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Biomedical subjects

G Mendez

Publications and source records attributed to G Mendez.

At least 19 recordsLinked to original sources

Treatment of pediatric non-Hodgkin lymphomas in a country with limited resources: results of the first national protocol in Nicaragua.

We report the results of a protocol for the diagnosis and treatment of pediatric non-Hodgkin lymphomas (NHL) conducted in Nicaragua in the context of an international collaborative program. Fifty-three children with NHL treated between 1996 and 2003 were retrospectively evaluated. Therapy was designed based on local drug availability and affordability with dose and schedule adaptations for Burkitt and lymphoblastic lymphomas. With a median follow-up of 3 years, the projected 9-year overall survival was 63% and event-free survival 53%. The treatment was efficacious, feasible, and well tolerated in spite of the local socio-economical conditions.

Adolescent↗

Treatment of childhood Wilms' tumor without radiotherapy in Nicaragua.

BACKGROUND: Recent trends in therapeutic strategies for Wilms' tumor are based on an attempt to reduce or omit radiotherapy (RT) in a sizable fraction of patients. We report here the clinical and histological features as well as the results obtained in 37 children (23 males, 14 females; median age at diagnosis 3 years, range 0.8-8 years) diagnosed between 1991 and 1996, and treated with chemotherapy (CT) and surgery at La Mascota Hospital, Managua, Nicaragua. PATIENTS AND METHODS: Patients were grouped as follows: those who underwent surgery at diagnosis (group A, n = 4), patients who received preoperative CT because of large tumor size (group B, n = 27), lung metastases (n = 5) or bilateral disease (n = 1) (group C, n = 6). Treatment consisted of vincristine (VCR) and actinomycin-D (ACTD) for 24 weeks in group A, and of VCR, ACTD and adriamycin for 68 weeks in groups B and C. Histology was classified as favorable in 30 patients (81%), unfavorable in six patients (all of group B) and unknown in one. RESULTS: With a median follow-up time of 6.4 years the event-free survival for the whole group was 80.1%+/-6.8 (SE). No event occurred beyond 5 years of diagnosis. CONCLUSIONS: These results suggest that RT does not appear necessary for the majority of patients, and that an excellent surgical approach associated with an intensive CT schedule can control the disease, even in the absence of adequate information on the intra-abdominal tumor extent.

Antineoplastic Combined Chemotherapy Protocols↗

Monocyte differentiation and HIV replication after prolonged culture of peripheral blood mononuclear cells from HIV-infected individuals.

Primary cultures of peripheral blood mononuclear cells (PBMC) from 51 HIV+ hemophiliac patients (HIV+ PBMC) were set up, allowing undisturbed cellular interaction in the absence of any exogenous stimuli. The optimum time for p24 detection was between 12 and 25 days. Infective virus was recovered from the culture supernatants (HIV+ SN) and the amount of p24 released ranged from 25 to 5300 pg/ml. Cells of the monocyte/macrophage (M/M) lineage were the main source of HIV in the HIV+ SN, as judged by intracellular staining of permeabilized cells with anti-p24 (KC57 monoclonal antibody) and flow cytometry analysis. M/M activation, differentiation, and proliferation occurred along the culture before the peak of in vitro HIV replication. Release of HIV p24 was highest in patients with >200 CD4+ T lymphocytes/mm3 who did not receive highly active antiretroviral therapy (HAART), but it was still detectable in 60-90% of patients who had responded to 1-2 years of HAART, reducing their plasma viral load to undetectable levels. It is proposed that this simple experimental system can be used to assess ongoing HIV infection of M/M with the patient's own viral variants.

Antiretroviral Therapy, Highly Active↗

North-South twinning in paediatric haemato-oncology: the La Mascota programme, Nicaragua.

We describe the La Mascota twinning programme between La Mascota paediatric hospital in Managua, Nicaragua, and hospitals in Monza and Milan, Italy, and Bellinzona, Switzerland. The programme was based on the belief that an attempt to reduce the gap in mortality from cancer in childhood between developed and less developed countries should become an integral part of the care and research activity of a haemato-oncological department of a developed country and not simply an exercise in solidarity. This programme for acute lymphoblastic leukaemia shows that intellectual, organisational, and financial resources can be generated by a twinning programme. What is vital for such programmes is a long-term commitment to a comprehensive and holistic strategy that incorporates supply of drugs, training and supervision of health professionals, and the care of the children and of their parents.

Child↗

Functional capacity of colostral leukocytes from women delivering prematurely.

The phagocytic, bactericidal, and metabolic activity of colostral leukocytes from mothers delivering preterm infants was compared with that of colostral leukocytes from mothers of term infants. In addition, the proliferative capacity of colostral lymphocytes was compared. Preterm adherent colostral leukocytes had a significantly higher phagocytic index than term colostral adherent leukocytes. Mean +/- SEM values were 5.4 +/- 0.5 versus 2.7 +/- 0.2, respectively (p less than 0.001). Bactericidal capacity against Escherichia coli and nitroblue tetrazolium reduction of preterm and term colostral leukocytes were comparable. Lymphocyte proliferative response was equivalent in preterm and term milk. We conclude that colostral leukocytes from preterm mothers are at least as functional in their antimicrobial activity and possibly phagocytose even better than the colostral cells of mothers of term infants.

Adult↗

Percutaneous biliary drainage in acute suppurative cholangitis.

One hundred and sixteen percutaneous drainage procedures of the biliary system were performed in a 2-year period. Eight of 9 acutely ill patients with the diagnosis of acute suppurative cholangitis were successfully treated nonoperatively. They represented 26% of all patients with benign or postsurgical obstruction referred for biliary decompression. Conversely, acute suppurative cholangitis only occurred in 2.3% of patients with underlying malignant disease. These observations are considered most relevant in predicting the purulent nature of the disease, with further implications for patient management. Early recognition and prompt decompression of the biliary system are mandatory, along with the appropriate antibiotic coverage. Our experience compares favorably with surgical results and the procedure is proposed as the method of choice for the initial treatment of acute suppurative cholangitis.

Acute Disease↗

Nonsurgical drainage of appendiceal abscesses.

Five patients with abdominal abscesses complicating appendicitis were successfully treated by catheter drainage. In two patients, the percutaneous procedure was performed after incomplete surgical drainage; in three patients it was used as the only means of initial drainage. No interval appendectomy was required and no complications were associated with the procedure. Percutaneous management of appendiceal abscesses can be proposed as an alternative to surgical drainage.

Abscess↗

Abandonment of endoprosthetic drainage technique in malignant biliary obstruction.

This report discusses a 3-year experience with the techniques of internal/external catheter and endoprosthetic stent drainage in 175 patients with obstructive jaundice. In 166 patients, the obstruction was bypassed satisfactorily. The complications encountered with these techniques are compared, and the radiation doses involved are emphasized. It is not necessary to put patients through the extra time and pain related to the placement of the endoprosthesis, because internal/external catheter placement produces the same desired result of biliary decompression without the higher radiation doses to the radiologist.

Adolescent↗

Retroperitoneal processes involving the psoas demonstrated by computed tomography.

Twenty-five patients were found to have retroperitoneal pathology involving the psoas muscle including nine patients with inflammatory lesions, three with hematomas, seven with adenopathy, one patient with leukemic infiltration of the psoas, and five with retroperitoneal tumors. Computed tomography (CT) offers a unique method to investigate pathological processes that affect the psoas. In addition, the abdominal films on 24 of the patients were analyzed to correlate the value of radiography with that of CT. Computed tomography confirms the belief that the mere presence of a retroperitoneal mass will not necessarily obliterate the psoas.

Abscess↗

Wedged pressure recording and injection of contrast medium into the hepatic veins: a study performed on the livers of cadavers to explain clinical findings.

Portal and hepatic veins were injected with Microfil in the normal and cirrhotic livers of cadavers. Based on pathologic and anatomic studies previously reported and on the present investigation, the authors explain the background of wedged hepatic pressure recording and the findings when contrast medium is injected into a catheter wedged in a hepatic vein.

Catheterization↗

Gallium-67 radionuclide imaging in acute pyelonephritis.

The symptoms and clinical course of patients with acute pyelonephritis are variable; likewise, urinalysis, blood cultures, and excretory urography may be normal or equivocal. The ability of gallium-67 to accumulate in areas of active inflammation was useful in the diagnosis of acute pyelonephritis in 12 cases. A multiplane tomographic scanner was used for imaging four of these patients. Initial experience with this scanner is also discussed.

Acute Disease↗

Percutaneous brush biopsy and internal drainage of biliary tree through endoprosthesis.

Percutaneous insertion of a permanent internal prosthesis for biliary tract decompression was successful in 15 patients with obstructive jaundice. Percutaneous brush biopsy of the obstructing lesion that preceded stent placement in six patients was successful in obtaining diagnostic tissue in four. Both techniques are described in detail with illustrative cases.

Adult↗

CT of acute pancreatitis: interim assessment.

a retrospective review of 102 ptients with the clinical diagnosis of acute pancreatitis undergoing computed tomographic (CT) evaluation during a 9 month period revealed 32 patients with abnormal CT scans. All 32 had enlargement of the pancreas. The extent of inflammatory process on these patients was examined. Twenty patients exhibited a phlegmonous mass extending into the region of the lesser sac. There was involvement of the left anterior pararenal space in 13 (the right in three and both in four). Eight patients demonstrated involvement of the posterior pararenal space, and in seven of these the inflammatory process extended down the psoas muscle into the pelvis. Five patients had involvement of the transverse mesocolon and small bowel mesentery. Eight patients developed a pseudocyst during the acute phase of the disease, 11 developed a pancreatic abscess, and two showed evidence of pancretic hemorrhage. This experience prompted a prospective study of the clinical course of acute pancreatitis relative to the extent of disease as recognized by CT.

Abscess↗

Gastrointestinal varices: percutaneous transheptic therapeutic embolization in 54 patients.

During a 5-year period, 54 patients underwent emergency percutaneous transhepatic protography for embolization of varices to control gastrointestinal bleeding. The portal vein could not be entered in six patients: five died and one survived a gastric devascularization procedure. In the 48 patients who had successful embolization, 19 went on to elective surgery with 12 survivors. Of the 29 patients who were not surgical candidates, 21 died. Categorizing these 48 patients according to the direction of flow in the portal vein showed that 36 had hepatopetal flow and three partial hepatopetal flow. Twenty patients survived. The remaining nine had hepatofugal flow. None of these patients survived the hospitalization. Criteria are described for selecting patients in whom embolization of varices through the percutaneous transhepatic route will be of maximum therapeutic benefit.

Adult↗

Diagnostic and therapeutic aspirations of fluid containing masses: the role of ultrasound and computed tomography.

Twenty-eight patients have undergone diagnostic and/or therapeutic aspiration of fluid containing masses at Jackson Memorial Hospital over the last 8 months. The majority were diagnosed and aspirated under ultrasonic control while in a few cases CT was required. In 19 patients, a therapeutic aspiration was attempted. In 17, this was successful, none of these patients required surgical intervention. The role of ultrasound and CT in the diagnosis and treatment of fluid collection is emphasized. The technique for both diagnostic and therapeutic aspirations is stressed as well.

Abscess↗

The role of computed tomography in the diagnosis of renal and perirenal abscesses.

Computed tomography was done on 4 patients suspected of having an intrarenal or perirenal abscess based on clinical grounds and an abnormal excretory urogram. Intrarenal abscesses with perinephric extension were demonstrated in 3 patients and a solitary perinephric abscess was demonstrated in 1. Computed tomography is a valuable tool in the diagnostic study of suspected intrarenal and perirenal abscesses because not only can the primary abscess be shown but also its possible extrarenal extension.

Abscess↗