Comprehensive germline mutation analysis and clinical profile in a large cohort of Brazilian xeroderma pigmentosum patients

BACKGROUND

Xeroderma pigmentosum (XP) patients present a high risk of developing skin cancer and other complications at an early age. This disease is characterized by mutations in the genes related to the DNA repair system.

OBJECTIVES

To describe the clinical and molecular findings in a cohort of 32 Brazilian individuals who received a clinical diagnosis of XP.

METHODS

Twenty-seven families were screened for germline variants in eight XP-related genes.

RESULTS

All patients (N = 32) were diagnosed with bi-allelic germline pathogenic or potentially pathogenic variants, including nine variants previously undescribed. The c.2251-1G>C XPC pathogenic variant, reported as the founder mutation in Comorian and Pakistani patients, was observed in 15 cases in homozygous or compound heterozygous. Seven homozygous patients for POLH/XPV variants developed their symptoms by an average age of 7.7 years. ERCC2/XPD, DDB2/XPE and ERCC5/XPG variants were found in a few patients. Aside from melanoma and non-melanoma skin tumours, a set of patients developed skin sebaceous carcinoma, leiomyosarcoma, angiosarcoma, mucoepidermoid carcinoma, gastric adenocarcinoma and serous ovarian carcinoma.

CONCLUSIONS

We reported a high frequency of XPC variants in 32 XP Brazilian patients. Nine new variants in XP-related genes, unexpected non-skin cancer lesions and an anticipation of the clinical manifestation in POLH/XPV cases were also described.

The Iberian legacy into a young genetic xeroderma pigmentosum cluster in central Brazil

In central Brazil, in the municipality of Faina (state of Goiás), the small and isolated village of Araras comprises a genetic cluster of xeroderma pigmentosum (XP) patients. The high level of consanguinity and the geographical isolation gave rise to a high frequency of XP patients. Recently, two founder events were identified affecting that community, with two independent mutations at the POLH gene, c.764 + 1 G > A (intron 6) and c.907 C > T; p.Arg303* (exon 8). These deleterious mutations lead to the xeroderma pigmentosum variant syndrome (XP-V). Previous reports identified both mutations in other countries: the intron 6 mutation in six patients (four families) from Northern Spain (Basque Country and Cantabria) and the exon 8 mutation in two patients from different families in Europe, one of them from Kosovo. In order to investigate the ancestry of the XP patients and the age for these mutations at Araras, we generated genotyping information for 22 XP-V patients from Brazil (16), Spain (6) and Kosovo (1). The local genomic ancestry and the shared haplotype segments among the patients showed that the intron 6 mutation at Araras is associated with an Iberian genetic legacy. All patients from Goiás, homozygotes for intron 6 mutation, share with the Spanish patients identical-by-descent (IBD) genomic segments comprising the mutation. The entrance date for the Iberian haplotype at the village was calculated to be approximately 200 years old. This result is in agreement with the historical arrival of Iberian individuals at the Goiás state (BR). Patients from Goiás and the three families from Spain share 1.8 cM (family 14), 1.7 cM (family 15), and a more significant segment of 4.7 cM within family 13. On the other hand, the patients carrying the exon 8 mutation do not share any specific genetic segment, indicating an old genetic distance between them or even no common ancestry.

A genetic cluster of patients with variant xeroderma pigmentosum with two different founder mutations

BACKGROUND

Xeroderma pigmentosum (XP) is a rare human syndrome associated with hypersensitivity to sunlight and a high frequency of skin tumours at an early age. We identified a community in the state of Goias (central Brazil), a sunny and tropical region, with a high incidence of XP (17 patients among approximately 1000 inhabitants).

OBJECTIVES

To identify gene mutations in the affected community and map the distribution of the affected alleles, correlating the mutations with clinical phenotypes.

METHODS

Functional analyses of DNA repair capacity and cell-cycle responses after ultraviolet exposure were investigated in cells from local patients with XP, allowing the identification of the mutated gene, which was then sequenced to locate the mutations. A specific assay was designed for mapping the distribution of these mutations in the community.

RESULTS

Skin primary fibroblasts showed normal DNA damage removal but abnormal DNA synthesis after ultraviolet irradiation and deficient expression of the Polη protein, which is encoded by POLH. We detected two different POLH mutations: one at the splice donor site of intron 6 (c.764 +1 G>A), and the other in exon 8 (c.907 C>T, p.Arg303X). The mutation at intron 6 is novel, whereas the mutation at exon 8 has been previously described in Europe. Thus, these mutations were likely brought to the community long ago, suggesting two founder effects for this rare disease.

CONCLUSIONS

This work describes a genetic cluster involving POLH, and, particularly unexpected, with two independent founder mutations, including one that likely originated in Europe.

Use of nanofiltration for potable water from an aquifer recharged with wastewater

This paper presents the comparison of nine nanofiltration membranes to treat water coming from an aquifer recharged with wastewater and used as municipal supply in the Tula Valley, Mexico. The comparison was made based on (a) the amount of water produced; (c) the capability to produce a <1 mg TOC/L effluent without entirely eliminating salts, (b) the removal of specific organic and microbiological pollutants, and (c) the reduction of toxicity and mutagenicity from water. From the tested membranes, only four produce an effluent with <1 TOC mg/L, and three totally retained dibutyl phthalate, diethyl phthalate and hydroxytoluene butylate. Influent mutagenicity (Ames test) was negative but these was a certain degree of toxicity when Tetrahymena pyriformis was used as indicator. Toxicity was partially reduced by some of the NF membranes. The best membrane had a flux of 95 L m(-2)h(-1) and removal efficiencies of 98% for TOC, 92% for AUV(254), and 92% for TDS. The permeate had a final hardness of 76 mg/L and an alkalinity of 124 mg/L. Additionally, this membrane removed totally specific organic compounds, total and fecal coliforms and almost all the somatic coliphages.

New once-daily, highly effective rescue triple therapy after multiple Helicobacter pylori treatment failures: a pilot study

BACKGROUND

Helicobacter pylori treatment failure is a growing problem in daily practice.

AIM

To determine the efficacy of the combination of rabeprazole, levofloxacin and furazolidone as a rescue therapy.

METHODS

Duodenal ulcer patients previously submitted, without success, to at least two H. pylori treatment regimens were included. Gastroscopy (urease test, histological examination and culture) and (13)C-urea breath test were performed. All patients received a combination of rabeprazole 20 mg, levofloxacin 500 mg and furazolidone 200 mg (two tablets) administered in a single dose in the morning for 10 days. Clinical examination and a new (13)C-urea breath test were performed 90 days after therapy.

RESULTS

Twelve patients (eight females and four males), mean age 43 (30-58) years were included. Two patients failed to complete the treatment because of nausea and vomiting. Ten patients completed the study and took all the medications as advised. Culture was obtained in six patients: 100 and 83% of the samples were sensitive to furazolidone and levofloxacin, respectively. Per-protocol and intention-to-treat eradication rates were 100 and 83% (P = 0.019).

CONCLUSIONS

the combination of rabeprazole, levofloxacin and furazolidone in a single daily dose for 10 days constitutes a highly-effective and low-cost alternative as a third-line therapy in patients infected with H. pylori.

Development of a bioactive packaging cellophane using Nisaplin as biopreservative agent

AIMS

Production of a nisin-containing cellophane-based coating to be used in the packaging of chopped meat.

METHODS AND RESULTS

The adsorption of nisin to cellophane 'P' type surface was studied at 8, 25, 40 and 60 degrees C using different concentrations of nisin. Then, the antimicrobial activity of adsorbed nisin to cellophane surface was determined in fresh veal meat for effectiveness in reducing the total aerobic bacteria. The adsorption of nisin to cellophane was higher at 8 degrees C. The developed bioactive cellophane reduced significantly the growth of the total aerobic bacteria (by ca 1.5 log units) through 12 days of storage at 4 degrees C.

CONCLUSIONS

Bioactive cellophane packaging could be used for controlling the microbial growth in chopped meat.

SIGNIFICANCE AND IMPACT OF THE STUDY

Nisin-adsorbed bioactive cellophane would result in an extension of the shelf life of chopped meat under refrigeration temperatures.

Once-daily, low-cost, highly effective Helicobacter pylori treatment to family members of gastric cancer patients

BACKGROUND

Helicobacter pylori eradication in family members of gastric cancer patients is now widely accepted, although problems related to costs and compliance persist.

AIM

To compare the efficacy, tolerability and long-term re-infection rates of two once-daily regimens for the eradication of H. pylori in family members of gastric cancer patients.

METHODS

106 first-degree family members of gastric cancer patients were recruited and submitted to the 13C-urea breath test (UBT) to detect H. pylori. If positive, they were randomly allocated to receive a combination of lanzoprazole 30 mg, clarithromycin OD (extended-release formulation) 500 mg and furazolidone 400 mg, once daily, in the morning, for 7 days (Group A) or the same regimen with only 200 mg furazolidone (Group B). Eradication was confirmed by urea breath test performed 6 weeks after treatment. 13C-urea breath test was repeated at 944 (784-1258) days after treatment in successfully treated participants to look for re-infection.

RESULTS

Twenty-five participants were H. pylori negative and two H. pylori-positive individuals refused to sign the informed consent and were excluded. Therefore, 79 participants were studied. Forty participants were allocated to Group A and 39 to Group B. All participants completed treatment. Adverse effects, mostly mild, were observed in 18% of Group A and 18% of Group B (N.S.). The intention-to-treat eradication rate was 87.5% in Group A and 61.5% in Group B (P = 0.006). The mean annual re-infection rate was 3%.

CONCLUSIONS

The combination of lanzoprazole 30 mg, one tablet of clarithromycin OD (extended release formulation) 500 mg and furazolidone 400 mg, once daily for 7 days, constitutes an inexpensive, safe and effective alternative for anti-H. pylori therapy in family members of gastric cancer patients.

Efficacy and tolerability of pantoprazole versus ranitidine in the treatment of reflux esophagitis and the influence of Helicobacter pylori infection on healing rate

Patients with reflux esophagitis (grade II or III, Savary-Miller, intention-to-treat, n=256, age range 19-82 years) were randomly assigned to a double-blind, double-dummy treatment with either pantoprazole 40 mg once daily or ranitidine 150 mg twice daily. After 4 weeks, each patient was clinically and endoscopically assessed. Failure to heal required a further 4 weeks of treatment and a new evaluation thereafter. After 4 weeks, healing of lesions was confirmed in 63% (69 out of 109) of patients receiving pantoprazole and in 22% (25 out of 113) receiving ranitidine (P < 0.001, per protocol population). After 8 weeks, the cumulative healing rates were 88% and 46%, respectively (P < 0.001). Complete freedom from esophagitis-related symptoms (acid eructation, heartburn, pain while swallowing) was greater in the pantoprazole than in ranitidine group after 2 and 4 weeks (74% vs. 47%; 87% vs. 52%, respectively, P < 0.001). After 4 weeks, the healing rate was 76% in Helicobacter pylori (Hp)-positive vs. 45% in Hp-negative patients treated with pantoprazole (P < 0.01). The Hp status did not influence healing rates in patients treated with ranitidine. The most frequent adverse events in the pantoprazole group were diarrhea and somnolence (2-3% of patients), and in the ranitidine group, headache, diarrhea, dizziness, increase of liver enzymes and pruritus (2-4% of patients). In conclusion, pantoprazole was more effective than ranitidine in the healing rate and relief from reflux esophagitis-associated symptoms, and Hp infection was associated with higher healing rate during therapy with pantoprazole but not with ranitidine.

Application of isotope-selective non-dispersive infrared spectrometry for the evaluation of the 13C-urea breath test: comparison with three concordant methods

The aim of this work was to compare the performance of isotope-selective non-dispersive infrared spectrometry (IRIS) for the 13C-urea breath test with the combination of the 14C-urea breath test (14C-UBT), urease test and histologic examination for the diagnosis of H. pylori (HP) infection. Fifty-three duodenal ulcer patients were studied. All patients were submitted to gastroscopy to detect HP by the urease test, histologic examination and 14C-UBT. To be included in the study the results of the 3 tests had to be concordant. Within one month after admission to the study the patients were submitted to IRIS with breath samples collected before and 30 min after the ingestion of 75 mg 13C-urea dissolved in 200 ml of orange juice. The samples were mailed and analyzed 11.5 (4-21) days after collection. Data were analyzed statistically by the chi-square and Mann-Whitney test and by the Spearman correlation coefficient. Twenty-six patients were HP positive and 27 negative. There was 100% agreement between the IRIS results and the HP status determined by the other three methods. Using a cutoff value of delta-over-baseline (DOB) above 4.0 the IRIS showed a mean value of 19.38 (minimum = 4.2, maximum = 41.3, SD = 10.9) for HP-positive patients and a mean value of 0.88 (minimum = 0.10, maximum = 2.5, SD = 0.71) for negative patients. Using a cutoff value corresponding to 0.800% CO2/weight (kg), the 14C-UBT showed a mean value of 2.78 (minimum = 0.89, maximum = 5.22, SD = 1.18) in HP-positive patients. HP-negative patients showed a mean value of 0.37 (minimum = 0.13, maximum = 0.77, SD = 0.17). IRIS is a low-cost, easy to manage, highly sensitive and specific test for H. pylori detection. Storing and mailing the samples did not interfere with the performance of the test.

Histology of the mucosa of gastric antrum and body before and after eradication of Helicobacter pylori

1. Helicobacter pylori status and the histology of the antral and oxyntic mucosa were evaluated in 25 patients with duodenal ulcer treated with a triple schedule of furazolidone, metronidazole and amoxicillin, and in 16 patients treated only with cimetidine. 2. Before treatment, H. pylori was detected in all patients. One month after treatment with the antimicrobial agents, H. pylori was not found in 18 (72.0%) of 25 patients treated with the triple schedule. In the patients treated with cimetidine (N = 16) the H. pylori tests continued to be positive after treatment. 3. Inflammatory activity and intensity of gastritis were significantly reduced in patients treated with the antimicrobial agents but not in cimetidine-treated patients. Three patients who had negative cultures and improvement of gastritis 1 month after treatment became H. pylori positive again within 2 months, with concomitant reappearance of gastritis. 4. This study provides additional evidence that histological gastritis observed in H. pylori-positive patients with duodenal ulcer is due to the presence of the microorganism.

Effect of Helicobacter pylori eradication on antral gastrin- and somatostatin-immunoreactive cell density and gastrin and somatostatin concentrations

The density of antral gastrin (G)- and somatostatin (D)-immunoreactive cells and the contents of antral gastrin and somatostatin were investigated in endoscopic antral biopsy specimens from patients with duodenal ulcer before and after eradication of Helicobacter pylori. After H. pylori eradication both antral somatostatin concentration (p = 0.0002) and antral D-cell density (p = 0.01) increased significantly. Conversely, although the number of G-cells was unchanged, antral (p = 0.0002) and serum (p = 0.001) gastrin contents decreased significantly. The number of oxyntic D-cells did not change significantly. These results strongly suggest that the hypergastrinaemia observed in H. pylori-positive patients may be due to a deficiency in antral somatostatin, which normally inhibits the synthesis and release of gastrin.

The effect of chronic ingestion of ethanol on modulation of granulomatous inflammation in experimental schistosomiasis in mice

We studied the role of ethanol on the modulation of liver granulomata around Schistosoma mansoni eggs in mice. Albino mice, receiving 7% ethanol as the sole drinking liquid, at 60 and 90 days post-infection, presented smaller granulomata than controls did, when sacrificed at 120 days post-infection. No differences in diameters could be observed, when ethanol was given 4 months before up to 120 days after infection. The results suggested that modulation of schistosome granulomata by ethanol ingestion varies with time and duration of drug consumption.

Comparison of the urease test and of direct smear examination in the control of treatment of Helicobacter pylori-induced infection

The sensitivity and specificity of the preformed urease test and of carbolfuchsin-stained smears for the diagnosis of the presence of Helicobacter pylori in gastric mucosa were evaluated before and after antimicrobial treatment. The results obtained by culture were used as the reference point. We studied 41 patients with endoscopically diagnosed duodenal ulcer. Twenty-five of these were treated with furazolidone (100 mg t.i.d.), amoxicillin (500 mg t.i.d.) and metronidazole (250 mg t.i.d.) for 5 days and then with only furazolidone (100 mg t.i.d.) for an additional 25 days. The 16 control patients were treated with cimetidine (800 mg, 4 times a day). The sensitivity of the urease test and of direct smear examination was 100% before treatment and 84.6% and 92.3%, respectively, after treatment. We conclude that the urease test and carbolfuchsin-stained smears, which are highly sensitive for H. pylori diagnosis, present reduced sensitivity when they are employed for the follow-up of patients treated with antimicrobials.

Treatment of duodenal ulcer with omeprazole or ranitidine in a Brazilian population: a multicenter double-blind, parallel group study

Two hundred and forty-one patients with at least one ulcer at stage A1 or A2, measuring at least 5 mm in its larger diameter, were included in this Brazilian double-blind randomized study. Patients received omeprazole 20 mg in the morning (n = 120) or ranitidine 300 mg at night (n = 121) for 2 wk; unhealed ulcers were treated for an additional 2 wk. At the end of 4 wk, unhealed ulcers were treated openly with omeprazole 20 mg o.m. for 4 wk. Healing rates at 2 and 4 wk were 67.3% and 92.9% for omeprazole and 39.8% and 82.0% for ranitidine (per protocol analysis). Results were similar when analyzed as intention to treat (p significant in favor of omeprazole). Epigastric day-time pain was the most common of all symptoms (89.2%), but only heartburn at day 15 showed a significantly better response to omeprazole than to ranitidine. A multivariate analysis (logit analysis) showed that the odds in favor of healing were greater for small ulcers, nonsmokers, and omeprazole treatment.

Duodenal ulcer and eradication of Helicobacter pylori in a developing country. An 18-month follow-up study

Forty-eight patients with endoscopically proven duodenal ulcer (DU) and Helicobacter pylori infection detected by 14C-urea breath test (BT) were assigned to 5 days of treatment with furazolidone, metronidazole, and amoxicillin in addition to eventual classical anti-ulcer agents if necessary. Clinical evaluation and BT were repeated at 2, 6, and 18 months after therapy to determine H. pylori eradication or reinfection. Endoscopy was also repeated at 6 and 18 months after treatment to detect DU relapse. In 29 (60%) patients H. pylori had been eradicated at 2 months after therapy, and in 19 (40%) infection persisted. After successful eradication, 6 of 29 (20.7%) were reinfected. All 24 patients who were negative at the 18-month evaluation were asymptomatic, free of anti-ulcer drugs, and with healed ulcers, whereas among the 19 positive patients followed up, 11 (57%) continued to be symptomatic and still using anti-ulcer agents (p less than 0.010), and 10 (53%) showed active ulcers at endoscopy (p less than 0.010). H. pylori eradication is clearly followed by long-term remission of DU. Reinfection may be an additional problem in treating DU patients in developing countries.

Evaluation of the routine use of the nasogastric tube in digestive operation by a prospective controlled study

This prospective, randomized controlled trial was undertaken to evaluate the effect of tube decompression of the stomach after surgical procedure on the digestive tract. One hundred and nine patients were randomly allocated to postoperative treatment with (57 patients) or without (52 patients) nasogastric tubes. No significant differences were found between the two groups in the duration of hospitalization, time to begin peroral fluid intake, occurrence of hiccups, vomiting, nausea, parotiditis, nasal septum necrosis, anastomotic leak and wound dehiscence. Moreover, abdominal distension, pyrosis, otalgia, dysphagia, odynophagia and atelectasis occurred more often in intubated patients as shown by chi-square analysis of the data with Yates correction, with the level of significance at p = less than 0.05. Tube decompression of the stomach does not relieve intestinal paralysis after digestive operations. These data seem to indicate that the routine prophylactic use of a nasogastric tube is unnecessary in gastrointestinal operations.

A simple and economical modification of the Masson-Fontana method for staining melanin granules and enterochromaffin cells

Enterochromaffin cells from the small intestine of man, guinea pig, dog, chicken, rabbit, cat and rat were stained using the Masson-Fontana ammoniacal silver method with varying dilutions of silver nitrate solution (0.25 to 5 g per 100 ml of distilled water) and incubation temperatures (60 C and 75 C). The 0.5% solution of silver nitrate gave an argentaffin pattern similar to that of the 5% solution and had two major advantages: economically, since much less silver nitrate is used, and methodologically, since low background resulted with tissue of those species (rat, cat and rabbit) that required unusually long incubation. The staining of melanocytes was similar for all dilutions at the usual staining time (15-30 min).