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Biomedical subjects

M M Perez

Publications and source records attributed to M M Perez.

11 recordsLinked to original sources
PubMed2001

Clinical application of multiplex quantitative fluorescent polymerase chain reaction (QF-PCR) for the rapid prenatal detection of common chromosome aneuploidies.

The clinical application of quantitative fluorescent polymerase chain reaction (QF-PCR) for rapid prenatal detection of chromosome aneuploidies has been limited in most studies to the detection of autosomal trisomies. Recently it has been shown that a newly identified highly polymorphic marker, termed X22, which maps to the Xq/Yq pseudoautosomal region of the sex chromosomes, used together with the X-linked short tandem repeat (STR) HPRT, allows the accurate detection of gonosome aneuploidies. We have developed a rapid assay, which includes these STR markers together with a sequence of the amelogenin region of the sex chromosomes and selected highly polymorphic autosomal STR. Two more X chromosome markers, as yet not used in previous QF-PCR applications, were also included in the assay. The molecular test was then used in a clinical trial on 551 uncultured amniotic fluid samples, allowing the assessment of copy number for chromosomes X, Y and 21 in 100% of cases. In the course of this study, two fetuses with Turner's syndrome and one with Klinefelter's syndrome were identified along with 17 autosomal trisomies. The assay proved to be so efficient and reliable that in most aneuploidy cases, in which ultrasound findings were in agreement with the molecular result, therapeutical interventions were possible without waiting for the result of cytogenetic analysis.

Adult↗
PubMed2000

A kinetic study on the interaction between tazobactam (a penicillanic acid sulphone derivative) and active-site serine beta-lactamases.

The interaction between tazobactam and several chromosome- and plasmid-encoded (TEM, SHV, PSE types) class A and C beta-lactamases was studied by spectrophotometry. Tazobactam behaved as a competitive inhibitor or inactivator able to restore in several cases the efficiency of piperacillin as a partner beta-lactam. A detailed kinetic analysis permitted measurement of the acylation efficiency for some cephalosporinases and broad-spectrum beta-lactamases; the presence of a turn-over of acyl-enzyme complex was also evaluated.

Acinetobacter↗
PubMed1997

The long-term stability of LeFort I maxillary downgrafts with rigid fixation to correct vertical maxillary deficiency.

This study evaluated the long-term stability of LeFort I maxillary downgrafts with rigid fixation in 28 patients with vertical maxillary deficiency. Preorthodontic, presurgical, immediate postsurgical, and an average of 16 months postsurgical cephalometric radiographs were evaluated. The results indicated that overall vertical maxillary stability after downgraft was good with 80% of the cases showing superior relapse of 2 mm or less. The mean amount of postoperative relapse represented 28% of the surgical downgraft. No correlation was found between the amount of the maxillary downgraft and the subsequent postsurgical vertical stability of the maxilla. No difference was found in the vertical stability of the maxilla comparing one-jaw and two-jaw procedures. It was also found that there was no difference in the vertical stability of the maxilla between single-segment and multiple-segment maxillary procedures, and also when comparing standard and high LeFort I osteotomy techniques. In addition, occlusal plane rotation of surgery, as well as the type of presurgical orthodontic movement, were both found to have no influence on postoperative stability of the maxilla.

Adolescent↗
PubMed1985

Epileptic psychosis: an evaluation of PSE profiles.

Data are presented on 24 patients with epilepsy and psychosis whose clinical presentation was rated using the Present State Examination (PSE). Seventeen had complex partial seizures and a diagnosis of temporal lobe epilepsy, seven had generalised epilepsy. An association between a CATEGO category of nuclear schizophrenia (NS) and a lesion of the left side was noted. No clear link between depressive symptoms and a right-sided focus was discovered. Affective disorders were noted in both groups of epileptic patients, although paranoid psychoses were commoner in the temporal lobe group. There was also a tendency for the latter to have more delusions of persecution, ideas of reference, and special features of depression. The group rated as NS appear less likely to show evidence of intellectual deterioration than the other psychotic patients; in addition, the interval between the onset of their epilepsy and the onset of their psychosis is shorter. Radiological assessment by CAT reveals few differences between groups, but the psychotic samples do show higher than expected values on a number of variables, in particular the bilateral septum-caudate distance and the size of the third and fourth ventricle.

Adult↗
PubMed1983

Assessment of weight loss, food intake, fat metabolism, malabsorption, and treatment of pancreatic insufficiency in pancreatic cancer.

In 12 patients with biopsy-proven pancreatic ductal adenocarcinoma, the following were determined: (1) whether decreased food intake, malabsorption, or altered fat metabolism were associated with weight loss; (2) the effect of pancreatic extract as treatment for malabsorption; and (3) the accuracy of the triolein breath test for detection of steatorrhea. Weight loss occurred in 11 patients and only in patients who had either malabsorption (n = 5), low coefficients of caloric consumption (n = 2), or both (n = 4). Nine patients had fat malabsorption, six had protein malabsorption, and caloric consumption was decreased in seven patients. Metabolism of oleic acid was significantly decreased (P less than 0.01) compared to normal subjects and correlated with basal metabolic rates (r = 0.6; P less than 0.05) which were within the range of normal values for age and sex. Body weight loss correlated only with coefficients of fat and protein absorption (r = 0.59; P less than 0.05). Treatment of patients with pancreatic extract resulted in significant improvement in absorption in those with moderate to severe fat or protein malabsorption (coefficient of absorption less than 80%) but no significant improvement occurred in patients with mild fat or protein malabsorption. The triolein breath test was abnormal in all patients with fat malabsorption and predicted improvement of fat absorption in five of six patients with steatorrhea who were treated with pancreatic extract. Thus, in pancreatic cancer, weight loss is associated with malabsorption; exogenous pancreatic extract significantly improves moderate to severe fat or protein malabsorption, and the triolein breath test detects fat malabsorption and predicts the treatment response to pancreatic extract.

Adult↗
PubMed1980

Effect of theophylline, terbutaline, and their combination on the immediate hypersensitivity skin-test reaction.

Methylxanthines and beta agonists can be expected to inhibit the antigen-induced hypersensitivity skin-test reaction by affecting cyclic 3', 5'-adenosine monophosphate (cyclic AMP) metabolism, yet in vivo studies produce conflicting results. The discontinuation of these drugs prior to skin testing may result in the exacerbation of asthmatic symptoms; however, if these drugs are maintained, the validity of the test remains in question. To determine the effect of these drugs on the skin-test response, 15 patients received theophylline, terbutaline, the combination, and placebo in a double-blind study. No statistically significant difference (p greater than 0.05) was found for the areas of wheal and flare in response to injected allergens or histamine, between placebo and theophylline, terbutaline, and their combination. A marginal decrease in wheal area in response to codeine following combination therapy was observed. Therapeutic theophylline and terbutaline serum concentrations were documented. There is no need to discontinue theophylline or terbutaline prior to skin testing.

Adult↗
PubMed1980

Epileptic psychosis--diagnostic comparison with process schizophrenia.

The mental states of 23 epileptic psychotic patients and 10 patients with process schizophrenia were compared, using the Present State Examination. The epileptics displayed marked heterogeneity of psychiatric diagnoses. Disturbances of affect underlying the psychosis or presenting as manic-depressive psychosis were frequent and independent of the type of epilepsy. Schizophrenic psychosis, classified with psychopathological criteria similar to those used in the non-epileptic schizophrenic group, was significantly associated with temporal lobe epilepsy. Psychoses other than schizophrenia, however, were present in 5 out of 16 patients with temporal lobe epilepsy. These results support a relationship between schizophrenic symptoms and temporal lobe pathology and emphasize the need to use reproducible methods of diagnosis in psychiatric research.

Adolescent↗
PubMedDate not supplied

Mapping of genetic deletions on the long arm of chromosome 22 in human pancreatic adenocarcinomas.

The molecular mechanisms of carcinogenesis in pancreatic cancer are still poorly understood, although the inactivation of tumor suppressor genes at multiple loci is suspected. We investigated the loss of heterozygosity (LOH) on chromosome 22 in pancreatic cancer by means of a PCR-based microsatellite analysis of archival paraffin-embedded histological sections in order to better define deleted region(s) and to test whether the NF-2 gene is involved. Using a panel of thirteen markers that spanned the long arm of chromosome 22, loss of heterozygosity was identified for at least one locus in 37% of investigated pancreatic adenocarcinomas. These deletions are clustered into two separate areas of the chromosome 22--one proximal to the NF-2 gene and one distal. The NF-2 gene itself is not involved. These regions are likely locations of tumor suppressor genes that may contribute to the development of pancreatic cancer.

Adenocarcinoma↗