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Biomedical subjects

I Roca

Publications and source records attributed to I Roca.

At least 19 recordsLinked to original sources
PubMed2005

Usefulness of sentinel lymph node detection in early stages of cervical cancer.

PURPOSE: Sentinel lymph node (SLN) mapping in combination with surgical biopsy is an emerging technique for use in the early stages of cervical cancer. The purpose of this study was to evaluate the technique in a series of 40 consecutive women with early stage cervical cancer. METHODS: Forty patients with early stage cervical cancer [FIGO stage IA2 (2), IB1 (34), IB2 (1) or IIA (3)] were referred for radical hysterectomy with pelvic lymphadenectomy. Patients were submitted to preoperative lymphoscintigraphy (four 99mTc-nanocolloid injections around the tumour) and intraoperative SLN detection. Hand-held or laparoscopic gamma probes were used to locate SLNs during surgery. RESULTS: The mean number of SLNs was 2.5 per patient (interiliac 49%, external iliac 19%). Of the total of 99 SLNs, six, in four women, showed metastases (all 68 non-SLNs removed were negative). In the other 36 patients, all the removed lymph nodes (sentinel and non-sentinel) were negative (0% false negative rate). During the follow-up (median 25 months), only two patients presented distant metastases: one died 6 months after surgery (two of three SLNs positive, both hot and blue), while the second patient is alive 4 years after surgery (lung metastasis, no isotope drainage, negative blue SLN). The survival rate was 95% and disease-free survival, 97%. CONCLUSION: SLN surgical biopsy based on lymphoscintigraphy and blue dye is a feasible and useful technique to avoid lymph node dissection in the early stages of cervical cancer. It has a high negative predictive value, can be incorporated into clinical routine (laparoscopy or open surgery) and is close to achieving validation in this setting.

Adult↗
PubMed2004

The open reading frame present in the nrdEF cluster of Corynebacterium ammoniagenes is a transcriptional regulator belonging to the GntR family.

In this work we have identified the cagntR gene, present between the nrdE and nrdF genes of Corynebacterium ammoniagenes, as a transcriptional regulator belonging to the GntR family. This gene encodes a transcriptional factor actively transcribed in the opposite direction relative to the nrdHIEF operon. It is expressed in a cell-culture-dependent fashion and, although the members of this family have been reported to regulate transcription of genes found within their vicinity, we have shown that cagntR is not involved in the transcriptional regulation of either nrdE or nrdF. The role of this regulator, however, remains unknown.

Amino Acid Sequence↗
PubMed2003

Corynebacterium ammoniagenes class Ib ribonucleotide reductase: transcriptional regulation of an atypical genomic organization in the nrd cluster.

Ribonucleotide reductases (RNRs) are a family of complex enzymes that play an essential role in all organisms because they catalyse de novo synthesis of deoxyribonucleotides required for DNA replication and repair. Three different classes of RNR have been described according to their metal cofactors and organic radicals. Class Ib RNR is encoded in four different genes (nrdH, nrdI, nrdE and nrdF) organized in an operon. The authors previously cloned and sequenced the genes encoding the active class Ib RNR of Corynebacterium ammoniagenes and showed that these genes are clustered in an atypical nrdEF region, which differs from that of other known class Ib enzymes because of an intergenic sequence (1171 bp) present between nrdE and nrdF. This study investigated the transcriptional organization and regulation of this nrd region by RT-PCR. Three different and independent mRNA were found (nrdHIE, nrdF and an ORF present in the intergenic region), each one being transcribed from its own promoter and being essential for normal growth. The ratio of nrdF to nrdHIE mRNA was 9.1, as determined by competitive RT-PCR; the expression of both nrdHIE and nrdF was found to be dependent on the culture growth phase, and was induced in the presence of hydroxyurea, manganese and hydrogen peroxide. This is believed to be the first direct evidence for a manganese-dependent transcriptional regulation of nrd genes. These results suggest a common and coordinated regulation of the different nrd genes, despite their being transcribed from independent promoters.

Aerobiosis↗
PubMed1998

Determination of cobalt, manganese, and alcohol content in beers.

The purpose of this study was to investigate the degree of exposure to cobalt and manganese through the consumption of different brands of commercial beers widely consumed in Spain, considered as two groups according to their alcohol content. The Mn and Co concentrations in beer samples ranged from 25.29 to 228.60 micrograms/liter and 0.16 to 0.56 micrograms/liter, respectively. These contents do not differ from those found in other countries, and all comply with the maximum levels permitted by law. Significant differences occurred only in Mn content between beers with and without alcohol. The consumption of alcoholic beers contributes to an increased body burden of Mn among heavy consumers. According to the low levels of Co found in both types of beers, we can suggest that there is no risk of suffering cardiomyopathies and there is no significant contribution to the total intake of the element in heavy beer drinkers.

Alcohols↗
PubMed1998

Hepatobiliary scintigraphy in current pediatric practice.

Hepatobiliary scintigraphy is the only non-invasive technique providing real-time assessment of hepatocytes function and bile progression from the liver to the intestine; for this reason it is of great importance in the study of jaundice and many other disorders of the liver and the biliary tract in children. Ultrasonography is the initial method of evaluating the intra- and extrahepatic bile ducts dilatation; the differential diagnosis between biliary atresia and neonatal hepatitis cannot however be done without hepatobiliary scintigraphy. Cystic fibrosis patients also require hepatobiliary scintigraphy; liver and biliary tract disease can really occur independently of the underlying disease severity and the presence of steatorrhea. Hepatobiliary imaging in children who have undergone liver transplantation is of major importance; it can assess vascularity, parenchymal function, biliary drainage, possible presence of a bile leak and obstruction; it has very good sensitivity and specificity for the detection of biliary leak and biliary stricture. Due to these important clinical conditions being studied in pediatrics, both qualitative and quantitative informations (functional indices obtained from radioactivity/time curve analysis) need to be extracted; in addition, SPECT acquisition allows more accurate evaluation of abdominal activity during the excretory phase.

Biliary Tract Diseases↗
PubMed1997

Pulmonary perfusion scintigraphy in the evaluation of the severity of bronchopulmonary dysplasia.

OBJECTIVE: The objectives of this study were to analyze the changes in pulmonary perfusion in bronchopulmonary dysplasia (BPD) and to assess the advantages of this method in evaluating the severity of BPD. PATIENTS AND METHODS: The study group was made up of 10 children with BPD, matched with a control group of 12 children. The criteria for matching were birth weight, gestational age and need for ventilation for more than 3 days. Clinical and roentgenographic scoring systems were applied on the 21st day of life. At 6 months of corrected age, clinical evolutive severity was evaluated and a pulmonary perfusion scintigraphy using technetium-99 was performed in each child. The scintigraphic findings were classified in five categories ranging from normal to severely affected, depending on the degree and localization of perfusion abnormalities. Another score was obtained by assigning a value from 1 to 5 to each pulmonary lobe, depending on the concentration of the tracer. RESULTS: The study of clinical, roentgenographic and evolutive scores always showed higher values in children with BPD, with good correlation between methods (P < 0.001). In the BPD group, abnormal lung perfusion patterns were more frequent and more severe (P < 0. 05), the lobe scoring was higher (P < 0.05), and a lower count rate was found (P < 0.01). CONCLUSION: Pulmonary scintigraphy is a useful technique in evaluating the severity of BPD.

Bronchopulmonary Dysplasia↗
PubMed1995

[Management of primary congenital megaureter with early diagnosis].

We present our follow-up protocol of congenital megaureter (PCM) diagnosed early thanks to showing prenatal ultrasound the dilatation in the urinary system. 47 PCM were studied retrospectively in 35 babies, out of 240 cases of prenatal renal dilatation, from 1984 to 1993. The final diagnosis was established with the early use of ultrasound, cystography, intravenous urography (IVU) and isotope test. The latter two gave hints as to the existence of obstruction, which was the main criterion for early surgery to be prescribed. The surgical treatment, when it was necessary, consisted of ureter reimplantation (Cohen type), following the resection of the stenotic segment. When it was necessary short distal tapering (3-4 cm) was performed. For the follow-up ultrasound, IVU and isotope test were used. Out of the 35 patients observed, 11 were girls and 24 boys, 9 (25.7%) of the PCM were from the right side, 14 (40%) from the left side and 12 (34.2%) bilateral. 36 PCM (76.6%) were non-obstructive and only follow-up was performed. 5 of them, in 3 patients, had infections and were operated on together with the 11 obstructed PCM. In total, 16 PCM were reimplanted, and associated tapering was need in 7 of them. Other 3 patients were operated on for associated pathology. The post-surgical complications were 2 cases or reflux and 1 uric stone that did not need surgery. The development of all cases was favorable. The protocol has been useful for the selection for early surgical intervention of the subsidiary megaureters from those that can be develop without risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1994

[Nocturnal spasmodic cough in the infant. Evolution after antireflux treatment].

Several studies have shown the relationship between gastro-oesophageal reflux, bronchial asthma and chronic nocturnal cough and this should not be neglected, particularly in patients who present an unfavourable development in spite of conventional treatment. For diagnosis of gastroesophageal reflux, amongst other investigations, esophageal gammagraphy of swallowing, that detects alterations in the mobility of the oesophagus, secondary to a possible oesophagitis. The objective of this study was to evaluate the clinical progress and gammagraphy of a group of children with chronic predominantly nocturnal cough (with or without bronchial asthma) with initially pathological esophageal gammagraphy, after three months of treatment with gastrokinetic drugs (cisapride against domperidone) and postural dietetic limits, in comparison with a reference group who, although having followed the limits in question had not received the pharmacological treatment. From the clinical viewpoint, cough disappeared in 64.5% of cases without significant statistical differences between the two groups. Gammagraphy became normal in 20/55 cases, improved in 10/55 cases and was unchanged in 25/55. Although there was no significant difference, gammagraphy development was better in children who received domperidone. The agreement between clinical progress and gammagraphy was 60% with a large number of false positives in the gammagraphy. We believe that the simple introduction of the postural-dietetic measures may improve the clinical control in the type of patients who present with a chronic nocturnally predominant cough that does not yield to conventional treatment.

Adolescent↗
PubMed1992

[Renal transplantation in children: punction-aspiration biopsy and renogram with 99mTc-DTPA].

BACKGROUND: Renal transplantation in children raises numerous diagnostic problems. The renography obtained with diethyltriaminopentaacetic acid marked with (99mTc metastable technetium (99mTc-DTPA) was compared with fine needle aspiration biopsy (FNAB) in search of a better interpretation of post-transplant crisis: rejection, acute tubular necrosis, toxicity by cyclosporin A and infection. METHODS: Sixteen acute post-transplant episodes were studied in 13 children submitted to renal transplantation. The post-transplant time was 6 days to 2.5 years. The basal renography and FNAB were carried out following the initial clinical manifestations and over a period of less than one week. The vascular and renographic phases were evaluated by interpreting the renography and were compared to previous renographies. The diagnosis of the aspiration biopsy was expressed as: normal, acute tubular necrosis, total necrosis, toxicity by cyclosporin A, viral infection and rejection. RESULTS: Results agreed in 14 out of 16 cases: 1 normal, 3 acute tubular necrosis by renography and cellular necrosis by cytology, 9 rejections and 1 infection (increase in renal transit time). In the 2 cases with total necrosis of 100% followed by loss of renal allograft, the renographic diagnosis was severe vascular rejection with a negative prognosis. CONCLUSIONS: In this series FNAB confirmed the renography as useful in the early diagnosis of complications which may appear in children undergoing renal transplantation.

Biopsy, Needle↗
PubMed1992

Some morphologic changes induced by Nd:YAG laser on the noncoated enamel surface: a scanning electron microscopy study.

The enamel surface layer of some human teeth was treated with the low-energy Nd:YAG laser at 8 mJ pulse energy. These samples were previously etched with 0.05 M orthophosphoric acid to reduce the surface reflection. The treated samples, as well as the control samples, were widely studied by scanning electron microscopy, and, in the lased group, significant morphologic changes affecting the enamel surface were observed. Those changes reveal principally the loss of the typical surface structure of the acid-etched enamel. The hydroxyapatite prisms were not discernible, and there was a decrease in the roughness of the lased surface enamel. These laser-induced structural changes may be related to the increased resistance to the calcification reported by many authors.

Acid Etching, Dental↗
PubMed1990

A radiopharmaceuticals schedule for imaging in paediatrics. Paediatric Task Group European Association Nuclear Medicine.

There is no standard schedule for the amounts of radiopharmaceutical administered to children at present. Various alternative methods are currently in practice, all with some support from the literature. Optimization of the amount of radiopharmaceutical to be administered is discussed in relation to the radiation burden of such an examination. The Paediatric Task Group of the European Association of Nuclear Medicine has investigated the current situation and now suggests a method for standardization of administered amounts of radiopharmaceutical in paediatrics. The fraction of the adult amount of radiopharmaceutical to be administered should be calculated from the child's body weight according to the accompanying table. In small infants, the minimum amount of a radiopharmaceutical is discussed and suggested amounts to be administered are presented.

Body Weight↗