Identification of an operon involved in the assimilatory nitrate-reducing system of Azotobacter vinelandii

A number of mutants lacking nitrate reductase (Nas-) or nitrite reductase (Nis-) activities have been isolated and characterized. An operon including two new genes (nasA and nasB) has been defined and cloned from an Azotobacter vinelandii gene bank. nasA encodes for nitrite reductase apoenzyme, whereas nasB is specific for nitrate reductase activity. Nitrate reductase exerts a regulatory effect on nasAB.

Endometrial changes in postmenopausal breast cancer patients receiving tamoxifen

OBJECTIVE

To assess the estrogenic effect of tamoxifen and associated pathologic changes of the endometrium in postmenopausal breast cancer patients.

METHODS

The endometrium of 103 gynecologically asymptomatic postmenopausal breast cancer patients was examined. Fifty-one had been treated with tamoxifen and 52 had not received any hormonal treatment. The two groups were similar in age, parity, age at menopause, and body mass index.

RESULTS

Compared with the control subjects, the tamoxifen patients had a thicker endometrium (mean +/- standard deviation 10.4 +/- 5.0 versus 4.2 +/- 2.7 mm; P = .0001) and larger uterine volume (45 +/- 27 versus 25 +/- 11 cm3; P = .001), as determined by transvaginal sonography. Hysteroscopy showed an atrophic endometrium in 28% of the patients in the tamoxifen group, as compared with 87% of the control patients (P = .0001). Endometrial polyps were more frequent in the tamoxifen group (36 versus 10%; P = .004), which included one patient with atypical hyperplasia, one with adenomatous hyperplasia, and one with endometrial adenocarcinoma; two controls had endometrial adenocarcinoma.

CONCLUSION

The results provide evidence for an estrogenic effect of long-term tamoxifen treatment on the postmenopausal uterus and show it to be associated with an increased occurrence of polyps.

Functional expression of the alpha 2 and alpha 3 isoforms of the Na,K-ATPase in baculovirus-infected insect cells

Multiple isoforms of both the alpha and beta subunits of Na,K-ATPase have been identified. Elucidating their roles has been complicated by the fact that most tissues express multiple isoforms and purification techniques specific for each isoform have not been achieved. The baculovirus expression system, which uses the baculovirus Autographica californica to infect insect cells, is an ideal system for studying the Na,K-ATPase isoforms since high amounts of foreign proteins can be produced and some insect cell lines have low levels of endogenous Na,K-ATPase. Recombinant baculoviruses containing the cDNAs for the alpha 2, alpha 3, and beta 1 isoforms of the rat Na,K-ATPase were prepared and used to infect Sf-9 cells, an insect cell line derived from the ovary of the fall armyworm Spodoptera frugiperda. By using this system, Na,K-ATPase alpha 2 and alpha 3 subunits that were antigenically and electrophoretically indistinguishable from the native subunits were produced. When each subunit is expressed independently in the Sf-9 cells, it is primarily delivered to the plasma membrane. Although the isolated expression of each Na,K-ATPase subunit did not render active Na,K-ATPase molecules, the coexpression of alpha 2 or alpha 3 with beta 1 resulted in catalytically active molecules. This activity could be measured as a ouabain-sensitive ATPase activity or directly demonstrated using either [gamma-32P]ATP or 32Pi to identify the phosphorylated intermediates of the alpha 2 and alpha 3 isoforms. [3H]Ouabain binding studies showed that both isoforms are capable of binding the cardiotonic steroid with high affinity, alpha 3 being more sensitive to ouabain. These results demonstrate that the baculovirus system is suitable for the expression of the Na,K-ATPase isoforms and should provide a useful method for the characterization of the enzymatic properties of each isoform.

Influence of Epstein-Barr virus genomes on patient survival in Hodgkin's disease

In previous studies, Epstein-Barr virus was considered a possible etiologic factor in Hodgkin's disease. Two hundred twenty-nine cases of Hodgkin's disease were investigated for the presence of Epstein-Barr virus DNA using the polymerase chain reaction technique on formalin-fixed, paraffin-embedded lymph node tissue to clarify the clinical importance of the incidence of this genome. In 42 cases (18.3%), genomic DNA was not amplifiable. The remaining 187 cases included the following subtypes: lymphocyte-predominant type (n = 13), nodular sclerosis type (n = 98), mixed cellularity type (n = 68), and lymphocyte-depleted type (n = 8). Sixty-six cases (35.2%) were positive for Epstein-Barr virus DNA. In the statistical analysis of available follow-up data from 130 patients, no influence of a positive Epstein-Barr virus DNA finding on length of survival time was revealed. This was true within the cohort of all patients and within the histologically defined subtypes of Hodgkin's disease. In this investigation, detection of Epstein-Barr virus DNA by polymerase chain reaction showed no prognostic relevance for patients with Hodgkin's disease.

Cloning and sequence of a gene encoding the L7/L12 ribosomal protein equivalent of Streptomyces antibioticus

A 50S ribosomal(r) protein from the vegetative mycelium of Streptomyces antibioticus, that is absent or modified in the spore 50S r-subunit, was purified by HPLC. Determination of its N terminus and comparison with amino acid sequence data bases indicated a strong homology with the L7/L12 r-protein from Streptomyces griseus. Screening of a cosmid library of S. antibioticus chromosomal DNA with a 20-mer oligodeoxyribonucleotide probe, corresponding to an internal region of the N terminus, allowed the isolation of two hybridizing clones. A 0.90-kb HindIII-BamHI fragment from one of these clones was sequenced and found to contain a 387-bp open reading frame. The deduced gene product shows clear homology with L7/L12 r-protein equivalent from different bacteria.

Excretion of ammonium by a nifL mutant of Azotobacter vinelandii fixing nitrogen

A mutation in the gene upstream of nifA in Azotobacter vinelandii was introduced into the chromosome to replace the corresponding wild-type region. The resulting mutant, MV376, produced nitrogenase constitutively in the presence of 15 mM ammonium. When introduced into a nifH-lacZ fusion strain, the mutation permitted beta-galactosidase production in the presence of ammonium. The gene upstream of nifA is therefore designated nifL because of its similarity to the Klebsiella pneumoniae nifL gene in proximity to nifA, in mutant phenotype, and in amino acid sequence of the gene product. The A. vinelandii nifL mutant MV376 excreted significant quantities of ammonium (approximately 10 mM) during diazotrophic growth. In contrast, ammonium excretion during diazotrophy was much lower in a K. pneumoniae nifL deletion mutant (maximum, 0.15 mM) but significantly higher than in NifL+ K. pneumoniae. The expression of the A. vinelandii nifA gene, unlike that of K. pneumoniae, was not repressed by ammonium.

Cloning and disruption of a fragment of Streptomyces halstedii DNA involved in the biosynthesis of a spore pigment

A 5.2-kb BamHI fragment of Streptomyces halstedii was cloned by homology to the actI-carrying fragment which codes for part of the actinorhodin polyketide synthase of Streptomyces coelicolor A3(2). Gene disruption using the integrative plasmid vector, pGM160, and gene replacement experiments using a fragment mutated by introducing a cassette containing the gene encoding thiostrepton resistance, showed that the alteration of this region in the chromosome of S. halstedii caused sporulating colonies to remain white instead of taking on the typical green colour of sporulating wild-type colonies. This suggests that this fragment is involved in the biosynthesis of a spore pigment. In addition, the BamHI fragment complemented the whiE mutation of S. coelicolor C107 which confers to this mutant a white phenotype, indicating that both pigments could have a similar biosynthetic origin.

The product of the nitrogen fixation regulatory gene nfrX of Azotobacter vinelandii is functionally and structurally homologous to the uridylyltransferase encoded by glnD in enteric bacteria

We sequenced the nitrogen fixation regulatory gene nfrX from Azotobacter vinelandii, mutations in which cause a Nif- phenotype, and found that it encodes a 105-kDa protein (NfrX), the N terminus of which is highly homologous to that of the uridylyltransferase-uridylyl-removing enzyme encoded by glnD in Escherichia coli. In vivo complementation experiments demonstrate that the glnD and nfrX products are functionally interchangeable. A vinelandii nfrX thus appears to encode a uridylyltransferase-uridylyl-removing enzyme, and in this paper we report the first sequence of such a protein. The Nif- phenotype of nfrX mutants can be suppressed by a second mutation in a recently identified nifL-like gene immediately upstream of nifA in A. vinelandii. NifL mediates nif regulation in response to the N status in A. vinelandii, presumably by inhibiting NifA activator function as occurs in Klebsiella pneumoniae; thus, one role of NfrX is to modify, either directly or indirectly, the activity of the nifL product.

Hepato-splenic distribution of 99Tcm-phytate and hepato-enteric distribution of 99Tcm-DISIDA in mice with carbon tetrachloride-induced acute liver damage

The hepato-enteric distribution of 99Tcm-labelled DISIDA and the hepato-splenic distribution of 99Tcm-labelled phytate were studied in controls and in mice with carbon tetrachloride-induced acute liver damage. The test group animals showed a diminished excretion of DISIDA to intestine with retention of this tracer in the liver and an increased splenic uptake of phytate. No changes in the hepatic uptake of phytate were found. The joint evaluation of both tracers in the study of diffuse liver disease is discussed.

Flow cytometric analysis of DNA ploidy in large cleaved cell lymphomas

The results of nuclear DNA content analysis of a series of 28 patients with large cleaved follicular centre cell non-Hodgkin's lymphomas (NHL) are reported. DNA aneuploidy was found in 11 (39 per cent) cases. The DNA indices of the DNA-aneuploid peaks ranged from 1.14 to 2.28. Seven (25 per cent) cases were tetraploid. DNA ploidy was not associated with prognosis. The percentage of S phase cells (SPF) ranged from 2.0 to 30.5 per cent (median 5.1 per cent). Lymphoma patients with SPF higher than 9.7 per cent had a worse survival rate than patients with lymphoma with less than 9.7 per cent S phase cells but the difference did not reach statistical significance. The results of the DNA ploidy and SPF were comparable to those of intermediate and high grade malignancy NHLs.

A chromosomal linkage map of Azotobacter vinelandii

A chromosomal map of Azotobacter vinelandii strain UW was constructed. The map was based on measures of cotransfer of various markers mediated by plasmids R68.45 and pJB3JI, on results obtained from conjugal experiments with R-primes, and on recombinants obtained by chromosomal transfer mediated by RP4/Tn5-Mob.

Differentiation of rat hippocampal neurons induced by estrogen in vitro: effects on neuritogenesis and Na, K-ATPase activity

To gain insight into the mechanisms responsible for differentiation of hippocampal neurons growing in vitro, the effects of estrogen on neuritic development and on activity and distribution of isoforms of the Na, K-ATPase, were evaluated. Dissociated cells from hippocampi of 19-day-old rat fetuses were raised for 5 days in the presence or absence of 100 nM estradiol-17 beta (E2) in minimum essential medium supplemented either with 10% untreated fetal calf serum (MEM-10) or with 10% fetal calf serum previously adsorbed with dextran-activated charcoal (MEM-10-Cha). Cultures in MEM-10 showed larger neuritic length and increased levels of Na, K-ATPase activity than cultures in MEM-10-Cha. In cells cultured in MEM-10 medium, the addition of E2 resulted in selective enhancement of axonal length with a concomitant increase in the alpha-2 isoform of the Na, K-ATPase, whereas a decrease was found in the form most sensitive to ouabain; the total enzymatic activity remained unchanged. Conversely, in cultures raised in MEM-10-Cha, E2 did not affect Na, K-ATPase activity or neuritogenesis. These results show that two presumably independent probes of cellular differentiation of hippocampal neurons (i.e., neuritogenesis and patterns of Na, K-ATPase activity) were concurrently regulated by E2 and that such regulation depended on interaction with factor(s) present in calf serum. The well-known neuritogenic effect of E2 is hereby extended to hippocampal neurons, although for these cells it seems to be restricted to axons.

Detection of a highly ouabain sensitive isoform of rat brainstem Na,K-ATPase

The present work provides evidence for the existence in rat brainstem of a form of Na,K-ATPase catalytic subunit that displays a high affinity for ouabain (Kd about 10(-9) M). Its kinetic identification was made out from studies on dose response curves of ouabain inhibition of Na,K-ATPase activity, ouabain inhibition of Na(+)-dependent phosphorylation from ATP and ouabain stabilized phosphoenzyme formation from inorganic phosphate (Pi). In all these studies this isoform comprises around 11 percent of the total Na,K-ATPase enzyme. The PAGE electrophoretic mobility of its phosphoprotein obtained from Pi in the presence of ouabain is lower than that of the alpha-1 form but it cannot be distinguished from that of alpha-2. Whether this highly ouabain sensitive form corresponds to the alpha-3 isoenzyme or represents the translational product of one of the additional genes described for the large catalytic subunit remains at the moment an open question.

Prognostic factors in recurrent breast cancer: relationships to site of recurrence, disease-free interval, female sex steroid receptors, ploidy and histological malignancy grading

Site of first recurrence, disease-free interval (DFI), female sex steroid receptors, ploidy measurements as well as histological grading have been analysed as potentially valuable predictive factors in 313 cases of recurrent breast cancer. Univariate and multivariate analyses show histological grading, site of recurrence and disease free interval to be useful prognostic variables when assessing prognosis once disease has recurred. High concentrations of oestrogen receptors (ER) were found in patients with bone metastases, whereas lower concentrations of ER were related to visceral recurrences. Ploidy measurements failed in this study to give any predictive information once disease recurred.

Treatment of advanced breast cancer with 20 mg toremifene, a phase II study. Preliminary communication

Fourteen postmenopausal women with estrogen-receptor positive advanced breast cancer and no prior cytostatic treatment received 20 mg toremifene daily as a single dose after a loading dose (120----60----60 mg) for the first 3 days. All were evaluable and had undergone at least 6 weeks' treatment. Results were: no complete remissions (CR), 3 partial remissions (PR), 8 no change (NC) and 3 cases of progressive disease (PD). Three patients had mild side effects: nausea, insomnia, sweating and arm pain.

Safety and efficacy of toremifene in breast cancer patients. A phase II study

46 postmenopausal women with estrogen receptor positive breast cancer entered a phase II study with a novel antiestrogen, toremifene. Patients had either recurrent or primarily inoperable advanced disease. No prior or concurrent cytostatic or hormonal treatment was allowed. Eight patients (17%) achieved complete response (CR), 17 (37%) partial response (PR) and 13 (28%) had stabilization of their disease at least for three months. The mean durations of responses were 52 +, 53 + and 27 + weeks, respectively, with 5 patients in CR, 6 in PR and 1 with no change (NC) still continuing the treatment. No significant differences could be seen in response rates according to the concentration of estrogen receptors or presence of progesteron receptors in this group of patients. Toxicity was not a problem, in general, the treatment was well tolerated. Two side effects (sweating and vertigo) were classified as severe and one patient after achieving PR interrupted the treatment because of tremor.

Isolation of a high frequency donor of Rhodobacter capsulatus by integration of the plasmid pMT1000 into the chromosome

The temperature-independent clone of Rhodobacter capsulatus UA7041, carrying the temperature-sensitive plasmid pMT1000, has been obtained by selection for plasmid markers at the non-permissive temperature. The transfer to Escherichia coli of all drug resistance encoded by pMT1000 was of about 10(-7) when the donor was the UA7041 strain, and of 5 x 10(-4) when the donor was the temperature-sensitive strain of R. capsulatus. Electrophoretic analyses showed no plasmid band typical of the autonomous pMT1000 in the UA7041 strain. Furthermore, UA7041 cells were also able to mobilize chromosomal markers of R. capsulatus at a frequency of about 10(-4) per donor cell. All these results lead us to conclude that the plasmid pMT1000 is integrated in the chromosome of the UA7041 strain. The analysis of the co-transfer frequencies of trp and his markers has shown that the chromosome mobilization in the UA7041 strain of R. capsulatus is unidirectional from a single origin. Our data also show that the pMT1000 plasmid may be useful to the construction of chromosomal, high-frequency donor strains.

Improving the prognostic value of DNA flow cytometry in breast cancer by combining DNA index and S-phase fraction. A proposed classification of DNA histograms in breast cancer

To optimize the prognostic value of DNA flow cytometry in breast cancer the authors calculated several parameters from the DNA histogram, including the DNA index, the size and number of aneuploid peaks as well as S-phase and G2/M-phase cell cycle fractions. Of these, DNA index and S-phase fraction (SPF) proved to be the most valuable prognostic indices. DNA aneuploidy was associated with a three-fold risk of death as compared to DNA diploidy (P less than 0.0001). The highest risk of death was associated with hypertetraploid (greater than 2.20) DNA index, whereas a tetraploid DNA index (1.80-2.20) was associated with a relatively low risk. The SPF had significant additional prognostic value in both DNA diploid (P = 0.0002) and DNA aneuploid (P = 0.02) tumors. By combining DNA index and SPF the authors defined three types of DNA histograms, which were associated with favorable, intermediate, and poor prognosis of the patients. DNA diploidy together with low (less than 7%) SPF (type I DNA histogram) was associated with very favorable prognosis, whereas DNA aneuploidy with high DNA index (greater than 2.20) or high (greater than 12%) SPF (type III DNA histogram) was related to the worst prognosis with approximately eight-fold relative risk of death. In a Cox multivariate regression analysis the type of DNA histogram was an independent and most powerful prognostic indicator in breast cancer. The other independent factors in the Cox analysis were primary tumor size, nodal status, and progesterone receptor status.

Characterization of extracellular matrix in non-Hodgkin's lymphomas

Basement membrane proteins laminin, type IV collagen and aminoterminal propeptide of type III collagen (type III pN-collagen) are important components of extracellular matrix of normal lymph nodes; they are present in reticular fibres and in the walls of blood vessels and sinuses. We have studied the distribution of these proteins in 45 cases of non-Hodgkin's lymphomas representing different types of Kiel classification. Light microscopic immunohistochemistry was used on sections from formalin fixed, paraffin embedded biopsy specimens. Reticular cells were identified by using antibodies against S-100 protein, a marker for dendritic and interdigitating reticulum cells, and against cystatin A for the demonstration of follicular dendritic reticulum cells. The findings of the immunohistochemical stainings were generally similar in the different lymphoma types. Thus the method for the demonstration of extracellular matrix proteins could not give obvious aid for lymphoma classification. BM stainings proved to be efficient in the demonstration of sinuses. Marginal and medullary sinuses of the nodal cases were either totally or partly spared and open also in the cases in which there was extracapsular growth. The fibre content was variable, but generally the distribution of all the three extracellular matrix proteins was comparable with each other and mainly corresponded with the pattern seen in conventional Gomori's reticulin stain. This also holds for the tumor tissue infiltrated through the capsule and for extranodal cases. Areas of sclerosis of some cases contained only type III pN-collagen. Reticular fibres were at places seen to be closely associated with cells of spindle or dendritic shape. A few reticulum cells could be found to show cytoplasmic staining for laminin, type IV collagen and type III pN collagen. This finding suggests that the cells are synthetizing these proteins. The amount of cells staining for cystatin A or S-100 protein did not generally correlate with the amount of fibres, and most of the stained cells were not closely associated with fibres. The results show that in non-Hodgkin's lymphomas basement membrane proteins and type III pN-collagen are important components of reticular fibres. Results also indirectly support the main role of fibroblastic reticulum cells in the production of the fibres.

Toremifene, a new antiestrogenic compound, for treatment of advanced breast cancer. Phase II study

Forty-six postmenopausal women with estrogen receptor positive advanced breast cancer were treated with the novel antiestrogen toremifene in this phase II study. The patients had no prior or concurrent hormonal or cytostatic treatment. Sixty milligrams of toremifene was given as a single daily dose for a minimum treatment period of 6 weeks. Eight patients (17%) achieved complete response, 17 (37%) partial response and 12 (26%) showed no change. The median durations of responses were 93, 66 and 24 weeks, respectively. Three patients still continue the treatment in complete response, four patients in partial response. No significant differences in response rates could be seen when related to different estrogen receptor concentrations. The treatment was well tolerated, only two patients had remarkable side-effects; one of the patients interrupted the treatment mainly because of tremor. Our conclusion is that toremifene is an effective, safe and in clinical practice easily applied choice of treatment in estrogen receptor positive advanced breast cancer.

Tumour DNA ploidy as an independent prognostic factor in breast cancer

We determined nuclear DNA content from 308 archival paraffin-embedded malignant breast tumours and evaluated the survival of the patients by univariate and multivariate statistical analyses. The overall 8-year survival rate of stage I-III breast cancer patients was 74.3% in DNA-diploid and 51.2% in DNA-aneuploid tumours (P less than 0.0001). DNA ploidy had prognostic significance in both node-negative and node-positive breast cancer, primarily in cases with steroid receptor-positive tumours. In a Cox multivariate analysis DNA ploidy (P = 0.001), primary tumour size (P = 0.0007), nodal status (P = 0.04) and the content of progesterone receptors (P = 0.0008) emerged as significant independent prognostic factors, whereas oestrogen receptor status, age and menopausal status of the patients had no significant independent prognostic value. If the histological grade of ductal carcinomas was also included in the Cox model, both grade and DNA ploidy had independent prognostic effect. In conclusion, our results indicate that the analysis of DNA ploidy is a useful adjunct in the assessment of prognosis for breast cancer patients.

A new triphenylethylene compound, Fc-1157a. II. Antitumor effects

The antitumor effects of a new antiestrogen, Fc-1157a have been studied in vitro and in vivo. In vitro the effect of Fc-1157a was comparable to that of tamoxifen. The effect was dose-dependent, and at concentrations higher than 10(-6) mol/1 Fc-1157a induced real cell death of the MCF-7 cells. In DMBA-induced mammary cancer in rats Fc-1157a decreased the number of new tumors and inhibited the growth of existing tumors, these effects being statistically highly significant. The ratio of growing tumors to stable and regressing tumors was significantly decreased. Although these effects were slightly stronger with Fc-1157a than with tamoxifen, the difference between these two compounds was not statistically significant. Murine uterine sarcoma, an estrogen receptor-negative tumor, was resistant to tamoxifen, but was statistically significantly inhibited by high doses (100 and 200 mg/kg-1 day-1 for 5 days) of Fc-1157a. The antitumor effects of Fc-1157a are due mainly to the antiestrogenic activity. At high concentrations in vitro and at high doses in vivo Fc-1157a exerts antitumor effects some of which are different from those of tamoxifen and are directed even against estrogen receptor-negative tumors. The exact mechanism of the observed cytolytic effect at high doses is unknown.

A new triphenylethylene compound, Fc-1157a. I. Hormonal effects

The basic pharmacological and biochemical properties of a new antiestrogen, Fc-1157a, are described. Fc-1157a is bound specifically and with high affinity to estrogen receptors. The binding is competitive with estradiol. Fc-1157a treatment induces translocation of estrogen receptors from cytoplasm to nucleus. The turnover rate of nuclear estrogen receptors is markedly lower than with estradiol, but is more rapid than after tamoxifen. Fc-1157a is an almost pure antiestrogen in rat uterus, but has intrinsic estrogenic activity in mouse uterus. In animal experiments Fc-1157a has shown antitumor properties, which are described in the companion paper.

The Lukes-Collins and Kiel classifications for non-Hodgkin lymphomas. A retrospective study considering both classifications and their relationships to stage, sex, age, and survival

359 patients with non-Hodgkin lymphomas referred to Oulu University Hospital between 1964 to 1981, inclusive, were reclassified histologically according to the criteria of Lukes-Collins as well as Lennert's histological classifications. The requirements to enter this study were fulfilled only in 280 cases. After the evaluation of the results certain observations emerged. Firstly, within the Lukes-Collins classification: Nodularity was predominantly related to the SC and LC types. Nodularity is indicative of better survival. The Lukes-Collins classification correlates well with clinical stage as well as with age. The Burkitt and convoluted types were found to be predominantly related to childhood or to younger patients and the non-Burkitt type most frequently to the older groups. The Lukes-Collins classification separates well two clear prognostic groups, the favourable group (LC, SC, PC, and SL types), with an overall median survival of 44 months, and the unfavourable group (LNC, IS, convoluted, undefined, and SNC types), with an overall median survival of 11 months. No differences in survival were observed between the LNC, LC, and IS diffuse types. Stage, general symptoms and laboratory findings were also evaluated. Secondly, within the Kiel classification: Nodularity has been found mainly in the CB-CC type, but also in 27% of the CC cases. The relationship of the subtypes according to the Kiel classification and age resembles the same relation found with the Lukes-Collins classification. According to the Kiel classification, the Burkitt, convoluted, and lymphoblastic types were related to children and young adults. A proportion of the LB type occurs also in older groups. Three prognostic groups were identified, the favourable (CB-CC foll. and PC types), with an overall median survival in excess of 80 months, an intermediate group (CB-CC foll. - diff., CC, and CLL), with an overall median survival of 38 months, and an unfavourable group (Conv, CB, CB-CC diff., UC, IB, and Burkitt types), with a median survival of 11 months. The CC type in this study was controversial in its morphological acceptability.

Complete replacement of the ascending aorta with reimplantation of the coronary arteries in patients with full Marfan syndrome

Four patients with Marfan syndrome developed severe aortic insufficiency requiring complete replacement of the ascending aorta with reimplantation of the coronary arteries by the technique of Cabrol. All patients have remained asymptomatic in NYHA class I.

Gallium-67 localization in a mycotic aneurysm of the thoracic aorta

Localization of Ga-67 in a mycotic aneurysm of the thoracic aorta in a renal transplant recipient is reported. This procedure complements other imaging methods in the diagnosis of this serious condition and may be preferable to In-111 leukocytes because of its ready availability.

Behaviour of dendritic reticulum cells possessing immunoreactive acid cysteine-proteinase inhibitor in human lymphoid secondary follicles and in follicular-centre cell lymphomas

In our previous studies acid cysteine-proteinase inhibitor (ACPI) was shown to be a common characteristic of human squamous epithelia and dendritic reticulum cells (DRC) in lymphoid secondary follicles. In the present study, the behaviour of ACPI-immunoreactive DRC in reactive lymphoid secondary follicles and neoplastic follicles of follicular-centre cell (FCC) lymphomas was compared by the peroxidase-antiperoxidase method. The secondary follicles in reactive lymphoid tissues revealed a staining pattern characteristic of DRC comparable with the results of other studies. Contrary to this, the number of ACPI-positive DRC in the neoplastic lymphoid follicles was greatly reduced. This was occasionally accompanied by a weak reaction and in many cases the DRC were totally abolished. Moreover, morphological aberrations were observed in ACPI-positive DRC, especially diminution and shortening of dendritic processes. On occasion, ACPI-positive cell types were observed, which may represent intermediate forms between DRC and fibroblastic reticulum cells. Only one case--with a rather favourable clinical outcome (out of 41 follicular FCC lymphomas) exhibited an ACPI-positive DRC pattern comparable with that of reactive lymphoid follicles. Thus it seems that the ACPI-immunohistochemistry of DRC provides an additional tool for discerning the difference between reactive and neoplastic lymphoid follicles. This method is of particular value since it can be used with formalin-fixed, paraffin-embedded tissues. There was a tendency among the follicular FCC lymphoma patients towards a better survival rate for those with ACPI-positive DRC than for those lacking this cell type, although no statistically significant differences emerged from this limited material.

Estrogen and progesterone receptors in breast cancer: relationships to tumour histopathology and survival of patients

Estrogen receptor (ER) and progesterone receptor (PR) concentrations were measured in the tumours of 399 cases of primary breast carcinoma. Histological type and histological grading was also analysed. The correlation between survival and histological grading was observed and found to be of high significance statistically. Longer survival of patients with ER- and/or PR-positive tumours was also observed, but the ER and PR prognostic value did not reach the same magnitude as histological alone. The prognostic accuracy in breast cancer, when histological grading, ER and PR were used together, failed to reach statistically significant values. A lower proportion of ER- and PR-positive tumours were found in histological grade III. The majority of the tumours belonging to specific histological variants of carcinoma were ER- and/or PR-positive. Relationships between ER, PR, menopausal status, and age were also noted. It was apparent that the prognostic value of PR concentrations in the tumour was more relevant than that of ER alone.

Myeloneuropathy and macrocytosis associated with nitrous oxide abuse

After four months of excessive nitrous oxide (N2O) exposure, a dentist had myeloneuropathy with spastic paraparesis, Lhermitte's sign, sensory shading, loss of position and vibration sense, ataxia, and impotence. Macrocytosis, hypersegmented neutrophils, and a reduced vitamin B12 level were associated with normal findings on gastric analysis and Schilling test. Complete hematologic and neurologic recovery followed N2O avoidance and vitamin therapy for six months.

Neuroradiological correlates of frontally predominant intermittent rhythmic delta activity (FIRDA)

A correlative, retrospective review of 80 consecutive cases of EEG FIRDA was performed with regard to the neuroradiological findings: 62 of the 80 patients had had CAT scan evaluations. Of the 61 patients with structural pathology, 53 had CAT scans which were abnormal in 40 (76%); of the 19 patients with 'non-structural' (mostly metabolic) brain lesions, 10 had normal CAT scans. In the structural group with normal CAT scans, the presence of pathology was demonstrated by arteriography (5 cases), radionuclide cysternography (1 case), brain scan (1 case), or pathological examination. Patients with 'non-structural' FIRDA had a significantly higher probability of being in an altered state of consciousness and of having abnormal background activity in their EEG. Focal EEG abnormalities are more frequently associated with structural lesions and FIRDA. If FIRDA is present on the EEG, further neuroradiological studies should be considered, especially with other electroclinical information suggests a non-metabolic substrate.

Preserved arterial grafts in microvascular surgery

The patency rates of arterial grafts preserved by immersion in 70% alcohol and arterial grafts preserved by ficin digestion and dialdehyde tanning were compared with the patency rate of fresh autogenous vein grafts in 5-mm defects in the femoral arteries of 50 rats. The overall patency rate for the fresh vein grafts was 90%. The patency rate at 2 weeks for the alcohol-preserved arterial grafts was 40%; the patency rate for the dialdehyde-tanned arterial grafts at 2 weeks was 30%. The difference between the rates for the fresh vein grafts and the alcohol-preserved and dialdehyde-tanned grafts was statistically significant (P less than 0.01 and P less than 0.001, respectively). At 2 months there was no statistically significant difference in the rates between the autogenous vein grafts and the preserved arterial grafts, probably because of recanalization of grafts that had occluded primarily. From the data, it is concluded that fresh autogenous vein grafts are still superior to preserved arterial grafts in microvascular surgery.

Acid alpha-naphthyl acetate esterase (ANAE) activity and DNA synthesis of lymph nodes cells in Hodgkin's disease

Lymph node and peripheral blood lymphocytes in a case of Hodgkin's disease (mixed cellularity) were studied using May-Grünwald-Giemsa (MGG), acid naphthyl acetate esterase (ANAE), immunoperoxidase staining and lymphocyte surface markers, autoradiographic, and lymphocyte stimulation techniques. According to MGG staining and autoradiographic studies of lymph, node cells, small lymphocytes, intermediate lymphoid cells, and large mononuclear cells resembling in-vitro stimulated immunoblasts, Hodgkin's cells and Reed-Sternberg (RS) cells formed a morphologically continuous DNA synthetizing series. A large majority of small lymphocytes from a lymph node were ANAE positive, thus being T-lymphocytes, and formed rosetts around large mononuclear cells and RS cells. Most RS and large mononuclear cells had ANAE positive spots in the cytoplasm, thus resembling T-lymphocytes more than diffusely staining monocytes. These cells did not contain cytoplasmic immunoglobulin and were muramidase negative. Both lymph node and peripheral blood lymphocytes responded strongly to PHA. The role of T-lymphocytes in Hodgkin's disease and the origin of RS cells are are discussed on the basis of the findings.

A controlled surgical approach to annulo-aortic ectasia

Annulo-aortic ectasia has attracted much surgical attention in the last 20 years. Replacement of the aortic valve and ascending aorta from the valve ring to just proximal to the innominate artery eliminates most, if not all, the pathologically involved tissue. Composite valve-Dacron tube grafting, plus elective saphenous vein grafts from the coronary orifices to the Dacron tube or distal aortic wall, provide a safe systematic approach to this entity. A review of surgical techniques and a description of a successful case employing this method are presented.

Dissection and rupture of the ascending aorta. Unusual complications of aortocoronary bypass surgery

This is a report concerning two cases of unusual complications, dissection and rupture of the ascending aorta, secondary to saphenous vein bypass surgery. We recommend that evaluation of patients undergoing saphenous vein bypass surgery include careful image-intensifier fluoroscopic examination during coronary arteriography. If aneurysmal dilatation of the aorta or calcification is observed, ascending aortography should be performed to better evaluate the aorta, and surgeons should be alerted to use appropriate maneuvers and techniques to minimize the risk of complications in the aortic site of the vein anastomosis. Internal mammary coronary-artery bypass should be the procedure of choice in such conditions.

Superior vena cava obstruction and dissecting aortic aneurysm

A dissecting aneurysm of the aorta led to formation of a fistula from the aneurysmal sac to the left atrium and caused obstruction of the superior vena cava. We do not know of any previous reports of this clinical syndrome.