PubMed Health⌕ Search

Biomedical subjects

A Zuluaga

Publications and source records attributed to A Zuluaga.

At least 19 recordsLinked to original sources
PubMed2007

Mixed epithelial and stromal tumour of the kidney with luteinised ovarian stroma.

We report a case of a 9-cm mixed epithelial and stromal tumour of the kidney in an obese 70-year-old woman with diabetes. The ovarian-type stroma had a spindle cell component that was positive for progesterone receptors and had the hitherto unreported presence of abundant foci of luteinised stromal cells with characteristic immunohistochemical positivity to alpha-inhibin, calretinin, aromatase and gonadotropin-releasing hormone (GnRH) receptors. We conclude that the stromal component is identical to ovarian cortical stroma. We believe that ovarian-type stroma occurs in extragenital tumours as a result of an epithelial-stromal interaction in an environment of hormonal hyperstimulation.

Aged↗
PubMed2005

Pure testicular carcinoid associated with intratubular germ cell neoplasia.

This case report describes for the first time a case of pure testicular carcinoid pre-aortic lymph node metastases in a 25 year old patient with carcinoid syndrome. The simultaneous occurrence of intratubular germ cell neoplasia in the surrounding testicular tissue was identified by OCT4 and placental-like alkaline phosphatase positivity. This confirmed that the tumour had a germ cell origin in the testis, rather than being a metastasis from an extragenital carcinoid.

Adult↗
PubMed2002

Assessing the use of p16(INK4a) promoter gene methylation in serum for detection of bladder cancer.

OBJECTIVE: This study was undertaken to investigate whether hypermethylation in p16(INK4a) gene promoter could serve as plasma biomarker of bladder cancer. METHODS AND PATIENTS: We examined the p16(INK4a) status using methylation-specific PCR in 86 cancer patients and 49 controls (31 healthy people and 18 patients with benign urological diseases). RESULTS: The p16(INK4a) methylation was found in 22% of the serum samples and in 26% of the bladder cancer biopsies; one of them with carcinoma in situ. The presence of hypermethylated p16(INK4a) in serum seems to be a product from tumour cells because a strong statistical association was found between both matched DNA signals (p<0.0001). Using the control group, the presence of methylated p16(INK4a) in the serum of individuals with suspicion of bladder cancer was found to be associated with the tumour presence (p=0.0009). Aberrant p16(INK4a) methylation was also observed in one non-cancer patient, which is undergoing further assessment. CONCLUSIONS: According with our results, methylation of p16(INK4a) promoter may be involved in the bladder cancer genesis and the presence of p16(INK4a) methylated in serum of these patients could be useful in the cancer diagnosis with values of sensitivity, specificity and positive predictive value of 0.226, 0.950 and 0.98, respectively. These figures support the use of methylated p16(INK4a) as a new class of tumour marker in bladder cancer.

Aged↗
PubMed2001

Fluorescence spectroscopy of epithelial tissue throughout the dysplasia-carcinoma sequence in an animal model: spectroscopic changes precede morphologic changes.

BACKGROUND AND OBJECTIVE: The hamster cheek pouch carcinogenesis model, using chronic treatments of dimethylbenz[alpha]anthracene (DMBA) was used as a model system to investigate changes in epithelial tissue autofluorescence throughout the dysplasia-carcinoma sequence. STUDY DESIGN/MATERIALS AND METHODS: Fluorescence emission spectra were measured weekly from 42 DMBA-treated animals and 20 control animals at 337, 380, and 460 nm excitation. A subset of data in which histopathology was available was used to develop diagnostic algorithms to separate neoplastic and non-neoplastic tissue. The change in fluorescence intensity over time was examined in all samples at excitation-emission wavelength pairs identified as diagnostically useful. RESULTS: Algorithms based on autofluorescence can separate neoplastic and non-neoplastic tissue with 95% sensitivity and 93% specificity. Greatest contributions to diagnostic algorithms are obtained at 380 nm excitation, and 430, 470, and 600 nm emission. Changes in fluorescence intensity are apparent as early as 3 weeks after initial treatment with DMBA, whereas morphologic changes associated with dysplasia occur on average at 7.5-12.5 weeks after initial treatment. CONCLUSIONS: Fluorescence spectroscopy provides a potential tool to identify biochemical changes associated with dysplasia and hyperplasia, which precede morphologic changes observed in histologically stained sections.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2000

Papillary serous carcinoma of the tunica vaginalis testis.

This is a case report of a testicular papillary serous carcinoma of ovarian type (PSCOT) diagnosed in a 50-year-old man. The tumor presented in the form of multiple papillary exophytic excrescencies on the visceral tunica vaginalis testis lining the inner surface of a hydrocele sac. The tumor was histologically a papillary serous carcinoma with numerous psammoma bodies, indistinguishable from similar tumors arising on the surface of the ovary. Following the tumor's surgical removal, the patient was treated with the same drugs used to treat ovarian serous carcinomas, and he is alive two years after the initial diagnosis. PSCOT must be distinguished from mesothelioma of the tunica vaginalis testis, a tumor with a most unfavorable prognosis. As shown here, immunohistochemical findings can be useful for formulating the correct diagnosis of PSCOT.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Optimal excitation wavelengths for in vivo detection of oral neoplasia using fluorescence spectroscopy.

There is no satisfactory mechanism to detect premalignant lesions in the upper aero-digestive tract. Fluorescence spectroscopy has potential to bridge the gap between clinical examination and invasive biopsy; however, optimal excitation wavelengths have not yet been determined. The goals of this study were to determine optimal excitation-emission wavelength combinations to discriminate normal and precancerous/cancerous tissue, and estimate the performance of algorithms based on fluorescence. Fluorescence excitation-emission matrices (EEM) were measured in vivo from 62 sites in nine normal volunteers and 11 patients with a known or suspected premalignant or malignant oral cavity lesion. Using these data as a training set, algorithms were developed based on combinations of emission spectra at various excitation wavelengths to determine which excitation wavelengths contained the most diagnostic information. A second validation set of fluorescence EEM was measured in vivo from 281 sites in 56 normal volunteers and three patients with a known or suspected premalignant or malignant oral cavity lesion. Algorithms developed in the training set were applied without change to data from the validation set to obtain an unbiased estimate of algorithm performance. Optimal excitation wavelengths for detection of oral neoplasia were 350, 380 and 400 nm. Using only a single emission wavelength of 472 nm, and 350 and 400 nm excitation, algorithm performance in the training set was 90% sensitivity and 88% specificity and in the validation set was 100% sensitivity, 98% specificity. These results suggest that fluorescence spectroscopy can provide a simple, objective tool to improve in vivo identification of oral cavity neoplasia.

Algorithms↗
PubMed1996

Cervical spine trauma: how much more do we learn by routinely using helical CT?

Assessment of suspected cervical spine injuries remains a major debate in trauma care. It is generally accepted that many fractures are missed or incompletely shown at radiography, mainly because of suboptimal studies obtained in obtunded, uncooperative trauma victims. In a series of 88 severely traumatized patients, the authors retrospectively determined the type, distribution, and significance of such missed lesions. This assessment was made by comparing radiographs and helical computed tomographic (CT) scans of the cervical spine and reviewing medical records in these cases. Of the 88 patients, 32 patients had cervical spine fractures (n = 50) that were not revealed or were incompletely demonstrated at radiography. Most missed fractures occurred at the C-1 to C-2 and C-6 to C-7 levels, and most involved the transverse processes and the posterolateral elements of the vertebrae. One-third of the patients with missed fractures had either clinically significant or unstable injuries, as determined on the basis of mechanistic or imaging criteria. Helical CT can depict significant fractures not shown by plain radiography and should be added routinely to the initial screening for cervical spine fractures in polytrauma victims.

Adolescent↗
PubMed1995

Malignant large cell calcifying Sertoli cell tumor of the testis.

An otherwise normal 48-year-old man had malignant large cell calcifying Sertoli cell tumor of the testis. There were lymph node involvement and albugineal invasion at orchiectomy, and pulmonary metastases developed despite radiotherapy and chemotherapy. Our case and, to our knowledge, the only other reported case of malignant large cell calcifying Sertoli cell tumor had clinical and histopathological features related to aggressiveness, such as unusual patient age, large tumor size, cellular pleomorphism, high mitotic rate, necrosis and aneuploid deoxyribonucleic acid. Such characteristics are not found in benign large cell calcifying Sertoli cell tumors. Associated findings included granular change of the epididymal lining, probably due to compression by the large tumor.

Calcinosis↗
PubMed1994

Adenocarcinoma of the renal pelvis. A report of two cases.

Two cases of intestinal-type adenocarcinoma of the renal pelvis (ARP) in 48- and 63-year-old females are presented. Both had a previous history of urinary obstructive disease, one secondary to staghorn calculus and the other to postirradiation stenosis following treatment for carcinoma of the cervix. Immunohistochemical findings revealed marked positivity to epithelial membrane antigen and focal positivity to cytokeratins and carcinoembryonic antigen. Chronic irritation of the renal pelvis plays an important role in the pathogenesis of ARP. In one of our cases of multicentric origin, the synergistic effect of pelvic irradiation and cyclophosphamide chemotherapy in a patient with a previous squamous cell carcinoma of the cervix, may be responsible for the pathogenesis of the ARP.

Adenocarcinoma↗
PubMed1993

[Antimicrobial prophylaxis in urethrocystoscopy. Comparative study].

Instrumentation of lower urinary tract is a predisposing factor for the development of urinary infection. Incidence of infective complications following urethrocystoscopy has been evaluated in a multicenter, prospective, comparative and randomized study in 2,284 patients, who had a previous negative urine culture. Patients were randomized into two groups: one to be used as control and the other one to received antimicrobial prophylaxis prior to instrumentation (ceftriazone, 1 gr intramuscular). Clinical and microbiological responses were evaluated at 48-72 hours and 4 weeks after cystoscopy. Symptomatic bacteriuria was observed in 10.2% of patients in the control group and in 2.5% in the prophylaxis group (p < 0.000); asymptomatic bacteriuria in 3.02% and 1.52% (p > 0.05) and irritative syndrome with sterile urine in 2.93% and 2.60% (p > 0.05), respectively. Thus, the use of prophylaxis reduced the incidence of infective complications in these patients.

Adolescent↗
PubMed1989

[Parathormone, cyclic AMP, 1,25 dihydroxyvitamin D and osteocalcin in hypercalciuric renal lithiasis].

A study was undertaken in 46 subjects; 21 patients diagnosed as having HRL and 25 volunteers patients. Biochemical and hormonal analyses were performed in the study population, including determination of Ca, P, Mg, Cr in blood and urine, phosphate tubular resorption (PTR), maximum tubular phosphate resorption (MTPR), fasting calcium secretion (FCS), alkaline phosphatase (AP), hydroxyprolinuria (HPR), osteocalcin (BGP), parathormone (PTH), cAMP, and 1-25(OH)2D. The stone formers showed lower calcemia values (p less than or equal to 0.005d), higher phosphaturia, and magnesiuria (p less than or equal to 0.0005), higher FCS (P less than or equal to 0.005) and higher values for PTH (p less than or equal to 0.01) and cAMP (p less than or equal to 0.0025). No significant differences were observed for the other parameters evaluated. Classification of the patient group into 2 subgroups (renal SbR and absorptive SbA) according to FCS values greater or lower that 0.16 mg/dl, the SbR patient group revealed a higher PTH and 1-25(OH)2D values (p less than or equal to 0.05). There appears to be no increase of bone resorption since AP, HPR, and BGP values in our patients fell within normal ranges. The 1-25(OH)2D levels were also normal and, with respect to the control group, were only elevated for the SbR patient group, whose PTH levels were also observed to be elevated. These increments appear to be related and may result in intermediate forms between renal and absorptive hypercalciuria.

Adult↗