Biomedical subjects
G Delgado
Publications and source records attributed to G Delgado.
Process of Carbonate Precipitation by Deleya halophila
Scanning electron microscopy and X-ray dispersive energy microanalysis were used to investigate the formation of carbonate crystals by Deleya halophila. The formation of calcium carbonate crystals (polymorphous aragonite) by D. halophila is a sequential process that commences with a nucleus formed by the aggregation of a few calcified bacterial cells and the subsequent accumulation of more calcified cells and carbonate, which acts to weld the bacteria together. The process leads to the formation of spherical bioliths measuring approximately 50 &mgr;m in diameter. The mechanism of carbonate precipitation by D. halophila under our working conditions represents a process of induced biomineralization.
Bioactive polyacetylenes from Bidens pilosa.
From the methanolic extract of the whole plants of Bidens pilosa the new beta-D-glucopyranosyloxy-3-hydroxy-6(E)-tetradecen-8, 10,12-triyne besides a known polyine has been isolated and identified mainly by IR and NMR methods. The new compound showed overgrowing action against normal and transformed human cell lines in culture.
[Mitomycin C for the treatment of superficial tumors of the bladder (Tis-Ta-T1) with one or more risk factors. Argentinian Cooperative Group of Oncourology (GCAO)].
OBJECTIVES: To determine the efficacy and toxicity of intravesical mitomycin C in superficial bladder tumors (Tis Ta T1) completely resected with one or more risk factors. (Protocol U. 01/90). METHODS: The patients received six instillations weekly of 40 mg mitomycin C within 15 days post-TUR of a superficial bladder tumor with one or more risk factors: histological grade 3, tumor size more than 3 cm and/or multicentric lesion. The patients were evaluated by cystoscopy every three months for the first two years and every six months thereafter. Toxicity was evaluated according to Miller's score. Tumor recurrence, disease-free interval and survival were analyzed. RESULTS: 126 patients were entered into the study; of these, 110 were evaluable. At 18 months mean follow-up (range 6-36 months), 77 patients (70%) remain disease-free; the mean time to recurrence was 13.8 months. There were no differences between patients with one, two or three risk factors or those who received or did not receive previous treatments. The patients tolerated the treatment well; there were no dropouts or systemic toxicity. CONCLUSIONS: 1. At 18 months mean follow-up, 77 of 110 patients (70%) remain disease-free; 2. The mean time to recurrence was 13.8 months; 3. Local toxicity was minimal; 4. There were no dropouts due to toxicity; 5. Systemic toxicity was not observed.
Retroperitoneal radical hysterectomy.
A surgical technique is presented which combines both the abdominal and vaginal approaches to radical hysterectomy with significant modifications to allow it to be named "retroperitoneal" radical hysterectomy. Small oblique skin incisions are made 1 cm superior to the inguinal ligament exposing the retroperitoneal structures. The round ligament, uterine artery, ovarian vessels, and cardinal ligament are divided without entering the peritoneal cavity. The remainder of the procedure is completed by a modified Schauta technique. Eight patients with Stage I cancer of the cervix underwent this operation. The expected surgery time should be 3 1/2-4 hr once the surgical team becomes familiar with the procedure, with a blood loss similar to that of the Meigs procedure. Patients tolerated the procedure with minimal discomfort. Total hospital days was limited to 4 days or less in all but the first patient. One patient was discharged on the evening of surgery. No significant complications were reported except some degree of bladder atony that required self-catheterization for a short period of time. We believe that this surgical procedure fulfills the principles of a radical abdominal hysterectomy with less operative time and shorter hospital stay, and employs conventional surgical skills.
The role of p53 and HPV in cervical cancer.
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Bilateral pallidostriatal necrosis caused by a wasp sting: a clinical and pathological study.
A previously healthy man developed an acute encephalopathy with coma after a single wasp sting on his chin. Brain CT showed bilateral pallidostriatal radio-lucencies. He died 72 hours after the sting with no evidence of primary cardiorespiratory failure or allergic reaction. Pathological findings were bilateral pallidostriatal necrosis and diffuse neuronal damage in the frontal, temporal, and parietal cortex. The neurotoxic effect of the poison, together with a hypersensitivity are the most likely explanations for this unusual encephalopathy.
Diurnal variations in the fatty acid composition of milk fat from marginally nourished women.
This investigation was designed to test whether the composition of free fatty acids varied in the milk of a group of marginally nourished women, throughout the day in response to their habitual pattern of eating. Ten fully lactating women, aged 19 - 29 years, weighing 53.3 +/- 7.7 kg, with a mean height of 145.5 +/- 4.5 cm volunteered for the study. They ate two standardized meals a day at 8 and 16 h. Milk samples were pumped out every 4 h, for a period of 24 h, starting at 8:00 A.M. Milk fat was extracted with hexane and the fatty acid content was determined in a gas chromatograph. No changes were noted in the mean diurnal pattern of individual fatty acids throughout the day. Saturated medium-chain (MCFA), and long-chain fatty acids (C16:0, C18:0) were significantly lower and unsaturated long-chain fatty acids (C16:1, C18:1, C18:2) (UFA) were higher than that of reference well nourished women. Analyzed by individual cases, the changes in the sum of UFA were followed by mirror changes in MCFA. Diurnal peaks of total fat were associated with the peak of UFA, whereas troughs of total fat were associated with troughs of UFA but peaks of MCFA. It is suggested that the low total milk fat reported in these women might be the combined result of a limited intake of dietary fat and a limited ability of the mammary tissue to synthesize de novo fatty acid.
Vulvar reconstruction using a mons pubis pedicle flap.
The treatment of early vulvar carcinoma has moved toward less radical surgery with reconstruction. This report describes our preliminary experience with a mons pubis flap that is simple and appears safe, reliable, and gives excellent cosmetic and functional results following radical hemivulvectomy. Four patients have undergone this procedure with excellent results. The flap brings pliable, hair-bearing skin which authentically mimics the normal side, thus providing good sexual function. The mons pubis pedicle flap should be considered in patients undergoing radical hemivulvectomy where an excellent cosmetic result is desirable.
Thrombocytosis in surgically treated stage IB squamous cell cervical carcinoma (A Gynecologic Oncology Group study).
Thrombocytosis has previously been shown to be an unfavorable prognostic factor in cervical cancer patients treated with irradiation. We evaluated the significance of thrombocytosis (platelet count > 400 x 10(9)/liter in 623 surgically treated patients with stage IB squamous cell carcinoma of the cervix. These patients had no gross evidence of extrauterine disease at the time of exploration, and none had metastasis to the para-aortic nodes. Fifty-nine (9.5%) of these 623 patients had thrombocytosis. The 5-year survival for patients with thrombocytosis was 82% compared to 83.5% for patients with normal platelet count (P = 0.4). Pelvic node metastasis was present in 13 (22%) of 59 patients with thrombocytosis, and 77 (13.7%) of 564 patients with normal platelet count (P = 0.1). There was a significant correlation between tumor size and platelet count. Patients with thrombocytosis had a mean tumor size of 27.9 mm, while it was 20.4 mm in patients without thrombocytosis (P = 0.002). Other factors found to be associated with thrombocytosis in this population were elevated white blood cell (WBC) count (P = 0.009) and history of chronic obstructive pulmonary disease (COPD) (P = 0.02). In a multivariate analysis for thrombocytosis adjusted for COPD, WBC count, and tumor size, tumor size continued to be statistically significant (P = 0.01). These data suggest that thrombocytosis is a marker of tumor burden and not an independent prognostic factor for progression-free interval or survival.
Magnetic resonance angiography in meningovascular syphilis.
Meningovascular neurosyphilis (MN) is an unusual cause of stroke in young adults. The clinical manifestations include prodromal symptoms weeks or months before definitive stroke. The diagnosis is based on clinical findings and examination of the serum and cerebrospinal fluid. We report a case of MN with basilar artery irregularities demonstrated by magnetic resonance angiography.
Detection of human herpesvirus-6 in paraffin-embedded tissue of cervical cancer by polymerase chain reaction.
The polymerase chain reaction (PCR) was used to detect human herpesvirus-6 (HHV-6) DNA sequences from paraffin-embedded tissue from cervical cancer patients. Two of eight cases were positive for HHV-6 using two sets of HHV-6 primers. Hybridization of PCR products with specific radioisotope-labeled oligonucleotide probes confirmed the results. Furthermore, HHV-6 typing was possible by adapting restriction endonuclease digestion of PCR product. This method is useful for retrospective studies in investigating the etiologic role of HHV-6 in the development of human diseases.
Cytotoxic and antimicrobial screening of selected terpenoids from Asteraceae species.
Twelve pure compounds originally obtained through a systematic chemotaxonomical study with Mexican plants of the Asteraceae, were subjected to a cytotoxic and in vitro antimicrobial screening. Three different cell lines in culture (KB, KB-VI and P388) were used in the cytotoxicity assay, while antimicrobial activity was tested against Gram-positive and Gram-negative bacteria, as well as Candida albicans. Of the twelve terpenoids tested, only taraxasterol showed antimicrobial activity against Staphylococcus aureus. The significant cytotoxic activity exhibited by five sesquiterpene lactones, and the moderate cytotoxicity of an eudesmane, is discussed.
Non-O1 Vibrio cholerae O139 Bengal is genetically related to V. cholerae O1 El Tor Ogawa isolated in Mexico.
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Detection of human herpesvirus 6 and human papillomavirus 16 in cervical carcinoma.
A subset of human papillomaviruses (HPVs) is associated with the majority of cervical cancers; however, cofactors appear to be required for carcinogenic progression of HPV-induced neoplasia. As human herpesvirus-6 (HHV-6) was recently shown to infect cervical epithelial cells in vitro and activate transcription of HPV-transforming genes, human cervical dysplasia and cancers were analyzed for the presence of HHV-6 by multiple methods, including polymerase chain reaction, slot blot, Southern blot, and in situ hybridization. HHV-6 DNA sequences were detected in 6 of 72 cases of squamous cervical carcinoma and cervical intraepithelial neoplasia. HPV-16 was found in four of the HHV-6-positive cases (two squamous cervical carcinomas and two cervical intraepithelial neoplasias). None of the 30 normal cervices and biopsies of patients with cervicitis was positive for HHV-6 DNA. These results are the first suggestion of an in vivo association between HHV-6 and some cervical neoplasia.
[Multiple cerebral cavernous angiomas and magnetic resonance].
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Colonic surgery in gynecologic oncology. Risk factor analysis.
Colonic surgery is a critical part of gynecologic oncology care. A 12-year review of colonic surgery on a gynecologic oncology service was performed evaluating risk factors and their impact on postoperative morbidity. There were 124 procedures performed on 92 patients; 9 patients had no prior surgery, chemotherapy or radiation. Fifty-six percent of the patients were considered malnourished on the basis of a serum albumin level < 3.5 g/dL. The 124 procedures consisted of 57 colon resections with primary reanastomosis, 10 small bowel-colon bypass procedures and 57 colostomies. Of the 57 (67%) colostomy operations, 38 also had concomitant abdominal-pelvic procedures. There were 15 major bowel complications and 17 major systemic postoperative complications. Prior surgery and poor nutritional status significantly correlated with postoperative morbidity; however, prior radiation did not reveal an increased risk for postoperative complications.
Histopathologic predictors of the behavior of surgically treated stage IB squamous cell carcinoma of the cervix. A Gynecologic Oncology Group study.
Disagreement persists about the superiority of Reagan and Ng's method over that of Broders' for the histologic grading of squamous carcinoma of the cervix. Uncertainty about the predictive value and reproducibility of any of the grading methods prompted a comparison of factors previously suggested as indicating the biologic behavior for cervical squamous carcinoma. One hundred ninety-five women, who were enrolled in a Gynecologic Oncology Group treatment protocol of Stage IB squamous carcinoma of the cervix and underwent radical hysterectomy with pelvic and paraaortic node sampling, formed the study population. The tumors were graded first by participating institutional pathologists, with submitted slides subjected to an independent review by two pathologists (R.J.Z. and S.W.). The histologic parameters examined included the presence and amount of keratinization, nuclear pleomorphism, mitotic rate, gestalt grading, pattern of invasion at the stromal interface, and inflammatory cell infiltrate. The depth of invasion and presence or absence of vascular invasion also were assessed. The probability of pelvic lymph node metastasis and the progression-free interval were determined for each parameter. Surprisingly, none of the grading methods was effective in predicting nodal spread or progression-free interval. However, an increasing depth of invasion strongly correlated with nodal spread and a diminished progression-free interval (P less than 0.0001). Vascular invasion was less effective in these predictions (0.05 less than P less than 0.10). Both measurements were reasonable reproducible. It was concluded that histologic grading of surgically treated cervical carcinoma is not useful but that the depth of invasion and vascular invasion are important predictors of behavior that should be reported routinely.