Identification of GB3 as a Novel Biomarker of Tumor-Derived Vasculature in Neuroblastoma Using a Stiffness-Based Model

Neuroblastoma (NB) is a childhood cancer in sympathetic nervous system cells. NB exhibits cellular heterogeneity, with adrenergic and mesenchymal states displaying distinct tumorigenic potentials. NB is highly vascularized, and blood vessels can form through various mechanisms, including endothelial transdifferentiation, leading to the development of tumor-derived endothelial cells (TECs) associated with chemoresistance. We lack specific biomarkers for TECs. Therefore, identifying new TEC biomarkers is vital for effective NB therapies. A stiffness-based platform simulating human arterial and venous stiffness was developed to study NB TECs in vitro. Adrenergic cells cultured on arterial-like stiffness transdifferentiated into TECs, while mesenchymal state cells did not. The TECs derived from adrenergic cells served as a model to explore new biomarkers, with a particular focus on GB3, a glycosphingolipid receptor implicated in angiogenesis, metastasis, and drug resistance. Notably, the TECs unequivocally expressed GB3, validating its novelty as a marker. To explore targeted therapeutic interventions, nanoparticles functionalized with the non-toxic subunit B of the Shiga toxin were generated, because they demonstrated a robust affinity for GB3-positive cells. Our results demonstrate the value of the stiffness-based platform as a predictive tool for assessing NB aggressiveness, the discovery of new biomarkers, and the evaluation of the effectiveness of targeted therapeutic strategies.

Polymorphism AGT2 (rs4762) is involved in the development of dermatologic events: Proof-of-concept in hepatocellular carcinoma patients treated with sorafenib

BACKGROUND

Dermatologic adverse events (DAEs) are associated with a better outcome in patients with hepatocellular carcinoma (HCC) irrespective of the therapeutic agent received. The exact mechanisms associated with the development of DAEs are unknown although several studies point to direct toxicity of tyrosine kinase inhibitors (TKIs) to the skin or an immune-mediated reaction triggered by the oncologic treatment. As is the case in other conditions, individual genetic variants may partially explain a higher risk of DAEs.

AIM

To evaluate the contribution of several gene variants to the risk of developing DAEs in HCC patients treated with TKIs.

METHODS

We first analyzed 27 single-nucleotide polymorphisms (SNPs) from 12 genes selected as potential predictors of adverse event (AE) development in HCC patients treated with sorafenib [Barcelona Clinic Liver Cancer 1 (BCLC1) cohort]. Three additional cohorts were analyzed for AGT1 (rs699) and AGT2 (rs4762) polymorphisms-initially identified as predictors of DAEs: BCLC2 (n = 79), Northern Italy (n = 221) and Naples (n = 69) cohorts, respectively. The relation between SNPs and DAEs and death were assessed by univariate and multivariate Cox regression models, and presented with hazard ratios and their 95% confidence intervals (95%CI).

RESULTS

The BCLC1 cohort showed that patients with arterial hypertension (AHT) (HR = 1.61; P value = 0.007) and/or AGT SNPs had an increased risk of DAEs. Thereafter, AGT2 (rs4762) AA genotype was found to be linked to a statistically significant increased probability of DAEs (HR = 5.97; P value = 0.0201, AA vs GG) in the Northern Italy cohort by multivariate analysis adjusted for BCLC stage, ECOG-PS, diabetes and AHT. The value of this genetic marker was externally validated in the cohort combining the BCLC1, BCLC2 and Naples cohorts [HR = 3.12 (95%CI: 1.2-8.14), P value = 0.0199, AGT2 (rs4762) AA vs AG genotype and HR = 2.73 (95%CI: 1.18-6.32) P value = 0.0188, AGT2 (rs4762) AA vs GG genotype]. None of the other gene variants tested were found to be associated with the risk of DAE development.

CONCLUSION

DAE development in HCC patients receiving TKIs could be explained by the AGT2 (rs4762) gene variant. If validated in other anti-oncogenic treatments, it might be considered a good prognosis marker.

Activated Lymphocytes and Increased Risk of Dermatologic Adverse Events during Sorafenib Therapy for Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma is the second cause of cancer-related death worldwide. Of those advanced-stage patients who are treated with sorafenib, those who develop early dermatologic adverse events have a better prognosis. These events are possibly immune-related. Therefore, we analyzed the phenotype of 52 sorafenib-treated patients’ circulating lymphocytes throughout treatment. We found that different co-stimulatory and immune exhaustion markers, such as Programmed cell death protein 1 (PD-1) and DNAX accessory molecule 1 (DNAM-1) amongst others, correlate with the probability of developing these adverse events, both before and during the treatment. We also compared the phenotype of those lymphocytes expressing DNAM-1 with those that do not, and while NK DNAM-1-expressing cells have a co-stimulatory phenotype, T DNAM-1-expressing cells are immune-suppressors. Overall, we set a rationale for the combination of sorafenib and immune-targeted therapies; and for the use of immune markers (such as DNAM-1) for patients’ prognosis evaluation.

Abstract

Advanced hepatocellular carcinoma patients treated with sorafenib who develop early dermatologic adverse events (eDAEs) have a better prognosis. This may be linked to immune mechanisms, and thus, it is relevant to assess the association between peripheral immunity and the probability of developing eDAEs. Peripheral blood mononuclear cells of 52 HCC patients treated with sorafenib were analyzed at baseline and throughout the first eight weeks of therapy. T, B, Natural Killer cells, and their immune checkpoints expression data were characterized by flow cytometry. Cytokine release and immune-suppression assays were carried out ex vivo. Cox baseline and time-dependent regression models were applied to evaluate the probability of increased risk of eDAEs. DNAM-1, PD-1, CD69, and LAG-3 in T cells, plus CD16 and LAG-3 in NK cells, are significantly associated with the probability of developing eDAEs. While NK DNAM-1⁺ cells express activation markers, T DNAM-1⁺ cells induce immune suppression and show immune exhaustion. This is the first study to report an association between immune checkpoints expression in circulating immune cells and the increased incidence of eDAEs. Our results support the hypothesis for an off-target role of sorafenib in immune modulation. We also describe a novel association between DNAM-1 and immune exhaustion in T cells.

Pharmacokinetics and pharmacogenetics of sorafenib in patients with hepatocellular carcinoma: Implications for combination trials

BACKGROUND & AIMS

Sorafenib and lenvatinib are the first-line treatments approved in hepatocellular carcinoma (HCC), but information is lacking about the relationships between their pharmacokinetics, patients pharmacogenetic profiles, adverse events (AE) and overall survival. We aimed to elucidate these relationships of tyrosine Kinase Inhibitors, such as sorafenib, in order to improve the design of trials testing it in combination with checkpoint inhibitors.

METHODS

We assessed the pharmacokinetics of sorafenib and its N-oxide metabolite at day-0, day-7, day-30, day-60, day-90, day-120, day-150 and day-180 and nine single-nucleotide polymorphisms (SNP) in five genes related to sorafenib metabolism/transport to identify the best point for starting the combination between tyrosine kinases and checkpoint inhibitors.

RESULTS

We prospectively included 49 patients (96% cirrhotic, 37% hepatitis-C, 82% Child-Pugh-A and 59% BCLC-C). Pharmacokinetic values peaked at day-7 and progressively declined until day-60. In the 16 patients without further dose modifications after day-60, pharmacokinetic values remained stable through day-180 (sorafenib P = .90; N-oxide P = .93). Pharmacokinetic values were higher in patients with early dermatological adverse events and lower in patients with early diarrhoea. Sorafenib and N-oxide pharmacokinetic values varied linearly with different alleles of MRP2*3972.

CONCLUSIONS

Sorafenib's pharmacokinetics is heterogeneous across HCC patients. This heterogeneity affects adverse events development and must be taken into account in setting the dose and timing of its combination with checkpoint inhibitors.

Analysis of the porcine APOA2 gene expression in liver, polymorphism identification and association with fatty acid composition traits

APOA2 is a protein implicated in triglyceride, fatty acid and glucose metabolism. In pigs, the APOA2 gene is located on pig chromosome 4 (SSC4) in a QTL region affecting fatty acid composition, fatness and growth traits. In this study, we evaluated APOA2 as a candidate gene for meat quality traits in an Iberian × Landrace backcross population. The APOA2:c.131T>A polymorphism, located in exon 3 of APOA2 and determining a missense mutation, was associated with the percentage of hexadecenoic acid [C16:1(n-9)], linoleic acid [C18:2(n-6)], α-linolenic acid [C18:3(n-3)], dihomo-gamma-linolenic acid [C20:3(n-6)] and polyunsaturated fatty acids (PUFAs) in backfat. Furthermore, this SNP was associated with the global mRNA expression levels of APOA2 in liver and was used as a marker to determine allelic expression imbalance by pyrosequencing. We determined an overexpression of the T allele in heterozygous samples with a mean ratio of 2.8 (T/A), observing a high variability in the allelic expression among individuals. This result suggests that complex regulatory mechanisms, beyond a single polymorphism (e.g. epigenetic effects or multiple cis-acting polymorphisms), may be regulating APOA2 gene expression.

[Efficiency and risk factors in the cognitive-behavioural treatment for smoking cessation in pregnancy]

BACKGROUND AND OBJECTIVE

The aim of this study is to quantify the efficiency of the cognitive-behavioural treatment for smoking cessation in pregnancy and to evaluate the risk factors of success or failure for the abstinence before the childbirth.

PATIENTS AND METHOD

We studied 74 pregnant smoking women who, between January 2003 and January 2004, came to their obstetric regular control in the Hospital Casa Maternitat-Hospital Clínic i Provincial de Barcelona, and who voluntarily acceded to the cognitive-behavioural treatment without replacement of nicotine for the smoking cessation that they were offered.

RESULTS

44% of women who made the program of visits came abstinent to the childbirth, and of them, 93.1% was abstinent during the quarantine. 51.5% reduced the consumption and 4.5% didn't change or increased the consumption. The fact that someone smokes at home (p = 0.006), the degree of dependence to the nicotine (p = 0.015) and a consumption of coffee superior to 3 daily cups (p = 0.039), in an equation of logistic regression, classified both groups (abstinence/not abstinence).

CONCLUSIONS

The efficiency of a program based on cognitive-behavioural therapy, without replacement of nicotine, for the smoking cessation in the pregnancy is confirmed in our sample. We propose to consider risk factors of treatment failure the fact that someone smokes at home and a daily high consumption of coffee.

Probability matching involves rule-generating ability: A neuropsychological mechanism dealing with probabilities

Probability matching is a nonoptimal strategy consisting of selecting each alternative in proportion to its reinforcement contingency. However, matching is related to hypothesis testing in an incidental, marginal, and methodologically disperse manner. Although some authors take it for granted, the relationship has not been demonstrated. Fifty-eight healthy participants performed a modified, bias-free probabilistic two-choice task, the Simple Prediction Task (SPT). Self-reported spurious rules were recorded and then graded by two independent judges. Participants who produced the most complex rules selected the probability matching strategy and were therefore less successful than those who did not produce rules. The close relationship between probability matching and rule generating makes SPT a complementary instrument for studying decision making, which might throw some light on the debate about irrationality. The importance of the reaction times, both before and after responding, is also discussed.

Phase II study of capecitabine (X) + docetaxel (T) as neoadjuvant treatment in patients (pts) with locally advanced breast cancer (LABC) including biological correlates

664

Background: X and T have demonstrated synergy in preclinical studies and survival benefits in metastatic BC. We aimed to determine whether the high efficacy of XT could translate into the neoadjuvant setting. Methods: Expression levels (mRNA) of 3 enzymes involved in X intratumoral activation and metabolism (thymidylate synthase [TS], thymidine phosphorylase [TP] and dihydropyrimidine dehydrogenase [DPD]), were determined in tumor biopsies before treatment and their relationship with clinical and pathological response analyzed using Fisher’s Exact Test. Pts with stage IIIA/IIIB LABC, adequate organ function and KPS ≥80 received 4 cycles of X 1250mg/m2 (1000mg/m2 for age >60) bid d1–14 and T 75mg/m2 d1 q3w followed by surgery, adjuvant AC q3w × 4 ± tamoxifen according to ER and PR status. The primary endpoint was pCR. Results: We enrolled 34 pts with LABC IIIA (44%)/IIIB (56%): median age 52y (30–72); KPS ≥90 (76%); median tumor size 6.8cm (2–20); N0 (20%), N1 (41%), N2/3 (35%); ER+PR-/p53+/HER2+ (23/24/28%). 128 cycles of X and T were administered (median 4, range 1–5). Main G3/G4 toxicities were: HFS 32%, diarrhea 15%, asthenia 9%, stomatitis 6% and neutropenia 71%. There were no treatment-related deaths. 2 pts were withdrawn prematurely due to adverse events. The overall response in 32 evaluable pts was 78%, including 5 CRs and 20 PRs. 6/29 pts evaluable for pathological response had pCR (20%), and 10 (33%) had ≤10mm residual tumor (3 microscopic RD) in breast. Nodal involvement after chemotherapy was N0 (33%), N1 (33%), N2 (27%), N3 (7%), and the rate of breast-conserving surgery was 17%. High TP/DPD ratio was associated with CR (p=0.037) and both high TP/DPD and low TS/DPD ratio appeared to correlate with residual tumor ≤10 mm (p=0.028). Conclusions: Neoadjuvant XT appears to be highly active. Safety was similar to that reported in anthracycline-pretreated pts but with less stomatitis. In this small sample, a high TP/DPD ratio appears to correlate with clinical response and a favorable enzymatic profile (high TP/DPD and low TS/DPD ratio) may predict for high pCR. A further prospective study is required to validate this hypothesis.

No significant financial relationships to disclose.

[Nicotine replacement therapy versus gradual smoking withdrawal in smoking cessation]

BACKGROUND AND OBJECTIVE

The aim was to study the effectiveness of the gradual nicotine withdrawal without nicotine replacement therapy (NRT) as a method of smoking cessation during a three years follow-up period in the cognitive-behavioural context in the clinical work of the Clinic Hospital Unit.

PATIENTS AND METHOD

Two groups of patients with similar sociodemographic and clinical characteristics and the same degree of nicotine dependence according to the Fageströmtest were compared. We included 111 patients treated for smoking cessation in the Unit Hospital: 84 patients, under the cognitive-behavioural model, were treated with NRT and 27 patients, under the same model, were treated only with gradual nicotine withdrawal without NRT.

RESULTS

There was not a significant difference between the effectiveness of the NRT (65.3%) and that of the gradual nicotine withdrawal without the NRT (51.8%) on smoking cessation(X2 =1.612; p = 0.204) at the first year or during a 3 years follow-up period (NRT: 41% and gradual nicotine withdrawal: 36%; X2: 0.124; p = 0. 725).

CONCLUSIONS

The gradual nicotine withdrawal without NRT scheme shows the same degree of effectiveness at the first year and during a three years follow-up period as that of the nicotine replacement therapy scheme on smoking cessation.

A randomized trial on the efficacy of group psychoeducation in the prophylaxis of recurrences in bipolar patients whose disease is in remission

BACKGROUND

Studies on individual psychotherapy indicate that some interventions may reduce the number of recurrences in bipolar patients. However, there has been a lack of structured, well-designed, blinded, controlled studies demonstrating the efficacy of group psychoeducation to prevent recurrences in patients with bipolar I and II disorder.

METHODS

One hundred twenty bipolar I and II outpatients in remission (Young Mania Rating Scale score <6, Hamilton Depression Rating Scale-17 score <8) for at least 6 months prior to inclusion in the study, who were receiving standard pharmacologic treatment, were included in a controlled trial. Subjects were matched for age and sex and randomized to receive, in addition to standard psychiatric care, 21 sessions of group psychoeducation or 21 sessions of nonstructured group meetings. Subjects were assessed monthly during the 21-week treatment period and throughout the 2-year follow-up.

RESULTS

Group psychoeducation significantly reduced the number of relapsed patients and the number of recurrences per patient, and increased the time to depressive, manic, hypomanic, and mixed recurrences. The number and length of hospitalizations per patient were also lower in patients who received psychoeducation.

CONCLUSION

Group psychoeducation is an efficacious intervention to prevent recurrence in pharmacologically treated patients with bipolar I and II disorder.

Structure and function relationships of the respiratory muscles

Potential relationships between the structure of the diaphragm and external intercostals and several indices of respiratory muscle function, lung function and nutrition in 27 patients (61+/-10 yrs of age) subjected to thoracotomy as a result of a lung neoplasm have been investigated. Prior to surgery the nutritional status of the patients was assessed and lung function (spirometry, lung volumes, transfer factor of the lungs for carbon monoxide, arterial blood gases) and respiratory muscle function (maximal inspiratory pressure (MIP) and diaphragmatic function were measured). Biopsies of the diaphragm (and external intercostals) were obtained during surgery. On average, patients showed mild airflow limitation (forced expiratory volume in one second (FEV1), 70+/-14% of predicted value, FEV1/forced vital capacity (FVC), 70+/-9%) with some air trapping (residual volume (RV), 139+/-50% pred) and normal gas exchange (arterial oxygen tension (Pa,O2), 11.3+/-1.33 kPa (85+/-10 mmHg)) and arterial carbon dioxide tension (Pa,CO2) 5.4+/-0.5 kPa (40.6+/-4 mmHg). MIP was 77+/-25% pred; maximal transdiaphragmatic pressure was 90+/-27 cmH2O. Most morphometric measurements of the diaphragm and external intercostals were within the range of values reported previously in other skeletal muscles. The size of the fibres of these two respiratory muscles was positively related (p<0.05) to MIP (% pred). There were no significant relationships between the structure of both muscles and nutritional status or any index of lung function. In conclusion, in the population studied, the fibre size of the diaphragm and external intercostals appears to relate to their ability to generate force.

High prevalence of subclinical Sjögren's syndrome features in patients with autoimmune thyroid disease

OBJECTIVE

To determine the prevalence of keratoconjunctivitis sicca and xerostomia related to Sjögren's syndrome (SS) in asymptomatic patients with diagnosed autoimmune thyroid diseases (AITD); and to investigate whether the immunopathologies of sialadenitis observed in AITD associated SS and primary SS are similar.

METHODS

One hundred seventy-six patients diagnosed with AITD (88 with Graves' disease, 40 Hashimoto's thyroiditis, 48 primary myxedema) were tested for keratoconjunctivitis sicca (Schirmer's test and rose bengal staining) and for xerostomia (salivary scintigraphy and labial salivary gland biopsy). Immunohistopathological studies were performed on cryostat sections of bucal mucosa biopsies using antibodies to CD3, CD4, CD8, CD20, CD14, CD25, LFA-1, ICAM-3 HLA class II, tumor necrosis factor-alpha, interleukin 1, and interferon-gamma.

RESULTS

Nineteen of 52 (37%) patients with AITD fulfilled the criteria for xerostomia and 39/170 (23%) for keratoconjunctivitis sicca. Features of SS were diagnosed in 43 of 176 (24%) patients with AITD, with similar prevalence in Graves' (20%). Hashimoto's thyroiditis (27%), and primary myxedema (29%). In AITD associated SS, infiltrating lymphocytes were mainly CD3+ T lymphocytes, with a CD4/CD8 ratio of 2:1. In most patients infiltrating lymphocytes expressed activation markers, HLA class II molecules, and interleukin 2 receptor (CD25). In some patients HLA class II was inappropriately expressed in the epithelial gland cells.

CONCLUSION

The finding that a third of patients with AITD have SS features confirms that AITD and SS are mutually associated. Together with the similarity of immunopathology of sialadenitis in AITD associated SS in primary SS, this supports the theory that SS and AITD are 2 autoimmune diseases closely related pathogenetically.

Immunohistochemistry of minor salivary gland biopsy specimens from patients with Sjögren's syndrome with and without hepatitis C virus infection

OBJECTIVES

To characterise phenotypically the minor salivary glands of patients with clinical and histological features of Sjögren's syndrome (SS) infected with hepatitis C virus (HCV).

PATIENTS AND METHODS

75 consecutive patients with SS (31 primary SS, 44 secondary SS) diagnosed by preliminary European classification criteria. The presence of anti-HCV antibodies was detected by commercial third generation ELISA and by a second generation immunoblot assay. Presence of HCV genome in serum was determined by polymerase chain reaction analysis. Expression of CD3, CD4, CD8, CD20, HLA-DR, and CD25 molecules in lymphocytic and epithelial cells on minor salivary glands was detected by immunohistochemical assays. Expression of interferon gamma and interleukin 4 cytokines was determined by in situ hybridisation.

RESULTS

Six of 31 primary SS (19%) and one of 44 secondary SS (2%) serum samples were positive for anti-HCV by ELISA. Three samples were positive, three indeterminate, and one sample corresponding to a secondary SS patient was negative by immunoblot. The three immunoblot positive serum samples were also HCV-RNA positive by PCR assay. The study of lymphocytic cells in the diffuse infiltrate of minor salivary glands showed a predominance of the CD3 lymphocytic population. A predominance of CD4 over CD8 T cells (ratio 2:1) was observed in HCV and non-HCV infected patients. The analysis of the lymphocytic focus showed that the HCV infected patients had a predominance of CD20 positive cells. Activation molecules (CD-25 and HLA-DR) were expressed in HCV and non-HCV infected patients in lymphocytic and epithelial cells, however epithelial cell expression of CD25 was low in HCV infected patients. As expected, a pronounced Th1 response was observed in the lymphocytic foci of HCV patients.

CONCLUSIONS

HCV infected patients may develop an autoimmune sialadenitis, similar to that described in primary SS.

[Muscle relaxants in the morphometric study of the respiratory muscles in human beings]

The morphological examination of respiratory muscle can be affected by muscular contraction following biopsy. Most morphometric studies of respiratory muscles, however, have been carried out without taking into account this factor, the effect of which can be reduced by using relaxants when taking samples. Objective. To examine the effect of using a relaxant in the morphometric analysis of muscle fibers. We examined 31 muscle samples from 7 patients. Immediately after removal, each pipe was divided in half. One was placed in an isotonic physiological solution and the other in a solution of curare 0.02%. Later, both samples were processed for morphometric study with ATP-ase, NADTH and PAS tincture. Morphological data recorded for the different types of fibers included measurement of minimum diameter (Dmin), atrophy and hypertrophy indices (AI and HI) and heterogeneity of distribution (SDDmin). The Dmin was smaller in fibers transported in a curare solution than in those transported in physiological solution (67 +/- 2 microns vs. 71 +/- microns, p < 0.05). The same was true of SDDmin (13 +/- 3 vs. 12 +/- 3, p < 0.05), HI (300 +/- 88 vs. 457 +/- 107, p < 0.05). Likewise, we found a similar direct correlation between size of fibers processed with physiological solution and those processed in curare (Dmin, r = 0.731, p < 0.001; HI, r = 0.827, p < 0.001; SDDmin, r = 0.636, p < 0.0001). The use of relaxants in processing muscle samples prevents contraction and should be used systematically in the morphological analysis of muscle fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-2 receptor expression in salivary glands of patients with Sjögren's syndrome

OBJECTIVE

To study interleukin-2 receptor (IL-2R) expression in lymphocytic and epithelial cells in salivary glands of patients with Sjögren's syndrome (SS).

METHODS

Minor salivary glands of 29 patients with primary SS, 28 with secondary SS, 19 with autoimmune diseases without SS, and 17 controls were studied using immunohistochemical techniques. Sections were analyzed with 3 different antibodies reacting with CD25 molecule.

RESULTS

The presence of IL-2R (CD25) was observed in minor salivary gland lymphocytic infiltrate in 26 (89.6%) primary SS, 24 (85.7%) secondary SS, and 16 (84%) autoimmune diseases without SS. CD25 antibody was expressed in epithelial cells in 12 (41%) patients with primary SS and 11 (39%) with secondary SS, but was absent in the group of autoimmune diseases without SS and the control group.

CONCLUSION

The lymphocytic infiltrate of minor salivary gland expressed IL-2R in patients with primary SS, secondary SS and autoimmune diseases without SS. IL-2R expression in epithelial cells was only present in patients with primary or secondary SS.

The gene PPG encodes a novel yeast protein phosphatase involved in glycogen accumulation

Degenerate oligonucleotides were used to selectively amplify yeast genomic sequences related to Ser/Thr protein phosphatases. Among the sequences obtained, clone ST4-2 was found to code for a novel sequence related to previously known phosphatases. A size-selected yeast genomic library was constructed and screened using clone ST4-2 as probe, and one positive clone, named PPG, was isolated. DNA sequencing of a 1.8-kilobase pair fragment of this clone revealed an open reading frame of 1104 base pairs which codes for a 368-amino acid protein. On the basis of its amino acid sequence, the product of gene PPG would be an acidic protein, structurally more related to type 2A than to type 1 or 2B phosphatases, and is characterized by an extension of about 50 amino acids at the carboxyl terminus. The gene, which is located in chromosome XIV, is expressed as a 1.3-kilobase mRNA and is not essential for growth. Haploid mutants carrying a disrupted copy of the gene were able to grow in glucose as well as in other carbon sources, but they accumulated less glycogen than the wild type strain. However, the state of activation of glycogen synthase was essentially identical in wild type and mutant cells. The finding that, in early exponential phase, mutant cells contain higher levels of glycogen phosphorylase a, in addition to a lower amount of total glycogen synthase activity observed in medium-late exponential phase, could account for the difference found in glycogen accumulation.

Glycogen metabolism in a Saccharomyces cerevisiae phosphoglucose isomerase (pgil) disruption mutant

Disruption of the gene pgil of Saccharomyces cerevisiae, which codes for phosphoglucose isomerase, results in a dramatic increase in the amount of intracellular glycogen in early exponential cultures. The level of glucose 6-phosphate was much higher in mutant than in wild-type cells. Phosphorylase a activity and the state of activation of glycogen synthase were also investigated. Phosphorylase a activity was rather low along the culture in wild-type cells, whereas it was consistently higher in mutants. Glycogen synthase was mostly in the active form in early-medium exponential cultures in wild-type cells whereas the activation state of this enzyme in mutant cells, although lower at the earlier steps of the culture, did not differ from wild-type cells at later stages. The fact that the intracellular levels of UDP-glucose are markedly increased in mutant cells suggest that the observed accumulation of glycogen results from a rise in substrate availability rather than from the activation of the enzyme responsible for the synthesis of the polysaccharide.

[Eosinophilic cystitis as a special form of response to mitomycin C. Analysis and comments on our cases]

We analyzed 29 cases of eosinophilic cystitis in a group of 80 patients with lower urothelial carcinoma who had been treated with mitomycin-C. Only 6 cases (20.7%) had presented symptoms and signs compatible with acute cystitis. The remaining patients had been diagnosed histopathologically by routine follow-up bladder biopsy. Urine cytology revealed abundant eosinophils in 58.6% of the patients with eosinophilic cystitis while urine culture was negative for all patients. No patient had a previous history of allergy or asthma. We discuss the possible etiopathogenic mechanisms of this rare nosologic entity, the relationship to the immune system and the role of the foregoing in the capacity to control urothelial carcinoma locally.

Evolution of benign rheumatoid nodules into rheumatoid arthritis after 50 years

A patient with benign rheumatoid nodules who developed rheumatoid arthritis after 50 years is described.