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Biomedical subjects

A Rubio

Publications and source records attributed to A Rubio.

At least 91 records · Page 5Linked to original sources
PubMed1998

[Transesophageal echocardiography follow-up of patients operated on using the Bono-Bentall technique in aneurysms or dissection of the ascending aorta].

INTRODUCTION: Increasingly patients are surviving after reconstructive surgery of the ascending aorta. These patients require follow-up to detect postoperative prognostic markers, such as persistence of the flow in a false lumen, intimal rupture, or graft complications. We conducted a study with transthoracic and transesophageal echocardiography in order to detect residual abnormalities and establish the usefulness of this technique in a group of patients after Bono-Bentall surgery for ascending aorta pathology. PATIENTS AND METHODS: Twelve patients were studied with transthoracic and transesophageal echocardiography, four after surgery for annulo-aortic ectasia with severe aortic insufficiency and eight for type A aortic dissection. The Bono-Bentall surgical procedure was used in all the patients with Cabrol's modification being added in three. RESULTS: Seven of the eight (87%) patients with aortic dissection had residual abnormalities: five persistence of the distal dissection, one pseudo-aneurysm, and one peritubular haematoma. A residual lesion (pseudo-aneurysm) was found in just one of the four patients (25%) who underwent surgery for annulo-aortic ectasia. The ejection fraction was normal in those patients who had been operated on for aortic dissection and depressed in those who had annulo-aortic ectasia (60 +/- 9 vs 40 +/- 10; p = 0.005). CONCLUSIONS: In patients undergoing surgery with the Bono-Bentall procedure there is a high incidence of residual aortic abnormalities, especially when the operation is for aortic dissection. Transesophageal echocardiography is an ideal diagnostic method for the detection and follow up of residual abnormalities after ascending aorta surgery. We believe this technique should be included in the periodic follow up of these patients.

Adult↗
PubMed1998

Dynamics of serum cytokines in patients with visceral leishmaniasis and HIV-1 co-infection.

Serum cytokine levels and peripheral T cell subpopulations of HIV-1-infected patients before, during and after active visceral leishmaniasis (VL) were analysed and compared with appropriate controls. At VL diagnosis, co-infected patients showed higher serum levels of interferon-gamma (IFN-gamma) than matched HIV-1 controls without VL, and lower serum concentrations of IL-10 than non-immunocompromised VL controls. High levels of tumour necrosis factor-alpha (TNF-alpha) and IFN-gamma were present in the sera of HIV-1-infected patients with active VL. TNF-alpha remained elevated after VL recovery. A steady decline in the CD4+ cell count, an increase of serum HIV viraemia and a progressive seroconversion for the HIV-1 p24 antigen was observed during the course of VL disease. Thus, an aberrant activation of the TNF system with possible negative immunological and virological consequences is present in HIV-1-infected patients with VL. A more extensive prospective validation of these findings in a bigger cohort of patients will nevertheless be necessary. The results support the hypothesis that different opportunistic infection agents may trigger the production of proinflammatory cytokines during immunodeficiency, and in this way accelerate the course of HIV-1 disease.

AIDS-Related Opportunistic Infections↗
PubMed1998

MR imaging of the mamillothalamic tract.

PURPOSE: To demonstrate the normal and abnormal appearance of the mamillothalamic tract (MTT) on cranial magnetic resonance (MR) images. MATERIALS AND METHODS: Two formalin-fixed normal human brain specimens sectioned in axial and coronal planes were used to demonstrate the normal anatomy of the MTT. MR images were obtained in 32 volunteers. Proton-density-weighted coronal and axial pulse sequences were used. The images were evaluated for visualization quality and size and signal intensity of the MTTs in correlation with the specimens. Abnormal MTTs were identified on cranial MR images in two patients, and the imaging findings were analyzed. The clinical history of the patients was also reviewed to determine the effect of these findings on patient care. RESULTS: Normal MTTs were easily identified on MR studies of cadaveric brains and of the brains of the human volunteers. On MR images, normal MTTs were commonly symmetric in appearance, with signal intensity equal to that of other normal fiber tracts. The abnormal MTTs showed high signal intensity on images obtained with a long repetition time or asymmetric volume loss and were associated with atrophy of the ipsilateral mamillary body. CONCLUSION: Normal MTTs are readily visible on conventional MR images. Abnormality of the MTT is a very subtle finding but may be a marker of a limbic system abnormality.

Adult↗
PubMed1998

A review of Lewy body disease, an emerging concept of cortical dementia.

Dementia associated with cortical Lewy bodies on neuropathologic examination may comprise the second largest category of age-related cognitive impairment, after Alzheimer's disease. Despite its prevalence, a consensus has not yet been reached regarding the terminology, neuropathologic criteria, or clinical symptomatology of this postulated nosologic entity. Lewy body disease (LBD) is beginning to be diagnosed clinically in neuropsychiatric clinics, but universally accepted diagnostic criteria for LBD remain to be validated. In this article the authors review the literature on LBD, including both neuropathologic and clinical findings.

Aged↗
PubMed1998

Lewy body disease: can we diagnose it?

The authors assessed the accuracy of published clinical criteria and their own modifications of those criteria in diagnosing Lewy body disease (LBD). Clinical diagnoses were made by two clinicians, blinded to neuropathologic diagnoses, using the Rochester Alzheimer's Disease Center database and traditional medical records. Neuropathologic diagnoses were made according to published guidelines. Results from 21 Alzheimer's disease and 18 LBD patients indicated that no set of clinical criteria was accurate in diagnosing LBD. The only significant predictor of LBD in this population was depression, which was more common in LBD than in Alzheimer's disease. The authors conclude that clinical identification of LBD is an important but unresolved neurological problem.

Adult↗
PubMed1997

X-ray-induced synaptonemal complex damage during meiotic prophase in female fetuses of Rattus norvegicus.

The different types of damage (synaptic anomalies, chromosome reorganizations and nucleolar fragmentation) observed in oocytes from female rat fetuses irradiated at 14, 16 and 18 days of gestation (d.g.), respectively, indicates the existence of a special sensitivity at the different stages of prophase to X-rays. At the highest dose (5 Gy), we observed a decrease in some of the synaptonemal complex indicators of chromosomal damage, probably reflecting a selection against cells with the highest degree of chromosome anomalies.

Animals↗
PubMed1997

Motor neuron disease and angiotropic lymphoma.

BACKGROUND: The number of patients with motor neuron disease (MND) and a concomitant hematologic disorder appears to be overrepresented. Angiotropic large cell lymphoma, a rare and aggressive type of lymphoma, has been associated with MND only once (to our knowledge) prior to this report. There are more than 35 cases of MND associated with lymphoma or monoclonal gammopathy reported in the literature. The nature of this association remains disputable. OBJECTIVE: To investigate whether the association between some MNDs and certain hematologic disorders is coincidental or pathogenetically related. CASE PRESENTATION: We describe the clinical and neuropathologic findings in a case involving a 70-year-old man with a rapidly progressive lower MND who at autopsy also exhibited angiotropic large cell lymphoma without ischemic lesions in the nervous system. CONCLUSIONS: This case supports the notion that the association between some MNDs and certain hematologic disorders is not coincidental but pathogenetically related. A 2-hit hypothesis is proposed in which an initial abnormal glycosylation in motoneurons would require the production of an appropriate autoantibody for disease expression.

Aged↗
PubMed1997

Phenotypic variability of CADASIL and novel morphologic findings.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a non-arterio-atherosclerotic, non-amyloidotic arteriopathy affecting preferentially the small arteries and arterioles of the brain. The morphologic hallmark is the presence of a characteristic granular alteration of the arterial media that ultrastructurally corresponds to the accumulation of electron-dense material surrounding the smooth muscle cells. Although the presence of this granular osmiophilic material (GOM) was originally described as limited to brain vessels, identical electron microscopic findings have been demonstrated in the media of peripheral tissue arteries, allowing for a pathologic diagnosis of the disease by a simple skin, muscle or nerve biopsy. We report some atypical features identified in our CADASIL patients that broaden the phenotypic expression of this disease. Firstly, we identified a cortical infarct in an otherwise typical CADASIL patient. Secondly, we observed GOM in skin arteries of a 30-year-old man with hemiplegic migraine, the son of a woman who had died with CADASIL. This confirms that it may be possible to diagnose the disease at a preclinical stage by the ultrastructural evaluation of peripheral tissue biopsy material, particularly for individuals for whom there is a supporting family history. Thirdly, ultrastructural examination of the skin, and subcutaneous and striated muscle of an unrelated and apparently sporadic patient with neuropathologic and neuroradiologic evidence of CADASIL in meningeal and cerebral vessels failed to reveal diagnostic lesions in peripheral arteries. Thus, the possibility of a false-negative pathologic diagnosis in patients with a clinicoradiologic diagnosis of CADASIL, if one relies solely on a peripheral tissue biopsy, does exist. Additionally, we have identified heat shock proteins (Hsp70 and alphaB crystallin) and ubiquitin in the vascular myocytes of affected arteries. B crystallin also seemed to be deposited extracellularly, which suggests that GOM also might be immunoreactive for alphaB crystallin.

Adult↗
PubMed1997

Different experimental conditions which regulate type II 5'-deiodinase mRNA in rat Harderian gland.

In the present study, we describe the modifications in the expression of type II 5'deiodinase activity (5'D) in Xenopus laevis oocytes by injection of polyadenylated (poly A) mRNA from hypothyroid rat Harderian gland. The time-course study showed that the expression of the enzyme was dependent on time. Thus, enzyme activity was observed in oocytes 6 and 12 hours after the injection with poly A mRNA, reaching a maximal value at 24 hours. The activity was partially inhibited by 6-n-propyl-thiouracil, completely inhibited by iopanoic acid and exhibited a higher affinity for the T4 (Km=1.5 nM) than rT3 (Km=20 nM). The expression of the enzyme was modified in different experimental conditions: (a) exhibited diurnal variations with maximal peak values at night, (b) was inhibited by light at night and, (c) was activated by isoproterenol. On the other hand, we have also identified, for the first time, the size of mRNA capable of inducing 5'D in rats.

Adrenergic beta-Agonists↗
PubMed1997

[Asymptomatic aortic dissection in a patient with aortic valve prosthesis].

The occurrence of iatrogenic aortic dissection after aortic valve replacement is uncommon, usually late, and exceptionally asymptomatic. We present here a case of dissecting aneurysm suspected by excessive mediastinal dilatation observed in the routine annual roentgenogram exam of a patient who has had an aortic valve prosthesis for thirteen years. The confirmation with other diagnostic methods and its successful surgical treatment are also described.

Aortic Dissection↗
PubMed1997

March 1997--4 year old girl with ring chromosome 22 and brain tumor.

A four year old Caucasian girl with a constitutional ring chromosome 22 abnormality and developmental delay presented with increasing ataxia and a six week history of non-specific symptoms. Imaging studies demonstrated a large third ventricular tumor with apparent involvement of the septum. Microscopic and immunohistochemical studies demonstrated an atypical teratoid/rhabdoid tumor. This tumor is compared and contrasted to peripheral malignant rhabdoid tumors and central primitive neuroectodermal tumors. The role of a putative tumor suppressor gene on the long arm of chromosome 22 in the pathogenesis of these tumors is also discussed.

Brain Neoplasms↗
PubMed1997

Solitary subglottic neurofibroma: MR findings.

We present a case of subglottic neurofibroma, which is of interest because laryngeal neurofibroma rarely occurs in the subglottic space. Nonspecific MR findings did not allow us to exclude the preoperative diagnosis of hemangioma.

Biopsy↗
PubMed1997

[Diagnosis and treatment of laryngeal radionecrosis].

Three cases of laryngeal radionecrosis are reported. In two cases partial surgery after radiotherapy probably triggered the radionecrosis. All patients were treated successfully with medical therapy. Laryngeal radionecrosis is an uncommon complication of radiotherapy for carcinoma of the head and neck. The interval between conclusion of radiation therapy and development of radionecrosis ranges from 3 to 12 months. Neither computed tomography nor magnetic resonance imaging differentiate between necrotic tissue and recurrent tumor. Humidification, broad spectrum antibiotics, steroids, and hyperbaric oxygen, with or without surgery, are successful in many cases.

Carcinoma, Squamous Cell↗
PubMed1996

Effect of X-rays on germ cells in female fetuses of Rattus norvegicus irradiated at three different times of gestation.

We analyzed the effect of X-rays on the number of recoverable germ cells in female rat fetuses irradiated at three different times of gestation: 14 days (oogonia), 16 days (leptotene) and 18 days (zygotene). Our results show that irradiation significantly decreases the number of germ cells, and increases the incidence of synaptonemal complex fragmentation. The different sensitivity of the germ cells to irradiation could depend on the meiotic stage at the time of irradiation.

Animals↗
PubMed1996

Sexual differences in 5'-deiodinase activity in the Harderian gland of Syrian hamsters and the effect of pinealectomy: regulation by androgens.

Sexual differences on thyroxin 5'-deiodinase (5'-D) in the Harderian gland of Syrian hamsters were investigated. We compared the 24-h profile of 5'-D activity in male and female hamsters, observing a clear rhythm in males but not in females. Female values were always significantly higher than male ones. After pinealectomy day/night variations in male 5'-D activity at the time points studied were abolished, results that are in correlation with serum thyroid hormones. We also studied the regulation by androgen of the enzyme activity. Basal 5'-D activity increased in castrated males and levels fell when animals were implanted with testosterone or its product 5 alpha-dihydrotestosterone (DHT). Female 5'-D activity was also inhibited by androgens. As only the addition of DHT in the presence of epitestosterone, an inhibitor of the conversion of testosterone on DHT, in castrated males was able to decrease 5'-D activity to the control animal levels, we suggest a probable direct effect of DHT by itself.

Androgens↗