Biomedical subjects

M V Meng

Publications and source records attributed to M V Meng.

21 records · Page 2Linked to original sources

PubMed1995

Partial nephrectomy: technique, complications and pathological findings.

PURPOSE: We evaluate whether partial nephrectomy can be performed safely and efficaciously for renal tumors. MATERIALS AND METHODS: The results of 67 partial nephrectomies performed between 1977 and 1994 for renal cell carcinoma (51), oncocytoma (9), angiomyolipoma (3), transitional cell carcinoma (3) and other nonneoplastic lesions (2) were analyzed retrospectively in detail. RESULTS: Diminished complication rates were noted after 1988, and were attributed to improvements in surgical technique and an increased incidence of smaller, serendipitously discovered tumors. Although 35.5% of the patients had preoperative renal impairment (mean serum creatinine 2.1 mg./dl.), there were minimal changes in renal function and no patient required acute hemodialysis following partial nephrectomy. Among 42 patients with clinical stage T1 to T2 renal cell carcinoma undergoing partial nephrectomy local recurrence was identified in 8.3% of those with primary neoplasms. All 6 patients with local recurrence had negative surgical margins, recurrence often, distant from the operative site and multifocal disease, implicating multicentricity as the etiology of local recurrence. Five patients (83.3%) with local recurrence were alive and asymptomatic at a mean of 138 months after partial nephrectomy. Since capsular penetration was identified in 5 of 27 renal cell carcinomas (18.5%) with a diameter of 3.5 cm. or less, aggressive surgical resection with adequate tumor-free parenchymal and perinephric margins is necessary even for small lesions. CONCLUSIONS: With improved surgical techniques, including regional hypothermia, intraoperative sonography, meticulous dissection and injection of the collecting system with methylene blue, partial nephrectomy is safe and effective in properly selected patients.

Adolescent↗

PubMed1995

Intraoperative sonography for the evaluation and management of renal tumors: experience with 100 patients.

PURPOSE: Intraoperative sonography was used to evaluate prospectively the renal parenchyma of patients undergoing surgery for presumed renal neoplasia. MATERIALS AND METHODS: One surgeon (F.F.M.) evaluated 100 kidneys using a triple-head sector ultrasonic transducer (5 MHz., 7.5 MHz. and 10 MHz. with duplex Doppler imaging). The size, number, echo texture, location, and relationship of suspected lesions to the collecting system, vasculature and renal capsule were recorded. Real-time Doppler imaging was used to distinguish among renal arteries, renal veins and the collecting system. Sonography was used to delineate the extent of the tumor and presence or absence of satellite lesions. All patients were evaluated preoperatively with abdominal computerized tomography. RESULTS: Under ultrasonic guidance partial nephrectomy was done in 40 cases, radical nephrectomy in 56, unroofing of renal cysts in 3 and renal biopsy in 1. Of the patients 8 were considered candidates for partial nephrectomy but underwent radical nephrectomy after intraoperative sonography revealed more extensive tumor, especially at the renal hilum. Similarly, 3 patients with a suspected malignancy were spared nephrectomy after intraoperative sonography and frozen section analysis revealed benign multilocular cysts. All surgical margins after sonographic evaluation were negative in patients undergoing partial nephrectomy. CONCLUSIONS: Intraoperative ultrasound is a useful adjunct for the dynamic evaluation of renal tumors in the surrounding environment of renal cysts, the collecting system and the renal vasculature. It is particularly beneficial in defining preoperative indeterminate renal lesions and in evaluating extrarenal structures for tumor involvement, such as the renal vein, inferior vena cava, adrenal gland and liver. Intraoperative sonography is most useful during partial nephrectomy and may improve tumor-free surgical margins. Sonography is routinely used during partial nephrectomy.

Adult↗

PubMed1990

Apolipoprotein A-I metabolism in subjects with a PstI restriction fragment length polymorphism of the apoA-I gene and familial hypoalphalipoproteinemia.

Familial hypoalphalipoproteinemia (hypoalpha), characterized by a decreased high density lipoprotein level, is associated with an increased incidence of premature cardiovascular disease. Restriction fragment length polymorphism analysis of genomic DNA has detected a polymorphism for the PstI restriction endonuclease near the apoA-I gene, with either a 2.2 or a 3.3 kb fragment. The latter has been previously found to occur with significantly higher frequency in probands of families with familial hypoalpha. ApoA-I was isolated from three unrelated subjects with familial hypoalpha and the 3.3 kb PstI polymorphism of the apoA-I gene, and from normal control subjects. The apoA-I from the hypoalpha subjects was structurally normal as determined by amino acid analysis and by two-dimensional gel electrophoresis. When normal apoA-I and hypoalpha apoA-I were simultaneously injected into either normal controls or hypoalpha subjects, both forms of apoA-I were catabolized at the same rate in the same subject, indicating that the hypoalpha apoA-I is also metabolically normal. Analysis of the kinetics of metabolism of apoA-I in the hypoalpha subjects, compared to the normal controls, revealed that the reduced plasma levels of apoA-I were due to an increased apoA-I fractional catabolic rate, and that the synthetic rate was normal. Based on these results, we conclude that the apoA-I gene in these hypoalpha subjects is normal, and the PstI polymorphism near the apoA-I gene, which is associated with familial hypoalpha, is likely to be a marker for a mutant gene closely linked to, but not in, the apoA-I gene.

Adult↗