Lymphocyte targeting of the brain in adoptive transfer cryolesion-EAE

Lymphocyte infiltration and microglial activation in experimental autoimmune encephalomyelitis (EAE) are mainly centred on the spinal cord. However, a cryolesion to one cerebral hemisphere (cryolesion-EAE) induces six-fold enhancement of EAE in the cerebral hemispheres and removal of the cervical lymph nodes reduces such enhancement by 40 per cent. This study tests the hypothesis that lymphocytes from donor rats with cryolesion-EAE will selectively target the brain rather than the spinal cord when transferred to naive recipients. Acute EAE was induced in 15 Lewis rats (donors); ten donors received a cryolesion to the left cerebral hemisphere 8 days post-inoculation of antigen and adjuvant. Five rats with EAE received no cryolesion. Lymphocytes from cryolesion-EAE donors or from EAE-only donors were cultured for 72 h in medium containing myelin basic protein and then injected into a total of 21 naive recipients, which were killed 8 days later. The severity of EAE in brains and spinal cords was assessed in immunocytochemically stained sections by quantifying the number of vessels showing lymphocyte cuffs (W3/13 antibody) and the level of MHC class II antigen expression by microglia (OX6 antibody). When compared with recipients of EAE-only donor lymphocytes, the severity of cerebral EAE was increased 2- to 2.6-fold in the recipients of crylesion-EAE donor lymphocytes (p < 0.01); EAE in the spinal cord was reduced. These results suggest that lymphocytes from cryolesion-EAE donors preferentially target the brain in recipient animals in preference to the spinal cord. By analogy with cryolesion-EAE, focal central nervous system (CNS) damage with drainage of auto-antigens to regional lymph nodes in man may play a role in determining the site and timing of initial and recurrent multiple sclerosis lesions.

Stenting therapy for stenosing airway diseases

Tracheobronchial stents have proved very valuable in the management of airway stenosis due to a variety of causes, both benign and malignant. These include benign strictures which are post-traumatic (e.g. after intubation), post anastomotic (e.g. after lung transplantation), or post inflammatory (e.g. after inflammatory conditions such as tuberculosis or Wegener's granulomatosis); as well as narrowing due to malignant involvement of large airways. In addition, airway stents have been used to treat tracheobronchomalacia and oesophageal-airway fistulae. The insertion of the stent may need to be combined with other procedures such as airway dilatation, laser photocoagulation, brachytherapy or a mixture of these treatment modalities. Stents have been fashioned out of silicone, wire mesh or a combination of these materials, but the perfect stent has yet to be devised. Common problems include displacement and obstruction with secretions or granulation tissue. Less commonly the stent may perforate the airway wall, sometimes into the accompanying blood vessel. Nonetheless, airway stents are valuable tools in the management of airway narrowing.

Expression of the fgl2 and its protein product (prothrombinase) in tissues during murine hepatitis virus strain-3 (MHV-3) infection

Murine Hepatitis Virus Strain 3 (MHV-3) produces fulminant hepatitis with 80-90% mortality in Balb/cJ mice. Previous studies in our laboratory have shown that peritoneal macrophages from MHV-3 infected mice produce a procoagulant (PCA) which has the ability to cleave prothrombin to thrombin (prothrombinase) encoded by the gene fgl2 located on chromosome 5. PCA accounts for sinusoidal thrombosis and hepatic necrosis and the necrosis and mortality can be prevented by treatment of animals with a monoclonal antibody to PCA. These present studies were designed to examine the expression of this gene (mRNA by Northern analysis and in situ hybridization) and the gene product PCA (immunochemistry) in tissues recovered from MHV-3 infected Balb/cJ mice in an attempt to explain the liver specific nature of MHV-3 disease. Fgl2 gene expression was detected as early as 8 hours after MHV-3 infection which persisted to 48 hours in the liver, spleen and lungs whereas no gene expression was seen in the brain or kidneys despite the fact that equivalent viral titers were detected in all tissues at all times. In the liver, fgl2 gene expression was confined to endothelial and Kupffer cells with no expression in hepatocytes. Immunochemistry localized the PCA protein to Kupffer cells and endothelial cells and necrotic foci within the liver. No PCA protein was detected by immunochemistry in any other tissues at any time during the course of MHV-3 infection. These results explain the liver specific nature (fulminant hepatitis) of MHV-3 infection and provides further evidence for the role of PCA in the pathogenesis of fulminant hepatitis. MHV-3 induces selective transcription of the gene fgl2 and only hepatic reticuloendothelial cells produce functional protein (PCA) which is known to account for fulminant hepatic failure produced by MHV-3.

A survey of lead-based paint abatement projects performed in public buildings in Erie and Crawford Counties, Pennsylvania, during the time period 1995-1997

A survey of lead-based paint abatement projects in public buildings of Crawford and Erie Counties, Pennsylvania, was conducted during the time period January 1995 to March 1997. These survey results suggest that few lead abatement projects were performed during this time period. Projects that were performed commonly did not employ proper lead abatement practices as described by the U.S. Occupational Safety and Health Administration, U.S. Environmental Protection Agency, and U.S. Department of Housing and Urban Development. These data suggest that most contractors and public officials have misunderstandings of both environmental regulations and required procedures for safe and effective lead-based paint abatement.

Effect of interferon therapy on hepatitis C virus RNA in whole blood, plasma, and peripheral blood mononuclear cells

Fifty-two patients with chronic hepatitis C virus (HCV) infection were treated with standard doses of interferon alfa-2b. During treatment, HCV RNA detection was studied in samples of whole blood (WB), plasma (Pl), and peripheral blood mononuclear cells (PBMCs). Individuals were classified as sustained responders (SRs), complete responders with relapse (CRs), partial responders (PRs), or nonresponders (NRs) according to normalization of serum alanine transaminase (ALT) during treatment and follow-up. Before treatment, 100% of WB samples and more than 95% of Pl and PBMC samples were positive for HCV RNA. During treatment, there was progressive clearance of HCV RNA from Pl and PBMCs in SRs and CRs, but CRs had significantly more positive WB samples during and following treatment (P <.0001). At 6 months, only 10% of CR patients were positive by Pl assay, but 50% were positive by WB assay (P <.01). In the PR group, all WB samples remained positive throughout treatment, although 25% to 40% of PBMC and Pl samples became negative for HCV RNA during the first 2 months of therapy (WB > Pl or PBMC; P < .001). However, at later times during treatment most Pl and PBMC samples in the PR group were positive. Samples from the NR group showed no clearance of HCV RNA from WB, Pl, or PBMC fractions. These data document the increased sensitivity of WB assays for detecting HCV RNA in the peripheral blood of patients during interferon therapy. Furthermore, our findings suggest that WB analysis of HCV RNA may be a useful parameter to monitor in determining the end point of interferon therapy.

Resistance to murine hepatitis virus strain 3 is dependent on production of nitric oxide

The strain-specific spectrum of liver disease following murine hepatitis virus type 3 (MHV-3) infection is dependent on inflammatory mediators released by macrophages. Production of nitric oxide (NO) by macrophages has been implicated in resistance to a number of viruses, including ectromelia virus, vaccinia virus, and herpes simplex virus type 1. This study was undertaken to define the role of NO in MHV-3 infection. Gamma interferon-induced production of NO inhibited growth of MHV-3 in a murine macrophage cell line (RAW 264.7). Viral inhibitory activity was reproduced by the NO donor S-nitroso-N-acetyl-DL-penicillamine (SNAP), whereas N-acetyl-DL-pencillamine (NAP), an inactive analog of SNAP, had no effect. Electron microscopy studies confirmed the inhibitory effects of NO on viral replication. Peritoneal macrophages isolated from A/J mice known to be resistant to MHV-3 produced a fivefold-higher level of NO and higher levels of mRNA transcripts of inducible NO synthase in response to gamma interferon than macrophages from susceptible BALB/cJ mice. SNAP inhibited growth of MHV-3 in macrophages from both strains of mice to similar degrees. In vivo inhibition of NO by N-monomethyl-L-arginine resulted in loss of resistance to MHV-3 in A/J mice. These results collectively demonstrate a defect in the production of NO in macrophages from susceptible BALB/cJ mice and define the importance of endogenous NO in resistance to MHV-3 infection in resistant A/J mice.

Ribavirin inhibits viral-induced macrophage production of TNF, IL-1, the procoagulant fgl2 prothrombinase and preserves Th1 cytokine production but inhibits Th2 cytokine response

Ribavirin, a synthetic guanosine analogue, possesses a broad spectrum of activity against DNA and RNA viruses. It has been previously shown to attenuate the course of fulminant hepatitis in mice produced by murine hepatitis virus strain 3. We therefore studied the effects of ribavirin on murine hepatitis virus strain 3 replication, macrophage production of proinflammatory mediators including TNF, IL-1, and the procoagulant activity (PCA), fgl2 prothrombinase; and Th1/Th2 cytokine production. Although ribavirin had inhibitory effects on viral replication (<1 log), even at high concentrations complete eradication of the virus was not seen. In contrast, at physiologic concentrations (up to 500 microg/ml), ribavirin markedly reduced viral-induced parameters of macrophage activation. With ribavirin treatment, the concentrations of PCA, TNF-alpha and IL-1beta all decreased to basal concentrations: PCA from 941 +/- 80 to 34 +/- 11 mU/10(6) cells; TNF-alpha from 10.73 +/- 2.15 to 2.74 +/- 0.93 ng/ml; and IL-1beta from 155.91 +/- 22.62 to 5.74 +/- 0.70 pg/ml. The inhibitory effects of ribavirin were at the level of gene transcription as evidenced by Northern analysis. Both in vitro and in vivo, ribavirin inhibited the production of IL-4 by Th2 cells, whereas it did not diminish the production of IFN-gamma in Th1 cells. In contrast, ribavirin had no inhibitory effect on TNF-alpha and IL-1beta production in LPS-stimulated macrophages. These results suggest that the beneficial effects of ribavirin are mediated by inhibition of induction of macrophage proinflammatory cytokines and Th2 cytokines while preserving Th1 cytokines.

Fulminant hepatic failure in murine hepatitis virus strain 3 infection: tissue-specific expression of a novel fgl2 prothrombinase

Activation of the immune coagulation system has been implicated in the pathogenesis of fulminant liver failure caused by murine hepatitis virus strain 3 (MHV-3). The recent discovery of the fgl2 gene, which encodes for MHV-3-induced prothrombinase (fgl2 prothrombinase), allows for fundamental studies to determine the molecular basis for fulminant liver failure. Transcription of the fgl2 gene and translation of the protein it encodes were examined in the liver and other organs of susceptible mice following MHV-3 infection. No constitutive expression of the fgl2 gene or the fgl2 prothrombinase was detected. Within 12 to 24 h of MHV-3 infection, however, fgl2 gene transcripts were detected in large amounts in the liver, spleen, and lungs, all of which are rich in reticuloendothelial cells, but were only focally present in small amounts in the kidney and brain. There was sequential detection of fgl2 prothrombinase in the liver, where it was localized specifically to the endothelium of intrahepatic veins and hepatic sinusoids; this was allowed by fibrin deposition, which resulted in confluent hepatocellular necrosis. These results provide further evidence for the role of the selective expression of this novel fgl2 prothrombinase in the pathogenesis of MHV-3-induced fulminant liver failure.

Role of cervical lymph nodes in autoimmune encephalomyelitis in the Lewis rat

Lymphocytes enter the central nervous system (CNS) in response to virus infections and in autoimmune diseases, such as multiple sclerosis (MS), but the origin of such lymphocytes is unclear. This study investigates the role of the cervical lymph nodes as a source of lymphocytes involved in experimental autoimmune disease of the brain. Acute active experimental autoimmune encephalomyelitis (EAE) is used as a model for the autoimmune aspects of MS and is characterized by lymphocyte and monocyte invasion and microglial activation, mainly in the spinal cord, 12-15 days post-inoculation (dpi) of antigen. Few lesions occur in the cerebral hemispheres in acute EAE, but a cryolesion to the surface of the brain 8 dpi results in a six-fold enhancement of cerebral EAE. The present study tests the hypothesis that cervical lymphadenectomy will reduce the enhancement of cerebral EAE induced by a cryolesion. Acute EAE was induced in 25 Lewis rats and a cryolesion to the brain, 8 dpi, in 16 rats was immediately followed by either cervical lymphadenectomy (n = 8) or sham lymphadenectomy (n = 8). The severity of EAE at 15 dpi, in the brain and spinal cord, was evaluated using immunocytochemistry for T lymphocytes (W3/13) and MHC class II expression (OX6). The results of the study showed that cervical lymphadenectomy reduced the level of cerebral EAE induced by a cryolesion by 40 per cent when compared with the sham-operated animals (P < 0.01). This suggests that cervical lymph nodes play a pivotal role in the induction of EAE in the brain, possibly as a site for 'priming' T cells to target the brain. Investigation of the interrelationships between cervical lymph nodes and the brain in man may lead to new therapeutic strategies for multiple sclerosis.

Intermittent claudication should not be treated by surgery

This debate examines the proposition that surgery is unnecessary or obsolete in the management of intermittent claudication. The case for this argument is that many patients have stable disease or respond well to conservative measures, that claudication is an expression of a systemic cardiovascular illness and that surgery can be replaced by endovascular techniques with equal success, and less disadvantage in the event of treatment failure. The case against the motion is that claudication is associated with repeated cycles of ischaemia and reperfusion, and that these contribute to excess cardiovascular mortality states and, furthermore, that surgery is the only option to relieve symptoms for many patients, especially those with distal disease.

Large adrenal cysts in teenage girls: diagnosis and management

Large adrenal cysts usually occur in the fifth and sixth decades of a patient's life but are rare in the first two decades. This paper presents the clinical, cross-sectional imaging, surgical, pathological and follow-up data of three teenage girls with large adrenal cysts. Two had vague upper abdominal pain and, in the other, the cyst was found incidentally. The cysts were surgically removed in two patients, while in the third, follow-up imaging has shown no change in the cyst over a 4-year period, suggesting that conservative management is a reasonable option.

[Immunologic significance of lymphatic drainage of the brain]

Despite the evidence for immunological reactions in the human CNS, in viral encephalitis and in multiple sclerosis, connections between the brain and the immune system are poorly understood. In rodents, tracers injected into the interstitial fluid of the brain drain to the cervical lymph nodes by perivascular pathways in the brain and nasal lymphatics. Similar pathways could serve as lymphatics in the human brain. In the present study, we test the hypothesis that lymphatic drainage of the brain and cervical lymph nodes play a key role in T-cell mediated immunity of the brain. Experimental allergic encephalomyelitis (EAE) was induced in Lewis rats by the injection of guinea pig spinal cord homogenate in complete Freund's adjuvant into the foot pads. This resulted in paralysis of the hind limbs and infiltration of lymphocytes and microglial activation centred mainly on the spinal cord; little inflammation was seen in the cerebrum. When a brain wound, in the form of cryolesion, was inflicted on one cerebral hemisphere, 8 days after the induction of EAE, there was a 6-fold enhancement of EAE lesions in the brain. This enhancement was reduced by 40% cervical lymphadenectomy at the time of the cryolesion. These results suggest that cervical lymph nodes play a pivotal role in cerebral EAE and may be a major source of brain-directed lymphocytes. If similar mechanisms apply in man, study of cervical lymphocytes and their manipulation could open new therapeutic avenues for the treatment of multiple sclerosis.

Evaluation of liver transplantation for high-risk indications

BACKGROUND

Appropriate use of orthotopic liver transplantation (OLT) requires continued assessment of the indications for transplantation as a number of diseases are associated with a poor prognosis. High-risk patients are those who have a poor survival or high incidence of recurrent disease (patients with tumours, hepatitis B- or hepatitis C-induced cirrhosis, fulminant hepatic failure or primary graft non-function). In addition, retransplantation may be associated with a poor outcome.

METHODS

A retrospective review was made of the records of all adult patients undergoing OLT at this hospital between October 1985 and July 1994.

RESULTS

A total of 396 liver transplants were performed in 364 patients. The 1- and 3-year actuarial survival rates were 81 and 69 per cent respectively. The overall survival rate of high-risk patients was significantly lower than that for all OLT recipients (P < 0.05). While no patients transplanted for hepatitis C have developed graft failure, recurrent hepatitis occurred in 15 of 35 patients.

CONCLUSION

Strict selection criteria and appropriate perioperative investigations and interventions are required to improve the results of OLT in these high-risk patients.

Biliary atresia: should all patients undergo a portoenterostomy?

PURPOSE

The management of noncorrectable extra hepatic biliary atresia includes portoenterostomy, although the results of the surgery are variable. This study was done to develop criteria that could successfully predict the outcome of surgery based on preoperative data, including percutaneous liver biopsy, allowing a more selective approach to the care of these babies.

METHODS

The charts and biopsy results of 31 patients who underwent a Kasai procedure for biliary atresia between 1984 and 1994 were reviewed. Values for preoperative albumin, bilirubin, age of patient at Kasai, and lowest postoperative bilirubin were recorded. Surgical success was defined as postoperative bilirubin that returned to normal. A pathologist blinded to the child's eventual outcome graded the pre-Kasai needle liver biopsy results according to duct proliferation, ductal plate lesion, bile in ducts, lobular inflammation, giant cells, syncitial giant cells, focal necrosis, bridging necrosis, hepatocyte ballooning, bile in zone 1, 2, and 3, cholangitis, and end-stage cirrhosis. Clinical outcome was then predicted.

RESULTS

Success after portoenterostomy could not reliably be predicted based on gender, age at Kasai, preoperative bilirubin or albumin levels. Histological criteria, however, predicted outcome in 27 of 31 patients (P < .01). Fifteen of 17 clinical successes were correctly predicted; as were 12 of 14 clinical failures (sensitivity, 86%; specificity, 88%). Individually, the presence of syncitial giant cells, lobular inflammation, focal necrosis, bridging necrosis, and cholangitis, were each associated with failure of the portoenterostomy (P < .05). Bile in zone 1 was associated with clinical success of the procedure (P < .05).

CONCLUSIONS

Based on the predictive information available in a liver biopsy, we conclude that those patients who will not benefit from a Kasai procedure can be identified preoperatively, and channeled immediately to transplantation.

Behavioral and neuroendocrine responses to m-chlorophenylpiperazine in subtypes of alcoholics and in healthy comparison subjects

OBJECTIVE

The purpose of this study was to explore central serotonergic functions in subgroups of alcoholics and in healthy comparison subjects.

METHOD

The mixed serotonin (5-HT) agonist/antagonist m-chlorophenylpiperazine (m-CPP) was administered to male alcoholic patients who were classified according to the criteria of von Knorring et al. as type I alcoholics (late onset) (N = 16) or type II alcoholics (early onset with antisocial traits) (N = 24) and to 22 healthy comparison subjects. Psychological, physiological, and neuroendocrine measures were obtained before and after the m-CPP infusion.

RESULTS

m-CPP elicited subtype-related differential effects among the alcoholics; the type I alcoholics reported more anger and anxiety, and the type II alcoholics reported increased euphoria and a greater likelihood of drinking. The healthy comparison subjects exhibited a greater increase in plasma ACTH response to the m-CPP infusion than the alcoholics regardless of subtype.

CONCLUSIONS

Differences in certain 5-HT receptor functions may explain some of the clinical characteristics that differentiate the type II and type I subgroups of alcoholic patients. Furthermore, alcoholics may have reduced sensitivity of 5-HT2C receptors in comparison with healthy subjects.

Lymphocyte targeting of the central nervous system: a review of afferent and efferent CNS-immune pathways

The central nervous system (CNS) in considered to be an immunological privileged site. However, inflammatory reactions in response to virus infections, in multiple sclerosis (MS) and in experimental autoimmune encephalomyelitis (EAE) suggest that there are definite connections between the CNS and the immune system. In this review, we examine evidence for afferent and efferent pathways of communication between the CNS and the immune system, the pivotal role of regional lymph nodes in T-cell mediated autoimmune disease of the CNS, and the factors involved in lymphocyte targeting of the CNS. Afferent pathways of lymphatic drainage of the brain are well established in a variety of species, especially rodents. Fluid and antigens appear to drain along perivascular spaces populated by immunocompetent perivascular cells. Drainage pathways connect directly via the cribriform plate to nasal lymphatics and cervical lymph nodes. Soluble antigens draining from the brain induce antibody production in the cervical lymph nodes. Using a model of cryolesion-enhanced EAE, we review the role of lymphatic drainage and cervical lymph nodes in the enhancement of cerebral EAE. If a brain wound in the form of a cryolesion is produced 8 days post inoculation (dpi) of antigen in the induction of acute EAE, there is a 6-fold increase in severity of cerebral EAE by 15 dpi. Removal of the cervical lymph nodes significantly reduces such enhancement of EAE. These findings suggest that drainage of antigens from the brain to the cervical lymph nodes, in the presence of activated lymphocytes in the meninges or CNS, results in an enhanced second wave of lymphocytes targeting the brain. In examining the efferent immune pathway by which lymphocytes home to the CNS, several studies have characterized the phenotype of infiltrating T lymphocytes by the use of immunocytochemistry or FACS analysis. T-cells infiltrating the CNS are recently activated/memory lymphocytes typified by their high expression of CD44, LFA-1 and ICAM-1 and low expression of CD45RB in the mouse. Following the induction of EAE in susceptible mice, ICAM-1 and VCAM-1 are dramatically upregulated on CNS vessels; lymphocytes bind to such vessels via the interaction of their known ligands, LFA-1/Mac-1 and alpha 4-integrins, at least in vitro. It appears that alpha 4-integrin plays a key role in lymphocyte recruitment across the blood-brain barrier and may be a major factor in lymphocyte targeting of the CNS. Definition of factors involved in the afferent and efferent connections between the CNS and the immune system may clarify mechanisms involved in immune privilege of the CNS and may open significant therapeutic opportunities for multiple sclerosis.

Loss of resistance to murine hepatitis virus strain 3 infection after treatment with corticosteroids is associated with induction of macrophage procoagulant activity

Activation of the immune coagulation system has been implicated in the pathogenesis of liver injury following infection of inbred mice with murine hepatitis virus strain 3 (MHV-3). Following MHV-3 infection, macrophages isolated from MHV-3-susceptible and -semisusceptible inbred strains of mice express increased procoagulant activity (PCA), whereas macrophages from resistant strains express no increase in PCA over basal levels. The PCA induced by MHV-3 is a prothrombinase, encoded by the gene Fgl-2, which encodes a fibrinogen-like protein (musfiblp). In this study, MHV-3-resistant A/J mice treated with methylprednisolone prior to infection with MHV-3 developed elevated levels of alanine aminotransferase in serum and died within 10 days of infection, with histological findings of fulminant hepatitis. In vitro, macrophages isolated from A/J mice and pretreated with methylprednisolone produced a marked increase in functional PCA following infection with MHV-3. The PCA was shown to be a prothrombinase by its ability to cleave 125I-prothrombin. Northern blot analysis of RNA transcripts from these macrophages demonstrated increased transcription of the Fgl-2 gene relative to that in macrophages which had not been pretreated with methylprednisolone prior to MHV-3 infection. Methylprednisolone pretreatment of MHV-3-infected macrophages stabilized the Fgl-2 mRNA. Thus, loss of resistance to MHV-3 secondary to methylprednisolone therapy is associated with increased transcription and stability of Fgl-2 mRNA resulting in expression of the Fgl-2 gene product, musfiblp. These results provide further insight into mechanisms of PCA regulation in response to MHV-3 infection in inbred strains of mice.

Kupffer cell erythrophagocytosis and graft-versus-host hemolysis in liver transplantation

BACKGROUND & AIMS

Graft-versus-host hemolysis (GVHH) syndrome develops in approximately half of patients undergoing ABO-unmatched liver transplantation. The clinical and laboratory presentations of GVHH syndrome often mimic acute rejection, leading to liver biopsy for definitive diagnosis. The purpose of this study was to investigate if there are specific histological findings that permit diagnosis of GVHH syndrome and to assess the relationship between GVHH syndrome and rejection.

METHODS

Clinical and laboratory evidence of GVHH syndrome, results of liver biopsy, and clinical outcome were assessed in 30 ABO-unmatched liver transplant recipients. Biopsy results were compared with those of two control groups consisting of patients who had normal liver test findings (protocol biopsy) and rejection.

RESULTS

Sixteen of the 30 patients (53%) had evidence of GVHH syndrome. Erythrophagocytosis was noted in each biopsy specimen, and the degree of phagocytosis correlated significantly with the amount of blood given after postoperative day 5 (r = 0.9; P < 0.02). Electron-microscopic studies performed randomly in 5 patients showed that the red cells were located in Kupffer cells. In contrast, erythrophagocytosis was minimal in the two control groups. Despite an incidence and severity of rejection similar to those in other liver transplant patients, serum transaminase levels were significantly higher in patients with GVHH syndrome.

CONCLUSIONS

Erythrophagocytosis is a sensitive histological marker of GVHH syndrome. The severity of rejection and response to antirejection therapy should be monitored by markers other than transaminases in patients with GVHH syndrome.

Excess zinc associated with severe progressive cholestasis in Cree and Ojibwa-Cree children

BACKGROUND

High hepatic copper concentrations have been reported in several liver disorders. We report six Native Canadian children with severe chronic cholestatic liver disease, who had excess hepatic copper and zinc.

METHODS

The children, aged 22 months to 8 years, came from northern Ontario, Canada. All were referred for possible liver transplantation because of end-stage liver disease. We examined explanted liver samples (or liver biopsy material in one case) by scanning transmission electronmicroscopic (STEM) X-ray elemental microanalysis and atomic absorption spectrophotometry. Samples from four controls (two with no liver pathology, one with biliary atresia, and one with Wilson's disease) were also analysed by atomic absorption spectrophotometry.

FINDINGS

The explanted livers showed similar distinctive signs of advanced biliary cirrhosis, and on electronmicroscopy there were dense deposits in enlarged lysosomes and in cytoplasm. Hepatic copper concentrations were many times higher in the five patients with measurements (47.6-56.9 microgram/g dry weight) than in two samples of normal control liver tissue (2.3 and 2.9 microgram/g). Similarly, hepatic zinc concentrations were many times higher in the patients than in controls (104-128 vs 1.9-3.2 microgram/g dry weight).

INTERPRETATION

The excess copper may be due to chronic cholestasis but the excess zinc is unexplained. Since three of the patients are related (shared grandparents), a genetic disorder of metal metabolism is possible, but we cannot exclude environmental factors.

The changing pattern of venous thromboembolic disease

A review of 14,667 necropsy reports for every year from 1965 to 1990 and 6,436 diagnostic venograms performed from 1976 to 1990 was undertaken at a single teaching hospital. A progressive reduction in the percentage of necropsies reporting fatal pulmonary embolism from 6.1 to 2.1%, occurred over the 25-year period (chi(2) tests for linear trend with time p < 0.00001). Over the last decade, there has been a significant reduction in the rate of venographically diagnosed postoperative deep vein thrombosis (DVT) from 49.9 to 24.7 per 100,000 population (p < 0.0001) which was in marked contrast to the constant rate of non-postoperative DVT. Our findings suggest that the introduction of thromboprophylactic measures, in addition to changes in hospital practice, may have had a highly significant effect on the pattern of this serious, but potentially avoidable disease.

Tetrasomy of chromosome 8 in a patient with acute myeloid leukemia

We report a case of acute myeloid leukaemia (AML), FAB classification M2, associated with tetrasomy 8. This chromosomal aberration was detected using conventional cytogenetics and flourescent in-situ hybridization (FISH). Using FISH, the pre-treatment cells with tetrasomy 8 were disomic for chromosome 7. A small number of tetrasomy 8 cells were found post-treatment, but these were tetrasomic for chromosome 7. The significance of this is considered, and the literature regarding tetrasomy 8 in acute myeloid leukaemia is reviewed.

Adaptation of the TdT assay for semi-quantitative flow cytometric detection of DNA strand breaks

The enzyme Terminal Deoxynucleotidyl Transferase (TdT) is a DNA polymerase which can be used to label DNA strand breaks by the incorporation of a labelled nucleotide followed by a fluorescent detection step. The amount of label incorporated can then be assessed by flow cytometry. The mechanism of action of TdT, however, will allow the addition of varying numbers of nucleotides to the free 3' termini produced by DNA strand breaks. The substitution of Digoxigenin (DIG) labelled dideoxy-nucleotides for labelled deoxy-nucleotides in the TdT assay will limit the addition of label to a DNA break to a single nucleotide, thus ensuring a direct relationship between an increase in DNA strand breaks and an increase in fluorescence. We have used this adaptation of the TdT Assay to evaluate DNA damage incurred in lymphocytes, from patients with Chronic Lymphocytic Leukaemia (CLL), on exposure to UV irradiation and apoptosis-inducing drugs, fludarabine and 2-Chloro-2'-deoxyadenosine (2-CdA). This technique may give a good indication of the susceptibility of CLL patients to apoptosis inducing drugs, and hence an indication of the likely response to these therapies.