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Biomedical subjects

A Alves

Publications and source records attributed to A Alves.

At least 37 records · Page 2Linked to original sources

[Diagnostic and therapeutic strategy in duodenal diverticular bleeding: report of two cases and review of the literature].

Host of the duodenal diverticulum are asymptomatic and located on the second part of the duodenum; these diverticula may induce major haemorrhage on rare occasions. We report on two patients who presented with massive upper gastrointestinal bleeding originating from a duodenal diverticulum. One patient was successfully treated by endoscopy and the other patient required diverticulectomy with successful outcome.

Aged↗

[Surgical management for slow-transit constipation].

Less than 10% of patients with slow-transit constipation require surgical management after failure of medical treatment. Preoperative clinical, psychological and colorectal routine investigations (ie colonic transit test, anorectal manometry and defecography) are mandatory in order to highly select the patients. To day, the surgical management of slow-transit constipation consists of subtotal colectomy with ileorectal anastomosis, eventually by laparoscopic approach. Although, surgical management improves slow-transit constipation in two thirds of the patients, small bowel obstruction, abdominal pain and constipation recurrence can occur in 25%, 50%, and 10% of the patients respectively.

Constipation↗

Acute bacterial cystitis does not cause deoxyribonucleic acid damage detectable by the alkaline comet assay in urothelial cells of dogs.

Considering the high incidence of dogs with acute bacterial cystitis (BC) and the relationship among inflammation, genotoxicity, and carcinogenesis, we conducted a case-control study comparing the frequency of deoxyribonucleic acid (DNA) lesions assessed by the comet assay between disease-free animals (13 males and 13 females) and cytology-confirmed cases of acute BC (12 males and 12 females), which was mainly caused by Staphylococcus sp. (40%) and Escherichia coli (35%). The results show no increase in DNA damage in cells obtained by bladder washings and no influence of age, sex, and breed due to acute BC. In conclusion, DNA damage was seemingly not associated with the infection by specific bacteria.

Animals↗

Heterocyclic acetals in Madeira wines.

The maturation of Madeira wines usually involves exposure to relatively high temperatures which affect the aroma and flavour composition leading to the formation of the typical and characteristic bouquet of these wines. The formation of heterocyclic acetals (1,3-dioxanes and 1,3-dioxolanes) was investigated in order to determine levels and for possible use as indicators of wine age. The results show a linear correlation of the investigated acetals with wine age but suggest that the acetalization reaction is not particularly affected by the drastic oxidative conditions observed during maturation.

Acetals↗

Hepatic resection for metastatic renal tumors: is it worthwhile?

BACKGROUND: Liver metastases of malignant renal tumors are regarded as having an ominous prognosis because they are infrequently amenable to radical surgery and respond poorly to chemotherapy. Little is known of the outcome of isolated metastases to the liver for which resection is potentially curative. METHODS: Data on 14 patients with liver metastases from renal tumors who underwent a liver resection in a single center between 1982 and 2001 were analyzed retrospectively. RESULTS: There was no operative or postoperative mortality. The median survival was 26 months, with a survival rate of 69% at 1 year and 26% at 3 years. The curative pattern of hepatectomy (2-year survival, 69% vs. 0%; P =.001), an interval between the nephrectomy and the diagnosis of liver metastases in excess of 24 months (2-year survival, 71% vs. 25%; P =.05), tumor size <50 mm (2-year survival, 83% vs. 17%; P =.006), and the possibility of achieving a repeat hepatectomy in the case of recurrence (2-year survival, 100% vs. 21%; P =.02) were associated with a better outcome after the liver resection. Four patients were alive without evidence of disease at 6, 12, 26, and 96 months after the first hepatic resection, and one was alive with hepatic recurrence 18 months after resection. CONCLUSIONS: In patients with liver metastases of malignant renal tumors, an aggressive policy for achieving tumor eradication seems to offer a chance for long-term survival, especially after a long disease-free interval from the nephrectomy. However, despite an aggressive policy for achieving tumor eradication, recurrence frequently occurs after liver resection.

Adult↗

p63: a novel myoepithelial cell marker in canine mammary tissues.

Several immunohistochemical markers have been used to demonstrate the presence of myoepithelial cells in order to determine their role in the histogenesis of mammary tumors. p63, a recently characterized p53 homologue, is consistently expressed in myoepithelial cells of the human breast; however, no assessment of its immunoreactivity has been reported so far in canine mammary tissues. We investigated p63 immunohistochemical expression, as a novel myoepithelial cell nuclear marker, in 81 samples of normal (n = 2), hyperplastic (n = 11), and neoplastic (n = 68) canine mammary tissues. Myoepithelial phenotype was confirmed by using complementary monoclonal antibodies: alpha-smooth muscle actin, cytokeratin 14, cytokeratin AE1/AE3, and vimentin. p63 expression was observed in 91.4% (74/81) of the samples evaluated. Normal mammary glands, mammary hyperplasias, and benign tumors showed 100% immunoreactivity, with p63 expression restricted to myoepithelial cell nuclei. In general, benign mixed tumors showed a basal cell compartment immunoreactive to p63, with a gradual decrease of its expression during myoepithelial transformation. p63 expression was found in 72% of malignant tumors, allowing myoepithelial or basal cell identification in spindle-cell carcinomas (2/2), tubulopapillary carcinomas (8/9), solid carcinomas (7/10), and carcinosarcomas (1/3). The osteosarcoma analyzed was p63 negative. In our series, stromal components were consistently nonreactive to p63. In conclusion, the present study reveals p63 as a sensitive and highly specific marker of myoepithelial cells in canine mammary tissues, and the authors suggest p63 as an additional marker for defining myoepithelial histogenesis.

Animals↗

Direct determination of chlorophenols in landfill leachates by solid-phase micro-extraction-gas chromatography-mass spectrometry.

Landfill leachates represent a serious environmental concern with regard to trace priority pollutants introduced into the aquatic environment. From the analytical point of view, they constitute complex matrices because of their high organic matter content and competition with the trace analytes in the extraction procedure. Although the use of SPME to extract chlorophenols in leachates has already been described in several publications, the limited number of chlorophenols restricts this analysis field of application. This paper presents a new analytical methodology to determine 13 chlorophenols and phenol by SPME-GC-MS in landfill leachates. The overall analysis was performed in 90 min and the detection limits range from 0.005 microg/l (pentachlorophenol) to 2.5 microg/l (phenol). Reproducibility, expressed by the coefficient of variation of repeated extractions at different concentration levels of the analytes, was on average inferior to 10%. Recovery, evaluated by standard addition to leachates, was 86.2% on average. Pentachlorophenol, 2,3,4,5-tetrachlorophenol and 2,3,4,6-tetrachlorophenol were the sole analytes detected at nanogram level in the landfill leachates analysed.

Chlorophenols↗

[Diagnostic and therapeutic strategy for an incidental finding of an adrenal mass].

The incidental finding of an unsuspected adrenal mass ranges from 0.5% to 5% in abdominal CT series. The optimal diagnostic approach to such masses is to diagnose malignant or secretory tumors requiring excision and to otherwise avoid unnecessary surgery. Physical examination generally contributes little. A standard biochemical evaluation should include the measurement of 24 hour urinary catecholamines and metanephrine, urinary free cortisol and plasma cortisol levels at 8 a.m. and 8 p.m. combined with an overnight low-dose dexamethasone suppression test, serum potassium assay, and determination of upright plasma aldosterone to plasma renin activity. These tests will serve to screen for pheochromocytoma, subclinical Cushing's syndrome, and primary hyperaldosteronism respectively. Imaging characteristics suggestive of malignancy include: size greater than 4 cm., heterogeneous lesion and/or density greater than 20 Hounsfield Units on CT scan, slow enhancement with delayed washout after intravenous contrast injection on CT scan, and slightly decreased signal intensity in out of phase (fat suppressed) MR acquisition. Fine-needle aspiration biopsy should be performed only if metastatic disease is suspected. Adrenal scintigraphy with iodocholesterol may be useful where adenoma with subclinical Cushing's syndrome or solid tumor is suspected. In summary, the following strategy is recommended for the management of adrenal incidentalomas : mass lesions larger than 4 cm. and hormone-secreting tumors should be removed. All non-secreting adrenal incidentalomas smaller than 4 cm. in diameter should be followed by serial imaging at regular intervals (6, 12, and 36 months) and by endocrine reevaluation at one year.

Adrenal Cortex Function Tests↗

Identifying patients with T3-T4 node-negative colon cancer at high risk of recurrence.

PURPOSE: Adjuvant chemotherapy is effective for node-positive colon cancer patients. In node-negative patients, it could be justified in high-risk patients. The purpose of this study was to determine clinical and pathological findings associated with tumor recurrence in T3-T4 node-negative colon cancer patients. METHODS: From 1974 to 1993, 108 patients undergoing colectomy for T3-4N0M0 colon cancer, without adjuvant chemotherapy, followed until death or for a minimum of five years, were divided into two groups: patients without recurrence (n = 74) and those dead from colon cancer or alive with recurrence (n = 34). Thirty-three clinical and pathological findings were studied. RESULTS: In univariate analysis, the following were significantly associated with a high risk of tumor recurrence: male patients (P = 0.006), bowel obstruction (P < 0.001), weight loss >5 Kg (P = 0.03), circumferential tumor (P = 0.02), macroscopic or microscopic pericolic organ invasion (T4 stage; P < 0.001), perineural invasion (P = 0.02), vascular invasion (P = 0.045), poor tumor differentiation (P = 0.005), mesocolic invasion >1 cm (P = 0.009), less than 14 uninvolved nodes on the specimen (P = 0.03), and visceral peritoneal invasion (T4; P < 0.001). In multivariate analysis, the following were independent prognostic factors of recurrence: male patients (P = 0.005), bowel obstruction (P = 0.002), pericolic organ invasion (i.e., T4 tumor; P = 0.02), and less than 14 uninvolved nodes on a specimen (P = 0.01). On the other hand, preoperative carcinoembryonic antigen serum level, size and tumor location, blood transfusion, and mucin production were not associated with higher risk of tumor recurrence. CONCLUSION: Our study identifies a subgroup of patients with node-negative colon cancer at high risk of recurrence, who could be included in priority trials of adjuvant chemotherapy.

Adult↗

Development of a SPME-GC-ECD methodology for selected pesticides in must and wine samples.

A method for the determination of some pesticide residues in must and wine samples was developed using solid-phase microextraction (SPME) and gas chromatography-electron capture detection (GC/ECD). The procedure only needs dilution as sample pre-treatment and is therefore simple, fast and solvent-free. Eight fungicides (vinclozolin, procymidone, iprodione, penconazole, fenarimol, folpet, nuarimol and hexaconazole), one insecticide (chlorpyriphos) and two acaricides (bromopropylate and tetradifon) can be quantified. Good linearity was observed for all the compounds in the range 5-100 microg/L. The reproducibility of the measurements was found acceptable (with RSD's below 20%). Detection limits of 11 microg/L, on average, are sufficiently below the proposed maximum residue limits (MRL's) for these compounds in wine. The analytical method was applied to the determination of these compounds in Portuguese must and wine samples from the Demarcated Region of Alentejo, where any residues could be detected.

Chromatography, Gas↗

Mushroom poisoning with Amanita phalloides - a report of four cases.

Amanita mushroom poisoning is a rare but serious occurrence. Physicians need to recognize the phalloides syndrome promptly and to institute effective treatment as soon as possible in order to avoid the often fatal complications. The authors report four cases of Amanita poisoning, two of which resulted in fulminant hepatic failure and required orthotopic liver transplantation. The clinical symptoms and signs, laboratory alterations, and therapeutic options available are discussed.

Journal Article↗

Predictive factors for perioperative blood transfusions in rectal resection for cancer: A multivariate analysis of a group of 212 patients.

BACKGROUND: In colorectal cancer surgery, allogeneic blood transfusions have reportedly been associated with higher rates of postoperative complications and tumor recurrence. However, because of the increased cost of alternative types of blood transfusions (eg, the use of autologous blood or erythropoietin administration), their routine use cannot be recommended. This study evaluated the risk factors for perioperative blood transfusions in resection for rectal cancer in order to identify patients who could benefit from these methods. METHODS: From 1990 to 1997, 212 consecutive patients who underwent elective rectal resection for cancer were reviewed. The associations between perioperative heterologous blood transfusion and 18 patient-, tumor-, surgical-, and treatment-related variables were assessed by univariate and multivariate analysis. RESULTS: Of the 212 patients, 72 (34%) received transfusions. Multivariate analysis revealed that 5 preoperative variables were significant risk factors for perioperative blood transfusion: age > 65 years (P =.03), body mass index > 27 kg/m(2) (P =.04), preoperative hemoglobin < or = 12.5 g/dL (P <.0001), American Society of Anesthesiologists status > 2 (P =.024), and additional surgical procedures (P =.018). In patients with anemia, the risk of transfusion was at least 47% in patients with 1 other risk factor or more. In nonanemic patients, the risk of transfusion was under 11% in patients with 1 risk factor or none, but increased to 47% in those with 2 or more risk factors. CONCLUSIONS: Our analysis of risk factors for perioperative blood transfusion in rectal resection for cancer must be considered to constitute guidelines for a more responsible use of the expensive alternatives to allogeneic blood transfusion.

Aged↗

Morphological aspects of rabbit masseter muscle after cervical sympathectomy.

The objective of this paper was to study the effect of sympathetic innervation on morphological and histochemical aspects of skeletal muscle tissue. Rabbit masseter muscle was studied using histochemical and immunohistochemical methods for periods of up to 18 months post-sympathectomy. The morphological and enzymatic characteristics of control masseter muscles were similar on both the left and right sides. The main features were muscle fibres with a mosaic pattern and a predominance of type IIa fibres, followed by type I. Type IIb fibres showed very low frequency. Sympathectomized animals showed varying degrees of metabolic and morphological alterations, especially 18 months after sympathectomy. The first five groups showed a higher frequency of type I fibres, whilst the oldest group showed a higher frequency of type IIb fibres. In the oldest group, a significant variation in fibre diameter was observed. Many fibres showed small diameter, atrophy, hypertrophy, splitting, and necrosis. Areas with fibrosis were observed. Thus cervical sympathectomy induced morphological alterations in the masseter muscles. These alterations were, in part, similar to both denervation and myopathy. These findings indicate that sympathetic innervation contributes to the maintenance of the morphological and metabolic features of masseter muscle fibres.

Adipose Tissue↗

[Can common bile duct lithiasis be removed laparoscopically without external biliary drainage?].

AIM OF THE STUDY: To evaluate the indications, feasibility and results of laparoscopic treatment of common bile duct stones without biliary drainage. PATIENTS AND METHODS: Between 1992 and 1999, laparoscopic procedures were performed in 70 consecutive patients, mean age 60 +/- 15 years (range: 18-82). Stone removal was attempted via the cystic duct (n=25) or choledocotomy (n=45). The emptiness of the common bile duct was checked by intraoperative cholangiography or endoscopy. After choledocotomy, closure was performed by interrupted or non-interrupted suture with slowly resorbable thread. Transcystic drainage was used whenever necessary. RESULTS: Nine conversions to laparotomy were necessary (12.8%). Among the 61 patients who had an exclusively laparoscopic procedure, 21 were treated via the transcystic route and 40 through choledocotomy. Biliary endoscopy was possible in only 10 of the 21 patients (47.6%) treated via the transcystic route and in all with choledocotomy. No biliary drainage was used in 16 of the 21 patients treated via the transcystic route and in 39 of the 40 treated through choledocotomy. The 30-day mortality was 1/61 (1.6%). Morbidity was 9.8% and 2 patients underwent a second laparoscopic procedure (one fistula on a choledocotomy suture, one hemoperitoneum of unknown origin). An endoscopic sphincterotomy for residual stone was necessary in 4 patients (4/61, 6.5%), 2 after choledocotomy for an unrecognized stone without biliary drainage. CONCLUSIONS: These results confirm the feasibility of laparoscopic treatment of common bile duct stones and suggest it can be performed without biliary drainage in most cases.

Adolescent↗

Monitoring organochlorine pesticides from landfill leachates by gas chromatography-electron-capture detection after solid-phase microextraction.

Landfill leachates contain significant amounts of organic carbon, nitrogen and heavy metals as well as other specific trace organic compounds like organochlorine pesticides. In this study a simple and reliable methodology was improved to detect organochlorine pesticides in leachate samples by using a previous solid-phase microextraction procedure [with a 100 microm poly(dimethylsiloxane) fiber] and chromatographic analysis by GC-electron-capture detection. The extraction time, temperature, ionic strength of the solution and sampling of the headspace were the parameters studied. Reproducibility achieved values below 20% RSD, and standard addition was used for pesticides confirmation.

Chromatography, Gas↗