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Biomedical subjects

L D Truong

Publications and source records attributed to L D Truong.

At least 37 records · Page 2Linked to original sources

Extensive lipomatous metaplasia in bilateral macronodular adrenocortical hyperplasia.

OBJECTIVE: We describe a case of macronodular hyperplasia with marked adrenal enlargement in which mature adipose tissue was a significant component. To our knowledge, this condition has not been reported previously. METHODS: A 42-year-old woman with newly diagnosed Cushing's syndrome underwent endoscopic bilateral adrenalectomy to remove bilateral adrenal masses. RESULTS: Both adrenal glands displayed features of macronodular hyperplasia with marked adrenal enlargement, and abundant mature adipose tissue was identified in some nodules of both glands. CONCLUSIONS: Lipomatous metaplasia is histologically demonstrated in a case of macronodular hyperplasia with marked adrenal enlargement. This distinctive change may be secondary to metaplastic transformation of either stromal cells or adrenocortical cells. The presence of lipomatous metaplasia would appear to indicate adrenocortical process, since, to our knowledge, it has never before been described in the adrenal nodule.

Adipose Tissue↗

p53 immunolocalization in cell block preparations of squamous lesions of the neck: an adjunct to fine-needle aspiration diagnosis of malignancy.

OBJECTIVE: Mutations of the p53 tumor suppressor gene, with consequent nuclear p53 protein accumulation, are among the most common genetic abnormalities in human cancers. The purpose of this study was to determine the utility of p53 immunostaining as an adjunct to the diagnosis of malignancy in fine-needle aspirations of squamous lesions of the neck. MATERIALS AND METHODS: Using a monoclonal antibody to the p53 protein and a standard avidin-biotin complex technique, immunostaining was performed on paraffin-embedded cell blocks of 20 cases with the following cytologic diagnoses: (1) metastatic squamous cell carcinoma (SCC) (7 cases); (2) atypical squamous cells, SCC cannot be excluded (7 cases); and (3) cytologic findings consistent with branchial cleft cyst (6 cases). Tissue or clinical follow-up was available in all cases. RESULTS: Five (71%) of 7 cases with an unequivocal cytologic diagnosis of metastatic SCC were positive for p53 protein. Tissue follow-up confirmed metastatic SCC in all of these 7 cases. Of the 7 cases with cytologic diagnosis of atypical squamous cells, 2 were negative and 5 (71%) were positive for p53 protein. Subsequent excisional biopsies in these cases revealed metastatic SCC (6 cases) and branchial cleft cyst (1 case). The squamous cells in all 5 cases with cytologic findings consistent with branchial cleft cyst were negative for p53 protein; tissue follow-up confirmed the diagnoses of branchial cleft cyst in 4 cases. In the remaining 2 cases excision was not performed, as the cystic lesion was completely decompressed and, clinically, no recurrences were identified at 14 and 8 months of follow-up. CONCLUSIONS: Our findings suggest that p53 immunostaining is helpful in differentiating benign and malignant squamous lesions. While negative staining for p53 does not exclude malignancy, positive immunostaining may aid in accurate fine-needle aspiration diagnosis of malignancy in cytomorphologically equivocal squamous lesions of the neck.

Biopsy, Needle↗

Pheochromocytoma associated with neuroendocrine carcinoma. A new type of composite pheochromocytoma.

The coexistence of pheochromocytoma and other tumor types in a single adrenal gland has been rarely documented. This type of pheochromocytoma is designated "composite" or "mixed," depending on whether the pheochromocytoma and the nonpheochromocytoma components show the same embryologic origin. The nonpheochromocytoma components reported in the composite pheochromocytoma include ganglioneuroma, ganglioneuroblastoma, neuroblastoma, and malignant schwannoma. The components found in the mixed pheochromocytoma include adrenal cortical neoplasms and spindle cell sarcoma. We report a unique case of composite pheochromocytoma in which the nonpheochromocytoma element is a neuroendocrine carcinoma. The histologic and the immunohistochemical profiles of the 2 distinct components of this tumor were typical for those of pheochromocytoma and neuroendocrine carcinoma. This dual differentiation was also supported by ultrastructural findings. This case not only broadens the morphologic spectrum of composite pheochromocytoma but also provides some additional insight into the histogenesis of this rare but fascinating type of tumor.

Adrenal Gland Neoplasms↗

Collagen polyp of the urinary tract: a report of two cases.

Injection of collagen into the urethral or bladder wall has gained popularity as an effective way to control urinary stress incontinence. The same technique has recently been used to improve function of urinary pouches surgically created from intestinal segments. We report the first two cases of a polypoid lesion in these structures, both of which were composed of injected collagen. The first lesion occurred in the ileal urinary pouch of a 41-year-old paraplegic man who had cystoprostatectomy for severe spasm and repeated infection of the bladder. The pouch, removed for repeated infection, showed a 2.5-cm submucosal polyp. The second lesion was in the urethra of a 71-year-old man who underwent radical retropubic prostatectomy for prostatic carcinoma, followed by artificial urethral sphincter placement. Follow-up cystoscopy revealed a proximal urethral polyp that was biopsied. In both cases, collagen was injected into these structures for controlling urinary incontinence. Histologically, the polyps were caused by submucosal accumulation of injected collagen with pathognomonic features (i.e., eosinophilic, homogeneous, and poorly cellular material that was faintly positive by the periodic acid-Schiff and strongly positive by the trichome stain). These two cases expand the list of differential diagnoses for a polypoid lesion in the intestinal and urinary tracts and illustrate the morphology of injected collagen. A familiarity with these changes is diagnostically helpful because an increasing number of specimens removed for therapeutic failure of injected collagen are expected.

Adult↗

Adult mesoblastic nephroma: expansion of the morphologic spectrum and review of literature.

Mesoblastic nephroma (MN) is a distinctive tumor that is seen mostly in early infancy and that consists of classic and cellular (atypical) variants. Mesoblastic nephroma rarely occurs in adulthood, but MN in this age group still is poorly characterized because there are only 17 reported cases. We describe five additional cases of adult MN, including one case of the cellular variant, characterize the immunohistochemical profiles in detail, and critically review the previously reported cases. The collective data obtained from these 22 cases of adult MN showed that the patients predominantly were women (20 cases), ranging in age from 19 to 78 years, who were asymptomatic (5 cases) or had nonspecific signs and symptoms referable to a renal mass. Twenty tumors were classified as classic and 2 as cellular. The tumors were 2-24 cm, well circumscribed, and partially encapsulated and displayed a solid/ cystic cut surface, with a predominantly solid component in most tumors. One tumor, however, was almost purely cystic. Most tumors extended to the renal sinus. and some appeared entirely intrapelvic on imaging studies; however, gross and microscopic evaluation did not show destructive invasion of the pelvic wall. Extension of the tumor beyond the renal capsule has not been described. Each tumor was composed of epithelial and stromal components both. The epithelial component, which displayed no difference between the classic and cellular variants, was composed of isolated or clustered tubules and cysts lined by a benign epithelium with a wide range of cytologic differentiation. The stromal cells were composed of fibroblasts, myofibroblasts, and smooth muscle cells in various combinations. Stromal cellularity was low for the classic variant but high for the cellular variant. Hemorrhage, necrosis, and high mitotic index were noted in the stroma of the cellular, but not in the classic variant. Immunohistochemical study applied to the five current cases and seven normal control kidneys confirmed the presence of fibroblasts, myofibroblasts, smooth muscle cells, and prominent vessels in the stroma of each tumor. Most cysts and tubules within the tumors had a distinctive immunohistochemical profile, similar to that of collecting duct but different from those of other portions of the nephron in the normal control kidneys. After total or partial nephrectomy, without adjuvant chemotherapy or radiotherapy, 19 patients, including the 2 with cellular MN, were alive and well at 8-months to 48-years follow-up. Follow-up was not available in two patients. The remaining patient had recurrence at the surgical site 24 years after nephrectomy. Adult MN displays a distinctive morphologic spectrum that parallels that of its pediatric congener. It probably is a benign tumor that can be treated successfully by complete excision. The collecting duct differentiation expressed by most tubules and cysts of adult MN implies ureteric bud, which is the exclusive embryologic origin of collecting duct, as an important element in the histogenesis of this rare but fascinating type of tumor.

Adult↗

Chronic obstructive uropathy in severe combined immunodeficient (SCID) mice: lymphocyte infiltration is not required for progressive tubulointerstitial injury.

Progressive renal injury in humans and experimental animal models is characterized by tubular atrophy, infiltration of mononuclear inflammatory cells, and interstitial fibrosis. Permanent unilateral ureter ligation represents a reproducible model for investigating mechanisms of progressive kidney injury, and in the rat is characterized by tubular epithelial cell proliferation followed by apoptosis and progressive infiltration of monocytes and lymphocytes. Nevertheless, whether monocytes or lymphocytes play a dominant role in causing tubulointerstitial damage remains to be elucidated. In the current study, a model of chronic obstructive uropathy in the mouse is established and the role of lymphocyte infiltration in the evolution of the tubule and interstitial alterations is investigated. Permanent ligation of the left ureter in wild-type (C3H/HeJ) mice resulted in progressive atrophy of tubules and interstitial fibrosis compared with the contralateral kidney over a 30-d period. Immunoperoxidase studies on frozen sections taken from kidneys at 0, 3, 10, 20, and 30 d after ureter ligation showed that the tubulointerstitial injury was accompanied by a marked and progressive increase in interstitial macrophages and T lymphocytes, with no appreciable increase in B lymphocytes. No increase in inflammatory cells was detected in contralateral kidneys over the same time frame. The significance of T lymphocyte infiltration was examined by comparing the degree of tubular atrophy and interstitial fibrosis and the nature and quantity of the inflammatory infiltrate in wild-type mice and C3HSMn.C-Scid/J (SCID) mice subjected to permanent left ureter ligation. SCID mice have genetic defects in immunoglobulin and T cell receptor gene rearrangements and are devoid of circulating mature B and T lymphocytes. Wild-type and SCID mice developed tubular atrophy and interstitial volume expansion in the ligated kidney to the same degree and at the same rate. SCID mice developed a prominent and marked monocyte/macrophage infiltrate in the ligated kidney, which was essentially equal to that in wild-type mice. In contrast, consistent with the known absence of mature lymphocytes in SCID mice, there was essentially no T lymphocyte infiltration into the ligated kidney of SCID mice. These results demonstrate the effective establishment of the model of maintained unilateral ureter ligation in mice, which is readily applicable to genetic mutant strains thus allowing for specific investigation of the role of individual components of the inflammatory response in progressive tubulointerstitial injury. These studies further demonstrate that lymphocyte infiltration is not required for progressive tubular atrophy and increased interstitial fibrosis after maintained unilateral ureter ligation.

Animals↗

Image analysis of proliferating cell nuclear antigen expression and immunohistochemical profiles in renal cell carcinoma associated with acquired cystic kidney disease: comparison with classic renal cell carcinoma.

Renal cell carcinoma (RCC) arising in acquired cystic kidney disease (ACKD) is considered to be a tumor of low malignant potential, compared with classic RCC. The aim of the present study was to identify any significant differences in the antigenic profiles or tumor cell proliferative activity of ACKD-associated RCC and classic RCC that might be responsible for differences in their biologic behavior. We studied the immunohistochemical profiles and proliferative activity of 12 classic RCCs and 5 ACKD-associated RCCs with markers of proximal tubules (Leu M1, alpha-1 antitrypsin, CAM 5.2), markers of distal tubules (Arachis hypogaea lectin, AE1/AE3, epithelial membrane antigen [EMAJ, CAM 5.2), vimentin, and proliferating cell nuclear antigen (PCNA). We performed proliferation analysis with the CAS 200 image analysis system. For each case, 8 to 20 fields of tumor tissue in the areas of maximal PCNA staining were quantitated, and the percentage of PCNA-positive nuclear area for each individual tumor was calculated. All of the five ACKD-associated RCCs expressed AE1/AE3, EMA, and CAM 5.2 in more than 50% of the tumor cells. Arachis hypogaea lectin was significantly expressed in three of the five ACKD-associated RCCs. Leu M1 and alpha-1 antitrypsin reacted with fewer than 10% of the tumor cells in all of the five ACKD-associated RCCs. In contrast, the 12 classic RCCs showed expression of CAM 5.2 in 11 cases, alpha-1 antitrypsin in 10 cases, Leu M1 in 9, EMA in 8, and AE1/AE3 in 3 cases in more than 50% of the tumor cells and a totally negative reaction with Arachis hypogaea lectin in 8 cases, EMA in 4, AE1/AE3 in 4, and vimentin in 5 cases. Although coexpression of proximal and distal tubule markers was seen in some cases of RCC in either category, there was uniform and strong staining for distal tubule markers in ACKD-associated RCC and for proximal tubule markers in classic RCC. The mean percentage of PCNA-positive nuclear area for the ACKD-associated RCCs (2.41%) was significantly (P < .05) less than that of the classic RCCs (21.42%). The differences in expression of proximal and distal tubule markers and proliferative activity might be responsible for the differences in the biologic behavior of ACKD-associated RCC and classic RCC.

Adult↗

Elevated expression of caveolin is associated with prostate and breast cancer.

To identify genes associated with prostate cancer progression, we developed a strategy involving the use of differential display-PCR with a panel of genetically matched primary tumor- and metastasis-derived mouse prostate cancer cell lines. We isolated a cDNA fragment with homology to the mouse caveolin-1 gene. Northern blotting with this fragment revealed increased caveolin expression in metastasis-derived cell lines relative to primary tumor-derived cell lines. Western blotting with a polyclonal caveolin antibody confirmed increased caveolin protein in metastasis-derived mouse cell lines and expression in three of four human prostate cancer cell lines. Immunohistochemical analysis of a human prostate cancer cell line demonstrated a prominent granular pattern of caveolin accumulation. Subsequent analysis of mouse and human prostate specimens revealed minimal caveolin expression in normal epithelium with abundant staining of smooth muscle and endothelium. The frequency of caveolin-positive cells was increased in prostate cancer with markedly increased accumulation of caveolin and a granular staining pattern in lymph node metastatic deposits. In human breast cancer specimens, increased caveolin staining was detected in intraductal and infiltrating ductal carcinoma as well as nodal disease. Caveolin therefore appears to be associated with human prostate cancer progression and is also present in primary and metastatic human breast cancer.

Animals↗

Cell apoptosis and proliferation in obstructive uropathy.

Distinct patterns of cell proliferation and apoptosis have been recognized for tubular, interstitial, and glomerular cells in chronic obstructive uropathy (OU). In many experimental models of OU, tubular cell apoptosis develops quickly after ureter ligation, peaks between 7 and 24 days postobtruction (about 30-fold of control), and tapers thereafter. Apoptosis initially involves the dilated collecting ducts, but subsequently spreads to other tubules. Tubular cell apoptosis probably accounts for renal tissue loss in OU because a direct correlation between its degree and the decline in dry kidney weight is well-documented. Pronounced tubular cell proliferation occurs shortly after ureter ligation, peaks at about day 6 (60-fold above control), and quickly subsides to baseline. Because the peak of tubular cell proliferation immediately precedes the onset of tubular cell apoptosis, a pathogenetic link may exist between these two processes. Interstitial cell apoptosis occurs with an increasing frequency throughout the course of OU (up to 35-fold above control). Interstitial cell proliferation appears in a bimodal pattern with the early peak coinciding with that of tubular cell proliferation and consisting mostly of fibroblasts, whereas the later peak consists mostly of inflammatory cells. Glomerular cell apoptosis and proliferation are not different from control, which explains, in part, the structural integrity of the glomeruli throughout the disease course. Although the general pathways of cell apoptosis and proliferation are well known, the molecular control of these processes in OU is poorly understood. In addition, whether apoptosis or proliferation of tubular and interstitial cells is differentially regulated remains to be studied. However, several molecules known to be activated or overexpressed in kidney with OU may modulate cell apoptosis and proliferation. The relevant functions of these molecules include induction of apoptosis (angiotensin II, reactive oxygen species, jun-N-terminal kinase, p53), inhibition of the cell cycle (transforming growth factor-beta, p21), inhibition of apoptosis (clusterin, epidermal growth factor, insulin-like growth factor, bcl-2, osteopontin), or promotion of interstitial fibroblast proliferation (platelet-derived growth factor).

Angiotensin II↗

Adenoviral delivery of E2F-1 directs cell cycle reentry and p53-independent apoptosis in postmitotic adult myocardium in vivo.

Irreversible exit from the cell cycle precludes the ability of cardiac muscle cells to increase cell number after infarction. Using adenoviral E1A, we previously demonstrated dual pocket protein- and p300-dependent pathways in neonatal rat cardiac myocytes, and have proven that E2F-1, which occupies the Rb pocket, suffices for these actions of E1A. By contrast, the susceptibility of adult ventricular cells to viral delivery of exogenous cell cycle regulators has not been tested, in vitro or in vivo. In cultured adult ventricular myocytes, adenoviral gene transfer of E2F-1 induced expression of proliferating cell nuclear antigen, cyclin-dependent protein kinase 4, cell division cycle 2 kinase, DNA synthesis, and apoptosis. In vivo, adenoviral delivery of E2F-1 by direct injection into myocardium induced DNA synthesis, shown by 5'-bromodeoxyuridine incorporation, and accumulation in G2/M, by image analysis of Feulgen-stained nuclei. In p53(-)/- mice, the prevalence of G1 exit was more than twofold greater; however, E2F-1 evoked apoptosis and rapid mortality comparably in both backgrounds. Thus, the differential effects of E2F-1 on G1 exit in wild-type versus p53-deficient mice illustrate the combinatorial power of viral gene delivery to genetically defined recipients: E2F-1 can override the G1/S checkpoint in postmitotic ventricular myocytes in vitro and in vivo, but leads to apoptosis even in p53(-)/- mice.

Adenoviridae↗

Development of experimental model of chronic pyelonephritis with Escherichia coli O75:K5:H-bearing Dr fimbriae: mutation in the dra region prevented tubulointerstitial nephritis.

Escherichia coli that express Dr fimbriae and related adhesins recognize the common receptor decay accelerating factor. E. coli strains that express adhesins of the Dr family were postulated to be associated with cystitis (30-50%), pregnancy-associated pyelonephritis (30%), and chronic diarrhea (50%). In this study, we investigated the hypothesis that E. coli renal interstitial binding mediated by the Dr adhesin may be important for the development of chronic pyelonephritis. An insertional dra mutant, E. coli DR14, of the clinical E. coli isolate IH11128 bearing Dr fimbriae, was constructed and used to characterize persistence of infection and interstitial tropism in an experimental model of ascending pyelonephritis. Quantitative cultures of kidney homogenates indicated that Dr hemagglutinin positive (Dr+) E. coli IH11128 established a 1-yr colonization of renal tissue. In the Dr hemagglutinin negative (Dr-) group, 50% of animals cleared infection within 20 wk and 100% between 32 to 52 wk. Dr+ E. coli colonized the renal interstitium. Significant histological changes corresponding to tubulointerstitial nephritis including interstitial inflammation, fibrosis, and tubular atrophy were found in the kidney tissue of the Dr+ but not the Dr- group. A substantial amount of fimbrial antigen was detected in the parenchymal regions affected by interstitial inflammation and fibrosis. The obtained results are consistent with the hypothesis that mutation within the dra region, affecting E. coli binding to tubular basement membranes, prevented renal interstitial tropism and the development of the changes characteristically seen in tubulointerstitial nephritis.

Animals↗

Adhesion molecules and rejection of renal allografts.

Despite an increasing amount of immunohistochemical and molecular biology data relating to the pathogenesis of kidney transplant rejection, the pathological diagnosis of this condition still rests on routine light microscopy. The detection of changes in expression and distribution of adhesion molecules in renal allograft biopsies may open a new era of increased accuracy of rejection diagnosis. Of the various adhesion molecule reactivities, peritubular capillary VCAM-1 staining appears to be the most specific finding for chronic rejection. This same staining reaction is seen in acute rejection, but may have less specificity in that setting.

Animals↗

Glomerulomegaly and proteinuria in a patient with idiopathic pulmonary hypertension.

Glomerulomegaly is a histologic finding present in idiopathic pulmonary hypertension, congenital cyanotic heart disease, morbid obesity associated with sleep apnea syndrome, sickle cell disease, and polycythemic states. This study examines the case of a 34-yr-old woman with idiopathic pulmonary artery hypertension who presented with nephrotic-range proteinuria. Kidney biopsy revealed enlarged glomeruli with mesangial-proliferative glomerulonephritis. A review of the pertinent literature and a discussion of the proposed pathophysiologic mechanisms leading to glomerulomegaly are presented.

Adult↗

Horseshoe kidney is associated with an increased relative risk of primary renal carcinoid tumor.

PURPOSE: Carcinoid tumor is a rare neoplasm of the kidney with an unknown histogenesis. Of only 31 cases previously reported in the literature 4 arose within horseshoe kidneys. We report a case of primary carcinoid tumor arising within a horseshoe kidney and discuss the unique insight it provided into the pathogenesis of this tumor. MATERIALS AND METHODS: We reviewed in detail all 31 reported cases of renal carcinoid tumor and, using reported incidence rates of horseshoe kidney, we calculated the relative risk of renal carcinoid tumor arising within a horseshoe kidney. Immunohistochemical staining for neuroendocrine related markers was performed on tissue sections from the present carcinoid tumor, the adjacent kidney and 5 control samples of normal renal parenchyma. RESULTS: Of the reported tumors 15.6% occurred in horseshoe kidneys, yielding a calculated relative risk of 62. The present tumor was multifocal, arising from the wall of a cystic lesion and possibly representing a dilated calix within the isthmus. Intestinal epithelium lining the cyst cavity exhibited multifocal neuroendocrine cell hyperplasia with an immunohistochemical profile identical to that of the carcinoid tumor cells. CONCLUSIONS: The relative risk of renal carcinoid tumor developing in a horseshoe kidney is markedly greater than that for Wilms tumor or transitional cell carcinoma. The clinical course of renal carcinoid tumor arising within a horseshoe kidney appears to be more benign than that of the nonhorseshoe variant. Our observations support the hypothesis that renal carcinoid tumors may arise from neuroendocrine cells within foci of metaplastic or teratomatous epithelium within the kidney.

Carcinoid Tumor↗

Integrated expression of glomerular extracellular matrix proteins and beta 1 integrins in monoclonal light chain-related renal diseases.

Light-chain deposition disease (LCDD) and amyloid light-chain amyloidosis (AL-Am) represent the two classical diseases associated with glomerular alterations in monoclonal light chain-related renal diseases. LCDD is characterized by deposition of extracellular matrix proteins in the mesangium, thus creating the morphologic appearance recognized as nodular glomerulosclerosis. In AL-Am, the mesangial matrix is replaced by polymerized light chains in the form of amyloid fibrils. Integrins are responsible for cell-to-cell and cell-to-matrix communication and, therefore, are expected to play a key role in the alterations encountered in these two diseases. The present article addresses the expression of selected extracellular matrix proteins (collagen IV, laminin, fibronectin, and tenascin) and their respective receptor beta 1 integrins (alpha 2, alpha 3, alpha 5, and alpha 9) in glomeruli with LCDD and AL-Am by immunohistochemical methods. The corresponding integrin (alpha 9 beta 1) co-localized with tenascin in the center of the mesangial nodules in LCDD. In AL-Am, tenascin is found primarily at the periphery of replaced mesangial areas and in the remaining mesangium not replaced by the amyloid. Tenascin co-localized with alpha 9 beta 1 integrin in mesangial areas in the earlier phases of the process. Fibronectin, laminin, and collagen IV, although increased in absolute amounts, are pushed toward the periphery of mesangial areas, in which correlated expression of their corresponding beta 1 integrins (alpha 2, alpha 3, and alpha 5, respectively) is documented in both LCDD and AL-Am. Deposition of tenascin might be at least partially responsible for the perpetuation and irreversibility of the glomerular lesion in LCDD.

Albumins↗

Urinary obstruction causes irreversible renal failure by inducing chronic tubulointerstitial nephritis.

Obstruction of urinary tract is a frequent cause of transient renal dysfunction, which, in the majority of cases, is reversible. Urinary obstruction can occasionally cause chronic renal failure, in spite of successful relief of the obstruction. Sonographic and pathologic studies show renal atrophy, interstitial fibrosis, and interstitial inflammation, which explain the loss of renal function. Herein, we report two cases of bilateral obstructive nephropathy due to prostatic hyperplasia, in which renal ultrasound demonstrated hydronephrosis and normal cortical thickness. In both cases, the renal failure persisted even after urinary obstruction was relieved by continuous catheter drainage. Renal biopsy showed that in each case the cause of the irreversible renal failure was chronic tubulointerstitial nephritis. It is concluded that renal biopsy can be of diagnostic, as well as of prognostic value in obstructive nephropathy, especially when relief of the obstruction is not followed by restoration of the renal function.

Aged↗

Apoptosis in renal cell carcinoma: detection by in situ end-labeling of fragmented DNA and correlation with other prognostic factors.

Because stage and grade of renal cell carcinoma (RCC) sometimes fail to predict the patient's outcome, additional prognostic predictors are needed. Apoptosis is a process of programmed cell death seen in both normal and neoplastic tissues, which has been shown to have prognostic significance in some tumor types. Forty-seven RCCs were studied for size, grade, stage, apoptosis, and proliferation. Fragmented DNA, a hallmark of apoptosis, was detected in situ by a process in which the fragmented DNA was labeled with a biotinylated nucleotide, which, in turn, was detected by an avidin-biotin-peroxidase labeling system. The proliferating tumor cells were detected by immunostaining with the MIB-1 antibody. The apoptotic index and proliferation index of each RCC were expressed as the number of tumor cells undergoing apoptosis and proliferation per 1,000 tumor cells. For grade I to IV RCCs, the median proliferative index was 13, 41, 119, and 143; the median apoptotic index was 8, 12, 39, and 73. For stage I to IV RCCs, the median proliferative index was 21, 34, 70, and 144; the median apoptotic index was 8, 9, 20, and 69. There was a statistically significant correlation of tumor grade, stage, and size with both proliferative index and apoptotic index. There was a statistically significant correlation between proliferation index and apoptotic index. In conclusion, apoptosis can be easily and reliably recognized by the in situ end labeling of fragmented DNA and may help predict the outcome of RCC.

Antibodies, Monoclonal↗