BCL6 gene rearrangement and other cytogenetic abnormalities in diffuse large cell lymphoma

Evidence for rearrangement of the BCL6 gene at 3q27 has been documented in 20-30% diffuse lymphomas with a large cell component (DLLC), and was found to be of prognostic significance at the time of diagnosis. To incorporate these observations into current cytogenetic and clinical prognostic models, 76 cases of DLLC with known BCL6 status were analyzed. Cytogenetic indicators of progression, including trisomy 7, trisomy 12, del(6)(q21q25), and structural alterations of 17p were less frequent in BCL6 rearranged DLLC compared to BCL6 germline tumors. Despite a 93% overall survival at median follow-up of 30 months, a trend for continued relapse resulted in a projected freedom from progression for the BCL6 rearranged cohort of 66% at 4 years, compared to 39% for the BCL6 germline cohort. Six cases among the BCL6 rearranged group lacked additional cytogenetic indicators of progression and remained free of disease at follow-up in excess of 7 years, whereas BCL6 rearranged cases with increasing numbers of cytogenetic aberrations showed decreased intervals free from progression of disease. These results suggest that BCL6 rearrangement should be combined with other known clinical and cytogenetic indicators in prognostic analyses of patients with DLLC.

Inhibition of Western-diet induced hyperproliferation and hyperplasia in mouse colon by two sources of calcium

A Western-style diet containing high-fat and phosphate, and low calcium and vitamin D was fed to mice for 20 weeks. Starting at week 8, subgroups of animals received the Western-style diet supplemented by two different calcium sources: tricalcium phosphate and calcium citrate malate. Hyperproliferation (increased [3H]thymidine-labelled cells/colonic crypt) and hyperplasia (increased total epithelial cells/crypt) developed in the sigmoid colon after 8 weeks of feeding the Western-style diet confirming previous results, and these were reversed at later periods by the addition of the two calcium sources to the Western-style diet. Findings indicate that the modified colonic epithelial cell hyperproliferation and hyperplasia which have been associated with subsequent development of colonic neoplasia, are induced in mice fed a Western-style diet, and the addition of calcium to the diet inhibited their development in the colonic mucosa.

Rearrangement of the bcl-6 gene as a prognostic marker in diffuse large-cell lymphoma

BACKGROUND

About 40 percent of non-Hodgkin's lymphomas are diffuse lymphomas with a large-cell component (DLLC). Current therapy can induce a long-term remission in half the patients with DLLC, but more intensive treatment has the potential to improve outcome, particularly in patients at high risk for treatment failure. Clinical and cytogenetic markers can identify subgroups at high or low risk. Rearrangement of a novel candidate proto-oncogene, bcl-6, is a possible prognostic indicator in DLLC.

METHODS

We performed Southern blot hybridization to detect bcl-6 and bcl-2 gene rearrangement in samples of lymphoma from 102 patients with B-cell DLLC. The results were correlated with the patients' histologic features, age, disease stage, tumor sites and bulk of disease, serum lactate dehydrogenase level, and treatment outcome.

RESULTS

Rearranged bcl-6 was found in 23 cases, and rearranged bcl-2 in 21 cases. Nineteen of the patients with rearranged bcl-6 had extranodal DLLC, two had primary splenic lymphomas, and only one had bone marrow involvement. Thirty-six months after diagnosis, the proportion with freedom from progression of disease was projected to be 82 percent (95 percent confidence interval, 66 to 98 percent) among the patients with rearranged bcl-6, as compared with 56 percent (95 percent confidence interval, 43 to 70 percent) for the patients with germ-line bcl-6 and bcl-2 and 31 percent (95 percent confidence interval, 8 to 53 percent) for the patients with rearranged bcl-2. The status of the bcl-6 gene was an independent prognostic marker of survival and freedom from disease progression in a multivariate model and added predictive value to established prognostic signs.

CONCLUSIONS

Rearrangement of the bcl-6 gene correlated with a favorable clinical outcome in DLLC and may thus serve as a prognostic marker in patients with this form of malignant lymphoma.

Mutagenesis of a gene encoding a cytochrome o-like terminal oxidase of Azotobacter vinelandii: a cytochrome o mutant is aero-tolerant during nitrogen fixation

The amino acid sequence obtained by translating the nucleotide sequence of a 0.55 kb fragment, amplified from Azotobacter vinelandii chromosomal DNA by PCR, was 57% identical to part of the Escherichia coli cyoB gene, encoding subunit I of the cytochrome bo-type quinol oxidase. This fragment was mutated in vitro by insertion of a kanamycin-resistance cassette and introduced into the chromosome of A. vinelandii by homologous recombination. The mutant contained no spectrally detectable cytochrome o. However, in the stationary phase of growth, the level of the alternative oxidase (cytochrome bd) was 11-fold higher than in the wild-type strain. Respiration of the mutant was insensitive to chlorpromazine, an inhibitor thought to act specifically on cytochrome o. Cytochrome o-deficient mutants fixed nitrogen in air, clearly distinguishing the role of this oxidase from that of cytochrome bd, which is required for respiratory protection of oxygen-labile nitrogenase.

Verification of the Acute Physiology and Chronic Health Evaluation scoring system in a Hong Kong intensive care unit

OBJECTIVES

To validate the Acute Physiology and Chronic Health Evaluation (APACHE II) severity of illness scoring system in Chinese patients in a multidisciplinary intensive care unit (ICU) in Hong Kong. To audit the service and utilization of an ICU with a low ICU to hospital bed ratio.

DESIGN

Prospective data collection and review.

SETTING

A 12-bed multidisciplinary ICU within a 1,430-bed tertiary care university hospital.

PATIENTS

Data from 1,573 of 1,814 consecutive patients admitted to the ICU from May 1988 to November 1990 were studied. The patients were all Chinese.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The patients' clinical details and APACHE II scores were recorded on day 2 of admission and reviewed at hospital discharge or after death. The APACHE II scores, risk of death values, age, and length of ICU stay between survivors and nonsurvivors were compared by two-sample t-tests. Relationships between mortality and APACHE II score, risk of death, and results from previous studies were investigated using the Pearson product-moment coefficient and regression analysis. Predictive capacity of risk of death was assessed by receiver operating characteristic curve analysis. The hospital mortality rate for study patients was 36%. Survivors were younger, had shorter ICU stays, lower APACHE scores, and lower risk of death values than nonsurvivors (p < .001). There was close correlation (r2 = .81, .77, and .76 for all patients, operative group, nonoperative group, respectively) between APACHE II scores and predicted risk of death values. Risk of death was an accurate group predictor of death in all patients and in separate operative and nonoperative groups. Areas under the receiver operating characteristic curves were 0.89 (all patients), 0.85 (operative), and 0.88 (nonoperative). Neither the Apache II scores nor risk of death scores were sufficiently accurate to predict outcome of individual patients. There was close concordance between observed and predicted mortality of patient groups. Mortality ratio was 0.97 (all patients), 0.89 (operative group), and 1.02 (nonoperative group). Chronological age, per se, was not a good predictor of mortality. The audit of the ICU service showed a short length (4.2 days) of ICU stay and high bed occupancy (80%). Subgroups of low-risk, postoperative patients with good outcomes and poor-risk patients admitted after cardiopulmonary arrest with a high mortality rate were identified.

CONCLUSIONS

The APACHE II scoring system was an accurate predictor of group outcome in a Chinese population, making it suitable for comparisons between countries. Application of the APACHE II scoring system in a clinical audit facilitates critical appraisal of an ICU service. Problems identified by the study were a shortage of ICU beds and delayed referrals of patients.

The effects of calcium supplementation and exercise on bone density in elderly Chinese women

A randomized controlled trial was carried out to determine whether calcium supplementation and load-bearing exercise can increase or maintain bone mass in the elderly. Fifty Chinese women, aged 62-92 years, living in a hostel for the elderly in Hong Kong were randomized to enter one of four treatment groups: (I) calcium supplementation of 800 mg (as calcium lactate gluconate) daily; (II) load-bearing exercise four times a week plus a daily placebo tablet; (III) calcium supplementation daily and load-bearing exercise four times a week; (IV) a placebo tablet daily. The interventions went on for 10 months. The bone mineral density (BMD) was measured at three sites in the hip (femoral neck, Ward's triangle and intertrochanteric area) and the L2-4 level of the spine. The percentage change in BMD in 10 months was used as the main outcome measurement. The parathyroid hormone level and indices of bone metabolism were also measured before and after 10 months of intervention. The BMD at Ward's triangle and the intertrochanteric area increased significantly in subjects on calcium supplement (p less than 0.05), but there was no significant change at the spine and femoral neck. Exercise had no effect on bone loss at any site. However, the results of two-way analysis of variance showed a significant joint effect of calcium supplements and exercise at the femoral neck (p less than 0.05), but not at the other sites. The parathyroid hormone levels fell significantly in subjects on calcium supplements (p less than 0.01). Calcium supplement in the form of calcium lactate gluconate was adequately absorbed in elderly Chinese women with a calcium intake of less than 300 mg per day. It was effective in reducing bone loss at the hip, and there may be interaction effects with exercise in maintaining bone density.

Serodiagnosis of Lyme borreliosis by western immunoblot: reactivity of various significant antibodies against Borrelia burgdorferi

The significance of various antibodies against Borrelia burgdorferi was studied by Western blot (immunoblot) by using 578 human serum samples. The proteins regularly detected by using samples from patients with Lyme borreliosis were those with bands with molecular masses of 94, 83, 75, 66, 60, 55, 46, 41, 39, 34, 31, 29, 22, and 17 kDa. The detectable frequencies of most of these proteins appeared to be significantly different between the sera from patients with Lyme borreliosis and those from normal control individuals as well as from the group with syphilis. The 39-kDa protein band recognized by polyvalent antibody was found to be the most significant marker for Lyme borreliosis. Furthermore, an anti-39-kDa immunoglobulin M response was detected in the samples from patients with early-stage Lyme borreliosis. Results from the use of monoclonal antibodies and patient sera revealed that the 39- and 41-kDa proteins may be structurally related but are immunologically distinct antigens. The significance of antibody reactivities to the 41-, 94-, 22-, 31-, and 34-kDa protein bands is also discussed.

Are demented patients with Parkinson's disease accurately reflected in prevalence surveys? A survival analysis

We re-reviewed 257 patient records previously reviewed for an incidence study of dementia in Parkinson's disease (PD) to determine the frequency, date of death, and cause of death. We posited that if disease duration is shortened when dementia occurs, then dementia may be far more common than reflected in prevalence studies. There were 17 deaths among 65 demented patients and 28 deaths among 168 nondemented patients. When we matched a subset of the nondemented patients to the demented patients by age and disease duration distributions, the demented subjects had significantly more deaths (p less than 0.02), and survival among demented subjects was decreased (p less than 0.05). Dementia was a significant predictor of death in this sample. We conclude that dementia reduces survival in patients with PD. Incidence is a much better measure of dementia in PD than prevalence because shortened duration makes it less likely to detect dementia in prevalence surveys.

The ANB1 locus of Saccharomyces cerevisiae encodes the protein synthesis initiation factor eIF-4D

The Saccharomyces cerevisiae anaerobic gene (ANB1) is negatively regulated both by oxygen and heme. We have shown recently that an upstream repressor site located in the 5'-flanking region of this gene controls its expression (Mehta, K.D., and Smith, M. (1989) J. Biol. Chem. 265, 8670-8675). In this paper, we present the complete genomic sequence of the ANB1 locus of S. cerevisiae. The ANB1 locus encodes a protein of 157 residues with an Mr of 17, 134. The deduced amino acid sequence of the ANB1 gene product shows strikingly extensive sequence and structural homology (63.5% identical residues and an additional 15% conservative substitutions) to the 154-amino-acid-long human and rabbit eukaryotic translation initiator factor (eIF)-4D. Factor eIF-4D is the only known mammalian protein that undergoes a unique post-translational modification of Lys-50 to the amino acid hypusine, and interestingly the same lysine is also present in the ANB1 gene product. Results presented provide strong evidence that the ANB1 locus that encodes a transcript, tr-2, and a second locus encoding a transcript, tr-1, together encode two forms of yeast eIF-4D. Interestingly, heme regulates both the loci in an opposite manner; as a result it can dictate the isoform available under conditions of high and low oxygen tension. The ROX1 locus of S. cerevisiae is known to regulate CYC1, COXVb, and ANB1 genes at the transcriptional level; the ROX1 locus thus regulates all known anaerobically expressed genes that are involved in different cellular functions such as respiration and protein synthesis.

Antiviral activities of hybrids of two major human leukocyte interferons

Four hybrid human leukocyte interferon (LeIF or IFN-alpha) genes have been constructed by in vitro recombination of LeIF-A (IFN-alpha 2) and LeIF-D (IFN-alpha 1) genes at common restriction endonuclease sites located within their coding regions. These hybrid genes have been expressed in E. coli under trp promoter control. The interferons produced [LeIF-AD (BglII), -AD (PvuII), -DA (BglII), -DA (PvuII)] have antiviral properties distinct from the parental molecules LeIF-A and -D, varying considerably in their abilities to inhibit plaque formation by different viruses in a range of mammalian cells. All six of the cloned LeIFs exhibit the heat stability, pH 2 stability and antigenic specificity of natural leukocyte interferons.

Deficiency of suppressor T cells in the hyperimmunoglobulin E syndrome

The status of suppressor T cells (Ts) was assessed in seven children with the hyper IgE syndrome (recurrent staphylococcal infections, eczematous skin rash, and elevated serum IgE) to determine whether a deficiency in Ts is associated with increased IgE synthesis. When circulating T cells and their subsets were enumerated with the aid of monoclonal antibodies that identify T cells (T3), helper/inducer T cells (T4), and suppressor/cytotoxic T cells (T8), there was a selective deficiency of T3+ cells (51.7+/-11.2% vs. 66+/-5% for normal controls) and of T8+ cells (7.5+/-4.4% vs. 22+/-4% for normal controls) but not of T4+ cells (36.5+/-7.5% vs. 37+/-3% for normal controls). Suppressor T cell function was assessed by examining the ability of mononuclear cells incubated for 48 h with concanavalin A to suppress the proliferation of fresh autologous mononuclear cells in response to the mitogens phytohemagglutinin and pokeweed mitogen. All seven patients were severely deficient in concanavalin A-inducible suppressor cells. In vitro de novo synthesis of IgE in 6-d cultures of peripheral blood lymphocytes was measured in four patients by a solid-phase radioimmunoassay. Mononuclear cells from all four patients synthesized spontaneously increased quantities of IgE in vitro (4,950+/-3,760 pg/10(6) cells vs. 250+/-215 pg/10(6) cells for eight normal controls). IgE synthesis was suppressed by the addition of parental T cells to the culture. Elimination of the T8+ subset, but not of the T4+ subset, by complement-dependent lysis resulted in the loss of the capacity of parental T cells to suppress IgE synthesis. These results suggest that a deficiency of Ts underlies the elevated IgE levels observed in the hyper IgE syndrome.

Bacterial synthesis of a novel human leukocyte interferon

A novel human leukocyte interferon cDNA clone (LeIF B) was identified in a cDNA library prepared using polyadenylated mRNA of a myeloblastoid cell line. The nucleotide sequence of LeIF B differs significantly from other published leukocyte interferon cDNA sequences. An expression plasmid was constructed which directs the synthesis in E. coli of 8 x 10(7) interferon units per liter of culture. LeIF B exhibits markedly different specificities from another bacterially synthesized human leukocyte interferon, LeIF A.

Synthesis of human fibroblast interferon by E. coli

A cDNA library was constructed using mRNA from human fibroblasts induced with poly(I):poly(C). A bacterial clone containing fibroblast interferon cDNA sequences was identified by hybridization to a cDNA probe synthesized using deoxyoligonucleotide primers which hybridize to fibroblast interferon mRNA specifically. Expression plasmids were constructed which permitted the synthesis in E. coli of 8 x 10(7) units of human fibroblast interferon per liter of culture. The bacterially produced fibroblast interferon is indistinguishable from authentic human fibroblast interferon by several criteria.

Plasma concentrations of isosorbide dinitrate and its metabolites after chronic high oral dosage in man

1 We have previously reported that vasodilator headache due to isosorbide dinitrate (ISDN) can be circumvented by using small 'priming' doses for an induction period of 1-2 weeks, after which it is possible to increase to dose rapidly to 360-720 mg, daily without recurrence of headache and without toxicity. The present study corroborates this earlier finding. 2. Chronic oral administration of doses of ISDN of this order of magnitude results in prolonged high plasma concentrations of the parent compound, as well as higher levels of the metabolites 2-ISMN and 5-ISMN. 3. It is our thesis that chronic high oral dosage of ISDN saturates the intrahepatic biotransformation process, and allows high concentrations of ISDN and its metabolites to enter the systemic circulation.

Effect of DNA delay mutations of bacteriophage T4 on genetic recombination

Studies have been made of the effect of the DNA delay mutations of bacteriophage T4 on growth and genetic recombination in a number of Escherichia coli hosts. DNA delay mutations in genes 39, 52, 58 (61), and 60 result in abnormally high recombination frequencies. These high recombination frequencies are discussed in the context of other observations.

Regional sweating in eskimos compared to Caucasians

After pharmacological stimulation, prints of functioning sweat glands were obtained from 17 skin sites on the face, body, and limbs of 37 adult male Eskimos and 21 Caucasian controls.Eskimos showed greater numbers and greater activity of functioning sweat glands on exposed parts of the face such as nose and cheeks, while responding with significantly less sweat gland activity on all body surfaces that are normally heavily clothed in winter. Trunks, arms, hands, legs, and feet showed a progressive reduction of sweat gland response in the order of one-half on the trunk to one-fifth on feet when comparing mean sweat gland counts per square centimeter in Eskimos and controls. The comparative reduction of sweat gland response in the Eskimos progressed in the same order as the distance of the part from the body core, and as the risk of the part to freezing. Therefore, this reduction of sweat gland activity may represent a morphological and/or functional adaption to environmental conditions including climate and clothing.