Biomedical subjects

Maria M Rodriguez

Publications and source records attributed to Maria M Rodriguez.

13 recordsLinked to original sources

PubMed2006

Liver glycogen bodies: ground-glass hepatocytes in transplanted patients.

Ground-glass hepatocytes have been described in Lafora's disease, fibrinogen deposition, hepatitis B, type IV glycogenosis, and alcohol aversion (cyanamide) therapy. We encountered ground-glass hepatocytes with intracytoplasmic inclusions in four liver biopsies from three transplanted patients who had none of the above-mentioned underlying diseases. One patient was a 4-year-old boy who had a kidney transplant for severe ureterovesical reflux. Patient 2 was a 52-year-old man who had two liver transplants because of hepatitis C. The third patient was a 7-month-old girl who underwent a multivisceral transplant because of necrotizing enterocolitis and liver failure induced by total parenteral nutrition. The patients developed liver abnormalities from 45 days to 4 years after their transplants. The livers showed conspicuous ground-glass hepatocytes in 90% of the children's samples and 30% of the adult liver cells. The cytoplasmic bodies stained strongly for Gomori methenamine-silver; they were positive for periodic acid-Schiff without diastase, but negative after diastase digestion. They were negative for colloidal iron and hepatitis B core and surface antigens. Electron microscopy revealed non-membrane bound aggregates of glycogen. Idiopathic ground-glass hepatocytes occur in transplanted patients and represent accumulation of altered glycogen. However, their clinical significance and cause are not entirely elucidated.

Child, Preschool↗

PubMed2006

PRCC-TFE3 renal cell carcinoma in a boy with a history of contralateral mesoblastic nephroma.

The genetics of renal tumors in children is widely recognized. However, most of the studies published to date emphasize the association between Wilms tumor and the WT-1 gene. Recently, a unique translocation between the X chromosome and chromosome 1 or t(X;1) has been described in several reports of renal cell carcinomas (RCCs) diagnosed in children and adolescents that results in PRCC-TFE3 gene fusion. We report here a 9-year old African-American boy with a history of a right congenital mesoblastic nephroma treated with nephrectomy and followed by annual checkups. After 9 years, he was diagnosed with a mass at the hilum of the left kidney during the work-up of new-onset hypertension. A limited biopsy revealed densely hyalinized connective tissue that was initially interpreted to be a hyalinized contralateral mesoblastic nephroma. The child received chemotherapy, but the mass continued to grow. He underwent a left nephrectomy, and the pathology was diagnostic for a clear cell RCC. Chromosomal analysis disclosed a t(X;1)(p11.2;q21) translocation, which is known to result in a PRCC-TFE3 gene fusion. The tumor showed nuclear labeling for TFE3 protein by immunohistochemistry, supporting the above diagnosis. He has been on hemodialysis, is tumor free, and has not been receiving chemotherapy for 24 months. This is the first report of a RCC as a second malignant neoplasm in a child treated for a congenital mesoblastic nephroma.

Basic Helix-Loop-Helix Leucine Zipper Transcriptio↗

PubMed2005

Giant aneurysm of the atrial septum associated with premature closure of foramen ovale.

Premature closure or restriction of foramen ovale (PCFO) is a rare congenital anomaly that can lead to a wide spectrum of cardiac malformations. This spectrum of secondary malformations appears to depend on the gestational timing of closure of the foramen ovale and to the degree of restriction. Earlier in the gestation, closure of the foramen has been associated with severe hypoplasia of the left ventricle whereas later closure has been associated with right heart failure and rarely with the formation of an aneurysm of the atrial septum. We describe the case of a 1 day old infant in whom PCFO resulted in severe right heart failure in addition to the formation of a giant atrial septal aneurysm.

Heart Aneurysm↗

PubMed2005

Comparative renal histomorphometry: a case study of oligonephropathy of prematurity.

Children born with very low birth weight have a decreased nephron number. Low nephron mass is associated with adult hypertension, proteinuria, and diabetes mellitus. The histomorphometry and radial glomerular count (RGC) of a total nephrectomy from a child with renal disease associated with extreme prematurity was compared with the kidney from a full-term age-matched child of normal gestation with chronic renal failure due to focal and segmental glomerulosclerosis (FSGS) and to a child without renal disease. Bowman's space area, mesangium and mesangial tuft area were determined in 50 glomeruli of each specimen by computer-assisted morphometry. RGC was 4 in the ex-preterm child, 8 in the patient with FSGS, and 9 in normal control. The patient with FSGS had larger glomerular area expressed as square micrometers (mum(2)) of Bowman's capsule, the mesangium and the mesangial tuft area measurements than the normal control and the child born preterm who subsequently developed renal failure had significantly larger Bowman's capsule and mesangium than the two controls. This case report begins to identify important pathologic findings of decreased nephron numbers and glomerulomegaly associated with preterm birth.

Case-Control Studies↗

PubMed2004

Langerhans' cell histiocytosis: pathology, imaging and treatment of skeletal involvement.

Langerhans' cell histiocytosis (LCH) is manifested in a variety of ways, the most common being the eosinophilic granuloma, a localized, often solitary bone lesion that occurs predominantly in the pediatric age group. The hallmark of LCH is the proliferation and accumulation of a specific histiocyte: the Langerhans' cell. In bone this may cause pain and adjacent soft-tissue swelling, but some lesions are asymptomatic. LCH can involve any bone, but most lesions occur in the skull (especially the calvarium and temporal bones), the pelvis, spine, mandible, ribs, and tubular bones. Imaging diagnosis of the disease in bone is first based on the plain radiographic appearance, which is usually a central destructive, aggressive-looking lesion. In the skull, the lesions develop in the diploic space, are lytic, and their edges may be beveled, scalloped or confluent (geographic), or show a "button sequestrum." Vertebral body involvement usually causes collapse, resulting in vertebra plana. With significant recent improvements in the quality of gamma cameras, imaging techniques, and in studying children, bone scintigraphy at diagnosis and on follow-up usually reveals the sites of active disease, especially when the involvement is polyostotic. CT and MR imaging are very useful in providing detailed cross-sectional anatomic detail of the involved bone, including the bone marrow and the adjacent soft tissues. CT is better suited for demonstrating bone detail and MR imaging for bone marrow and soft-tissue involvement.

Bone Diseases↗

PubMed2004

Protective effect of pentoxifylline on volume-induced lung injury in newborn piglets.

To evaluate the efficacy of pentoxifylline (PTXF) in the attenuation of lung inflammation during volume-induced lung injury (VILI) in newborn piglets, 17 newborn piglets were mechanically ventilated with a large tidal volume (50 ml/kg) for a period of 8 h. They were randomly assigned to a placebo (PL, n = 9) or a treatment group (PTXF, n = 8) that received PTXF (20 mg/kg as a bolus, followed by a continuous infusion of 5 mg/kg/h). Hemodynamics, lung mechanics and arterial blood gases were measured during the 8 h of study. Serum and tracheoalveolar fluid (TAF) platelet-activating factor (PAF) and thromboxane (TXB(2)) levels were obtained at baseline and at 8 h, while lung tissue myeloperoxidase (MPO) and wet to dry weight were assessed after the completion of the study. In the PL group, a marked increase in TAF PAF and TXB(2) levels was observed only in TAF, suggesting that the inflammatory process was localized within the lungs. A significant decrease in lung tissue MPO activity (p < 0.005) and lung wet to dry weight ratio (p < 0.04) was observed in the PTXF group. There were no differences in hemodynamics, arterial blood gases or lung mechanics measurements between groups. A significant reduction in pulmonary inflammatory response was observed during VILI in the PTXF pretreated animals. These results suggest that PTXF may be effective in modulating lung inflammation associated with mechanical ventilation in neonates.

Animals↗

PubMed2004

A functional immature model of chronic partial ureteral obstruction.

BACKGROUND: The most common nonlethal congenital anomaly of the urinary tract is ureteral obstruction without dysplasia. Although rarely progressive, the morbidity associated with metabolic and surgical management is considerable. Our study was designed to measure local and systemic pathophysiologic mechanisms in an immature model of chronic partial unilateral ureteral obstruction (UUO) after completion of glomerulogenesis. METHODS: A partial UUO was created by the method of "psoas wrap" in young male weanling rats. Control animals were sham operated. Three groups were divided as follows: sham (N= 15), UUO (N= 18), and UUO + angiotensin-converting enzyme (ACE) (N= 16) inhibitor, enalapril. Renal glomerular and tubular functions were determined by creatinine and uric acid clearances. Diuresis was assessed by urine volume, osmolality, and fractional solute excretions from samples above and below the obstruction. Proteinuria was determined by the urine protein/creatinine ratio (Up/c). RESULTS: Proteinuria was attenuated in UUO + ACE-treated animals. The hyperuricemia of the immature UUO animals was avoided by an increase in the clearance of uric acid in the UUO + ACE-treated group. Fractional solute excretions suggested a diversion of diuresis to the contralateral unobstructed kidney. CONCLUSION: Angiotensin blockade during chronic UUO in young rats affords protection by attenuating proteinuria, promoting uricosuria, and diverting solute diuresis. These data suggest a complex interaction of local and systemic mechanisms unique to the maturing kidney.

Animals↗

PubMed2003

MR evaluation of arrhythmogenic right ventricular cardiomyopathy in pediatric patients.

OBJECTIVE: The aim of our study was to correlate the findings of three MR imaging sequences with the clinical findings of possible arrhythmogenic right ventricular cardiomyopathy in pediatric patients. MATERIALS AND METHODS: Twenty-six consecutive pediatric patients underwent MR imaging with ECG-gated non-breath-hold spin-echo T1-weighted non-fat-suppressed and fat-suppressed sequences. The MR images were evaluated for thinning or fat signal in the right ventricular wall and for enlargement or increased trabeculation of the right ventricle or right ventricular outflow tract. Cine MR imaging was used to assess wall motion abnormalities. Cardiac biopsy was performed in 17 patients. Biopsy results and other clinical findings suggesting arrhythmogenic right ventricular cardiomyopathy were tabulated. RESULTS: Two MR imaging studies were of poor quality as a result of arrhythmias, and one study was incomplete. In the 23 remaining patients, there were (mean +/- SD) 1.5 +/- 1.0 and 0.8 +/- 1.0 findings of possible arrhythmogenic right ventricular cardiomyopathy in the non-fat-suppressed and the fat-suppressed sequences, respectively. Fat-compatible signal in the myocardium was detected in 16 (70%) of 23 non-fat-suppressed studies and in five (22%) of 23 fat-suppressed studies (p = 0.003). The non-fat-suppressed sequence had a higher sensitivity (75% vs 43%) and a lower specificity (38% vs 75%) for fatty infiltration than did the fat-suppressed sequence when correlated with the biopsies. The linear correlation between all MR findings and all clinical diagnostic criteria, including biopsy, was better for the combination of cine and both T1 sequences (r = 0.58) than for the non-fat-suppressed (r = 0.53) or fat-suppressed (r = 0.46) T1 sequences alone. CONCLUSION: MR imaging showed moderate correlation with the clinical criteria in the diagnosis of arrhythmogenic right ventricular cardiomyopathy.

Adolescent↗

PubMed2002

Leukotrienes mediate neurogenic inflammation in lungs of young rats infected with respiratory syncytial virus.

Respiratory syncytial virus (RSV) infection potentiates neurogenic inflammation in rat airways. Because some vascular effects of sensory nerves are mediated by cysteinyl leukotrienes (cysLTs), we studied whether the receptor antagonist montelukast inhibits neurogenic plasma extravasation in RSV-infected rats. Pathogen-free rats were inoculated at 2 wk (weanlings) or 12 wk (adults) of age with RSV or virus-free medium and treated with montelukast or its vehicle starting 1 day before inoculation. Five days postinoculation, we measured the extravasation of Evans blue-labeled albumin in the respiratory tract after stimulation of sensory nerves with capsaicin. Montelukast had no effect in the extrapulmonary airways but abolished albumin extravasation in the intrapulmonary airways of RSV-infected rats, with a larger effect in weanlings than in adults. Increased concentrations of 5-lipoxygenase-encoding mRNA and cysLTs, as well as numerous mast cells, were detected in the lung tissues of RSV-infected weanling rats. These observations suggest that the release of neuropeptides from capsaicin-sensitive sensory nerves and nonneuronal cells in the lungs of RSV-infected young rats increases vascular permeability by promoting the release of leukotrienes from mast cells.

Age Factors↗

PubMed2002

Nerve growth factor and nerve growth factor receptors in respiratory syncytial virus-infected lungs.

Nerve growth factor (NGF) controls sensorineural development and responsiveness and modulates immunoinflammatory reactions. Respiratory syncytial virus (RSV) potentiates the proinflammatory effects of sensory nerves in rat airways by upregulating the substance P receptor, neurokinin 1 (NK(1)). We investigated whether the expression of NGF and its trkA and p75 receptors in the lungs is age dependent, whether it is upregulated during RSV infection, and whether it affects neurogenic inflammation. Pathogen-free rats were killed at 2 (weanling) to 12 (adult) wk of age; in addition, subgroups of rats were inoculated with RSV or virus-free medium. In pathogen-free rats, expression of NGF and its receptors in the lungs declined with age, but RSV doubled expression of NGF, trkA, and p75 in weanling and adult rats. Exogenous NGF upregulated NK(1) receptor expression in the lungs. Anti-NGF antibody inhibited NK(1) receptor upregulation and neurogenic inflammation in RSV-infected lungs. These data indicate that expression of NGF and its receptors in the lungs declines physiologically with age but is upregulated by RSV and is a major determinant of neurogenic inflammation.

Aging↗

PubMedDate not supplied

Concurrent infantile hemangioendothelioma and mesenchymal hamartoma in a developmentally arrested liver of an infant requiring hepatic transplantation.

A newborn female underwent a surgical resection for a hepatic mass discovered prenatally by ultrasonography, and diagnosed pathologically as a mesenchymal hamartoma. Within 4 months after surgery, multiple cutaneous hemangiomas developed and a multinodular mass was detected in the liver. A liver biopsy showed an infantile hemangioendothelioma with type I features. An orthotopic liver transplant was performed due to the extensive nature of the hepatic involvement and progressive respiratory compromise. Virtually the entire liver was involved by a large infantile hemangioendothelioma. A multicystic mesenchymal hamartoma was also found on the left side. In addition, the uninvolved hepatic parenchyma had features recapitulating the fetal liver. This simultaneous involvement of the liver by a mesenchymal hamartoma and infantile hemangioendothelioma is unique. A review of the literature revealed only one incompletely characterized case with similar findings.

Female↗

PubMedDate not supplied

Molar gestations and hydropic abortions differentiated by p57 immunostaining.

Classification of molar gestations into complete and partial and their differentiation from hydropic abortions traditionally are accomplished by morphology alone. The process sometimes may be inaccurate or inconclusive. With the availability of p57 immunostaining it may be possible to objectively classify these lesions. We used p57 for the differential diagnosis of hydropic abortions and molar gestations and correlated the findings with the clinical outcome of patients in each category. First, 86 cases were originally classified by histomorphology into hydropic abortion (42) and molar gestations (23 complete and 21partial). Based on the pattern of p57 staining the cases were reclassified into 45 hydropic abortions, 15 partial moles and 26 complete moles (3 cases with previous diagnosis of complete mole based on morphology were reclassified as hydropic abortion). Clinical follow-ups ranged from 6-24 months and showed persistent trophoblastic disease in 8 cases (31%) of complete moles and 3 cases (20%) of partial moles (p = 0.47). No hydropic abortion cases demonstrated persistent trophoblastic disease. One patient with partial mole developed choriocarcinoma. This study confirms that p57 objectively distinguishes hydropic abortions from molar gestations (partial and complete moles). This differentiation is clinically relevant since patients with hydropic abortions do not need to be followed while patients with molar gestations do.

Abortion, Spontaneous↗

PubMedDate not supplied

Developmental renal pathology: its past, present, and future.

Congenital anomalies of the kidney and urinary tract are responsible for approximately 40% of cases of childhood end-stage renal failure in the United States. This article describes the spectrum of developmental renal lesions in children (including renal agenesis, dysplasias, hereditary hydronephrosis, autosomal recessive and dominant polycystic kidneys, vesicoureteral reflux, diabetic embryopathy, some teratogenic drugs affecting renal development, and syndromes associated with renal dysplasias). The article quotes some historic references that established the foundation for further studies; reviews the embryology, pathology, postnatal renal development, and its possible consequences of renal function; as well as recent advances in fetal ultrasonography and molecular biology with some novel treatment and diagnostic modalities. Finally, an attempt is made to predict several future avenues in pharmacogenetics that are being built currently and that will allow a better prognosis for many children with congenital renal conditions.

Child↗