscle. Venular endothelium from the lung of children with LIP, but not uninflamed lung from other children with AIDS or lung from children with nonspecific pneumonitis, expressed high levels of vascular cell adhesion molecule-1 (VCAM-1) protein. In turn, inflammatory cells expressing very late activation antigen-4 (VLA-4), the leukocyte ligand for VCAM-1, were the predominant perivascular infiltrate associated with vessels expressing VCAM-1. Expression of other endothelial adhesion molecules, including intracellular adhesion molecule-1 and E-selectin, was not uniformly associated with LIP. Using a tissue adhesion assay combined with immunohistochemistry for VCAM-1, we show that CD8(+) T cell clones that express VLA-4 bind preferentially to pulmonary vessels in sites of LIP: vessels that expressed high levels of VCAM-1. When tissues and cells were pretreated with antibodies to VCAM-1 or VLA-4, respectively, adhesion was inhibited by >/=80%. Thus, infiltration of alveolar septae with CD8(+) T cells was highly correlative with VCAM-1/VLA-4 adhesive interactions, and focal expansion of B cells was coincidental to co-infection with EBV.

Evaporative Tunnel Cooling of Dairy Cows in the Southeast. I: Effect on Body Temperature and Respiration Rate

The techniques used to mitigate the effects of heat stress on lactating dairy cows are often overwhelmed in the southeastern United States, where elevated heat and humidity often persist for extended periods. A model free-stall barn located at the North Mississippi Branch Experiment Station in Holly Springs was used to evaluate the potential of tunnel ventilation with evaporative cooling to alleviate heat stress in lactating dairy cows. Two studies were conducted using 2 groups of 10 lactating Holsteins housed in the tunnel barn (inside) and 2 groups of matched herdmates housed in an adjacent covered free-stall barn (outside), which was cooled by fans and sprinklers during 2001 or by shade and fans alone in 2003. Peak daytime temperatures inside were 5.2 +/- 0.18 degrees C below that outside in 2001 and 3.1 +/- 0.20 degrees C lower in 2003. Although evaporative cooling increased humidity by 22%, cows housed in the tunnel barn received 84% less exposure to moderate heat stress (temperature-humidity index > 80) in both years. Cooling cows with evaporative tunnel ventilation reduced respiration rates by 15.5 +/- 0.56 breaths/min and rectal temperatures by 0.6 +/- 0.02 degrees C compared with shade and fans alone in 2003. Cooling cows with evaporative tunnel ventilation reduced respiration rates by 13.1 +/- 0.78 breaths/min and rectal temperatures by 0.4 +/- 0.03 degrees C compared with fans and sprinklers in 2001. Thus, tunnel ventilation cooling dramatically reduced the exposure to heat stress and improved the comfort of lactating dairy cows when compared with traditional cooling technologies under the conditions present in the southeastern United States.

Evaluation of a telerobotic system to assist surgeons in microsurgery

A tool was developed that assists surgeons in manipulating surgical instruments more precisely than is possible manually. The tool is a telemanipulator that scales down the surgeon's hand motion and filters tremor in the motion. The signals measured from the surgeon's hand are transformed and used to drive a six-degrees-of-freedom robot to position the surgical instrument mounted on its tip. A pilot study comparing the performance of the telemanipulator system against manual instrument positioning was conducted at the University of Southern California School of Medicine. The results show that a telerobotic tool can improve the performance of a microsurgeon by increasing the precision with which he can position surgical instruments, but this is achieved at the cost of increased time in performing the task. We believe that this technology will extend the capabilities of microsurgeons and allow more surgeons to perform highly skilled procedures currently performed only by the best surgeons. It will also enable performance of new surgical procedures that are beyond the capabilities of even the most skilled surgeons.

Combined antiviral effects of paired nucleosides against guinea pig cytomegalovirus replication in vitro

Several promising antiviral nucleosides have been tested in paired combinations against guinea pig cytomegalovirus (GPCMV) replication in guinea pig embryo (GPE) cells by plaque reduction assay; these are [9-(2-hydroxy-1-3-2-dioxaphosphorinan-5-yl)oxymethyl]-guanin e P-oxide (2'nor-cGMP, compound 164), [4-amino-5-bromo-7-(2-hydroxyethoxymethyl)-pyrrolo(2,3-d)pyrimidine] (compound 102), (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC), 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG), 9-(2-hydroxyethoxymethyl)-guanine (acyclovir, ACV) and 3'-azido-3'-deoxythymidine (zidovudine, AZT). Various degrees of interactions were observed; i.e. synergistic reactions were noted in the presence of compound 164/compound 102 and compound 164/DHPG combinations at all concentrations tested. HPMPC/DHPG combinations were synergistic at relatively lower concentrations of DHPG, but became antagonistic as the concentration of DHPG increased. Combinations of compound 164/ACV and DHPG/AZT were antagonistic.

Zidovudine Antagonizes the Antiviral Effects of Ganciclovir against Cytomegalovirus Infection in Cultured Cells and in Guinea Pigs

The antiviral effects of ganciclovir (DHPG) combined with zidovudine (AZT) at several dosages against cytomegalovirus infection were evaluated in cultured cells and in Hartley guinea pigs. Combinations of DHPG and AZT at fixed ratios ranging from 1:0.1 to 1:1 showed reduced antiviral effects of DHPG in cultured human lung fibroblast (HEL) cells and guinea pig embryo (GPE) cells infected with human cytomegalovirus and guinea pig cytomegalovirus, respectively. Synergistic cytotoxicity (CI values < 1) was noted in HEL and GPE cell cultures at all DHPG/AZT combinations tested. In vivo experiments using a fixed ratio at three dosage levels for treatment of GPCMV infected guinea pigs for 5 days did not show significant antagonistic antiviral nor synergistic toxic effects at lower dosages. When GPCMV infected guinea pigs were treated with DHPG and AZT in combinations at 40/20, 40/40 and 40/80 mg kg−1 day 1 for 7 days, a significant increase of GPCMV infectivity titres in the salivary gland, lung and spleen were noted when compared with those animals treated with DHPG 40mg kg−1 day−1 alone. In addition, histopathological findings showed more cytotoxicity in the bone marrow of infected and non-infected animals treated wth DHPG/AZT combinations than animals treated with each drug alone. These results suggest that AZT antagonizes the antiviral effects of DHPG against HCMV and GPCMV replication in cultured cells and GPCMV infection in guinea pigs with increased cytotoxicity in cultured cells and in bone marrow of animals receiving the drug combinations.

Utility of the Seashore Tonal Memory Test in neuropsychological assessment

This study assessed the diagnostic utility of the Seashore Tonal Memory Test in detecting and localizing cerebral lesions. A group of 238 subjects with focal or diffuse cerebral lesions and a group of 112 normal comparison subjects were administered the Seashore Tonal Memory Test and the Halstead-Reitan Battery. All brain-damaged subgroups did significantly worse than the normal group on the Tonal Memory Test. Patients with right-hemisphere lesions were more impaired on this test than were those with left-hemisphere lesions. In contrast, Seashore Rhythm Test scores were not significantly different for groups with right- versus left-hemisphere lesions. Tonal Memory performance was not found to be related to more precise location of structural lesions within the right hemisphere. Step-wise discriminate function analyses indicated that the Tonal Memory Test adds to the Halstead-Reitan Battery in discriminating left-hemisphere from right-hemisphere lesions and that, for this purpose, it was a better discriminator than all but one of the individual tests currently in the battery.

Demonstration of cytomegalovirus and retrovirus pseudotypes in cultured guinea pig cells

A mixed viral infection with a cytomegalovirus and a retrovirus in cultured guinea pig embryo (GPE) cells was investigated. The expression of an endogenous guinea pig retrovirus (GPRV) in cultured guinea pig cells was induced by a medium containing 5-bromo-2'-deoxyuridine and dexamethasone. When the induced GPE cells were superinfected with a guinea pig cytomegalovirus (GPCMV), pseudotype virions were observed. Morphological characterization of both viruses and their locations within infected cells was achieved by examination of thin sections of infected cells with transmission electron microscopy. Immunolabeling with colloidal gold particles, 5 or 15 nm in size, permitted the identification of each virus type using GPCMV- or GPRV-specific polyclonal antibodies and the detection of a population of GPCMV and GPRV particles which expressed antigens of both viruses on their envelopes. Enhanced reverse transcriptase activity of GPRV and reduced infectivity titers of GPCMV was noted in dually infected cultures. These data suggest that interaction between GPCMV and GPRV had occurred in dually infected GPE cells and that expression of GPRV was enhanced.

Epstein-Barr virus RNA detection and glandular differentiation in nasopharyngeal carcinoma: report of 2 cases

Most tumors arising in the nasopharynx are either squamous cell carcinoma or so-called undifferentiated carcinoma of the nasopharyngeal type. Primary adenocarcinomas of the nasopharynx are rare, and glandular differentiation in undifferentiated carcinoma of the nasopharyngeal type has not been reported to date. We report 2 cases of undifferentiated carcinoma of the nasopharyngeal type that show distinct glandular differentiation by light microscopy, histochemistry, immunohistochemistry, and ultrastructure. Both tumors showed equal positivity for Epstein-Barr virus latent membrane protein and in situ hybridization for Epstein-Barr virus genome in the undifferentiated areas of the tumor and those featuring glandular differentiation.

Preservation of neutrophils in CPD-adenine

Human neutrophils were stored in vitro in CPD or CPD-adenine plasma under conditions designed to simulate those of leukapheresis followed by short-term preservation. Viability, morphology by light microscopy, and phagocytic ability of cells stored in either anticoagulant were similar when studied sequentially during 72 hours of storage. Thus, CPD-adenine offered no advantage, under the conditions employed, over standard CPD without adenine.

Inhibition of rat liver transaminases by low levels of acetaldehyde and the pharmacologic effects of B6 vitamers

To better define the significance and mechanism of acetaldehyde-mediated transaminase inhibition, acetaldehyde metabolism was studied in rat liver homogenates and cytosols. When either preparation was incubated at 37 degrees with 1.5 mM acetaldehyde for 4 hr, acetaldehyde levels fell rapidly in the first 30 min and little inhibition of aspartate aminotransferase (GOT) or alanine aminotransferase (GPT) resulted. In contrast, incubation with 50 mM ethanol also resulted in a peak acetaldehyde level of 1.0 to 1.5 mM by 2 hr, but this level was then maintained for the next 2 hr and transaminases were inhibited by 20-35%. Sequential addition of low dose (125-250 microM) pulses of acetaldehyde to rat liver preparations resulted in a progressive decrease in the rate of acetaldehyde disappearance. When the pulsing schedule was adjusted accordingly to maintain acetaldehyde levels between 50 and 250 microM for 8 hr, transaminases were again inhibited by 20-40%. Finally, addition of 1-5 mM pyridoxal and pyridoxal 5'-phosphate, aldehydic B6 vitamers, to cytosols 2-4 hr after pulsing with acetaldehyde was begun, almost completely prevented further transaminase inhibition. In contrast, the non-aldehydic B6 vitamers, pyridoxine, pyridoxamine and pyridoxamine 5'-phosphate, did not affect acetaldehyde-mediated transaminase inhibition. These findings suggest that (1) prolonged exposure to low levels of acetaldehyde impairs acetaldehyde metabolism in rat liver homogenates and cytosols; (2) acetaldehyde toxicity may be more dependent on sustained exposure to acetaldehyde than on the peak level of acetaldehyde attained; and (3) aldehydic B6 vitamers can modify on-going acetaldehyde-mediated transaminase inhibition.

The role of psychological factors in the report of building-related symptoms in sick building syndrome

Sick building syndrome (SBS) is an increasingly common problem, although continued skepticism exists regarding its validity. Because of this, the attribution of complaints to psychogenic causes or mas hysteria persists. In this study (N = 111), self-report measures of psychopathology (Minnesota Multiphasic Personality Inventory [Hathaway & McKinley, 1983] and SCL-90-R [Derogatis, 1983]) and physical symptom reports failed to discriminate symptomatic from nonsymptomatic workers in an affected building but could more generally differentiate workers in the target building from control subjects. These results suggest that SBS cannot be justifiably attributed to psychological factors alone, although working in a contaminated environment appeared to have deleterious psychological consequences for some workers. Smoking history (in pack/years [packs per day x number of years smoked]) was reliably associated with the development of symptoms in exposed workers. Issues related to the assessment of psychological complaints in SBS are discussed.

Combined treatment with 2'-nor-cGMP and ganciclovir against cytomegalovirus infection in a guinea pig model

The combination 2'-nor-cGMP/DHPG at fixed ratios 1:5, 1:10 and 1:20 showed synergistic antiviral effects against GPCMV replication in vitro with CI value < 1. In vivo, a fixed ratio of 1:10 at three different dosage levels of 1.25/12.5 mg, 2.5/25 mg and 5/50 mg/kg/day 2'-nor-cGMP/DHPG combination showed only additive results when compared with each drug alone. However, synergistic antiviral effects were obtained when infected guinea pigs were treated with 2'-nor-cGMP/DHPG combination 2.5/10 mg/kg/day (1:4). A significantly lower GPCMV infectivity titer was noted in the salivary gland, lung and spleen of infected guinea pigs treated with the combination of 2'-nor-cGMP/DHPG 2.5/10 mg/kg/day, as compared to animals treated with a corresponding dose of each drug alone. In addition, GPCMV-infected animals treated with the latter combination showed increased body weight than when either drug was used alone. Histopathologically, each drug alone reduced the viral induced changes in the lung and spleen, but the combination therapy reduced these changes still further. Toxic changes seen in the kidney and bone marrow of infected animals treated with 2'-nor-cGMP, 2.5 mg/kg/day were not significantly increased when DHPG 10 mg/kg/day was added to the regimen. Therefore, combined treatment with 2'-nor-cGMP/DHPG in appropriate concentration is more helpful for acute cytomegalovirus infection in guinea pigs than when either drug was used alone.