Histopathology of typhoid enteritis: morphologic and immunophenotypic findings.

Enteric fever is a systemic illness caused by Salmonella infection, with S. typhi, S. paratyphi, and S. enteritidis being the most common serotypes. Humans are the only reservoir for S. typhi, and its predilection for the ileum is due to the fact that organisms enter the body by translocation across specialized Peyer's patch epithelium and then proliferate in the mucosal macrophages. The lesions in bowel and mesenteric lymph nodes are distinctive and mimic Kikuchi-Fujimoto disease and Rosai-Dorfman disease as well as infections caused by some non-salmonella bacteria. The four cases presented in this report, two culture-confirmed, all exhibited ileal mucosal hypertrophy caused by a neutrophil-poor monocyte/macrophage-rich hyperplasia. Though diffuse areas were present, much of the lesional proliferation was nodular, representing macrophage infiltration and colonization by the monocytes and macrophages. Immunophenotypic studies, which showed a CD68+, lysozyme+, UCHL-1+, OPD4-, CD4-, s100- profile, were helpful in distinguishing these lesions from other processes, including Kikuchi-Fujimoto disease and Rosai-Dorfman disease. Although rare in developed countries, enteric fever should be considered in any patient with recent travel to endemic areas and in the context of illness thought to be related to contaminated foods.

Cysticercosis in Nepal: a histopathologic study of sixty-two cases.

Human cysticercosis, an infection caused by larvae of Taenia solium, is a major public health problem in many developing countries. Sixty-two of 23,402 biopsy cases have been detected as cysticercosis in the last 5 years in Patan Hospital. Most (82%) of the patients presented with solitary skin nodules, another 10% with nodules in the oral mucosa, and 8% in the breast. Forty cases were identified from the Kathmandu valley and the rest from outside Kathmandu. Most patients were younger than 30 years of age (mean, 21+/-11 years). Statistically, there was no difference between males (0.28%) and females (0.24%). The average size of cysticercosis was 19 mm in diameter, and the histology of cysticercosis showed fibrous walled cysts covered by several layered epithelioid cells with a few Langhans' giant cells and infiltration of eosinophils without caseous necrosis. These cysticercosis findings from an endemic area will be helpful for doctors who examine immigrant patients in nonendemic areas.

Squamous cell carcinoma of the foot arising in chronic ulcers in leprosy patients.

Squamous cell carcinoma (SCC) of the foot is a rare sequelae of chronic ulceration secondary to leprosy neuropathy. Most of the tumours are relatively slow growing and tend to metastasize late. Survival after local excision is generally good. In this series of 17 patients so far there have been 3 deaths attributable to SCC, all of whom presented with locally advanced tumours and lymph node metastasis.

Cytochrome P450 2B1 immunoreactivity in bronchiolar and alveolar epithelial cells after exposure of rats to ozone.

Pulmonary cytochrome P450 (P450) plays an important role in the metabolism of xenobiotics. We have previously demonstrated that exposure to ozone (O3), a major oxidant of photochemical smog, increases P450 content and xenobiotic metabolizing activities in the rat lung. Therefore, it is conceivable that O3 exposures modify the pattern and potency of xenobiotic metabolism. The aim of this study is to examine the effect of O3 exposure on localization of P450 in the lung. After exposure of rats to 0.4 ppm O3 for 14 days, the concentration of P450 2B1, the main isozyme of P450 in the lung, increased to 214% of the control value. By immunohistochemical analyses, O3 exposure caused hypertrophy and hyperplasia of P450 2B1-positive non-ciliated bronchiolar epithelial (Clara) cells, showing an increase in the cell number to 128% of the control level. At the proximal alveoli, O3 exposure induced hypertrophic epithelial cells that presented immunoreactivity to P450 2B1 and morphological characteristics of both type 1 and type 2 cells. These hypertrophic cells had lamellar inclusion bodies, microvilli, and extended cytoplasm. Typical type 2 cells did not react with anti-P450 2B1 antibody even after O3 exposure. These data suggest that O3 exposure may activate the P450-mediated xenobiotic metabolism in the pulmonary epithelial cells, and that expression of P450 2B1 in the pulmonary epithelial cells might be regulated by the factors involved in the process of the differentiation from type 2 to type 1 cells.

The role of complement-derived chemotactic factors in lung injury induced by preformed immune complexes.

Our previous studies have suggested a role for complement fragments presumably activated by immune complexes in patients with hypersensitivity pneumonitis. The present study has shown that circulating complement depletion by cobra venom factor resulted in the reduction in severity of immune-complex-mediated pulmonary inflammation. The activity of chemotactic factors for neutrophils generated in bronchoalveolar lavage fluids in complement-depleted animals was significantly diminished to 61.2% compared to the undepleted animals. In addition, reduced activity of chemotactic factors resulted in a marked reduction of accumulation of neutrophils in bronchoalveolar lavage fluids indicating that chemotactic factors play an important role in the sequestration of neutrophils on the alveolar side of the lung. In conclusion, chemotactic factors in bronchoalveolar lavage fluids which preceded the accumulation of polymorphonuclear cells are partially derived from complement.

[A case of endobronchial minute leiomyoma and literature review of the 66 cases of endotracheal and endobronchial leiomyoma reported in Japan].

A case of endobronchial minute leiomyoma successfully treated by bronchoscopically directed forceps biopsy is described. A 42-year-old male with a 20 pack-year smoking history was admitted for dry cough occurring at night. Chest X-ray showed no abnormal shadows. The tumor, measuring 2 by 2 mm, was located in the right B7. The clinical characteristics of the 66 cases of endotracheal and endobronchial leiomyoma reported in Japan are also discussed. The male to female ratio of this disease was 2:3. Middle-aged people were most, commonly affected. Usually, obstructive pneumonia or atelectasis, which develops distal to the lesion, causes respiratory symptoms and chest X-ray abnormality. However, 10% of cases were asymptomatic and 30% had a negative chest X-ray. There were 7 cases of endobronchial minute leiomyoma, measuring less than 10 mm in diameter. Of these, three cases had only hemoptysis and had no chest X-ray abnormality. In such cases fiberoptic bronchoscopy is may be the only useful procedure for the diagnosis of this disease.

Hypersensitivity pneumonitis induced by hexamethylene diisocyanate.

A case of hypersensitivity pneumonitis (HP) induced by hexamethylene diisocyanate (HDI) is described. Serial determinations of the lymphocyte surface phenotypes by two-color assay revealed the following: 1) increased activated cytotoxic T lymphocytes in the bronchoalveolar lavage fluid (BALF), and 2) increased percentage and absolute number of non-major histocompatibility complex (MHC)-restricted natural killer (NK) cells in the peripheral blood (PB) during the recovery phase of the disease. These findings were considered to be related to the activity of the disease.

Interstitial lattice shadow and mediastinal lymphadenopathy with an elevation of carcinoembryonic antigen in severe pulmonary alveolar proteinosis.

A case of severe pulmonary alveolar proteinosis (PAP) with interstitial involvement, mediastinal lymphadenopathy and an elevation of carcinoembryonic antigen (CEA) in the bronchoalveolar lavage (BAL) fluid and the serum is presented. Alveolar macrophages may play a major role in these rare and seemingly unrelated findings.

Electron-microscopic evidence for cytochrome P-450 in Clara cells and type I pneumocytes of the rat lung.

Using immunoelectron microscopy, we examined the distribution of cytochrome P-450 in rat lungs and determined the cell types in which P-450 was localized. To demonstrate P-450, a rabbit polyclonal antibody against P-450b (P-450 IIB1), the major constitutive isozyme of rat pulmonary P-450, was used. Strong reactivity for anti-P-450b antibody was observed in nonciliated bronchial and bronchiolar epithelial cells (Clara cells) and type I pneumocytes. Type II pneumocytes and Kultschitzky cells showed no reactivity. Most ciliated cells were negative, although a small number in peripheral bronchioles showed a weakly positive reaction. Endothelial cells and other mesenchymal cells were P-450b negative. Many studies have suggested that the Clara cell was metabolically very active and had P-450 containing mixed function oxidase systems. Our study shows that both Clara cells and type I pneumocytes have P-450 and may play an important role in the metabolism of xenobiotics. The metabolic significance of type I pneumocytes was not recognized, but it is reasonable to postulate that type I pneumocytes may have a xenobiotic metabolic function because they comprise most of the surface area of the lungs and are thus extensively exposed to the environment.

Case report of desquamative interstitial pneumonia: documentation of preserved pulmonary function after twelve clinical relapses.

We describe a case of desquamative interstitial pneumonia diagnosed in a 25-year-old woman who relapsed 12 times during a 20-year follow-up period. In each relapse, the involved sites were different and the patient ultimately recovered without resultant pulmonary ventilatory defects. Bronchoalveolar lavage performed during the 12th relapse revealed a remarkable increase in the number of total cells and showed a low CD4+/CD8+ ratio in the lymphocyte subset.

A case of bronchiolitis obliterans organizing pneumonia associated with primary Sjögren's syndrome who died of superimposed diffuse alveolar damage.

Bronchiolitis obliterans organizing pneumonia (BOOP) developed in association with primary Sjögren's syndrome in a 69-year-old female. She died of diffuse alveolar damage superimposed on BOOP in spite of corticosteroid therapy.

A case of cyclophosphamide-induced interstitial pneumonitis diagnosed by bronchoalveolar lavage.

A successfully treated case of cyclophosphamide pneumonitis, which developed during treatment for a leukemic phase of B-cell non-Hodgkin's lymphoma, is documented. Subtyping of lymphocytes in the peripheral blood and the bronchoalveolar lavage fluid easily excluded a possible diagnosis of pulmonary involvement of lymphoma. Bronchoalveolar lavage is a useful approach to determine the correct etiology of pneumonitis.

Alteration in surface structure of Clara cells and pulmonary cytochrome P-450b level in rats exposed to ozone.

Changes in the surface structure of Clara cells in the terminal bronchioles following exposure of rats to 0.4 ppm ozone (O3) for 14 days were evaluated and compared to the content of pulmonary cytochrome P-450, an enzyme active in xenobiotic metabolism. Exposure to O3 caused a striking alteration of Clara cells in the terminal bronchiole. After 6 h exposure apical protrusions of Clara cells enlarged and these Clara cells formed clusters. However after 24 h exposure, the Clara cells decreased in number and flattened. They increased in number and enlarged again during the subsequent period of exposure. By the 14th day of O3 exposure the number of Clara cells had increased significantly. The content of cytochrome P-450b (IIB1), a main isozyme of pulmonary cytochromes P-450 of rats, was determined by an immuno-blotting method using anti-cytochrome P-450b antibody. The cytochrome P-450b in the rats exposed to O3 increased significantly to 1.37- and 1.81-times that of the control on the 7th and 14th days, respectively. Immuno-electron microscopy demonstrated that cytochrome P-450b was localized abundantly in endoplasmic reticulum of Clara cells. Morphological alterations in Clara cells appear to be closely related with changes in the cytochrome P-450b content of the lung.

Sequential changes in lung injury induced by preformed immune complexes.

Immune complexes formed in the airside may be involved in the early parenchymal changes in hypersensitivity pneumonitis. The present study was undertaken to compare the responses of animals after an intratracheal injection with preformed immune complexes to those of patients with acute hypersensitivity pneumonitis, with special emphasis on sequential bronchoalveolar lavage findings and the possible role of chemotactic factors in the immune complex-induced lung injury. An increased number and percentage of polymorphonuclear cells could be detected in bronchoalveolar lavage fluids of guinea pigs within 48 hr following an intratracheal injection of preformed immune complexes. Chemotactic factor activity preceded the observed increase of polymorphonuclear cells in bronchoalveolar lavage fluids, suggesting a role for chemotactic factors in the sequestration of these cells in the lung. In addition, this study confirmed the usefulness of bronchoalveolar lavage in evaluating the pulmonary findings because the changes in bronchoalveolar lavage cell populations correlated with sequential histological findings. The sequential characteristics of the involved areas were noted to be of a peribronchial or bronchiolar infiltration with polymorphonuclear cells at early stages, then alveolar sac infiltration, followed by mild infiltration of mononuclear cells into the alveolar walls. The findings suggest a possible role for chemotactic factors in the accumulation of polymorphonuclear cells, and the sequential changes of bronchoalveolar lavage and histological findings in animals are comparable to those in patients with acute hypersensitivity pneumonitis.

Pulmonary clear cell carcinoma.

A case of pulmonary clear cell carcinoma is demonstrated. A large left lower lobe mass, without lymphadenopathy was detected on a screening chest X-ray, and a left lower lobectomy was performed. The tumor was composed predominantly of clear cells with some areas showing cells typical for small cell carcinoma. Ultrastructurally, the larger clear cell had cytoplasm containing many rough endoplasmic reticuli and free ribosomes, while the smaller dark cell showed a serrated nucleus and scanty cytoplasm having many free ribosomes without neurosecretory granules. This is the first report on pulmonary clear cell carcinoma with small cell carcinoma patterns, and this case will throw doubt on the conclusion of previous studies that clear cell carcinoma is not a separate entity.

Pleural mesothelioma after neighborhood exposure to asbestos during childhood.

A 38-year-old woman with pleural mesothelioma who had a history of neighborhood asbestos exposure during her childhood was demonstrated. She had no known history of occupational asbestos exposure. This is the first case of mesothelioma with neighborhood asbestos exposure reported in Japan. Previously-reported cases of mesothelioma with neighborhood asbestos exposure in the English language literature were reviewed.

A case of 'bronchial string'--a rare anomaly of the bronchus.

An incidental string-like structure spanning the lumen of the intermediate bronchus was found during bronchoscopy in an 18-year-old woman. We consider that the lesion may be a rare fibrous anomaly of the bronchus and may be closely related to a bronchial web. We have named this unusual structure 'bronchial string'.

Minute squamous cell carcinoma arising in the wall of a congenital lung cyst.

A case of minute squamous cell carcinoma arising in a congenital lung cyst is reported. Two aspects of this case were notable. First, we were able to make the diagnosis of squamous cell carcinoma by bronchial lavage at an early stage. Second, to our knowledge, this is the first case of probable de novo origin of squamous cell carcinoma in a congenital lung cyst.