Prevalence and significance of pancreatic acinar metaplasia at the gastroesophageal junction

Pancreatic acinar metaplasia (PAM), defined as nodules of glandular tissue forming acini composed of cells with coarse apical eosinophilic granules, with or without mucous cells, was recently recognized in gastric mucosa, but its significance is not known. As part of a study on intestinal metaplasia at the gastroesophageal junction (GEJ), we evaluated the prevalence and clinical and histologic correlates of PAM in biopsy specimens from the gastroesophageal squamocolumnar junction. All adult patients having elective upper gastrointestinal endoscopy over a 6-month period were invited to participate. Clinical data and endoscopic findings were recorded. Biopsy specimens, obtained from both sides of the apparent squamocolumnar junction, were processed routinely and reviewed (without knowledge of the clinical data) to evaluate types of epithelium, types and degree of inflammation, and the presence of PAM. The presence or absence of PAM was then correlated with the other histologic findings and with the clinical and endoscopic data. The study comprised 155 patients (79 women, 76 men; 139 white patients, nine black patients, and seven patients of other ethnic groups). Their mean age was 52 years (range: 18-89 years). PAM was present in 37 patients (24%). PAM was not associated with any of the reported symptoms, endoscopic evidence of esophagitis or columnar epithelium in the distal esophagus, or any of the histologic features evaluated, including active esophagitis, intestinal metaplasia at the GEJ, active and chronic gastritis, intestinal metaplasia in the stomach, and Helicobacter infection. Although PAM is present in a considerable proportion (24%) of patients with mucosal biopsy specimens from the squamocolumnar junction, it appears to be an incidental finding unrelated to clinical or histologic abnormalities. We therefore suggest a congenital, rather than an acquired, origin for this entity.

Effective reduction of Helicobacter pylori infection after upper gastrointestinal endoscopy by mechanical washing of the endoscope

BACKGROUND/AIMS

To investigate the frequency of endoscopic transmission of Helicobacter pylori and the efficiency of disinfection in different washing methods of endoscopes.

MATERIALS AND METHODS

IgG antibodies to H. pylori in patients prospectively followed who underwent first endoscopic examination at the National Taiwan University Hospital from 1982 to 1993 were measured. A total of 132 subjects who were negative for H. pylori IgG antibody test before examination and who were with negative endoscopic findings were enrolled. Among the 132 seronegative patients, 60 were examined before June 1989 when manual washing was adopted for endoscope cleaning and 72 received examination after mechanical washing were routinely used in our endoscopy unit.

RESULTS

During a follow-up period of 6 months or more, 5 patients in the manual washing group sero-converted while none in the mechanical washing group seroconverted (5/60 vs 0/72. p = 0.02).

CONCLUSION

The results suggested that the risk of endoscopic transmission of H. pylori is substantial and mechanical washing is efficient in preventing this iatrogenic spread.

Low-grade gastric B-cell lymphoma of mucosa-associated lymphoid tissue: clinicopathologic analysis of 19 cases

Low-grade gastric B-cell lymphoma of mucosa-associated lymphoid tissue type (MALToma) is a recently recognized disease entity. We report the clinicopathologic features of 19 patients with MALToma in Taiwan. The 19 patients included eight men and 11 women, ranging in age from 26 to 77 years, with a mean age of 58.8 years. Most complained of abdominal pain or gastrointestinal bleeding. The endoscopic and gross features of the gastric lesions revealed erosion (flat type), ulceration (depressed type), cobblestone appearance or abnormal gastric folds (elevated type), mimicking chronic gastritis, ulcer or early gastric carcinoma. Typical histopathologic features included lymphoepithelial lesion and extensive mucosal infiltration of centrocyte-like cells in all cases. Clonality analysis of the variable-diversity-joining region of the immunoglobulin gene by semi-nested polymerase chain reaction demonstrated monoclonality in 72% of the cases. Helicobacter pylori bacilli (H. pylori) could be identified on histologic sections in 15 cases (78.9%); the serologic test for H. pylori was positive in 12 of 13 patients tested (92%). In six patients receiving triple therapy (amoxicillin, bismuth subcitrate and metronidazole), five showed significant histologic regression with eradication of H. pylori 4 to 6 months after the start of treatment; one patient showed persistent lesions and presence of H. pylori. However, persistence of residual lymphoid cells and monoclonality of the immunoglobulin gene, could still be demonstrated in four cases. Of nine patients treated with surgery or chemotherapy, two died: one due to concomitant gastric carcinoma and the other one due to sudden apnea. No recurrence was observed in the remaining seven patients. The remaining four patients were lost to follow-up. Our experience confirmed that gastric MALToma is a low-grade neoplastic process. The dramatic response of gastric MALToma to anti-H. pylori treatment suggests that H. pylori infection is closely related to the pathogenesis of low-grade gastric MALToma. However, long-term follow-up is mandatory due to the persistence of the monoclonality of the immunoglobulin gene in the residual lymphoid cells after treatment.

Adrenal adenomas: relationship between histologic lipid and CT and MR findings

PURPOSE

To assess the relationship between the quantity of lipid in resected adrenal adenomas and the unenhanced computed tomographic (CT) attenuation number and the relative change in signal intensity on chemical shift magnetic resonance (MR) images.

MATERIALS AND METHODS

The percentage of lipid-rich cortical cells in histologic sections from 20 resected adrenal adenomas was assessed. The results were correlated with the corresponding unenhanced CT attenuation number or the relative change in signal intensity on chemical shift MR images, or both.

RESULTS

There was an inverse linear relationship between the percentage of lipid-rich cortical cells in the adrenal adenomas and the unenhanced CT attenuation number (R2 = .68, P = .0005). There was a similar inverse linear relationship to the relative change in MR signal intensity on chemical shift images by using both quantitative (R2 = .83, P = .004) and qualitative (R2 = .70, P = .019) assessment.

CONCLUSION

The presence and amount of histologic lipid in many adrenal adenomas accounts for their low attenuation on unenhanced CT scans and their loss in relative signal intensity on chemical shift MR images.

Fine needle aspiration cytology of the oxyphil variant of papillary carcinoma of the thyroid. A report of three cases

BACKGROUND

A number of histologic variants of papillary carcinoma of the thyroid have been described, including an oxyphil cell subtype (OVPC). Few OVPC cases have been detailed cytologically.

CASES

Smears prepared from aspiration biopsies, as well as the corresponding histologic sections and clinical histories, were reviewed for three cases. Two patients had asymptomatic thyroid tumors, and the third developed neck tumors after thyroid cancer surgery. All smears revealed scattered papillary groups and monolayered sheets. The large, neoplastic cells had abundant, granular cytoplasm and eccentrically placed nuclei. Nuclear grooves and intranuclear inclusions were variably present. Psammoma bodies and colloid were not identified. Histologically the tumors consisted predominantly of oxyphil cells arranged in papillary patterns and with nuclear features of usual papillary carcinoma (UPC).

CONCLUSION

OVPC can be diagnosed in smears composed predominantly of large oxyphil cells but showing features associated with UPC and can be cytologically distinguished from follicular oxyphilic tumors and UPC.

Rapid hepatic failure associated with a contracted liver mimicking cirrhosis in a case of nasopharyngeal carcinoma with liver metastasis

A 46-year-old women had an undifferentiated nonkeratinizing nasopharyngeal carcinoma, locally controlled by radiotherapy. Initially, she had normal liver function tests and normal hepatic ultrasonography. Seven months later, she experienced a rapidly progressive hepatic failure manifested by the development of ascites, elevation of serum bilirubin level, and prolongation of prothrombin time. Imaging studies showed a contracted liver and serum biochemical tests were compatible with chronic liver disease, except for an increase of alkaline phosphatase and gamma-glutamyl transpeptidase levels. An endoscopic retrograde cholangiogram ws compatible with changes of sclerosing cholangitis. The patient died of hepatic decompensation within two months. A liver necropsy disclosed diffuse infiltration of carcinoma cells into the hepatic sinusoids and obliterative angio-invasion of the tumor cells with massive fibrotic stroma replacing almost all hepatocytes. In situ hybridization demonstrated expression of Epstein-Barr virus transcripts EBER1 in the tumor cells and proved a metastatic nasopharyngeal carcinoma. The contracted liver is likely to be explained by the tumor-associated desmoplastic change and the obliterative angio-invasion of the tumor. It is important to be aware that, although rare, such an unusual pattern of liver metastasis may mimick cirrhosis clinically and cause rapid hepatic failure in patients with nasopharyngeal carcinoma.

Epidermoid cysts of the testis: diagnosis by ultrasonography and magnetic resonance imaging resulting in organ-preserving surgery

OBJECTIVE

To present experience in the diagnosis and management of patients with an epidermoid cyst of the testes and to confirm the role of conservative surgery.

PATIENTS AND METHODS

The records from the last 26.5 years of patients diagnosed as having a testicular tumour were reviewed retrospectively. Those patients with a confirmed epidermoid cyst were evaluated for age, clinical assessment, methods of diagnosis, treatment and follow-up.

RESULTS

Amongst a total of 131 testicular tumours, 11 patients (8.4%; mean age 25.7 years, range 21-35) were diagnosed pathologically as having an epidermoid cyst. Pre-operative suspicion of the benign nature of the lesions was supported by testicular ultrasonography in six patients and supplemented with magnetic resonance imaging (MRI) in one. An operation sparing the testicles was performed in eight patients after the diagnosis of epidermoid cyst was confirmed from frozen sections. Three patients were treated by radical orchidectomy. There were no relapses after a median follow-up of 47.3 months (range 2-82).

CONCLUSION

In this series, the relative incidence of epidermoid cyst was higher than that reported in the literature (1-2%). Ultrasonography and MRI of the testes may allow the diagnosis to be made preoperatively. The absence of relapse in these patients further supports the use of organ-sparing surgery in these young men.

Qualifiers of atypical squamous cells of undetermined significance help in patient management

According to the recommendations of the Bethesda System, the diagnosis of atypical squamous cells of undetermined significance (ASCUS) should be further qualified, when possible, as to whether a reactive or a squamous intraepithelial lesion (SIL) is favored. To determine the utility of this recently proposed terminology, we undertook this study to correlate the diagnosis of ASCUS (with or without qualifiers) with results obtained from examination of biopsy specimens. All patients were identified for the study who had a coloposcopically obtained cervical biopsy specimen or endocervical curettage specimen recorded in the surgical pathology files at Beth Israel Hospital, Boston, Massachusetts, from April 1994 through September 1994 and had either prior or concurrent Pap smear(s) reported as ASCUS, ASCUS-favor reactive, ASCUS-favor SIL, or SIL-low grade (SIL-LG). Patients with a cytologic diagnosis of SIL-LG served as a reference group. A total of 435 patients with 485 Pap smears were included. The prevalence rates of biopsy-proven SIL in patients with a cytologic diagnosis of ASCUS-favor reactive, ASCUS, ASCUS-favor SIL, and SIL-LG were 10, 28, 36, and 55%, respectively. The difference between cases diagnosed as ASCUS (with or without qualifiers) and SIL-LG, with respect to the presence of SIL at examination of the biopsy specimen, was statistically significant (P < 0.001 for all correlations). Cases diagnosed as ASCUS-favor reactive had a significantly lower rate of biopsy-proven SIL compared with those diagnosed as ASCUS and ASCUS-favor SIL (P < 0.01 for both correlations). A significant proportion of biopsy specimens with Pap smear diagnosis of ASCUS-favor SIL had SIL-high grade (15%). In contrast, an underlying SIL-high grade is much less likely in patients with ASCUS (unqualified) (3%) or when a reactive process is favored (3%). It seems justified to manage patients with ASCUS-favor SIL in a manner similar to those with SIL-LG. A conservative management seems appropriate for patients with ASCUS and ASCUS-favor reactive.

Single-step hybridization screening for recombinant DNA clones with correct insert orientation and intact junction using a junctional oligonucleotide probe

Cloning of DNA fragments with blunt ends or identical protruding ends results in colonies with the insertion sequence existing in two possible orientations. The orientation and the junctional sequence of the positive clones need to be established by means of restriction analysis and/or sequencing. Here, we proposed a rapid one-step method for the screening of clones not only with the desired orientation, but also with an intact junctional sequence. In this method, a 16-18 meric oligonucleotide probe synthesized according to the expected vector-insert junctional sequence is used as a probe in colony hybridization screening. Using this strategy, only recombinant clones which fulfill the above criteria will show positive signals in hybridization.

Differentiation and grouping of isolates of the Ganoderma lucidum complex by random amplified polymorphic DNA-PCR compared with grouping on the basis of internal transcribed spacer sequences

Laccate polypores of the Ganoderma lucidum species complex are widespread white rot fungi of economic importance, but isolates cannot be identified by traditional taxonomic methods. Parsimony analysis of nucleotide sequences from the internal transcribed spacers (ITS) of the ribosomal gene (rDNA) distinguished six lineages in this species complex. Each ITS lineage may represent one or more putative species. While some isolates have identical ITS sequences, all of them could be clearly differentiated by genetic fingerprinting using random amplified polymorphic DNA (RAPD). To investigate the suitability of RAPD markers for taxonomic identification and grouping of isolates of the G. lucidum complex, RAPD fragments (RAPDs) were used as phenotypic characters in numerical and parsimony analyses. Results show that data from RAPDS do not distinguish the same clades as ITS data do. Groupings based on analysis of RAPD data were very sensitive to the choice of the grouping method used, and no consistent grouping of isolates could be proposed. However, analysis with RAPDs did resolve several robust terminal clades containing putatively conspecific isolates, suggesting that RAPDs might be helpful for systematics at the lower taxonomic levels that are unresolved by ITS sequence data. The limitations of RAPDs for systematics are briefly discussed. The conclusion of this study is that ITS sequences can be used to identify isolates of the G. lucidum complex, whereas RAPDs can be used to differentiate between isolates having identical ITS sequences. The practical implications of these results are briefly illustrated.

Cytologic features of clear cell carcinoma of the urethra and urinary bladder

Clear cell carcinoma (CCL) arising in the lower urinary tract is unusual and we report the cytohistologic findings of three cases retrieved from our files. All patients presented with bleeding, and the tumors were localized in either the urethra or bladder base. Filter and cytocentrifuge preparations of the urine were studied and all cases displayed numerous scattered aggregates or single tumor cells in an inflammatory background. The enlarged cells had abundant clear, wispy cytoplasm with discrete vacuolation. Hobnail and signet ring cells were apparent. The nuclei had granular to vesicular chromatin with prominent often multiple nucleoli. The tumors were histologically distinctive and typically had a tubulocystic configuration with varying proportions of papillary and diffuse patterns. One patient has died of metastatic cancer and two are presently free of tumor. The cytohistologic features of this cancer are characteristic and from our review we conclude that this lesion can be diagnosed by cytologic means.

ThinPrep processing of endoscopic brushing specimens

To evaluate ThinPrep (Cytyc, Marlborough, MA) processing of endoscopic brushing specimens for cytologic examination, ThinPrep slides and direct smears of 29 gastrointestinal (GI) and 22 bronchial brushings were compared. Clinicians prepared the direct smears. The brush was then immersed in CytoLyt (Cytyc) and one ThinPrep slide made. All cases had corresponding biopsies. Smears and ThinPrep slides were screened and reviewed independently. Screening time per case was recorded. All slides were evaluated for cellularity, quality, cellular preservation, and quantity of diagnostic cells. A diagnosis was rendered for each case. Cytologic and histologic diagnoses were correlated. Follow up was obtained for cases with discrepant histologic and cytologic diagnosis. Twenty-three brushings were from esophagus, 5 stomach, 1 duodenum, and 22 lung. An average of 3.6 direct smears (range 2-6) was made for each case. Average screening time per case was 12 minutes for GI direct smear, 15 minutes bronchial direct smear, 4 minutes GI ThinPrep slide, and 9 minutes bronchial ThinPrep slide. ThinPrep slides were superior to direct smears in cellularity, quantity of diagnostic cells, and quality of slides. ThinPrep slides and direct smears showed comparable cellular preservation. The sensitivity of detecting malignancy by biopsy, direct smears, and ThinPrep slides was 81%, 75%, and 75%, respectively. One false-positive diagnosis was made on cytology with both direct smear and ThinPrep slide, a case with radiation atypia. In conclusion, ThinPrep slides are at least comparable to direct smears in cytologic examination of brushings. However, false-positive diagnosis is a possible potential pitfall.

Growth factor expression and proliferation kinetics in periampullary neoplasms in familial adenomatous polyposis

BACKGROUND

Patients with familial adenomatous polyposis develop periampullary adenomas at a high rate. However, little is known regarding the factors that control the growth, the natural history, or the malignant potential of these tumors.

METHODS

In this study, the authors systematically evaluated the expression of the intestinal peptide growth factor, transforming growth factor-alpha (TGF-alpha), and its corresponding receptor, epidermal growth factor-receptor (EGF-R), in 49 periampullary adenomas and 6 periampullary carcinomas from 29 patients. Tumor proliferation rates were evaluated with the MIB-1 antibody.

RESULTS

All periampullary adenomas and carcinomas (100%) had TGF-alpha expression, whereas 63% of adenomas and 67% of carcinomas expressed EGF-R. The extent of TGF-alpha expression was greater in carcinomas compared with adenomas and increased progressively in adenomas relative to the degree of dysplasia and villous architecture of these lesions. The extent of EGF-R expression correlated only with the degree of dysplasia in adenomas. With regard to proliferation kinetics, higher MIB-1 labeling indices were observed in adenomas that were larger, more severely dysplastic, and villous. Transforming growth factor-alpha, and to a lesser extent, EGF-R expression, correlated directly with the MIB-1 labeling indices.

CONCLUSIONS

These results support the adenoma-carcinoma sequence in the progression of malignancy in the duodenum in familial adenomatous polyposis, suggesting a possible involvement for TGF-alpha and EGF-R expression in this process.

Evaluation with receptor binding assay on the water extracts of ten CNS-active Chinese herbal drugs

In the present study, we established receptor binding assays to evaluate the water extracts of ten central nervous system (CNS)-active Chinese herbal drugs. These ten herbal drugs are Chaihu (Radix Bupleuri), Chuanxiong (Rhizoma Chuanxiong), Danggui (Radix Angelicae sinensis), Danshen (Radix Salviae miltiorrhizae), Duhuo (Radix Angelicae pubescentis), Hangqin (Radix Scutellariae), Qinjiao (Radix Gentianae macrophyllae), Shengma (Rhizoma Cimicifugae), Suanzaoren (Semen Zizphi spinose), and Yangjihua (Flos Daturae). The results indicated that these water extracts contained the principles acting on the dopamine (D1 & D2), muscarinice acetylcholine (M1), or 5-HT (5-HT1A & 5-HT2) receptors, or the benzodiazepine and the gamma-amino-n-butyric acid (GABA) binding sites of GABAA receptors as determined by receptor binding assays. The receptors or binding sites which predominantly acted by each water extract are listed as follows: Chaihu: D2, 5-HT1A, GABA; Chuanxiong: GABA, 5-HT1A; Danggui: GABA, 5-HT1A; Danshen: BDZ; Duhuo: GABA, 5-HT1A, D2, D1; Hangqin: BDZ, D1, 5-HT1A; Qinjiao: GABA, BDZ, 5-HT1A, D2; Shengma: 5-HT1A; Suanzaoren: 5-HT1A, 5-HT2, GABA; Yangjihua: M1, 5-HT1A, 5-HT2. These results provided evidence to explain the CNS effects of these herbal drugs at the receptor level. Furthermore, these results provided information to direct the isolation and purification of receptor-interactive compounds from these herbal drugs.

Effects of halothane on the nicotinic acetylcholine receptor from Torpedo californica

To determine whether the binding of anesthetics to key membrane receptors is a plausible mode of action, we modeled the effect of the general anesthetic halothane in the nicotinic acetylcholine receptor membrane system isolated from Torpedo californica. Our results demonstrated that halothane inhibits the binding of [3H]phencyclidine ([3H]PCP) to the acetylcholine receptor. The inhibition was reversible, concentration dependent, and had an equilibrium dissociation constant (Kd) of 2.2% atm halothane at 25 degrees. Double-reciprocal plots of the halothane effects at various phencyclidine (PCP) concentrations imply that, under equilibrium conditions, halothane inhibits [3H]PCP binding competitively. In contrast, results from kinetic studies showed that the rate of PCP dissociation is highly sensitive to halothane with EC50 = 0.8% atm halothane in nitrogen. Several possible interpretations are discussed; however, the basic observation was that the kinetics of [3H]PCP binding to the nicotinic acetylcholine receptor was affected by halothane at low concentrations in this model system.

Different pharmacological actions of adenosine on gastric function and mucosal damage in normotensive and spontaneously hypertensive rats

It has been reported that there are functional defects in the purinergic system in spontaneously hypertensive rats (SHR). The following experiments examined the gastric effects of adenosine in these animals. SHR had a significantly higher gastric mucosal blood flow (GMBF), but the secretion of acid and pepsin was not different from that of normotensive counterparts. In SHR, adenosine (s.c. 3.75 or 7.5 mg/kg) time- and dose-dependently decreased gastric acid secretion and GMBF. The nucleoside, however, did not affect the pepsin secretion. In normotensive rats, gastric acid secretion was also reduced, but not to the extent of SHR. The GMBF was increased instead. Adenosine potentiated ethanol-induced mucosal damage in SHR, which was likely caused by GMBF reduction. It is concluded that adenosine produces a greater depressive action on the stomach in SHR. These differential actions are probably due to the genetic difference between the two types of animals.

[Regulatory effect of ventral tegmental area on sleep-wakefulness in rats]

Experiments were performed on 31 male SD rats. The results were as follows: (1) The time of waking was increased during the second and third hours after microinjection of 3.3 and 6.6 nmol bromocriptine into bilateral VTA (P < 0.01), but the 1.33 nmol group was without significant effect. (2) The time of waking was decreased during the second and third hours after microinjection of 2 and 4 nmol SCH23390 into VTA (P < 0.01 and P < 0.05 respectively), while 3.4 nmol sulpiride group was without effect. (3) One week after administration of kainic acid (0.3 microgram), the rats presented less time of waking in the day (P < 0.05), while sleep-wakefulness cycle at night showed no change. The results suggest that bromocriptine could increase wakefulness by activating VTA DA neurons via D1 receptor and that the DA neurons might exert a tonic effect for maintaining the wakefulness at the daytime.

Mg2+ enhances high affinity [3H]8-hydroxy-2-(di-n-propylamino) tetralin binding and guanine nucleotide modulation of serotonin-1a receptors

The effects of MgCl2 on the binding of the serotonin 1a (5HT1a) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin ([3H]8-OH-DPAT) to bovine hippocampal membranes were investigated. MgCl2 was found to enhance both [3H]8-OH-DPAT binding and guanine nucleotide modulation of high affinity binding. The effect of Mg2+ on promoting high affinity agonist binding was due to a 3.3 fold decrease in the dissociation constant rather than an increase in the number of binding sites. Mg2+ acted to increase the efficacy of the nonhydrolyzable GTP analog 5' guanylylimidodiphosphate (GppNHp) in promoting the interconversion of high and low affinity states. Addition of MgCl2 significantly increased the sensitivity of [3H]8-OH-DPAT binding to GppNHp, decreasing the concentration needed for half-maximal inhibition of binding from greater than 50 mu M to 300 nM. Our findings that Mg2+ enhances high affinity [3H]8-OH-DPAT binding without change in number of binding sites and that guanine nucleotide modulation of binding can occur in the absence of Mg2+ suggests that ternary complex formation between receptor, ligand and G-protein can occur in the absence of Mg2+.

Partial protection against malaria by immunization with Leishmania enriettii expressing the Plasmodium yoelii circumsporozoite protein

Since infection with Leishmania species induces CD4+ and CD8+ anti-leishmania T cells, we assessed protection against malaria by immunization with Leishmania enriettii transfected with the gene encoding the Plasmodium yoelii circumsporozoite protein (PyCSP). The recombinant plasmid appeared to be a circular episome in the host cells. Reverse transcription PCR showed that the PyCSP was trans-spliced by the addition of the 39-bp spliced leader of L. enriettii at its 5' end. The transfectant expressed a protein in a pattern similar to that found in the sporozoite itself. Immunofluorescence and immunoelectron microscopy indicated that PyCSP was abundantly expressed on the surface of the parasite. Mice immunized with the transfectant produced antibodies to sporozoites, had a delay in onset of parasitemia after challenge, and 4 of 22 (18%) were completely protected. The protected mice had cytotoxic T lymphocytes against the PyCSP. Immunization with recombinant vaccinia, Salmonella typhimurium, and pseudorabies virus expressing the PyCSP induces excellent immune responses, but has not been shown to protect against challenge. Thus, the modest protection found in these initial studies represents a step forward. After further work Leishmania may prove to be an important live vector vaccine system for induction of protective immune responses.