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Biomedical subjects

A Muñoz

Publications and source records attributed to A Muñoz.

At least 217 records · Page 12Linked to original sources
PubMed1998

Organization of the caudal rhombencephalic alar plate of the ribbed newt Pleurodeles waltl: evidence for the presence of dorsal column and lateral cervical nuclei.

As part of a recent program on the evolution of somatosensory systems in vertebrates, the cytoarchitecture, chemoarchitecture, and fiber connections of the caudal rhombencephalic alar plate were studied in the ribbed newt, Pleurodeles waltl. This part of the brain stem includes ill-defined dorsal column and lateral cervical nuclei. A cytoarchitectonic analysis revealed that the caudal medullary alar plate consists of an inner and an outer cell layer. The dorsomedial part of the outer cell layer at the obex level contains the dorsal column nucleus (DCN), whereas its ventrolateral part constitutes the lateral cervical nucleus (LCN). NADPH-diaphorase histochemistry and calbindin D-28k immunohistochemistry clearly delineate the main components of the compact inner cell layer, i.e. the nucleus of the solitary tract dorsally and the nucleus of the descending trigeminal tract ventrally. Neither NADPH-diaphorase-labeled nor calbindin D-28k positive neurons were observed in the DCN and LCN. With anterograde and retrograde tracing, the DCN and LCN were further delineated. Labeling of ascending dorsal root projections showed that the dorsal column and the DCN are somatotopically arranged: lumbar primary afferent fibers terminate on medial DCN neurons, whereas cervical primary afferent fibers terminate on lateral DCN neurons. The LCN is densely innervated by the dorsolateral funiculus. Retrograde tracing showed extensive, predominantly contralateral projections of both the DCN and LCN to the torus semicircularis and the ventral thalamus. These data show that even in the poorly segregated caudal rhombencephalic alar plate of urodeles a DCN and LCN can be distinguished with afferent and efferent projections comparable to those in anurans and other terrestrial vertebrates.

Animals↗
PubMed1998

Automobile accidents in patients with sleep apnea syndrome. An epidemiological and mechanistic study.

To investigate the association between sleep apnea syndrome (SAS) and automobile accidents, and to evaluate potential underlying mechanisms, we prospectively recruited 60 consecutive patients with SAS (apnea-hypopnea index, 58 +/- 3 h-1) and 60 healthy control subjects, matched for sex and age. The number of automobile accidents during the past 3 yr was obtained from participants and insurance companies. We quantified the degree of daytime sleepiness (Epworth scale), anxiety and depression (Beck tests), and we assessed the level of vigilance (PVT 192) and driving performance (Steer-Clear). Patients had more accidents than control subjects (OR: 2.3; 95% CI: 0.97 to 5.33) and were more likely to have had more than one accident (OR: 5.2; 95% CI: 1.07 to 25.29, p < 0.05). These differences persisted after stratification for km/yr, age, and alcohol consumption. Patients were more somnolent, anxious, and depressed than control subjects (p < 0.01), and they had a lower level of vigilance and poorer driving performance (p < 0.01). Yet, we did not find any correlation between the degree of daytime sleepiness, anxiety, depression, the number of respiratory events, nocturnal hypoxemia, level of vigilance, or driving simulator performance and the risk of automobile accidents among SAS patients. In conclusion, patients with SAS have an increased risk of automobile accidents. None of the clinical or physiological markers commonly used to define disease severity appear able to discriminate those patients at higher risk of having an automobile accident.

Accidents, Traffic↗
PubMed1998

Oltipraz chemoprevention trial in Qidong, People's Republic of China: modulation of serum aflatoxin albumin adduct biomarkers.

In 1995, 234 adults from Qidong, People's Republic of China, were enrolled and followed in a Phase IIa 4-methyl-5-(N-2-pyrazinyl)-1,2-dithiole-3-thione (oltipraz) chemoprevention trial. Residents of this area are at high risk for development of hepatocellular carcinoma, in part due to consumption of aflatoxin-contaminated foods. The intervention was a randomized, placebo-controlled, double-blind study. Elements of the study design and clinical outcomes have been recently published (Jacobson et al, Cancer Epidemiol. Biomark. Prev., 6: 257-265, 1997). The primary objective was to conduct a preliminary assessment of the ability of oltipraz to modulate levels of a validated biomarker of aflatoxin exposure and of the risk of hepatocellular carcinoma by determining levels of aflatoxin-albumin adducts in sera. Healthy eligible individuals were randomized into three arms to receive p.o. 125 mg of oltipraz daily, 500 mg of oltipraz weekly, or placebo for 8 weeks. There were no consistent changes in biomarker levels in the placebo arm over the 16-week observation period, nor was any apparent effect observed in the arm receiving 125 mg of oltipraz each day. However, individuals receiving 500 mg of oltipraz once a week for 8 weeks showed a triphasic response to oltipraz. No effect was observed during the 1st month of the intervention, whereas a significant (P = 0.001) diminution in adduct levels was observed during the 2nd month of active intervention and during the lst month of follow-up. A partial rebound in adduct levels toward baseline values was observed during the 2nd month postintervention. Linear regression models up to week 13 confirmed a significant (P = 0.008) weekly decline of biomarker levels in the group receiving 500 mg of oltipraz once a week. However, despite these effects relative to baseline values within the 500-mg weekly arm, there were no statistically significant differences in biomarker trajectories between treatment arms. The genotype for glutathione S-transferase M1, an oltipraz-inducible isoform involved in the detoxification of aflatoxin B1, did not appear to affect either baseline levels or rates of decline in the biomarker. A follow-up Phase IIb trial with a longer intervention period will be necessary to determine the full extent to which aflatoxin biomarker burden can be reduced and whether diminution of biomarkers can be sustained over the long term.

Adult↗
PubMed1998

[Antiochian genealogies in which idiopathic epilepsy presents familial conglomeration. Simulations of power for the detection of genetic linkage].

OBJECTIVE AND METHODS: We have analyzed a set of multigenerational extended pedigrees ascertained from affected cases of idiopathic epilepsy in the Antioquian Neurologic Institute. All pedigrees show familial aggregation of several forms of non myoclonic idiopathic epilepsy. In a recent paper, we have demonstrated that generalized idiopathic epilepsy of the awakening type is better explained by the existence of a major gene. In this paper, we have explored by simulation techniques the usefulness of the bigger pedigrees for linkage analysis. By using simlink and taking into account the parameters of the major gene, we have estimated that total power of three families is approximately 100 million times favoring the linkage detection. RESULTS AND CONCLUSIONS: These analyses suggest that the major gene accounting by the susceptibility to develop generalized idiopathic epilepsy of the awakening type could be localized by typifying affected families belonging to the Paisa community from Antioquia, Colombia (Acta Neurol Colomb 1997; 13: 69-75).

Adolescent↗
PubMed1998

Primary lingual abscess presenting as acute swelling of the tongue obstructing the upper airway: diagnosis with MR.

We report the sudden development of an inflammatory process thought to be of the floor of the mouth with subsequent involvement of the respiratory airway. MR imaging showed an enhancing posterior lingual lesion, consistent with an abscess. Immediate surgical drainage relieved the symptoms. MR imaging allowed accurate diagnosis, which was essential for surgical planning in a condition that was otherwise difficult to diagnose.

Abscess↗
PubMed1998

[Use of 99mTc-tetrofosmin scintigraphy in the diagnosis of patients with hyperparathyroidism].

UNLABELLED: The aim of the work was to study the diagnostic value of 99mTc-tetrofosmin to localize anomalous parathyroid glands in patients with hyperparathyroidism. METHODS: We have studied 33 patients: 12 with primary and 21 with secondary hyperparathyroidism, 9 of them renal graft recipients. Sixteen patients underwent surgery, 12 with primary and 4 with secondary hyperparathyroidism. All patients were injected with 740 MBq of 99mTc-tetrofosmin. Subsequently at 15, 30 and 60 minutes images were acquired for 300 seconds using a pin-hole collimator. A pertechnetate thyroid scintigraphy was obtained in 7 cases (24-48 h later) when the thyroid activity made difficult the identification of parathyroid glands. RESULTS: In the group of patients with primary hyperparathyroidism, all cases showed a focal uptake in lower right localization. In the secondary hyperparathyroidism group, 12 patients showed diffuse tracer uptake in two or more glands and histology confirmed hyperplasia in four of them. Seven cases showed a greater focal uptake in a gland: two of them were renal graft recipients and three were chronic renal failure cases in haemodyalisis, and two were evaluated postsurgery showing uptake in the remnant parathyroid gland. The two remaining patients had a normal scintigraphy and corresponded to two false negative cases. In conclusion, our results suggest that 99Tc-tetrofosmin may be used as a suitable tracer for preoperative detection and screening of anomalous parathyroid glands.

Adenoma↗
PubMed1998

Quality of life in young adults having received a BMT during childhood: a GETMON study. Grupo Español de Trasplante de Médula Osea en el Niño.

A quality-of-life questionnaire study was administered in a group of 98 disease-free survivors more than 3 years after BMT. All participants were over the age of 17 years at the time of the survey. The transplants were performed between 1981 and 1993 in eight Spanish hospitals. Eighty-three percent of patients had undergone BMT for neoplastic disease. Seventy-three per cent received an allogeneic bone marrow transplantation. A modified version of a questionnaire applied in Stanford Hospital to evaluate quality of life in adults after BMT was used. A single investigator was responsible for interviewing all subjects by telephone. We compare these results with the same questionnaire applied in a control group of 58 healthy subjects of similar age. The most significant results were: BMT patients valued their quality of life more highly than the control group. The mean score for global quality of life was 8.19+/-0.17 in BMT group as compared to 7.54+/-0.13 in control group (P=0.0013). Studies were cited as the major concern in both groups: 24% in BMT group and in 69% in control group (C.I. 95%=0.59 to 0.30). The patients in the BMT group considered they had fewer problems in comparison with the control group regarding interpersonal relationships with family members and friends, sleep, depression and leisure possibilities. However, they considered they had more problems concerning their physical appearance, studies and work possibilities than their peers. Considerations regarding weight, height, sexual functioning, anxiety, tendency to suffer illness and problems with insurance were similar in both groups.

Adolescent↗
PubMed1998

[Radionuclide scan with TC-99m-tin colloid in the evaluation of orthopedic implant infections].

We have studied 26 patients (32-77 years old, 16 females) with suspicion of joint arthroplasty infection: 11 total hip replacements, 12 total knee replacements and 3 osteosinthesys. A bone scintigraphy with MDP-99mTc, a scintigraphy with HMPAO-WBC and a scintigraphy with 99mTc-stannous colloid were made in all patients. The final diagnostic was based in joint cultures and clinic and radiologic evolution of the patients. The earliest phase of the bone scintigraphy was positive in 18 patients. The later phase was positive in all them. The WBC was positive in 20 out of 26 patients. The bone marrow scintigraphy showed a congruent pattern with WBC in 18 patients (17 infected and 1 without infection). The other ones (8 patients) showed an incongruent pattern (7 with infection and 1 without it). The results show that the bone marrow scintigraphy with 99mTc-stannous colloid improves the accuracy of the diagnostic of bone prosthesis infection and should be included into the diagnosis protocol of this disease.

Adult↗
PubMed1998

[Treatment of mitochondrial diseases].

Until gene therapy is perfected, developed should reaching for a curative treatment of mitochondrial diseases in a next future, the present management of these metabolic disorders is directed to obtain the optimum energetic efficiency of dysfunctional mitochondria. Among other general measures the patient must avoid fever, exhausting exercise and drugs that inhibit mitochondrial metabolism. Dietetic restrictions are more useful in lipidic disorders, such as fatty acid oxidation or carnitine cycle defects, in which diets free of long chain and very long chain fatty acids are recommended. Pharmacological therapy should always be attempted, since some patients may experience a beneficial response. In respiratory chain deficits, coenzyme Q is the most widely used drug, although in the only double blind placebo-controlled study performed, results were contradictory. In isolated cases, vitamins K3, B2, C and E have been useful. Exogenous carnitine treatment may improve symptoms (sometimes dramatically) in patients with primary or secondary carnitine deficit. Dichloroacetate administration has a mild benefit in some cases of Leigh disease due to pyruvate dehydrogenase deficiency. Finally, sustained aerobic exercise may ameliorate symptoms of exercise intolerance due to mitochondrial dysfunction.

Humans↗
PubMed1998

[Scintigraphic assessment of the severity of inflammatory bowel disease using Tc 99m exametazime-labeled leukocytes].

The aim of the work was to value the utility of semiquantitative scintigraphics indexes (GI) as predictive factor of activity grade of intestinal inflammatory process in patients with confirmed diagnosis of inflammatory bowel disease (IBD). 64 patients have been studied (39 males and 25 females), mean age was 40,2 years (range: 18-88 years) with diagnosis of IBD in acute exacerbation confirmed by endoscopy and biopsy. In all patients was obtained abdominal scintigraphy with 99mTc-exametazine labelled leukocytes. The severity of intestinal inflammatory process was quantified using clinical indexes -Truelove-Witts index (TI) for ulcerative colitis (UC) and Crohn's disease activity index (CDAI), Harvey index (HI) for Crohn disease (CD)-, endoscopic index (EI) and haematological parameters: erythrocyte sedimentation rate (ESR), hematocrit, haemoglobin, leukocyte and platelet count, fibrinogen and albumin level. In all the scans regions of interest were drawn over liver, spleen, bone, abdominal background and positive intestinal segments. Subsequently three GI were calculated: GI1, GI2 and GI3 for the scans obtained at 30 min (P) and 3 h p.i. (T). The evaluation of UC severity showed significant correlation between: 1) The GI1 P and T and TI, EI, ESR, leukocyte and platelet count; 2) The GI2 P and TI and EI; 3) The IG2 T and EI, hematocrit and platelet count; 4) The GI3 P and TI, EI, ESR and platelet count; 5) The GI3 T and TI, EI, leukocytes and platelet count. In the evaluation of CD was observed significant correlation between the GI1 P and GI3 P with the CDAI and EI, between the GI1 T and the GI3 T with the CDAI and ESR; the GI2 did not show significant correlation with any of the valorised parameters. In conclusion, the scintigraphic activity indexes based in the semiquantitative evaluation of scans obtained with 99mTc-exametazine labelled leukocytes showed usefulness in the evaluation of the IBD severity, especially in the UC. Among the studied indexes, IG1 seems the more accurate.

Adolescent↗
PubMed1998

[Nonmetastatic accumulations in bone radionuclide scans in a patient with breast neoplasm].

A 51 year old woman with breast cancer four years ago was studied by bone scintigraphy. At the moment of the study she had bone pain. The bone scintigraphy showed uptake in humerus and femur and no more uptake in other zones of axial skeleton. Then, we made others radiological procedures (X-Ray and MRI) with the aim to make an accurate diagnosis. Then a diagnosis of benign bone tumours; enchondroma was made. It means something obvious but very interesting. In case of doubt we ever have to compare the bone scintigraphy with other diagnostic. examinations.

Bone Neoplasms↗
PubMed1998

Treatment of Ph1-positive chronic myelogenous leukemia in children: comparison between allogeneic bone marrow transplantation and conventional chemotherapy. Spanish Working Party for BMT in Children (GETMON).

BACKGROUND AND OBJECTIVE: To compare the estimated survival and disease-free survival between children with Ph1-positive chronic myeloid leukemia treated with allogeneic bone marrow transplantation or conventional chemotherapy. DESIGN AND METHODS: In this retrospective study we compared the results obtained in a group of 14 children who received allogeneic bone marrow transplantation (BMT) between 1983 and 1993, and another group of 27 children treated with busulfan, hydroxyurea or alpha-interferon during the same time period. Patients were transplanted at a median of 7 months from diagnosis and all except one were in their first chronic phase. Conditioning consisted in total body irradiation and cyclophosphamide in 12 cases, and busulfan was added in two. RESULTS: Of the 14 patients treated with BMT, two died of transplant-related complications and two relapsed 18 and 48 months after the BMT. Ten children remain alive and disease free at a median follow up of 60 months. The probability of DFS at 5 years is 70%. Of the 27 patients treated with chemotherapy, 22 have died at a median of 36 months from diagnosis. The probability of survival at 5 years is 5% versus 83% for the BMT group (p = 0.001). INTERPRETATION AND CONCLUSIONS: Allogeneic BMT is a safe and very effective treatment for Ph-positive CML in children. Patients who have an HLA-identical sibling donor must receive a transplant as soon as possible after being diagnosed.

Adolescent↗
PubMed1998

[Polycystic ovary syndrome: relationship of insulin tissular sensitivity, LH secretion and ovarian morphophysiologic changes].

BACKGROUND: Insulin resistance to LH hypersecretion are recognized features of polycystic ovary syndrome. Previous studies have suggested that both defects are independent from each other. AIM: To examine the relationship between insulin sensitivity and LH secretion in women with polycystic ovary syndrome. PATIENTS AND METHODS: Eighteen women with clinical and biochemical evidence of hyperandrogenism, normal oral glucose tolerance test and polycystic ovaries on ultrasonography, were studied. Insulin sensitivity was assessed using the insulin tolerance test. LH secretion was studied integrating LH values of blood samples taken every 10 minutes for 6 h. Testosterone, testosterone index, SHBG and IGFBP-1 were measured in three selected samples and ovarian volume was assessed by ultrasound. RESULTS: Insulin sensitivity ranged from 0.06 to 0.75 and the area under the curve for LH, from 532 to 8.517 IU/L/6 h. No correlation was found between these two parameters and between each parameter and ovarian volume or androgen concentration. Positive correlations were observed between insulin sensitivity and SHBG concentrations (r = 0.612 p < 0.01) and IGFBP-1 concentrations (r = 0.588 p < 0.001). When compared to patients body mass index of less than 30 kg/m2, patients with body mass index over 30 kg/m2 had significantly lower insulin sensitivity and higher LH levels. In the latter a positive correlation between insulin sensitivity and the area under the curve for LH was observed (r = 0.683 p < 0.02). CONCLUSIONS: Obese polycystic ovary syndrome patients exhibited an inverse correlation between insulin resistance and LH hypersecretion, suggesting a relationship between both defects.

Adult↗
PubMed1997

Nuclear hormone receptor antagonism with AP-1 by inhibition of the JNK pathway.

The activity of c-Jun, the major component of the transcription factor AP-1, is potentiated by amino-terminal phosphorylation on serines 63 and 73 (Ser-63/73). This phosphorylation is mediated by the Jun amino-terminal kinase (JNK) and required to recruit the transcriptional coactivator CREB-binding protein (CBP). AP-1 function is antagonized by activated members of the steroid/thyroid hormone receptor superfamily. Recently, a competition for CBP has been proposed as a mechanism for this antagonism. Here we present evidence that hormone-activated nuclear receptors prevent c-Jun phosphorylation on Ser-63/73 and, consequently, AP-1 activation, by blocking the induction of the JNK signaling cascade. Consistently, nuclear receptors also antagonize other JNK-activated transcription factors such as Elk-1 and ATF-2. Interference with the JNK signaling pathway represents a novel mechanism by which nuclear hormone receptors antagonize AP-1. This mechanism is based on the blockade of the AP-1 activation step, which is a requisite to interact with CBP. In addition to acting directly on gene transcription, regulation of the JNK cascade activity constitutes an alternative mode whereby steroids and retinoids may control cell fate and conduct their pharmacological actions as immunosupressive, anti-inflammatory, and antineoplastic agents.

Activating Transcription Factor 2↗
PubMed1997

Hand/face border as a limiting boundary in the body representation in monkey somatosensory cortex.

Horizontal intracortical connections may form one substrate for representational plasticity in somatosensory cortex. Electrophysiological mapping demonstrated the finer details of the representations of the hand, lower jaw, neck, and face in area 3b of normal macaque monkeys. Injections of two fluorescent tracers then defined the extent to which horizontal connections crossed from the face into the hand representations and vice versa in area 3b. Connections are widely distributed within cortical representations of skin areas innervated by cervical nerves or by the trigeminal nerve but do not cross a border defined by the anterior limit of the representation of skin innervated by the second cervical nerve. This border separates the representation of the muzzle, innervated only by the mandibular nerve, and the representation of the lower jaw and neck region, innervated by the second and third cervical nerves but overlapped by the mandibular nerve. Thus, the muzzle representation lacks connections with the hand and with the lower jaw and neck representations, but the representations of the hand and of the lower jaw and neck are strongly interconnected. Overlap of the hand and of the lower jaw and neck representations and of their horizontal intracortical connections may form one basis for expansions of the lower jaw representation into that of the hand when peripheral input from the hand is lost. Lack of connections with the rest of the face representation may limit this spread.

Afferent Pathways↗
PubMed1997

Plasma viral load and CD4+ lymphocytes as prognostic markers of HIV-1 infection.

BACKGROUND: The rate of disease progression among persons infected with human immunodeficiency virus type 1 (HIV-1) varies widely, and the relative prognostic value of markers of disease activity has not been defined. OBJECTIVE: To compare clinical, serologic, cellular, and virologic markers for their ability to predict progression to the acquired immunodeficiency syndrome (AIDS) and death during a 10-year period. DESIGN: Prospective, multicenter cohort study. SETTING: Four university-based clinical centers participating in the Multicenter AIDS Cohort Study. PATIENTS: 1604 men infected with HIV-1. MEASUREMENTS: The markers compared were oral candidiasis (thrush) or fever; serum neopterin levels; serum beta 2-microglobulin levels; number and percentage of CD3+, CD4+, and CD8+ lymphocytes; and plasma viral load, which was measured as the concentration of HIV-1 RNA found using a sensitive branched-DNA signal-amplification assay. RESULTS: Plasma viral load was the single best predictor of progression to AIDS and death, followed (in order of predictive strength) by CD4+ lymphocyte count and serum neopterin levels, serum beta 2-microglobulin levels, and thrush or fever. Plasma viral load discriminated risk at all levels of CD4+ lymphocyte counts and predicted their subsequent rate of decline. Five risk categories were defined by plasma HIV-1 RNA concentrations: 500 copies/mL or less, 501 to 3000 copies/mL, 3001 to 10000 copies/mL, 10001 to 30000 copies/mL, and more than 30000 copies/mL. Highly significant (P < 0.001) differences in the percentages of participants who progressed to AIDS within 6 years were seen in the five risk categories: 5.4%, 16.6%, 31.7%, 55.2%, and 80.0%, respectively. Highly significant (P < 0.001) differences in the percentages of participants who died of AIDS within 6 years were also seen in the five risk categories: 0.9%, 6.3%, 18.1%, 34.9%, and 69.5%, respectively. A regression tree incorporating both HIV-1 RNA measurements and CD4+ lymphocyte counts provided better discrimination of outcome than did either marker alone; use of both variables defined categories of risk for AIDS within 6 years that ranged from less than 2% to 98%. CONCLUSIONS: Plasma viral load strongly predicts the rate of decrease in CD4+ lymphocyte count and progression to AIDS and death, but the prognosis of HIV-infected persons is more accurately defined by combined measurement of plasma HIV-1 RNA and CD4+ lymphocytes.

Acquired Immunodeficiency Syndrome↗