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Biomedical subjects

B Delahunt

Publications and source records attributed to B Delahunt.

At least 19 recordsLinked to original sources

HLA-DRB1 and HLA-DQB1 polymorphisms in Pacific Islands populations.

Allele frequency distributions of the HLA-DRB1 and HLA-DQB1 genes were investigated in four Pacific Islands populations from the Cook Islands, Samoa, Tokelau and Tonga. Limited diversity was observed for both the HLA-DRB1 and HLA-DQB1 loci. Five HLA-DRB1 alleles were observed to be the most frequent amongst all the studied Pacific Islands populations. They were: HLA-DRB1*0403, HLA-DRB1*08032, HLA-DRB1*09012, HLA-DRB1*11011 and HLA-DRB1*1201. Cook Islanders had the largest number of low frequency DRB1 alleles followed by Samoans, Tokelauans and Tongans, most of which may be attributed to reported non-Polynesian admixture. The most frequently observed DQB1 alleles in the four studied Pacific Islands populations were those of the DQ3 subgroup of alleles HLA-DQB1*03011, HLA-DQB1*0302 and HLA-DQB1*03032 as well as HLA-DQB1*05031 and HLA-DQB1*06011. Cook Islanders had the highest number of rare HLA-DQB1 alleles, the distibution being similar to that of the HLA-DRB1 allele. While, in general, the values of homozygosity for DRB1 and DQB1 were observed to be lower then expected under neutrality, a statistical significance was observed in Tongans, Samoans and Tokelauans for the DQB1 locus and in Tongans for the DRB1 locus. Differences were observed between allele frequency distributions for Tokelauans compared to the other three populations. This was also demonstrated by principal component analysis of DRB1 and DQB1 allele frequencies, which separated the Tokelauan population from Cook Islanders, Tongans and Samoans. Tongans and Samoans were separate from the other Polynesian populations in the phylogenetic trees. Observed allele and haplotype frequencies were found to be in agreement with previously published HLA-DRB and HLA-DQB Polynesian data.

Asian People↗

VHL and FHIT locus loss of heterozygosity is common in all renal cancer morphotypes but differs in pattern and prognostic significance.

Deletions involving 3p are believed to be typical for conventional (clear cell) renal cell carcinoma (cRCC), with confirmed and suspected targets being the VHL and FHIT tumor suppressor genes, respectively. By contrast, 3p deletions are felt to be rare in papillary RCC (pRCC) and chromophobe RCC (chRCC); however, this belief is based on relatively scant data. In particular, 3p14.2 deletions, possibly resulting in FHIT inactivation, have been rarely studied in pRCC or chRCC even though they may be relevant in early renal tumorigenesis. We therefore examined 3p deletion rates and patterns in pRCC and chRCC with particular attention to 3p14.2. We examined 16 chRCCs and 27 pRCCs for loss of heterozygosity (LOH) at 3p25-26 and 3p14.2 using 13 well-mapped microsatellite markers. Those pRCC with LOH at 3p25-26 were also screened for VHL gene mutations. The results were correlated with tumor histology and patient outcome and compared with data we had obtained previously on cRCC. We found similar overall 3p LOH rates in pRCC (59%), chRCC (86.6%), and cRCC (75.8%). In pRCC and chRCC, LOH at 3p25-26 was more common than at 3p14.2, whereas the converse was true for cRCC. In the pRCC with 3p25-26 LOH, we confirmed that this was not associated with mutations of the VHL gene. At 3p14.2, LOH rates of pRCC were lower than those of cRCC and chRCC (p<0.02). All morphotypes showed a predominately interstitial LOH pattern, which was most pronounced in the 3p14.2 region in cRCC. 3p LOH in chRCC was associated with improved patient outcome, mirroring our previous cRCC data. We conclude that 3p LOH is a universal phenomenon in RCC, but has different underlying mechanisms, molecular targets, and implications in the different morphotypes, although FHIT inactivation may play a role in both cRCC and chRCC tumorigenesis.

Acid Anhydride Hydrolases↗

The presence of atypical small acinar proliferation in prostate needle biopsy is predictive of carcinoma on subsequent biopsy.

OBJECTIVE: To determine the clinical significance of nondiagnostic small acini showing cellular atypia (atypical small acinar proliferation) in prostatic biopsies of patients with clinical findings suggestive of malignancy. PATIENTS AND METHODS: Of 331 patients who underwent thin-core biopsy of the prostate over a 30-month period, 21 (6.3%) had atypical histological features, and of these 17 underwent repeat biopsy. In addition, a further 20 patients with normal histology underwent repeat biopsy for persistent abnormal clinical findings. The incidence and Gleason score of carcinomas subsequently diagnosed in the two groups were compared. The predictive significance of patient age, prostate specific antigen (PSA) level and digital rectal examination (DRE) findings were compared between both patient groups, those in each group subsequently found to have carcinoma, and between patients with malignant or normal repeat biopsies who had either atypical or normal initial biopsies. RESULTS: Nine patients with atypical histology and four with normal histology on initial biopsy were found to have carcinoma on subsequent biopsy (P = 0.036). The site of carcinoma diagnosed in the repeat biopsy frequently differed from that of the initial atypical biopsy. The Gleason primary pattern was not significantly different between the groups. Neither patient age, PSA level nor DRE findings differed between patients with initial normal or atypical biopsy, or in these groups for those in whom carcinoma was subsequently diagnosed. These clinical features did not distinguish between those with carcinoma or normal findings on repeat biopsy who had an initial atypical biopsy, while only PSA level varied significantly in patients with normal or malignant repeat biopsy in the group with an initial normal biopsy. CONCLUSION: The presence of atypia on initial biopsy is a strong predictor of malignancy in subsequent biopsy specimens.

Biopsy, Needle↗

Morphologic typing of papillary renal cell carcinoma: comparison of growth kinetics and patient survival in 66 cases.

Whereas papillary renal cell carcinoma is now established as a subtype of renal cell neoplasia, division of these tumors into 2 distinctive morphotypes has been proposed. Type 1 tumors have cells with scanty pale cytoplasm arranged in a single layer on the basement membrane of papillary cores. In these tumors, psammoma bodies and foamy macrophages are frequently seen, and the tumors frequently express cytokeratin 7. Type 2 tumor cells have pseudostratified nuclei and usually have voluminous eosinophilic cytoplasm. Recent studies have supported this subclassification of papillary renal cell carcinoma by demonstrating differing genotypes for type 1 and 2 tumors. To further study the subclassification of papillary renal carcinoma, we compared clinical features, nuclear grade, stage, tumor growth kinetics, and survival in a series of 50 type 1 and 16 type 2 papillary renal cell carcinomas. Comparison of patient age at presentation, sex, and primary tumor size shows no significant difference between the 2 tumor types. Type 1 tumors were of significantly lower Fuhrman grade (P =.0001) and higher Robson stage (P =.009) than type 2 tumors. There was no significant difference when tumors were staged according to the TNM classification. Assessment of tumor growth kinetics showed significantly different mean silver-staining nucleolar organizer region (AgNOR) scores and Ki-67 indices (AgNOR type 1, 3.83, type 2, 7.24, P =.0001; Ki-67 type 1, 3.17%, type 2, 6.01%, P =.0002). Multivariate analysis showed tumor type (P =.03), presence of metastases (P =.04), AgNOR score (P =.001), and Ki-67 index (P =.03) to be independently associated with survival. These results provide evidence of the clinical utility of dividing papillary renal cell carcinomas into 2 types according to histologic characteristics.

Adult↗

Serum creatine kinase levels parallel the clinical course for rhabdomyomatous Wilms tumor.

A right-sided renal mass in an 11-month-old girl was diagnosed by percutaneous needle biopsy as Wilms tumor, which on histologic examination was found to be predominantly rhabdomyomatous. As part of the examination, serum creatine kinase (CK) and CK-MB levels were measured and were significantly elevated at 994 U/L (reference range, 42-180 U/L) and 40 U/L (reference range, 0-3 U/L), respectively. Subsequently, an 8-month-old girl was admitted to the hospital with septicemia and was found to have an abdominal mass. A diagnosis of bilateral Wilms tumor was made following percutaneous biopsy of both kidneys; histologic examination confirmed that the tumor was predominantly rhabdomyomatous. Serum CK and CK-MB levels also were measured and were significantly elevated at 685 U/L and 84.4 U/L, respectively. In both cases, the serum CK and CK-MB levels reflected the clinical course; elevation in serum levels was associated with tumor recurrence, infarction, or chemotherapy-related necrosis. We conclude that these enzymes have clinical usefulness as markers for Wilms tumor showing rhabdomyomatous morphologic features.

Antineoplastic Combined Chemotherapy Protocols↗

Evolving classification of renal cell neoplasia.

The development of consensus classifications for renal epithelial neoplasia in 1996 and 1997 led to the recognition of renal adenoma, renal oncocytoma and metanephric adenoma/adenofibroma as benign tumors and conventional (clear cell) renal cell carcinoma (RCC), papillary RCC, chromophobe RCC and collecting duct carcinoma as malignant morphotypes. While the overwhelming majority of renal adenomas and metanephric adenomas are benign, malignant transformation of both types have been described and genetic predictors of malignant transformation are as yet unknown. The main groups of malignant renal tumors are associated with characteristic genetic changes; conventional RCC (-3p), papillary RCC (+7, +17, -Y), chromophobe RCC (hypodiploid). Recent studies have also shown focal loss of heterozygosity of 3p segments in papillary and chromophobe RCC, indicating that 3p mutations are not confined to the conventional RCC morphotype and suggesting the presence of an important tumor suppressor gene at this site. Sarcomatoid metaplasia may occur in any morphotype and this is associated with a poor prognosis. More recently additional varieties of conventional RCC (multilocular cystic RCC), collecting duct carcinoma (medullary renal carcinoma) and papillary RCC (Types 1 and 2), each showing a characteristic morphology, have been recognized.

Carcinoma, Renal Cell↗

Progeria kidney has abnormal mesangial collagen distribution.

It has been suggested that progeria, a congenital disorder associated with clinical features that resemble premature aging, may be the result of a connective tissue abnormality. Although to date the clinical and pathologic features for 14 autopsied cases of progeria have been reported, details as to the renal changes in progeria are scanty. We investigated the histological features from a male and female with progeria who died aged 11 years and 20 years respectively. In our young male subject there was no glomerulosclerosis, while the kidney from the older subject showed focal renal scarring with focal glomerulosclerosis and associated tubular atrophy. Two small papillary adenomas were present within the renal cortex of the latter subject. In both cases non-sclerotic glomeruli were moderately enlarged with expansion of mesangial matrix. Immunohistochemical detection of collagens showed absence of collagen I and III within the mesangium of non-sclerotic glomeruli, while there was moderate to marked expression of collagen IV, V and VI. Collagen V is thought to be involved in matrix assembly while collagen VI probably has a regulatory role in extracellular matrix development and these are either not seen or are very weakly expressed in normal renal mesangium. The distribution of collagen within the mesangium of progeria kidney is evidence in support of the concept that progeria is a primary connective tissue disorder.

Adult↗

Immunohistochemical evidence for mesothelial origin of paratesticular adenomatoid tumour.

AIMS: To investigate the histogenesis of paratesticular adenomatoid tumour by use of immunohistochemical markers for a variety of carcinomas and mesothelioma. METHODS AND RESULTS: Immunohistochemical staining of sections from 12 cases of paratesticular adenomatoid tumour was undertaken using primary antibodies to antigens expressed by benign epithelial cells and carcinoma (cytokeratin AE1/AE3, cytokeratin 34ssE12, epithelial membrane antigen, MOC-31, Ber-EP4, CEA, B72.3, LEA.135, Leu M1), stromal and vascular markers (vimentin, CD34, factor VIII), and mesothelioma-associated antigens (thrombomodulin, HBME-1, OC 125) and p53 protein. There was absence of immunohistochemical expression of epithelial/carcinoma markers MOC-31, Ber-EP4, CEA, B72.3, LEA.135, Leu M1 and to factor VIII and CD34. All tumours expressed cytokeratin AE1/AE3, epithelial membrane antigen and vimentin, with weak expression of cytokeratin 34ssE12 in 25% of tumours. Each tumour showed expression of thrombomodulin, HBME-1 and OC 125 in a membranous distribution. p53 protein expression was not detected. CONCLUSIONS: The immunohistochemical profile of paratesticular adenomatoid tumour is strongly supportive of a mesothelial cell origin.

Adenomatoid Tumor↗

The histology and growth kinetics of canine renal oncocytoma.

A renal oncocytoma was diagnosed in a 10-year-old English springer spaniel with a 5-month history of anorexia, vomiting and weight loss. The tumour, which was localized to the kidney, was treated by simple nephrectomy and the dog made a full recovery. Histologically, the tumour consisted of cells with abundant eosinophilic cytoplasm forming acini and alveolar nests set within a loose fibrovascular stroma. The results of cell kinetic studies (AgNOR score 2.68, PCNA index 5.2%) were comparable with findings reported for benign human renal tumours. This appears to be the first reported case of renal oncocytoma in a dog.

Adenoma, Oxyphilic↗

Role of eosinophils in the pathogenesis of Mycobacterium bovis BCG infection in gamma interferon receptor-deficient mice.

A profound eosinophil infiltration of granulomas is observed in the lungs of Mycobacterium bovis bacillus Calmette Guérin-infected gamma interferon receptor-deficient mice. Blockade of eosinophil proliferation and recruitment into the lung by treatment with anti-interleukin-5 monoclonal antibody marginally reduced mycobacterial growth within the lung but did not affect dissemination of the infection to other tissues.

Animals↗

Loss of heterozygosity at 3p14.2 in clear cell renal cell carcinoma is an early event and is highly localized to the FHIT gene locus.

The VHL tumor suppressor gene (TSG) at 3p25-26 is strongly implicated in the pathogenesis of clear cell renal cell carcinoma (cRCC). In addition, 3p14.2 and 3p21 are suspected of harboring additional TSGs in cRCC, with FHIT being a candidate TSG at 3p14.2. We examined 87 microdissected, histologically well-defined cRCCs classified according to tumor-node-metastasis (TNM) stage (stage 1, 23 cases; stage 2, 14 cases; stage 3, 24 cases; stage 4, 26 cases) and Fuhrman grade (grade 1, 24 cases; grade 2, 19 cases; grade 3, 19 cases; grade 4, 8 cases; sarcomatoid cRCC, 17 cases) for loss of heterozygosity (LOH) at 3p14.2 and 3p25-26 using a series of precisely mapped microsatellite probes. We found that LOH at 3p14.2 exceeded LOH at 3p25-26 in frequency (69% versus 48.3%; P < 0.03) and was highly localized to markers within the FHIT gene locus (D3S1300 and D3S4260), with the majority of chromosomal breakpoints also mapping to this region. In addition, 3p14.2 LOH (P < 0.03), but not 3p25-26 LOH (P = nonsignificant), was associated with lower tumor grades (grades 1-3). These findings suggest that 3p14.2 genomic deletions may be among the earliest events in cRCC pathogenesis, preceding genomic deletions at the VHL locus. FHIT, or an as yet undiscovered TSG mapping to the D3S4103-D3S4260 interval, could be the molecular target of the 3p14.2 deletions.

Acid Anhydride Hydrolases↗

Sarcomatoid renal carcinoma: the final common dedifferentiation pathway of renal epithelial malignancies.

Sarcomatoid renal carcinoma (SRC) is an aggressive neoplasm with an age and gender distribution similar to that of conventional (clear cell) renal cell carcinoma (RCC). Genetic and morphologic evidence indicates that the tumor results from de-differentiation of renal epithelial malignancy and associations with RCC, papillary renal carcinoma, chromophobe renal carcinoma and collecting duct carcinoma have been reported. The tumor is composed of sheets of malignant spindle cells that have immunohistochemical and ultrastructural features of both stromal and epithelial cells, and may contain myxoid areas containing osteoclast-like giant cells or pleomorphic sarcomatoid spindle cells resembling rhabdomyoblasts. Rare cases of osteogenic SRC have been described. The tumor shows marked proliferative activity in growth kinetic studies and is usually associated with a poor patient survival that is best predicted by staging.

Adult↗

CTLA-4 blockade enhances the immune response induced by mycobacterial infection but does not lead to increased protection.

The murine immune response to a pulmonary mycobacterial infection is slow to develop, allowing bacterial numbers to increase in the lung for several weeks after infection. We sought to enhance the protective immune response induced during Mycobacterium bovis BCG infection by administering an antibody that blocks the interaction of CTLA-4 with its ligands, CD80 and CD86. We found that injection of anti-CTLA-4 monoclonal antibody (MAb) greatly enhanced and accelerated the immune response, as measured by increased cellularity of the draining mediastinal lymph nodes, and enhanced antigen-inducible proliferation and gamma interferon production by mediastinal lymphocytes in vitro. However, despite the apparently enhanced immune response in the mediastinal lymph node following treatment with anti-CTLA-4 MAb, there was no improvement in clearance of mycobacteria in the lungs, liver, or spleen. Examination of the primary site of infection, the lung, revealed that CTLA-4 blockade had no effect on the number or function of lymphocytes infiltrating the infected lung tissue. Taken together, these data suggest that in vivo CTLA-4 blockade enhances mycobacterial-infection-induced lymphocyte expansion and effector cell cytokine production in the draining lymph node but does not alter the number or function of lymphocytes at the primary site of infection and therefore does not lead to enhanced clearance of the infection.

Abatacept↗

Infection of mice with Mycobacterium bovis-BCG induces both Th1 and Th2 immune responses in the absence of interferon-gamma signalling.

A murine pulmonary infection model using Mycobacterium bovis-BCG was used to study the development of Th1 and Th2 type responses in mice lacking a functional IFN-gamma receptor (IFN-gamma R-/-). Strikingly, the IFN-gamma R-/- mice maintained the Th1 response and developed a profound M. bovis-BCG, specific Th2 type immune response characterized by IL-5-producing CD4+ T cells, eosinophil infiltration of granulomas, and significantly elevated serum IgE levels. The increase in IL-5 production and eosinophil recruitment into the lung could be detected within the first 1-2 weeks of infection, indicating that the Th2 response was not due to greatly enhanced bacterial numbers observed later in infection. These results clearly indicate that IFN-gamma acts during M. bovis-BCG infection to suppress the development of Th2 immune responses. Furthermore, they demonstrate that IFN-gamma is not a necessary cofactor in the development of Th1 type cells secreting IFN-gamma. In conclusion, these data demonstrate that IFN-gamma plays a major role in suppressing a potentially disease-promoting Th2 immune response during mycobacterial infections.

Animals↗