A sequence-specific DNA-binding protein interacts with the xlnC upstream region of Streptomyces sp. strain EC3

The alignment of the promoter region of several Streptomyces xylanases shows three conserved sequences which could be involved in gene regulation. By electromobility shift assays these specific sequences, present only in Streptomyces xylanolytic strains, were identified as protein-binding sites. The sequence required for efficient recognition by the retarding protein appeared to be a 4-bp inverted repeat: 5'-CTTT-Nx-AAAG-3'. The DNA-protein affinity was influenced by the culture conditions.

The metabolic organization of the adult human liver: a comparative study of normal, fibrotic, and cirrhotic liver tissue

Little is known about the alterations of metabolic organization of the human liver tissue in chronic liver diseases. We therefore compared the distribution of the following zonal metabolic markers in 10 samples of normal liver tissue, 10 samples of fibrotic tissue, and 22 samples of cirrhotic tissue: (a) the enzymatic activities of glucose-6-phosphatase (G6P), lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), nicotinamide-adenine-dinucleotide-phosphate [NAPH] dehydrogenase (ND), beta-hydroxybutyrate dehydrogenase (HBDH), and glutamate dehydrogenase (GDH); (b) the protein glutamine synthetase (GLS); and (c) albumin messenger RNA (mRNA). The normal human hepatic lobule was characterized by the periportal predominance of G6P and SDH enzymatic activities and albumin mRNAs, the perivenous predominance of ND and GDH, the restriction of GLS to a small perivenous compartment, and the predominanc of beta-HBDH at the contact of both portal tracts and centrilobular veins. In fibrosis, the overall metabolic organization of the normal liver tissue was retained. The expression of periportal markers predominated around enlarged portal tracts and that of perivenous markers around residual centrilobular veins. GLS was constantly detected at the contact of centrilobular veins. In cirrhotic nodules, no zonation was observed for most enzymatic activities or for albumin. Only G6P usually predominated at the periphery of the nodules. GLS was constantly undetectable. No difference accordingly to the etiology of the underlying disease was observed. In conclusion, the normal human hepatic lobule presents a marked metabolic zonation, preserved in fibrotic lesions, but lost in cirrhotic nodules. The alterations of the metabolic organization observed in cirrhosis might contribute to the pathogenesis of some of the metabolic disorders associated with advanced liver disease.

Coexpression of periportal and perivenous enzymes in rat hepatocytes after experimental bile duct ligation: comparison with intrasplenically transplanted hepatocytes

The coexpression of normally periportal and perivenous markers has been described in heterotopically transplanted hepatocytes. To determine whether such a coexpression might also occur in hepatocytes retaining their original intrahepatic location, we compared in bile-duct-ligated livers and intrasplenically transplanted hepatocytes, the expression and distribution of the predominantly periportal glucose-phosphatase, succinate dehydrogenase, and lactate dehydrogenase, the predominantly perivenous glutamate dehydrogenase, NADPH-dehydrogenase, and beta-hydroxybutyrate dehydrogenase, and the strictly perivenous glutamine synthetase. The coexpression of high levels of the two periportal markers glucose-6-phosphatase and lactate dehydrogenase and of the perivenous marker NADPH dehydrogenase was observed in two situations: in clusters of hepatocytes isolated within the ductular proliferation in bile-duct-ligated livers and the majority of intrasplenically transplanted hepatocytes. The expression of glutamine synthetase was different according to the site. The protein was observed in certain intrasplenically transplanted hepatocytes bordering the splenic vessels but was never detected in hepatocyte clusters found in bile-duct-ligated livers. Our study therefore suggests that the coexpression of periportal and perivenous markers in the same hepatocytes is likely to be a non-specific consequence of the loss of the normal connections of hepatocytes with the normal liver microcirculation.

Eczematous-like drug eruption induced by synergistins

The authors report 4 cases of eczematous-like drug eruption after oral ingestion of synergistins, pristinamycin (3 cases) and virginiamycin (1 case). The lesions occurred after contact sensitization with topical virginiamycin. The clinical symptoms appeared a few hours after ingestion: a generalized maculopapular eruption, sometimes with general symptoms of anaphylactic reaction. Eczema appeared again on initial areas of contact dermatitis. There is a common allergenic group between these 2 antibiotics, which is a macrocyclic lactone. Physiopathology of this drug eruption is not clear: allergic reaction of the delayed type or anaphylactic reaction. Patients allergic to virginiamycin should be strongly cautioned against oral pristinamycin.

Effect of diethylmaleate on bile secretion and ultrastructural appearance of hepatocytes in normal rats and mutant rats with defective organic anion secretion

Diethylmaleate is an organic anion secreted into bile as a glutathione conjugate. Its transport by the hepatocyte is associated with dilatation of the Golgi apparatus and the appearance of small vesicles in the pericanalicular area. It has been speculated that the Golgi apparatus could play a role in the intracellular transport and/or the biliary canalicular secretion of diethylmaleate. The purpose of this work was to determine whether the alterations in the Golgi apparatus and the pericanalicular vesicles could mediate the canalicular secretion of diethylmaleate. Diethylmaleate biliary secretion and diethylmaleate-induced bile flow were measured in Sprague-Dawley rats, and in TR- rats which have an inherited defect in the excretion into bile of organic anions, including glutathione conjugates. Livers of both Sprague-Dawley and TR-rats were examined by electron microscopy, to characterize the changes in intracellular organelles. In Sprague-Dawley rats, as previously described, diethylmaleate administration was associated with an increase in bile flow, which was parallel in time to the secretion into bile of diethylmaleate conjugates. Electron microscopic examination of the liver after diethylmaleate administration showed dilatation of the Golgi saccules. In contrast, in TR- rats, the increase in bile flow and the secretion of diethylmaleate conjugated were nearly absent. Nevertheless, electron microscopic examination showed a dilatation of the Golgi saccules similar to that observed in Sprague-Dawley rats. TR- rats, in addition to the changes in the Golgi apparatus, had marked dilatation of the endoplasmic reticulum. These results show that biliary secretion of diethylmaleate conjugates was severely impaired in TR- rats, in spite of a dilatation of the Golgi apparatus and of the endoplasmic reticulum. We conclude that it is unlikely that the alterations in the Golgi apparatus (and the endoplasmic reticulum) induced by diethylmaleate play a role in the canalicular secretion of diethylmaleate. We do not exclude the possibility that these organelles could play a role in intracellular transport of this compound. Alternatively, these alterations could be due to a "toxic" effect of diethylmaleate accumulation in hepatocytes.

Hodgkin's disease after transplantation

Hodgkin's disease (HD) has seldom been reported after transplantation. Epstein-Barr virus (EBV) is present in about 50% of Reed-Sternberg cells in HD developing in immunocompetent individuals, but is more frequently found in HD of acquired immune deficiency syndrome patients. We report 7 cases of HD that occurred in transplant recipients. Clinical and pathological data and studies of EBV reveal specific features of HD after transplantation. Six patients received kidney transplants and 1 patient received combined kidney and pancreas transplantation. Immunosuppressive therapy consisted of cyclosporine, steroids, azathioprine, and antilymphocyte globulins. One patient received, in addition, anti-CD3 mAb therapy and an EBV+ B cell lymphoma developed. Retrospective EBV serological data from patients were collected. Tumors were classified according to pathology. EBV studies were conducted by immunohistochemical methods with monoclonal antibodies to EBV-latent membrane protein (LMP) or EBV-nuclear antigen 2 (EBNA2), and by in situ hybridization for latent nuclear EBV-early RNAs (EBERs). The mean lapse of time between transplantation and HD was 49 months. Six patients presented with enlarged lymph nodes and 1 patient presented with liver involvement. HD was classified as IA in 2 patients, IIA in 3 patients, IIIB in 1 patient, and IVB in 1 patient. Four patients had primary EBV infection after graft, before HD, and the others reactivated latent EBV infection. Histological subtypes were mixed cellularity in 6 cases and lymphocytic depletion in 1 case. Latent EBV infection was detected with EBERs in all tumors. Reed-Sternberg cells expressed LMP, and were negative for EBNA2 expression. Six patients were treated: 2 patients at stage I received radiotherapy, and relapsed within 1 year with a more advanced stage of HD; chemotherapy was indicated as primary therapy in 5 patients, and as salvage therapy in 2 patients; it was associated with radiotherapy in 4 patients. Immunosuppressive therapy was reduced in all patients. Four patients were alive and in complete remission 18, 25, 31, and 67 months after chemotherapy, with a functioning graft in 3 patients. Two patients died of infection. Mixed cellularity is the most frequent histological subtype observed in HD occurring in transplant patients. EBV is present in all Reed-Sternberg cells. Posttransplant HD shows similarities with human immunodeficiency virus-associated HD. These facts argue for a role of EBV infection and immunosuppression in the progression of HD after transplantation.

Cloning and nucleotide sequence of a xylanase-encoding gene from Streptomyces sp. strain EC3

Using the p1J702 vector, a xylanase-encoding gene (xin) of Streptomyces sp. EC3 has been cloned by functional complementation of a mutant of Streptomyces lividans TK24, producing xylanase at a very low level. Normal level of xylanase synthesis was restored in at least three clones, containing the same 3802 bp Sstl DNA fragment. In this fragment, several open reading frames (ORFs) have been identified, one of which coded for a xylanase; the products of the other ORFs did not show homology with any of the already known proteins. The complete nucleotide sequence of the 3802 bp Ssti insert has been determined on both strands. Xylanase is very probably synthesized as a 240 amino acid (aa) precursor (25949 Da) including a long (49 aa) signal sequence presenting significant similarity with the signal sequences of other Streptomyces xylanase genes. The xylanase aa sequence showed a clear homology with the aa sequences of other xylanases of the glycanase G family. The xln gene has been introduced into Streptomyces parvulus, a naturally xylanase-negative species. In contrast with its expression in Streptomyces sp. EC3, in S. parvulus, xln was expressed constitutively, a probable consequence of the absence of a regulatory system.

Delayed hypersensitivity at the injection sites of a low-molecular-weight heparin

We report a case of delayed hypersensitivity to a low-molecular-weight heparin. The patient presented with eczema at the site of subcutaneous injections and allergy tests confirmed the clinical diagnosis. There were positive tests with 3 low-molecular-weight heparins and unfractionated subcutaneous calcium heparin but negative with intravenous sodium heparin. Although delayed hypersensitivity to low-molecular-weight heparins is rare, the possibility of cross-allergy to unfractionated heparin could be a therapeutic problem for some patients.

Late acute failure of well-HLA-matched renal allografts with capillary congestion and arteriolar thrombi

Seventeen cases of a histologically and clinically unusual renal acute dysfunction in kidney recipients, individualized among a population of 1378, are reported. The basic histological lesion was a huge capillary congestion, associated with capillary and arteriolar thromboses or parenchymal necrosis in most patients, and contrasting with the absence of the classical features of acute cellular rejection, i.e., tubulitis, glomerulitis, edema, and infiltrate. The corresponding clinical history was characterized by its early timing in the course of transplantation (< 3 months), its sudden occurrence in patients usually having good transplant function, leading to end-stage renal failure in a few days, and its resolution under rejection treatment. The occurrence of this syndrome was significantly linked with a good HLA matching: 13 of the 17 recipients were HLA-DR matched (P < 0.0001). The etiology of this syndrome remains unknown. There was no evidence for graft vessel thrombosis. Because of some histological similarities, the usual causes of the hemolytic uremic syndrome, including bacterial and viral infections or cyclosporine arteriolopathy, were discussed. Acute vascular rejection was suspected, but the cross-match was negative on T lymphocytes in all cases and anti-HLA class I and II antibodies were not found to develop at the time of transplant dysfunction, except in 1 patient, in whom the detected anti-DR antibodies were not directed at the kidney donor. Anti-human umbilical vein endothelial cell antibodies, detected in an antibody-dependent cellular cytotoxicity assay, were present in 6 patients (of the 14 tested) at the onset of renal failure, but they were either absent (n = 3) or already present at the time of transplantation (n = 5) in the other 8 patients. Therefore, reliable arguments are lacking to conclude that this acute transplant dysfunction is an acute vascular rejection and its strong association with HLA matching has, as yet, no satisfactory explanation.

[Identification of spermatozoa L-selectin and two potential pellucida ligands]

At the molecular level, gamete interactions partly depend on zona pellucida-glycoproteins fucosylation. We show, by immunocytochemistry, the sialyl-lewisx and sialyl-lewisa oligosaccharides on human zonae pellucidae. These epitopes are potential ligands of cell adhesion molecules named selectins which are known to play a role in endothelium-leukocyte interactions. By immunofluorescence, we find the leukocyte selectin (L-selectin) on the spermatozoa head. Preincubation of spermatozoa with an anti-L-selectin monoclonal antibody produces a significant inhibition of zona pellucida tight binding, under hemizona assay conditions. In contrast, preincubation of the zonae pellucidae with anti-sialyl-lewisx or anti-sialyl-lewisa antibodies does not produce a significant inhibition of spermatozoa binding. Western blot analysis of spermatozoa-detergent extracts revealed a band at approximatively 90 kDa with the anti-L-selectin monoclonal antibody. This spermatozoa selectin could play a role in human spermatozoa-zona pellucida binding. Zona-ligands have yet to be precisely defined.

High dose radiochemotherapy followed by autologous stem cell transplantation in four patients with multiple lymphomatous polyposis

BACKGROUND

Multiple lymphomatous polyposis (MLP) results from gastrointestinal involvement by a B-cell lymphoma that originates from the mantle zone of lymphoid follicles. This well described clinicopathologic entity has a poor prognosis: the rate of complete response after conventional chemotherapy is very low. High dose radiochemotherapy with autologous stem cell transplantation (ASCT), which is one of the most intensive treatments of lymphoma, to the authors' knowledge has not been evaluated in the treatment of MLP.

METHODS

Four consecutive patients with MLP were treated with high dose radiochemotherapy and ASCT while they were in partial response after conventional chemotherapy.

RESULTS

Three patients achieved a complete clinical and histologic response and one achieved a complete clinical resolution of symptoms, but with persistent histologic lesions. Progression free survival ranged from 11 to 35 months.

CONCLUSIONS

Autologous stem cell transplantation for patients with MLP is feasible and may be more effective than conventional chemotherapy. However, further studies are needed to assess the actual place of this type of treatment in the management of MLP.

Selective lysis of autologous tumor cells by recurrent gamma delta tumor-infiltrating lymphocytes from renal carcinoma

We show here that tumor infiltrating lymphocytes (TIL) derived from three renal carcinoma (RC) tumors, which developed in the same patient over a 3-yr period, were systematically enriched in gamma delta + T cells (27-74%) after short term in vitro culture. Analysis of the repertoire of gamma delta + TIL and PBL from this patient, revealed the predominant expression of structurally diverse V delta 1 gamma delta TCR by TIL from the three tumors, contrasting with the classically dominant use of V delta 2 TCR by PBL. Functional analysis further showed that, independently of the V gamma genes expressed, all the V delta 1+ TIL clones exhibited a lytic activity apparently restricted to RC lines, while V gamma 9+V delta 2+ clones (either PBL- or TIL-derived) had a broad killing activity. Surprisingly most V delta 1+ CTL clones lysed several allogeneic, but not the autologous, RC lines. Only one V gamma 3+V delta 1+ TIL clone, identified by its specific variable TCR gene sequence, consistently killed autologous tumor cells, apparently via TCR-mediated MHC-unrestricted recognition. This clone also lysed two allogeneic RC lines out of four tested but did not kill 30 non-RC lines, except for one breast carcinoma line. Significantly, this clone was found in recurrent fashion in all three tumors analyzed, including a metastasis. The high frequency of V delta 1 expressing RC-reactive gamma delta cells among TIL from this patient suggests that this gamma delta subset was selectively trapped and/or preferentially induced to proliferate in the autologous tumors. The recurrence of a single V gamma 3+V delta 1+ gamma delta clone, reacting with autologous tumor cells, inside three tumors of different localizations additionally suggests that, for this clone, intratumor selection and/or proliferation was due to TCR-mediated recognition of a non-MHC-restricted RC-specific Ag.

Selective lysis of autologous tumor cells by recurrent gamma delta tumor-infiltrating lymphocytes from renal carcinoma

We show here that tumor infiltrating lymphocytes (TIL) derived from three renal carcinoma (RC) tumors, which developed in the same patient over a 3-yr period, were systematically enriched in gamma delta + T cells (27-74%) after short term in vitro culture. Analysis of the repertoire of gamma delta + TIL and PBL from this patient, revealed the predominant expression of structurally diverse V delta 1 gamma delta TCR by TIL from the three tumors, contrasting with the classically dominant use of V delta 2 TCR by PBL. Functional analysis further showed that, independently of the V gamma genes expressed, all the V delta 1+ TIL clones exhibited a lytic activity apparently restricted to RC lines, while V gamma 9+V delta 2+ clones (either PBL- or TIL-derived) had a broad killing activity. Surprisingly most V delta 1+ CTL clones lysed several allogeneic, but not the autologous, RC lines. Only one V gamma 3+V delta 1+ TIL clone, identified by its specific variable TCR gene sequence, consistently killed autologous tumor cells, apparently via TCR-mediated MHC-unrestricted recognition. This clone also lysed two allogeneic RC lines out of four tested but did not kill 30 non-RC lines, except for one breast carcinoma line. Significantly, this clone was found in recurrent fashion in all three tumors analyzed, including a metastasis. The high frequency of V delta 1 expressing RC-reactive gamma delta cells among TIL from this patient suggests that this gamma delta subset was selectively trapped and/or preferentially induced to proliferate in the autologous tumors. The recurrence of a single V gamma 3+V delta 1+ gamma delta clone, reacting with autologous tumor cells, inside three tumors of different localizations additionally suggests that, for this clone, intratumor selection and/or proliferation was due to TCR-mediated recognition of a non-MHC-restricted RC-specific Ag.

Phototoxic and photoprotective effects of topical isothipendyl

Isothipendyl, an H1-receptor antagonist, is an antihistamine used as an antiallergic drug. Its molecular structure is close to the phenothiazines, but it has different photobiological properties. Like phenothiazines, isothipendyl is phototoxic with ultraviolet A (UVA) but it reduces the erythema response to UVB radiation. Isothipenyl seems to have the same protective properties as a sunscreen because its UVB protective properties are effective only if the substance is applied prior to exposure.

Deletion cartography around the D13S25 locus in B cell chronic lymphocytic leukemia and accurate mapping of the involved tumor suppressor gene

The presence of an unidentified tumor suppressor gene on the long arm of chromosome 13 which could be involved in the development of B cell chronic lymphocytic leukemia has been suspected because of frequent deletions of the locus D13S25 which lies 1.6 cM telomeric to the retinoblastoma gene. In order to accurately map this gene, cells from 25 B cell chronic lymphocytic leukemia tumors have been analyzed for allelic loss using a panel of microsatellite markers located in this region. These markers, which stretch from the retinoblastoma gene to the Wilson disease gene, have been ordered for their rank from centromere to telomere. In addition to the data obtained from deletion pattern of these markers, results from preliminary pulse-field electrophoresis studies enable us to redefine the minimal deleted area from more than 1 cM to 280 kilobase around D13S25.

Captopril and aspirin in treatment of renal microangiopathy in primary antiphospholipid syndrome

Treatment of antiphospholipid syndrome (APS) is controversial. We report a case of renal microangiopathy in a 40-year-old woman with APS. The nephropathy was isolated without signs of disseminated thrombotic microangiopathy or progressive systemic sclerosis. Similarities with sclerodermatous kidney and an increase in plasma renin activity led us to initiate treatment with aspirin and captopril, with excellent control of the renal syndrome. We believe this therapeutic regimen may be an effective means of treating the renal microangiopathy of APS.

[Hypercalcemia in cancer patients. Who, when and how to treat?]

The most frequent, potentially fatal, metabolic complication in cancer patients is hypercalcemia. After a discussion of cancer-associated hypercalcemia, we propose an individualized intervention model based on an analysis of the clinical situation, the prognosis, and available treatment options.

Distribution of albumin, alpha 1-inhibitor 3 and their respective mRNAs in periportal and perivenous rat hepatocytes isolated by the digitonin-collagenase technique

The expression of albumin and alpha 1-inhibitor 3 genes was investigated in rat cell suspensions enriched in periportal (n = 10) and perivenous (n = 10) hepatocytes obtained by the digitonin-collagenase technique. The degree of enrichment of the cell suspensions was assessed: (1) by enzymic assays for the periportal marker alanine aminotransferase and for the perivenous marker glutamine synthetase; and (2) by their content of mRNAs for the periportal marker hepatic glutaminase and for glutamine synthetase. The existence of an antegrade intra-lobular gradient for albumin and alpha 1-inhibitor 3 mRNAs was demonstrated, with periportal:perivenous ratios of 2.33 and 3.80, respectively. However, no gradient was demonstrated for the respective protein contents with corresponding ratios of 0.98 and 1.21. A certain degree of overlap existed between periportal and perivenous suspensions for their content in albumin and alpha 1-inhibitor 3 mRNAs. A morphometrical analysis of the surface of digitonin-permeabilized hepatic tissue revealed that this overlap could be explained by a variable extent of permeabilization of the mediolobular zone from one rat to another and from one lobule to another in a given animal. These results suggest that while the digitonin-collagenase technique is well suited for studies in vitro of proteins expressed in sharp intra-lobular gradients or restricted to an intra-lobular compartment, it is not completely reliable for proteins distributed in continuous moderate intra-lobular gradients, such as albumin and alpha 1-inhibitor 3.

Autologous bone marrow transplantation using TBI and CBV for disseminated high/intermediate grade cutaneous non-epidermotropic non-Hodgkin's lymphoma

Patients with stage IV high/intermediate grade cutaneous non-epidermotropic lymphoma of skin as first localization of the disease have a poor prognosis. In this setting, autologous bone marrow transplantation (BMT) has rarely been evaluated. We report here on the treatment of four patients with such lymphomas with autologous BMT using 12 Gy total body irradiation (TBI) and CBV (cyclophosphamide, carmustine and etoposide). Using a plexiglass screen, TBI delivered an homogenized dose to the skin. With this conditioning regimen, all patients are still in complete remission 22, 44, 46 and 51, respectively, months after high-dose chemotherapy, TBI and autologous BMT.

Contact photosensitivity to nonoxynol used in antiseptic preparations

Nonoxynols are nonionic surface-active agents used as surfactant in numerous cosmetic products and antiseptic preparations. Recently nonoxynol contact allergy has been described. We report two patients who presented a contact photosensitivity to nonoxynol 10 contained in Hexomédine transcutanée. Among 32 control subjects, we found 13 positive photopatch tests to Hexomédine transcutanée and 4 positive photopatch tests to nonoxynol 10. Surprisingly, the authors observed that only undiluted nonoxynol was phototoxic.

Identification of two acidic residues involved in the catalysis of xylanase A from Streptomyces lividans

On the basis of similarities between known xylanase sequences of the F family, three invariant acidic residues of xylanase A from Streptomyces lividans were investigated. Site-directed-mutagenesis experiments were carried out in Escherichia coli after engineering the xylanase A gene to allow its expression. Replacement of Glu-128 or Glu-236 by their isosteric form (Gln) completely abolished enzyme activity with xylan and p-nitrophenyl beta-D-cellobioside, indicating that the two substrates are hydrolysed at the same site. These two amino acids probably represent the catalytic residues. Immunological studies, which showed that the two mutants retained the same epitopes, indicate that the lack of activity is the result of the mutation rather than misfolding of the protein. Mutation D124E did not affect the kinetic parameters with xylan as substrate, but D124N reduced the Km 16-fold and the Vmax. 14-fold when compared with the wild-type enzyme. The mutations had a more pronounced effect with p-nitrophenyl beta-D-cellobioside as the substrate. Mutation D124E increased the Km and decreased the Vmax. 5-fold each, while D124N reduced the Km 4.5-fold and the Vmax. 75-fold. The mutations had no effect on the cleavage mode of xylopentaose.

Photocontact allergy to oxybenzone: ten years of experience

Intolerance of sunscreen agents has often been reported in the literature. This mainly comprises photosensitization to sunscreens such as oxybenzone. The aims of this study were to establish the incidence of photocontact allergy to oxybenzone and its relationship with the use of other cosmetics. From 1982 to 1992 we performed photopatch tests on 283 patients with suspected photodermatosis. Forty-six patients (16%) had positive reactions: 61 positive photopatch tests and 9 positive patch tests. Photocontact allergy to sunscreens was divided into 2 main groups: 35 cases to oxybenzone and 17 cases to para-aminobenzoic acid and its derivatives. Among our 35 cases of photoallergy to oxybenzone, more than one third had photoallergy to a daily moisturizer that contained oxybenzone.

Expression of complement-regulatory proteins in normal and UW-preserved human liver

BACKGROUND/AIMS

Somatic cells are protected against complement-mediated injury by specialized membrane proteins, known as complement-regulatory proteins (CRP). The knowledge of the pattern of CRP expression in the liver is important to evaluate the role of complement-mediated injury in graft rejection.

METHODS

We determined the distribution of four main CRP: membrane cofactor protein (MCP), decay accelerating factor (DAF), protectin, and complement receptor 1 (CR1) in 30 histologically normal livers, 13 samples from University of Wisconsin cold-storage solution (UW)-preserved tissue and 17 postoperative biopsies of UW-preserved allografts.

RESULTS

In normal liver, hepatocytes expressed only MCP. Bile duct cells were reactive for MCP and protectin. Sinusoidal endothelial cells expressed MCP and protectin but displayed no or faint expression of DAF. Endothelial cells of portal vessels and centrilobular veins expressed high levels of DAF, MCP, and protectin. No expression of CR1 was observed. No change in CRP expression was usually detected after UW preservation, except for protectin, induced on hepatocytes in 9 samples of UW-preserved liver tissue and in 9 allografts.

CONCLUSIONS

Hepatocytes and sinusoidal endothelial cells, which have a defective expression of CRP, might be at risk for complement-mediated injury. However, this risk is not aggravated after UW preservation.

Contact dermatitis from a textile flame retardant

We report a case of contact sensitivity to Flammentin ASN, a flame retardant used on cotton and wool. The patient was a painter who was protecting his face with a white cotton cap. He presented with eczema of the forehead at the sites of cap contact. Patch tests with the treated cap and flame retardant were positive; a formaldehyde patch test was negative. Flame retardants are used in construction, materials and textiles. Contact sensitivity is rarely described and we compare our case to those published in the literature.

Increase in catalytic activity and thermostability of the xylanase A of Streptomyces lividans 1326 by site-specific mutagenesis

The xylanase A gene from Streptomyces lividans was modified by site-directed mutagenesis, selecting for mutations that improved the catalytic activity and thermostability of the enzyme. Mutant notation uses the one-letter abbreviation for amino acids. The first and the last letters represent, respectively, the residue to be changed and the replacing residue. The number indicates the position of the substitution. The mutant enzymes F155Y, R156E, R156K, and N173D were respectively 28, 10, 50, and 25% more active than the wild-type enzyme. In addition, the half-lives at 60 degrees C of the R156E and N173D xylanases were respectively 6 and 40 min longer than that of the wild-type enzyme even in the absence of substrate. The favorable single mutations were combined to generate the double mutants E156/173D and K156/173D, which were 22 and 47% less active than the wild type. However, the activity half-life of the E156/173D enzyme at 60 degrees C was twice that of the xylanase A. The pH-activity profiles of all the mutant xylanases were similar to that of the wild-type enzyme.

Alteration of the cleavage mode and of the transglycosylation reactions of the xylanase A of Streptomyces lividans 1326 by site-directed mutagenesis of the Asn173 residue

The amino acid replacement of Asn173 by Asp in the xylanase A (Xln A) of Streptomyces lividans significantly altered its enzymic properties. A time-course hydrolysis of xylan showed that the altered xylanase ([N173D] Xln A) initially produced larger amounts of xylose (X1), xylobiose (X2) and xylotriose (X3) than Xln A, but less xylotetraose (X4). The bond-cleavage frequencies were determined for both enzymes using xylopentaose (X5), xylotetraose (X4) and xylotriose (X3) labelled at the reducing end of the molecule. Xln A hydrolysed X5, yielding 56% X2 and 44% X3, while [N173D]Xln A liberated 90% X2 and only 10% X3. Both enzymes hydrolysed X4 into 100% X2 and X3 into 100% X1. Transglycosylation reactions were detected in HPLC hydrolysis patterns using high substrate concentrations, where larger products than the starting substrates were formed. Their subsequent degradation also affected the yield of hydrolysis products. Using X5 as substrate, products from xylohexaose (X6) up to xylooligosides larger than xylooctaose (X8) were synthesized by Xln A, while [N173D]Xln A produced only a small amount of xyloheptaose (X7) and X8. Xln A hydrolysed X5 into an equivalent amount of X4 and X2 and 1.5-fold more X3. However, [N173D]Xln A yielded the same amount of X3 and X2 but half as much X4. With X4 as substrate, Xln A synthesized twofold more X7 and X6 than [N173D]Xln A. Xln A liberated 1.4-fold more X3 than X2, while [N173D]Xln A yielded twofold more X2 than X3. Xln A liberated almost fourfold more X2 than X1 from X3, while [N173D]Xln A produced only twofold more X2 than X1. These results indicated that the negative charge introduced by the mutation greatly affected the transglycosylation reaction catalysed by this xylanase.

Testicular tumor and the acquired immunodeficiency syndrome

Immunocompromised patients, particularly those suffering from the acquired immunodeficiency syndrome (AIDS), present an increased risk of tumoral pathology. From the observation of a testicular lymphoma associated with Epstein-Barr virus in a HIV + patient, we review 19 cases of testicular tumor in HIV + patients previously published in the literature. These tumors are either lymphomas (4 cases) or germ cell tumors (15 cases). Their diagnosis was not difficult, although in the first stages enlarged and painful testicles are often wrongly identified as orchiepididymitis and treated as such. Therapy management proves to be delicate as a result of the significant tumor spread seen in these patients with dysfunctional immune systems. Regarding lymphomas, a low-dose multiagent chemotherapy with intrathecal chemotherapy was recommended by Levine. Concerning germ cell tumors, Wilson prefers an instant aggressive treatment with retroperitoneal lymphadenectomy (whether or not combined with chemotherapy) to avoid the risk of recurrence. In fact, tumor relapses will be difficult to control in the progressive stages of immunodeficiency syndrome.

99Tcm-labelled anti-fibrin Fab' fragment for evaluating the course of venous thrombosis in the rabbit

Immunoscintigraphy was performed using the Fab' fragment of 99Tcm-labelled T2G1s anti-fibrin monoclonal antibody in a rabbit experimental model of venous thrombosis of known and increasing age (1, 3 and 7 days). Scans were positive in 3/7 cases for 1-day thrombosis (fibrin-poor network) and in 7/7 cases for 3-day thrombosis (fibrin-rich network). In rabbits with 7-day thrombosis, the scan was positive (2/4 cases) only when connective tissue was not present in the clot. Scintigraphic results were concordant with those of biodistribution studies showing the mean percentage of injected dose per gram 99Tcm-T2G1s present in the thrombosed vein wall (0.043, 0.082 and 0.07 for thrombi at 1, 3 and 7 days, respectively). Mean thrombosed vein wall-to-blood ratios were 1.027, 2.291 and 1.301, respectively. Immunoscintigraphy with T2G1s anti-fibrin monoclonal antibody thus enabled hematological status to be evaluated.

Detection of human papillomavirus in squamous intraepithelial lesions by consensus and type-specific polymerase chain reaction

Polymerase chain reaction (PCR) was used to identify human papillomavirus (HPV) in 216 cervical biopsy specimens from women referred to the gynecological out-patient unit for colposcopy because of an abnormal smear. HPV DNA was screened using type-specific primers for HPV6, 11, 16, 18, 31 and 33 (TS-PCR) as well as a consensus primer located in the E1 region of the HPV genome (C-PCR). TS-PCR specificity was validated by Southern blot analysis. Low-grade (SIL 1) and high-grade (SIL 2) squamous intraepithelial lesions were found in 165 biopsies. HPV16 detection was better with PCR than Southern blot, particularly for SIL 1 and SIL 2. The fact that 10% of HPV16 (all SIL 2) were not detected by C-PCR indicates that both PCR techniques should be performed. C-PCR also detects uncharacterized HPV types (8.6% prevalence in our results), mainly in SIL 1 and SIL 2. HPV16, the most frequently isolated type (prevalence 21%), was associated with SIL 2 in 83% of cases. A low HPV prevalence was found in specimens without dysplastic cells. These results suggest that PCR may be an important tool for identifying women at risk for developing dysplasia or cervical cancer.

Early colchicine administration reduces hepatic fibrosis and portal hypertension in rats with bile duct ligation

Chronic administration of colchicine has been suggested as a potential treatment for hepatic fibrosis. The purpose of this study was to examine the effects of chronic oral administration of colchicine on the histological and hemodynamic abnormalities of bile duct ligation in the rat. Forty-eight rats with ligation-section of the common bile duct were randomly and blindly assigned to receive either colchicine (50 mu/kg day) or placebo by gavage for 4 weeks. At the end of the treatment period, morphometric analysis showed that hepatocyte and sinusoidal volume fractions were significantly higher in rats treated with colchicine than in rats receiving placebo (42.4 +/- 1.3 vs. 32.1 +/- 2.6% (mean +/- S.E.) and 8.3 +/- 0.6 vs 4.7 +/- 0.4%, respectively), while bile duct volume fractions (reflecting bile ductular proliferation) and connective tissue fractions were significantly lower in rats treated with colchicine than in rats receiving placebo (12.1 +/- 0.9 vs. 17.0 +/- 0.1% and 37.2 +/- 0.9 vs. 46.1 +/- 2.0%, respectively). Portal pressure (13.4 +/- 0.7 vs. 17.8 +/- 0.5 mmHg), portal tributary blood flow (5.8 +/- 0.4 vs. 8.7 +/- 0.5 ml.min-1.100 g-1) and cardiac index (40.8 +/- 2.3 vs. 50.6 +/- 1.5 ml.min-1.100 g-1) were significantly lower in colchicine-treated rats than in placebo treated animals. In conclusion, in rats with bile duct ligation, colchicine limits the severity of liver lesions and, consequently, of portal hypertension and hyperkinetic syndrome.

Effects of digitonin on the intracellular content of rat hepatocytes: implications for its use in the study of intralobular heterogeneity

Anterograde or retrograde perfusion of rat liver with digitonin selectively permeabilizes the periportal or the perivenous zone of the hepatic lobule. Digitonin perfusion is used to analyze the effluents released by permeabilized hepatocytes or, combined with collagenase perfusion, to obtain cell suspensions enriched in either periportal or perivenous hepatocytes. Despite the wide use of digitonin to study lobular heterogeneity, its affects on rat hepatocytes are not well documented. We therefore analyzed the effects of digitonin perfusion on the intracellular content of rat hepatocytes by combining electron microscopy, histoenzymology, immunohistochemistry, and in situ hybridization. At the concentration currently used for the study of lobular heterogeneity, digitonin perfusion induced a marked cytosolic clarification of permeabilized hepatocytes, while most organelles except mitochondria were well preserved. In the digitonin-altered zones, there was no histochemical detection of non-membrane-bound enzymes (lactate dehydrogenase, glutamate dehydrogenase), whereas membrane-bound enzymes (succinate dehydrogenase, beta-hydroxybutyrate dehydrogenase, NADPH dehydrogenase, glucose-6-phosphatase) were still detected. Immunohistochemistry and in situ hybridization revealed significant amounts of several plasma proteins (albumin, alpha 2-macroglobulin, alpha 1-inhibitor 3, alpha 1-acid glycoprotein) and their respective mRNAs in digitonin-permeabilized hepatocytes. The demonstration that digitonin-permeabilized hepatocytes retain many intracellular constituents shows that biochemical analysis of cellular effluents released from digitonin-permeabilized hepatocytes must be interpreted with caution and that the apparent characteristics of cell suspensions obtained by the digitonin-collagenase technique might be significantly altered by contamination with permeabilized hepatocytes from the opposite zone.

Parenchymal innervation of normal and cirrhotic human liver: a light and electron microscopic study using monoclonal antibodies against the neural cell-adhesion molecule

Hepatic innervation participates in the control of sinusoidal blood flow and in the regulation of certain metabolic functions of the liver. The study of the distribution of hepatic nerves has been hampered by the lack of adequate markers. We therefore tested the value of the neural cell-adhesion molecule (NCAM) as a probe for the study of parenchymal nerves in the normal and cirrhotic human liver. Four antibodies against various epitopes of NCAM were tested by light and electron microscopic immunohistochemistry: Leu19, ERIC-1, VC1.1, and HNK-1. Their reactivity was compared with that of antibodies against the following neural cell markers: S100 protein, neurofilaments, and neuron-specific enolase (NSE). The tissue reactivity of anti-NCAM antibodies was variable, suggesting a microheterogeneity of the NCAM molecule in the normal liver. Clones Leu19 and ERIC-1 proved to be the most sensitive of the anti-NCAM antibodies. Their sensitivity was superior to that of the antibodies directed against the other neural cell markers tested. In the normal liver, both Leu19 and ERIC-1 demonstrated a heterogeneous distribution of nerve fibers inside the hepatic lobule. Intralobular nerve fibers predominated in Zone 1. This might contribute to the constitution of distinct zonal microenvironments inside the hepatic lobule. In cirrhosis, no nerve fiber was detected inside parenchymal nodules; no nerve plexus was visible at the contact of proliferating neoductules. These alterations might contribute to the pathogenesis of the hemodynamic and metabolic disorders observed in cirrhosis.

Activation of nuclear protooncogenes and alpha-fetoprotein gene in rat liver during the acute inflammatory reaction

Nuclear protooncogene and alpha-fetoprotein gene expression is stimulated in hepatocytes during liver regeneration and by various growth factors in vitro. Metabolic adaptation of hepatocytes has been implicated in such gene reprogrammation. We examine here whether induction of an acute inflammation, a physiological situation of important metabolic adjustments, also triggers activation of nuclear oncogenes and of the AFP gene in rat liver. C-fos, c-jun and c-myc mRNA accumulated on Northern blots between 4-12 h of inflammation and the steady-state level of two small alpha-fetoprotein transcripts characteristic of the adult liver increased at 4 h and 24 h of inflammation. In situ hybridization showed accumulation of the mRNA of the four genes studied in all hepatocytes, without any zonal lobular heterogeneity. 3H-histoautoradiography and mitotic counts indicated an inhibition of DNA synthesis and mitosis, prolonged for at least 48 h after inflammation. Thus acute inflammation triggers the activation of nuclear protooncogenes and alpha-feto-protein gene in hepatocytes, but this activation is not followed by passage into the replicative cycle.

Growth and differentiation of rabbit tracheal outgrowths in primary cultures: influence of substrata

We show that in rabbit tracheal outgrowths, ciliated cells can express an affinity for the isolectin BSI-B4, known to preferentially bind to basal cells. In multi-layered outgrowths grown on a thick collagen gel, a low percentage of ciliated cells are labelled by BSI-B4. This percentage increases with the aging of cultures. In monolayers developed on thin coatings of collagen or matrigel, a high percentage of ciliated cells show affinity for BSI-B4, even within young cultures.

[Extramedullary hematopoiesis. An unusual cause of Pagetic spinal cord compression]

An original case is reported: spinal cord compression due to extramedullary hematopoiesis of the epidural space, related to Paget's disease of bone, successfully treated by surgery. Extramedullary hematopoiesis, usually occurring in cases of hematological disease, can also complicate Paget's disease, probably by bone effraction mechanism. A review of literature has found 5 other cases of extramedullary hematopoiesis occurring in Paget's disease, without hematological disease. Medullar scintigraphy (Indium111, Technetium99 Sulfur colloid) can confirm the diagnosis after X-ray findings, without the need for biopsy. Awareness knowledge of this complication can sometimes avoid invasive investigation. Low dose radiotherapy is useful in the case of hematological disorders. In Paget's disease, there is a risk of sarcomatous degeneration. In our patient, surgery cured cord compression, but it relapsed because of extensive fibrosis, in complicating surgical hemorrhage.

[Bone marrow necrosis in malignant hemopathies. 7 cases]

The authors report 7 cases of bone marrow necrosis during hematological malignant diseases:3 leukemia, 4 lymphoid malignancies. The main clinical features were bone pain and fever. The bone marrow aspiration and/or biopsy allow diagnosis. The prognosis was in all cases very poor.

Primary Epstein-Barr virus infection with clonal T-cell lymphoproliferation

A case of fatal Epstein-Barr virus infection in a previously healthy girl who was first found to have severe infectious mononucleosis with spontaneous recovery is reported. Because an abnormal immune response to the virus persisted, the disease relapsed, manifesting in cutaneous and pulmonary lesions associated with hemophagocytic syndrome responsible for death. Pathologic findings were characterized by polymorphous atypical lymphoid infiltrate, prominent necrosis, and histiocytic hyperplasia. Lymphoid cells displayed CD8 phenotype and clonal T-cell receptor gene rearrangement. Viral genome was detected in lesions by Southern blot and located in nuclei of lymphoid cells by in situ hybridization. Pathologic findings suggested fatal infectious mononucleosis; however, phenotype and genotype favored a malignant diagnosis. Clonality was demonstrated to have arisen during primary infection. Virologic examination indicated that Epstein-Barr virus was a causative agent. Such a process belongs to the recently recognized spectrum of Epstein-Barr virus-related T-cell lymphoproliferative disorders that might overlap fatal infectious mononucleosis in patients who are especially vulnerable to the virus.

Cloning and expression in Escherichia coli of a xylanase-encoding gene from the yeast Cryptococcus albidus

In the yeast, Cryptococcus albidus, a comparison between the sequence of the xylanase (XLN)-encoding chromosomal gene (XLN) and the cDNA sequence reveals the presence of seven introns, ranging in length from 51 to 69 bp. One of their 5' splice site sequences is similar to the consensus sequence for yeast, while the other six resemble the consensus sequence for higher eukaryotes. Their 3' end splice site sequences are representative of the conserved sequence found in eukaryotes. Their putative branching point sequences are different from the well-known conserved sequence, 5'-TACTAAC, observed in yeast, but again resemble the mammalian one. The cDNA encoding XLN is expressed by Escherichia coli, under the control of the lacZ promoter. The gene product remains inside the cell and has a molecular size of 40 kDa, which matches the size of the nonglycosylated protein. When compared to the glycosylated enzyme, the nonglycosylated XLN from E. coli shows twofold less affinity for substrate and its Vmax is 100-fold lower. Moreover, the nonglycosylated XLN only acts on large xylan polymers and very slightly on xylohexaose.

Secretion of a Cryptococcus albidus xylanase in Saccharomyces cerevisiae

The xylanase(XLN)-encoding gene(XLN) of Cryptococcus albidus and its cDNA were each inserted into the vector, pVT100, for expression in Saccharomyces cerevisiae. Expression was under the control of either their own promoter or the gene encoding alcohol dehydrogenase (ADH1) promoter. Yeast transformed with plasmids containing the cDNA of the structural XLN gene and the XLN promoter produced active extracellular XLN when grown with galactose as carbon source. However, with glucose as carbon source, XLN was repressed. Using the ADH1 promoter, which is stimulated by glucose, XLN was secreted into the culture medium. In both cases, the secreted 48-kDa enzyme corresponded to the native XLN produced by C. albidus. With the plasmid bearing the genomic XLN gene, there was transcription, but the seven introns interrupting XLN were not spliced out by S. cerevisiae and no enzyme was produced.