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Biomedical subjects

S P Hammar

Publications and source records attributed to S P Hammar.

At least 19 recordsLinked to original sources
PubMed1995

Granulomatous vasculitis.

Vasculitides are classified by the size of the vessel involved and by the nature of the inflammatory process. Pulmonary granulomatous vasculitis encompasses several entities that are in general characterized by granulomatous inflammation, extensive necrosis, and a variegated cellular infiltrate. Wegener's granulomatosis is a prototype of granulomatous vasculitis and is a disease of unknown etiology that often involves the upper respiratory tract, the lower respiratory tract, and the kidneys. Some of the entities initially classified as pulmonary granulomatous vasculitis have subsequently been found to represent other entities; specifically, lymphomas (lymphomatoid granulomatosis) and part of the spectrum of bronchopulmonary aspergillosis (bronchocentric granulomatosis). In addition, it is recognized that certain infectious conditions, specifically the necrotizing inflammatory processes caused by fungi and mycobacteria, can show granulomatous vasculitis and can be confused with Wegener's granulomatosis. The mechanism by which pulmonary granulomatous vasculitis occurs is not well understood, although is thought to have an immunologic basis. A great deal of data has been accumulated concerning antineutrophil cytoplasmic autoantibodies and the role that these antibodies might play in the development of these conditions.

Churg-Strauss Syndrome↗
PubMed1992

Cutaneous T-cell lymphoma. Evaluation of pretreatment skin biopsy specimens by a panel of pathologists.

BACKGROUND AND DESIGN: Cutaneous T-cell lymphoma (CTCL) frequently presents a difficult diagnostic challenge for the clinician and pathologist. To assess the diagnostic validity of conventional histopathologic findings in CTCL, pretreatment skin biopsy specimens were scored prospectively and independently by a panel of five to seven dermatopathologists and pathologists. Scores were compared with disease outcome. Repeatability of these scores was examined among observers and for the same observer. The study population consisted of 165 subjects, initially referred for suspected mycosis fungoides or Sézary syndrome. Ninety-two patients determined to have CTCL have been followed up for 6.3 +/- 3.5 years (mean +/- SD) and are categorized according to disease outcome: 22 are in complete remission, 35 are in partial remission, three have progressive lymphoma, 15 died of disease, 13 died of other causes, and four were unavailable for follow-up. Seventy-three patients determined not to have CTCL have been followed up for 5.3 +/- 3.2 years without subsequent clinicopathologic evidence of CTCL. These longitudinal data allowed comparisons of the clinical course with the original histologic interpretations. RESULTS: Data showed that the histologic scores rendered by the pathology panel did not correlate with stage of disease and were not an accurate predictor of clinical outcome, because the histologic ratings did not discriminate between patients who eventually had complete remission and those with either progressive lymphoma or who have died of disease. The results also substantiate the low inherent reliability of histopathologic findings in CTCL. Large differences existed among pathologists in scoring the study populations and repeated reading of selected cases by the same panel member resulted in a change of diagnosis 15% of the time. Among the histologic features evaluated, only the presence of mitoses in the infiltrating cells showed a trend toward an unfavorable outcome. CONCLUSION: Pathologic diagnosis in the CTCL disease spectrum should be interpreted with caution and then only in conjunction with the clinical evaluation. As expected, the use of an average value from a panel of readers added a component of stability to the histologic interpretation.

Biopsy↗
PubMed1992

Amphicrine carcinoma of the uterine cervix.

A case of amphicrine carcinoma of the uterine cervix is described in a 27-year-old woman whose initial cervical biopsy specimen showed small cell undifferentiated neuroendocrine carcinoma. Despite an initial complete clinical response to VP-16 and carboplatin, residual tumor was noted in the cervical cone biopsy specimen and she was treated with external-beam irradiation and cesium implants. The neoplasm subsequently metastasized and required additional VP-16 and carboplatin for control. The pathologic features and biologic behavior of this unusual type of neuroendocrine neoplasm are described in this case report.

Adult↗
PubMed1992

Controversies and uncertainties concerning the pathologic features and pathologic diagnosis of asbestosis.

Asbestos is a fibrous silicate mineral that has been known for decades to cause pulmonary scarring, referred to as asbestosis. The simplest definition of asbestosis is the presence of pulmonary fibrosis as a result of accumulation of airborne asbestos in the lungs. Not infrequently, the terms "asbestos" and "asbestosis" are used incorrectly (interchangeably) by medical personnel, and sometimes pleural fibrosis caused by asbestos is incorrectly referred to as asbestosis. The earliest lesion of asbestosis, as defined by the CAP-NIOSH Committee is peribronchiolar fibrosis, although controversy exists as to how specific this lesion is with respect to causation by asbestos, and whether this lesion progresses to grade 4 asbestosis. In addition, some authorities in the field suggest that the term "asbestosis" be used only for diffuse interstitial fibrosis. The mechanism by which asbestos causes interstitial fibrosis remains poorly understood, and in recent years, pathologic changes such as organizing pneumonitis-bronchiolitis obliterans, and lymphocytic interstitial pneumonitis, have been described in persons occupationally exposed to asbestos, suggesting that the pulmonary lesions caused by asbestos represent a wider spectrum than had previously been appreciated. By defining areas of uncertainty, medical science will eventually clarify areas of disagreement concerning asbestosis which will eventually lead to a better understanding of this disease.

Asbestos↗
PubMed1991

Synovial sarcoma. Inter-relationship of the biphasic and monophasic subtypes.

In order to assess minimum diagnostic criteria for synovial sarcoma, particularly the monophasic variety, and the inter-relationship between the monophasic and biphasic types, 32 examples were studied histologically, immunohistochemically (26 cases), and ultrastructurally (13 cases). Of the six biphasic synovial sarcomas examined by electron microscopy, the spindle cell component did not show evidence of epithelial differentiation or resemble the epithelial phase, but did appear fibroblastic; no tumor cells transitional between the spindle and epithelial component were evident. In contrast, all of the seven monophasic lesions had ultrastructural growth patterns and some cellular features approximating the epithelial cells of the biphasic variant. In 11 biphasic synovial sarcomas, epithelial membrane antigen was detected in the glandular epithelium of all cases and cytokeratins in eight cases; in no case were these antigens detected in the spindle cell regions of biphasic lesions. Of the 15 monophasic synovial sarcomas, two were positive for cytokeratins and four for epithelial membrane antigen. Thus, the detection of epithelial markers either immunohistochemically or by electron microscopy (or both) should be the minimal diagnostic criteria for monophasic synovial sarcomas. Based on these findings, it is suggested that monophasic synovial sarcomas do not represent the spindle cell or "stromal" phase of biphasic synovial sarcomas, but are a poorly differentiated variant of the latter. As others have suggested, these tumors are, in fact, carcinosarcomas and carcinomas of the soft tissues and the designation synovial sarcoma is inappropriate for this tumor class.

Adolescent↗
PubMed1991

Azathioprine combined with prednisone in the treatment of idiopathic pulmonary fibrosis: a prospective double-blind, randomized, placebo-controlled clinical trial.

Twenty-seven newly diagnosed patients with idiopathic pulmonary fibrosis (IPF) who were previously untreated for IPF were enrolled in a prospective, double-blind, randomized, placebo-controlled study to compare the therapeutic effect of combined prednisone/azathioprine (n = 14) with prednisone plus placebo (n = 13). Prednisone was started at 1.5 mg/kg/day (not to exceed 100 mg/day) for the first 2 wk followed by a biweekly taper to a maintenance dose of 20 mg/day. Azathioprine was administered at a daily dose of 3 mg/kg (not to exceed 200 mg/day). The patients tolerated the use of azathioprine well with few associated side effects. Changes in lung function at 1 yr, as measured by resting alveolar-arterial oxygen difference P[A-a]O2, FVC, and single breath diffusing capacity for carbon monoxide (DLCOSB), were all somewhat better in the azathioprine/prednisone group compared with the prednisone alone group, although none of these comparisons were statistically significant. Six of 14 (43%) patients randomized to prednisone plus azathioprine died during the 9-yr follow-up period, compared with 10 of 13 (77%) patients randomized to prednisone plus placebo. A Cox model survival analysis shows a nonsignificant but potentially large survival advantage for azathioprine/prednisone (hazard ratio 0.48, with 95% confidence interval increasing from 0.17 to 1.38). When adjusted for age, the survival advantage of azathioprine/prednisone becomes marginally significant (hazard ratio 0.26, with 95% confidence interval increasing from 0.08 to 0.88; p = 0.02 by large sample approximation, p = 0.05 by randomization test). We conclude that combined prednisone and azathioprine is a safe and possibly effective regimen for the treatment of IPF.(ABSTRACT TRUNCATED AT 250 WORDS)

Azathioprine↗
PubMed1989

Tubuloreticular structures and cylindrical confronting cisternae: a review.

Tubuloreticular structures (TRS) and cylindrical confronting cisternae (CCC) are unique subcellular structures that arise from the membranes of the rough endoplasmic reticulum of a variety of cell types. In vivo, they occur most frequently in endothelial cells and lymphocytes from patients with autoimmune diseases and viral infections; they are seen in these cells in almost all acquired immunodeficiency syndrome (AIDS) patients. The inducer(s) of TRS and CCC in vivo is (are) not firmly established. However, clinical and experimental studies indicate that the occurrence of these structures in these diseases is directly related to the endogenous elevation of alpha- and beta-interferon but not to gamma-interferon. Although CCC have been seen and reported to occur in human and primate cells since the late 1970s, their presence did not arouse much clinical and scientific interest until 1983 when they were observed in lymph node tissues of AIDS patients. The nature and pathogenesis of TRS and CCC are obscure. Through the years, many hypotheses have been proposed. They range from suggestions of these structures being incomplete viral particles to being nothing more than accumulated proteins; and from reference to these structures as specific markers for diseases to a generalized cell reaction to certain biological stimuli. In vitro investigations with lymphoblastoid cell lines have contributed a great deal in illuminating the potential clinical significance and the in vivo inducer(s) of TRS and CCC. Both the TRS and CCC are now known to be induced in vitro by alpha- and beta-interferon in some lymphoblastoid cell lines. However, only TRS and not CCC are induced in healthy donor lymphocytes and endothelial cells. Isolation of TRS and CCC using the lymphoblastoid cell system will help clarify the nature, the pathogenesis, and the importance of TRS and CCC in human diseases.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Familial mesothelioma: a report of two families.

Five reports of familial mesothelioma in which mesotheliomas occurred in two or more family members have been recorded in the medical literature. In this report, we describe two examples of familial mesothelioma. In one family, three brothers who worked in the asbestos insulation industry developed mesothelioma. In the second family, the father, who was occupationally exposed to asbestos, died from a tubulopapillary peritoneal mesothelioma 11 years before his son died from an identical histologic type of peritoneal mesothelioma. Our report, as with those previously recorded, suggests that genetic factors may be important in the genesis of some mesotheliomas.

Adult↗
PubMed1989

Pulmonary histiocytosis X: comparison of radiographic and CT findings.

The authors retrospectively evaluated radiographs, computed tomographic (CT) scans, and results of pulmonary function tests (when available) for 17 patients with biopsy-proved pulmonary histiocytosis X. In 11 patients, high-resolution CT was used. In 12 patients, CT demonstrated cystic air spaces, usually less than 10 mm in diameter. In three of these 12, cysts were the only abnormality, but in six others, nodules (usually less than 5 mm in diameter) were also present. Two patients had only nodules and one, only emphysema. CT showed that many lesions that appeared reticular on plain radiographs were actually cysts. CT showed no central or peripheral concentration of lesions, but it did reveal that many small nodules were distributed in the centers of secondary lobules around small airways. CT findings correlated better with the diffusing capacity (rho = -0.71) than did the plain radiographic findings (rho = -0.57). Thus, CT was better than radiography at showing the morphology and distribution of lung abnormalities.

Adult↗
PubMed1988

Acute granulomatous interstitial nephritis due to co-trimoxazole.

A 51-year-old man with diabetes mellitus and mild hypertension developed acute interstitial nephritis 4 days after starting a course of co-trimoxazole for bronchopneumonia. Following initial symptoms of overt hypersensitivity, he developed azotemia and renal tubular dysfunction with malaise and anorexia requiring hospitalization. Renal pathology demonstrated an acute granulomatous interstitial nephritis superimposed on chronic diabetic renal disease.

Anti-Infective Agents↗
PubMed1987

Lung cancer classification: the relationship of disease extent and cell type to survival in a clinical trials population.

The staging and histologic cell type of patients in the Lung Cancer Study Group (LCSG) clinical trials program are reviewed and confirmed or resolved at the reference center for anatomic and pathologic classification of lung cancer. A high level of consistency in classification has been achieved through the use of criteria that minimize intraobserver variability. The data obtained from the review project have been used to characterize the relationship of disease extent and cell type to survival in the clinical trials population. Survival characteristics were generated for 1,121 patients who underwent apparent complete resection of nonsmall cell lung cancer and were subsequently entered into various protocols to receive either adjuvant treatment or no further therapy. The end results study provides some insight regarding the biological behavior of squamous cell carcinoma and adenocarcinoma of the lung in terms of the anatomic extent of disease at the time of apparent complete resection. Patients with squamous cell carcinoma had an outcome superior to that of patients with adenocarcinoma in every TNM subset. The differences in survival according to these major cell types were significant overall and in the T1 N0, T1 N1, and T2 N1 subsets but not in the TNM subsets in stage III disease. Histologic cell type and extent of disease are important factors in survival expectations; thus the accuracy and reproducibility of these classifications plays a significant role in the evaluation of differing modalities of treatment.

Actuarial Analysis↗
PubMed1987

Serosal tissue: reactive tissue as a model for understanding mesotheliomas.

Serosal tissues consist of a surface mesothelial layer and subsurface spindled connective tissue cells. Surface cells are decorated with antibodies to both low and high molecular weight cytokeratin whereas subserosal cells only express the intermediate filament vimentin. Serosal injury results in the proliferation of multipotential subserosal cells (MSC) which have the ultrastructural morphology of myofibroblasts and yet co-express low molecular weight cytokeratin and vimentin. These cells appear responsible for the re-establishment of surface mesothelium during which they acquire high molecular weight cytokeratin and loose vimentin. There are many parallels between reactive and neoplastic serosal tissues. Desmoplastic/sarcomatoid mesotheliomas resemble the MSC and co-express low molecular weight cytokeratin and vimentin and epithelial mesotheliomas resemble surface mesothelium and express both low and high molecular weight cytokeratin. The ability of normal serosal tissue to modulate its cell shape and intermediate filament expression helps understand the diversity of serosal tumors.

Antibodies↗
PubMed1986

Reactive and neoplastic serosal tissue. A light-microscopic, ultrastructural, and immunocytochemical study.

Normal and reactive non-neoplastic serosal tissues and a spectrum of serosal neoplasms were studied using light-microscopic, ultrastructural, immunocytochemical, gel electrophoretic, and immunoblot techniques. Normal surface mesothelium expressed both low- and high-molecular-weight cytokeratins, whereas the scattered submesothelial cells were decorated only with antibodies to vimentin. Reactive non-neoplastic subserosal cells, however, coexpressed both low-molecular-weight cytokeratin and vimentin and demonstrated the ability for surface differentiation during which higher-molecular-weight cytokeratins were acquired and vimentin was lost. The authors suggest the term "multipotential subserosal cells," recognizing the unique intermediate filament expression of reactive subserosal cells and the ability for surface differentiation. The intermediate filament expression of the sarcomatoid/desmoplastic mesotheliomas resembled the MSC, whereas epithelial mesotheliomas resembled surface mesothelium. These findings have potential usefulness for diagnostic pathology.

Carcinoma↗
PubMed1986

Sclerosing mesenteritis. Response to cyclophosphamide.

We present two patients with an aggressive form of sclerosing mesenteritis characterized by a progressive, life-threatening course, prominent retroperitoneal disease, and tubuloreticular structures in one case, an ultrastructural feature associated with autoimmune and cyclophosphamide-responsive diseases. In both patients, aggressive immunosuppressive medical therapy with cyclophosphamide resulted in prompt, dramatic improvement, without recurrence. When the diagnosis of sclerosing mesenteritis is established, we recommend early aggressive medical therapy with cyclophosphamide, particularly when tubuloreticular structures are present.

Administration, Oral↗
PubMed1985

Coexpression of intermediate filaments in human epithelial neoplasms.

A wide variety of human neoplasms were examined by immunocytochemical and ultrastructural techniques. In most, one intermediate filament (IF) type was expressed reflecting the tissue of origin. However, multiple classes of intermediate filaments were regularly found in a subgroup of these tumors. We chose to subdivide them into those with a complex or mixed growth pattern, and those which showed a more "monomorphic" histologic growth pattern. This latter group is the subject of this paper. Regular coexpression of cytokeratin and vimentin was observed in tumors of endometrial, thyroid, ovarian and renal origin, and coexpression of cytokeratin and neurofilament was observed in a subgroup of neuroendocrine tumors. Immunocytochemical/ultrastructural correlation demonstrated few, if any, observable intermediate filaments in tumors expressing only low molecular weight cytokeratin, whereas vimentin and neural filament characteristically were randomly dispersed or formed whorled bundles of cytoplasmic filaments. The potential diagnostic usefulness of these observations in surgical pathology is discussed.

Carcinoid Tumor↗
PubMed1985

Neuroendocrine skin carcinoma coexpressing cytokeratin and neurofilament proteins.

Neuroendocrine (Merkel cell) carcinomas of the skin have been recognized as such for several years. Given the reported wide variability in the morphology and clinical evolution of these tumors, the notion that may they comprise several variants rather than a single type has been advocated. Electron microscopy has played a key role in the early recognition of these tumors while immunohistochemical studies for various neuroendocrine markers have facilitated their subsequent diagnosis and improved our understanding as to their complexity by the demonstration of immunoreactivity for NSE (neuron specific enolase) and a number of neuropeptides. There has also been considerable interest in the study of the cytoskeletal intermediate filament complement of neuroendocrine neoplasms in general and of those of the skin in particular. Early reports indicated that neuroendocrine skin carcinomas had neurofilaments while subsequent investigations determined that they had cytokeratin. However, more recent studies have indicated that at least some neuroendocrine skin carcinomas could in fact coexpress both aforementioned classes of intermediate filament proteins. This brief report is presented to confirm the latter investigations.

Carcinoma↗