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Biomedical subjects

M D Morales

Publications and source records attributed to M D Morales.

8 recordsLinked to original sources
PubMed2005

Rapid and highly sensitive electrochemical determination of alkaline phosphatase using a composite tyrosinase biosensor.

The use of an amperometric graphite-Teflon composite tyrosinase biosensor for the rapid monitoring of alkaline phosphatase (ALP), with no need of an incubation step and using phenyl phosphate as the substrate, is reported. Phenol generated by the action of ALP is monitored at the tyrosinase composite electrode through the electrochemical reduction of the o-quinone produced to catechol, which produces a cycle between the tyrosinase substrate and the electroactive product, giving rise to the amplification of the biosensor response and to the sensitive detection of ALP. The current was measured at -0.10 V 5 min after the addition of ALP. As a compromise between high ALP activity and high sensitivity for the detection of phenol, a pH of 8.5 was chosen. The substrate concentration was also optimized. A linear calibration plot was obtained for ALP between 2.0 x 10(-13) and 2.5 x 10(-11), with a detection limit of 6.7 x 10(-14) M. Different types of milk were analyzed with good results, using an extremely simple and rapid procedure.

Agaricales↗
PubMed2004

[Corynebacterium urealyticum in renal trasplantation. CT and sonography imaging characteristics of encrusted cistitis and pielitis].

PURPOSE: Its described three cases of Corynebacterium urealyticum (CU) infection in patients with renal transplantation and one of its most serious consequences: encrusted pyelitis and cystitis. It is explained the principal keys for its diagnosis, based in the appearance of alkaline pH in in urine analysis (alkaline urine), positives urinary cultures for CU, and the CT and US studies revealed the characteristic images of calcifications in the wall of renal pelvis and bladder. PATIENTS: Three male patients with renal transplantation and CU infection that caused encrusted pyelitis in two of the cases and encrusted cystitis in one case. RESULTS: Calcifications of the urinary tract were noticed in CT in all the patients. In two cases bladder stones were linear, and in the third case they were fundamentally coarse and placed in pelvis. The diagnosis suspicion showed by the images was confirmed by the use of prolonged urine cultures, necessary for detecting CU. All the patients were treated with vancomycin, with success in two of the cases and, finally needing surgery, and after loss of the graft, in the other case. CONCLUSION: Encrusted pyelitis and cystitis are cronic and severe infections of the urinary tract. Calcic struvite incrustations in the urothelium are characteristics of this infection. CT is a choice technique for the diagnosis and followup of the calcifications after treatment.

Adult↗
PubMed1993

Microsurgery in gaining paediatric vascular access for haemodialysis.

One hundred and one surgical procedures performed in children for construction and maintenance of vascular accesses for haemodialysis were retrospectively analyzed. There were 86 operations performed to create a new fistula in patients without vascular access or with nonrecoverable failed angio-access. Fifteen surgical procedures were performed to treat fistula complications. The new fistulas were radiocephalic n = 60 (70%), ulnar-basilic n = 5 (5.8%), antecubital n = 9 (10.3%), and PTFE grafts n = 12 (14%). Microsurgical techniques were used in all cases, including PTFE graft fistulas. A microscope was used in 56 cases (55.4%) and magnifying loupes (x 2.5 magnification) in the rest of the operations. Early-failure rate for radiocephalic fistulas was 10%. Cumulative patency rates in radiocephalic fistulas were 79%, 75%, and 70% at 1, 2, and 5 years, respectively. No statistical differences were found from the cumulative patency curve of 730 radial-cephalic fistulas performed in adults during the same period of time. Radiocephalic fistulas can be constructed in most paediatric cases using microsurgical technique. Elbow fistulas can be the second-choice vascular access, and PTFE grafts can be reserved for children with exhaustion of autologous veins. Brachial-jugular PTFE grafts can be used in cases of subclavian vein stenosis.

Adolescent↗
PubMed1992

[Second neoplasms as a late complication of the treatment of Hodgkin's disease].

PURPOSE: To determine the incidence of a second malignancy in patients with Hodgkin's disease (HD) diagnosed and treated in the same hospital. PATIENTS AND METHODS: A retrospective study was performed on 99 patients diagnosed and treated for HD in the Hospital San Carlos, in Madrid, between January 1976 and december 1987. The clinical records were revised; the diagnosis and staging followed the Rye and Ann Arbor criteria, and the treatment included radiation therapy (RT), chemotherapy (CT), or a combination of both. The diagnosis of the second malignancy was based upon clinical, analytical, radiological and histological records. RESULTS: The median age in the series was 31 years (16-82) and the M/F ratio was 61/38. The stage distribution was: I-9; II-29; III-31, and IV-30. Twenty-six patients received RT alone, 59 were treated with CT, and 14 received RT plus CT. A second neoplasm was found in 6 patients (6%), of whom 4 developed a myelodysplastic syndrome (MDS) and 2 a solid tumour. All the patients who had MDS had received MOPP or C-MOPP chemotherapy, associated in two of them with extensive RT. Both patients with solid tumour had been given CT+RT. The median time of presentation of the second malignancy since the diagnosis od HD was 89 months (48-174) for MDS and 120 months for the solid tumours. The four MDS patients have died, 2 for ANLL-M5, one for SRA and the remainder for cerebral haemorrhage, not yet evolved into acute leukaemia. The two patients which solid tumours are alive and seemingly in complete remission at 12 and 10 months, respectively, of the diagnosis of the second malignancy. CONCLUSIONS: 1) All the patients with second neoplasms had been previously treated with CT (MOPP or C-MOPP) or CT+RT. 2) Non-Hodgkin's lymphoma has not appeared in any of the patients in this series. 3) An endless follow-up of patients with HD seems important in order to achieve an early diagnosis of other malignant complications which, although in case of MDS have poor prognosis, in case of solid tumours may do well with adequate treatment.

Adolescent↗
PubMed1992

[Treatment of amyotrophic lateral sclerosis with daily intrathecal TRH. A year's experience. Pilot study II].

This study presents the experience of one year of treatment in patients with amyotrophic lateral sclerosis, with intrathecal TRH administered daily by a subcutaneous reservoir connected to the intrathecal lumbar space by a double catheter system as to provide continuous circulation of CSF and to avoid sac formation since this would be a source of infection. Clinical evaluation was carried out with a scale developed by the authors with the main aim of evaluating the loss of vital motor abilities and not as a localized evaluation. Secondary effects due to the implantation of the reservoir in addition to its use are presented although data were not important. Intrathecal administration of TRH was carried out similarly (600 micrograms/day) with secondary effects being the same as those by other routes of administration although of a lesser intensity. The results of the clinical evaluation at the beginning and end of the treatment as well as after patient follow up demonstrated that beneficial effects do not occur equally in all patients but rather are transitory and do not improve the natural evolution of the disease. The authors conclude that, methodologically, this series study does not enter within the frame of an advisable statistical study since the aim is to provide data for a future controlled study.

Adult↗