Biomedical subjects

A Paz

Publications and source records attributed to A Paz.

At least 19 recordsLinked to original sources

PubMed1999

Lymph node revealing solution: a rapid method for the fixation of cystectomy specimens.

The objective of this study was to describe the use of the lymph node revealing solution (LNRS) for rapid fixation of total cystectomy specimens, and to compare it with formalin fixation. LNRS is a mixture of 95% ethanol, diethyl ether, glacial acetic acid and buffered formalin (65:20:5:10 v/v) prepared under a fume-hood. Sixteen consecutive cystectomy specimens were fixed for two hours either in LNRS or in buffered formalin. Representative sections were embedded in paraffin, sectioned and stained with H&E, periodic acid Schiff, alcian-blue, and immunostained for cytokeratins 20, high and low molecular weight cytokeratins, prostatic specific antigen, Factor VIII related antigen, s-100 protein, and protein kinase C isoenzymes. Results showed that the tissues were well fixed after 2 hours in LNRS, and were not fixed after 2 hours in formalin. Processing and sectioning of the paraffin blocks of the LNRS fixed tissue was excellent; it was impossible in the sections fixed for 2 hours in formalin. All the stains were excellent after LNRS fixation. We conclude that fixation of cystectomy specimens in LNRS requires only two hours and results in excellent stained slides. It is therefore recommended for cystectomy specimens.

Biomarkers, Tumor↗

PubMed1999

Double-phase 99mTc-sestamibi scintimammography and trans-scan in diagnosing breast cancer.

UNLABELLED: The goal of our study was to assess the value of both scintimammography with 99mTc-sestamibi (SMM) and trans-scan (T-scan) in detecting breast cancer. METHODS: A total of 121 women were evaluated by palpation, mammography, SMM and T-scan. SMM was performed in the prone, breast dependent position. Immediate and delayed views (double-phase) were obtained. T-scan is a new breast imaging method that maps noninvasively the distribution of tissue electrical impedance and capacitance. RESULTS: SMM had 88.9% sensitivity, 88.4% specificity and 88.4% accuracy in detecting breast cancer. SMM had 100% sensitivity in detecting breast tumors >1 cm and only 66% sensitivity in detecting tumors <1 cm. T-scan had 72.2% sensitivity and 67% specificity in detecting breast cancer. It detected one more breast cancer than SMM, at the expense of 27 additional false-positive results. CONCLUSION: Double-phase SMM was sensitive and specific in detecting breast cancer. This method may reduce the rate of negative breast biopsies in tumors >1 cm. T-scan was only moderately accurate in detecting breast cancer. Its addition to SMM did not improve significantly the rate of breast cancer detection. However, because of its complete noninvasiveness, large-scale applicability and low cost, T-scan deserves further refining.

Adult↗

PubMed1998

IgG isotype specific immune response in rats infected with Fasciola hepatica.

Antibody responses (IgG1, IgG2a, IgG2b, and IgG2c subclasses) against Fasciola hepatica L. in rats infected with metacercariae were analysed by ELISA. Animals of group 1 (R-1) remained infected throughout 21 weeks, and rats of group 2 (R-2) received a single oral dose of triclabendazole (Fasinex 10%, Ciba-Geigy) at 4 weeks after infection. Group C (R-C) consisted of rats left intact which served as uninfected controls. All IgG subclasses increased during the first weeks after infection, but when triclabendazole was administered IgG1 and IgG2b diminished markedly. IgG2c showed a different profile to the other antibodies evaluated, increasing earliest and decreasing profoundly from the 9-11th week after infection (w.a.i). The infected-untreated rats produced higher titres of antibodies than the rats of R-2, and these differences were statistically significant (p < 0.05) in all subclasses evaluated except in IgG2a titres.

Animals↗

PubMed1998

Dislodgment and accelerated degradation of Ras.

Membrane anchorage of Ras oncoproteins, required for transforming activity, depends on their carboxy-terminal farnesylcysteine. We previously showed that S-trans,trans-farnesylthiosalicylic acid (FTS), a synthetic farnesylcysteine mimetic, inhibits growth of ErbB2- and Ras-transformed cells, but not of v-Raf-transformed cells, suggesting that FTS interferes specifically with Ras functions. Here we demonstrate that FTS dislodges Ras from membranes of H-Ras-transformed (EJ) cells, facilitating its degradation and decreasing total cellular Ras. The dislodged Ras that was transiently present in the cytosol was degraded relatively rapidly, causing a decrease of up to 80% in total cellular Ras. The half-life of Ras was 10 +/- 4 h in FTS-treated EJ cells and 27 +/- 4 h in controls. The dislodgment of membrane Ras and decrease in total cellular Ras were dose-dependent: 50% of the effects occurred at 10-15 microM, comparable to concentrations (7-10 microM) required for 50% growth inhibition in EJ cells. Higher concentrations of FTS (25-50 microM) were required to dislodge Ras from Rat-1 cell membranes expressing normal Ras, suggesting some selectivity of FTS toward oncogenic Ras. Membrane localization of the prenylated G beta gamma of heterotrimeric G proteins was not affected by FTS in EJ cells. An FTS-related compound, N-acetyl-S-farnesyl-L-cysteine, which does not inhibit EJ cell growth, did not affect Ras. FTS did not inhibit growth of Rat-1 cells transformed by N-myristylated H-Ras and did not reduce the total amount of this Ras isoform. The results suggest that FTS affects docking of Ras in the cell membrane in a rather specific manner, rendering the protein susceptible to proteolytic degradation.

Acetylcysteine↗

PubMed1998

Subclasses of IgG in different aged rats with fasciolosis.

The variations in antibody responses (total IgG and IgG1, IgG2a, IgG2b, and IgG2c subclasses) were studied in two groups of rats infected with metacercariae of the trematode Fasciola hepatica L. Animals of group 1 were 4 weeks old, and rats of group 2 were 13 weeks old. All IgG subclasses increased during the course of infection except IgG2c, which decreased. The younger rats reached more marked responses than the older, at least during the period of this trial. IgG1 and IgG2a antibodies reached the highest levels, and among these two, IgG2a response was slightly superior to IgG1.

Age Factors↗

PubMed1998

Atypical microangiopathy in a patient treated with ticlopidine.

Microangiopathies are rare complications during treatments with ticlopidine. We describe an atypical microangiopathy, affecting almost exclusively myocardium, and thrombocytopenia, shortly after onset of ticlopidine. The patient died a few days after. Autopsy showed no bleedings or large thrombi in most organs, but were compatible with microangiopathy in myocardial small vessels.

Humans↗

PubMed1998

Comparison of radionuclide scrotal blood-pool index versus gonadal venography in the diagnosis of varicocele.

UNLABELLED: The purpose of our study was to assess the value of a radionuclide scrotal blood-pool index (SBPI) in diagnosing and grading clinical and subclinical varicocele. METHODS: Scrotal scans were performed on 1360 infertile patients. Thirty fertile patients with a normal scrotum on palpation served as controls. The patients' red blood cells were labeled in vivo by administration of stannous ions of pyrophosphate followed by the intravenous administration of 99Tc-pertechnetate. The scans initially were inspected visually and, when bilateral varicocele was excluded, a computerized analysis of the ratio of the blood-pool activity in each hemiscrotum (SBPI) permitted accurate grading of the varicocele. A subgroup of 224 patients was selected randomly and had gonadal venography. The results of physical examination, scrotal scan, gonadal venography and semen analysis were compared. RESULTS: Normal values of SBPI (0.9-1.1) were derived from the control group. There was a 93.5% correlation between palpation and SBPI grade in diagnosing palpable varicocele. When compared to gonadal venography, subclinical varicocele was demonstrated by scrotal scan in 54.8% of infertile male patients with abnormal semen analysis, normal female partners and no other cause of infertility. Of these patients, 32.6% had, unexpectedly, Grade 2 or 3 varicocele. Right and bilateral varicocele were demonstrated three times as often by scrotal scan than by palpation. SBPI was accurate in diagnosing recurrent varicocele but there was a low correlation (61.1%) between SBPI and gonadal venography grade. There was a high correlation between SBPI grade and sperm analysis grade. CONCLUSION: SBPI grading of varicocele was validated as an accurate, quantitative and noninvasive method of grading varicocele, equivalent to the grading system by palpation in a large group of infertile patients. The main contribution of SBPI was in detecting and grading subclinical varicocele in infertile patients with no other cause of infertility. SBPI also was accurate in diagnosing but not in grading recurrent varicocele.

Adolescent↗

PubMed1997

The role of external sphincterotomy for patients with a spinal cord lesion.

For the last three decades external sphincterotomy has been well accepted as a treatment for bladder outlet obstruction in patients with a spinal cord lesions. Recently, however, its value has been brought into question. To assess the current place of this procedure in the treatment of the neuropathic bladder of spinal origin, we studied the outcomes of sphincterotomy in 32 patients. Post-voiding residual urine volume decreased after surgery in 27 patients (84%), considerably in 22 (69%) of them. Clinical infection resolved in 14 out of 19 patients (74%), hydronephrosis disappeared in two out of three (66%), and vesicourethral reflux improved in three out of five (60%) and was cured in two (40%). Six of the patients (19%) were freed from catheterization, but two patients (6%) lost partial continence. Sphincterotomy is an important tool in the treatment of spinal patients with bladder outlet obstruction and should be considered when the proper indications exist.

Adult↗

PubMed1997

The clinical and histological features of transitional cell carcinoma of the bladder with microcysts: analysis of 12 cases.

OBJECTIVE: To describe the clinical course and histological features of transitional cell carcinoma (TCC) of the bladder with microcysts. PATIENTS AND METHODS: Among 940 patients with bladder TCC diagnosed at our institution during a 5 year period. 12 (1.2%; eight men and four women, mean age 71.1 years, range 52-85) were diagnosed histologically as having microcystic TCC. Sections of the tumours were stained with haematoxylin and eosin, periodic acid-Schiff and Alcian blue and clinical data obtained from the patients' records. RESULTS: Of the 12 patients with bladder TCC with microcysts, three had tumours confined to the epithelium, six had tumour invasion of the lamina propria and three had muscle invasion. One patient had low-grade TCC and 11 had high-grade TCC; six patients had a second primary tumour; three had a colon carcinoma, one a villous adenoma of the caecum, one a locally advanced carcinoma of the prostate and the last a squamous cell carcinoma of the uterine cervix. CONCLUSIONS: Microcystic TCC was associated with high-stage and high-grade bladder tumours and with other primary tumours, especially of the colon. Screening these patients for asymptomatic tumours of the colon is suggested.

Aged↗

PubMed1997

Lymph-node revealing solution: a new method for detecting minute lymph nodes in cystectomy specimens.

OBJECTIVE: To describe the use of a new lymph-node revealing solution (LNRS) for detecting lymph node involvement in total cystectomy specimens from patients with locally confined invasive transitional cell carcinoma (TCC) of the bladder, and to compare the results obtained with those using the conventional method (palpation and sectioning perivesical fat) that may fail to detect very small lymph nodes. MATERIALS AND METHODS: Of 12 cystectomy specimens obtained from patients with TCC, six in which 0-3 metastatic nodes were identified by the conventional method were further investigated using LNRS. The revealing solution comprised 95% ethanol, diethyl ether, glacial acetic acid and buffered formalin (65:20:5:10 v/v) prepared under a fume-hood. After evaluation using the conventional method, the specimens were immersed for 6-12 h in the solution, washed under running tap water and the adipose tissue sectioned at intervals of 2-3 mm. Lymph nodes were identified as white, chalky nodules against the background of yellow fat. The number of the lymph nodes identified by conventional and the LNRS methods was recorded and classified according the TNM system. RESULT: Twenty-two lymph nodes were detected by the conventional method, of which four were positive for tumour metastasis. Using the LNRS, an additional 21 nodes were identified among which 12 were positive. The mean size of the lymph nodes detected by the conventional and LNRS methods was 7.96 mm and 3.81 mm, respectively. The stage of three patients was increased (Nx to N2, N0 to N2 and N1 to N2) and therefore two of these patients received adjuvant chemotherapy. CONCLUSIONS: LNRS significantly enhanced the yield of normal and metastatic nodes of cystectomy specimens and may identify smaller nodes. The LNRS method allows a more accurate staging with better assessment of the prognosis and need for adjuvant therapy.

Carcinoma, Transitional Cell↗

PubMed1997

Lymph node revealing solution: a new method for detection of minute axillary lymph nodes in breast cancer specimens.

The staging and prognosis of patients with breast cancer is related to the presence or absence of axillary lymph node involvement. However, in some cases no lymph nodes or too small a number of lymph nodes are revealed by the traditional method of palpating and sectioning the axillary fat. In the present study we demonstrate the usefulness of the lymph node revealing solution (LNRS) in breast cancer. Specimens from 13 patients, in whom <10 lymph nodes were identified in the axilla by the traditional method, were included in the study. After excising the lymph nodes by the traditional method, axillary tissue was immersed in LNRS for 6-12 hours. Additional lymph nodes, which stood out as white chalky nodules, were excised and processed as usual. The LNRS increased the mean number of nodes per case from 6.0+/-2.5 found by the traditional method to 12.54+/-4.61 nodes per case (p < 0.01). The size of the nodes identified by the LNRS was significantly smaller (p < 0.01) than those detected by the traditional method. The LNRS changed the lymph node stage of the disease in four of the studied cases (30%). LNRS seems to be the technique of choice for detection of axillary lymph nodes in cases where the number of detected lymph nodes by the traditional method is too small for accurate staging.

Axilla↗

PubMed1997

Effect of meal composition on alertness and performance of hospital night-shift workers. Do mood and performance have different determinants?

We have studied the effect of diet composition on performance during, and after night-shift work. On three occasions 21 night workers at the Hadassah University Hospital, Jerusalem ate one of three meal plans--a diet enriched with protein (PROT 52%), carbohydrate (CHO 70%) or their regular (REG) diet (PROT 18%, CHO 55%); fat composition was held constant (ca. 27%). Outcome measures were subjective alertness, psychometric performance, and plasma concentrations of glucose, insulin and amino acids. Insulin and glucose levels were similar after the different diets. There were no clear relationships between tyrosine and tryptophan ratios and performance. However, within PROT diet, differences in psychometric performance correlated with glucose (p = 0.05) and insulin concentrations (p = 0.04), and the tyrosine:large neutral amino acid ratio correlated with alertness (p = 0.05). After the CHO diet, glucose concentrations related to sleepiness (p = 0.035). In this population, self-selected for night-shift work, there were no clear-cut differences in subjective feelings or objective performance between the different diets. The preferred regular diet gave the best performance and had a metabolic profile similar to the CHO diet. This suggests that a CHO:PROT ratio of around 3.0 might give the optimal balance between mood and performance during night-shift work.

Adult↗

PubMed1997

A genetic sequence change in the 3'-noncoding region of the androgen receptor gene in prostate carcinoma.

OBJECTIVE: We intended to identify structural changes in the hormone-binding domain and C-terminal region of the androgen receptor (AR) gene in carcinoma of prostate specimens. METHODS: Twelve prostate cancer specimens from prostate resections were analyzed for the presence of mutations in the E-H exons and part of the 3'-untranslated region of the AR cDNA, using RT-PCR and direct sequencing. RESULTS: A polymorphic sequence spanning 17 nucleotides was identified in the 3'-untranslated region of the AR cDNA from one prostate carcinoma tissue, suggesting the presence of a somatic mutation. No mutations were identified in the coding sequence of the hormone-binding domain of the AR cDNA. CONCLUSION: These results suggest that AR mutations are probably uncommon molecular events in the early stages of prostate cancer.

Adenocarcinoma↗

PubMed1997

Transvesical prostatectomy in elderly patients.

PURPOSE: We assessed the results of transvesical prostatectomy in patients older than 80 years. MATERIALS AND METHODS: We studied 98 patients 80 to 90 years old who underwent transvesical prostatectomy between 1986 and 1993, including those with a large prostate (preoperative estimated weight more than 80 gm.), numerous or large cystolithiasis and large bladder diverticulum, which are indications for open prostatectomy. Clinical data were obtained by chart review. RESULTS: The indications for surgery were urinary retention in 53 patients (54%), severe obstructive urinary symptoms in 18 (18.4%), cystolithiasis in 17 (17.3%), prostatic bleeding in 10 (10.2%) and bladder diverticulum in 2 (2%). Accompanying diseases were present in 69 patients (70.6%), including ischemic heart disease in 41 (42%), diabetes mellitus in 17 (17.3%) and arterial hypertension in 14 (14.3%). A total of 59 patients (60.2%) underwent surgery while under general anesthesia and 39 (39.8%) received regional anesthesia. Average operative time was 62 minutes. Of the patients 40 (40.8%) received 1, 14 (14.3%) received 2 and 2 (2%) received 4 units of blood. No postoperative deaths or life threatening complications were noted. The immediate postoperative complications included urinary tract infection in 20 patients (20.5%), wound infection in 3 (3.0%) and orchiepididymitis in 3 (3.0%). Postoperative mild to moderate incontinence was noted in 2 patients (2.0%). Bladder neck constriction and urethral strictures occurred in 4 (4.1%) and 3 (3.0%) patients, respectively. CONCLUSIONS: Transvesical prostatectomy can be performed safely in elderly patients with a low morbidity rate.

Age Factors↗

PubMed1997

Postejaculation serum prostate-specific antigen level.

OBJECTIVE: This study was carried out to determine whether ejaculation may modify the serum prostate-specific antigen (PSA) level and to investigate whether postejaculation serum PSA may play a role in male hypofertility work-up. METHODS: Serum PSA concentration was determined before and 1 h after ejaculation in 18 healthy men (group A) and in 16 men with male-factor infertility (group B). PSA change (delta) was recorded and analyzed. RESULTS: Postejaculation serum PSA differed significantly from basal levels (p = 0.0037 by the Wilcoxon signed rank test). Following ejaculation, a rise was noticed in 74% of subjects. The median relative change in PSA concentration was 54%. No difference in respect to mean, median and relative change was observed between study groups. In two cases (6%), PSA rose from normal level to more than 4 ng/ml. CONCLUSION: A significant postejaculation serum PSA elevation does occur, it is thus recommended that men abstain from ejaculation for 24 h prior to PSA sampling. Postejaculation PSA was not found to significantly correlate with hypofertility.

Adult↗

PubMed1996

[Late solitary metastases of breast origin presenting as primary colonic carcinoma].

The case of a 72-year-old woman with 2 solitary metastases to the colon of breast origin with mimicked primary colonic cancer is presented. The primary breast lesion was an infiltrating duct carcinoma and the metastases to the colon were discovered 6 years later. Some of the regional lymph nodes draining the colon were infiltrated by tumor, probably originating from the 2 colonic metastases. This is an unusual condition that has not as yet yet been reported.

Aged↗

PubMed1996

The pattern of radionuclide scrotal scan in torsion of testicular appendages.

The aim of this study was to define the radionuclide scrotal imaging (RSI) pattern in cases of torsion of testicular appendages and to correlate it with the duration of symptoms. Two hundred and seventeen patients with acute scrotal pain were evaluated prospectively during the past 13 years. Two groups of patients were defined according to the interval between the onset of symptoms and the performance of RSI: group A comprised patients in whom RSI was performed within 5 h after the onset of symptoms, while group B comprised patients in whom RSI was performed between 5 and 24 h after the onset of symptoms. An SPX-4 Elscint or an Apex 405 gamma camera with a parallel hole or converging collimator was used. Between 5 and 15 mCi of technetium-99m pertechnetate was injected as a bolus intravenously. The radionuclide angiogram consisted of six to eight consecutive 5-s frames. The scrotal static scan was obtained immediately following the radionuclide angiogram. The "hot dot" sign, which is a small spot of increased tracer perfusion and uptake on RSI, was not present during the first hours after the onset of symptoms. Therefore, RSI is inaccurate and is not indicated for the diagnosis of torsion of testicular appendages of less than 4-5 h duration. The hot dot sign was, however, demonstrated on the RSI in 45% of the patients with scrotal pain lasting between 5 and 24 h. The overall sensitivity and accuracy of RSI in diagnosing torsion of testicular appendages in this group of patients were 68% and 79%, respectively. In all the patients with a positive hot dot sign, torsion of testicular appendages was found at exploration (specificity 100%). Therefore, the hot dot sign was found to be pathognomonic of torsion of testicular appendages.

Adolescent↗

PubMed1996

A computer-assisted molecular epidemiologic approach to confronting the reemergence of tuberculosis.

Molecular epidemiologic approaches have provided important insights into the pathogenesis and epidemiology of tuberculosis. However, continued progress in this field will be reliant on the development of computerized information management systems capable of analyzing large numbers of bacterial DNA fingerprints and incorporating this with data collected as part of conventional disease surveillance. The specific attributes of these computer systems must be tailored to the nature and scope of the research question. In this article, the authors describe a system being used for the surveillance of Mycobacterium tuberculosis strains in San Francisco. The current performance characteristics are described, and potential future developmental directions are outlined. This system demonstrates several general principles of computerized molecular epidemiology that are likely to be of increasing applicability to a variety of pathogens.

Computer Simulation↗