Specific Nucleotides in the Common Region of the Begomovirus Tomato Rugose Mosaic Virus (ToRMV) Are Responsible for the Negative Interference over Tomato Severe Rugose Virus (ToSRV) in Mixed Infection

Mixed infection between two or more begomoviruses is commonly found in tomato fields and can affect disease outcomes by increasing symptom severity and viral accumulation compared with single infection. Viruses that affect tomato include tomato severe rugose virus (ToSRV) and tomato rugose mosaic virus (ToRMV). Previous work showed that in mixed infection, ToRMV negatively affects the infectivity and accumulation of ToSRV. ToSRV and ToRMV share a high degree of sequence identity, including cis-elements in the common region (CR) and their specific recognition sites (iteron-related domain, IRD) within the Rep gene. Here, we investigated if divergent sites in the CR and IRD are involved in the interaction between these two begomoviruses. ToSRV clones were constructed containing the same nucleotides as ToRMV in the CR (ToSRV-A(ToR:CR)), IRD (ToSRV-A(ToR:IRD)) and in both regions (ToSRV-A(ToR:CR+IRD)). When plants were co-inoculated with ToRMV and ToSRV-A(ToR:IRD), the infectivity and accumulation of ToSRV were negatively affected. In mixed inoculation of ToRMV with ToSRV-A(ToR:CR), high infectivity of both viruses and high DNA accumulation of ToSRV-A(ToR:CR) were observed. A decrease in viral accumulation was observed in plants inoculated with ToSRV-A(ToR:CR+IRD). These results indicate that differences in the CR, but not the IRD, are responsible for the negative interference of ToRMV on ToSRV.

Begomovirus populations in single plants are complex and may include both well-adapted and poorly-adapted viruses

Begomoviruses (single-stranded DNA plant viruses transmitted by whiteflies) are economically important pathogens causing epidemics worldwide. Tomato-infecting begomoviruses emerged in Brazil in the 1990's following the introduction of Bemisia tabaci Middle East-Asia Minor 1. It is believed that these viruses evolved from indigenous viruses infecting non-cultivated hosts. However, tomato-infecting viruses are rarely found in non-cultivated hosts, and vice-versa. It is possible that viral populations in a given host are composed primarily of viruses which are well adapted to this host, but also include a small proportion of poorly adapted viruses. Following transfer to a new host, the composition of the viral population would shift rapidly, with the viruses which are better adapted to the new host becoming predominant. To test this hypothesis, we collected tomato and Sida plants growing next to each other at two locations in 2014 and 2018. Total DNA was extracted from tomato and Sida samples from each location and year and used as a template for high-throughput sequencing. Reads were mapped following a highly stringent set of criteria. For the 2014 samples, >98% of the Sida reads mapped to Sida micrantha mosaic virus (SiMMV), but 0.1% of the reads mapped to tomato severe rugose virus (ToSRV). Conversely, >99% of the tomato reads mapped to ToSRV, with 0.18% mapping to SiMMV. For the 2018 samples, 41% of the Sida reads mapped to three Sida-adapted viruses and 0.1% of the reads mapped to ToSRV, while 99.9% of the tomato reads mapped to ToSRV. These results are consistent with the hypothesis that viral populations in a single plant are composed primarily of the virus that is better adapted to the host but also include a small proportion of viruses that are poorly adapted.

Multivariate analysis in a genetic divergence study of Psidium guajava

The family Myrtaceae is widespread in the Atlantic Forest and is well-represented in the Espírito Santo State in Brazil. In the genus Psidium of this family, guava (Psidium guajava L.) is the most economically important species. Guava is widely cultivated in tropical and subtropical countries; however, the widespread cultivation of only a small number of guava tree cultivars may cause the genetic vulnerability of this crop, making the search for promising genotypes in natural populations important for breeding programs and conservation. In this study, the genetic diversity of 66 guava trees sampled in the southern region of Espírito Santo and in Caparaó, MG, Brazil were evaluated. A total of 28 morphological descriptors (11 quantitative and 17 multicategorical) and 18 microsatellite markers were used. Principal component, discriminant and cluster analyses, descriptive analyses, and genetic diversity analyses using simple sequence repeats were performed. Discrimination of accessions using molecular markers resulted in clustering of genotypes of the same origin, which was not observed using morphological data. Genetic diversity was detected between and within the localities evaluated, regardless of the methodology used. Genetic differentiation among the populations using morphological and molecular data indicated the importance of the study area for species conservation, genetic erosion estimation, and exploitation in breeding programs.

iceA genotypes of Helicobacter pylori strains isolated from Brazilian children and adults

Data concerning the geographic distribution of iceA alleles are scarce, and information on the association of the gene with the disease is rare and still controversial. Furthermore, no such study has been developed in Brazil, where duodenal ulcer and gastric adenocarcinoma are very common. We investigated, by PCR, the frequency of iceA alleles and cagA status in Helicobacter pylori strains isolated from 142 patients (62 children and 80 adults; 66 female; mean age, 30.0 years; age range, 3 to 78 years) with gastritis, duodenal ulcer, or gastric adenocarcinoma. iceA was identified in bacterium samples obtained from all patients. Eleven (7.7%) of them were infected with multiple strains. Among the patients with nonmixed infection, iceA2 allele was detected in 118 (90.1%). iceA2 allele was associated with ulcer (P = 0.02) and with carcinoma (P = 0.001). iceA2 amplicons of 229, 334, or 549 bp were detected, but none of them was associated with the patient's disorder. iceA2 strains were more frequent in patients older than 7 years (P = 0.001). The gene was also more frequent in strains obtained from males (P = 0.02). cagA was more common in strains obtained from carcinoma (P = 0.0008) and ulcer patients (P < 0.006). cagA-positive strains were more frequent in children older than 7 years (P < 0.003). No association between cagA status and sex was found (P = 0.28). In conclusion, we think iceA should not be used as a reliable marker for predicting the clinical outcome of H. pylori infection.

Increased intracellular content of enteroglucagon in proximal colon is related to intestinal adaptation to germ-free status

Changes in the frequency of endocrine cells are evidence of intestinal adaptation to germ-free (GF) status. Not only the distribution of these cells along the intestine, but also the differences in intracellular content of these regulatory peptides may be explored to explain functional and structural aspects of GF intestinal adaptation. Focusing on the endocrine L-cells, we analyzed the intracellular content of enteroglucagon (EG) and peptide YY (PYY) throughout the intestine of the 14 GF and 14 conventional (CV) mice by using immunohistochemistry and the supra-optimal dilution technique. The percentage of EG-immunoreactive cells, but not of PYY-immunoreactive cells stained at supra-optimal dilution was significantly higher in the proximal colon of GF mice than in the CV counterparts (P < 0.05). Since the content of co-stored PYY did not differ between GF and CV mice, the higher content of EG was compatible with a selective cellular response. Moreover, in the cecum of GF mice, the density of EG-immunoreactive cells was significantly higher than that of PYY-immunoreactive cells (P < 0.05). These results are consistent with preferential production of EG by L-cells at the expense of PYY in the proximal colon and in the enlarged cecum of GF mice. In addition, they may reflect the dynamics of the GF intestinal epithelium and/or be correlated with the higher serum levels of these peptides. The role of endocrine cells needs to be better studied in human and other experimental adaptative conditions in order to elucidate the regulatory mechanisms of intestinal functions.

[Distal gastric carcinoma with duodenal invasion. Histopathologic study and review of the literature]

Gastric carcinoma with duodenal invasion is reported in 11% to 33.3% of surgical specimens. In spite of this high frequency, it is not easily recognised during the surgical proceeding or at gross examination. The study of risk factors like histological type, tumor stage and extension of duodenal invasion can be useful in establishing the best surgical approach in order to diminish the risk of local recurrence. We report 50 cases of distal gastric carcinoma in which we analysed the tumor extension in the different layers of the duodenal wall; duodenal invasion was correlated with histological type, level of infiltration in the gastric wall and presence of vascular invasion. Duodenal invasion was observed in 27 cases (54%), 17/32 of intestinal type (53%), 9/10 of diffuse type (90%) e 1/8 of non-classifiable tumours (12.5%). Diffuse type carcinoma was the most important risk factor for invasion (OR = 11; CI 95%: 1.20 to 254.16; P < 0.01). Most of the cases (21/27, 77%) were stage III or IV. The submucosal layer was the most frequent (22/27 cases, 81%) and also most extensively (8.21 +/- 9.75 mm) invaded. We conclude that the risk of duodenal invasion is higher in diffuse type tumours and in stage III or IV. Distal surgical resection should be wider in these cases and determined by frozen section biopsy specimen at the point of transection.

Gastric carcinoma exhibits distinct types of cell differentiation: an immunohistochemical study of trefoil peptides (TFF1 and TFF2) and mucins (MUC1, MUC2, MUC5AC, and MUC6)

The expression of trefoil peptides (TFF1 and TFF2) and mucins (MUC1, MUC2, MUC5AC, and MUC6) has previously been described in gastric polyps. In the present study, the expression profile of these trefoil peptides and mucins was characterized in 96 gastric carcinomas, in an attempt to further the understanding of the histogenesis and cell differentiation of gastric carcinoma. Taking together the co-expression of trefoil peptides and mucins, three phenotypes were defined: complete gastric, incomplete gastric, and non-gastric phenotype. Gastric differentiation (complete and incomplete) was observed in 30 out of 33 (90.9%) diffuse carcinomas and in 38 out of 53 (71.7%) intestinal carcinomas. Non-gastric differentiation was observed in only three (9.1%) diffuse carcinomas and in 15 (28.3%) intestinal carcinomas. The phenotypes observed in intestinal carcinomas were similar to those previously observed in adenomatous polyps, whereas most diffuse carcinomas mimicked the phenotype of hyperplastic polyps. The percentage of cases displaying a non-gastric phenotype was higher, though not significantly, in tumours that had invaded the gastric wall than in T1 tumours, regardless of histotype. It is concluded that gastric-type differentiation is retained in the majority of gastric carcinomas, being more prominent in diffuse than in intestinal carcinomas, and in early than in advanced carcinomas.

Gastric carcinoma exhibits distinct types of cell differentiation: an immunohistochemical study of trefoil peptides (TFF1 and TFF2) and mucins (MUC1, MUC2, MUC5AC, and MUC6)

The expression of trefoil peptides (TFF1 and TFF2) and mucins (MUC1, MUC2, MUC5AC, and MUC6) has previously been described in gastric polyps. In the present study, the expression profile of these trefoil peptides and mucins was characterized in 96 gastric carcinomas, in an attempt to further the understanding of the histogenesis and cell differentiation of gastric carcinoma. Taking together the co-expression of trefoil peptides and mucins, three phenotypes were defined: complete gastric, incomplete gastric, and non-gastric phenotype. Gastric differentiation (complete and incomplete) was observed in 30 out of 33 (90.9%) diffuse carcinomas and in 38 out of 53 (71.7%) intestinal carcinomas. Non-gastric differentiation was observed in only three (9.1%) diffuse carcinomas and in 15 (28.3%) intestinal carcinomas. The phenotypes observed in intestinal carcinomas were similar to those previously observed in adenomatous polyps, whereas most diffuse carcinomas mimicked the phenotype of hyperplastic polyps. The percentage of cases displaying a non-gastric phenotype was higher, though not significantly, in tumours that had invaded the gastric wall than in T1 tumours, regardless of histotype. It is concluded that gastric-type differentiation is retained in the majority of gastric carcinomas, being more prominent in diffuse than in intestinal carcinomas, and in early than in advanced carcinomas.

Immunoblot analysis of humoral immune response to Helicobacter pylori in children with and without duodenal ulcer

Several studies have demonstrated that enzyme-linked immunosorbent assay is not a sensitive and specific method to diagnose Helicobacter pylori infection in children, especially in the younger ones. Since serum immune response can also be determined by immunoblotting and it permits the detection of antibodies to virulence factors such as CagA and VacA, we evaluated the accuracy of a commercial immunoblotting test to diagnose H. pylori infection and to assess the humoral immune response to different H. pylori antigens in 122 children who underwent upper gastrointestinal endoscopy. The presence of H. pylori was determined in antral biopsy specimens by culture, preformed urease test, and histological analysis. H. pylori was identified by microbiological and histopathological methods in 66 children (including all of the 21 who had duodenal ulcer). Antibodies to H. pylori were detected in 63 infected children and in 8 noninfected ones. The sensitivity, specificity, and positive and negative predictive values of the immunoblotting test were 95.5, 85.7, 88.7, and 94.1%, respectively. The number of immunoreactive bands increased with age (P = 0.003), and the bands of 35 kDa (P = 0.013); 89 kDa, the VacA antigen (P = 0.001); and 116 kDa, the CagA antigen (P = 0.00004) were more frequently observed in older children. The frequency of the bands of 89 kDa (P = 0.001) and 116 kDa (P = 0.03) was higher in children with duodenal ulcer than in H. pylori-positive children without the disease. In conclusion, the immunoblotting test appears to be useful for the diagnosis of H. pylori infection in children, even in the younger ones.

Patterns of expression of trefoil peptides and mucins in gastric polyps with and without malignant transformation

The expression of two trefoil peptides (TFF1 and TFF2) and four mucins (MUC1, MUC2, MUC5AC, and MUC6) was evaluated by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) in 29 gastric polyps, 10 hyperplastic and 19 adenomatous, eight of which displayed malignant transformation. The aims of this study were to characterize the expression profile of these molecules in each type of polyp and to investigate possible modifications of the profile during the process of malignant transformation. All hyperplastic polyps displayed immunoreactivity for TFF1, MUC5AC, and MUC1 in more than 75 per cent of the cells. In adenomatous polyps, three main phenotypes could be identified: complete gastric phenotype (co-expression of TFF1 and MUC5AC)-nine cases (47.4 per cent); incomplete gastric phenotype (TFF1-positive and MUC5AC-negative)-seven cases (36.8 per cent); non-gastric (intestinal) phenotype (no expression of TFF1 or MUC5AC)-three cases (15.8 per cent). Data yielded by immunohistochemistry and RT-PCR showed a good correlation for both TFF1 and TFF2. One hyperplastic and seven adenomatous polyps with villous architecture displayed foci of diffuse and intestinal-type carcinoma, respectively; in all of these cases, MUC1 expression and signs of gastric differentiation were observed in both the non-malignant and the carcinomatous component. It is concluded that gastric differentiation is a feature of hyperplastic polyps and of a subset of adenomatous polyps which is shared by early carcinomas arising in some of these polyps, regardless of the histological type of polyp and of carcinoma.

Gastric carcinoma exhibits distinct types of cell differentiation: an immunohistochemical study of trefoil peptides (TFF1 and TFF2) and mucins (MUC1, MUC2, MUC5AC, and MUC6)

The expression of trefoil peptides (TFF1 and TFF2) and mucins (MUC1, MUC2, MUC5AC, and MUC6) has previously been described in gastric polyps. In the present study, the expression profile of these trefoil peptides and mucins was characterized in 96 gastric carcinomas, in an attempt to further the understanding of the histogenesis and cell differentiation of gastric carcinoma. Taking together the co-expression of trefoil peptides and mucins, three phenotypes were defined: complete gastric, incomplete gastric, and non-gastric phenotype. Gastric differentiation (complete and incomplete) was observed in 30 out of 33 (90.9%) diffuse carcinomas and in 38 out of 53 (71.7%) intestinal carcinomas. Non-gastric differentiation was observed in only three (9.1%) diffuse carcinomas and in 15 (28.3%) intestinal carcinomas. The phenotypes observed in intestinal carcinomas were similar to those previously observed in adenomatous polyps, whereas most diffuse carcinomas mimicked the phenotype of hyperplastic polyps. The percentage of cases displaying a non-gastric phenotype was higher, though not significantly, in tumours that had invaded the gastric wall than in T1 tumours, regardless of histotype. It is concluded that gastric-type differentiation is retained in the majority of gastric carcinomas, being more prominent in diffuse than in intestinal carcinomas, and in early than in advanced carcinomas.

Factors associated with Helicobacter pylori infection by a cagA-positive strain in children

Although infection with a cagA-positive Helicobacter pylori strain is considered a risk factor for the development of duodenal peptic ulcer in adults, this association has not been demonstrated in children. The presence of cagA was investigated by polymerase chain reaction in H. pylori strains isolated from 27 children with duodenal ulcer and 53 without duodenal ulcer. All patients (100%) with duodenal ulcer and 33 (62.3%) without ulcer were colonized by a cagA-positive strain (P=.00007). A cagA-positive status was also associated with a more marked macroscopic gastritis, with a greater inflammatory infiltrate of both mononuclear and polymorphonuclear cells in the antral and oxyntic gastric mucosae and degenerative and regenerative changes of the gastric mucosa. Increased cagA positivity was also associated with increased age, but no association between cagA-positive status and sex was observed.

Microsatellite instability in hyperplastic and adenomatous polyps of the stomach

BACKGROUND

Few studies have focused on the presence and significance of microsatellite instability (MSI) in gastric polyps, and the results on record are conflicting. The aim of the current study was to address this issue, taking into consideration the 2 main types of gastric polyps, the coexistence of foci of malignant transformation, and the expression of p53 and ERBB-2.

METHODS

Six hyperplastic polyps, 10 adenomatous polyps, and 4 adenomatous polyps displaying foci of malignant transformation (intestinal-type carcinoma) were studied for MSI. The authors analyzed a mononucleotide repeat microsatellite (BAT-26) and 5 dinucleotide repeats in microdissected formalin fixed, paraffin embedded tissue sections that were representative of the lesions. Expression of p53 and ERBB-2 were evaluated by immunohistochemistry.

RESULTS

BAT-26 positivity was detected in 1 of 6 hyperplastic polyps (16.7%) and in 2 of 10 adenomas (20%) without malignant transformation. In the 4 adenomatous polyps with carcinomatous foci, BAT-26 positivity was detected in 2 cases (50%) in both (adenomatous and carcinomatous) components of the lesions. p53 immunoreactivity was observed in 6 adenomatous polyps, 2 of them with malignant transformation. Overexpression of the ERBB-2 protein was detected in 1 adenomatous polyp with malignant transformation.

CONCLUSIONS

Replication error (RER+) phenotype occurs in both hyperplastic and adenomatous polyps of the stomach. The highest frequency is observed in adenomatous polyps with carcinomatous foci, suggesting that MSI may play a role in the process of malignant transformation in this setting. No significant association was observed between RER+ phenotype and overexpression of p53 or ERBB-2 proteins.

Patterns of expression of trefoil peptides and mucins in gastric polyps with and without malignant transformation

The expression of two trefoil peptides (TFF1 and TFF2) and four mucins (MUC1, MUC2, MUC5AC, and MUC6) was evaluated by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) in 29 gastric polyps, 10 hyperplastic and 19 adenomatous, eight of which displayed malignant transformation. The aims of this study were to characterize the expression profile of these molecules in each type of polyp and to investigate possible modifications of the profile during the process of malignant transformation. All hyperplastic polyps displayed immunoreactivity for TFF1, MUC5AC, and MUC1 in more than 75 per cent of the cells. In adenomatous polyps, three main phenotypes could be identified: complete gastric phenotype (co-expression of TFF1 and MUC5AC)-nine cases (47.4 per cent); incomplete gastric phenotype (TFF1-positive and MUC5AC-negative)-seven cases (36.8 per cent); non-gastric (intestinal) phenotype (no expression of TFF1 or MUC5AC)-three cases (15.8 per cent). Data yielded by immunohistochemistry and RT-PCR showed a good correlation for both TFF1 and TFF2. One hyperplastic and seven adenomatous polyps with villous architecture displayed foci of diffuse and intestinal-type carcinoma, respectively; in all of these cases, MUC1 expression and signs of gastric differentiation were observed in both the non-malignant and the carcinomatous component. It is concluded that gastric differentiation is a feature of hyperplastic polyps and of a subset of adenomatous polyps which is shared by early carcinomas arising in some of these polyps, regardless of the histological type of polyp and of carcinoma.

Patterns of expression of trefoil peptides and mucins in gastric polyps with and without malignant transformation

The expression of two trefoil peptides (TFF1 and TFF2) and four mucins (MUC1, MUC2, MUC5AC, and MUC6) was evaluated by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) in 29 gastric polyps, 10 hyperplastic and 19 adenomatous, eight of which displayed malignant transformation. The aims of this study were to characterize the expression profile of these molecules in each type of polyp and to investigate possible modifications of the profile during the process of malignant transformation. All hyperplastic polyps displayed immunoreactivity for TFF1, MUC5AC, and MUC1 in more than 75 per cent of the cells. In adenomatous polyps, three main phenotypes could be identified: complete gastric phenotype (co-expression of TFF1 and MUC5AC)-nine cases (47.4 per cent); incomplete gastric phenotype (TFF1-positive and MUC5AC-negative)-seven cases (36.8 per cent); non-gastric (intestinal) phenotype (no expression of TFF1 or MUC5AC)-three cases (15.8 per cent). Data yielded by immunohistochemistry and RT-PCR showed a good correlation for both TFF1 and TFF2. One hyperplastic and seven adenomatous polyps with villous architecture displayed foci of diffuse and intestinal-type carcinoma, respectively; in all of these cases, MUC1 expression and signs of gastric differentiation were observed in both the non-malignant and the carcinomatous component. It is concluded that gastric differentiation is a feature of hyperplastic polyps and of a subset of adenomatous polyps which is shared by early carcinomas arising in some of these polyps, regardless of the histological type of polyp and of carcinoma.

Evaluation of enzyme-linked immunosorbent assay for the diagnosis of Helicobacter pylori infection in children from different age groups with and without duodenal ulcer

BACKGROUND

Although enzyme-linked immunosorbent assay (ELISA) is highly sensitive and specific for the diagnosis of Helicobacter pylori infection in adults, their performance in children is still controversial.

METHODS

A second-generation ELISA was used to evaluate the IgG response to H. pylori in the serum of 130 consecutive children who underwent upper gastrointestinal endoscopy. The presence of H. pylori was determined in antral biopsy specimens by culture, urease test, and histologic analysis.

RESULTS

Sixty-eight children (all of the 20 who had duodenal ulcer) were H. pylori positive by microbiologic test. Immunoglobulin G antibodies to H. pylori were detected in 79.4% of the infected children and in 8.1% of the noninfected ones. The sensitivity of the test was higher in patients with duodenal ulcer (100%) than in those without (70.8%). When used in children of different ages the test also presented differences in sensitivity: 44.4% in children 2 to 6 years old; 76.7% in children 7 to 11 years old, and 93.1% in children 12 to 16 years old (p = 0.006). The serum immunoglobulin G concentration was significantly higher (p = 0.0003) in children with duodenal ulcer than in those without and was higher in older children than in younger ones without duodenal ulcer (p = 0.05).

CONCLUSIONS

The accuracy of the test in children with duodenal ulcer and in children more than 12 years old was good; however, in children up to 12 years of age without duodenal ulcer, the sensitivity of the test was too low to be used for screening purposes or to rule out the presence of infection.

cagA-positive Helicobacter pylori and risk for developing gastric carcinoma in Brazil

To evaluate a possible association between infection with cag A-positive strains and gastric carcinoma increased risk we studied 119 Helicobacter pylori-positive patients with gastric carcinoma and 119 matched controls. The presence of cag A gene was investigated by PCR in H. pylori isolates and in gastric biopsy specimens. A significant association was found between cag A-positive status and distal gastric carcinoma for both the intestinal and diffuse types of tumor for both males and females. On the other hand, no association was observed between cag A-positive status and proximal gastric carcinoma.

cagA-positive Helicobacter pylori and risk for developing gastric carcinoma in Brazil

To evaluate a possible association between infection with cag A-positive strains and gastric carcinoma increased risk we studied 119 Helicobacter pylori-positive patients with gastric carcinoma and 119 matched controls. The presence of cag A gene was investigated by PCR in H. pylori isolates and in gastric biopsy specimens. A significant association was found between cag A-positive status and distal gastric carcinoma for both the intestinal and diffuse types of tumor for both males and females. On the other hand, no association was observed between cag A-positive status and proximal gastric carcinoma.

Distribution of enteroglucagon- and peptide YY-immunoreactive cells in the intestinal mucosa of germ-free and conventional mice

There are evidences that microflora modulates endocrine cells in the gastrointestinal tract. In the present study we investigated the distribution of EG- and PYY-immunoreactive cells throughout the intestine of adult male NMRI conventional and germ-free mice. EG-immunoreactive cells were significantly more frequent in the proximal and middle colon than in the remainder of the intestine in both groups. In germ-free animals, these cells were more frequent in the cecum and less frequent in the distal ileum compared to conventional mice. PYY-immunoreactive cells were more frequent in the distal colon than in the remainder of the intestine in both groups, but they were significantly more frequent in the middle and distal colon of germ-free animals than in that of conventional counterparts. The number of EG-immunoreactive cells was 4.5-fold higher than the number of PYY-immunoreactive cells in the cecum of germ-free mice. The present results indicate the existence of an inverse gradient of EG- and PYY-immunoreactive cells along the colon, which is not significantly changed in the absence of a microflora. PYY production seems to be more significant in the distal colon. The cecum and the proximal portion of the colon are probably the regions of greatest functional importance for EG production, which is related to the microflora and probably to fermentation products, whether or not the effect of this peptide is trophic or antitrophic.

Higher incidence of Gastrospirillum sp. in swine with gastric ulcer of the pars oesophagea

Gastric ulcer in swine is characterized by an area of acid-peptic digestion, occurs usually in the pars oesophagea of the stomach, and has unknown etiopathogenesis. The present work was carried out to investigate the prevalence of the newly described spiral-shaped microorganism Gastrospirillum sp. ("Gastrospirillum suis") in stomachs of abattoir pigs with and without gastric ulcer. Stomachs were removed from 32 consecutive pigs presenting apparently normal mucosa and from 32 additional consecutive pigs presenting frank, chronic gastric ulcer of the pars oesophagea. Fragments of antral, oxyntic, cardiac and pars oesophagea regions were taken from each stomach and processed for histology and for identification of Gastrospirillum sp. in tissue sections. The microorganisms were identified mainly in the mucous layer and in gastric foveolas of the antral and oxyntic mucosa. Forty pigs (62.5%) were positive for Gastrospirillum sp.; among them, 27 (67.5%) had gastric ulcer, and 13 (32.5%) had no ulcer. Twenty-four pigs (37.5%) were negative for Gastrospirillum sp.; among them, five (20.8%) presented with gastric ulcer, and 19 (79.2%) had no ulcer. There was a significant difference between pigs with and without gastric ulcer in regard to the presence of Gastrospirillum sp. (P < 0.01). The spiral-shaped microorganism Gastrospirillum sp. that inhabits the stomach of pigs should be considered a possible factor connected with the etiopathogenesis of swine gastric ulcer.

Prevalence of Helicobacter pylori in Brazilian patients with gastric carcinoma

Investigators have speculated on the role of Helicobacter pylori in gastric carcinogenesis. The current study was performed to evaluate prospectively the prevalence of H. pylori infection in the stomachs of Brazilian patients with gastric carcinoma. Forty patients receiving gastrectomy for gastric carcinoma were studied. H. pylori was examined in four areas without atrophy or with minor atrophic changes. Mucosal fragments were obtained for microbiologic studies in 19 cases. H. pylori was detected in 82.5% of the cases. Of the cases evaluated by histologic and microbiologic methods, 94% had positive results by at least one method. In most cases there were small numbers of microorganisms. There was no correlation between the site and histologic type of neoplasia and the presence of H. pylori. The use of more than one diagnostic method improves H. pylori detection in gastric carcinoma. The small number of microorganisms observed in gastric carcinoma cases may lead to an underestimate of H. pylori in histologic sections. This might explain the variation in H. pylori infection rates reported for patients with gastric carcinoma.

The inflammatory response of the gastric mucosa of mice experimentally infected with "Gastrospirillum suis"

To establish an experimental model to study gastric spiral non-cultivable bacteria, 30 4-week-old female CFW (LOB) mice were inoculated with porcine gastric mucus containing "Gastrospirillum suis" and 25 mice were inoculated with mucus without "G. suis". Mice were examined 3, 7, 14, 21, 28 and 60 days after inoculation. Fragments from the membranous, oxyntic and antral gastric mucosa and from the duodenal mucosa were obtained for histological and microbiological analysis. Tightly spiralled bacteria were seen in smears and in histological sections of the antral and oxyntic mucosa from all G. suis-infected mice. The pre-formed urease test also gave positive results in both tissues. In control mice, no tightly spiralled bacteria were seen. By 7 days after inoculation, the test animals had developed an inflammatory infiltrate of mononuclear cells, some neutrophils and a few eosinophils, mainly in the lower third of the antral and oxyntic mucosa, which persisted for the remainder of the observation period. This model can assist in the understanding of several clinical, pathological and immunological aspects of infection with spiral gastric bacteria, particularly those associated with non-cultivable spiral bacteria.

Chronic gastritis and Helicobacter pylori in digestive form of Chagas' disease

Patients with the digestive form of Chagas' disease frequently present chronic gastritis. As the microorganism Helicobacter pylori is now accepted as the most common cause of human chronic gastritis, the present work was undertaken to verify a possible relationship between the presence of this bacterium and inflammatory changes of antral mucosa in chagasic patients. Seventeen chagasics, with megaesophagus and or megacolon were studied. Fragments from two different regions of antral mucosa were obtained by endoscopy, fixed in 4% neutral formaldehyde and embedded in paraffin. The sections were stained by haematoxylin and eosin for histology analysis, and by carbolfuchsin for H. pylori identification. H. pylori was found in 16 (94.1%) chagasic patients, all of them presenting chronic gastritis. Superficial gastritis was seen in 9 (52.9%) while atrophic gastritis was present in 8 (47.1%) patients. H. pylori was present on gastric mucosa of 8 (100%) patients with atrophic gastritis and of 8 (88.8%) patients with superficial gastritis. We concluded that the microorganism H. pylori should be considered a possible factor connected with the etiopathogenesis of chronic superficial and atrophic gastritis frequently observed in patients with the digestive form of Chagas' disease.

Spiral bacterium associated with gastric, ileal and caecal mucosa of mice

A spiral shaped bacterium was seen in smears and histological sections (stained by carbolfuchsin) of gastric, ileal and caecal mucosa as well as in stool smears from mice. A significant correlation between the presence of the spiral bacterium and the occurrence of gastritis was observed but the ileal and caecal mucosa seemed unaffected. The bacterium was Gram negative and grew on BHM and Skirrow's medium, under microaerophilic conditions, at 37 degrees C. Its major biochemical characteristics included positive catalase and oxidase reactions and a rapidly positive urease test. There were 2 or 3 spiral turns per cell and a tuft of up to 12 sheathed flagella on each pointed end. Entwined, braided periplasmic fibrils covered the surface of the cell. This spiral bacterium seemed to be part of the normal intestinal flora but was associated with gastritis.

Histopathological study of porcine gastric mucosa with and without a spiral bacterium ("Gastrospirillum suis")

Tightly spiralled bacteria ("Gastrospirillum suis") were seen in the pyloric mucosa of the stomach of 13 (10.8%) of 120 pigs that appeared clinically healthy at slaughter and in the fundic mucosa of three (5.0%) out of 60 pigs. The spiral organism could not be cultured from any pig. Chronic gastritis was observed in the pyloric mucosa of 53 (44.2%) of 120 pigs and in the fundic mucosa of 7 (11.7%) of 60 pigs. The 13 pigs with spiral bacteria in the pyloric region comprised one animal (7.7%) with normal pyloric mucosa, two (15.4%) with "borderline gastritis", and 10 (76.9%) with chronic gastritis--in one instance accompanied by signs of activity (numerous polymorphonuclear cells). The three pigs with spiral bacteria in the fundic mucosa comprised two animals with a normal fundic region and one with "borderline gastritis". The presence of the spiral bacterium was significantly associated with pyloric gastritis (p = 0.013) and with numbers of lymphoid follicles (p = 0.014).

Usefulness of immunocytochemical demonstration of neuron-specific enolase in the diagnosis of Hirschsprung's disease

The work reported here was carried out to study the importance of immunocytochemical staining of neuron-specific enolase (NSE) in the diagnosis of Hirschsprung's disease and to compare its results with those obtained by hematoxylin-eosin (H&E) staining in consecutive sections. A retrospective study was made on 51 rectal mucosal biopsies and 19 colorectal surgical specimens from 52 patients clinically suspected of Hirschsprung's disease. Several consecutive sections from all cases were restained by H&E and for NSE demonstration. Sixteen (31%) patients had a histological diagnosis of Hirschsprung's disease, 9 (17%) had hypoganglionosis, 4 (8%) had neuronal intestinal dysplasia, and 2 (4%) had normal histology. In eight patients (15%) hypoganglionosis remained dubious, and in 10 (19%) the diagnosis was inconclusive. Although the NSE staining improved the identification of the nervous tissue of the colon, both H&E and NSE staining proved to be of equal value in the assessment of the presence of neurons in the rectal wall of people with clinically suspected cases of Hirschsprung's disease. Ten H&E-stained sections from different levels of the biopsy specimen would be enough to detect ganglion cells in most cases.

[Anatomo-histological and histochemical study of acute lesions of the gastroduodenal mucosa, produced by ethanol, before and after truncal vagotomy plus pyloroplasty in rats]

The anatomo-pathologic alterations determined by ethanol in the gastroduodenal mucosa of rats are studied, as well as its action about truncal vagotomy plus pyloroplasty (VT + P). We use albino rats submitted to the administration of ethanol, 33% --via orogastric catheter- and to truncal vagotomy plus pyloroplasty, as well the association of the 2 variants. The utilization of ethanol, according to the up to date methodology, can be confirmed by a simple experimental production method of acute ulcer in rats. The VT + P determined acute ulcers in the 24 hour observation group, besides acute inflammatory lesions and with the decrease of mucins, diffusively, in the gastroduodenal mucosa. The performance of VT + P, 2 hours after the administration of ethanol, period in which the lesions are entirely settled, determined and aggravation of the gastric lesions through the increase of the media ulcerous gastric area and its histological aspects. On the other hand, the performance of VT + P, followed by the administration of ethanol 2 hours after, also determined an aggravation of gastric lesions, according to the same former parameters. When it was the time to perform the VT + P, 10 days before the administration of ethanol, or the inverse, a small reduction at the ulcerous gastric area had accrued but it did not amount to much. There was not a characterization of preventive effects or curative of this surgical procedure considering the gastric lesions produced by ethanol, but there was characterization of aggravating effect. All the possible hypothesis to the aggravation of these lesions are also discussed with the utilization of VT + P, as well its clinical use on the human being.

Pontoneocerebellar hypoplasia: report of a case in a newborn and review of the literature

A case of pontoneocerebellar hypoplasia (PNCH) in a 9-day-old child--the youngest in the literature--is described. Right after birth the child showed serious respiratory insufficiency and developed frequent episodes of apnea and cardiorespiratory arrests, dying on the 9th day. Postmortem examination showed significant alterations only in the brain. There was intense neuron reduction in the pontine, arcuate, inferior olivary and dentate nuclei, reduction of Purkinje cells and of the granular layer of the cerebellum and the disappearance of the pontocerebellar fibers, together with dense fibrillary astrocytosis, which seems to have first appeared in the pontine nuclei. This case is compared with others in the literature and attention is drawn to the more intense, and probably initial, involvement of the pontine nuclei. The time of appearance of pontoneocerebellar hypoplasia is commented upon, based on data concerning the ontogenesis of the structure and on the presence or absence of gliosis in the pontine nuclei and persistence of the fetal pattern in the inferior olivary and dentate nuclei. It is suggested that the process may start in the 2nd or 3rd month of fetal life, or even later, as probably occurred in the present case, during the second or third trimester of intrauterine life.

[Cerebellar agenesia associated with microencephaly and agyria: report of an autopsied case in a newborn infant and a review of the literature]

A post-mortem examined case of cerebellar agenesis associated with microcephaly, agyria and deformities of the extremities and of the external ear in a newborn is presented. Such an association has not yet been reported in the literature. This is the seventh case of cerebellar agenesis ever registered in the literature. This case is compared with other previously published cases and the possible etiological factors involved as well as the period during which the cerebral malformations appeared in the present case are commented upon.

Parietal cell carcinoma of the stomach and Ménétrier's disease

A case of gastric parietal cell carcinoma, a newly recognized entity, associated with Ménétrier's disease, is presented. The tumor presented a excavated ulcer 6 x 6 cm in diameter surrounding the cardiac region. Metastasis in the greater curvature and epiploon++ lymph nodes were identified. The mucosa of gastric body and fundus showed large thickened tortuous folds and the histological pattern of Ménétrier's disease.

[APUD cells in gastric cancer]

Endocrine cells (APUD cells) of digestive mucosa can be source of neoplasias, usually called "carcinoids". Nevertheless, there are some reports in literature about the presence of APUD cells in carcinomas as a tumor component. However, these tumors seem to have not the biological and clinical behavior of carcinoids. These types of neoplasias have been reported mainly in stomach and colon. In the present work, the frequency of APUD cells was studied in 42 gastric carcinomas. Argyrophil cells were observed in six cases (14.3%) and argentaffin cells in one (2.3%); their histopathological pattern were well differentiated adenocarcinoma (5) and "signet ring cell carcinoma" (1). The APUD cell distribution and number in these neoplasias were quite irregular in each case examined and in different areas of the same case.

[Histological analysis of the gastric mucosa, enterochromaffin cells and gastrin-producing cells in endoscopic biopsies of patients with achlorhydria]

Twenty achlorhydric patients and five controls were submitted to gastric endoscopic biopsies in order to study the histological pattern of the gastric mucosa and the number of enterochromaffin (EC) and gastrin (G) cells of the antral mucosa. The histological changes of the oxyntic mucosa of achlorhydric patients were variable being the predominant pattern the severe chronic atrophic gastritis. The antral mucosa was normal in appearance or revealed mild degree of gastritis. In the most achlorhydric patients the antral EC cell number was decreased when compared to the controls and the G cell number were relatively numerous. The results of the present work are suggestive of an increased G:EC cell ratio in achlorhydric patients.

Human pulmonary granulomas caused by Chrysosporium parvum var. crescens (Emmonsia crescens)

Multiple lung nodules were found at autopsy of a 56-year-old man who died of unrelated cause. The nodules contained adiaspores which were identified as those of Chrysosporium parvum var. crescens.

Phaeohyphomycotic cyst: a clinicopathologic study of the first four cases described from Brazil

Four cases of phaeohyphomycosis in the form of chronic and isolated cysts are presented. The cysts were strictly confined to the subcutaneous tissue, with no involvement of the corresponding skin. Patients were asymptomatic, without satellite lesions or regional lymphadenopathy. The clinicopathologic importance of this type of phaeohyphomycosis is discussed. As far as we know, our cases are the first described from Brazil.

[Precancerous lesions associated with atrophic chronic gastritis and gastric peptic ulcer]

Among the gastric lesions related to an increased risk for gastric cancer (precancerous conditions) two have deserved special attention, i.e., atrophic gastritis and peptic ulcer. In this paper the authors study the incidence of glandular dysplasia in atrophic gastritis and gastric peptic ulcer. In 148 cases of atrophic gastritis dysplastic lesions were diagnosed in 92 (62,0%): 63 cases (68,4%) with mild dysplasia, 25 cases (27,0%) with moderate dysplasia and 4 cases (4,3%) with severe dysplasia. In 329 gastric peptic ulcers examined there were 51 (15,5%) with dysplastic lesions: in 34 cases (66,6%) there was mild dysplasia, 12 cases (23,5%) moderate dysplasia and (9,8%) severe dysplasia. A prospective study with histological multiple sections from the stomach would be helpful for better understanding of these precancerous lesions.