Frequent allelic losses of 9p21 markers and low incidence of mutations at p16(CDKN2) gene in non-Hodgkin lymphomas of B-cell lineage

We present an allelotype analysis of 35 cases of non-Hodgkin lymphomas and normal pairs using four microsatellite markers that flank the region occupied by the CDKN2 gene locus at 9p21. Frequent allelic losses (LOH) were detected in B-cell lineage NHLs, including Burkitt lymphoma (33.3% of total, if we only consider high grade tumors). In five of these tumors LOH did not include the CDKN2 gene. Mutational analysis of exon 1 and 2 of CDKN2 (SSGP and sequencing of abnormal bands) revealed a nonsense mutation (Arg72Ter) in one tumor (case 10), where the second hit of the Knudson's model consisted of the elimination of the wild type allele. In view of these results, the hypothesis of two different candidate tumor suppressor gene regions around the CDKN2 locus remains an intriguing possibility.

[Value of protein 53 expression in lymphoma. Its correlation with genetic mutations]

PURPOSE

p53 is a tumour suppressor gene encoding a nuclear phosphoprotein that plays an important role in the control of normal cell proliferation. We have tried to establish the value of expression of the p53 protein in malignant lymphomas and its correlation with the presence of structural gene abnormalities.

MATERIAL AND METHODS

230 cases of lymphomas (11 Hodgkin's disease and 219 non-Hodgkin's) were studied by immunohistochemistry using an anti-p53 monoclonal antibody (DO-7, DAKO). Sections were heated by pressure cooker in 0.01 M sodium citrate buffer pH 6 as a method for antigen unmasking. The quantification of levels of nuclear p53 protein were measured with an Image Analyzer (CAS-200, Becton-Dickinson S.A.). We have also searched for mutations in a series of 94 lymphomas using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis in exons 5 to 9 of the p53 gene and the sample showing abnormal pattern were sequenced.

RESULTS

p53 immunoreactivity has been detected in 82.6% of cases. The percentage of positive cells varies in a wide range which was divided into 0% (17.39%), less than 5% (57.39%), between 5-10% (13.91%) and more than 10% (11.30%). In all lymphoma subtypes, we have found the majority of cases show levels less than 10% and few more than 10%. We found abnormal bands in 9 of 94 lymphomas with different diagnosis (1 ALCL, 1 T-LNH, 2 B-LNH, 2 centroblastic, 1 lymphoblastic and 2 MALT). Two cases resulted to be a silent base change which not alter the function of the p53 protein and represent a common polymorphism. Seven cases showed single base pair missense mutations in all of them. Mutations in codons 179, 248 and 273 correspond to some of the typical hotspots described in p53 gene.

CONCLUSIONS

p53 expression, is a frequent finding in malignant lymphomas, is variable and relates to histological subtype. The results suggest that positive immunocytochemistry cannot be used to determine which tumours have mutations of p53 because the existence of cases with discrepancies between overexpression of the protein and presence of mutations.

Activation of the IFN-inducible enzyme RNase L causes apoptosis of animal cells

The interferon (IFN)-induced enzyme RNase L produced by a recombinant vaccinia virus (VV) causes death of mammalian cells with morphological and biochemical characteristics of apoptosis. Coexpression of 2-5A-synthetase enhances apoptosis induced by RNase L Activation of endogenous RNase L by infection with a VV ts mutant (ts22) or with wild-type virus in the presence of the antipoxvirus drug isatin-beta-thiosemicarbazone, a treatment known to significantly increase the amount of double-stranded RNA late during infection, also causes pronounced apoptosis of infected cells. The effects observed with recombinant virus-derived RNase L or with the endogenous enzyme are specific, since apoptosis also occurs in cells derived from mice lacking the IFN-induced protein kinase (PKR). The apoptosis antagonist Bcl-2 prevents induction of cell death by RNase L activation. Apoptosis of mammalian cells by RNase L activation could be a mechanism mediating anticellular actions of IFN.

Correlation between mutations in p53 gene and protein expression in human lymphomas

A discordance between p53 protein overexpression and the presence of mutations in the gene has been observed in many types of tumors, including human lymphomas. To probe this finding, we have studied a large series of 94 lymphomas of different pathologic types and histologic differentiation. Analyzing exons 5-9, we have found mutations in the p53 gene in 7 of 94 cases distributed in different subtypes: 4/12 (33%) high-grade B-cell non-Hodgkin's lymphomas (B-NHLs), in 1 of 5 (20%) high-grade mucosa-associated lymphomas (MALT), in 1 of 22 (4.5%) anaplastic large cell lymphoma (ALCL), and in 1 of 24 (4%) T-cell NHLs. Immunostaining with anti-p53 antibody DO-7 was possible in 87 lymphomas, and overexpression of p53 protein was observed in 16 cases (18%). A discrepancy between the results of SSCP and immunostaining was detected on 18 tumor samples. Two cases with mutations in the gene showed no altered protein expression and 16 cases overexpressed p53 protein had no point mutations. In these cases, the possibility that mutations occur outside the exons studied has been tested and the entire coding sequence analyzed. Only one case showed a mutation in exon 10, and we found two cases carrying a polymorphism in exon 4 and in intron 10. We conclude that mutations in p53 occur mainly in high-grade B-cell NHLs. Although not limited to a specific subtype of lymphoma, they may be rare in Hodgkin's disease and in low-grade lymphomas. The discrepancies between overexpression and presence of mutations suggest (1) the existence of another mechanism to stabilize the p53 protein, and (2) that the immunohistochemistry cannot be used to predict mutations in the gene.

Hypermethylation of a 5' CpG island of p16 is a frequent event in non-Hodgkin's lymphoma

Hypermethylation of a 5' CpG island of p16 gene has been recently described as a possible way of inactivation of this tumor suppressor gene, alternative to deletions and mutations. We have investigated if hypermethylation of a 5' CpG island of p16 occurs in non-Hodgkin's lymphoma (NHL) and normal lymphoid tissue. A total of 82 NHLs were examined for p16 methylation by Southern blot and PCR analysis. Hypermethylation was detected in approximately 20% of B cell lymphomas of both low and high grade and in 15% of T cell NHL. The highest rate of p16 gene methylation in tumors was found among MALT (mucosa-associated lymphoid tissue) lymphomas in which the percentage of cases with p16 gene methylation reached 67%. However, normal lymphoid tissue was always unmethylated at p16 locus. These results indicate that p16 gene methylation is a frequent event in NHLs, mainly in MALT lymphomas, and suggest that it could be an important mechanism of inactivation of this gene.

Inducible expression of the 2-5A synthetase/RNase L system results in inhibition of vaccinia virus replication

Studies of interferon (IFN)-treated virus-infected animal cells have revealed the 2-5A system (2-5A synthetase/RNase L enzymes) as being responsible for virus inhibition only in the case of picornaviridae. To investigate whether those IFN-induced enzymes could be responsible for inhibition of poxvirus replication, we have generated recombinant vaccinia viruses (VV) containing the corresponding genes (VV-2-5AS and VV-RL, respectively). RNase L produced in cells infected with VV-RL leads to rRNA degradation and inhibition of virus protein synthesis, which correlates with about 92% reduction in virus yields by 48 hr after infection. Combined expression of this enzyme with 2-5A-synthetase further inhibits virus yields. The pattern of rRNA fragments produced by infection with viruses VV-RL and/or VV-2-5AS is the characteristic for activation of the 2-5A pathway by IFN treatment. Combined infection of VV-RL together with vesicular stomatitis virus (VSV) demonstrates this inhibition to be specific for VV and not due to a general effect. Breakdown of rRNA is largely due to the recombinant vector-derived enzyme, since a C-terminal deletion mutant of RNase L is inactive and the extent of rRNA degradation induced by infection with VV-RL is similar in cells treated or not with IFN. Moreover, the anti-VV effects of RNase L is also observed in a cell line lacking the endogenous ds RNA-dependent protein kinase (PKR). Thus, our findings provide direct evidence for antiviral activity of the 2-5A system on poxviruses.

Evaluation of the international index in the prognosis of high grade gastric malt lymphoma

The International Prognostic Index identifies four risk groups with different survival rates in aggressive non-Hodgkin's lymphoma. We have studied whether a slight modification of this index has prognostic significance in high grade gastric B-cell MALT lymphoma. In 53 patients with high grade gastric B-cell MALT lymphoma the following survival factors were investigated: age over or under 60 years, sex, B symptoms, more than one extranodal site of involvement other than the stomach, serum LDH levels, performance status, stage I/IIE1/IIE2 v.s. stage III/IV, treatment with surgery, chemotherapy or both modalities together and the four risk groups as defined by the Modified International Prognostic Index (MIPI). A multivariate Cox's test was used to evaluate the independent prognostic significance on survival of all the above variables. Advanced stage (III/IV) and involvement of more than one extranodal site not including stomach were the only variables influencing survival. The MIPI was not sufficient to separate groups with significant differences in survival or to stratify prognostic groups. In this series, the MIPI did not show prognostic significance in high grade gastric B-cell MALT lymphoma.

[Clinico-morphologic reconsideration of anaplastic lymphoma. Retrospective study of 60 patients with aggressive clinical course and multiple recurrences]

PURPOSE

To identify anaplastic large cell lymphoma Ki-1+ (ALCL-Ki-1+) among a group of patients with aggressive Hodgkin's disease (HD) and to know the biological behaviour of the neoplasia (ALCL-Ki-1+).

PATIENTS AND METHODS

Biopsies and clinical data of sixty patients with previous morphological diagnosis of HD lymphocytic depletion (LD), syncytial variant of nodular esclerosis (NE-II) and other subtypes of HD with aggressive clinical features were reviewed. A morphological, immunohistochemical (IHQ), proliferative and flow cytometric (FCM) studies were performed in lymph node biopsies.

RESULTS

Morphological study and IHQ identify three groups: 15 patients (25%) lymphocytic predominance (LP) HD, 36 (60%) ALCL-Ki-1+ and 9 (15%) of non-Hodgkin's lymphoma (NHL) and unclassifiable cases. Nine cases of LP show anaplastic and variable immunophenotype being the rest of B-cell nature. 75% of LP patients showed long survival and frequent second neoplasias (47%). ALCL-Ki-1+ group had good initial response to therapy (84%) and multiple relapses, 67% showed CD15 positive marker (the so-called ALCL-HD related).

CONCLUSIONS

A retrospective study of a selected group of patients previously diagnosed of aggressive HD showed different pathological subtypes: LP, LP with anaplastic areas, ALCL-Ki-1+ Hr (Hodgkin's related) and ALCL-Ki-1+ (classical type), all of them were CD30+, which could represent different stages of the same neoplasia.

African swine fever virus gene A179L, a viral homologue of bcl-2, protects cells from programmed cell death

The African swine fever virus (ASFV) open reading frame A179L, which is similar to the human proto-oncogene bcl-2, has been cloned and expressed in vaccinia virus under control of the pEIL synthetic early/late promoter. The A179L gene product prevented cell death in HeLa and BSC-40 cells doubly infected with another recombinant vaccinia virus expressing the interferon-induced double-stranded RNA-activated protein kinase (p68 kinase), which activates a rapid cell death characteristic of apoptosis. This finding suggests that the A179L gene has a function similar to that of bcl-2 in preventing apoptosis and may play an important role during productive ASFV infection.

Metabolic effects of the combination of furosemide and captopril in rat

Diuretics typically provoke increased serum lipid levels and may provoke increased serum uric acid levels and/or glucose intolerance. Furosemide is widely used as an antihypertensive, but in patients for whom furosemide treatment alone proves insufficient to reduce hypertension, a common procedure is to co-administer the angiotensin-converting-enzyme (ACE) inhibitor captopril. The metabolic effects in rats of joint administration of furosemide (15 mg/kg/day) and captopril (2 mg/kg/day) are evaluated over a two-week period. At the end of this period, the serum levels of lipids, uric acid, bilirubin, proteins and various enzymes were determined as well as the effect of the treatment on intestinal absorption of glucose and calcium. Furosemide/captopril led to an increase in serum albumin and alkaline phosphatase levels, and a decrease in triglyceride levels. The results of this work support the view that this drug combination is suitable for hypertension treatment.

Incidence of homogeneously staining regions in non-Hodgkin lymphomas

We report a series of 86 non-Hodgkin's lymphomas (NHL) studied cytogenetically in which two cases with a homogeneously staining region (HSR) located on chromosome 19 and on chromosome 1, respectively, were observed. The low incidence detected (2.3%) suggests that HSR are rare events in NHL. An oncogenetic amplification study was performed with probes for genes that are currently known to undergo amplification and with probes for two genes located on chromosome 19q (AKT2 and BCL-3). We detected no amplification except for AKT2 putative oncogene in the lymphoma in which the HSR was located on chromosome 19. Because amplification of AKT2 putative oncogene has been detected in ovarian carcinomas bearing HSR and in this case NHL, we believe that this gene may be implicated in the pathogenesis of other neoplasias in cooperation with other genes. Further investigation is needed to confirm the low incidence of HSR in NHL and the origin of the amplified material.

[Histopathology of bone marrow biopsy in patients with human immunodeficiency virus infection]

PURPOSE

To describe morphology of bone marrow (BM) biopsy in HIV infected patients. To correlate histopathologic findings and clinico-haematological data. To consider the advantages of this method (BM biopsy) in the diagnosis of secondary infectious or tumoural accompanying processes.

MATERIAL AND METHODS

One hundred and fourteen BM biopsies of 103 HIV infected patients were retrospectively reviewed. The cases were selected from the records of Pathology Department of Jiménez Díaz-Foundation (from 1984 to 1993). All cases were studied with routine and immunohistochemical (IHQ) techniques against haematopoietic and proliferative markers. Clinico-haematological data were also reviewed.

RESULTS

Ninety per cent of biopsies showed morphological abnormalities: hypercellularity, myeloid hyperplasia and dysplasia of erythroid and megacariocytic series. Reticuline myelofibrosis and reactive lymphoplasmacytosis were also present. IHQ confirms the described histopathologic pattern. Twenty-two per cent of cases showed signs of infectious or tumoural diseases: mycobacteriosis (15%) and lymphomas (7%). Clinical manifestations were correlated with significant alterations in the BM: fever with hypercelullarity, constitutional syndrome and myelofibrosis with zidovudine therapy and infections with myelodysplasia.

CONCLUSIONS

Cytology, myelofibrosis and abnormal pattern of BM biopsies in HIV infected patients are characteristic: "the so-called AIDS BM pattern" as BM is a target organ in the HIV-related infections. BM biopsies are a good method to demonstrate stage of HIV disease and accompanying infectious or tumoural processes.

[T-cell-rich B-cell lymphoma: multifactorial study of 4 cases]

PURPOSE

With the correlational study of four cases in several areas (clinic, morphoimmunologycal, ultrastructural and genetic) we try to valorate the still controversial entity known as T-cell rich B-cell lymphoma (TRBL), and stablish some useful clues in order to settle down the differential diagnosis between TRBL, Hodgkin's disease (HD), and T-cell non-Hodgkin's lymphomas (TNHL).

PATIENTS AND METHODS

Cases proceeded from Oncology Department, and had been firstly misdiagnosed either as HD (3 cases) or as TNHL (1 case). Biopsies were processed and stained in routine way, H&E, Giemsa and Wilder. Immunohystological study, using monoclonal antibodies against B-cells, T-cells, histiocytes, activation and proliferation markers, was also performed with avidin biotine peroxidase (ABC) method. Ultrastructural study was performed in three of the cases; two patients were studied by PCR and Southern blot.

RESULTS

All of the cases showed a diffuse hystological pattern, with variable fibrosis, and proliferation of venules and capillaries. Small lymphoid cells, being positive for CD3, were dominant. Large blastic cells, positive for CD20, some of them with a Sternberg-like appearance, could be found, in a spitty pattern. Histiocytes were abundant and positive to CD68. Proliferation index (Ki-67) ranged between 13 and 24.5% being the stain mainly positive for B-cells and in a certain extent, also for T-cells. Ultrastructural features were closer to those of the NHL than to the ones found in HD. Molecular study failed to prove any rearrangement.

CONCLUSIONS

TRBL is a rare entity between B-cell NHL group. Diagnosis and differential diagnosis (mostly with HD and T-cell NHL) have to be properly made, because of the very distinct prognosis and therapy.

[Expression of latent membrane protein (LMP) in large-cell anaplastic lymphomas]

PURPOSE

The presence of Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP) was investigated in 40 cases of lymphoproliferative diseases which include Hodgkin's disease (HD), anaplastic large cell lymphoma (ALCL) and non-Hodgkin's lymphoma (NHL) of B and T-cell nature.

MATERIAL AND METHODS

All cases were immunophenotyped in paraffin-embedded lymph node tissues, with a complete panel of monoclonal antibodies against B-cells, T-cells, histiocytes, activation and proliferation markers and classified as: 24 anaplastic large cell lymphoma (ALCL, 8 classical type and 16 ALCL-HD related), 10 lymphocyte predominant HD (LP, 5 classical type and 5 with ALCL areas), 4 NHL (two T-Cell type and 2 T-cell rich B-cell NHL). Immunohistochemistry techniques were performed ABC-complex and phosphatase alkaline anti-phosphatase alkaline (APAAP).

RESULTS

LMP was detected in 35% (14/40) of total cases. In LP group one third of cases were LMP+. In ALCL-HD related cases 44% were LMP+ versus 13% in ALCL group. All LMP cases were CD30+ except one NHL-T and a T-cell rich B-cell NHL. The predominant immunophenotype was LMP+/CD20+ (57%) versus LMP+/CD20-. Most cases were of B-cell (36%) lineage. Null ALCL cases were LMP-.

CONCLUSIONS

LMP, the most oncogenic EBV protein could play a pathogenic role in lymphoproliferative processes. It is not exclusive of HD and appears in other NHL preferentially of B-cell nature, above all in ALCL cases relating the two neoplasias HD and ALCL, both CD30 positive.

[Large-cell anaplastic lymphomas: a genetic and immunophenotypic study]

PURPOSE

To characterize from a genetic point of view a group of non-Hodgkin's anaplastic large-cell lymphomas (ALCL) by Southern blot and PCR methods with different probes (molecular study) and with direct or post 24-78 hours cultures with GTC banding techniques (cytogenetic). To correlate the results to the immunophenotype performed with a complete panel of monoclonal antibodies (MoAb) according to avidin-biotine and alkaline phosphatase (APAAP) methods.

MATERIAL AND METHODS

Sixty cases of ALCL were reviewed and only 19 selected (with frozen or fresh material) because a complete immunohistologic and genotypic correlation had been done. According to CD15 expression two groups were considered, CD15+ (the so-called Hodgkin's related or Hodgkin's like) and CD15- or classical type.

RESULTS

Only 26.5% of cases showed immuno -genotypic correlation. Immunohistochemistry is an accurate method for activation, proliferation and B-cell nature, but T-cell cases were not stained because T-cell paraffin markers are not completely specific. CD15 group had only 30% rearranged cases with scarce cytogenetic abnormalities, as it occurs in Hodgkin's disease (HD). ALCL classical type showed 66% rearranged cases, and one of the T-cell cases showed an incomplete t (2:5) translocation or polyploid cell lines.

CONCLUSIONS

Both groups have different genetic and immunophenotypic behaviour which resembles HD or NHL. CD15 positive cases or ALCL HD-related constitute a borderline entity which has to be recognized because of the different therapy and clinical behaviour.

[Characterization of mutation of the P53 gene in lymphomas]

PURPOSE

To analyze P53 mutations in a series of NHL and to determine its implication in the inactivation of the tumor suppressor function.

MATERIAL AND METHODS

We analyzed 18 lymphomas by SSCP (exons 5 to 9) and subsequent sequencing technics to detect and characterize mutations on this gene. Loss of heterozigosity (LOH) was also studied with a VNTR near the p53 gene and with a intragenic microsatellite, comparing tumor and normal tissue.

RESULTS

We found altered bands by SSCP in 5 cases, 4 of them have been described by sequencing analysis. One case was a polymorphism and the others were missense mutations. All mutations appeared in high grade lymphomas. Only one case showed LOH in both VNTR and microsatellite.

CONCLUSIONS

This results suggest that p53 mutations may be associated with more malignant lymphomas.

[Radical surgery of locally advanced prostatic cancer]

Retrospective study in 51 patient with locally advanced prostate cancer (34 pT3 and 17 N+) selected from 88 radical prostatectomies performed between February 1985 and December 1993. An evaluation is made of the clinical/pathological stage correlation and the effectiveness of the different diagnostic methods (61% of understaging). The possibility to rescue locally spread tumours is analyzed, 7/51 (13.72%) patients receiving pre-operative neoadjuvant hormonal therapy. Estimated survival at 8 years was 82.6% of all patients treated with radical surgery and, at the end of the study, the situation of 30/46 (65.2%) patients assessed by digital rectal examination, quality of life index, PSA follow-up, abdominal ultrasound and/or CT, bone scan and chest X-ray, was an estimated 8-year disease-free evolution. It is observed that radical surgery and the post-surgical hormonal approach permit good survival in locally advanced prostate cancer and that the use of a neoadjuvant hormonal approach permit good survival in locally advanced prostate cancer and that the use of a neoadjuvant hormonal approach allows in many cases the rescue of patients for radical surgery.

Genetic instability of microsatellites in hematological neoplasms

Genetic instability has been recently related to point mutations on genes involved in DNA repair pathway of errors produced during replication. These molecular alterations have been described in hereditary and sporadic colon carcinomas and related tumors. To examine genetic instability on lympho- and myeloproliferative processes, we analyzed the behaviour of 10 microsatellite markers and one VNTR on different chromosomes in 10 patients with non-Hodgkin lymphomas (NHL), one patient with acute lymphoblastic leukemia (ALL) and 10 patients with acute myeloid leukemia (AML). Mobility shifts were found in three of those cases. One of them showed genetic instability for several markers--microsatellites and VNTR- and the other two showed differences for only one marker. As a correlation between point mutations in MSH2 gene and the presence of genetic instability in hereditary non-polyposis colon cancer (HNPCC) and related tumors has been found, we analyzed the sequence of a conversed region of this gene in the cases showing this phenomenon. We only found a polymorphism, previously described, in 669 codon from cDNA.

[Evaluation of specificity of pneumococcal antigen detection in clinical samples by using the polymerase chain reaction as reference method]

BACKGROUND

Sensitivity and specificity of latex agglutination test on samples obtained by transthoracic needle aspiration was evaluated for diagnosis of pneumococcal pneumonia by using the polymerase chain reaction as reference method.

METHODS

Samples from 29 patients with community acquired pneumonia were processed for culture, antigen detection and polymerase chain reaction. The latex agglutination test was performed with a reagents kit (Slidex méningite kit, BioMérieux, France) using the procedure recommended by the manufacturer. The polymerase chain reaction was carried out by using two primers: Pn2x up and Pn2x down that amplify the PBP2x gene of Streptococcus pneumoniae.

RESULTS

Culture was positive in 5 patients, antigen detection in 15 and polymerase chain reaction in 14 patients. The specificity of latex agglutination test was 93% compared with polymerase chain reaction as reference method.

CONCLUSION

The pneumococcal antigen detection by latex agglutination test is as sensitive as the polymerase chain reaction, it seems to be highly specific, and it is rapid and easy to perform.

B-cell follicular lymphomas: clinical and biological characteristics

Seventy cases of follicular B-cell lymphomas were studied: 37 cases derived from the follicular centre [27 centroblastic-centrocytic (CB-CC) and 10 centroblastic (CB)] and 33 from the mantle zone [mantle-cell lymphoma (ML)]. Presenting features as well as response to therapy, time free of symptoms and survival were reviewed. All the cases were diagnosed and classified with routine and immunohistochemistry methods. In 61 cases tumors were studied with specific markers in a CAS-200 Image Analyser. Flow cytometry (FCM) was also done and correlated with proliferative-values and survival. A minor aggressive course of CB-CC and ML was demonstrated, with ML being the most benign form (lower proliferation rate and longest survival). Ploidy did not correlate with histological subtypes, survival or response to therapy. These results confirm the utility of biodynamic studies in lymphoid neoplasias.

Chemical and 13C NMR studies of Enterolobium cyclocarpum gum and its degradation products

A structural study of the gum exudate from Enterolobium cyclocarpum has been carried out using chemical methods and 13C NMR spectroscopy. The results reveal that the structure of this gum is essentially a beta-(1-->3)-galactan. Some galactoses are 6-O-linked and others also occur as terminal residues. There is evidence that supports the presence of alpha-L-arabinofuranose and beta-L-arabinopyranose. beta-D-Glucuronic acid may be present as terminal and internal residues, while the 4-O-methyl-alpha-D-glucuronic acid residues exist predominantly in internal positions.

Chemical and spectroscopic studies of Cercidium praecox gum exudate

The structure of the polysaccharide from Cercidium praecox (R&P) Harms gum exudate has been studied by Smith degradation, by sugar and methylation analyses, and by 13C NMR spectroscopy. The results showed a (1-->4)-xylan core. Some xylose residues are substituted at O-2 by alpha-D-glucuronic acid and 4-O-methyl-alpha-D-glucuronic acid residues. beta-D-Glucuronic acid is present, probably as terminal residues. The arabinose is present as alpha-L-furanose and beta-L-pyranose.

Efficacy of Chemical Disinfectants against Turbot Aquareovirus

The susceptibility of turbot aquareovirus to five chemical agents was examined. Treatment with 5 mg of malachite green per liter or 500 mg of iodine per liter resulted in a 90% reduction in virus titer within 1 h. Complete inactivation within 5 min was obtained with 2% formalin, 42.5% isopropanol, or 15 mg of free available chlorine per liter. Lower concentrations of chlorine were ineffective.

[Detection of monoclonality in non-Hodgkin's B-cell lymphomas using PCR]

PURPOSE

To evaluate the reliability of a PCR technique for the detection of monoclonal B-cell non-Hodgkin's lymphoma (NHL) in a group of patients previously showing monoclonal gene rearrangement with Southern Blot techniques.

PATIENTS AND METHODS

A group of 22 cases of NHL were studied with immunocytochemical techniques by means of a complete monoclonal antibody panel after previous demonstration of monoclonal rearrangement with the JH probe. Specific Fr2 and Fr3 priming of the variable regions of the IgH genes was used. One positive and two negative controls were used on each PCR test.

RESULTS

Monoclonal lymphoma was detected in 18 cases (82%), seven of them with Fr2 and Fr3, whereas five cases had Fr2 and the remainders had only Fr3.

CONCLUSION

PCR seems a good alternative for detecting monoclonal lymphoproliferative syndromes instead of Southern Blot due to both its specificity and high sensitivity. The hypotheses to explain false negative results are discussed.

Chronic recurrent multifocal osteomyelitis after acute lymphoblastic leukaemia

We describe an 8 year old girl who developed chronic recurrent multifocal osteomyelitis (CRMO) in the ilium and clavicle. Treatment for an acute lymphoblastic leukaemia had been finished two months before. After antibiotic therapy, the clinical symptoms improved and no fresh lesions appeared. The aetiology of CRMO is unknown, but we feel that infection may precipitate an immunological reaction.

DNA content in non-Hodgkin's lymphoma. Comparison between flow cytometry and cytogenetics in fresh and paraffin-embedded tissue

DNA content of 36-non-Hodgkin's lymphomas was analyzed by flow cytometry (FCM) and cytogenetics (CG), 21 in fresh and 15 in paraffin-embedded tissue. The results of both techniques were coincident in 60% of the fresh tissue samples and in 45% of the paraffin-embedded ones, the reason for this difference could be the poor resolution of DNA histograms from paraffin-embedded tissue. All samples judged as aneuploid by FCM were aneuploid also by CG. Some samples with a hyperdiploid population by CG gave a diploid population by FCM with a 'false' high DNA-synthesis (S) fraction. From a technical point of view, CG and FCM have to be performed on the same fresh tissue.

[Biology of secondary nodal follicular b-lymphomas. A patho-dynamic study]

PURPOSE

To assess the aggressivity factors and tumour prognosis in a series of non-Hodgkin lymphomas by the use of computer-quantified specific antibodies and flow cytometry.

PATIENTS AND METHODS

Sixty-one cases of follicular B-cell lymphoma: 34 of the germinal centre (24 centroblastic-centrocytic, CB-CC, and 10 centroblastic, CC) and 27 of the follicular cortex (FCL), were studied. All the cases had been diagnosed between 1971 and 1992 at the Pathology Department of the Fundación Jiménez Díaz. Morphologic and immunophenotype diagnosis was made on each case. Tumour proliferation studies were performed after labelling nuclei with proliferent nucleic acid-associated protein (PC 10); the positive nuclear areas were later quantified in a CAS-200 image analyser by means of proliferation programmes (PI) and nuclear receptors (ER). A flow cytometry study of ploidy was carried out on each case. The values attained were correlated with survival in months. The Wilcoxon's test for independent variables was used for the statistical study.

RESULTS

The PI programme showed lowest proliferation for FCL (7.4%) followed by intermediate proliferation in CB-CC (16.9%) and high proliferation in CB (31.7%). The PC-10 results attained with both PI and ER programmes showed statistically significant correlation (p < 0.01). The correlation between ploidy, as quantified by flow cytometry, and survival showed statistically significant differences between diploid and aneuploid cases (p < 0.01); similar findings apply for diploids and diploids with high synthesis phase (p < 0.01).

CONCLUSION

These findings support the usefulness of cell kinetics studies in lymphoma, and contribute to validate different evolutive patterns in accordance with the histologic subtype.

The detection of B-cell monoclonal populations by polymerase chain reaction: accuracy of approach and application in gastric endoscopic biopsy specimens

The recently developed strategy for the detection of monoclonal B-cell populations, based on the selective amplification of predominant immunoglobulin heavy chain gene (IgH) rearrangement, is seen to be a suitable alternative to Southern blot analysis. The new technique uses a pair of consensus primers for variable (VH) and joining (JH) regions. We first tested the accuracy of this new approach on a broad series of 67 samples that had been well characterized by both Southern blot and immunohistochemical techniques before being subjected to blind testing. Our results show that this technique gave 100% specificity (absence of false-positive results) and approximately 70% sensitivity (30% false-negative results). The only exception was the presence of an IgH polymerase chain reaction ambiguous result in a case of Sezary's syndrome. The polymerase chain reaction technique was then applied to a panel of 27 frozen gastric endoscopy biopsy specimens following previous clinical suspicion of lymphoma. Monoclonality was detected in nine of 13 samples previously diagnosed as lymphomas and in one of two carcinomas. Further examination of the gastrectomy specimen in the latter case disclosed a B-cell lymphoma associated with the carcinoma. In spite of its limited sensitivity, the high specificity attained by this technique in the detection of monoclonality makes it a useful adjunct to routine morphologic criteria, as it is sometimes capable of detecting true positive cases that conventional morphology studies show to be negative.

[Follicular mantle lymphoma: clinicopathologic and cell proliferation of 11 cases]

BACKGROUND

The aim of the present was to study the biologic behavior of the lymphomas of the follicular mantle by analysis of different indexes of neoplastic cell proliferation and their relation with the clinical symptoms, prognosis and survival of the patients.

METHODS

Light microscope, ultrastructural, and frozen and paraffin immunohistochemical studies were performed including the proliferative markers Ki-67 and PC10, flow cytometry and analysis of cell cycle in biopsy samples. Clinical data of 11 patients were collected in addition to therapeutic response and survival.

RESULTS

Lymphoma of the follicular mantle is constituted by small sized cell elements with a variable pattern of tumoral growth in the lymph nodes. In normal lymphocytes of the follicular mantle the immunophenotype shows expression of IgM + IgD and a light chain in the cell surface. From a clinical point of view, massive splenomegaly and disseminated stage are the most outstanding characteristics. One third of the cases analyzed presented an aneuploid neoplastic population. According to the PC10 marker, the proliferative index ranged from 2.9 to 14.7% of neoplastic cellularity (mean 7.0). The percentage of cells in the phases S, G2 and M of the cell cycle by flow cytometry varied from 14 to 35 (mean 23%). Neither the cell ploidy nor the tumoral proliferative index were related with the survival of the patients (53 +/- 51 months).

CONCLUSIONS

Lymphoma of the follicular mantle is a clinical pathological entity of low biologic aggressivity. Cell aneuploidy or ploidy and the tumoral proliferative index did not establish differences in prognosis or survival in this series.

Formation of a perbenzoic acid derivative in the photodegradation of fenofibrate: phototoxicity studies on erythrocytes

The phototoxic antihyperlipoproteinemic drug fenofibrate (1) is photolabile under aerobic conditions. Irradiation of a methanol solution of 1 produces, under oxygen, photoproducts 2, 3, and 4. A peroxidic photoproduct 2 was isolated and identified. The biologically active antioxidants glutathione and cysteine efficiently reduce 2 to its acid. This photoproduct was also capable of efficiently oxidizing tetramethyl phenylendiamine (TMP) through an electron transfer mechanism, detecting a TMP+ species by UV-visible spectrometry. Fenofibrate was screened in vitro at different concentrations for UV-visible-induced phototoxic effects in a photohemolysis test, under oxygen as well as argon. The photohemolysis rate was low under anaerobic conditions. No hemolysis occurred without irradiation. The isolated photoproduct 2 induced hemolysis without irradiation.

Photodegradation of benzydamine: phototoxicity of an isolated photoproduct on erythrocytes

Benzydamine hydrochloride (Tantum, 1) is a photoallergic and phototoxic anti-inflammatory and analgesic agent. This drug is photolabile under aerobic and anaerobic conditions. Irradiation of a methanol solution of benzydamine under oxygen or argon at 300 nm affords 5-hydroxybenzydamine (2) and 2-beta-dimethylaminopropyl-1-benzylindalolin-3-one (3) as the main isolated and spectroscopically identified photoproducts. A radical intermediate was evidenced by thiobarbituric acid that was used as a radical sonde, as well as by the dimerization of cysteine. Erythrocyte lysis photosensitized by 1, 2, and 3 was investigated.

Peripheral T-cell lymphoma: a clinicopathological study of 41 cases and evaluation of the prognostic significance of the updated Kiel classification

A total of 41 non-cutaneous peripheral T-cell lymphomas were classified following the updated Kiel classification. Of these, 20 cases belonged to the low-grade group (T-cell chronic lymphocytic leukaemia, 3; lymphoepithelioid, 5; angioimmunoblastic, 4; pleomorphic small cell, 8) and 21 to the high grade group (pleomorphic medium and large cell, 11; immunoblastic, 3; large-cell anaplastic Ki-1 positive, 7). Seventy per cent showed a CD4+/CD8-phenotype, 39% a defective phenotype and 88% an activation phenotype. Eighty per cent had B-symptoms, 63% hepatomegaly, 48% splenomegaly and 26% had involvement of more than three lymphoid areas. Bone marrow was infiltrated in 34%, central nervous system in 4%, lung in 12% and skin in 14.6%. Seventeen per cent presented with extranodal disease and 82.8% had stage III/IV disease. Hypergammaglobulinaemia was found in 29%, hypercalcaemia in 7%, raised LDH serum levels in 58% and HTLV-I antibodies in only one case. Of the 37 treated patients 18 (48%) achieved a complete remission, but 33% relapsed. Mortality was 59% and actuarial overall survival at 38 months was 0.32. In the comparison of the clinical, analytical and immunophenotypic variables and outcome between low and high grade groups, only the average of bone marrow infiltration in the low grade and stage I-II, presence of defective phenotypes and higher Ki-67 positivity in the high grade group were significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

[Detection of Pneumocystis carinii in clinical samples by the polymerase chain reaction. Comparison with the methenamine silver technique]

BACKGROUND

A comparison of polymerase chain reaction (PCR) with methenamine silver stain was performed on clinical specimens for diagnosis of Pneumocystis carinii pneumonia in immunosuppressed patients.

METHODS

25 clinical samples (10 induced sputa, 12 transthoracic needle aspirations and 2 bronchoalveolar lavages) from 17 patients with AIDS and respiratory symptoms were studied. We performed DNA amplification by using 2 primers that amplify the mitochondrial large rDNA sequence of P. carinii.

RESULTS

The sensitivity and specificity of the PCR technique were 92.8% and 100% respectively, with a positive predictive value of 100% and negative predictive value of 92.3%. The sensitivity of the silver stain were 65%, specificity 100%, positive predictive value 100% and negative predictive value 63%.

CONCLUSION

The PCR technique is more sensitive than the methenamine silver stain for detecting Pneumocystis carinii in respiratory specimens from patients with pneumonia. Consequently it could be a very good alternative to classical methods in diagnosis of P. carinii infections.

Primary pleomorphic T-cell lymphoma of the spleen

We report a case of primary splenic T-cell lymphoma that posed difficult problems in differential diagnosis with erythrophagocytic T-gamma lymphoma and inflammatory pseudotumor of the spleen. The need for immunophenotypic and molecular studies for establishing the correct diagnosis and the importance of early detection and treatment, is emphasized in the light of the relatively good prognosis of splenic lymphoma, diagnosed in the early stages of disease.

[Acute toxoplasmosis. Laboratory diagnosis]

BACKGROUND

The microbiological diagnosis of acute toxoplasmosis in immunosuppressed patients, cannot, usually, be done through serological techniques. The methods for isolation or direct detection of parasite are the only ones that might be helpful to determine an earlier diagnosis, on these patients.

METHODS AND RESULTS

The use of urine in 3 patients with acute toxoplasmosis, allowed us to isolate the parasite after inoculation of the sample in human embryonic fibroblast cell line (MRC-5).

CONCLUSION

In our opinion urine could be an adequate sample for isolation or detection of Toxoplasma gondii in immunosuppressed patients, and an alternative to serological methods, as well.

Photoproducts of benzydamine and azapropazone: demonstration of their phototoxicity in vitro

Red blood cell lysis, photosensitized by the products of the aerobic photolysis of benzydamine (1) and azapropazone (4), was investigated. Irradiation of a methanol solution of 1 and 4 under oxygen produces the photoproducts 3-hydroxy-benzydamine, (2), 2-(3-dimethylaminopropyl)-1-benzylindazolin-3-one (3) and 3-dimethylamino-7-methyl-1,2,4-benzotriazine (5). The mechanism of the photodegradation of 1 was examined. Photoproducts 3 and 5 produce singlet oxygen as demonstrated by trapping with 2,5-dimethylfuran. The photohemolysis rate for the photoproducts 3 and 5 was enhanced by deuterium oxide and oxygen. No change was observed in the presence of reduced glutathione. The photohemolysis rate was low under anaerobic conditions.

Pathogenic activities of live cells and extracellular products of the fish pathogen Pasteurella piscicida

The pathobiological activities in vivo and in vitro of live cells and extracellular products (ECP) of eleven Pasteurella piscicida strains of different origin were examined. Infectivity trials showed that P. piscicida did not possess strict host specificity since the majority of the isolates were virulent for gilthead seabream, rainbow trout and turbot, with LD50 values ranging between 10(3) and 10(6) live cells. However, none of the strains tested were pathogenic for mice (LD50 > 10(8) cells)). In addition, the ECP were strongly toxic for fish (LD50 ranging from 1.0 to 4.6 micrograms protein per g fish), which clearly demonstrates their important role in the pathogenesis of pasteurellosis. All the ECP samples were cytotoxic for fish and homoiothermic cell lines, possessed notable phospholipase activity and displayed haemolytic activity for sheep, salmon and turbot erythrocytes (but not for trout erythrocytes). However, the production of proteolytic enzymes differed among the P. piscicida strains. Although no strain displayed elastase activity, five isolates (the Japanese and Italian strains) hydrolysed casein and gelatin. All these biological activities in vivo and in vitro were lost after heat treatment (100 degrees C for 10 min). The general enzymic patterns of both live cells and ECP evaluated by the API-ZYM system also revealed some variation among the P. piscicida isolates. Generally, whole cells showed a wider range of enzymic activities than ECP. The results presented here are important for the selection of strains in the development of effective polyvalent pasteurellosis vaccines containing both whole cells and ECP.

[Castleman's disease. A multifactorial study]

A case of Castleman's disease (hialino-vascular subtype) in a female patient 15-years-old is considered. Clinically there were isolated lymphadenopathies which relapsed after surgery and absence of general syndrome. Histoimmunological and electron microscopic studies were performed as DNA rearrangement and cytogenetics in order to exclude genetic abnormalities and monoclonality of this disorder. The role of follicular dendritic component in discussed.

[T-lymphomas with splenic presentation]

Three cases of lymphomas with splenomegaly onset, without peripheric adenopathies, which required laparotomy to be diagnosed, are discussed. One of the cases was a primary splenic lymphoma and the other two were associated with reactive hemophagocytosis. Other malign lymphoproliferative processes of predominant splenic onset are discussed.