High-Fat-Diet-Induced Obesity Produces Spontaneous Ventricular Arrhythmias and Increases the Activity of Ryanodine Receptors in Mice

Ventricular arrhythmias are a common cause of sudden cardiac death, and their occurrence is higher in obese subjects. Abnormal gating of ryanodine receptors (RyR2), the calcium release channels of the sarcoplasmic reticulum, can produce ventricular arrhythmias. Since obesity promotes oxidative stress and RyR2 are redox-sensitive channels, we investigated whether the RyR2 activity was altered in obese mice. Mice fed a high fat diet (HFD) became obese after eight weeks and exhibited a significant increase in the occurrence of ventricular arrhythmias. Single RyR2 channels isolated from the hearts of obese mice were more active in planar bilayers than those isolated from the hearts of the control mice. At the molecular level, RyR2 channels from HFD-fed mice had substantially fewer free thiol residues, suggesting that redox modifications were responsible for the higher activity. Apocynin, provided in the drinking water, completely prevented the appearance of ventricular arrhythmias in HFD-fed mice, and normalized the activity and content of the free thiol residues of the protein. HFD increased the expression of NOX4, an isoform of NADPH oxidase, in the heart. Our results suggest that HFD increases the activity of RyR2 channels via a redox-dependent mechanism, favoring the appearance of ventricular arrhythmias.

IL-17A levels increase in the infarcted region of the left ventricle in a rat model of myocardial infarction

Th17 cells, a recently described subtype of CD4+ effector lymphocytes, have been linked to cell-mediated autoimmune and inflammatory diseases as well as to cardiovascular diseases. However, the participation of IL-17A in myocardial ischemic injury has not been clearly defined. We therefore conducted the present study to evaluate IL-17A and Th17-related cytokine levels in a rat model of myocardial infarction (MI). MI was induced in male Sprague Dawley rats by coronary artery ligation. Controls were sham-operated (Sh) or non-operated (C). Blood and samples from the left ventricle (LV) were collected at weeks 1 and 4 post-MI. At week 1, MI animals exhibited increased IL-6, IL-23 and TGF-β mRNA levels with no apparent change in IL-17 mRNA or protein levels in whole LV. Only TGF-β mRNA remained elevated at week 4 post-MI. However, further analysis revealed that IL-17A mRNA and protein levels as well as IL-6 and IL-23 mRNA were indeed increased in the infarcted region, though not in the remote non infarcted region of the LV, except for IL-23 mRNA. The increased expression of IL-17A and Th17-related cytokines in the infarcted region of LV, suggests that this proinflammatory pathway might play a role in early stages of post MI cardiac remodelling.

On the occurrence of Anaecypris hispanica, an extremely endangered Iberian endemism, in the Guadalquivir River basin

The jarabugo Anaecypris hispanica, considered endemic to the Guadiana River basin, has been found in the Guadalquivir River. First genetic data showed a high degree of similarity to those of the Guadiana River populations. The genetic study recovered five different groups of haplotypes, the Guadalquivir River specimens belong to the largest and most widely extended group.

[Associated clinical features in 41 patients with anal epidermoid carcinoma, studied at a cancer center]

OBJECTIVE

To investigate the main associated clinical characteristics in a group of patients with squamous cell carcinoma of the anus.

BACKGROUND

Anal carcinoma is associated with sexually transmitted viral carcinogenesis.

MATERIAL AND METHODS

We analyzed the charts of patients with squamous cell carcinoma of the anus treated during 1994 and 1995. Demographic characteristics, presence of HIV-1, sexual behavior and the presence of anal warts were analyzed.

RESULTS

There were 41 patients, 26 females and 15 males with a mean age of 61 and 45 years respectively. Twenty-three patients (56%) had history of anal intercourse, 17 (41%) had anal warts and 12 (29%) were HIV-1 (+). This factors were observed more frequently in the male population (p < 0.001). The patients who had anal intercourse had more frequently anal warts and HIV-1(+) compared with those who did not (p < 0.001 in both). The HIV-1 (+) patients had more frequently anal intercourse and anal warts than those HIV-1(-) (p < 0.001 in both).

CONCLUSION

1) male population develop squamous cell carcinoma of the anus earlier than female population, 2) there is a high incidence of homosexuality, anal warts and HIV-1(+) in the male population; these findings suggest different mechanism of carcinogenesis in both gender.

[Colitis cystica profunda. A case report]

OBJECTIVE

To present a pathology not previously informed in national literature.

BACKGROUND

Colitis cystica profunda (CCP) is a rare benign entity and with an unknown etiology. There are 148 cases documented in world literature at the present time. Histologically it is defined as the obliteration of lamina propria by fibroblasts and the presence of submucous cysts. It comes in localized, segmental or diffuse forms and associated to other entities as solitary rectal ulcer, rectal prolapse, alterations in the pelvic floor, etc. Treatment can be medical or surgical according to severity of its manifestations.

METHOD

A case of CCP is revised as well as the treatment effectuated.

RESULTS

A case of patient with the diagnosis of CCP of localized type is presented, which principal symptom was transanal mucous secretion; on physical exploration a sessile mucous polypoid formation at 8 cm from anal verge was found and was treated with surgical resection with a satisfactory outcome.

CONCLUSIONS

In a patient with alterations in pelvic floor or puborectal bundle contraction and sigmoidorectal intussusception CCP must be suspected. Treatment can be medical with a high percentage of failure being optimal treatment the surgical one.

[Colonic adenoma: risk factors for their malignant transformation]

BACKGROUND

Almost all colorectal cancers develop from adenomatous polyp, its detection and resection prevent the malignization. Several adenoma characteristics like: number, size, morphology, histologic type and grade of dysplasia have become considered as malignization risk factors.

AIMS

This study was designed to determine the frequency of colorectal adenoma and the principal risk factors for malignization.

METHODS

Between June of 1989 and July of 1994, 846 colonoscopies were performed and retrospectively analyzed in the same number of patients. The patients with colorectal polyps were chosen for the analysis of this study as well all the polyps characteristics, to determine the risk factors for malignization.

RESULTS

There were 183 patients (21.6%) with 322 colorectal polyps. Of all of them, only 214 (66.4%) underwent colonoscopy snare resection and were studied; 120 (57%) were neoplastic polyps and 94 (43%) non neoplastic; among those neoplastic polyps, 100 (83.4%) were tubular adenomas, 11 (9.1%) were tubulovillous adenomas, and 9 (7.5%) were villous adenomas. We found 16 (7.4%) polyps with adenocarcinoma, 14 (87.5%) were found in patients older than 50 years of age and in polyps larger than 1 cm in diameter (p 0.040). Eleven (68.7%) were sessiles (p 0.001).

CONCLUSIONS

After the evaluation of polyps, the tubular adenomas were the neoplastic polyps more frequently found. In this particular study, the patient age, polyp size and morphology were the more statistically significant risk factors for malignization in our patient group.