Reduction of cell proliferative activities of gastric stump adenomatous hyperplasias after bile reflux diversion in rats

Previously we reported the majority of lesions induced by bilereflux, in the absence of chemical carcinogens, in the rat remnantstomach to consist primarily of gastric type and secondarilyof intestinal type cells, and that they are reversible afterdiversion of bile reflux. The present study was designed toevaluate changes in proliferative activities in cells of eachtype under these conditions. The frequency of adenomatous hyperplasia(AH) induced in the gastric stump mucosa by duodenal contentreflux after Billroth II partial gastrectomy (BII) increaseduntil the 54th week of the experiment. Roux-en-Y (RY) surgicalprocedure which prevents duodenal reflux performed at the 24thor 36th week after BII led to a decrease in AH. Cell contentof the lesions was analyzed using routine H&E staining,immunohistochemical staining for pepsinogen isoenzyme 1 andhistochemical procedures for mucins (paradoxical concanavalinA, galactose oxidase Schiff and sialidase galactose oxidaseSchiff reactions) and proliferation in each compartment evaluatedby an immunohistochemical method using bromodeoxyuridine (BrdU)and a monoclonal antibody against BrdU. At the 54th week thenumber of BrdU-labeled cells per normal pyloric column was significantly(P < 0.05) increased to 10.63/pit after the BII operation,while it diminished to 5.23/pit after RY diversion, this beingthe same level as with the RY procedure alone. AH maintaineda high rate of BrdU incorporation at 12.7% after BII operation,which was also significantly reduced (P < 0.01) to 7.0% bythe RY surgery. The intestinal type cell showed highest (22.2%),the surface mucous type cell showed the next (16.5%) and thepyloric gland type cell showed lowest (5.2%) BrdU labeling indicesafter BII operation. All the cell types in AH showed similarproportional decreases in BrdU incorporation after RY diversion.Thus surgical intervention reverses the cell proliferation causedby bile reflux in the gastric stump.     

The influence of stimulus parameters on the visual field indices by automated projection perimetry

The various stimulus parameters offered by two standard automated projection perimeters [Humphrey Field Analyser 630 (HFA) and Octopus 2011, namely, stimulus size and location and the interaction of adaptation level and stimulus duration, were compared in a sample of 20 patients attending a glaucoma clinic using the visual field indices mean defect (MD), loss variance (LV), short-term fluctuation (SF) and corrected loss variance (CLV). LV and SF were greater with Octopus program 32 compared with Octopus program G1 (P < 0.02). No difference in the indices was found between stimulus sizes I and III for HFA program 30-2. MD was greater for program 30-2 compared with program 32 (P < 0.002) when expressed in terms of log (L/L) whereas LV (P < 0.02) and SF (P < 0.02) were greater for program 32. All differences were considered to be negligible in the clinical sense.     

Variation in smoking-related lung cancer risk factors by cell type among men in Argentina: a case-control study

A high mortality rate for lung cancer (62.7 per 100,000) is found in Rosario, Argentina. To investigate the reasons for this high rate, a case-control study was carried out among 215 male cases with histologically confirmed lung cancer and 433 hospitalized controls for conditions unrelated to tobacco consumption. Odds ratios (OR) of squamous cell (SQ), adenocarcinoma (AD), and small cell (SM) carcinoma of the lung associated with different characteristics of the smoking habit were quantified. Ninety-eight percent of the cases had smoked regularly. Smokers were significantly younger at diagnosis than ex-smokers (P<0.0001), a pattern consistent for all cell types. The ORs for the heaviest cf the lowest consumption categories were 15.3 for SQ, 11.6 for AD, and 11.6 for all lung cancer (P<0.0001). Risks associated with the use of unfiltered cigarettes were three to five times higher than those for filtered cigarettes, depending on cell types. For ex-smokers, risks after 10 years of nonsmoking were about 12 times lower than those of current smokers (P<0.001). To halt further increases in lung cancer, preventive measures in Argentina should be directed primarily towards smoking control.Ms Pezzotto and Drs Bay, Morini, and Poletto are with the Institute of Immunology, School of Medicine, National University of Rosario, Argentina. Dr Mahuad is with Hospital Italiano Rosario, Argentina. Address correspondence to Ms Pezzotto, Inst. Inmunologia, Facultad de Medicina, Santa Fe 3100, 2000 Rosario, Argentina.     

Calcium channel modulation by dihydropyridines modifies sufentanil-induced antinociception in acute and tolerant conditions

Summary The study was aimed at elucidating the possible participation of l-type Ca²⁺ channel in the acute analgesic effect of an opiate and the development of tolerance to this action. Sufentanil, a selective p agonist, and two dihydropyridines, the Ca²⁺ antagonist nimodipine and the Ca²⁺ agonist Bay K 8644, were selected. The tail-flick test was used to assess the nociceptive threshold. In naive rats, nimodipine (200 g/kg) potentiated the analgesic effect of sufentanil reducing the ED₅₀ from 0.26 to 0.08 g/kg. Similar results were observed with its (–)-enantiomer Bay N 5248, while the (+) enantiomer Bay N 5247 was ineffective. Tolerance to the opiate was induced by chronic subcutaneous administration of sufentanil with minipumps (2 g/h, 7 days). In these conditions the dose-response curve to sufentanil was displaced to the right and the ED₅₀ was increased to 1.49 g/kg. In tolerant rats, nimodipine preserved its potentiating ability and prevented the displacement to the right of the sufentanil dose response-curve (ED₅₀ = 0.48 g/kg). When nimodipine was pumped (1 g/h, 7 days) concurrently with sufentanil, the development of tolerance to the opioid was not disturbed. However, the expression of tolerance was abolished and even the effect of acutely administered sufentanil was markedly potentiated (ED₅₀ = 0.03 g/kg). Similar experiments were performed with Bay K 8644. In naive rats, Bay K 8644 at a low dose (20 g/kg) that behaves as a calcium agonist, antagonized the analgesic effect of sufentanil (ED₅₀ = 0.58 g/kg), whereas at a high dose (200 g/kg) it potentiated this action (ED₅₀ = 0.15 g/kg). In tolerant rats, Bay K 8644 (20 g/kg) preserved its antagonizing ability inducing a displacement to the right of the sufentanildose-response curve (ED₅₀ = 4.2 g/kg). When Bay K 8644 was pumped (1 g/h, 7 days) concurrently with sufentanil, it enhanced the expression of tolerance to the opiate (ED₅₀ = 3.8 g/kg). These results suggest that the calcium fluxes through the l-type channel in neurones are functionally linked to the activation of the opiate receptor: the blockade of the channel increased the potency of sufentanil, whereas its activation reduced the potency of the opiate. In chronic experiments, DHPs concurrently administered with sufentanil did not affect the development of tolerance to the opiate. However, nimodipine prevented the expression of this phenomenon. Even more, the animals became hypersensitive to the opiate suggesting that the adaptative mechanisms induced by chronic opiate could be affected by chronic nimodipine.This work was supported by grants from Universidad de Cantabria-Caja Cantabria (1988) and Bayer AG, Wuppertal, FRGPredoctoral Fellow: Fondo de Investigaciones Sanitarias de la Seguridad Social.Send offprint requests to: M. A. Hurlé at the above address     

Biochemical interactions between methotrexate and 1-β-d-arabinofuranosylcytosine in hematopoietic cells of children: a Pediatric Oncology Group study

Summary Children with acute lymphocytic leukemia (ALL) in remission were treated with overlapping sequential infusions of methotrexate (MTX) and 1--d-arabinofuranosylcytosine (araC) as part of continuation therapy. The doses and the sequence were chosen to mimic conditions that produced greater than additive antineoplastic activity with these two drugs in preclinical studies. To assess the potential for the drug combination to exhibit greater than additive effect in vivo, we investigated several biochemical parameters that had been associated with synergism in vitro. Because the patients were in remission, the intracellular parameters could only be measured in cytologically normal hematopoietic cells. We observed that (1) the mean plasma concentrations of MTX and araC were above those required to obtain a greater than additive cytotoxicity with the two drugs in tissue culture; (2) MTX did not have a significant antipurine effect in bone marrow mononuclear cells; (3) the mean intracellular concentration of deoxycytidine triphosphate (dCTP) was significantly lower after treatment with the drug combination than after therapy with araC alone; and (4) the ratio of araC triphosphate (araCTP) to dCTP was 2.6 times higher after treatment with the combination than after araC alone. These results indicate that it is possible to achieve in patients the biochemical conditions associated with the greater than additive antineoplastic activity of MTX and araC in vitro.Abbreviations ALL acute lymphocytic leukemia - araC 1--d-arabinofuranosyluracil - araCTP araC triphosphate - araU 1--d-arabinofuranosyluracil - dNTPs deoxyribonucleoside triphosphates - MTX methotrexate - TCA trichloroacetic acid Supported in part by grants from the National Cancer Institute, National Institutes of Health (CA-38 053; CA-33572, CA-32278, CA-38 859, CA-29 691, and CA-30 969). Preliminary reports on the biochemical data were published by E. M. N., A. M. T., and D. P. inProc Am Assoc Cancer Res 24: 133 (1983) and those on the clinical data, by R. A K., E. M. N., D. P. R. B. R., M. B. H., Y. R., and A. I. F. inProc Am Soc Clin Oncol 3: 201 (1984)     

Expanding allelic and phenotypic spectrum of ZC4H2-related disorder: A novel hypomorphic variant and high prevalence of tethered cord

ZC4H2 (MIM# 300897) is a nuclear factor involved in various cellular processes including proliferation and differentiation of neural stem cells, ventral spinal patterning and osteogenic and myogenic processes. Pathogenic variants in ZC4H2 have been associated with Wieacker-Wolff syndrome (MIM# 314580), an X-linked neurodevelopmental disorder characterized by arthrogryposis, development delay, hypotonia, feeding difficulties, poor growth, skeletal abnormalities, and dysmorphic features. Zebrafish zc4h2 null mutants recapitulated the human phenotype, showed complete loss of vsx2 expression in brain, and exhibited abnormal swimming and balance problems. Here we report 7 new patients (four males and three females) with ZC4H2-related disorder from six unrelated families. Four of the 6 ZC4H2 variants are novel: three missense variants, designated as c.142T>A (p.Tyr48Asn), c.558G>A (p.Met186Ile) and c.602C>T (p.Pro201Leu), and a nonsense variant, c.618C>A (p.Cys206*). Two variants were previously reported : a nonsense variant c.199C>T (p.Arg67*) and a splice site variant (c.225+5G>A). Five patients were on the severe spectrum of clinical findings, two of whom had early death. The male patient harboring the p.Met186Ile variant and the female patient that carries the p.Pro201Leu variant have a relatively mild phenotype. Of note, 4/7 patients had a tethered cord that required a surgical repair. We also demonstrate and discuss previously under-recognized phenotypic features including sleep apnea, arrhythmia, hypoglycemia, and unexpected early death. To study the effect of the missense variants, we performed microinjection of human ZC4H2 wild-type or variant mRNAs into zc4h2 null mutant zebrafish embryos. The p.Met186Ile mRNA variant was able to partially rescue vsx2 expression while p.Tyr48Asn and p.Pro201Leu mRNA variants were not. However, swimming and balance problems could not be rescued by any of these variants. These results suggest that the p.Met186Ile is a hypomorphic allele. Our work expands the genotypes and phenotypes associated with ZC4H2-related disorder and demonstrates that the zebrafish system is a reliable method to determine the pathogenicity of ZC4H2 variants.     

Immunological evidence of an early seroconversion to oncogenic Merkel cell polyomavirus in healthy children and young adults

Oncogenic Merkel cell polyomavirus (MCPyV) provokes a widespread and asymptomatic infection in humans. Herein, sera from healthy children and young adults (HC, n = 344) aged 0–20 years old were evaluated for anti-MCPyV immunoglobulin G (IgG) and IgM antibodies employing a recently developed immunoassay. Serum MCPyV IgG data from healthy subjects (HS, n = 510) and elderlies (ES, n = 226), aged 21–65/66–100 years old, from our previous studies, were included. The anti-MCPyV IgG and IgM rates in HC sera were 40.7% and 29.7%, respectively. A lower prevalence of anti-MCPyV IgGs was found in HC aged 0–5 years old (13%) compared to 6–10 (52.3%), 11–15 (60.5%) and 16–20 years old (61.6%) cohorts. Age-stratified HCs exhibited similar anti-MCPyV IgM rates (27.9%–32.9%). Serological profiles indicated that anti-MCPyV IgGs and IgMs had low optical densities (ODs) during the first years of life, while IgM ODs appeared to decrease throughout young adulthood. A lower anti-MCPyV IgGs rate was found in HC (40.7%) than HS (61.8%) and ES (63.7%). Upon the 5-years range age-stratification, a lower anti-MCPyV IgGs rate was found in the younger HC cohort aged 0–5 years old compared to the remaining older HC/HS/ES cohorts (52.3%–72%). The younger HC cohort exhibited the lowest anti-MCPyV IgG ODs than the older cohorts. Low anti-MCPyV IgMs rates and ODs were found in the 21–25 (17.5%) and 26–30 (7.7%) years old cohorts. Our data indicate that, upon an early-in-life seroconversion, the seropositivity for oncogenic MCPyV peaks in late childhood/young adulthood and remains at high prevalence and relatively stable throughout life.     

Mixed Hyperbranched/Triblock Copolymer Micelle Assemblies: Physicochemical Properties and Potential for Drug Encapsulation

Mixed micelles have numerous advantages while requiring little to no effort in preparation. This study aims to produce mixed micelle nanostructures from a linear triblock copolymer and a hyperbranched random copolymer, and is able to be loaded with the weakly water-soluble drugs curcumin and indomethacin. Different preparation techniques are employed to produce mixed micelles comprised of Pluronic F127 block copolymer, and hyperbranched poly[(ethylene glycol) methyl ether methacrylate-co-lauryl methacrylate], H-[P(OEGMA-co-LMA)], copolymer. Few studies have dabbled in these types of coassemblies, which provides insight into how structural differences of each copolymer can affect the formation of micelles. To determine the properties of the emerging nanostructures in aqueous environments, including their size, homogeneity, and surface charge, different physicochemical techniques are used, such as light scattering and spectroscopic methods. The results reveal that the copolymers combine, and spontaneously self-assemble into mixed micelle-like nanostructures in aqueous environments, whereas both systems of neat and drug-loaded nanostructures exhibit desirable properties such as small average micelle hydrodynamic radii and low size polydispersity indices. The nanostructures that result from the effective encapsulation of curcumin exhibit outstanding stability over 169 days. The fluorescent qualities of curcumin persist after encapsulation, making the novel nanostructures excellent candidates for bioimaging applications.