Dysplasia in short-segment Barrett's esophagus: a prospective 3-year follow-up

OBJECTIVE

Short segments of intestinal metaplasia in the distal esophagus are being recognized with increasing frequency. Both long and short segments of Barrett's esophagus can progress to dysplasia and cancer. However, the risk of short-segment Barrett's esophagus (SSBE) for the development of dysplasia and adenocarcinoma of the esophagus is not yet known. Our purpose, therefore, was to determine the frequency with which dysplasia occurs in patients with SSBE.

METHODS

Patients with SSBE were followed prospectively for the development of dysplasia. SSBE was defined as <3 cm of Barrett's-appearing epithelium above the gastroesophageal junction at endoscopy, with intestinal metaplasia on biopsy as documented by alcian blue stain at pH 2.5 on at least two endoscopic biopsies 6 months apart. Patients had interval upper endoscopy with systematic biopsy of the Barrett's segment.

RESULTS

Fifty-nine SSBE patients were identified. The mean length of Barrett's mucosa was 1.5 +/- 0.1 cm; the mean age of the patients was 63.1 +/- 1.3 yr. Five patients had low-grade dysplasia (LGD) at initial endoscopy, for a prevalence of 8.5%; none had high grade dysplasia (HGD). Thirty-two patients had follow-up endoscopy over a mean period of 36.9 +/- 5.4 months. Five of these patients developed dysplasia on follow-up, three with LGD and two with HGD, the incidence of any dysplasia being 5.7% per year. One patient with HGD that developed during surveillance progressed to adenocarcinoma of the esophagus over a 2-yr period. The other patient with HGD had LGD on follow-up endoscopy. Six patients with initial LGD had no evidence of dysplasia on follow-up.

CONCLUSIONS

The prevalence of dysplasia was 8.5% with an incidence of 5.7% per year in this group of SSBE patients, followed prospectively. Although dysplastic changes may not be identified on follow-up examination, some patients progress to adenocarcinoma. Therefore, we recommend surveillance endoscopy and biopsy in patients with SSBE just as in those with long-segment Barrett's esophagus.

Activation of ErbB2 during wallerian degeneration of sciatic nerve

We used anti-phosphopeptide-immunodetecting antibodies as immunohistochemical reagents to define the location and activity state of p185(erbB2) during Wallerian degeneration. Nerve damage induces a phosphorylation event at Y1248, a site that couples p185(erbB2) to the Ras-Raf-MAP kinase signal transduction pathway. Phosphorylation of p185(erbB2) occurs within Schwann cells and coincides in time and space with Schwann cell mitotic activity, as measured by bromodeoxyuridine uptake. These visual images of receptor autophosphorylation link activation of p185(erbB2) to the Schwann cell proliferation that accompanies nerve regeneration.

Is Barrett's esophagus associated with intestinal metaplasia of the gastric cardia?

OBJECTIVE

Barrett's esophagus has been associated with adenocarcinoma of the esophagogastric junction and gastric cardia. The purpose of this study was to determine whether patients with Barrett's esophagus have a higher prevalence of intestinal metaplasia involving the gastric cardia than those without Barrett's esophagus.

METHODS

Two groups of patients were compared for the prevalence of intestinal metaplasia of the gastric cardia. Group 1 included 50 patients with well-defined Barrett's esophagus who were being followed in an endoscopic surveillance program. Group 2 consisted of 104 individuals participating in a separate study identifying the prevalence of cardia intestinal metaplasia in patients undergoing elective upper endoscopy. Both groups had biopsy specimens taken from the gastric cardia. Eleven patients in group 2 were found to have Barrett's esophagus and were excluded from the analysis. Histological evidence of intestinal metaplasia was defined as specialized columnar epithelium containing goblet cells staining with Alcian blue at pH 2.5.

RESULTS

The prevalence of cardia intestinal metaplasia in the 50 patients in group 1 (Barrett's esophagus) was 22%, whereas the prevalence in the 93 patients in group 2 (no Barrett's esophagus) was 24%, which was not a statistically significant difference. A significant difference between groups still could not be identified when the results were examined with regard to equal number of biopsy specimens taken. None of the patients in either group had dysplasia identified within the cardia intestinal metaplasia.

CONCLUSIONS

Patients with Barrett's esophagus do not have a higher prevalence of intestinal metaplasia of the gastric cardia than those presenting for routine endoscopy. Although intestinal metaplasia of the gastric cardia is a relatively common finding, dysplasia is uncommon. Therefore, we suggest that screening biopsy specimens of the gastric cardia in patients with Barrett's esophagus be limited to study protocols at this time. In addition, we believe that these data raise the question of whether a true association exists between Barrett's esophagus and gastric cardia cancer.

Trk receptors function as rapid retrograde signal carriers in the adult nervous system

During development target-derived neurotrophins promote the survival of neurons. However, mature neurons no longer depend on the target for survival. Do target-derived neurotrophins retain retrograde signaling functions in mature neurons, and, if so, how are they executed? We addressed this question by using a phosphotyrosine-directed antibody to locate activated Trk receptors in adult rat sciatic nerve. We show that catalytically active Trk receptors are located within the axon of adult rat sciatic nerve and that they are distributed throughout the length of the axons. These catalytically active receptors are phosphorylated on tyrosine at a position that couples them to the signal-generating proteins Ras and PI3 kinase. Neurotrophin applied at sciatic nerve terminals increases both catalytic activity and phosphorylation state of Trk receptors at distant points within the axons. Trk activation initiated at the nerve terminals propagates through the axon toward the nerve cell body at an initial rate that exceeds that of conventional vesicular transport. However, our data suggest that this rapid signal is nevertheless vesicle-associated. Thus, in mature nerves, activated Trk receptors function as rapid retrograde signal carriers to execute remote responses to target-derived neurotrophins.

A comparative study of silver binding nucleolar organiser regions (AgNORs) of breast lesions in histological sections and fine needle aspiration smears

The study presents a comparative profile of AgNOR dot counting in different types of breast lesions in histopathological (HP) sections and fine needle aspiration cytology (FNAC) smears. The breast lesions chosen were non-neoplastic lesion like fibroadenosis, benign neoplastic lesion like fibroadenoma and malignant neoplastic lesion like infiltrating duct carcinoma-grade 2. The AgNOR counts of non-neoplastic lesion were significantly less in number than the neoplastic lesions--both benign and malignant, in both the HP section and FNAC smear. But the counts did not show significant difference in the two neoplastic lesions eg, fibroadenoma and infiltrating duct carcinoma-grade 2, in both the HP section and FNAC smear. The appearance of the dots, as felt by the observers, were more discriminating between the three lesions, eg, uniform small compact centrally placed in fibroadenosis; mostly uniform small compact but occasional large irregular in fibroadenoma and large irregular marginally located in infiltrating duct carcinoma. Counting was easier and the appearance of the dots more easily discernible in FNAC smear than the HP section as the smear was monolayer and the malignant cells were easily detected from macrophages and stromal cells. But the tissue fluid or secretions or blood when present in the smear gave the smear a dirty background which was disturbing to the observers. Thus this AgNOR technique, when applied in HP section or FNAC smear, appears cost ineffective, lengthy and tedious procedure; did not offer absolute histochemical discriminant for malignancy from benignancy. But the shape and size distribution and appearance of the dots showing much variability in FNAC smear than the HP section, might be of some help in the diagnosis of malignancy and discriminating from benignancy.

A functional telomerase RNA swap in vivo reveals the importance of nontemplate RNA domains

The ribonucleoprotein (RNP) enzyme telomerase is required for replication of eukaryotic chromosomal termini. The RNA moiety of telomerase is essential for enzyme function and provides the template for telomeric DNA synthesis. However, the roles of its nontemplate domains have not been explored. Here we demonstrate that a novel interspecies telomerase RNA swap in vivo creates a functional but aberrant telomerase. Telomerase RNA from the ciliate Glaucoma chattoni was expressed in Tetrahymena thermophila cells. The telomerase RNAs from these two species have almost superimposable secondary structures. The template region base sequence is identical in the two RNAs, but elsewhere their sequences differ by 49%. This hybrid telomerase RNP was enzymatically active but added only short stretches of telomeric repeat tracts in vivo and in vitro. This new enzyme also had a strong, aberrant DNA cleavage activity in vitro. Thus, molecular interactions in the RNP involving nontemplate RNA domains affect specific aspects of telomerase enzyme function, raising the possibility that they may regulate telomerase activity.

Aspergillus nidulans maintains short telomeres throughout development

We report the identification and cloning of the telomeres of the filamentous fungus,Aspergillus nidulans. We have identified three classes of cloned chromosomal ends based on the telomere-associated sequences (TASs) and demonstrated that the telomeric repeat sequence is TTAGGG, identical to that found in vertebrates, including humans, and some lower eukaryotes. One category of telomere clones was found to contain internal, variant TAAGGG repeats. The A.nidulans telomeric tract length is strikingly short (4-22 repeats). We demonstrate that telomere length is remarkably stable in different cell types and at altered growth temperatures, suggesting a highly regulated mechanism for length control.

Intestinal metaplasia of the gastric cardia

OBJECTIVE

Although the incidence of gastric adenocarcinoma in the U. S. is declining, the incidence of cancer localized to the gastric cardia has risen dramatically. It is not yet clear whether cancer of the gastric cardia arises from a premalignant lesion such as intestinal metaplasia (IM). The purpose of this study was to determine the prevalence of IM involving the cardia in patients presenting for elective EGD, and evaluate potential associated factors.

METHODS

During a 7 month period patients referred for elective EGD at the Tucson VA Medical Center were invited to participate in the study. Prior to EGD each patient was surveyed with regard to GERD symptoms and smoking and alcohol history. During EGD note was made of the presence of esophagitis, hiatus hernia, and Barrett's-appearing mucosa. The esophagogastric junction (EGJ) was defined as the end of the tubular esophagus coinciding with the proximal heads of the gastric folds. Seven biopsies were taken from specific sites in the antrum, angularis, cardia, and EGJ. Biopsy specimens were stained with a combination of H & E and Alcian blue at a pH of 2.5. Histologic evidence of IM was defined as columnar-type epithelium including goblet cells staining with Alcian blue. Patients were also evaluated for H. pylori infection by histologic and serologic examinations.

RESULTS

There were 104 patients (99 male, 5 female) with a mean age of 61.6 years. Twenty-four (23%) were found to have IM involving the gastric cardia, although none of these had dysplasia. Eleven patients (11%) had Barrett's esophagus; however, only 2 of these had concomitant IM of the cardia. On the other hand, 9 of the 24 with IM of the cardia had concomitant IM elsewhere in the stomach. Forty-nine patients (47%) were found to be positive for H. pylori infection and there was a significant association between H. pylori infection and IM of the gastric cardia (p = 0.03).

CONCLUSIONS

These data show that IM of the gastric cardia is a relatively common finding and is associated with H. pylori infection. Although dysplasia was not identified, long-term follow-up studies will be necessary to determine the incidence of dysplasia or adenocarcinoma developing from IM of the cardia.

Effect of short-term dermal toxicity of fenvalerate on residue, cell architecture and biochemical profiles in broiler chicks

Effect of fenvalerate on cell architecture, tissue biochemical parameters and its residual concentration was studied in broiler chicks following dermal application at 0.1 and 1% in ethanol once daily for 31 days. It did neither produce loss of body weight nor clinical signs of toxicity. Kidney contained maximal residue followed by heart, fat, liver and brain after 0.1%; and fat contained maximal residue followed by kidney, heart, liver and brain after 1% application. Fenvalerate (0.1%) increased the aspartate aminotransferase (AST) (except brain), alanine aminotransferase (ALT), alkaline phosphatase (AP), acid phosphatase (AcP) (only brain) activities, glycogen level (only liver) in liver, kidney, heart and brain tissues; and 1% increased the AST (except brain), ALT, AcP (except liver and kidney), AP (only heart), glycogen (only liver) and decreased AP (except heart), AcP (only kidney), cholesterol (except liver and heart), and acetylcholinesterase (AChE) (liver and brain) of liver, kidney, heart and brain tissue homogenates respectively. Histopathological examination in general showed aggregation of mononuclear cells in liver, around the kidney tubules and cardiac muscle fibre. In addition, fibrosis in the periportal area of liver, proliferation of ureter and tubular degeneration, and congestion of endocardial vessels were also observed. The intensity of cellular changes was more marked after 1% dermal application.

Efficacy of risperidone in reducing positive and negative symptoms in medication-refractory schizophrenia: an open prospective study

BACKGROUND

Although risperidone has been shown to be an effective antipsychotic medication in schizophrenia, the clinical studies performed for the Food and Drug Administration's approval process focused on only a mixed group of schizophrenic patients. Most of these studies did not directly address the efficacy of risperidone in chronic nonresponding schizophrenics. To better evaluate whether risperidone has a substantial degree of efficacy in schizophrenic non-responders, we conducted an open prospective study of risperidone in a sample of chronically hospitalized schizophrenic patients.

METHOD

Twenty-five patients who met DSM-III-R criteria for schizophrenia or schizoaffective psychosis, who were chronically hospitalized at a tertiary care state facility, and who had not responded to conventional neuroleptics were evaluated before and during treatment with risperidone by using several standard rating scales and adjunctive assessments.

RESULTS

Endpoint analysis showed that 36% (N = 9) of the patients were classified as responders on the basis of at least a 20% decrease in total Brief Psychiatric Rating Scale score at final evaluation. A higher percentage of patients were classified as responders when other rating scale criteria were used. Reductions in psychopathology scores were seen in scales reflecting positive symptoms but not in scores of negative symptoms. High baseline negative symptom scores were correlated with poorer response to risperidone as indicated by the decrease in positive symptom scores.

CONCLUSION

This study offers evidence that risperidone may reduce positive symptoms of schizophrenia for a subgroup of chronically hospitalized schizophrenic patients who have not responded to conventional neuroleptics. The comparative evaluation of the efficacy of risperidone versus that of clozapine in these types of patients requires further study.

Differential utilization of Trk autophosphorylation sites

Tyrosine autophosphorylation controls the catalytic and signaling activities of the neurotrophin receptors, the Trks. To analyze the regulation of distinct tyrosine sites, we generated a panel of antibodies that report the phosphorylation state of individual tyrosines within the Trk cytoplasmic domain. Using pheochromocytoma-derived cell lines, we show that individual tyrosines within the nerve growth factor receptor TrkA are phosphorylated in a non-coordinate fashion following receptor activation. The non-coordinate response of these tyrosines reflects their separate functions in regulating the catalytic and signaling activities of Trk receptors. The differential utilization of distinct sites on Trk receptor tyrosine kinases suggests that the receptor can specify both the timing and the nature of neurotrophin-stimulated signal transduction pathways. Moreover, we show that these Trk autophosphorylation sites, which have hitherto been mapped and characterized only in non-neuronal cell lines, are activated in normal neurons in response to ligand stimulation.

Liver histology in anti-HCV-positive persons with normal or minimally elevated aminotransferases

The significance of a positive hepatitis C virus (HCV) screening test in asymptomatic blood donors with normal or near normal aminotransferases was studied along with the usefulness of HCV RNA polymerase chain reaction (PCR) testing for predicting chronic hepatitis in these individuals. One hundred and thirty-nine volunteer blood donors who were found positive by second generation ELISA for antibodies to HCV agreed to participate in the study. Thirty-one of them were supplemental test positive, had ALT values less than twice normal, and were followed over a minimum of 12 months. Thirteen consented to percutaneous liver biopsy and also had HCV RNA determination by PCR. Ten of the 13 subjects were positive for HCV RNA by PCR. Of the nine who were positive for HCV RNA and had adequate tissue for evaluation, seven had evidence of chronic hepatitis, three with limiting plate necrosis. Lobular inflammation was similar in severity to that found in the portal region. In addition, two had periportal fibrosis, and one had bridging fibrosis. Of the three subjects who were negative for HCV RNA, only one had portal inflammation which was limited to the portal region. None of these three had lobular changes, or periportal or bridging fibrosis. Of the three normal biopsies, two were from subjects who were negative for HCV RNA. The sensitivity and specificity of HCV RNA testing for chronic hepatitis was 87.5% and 50%, respectively, yielding an overall accuracy of 75%. We conclude that asymptomatic blood donors with antibodies to HCV, normal or mildly elevated liver tests, and HCV RNA may have abnormal liver histology indicating the potential for progressive liver disease. HCV RNA testing by PCR may be clinically useful as a noninvasive means to discriminate between those with and without chronic liver disease.

A study of aggregation of 9-(dicyano-vinyl)julolidine

Di(cyano vinyl)julolidine (DCVJ) is a fluorescent probe which has been used to monitor the local mobility of its binding sites on proteins. It shows a concentration dependence of its emission spectrum in water. At higher DCVJ concentrations, a longer wavelength band appears. The latter increases relative to the shorter wavelength band as a function of increased DCVJ concentration. Absorption and excitation spectra indicate that the concentration dependent emission in the longer wavelength is a consequence of association in the ground state and subsequent excimer formation. DCVJ forms two types of complexes with gamma-cyclodextrin, one of which shows the longer wavelength emission band. Analysis of stoichiometry of association also suggests that longer wavelength emission band may be a consequence of association of two molecules of DCVJ in the gamma-cyclodextrin cavity. Possible uses of such excimer formation in biological systems have also been discussed.

Fine needle aspiration cytology of bone and joint lesions: an assessment

Fine needle aspiration cytology and subsequent correlation with histology and therapeutic follow-up was done in 198 cases of bone and joint lesions. Overall accuracy was found to be 87.34%; false diagnosis was recorded in 4.5% of cases; 8.08% cases were excluded from correlation as they did not turn up for further treatment or follow-up after the diagnosis. False diagnosis was encountered mostly with inflammatory lesions and primary neoplasms, diagnosing osteosarcoma and Ewing's sarcoma as chronic inflammatory lesion, chondroma as chondrosarcoma and vice versa. The possible cause of default has been discussed. The benign cystic lesions could be diagnosed with almost 100% accuracy by fine needle aspiration cytology where 10% cases were excluded as they could not be followed up.

Purification and characterization of a low molecular weight endogenous glutamate binding inhibitor (LGBI) in porcine brain

One of the endogenous substances which modulate glutamate receptor binding was isolated and highly purified from porcine brain. The purification involved extraction of brain tissue with doubled distilled water, followed by gel filtration, anion exchange, cation exchange, and several steps of C18 reverse-phase high performance liquid chromatography (HPLC). A low molecular weight glutamate binding inhibitor (LGBI) was purified to apparent homogeneity as judged from the elution profile of an HPLC column, in which a symmetrical peak was obtained when the eluate was monitored at 220 nm. The LGBI appears to be a small molecule (< 2 kD) that is heat- and acid/base-stable. The highly purified LGBI has no effect on GABAA and benzodiazepine receptor binding. The LGBI is not L-glutamate, L-aspartate or other negatively charged endogenous substances, since they are clearly separated from the LGBI in anion exchange chromatography. The inhibitory effect of the LGBI on [3H]L-glutamate binding is reversible, and it only changes the Bmax while the Kd remains the same. Since the membrane preparations used for [3H]L-glutamate binding assays for the detection of LGBI activity were enriched with quisqualate (QA)-sensitive subtypes, it was suggested that the LGBI could be a modulator of the QA receptor. Some amino acids which produce significant inhibition of glutamate binding activity were also compared with the LGBI, and they all showed no resemblance to the LGBI. The chemical structure of the LGBI remains to be determined.

Study of benign superficial cysts by fine needle aspiration cytology

Fine needle aspiration cytology of 213 cases of different cystic lesions from various regions of body and different superficial organs was analysed in an attempt to present the experience of the authors in the diagnosis of such lesions. The predominant lesion diagnosed by fine needle aspiration cytology was adnexal cyst/sebaceous cyst (41 cases) followed by vascular hamartoma (40 cases) and thyroglossal cyst (9 cases). One hundred fifty-eight (74.2%) out 213 cases were confirmed histopathologically. There was false negative diagnosis in 14 cases (6.6%). The remaining 41 (19.2%) cases did not turn up for further treatment. The fallacies that have been recorded in the diagnosis of thyroid cysts, salivary gland cysts and breast cysts in respect of papillary cystic thyroid carcinoma, muco-epidermoid carcinoma of salivary gland and intraductal carcinoma with fibrocystic disease of breast respectively have been highlighted in the present study.

Architecture of telomerase RNA

Telomerase, an essential ribonucleoprotein reverse transcriptase, adds telomeric DNA to the ends of eukaryotic chromosomes. We examined the conformational properties of the naked RNA moiety of telomerase from two related ciliates, Tetrahymena thermophila and Glaucoma chattoni. As well as finding evidence for features proposed previously on the basis of phylogenetic comparisons, novel conserved structural properties were revealed. Specifically, although the region around helix III was previously proposed to form a pseudoknot, our results indicate that in the naked RNA this region maintains a level of 'plasticity', probably in an equilibrium favoring one of two helices. In addition, these studies reveal that the templating domain is not entirely single-stranded as previously proposed, but is ordered due to constraints imposed by other parts of the RNA. Finally, our results suggest that the GA bulge in helix IV may introduce a structurally conserved kink. We now propose a 'two-domain' structure for the telomerase RNA based on function: one conformationally flexible domain, which includes the template and the region around helix III, involved with enzymatic function, and a second largely helical domain, including helices I and IV and the proposed kink, which may serve as a scaffold for protein binding.