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S B Kapadia

Publications and source records attributed to S B Kapadia.

At least 19 recordsLinked to original sources
PubMed1999

Cellular immune responses are essential for the development of Helicobacter felis-associated gastric pathology.

The bacteria Helicobacter pylori is a major human pathogen that infects over half of the world's population. Infection initiates a series of changes in the gastric mucosa, beginning with atrophic gastritis and leading in some patients to peptic ulcer disease, mucosa-associated lymphomas, and gastric adenocarcinoma. Although this cascade of events clearly occurs, little is known about the role of the host immune response in disease progression. We have utilized the C57BL/6 Helicobacter felis mouse model to critically analyze the role of the adaptive immune response in the development of Helicobacter-associated gastric pathology. Infection of B and T cell-deficient RAG-1-/- mice or T cell-deficient TCRbetadelta-/- mice with H. felis resulted in high levels of colonization, but no detectable gastric pathology. Conversely, infection of B cell-deficient microMT mice resulted in severe gastric alterations identical with those seen in immunocompetent C57BL/6-infected mice, including gastric mucosal hyperplasia and intestinal metaplasia. These results demonstrate that the host T cell response is a critical mediator of Helicobacter-associated gastric pathology, and that B cells and their secreted Abs are not the effectors of the immune-mediated gastric pathology seen after H. felis infection. These results indicate that in addition to specific Helicobacter virulence factors, the host immune response is an important determinant of Helicobacter-associated disease.

Animals↗
PubMed1999

HIV-associated Waldeyer's ring lymphoid hyperplasias: characterization of multinucleated giant cells and the role of Epstein-Barr virus.

Lymphoid hyperplasia of Waldeyer's ring (WR) is an often-symptomatic complication of human immunodeficiency virus (HIV) infection. A characteristic but not well explained finding is the presence of multinucleated giant cells (MNGCs) adjacent to crypt or surface epithelium. To further elucidate the MNGCs and assess their relationship to HIV and Epstein-Barr virus (EBV), 12 specimens from 11 HIV-positive patients were stained with antibodies to HIV-1 p24, EBV (latent membrane protein, LMP-1), histiocytes (CD68), and other antigen-presenting cells: S-100 protein, the Langerhans cell (LC) marker CD1a, and the follicular dendritic cell (FDC) marker (CD21). Double immunofluorescent staining to assess co-expression of p24 and cell-specific markers was performed and analyzed by laser-scanning confocal microscopy with 3-dimensional reconstruction. In situ hybridization for EBV-encoded small RNA (EBER) was performed in all cases. Immunostains showed MNGCs labeled for p24, S-100, and CD68, but not CD1a. In 1 case, rare MNGCs were CD21-positive. EBV LMP-1 was uniformly negative, although EBER-positive lymphocytes were seen by in situ hybridization in 9 of 12 specimens (numerous in only 3 specimens). Double immunofluorescent staining showed co-localization of p24 with CD68 and S-100. Our results suggest that MNGCs are generally HIV-infected, EBV-negative, and most likely represent an unusual S-100-positive histiocyte subset (not LC or FDC). Their exact pathophysiologic role remains uncertain. EBV does not appear to play a major role in the pathogenesis of WR lymphoid hyperplasias in HIV infection.

Adult↗
PubMed1999

Subtotal maxillectomy for melanotic neuroectodermal tumor of infancy.

Melanotic neuroectodermal tumor of infancy is a rare pigmented neoplasm occurring in infants before 1 year of age. It is a rapidly growing tumor that most frequently affects the craniofacial skeleton. Although melanotic neuroectodermal tumor of infancy is benign in the vast majority of cases, inadequate excision, occasional multicentricity, and a small malignant potential result in a fairly high recurrence rate. On the basis of data obtained from the literature and our clinical experience, we advocate an aggressive surgical approach consisting of complete surgical excision when vital structures are not involved. Histopathologic confirmation of complete excision is mandatory to minimize the risk of recurrence and provide the patient with curative treatment and minimal morbidity.

Humans↗
PubMed1999

Murine gammaherpesvirus 68 encodes a functional regulator of complement activation.

Sequence analysis of the murine gammaherpesvirus 68 (gammaHV68) genome revealed an open reading frame (gene 4) which is homologous to a family of proteins known as the regulators of complement activation (RCA proteins) (H. W. Virgin, P. Latreille, P. Wamsley, K. Hallsworth, K. E. Weck, A. J. Dal Canto, and S. H. Speck, J. Virol. 71:5894-5904, 1997). The predicted gene 4 product has homology to other virally encoded RCA homologs, as well as to the complement-regulatory proteins decay-accelerating factor and membrane cofactor protein. Analyses by Northern blotting and rapid amplification of cDNA ends revealed that gene 4 is transcribed as a 5.2-kb bicistronic transcript of the late kinetic class. Three gammaHV68 RCA protein isoforms (60 to 65 kDa, 50 to 55 kDa, and 40 to 45 kDa) were detected by Western blotting of infected murine NIH 3T12 fibroblast cells. A soluble 40- to 45-kDa isoform was detected in the supernatants of virally infected cells. Flow cytometric analysis revealed that the gammaHV68 RCA protein was expressed on the surfaces of infected cells. Supernatants from virally infected cells contained an activity that inhibited murine complement activation as measured by inhibition of C3 deposition on activated zymosan particles. Recombinant gammaHV68 RCA protein, containing the four conserved short consensus repeats, inhibited murine C3 deposition on zymosan via both classical and alternative pathways and inhibited deposition of human C3 on activated zymosan particles. Expression of this inhibitor of complement activation, both at the cell surface and in the fluid phase, may be important for gammaHV68 pathogenesis via the inhibition of innate and adaptive immunity.

Amino Acid Sequence↗
PubMed1998

Osteosarcoma of the larynx.

Malignant mesenchymal tumors of the larynx constitute 0.3% to 1% of all laryngeal cancers, and of these osteosarcoma is the rarest. Our review of the literature identified only 12 cases of osteosarcoma of the larynx, all of which occurred in men. Rarely, osteosarcoma of the larynx may follow radiation therapy for squamous cell carcinoma, or the larynx may be the site of metastatic osteosarcoma. We report a case of primary laryngeal osteosarcoma arising in the cricoid cartilage and the first case of osteosarcoma of the larynx occurring in a woman.

Cricoid Cartilage↗
PubMed1998

A near-haploid bone marrow karyotype in systemic mast cell disease: is it characteristic of the disease or an incidental finding?

We present the case of a 40-year-old man with aggressive systemic mast cell disease. The patient had a predominant near-haploid clone in his bone marrow cells, detected by cytogenetic analysis performed at the time of diagnosis. The similarities between this case and a previously published case of near-haploidy in a patient with malignant mastocytosis suggest that near-haploidy may be a characteristic of aggressive systemic mast cell disease rather than an incidental finding.

Adult↗
PubMed1998

Confocal microscopy assessment of lymphoid tissues with follicular hyperplasia from patients infected with human immunodeficiency virus type 1.

OBJECTIVE: To characterize human immunodeficiency virus (HIV) infection of lymphoid tissues during follicular hyperplasia. METHODS: We examined 10 tonsil/adenoid, 3 parotid lymphoepithelial cyst, and 7 lymph node specimens that had been surgically removed from 13 patients infected with HIV-1. Characteristics of productive HIV-1 infection were assessed using immunocytochemistry for HIV-1 p24. Cellular colocalization was determined with the aid of a confocal microscope using double immunofluorescent staining for HIV-1 p24 and cell-specific markers. RESULTS: All specimens showed follicular hyperplasia. Using confocal microscopy with three-dimensional reconstruction, HIV-1 p24 was seen to be "intimately" colocalized with CD21 within the germinal centers. While lymphoid follicles were generally hyperplastic, only a subset of these follicles contained HIV-1 p24. Occasional HIV-1-expressing mononuclear cells identified outside follicles stained for CD68 or CD3. CONCLUSIONS: The differential involvement of hyperplastic follicles by HIV-1 within individual lymphoid tissues and the intimate colocalization of HIV-1 p24 and CD21 suggest that infected follicular dendritic cells may be an important reservoir of HIV-1 during follicular hyperplasia.

Adult↗
PubMed1998

Prostatic carcinoma with signet ring cells: a clinicopathologic and immunohistochemical analysis of 12 cases, with review of the literature.

Prostatic adenocarcinoma with a signet ring cell (SRC) component is a rare, incompletely characterized variant that must be distinguished from similar tumors of bladder or gastric origin. In this study, we used mucin and immunoperoxidase stains on formalin-fixed, paraffin-embedded sections from 12 prostatic adenocarcinomas with SRC components, with antibodies to prostate-specific antigen (PSA), cytokeratins, MIB-1, bcl-2, c-MET, CD44v6, and CD44v7; we performed a comparison study on six bladder and seven gastric carcinomas with SRCs. The prostatic SRC component was always associated with the usual high-grade adenocarcinoma. Both components were positive for PSA, AE1/AE3, and CAM 5.2 (12 cases of 12) and also expressed c-MET (5 cases of 9), CD44v6 (9 of 10), and CDv7 (9 of 10). Only rare cells stained for bcl-2 (3 cases of 9). The mean MIB-1 proliferation index was 8%. Intracellular mucin was identified (periodic acid-Schiff with diastase predigestion (PAS-D) in 9 cases of 10, mucicarmine in 5 of 10, alcian blue in 6 of 10). Bladder and gastric tumors were positive for PSA (3 cases of 6 and 2 of 7, respectively), using a polyclonal antibody, and for bcl-2 (5 cases of 6, 2 of 7), c-MET (6 of 6, 6 of 7), CD44v6 (5 of 6, 6 of 7), and CD44v7 (4 of 6, 4 of 7), with mean MIB-1 proliferation indices of 15 and 35%, respectively. All were negative for cytokeratin 34 beta E12. We conclude that prostatic adenocarcinomas with SRC components are typically accompanied by high-grade adenocarcinoma; are variably positive for mucin, with PAS-D being the most sensitive stain; show expression of PSA, cytokeratins, MIB-1, bcl-2, c-MET, and CD44 similar to that shown by high-grade adenocarcinoma components; have a low MIB-1 proliferation index; and are not always distinguishable from SRC components of bladder and stomach carcinomas with any of the above stains, including PSA.

Aged↗
PubMed1998

Expression of androgen receptor, gross cystic disease fluid protein, and CD44 in salivary duct carcinoma.

Salivary duct carcinoma (SDC) is an infrequent, aggressive tumor with a histologic similarity to ductal breast carcinoma. It must be differentiated from breast metastasis and other high-grade salivary tumors with glandular differentiation. Its histologic similarity to breast carcinoma raises the possibility that hormonal manipulation might also be of use in its treatment. Little is known concerning its pathogenesis. Expression of variant isoforms of CD44, a transmembrane molecule involved in cell-matrix interactions, confers metastatic potential on carcinoma cells in animal models and might also be important in the clinical progression of some human tumors. To address these diagnostic, therapeutic and pathogenetic issues, we performed an immunohistologic study on formalin-fixed, paraffin-embedded sections of 12 SDCs (7 from men, 5 from women), using antibodies to androgen receptor (AR), estrogen receptor (ER), progesterone receptor (PR), gross cystic disease fluid protein (GCDFP-15), CD44s, and CD44v6. A mucicarmine stain was also performed in each case. Luminal and focal intracellular mucin positivity was observed in 11 of the 12 tumors. There was strong, diffuse reactivity for AR in 11 of 12 and of GCDFP-15 in 12 of 12, and nonreactivity for ER and PR in 12 of 12. CD44s was negative (9 of 12) or only focally positive (3 of 12), and CD44v6 was diffusely positive in 12 of 12. Our study shows that most SDCs have luminal and focal intracellular mucin; that the immunophenotype AR+/ER-/PR-/GCDFP+ in a malignant salivary tumor with an intraductal (in situ) pattern is characteristic of SDC but does not completely exclude metastasis from the breast, which might also be AR+ and ER/PR- in a lesser proportion of cases; that enhanced expression of CD 44v6 might be an indication of its link to tumorigenesis; and that uniform AR expression raises the possibility that antiandrogen therapy might have a role in the management of patients with disseminated disease.

Aged↗
PubMed1997

Salivary gland lymphoid infiltrates associated with lymphoepithelial lesions: a clinicopathologic, immunophenotypic, and genotypic study.

The criteria for distinguishing benign lymphoepithelial lesions (BLEL) from low grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) type in salivary glands and the significance of genotypically documented clonality in this setting are controversial. In addition, the clinical implications of a neoplastic diagnosis are unclear. The histopathologic features of 68 specimens from 49 patients with at least one salivary gland biopsy with LEL together with available clinical data were, therefore, reviewed. Paraffin section immunohistochemical (IHC) stains for kappa, lambda, CD3, CD20, and CD43; in situ hybridization (ISH) for kappa and lambda; and polymerase chain reaction (PCR) for immunoglobulin (Ig) HC rearrangement were performed. The 61 salivary gland specimens were classified as BLEL-13, BLEL with monocytoid B-cell (MBC) halos (BLEL-halo-8), low grade B-cell lymphoma of MALT type with confluent zones of MBC or other atypical lymphocytes (ML-MALT-24), low grade B-cell lymphoma of MALT type with monoclonal plasma cells (ML-MALT-PC-12), and high grade B-cell lymphoma of MALT type (MALT-high grade-4). Soft tissue and perineural invasion was not observed in BLEL and was most common in the MALT lymphomas. Lymph node involvement was identified in six patients at the time of their salivary gland MALT lymphomas but in none with BLEL. CD43+ B cells were seen most commonly in ML-MALT but were present in all other categories except MALT-high grade. Clonal B cells were identified by PCR in 5 of 12 BLEL, 5 of 8 BLEL-halo, 17 of 22 ML-MALT, 6 of 10 ML-MALT-PC, and 3 of 3 MALT-high grade biopsies. All ML-MALT-PC were clonal by ISH or IHC. Repeat biopsies in 14 patients most commonly showed a BLEL/ML-MALT lesion in an ipsilateral or contralateral salivary gland with one transformation to a MALT-high grade. Although only a few patients are known to have received chemoradiation or radiation therapy, most patients with low-grade lesions have pursued an indolent course. These data show the presence of two types of borderline lesions within the spectrum of lymphoid proliferations associated with salivary gland LEL. One has clonal B cells without histological features of neoplasia and the other nonconfluent MBC extending beyond the confines of LEL ("halos"). They share some features with the infrequent nonneoplastic BLEL and others with the more common low-grade B-cell lymphomas of MALT. A few high-grade B-cell lymphomas of MALT were also identified including a rare example of transformation from a low- to high-grade lesion. The optimal therapeutic approach for the borderline and low-grade lesions and the reason why so many of the lymphoproliferative lesions associated with LEL remain localized to the neck remain to be defined.

Adult↗
PubMed1997

Neural cell adhesion molecule in adenoid cystic carcinoma invading the skull base.

Neural cell adhesion molecules (N-CAMs) are expressed in neuromuscular tissues, neuroblastoma, and small cell lung carcinoma. Adenoid cystic carcinoma may invade the skull by either direct extension or neural involvement, particularly along the second and third divisions of the trigeminal nerve (V2 and V3). Eighteen patients with adenoid cystic carcinoma that invaded the skull base were studied. The tumors were graded into predominantly solid (3), cribriform (11), or tubular-trabecular (4) patterns, and neural involvement was evaluated histologically. Paraffin sections were examined by use of monoclonal antibodies for N-CAM and Ki-67, a proliferation marker, with the avidin-biotin-peroxidase method. Fifteen (83%) tumors showed perineural involvement; in the remaining three cases no nerves were present for histologic examination. Fourteen (93%) of 15 tumors with perineural involvement were reactive with N-CAM. Proliferation, measured by the presence of nuclear Ki-67, was markedly increased in tumors with predominantly solid patterns. We demonstrated that N-CAM is expressed in adenoid cystic carcinoma. The role of N-CAM as a neurodeterminant that facilitates the spread of adenoid cystic carcinoma along nerves, however, remains unanswered and warrants further study.

Antibodies, Monoclonal↗
PubMed1996

The role of p53 mutation and protein expression in primary and recurrent adenoid cystic carcinoma.

Adenoid cystic carcinoma (ACC) is a malignant tumor of salivary gland origin having a propensity for spread by direct extension or perineural invasion with frequent recurrences. Previous reports have shown that tumor behavior is not always predicted by histological pattern or stage. Little is known of the role of p53 tumor suppressor gene mutation and altered protein expression with respect to ACC pathobiology and recurrence. The authors analyzed a group of 14 ACC specimens (seven primary; seven recurrent) from 13 patients treated between 1987 to 1993. Formalin-fixed, paraffin-embedded specimens were reviewed and subjected to, immunohistochemistry (p53, DO-7, DAKO, Nutley, NJ; and WAF-I, Ab-1, Oncogene Sciences, Uniondale, NY) on 4-microm-thick histological sections as a prelude to p53 genotyping. In one case, sequential material representing primary and recurrent tumor was analyzed. Each tumor specimen was topographically genotyped for p53 point mutational change. Minute tissue samples were removed from unstained sections, polymerase chain reaction (PCR) amplified for p53 exons 5 to 8, and then underwent direct DNA sequencing. Six of seven primary ACCs were p53 immunostain negative. Four of seven recurrent (57%) ACCs were p53 immunopositive. These tumors showed varying degrees of p53 immunopositivity ranging from diffuse, intense staining of most tumor cells (n = 1) to interspersed, strongly positive cells mixed with predominantly p53 immunonegative cells (n = 4). All tumors were WAF-I immunostain negative. Two of the most immunopositive recurrent tumors each manifested a single type of p53 point mutation detected by p53 DNA genotyping (p53 exon 5:codon 175 and p53 exon 6:codon 199). In the case in which both primary and recurrent tumor was available, only the recurrent tumor contained point mutational damage. Negative immunostaining for p53 in primary ACC suggests that p53 mutation is not important in early events involving development of this tumor. In contrast, the frequent presence of p53-positive cells and the detection of point mutations in recurrent ACC suggests that p53 alterations are involved in later stages of tumor progression, important in the phenomenon of ACC recurrence.

Adult↗
PubMed1996

Lymphoepithelial carcinoma of the larynx and hypopharynx: study of eight cases with relationship to Epstein-Barr virus and p53 gene alterations, and review of the literature.

Eight cases of lymphoepithelial carcinoma (LEC) of the larynx and hypopharynx were evaluated for clinicopathologic features, and the presence of the Epstein-Barr virus (EBV) and p53 alterations. The seven men and one woman, all of non-Asian descent, averaged 64 years of age. Eighty-eight percent had histologically confirmed cervical lymph node metastasis at diagnosis. None had systemic disease. Seven of eight patients available for follow-up (mean, 17.7 months) were alive and free of disease, although one did develop recurrent tumor in the neck. Four tumors were composed, histologically, of pure LEC. Four others had foci of both LEC and conventional squamous cell carcinoma. All eight tumors exhibited alterations in p53 expression, but none was positive for EBV. Combining these 8 cases with the 15 previously published cases in the English literature indicate that LEC in this site is a rare, rather aggressive tumor, primarily of older adults (mean, 62 years) with a propensity for early cervical lymph node metastasis and eventual distant dissemination and death from disease in about one third of patients. Although p53 alterations are common and of no apparent prognostic significance, LEC at this site seems to have little, if any, relationship to the EBV in patients of non-Asian origin.

Aged↗
PubMed1996

Chondrosarcoma of the nasal septum: skull base imaging and clinicopathologic correlation.

Chondrosarcoma arising in the head and neck and craniofacial region is an uncommon lesion. The nasal septum is a particularly rare site of origin, with approximately 30 cases previously reported in the English literature. We present six new cases of chondrosarcoma arising in the nasal septum. Each of these tumors required cranial base surgical approaches for removal. Current imaging techniques allow a very accurate diagnosis to be made before biopsy. The characteristic ring-forming calcifications seen on computed tomography scans can be correlated with the histologic pattern of calcification. Magnetic resonance imaging techniques allow precise definition of tumor extent, which is particularly important because the disease is best treated with primary surgery. Advances in imaging and surgical techniques allow a much more complete tumor removal. It is hoped that this will increase the likelihood of cure in these patients. Surgical management and indications for adjuvant therapy are discussed.

Adult↗