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Biomedical subjects

M Molina

Publications and source records attributed to M Molina.

At least 19 recordsLinked to original sources

Non stenotic food impaction due to eosinophilic esophagitis: a potential surgical emergency.

AIM: Eosinophilic esophagitis (EoE) is an emergent condition in which a mucosal infiltrate of > 20 eosinophils per high power microscopic field is accompanied by motor disturbances that may cause food impaction in the absence of esophageal stricture. We report a series of such cases to point out the potential involvement of pediatric surgeons in diagnosis and treatment. Furthermore, data on the motor function of the esophagus investigated manometrically is included. MATERIAL AND METHODS: Thirteen patients with EoE were referred to our emergency room for acute food bolus impaction. Their median age at diagnosis was 12 years (range 7.6-14.4). History of allergy, endoscopy with biopsy and esophageal function (24-h combined ambulatory manometry with simultaneous pH-metry) were investigated. RESULTS: In 7 patients emergency endoscopic extraction of the impacted bolus was necessary. Allergic tests were positive in eight patients. The pH probe showed gastroesophageal reflux in two cases. Upon endoscopy, typical features of EoE (esophageal trachealization and whitish papular exudates) were found. Ambulatory 24-h manometry revealed abnormal motility of the distal esophagus with strikingly high amplitudes (> 150 mmHg) and long duration (> 7 sec) of the waves, particularly during the night. Six patients responded rapidly to steroids and/or antiallergic treatment. The remaining patients had a good outcome with dietary treatment alone. CONCLUSIONS: EoE is an emergent condition that may involve the pediatric surgeon in both the diagnosis and treatment. Typical endoscopic findings and biopsy are required for proper diagnosis. Ambulatory manometry reveals a marked propulsive dysfunction that explains impaction. This dysfunction is reversible, since the symptoms usually disappear with steroids or antiallergic treatment.

Adolescent↗

Intestinal transplantation in children: differences between isolated intestinal and composite grafts.

The results of the isolated intestinal grafts were compared with those of composite grafts (intestinal graft + liver) in a series of 18 transplantations performed in 17 children; 5 isolated intestinal grafts, 12 hepatointestinal grafts, and 1 multivisceral graft. Causes of intestinal failure were short bowel syndrome (n = 13), motility disorders (n = 2) and congenital epithelial disorders (n = 2). Transplantation was indicated due to end-stage liver disease (n = 14), loss of venous access (n = 2), untreatable diarrhea (n = 1) and high morbidity associated with a poor quality of life (n = 1). Six children, all with a composite graft, died after transplantation due to lymphoma (n = 2), sepsis (n = 1); intraabdominal bleeding (n = 1); pneumonia (n = 1); and overwhelming adenoviral infection (n = 1). Digestive autonomy was achieved in 16 of 18 grafts, the 11 surviving children are free of parenteral nutrition with a reasonably good quality of life. In conclusion, intestinal transplantation is a viable therapeutic alternative for children with permanent intestinal failure. The results of transplantation with an isolated intestine are clearly better that those with a composite graft.

Adolescent↗

Rubella and measles seroprevalence among women of childbearing age, Argentina, 2002.

To assess rubella and measles susceptibility among women of childbearing age we conducted a cross-sectional seroprevalence study in four cities and one rural area in Argentina. A convenience sample of women aged 15-49 years seeking care in public health-care institutions was selected (n=2804). Serum specimens were tested for rubella and measles IgG antibody titres. The overall susceptibility to rubella and measles was 8.8 and 12.5% respectively. Seroprevalence differences were found for both rubella (P<0.001) and measles (P=0.002) across sites. Rubella seroprevalence was higher in women aged >or=40 years than in younger women (P=0.04). Measles seroprevalence tended to increase with age (P<0.001). Approximately 15% of women aged 15-29 years were not immune to measles. No risk factors were associated with rubella seronegativity; however, age (P<0.001) and having less than four pregnancies (P<0.001) were factors associated with measles seronegativity. Our findings support the introduction of supplemental immunization activities targeting adolescents and young adults to prevent congenital rubella syndrome and measles outbreaks over time.

Adolescent↗

[Effect of irbesartan in proteinuric non-diabetic renal disease].

This randomized, prospective, two-arm clinical study evaluated the antiproteinuric and nephroprotective effects and the safety of treatment with an angiotensin II receptor antagonist (irbesartan) in patients with chronic glomerulonephritis (CGN) as compared to angiotensin-converting enzyme inhibitors (ACEIls). A total of 50 patients with CGN diagnosed by renal biopsy and protein levels in 24-hour urine higher than 1 g were enrolled. All patients received treatment for at least 24 months, 27 in group 1 (irbesartan) and 23 in group 2 (ACEs). A significant decrease in proteinuria (p < 0.001) was seen in both groups (49.2% in group, 1, and 44.8% in group 2) since the third month, and confirmed at 12 and 24 months of follow-up (58.1% and 62.7% in group 1, and 56.8% and 55.4% in group 2, respectively), with no significant differences being seen between the two groups. No differences were found in blood pressure control. No significant decrease was found in any of the groups in the glomerular filtration rate, but this showed higher values in the group treated with ACEIs (2.98 +/- 7.77 vs 1.64 +/- 6.84 ml/min/year), though the difference with irbersartan was not statistically significant. No side effects occurred among patients treated with irbesartan, whereas three patients initially treated with ACEIs showed intolerance (cough). In conclusion, irbesartan showed in our study an antiproteinuric and nephroprotective effect similar to ACEIs in patients with chronic glomerulonephritis, and its administration was also shown to be safe.

Adult↗

Distal forearm tourniquet for hand surgery.

To evaluate the usefulness of the tourniquet placed at the distal forearm, 30 patients were operated with the tourniquet set at the distal forearm using nerve-block anaesthesia. Pain during surgery, flexion of the fingers, bloodless field, and general complications during surgery and 18 months thereafter were recorded. The mean time of ischemia was 19.6+/-7.5 (10-50) min. A bloodless field was achieved in all cases, and pain during operation was low. Flexion of the fingers were found in most cases but was reducible and not annoying for the surgeon. There were no serious complications during surgery or at follow-up. The tourniquet placed at the distal forearm is painless, safe, and useful in hand surgery.

Adult↗

[Treatment of renal anemia with darbepoetin alfa administered once every other week in predialysis patients with chronic kidney disease and previously treated with epoetin alfa].

Darbepoetin alfa is an erythropoiesis-stimulating glycoprotein with up to 3 times longer half-life than recombinant human erythropoietin (rHuEPO) in humans. The aim of this study was to assess the efficacy and safety of darbepoetin alfa given once every other week as treatment of anemia in predialysis patients with chronic renal failure (CRF) previously treated with once-weekly epoetin alfa. A total of 42 CRF patients were included, all of whom had previously been treated with epoetin alfa and showed stable hemoglobin (Hb) levels without dose changes during the last 8 weeks prior to enrolment in this study. All patients received s.c. darbepoetin alfa once every other week at doses calculated from the protein mass equivalence between rHuEPO and darbepoetin alfa. Follow-up lasted for 24 weeks. Dose adjustments were conducted to preserve target Hb levels between 11 and 13 g/dl. Thirty-nine patients completed the 24 weeks of study. Hb levels increased during follow-up [mean values of 0.39 (p < 0.002), 0.58) (p < 0.001), and 0.83 g/dl (p < 0.001) at 8, 16 and 24 weeks, respectively] despite reducing the darbepoetin alfa dose up to 15% at 24 weeks [from 0.192 microg/kg body weight to 0.185, 0.178 and 0.163 at 8, 16, and 24 weeks, respectively (p < 0.001)]. No adverse events related to darbepoetin alfa were reported. In conclusion, these results show s.c. administration of darbepoetin alfa once every other week was superior to weekly epoetin alfa as a maintenance treatment for anemia in predialysis CRF patients, since the former provided higher Hb levels. Moreover, darbepoetin alfa administration was safe in these patients.

Aged↗

[Results of an intestinal transplantation program in Spain. Five years later].

BACKGROUND: More than two thirds of all intestinal transplantations (ITx) performed around the world correspondent to recipients younger than 18. OBJECTIVE: To analyze our 5-year experience in pediatric ITx. PATIENTS: We assessed the outcome of the 19 children included in list out of 41 patients considered for ITx from 1997. The main cause of intestinal failure was short bowel syndrome (14) followed by intestinal motility disorders (3) and congenit disorders of intestinal epithelium (CDIE) (2). The median of age, at the moment of including in the list, was 0.9 years (range 0.4-17) and median of weight was 6.4kg (range 0.4-29.3). Ten children were included for liver and small bowel transplantation (LSBTx), 7 to isolated small bowel (SBTx), and 2 for multivisceral transplantation (MVTx). Indications for SBx were hepatic fibrosis/cirrhosis (10), hepatic fibrosis in evolution (5) (to avoid later LSBTx), intractable diarrhoea (1), recurrent line infections (1), lost of central vein access (1), and bad quality of life in one. RESULTS: Five children died in the waiting list, after a median time of 325 days (range 19-581). Seven remain in the waiting list (median 139 days, range 30-778). In 3 of these the indication changed from SBTx to LSBTx because of progression to end stage liver disease. Six children recieved seven grafts (1 MVTx, 4 LSBTx, 2 SBx) after a median time in the waiting list of 352 days (range 66-732). Six out of seven grafts achieved normal function and all survivals reached full digestive autonomy after Tx. We had to rejection episodes, one with good response to medical treatment and one that required removal of intestinal allograft and later LSBTx. Two children died 1 because of problem not related to the procedure (hemorrage following liver biopsy) and one girl died 29 months after transplant due to post-transplantation lymphoproliferative disease. CONCLUSIONS: ITx is a realistic alternative in our country for children with intestinal failure. The main problems are immunologic (rejection, lynphoproliferative and disease) Shortage of small weight donors is a dramatic limitation that prompts the discussion of surgical alternatives.

Adolescent↗

[Change of EPO treatment from subcutaneous epoetin to intravenous epoetin or darbepoetin alpha].

This prospective, two-arm, clinical trial assesses the effectiveness in maintaining the levels of haemoglobin (Hb) between 11 and 13 g/d1 and the safety of changing the administration route (from subcutaneous to intravenous) of epoetin (rHuEPO) alpha at equidose versus a changeover to darbepoetin alpha, taking the exact equivalence in peptide mass between the two as referent in patients with chronic renal insufficiency (CRI) in haemodialysis. A total of 112 patients previously treated with epoetin and no dose modification during the 8 weeks prior to the study and stable levels of Hb were included. Of these, 92.1% finished the follow-up period (24 weeks). After changing the administration route of rHuEPO, a significant increase in the resistance index (REI, weekly dose per kilogram of weight/levels of hemoglobin) was observed with mean values of 2.73 (p < 0.018) and 4.37 (p < 0.001) after 16 and 24 weeks respectively, requiring an increase of the dose greater than 15% over the baseline in 6 1.1% of the patients. The changeover to, darbepoetin alpha, independently of the administration route, was accompanied by a decrease in REI starting in the 8th week (mean levels of 0.012, 0.018 and 0.023 after 8, 16 and 24 weeks respectively), significant (p < 0.001) at the 3 cutoff points of the study. The conversion factor increased significantly up to 1:260 in week 24. Both erythropoietic stimulating factors (EST) were well tolerated and no unexpected side effects were observed. In conclusion, treatment of anaemia with darbepoetin alpha in patients with CRI in haemodialysis previously treated with rHuEPO proved to be more effective than the use of epoetin intravenously, significantly improving the resistance index. In addition, the treatment with darbepoetin alpha was well tolerated in these patients.

Anemia↗

Pediatric intestinal transplantation.

AIM: Analyze the results of a paediatric intestinal transplantation (IT) program in Spain. PATIENTS: During an 5-year period, 18 children were included as candidates for IT. The causes for intestinal failure (IF) were short bowel syndrome (n=13), motility disorders (n=3), and congenital epithelial disorders (n=2). Nine children were admitted for a combined liver-small bowel transplant (LSBT), seven for an isolated intestinal transplantation (IIT) and two for a multivisceral transplantation (MVT). In three of the candidates for IIT the indication had to be changed to LSBT because of progression of the liver damage. RESULTS: Eight candidates are on the waiting list: four for LSBT, two for IIT, and two for MVT. Four children died before transplantation. All were children under 1 year and candidates for LSBT. One child died during an attempted MVT. Five children underwent transplantation. Grafts were IIT in two and LSBT in three. Of these children, two are on a normal diet (respective follow-up times: 40 and 18 months), two died, both with functioning liver and intestinal grafts (hemorrage after liver biopsy and lymphoproliferative disease), and one developed an untreatable rejection that lead to loss of the intestinal graft; currently, she is on the waiting list for LSBT. CONCLUSIONS: The morbidity and mortality of IT are high, but it is the only possible treatment for children in IF who cannot be adequately managed with parenteral nutrition. A severe problem is the the scarcity of suitable donors for the very low weight children who are candidates for LSBT.

Adolescent↗

[Protocol to evaluate automatic continuous positive airway pressure. Assessment of the usefulness of the Autoset-T device to determine optimal pressure for treating sleep apnea/hypopnea syndrome].

INTRODUCTION: Given the high prevalence of sleep apnea/hypopnea syndrome (SAHS) and great demand for conventional polysomnography (PSG) and long waiting lists, alternative means for diagnosing SAHS and titrating continuous positive airway pressure (CPAP) are needed. Automatic CPAP may play a role in meeting the last objective, not only for treatment but also for suggesting the optimum CPAP setting. OBJECTIVES: a) To define a protocol to assess the functioning of an automatic CPAP device by means of a mechanical model; b) to determine the behavior of automatically adjusted CPAP during PSG; c) to define the usefulness of automatic CPAP for indicating optimal CPAP pressure for patients with SAHS; d) to evaluate the efficacy of the automatically indicated pressure setting against conventional PSG. METHODS: Four protocols were carried out using the Autoset-T (AT) device. 1. Apneas, hypopneas, flow limitation, snoring and normal flow were simulated in a laboratory using a mechanical model in order to check AT functioning. 2. The behavior of the automatically adjusted CPAP was observed in real time during PSG in 12 patients with severe SAHS. 3. The agreement of CPAP titrated with the AT and with PSG was checked in a group of 39 patients with SAHS. 4. The efficacy of the CPAP pressure recommended by the AT was checked by PSG in a group of 14 patients with SAHS. RESULTS: With the AT, CPAP increased rapidly in response to apneas or snoring in the mechanical model and during conventional PSG; it took only a mean 2.8 3.1 min to rise from a baseline pressure of 4 cm H2O to a near-optimum pressure of 11 1 cm H2O. Once normal flow was reached CPAP slowly decreased, responding with great sensitivity to the slightest abnormality, especially snoring, but not changing in response to certain types of flow limitation. The pressure read visually on the AT was similar to the one recommended by PSG in most of the 39 patients (71%). The PSG performed after one month of using AT-recommended CPAP titration confirmed that the number of apneas, hypopneas (apnea/hypopnea index 6(1) and arousals (8 2) was normal for these SAHS patients. CONCLUSIONS: The AT increases pressure rapidly in the presence of respiratory events and maintains a normal breathing pattern in most patients. Visual reading of the AT pressure allows correct identification of the optimal CPAP setting for SAHS treatment.

Aged↗

[Activity of a pediatric intestinal transplantation program in Spain].

AIM: To analyze the outcome of children with intestinal failure (IF) included as candidates for intestinal transplantation (IT). Patients, Eight out of 23 children with IF assessed since July 1997 met criteria for IT and were included on the waiting list. The causes of IT were Short Bowel Syndrome (SBS) in 6 and Microvillus Inclusion Disease (MID) in 2. The indication of IT were end stage liver disease (ESLD) in 5 (related to total parenteral nutrition administration, TPN), progressive hepatic fibrosis in 2 and loss of venous access in 1. The patients with ESLD were included for combined liver-small bowel transplantation (LSBT) and the remaining for isolated intestinal transplantation (IIT). RESULTS: Two children died waiting for LSBT, 4 patients are on the waiting list, 2 for LSBT and 2 for IIT (length of stay: 4-11 months). Two children were transplanted, one with IIT in a 2.5 years old boy with MID, and one with LSBT in a 22 months girl with SBS and ESLD. Both patients recovered intestinal function after transplantation and are a live (follow-up of 19 and 10 months respectively). The LSBT's patient is under treatment for postransplant lymphoproliferative disease (PTLD). CONCLUSIONS: The lack of suitable donors for the small children candidate to IT explains the long period of stay on the waiting list and the high pretransplant mortality. Two strategies are possible; early referral of children with IF to a transplant center and surgical techniques like ex vivi-hepatic reductions of the LSB graft.

Child↗

Vibrational coupling as diagnostic for intramolecular hydrogen bonds of carbohydrates in aqueous solution.

The coupling of nuC-O and deltaO-D vibrations in the 1200-900 cm(-1) IR range leads to band shifting in opposite directions, which provides information on intramolecular hydrogen bonding of carbohydrates in aqueous solution. The aqueous solution IR spectra of 2-acetamide-1,6-anhydro-2-deoxy-D-glucopyranose and cis-1,2-cyclopentanediol and tetrahydrofuran-ethanol mixtures are reported. Frequency upshifting upon deuteration is observed for the nuC-O bands of both a hydrogen bond acceptor and donor in ether-hydroxyl and hydroxyl-hydroxyl contacts. The 1200-900 cm(-1) range can be used to reveal the presence of intramolecular hydrogen bonds in aqueous carbohydrates, unlike the OH stretching region, which cannot be used in this sense due to carbohydrate band masking by the strong nuOH IR absorption of water.

Carbohydrate Conformation↗

Use of a partial filling technique and reverse migrating micelles in the study of N-methylcarbamate pesticides by micellar electrokinetic chromatography-electrospray ionization mass spectrometry.

This study describes three ways to couple micellar electrokinetic chromatography (MEKC) on-line with electrospray ionization mass spectrometry (ESI-MS) for the analysis of N-methylcarbamate pesticides. The methods involved the use of a partial filling (PF) technique under basic conditions and the use of reverse migrating micelles (RMMs) under acidic and basic conditions. The use of RMMs in basic electrolyte solutions required coated capillaries with low electroosmotic flows, and capillaries coated with anionic poly(sodium 2-acrylamide-2-methylpropanesulfonate) were selected for the purpose. Before the on-line MEKC-ESI-MS coupling, the MEKC and MS conditions were separately optimized under off-line conditions. The methods were compared in terms of detection limits and the stability of the electrospray process. The PF method offered good separation but poorer stability of the electrospray relative to the other methods. A more stable electrospray performance was obtained with use of RMMs in acidic electrolyte solutions, but some of the analytes were protonated and could not be detected due to the increase in their retention factors. However, with the use of anionic polymer-coated capillaries and RMMs at pH 8.5, all analytes were successfully separated. The high-salt stacking method was applied to improve the sensitivity of MEKC-ESI-MS and the detection limits were in the range of 0.04-2.0 microg/ml.

Carbamates↗

Choline-binding domain as a novel affinity tag for purification of fusion proteins produced in Pichia pastoris.

The choline-binding domain (ChoBD) of the carboxy-terminal region of the Streptococcus pneumoniae amidase LYTA (C-LYTA) presents a strong affinity for tertiary amines. We report a method for single-step purification of proteins expressed in the methylotrophic yeast Pichia pastoris based on the fusion of C-LYTA to the protein of interest. We show that C-LYTA can be efficiently expressed and secreted in this host. Tagged proteins fused to this binding domain can be purified on inexpensive DEAE matrices. It therefore provides a useful system for the purification of recombinant proteins with high specificity suitable for industrial purposes.

Base Sequence↗