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Biomedical subjects

A Isla

Publications and source records attributed to A Isla.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Efficacy of arthrodesis in the posterior approach of cervical myelopathy: comparative study of a series of 36 cases].

OBJECTIVE: The effectiveness of arthrodesis associated to laminectomy as a treatment for cervical myelopathy has been retrospectively evaluated analysing the clinical evolution of 36 patients as well as the change in cervical column saggittal curvature comparing a group of patients with a simple laminectomy to another in whom laminectomy was accompanied by posterior arthrodesis. MATERIAL AND METHODS: 36 posterior approaches were performed to treat patients diagnosed of spondyloartrosic myelopathy between 1992 and 1999; 19 cases were treated with a simple laminectomy and other 17 also underwent arthrodesis with posterior instrumentation. The clinical evolution (using grades 0-5 on the Nurick scale) and cervical curvature have been evaluated for an average time interval of 40 months. RESULTS: Patients treated with laminectomy plus arthrodesis showed an average 1.24 point improvement on the Nurick scale in comparison to the 0.84 point improvement observed in patients treated with laminectomy alone. The cervical curvature attained a more physiological angulation in 53% of the patients with an arthrodesis and in 29% of the patients with simple laminectomy; curvature worsened in 7% of the patients with arthrodesis and in 24 degrees/a of those with laminectomy alone. CONCLUSION: Cervical myelopathy cases requiring a posterior approach for laminectomy obtain a better clinical evolution when an arthrodesis with posterior instrumentation is associated with the laminectomy. These patients also present improved cervical curvature as compared to the group without instrumentation.

Adult↗
PubMed2001

Inflammatory pseudotumor of the median nerve. Case report and review of the literature.

The authors report the presence of an inflammatory pseudotumor of the median nerve in a young woman who presented with a sensorimotor deficit in the median nerve area. Magnetic resonance (MR) images revealed a fusiform mass in the nerve, and the patient underwent surgery for a suspected peripheral nerve-sheath tumor. Her clinical condition improved slowly and notably. Histological study revealed a heterogeneous lymphoid infiltration with mononuclear cells, lymphocytes (mostly T cells), and plasmocytoid cells. Because of the unknown significance of this infiltration, the patient was examined to exclude the possible diagnosis of a systemic tumoral process. All the studies yielded negative results and no systemic disease was found. Later, control MR imaging revealed no tumoral remains, and electromyography demonstrated progressive improvement of median nerve function. The follow-up period has been 8 years. The cause of the lesion is unknown. The differential diagnosis includes benign and malignant peripheral nerve-sheath tumors, lymphoma, and all tumorlike lesions of peripheral nerves.

Adult↗
PubMed2001

Absence of mutation of the p73 gene in astrocytic neoplasms.

In subgroups of astrocytic neoplasms, including glioblastoma (GBM), mutations of the p53 tumour suppressor gene lead to loss of growth-suppressive properties. A p53-related gene termed p73 has recently been identified; its gene product shows structural and functional similarities to p53. After being mapped to chromosome region 1p36, p73 was proposed to act as a tumour suppressor gene, as this region is frequently deleted in a variety of human cancers, including astrocytic tumours. To determine whether p73 is involved in astrocytoma/GBM development, we analysed 10 pilocytic astrocytomas, 15 WHO grade II astrocytomas, 15 WHO grade III anaplastic astrocytomas, and 20 GBM for p73 gene alterations. In parallel, we used six polymorphic markers to determine the allelic status of region 1p36 in this tumour series. Although loss of heterozygosity was evidenced in 12 of 60 cases (20% of samples), PCR-SSCP and direct sequencing failed to detect any gene mutation in the entire coding region and intronic sequences of p73. Eight tumours displayed five distinct polymorphic nucleotide changes, also present in the corresponding normal DNA. These variations consisted of T-->C variation, with no change in Thr173; C-->T transition, with no change in His197; exon 9 simultaneous double change C-->T and T-->C , with no variations in Ala336 and His349, respectively, and C-->T change at exon 9/-24 position of intron 8. These results suggest that, in astrocytic gliomas, p73 may not play a major role as a tumour suppressor, but the relatively high incidence of LOH confirms the presence at 1p36 of an as yet unidentified gene of this category, with a key function in astrocytoma/GBM progression.

Astrocytoma↗
PubMed2000

Malignant triton tumor in the thoracic spine.

We present a 15-year-old patient diagnosed with peripheral neurofibromatosis (NF-1), who was admitted with paraparesis caused by a large intrathoracic tumor with an intracanalicular component that affected the spinal cord. After surgery his condition improved, but a year later he suffered a relapse and died. Histologically the tumor was diagnosed as malignant with neurogenic and myogenic differentiation ("malignant triton tumor"). Malignant triton tumors (MTT) are infrequent; those found in the head and neck and the upper or lower extremities have a better prognosis than those in the retroperitoneum, buttock, or trunk. It is not clear whether this variation is due to a difference in tumor grade, stage, or resectability, or whether it is a consequence of therapy.

Adolescent↗
PubMed2000

Periosteal glomus tumor of the femur: a case report.

Osseous abnormalities produced by glomus tumors located in soft tissues of the periungual region have been described. More rare is the location of a glomus tumor within bone, which usually is located in the phalanx of the fingers. However, to the authors' knowledge, there is no previous description of a glomus tumor located in a periosteal location of a long bone. A 50-year-old man with a glomus tumor in a periosteal location of the lower metaphysis of the femur without neoplastic erosion of the cortical surface is reported. Magnetic resonance imaging and intraoperative ultrasonography were needed to locate the lesion.

Femoral Neoplasms↗
PubMed2000

Intramedullary spinal cord metastasis. A case report.

This 54-year-old patient with a breast carcinoma of one year's evolution presented a progressive paraparesis and sphincter disregulation of a week evolution; MRI image showed a tumor in the medullary conus. She improved after removal of the conus mass. The histologic diagnosis was metastasis of adenocarcinoma. Metastasis at this level is infrequent and represents less than 1% of all spinal metastases. When the patients' general condition is good, surgery can relieve the neurologic deficit produced by the medullary mass.

Adenocarcinoma↗
PubMed1999

Anatomical and functional connectivity of the transected ulnar nerve after intercostal neurotization in cats.

OBJECT: Acute transfer of three intercostal nerves to the ulnar nerve was performed in cats for histological and clinical evaluation of a distal muscle reinnervation. METHODS: Infraclavicular intercostal-ulnar communications were created after dividing the motor branches of the upper intercostal nerves in 14 adult cats. Reinnervation of distal forelimb muscles in the ulnar territory was assessed by electromyographic (EMG) studies and motor function rating each month until 18 months postsurgery. In five of these treated animals, and in tour controls, horseradish peroxidase (HRP) was applied to the ulnar or intercostal nerves to study the amount and distribution of retrograde motor neuron labeling in the spinal cord. Also, samples of reinnervated muscles and neurotized ulnar nerves were processed to assess regeneration. Simple ulnar transection without reconstruction led to permanent atrophy of ulnar muscles, lack of recovery according to EMG or clinical studies, and disappearance of the ulnar motor neuron pool. In contrast, ulnar neurotization with the intercostal nerves led to a high rate of functional recovery, which began 5 months postsurgery, and progressed from muscle activity synchronized with ventilatory movements to spontaneous movements that were independent of respiration. This recovery was accompanied by substantial retrograde labeling of intercostal motor neurons after HRP application in the ulnar nerve. Cell counts showed that practically the whole motor neuron pool of the involved intercostal nerves contributed to reinnervation of the transected ulnar nerve. CONCLUSIONS: These findings demonstrate that the use of intercostal nerves to neurotize long brachial plexus nerves can achieve long-lasting and successful reinnervation of distal forelimb muscles.

Animals↗
PubMed1998

Is radical hepatic surgery safe?

BACKGROUND: A prospective review of 200 consecutive liver resections performed for benign and malignant disease, between 1989 and 1995 at the Hammersmith Hospital, was undertaken to evaluate the safety of radical hepatic resection. METHODS: The indications for operation were: hepatocellular carcinoma (n = 39), cholangiocarcinoma (n = 21), gall bladder carcinoma (n = 8), colorectal secondaries (n = 75), noncolorectal secondaries (n = 35), and benign disease (n = 26). Twenty patients were cirrhotic and 36 were jaundiced. Major resections were performed in 74% of cases and included 63 extended hepatectomies, 17 repeated resections for recurrent colorectal metastases, and 17 resections combined with vascular reconstruction. Total vascular exclusion of the liver was used in the majority of cases. RESULTS: The overall mortality rate was 5%. Thirty-day mortality was 2.5%. Sepsis and not hemorrhage was the most common cause of death. There were 101 complications that occurred in 37% of the patients. The main complications were subphrenic abscess and biliary leak. The extent of liver resection (major versus minor) significantly increased the risk of morbidity (46% versus 16%). Blood loss greater than 100 mL increased the risk of morbidity from 12% to 25%. CONCLUSIONS: Major hepatic resection can be achieved with acceptable mortality but high morbidity rates.

Adolescent↗
PubMed1998

p53 mutation is a poor prognostic indicator for survival in patients with hepatocellular carcinoma undergoing surgical tumour ablation.

Forty-two patients with hepatocellular carcinoma (HCC) were resected and their tumours were analysed for p53 mutations by GC-clamped denaturing gradient gel electrophoresis (DGGE), single-strand conformation polymorphism (SSCP) and gene sequencing. All the exons have been analysed in this study. Eight of 12 HCCs with cirrhosis due to viral hepatitis and the two patients with sarcomatoid changes displayed p53 mutations. In contrast, no mutation was observed in the fibrolamellar variant (n = 9), non-cirrhotics (n = 13) and alcoholic cirrhosis (n = 6). The mutations observed were in exons 5-8. Two mutations were observed in codons 136 and 213 as well as a T insertion between residues 156 and 157 (exon 5) and these are reported for the first time in HCC. Likewise, the silent mutation polymorphism in codon 213 was noticed in 3 of the 42 patients. Survival analysis of these patients after surgery showed the mean and median survival in patients with wild-type p53 to be 60 and 43 months respectively. In the group with p53 mutations, the mean and median survival was 15 and 12 months. The difference was statistically significant (P= 0.003).

Adolescent↗
PubMed1997

Gene therapy in brain tumours: implications of the size of glioblastoma on its curability.

The authors have used the thymidine kinase/ganciclovir system to block glioblastoma multiforme neoplastic cells in vivo, both in experimental animals and in two patients in which the more conventional therapies had been unsuccessful. In the Wistar rat it was found that the curability potential of the system is correlated with tumoral volume. Tumours smaller than 20 mm3 can be cured with defective retrovirus that do not carry the Herpes simplex thymidine kinase (Hsvtk) gene. While tumours smaller than 150 mm3 can regress totally by the kinase/ganciclovir system, those above that size cannot be cured by this treatment. In humans the situation seems very similar in that the authors have been unable either to reduce the tumour size of recurrent patients with tumour volumes larger than 100 cm2 applying the standard thymidine kinase/ganciclovir gene therapy or to prolong their survival time more than 8 months [7]. When a combination of size reduction by neurosurgery and gene therapy was used the survival time increased considerably. Two patients have been treated by partial surgery and repeated treatment with thymidine kinase/ganciclovir through an Ommaya reservoir connected to a catheter leading into the tumour cavity. The magnetic resonance imaging (MRI) of these patients show only a residual tumoral growth along side the tumoral bed. The procedure may be partially controlling the proliferation of cancerous cells, because, these two patients having recurrent glioblastoma, are alive 11 and 17 months after the beginning of the treatment.

Animals↗
PubMed1997

Brain tumor and pregnancy.

OBJECTIVE: To establish the indications for surgical intervention, at the appropriate gestational duration, for brain tumors in pregnant women, and to evaluate any association pregnancy hormones may have with the rate of growth or development of complications of brain tumors. METHODS: We observed seven women with brain tumors associated with pregnancy in a series of 126,413 pregnancies from 1983 to 1995. One woman presented with symptoms of intracranial hypertension, and neurologic signs were the first symptoms in two other women. One woman presented with a sudden hemorrhagic lesion, and three had focal seizures. All were evaluated with computed tomography, magnetic resonance imaging, or both. RESULTS: Six of the seven women had surgery; the seventh was treated with radiotherapy because the neuroradiologic studies suggested a quickly growing brainstem glioma. Diagnoses were confirmed on histology in six women: two with meningiomas, two with ependymomas, and two with low-grade astrocytomas (one of these had multiple astrocytomas). Estrogen and progesterone receptors were studied in two cases (one meningioma and one astrocytoma) and were present in both. CONCLUSION: Management of brain tumors should be tailored to the individual patient. There may be a relation between pregnancy hormones and the rate of brain tumor growth mediated through specific intracellular receptors.

Adult↗
PubMed1997

Evaluation of the effect of 3 different diets on the bioavailability of 2 sustained release theophylline matrix tablets.

Food-induced changes on bioavailability of 2 sustained release theophylline matrix tablets, which uses an hydrophilic matrix of Carbopol 974P and lipid matrix of hydrogenated castor oil (Cutina HR) as sustaining agents, have been studied in 2 different groups of 12 healthy male volunteers. The study design was a 4 x 4 Latin square involving 12 subjects who received a single dose of the tablet while fasting or with a standarized normal, high fat or high fat/high protein meal. The results for both formulations showed no differences in t1/2 and MRT when the tablets were administered with any type of diet. No differences in tmax and AUC were found when the Carbopol matrix tablet was administered with any class of diet. Higher Cmax were obtained when the tablet was administered with any class of meal. The analysis of the ratio Cmax/AUC evidenced that changes in Cmax for normal and high fat diet were attributable to higher rate of absorption, probably due to a delay in gastric emptying, thus avoiding the rapid formation of the gel structure which controls the liberation of theophylline. Three subjects showed a probable bioadhesive behavior of the formulation in the fasted condition. The lipid matrix tablet showed a statistical significant delay in tmax comparing the fasted condition with the different diets. AUC, Cmax, and the ratio Cmax/AUC did not change when the tablet was administered with the normal diet. High fat and high fat/high protein diets produced higher AUC (31% and 40%, respectively) and Cmax (40% and 56%, respectively) than under fasting condition. The analysis of the ratio Cmax/AUC indicated that changes in Cmax were more probably due to changes in the amount absorbed. In conclusion, a sustained-release theophylline tablet formulated as a lipid matrix is affected by any meal with a high fat content, probably because of the increase of pancreatic and biliary secretions promoted by the meal that would affect the matrix itself. Normal diet showed this behavior but only as a nonsignificant trend. It seems appropiate to recommend to dose both formulations at least 2 hours before meal, or under consistent conditions of fasting or nonfasting state to assure reproducible absorption or clinical response.

Area Under Curve↗
PubMed1997

[Factors associated with the incurability of epidemic neuropathy in Cuba].

56 patients were surveyed and reexamined at the Center for Medical and Surgical Research (CMSR) a year after the onset of the neuropathy epidemic. The possible factors associated with the occurrence were investigated to be studied together with the disease persistence, including the antibody titre of 33 of them, who had a previous serology against the biological agent (strain 47/IPK) isolated from the cerebrospinal fluid of a sick patient. A fourth of the patients (15 cases) were still ill. The loss of weight and the smoking habit were stressed as the factors most associated with the persistence of the clinical manifestations of epidemic neuropathy. In spite of the fact that the small number of patients who underwent the checkup limited the study, this is a basic document about the existent situation a year after the problem happened.

Antibodies, Viral↗
PubMed1996

Primary cranial vault lymphoma mimicking meningioma.

Primary lymphomas of the cranial vault are rare; only six patients have been described in the literature. We report a 75-year-old woman who was admitted to our hospital after a focal seizure. CT showed a homogeneous mass which, on contrast enhancement, was similar to a meningioma. The tumour was excised and found to be a centroblastic, centrocytic non-Hodgkin's lymphoma. Treatment was completed with radiotherapy and chemotherapy.

Aged↗
PubMed1996

Human malignant brain tumor response to herpes simplex thymidine kinase (HSVtk)/ganciclovir gene therapy.

Growing cells from human brain tumors have been treated in vitro and in vivo with murine therapeutic retroviral producer cells. The therapeutic retrovirus carried the potential suicide gene thymidine kinase (tk) from the herpes simplex virus (HSV). After a few days, in which a large proportion of the tumoral cells had the opportunity to acquire a copy of the retrovirus, treatment with ganciclovir was initiated and considered responsible for considerable cell death both in vitro and in vivo. The in vivo experiments were performed in five adult patients who had failed standard therapy and were expected to survive only a few weeks.

3T3 Cells↗
PubMed1995

[Absent or reverse diastolic umbilical flow].

We show our experience in the diagnostic and management of 19 pregnancies with absent or reverse diastolic blood flow velocity (ARFV) in the umbilical artery. The presence of ARFV was a rare condition (2.2% of the high risk patients), and it was associated with a poor prognosis shown by the high percentage of fetuses SGD (small for gestational age) (63.2%), malformations and hydrops fetalis (26%) and asphyxiated fetuses, giving a final perinatal mortality rate of 36.8%. In 8 cases (42.1%) the termination or pregnancy was delayed for at least 48 hours, allowing in some cases the administration of corticosteroid. There were significant differences when comparing the groups of survivors and non survivors in relation to the gestational age at the moment of delivery (33.1 +/- 3.4 vs 28.6 +/- 3.8 weeks), malformations (8.3 vs 57.1%) and C-section (91.7 vs 42.9%). Finally, we conclude that the presence of ARFV in the umbilical artery is associated with a critical fetal condition and termination of pregnancy should be considered. In this decision the gestational age and fetal and maternal well being ought to be taken into account when choosing the best moment and route of delivery.

Adult↗
PubMed1994

Serpentine aneurysm: regrowth after a superficial temporal artery-middle cerebral artery bypass and internal carotid artery ligation: case report.

Giant serpentine aneurysms (GSAs) are infrequent. We present a 37-year-old patient with a giant serpentine aneurysm of the left middle cerebral artery that was treated with a superficial temporal artery to middle cerebral artery bypass and ligature of the left internal carotid artery. After 2 years, the patient presented new symptoms of neurological deterioration and the computed tomographic scan and arteriography showed regrowth of the aneurysm, which was excised. Enlargement of a giant serpentine aneurysm once it has been treated with ipsilateral carotid ligation and/or bypass anastomosis is rare, and only two cases have been described previously.

Adult↗