Biomedical subjects

M S Fernández

Publications and source records attributed to M S Fernández.

At least 19 recordsLinked to original sources

PubMed2001

Prospective comparison of clinical and echocardiographic diagnosis of rheumatic carditis: long term follow up of patients with subclinical disease.

OBJECTIVE: To determine the frequency of occurrence and long term evolution of subclinical carditis in patients with acute rheumatic fever. DESIGN: Valvar incompetence was detected by clinical examination and Doppler echocardiographic imaging during the acute and quiescent phases of rheumatic fever. Patients were followed prospectively and submitted to repeat examinations at one and five years after the acute attack. Persistence of acute mitral and aortic lesions detected solely by echocardiography (subclinical disease) was compared with that of disease detected by clinical examination as well (thereby fulfilling the latest 1992 Jones criteria for rheumatic carditis). SETTING: Three general hospitals with a university affiliation in Chile. PATIENTS: 35 consecutive patients fulfilling the revised Jones criteria for rheumatic fever. Clinical and echocardiographic examination was repeated in 32 patients after one year and in 17 after five years. Ten patients had subclinical carditis on admission, six of whom were followed for five years. MAIN OUTCOME MEASURES: Auscultatory and echocardiographic evidence of mitral or aortic regurgitation during the acute attack or at follow up. RESULTS: Mitral or aortic regurgitation was detected by Doppler echocardiographic imaging in 25/35 rheumatic fever patients as opposed to 5/35 by clinical examination (p = 0.03). Doppler echocardiography revealed acute valvar lesions in 10 of 20 rheumatic fever patients who had no auscultatory evidence of rheumatic carditis (subclinical carditis). Three of these subclinical lesions and three of the clinical or auscultatory lesions detected on admission were still present after five years of follow up, emphasising that subclinical lesions are not necessarily transient. CONCLUSIONS: Doppler echocardiographic imaging improves the detection of rheumatic carditis. Subclinical valve lesions, detected only by Doppler imaging, can persist. Echocardiographic findings should be accepted as a major criterion for the diagnosis of rheumatic fever.

Adolescent↗

PubMed1999

Escherichia coli membrane fluidity as detected by excimerization of dipyrenylpropane: sensitivity to the bacterial fatty acid profile.

A coordinated study of membrane fluidity and fatty acid composition has been carried out in Escherichia coli W3110. The lipid acyl chain profile of the bacteria, altered by growing cells in steady state at 30, 37, 42, or 45 degrees C, was determined by gas chromatography of the fatty acid methyl esters. In parallel experiments, total membranes obtained from cells of the above-mentioned cultures were labeled with dipyrenylpropane and their relative fluidity was measured on the basis of the excimer to monomer fluorescence intensity ratio of the fluorophore. It has been found that, at constant assay temperature, fluidity determined with dipyrenylpropane decreases gradually with the growth temperature increment, from 30 to 45 degrees C. Interestingly, when fatty acid composition is taken into account, fluidity increases linearly in the range under study, with the proportion of unsaturated fatty acyl chains, both variables being highly correlated (0.924 </= r(2) </= 0.996). Our results show that dipyrenylpropane is a reliable and quantitative indicator of changes in membrane fluidity, driven by modifications in the acyl chain composition of bacterial lipids.

Chromatography, Gas↗

PubMed1999

Spontaneous biliary perforation and necrotizing enterocolitis.

A case of spontaneous bile-duct perforation in a 5-month-old boy with a history of necrotizing enterocolitis in his 1st week of life is reported. To our knowledge, this is the second case reported with such an antecedent, supporting a vascular etiology for some cases of spontaneous biliary perforation.

Ascites↗

PubMed1999

Fatty acid profile of Escherichia coli during the heat-shock response.

The possible changes in the fatty acid profile of Escharichia coli during heat-shock have been investigated. Bacteria growing in steady-state at 30 degrees C were subjected to an abrupt temperature upshift to 45 degrees C and held at the high temperature for various periods of time in order to elicit the heat-shock response. Fatty acid compositions of lipids extracted from samples taken at different times after the temperature upshift, as well as from cultures in steady-state at 30 and 45 degrees C, were determined by gas-chromatography. It has been found that the total unsaturates to total saturates ratio decreases gradually during heat-shock and that 30 min after the temperature jump, the reduction is equivalent to 57% of the difference between ratios corresponding to steady-state cultures at 30 and 45 degrees C. Consistent with this remodeling of lipid acyl chains, there is a decrease in the excimerization rate of the fluidity probe dipyrenylpropane incorporated into sonicated E. coli lipid extracts. Such modifications occur within the time-span of the heat-shock response, as judged from our previous measurements of the kinetics of change in heat-shock proteins induction ratio. Together, these results indicate that the control of membrane fluidity during the heat-shock response can be accounted for, at least in part, by an important change in the fatty acid composition of Escherichia coli lipids.

Escherichia coli↗

PubMed1999

[Laparoscopic transsection of Ladd's bands: a new indication for therapeutic laparoscopy in neonates].

Within the last ten years and by the introduction of some new instruments, laparoscopy is a safe and effective method that has been further extended in children. We report our experience in the treatment of laparoscopy on a seven day old newborn affected by malrotation with an intermittent duodenal obstruction. The treatment consisted of a duodenal liberation after the section was easily performed in congenital Ladd's bands. The spiral twists of the small intestine found in the upper gastrointestinal series, disappeared in a new study done after surgery. We consider this operation as a new indication for an operative laparoscopy. It allows a good visualization of this congenital abnormality, and it is easy to perform with a significantly reduced operative trauma.

Duodenal Obstruction↗

PubMed1999

[Single-system ectopic ureters. A review of 19 cases].

Single system ectopic ureters are usually associated with multiple congenital abnormalities and the corresponding renal units is frequently abnormal. 19 cases of single system ectopic ureters were diagnosed and treated in our hospital during the last 20 years. The patients were less than 11 years old. The abnormality was bilateral in two cases and the 63% of all had associated malformations, being the anorectal abnormalities the most frequent. The incidence of reflux into the ectopic ureter was 57%, and the association to unilateral or contralateral renal agenesis, 26.3%. Thirteen ectopic ureters were reimplanted successfully into the bladder, and the cases of nonfunctioning kidneys were removed (nephroureterectomy). The follow-up period was 10 months to 14 years, developing the 68% of the cases without any complication and a good renal function. Two patients were transplanted due to a kidney failure. Diagnosis is often extremely difficult and requires a high degree of suspicion. This diagnosis may be incidental, and it may be made during investigation of patients with other malformations. An early diagnosis and treatment must be made in order to avoid a disturbance of renal function. We wish to point up the high incidence of reflux into the ectopic ureter and the high association to renal agenesis in the single system ectopic ureters in comparison with ectopic ureter of duplex system.

Abnormalities, Multiple↗

PubMed1998

Long-gap esophageal atresia: reconstruction preserving all portions of the esophagus by Schärli's technique.

For distances of over 4-5 cm, esophageal replacement is almost always necessary in esophageal atresias. We present the technical details and describe our experience with esophageal reconstruction by elongation of the lesser curvature (Schärli's technique) in four cases of very long atresias. A retrosternal transposition was made without a thoracotomy in two children, and an orthotopic mediastinal route through a right thoracotomy was done in two others. There were two main complications: anastomotic leaks in three patients that closed spontaneously, and too-rapid gastric emptying, resulting in dumping symptoms that improved with time and diet. One patient developed an anastomotic stricture that responded to bouginage, while another had temporary feeding problems. Esophageal reconstruction by elongation of the lesser curvature provides a relatively simple method of esophageal replacement in children in that all portions of the esophagus are preserved. We propose this technique for early establishment of esophageal continuity in neonates.

Child, Preschool↗

PubMed1998

The interaction of phospholipase A2 with liposomes: an immunological approach to its study.

Porcine pancreatic phospholipase A2 (PLA2) has been incubated for 2 hours at 34 degrees C with rabbit anti-pig pancreatic PLA2 polyclonal antiserum in the absence or presence of phosphatidylcholine liposomes in different physical states. Subsequent assay of hydrolysis -triggered through addition of 5 mM Ca2+- at 34 degrees C, shows that preincubation with antiserum in the presence of 1,2-dimyristoyl-3-sn-phosphatidylcholine liquid-crystalline vesicles, renders the PLA2 activity undetectable, similarly to what is found if preincubation is carried out in the absence of liposomes. In contrast, 1,2-dipalmitoyl-3-sn-phosphatidylcholine liposomes, which at 34 degrees C are in the gel-phase, protect the enzyme from the antiserum effect. The results are consistent with a stronger binding of PLA2 to gel phase, as compared to liquid crystalline vesicles and suggest that through the physical interaction with liposomes in the gel state, the enzyme is shielded from reaction with the antibodies. Taking into account the characteristic hydrolysis profiles of vesicles in different physical states, it can be concluded that the above interpretation agrees with the proposal that PLA2-membrane association promotes the interfacial activation of the enzyme.

1,2-Dipalmitoylphosphatidylcholine↗

PubMed1997

Cantrell's pentalogy. Report of four cases and their management.

Four neonates with the uncommon Cantrell's pentalogy seen in our hospital within a 6-month period without any apparent factor in common are described, with a review of the world literature. The first case was diagnosed prenatally at 15 weeks' gestation, the earliest intrauterine finding in the literature. The occurrence of imperforate anus with the syndrome, observed in one of the cases, has not been previously reported. Two were operated upon and only one of the four survived. This high mortality was confirmed by similar cases reported by other authors.

Abdominal Muscles↗

PubMed1997

Role of type X collagen on experimental mineralization of eggshell membranes.

Type X collagen is a transient and developmentally regulated collagen that has been postulated to be involved in controlling the later stages of endochondral bone formation. However, the role of this collagen in these events is not yet known. In order to understand the function of type X collagen, if any, in the process of biomineralization, the properties of type X collagen in eggshell membranes were further investigated. Specifically, calvaria-derived osteogenic cells were tested for their ability to mineralize eggshell membranes in vitro. Immunohistochemistry with specific monoclonal antibodies was used to correlate the presence or absence of type X collagen or its propeptide domains with the ability of shell membranes to be mineralized. The extent of mineralization was assessed by Von Kossa staining, scanning electron microscopy and energy-dispersive spectroscopy. The results indicate that the non-helical domains of type X collagen must be removed to facilitate the cell-mediated mineralization of eggshell membranes. In this tissue, intact type X collagen does not appear to stimulate or support cell-mediated mineralization. We postulate that the non-helical domains of type X collagen function in vivo to inhibit mineralization and thereby establish boundaries which are protected from mineral deposition.

Amino Acid Sequence↗

PubMed1997

[The use of color doppler sonography of the acute scrotum in children].

The differential diagnosis of the causes of acute scrotum only by clinical means, is often very difficult and supposes the risk of making mistakes, which leaves to several unnecessary surgical explorations. By Colour Doppler Sonography we get some information about testicular flow that helps us in the diagnosis. During the last two years 72 consecutive cases of acute scrotum in children younger than 13 years old, were seen in our hospital emergency department. They all underwent testicular bilateral sonography with color flow imaging using a 7.5 MHz linear array transducer (Model Sonolayer Toshiba SSH-140 A). The sonographical diagnosis were: 45 epididymo-orchitis (62.5%), 8 testicular torsions (11%), 7 torsions of the appendix of testis (9.7%), 7 normal explorations (9.7%), 4 acute idiopathic scrotal oedema (5.5%) and a Henoch-Schönlein purpura (1.38%). Doppler examination showed a 97.2% sensibility and 72.2% specificity in the diagnosis of epididymo-orchitis and 88.88% sensibility and 100% specificity in the diagnosis of testicular torsion. The Colour Doppler Sonography should not minimize importance to the clinical explorations, but is very useful for the diagnosis of acute scrotal process, overcoat in inflammatory diseases.

Acute Disease↗

PubMed1997

[Ureteral ectopia in pediatric age: treatment and evolution in 55 cases].

In the last twenty years 55 children with ureteral ectopia were diagnosed and treated in our Hospital. Thirty seven of them were female (67.3%) and they presented the urinary tract infection like the most frequent symptomatology. Seven children were diagnosed during the first days after being born because the detection of hydronephrosis in the antenatal ultrasound; 36 were associated with complete ureteric duplication (65.4%) and the other 19 with single system (34.6%). Congenital abnormalities associated were seen in 14 patients with more frequency in those which presented single-system ectopic ureter (12/14), being the imperforate anus and the kidney agenesia those the most incidence. The most frequent points of opening were the bladder neck and posterior uretra. Diagnostic work-up included some radiological studies (abdominal ultrasound, intravenous urography, sequence mictional cystourethrography and vaginogram), isotopical tests, meticulous genital exploration, cystoscopy and vaginoscopy. 49.1% underwent conservative surgical treatment (7 ipsilateral ureteroureterostomy and 20 ureteral reimplantation) and 50.9% underwent total or partial nephroureterectomy, being the type of treatment depended on functionality of renal units. After treatment, 74.5% had not any incident; among all postsurgical complications, reflux reappearance was the most frequent (3 cases).

Anus, Imperforate↗

PubMed1997

Congenital intrahepatic portocaval shunt associated with trimethylaminuria.

A case of congenital portal-systemic shunting due to an intrahepatic connection diagnosed by ultrasound scanning and color Doppler in an 8-month-old girl is reported. She began to manifest trimethylaminuria 3 years later. At 7 years of age, she is asymptomatic without therapeutic measures except for diet. This is the seventh reported case and the third in a child to our knowledge.

Arteriovenous Malformations↗

PubMed1997

[Solid ovarian tumors in childhood].

We evaluate our experience in solid ovarian tumors at the Children's Hospital La Fe. The main aims of the study were finding out relevant clinical data for a correct clinical approach, and the optimal surgical attitude in order to obtain tumor relieving with preservation of fertility when possible. A review of 28 girls under 14 years with solid ovarian tumors was carried out. Previous history, initial symptoms and signs, analytical and radiological explorations, treatment and evolution were analysed. 17 benign and 11 malignant tumors were found. Main clinical data were acute abdominal pain and palpation of a mass. Surgery was performed in all of them: salpyngo-oophorectomy in 23 and oophorectomy in 5, with tumoral resection. All patients survive, with periodic follow-up. We remark the frequency of acute abdominal pain as initial symptom of an ovarian tumor, and the importance of a surgical attitude that, intending to be curative, would preserve fertility.

Adolescent↗

PubMed1997

[Our experience in portal cavernomatosis in childhood: cross-sectional study and analysis of results].

A retrospective and transversal study of our patients with portal cavernomatosis is developed, with the aim of comparing the evolution and the present status of the patients that have undergone different therapeutical approaches. Between 1975 and 1995, 15 patients with portal cavernomatosis have been treated. Personal history, signs and symptoms at the moment of diagnosis, and treatment were analyzed. Now, the controls have been made by physical examination and ECO-Doppler of the espleno-portal system. In 6 cases the absence of bleeding made surgery unnecessary. In the 9 patients with digestive haemorrhage, it could be controlled pharmacologically, with a later surgical approach. Now, all non-operated and 6 operated patients show splenomegaly, without bleeding. The ECO-Doppler shows colateral flow, the splenomegaly in the non-operated and the surgical shunts and the hepatofugal circulation in the operated patients. Looking at our results, we believe that prophylactic surgery is not indicated. In those cases of digestive bleeding, surgery after the complete resolution of the acute disease shows good results at a short and long term.

Child, Preschool↗

PubMed1996

[Neonatal intravaginal testicular torsion in an undescended testis].

We report a case of intravaginal testicular torsion with an unusual debut in a 30 day old patient which had undescended testis. We emphasize the need of a complete physical exploration of the child that go to the emergency service with inspecific symptoms of abdominal pain, and supposing the hemiscrotum was empty, is essential to reject a torsion of a cryptorchidic testicle. An immediate surgery is necessary in order to diagnose and treat this disturbance.

Cryptorchidism↗

PubMed1996

[Treatment with Ethibloc of lymphangiomas and venous angiomas].

Lymphangioma and venous angioma are a group of pathological entities which have required surgical treatment since years. Extension, localization and poor delimitation of some lesions have resulted in technical difficulties and serious complications. Our group began the sclerosing therapy with an injection of fibrin adhesive and, due to the lack of response in the first patient, a program with Ethibloc as an alternative substance was developed. We present 10 cases, 4 lymphangiomas and 6 venous angiomas. In 50% of our patients one single session of sclerotherapy was made, in 25% two sessions, and in the rest 25% three. From 10 cases, 4 are still on treatment, complete remission in 5 cases, and good evolution in one case (mixed lymphangioma). As a long-term complication, we have noticed fistulization in 3 cases, and expulsion of the sclerosing agent. In our experience, percutaneous sclerosis with Ethibloc should be the first therapeutic alternative.

Adolescent↗

PubMed1995

Membrane fluidity of Escherichia coli during heat-shock.

The excimer-forming fluorophore dipyrenylpropane has been used to measure the relative fluidity of total membranes isolated from Escherichia coli grown at 30 or 45 degrees C, or exposed to a heat-shock from 30 to 45 degrees C for various periods of time. Parallel experiments were performed using [35S]methionine pulse-labeling of cells, to study the induction of heat-shock proteins (HSPs) at different times after the sudden change in E. coli growth-temperature from 30 to 45 degrees C. Results suggest that upon an abrupt temperature upshift from 30 to 45 degrees C, membrane fluidity adjustment to the steady-state level at the high temperature, takes place during the E. coli heat-shock response.

Escherichia coli↗