Qualitative evaluation of postdoctoral trainee and faculty advisor experiences within a research-intensive school of pharmacy

BACKGROUND

Postdoctoral trainees play a vital role in securing grant funding, building alliances, and mentoring graduate students under the guidance of a mentor who can help develop their intellectual independence. However, the experiences of postdoctoral trainees, particularly within health professions schools, is largely unexplored. The purpose of this study was to investigate the experiences of postdoctoral trainees and faculty advisors at a public four-year school of pharmacy and identify areas of opportunity to improve postdoctoral training.

METHODS

Focus groups and interviews were conducted to elicit participants' experiences, perceptions, and suggestions for improvement. Stakeholder groups included postdoctoral trainees and faculty who serve as postdoctoral advisors. Thematic coding was used to identify semantic themes, and summaries of participant perceptions were generated. Results were mapped to the identity-trajectory framework.

RESULTS

Participants described various experiences related to intellectual growth, networking opportunities, and institutional support. In addition, participant agency was critical for developing career goals and navigating transitions. COVID-19 introduced unique challenges associated with transitioning to remote work and managing goals/motivation. Areas of opportunity were identified, such as improving infrastructure, enhancing mentoring, and enhancing communication.

CONCLUSION

Postdoctoral trainees play a critical role in the success of academic institutions. Scholarly endeavors that explore postdoctoral experiences, specifically those utilizing qualitative methods, can help pharmacy education better understand and meet the needs of postdoctoral trainees and faculty advisors. This study provides insight into the experiences of postdoctoral scholars and provides evidence for improving these training programs in schools of pharmacy.

Ortner syndrome and haemophilia

Compression and paralysis of the left recurrent laryngeal nerve by a dilated pulmonary artery is a rare complication of pulmonary hypertension. We here report the case of a patient with severe haemophilia A and HIV infection who presented with a persistent hoarseness of voice and a left vocal cord palsy caused by HIV-associated pulmonary hypertension. This case suggests that HIV-associated pulmonary hypertension should be suspected in any HIV patient presenting with unexplained left vocal cord palsy.

Hodgkin Lymphoma in a patient with mycosis fungoides: molecular evidence for separate cellular origins

We report the case of a man with mycosis fungoides (MF), who, 11 years after diagnosis, developed Hodgkin's disease. Although MF is associated with a higher than expected prevalence of other malignancies, including Hodgkin lymphoma, analysis of cells from the skin and lymph nodes showed findings that suggest a separate cellular origin for the two diseases.

Isolated B-cell lymphoma of the pituitary region: a rare clinical entity

Metastatic carcinoma in the pituitary region is a well-recognized clinical entity (Teears and Silverman, 1975), and lymphomatous involvement as part of systemic disease is well documented (Mathiasen et al, 2000). This article describes the unusual case of a B-cell lymphoma localized to the pituitary region without systemic involvement.

Relationship of leisure-time physical activity and occupational activity to the prevalence of obesity

OBJECTIVE

To assess the interaction between leisure-time physical activity (LTPA) and occupational activity (OA) on the prevalence of obesity.

DESIGN

Secondary data analysis of a population based cross-sectional US national sample (NHANES III).

SUBJECTS

A total of 4889 disease-free, currently employed adults over age 20 y.

MEASUREMENTS

Subjects body mass index (BMI) was categorized as (1) obese (BMI> or =30 kg/m(2)), or (2) non-obese (BMI<30 kg/m(2)). LTPA was divided into four categories: (1) no LTPA; (2) irregular LTPA; (3) regular moderate intensity LTPA; and (4) regular vigorous intensity LTPA. OA was grouped as (1) high OA and (2) low OA. Age, gender, race-ethnicity, smoking status, urbanization classification, alcohol consumption and income were statistically controlled.

RESULTS

In all, 16.8% (s.e. 0.7) of the total subject population were obese (15.1% (s.e. 1.1) of men and 19.1% (s.e. 1.1) of women). Logistic regression revealed that compared to those who engage in no LTPA and have low levels of OA, the likelihood of being obese is 42% (95% CI 0.35, 0.96) lower for those who engage in no LTPA and have high OA, 48% (95% CI 0.32, 0.83) lower for those who have irregular LTPA and have high levels of OA, and about 50% lower for all those who have regular LTPA through moderate or vigorous activity levels regardless of OA level.

CONCLUSION

When considering disease free adults above 20 y of age employed in high and low activity occupations, a high level of occupational activity is associated with a decreased likelihood of being obese.

Validity of inspiratory and expiratory methods of measuring gas exchange with a computerized system

The accuracy of a computerized metabolic system, using inspiratory and expiratory methods of measuring ventilation, was assessed in eight male subjects. Gas exchange was measured at rest and during five stages on a cycle ergometer. Pneumotachometers were placed on the inspired and expired side to measure inspired (VI) and expired ventilation (VE). The devices were connected to two systems sampling expired O(2) and CO(2) from a single mixing chamber. Simultaneously, the criterion (Douglas bag, or DB) method assessed VE and fractions of O(2) and CO(2) in expired gas (FE(O(2)) and FE(CO(2))) for subsequent calculation of O(2) uptake (VO(2)), CO(2) production (VCO(2)), and respiratory exchange ratio. Both systems accurately measured metabolic variables over a wide range of intensities. Though differences were found between the DB and computerized systems for FE(O(2)) (both inspired and expired systems), FE(CO(2)) (expired system only), and VO(2) (inspired system only), the differences were extremely small (FE(O(2)) = 0.0004, FE(CO(2)) = -0.0003, VO(2) = -0.018 l/min). Thus a computerized system, using inspiratory or expiratory configurations, permits extremely precise measurements to be made in a less time-consuming manner than the DB technique.

Validation of the COSMED K4 b2 portable metabolic system

The purpose of this investigation was to assess the accuracy of the COSMED K4 b2 portable metabolic measurement system against the criterion Douglas bag (DB) method. During cycle ergometry on consecutive days, oxygen consumption (VO2), carbon dioxide production (VCO2), minute ventilation (VE), and respiratory exchange ratio (R) were measured at rest and during power outputs of 50, 100, 150, 200, and 250W. No significant differences (P > 0.05) were observed in VO2 between the K4 b2 and DB at rest and at 250W. Though the K4 b2 values were significantly higher (P<0.05) than DB values at 50, 100, 150, and 200 W, the magnitude of these differences was small (0.088, 0.092, 0.096, and 0.088 L x min(-1), respectively). VCO2 and VE values from the K4 b2 were significantly lower than the DB at 200 and 250 W, while no significant differences were observed from rest through 150W. The slight overestimation of VO2 (50-200 W) combined with the underestimation of VCO2 (200 and 250W) by the K4 b2 resulted in significantly lower R values at every stage. These findings suggest the COSMED K4 b2 portable metabolic measurement system is acceptable for measuring oxygen uptake over a fairly wide range of exercise intensities.

Histopathological detection of owl's eye inclusions is still specific for cytomegalovirus in the era of human herpesviruses 6 and 7

BACKGROUND

Cytomegalovirus (CMV) is the prototype member of the beta-herpesvirinae, which can cause multiple organ dysfunction in the immunocompromised host. Human herpesvirus 6 (HHV-6) and HHV-7 are newer members of the beta-herpesvirinae that can cause febrile illness in young children and are also possible pathogens in the immunocompromised patient.

AIM

CMV is detected in histopathological sections by visualisation of owl's eye inclusion bodies. The aim of this study was to quantify the relation between CMV, HHV-6, and HHV-7 viral loads and the presence of owl's eye inclusions in histological sections.

METHODS

Histopathological examination of postmortem material and recording of owl's eye inclusion bodies were performed. CMV, HHV-6, and HHV-7 were detected by qualitative and quantitative polymerase chain reaction (PCR) from the same postmortem samples. Statistical analysis of the histopathological and PCR results was performed.

RESULTS

There was a significant association between the detection of owl's eye inclusion bodies and positive CMV PCR (p < 0.001); the median CMV viral load was significantly higher in samples that were positive for owl's eye inclusions (p < 0.001). No association was found between the presence of owl's eye inclusions and HHV-6 or HHV-7 positivity.

CONCLUSION

Histological detection of owl's eye inclusion bodies is an insensitive but highly specific method for detecting CMV organ involvement. Owl's eye inclusion bodies are not associated with HHV-6 or HHV-7 infection.

Determination of selected fate and aquatic toxicity characteristics of acrylic acid and a series of acrylic esters

Acrylic acid, methyl acrylate, ethyl acrylate, and butyl acrylate are commercially important and widely used materials. This paper reports the results of a series of fate and aquatic toxicity studies. The mobility in soil of acrylic acid and its esters ranged from 'medium' to 'very high'. Calculated bioconcentration factors ranged from 1 to 37, suggesting a low bioconcentration potential. Acrylic acid and methyl acrylate showed limited biodegradability in the five day biochemical oxygen demand (BOD5) test, while ethyl acrylate and butyl acrylate were degraded easily (77% and 56%, respectively). Using the OECD method 301D 28-d closed bottle test, degradability for acrylic acid was 81% at 28 days, while the acrylic esters ranged from 57% to 60%. Acrylic acid degraded rapidly to carbon dioxide in soil (t1/2 < 1 day). Toxicity tests were conducted using freshwater and marine fish, invertebrates, and algae. Acrylic acid effect concentrations for fish and invertebrates ranged from 27 to 236 mg/l. Effect concentrations (LC50 or EC50) for fish and invertebrates using methyl acrylate, ethyl acrylate, and butyl acrylate ranged from 1.1 to 8.2 mg/l. The chronic MATC for acrylic acid with Daphnia magna was 27 mg/l based on length and young produced per adult reproduction day and for ethyl acrylate was 0.29 mg/l based on both the reproductive and growth endpoints. Overall these studies show that acrylic acid and the acrylic esters studied can rapidly biodegrade, have a low potential for persistence or bioaccumulation in the environment, and have low to moderate toxicity.

Validation of Aerosport KB1-C portable metabolic system

The purpose of this study was to test the validity of the Aerosport KB1-C portable metabolic measurement system against the criterion Douglas bag method. During cycle ergometry, simultaneous measurements of minute ventilation (VE), oxygen consumption (VO2), and carbon dioxide production (VCO2) were made at rest and at power outputs of 50, 100, 150, 200, and 250 W. No significant differences (P > 0.05) were observed for VE, VO2, and VCO2 between the KB1-C and Douglas bag at 100, 150, and 250 W, while the KB1-C was significantly different (P < 0.05) from Douglas bag values at rest, 50, and 200 W. R values were found to be significantly different (P < 0.05) at 100, 150, and 200 W, while no significant differences were observed at rest, 50, and 250 W. The fractional concentrations of oxygen (FEO2) and carbon dioxide (FECO2) were not significantly different at 50, 100, 200, and 250 W while values at rest and 150 W were significantly different (P < 0.05). These findings show that the Aerosport KB1-C portable metabolic system is acceptable for measuring oxygen uptake in the range of 1.5 and 3.5 L x min(-1), using the medium flow pneumotach setting. At lower intensities, the low-flow pneumotach setting provides acceptable results.

Shorter survival in HIV-positive patients with diarrhoea who excrete adenovirus from the GI tract

Adenoviruses have been described as a cause of diarrhoea in patients infected with the human immunodeficiency virus (HIV). The prevalence of adenoviruses was studied in all HIV-positive patients presenting with diarrhoea at the Royal Free Hospital in London between 1991 and 1995. In addition, all postmortems carried out in HIV-positive individuals registered at the same centre between 1990 and 1997 were reviewed for evidence of adenovirus infection. Adenovirus was detected in 16.1% of patients presenting with diarrhoea. These individuals had a significantly lower CD4 count and were more likely to have had a diagnosis of acquired immunodeficiency syndrome (AIDS) than patients with diarrhoea in whom adenovirus was not detected. The median survival was 1 year compared with 2.4 years for those without adenoviruses; this difference remained significant (P = .008) after controlling for differences in CD4 counts between the groups. Gastrointestinal adenovirus excretion occurs at an advanced stage of HIV disease, and is associated with a poor prognosis. We suggest that adenoviruses may contribute to mortality in this population.

Interactions between beta-herpesviruses and human immunodeficiency virus in vivo: evidence for increased human immunodeficiency viral load in the presence of human herpesvirus 6

In vitro, beta-herpesviruses can stimulate or inhibit HIV replication under particular circumstances. In order to investigate the effects of beta-herpesvirus infection on HIV replication and vice versa at an organ level, we determined the quantitative relationships between cytomegalovirus (CMV), human herpesviruses (HHV) 6 and 7, and HIV-1 proviral DNA using quantitative competitive PCR methods in 141 organs collected at autopsy from 11 AIDS patients. The presence of HHV-6 DNA in an organ was significantly associated with elevated HIV-1 proviral DNA (difference in HIV median loads, 1.3 log10 genomes; P = 0.004). Consistent with this, there was a trend for the presence of HIV-1 proviral DNA to be associated with an elevated HHV-6 load (0.44 log10 difference; P = 0.07). In contrast, there were no significant differences between viral loads in the combinations of either CMV or HHV-7 with HIV-1 proviral DNA load. Pairwise combinations of the beta-herpesviruses revealed that the quantity of HHV-7 was increased in the presence of HHV-6 (difference in median loads, 1.3 log10; P = 0.001) and the quantity of HHV-6 was increased in the presence of HHV-7 (difference in median loads, 0.7 log10; P=0.002). These results demonstrate that the presence of HHV-6 in an organ is significantly associated with an elevated HIV-1 proviral load and have implications for understanding HIV pathogenesis in the human host and the role that beta-herpesviruses, especially HHV-6, might play as cofactors in the HIV disease process.

Retrospective neuropathological review of prion disease in UK haemophilic patients

In 1996, the CJD surveillance unit in Edinburgh, UK described nvCJD which was thought to be the human equivalent of bovine spongiform encephalopathy (BSE). The identification of prion protein in the tonsil of an affected individual has raised the question of transmission of nvCJD via blood products. This study examines the post mortem brains of 33 patients who were treated with clotting factor concentrate of predominately UK donor source during the years 1962-1995. The brains were examined by conventional histological methods and also for the prion protein using monoclonal antibodies KG9 and 3F4. No evidence of spongiform encephalopathy was found and the immunocytochemistry was negative for PrP in all cases. It is concluded that, at present, there is no evidence for the transmission of nvCJD via clotting factor concentrate to patients with haemophilia.

Quantitative differences in the distribution of zidovudine resistance mutations in multiple post-mortem tissues from AIDS patients

Replication of HIV introduces errors into the genome which are responsible for conferring a growth advantage over wildtype virus when drugs such as zidovudine (ZDV) exert a selective pressure. The molecular basis for HIV-1 resistance to ZDV has been mapped to codons 41, 67, 70, 215 and 219 of the reverse transcriptase gene both in vitro and in clinical samples of blood. This study has investigated the relationship between the quantitative prevalence of ZDV resistance in multiple organs of the same individual. Proviral HIV-1 load was measured by quantitative-competitive PCR in 90 samples from organs of 11 patients dying with AIDS. Nine of these patients had been prescribed zidovudine. The distribution of wildtype and mutant sequences at the positions 41, 67, 70, 215 and 219 of the reverse transcriptase was assessed using a point mutation assay. The results showed that the highest proviral loads were predominately found in lymph node, spleen and lung and there was a significant association between viral load and resistance to ZDV (P=0.008). Inter-organ distribution of wildtype and mutant sequences at codons 41, 67, 70, 215 and 219 was frequently not uniform and in some patients differed markedly between the lymphoreticular system and other organs. These results demonstrate that treatment of HIV-1 infection with zidovudine does not exert uniform selective pressures in multiple organs. These findings have implications for the interpretation of resistance data and design of treatment strategies for HIV, arguing in particular that alterations in therapeutic regimens should consider the likelihood of different resistance patterns being present in multiple sites within the same individual.

Changes in lung lymphocyte populations reflect those seen in peripheral blood in HIV-1 positive individuals

We have investigated the level of lymphocytosis present in the lung of human immunodeficiency virus (HIV)-1+ infected patients with and without pulmonary disease and how changes in natural killer (NK), B and T-cells seen in peripheral blood (PB) compare with those seen in bronchoalveolar lavage fluid (BALF). Lymphocyte subpopulations and their expression of activation, cytotoxic markers and memory status were characterized by triple immunofluorescence. Macrophages accounted for over 80% of the BAL cells. Only three out of 72 patients had a lymphocyte percentage >30%. No statistically significant differences in the relative proportions of NK, CD4 and CD8 populations were seen in BALF when compared to PB, except for a twofold increase in the percentage of activated CD8 cells in BALF. The only differences in BALF populations between the HIV-1+ groups were a lower percentage of CD4+ cells, and a higher percentage of activated CD8+ cells in the patients with pneumonitis. In the present cohort of patients there was little evidence for an overall lymphocytosis in bronchoalveolar lavage fluid of HIV-1+ subjects. Changes observed in lymphocyte subsets of bronchoalveolar lavage fluid populations reflected those in peripheral blood, and were similar for patients with and without pneumonitis. Evidence of increased CD8 subset activity in bronchoalveolar lavage fluid did, however, emerge.

Changes in lung lymphocyte populations reflect those seen in peripheral blood in HIV-1 positive individuals

We have investigated the level of lymphocytosis present in the lung of human immunodeficiency virus (HIV)-1+ infected patients with and without pulmonary disease and how changes in natural killer (NK), B and T-cells seen in peripheral blood (PB) compare with those seen in bronchoalveolar lavage fluid (BALF). Lymphocyte subpopulations and their expression of activation, cytotoxic markers and memory status were characterized by triple immunofluorescence. Macrophages accounted for over 80% of the BAL cells. Only three out of 72 patients had a lymphocyte percentage >30%. No statistically significant differences in the relative proportions of NK, CD4 and CD8 populations were seen in BALF when compared to PB, except for a twofold increase in the percentage of activated CD8 cells in BALF. The only differences in BALF populations between the HIV-1+ groups were a lower percentage of CD4+ cells, and a higher percentage of activated CD8+ cells in the patients with pneumonitis. In the present cohort of patients there was little evidence for an overall lymphocytosis in bronchoalveolar lavage fluid of HIV-1+ subjects. Changes observed in lymphocyte subsets of bronchoalveolar lavage fluid populations reflected those in peripheral blood, and were similar for patients with and without pneumonitis. Evidence of increased CD8 subset activity in bronchoalveolar lavage fluid did, however, emerge.

Cerebral nocardia abscesses in a patient with AIDS: correlation of magnetic resonance and white cell scanning images with neuropathological findings

We present a case of cerebral nocardiosis in a patient with AIDS. Space-occupying lesions were identified using magnetic resonance imaging (MRI) and white cell scanning. Nocardia asteroides was isolated from blood cultures. The patient's response to treatment with amikacin, imipenem and ceftriaxone was followed clinically and radiologically. When he died 6 months later, N. asteroides was isolated at post-mortem from a cerebral abscess. Although cerebral infections associated with the infiltration of neutrophils are rare in patients with AIDS, this case demonstrates that indium-labelled neutrophils can be used to identify a brain abscess and monitor its response to antimicrobial therapy.

Quantification of human herpesvirus 6 in immunocompetent persons and post-mortem tissues from AIDS patients by PCR

A quantitative competitive PCR assay for human herpesvirus 6 (HHV-6) was developed. Firstly, viral burden was determined in the blood of 25 healthy persons. Using 1 microgram of DNA, the prevalence of HHV-6 was 36% (9/25). Eight persons had viral loads of < or = 32 HHV-6 genomes/microgram DNA. The viral burden in the ninth individual was 1.2 x 10(6) HHV-6 genome copies/microgram DNA, which remained constant over a period of 10 months. This demonstrates the persistence of a high HHV-6 load in the absence of apparent disease. Secondly, HHV-6 burden was determined in 100 post-mortem tissues from seven AIDS patients and three controls. For all tissues combined, there was a statistically significant higher median viral load in AIDS patients (56 copies/microgram DNA, range 0-43321) compared to controls (10 copies/microgram DNA, range 0-423) (P = 0.04). The precision and reproducibility of this assay will allow hypotheses concerning the pathogenic potential of HHV-6 to be tested quantitatively.

Use of the polymerase chain reaction to detect genomes of human immunodeficiency virus and cytomegalovirus in post-mortem tissues

The polymerase chain reaction (PCR) was used to amplify a 149 base-pair region of the cytomegalovirus (CMV) genome and a 551 base-pair region of the HIV-1 proviral long terminal repeat (LTR) present in DNA extracted from post-mortem tissue. Multiple tissues (n = 116) obtained from 16 patients which were subjected to PCR were also subjected to cell culture and histopathological analyses. One hundred and seven samples (92%) contained CMV DNA and 66/116 (57%) contained HIV proviral DNA at a level of > or = 10 genomes. Both viruses were detected in 60/116 (51.7%) of samples, with co-infection most frequent in the lung (69%). Cell culture for CMV detected 9.3% of the PCR-positive samples, whilst histology identified CMV inclusions in 15.9% of samples, all of which were CMV PCR-positive. CMV was most frequently detected in adrenal and lung tissues by histology. These results show that co-infection with CMV and HIV is a common occurrence in organs from AIDS patients and provide further evidence for a role of cytomegalovirus in the pathogenesis of AIDS.

Distinct HIV-1 long terminal repeat quasispecies present in nervous tissues compared to that in lung, blood and lymphoid tissues of an AIDS patient

OBJECTIVE

To investigate the phylogenetic relationship of HIV-1 proviral long terminal repeat (LTR) variants present in postmortem samples of lymph node, spleen, lung, dorsal root ganglion and spinal cord as well as in the peripheral blood of an HIV-1-infected patient dying with AIDS.

DESIGN AND METHODS

Postmortem tissues were studied by a combination of histology, cell culture and molecular analyses. The patient had a stable CD4 count of 10 x 10(6)/I during the 12 months preceding death. A 540 base-pair fragment of the LTR including U3/R/U5 was amplified using polymerase chain reaction on proviral DNA from the five postmortem tissues and peripheral blood mononuclear cells obtained 2 months prior to death. The population of viral variants was determined by sequencing at least five plasmid clones of the amplicons. The relationship between the variants present in different body sites was investigated using molecular phylogeny methods.

RESULTS

HIV-1 was present in all organs analysed and correlated with the presence of abnormal histology. Genetic variation leading to divergence from the consensus sequence was more frequently present in characterized transcription factor binding sites within the LTR (P < 0.0001) although the HIV-1 LTR quasispecies in the different body sites showed similar, relatively low levels of divergence (intra-organ median heterogeneity ranging from 0.0094 to 0.017). Phylogenetic analysis showed that the spinal cord and dorsal root ganglion harboured an LTR population genetically distinct from that present in other organs and more closely related to a previously characterized neurotropic strain of HIV (strain JRcsf).

CONCLUSION

The independent clustering of HIV-1 LTR variants present in spinal cord and dorsal root ganglion shows that HIV-1 LTR evolution can occur in a compartmentalized fashion. The data show that the LTR is an important region to analyse in sequence variation studies of HIV since it may play a role in nervous tissue adaptation of HIV-1 and neuropathogenicity. Outgrowth of HIV-1 LTR variants that are most fit for the utilization of tissue-specific transcription factors can occur in the nervous tissue.

Comparison of the maximum tolerated dose (MTD) dermal response in three strains of mice following repeated exposure to acrylic acid

The dermal response of three strains of mice (ICR, C3H and B6C3F1) exposed to repeated doses of 0, 1 or 4% acrylic acid was examined over 13 wk. Microscopic and gross changes to the skin were classified as being indicative of exceeding the maximum tolerated dose (MTD), reaching the MTD, or tolerating the dose based on proposed MTD guidelines established in US Environmental Protection Agency (EPA) Workshops on dermal carcinogenesis bioassays. A significant number of animals in all three strains with repeated exposure to 4% acrylic acid experienced skin irritation that was classified as having reached or exceeded the MTD compared with animals exposed to either 1% acrylic acid or the 0% acrylic acid acetone control. These results were observed within the first 3 wk of exposure, but there was some accommodation to irritation by 8 wk of exposure. Microscopic findings provided a more sensitive index for exceeding MTD than gross observations taken only at autopsy, but generally correlated well for MTD if gross observations were taken at regular intervals during treatment. That is, to set MTD, gross observations could be used if taken over the entire course of the exposure, but using microscopic findings was generally a more reliable or sensitive measure. EPA guidelines suggest that it is inappropriate to conduct a dermal bioassay at concentrations that exceed the MTD. Acrylic acid at 4% in acetone clearly exceeded the MTD based on microscopic or gross observation criteria. At 4%, strain differences were evident by gross observation only, with the ICR strain being less susceptible to irritation than C3H or B6C3F1 strains. These strain differences were not apparent with microscopic examination. Acrylic acid at 1% in acetone, although demonstrating signs of minimal irritation, was fairly well tolerated by all mice in all strains. Thus, acrylic acid at 1% in acetone, one-quarter of the concentration that was in clear excess of the MTD, would be the appropriate dose concentration for lifetime skin studies based on MTD criteria.

Presence of CD3+CD8+Bcl-2(low) lymphocytes undergoing apoptosis and activated macrophages in lymph nodes of HIV-1+ patients

Infection with human immunodeficiency virus 1 causes profound changes in the lymph nodes of infected patients. In particular, large numbers of CD8+CD45RO+ T cells infiltrate both the paracortex and the germinal centers. These cells contained the cytotoxic granule-associated protein TIA-1 but showed no detectable levels of perforin and shared the same characteristics of the expanded, activated, short-lived CD8+ population found during acute viral infections. These cells expressed low levels of Bcl-2 and are likely to be short-lived in vivo as evidenced by the direct observation of CD8+ apoptotic cells in the paracortical areas of the infected nodes. Changes in the paracortical nonlymphoid populations were also seen. There were reactive changes in the blood vessels, and the macrophage population was expanded and activated. Furthermore, apoptotic bodies were seen in the cytoplasm of the activated CD68+RFD-7+RFD-1+ macrophages pointing to the phagocytic capacity of these cells and their role in the clearance of the apoptotic cells from the tissues. These observations suggest that the persistance of CD8+ population in human immunodeficiency virus 1 infection is not a result of the presence of an abnormal CD8+ population but rather a result of an inappropriate over-stimulation of the CD8+ cells.

Immunohistochemical study of vascular injury in acute multiple sclerosis

AIMS

To examine the vascular changes occurring in three archival cases of acute multiple sclerosis, and to provide immunohistochemical evidence of early endothelial cell activation and vascular occlusion in this condition.

METHODS

Central nervous system tissues from three cases of acute active multiple sclerosis and six non-inflammatory controls were stained using the following methods: haematoxylin and eosin, Luxol fast blue, cresyl violet, Bielschowsky's silver, and reticulin. Tissues were also immunostained with specific antibodies against collagen type IV, factor XIIIa, class II antigens, glial fibrillary acidic protein, and fibrinogen.

RESULTS

Early vascular endothelial cell activation which may progress to vasculitis and vascular occlusion including class II antigen expression and fibrin deposition were identified. The vascular changes were seen prior to cerebral parenchymal reaction and demyelination, and were not seen in control cerebral tissues.

CONCLUSION

It is proposed that vascular endothelial cell activation may be an early and pivotal event in the evolution of multiple sclerosis, and that demyelination may have an ischaemic basis in this condition. The vascular endothelium may contain an early element in the evolution of multiple sclerosis.

The value of per-operative smear examination during stereotactic biopsy

Sixty-two consecutive CT-directed stereotactic biopsies were studied retrospectively to determine the value of the per-operative smear examination. Overall, in 69% of cases the immediate smear result agreed with the definitive histology. However, a smear diagnosis of malignant glioma was more reliable than that of metastasis (with 100% and 55% agreement with the final result respectively). In those cases where the final histological diagnosis was that of malignant glioma, immediate smear preparations taken from the hypodense centre were found to be more reliable than those taken from the enhancing edge.

Methyl methacrylate: inhalation developmental toxicity study in rats

Methyl methacrylate (99.9% pure) was administered by vapor inhalation exposure to five groups (27 rats/group) of presumed pregnant rats (Crl:CD) at concentrations of 0 (control), 99, 304, 1,178, and 2,028 ppm for 6 hr/day on days 6-15 of gestation (G). Maternal body weight, feed consumption, and clinical signs were recorded throughout gestation. Dams were euthanized on day 20 G. Each uterus was weighed and corpora lutea, implantation sites and resorptions were counted. The number of fetuses per litter were counted and their location within the uterus recorded. All fetuses were weighed, sexed and examined for external and skeletal alterations. One half of the fetuses from each litter were examined for visceral alterations. No treatment-related deaths were noted at any concentration tested. Treatment-related effects on maternal body weight and feed consumption were noted at all exposure levels. The decreases in maternal body weight at 99 and 304 ppm were minimal and transient since they returned to control values by the next weighing period. When exposure was discontinued, body weight gain and feed consumption in all exposure groups returned to control values. There were no treatment-related changes in the number of litters produced or in the mean number per litter of corpora lutea, implantations, resorptions, live or dead fetuses, or sex ratio. Fetal body weights were similar between the control and treated groups. There were no treatment-related increases in the type or incidence of external, visceral, or skeletal malformations, developmental variations, or variations indicative of retarded development. Exposure to methyl methacrylate concentrations up to 2,028 ppm resulted in no embryo or fetal toxicity or malformations even at exposure levels that resulted in maternal toxicity.

Bacteriological evaluation of a down-draught necropsy table ventilation system

AIMS

To evaluate the microbiological efficacy of a down-draught necropsy table ventilation system (which surrounds the cadaver with a "curtain" of air under continuous extraction) during post mortem procedures.

METHODS

Air sampling was carried out both in the presence and absence of staff and cadaver and during a full post mortem procedure, with functioning and non-functioning table air extraction. The penetration of the air "curtain" was also examined during the use of an oscillating bone saw by means of a tracer organism, Bacillus subtilis var niger, painted on to the skull.

RESULTS

There was little difference between bacterial counts obtained in the presence of staff only, staff plus cadaver, or during a post mortem examination. With all counts obtained, however, there was a two to three-fold reduction when the ventilation was in operation compared with when the extract duct was occluded. Using the tracer organism, a two to three log reduction in counts was shown when the "curtain" was in operation during the use of the oscillating bone saw.

CONCLUSIONS

These results suggest that the system provides potential protection for post mortem room staff against airborne infections.

A clinico-pathological audit of opportunistic viral infections in HIV-infected patients

OBJECTIVE

To determine the prevalence of opportunistic viral infections in multiple tissues at postmortems of HIV-infected patients, and to relate these findings to their antemortem clinical course.

DESIGN

A study of viral infections in 16 tissues of HIV-positive postmortem cases, by a combination of histology and cell culture (virus isolation). Clinical details were abstracted retrospectively from patient records.

PATIENTS

Forty-seven consecutive autopsies, performed between 1985 and 1992.

SETTING

Autopsies were conducted by a single pathologist in a single London teaching hospital.

RESULTS

Opportunistic viral infections were detected in 72% of all cases, comprising cytomegalovirus (CMV, 66%), herpes simplex virus (11%), JC virus (6%) and adenovirus (2%). The most commonly infected tissues were lung, adrenal, gastrointestinal tract and central nervous system, although all tissue sites sampled could potentially support viral replication. Of 464 tissues tested by both histology and cell culture, histology alone detected CMV in 45 tissues and cell culture alone detected CMV in 31 tissues. We determined that CMV detection in postmortem gastrointestinal tissues and central nervous tissue was significantly associated with antemortem undiagnosed diarrhoea and encephalitis, respectively.

CONCLUSION

There is a high prevalence of opportunistic viral infections in late-stage HIV disease, which is best detected postmortem by the use of both histology and cell culture. Many of these infections correlate with undiagnosed symptoms antemortem. The ability of sensitive methods for virus detection to alert the clinician to such cases antemortem should be critically evaluated, as should attempts to influence the natural history of these infections by antiviral drugs. Continuing clinico-pathological audit is important for AIDS patients in order to monitor the impact of known opportunistic viral infections and to identify others which may emerge as immunosuppression becomes more profound.

Pathological findings correlated with MRI in HIV infection

MRI forms an important part of the assessment of patients with HIV-related disease presenting with cerebral symptoms. Eleven formalin-fixed brains were studied at 0.5 T using T2- and T1-weighted sequences. In two cases of progressive multifocal leucoencephalopathy and one case each of toxoplasmosis and lymphoma, the extent of white matter abnormality seen on MRI corresponded broadly with that on pathological examination. In general, however, histological changes were more frequent than lesions on MRI. Cases in which abnormalities were not seen with standard MRI included those with multiple tuberculous granulomata, multinucleate giant cells, microglial nodules, perivascular cuffing and cytomegalovirus inclusions. A common finding on MRI was punctate or patchy high signal in the basal ganglia on T2-weighted scans, seen in six cases. Corresponding histological changes included calcification of vessels with widened perivascular spaces, and mineralised neurones.

Primary cerebral lymphoma: a study of 47 cases probed for Epstein-Barr virus genome

AIMS

To determine the prevalence of Epstein-Barr virus genome in primary cerebral lymphomas occurring in the absence of immune suppression.

METHODS

Forty eight consecutive patients with lymphomas restricted to the central nervous system were identified, all of whom had had neurosurgical biopsies performed at the National Hospitals for Neurology and Neurosurgery, London. Only five patients had some form of underlying immune deficiency; 43 were apparently normal. The tumours were studied with immunohistochemical markers and by in situ hybridisation, using a biotinylated probe to the internal repeat region of Epstein-Barr virus.

RESULTS

All the lymphomas were B cell in origin. Tumours from the five immunosuppressed patients all showed hybridisation, as did two of the "spontaneous" tumours.

CONCLUSIONS

This is the largest series of cerebral lymphomas so far probed for Epstein-Barr virus genome: as more are examined, it is suggested that a small proportion of the tumours from immunocompetent patients will also contain the virus.

Pancreatic pseudocyst causing portal vein thrombosis and pancreatico-pleural fistula

Portal vein thrombosis and pancreatico-pleural fistula are unusual complications of chronic pancreatitis. We describe a patient with chronic alcoholic pancreatitis in whom erosion of the splenic vein led to portal vein thrombosis and to the development of a pancreatico-pleural fistula. We suggest that fistula formation may occur over a considerable time period as the portal vein thrombosis was diagnosed three years before the amylase-rich pleural effusions.

Prognosis in malignant glioma: a retrospective study of biopsy specimens by flow cytometry

The DNA ploidy of a series of 78 gliomas has been estimated by flow cytometry using cell suspensions prepared from paraffin embedded material. Apart from two oligodendrogliomas the tumours were all astrocytomas. Forty-nine (63%) tumours were found to have a diploid DNA distribution and 29 (37%) an aneuploid DNA distribution. The two oligodendrogliomas were both DNA aneuploid. No correlation was found between DNA ploidy and histological grade or DNA ploidy and survival. Both ploidy groups appear to have responded equally to therapy. In this study the factors associated with a short survival were advancing age and the presence of vascular endothelial proliferation, while the DNA ploidy and the cytological features do not appear as useful in predicting survival when examining biopsy material.

Neuropathology of the brain in HIV infection

The brains of 26 patients infected with the human immunodeficiency virus (HIV) were examined post mortem. All patients were men, aged 20-67 years (mean 38.8). 13 (50%) were homosexual, 3 (12%) were bisexual, 8 (31%) were haemophiliac, 1 was both an intravenous drug addict and homosexual, and 1 denied belonging to any risk group. Only 3 (12%) brains were normal, whereas 23 (88%) showed abnormalities that varied in severity and complexity. 11 were affected by more than one disease. In addition to neoplasms, opportunistic infections, and vascular lesions, 6 cases of HIV encephalitis were found, characterised by multinucleate giant cells which indicate the presence of HIV. Microglial-macrophage nodules (nodular encephalitis) occurred in 5 cases. Cerebral pathology differed between risk groups: all 6 patients with HIV encephalitis were homosexuals, whereas vascular lesions were more common in haemophiliacs. These observations have fundamental implications for clinical practice and indicate the importance of neuropathological examination in AIDS.

An immunohistological approach to persistent lymphadenopathy and its relevance to AIDS

Recent evidence has shown that not only AIDS but also the majority of 'unexplained' persistent, generalized lymphadenopathy (PGL) are related to HTLV-III/LAV infections. The early detection how these changes may proceed to AIDS then become a prime interest. Eleven patients with PGL (10 homosexual males and one heterosexual haemophiliac) have been studied by immunohistology using monoclonal antibodies to dendritic reticulum cells of the germinal centre, T and B lymphocyte subsets, plasma cells and factor VIII, as an endothelial marker. In six cases only follicular and paracortical hyperplasia was detected, while in five other cases destruction of the dendritic reticulum cell network was seen with this sensitive method. This early destruction may explain the release of activated B cells into the circulation and prove to be an ominous prognostic sign, as it appears to correlate with 'prodromal' symptoms. In four out of 11 cases the depletion of T4+ cells in the paracortex was not as severe as in the blood, indicating that T4+ cells may preferentially settle in tissues at the time of T4 lymphopenia. In addition, germinal centres contained an additional patchy infiltration of T8+ cells. A patient with Kaposi's sarcoma did not show germinal centre destruction but did reveal extensive plasma cell infiltrates. Immunohistology may contribute to the definition of prognosis and analysis of disease progression in patients with PGL.

Inhibition of leucocyte motility and prevention of immune-complex experimental colitis by hydroxychloroquine

The inhibitory effects of hydroxychloroquine on leucocyte motility have been compared with those of prednisolone. It has been shown to have similar potency to prednisolone as an inhibitor of human neutrophil and monocyte motility. Hydroxychloroquine has then been compared with placebo in the prevention of an immune-complex experimental colitis in rabbits. Rectal biopsies were taken from rabbits 24 hours after initiation of colitis, coded, and graded histologically. The summated gradings for acute inflammation and goblet cell depletion had worsened more in the control rabbits (mean grade +6.7) than in the treated rabbits (mean grade +1.8) P less than 0.05. There was no difference in the mononuclear cell infiltrate between the two groups. Hydroxychloroquine, which is a potent inhibitor of leucocyte motility, effectively prevents the acute inflammatory infiltrate in this experimental colitis model and therefore merits trial in human ulcerative colitis.

Father absence and cognitive performance in a large sample of six- to eleven-year-old children

The effects of father absence on educational achievement and intellectual development of 6-11-year-old children were investigated by employing a nationally representative sample of 5,493 father-present and 616 father-absent children from the Health Examination Survey of the National Center for Health Statistics. Scores on the WISC and the WRAT were significantly depressed for father-absent white children. Father-absent black children evidenced a decreased test performance only on measures of achievement. All decrements were small and accounted for approximately 1% of the variance. Following statistical control for SES, we associated no decrements with the father's absence/presence, and in some instances, small but significant increments were found to be associated with children from fatherless families. The role of SES in father absence is discussed, and the request for a paradigmatic shift in research in the area of father absence is reiterated.

Cystadenoma of the pancreas: a histological, histochemical and ultrastructural study of seven cases

Seven cases of cystadenoma of the pancreas were examined in detail histologically and histochemically and two variants were identified: a microcyst type lined by glycogen-rich cuboidal epithelium which also secretes some neutral mucins; and macrocystic type lined exclusively by mucus-secreting columnar cells which secrete predominantly sulphated acidic mucins with some neutral mucins. Electron microscopy of two cases of the microcystic variant showed neoplastic cells with an ultrastructure comparable to that of centroacinar cells of the normal exocrine pancreas.

Gastric function and histology in chronic renal failure

Gastric function and histology were investigated in 24 patients with untreated chronic renal failure. At endoscopy nine patients had oesophagitis, 12 patients were considered to have gastritis, and the duodenum appeared inflamed in 20 patients. Endoscopic biopsies were taken at standard sites in the stomach and duodenum; gastritis was found in all patients, and 17 patients had duodenitis. Stimulated acid secretion was impaired in seven out of 20 patients and acid hypersecretion was found in a further two patients. Pepsin output correlated well with acid output in these patients. Fasting serum gastrin levels were elevated in 12 of the 19 patients tested. Patients with atrophic gastritis had low acid outputs and hypergastrinaemia, and when extensive gastritis was present, the patients tended to have more severe renal failure and hyposecretion of acid. Three patients were studied again after regular haemodialysis or renal transplantation and were found to show marked endoscopic and histological improvement.