Virus removal studies using nanofiltration membranes

Nanofiltration of immunoglobulin products was investigated as a virus removal step using Planova-controlled pore size membranes. For these studies, purified preparations of an IgG and an IgM were tested with 15 nm and 35 nm Planovace nanofiltration membranes, respectively. The results of spiking studies with four model viruses indicated that both the Planova 15 and 35 membranes removed 6-7 log10 plaque or focus forming units of murine xenotropic retrovirus, simian virus 40 and pseudorabies virus. Although two tandem Planova 35 membranes were tested for clearance of poliovirus, only the Planova 15 membrane removed this virus. Nanofiltration experiments were carried out with protein concentrations up to 12 mg/ml for the IgG and 1-2 mg/ml for the IgM, and protein recovery was excellent.

Drug chirality: a consideration of the significance of the stereochemistry of antimicrobial agents

Approximately 25% of drugs are marketed as either racemates or mixtures of diastereoisomers. Such stereoisomers frequently differ in terms of their biological activity and pharmacokinetic profiles and the use of such mixtures may contribute to the adverse effects of the drug particularly if they are associated with the inactive or less active isomer. In recent years drug stereochemistry has become a significant issue for both the pharmaceutical industry and the regulatory authorities. The significance of stereoisomerism in antimicrobial agents is addressed in this review using examples drawn from the beta-lactams, as being representative of semisynthetic agents, and the quinolones, as examples of synthetic agents. Within these two groups of compounds it is clear that stereochemical considerations are of significance for an understanding of concentration effect relationships, selectivity in both action and inactivation and for an appreciation of the mode of action at a molecular level. In the case of some agents the use of a single isomer is precluded due to their facile epimerization, e.g. carbenicillin, in the case of others there are potential advantages with the use of single isomers, e.g. ofloxacin. However, in the case of latamoxef, a compound which undergoes in-vivo epimerization with a half-life similar to its apparent serum elimination half-life the situation is by-no-means clear cut. These agents emphasise the importance of considering each compound individually, i.e. on a case-by-case basis, before deciding to use a single isomer or stereoisomeric mixture.

Isradipine increases vascular prostaglandin I2-formation while the thromboxane B2-synthesis is diminished

PGI2- and TXA2-synthesis from vascular tissue samples derived from cultured (endothelial and smooth muscle) cells, rabbit aorta and human bypass surgery were determined using specific radioimmunoassays for the stable derivatives (6-oxo-PGF1a and TXB2, respectively) of these compounds. Cultured cells were incubated in presence of isradipine, rabbits were pretreated for 4 weeks receiving 0.3 mg isradipine/kg*day, while patients were on isradipine (5-10 mg total dose/day, per os twice daily) since 6-19 weeks. In presence of isradipine, cultured cells produced significantly (p < 0.01) more 6-oxo-PGF1a and significantly less TXB2 (p < 0.05). 6-oxo-PGF1a-formation in rabbit aorta was significantly (p < 0.01) higher in isradipine treated normocholesterolemic animals while no significant changes were seen in isradipine treated hypercholesterolemic animals. TXB2 was significantly (p < 0.01) depressed in the abdominal and the thoracic aortic segment of isradipine treated hypercholesterolemic animals and was not significantly influenced in isradipine treated normocholesterolemic animals. Similarly, PGI2-synthesis in human arterial specimen was significantly (p < 0.01) enhanced as compared to the untreated controls. These findings indicate a beneficial behaviour of isradipine on vascular wall eicosanoid profile, which may contribute to a variety of antiatherosclerotic actions at the vascular wall level and to an improvement in hemostatic balance already described.

Arterial wall rather than platelets is responsible for diminished thrombogenicity during isradipine therapy

We investigated whether the vessel wall or platelets are primarily responsible for the decreased thrombogenicity induced by the calcium channel blocker isradipine after endothelium removal. In a cross-perfusion model, rabbit aorta and iliac artery endothelium of receiver animals were removed by balloon catheter before being perfused with the blood of the blood donor rabbits. Donor and/or receiver animals were treated with 0.3 mg/kg isradipine intravenously (i.v.) daily for 1 week or with 10 mg acetylsalicylic acid (ASA) in addition. The other animals received vehicle only or ASA. The animals were divided into four groups (I-IV, total n = 24) consisting of four subgroups of 6 animals each. In all, 96 rabbits were examined. Immediately after the last administration of the respective drug, native blood from a donor rabbit was circulated (30 ml/min) through a deendothelialized segment of a receiver rabbit. The contract (C) and spread (S) platelets as well as the denuded surface covered with platelet aggregates (> 5 microns high) were quantified by morphometry. Deposition of [111In]oxine-labeled platelets was quantitatively determined per surface unit. In addition, prostaglandin I2 (PGI2) formation by the denuded aortic and iliac artery segment was determined. In group I, receiver rabbit pretreatment with isradipine exhibited decreased adhesion and aggregation of platelets, even when the donor rabbit was treated with solvent or ASA. In group II, concomitant treatment of donor animals with ASA and isradipine had no significant effect, whereas ASA isradipine treatment of receiver animals enhanced thrombogenicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Importance of concomitant viral infection during late acute liver allograft rejection

We have determined accompanying events and reviewed the management and outcome of late acute cellular rejection episodes in 384 consecutive liver recipients. A significant proportion of patients experienced concomitant viral infection (group 1, n = 15 [41%]), with CMV infection comprising the largest group and smaller contributions from other viruses (CMV, 30%; HSV, 5%; EBV, 3%; varicella zoster virus, 3%). Thirteen (35%) patients (group 2) developed late rejection associated with low maintenance immunosuppression, and in a further 10 patients (group 3), no accompanying factor could be identified. Refractory rejection was higher in late compared with early rejection episodes in our series (29% vs. 9.2%, P < 0.05). Antiviral chemotherapy administered in rejection episodes with concomitant viral infection, either as sole treatment in cases with accompanying hepatitis or as adjunctive therapy to further supplemental immunosuppression in episodes of steroid-resistant rejection, controlled the rejection process in all treated patients.

Inhibition of lung immunity after intratracheal instillation of benzo(a)pyrene

Benzo(a)pyrene (B(a)P) has been shown to suppress systemic immunity in experimental animals, which may contribute to the growth of the chemical-induced tumors. However, its effects on lung immunity after inhalation, a common route for human exposure in urban areas, has not been determined. These studies examine intratracheal B(a)P instillation on lung natural killer (NK) cell activity, alveolar macrophage (AM) functions, and susceptibility to tumor cell challenge in Fischer 344 (F-344) rats. Adult female F-344 rats were given a single intratracheal instillation of 0, 10, 20, or 40 mg B(a)P/kg body weight as a suspension, and lung NK cell activity and AM functions were examined 7, 21, or 100 d later. Although exposure to B(a)P did not alter cell recovery after lavage, histologic changes were observed as evidenced by granulomatous inflammation and squamous metaplasia. There was a slight but significant suppression of H2O2 and nitric oxide (NO) release from alveolar macrophages of treated animals as well as NK cell activity from the lung digest. A marked suppression of tumor necrosis factor-alpha (TNF alpha) and interleukin (IL-1) secretion in LPS- and/or cytokine-activated alveolar macrophages occurred. The suppressive effects were generally more severe on Day 7 after exposure than on Days 21 or 100, although IL-1 remained depressed through Day 100 after exposure. B(a)P exposure allowed for the increased growth of MADB106 metastatic tumor cells in the lung. These tumor cells were shown to be highly sensitive to lysis by immune-mediators, including TNF alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Nitric oxide generation. A predictive parameter of acute allograft rejection

The L-arginine:nitric oxide (NO) biosynthetic pathway has been proposed as an important mediator in host defense mechanisms and may therefore play a role in the acute allograft response. We have studied NO generation in liver allograft rejection and determined its value in immunological monitoring. Stable end products of this pathway have been determined serially in 50 primary liver recipients and compared with 2 known mediators and markers of acute allograft rejection (IL-2R positive lymphocytes and circulating TNF alpha). Plasma concentrations of acid-labile nitrosocompounds (NOx), which increased during acute allograft rejection (P < 0.0001), correlated with rejection severity and were reduced after administration of supplemental high dose glucocorticoids. Concentrations were significantly lower in nonrejection graft complications but were elevated during episodes of sepsis. Correlations between plasma NOx levels and circulating TNF-alpha (r = 0.451, P < 0.001) and IL-2R-positive lymphocytes in peripheral blood (r = 0.781, P < 0.001) were demonstrated. In a logistic analysis of these variables, plasma NOx was the most predictive parameter of an episode of acute cellular rejection. Nitric oxide generation in FK506-treated patients was lower compared with patients receiving a CsA-based immunosuppression regimen and was associated with a reduced frequency of acute rejection in the FK506 group. These data are consistent with a role for NO in the cellular alloantigen immune response and indicate that monitoring of plasma levels of NOx may be useful in the detection of acute allograft rejection.

Isradipine decreases arterial thrombogenicity in rabbits. A morphometric and radioisotopic study

The effect of isradipine, a calcium antagonist, on aortic and iliac wall thrombogenicity was examined in rabbits. After one week of dosing, the abdominal aortic and iliac artery endothelium was abraded using a Fogarthy catheter. One group of animals (n = 8) was dosed for one week with isradipine 0.3 mg/kg. A second group of animals received 10 mg acetylsalicylic acid (ASA)/kg daily in addition, while a third group received the vehicle only. Finally, a fourth group of animals (n = 8) was treated with ASA only. The percentage denuded surface covered with contact (unspread) platelets decreased significantly (p < 0.01) from 14.7 +/- 2.0 to 9.3 +/- 2.1 (6.2 +/- 0.8 to 3.7 +/- 0.4). The amount of contact and spread platelets was diminished from 84.9 +/- 5.6 to 71.4 +/- 4.4 (91.8 +/- 5.3 to 75.2 +/- 4.6). Platelet thrombi decreased from 7.4 +/- 0.9 to 4.6 +/- 1.4 (9.4 +/- 1.9 to 5.2 +/- 0.7) in the aortic and the iliac artery, respectively. In-platelet deposition decreased by 39.9 and 41.9%. Concomitant ASA therapy not only abolished the effect of isradipine but enhanced thrombogenicity, probably as a result of almost complete blockade of vascular PGI2-production.

Metastatic papillary carcinoma of thyroid in a patient undergoing allogeneic BMT for CML

A 30-year-old woman underwent HLA-compatible bone marrow transplant for chronic myeloid leukaemia. Her post-transplant course was complicated by disseminated aspergillus and CMV infections resulting in death 65 d post transplant. At post-mortem, multiple pulmonary metastases of papillary carcinoma of the thyroid were found with a small (< 8 mm) primary carcinoma in the thyroid. It is suggested that the progression of this tumour was related to the patient's immunocompromised state.

Isradipine inhibits mitotic and proliferative activity in the arterial wall

The anti-mitotic (3H-thymidine uptake quantified using autoradiography) and anti-proliferative (counting of activated smooth muscle cells on semithin sections) effects of the dihydropyridine calcium channel blocker isradipine (0.3 mg/kg) have been assessed in a rabbit arterial stress model. Isradipine caused a significant drop in both mitotic and proliferative activity. These effects were more pronounced by pretreatment (6 hours before lesion induction with desoxycorticosterone) with isradipine as compared to posttreatment (6 hours after experimental lesioning). The benefit induced by isradipine was abolished by aspirin treatment. In-vitro vascular prostacyclin formation and cholesterol content were not affected. These findings suggest that the anti-atherosclerotic action of isradipine on mitotic activity and cellular proliferation is mediated by a cyclooxygenase product, most likely via enhanced local vascular PGI2-synthesis.

Epstein-Barr virus in Hodgkin's disease and site of origin of tumour

Epstein-Barr virus (EBV) may be involved in the pathogenesis of Hodgkin's disease. We investigated whether EBV in Hodgkin's disease is related to the site of origin of the tumour. In 40 patients with stage I disease, there was a significant association between EBV latent membrane protein (LMP-1) expression and presentation in neck lymph nodes. There was no association in stage II-IV disease (57 cases). Nodular sclerosing subtype was rarely associated with LMP-1 expression. In some cases of Hodgkin's disease of mixed cellularity or lymphocyte predominant subtype originating in the neck, EBV may be an important aetiological co-factor.

Influence of human leukocyte antigen matching on liver allograft survival and rejection: "the dualistic effect"

To date only one published large series of human leukocyte antigen matching and liver allograft survival exists, and considerable confusion has arisen about the advantage or disadvantage of human leukocyte antigen matching. In the present study we have reinvestigated the relationship between human leukocyte antigen mismatch and graft survival in 466 first liver allografts, seeking to clarify the relationship between human leukocyte antigen and both acute rejection and the vanishing bile duct syndrome. In view of current criticism regarding the accuracy of serological tissue typing for human leukocyte antigen-DR, we have used both classic serology and restriction fragment length polymorphism analysis to ensure the accurate assignment of recipient DR types. In addition, we have used polymerase chain reaction amplification and allele-specific and sequence-specific oligonucleotide probes to retest the hypothesis that human leukocyte antigen class II matching may increase susceptibility to the vanishing bile duct syndrome. One-year graft survival was significantly lower in patients with zero or two human leukocyte antigen-A mismatches (52% and 63%, respectively) than in those with one human leukocyte antigen--A mismatch (69%) (p = 0.016 and p = 0.018). A similar effect of B mismatching was observed, with a 1-yr graft survival of 73% for those with one compared with 60% for those with two human leukocyte antigen-B mismatches. In contrast no correlation was found between DR mismatch and graft survival. Human leukocyte antigen class I matching appears to influence graft survival largely through the occurrence of acute rejection and the development of the vanishing bile duct syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Demonstration of natural Leishmania infection in asymptomatic dogs in the absence of specific humoral immunity

Asymptomatic dogs from a Kala-Azar endemic region were screened for infection status by parasitological, immunological and molecular techniques. Bone marrow was examined for the presence of parasites by NNN culture and by using the Lmet 2 DNA probe. All the samples were negative in culture but 24 of 41 were positive as determined by the probe. Cellular and humoral immunity were detected by T cell proliferation assays and IFAT respectively. Specific cellular and humoral immunity were found in 20 and 26 dogs respectively out of a total of 41 dogs examined. The vast majority of dogs with Leishmania-specific antibodies were found to be parasitologically positive using the DNA probe while almost half those that had demonstrable cellular immunity were apparently parasite free. The observation that dogs can develop cellular immunity following natural infection clearly indicates that there is a spectrum of canine leishmaniasis similar to that observed in the human disease. The prevalence of dog leishmanial infection must also be higher than was presumed.

Influence of human leukocyte antigen matching on liver allograft survival and rejection: "the dualistic effect"

To date only one published large series of human leukocyte antigen matching and liver allograft survival exists, and considerable confusion has arisen about the advantage or disadvantage of human leukocyte antigen matching. In the present study we have reinvestigated the relationship between human leukocyte antigen mismatch and graft survival in 466 first liver allografts, seeking to clarify the relationship between human leukocyte antigen and both acute rejection and the vanishing bile duct syndrome. In view of current criticism regarding the accuracy of serological tissue typing for human leukocyte antigen-DR, we have used both classic serology and restriction fragment length polymorphism analysis to ensure the accurate assignment of recipient DR types. In addition, we have used polymerase chain reaction amplification and allele-specific and sequence-specific oligonucleotide probes to retest the hypothesis that human leukocyte antigen class II matching may increase susceptibility to the vanishing bile duct syndrome. One-year graft survival was significantly lower in patients with zero or two human leukocyte antigen-A mismatches (52% and 63%, respectively) than in those with one human leukocyte antigen--A mismatch (69%) (p = 0.016 and p = 0.018). A similar effect of B mismatching was observed, with a 1-yr graft survival of 73% for those with one compared with 60% for those with two human leukocyte antigen-B mismatches. In contrast no correlation was found between DR mismatch and graft survival. Human leukocyte antigen class I matching appears to influence graft survival largely through the occurrence of acute rejection and the development of the vanishing bile duct syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiographically determined arteriopathy in liver graft dysfunction and survival

We evaluated the contribution of flush and selective hepatic angiography in defining the extent and pattern of major vessel and microvascular arterial lesions and their significance in graft survival. The 50 consecutive patients investigated comprised three clinical groups: Group A (n = 18) were patients with severe graft dysfunction within the first seven days post-transplantation. In this group six of 18 angiograms demonstrated intrahepatic attenuation of the arterial tree suggestive of acute cellular rejection and four of these grafts were lost, compared to a 78% graft survival in the non-arteriopathic group. Group B (n = 16) comprised patients with clinically suspected hepatic arterial thrombosis or stenosis, these diagnoses were confirmed in all patients compared to only 10 positive findings with doppler ultrasonography. Graft survival was only 10% in those patients with artery thrombosis as compared to 100% in those with arterial anastomotic stenoses. Group C patients (n = 16) had histologically confirmed chronic allograft rejection and in ten of them (65%) evidence of arteriopathy was demonstrated despite histological evidence of arteriopathy being present in only 19% of patients. All patients in this group with arteriopathic changes lost their grafts with the exception of one successfully treated with FK506. In two other patients reversibility of chronic rejection was observed, neither of whom had evidence of an arteriopathy.

Increase in in vivo low-density lipoprotein (LDL) receptor binding after PGE1 and 13,14-dihydro-PGE1 treatment in rabbits

In a total of 48 male rabbits, the influence of PGE1 and its metabolite, 13,14-dihydro-PGE1, on the liver LDL receptor was examined in vivo. One-half of the animals were fed a 1% cholesterol-enriched diet for 4 weeks, and the other 24 animals received their normal chow. One-third of the animals in both groups received PGE1 (5 micrograms/kg i.v.), another 13,14-dihydro-PGE1 (5 micrograms/kg i.v.), and the third was a control group receiving placebo injections only. The LDL-receptor activity (total LDL uptake by the liver vs. blood activity) after injection of radiolabelled [125I]LDL and LDL disappearance from plasma were quantified. In the cholesterol-supplemented animals, the radioactive LDL uptake was significantly (p < 0.001) lower compared to the control group. Both PGE1 and 13,14-dihydro-PGE1 caused a comparable increase in LDL uptake, the extent being more pronounced in the hypercholesterolemic animals. LDL disappearance in normocholesterolemic animals was much faster than in cholesterol-fed animals. Both of the PGs caused a faster disappearance, the extent being comparable. As a mechanism of action, an induction of messenger RNA for the receptor protein by the prostaglandins is discussed. These results indicate a hypolipidemic action of PGE1 and its biologically active metabolite at the receptor level.

The distribution of free and non-ionic vesicular sodium stibogluconate in the dog

The pharmacokinetics and tissue distribution of antimony after the administration of sodium stibogluconate in a free form or entrapped in vesicles prepared from non-ionic surfactant were studied in the dog. Animals were given either one or two intravenous bolus injection(s) equivalent to 45 mg Sb kg-1 as free drug or 0.625 or 0.685 mg Sb kg-1 as vesicular drug. Blood samples were taken at various times after dosing and antimony levels in various tissues were determined at 3 h, 48 h and 6 days after dosing. After free stibogluconate antimony clearance from the blood occurred in a rapid elimination phase with a blood half-life of 0.58 +/- 0.08 h. This rapid elimination phase did not occur after vesicular drug. Both drug preparations gave similar antimony levels in the spleen, liver and femur and humerus bone marrow at all time points assessed even though the vesicular dose was one-seventieth of the free drug dose. After the free drug there was marked urinary excretion of antimony and, as a result, increased kidney loading at the expense of other tissue. Vesicle-mediated drug delivery suppressed renal excretion and a much greater proportion of the antimony dose was recovered from tissue than was obtained after free drug. A hypothesis is presented to account for the differences in tissue antimony concentrations produced by the two formulations.

Failure of simple biochemical indexes to reliably differentiate fulminant Wilson's disease from other causes of fulminant liver failure

Serum, urine and tissue biochemical findings were studied in 21 cases of fulminant Wilson's disease with respect to the value of a recently described biochemical index based on serum alkaline phosphatase and total serum bilirubin levels, and these cases were compared with 193 other cases of fulminant liver failure. Serum bilirubin, alkaline phosphatase and AST levels found in fulminant Wilson's disease were significantly different from those found in other cases of fulminant liver failure, but differentiation from other causes of fulminant liver failure on the basis of these biochemical parameters was not possible. The alkaline phosphatase/bilirubin and aspartate AST/bilirubin ratios derived from the above parameters were also significantly lower in fulminant Wilson's disease than in other categories of fulminant liver failure, but distinction between diagnostic categories on this basis was not possible. When ratios that correctly identified all cases of fulminant Wilson's disease were selected, 59/190 (31%) and 84/190 (44%) cases of non-Wilsonian fulminant liver failure would erroneously be assigned a diagnosis of fulminant Wilson's disease, by alkaline phosphatase/bilirubin and AST/bilirubin ratios, respectively. A low alkaline phosphatase-to-bilirubin ratio (< 0.57) in any category of fulminant liver failure suggested a significantly worse prognosis than in cases with higher ratios (chi 2, Yates' corrected = 5.37, p = 0.02). In the Wilson's disease group, serum and hepatic copper and ceruloplasmin concentrations were normal in 4/21, 2/15 and 2/19, respectively, whereas urinary copper level was elevated in 18/18 and was the most valuable test in diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Demonstration of Leishmania specific cell mediated and humoral immunity in asymptomatic dogs

An ELISA and a lymphocyte proliferation assay were used for the detection of anti-Leishmania antibodies and parasite specific cellular immunity respectively in a preliminary study of canine leishmaniasis in Oporto, Portugal. A high rate of infection was found considering the comparatively small group sampled. Of 34 dogs examined two had anti-leishmanial antibodies but their lymphocytes did not proliferate in the presence of Leishmania infantum. Conversely two dogs demonstrated antigen specific lymphocyte proliferation in the absence of any detectable anti-parasite antibodies. To our knowledge this is the first time that cellular immunity and presumably resistance of dogs to leishmanial infection has been demonstrated. These results suggest that there may be a spectrum of canine leishmaniasis similar to that observed in the human disease.

Donated organ as a source of cytomegalovirus in orthotopic liver transplantation

The importance of the donated organ as a source of CMV was assessed in 120 patients following orthotopic liver transplant and the CMV infections that developed in these patients were graded by severity. Forty-four recipients were CMV antibody negative pre-transplant. Eighteen of these received organs from CMV antibody positive donors and 15 (83%) developed primary CMV infections, 13 (87%) of which were symptomatic. Twenty-six received organs from CMV antibody negative donors and only 2 (8%) became CMV positive post transplant (P less than 0.001). These data suggest that there would be a considerable advantage in matching CMV antibody negative recipients with negative donors. Forty-five percent of secondary infections were asymptomatic compared with 12% of primary infections, and only 11% became disseminated compared with 53% of primary infections. The secondary infections that followed transplantation of an organ from a CMV antibody positive donor were more likely to be symptomatic and were more severe than those in patients who received seronegative livers.

The diminished extracellular matrix production induced by isradipine, a calcium channel blocker, is completely abolished by cyclooxygenase inhibition

Collagen and glycosaminoglycan synthesis are well known to be enhanced during early atherogenesis. In this experimental study the synthesis of collagen was determined using 14C proline incorporation, the glycosaminoglycan production by means of 35S-sulphate incorporation and subsequent quantification by means of autoradiography. Isradipine, a new calcium channel blocker of the dihydropyridine family at a dose of 0.3 mg/kg significantly (p less than 0.01) decreased the incorporation of both the radioactive precursors. This effect was abolished by a concomitant aspirin treatment, while aspirin alone did not exert any significant effect on the precursor incorporation. These data suggest that isradipine, which is known to stimulate PGI2 synthesis, may exert this antiatherosclerotic inhibitory action on extracellular matrix production via the endogenous liberation of PGI2.

Liver function in acute viral hepatitis as determined by a hepatocyte-specific ligand: 99mTc-galactosyl-neoglycoalbumin

Twelve patients with recently diagnosed acute viral hepatitis underwent serial 99mTc-galactosyl neoglycoalbumin scanning of the liver (for up to 8 mo). Injection of 99mTc-galactosyl neoglycoalbumin (150 mBq) at a rate of 3.5 mg (50 nmol; 1 ml) revealed that the liver is the exclusive site of tracer uptake. Simulation of 99mTc-galactosyl neoglycoalbumin kinetics allowed quantification of galactosyl neoglycoalbumin binding to human hepatic binding protein. Return of liver function test scores to normal values was associated in two patients with hepatitis A, in four patients with hepatitis B and in two patients with non-A, non-B hepatitis virus infection, with increases in hepatic binding protein concentration (up to three times the initial concentration), binding rate constant and hepatic blood flow. In the other four patients (three patients with hepatitis B and one patient with cytomegalovirus infection) a prolonged course of disease was monitored. In the mean, hepatic binding protein increased from 0.41 +/- 0.11 mumol/L after onset of acute hepatitis (n = 12) to 0.78 +/- 0.21 mumol/L after 6 mo of follow-up (n = 10) (p less than 0.001). During this period, binding rate constant (72.4 +/- 12.6 vs. 82 +/- 11.5 mumol/L/sec; p less than 0.05) and hepatic blood flow (0.027 +/- 0.0051 vs. 0.031 +/- 0.0083 L/sec; p less than 0.05) increased. Hepatic binding protein concentration correlated highly with actual laboratory test results for liver function (r = 0.98; p = 0.0001). We conclude that scintigraphic evaluation of functional liver cell mass using the new receptor-tracer 99mTc-galactosyl neoglycoalbumin could provide an in vivo diagnostic means of quantifying liver function and assessing liver morphology. In addition, our findings suggest that changes in hepatic binding protein-receptor concentration are likely to occur in vivo.

Prostaglandin I2 and the nitric oxide donor molsidomine have synergistic effects on thromboresistance in man

1. In vitro synergistic effects of nitric oxide and prostaglandin I2 (PGI2) have been shown. Consequently we examined any potentiating effect of the nitric oxide donor molsidomine on the reduction in thrombogenicity produced by PGI2 in patients with peripheral vascular disease. 2. Thirty-six patients all with peripheral and also coronary artery disease were randomly allocated to receive PGI2 5 ng kg-1 min-1 for 6 h daily, 5 days a week for 5 weeks, alone (12 patients), with molsidomine 12 mg daily (12 patients) or molsidomine 12 mg daily alone (12 patients). 3. The effect of each treatment regimen was measured in terms of femoral artery platelet uptake and platelet survival after autologous 111Indium-oxine labelling. Molsidomine alone had no effect on platelet uptake or survival but in combination with PGI2 it significantly potentiated the decreased platelet uptake and prolonged platelet survival observed with PGI2 alone.

Modification of platelet function by isosorbide dinitrate in patients with coronary artery disease

The effect of a four weeks oral treatment with 100 mg isosorbide dinitrate (ISDN) daily on platelet function was evaluated in 40 patients (aged 40-65 years) with proven coronary artery disease. Isosorbide dinitrate decreased platelet reactivity to ADP (p less than 0.001), increased platelet sensitivity to PGI2 (p less than 0.01) while the production of TXB2 from exogenous arachidonic acid substrate and from endogenous substrate were both significantly reduced. Circulating platelet aggregates as measured by the Wu-test were markedly reduced (p less than 0.001) but there was little change in the plasma concentration of the platelet proteins beta-thromboglobulin and platelet factor 4. Overall, platelet activation correlated with smoking, hypertension and a family history of coronary artery disease. The reduced platelet activation seen during treatment with isosorbide dinitrate may contribute to the therapeutic benefit seen with this drug in patients with coronary artery disease.

In vivo quantification of cholesterol content in human carotid arteries by quantitative gamma-camera imaging after injection of autologous low density lipoproteins (LDL)

Low density lipoproteins (LDL) were isolated by immunoaffinity chromatography from 18 patients (31-70 years) suffering from primary hypercholesterolemia with angiographically proven atherosclerosis of either one or both carotid arteries. LDL were labeled with 123I (1 mCi/mg LDL) by the iodine monochloride method followed by purification with dialysis and immediately reinjected thereafter. Gamma-camera serial controls over carotid regions allowed visual detection of uptake of the radiocompound uptake in 12 out of the 18 patients. The lipid entry ratio (LER; counts over the vascular region/pixel as compared to the contralateral side after background subtraction) confirmed the visual findings. Whole body images performed until 20 h after reinjection showed 3 different kinetic types of LDL-influx into the vessel wall: decreasing (type I), increasing and then decreasing (type II) and continuously increasing (type III) with time. Four patients underwent endarterectomy within 2-7 weeks after gamma-camera imaging. Histological control revealed an extensive amount of "foam cells" in tissue samples derived during surgery and an absence of endothelial lining in samples belonging to patients with type II kinetics.

Isradipine improves platelet function in hypertensives

The effect of treatment for eight weeks with isradipine 1.25 mg twice daily for 4 weeks and thereafter 2.5 mg twice daily for 4 weeks on ex vivo platelet function was investigated in 10 male hypertensive patients, aged 51 (6.1) y. Systolic and diastolic blood pressure, platelet aggregation in response to ADP, serum thromboxane B2 and beta-thromboglobulin levels were significantly decreased at rest before exercise ergometry, during exercise and at rest after exercise. The platelet count, platelet sensitivity and the plasma levels of 6-oxo-prostaglandin F1 alpha were not affected by isradipine. It is concluded that a compound that lowers blood pressure and inhibits platelet activation may be of clinical benefit in the routine treatment of hypertension.

Management of acute and fulminant hepatitis A

Symptomatic viral hepatitis A usually only requires supportive therapy and the majority of cases are managed in the community. The prodromal symptoms of nausea, anorexia and lethargy tend to improve with the onset of clinical jaundice. Fulminant hepatic failure is said to be an uncommon complication, occurring in only 0.14-0.35% of hospitalized cases. However, an increasing incidence has been documented in some northern European countries where up to 20% of cases of fulminant viral hepatitis is due to hepatitis A. This trend parallels the increasingly delayed exposure to hepatitis A and the increased severity of the illness when contracted in later life. The risk of developing fulminant hepatic failure is best monitored using coagulation factor assays, with the prothrombin time and factor V levels being the most favoured. The diagnosis is established with the onset of encephalopathy. Patients progressing to grade 4 encephalopathy have a reasonably good prognosis compared to other aetiologies and survival rates of up to 67% have been obtained with medical management, despite the co-existence of such complications as cerebral oedema, renal and respiratory failure and the metabolic sequelae of acute liver failure. Nevertheless, some patients require emergency liver transplantation and 10 such patients have been reported to date. Transplantation is especially required in older patients (> 40 years) and those who are jaundiced for > 7 days before the onset of encephalopathy. The serum bilirubin and the prothrombin time complement these parameters in the decision making process.

The provision of secure psychiatric services in Leeds; Paper ii. A survey of unmet need

This paper reports the results of a survey of statutory and voluntary staff who are likely to have contact with people requiring treatment in the secure psychiatric facilities provided in Leeds. The survey seeks to assess whether there is under-provision of Secure Unit beds, and if the three-tier local secure service is adequately addressing the needs of patients in the Special hospitals, prisons and the community. Researchers monitored all demands for psychiatric reports to prison over a six-month period, to identify any unmet need for secure psychiatric facilities. The findings show that patients with a learning disability were unable to transfer from a Special Hospital to a lower level of security. There is also a significant unmet need for medium to long-stay Secure Unit beds, and that many patients in the community have significant unmet needs for access to psychiatric services, including structured, intensively staffed community accommodation.

The provision of secure psychiatric services in Leeds; Paper i. A point prevalence study

The results of a point prevalence study were used to assess the relative contributions of a local Special Care Unit, Regional Secure Unit and Special Hospitals to the provision of secure psychiatric services in Leeds. Over a six-month period, a comparison was undertaken of all patients admitted to the three tiers of security; particular emphasis was given to mentally abnormal offenders. Most admissions to the Special Care Unit were transferred from the general psychiatric wards; admissions to the Regional Secure Unit were mainly from the Court and prisons. On the census day, 7.1 patients per 100,000 population from the catchment area were in one of the three tiers of security, with the Special Hospitals providing the main long-stay service component. The findings show that the three tiers perform distinct, but complementary, functions, and emphasise a need for medium to long-stay secure facilities.

Autologous low-density lipoprotein labelling allows characterization of human atherosclerotic lesions in vivo as to presence of foam cells and endothelial coverage

The monitoring of local vascular kinetics after injection of autologous radiolabelled low-density lipoprotein (LDL) allows characterization of human atherosclerotic lesions as to the presence of foam cells and the quality of endothelial coverage. The following evidence exists: (1) dynamic imaging reveals two types of visual LDL accumulation in the vascular bed, one increasing, becoming visible sometimes only as late as after 24 h, and the other one appearing very early on, but decreasing with time; (2) the accumulation of iodine-123 LDL or iodine-131 LDL in the vascular bed shows three major types of local kinetic curves, which correlate with scintigraphic findings; (3) the accumulation of radiolabelled LDL in the vascular bed of humans in vivo is similar to its uptake in de- and re-endothelialized vessels of experimental animals using 125I-LDL; (4) morphological control in endarteriectomy samples confirms the hypothesis that this promising new approach may for the first time allow the in vivo monitoring of preclinical lesions in humans.

Low density lipoprotein labelling characterizes experimentally induced atherosclerotic lesions in rabbits in vivo as to presence of foam cells and endothelial coverage

The entry of autologous iodine-125 low density lipoprotein (125I-LDL) into the aortic wall in rabbits was measured. After abdominal endothelium abrasion with a Fogarthy catheter the animals were fed a 1% cholesterol-supplemented diet for 4 weeks. The animals were killed 1-48 h after administration of 25 muCi 125I-LDL. Local entry of radiolabelled LDL was estimated and correlated to endothelial surface lining and foam cell content, both controlled morphologically. Endothelialized segments showed the lowest entry of 125I-LDL, the maximum uptake was reached at around 8 h. In de-endothelialized segments the entry was higher and the peak later (12 h), while in re-endothelialized segments a continuous increase in 125I-LDL entry up to 48 h was measured. Number and extent of foam cells correlated with the entry of LDL. The data indicate the usefulness of LDL radiolabelling for qualitative in vivo information on surface lining and foam cell content.

Transplantation in primary biliary cirrhosis

Improved immunosuppressive regimens, better postoperative intensive care and judicious patient selection have all resulted in increased patient survival following orthotopic liver transplantation (OLT), which has become the preferred option for most patients with end-stage primary biliary cirrhosis (PBC). As with most other clinical series, PBC is now the most common indication for OLT in the King's College hospital and Cambridge programmes. To date (30 July 1990), 129 patients with PBC have been transplanted, with overall actual 1 and 5 year survival rates of 65 and 63% respectively. When patients transplanted since 1985 are considered, both the 1 and 2 year survival rates are 78%. Immediate operative mortality was 4.5%, generally due to uncontrollable bleeding, while further mortality within 30 days of operation--mainly consequent upon infection and multi-organ failure--has fallen from 40% prior to 1985 to 9% since 1988. Thirteen per cent of patients have been retransplanted for vanishing bile duct syndrome, manifest in this series invariably within the first 6 months following OLT. Although rehabilitation in this series was excellent, a significant percentage of cases have continuing problems with metabolic bone disease, hypertension and renal impairment, mainly due to cyclosporin toxicity.

Intravenous prostacyclin (PGI2) infusion to 108 patients with ischaemic peripheral vascular disease: phase II-open study

We recently reported the results of a double-blind trial of PGI2 in 108 patients with ischaemic peripheral vascular disease Stage II according to Fontaine. They were randomly allocated to receive an intravenous infusion of either PGI2 (6 ng/kg/min over 8 hours daily for 5 consecutive days) or placebo and classified as treatment responders or non-responders on the basis of changes in absolute and relative walking times. Patients treated with placebo and those who did not improve in this double blind trial entered an open trial in which they all received infusion of PGI2 (6 ng/kg/min over 8 hours daily for 5 consecutive days). The results of this open trial are reported here. Patients who had been allocated to PGI2 in the blind trial had significantly (p less than 0.01) longer walking times as compared to placebo-treated patients prior to receiving the second (PGI2) infusion. PGI2-infusion caused significant (p less than 0.01) prolongation of walking times in both groups up to the 2nd follow-up month. One month after infusion 52% (23 patients) of the initially placebo-treated patients and 31% (14 patients) of the initially PGI2-treated patients were scored as positive treatment responders (p less than 0.01).

Stenoses of vascular anastomoses after hepatic transplantation: treatment with balloon angioplasty

Vascular complications after liver transplantation include occlusion or stenosis at the sites of anastomosis in the hepatic artery, portal vein, and vena cava. From our experience with more than 600 liver transplants, vascular stenoses have been identified in 10 patients and treated by balloon angioplasty in nine. Three patients with hepatic artery stenosis and deteriorating graft function were treated by balloon angioplasty with a coaxial technique. A specially designed catheter facilitated a successful femoral artery approach. Portal vein stenoses in three patients resulted in portal hypertension. These were treated by balloon dilatation via transhepatic catheterization of the portal vein. Stenoses of the suprahepatic caval anastomosis were dilated in three patients with severe lower limb edema. Technical success was achieved in all three cases of hepatic artery stenosis with improvement in graft function. Recurrent stenoses in two patients were successfully treated with repeated dilatations. Portal hypertension resolved in two of three patients after portal venoplasty. Dilatation of a caval stenosis resulted in the resolution of leg edema in all three cases. Repeated dilatation was required in one case. No reduction in the portal venous pressure gradient occurred after venoplasty in one case, and an ultimately fatal caval thrombosis developed in one patient with caval stenosis before venoplasty could be performed. Our experience suggests that balloon angioplasty of arterial and venous stenoses complicating hepatic transplantation carries little risk and is a useful procedure for the treatment of these problems.

Epidemiology, bacteriology and control of an outbreak of Nocardia asteroides infection on a liver unit

An outbreak of Nocardia asteroides infection affecting seven patients is described. Over a 5-week period, five patients with liver disease admitted to a ward developed clinical and laboratory evidence of nocardiosis, and two further cases were diagnosed 3 and 5 months later. Three out of the five patients who received specific antimicrobial therapy responded to treatment; in three patients nocardia infection was considered to have contributed to death. In six out of the seven patients, nocardiosis followed immunosuppression. A common-source outbreak was considered to be responsible for infection in the first five patients. In two patients, presentation of infection 5 and 7 months after the first case may have been due to prolonged colonization or subclinical infection with Nocardia. Biotyping of the seven isolates using a fluorogenic biochemical method identified three distinct strains of N. asteroides. The most probable source of Nocardia was contaminated brick and plaster dust arising from building work in an area adjacent to the ward. However, samples of air, dust and water failed to yield N. asteroides. Infection control measures included ward closure followed by thorough cleaning, and formaldehyde fumigation.

Immunohistological analysis of the immunoreactivity of normal lymphoid cells and lymphomas with the monoclonal antibody OPD4

OPD4 is a recently described monoclonal antibody that recognizes a fixation-resistant 200 kD antigen restricted to a subset of T cells. Immunolabelling with OPD4 in paraffin sections of normal lymphoid tissues and cases of malignant lymphoma was compared with that of other antibodies in common use, including the T-cell restricted antibodies MT1 and UCHL1 and the B-cell restricted antibodies MB1, F8-11-13, and L26. OPD4 showed similar immunoreactivity to UCHL1 in normal tissues. OPD4 did not stain Reed-Sternberg cells in Hodgkin's disease. In non-Hodgkin's lymphomas, OPD4, like UCHL1, reacted with only 2/22 B-cell lymphomas. OPD4 was, however, less useful as a marker of T-cell lymphomas, staining only 11/32 cases, while UCHL1 stained 22/32 cases. We conclude that OPD4 is not a useful antibody for the routine diagnosis of T-cell lymphoma.

Intracranial and cerebral perfusion pressure changes before, during and immediately after orthotopic liver transplantation for fulminant hepatic failure

Several centres that perform liver transplantation for fulminant hepatic failure have experience of patients who have not regained consciousness despite adequate graft function. In some of these, decerebration because of elevation in intracranial pressure was thought to have occurred intraoperatively or in the early post-operative period. In the present study six patients with fulminant hepatic failure who were transplanted had extradural monitors inserted before operation. Intracranial pressure had been controlled prior to transplantation and rose during the pre-clamp phase of the operation. Levels fell during the anhepatic phase but rose again during the reperfusion phase (p = 0.033). Overall, from the induction of anaesthesia to the reperfusion phase there was a significant increase in mean intracranial pressure (p less than 0.01). The cerebral perfusion pressure fell after induction of anaesthesia from a median 54 mmHg (range 46-62) to a median 35 mmHg (range 19-49, p less than 0.001) in the pre-clamp phase and remained low throughout the operation. During the first 10 hours after transplantation, three patients had further episodes of intracranial hypertension requiring treatment and it is important that monitoring should be continued through this period.

p53 expression in colorectal tumors

The expression of the nuclear phosphoprotein p53 was studied immunohistochemically in a series of 150 benign and malignant colorectal tumors. Using monoclonal antibody PAb1801, tumors divided unequivocally into two groups on the basis of immunohistochemistry. Forty of the carcinomas (46.5%) showed positive staining but only 4 of the adenomas (8.7%) were positive (P less than 0.001). The few positive adenomas always showed moderate or severe dysplasia. Metaplastic polyps (n = 9) and small familial adenomatous polyposis-related adenomas (n = 9) were uniformly negative. Carcinomas with p53 expression did not differ from those without in terms of site, differentiation or the prognostic indicators of Dukes' stage, DNA ploidy, or tumor histology. The improved morphologic resolution available in periodate lysine paraformaldehyde dichromate (PLPD)-fixed, paraffin-embedded tissue permitted several conclusions to be made: p53 is confined to neoplastic nuclei; staining in positive tumors is heterogeneous and often more marked at the infiltrative margins; and staining intensity is dramatically reduced in mitotic cells. It is concluded that expression of immunohistochemically detectable p53 (probably representing mutated forms of the protein) occurs in some adenomas around the time of transition to carcinoma. Therefore there is an association with the appearance of infiltrative behavior but not with degree of tumor progression (including metastasis) at the time of resection.

Platelet lipoxygenase defect (Wien-Penzing defect) in two patients with myocardial infarction

In 2 male patients (35 and 38 years) presenting with myocardial infarction an abnormal conversion of exogenous 14C-arachidonic acid by the patients' platelets, incubated in vitro, was observed. Neither patient's platelets showed evidence of a lipoxygenase pathway. Platelet thromboxane formation from exogenous and endogenous substrate was high, while the platelet aggregation responses were normal. A myeloproliferative syndrome was excluded by bone marrow puncture. Similar defects have only been described so far in patients with myeloproliferative syndrome. This defect may be causative for the onset of clinical thrombotic events. It is speculative whether in vivo therapy with r-IFN alpha 1c might be able to eradicate the pathological platelet clone.

A serological investigation of human herpesvirus 6 infections in liver transplant recipients and the detection of cross-reacting antibodies to cytomegalovirus

Sera from 50 orthotopic liver transplant recipients were examined for antibodies to human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV), and the findings correlated with the clinical condition of the patients. Both primary and secondary HHV-6 infections were detected serologically following liver transplantation. Interpretation of serological assays is complicated by CMV and HHV-6 antibody cross reactions which were common. Sera from 5 patients became HHV-6 antibody negative following absorption with CMV infected cells. Thirty patients were initially seronegative for HHV-6 antibodies, 12 remained so following transplantation, 5 developed cross reacting antibodies, and 13 seroconverted. The seroconversions occurred at 4 to 8 weeks post-transplant in the same time period as CMV antibody rises. HHV-6 IgM was detected in only 4 of the 13. Of the 7 patients who had serological evidence of active HHV-6 infections but no evidence of CMV infection, 4 (56%) had fever, 1 (14%) hepatitis, 1 (14%) lung dysfunction, and 3 (42%) neurological disorders. In the 12 patients who remained HHV-6 antibody negative, there were fewer fevers and neurological disorders.

Demonstration of clonality in T-cell lymphoma using an anti-T-cell receptor variable region antibody panel

Frozen sections from 35 T-cell lymphomas were stained with the Diversi-T alpha beta T-Cell Receptor panel which includes seven antibodies to T-cell receptor variable region gene products. In five cases a monoclonal population of T-cells could be demonstrated (one case V beta 5+, three cases V beta 8+ and one case V beta 6+) and in a further case a biclonal population (V beta 5+ and V beta 8+). We conclude that this antibody panel is of limited usefulness for the demonstration of clonality in T-cell lymphoma.

Impaired conversion of exogenous arachidonic acid by platelets to thromboxane B2 and correction of that deficiency by interferon-alpha

In the course of an investigation of cyclooxygenase and 12-lipoxygenase activity in platelets of patients with myeloproliferative syndrome receiving treatment with interferon-alpha 2 patients showed unusual results which have not been reported so far. Both patients had thrombocytosis, in one case associated with polycythaemia. In platelets of both patients, a reduced conversion of exogenous 14C arachidonic acid to TXB2 was observed accompanied by a shift in conversion to PGE2 and 12-HETE in one patient and to 12-HETE alone in the other before therapy. These findings were paradoxically associated with evidence of enhanced platelet activation in vivo. Treatment of both patients with interferon-alpha resulted in reversal of the biochemical abnormalities and in clinical remission.