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Biomedical subjects

M Blazquez

Publications and source records attributed to M Blazquez.

12 recordsLinked to original sources
PubMed2006

LRRK2 mutations are a common cause of Parkinson's disease in Spain.

Pathogenic mutations in the leucine-rich repeat kinase 2 gene (LRRK2; PARK8) have been implicated in autosomal dominant, late-onset parkinsonism. The LRRK2 6055G > A (G2019S) mutation is the most common reported to date, and has been observed in a number of different European populations. So far, only the LRRK2 4321C > G (R1441G) mutation has been identified in the Spanish population. Herein we have assessed the frequency of G2019S in a referral-based series of 225 patients with Parkinson's disease (PD) from the region of Asturias, Northern Spain. The mutant allele was identified in five (2.7%) of the sporadic late-onset patients and was not present in control subjects. All carriers displayed genetic profiles consistent with the same haplotype, as previously reported for Lrrk2 G2019S-positive subjects. None of these patients presented with a family history of parkinsonism at the time of diagnosis. Thus, approximately 5% of sporadic patients with PD from the North of Spain have either Lrrk2 G2019S or R1441G substitutions.

Aged↗
PubMed1999

A novel p34(cdc2)-binding and activating protein that is necessary and sufficient to trigger G(2)/M progression in Xenopus oocytes.

The activation of maturation-promoting factor (MPF) is required for G(2)/M progression in eukaryotic cells. Xenopus oocytes are arrested in G(2) and are induced to enter M phase of meiosis by progesterone stimulation. This process is known as meiotic maturation and requires the translation of specific maternal mRNAs stored in the oocytes. We have used an expression cloning strategy to functionally identify proteins involved in G(2)/M progression in Xenopus oocytes. Here we report the cloning of two novel cDNAs that when expressed in oocytes induce meiotic maturation efficiently. The two cDNAs encode proteins of 33 kD that are 88% identical and have no significant homologies to other sequences in databases. These proteins, which we refer to as p33(ringo) (rapid inducer of G(2)/M progression in oocytes), induce very rapid MPF activation in cycloheximide-treated oocytes. Conversely, ablation of endogenous p33(ringo) mRNAs using antisense oligonucleotides inhibits progesterone-induced maturation, suggesting that synthesis of p33(ringo) is required for this process. We also show that p33(ringo) binds to and activates the kinase activity of p34(cdc2) but does not associate with p34(cdc2)/cyclin B complexes. Our results identify a novel p34(cdc2) binding and activating protein that regulates the G(2)/M transition during oocyte maturation.

Amino Acid Sequence↗
PubMed1997

Endoscopic ultrasonography for the initial staging and follow-up in patients with low-grade gastric lymphoma of mucosa-associated lymphoid tissue treated medically.

BACKGROUND: Endoscopic ultrasonography is an appropriate procedure to assess the depth of tumoral infiltration in primary gastric lymphoma. The aims of the present study were to characterize the endoscopic ultrasonographic aspects of low-grade gastric lymphoma of mucosa-associated lymphoid tissue and to determine the value of this procedure in medical treatment assessment. METHODS: Between 1991 and 1996, 15 patients with low-grade gastric lymphoma of mucosa-associated lymphoid tissue were treated with oral cyclophosphamide and/or anti-Helicobacter pylori treatment. Endoscopic ultrasonography was carried out at the time of the diagnosis in all patients, 8 of whom (4 in complete remission and 4 with a stable or progressive disease) had at least one endoscopic ultrasonography examination within the treatment period (median follow-up 17 months). RESULTS: The initial procedure showed an increased gastric wall thickness from 6 to 12 mm in 8 patients, equal to 5 mm in 5 patients, and normal in 2 patients. The thickening was predominantly of the mucosa alone and/or the submucosa but never extended beyond the muscularis propria. No lymph node was found. Gastric wall thickness returned to normal in the 4 patients in complete remission and remained thick in 3 of the 4 patients with a stable or progressive disease. Of these 3 patients, at least one set of biopsy samples, carried out during follow-up, showed the absence of lymphoma, but histology performed subsequently found evidence of disease. CONCLUSIONS: Endoscopic ultrasonography differentiates superficial from infiltrative types of gastric lymphoma of mucosa-associated lymphoid tissue, which may have a prognostic significance and confirms remission or persistence of the disease with medical treatment during follow-up. When the gastric wall remains thick, even if histology is negative, repeated biopsies should be performed to detect evolving disease or relapse.

Adult↗
PubMed1994

Luminescence spectroscopy of pyridoxic acid and pyridoxic acid bound to proteins.

Luminescence techniques, i.e. fluorescence and phosphorescence, have been employed to study pyridoxic acid bound to proteins through a stable amide linkage. Proteins tagged with 4-pyridoxic acid display the following fluorescence properties: (a) emission and excitation spectra centered at around 430 and 320 nm, respectively; (b) fluorescence quantum yields of 0.3-0.4 and (c) average decay times covering the range 8-9.6 ns. The fluorescence properties of the probe have been used to study the dynamics of the protein in the nanosecond time scale. In the absence of molecular oxygen, free and bound 4-pyridoxic acid exhibit long-lived emission at room temperature. The long-lived emission is red-shifted when compared to fluorescence and decays with average life times ranging over 2.2-0.6 ms depending on the nature of the protein. The fluorophore pyridoxic acid covalently linked to proteins is suitable to study the dynamics of proteins, i.e. fast and slow motions of the macromolecule in the nanosecond and millisecond time scales, respectively.

Fluorescence Polarization↗
PubMed1992

Low grade B cell mucosa associated lymphoid tissue lymphoma of the stomach: clinical and endoscopic features, treatment, and outcome.

A retrospective study of the clinical and endoscopic features of low grade gastric lymphomas of mucosa associated lymphoid tissue (MALT) in 16 patients together with treatment and outcome was undertaken. Immunohistochemical studies of fresh tissue easily distinguished MALT lymphoma from benign reactive lymphoid hyperplasia (pseudolymphoma) and showed that tumour cells had the characteristic phenotype indicative of their origin from MALT. Persistent epigastric pain was the main presenting complaint, and was often associated with acute bleeding, anaemia, or weight loss. Eight patients had a past history of recurrent peptic ulcers or gastritis. The endoscopic appearance suggested malignancy in only half the cases and was compatible with gastritis or a benign peptic ulcer in the remainder. There was extragastric involvement of other mucosal sites in eight patients (mainly the lung, but also the parotid gland and small bowel), but rarely was bone marrow and never the spleen or peripheral lymph nodes affected. Conservative treatment with long term cyclophosphamide was effective in both stage I and stage IV disease, and all the patients are alive after a median follow up of 4.5 years. These findings confirm that low grade gastric MALT lymphomas are usually indolent tumours with non-specific endoscopic aspects and show that dissemination to other mucosal sites was more frequent than previously reported. Monochemotherapy could be an effective alternative treatment to surgery.

Adult↗
PubMed1989

[Ischemic and inflammatory colitis in elderly subjects over 70].

Twenty-five cases of non-infectious, macroscopic colitis, observed consecutively in patients over 70, were studied. The final diagnosis was, in 12 instances, ischemic colitis, in 10 instances cryptogenetic colitis (6 ulcerative colitis and 4 Crohn's diseases), and in 3 instances, non-classified colitis. The clinical manifestations consisted of rectal bleeding (92%), abdominal pain (76%) and diarrhea (56%). In 3 cases, the ano-perineal lesions observed in Crohn's diseases were noted and, in one case, a pyoderma gangrenosum was present. Endoscopy and/or barium enema showed a lesion of the left colon in 92% of the cases and of the sigmoid colon in 80% of the cases. The prognosis was severe, requiring surgery in 32% of the cases (5 ischemic colitis, 3 cryptogenetic colitis), and a 24% mortality (3 ischemic colitis, 3 ulcerative colitis), secondary to the condition and the extent of the colic involvement. The best factors of the etiological diagnosis of colitis were: the type of onset of the symptoms, the presence of anal or cutaneous lesions, the information provided by endoscopy and histology, which were specific in 11 out of 20 cases. In 5 cases, the diagnosis was only made by examination of the surgical specimen; in 3 cases, the diagnosis remained uncertain. These results suggest that the clinical data combined with an early, minimally traumatizing left endoscopy in elderly patients, should allow a quick, positive and etiological diagnosis of colitis, in order to initiate a suitable treatment in most cases.

Aged↗
PubMedDate not supplied

Computerized system in intensive care medicine.

A complete understanding of the computer's capabilities and an exact identification and definition of the ICU problems/needs are essential for the complete control of patient records and the full utilization of the computer as a clinical tool.

Decision Making, Computer-Assisted↗
PubMedDate not supplied

[Severe digestive manifestations of rheumatoid purpura in adults].

The authors report three cases of Scholein-Henoch's purpura in adults which were characterized by atypical severity of the digestive signs which led to laparotomy. In one case, the digestive signs preceded the onset of the cutaneous purpura, which made the diagnosis difficult. The digestive impact was confirmed endoscopically (petechia, ulceration, ulcerated stenosis) in two of the three patients. Damage of the small intestine predominated, as in the literature, but only one patient required resection of the intestine. These observations highlight the importance of endoscopic exploration in cases of abdominal signs combined with Scholein-Henoch's purpura in adults. They also demonstrate the difficulty of evaluating the prognosis and treatment in severe, peritoneo-occlusive forms.

Adult↗