[Non-Hodgkin's lymphomas associated with the acquired immunodeficiency syndrome. A multicenter clinical study of 77 cases]

BACKGROUND

The aim of the present was to study the prevalence of non Hodgkin's lymphoma (NHL) in AIDS patients as well as the clinicopathologic characteristics, response to treatment and survival.

METHODS

From January 1984 to January 1991, 77 patients with NHL associated with AIDS diagnosed in 9 hospitals in Madrid were retrospectively studied.

RESULTS

Ninety-two per cent of the patients were men (mean age 30 years: range: 9-66 years), 62% were intravenous drug abusers and 20 (26%) homosexuals. Pathologic study determined that 62 (80%) patients had high grade NHL (44% small noncleaved), 17% immunoblastic and 20% unclassifiable, and 15 (20%) had intermediate grade (16% diffuse large cell) being all the cases of the B immunophenotype. Sixty-five per cent were in advanced stages and 69% had B symptoms. Extranodal localizations were present in 88%, bone marrow in 29% and CNS in 29%. Six cases had primary CNS lymphomas. 50% of the patients had less than 200 x 10(6)/l CD4 lymphocytes. Forty-seven patients were evaluable for response to chemotherapy: 12 (26%) showed a complete response 27 (57%) a partial response and 8 (17%) did not respond. Opportunistic infections developed in 18%. The estimated survival at 3 years was 14% (median 6 months). On univariate analysis the parameters related to the worst survival were: primary CNS lymphoma, liver involvement, lack of treatment response, LDH > or = 300 UI/l, alkaline phosphatase > or = 500 UI/l and ESR > or = 70 mm.

CONCLUSIONS

Non Hodgkin's lymphomas associated with AIDS usually behave in an "aggressive" way with a high frequency of advanced stages, B symptoms, high grade histologic subtypes and extranodal involvement. Response to treatment is poor, bone marrow toxicity frequent and survival short.

Mutations in the p16INK4/MTS1/CDKN2, p15INK4B/MTS2, and p18 genes in primary and metastatic lung cancer

We examined the genomic status of cyclin-dependent kinase-4 and -6 inhibitors, p16INK4,p15INK4B, and p18, in 40 primary lung cancers and 31 metastatic lung cancers. Alterations of the p16INK4 gene were detected in 6 (2 insertions and 4 homozygous deletions) of 22 metastatic non-small cell lung cancers (NSCLCs; 27%), but none were detected in 25 primary NSCLCs, 15 primary small cell lung cancers (SCLCs), or 9 metastatic SCLCs, indicating that mutation in the p16INK4 gene is a late event in NSCLC carcinogenesis. Although three intragenic mutations of the p15INK4B gene were detected in 25 primary NSCLCs (12%) and five homozygous deletions of the p15INK4B gene were detected in 22 NSCLCs (23%), no genetic alterations of the p15INK4B gene were found in primary and metastatic SCLCs. The p18 gene was wild type in these 71 lung cancers, except 1 metastatic NSCLC which showed loss of heterozygosity. We also examined alterations of these three genes and expression of p16INK4 in 21 human lung cancer cell lines. Alterations of the p16INK4 and p15INK4B genes were detected in 71% of the NSCLC cell lines (n = 14) and 50% of the NSCLC cell lines (n = 14), respectively, but there were none in the 7 SCLC cell lines studied. No p18 mutations were detected in these 21 cell lines. These results indicate that both p16INK4 and p15INK4B gene mutations are associated with tumor progression of a subset of NSCLC, but not of SCLC, and that p15INK4B mutations might also be an early event in the molecular pathogenesis of a subset of NSCLC.

Gastric B-cell mucosa-associated lymphoid tissue (MALT) lymphoma. Clinicopathological study and evaluation of the prognostic factors in 143 patients

BACKGROUND

Gastric MALT lymphoma can be histologically classified into two groups, low-grade (LG) and high-grade (HG); however, their natural history is poorly understood. We have studied a large retrospective series aiming to confirm whether the histological groups confer different clinical features and behavior and to analyze the prognostic factors in these patients.

PATIENTS AND METHODS

A series of 143 gastric B-cell MALT lymphomas is reported. Eighty-four were low-grade lymphomas (LG) and 59 were high-grade lymphomas (HG). Median follow-up was 36 months. The clinical and analytical parameters of the 84 LG patients were compared with those of the 59 HG patients. In the patients who had been operated on, the pathological features (macroscopical patterns, tumor size, involvement of resection margins, degree of parietal invasion and involvement of abdominal lymph nodes and adjacent viscera) of the LG patients were compared with those of the HG patients. The sites of relapses were studied. In the 132 treated and followed-up patients the influence of the treatment and that of clinical, analytical and pathological features on survival were investigated with the Kaplan and Meier and log-rank tests. To identify the factors with independent influence on survival, a Cox model was fitted for the whole series and separately for 53 HG patients.

RESULTS

HG group differed from the LG group by a significantly higher frequency of weight loss at presentation, palpable abdominal mass, hepatomegaly, peripheral lymphadenopathy, elevated serum LDH, higher incidence of stage III-IV and tumor/mass patterns in the endoscopy and in the gastrectomy specimen. The tumor was significantly larger in the HG group than in the LG and the deeper invasion of the gastric wall, the higher frequency of infiltration of the abdominal lymph nodes and the visceral extension were also significant in the HG group. Complete remission (CR) was achieved in 91% of the patients of the LG group, but was significantly lower, 70%, in the HG group. Relapses occurred in the stomach and also in non-MALT sites. In 132 treated and followed-up patients, elevated serum LDH, absence of CR, HG group and stage III-IV were associated with a worse survival. In the Cox multivariate model, stage was the only variable influencing survival, although stage was related to the histological grade. In the HG group, stage was also an independent significant risk factor, whereas treatment with surgery, chemotherapy or both was not. In the 103 patients treated with surgery, a worse survival was associated with the involvement of the resection borders, depth of the infiltration of the gastric wall, dissemination to distant abdominal nodes and adjacent organs, but not with the addition of chemotherapy.

CONCLUSIONS

Histological classification into LG and HG separates distinctive groups of gastric MALT lymphoma that show striking clinical and prognostic differences. Besides histological grade, stage is the most important prognostic feature.

Inhibition of ras-induced proliferation and cellular transformation by p16INK4

The cyclin-dependent kinase 4 (CDK4) regulates progression through the G1 phase of the cell cycle. The activity of CDK4 is controlled by the opposing effects of the D-type cyclin, an activating subunit, and p16INK4, an inhibitory subunit. Ectopic expression of p16INK4 blocked entry into S phase of the cell cycle induced by oncogenic Ha-Ras, and this block was relieved by coexpression of a catalytically inactive CDK4 mutant. Expression of p16INK4 suppressed cellular transformation of primary rat embryo fibroblasts by oncogenic Ha-Ras and Myc, but not by Ha-Ras and E1a. Together, these observations provide direct evidence that p16INK4 can inhibit cell growth.

Pneumonia caused by Listeria monocytogenes

Pneumonia due to Listeria monocytogenes is extremely uncommon. We report the case of an 87-year-old woman with no underlying immunosuppressive disease who presented with listerial pneumonia. Cutaneous anergy and a decrease in total lymphocyte count in this elderly woman could predispose her to listerial infection.

Cost efficient management of educational material

We retrospectively examined direct and indirect costs of providing a programmed text in Respiratory Pathophysiology using World-Wide Web (WWW) technology as compared to printed paper. The direct costs were $3678 and $3988 respectively. Neither of these costs includes the substantial cost of original development of the educational material. The indirect cost of distributing printed material is $1800. The indirect cost for electronic material is $1430 but this assumes an institutional commitment to a technology infrastructure which will be used for purposes other than just educational material distribution. Given such a commitment, educational material can be managed in a way that provides efficient distribution at less cost than traditional paper distribution. The effectiveness of electronic methods is dependent on usage. A comparison study of use and satisfaction of paper and electronic versions of the material is planned.

[The follow-up of transposition of the great arteries corrected by Senning's technic]

INTRODUCTION AND OBJECTIVES

The incidence of late complications after a physiological correction of the patients with transposition of the great arteries (D-TGA) is very significant, due to the alternative operation of the arterial switch.

METHODS

We studied 125 patients with D-TGA, treated with Senning surgical correction between december of 1978 and november of 1990. Surgery was performed at a mean age of 11.7 months (from 7 days to 11.2 years), and the postoperative mean follow-up was 7.3 years (from 1.4 to 14.3 years). We analyzed their evolutive clinical condition, ECG, Holter and echocardiogram-Doppler. Four groups were defined: A) Simple, 48.8%. B) Associated with ventricular septal defect, 22.4%. C) With pulmonary stenosis, 15.2%. D) Both anomalies, 13.6%.

RESULTS

Sixteen children died (12.8%), 11 of them on the postoperative period. The remaining 5 patients died, at a mean time of 34.3 months after surgery, because they were in cardiac failure. All of patients had enlargement of right ventricle and tricuspid regurgitation was observed in 39 children. There were 3 reoperations. Atrioventricular block was observed in 5.7% of the patients, 33.3% were not in sinus rhythm, 6.6% had atrial flutter-fibrillation, sinus node dysfunction was observed in 24.7%, and five permanent pacemakers were implanted (4.7%).

CONCLUSIONS

The later mortality is not high, and the clinical outcome is good, but the frequent rhythm disturbances and enlargement of the right ventricle could let us conclude the hypothesis that anatomical correction is an optimal alternative procedure.

Mutations and altered expression of p16INK4 in human cancer

Cell cycle arrest at the G1 checkpoint allows completion of critical macromolecular events prior to S phase. Regulators of the G1 checkpoint include an inhibitor of cyclin-dependent kinase, p16INK4; two tumor-suppressor proteins, p53 and RB (the product of the retinoblastoma-susceptibility gene); and cyclin D1. Neither p16INK4 nor the RB protein was detected in 28 of 29 tumor cell lines from human lung, esophagus, liver, colon, and pancreas. The presence of p16INK4 protein is inversely correlated with detectable RB or cyclin D1 proteins and is not correlated with p53 mutations. Homozygous deletions of p16INK4 were detected in several cell lines, but intragenic mutations of this gene were unusual in either cell lines or primary tumors. Transfection of the p16INK4 cDNA expression vector into carcinoma cells inhibits their colony-forming efficiency and the p16INK4 expressing cells are selected against with continued passage in vitro. These results are consistent with the hypothesis that p16INK4 is a tumor-suppressor protein and that genetic and epigenetic abnormalities in genes controlling the G1 checkpoint can lead to both escape from senescence and cancer formation.

[The combined treatment of anaplastic thyroid carcinoma]

Five patients with anaplastic thyroid carcinoma (ATC) were treated with chemotherapy (adriamycin 60 mg/m2 and cisplatin 90 mg/m2) followed by surgery and postoperative radiotherapy. The average survival in this series was 11.2 months. Partial response of the cervical tumoration was observed in 4 patients and of the distant metastasis, in 1 of 3 cases. One patient with mixed thyroid carcinoma (follicular and anaplastic) had complete remission of the disease. Four patients died: two due to metastatic disease and two due to local tumor growth. We conclude that this type of combined therapy is affective in patients with anaplastic thyroid carcinoma in terms of local control of the disease, avoiding mortality due to local invasion in some of these patients.

DNA structure in the nucleoprotein complex that activates replication of phage phi 29

Initiation of phage phi 29 DNA replication is activated by the viral protein p6 which forms a nucleoprotein complex at the replication origins, located at the linear genome ends. The complex consists of a DNA right-handed superhelix wrapped around a multimeric protein core. We have determined the superhelical path of the DNA in the complex, measuring the change in linking number induced by the protein, the surface-related helical repeat and the compaction of the DNA. One superhelical turn has approximately 63 bp (2.6 p6 dimers). Furthermore, we have determined that the DNA binding domain of protein p6 is located at the N-terminal region, predicted to form an amphipathic alpha-helix. We have obtained, by site-directed mutagenesis, protein p6 mutants in the polar side of the putative helix in which their DNA binding and replication activation properties were impaired or undetectable, in agreement with in vivo results.

Phage phi 29 protein p6: a viral histone-like protein

Phage phi 29 protein p6 is one of the most abundant viral proteins in phi 29-infected B subtilis cells, constituting about 4% of the total cellular proteins (about 3 x 10(6) copies/cell) at late infection. Electron microscopic studies showed that, in vitro, protein p6 forms heterogeneously-sized complexes all along phi 29 DNA, suggesting that protein p6 may have a role in genome packaging and organization. The low stability of the protein p6-phi 29 DNA complexes observed in vitro could reflect the dynamic nature of these complexes, to allow replication, transcription, and encapsidation of the genome. The protein p6-DNA complex consists of a DNA right-handed superhelix wrapped around a multimeric protein core. The DNA in this complex is strongly distorted and compacted. Protein p6 recognition signals have been mapped near the ends of the linear phi 29 DNA and act as nucleation sites for complex formation. Protein p6 does not recognize a specific sequence, but sequences with specific bendable properties that would favor the formation of the complex. Protein p6 represses transcription from the phi 29 C2 early promoter, and activates initiation of phi 29 DNA replication that occurs from both DNA ends. The formation of nucleoprotein complexes at the origins of replication, as well as the specific positioning of protein p6 with respect to the DNA ends are required for the activation of replication. This suggests that the proteins involved in the initiation step of phi 29 DNA replication, either directly interact with protein p6, or recognize a conformational change at a specific location in the DNA. The mechanism of activation could be the local and transient unpairing of DNA at specific sites, facilitated by the strong distortion of DNA conformation in the nucleoprotein complex.

A new regulatory motif in cell-cycle control causing specific inhibition of cyclin D/CDK4

The division cycle of eukaryotic cells is regulated by a family of protein kinases known as the cyclin-dependent kinases (CDKs). The sequential activation of individual members of this family and their consequent phosphorylation of critical substrates promotes orderly progression through the cell cycle. The complexes formed by CDK4 and the D-type cyclins have been strongly implicated in the control of cell proliferation during the G1 phase. CDK4 exists, in part, as a multi-protein complex with a D-type cyclin, proliferating cell nuclear antigen and a protein, p21 (refs 7-9). CDK4 associates separately with a protein of M(r) 16K, particularly in cells lacking a functional retinoblastoma protein. Here we report the isolation of a human p16 complementary DNA and demonstrate that p16 binds to CDK4 and inhibits the catalytic activity of the CDK4/cyclin D enzymes. p16 seems to act in a regulatory feedback circuit with CDK4, D-type cyclins and retinoblastoma protein.

[Chronic renal insufficiency and secondary hyperparathyroidism in rats. Biochemical and histological evaluation]

Chronic renal failure (CRF) in rats (surgical nephrectomy, 5/6) as well as its derived bone lesions have been studied. Eighty-five male Wistar rats were used, to which chronic renal failure was induced in 1 or 2 surgical times, the parameters of renal function in basal conditions and at different times after surgery being determined. With the method used chronic renal failure is induced with values of creatinine clearance 2/3 times lower than the initial ones (p < 0.05), which stabilize at the 7th week. On the other hand the parathyroid hormone levels (PTH) in serum triple (from 125 +/- 49 to 395 +/- 191, p < 0.05), and a decrease in the tubular phosphate reabsorption is produced (p < 0.001). In bone histology an increase in resorption and bone formation is observed as well as paratrabecular fibrosis, all of which is compatible with the histological diagnosis of hyperparathyroidism. The model of surgical renal insufficiency with ablation of 5/6 of the renal mass, reduces renal function to 1/3 of the initial values after 7 weeks, this procedure having a 20% global mortality without differences being observed between the carrying out of nephrectomies in 1 or 2 surgical times. This degree of CRF was accompanied by secondary hyperparathyroidism both at the biochemical and histological levels, findings which are of great usefulness for future experimental studies.

Multimeric complexes formed by DNA-binding proteins of low sequence specificity

Some proteins bind to double-stranded DNA with low sequence specificity, forming regular multimeric complexes that extend over large regions of DNA, strongly distorting its conformation. Formation of these complexes at particular DNA sites usually depends on the structural ability of the DNA to follow the path imposed by the protein array. These complexes are found in both prokaryotic and eukaryotic organisms and participate in processes such as DNA replication, transcription and packaging.

[Diffuse mediastinal lipomatosis and exogenous obesity]

A case of diffuse mediastinal lipomatosis (ML) is described, associated to exogenous obesity, infrequent entity, which is comprehended within the causes which can cause mediastinal broadening. The clinical characteristics of our observation and the general aspects of interest are reviewed for this type of mediastinal affectation.

Superhelical path of the DNA in the nucleoprotein complex that activates the initiation of phage phi 29 DNA replication

Initiation of bacteriophage phi 29 DNA replication is activated by protein p6, a viral double-stranded DNA-binding protein that forms a nucleoprotein complex at the viral replication origins. This complex consists of a DNA right-handed superhelix wrapped around a multimeric protein p6 core with protein p6 dimers regularly bound every 24 base-pairs (bp). In this paper, we have constructed a concatemer formed by direct repeats of a 24 bp sequence previously proposed to act as a signal for protein p6 binding at a phi 29 replication origin. DNase I footprinting shows that protein p6 binds to the concatemer in a similar way to the phi 29 DNA replication origins but with higher affinity, indicating that the 24 bp sequence is a recognition signal for protein p6. Furthermore, the concatemer was cloned in a plasmid and, by electron microscopy, it was shown to be the highest-affinity protein p6 binding region present in the plasmid. Based on these observations, the linking number change restrained by protein p6 has been measured in a series of plasmids containing concatemers with different numbers of 24 bp repeats; from the values obtained the linking number change restrained by a single protein p6 dimer has been estimated (delta Lkd = 0.1). In addition, when protein p6-DNA complexes fixed with glutaraldehyde were analysed by electron microscopy, it was observed that protein p6 compacts 4.2-fold the length of naked DNA. These data, together with the previously known value of the surface-related DNA helical repeat in the complex (12 bp), completely define the superhelical path of the DNA in the complex: one superhelical turn approximately involves 63 bp and 2.6 protein p6 dimers, and the DNA superhelix has a diameter of 6.6 nm and a slope of 14 degrees. The data obtained also indicate that the DNA in the protein p6-DNA complex is undertwisted (11.5 bp/turn) and strongly bent (66 degrees/12 bp). These DNA conformational changes might contribute to the activation of phi 29 DNA initiation of replication by protein p6.

[Yield of laboratory tests in the detection of excessive drinkers in the work place]

BACKGROUND

The identification of personnel consuming excess quantities of alcoholic beverages in the work place is necessary due to the economic, health, and laboral problems caused by alcohol. The objectivity of laboratory tests provides great credibility and these tests have replaced other methods as the anamnesis.

METHODS

A transversal study was carried out of the employees of a Barcelona enterprise. During the periodic medical check ups the consumption of alcoholic beverages and laboratory blood tests were obtained from the employees seven days previously.

RESULTS

All the laboratory tests presented a weak positive correlation with the consumption of alcohol. The calculation of diagnostic efficacy for weekly consumption equal to or grater than 280 g of pure alcohol in a male shows that the greatest sensitivity corresponds to mean corpuscle volume (33%) followed by gammaglutamyltranspeptidase (GGT) (16%) with high specificity being observed in both (85% and 93%, respectively). The results are better in employee consuming more than or equal to 420 g of alcohol weekly.

CONCLUSIONS

The diagnostic efficacy of laboratory tests in identifying subjects with elevated consumption of alcohol in the work place has low clinical performance and the use of anamnesis on the consumption of alcoholic beverages should first be evaluated.

DNA conformational change induced by the bacteriophage phi 29 connector

Translocation of viral DNA inwards and outwards of the capsid of double-stranded DNA bacteriophages occurs through the connector, a key viral structure that is known to interact with DNA. It is shown here that phage phi 29 connector binds both linear and circular double-stranded DNA. However, DNA-mediated protection of phi 29 connectors against Staphylococcus aureus endoprotease V8 digestion suggests that binding to linear DNA is more stable than to circular DNA. Endoprotease V8-protection assays also suggest that the length of the linear DNA required to produce a stable phi 29 connector-DNA interaction is, at least, twice longer than the phi 29 connector channel. This result is confirmed by experiments of phi 29 connector-protection of DNA against DNase I digestion. Furthermore, DNA circularization assays indicate that phi 29 connectors restrain negative supercoiling when bound to linear DNA. This DNA conformational change is not observed upon binding to circular DNA and it could reflect the existence of some left-handed DNA coiling or DNA untwisting inside of the phi 29 connector channel.

[Detection of hepatitis B virus DNA in serum by gene amplification in patients with chronic hepatitis B and in patients chronic hepatitis C]

BACKGROUND

The polymerase chain reaction (PCR) constitutes important methodological progress for detecting the presence of viral nucleic acids when these are found in small quantities in serum or tissues. The aim of this study was the use of PCR to detect DNA of the hepatitis B virus (HBV) in patients with chronic HBsAg positive hepatitis (HC-B) and in patients with chronic non A non B hepatitis with antibodies against the virus of hepatitis C (anti-HCV) positive (HC-C).

METHODS

The DNA of the HBV was determined with PCR in the serum of 40 patients with HC-B and in 15 with HC-C. Moreover, the presence of anti-HCV was studied in the patients with HC-B.

RESULTS

The presence of DNA of the HBV was detected by PCR in 69% of the HC-B patients presenting HBeAg positive and DNA of the HBV negative by simple hybridization as well as in 50% of the patients with HBeAg negative, anti-HBe positive and DNA of HBV negative by simple hybridization. In addition, DNA of HBV was detected by PCR in 27% (4/15) of the subjects with HC-C, three of whom had anti-HBc antibodies. On the other hand, 20% of the patients with HC-B had anti-HCV. Anti-HCV positivity was associated to a greater hypertransaminasemia in patients with HC-B in a non replicative phase.

CONCLUSIONS

PCR is a sensitive method for detecting viral replication. Its use permits the detection of low DNA concentrations of the HBV in a low but appreciable percentage of chronic negative HBsAg hepatitis. Coinfection by the B and C viruses of hepatitis is not exceptional and explains hypertransaminasemia in some HC-B in a non replicative phase.

[Value of fine needle aspiration cytology in the diagnosis and treatment of tumors]

We report the cytologic results of 186 fine needle aspirations on accessible lymph nodes and tumoral masses as well as deep masses under radiologic control. We assessed the ratios of diagnostic accuracy and the utility of this procedure for staging solid tumors and taking therapeutic decisions.

RESULTS

sensitivity, 89.6%; specificity, 100%; positive predictive value, 100%; negative predictive value, 57% and accuracy index, 89.2%. Using this technique we detected a metastatic disease in 62% of neoplastic patients. We took a therapeutic decision (active treatment or analgesia) in accordance with the results of the cytology in 63% of patients with solid tumors. Two patients, after a transthoracic aspiration, developed pneumothorax as a complication. Cytology by fine needle aspiration is a fast and simple method for diagnosing, staging and taking a therapeutic decision on patients with solid tumors.

[The treatment of large-cell non-Hodgkin's lymphomas with the MACOP-B protocol]

BACKGROUND

To investigate the results of the treatment of large-cell non-Hodgkin's lymphomas (LCNHL) with the MACOP-B chemotherapy protocol.

METHODS

20 patients with the following inclusion criteria were treated: LCNHL with a definite majority of large lymphoid cells and absence of previous therapy, HIV infection or severe underlying diseases.

RESULTS

Three patients died during therapy and 15 (75%) achieved a complete remission. Actuarial survival after 36 months (0.66) was significantly better (p = 0.05) than that of a comparable historical series of LCNHL treated with CHOP (0.28). Age, stages III-IV, B symptoms, large lymphatic mass (LLM) and bone marrow infiltration did not negatively affect survival. The toxicity of the MACOP-B protocol was high: mucositis (65%), cytopenia (55%), neuropathy (40%), complications of steroid therapy (15%), and mortality directly related with therapy in 15%. Residual masses were found after therapy in 7% (70%) with BD, which were localized in lymphoid areas or in parenchyma (spleen and kidney). Surgical exploration showed that the residual masses were not tumoral in three cases, and in another three magnetic resonance suggested inactive disease.

CONCLUSIONS

The MACOP-B protocol is highly effective for the treatment of LCNHL. The essential prognostic factor for survival in these NHL appears to be the cell composition with a great majority of large cells.

Transcription activation at a distance by phage phi 29 protein p4. Effect of bent and non-bent intervening DNA sequences

Protein p4 of the Bacillus subtilis phage phi 29 switches on the transcription of the viral late genes by binding to the viral late promoter at a region close to the RNA polymerase binding site. Gel retardation and DNase I footprinting assays show that the presence of protein p4 is required for RNA polymerase recognition of the late promoter. The protein p4 and RNA polymerase DNA binding sites have been separated by the insertion of bent and non-bent DNA sequences of different lengths. These mutant promoters were used to study in vitro their protein p4-dependent transcriptional activity and their interaction with both protein p4 and RNA polymerase. The results indicate that protein p4 is able to function at longer DNA distances from the RNA polymerase binding site than in the natural promoter. The extent of protein p4 activity depended on the length and conformation of the inserted DNA. Activation of transcription and RNA polymerase binding was favoured when the relative orientation of protein p4 and RNA polymerase was conserved and when the intervening DNA had a bent conformation. These data, together with the DNase I footprints, suggest that activation at distance by protein p4 involves a DNA loop held by the interaction of protein p4 and RNA polymerase.

Characterization of a DNA binding protein of bacteriophage PRD1 involved in DNA replication

Escherichia coli phage PRD1 protein P12, involved in PRD1 DNA replication in vivo, has been highly purified from E. coli cells harbouring a gene XII-containing plasmid. Protein P12 binds to single-stranded DNA as shown by gel retardation assays and nuclease protection experiments. Binding of protein P12 to single-stranded DNA increases about 14% the contour length of the DNA as revealed by electron microscopy. Binding to single-stranded DNA seems to be cooperative, and it is not sequence specific. Protein P12 also binds to double-stranded DNA although with an affinity 10 times lower than to single-stranded DNA. Using the in vitro phage phi 29 DNA replication system, it is shown that protein P12 stimulates the overall phi 29 DNA replication.

Types 1 and 2 plasminogen activator inhibitor and tumor necrosis factor alpha in patients with sepsis

We have determined the plasma concentrations of types 1 and 2 of plasminogen activator inhibitor (PAI-1 and PAI-2), tumor necrosis factor (TNF-alpha) and endotoxin in 47 patients with bacterial infection (22 patients presented with positive blood cultures). Results were compared with those observed in 30 healthy subjects. There was a significant increase in PAI-1 and TNF-alpha in patients as compared to controls (p less than 0.0001), whereas no differences for PAI-2 were observed. PAI-1 and TNF-alpha were significantly higher in 18 patients with gram-negative bacteremia as compared to all other patients (p less than 0.0001). However, no correlation between the analyzed parameters and either endotoxin or clinical outcome was observed. We conclude that there is an increase of PAI-1 and TNF-alpha in patients with sepsis, which is not related to the endotoxin concentration. Our results suggest that PAI-1, but not PAI-2, is the main plasminogen activator inhibitor in human sepsis.

A novel nucleoprotein complex at a replication origin

The viral protein p6, required for the protein-primed initiation of replication of Bacillus subtilis phage phi 29, forms a nucleoprotein complex at the viral replication origins that shows novel features. Deoxyribonuclease I and hydroxyl radical footprinting data, as well as the induction of positive supercoiling, support a model in which a DNA right-handed superhelix tightly wraps around a multimeric p6 core. The interaction occurs through the DNA minor groove. The activity of p6 not only requires the formation of the complex but also its correct positioning, indicating that the other proteins involved in the initiation of replication recognize, at a precise position, either the p6 core or the DNA conformational change induced by p6.

Hodgkin's disease in patients with antibodies to human immunodeficiency virus. A study of 22 patients

The experience of 22 Hodgkin's disease (HD) patients with human immunodeficiency virus type I (HIV) antibodies, collected from a cooperative study of six hospitals during 1984-1989 is presented. Young men (average age, 27.6 years) with a high incidence of intravenous drug abuse (86%) were found. The status of the HIV infection at diagnosis of HD was: four patients, acquired immune deficiency syndrome (AIDS); eight patients, persistent generalized lymphadenopathy (PGL); and ten patients, asymptomatic. The natural history of HD was unusual, with a high incidence of B symptoms (81%), advanced Stages III to IV (90%), bone marrow invasion (50%), cytopenias before treatment (45%), opportunistic infections (68%), and aggressive histologies. A decreased response to chemotherapy with poor marrow tolerance and a significant decrease in survival, 18 months, was observed. The AIDS and cytopenias pretreatment were associated with a shorter statistically significant survival, which defines the importance of immunodeficiency in HD prognosis. Complete remission after treatment was a factor that contributed to a longer statistically significant survival. The PGL or asymptomatic patients survived longer but also had a poor course, and five of them had AIDS criteria during evolution. A high incidence of HD in relation to non-Hodgkin's lymphoma (NHL) in patients with HIV infection in the six cooperating hospitals was found. Criteria for considering HD as an AIDS-associated lymphoproliferative disease in our environment are discussed.

Monocyte disorder causing cellular immunodeficiency: a family study

We report a familial type of monocyte dysfunction not recognized previously. This disorder was observed in a young adult man with a long clinical history of recurrent, self-limited episodes of cryptogenic fever accompanied by digestive and respiratory symptoms and repeated oral and skin infections. Lectin-induced lymphocyte transformation was reduced and skin tests revealed anergy to tuberculin and candidin. Monocytes from this patient exhibited markedly diminished expression of cytoskeletal vimentin intermediate filaments, HLA-DR antigens and immunological receptors for IgG Fc and C3b. These abnormal monocytes demonstrated impaired phagocytosis and reduced accessory cell function on PHA-mediated lymphocyte activation. Release of soluble lymphocyte-activating factors by these cells was found to be defective. Lymphocytes from the patient responded appropriately to lectin in the presence of normal monocytes. Two family members of the proband presented similar monocyte defects although they only manifested minor clinical symptoms. This syndrome underlines the interest of testing monocyte markers and function in subjects with clinical manifestations of immunodeficiency.

[Neutropenic enterocolitis during treatment of lymphoproliferative neoplasms]

In a series of 320 patients with lymphoid neoplasms treated with polychemotherapy, three patients with non-Hodgkin's lymphoma and one with myeloma were diagnosed as having neutropenic enterocolitis (NEC). All patients were adult, all had received multiple chemotherapeutic drugs and, during neutropenia, they had clinically presented with fever and abdominal pain, generally in the right lower quadrant. The diagnosis was clinical in all cases, and the imaging techniques provided only the suspicion of retro-cecal abscess in one of them. Two patients were operated on because of the development of features of peritoneal involvement, another because of septic shock and another because of retro-cecal abscess. Surgery and pathological study confirmed the diagnosis. The fundamental findings were ileocecal wall edema, mucosa ulceration, local necrosis, hemorrhage and thrombosis, and clusters of bacterial colonies without evidence of granulocytic or tumoral infiltration. NEC can develop with varying types of morphological involvement resulting in a highly variable clinical severity spectrum ranging from nonspecific abdominal symptoms to acute abdomen. Thus, diagnosis is very difficult and is only possible with a high suspicion index. It should rely on clinical data, which are unique, to assess the evolution and to indicate medical or surgical therapy. These therapeutic modalities should be individualized in each patient. All physicians treating neutropenic patients should be familiar with this condition and consider it in the differential diagnosis of abdominal pain.

[Treatment of chronic hepatitis B with lymphoblastoid alpha interferon]

Thirty-five patients with active chronic hepatitis B (ACH-B) were evaluated. They were in stable replicative phase (HBeAg +; DNA polymerase and ALT stable in two determinations at least one month apart) and had not been infected by delta virus or HIV-1. Thirty-four patients were heterosexual and no patient was a drug abuser except one. The 23 initial cases were followed up for 15 months without therapy. The subsequent 12 cases were treated with maximal doses of 2.5 megaunits/m2 of lymphoblastoid alpha interferon (IFN-L) daily for two weeks and three times a week during 10 more weeks. While in the controls only two cases (8.69%) lost the DNA-polymerase activity and HBeAg, 5 treated patients (41.66%; p less than 0.05) developed seroconversion to nonreplicative phase. No patient from the control series lost the HBsAg; however, this happened in 2 treated patients (16.66%). These results show that IFN-L is effective in heterosexual patients with ACH-B in replicative phase without delta virus or HIV-I co-infection.

A pilot study of thymus extract in chronic non-A, non-B hepatitis

In previous studies it has been suggested that activation of cellular immunity may have a role in controlling the activity of chronic non-A, non-B liver disease. We conducted a pilot study of therapy with a bovine thymus extract for 6 weeks in 15 consecutive patients with chronic non-A, non-B hepatitis, most of them sporadic cases. Treatment induced immunomodulation, and in five patients a significant but transient diminution in aminotransferase levels was observed associated with increments in several parameters of cellular immunity. This suggests that a longer administration of this or other related compounds, or treatment with a more potent immunomodulating agent, might be effective in these patients.

Naloxone-reversible monocyte dysfunction in patients with chronic fatigue syndrome

We studied monocyte function in 35 consecutive patients with chronic fatigue syndrome (CFS) and 25 healthy controls. Eighty-five per cent of the patients showed monocyte dysfunction characterized by marked reduction in the number of monocytes displaying immunoreactive cytoskeletal vimentin filaments, a low phagocytosis index, and a reduced expression of HLA-DR antigens. These values increased dramatically after incubation of the patients' monocytes with the opioid antagonist naloxone. Other immunological abnormalities also noted in the patients were low lymphocyte blastogenesis and diminished numbers of monocytes displaying receptors for Fc of IgG (FcR) and C3b (CR1). These findings suggest that an increased opioid activity acting through a classical receptor mechanism is active on monocytes from a high proportion of patients with CFS and that this represents a novel example of immunomodulation by opioid peptides in human disease. We suggest that endogenous opioids are involved in the pathogenesis of the chronic fatigue syndrome.

Signals at the bacteriophage phi 29 DNA replication origins required for protein p6 binding and activity

Protein p6 of Bacillus subtilis phage phi 29 binds specifically to the ends of the viral DNA that contain the replication origins, giving rise to a nucleoprotein structure. DNA regions recognized by protein p6 have been mapped by deletion analysis and DNase I footprinting. Main protein p6-recognition signals have been located between nucleotides 62 and 125 at the right phi 29 DNA end and between nucleotides 46 and 68 at the left end. In addition, recognition signals are also present at other sites within 200-300 bp at each phi 29 DNA end. Protein p6 does not seem to recognize a specific sequence in the DNA, but rather a structural feature, which could be bendability. The formation of the protein p6-DNA nucleoprotein complex is likely to be the structural basis for the protein p6 activity in the initiation of replication.

Cytoskeletal organization and functional changes in monocytes from patients with chronic hepatitis B: relationship with viral replication

Monocytes play an important role in the initiation and regulation of the antiviral immune response. These cells have a dense framework of intermediate filaments composed of vimentin monomers. In 35 patients with chronic hepatitis B, 26 healthy controls, seven patients with acute liver damage and eight patients with inactive HBsAg-negative cirrhosis, we investigated the expression of vimentin filaments, C3b and IgGFc receptors, HLA-DR molecules and the phagocytic activity in monocytes purified from venous blood. In the same subjects, we also studied the display of CD2, CD3 and CD5 on lymphocytes. In patients with chronic hepatitis B manifesting viral replication (n = 21; Group 1), the expression of vimentin filaments and the other functional monocyte parameters were decreased, whereas in patients in the nonreplicative phase of the disease (n = 14; Group 2) and in control cases with various forms of acute liver damage or inactive HBsAg-negative cirrhosis, they were similar to those found in healthy subjects. In Group 1, there was also a selective defect in the display of CD3 on lymphocytes. The expression of this molecule correlated with the functional state of monocytes. In three patients with chronic hepatitis B that changed from the replicative to the nonreplicative phase of the disease, the expression of vimentin filaments in monocytes and of CD3 on lymphocytes increased to normal levels. On the other hand, the incubation of patients' monocytes with gamma-interferon corrected the diminished expression of vimentin filaments and the other decreased functional parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Opioid peptides modulate the organization of vimentin filaments, phagocytic activity, and expression of surface molecules in monocytes

It is theorized that intermediate filaments are important in the modulation of membrane activity and cell motility; however, their functions are unknown. The assembly and organization of these filaments are under hormonal regulation. We investigated in human monocytes the in vitro effects of Met-enkephalin, Leu-enkephalin, and beta-endorphin on the expression of immunoreactive cytoskeletal vimentin filaments. We simultaneously examined their effect on the phagocytosis of Candida albicans and on the membrane display of surface molecules. The three opioid peptides markedly reduced the expression of vimentin filaments, the phagocytic activity, and the display of HLA-DR molecules at concentrations of 10(-6), 10(-8), and 10(-10) M. On the other hand, the intravenous administration of fentanyl, a synthetic opiate agonist, to patients undergoing surgery induced similar changes in monocytes. In other experiments, 10(-8) M beta-endorphin also decreased the expression of CR3 but did not influence the display of CD13, a surface protein of unknown function. Expression of vimentin filaments correlated directly with the display of HLA-DR antigens and CR3 and with the phagocytic activity. The results of this paper indicate that opiates and opioids, neuropeptides known to be released during stress, can directly depress several monocyte functions. Furthermore, from these data it may be speculated that intermediate filaments may regulate the membrane expression of some surface molecules and the phagocytic process.

Somatostatin analogues inhibit growth of pancreatic cancer by stimulating tyrosine phosphatase

Several analogues of somatostatin were examined in the Mia PaCa-2 human pancreatic cancer cell line for their ability to promote tyrosine phosphatase activity affecting the receptors for the epidermal growth factor. The inhibition of growth of the Mia PaCa-2 cells in culture was also evaluated to determine the mechanism of action of somatostatin analogues and their relative effectiveness in inhibiting cancer growth. Of the analogues tested D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) caused the greatest stimulation of tyrosine phosphatase activity. Analogue D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (RC-121) had less effect but was more potent than somatostatin-14. Analogue D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr(ol) (SMS 201-995) produced no significant dephosphorylation. The analogues displayed the same order of activity in assays on growth inhibition of Mia PaCa-2 cells in cultures. Analogue (SMS-201-995) caused virtually no tyrosine phosphatase stimulation or growth inhibition in this cancer cell line, although it possesses a much higher antisecretory activity than somatostatin-14 in normal tissues. These observations indicate that somatostatin and some of its analogues can act as growth inhibitors in cancer cells through the activation of tyrosine phosphatase. These data reinforce the view that somatostatin analogue RC-160 and related compounds could be used for treatment of pancreatic cancer.