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Biomedical subjects

J Castro

Publications and source records attributed to J Castro.

At least 55 records · Page 3Linked to original sources
PubMed1998

Comparison of routine flow cytometric DNA analysis of fresh tissues in two laboratories: effects of differences in preparation methods and background models of cell cycle calculation.

Routine flow cytometric DNA analysis was compared in two laboratories by using matched fresh-frozen breast cancer and soft tissue sarcoma biopsy specimens. Laboratory I applied the Vindelöv preparation method and an exponential background subtraction algorithm in the cell cycle calculation. Laboratory II used the Formalin-protease preparation technique and the sliced-nuclei background model. The results of the ploidy analysis showed good agreement between the two laboratories; however, the results of the cell cycle analysis showed considerable systematic differences between labs. Laboratory I obtained significantly lower values of S-phase fraction and higher values of G2-phase fraction than laboratory II. To explain these discrepancies, the effects of differences in the preparation methods and background subtraction algorithms were studied. The Vindelöv preparation method yielded higher debris and aggregation levels than the Formalin-protease technique and tended to give higher %S and %G2 values. When the two background models were used in the same histograms, the exponential background model tended to give %S values distinctly lower than and %G2 values almost identical to those obtained with the sliced-nuclei algorithm. The sum of these effects accounts for the observed inter-laboratory discrepancies. Different from the sliced-nuclei fit, the exponential background fit often did not accommodate to the original data in the <2c histogram region and resulted in a considerable inter-operator variability of %S calculation in histograms with <5% S. When aggregate correction was added to the sliced-nuclei algorithm, the differences between %S values in histograms from the two laboratories almost disappeared.

Algorithms↗
PubMed1998

Involvement of the Ink4 proteins p16 and p15 in T-lymphocyte senescence.

Little is known about the molecular background to senescence in T-lymphocytes. In fibroblast systems replicative senescence has been shown to correlate with a number of changes in the expression of the proteins normally regulating progression through the G1 phase of the cell cycle, and recently the Ink4 inhibitor p16 was implicated as a central regulator of replicative senescence in human fibroblasts. It has, however, been claimed that p16 is not expressed in T-lymphocytes. In the present study we have analysed G1 regulating proteins in ageing human T-lymphocytes. We show that PHA and IL-2 stimulated T-lymphocytes cease to proliferate after around 20 population doublings, these cells can not thereafter be restimulated to growth, and were also found to exhibit markers for senescence. We found that T-lymphocytes accumulate p16 and p15 protein during successive population doublings and display high levels of these proteins as they enter into replicative senescence. There was also an increased binding of p16 to the Cdk6 kinase in senescent cells, and a decreased Cdk6 as well as Cdk2 kinase activity. The levels of other G1 regulating proteins were also altered in the senescent cells, such as slightly elevated levels of p21/WAF1, and downregulation of Cdk2 and cyclinD3. The levels of p27/ Kip1 is down regulated in proliferating cells but rise to approximately 15% of the levels in un-stimulated quiescent cells. As a high proportion of T-cell childhood acute lymphoblastic leukaemias have deletions of both p15 and p16, our data suggest that inactivation of these genes makes it possible for leukemic cells to avoid senescence.

CD28 Antigens↗
PubMed1998

Transrectal ultrasonography: relationship with anorectal manometry, electromyography and sensitivity tests in irritable bowel syndrome.

Irritable bowel syndrome is the most frequently diagnosed disorder in gastroenterology. It has been demonstrated with specialized motility studies that these patients compared to healthy subjects show changes in rectoanal electrical and mechanical activity and in rectoanal sensitivity. However, until now no report has been published on morphological alterations in the rectum or the internal anal sphincter. Twenty-five consecutive patients with irritable bowel syndrome (mean age 32, range 17-47 years; 24 females) were evaluated prospectively by transrectal ultrasonography, rectal sensitivity studies, and recordings of both electrical and mechanical activity of the distal rectum and internal anal sphincter during a 2-h inter-digestive period. Ten healthy volunteers (mean age 34.5, range 19-50 years) served as a control group. Paired and non-paired Student's two-tailed t test and linear regression analysis were used. It was shown that muscle thickness of the rectum during rest (4.7 +/- 0.1 mm) was correlated neither with its rectal spike amplitude (0.73 +/- 0.1 mV) nor with rectal spike frequency (17.06 +/- 3.6 spike/2 h). In addition, the diameter of the internal anal sphincter (1.2 +/- 0.1 mm) was correlated neither with its resting pressure, nor with frequency (17.1 +/- 3.2/2 h), duration (14.9 +/- 1.5 s), or amplitude (14.1 +/- 1.9 mmHg), of inhibition of the spontaneous rectoanal inhibitory reflex. No correlation was found between ultrasonographic parameters and rectal distension variables (r = 0.03). This study demonstrates for the first time morphological anorectal changes in patients with irritable bowel syndrome compared to healthy subjects, in addition to showing that morphological changes are independent of physiological ones. Therefore both transrectal ultrasonography to determine anorectal morphology and electromanometry to assess anorectal function are important measures in the evaluation of patients with irritable bowel syndrome.

Adolescent↗
PubMed1998

Ten-year follow-up of helium ion therapy for uveal melanoma.

PURPOSE: To examine the results of helium ion irradiation in 218 patients with uveal melanoma treated more than 10 years ago. METHOD: A retrospective review was made of 218 patients (218 eyes) treated with helium ion radiation for uveal melanoma between 1978 and 1984. RESULTS: After helium ion irradiation, 208 (95.4%) of 218 eyes had local tumor control. Ten years after irradiation, 46 (22.4%) of 218 eyes had been enucleated; the majority of enucleations (37 of 46) resulted from anterior ocular segment complications. Ten years after radiation, 102 (46.8%) of the 218 patients were dead; 51 had non-melanoma-related deaths and 51 had died of metastatic melanoma. Best-corrected visual acuity after radiation was greater than 20/40 in 21 (23%) of 93 eyes of the patients who were alive and who had retained their eyes 10 or more years after treatment. In patients with tumors less than 6 mm in height and more than 3 mm distant from the nerve or the fovea, 13 (72%) of 18 retained visual acuity greater than 20/40. In contrast, only 11% of the patients with either thicker tumors or those close to the nerve or fovea retained that level of visual acuity. CONCLUSIONS: Helium ion irradiation of uveal melanoma is associated with good local tumor control and reasonable retention of the treated eye 10 years after treatment. In eyes with tumors less than 6 mm in thickness and more than 3 mm distant from the optic nerve and fovea, many retain excellent vision.

Adult↗
PubMed1998

Chronic pain in a community-based sample of men with spinal cord injury: prevalence, severity, and relationship with impairment, disability, handicap, and subjective well-being.

OBJECTIVE: To assess the prevalence, severity, and correlates of chronic pain in a community-based sample of men with spinal cord injury (SCI). DESIGN: Survey. SETTING: Community. PARTICIPANTS: Seventy-seven men with SCI randomly selected from a sampling frame solicited from the community. METHOD: Participants completed standardized questionnaires assessing many areas of life, were interviewed in their homes, and underwent a physical examination at a hospital. There they were interviewed by an anesthesiologist regarding chronic pain, and a nurse administered objective pain measures. RESULTS: Seventy-five percent of the men reported chronic pain. Chronic pain was associated with more depressive symptoms, more perceived stress, and poorer self-assessed health. Greater intensity of pain was related to less paralytic impairment, violent etiology, and more perceived stress. Area of the body affected by pain was related to independence and mobility. CONCLUSIONS: Because of the high prevalence of chronic pain in the population with SCI and its relation to disability, handicap, and quality of life, health care providers need to give this issue the same priority given to other SCI health issues. Analysis of individual pain components provides better information than assessing overall pain. It is futile to treat SCI pain without giving full attention to subjective factors.

Activities of Daily Living↗
PubMed1998

A comparison of cause-specific melanoma mortality and all-cause mortality in survival analyses after radiation treatment for uveal melanoma.

OBJECTIVE: To determine the causes and patterns of mortality after uveal melanoma radiation. DESIGN: A cohort study from a single institution was performed. Mortality was modeled using semiparametric survival techniques. All cause and cause-specific mortality analyses were performed. Mortality was compared with expected mortality from the U.S. census data. PARTICIPANTS: A total of 731 patients were studied, and 710 (97%) of these had medium or large melanomas. The mean tumor diameter was 11.3 mm, and the mean tumor thickness was 5.8 mm. Ciliary body was involved in 122 (17%) of patients. Complete follow-up was available on 99.6% (728 of 731) of patients. MAIN OUTCOME MEASURES: The authors analyzed the distribution and causes of post-treatment mortality. RESULTS: The 5- and 10-year all-cause Kaplan-Meier survival rates were 75.6% and 62.3%, respectively. Both melanoma risk factors (older age, ciliary body involvement, and larger tumor diameter) and nonmelanoma risk factors (older age and medical condition) were significant prognostic factors of all-cause mortality. Deaths from nonmelanoma causes accounted for 91 (42.3%) of 215 deaths. The 5-year and 10-year estimates of nonmelanoma deaths were 8.3% and 15.9%, respectively. Nonmelanoma mortality was similar to that observed in the general U.S. population (91 observed, 98.1 expected). Melanoma metastases accounted for 124 (57.7%) of 215 deaths. The 5- and 10-year estimates for probability of metastatic death were 16.1% and 21.8%, respectively. The largest tumor diameter was the best predictor for melanoma mortality; ciliary body involvement, older age, and distance from the fovea also were significant in multivariate analyses. CONCLUSION: A significant proportion of patients with uveal melanoma die of nonmelanoma causes after radiation. In analyzing prognostic factors, considerable information may be lost if analyses are based on all-cause mortality rather than cause-specific mortality.

Aged↗
PubMed1998

Lack of association between atopy and RsaI polymorphism within intron 2 of the Fc(epsilon)RI-beta gene in a Spanish population sample.

BACKGROUND: The B genotype of RasI polymorphism located within intron 2 of the Fc-IgE receptor I (Fc(epsilon)RI) gene was previously found to be increased in atopic patients from a Japanese population sample. METHODS: We studied these A/B genotypes in 70 Spanish atopic patients, and the results were compared to those of 51 nonatopic controls. RasI polymorphisms were studied by specific digestion of polymerase chain reaction fragments followed by polyacrylamide gel electrophoresis. RESULTS: The polymorphism frequency (A/A: 25/70, A/B: 28/70, B/B: 17/70) found in patients did not differ from the frequency in nonatopic control subjects. CONCLUSIONS: We did not find RasI polymorphisms associated with atopic disease. The genetic findings in atopy and asthma may be very different according to ethnic and local characteristics, and they must be carefully verified in different population samples.

Adolescent↗
PubMed1998

Subjective body-image dimensions in normal and anorexic adolescents.

The subjective body dimensions of adolescent anorexic patients and adolescents from the general population were studied by means of a new technique that combines certain characteristics of the 'body-site estimation' and the 'whole-image adjustment' procedures. The technique used (Subjective Body Dimensions Apparatus-SBDA) reveals the individual's idea of the size of the different parts of his/her body, and produces a life-size global silhouette. Eighty-five female anorexic patients (ages 12 to 18) were compared with 427 adolescents from the general population. The technique showed acceptable test-retest stability. The comparison group overestimated their thorax, waist and hips, and anorexic patients overestimated all parts of their body but their thorax, waist and hips especially. For all parts of the body, the anorexic group showed greater overestimation (p < .0001) than the comparison group.

Adolescent↗
PubMed1997

Assessing rearing behaviour from the perspectives of the parents: a new form of the EMBU.

The EMBU (Egna Minnen Beträffande Uppfostran) is a self-reporting questionnaire developed to assess memories of adults about their parents' rearing practices. In the present study, an exploratory factor analysis was carried out on items of the EMBU-P, a new version of the EMBU especially designed to obtain ratings from parents about their own rearing behaviour with their children. The factor analysis yielded a structure similar to that obtained with the original EMBU (Rejection, Emotional Warmth, Control Attempts and Favouring Subject), but composed of fewer items. The internal consistency was adequate for the three major scales. Some significant correlations emerged between the EMBU-P scales. The Rejection scale correlated negatively with the Emotional Warmth scale and positively with the Control Attempts scale. The latter also correlated positively with Emotional Warmth. There were no significant correlations between the scales and the age of the parents. The sex of the parents was significantly associated with the EMBU-P scores.

Adult↗
PubMed1997

Metastatic risk for distinct patterns of postirradiation local recurrence of posterior uveal melanoma.

OBJECTIVE: The purpose of the study is to compare the prognostic significance of horizontal/marginal versus vertical/diffuse patterns of postirradiation local recurrence of posterior uveal melanoma. DESIGN: The study design was a nonrandomized, retrospective clinical study. Semiparametric and nonparametric statistical techniques were used. PARTICIPANTS: Seven hundred sixty-six posterior uveal melanoma patients were studied. INTERVENTION: Either iodine-125 plaque or helium ion radiation therapy was performed. MAIN OUTCOME MEASURES: Local tumor recurrence and systemic metastasis were measured. RESULTS: Local tumor recurrence was detected in 66 (8.6%) of 766 irradiated tumors. The 5-year actuarial rate of local recurrence was 10%. The recurrence pattem was horizontal/marginal in 27 patients (41%) and vertical/diffuse in 39 patients (59%). Systemic metastasis was detected in 5 patients (19%) with horizontal/marginal recurrence and in 19 patients (49%) with vertical/diffuse recurrence. After known metastatic risk factors were controlled, the relative risk for metastasis was 2.2 for horizontal/marginal recurrence and 5.1 for vertical/diffuse recurrence (P = 0.05). The actuarial rate of systemic metastasis was 2.9% per year for all patients, 6.3% per year for patients with horizontal/marginal recurrence, and 15.5% per year for patients with vertical/diffuse recurrence. CONCLUSIONS: Postirradiation local recurrence of posterior uveal melanoma is a risk factor for systemic metastasis. Vertical/diffuse recurrences may be associated more strongly with metastatic disease than horizontal/marginal recurrences.

Adult↗
PubMed1997

Diabetic iris neovascularization. Natural history and treatment.

PURPOSE: To study the spontaneous progression from iris neovascularization to neovascular glaucoma, factors that determine how long it takes and the efficacy of therapy, we studied 81 eyes belonging to 67 diabetic patients. METHODS: The eyes were divided into three groups: control group (29 eyes, 26 patients), photocoagulation group (37 eyes, 30 patients) and cryotherapy group (15 eyes, 11 patients). The controls were observed for at least 12 months, and the treated group over at least the following 3 months. RESULTS: At the end of the follow-up period 12 of the 29 control group eyes (41.4%) had developed neovascular glaucoma and 6 (20.5%) increased neovascularization. Seven eyes (58%) that developed glaucoma did so within 3 months. There was no significant difference between the laser therapy (improvement: 84%) and cryotherapy group (80.5%). CONCLUSIONS: At the end of the 12-month follow-up period progression from iris neovascularization to neovascular glaucoma is very frequent. There was no difference between laser therapy and cryotherapy.

Cryotherapy↗
PubMed1997

Induction of apoptosis and inhibition of cell growth are independent responses to interferon-alpha in hematopoietic cell lines.

IFNs are capable of modulating a variety of cellular responses, including cell growth and apoptosis. The prospective connections between these two biological responses are not fully understood, and the molecular mechanisms underlying the effects of IFNs on these processes are not completely defined. We have investigated the relationship between IFN-alpha-induced apoptosis and cell cycle arrest in three hematopoietic cell lines, Daudi, U-266, and H9. It was found that IFN-alpha was a rapid and potent inducer of apoptosis in H9 and U-266 cells, whereas IFN-alpha-induced cell cycle arrest in Daudi cells is not associated with the onset of apoptosis. In H9 cells, apoptosis occurs without a preceding cell cycle block, whereas in U-266 cells, apoptosis occurs subsequent to G1 arrest. Cell cycle arrest per se, induced by serum starvation or treatment with aphidicolin, had only minor effects on the viability of these cell lines and did not abrogate the apoptosis-inducing capacity of IFN-alpha. Additionally, IFN-alpha-induced apoptosis occurred in cells from all cell cycle phases. Thus, we conclude that IFN-alpha-induced apoptosis seems to occur independent of cell growth inhibition. There were no changes in Bcl-2 or Bax protein levels that could account for the apoptosis-inducing effects of IFN-alpha in these cell lines. Moreover, examination of p53 status suggests that IFN-alpha-induced apoptosis in the U-266 and H9 cell lines occurs through a p53-independent pathway.

Apoptosis↗
PubMed1997

[Ultrasound diagnosis of salivary gland tumors].

The ultrasonic diagnosis of salivary gland tumors can give a more accurate information than clinical data alone. For example, it will help differentiate intraglandular from extraglandular tumors and benign from malignant processes. We conducted a prospective study in 39 patients with parotidal or submaxillary tumors. Patients were evaluated with a physical exam and a with ultrasound. Results indicate that only 53.86% of the physical examinations were correct in their diagnosis compared to 87.18% of the those done by ultrasound. Specificity and sensibility for malignancy was 96.43% and 81.81% respectively. These results were similar to those reported by other authors. We conclude that the use of ultrasound techniques in the study of salivary gland pathology is well justified, due to its capacity to provide high resolution, improving clinical diagnosis.

Adolescent↗
PubMed1997

Long-term follow-up after uveal melanoma charged particle therapy.

PURPOSE: To examine the results of helium ion irradiation in 218 uveal melanoma patients treated more than 10 years ago. METHODS: Retrospective review of 218 eyes treated with helium ion radiation for uveal melanoma between 1978 and 1984. Several parametric and non-parametric statistical analysis techniques were used. RESULTS: In 218 eyes treated with helium ion radiation for uveal melanoma, the mean dimension for largest basal diameter was 11.9 mm (range 5 mm to 24 mm). The mean tumor thickness was 6.7 mm (range 1.3 mm to 14.2 mm). Following helium ion radiation 208 (95.4%) of 218 eyes had local tumor control. At 10 years after radiation 46 (22.4%) of 218 eyes were enucleated; the majority (37 of 46) of enucleations were due to anterior ocular segment complications. At 10 years after radiation 102 (46.8%) of the 218 patients were dead; half had non-tumor related deaths and 51 died from metastatic melanoma. Best corrected visual acuity after radiation was > or = 20/40 in 21 of 93 eyes of patients that were alive and retained their eyes 10 or more years after treatment. In patients with tumors that were less than 6 mm in height and more than 3 mm away from the nerve or the fovea, 13 of 18 (72%) retained > or = 20/40. In contrast, only 11% of the patients with either thicker tumors or those close to the nerve or fovea retained that level of acuity. The actuarial enucleation rate at 5 years was 17.2% (2.7% S.E.) and at 10 years this was 22.4% (3.1% S.E). The recurrence tumor control rate at both 5 and 10 years was 5.3% (S.E 1.7%). CONCLUSIONS: Helium ion radiation of uveal melanoma is associated with good local tumor control and reasonable retention of the treated eye 10 years after treatment. In tumors that are less than 6 mm in thickness and greater than 3 mm from the optic nerve and fovea, many retain excellent vision. Approximately one-half of the deaths 10 years after treatment were due to non-tumor-related causes.

Adult↗
PubMed1997

[Massive inferior vena cava thrombosis associated with protein C deficiency. Clinical case].

Inferior vena cava thrombosis is infrequent and in 30% of cases, the potential cause is an alteration of the natural anticoagulant protein system. We report a 18 years old male with an inferior vena cava thrombosis that was associated to a protein C deficiency. He was successfully treated with an infusion of intravenous streptokinase during 30 hours and intravenous heparin during 10 days, followed by oral anticoagulation therapy.

Adolescent↗