Biomedical subjects

C E Diaz

Publications and source records attributed to C E Diaz.

7 recordsLinked to original sources

PubMed2000

Intraocular melanoma spread to regional lymph nodes: report of two cases.

PURPOSE: To report two cases of regional lymphatic spread of primary uveal melanoma. METHODS: The clinical records of two patients who underwent enucleation for uveal melanoma and later developed regional lymph node metastases were reviewed. One of the two eyes was initially treated with proton beam irradiation. Histologic sections of the enucleated eyes and excised lymph nodes were examined. RESULTS: The melanomas arose in the choroid and ciliary body of the two patients and spread to regional lymph nodes 2 years after enucleation. The choroidal melanoma recurred after irradiation, diffusely infiltrated the uveal tract, and extended into the conjunctiva via an emissary canal. The ciliary body melanoma spread through the trabecular meshwork to the conjunctiva. CONCLUSIONS: Choroidal and ciliary body melanoma may rarely exhibit regional lymph node metastasis. This mode of metastasis may occur after extraocular spread and invasion of conjunctival lymphatics.

Adult↗

PubMed1999

B16LS9 melanoma cells spread to the liver from the murine ocular posterior compartment (PC).

PURPOSE: To create a murine ocular melanoma model that consistently metastasizes to the liver. METHODS: Twelve-week-old C57BL6 mice (n=10) were inoculated in the posterior compartment (PC) of one eye with 5x10(5) tissue culture B16LS9 melanoma cells. The inoculated eyes were enucleated at two weeks and the mice were sacrificed with necropsies performed at four weeks post-inoculation. RESULTS: Melanoma grew and was confined to the eyes of all 10 mice. The melanoma hematogenously spread to the lungs in 9 of 10 mice and the liver in 8 of 10 mice. There was a positive correlation between pulmonary and liver metastasis (r=0.94). CONCLUSIONS: B16LS9 melanoma cells consistently hematogenously spread to the liver when implanted into C57BL6 mice eyes. The value of this model is unknown at this time since it is not known if the intrahepatic melanoma is capable of growing and killing the host.

Animals↗

PubMed1998

Pulmonary function in hospitalized infants and toddlers with cystic fibrosis.

UNLABELLED: In older children with cystic fibrosis (CF), well-documented improvements in lung function occur during hospitalization for treatment of pulmonary exacerbations. OBJECTIVES: (1) To test the hypothesis that improvement in lung function occurs in infants and toddlers hospitalized because of CF pulmonary exacerbations. (2) To compare changes in lung function measured during forced expiratory flow and tidal breathing. STUDY DESIGN: Seventeen infants and toddlers with CF were evaluated at the beginning and end of hospitalization by the rapid thoracic compression technique to yield maximal flow at forced residual capacity. Tidal mechanics were measured by the esophageal balloon technique to yield lung conductance and compliance. RESULTS: Lung function improved during the course of hospitalization. The greatest change was observed in measurements of maximal flow at functional residual capacity (.VmaxFRC), increasing from 38.5% +/- 6% predicted (mean +/- SEM) to 59.8% +/- 6% at the end (p < 0.005). Lung conductance (GL) increased from 60% +/- 6% to 78% +/- 8% (p < 0.02); lung compliance (CL) increased from 66% +/- 5% to 75% +/- 5% (p < 0.03). The degree of improvement of .VmaxFRC, GL, and CL was related to baseline measurements; those with poorer pulmonary function at baseline had the greatest degree of improvement during hospitalization. CONCLUSION: Assessments of airflow obstruction from measurements of .VmaxFRC and GL do not necessarily demonstrate similar findings in a given infant with CF, perhaps because these two techniques measure different physiologic properties. Changes in .VmaxFRC may best reflect the predominant pathophysiology of lung disease in infants and toddlers with CF.

Anti-Bacterial Agents↗

PubMed1998

Clinicopathologic findings in recurrent choroidal melanoma after transpupillary thermotherapy.

OBJECTIVE: This study aimed to report the clinicopathologic findings of recurrent choroidal melanoma after transpupillary thermotherapy (TTT). DESIGN: Two case reports. METHODS: The clinical histories and ophthalmologic findings of two patients with recurrent choroidal melanomas who did not respond to TTT were reviewed. Both patients had their eyes with the melanoma enucleated and processed routinely for light and electron microscopic examination. MAIN OUTCOME MEASURES: The eyes were examined for histopathologic and ultrastructural findings. RESULTS: Histopathologic examination showed choroidal melanomas with extensive tumor necrosis and hemorrhage. In areas, tumor cells appeared histologically intact and presumably viable, with ultrastructural evidence of melanogenesis. The eye from one patient was treated only with TTT and showed hemorrhagic necrosis with cytolysis and no changes to tissues surrounding the melanoma. The eye from the other patient, treated with TTT and a radioactive isotope of iodine (I125) plaque, exhibited areas of intact tumor, tumor necrosis, fibrosis, and radiation retinopathy. CONCLUSIONS: These two cases among a total treated series of 14 patients represent examples of uveal melanoma regrowth after TTT. Opaque media precluded adequate treatment in the first case that showed some TTT effect. The second case showed a combination of TTT and I125 effect and failed because of the aggressive nature of tumor.

Aged↗

PubMed1998

Finite element modeling of vocal fold vibration in normal phonation and hyperfunctional dysphonia: implications for the pathogenesis of vocal nodules.

A computer model of the vocal fold was developed using finite element modeling technology for studying mechanical stress distribution over vibrating vocal fold tissue. In a simulated normal phonation mode, mechanical stress was found to be lowest at the midpoint of the vocal fold and highest at tendon attachments. However, when other modes predominated, high mechanical stress could occur at the midpoint of the vocal folds. When a vocal fold mass was modeled, high shearing stress occurred at the base of the modeled vocal fold mass, suggesting that the presence of a vocal nodule or polyp is associated with high mechanical stress at the margins of the mass. This finding supports a hypothesis that mechanical intraepithelial stress plays an important role in the development of vocal nodules, polyps, and other lesions that are usually ascribed to hyperfunctional dysphonia.

Computers↗

PubMed1997

Pathology techniques.

Pathology techniques developed over the past decade may be successfully applied to the diagnosis of orbital disease. Tissue specimens may be immunophenotyped by immunohistochemical staining and flow cytometry. Immunohistochemical staining provides a qualitative analysis of localization of antigenic determinants and flow cytometry provides a quantitative analysis. The molecular biologic technique of polymerase chain reaction enables detection of minute amounts of material by amplification from DNA primers. Fine-needle aspiration biopsy is an alternative to open biopsy in select cases. The most important concept regarding these techniques is communication with the ophthalmic pathologist regarding the collection and interpretation of the specimen.

Diagnostic Techniques, Ophthalmological↗

PubMed1993

Chest wall motion before and during mechanical ventilation in children with neuromuscular disease.

Patients with neuromuscular disease can display paradoxic motion of the rib cage (RC) and abdomen (AB), which increases the work of breathing and predisposes to respiratory muscle fatigue. Long-term mechanical ventilation can reverse chronic hypercapnea and decrease the work of breathing in these patients. Changes in chest wall motion (CWM) that occur during mechanical ventilation have not been studied. We have assessed CWM using a calibrated respiratory inductive plethysmograph before and during mechanical ventilation in 5 children and young adults with neuromuscular disease and paradoxic breathing at rest. Asynchrony of CWM was quantitated by measuring the phase shift, theta, between RC and AB motion (0 degree = synchronous motion, 180 degrees = paradoxic motion). The volume contribution of the paradoxing compartment to tidal volume (PC/VT) was calculated. Before mechanical ventilation, mean +/- SEM VT was 122 +/- 17 mL, theta was 131 +/- 15 degrees C, and PC/VT was -27 +/- 6%. During mechanical ventilation, VT increased to 274 +/- 47 mL (P < 0.05), theta decreased to 41 +/- 14 degrees (P < 0.05), and PC/VT increased to +39 +/- 9% (P < 0.02). We conclude that mechanical ventilation improves RC/AB asynchrony and reverses the negative contribution to tidal volume of the paradoxing compartment in children and young adults with neuromuscular disease. This implies that mechanical ventilation assumes most or all the role of the respiratory pump in these patients, which provides a rationale for the use of chronic or nighttime ventilation in the treatment of respiratory muscle fatigue. Assessment of CWM may be useful in the determination of optimal ventilator settings in this population.

Abdomen↗