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A Martins

Publications and source records attributed to A Martins.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Abdominopelvic ultrasonography in suspected acute appendicitis: prospective study in adults].

STUDY AIM: The aim of this prospective descriptive study was to evaluate the accuracy of abdomino-pelvic ultrasonography in suspected acute appendicitis in adults. PATIENTS AND METHODS: From March to July 1998, 100 consecutive patients, 63 women, 37 men (mean age: 25 years), after examination by a visceral surgeon for suspected acute appendicitis, had an abdominal ultrasonography (US) examination with high frequency transducer (7.5 to 9 MHz). The US examination concerned appendice, periappendicular tissues and neighbouring organs. The US data were correlated with the histopathologic findings in operated on patients, and with the clinical and biological follow up in non operated patients. RESULTS: Fourty-seven patients had acute appendicitis; 53 were operated on and 47 non operated. Analysis of US data revealed sensitivity 91.5%, specificity 94.3%, positive predictive value 93.5%, negative predictive value 94.3%, accuracy 93%; 75% of the other diagnosis were found by US. CONCLUSION: Systematic abdominal ultrasonography in suspected acute appendicitis is recommended in adults.

Abdominal Pain↗
PubMed1999

Mutational analysis of vaccinia virus nucleoside triphosphate phosphohydrolase I, a DNA-dependent ATPase of the DExH box family.

Vaccinia virus nucleoside triphosphate phosphohydrolase I (NPH-I) is a DNA-dependent ATPase that serves as a transcription termination factor during viral mRNA synthesis. NPH-I is a member of the DExH box family of nucleic acid-dependent nucleoside triphosphatases (NTPases), which is defined by the presence of several conserved sequence motifs. We have assessed the contributions of individual amino acids (underlined) in motifs I (GxGKT), II (DExHN), III (SAT), and VI (QxxGRxxR) to ATP hydrolysis by performing alanine scanning mutagenesis. Significant decrements in ATPase activity resulted from mutations at nine positions: Lys-61 and Thr-62 (motif I); Asp-141, Glu-142, His-144, and Asn-145 (motif II); and Gln-472, Arg-476, and Arg-479 (motif VI). Structure-function relationships at each of these positions were clarified by introducing conservative substitutions and by steady-state kinetic analysis of the mutant enzymes. Comparison of our findings for NPH-I with those of mutational studies of other DExH and DEAD box proteins underscores similarities as well as numerous disparities in structure-activity relationships. We conclude that the functions of the conserved amino acids of the NTPase motifs are context dependent.

Acid Anhydride Hydrolases↗
PubMed1998

Pure red cell aplasia due to persistent B19 parvovirus infection in patient infected with human immunodeficiency virus type 1. Recovery with alpha-interferon therapy.

B19 parvovirus (PV) infection is ordinarily resolved with the production of specific antibodies that neutralize virus infectivity for erythroid host cells. Nevertheless persistent infection with B19 PV and pure red blood cell aplasia have been documented. A 27 year-old male. i.v. drug abuser, HIV+ and HCV was diagnosed of pure red cell aplasia. Six months later we had serologic evidence of persistent parvovirus infection. Interferon therapy, started for HCV infection, showed a marked improvement of anaemia and anti parvovirus IgM became negative. It is discussed the possible role of interferon therapy in persistent parvovirus infection.

Adult↗
PubMed1998

[Microsurgical reconstruction of the upper extremity. Experience with 24 free flaps].

The authors present the experience of 24 clinical cases of microsurgical reconstruction of the upper limb. These reconstructions were accomplished by different microvascular free flaps which were selected according to the type, size and location of the defects, having applied fasciocutaneous, adipofascial, myo, myocutaneous, tendofasciocutaneous, omentum flaps and 2nd toe transfers. The etiology was traumatic in 23 cases and tumoral in 1 case. A careful analysis was made for surgical times, selection and survival rate of the free flaps and the morphofunctional quality of the reconstructions. Microvascular free flaps are considered the choice technique for upper limb reconstruction, particularly for the hand in certain defects, considering the better anatomic and functional quality of the reconstructions.

Adolescent↗
PubMed1997

Structure-function analysis of the triphosphatase component of vaccinia virus mRNA capping enzyme.

The N-terminal 60 kDa (amino acids 1 to 545) of the D1 subunit of vaccinia virus mRNA capping enzyme is an autonomous bifunctional domain with triphosphatase and guanylyltransferase activities. We previously described two alanine cluster mutations, R77 to A (R77A)-K79A and E192A-E194A, which selectively inactivated the triphosphatase component. Here, we characterize the activities of 11 single alanine mutants-E37A, E39A, Q60A, E61A, T67A, T69A, K75A, R77A, K79A, E192A, and E194A-and a quadruple mutant in which four residues (R77, K79, E192, and E194) were replaced by alanine. We report that Glu-37, Glu-39, Arg-77, Glu-192, and Glu-194 are essential for gamma-phosphate cleavage. The five essential residues are conserved in the capping enzymes of Shope fibroma virus, molluscum contagiosum virus, and African swine fever virus. Probing the structure of D1(1-545) by limited V8 proteolysis suggested a bipartite subdomain structure. The essential residue Glu-192 is the principal site of V8 cleavage. Secondary cleavage by V8 occurs at the essential residue Glu-39. The triphosphatase-defective quadruple mutant transferred GMP to the triphosphate end of poly(A) to form a tetraphosphate cap structure, GppppA. We report that GppppA-capped RNA is a poor substrate for cap methylation by the vaccinia virus and Saccharomyces cerevisiae RNA (guanine-7) methyltransferases. The transcription termination factor activity of the D1-D12 capping enzyme heterodimer was not affected by mutations that abrogated ATPase activity. Thus, the capping enzyme is not responsible for the requirement for ATP hydrolysis during transcription termination.

Acid Anhydride Hydrolases↗
PubMed1996

Reinforcing properties of the substance P C-fragment analog DiMe-C7 in Carassius auratus.

The aim of the present study was to investigate whether two substance P (SP) fragments have reinforcing effects in Carassius auratus when the fish were tested in a place-preference experimental model. Fish were placed in a 3-compartment box in which one compartment gives access to two others that are not connected. The time spent in each compartment was recorded for 10 min in order to determine which one was preferred. Twenty-four hours later the fish were given one of the following ip treatments: 1) group VEH (N = 12), injected with teleost saline, 2) group DiMe-C7 (N = 12), injected with 33 micrograms/kg DiMe-C7, and 3) group SP1-7 (N = 12), injected with 167 micrograms/kg SP1-7. Immediately after treatment the fish were kept for 30 min in the compartment that was the least preferred on the day before and this procedure was repeated for 3 days. On the fifth day the fish were retested for 10 min to determine the time spent in each compartment. Two-way analysis of variance with treatments and testing as factors indicated a main effect (P < 0.0025) as well as a testing effect (P < 0.009). The post-hoc Scheffé multiple comparison test indicated that only the DiMe-C7 group presented an increase in the time spent in the paired compartment after treatment. We suggest that the C-terminal fragment of SP has reinforcing effects in Carassius auratus.

Animals↗
PubMed1996

Effects of dental decompensation on the surgical treatment of mandibular prognathism.

The dental compensation presented in patients with the Class III malocclusion, or mandibular prognathism, and its importance to the surgical-orthodontic treatment, was evaluated in this study. The study involved the cephalometric examination of two groups of patients, who were considered either adequately or inadequately treated during the presurgical orthodontic phase. The results showed that dental compensation is common in both the maxillary and mandibular arches. Such compensation is more frequently eliminated from the mandibular arch during presurgical orthodontic treatment. There was some correlation between decompensation and the amount of mandibular reduction during surgery and a strong correlation between cephalometric postsurgical mandibular excess and the lower anterior facial height.

Cephalometry↗
PubMed1995

Histologic and genetic assessment of explanted allograft valves.

A possible way of analyzing the immune response triggered by the allograft and the cellular viability is to compare immunocompetent and immunosuppressed patients, such as those having valve replacement and heart transplantation, respectively. These groups differ in immunosuppression therapy, preparation methods, valve hemodynamics. In the present study, we investigated polymerase chain reaction-amplified DNA flanking hypervariable (CA)n regions obtained from valve leaflets taken from patients having valve replacement or heart transplantation and performed a histologic analyses of the cells. In addition, we assessed an autograft valve to compare the hemodynamic effects on the cellular composition of the valve leaflet. We conclude that leaflet cellularity of the heart transplantation and autograft patients is superior to that of the valve replacement patients. These differences were consistent with the occurrence of an immune response in the valve replacement group, which was prevented or abrogated by immunosuppressive therapy administered to the heart transplantation group. However, it cannot be excluded that preparation procedures have a long-term effect on the extracellular matrix, leading to deterioration of cell adhesion and homing conditions.

Adult↗
PubMed1995

The allograft valve in heart transplantation and valve replacement. Genetic assessment of the origin of the cells by means of deoxyribonucleic acid profiles.

Assessment of the cellular origin of allograft valves is essential in comprehending their biologic behavior and in improving preparation methods. In this study we retrospectively analyzed 10 allografts obtained from patients who underwent valve replacement or heart transplantation. Histologic evaluation and deoxyribonucleic acid amplification by polymerase chain reaction technology with fluorescence labeled primers was performed on different parts of the valve leaflets. Automated analyses of the obtained amplimers showed in the heart transplantation group the presence of receptor cells interspersed with native donor cells in three cases. Preliminary results for the valve replacement group are inconclusive as yet.

Adult↗
PubMed1995

[Striato-pallido-dentate calcifications and acquired facial atrophy].

A family with two siblings presenting cerebral calcifications is reported. The sister was suffering from action tremor since the age of 10. The disease worsened by the age of 39. When aged 42, she was unable to walk and had severe rigidity and intellectual deterioration. She died at 43. The brother had mild debility. Action tremor started at the age of 14, without significant aggravation when seen at the age of 30. In both cases, brain CT scan showed calcifications of the dentate nuclei and cortical atrophy with ventricular enlargement. In addition, the sister had bilateral putaminal and pallidal calcifications. The other family members were unaffected and had normal CT scans. The nosology and the pathophysiology of this family report are discussed, particularly regarding the late occurrence of facial atrophy, reminiscent of the Cole-Engmann syndrome (Dyskeratosis Congenita).

Adult↗
PubMed1994

Genetic identification and nucleotide sequence of the DNA polymerase gene of African swine fever virus.

The DNA polymerase gene of African swine fever virus (ASFV) was mapped by marker rescue experiments using a phosphonoacetic acid-resistant mutant and hybridization with an oligonucleotide probe designed from the most conserved motif of family B DNA polymerases. Viral DNA fragments mapping in this region were cloned and sequenced. An open reading frame coding for a 1244 amino acid long peptide with a molecular mass of 142.5 kDa was determined from the sequence. A unique feature of ASFV DNA polymerase is the presence of 13 tandem repeats of the sequence Ala-Gly-Asp-Pro near the carboxyl end of the molecule. Comparison with 30 sequences of alpha-like DNA polymerases of cellular and viral origin showed that ASFV DNA polymerase has all the conserved motifs of family B DNA polymerases. A 3.9 kb transcript was detected by Northern hybridization and the transcription initiation and termination sites were mapped by S1 analysis and primer extension. Late transcription was initiated at a site different from the early transcription initiation site. A 145 kDa protein, consistent with the size of the gene, was identified by an in situ enzyme assay after gel electrophoresis of infected cell extracts.

African Swine Fever Virus↗
PubMed1993

[Value of congenital hypertrophy of the retinal pigment epithelium as diagnostic marker in familial adenomatous polyposis].

Familial Adenomatous Polyposis (FAP) is a dominant autosomic disease characterized by the development of hundreds to thousands of colonic adenomatous polyps. Affected patients have a 100% risk of colon cancer development if they are not submitted to a prophylactic colectomy. Identification of carriers depends on the detection of colonic polyps, and endoscopic surveillance must be offered to all descendents, including healthy individuals. Congenital hypertrophy of the retinal pigment epithelium (CHRPE) has been suggested to have a correlation with FAP trait, even before colonic polyp development. The objective of this study is to evaluate CHRPE as a diagnostic marker in FAP patients and descendents. CHRPE was studied in 26 members of 7 FAP families, using direct and indirect ophthalmoscopy, biomicroscopy and retinography. It was found in 62.5% of patients and in 10% of the descendents at risk. Two families did not show signs of CHRPE. Affected members in the remaining families, had positive examinations in 83.3% (two affected members were negative). These results suggest that CHRPE is an important diagnostic tool to identify FAP patients in those families which express the marker. To those descendents who have negative examinations, whether they belong to positive or negative CHRPE families, identification of FAP trait depends on endoscopic surveillance in order to detect colonic polyps.

Adenomatous Polyposis Coli↗
PubMed1988

A distally based median plantar flap.

The first metatarsophalangeal joint area is a very difficult one to reconstruct, needing skin that is thick, sensitive, and resistant to friction. Although the medial plantar island flap was initially described to resurface heel defects, we have used this flap as a cross-foot flap to recover the first metatarsophalangeal joint area. Its use has always required a second surgical procedure. To overcome this inconvenience, we describe the use of a flap based on the principle of reversing the direction of blood flow in a distal vascular pedicle to restore a defect of the anteromedial aspect of the foot. Good functional and aesthetic results were obtained.

Child↗
PubMedDate not supplied

Radiation-induced carcinoma of the rectum.

Carcinomas and sarcomas are known to develop after radiation therapy. A complete review of the literature regarding appearance of carcinoma of the rectum following radiation therapy to the pelvis was undertaken. The average interval between irradiation and diagnosis of the rectal cancer was 15.2 years, the range being from one year, two months to 33 years. We present a case of carcinoma of the rectum arising as two separate primaries 46 years after irradiation for an epidermoid carcinoma of the cervix. There were many pathologic changes related to the radiation therapy.

Adenocarcinoma↗
PubMedDate not supplied

Further experience with the posterior interosseous flap.

This paper describes and discusses some of the clinical applications of the posterior interosseous forearm flap in hand reconstruction, including the fact that larger areas of skin than previously reported can be used safely. It is based on a series of 21 patients, 50 anatomical dissections and 10 injection studies.

Adolescent↗