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Biomedical subjects

H Rosen

Publications and source records attributed to H Rosen.

At least 91 records · Page 5Linked to original sources

Protein tyrosine phosphatase inhibitors block myeloid signal transduction through the Fc gamma RI receptor.

Fc-receptor stimulation in certain myeloid cells results in an increase in oxygen consumption termed the respiratory burst. In this report we examine the effects of protein tyrosine phosphatase inhibitors on the Fc gamma receptor-induced myeloid respiratory burst. Antiphosphotyrosine immunoblotting of neutrophils stimulated with opsonized oil particles shows that Fc-receptor stimulation is associated with the tyrosine phosphorylation of cellular proteins. Pretreatment of neutrophils for 10 min with vanadate or phenylarsine oxide (PAO), protein tyrosine phosphatase inhibitors, augments tyrosine phosphorylation in response to Fc-receptor stimulation. Vanadate and PAO inhibit the respiratory burst in a dose-dependent fashion, but have no effect on Fc gamma receptor-mediated phagocytosis, suggesting that the inhibition of the respiratory burst is not due to a general inhibition of Fc gamma-receptor signaling. Neutrophil phagolysosomal membranes were isolated from vanadate-treated and control neutrophils after Fc-receptor stimulation show a reduction in protein tyrosine phosphatase activity and a reduction in the NADPH-dependent oxidase activity and contain greater amounts of phosphotyrosine, relative to control membranes. Vanadate did not inhibit the NADPH-oxidase directly or interfere with the superoxide assay. Vanadate and PAO also inhibited the respiratory burst of interferon-differentiated U937 cells in response to immune complex and Fc gamma RI crosslinking. Pretreatment of U937 cells with PAO completely blocks the serine phosphorylation of the gamma subunit of the Fc gamma R, a response that is associated with Fc gamma RI-receptor activation. The data supports the recent observation that CD45 modulates signal transduction through the Fc gamma RI receptor, suggesting that protein tyrosine phosphatases play a positive modulatory role in the signal relay pathway(s) involving the myeloid Fc gamma RI receptor, resulting in the phosphorylation of the gamma subunit and the activation of the NADPH-oxidase complex.

Amino Acid Sequence↗

Inactivation of Escherichia coli penicillin-binding proteins by human neutrophils.

Neutrophils use a variety of microbicidal mechanisms in their role as one of the primary arms of the human host defense system. We have previously observed that a cell-free system containing myeloperoxidase (MPO), one of the major components of the neutrophil's oxidative antimicrobial systems, inactivated microbial penicillin-binding proteins (PBPs), which mediate the formation of the peptidoglycan layer of eubacterial cell walls. This is a potentially important mechanism of MPO-mediated bacterial toxicity. Since numerous other microbicidal systems, both oxidative and nonoxidative, are used by whole neutrophils, we investigated the effect of intact neutrophils on Escherichia coli PBPs. Penicillin binding activity was progressively reduced by neutrophil exposure for all PBPs. Loss of penicillin binding activity correlated well with loss of microbial viability for almost all PBPs. Azide-treated neutrophils, MPO-deficient neutrophils, and chronic granulomatous disease neutrophils inactivated E. coli PBPs in a manner similar to that of normal neutrophils, suggesting that MPO-independent, and even oxygen-independent, microbicidal systems are also involved in inactivation of PBPs. PBP inactivation, an antimicrobial strategy used by beta-lactam-producing molds (and now by physicians), may be an important microbicidal mechanism used by human neutrophils.

Azides↗

Lipopolysaccharide induces proenkephalin gene expression in rat lymph nodes and adrenal glands.

The proenkephalin gene encodes a family of neuropeptides that was originally identified in brain tissue and adrenal glands. Recently, it was shown that proenkephalin is also expressed in cultured lymphoid cells. To elucidate the physiological significance of this expression, we examined the in vivo expression of proenkephalin in lymphoid tissues. We show here that exposing rats to the endotoxin lipopolysaccharide induces an intense and transient expression of proenkephalin in adrenal glands and lymph nodes. By using combined in situ hybridization and immunohistochemistry on tissue slices, we identified proenkephalin expression in macrophages located within the lymph nodes and in chromaffin cells within the adrenal glands. This in vivo expression of proenkephalin was enhanced by adrenaline. The present observations demonstrate that the immune system is a site of significant expression of proenkephalin and provide a basis for neuroimmune interactions.

Adrenal Glands↗

Increased erythrocyte sedimentation rate and a splenic mass.

This discussion was selected from the weekly Grand Rounds in the Department of Medicine, University of Washington School of Medicine, Seattle. Taken from a transcription, it has been edited by Jonathan G. Drachman, MD, Chief Medical Resident; Henry Rosen, MD, Professor and Associate Chair; and Paul G. Ramsey, MD, Professor and Chair of the Department of Medicine.

Adult↗

Benign colonic ulcers associated with nonsteroidal antiinflammatory drug ingestion.

Nonsteroidal antiinflammatory drugs can be associated with benign colonic ulcers. The ulcers are easily diagnosed by colonoscopy, and, if uncomplicated, they are best treated by cessation of the nonsteroidal antiinflammatory drugs. Benign colonic ulcers should be included in the differential diagnosis of any patient who presents with gastrointestinal complaints and is taking nonsteroidal antiinflammatory drugs.

Aged↗

Opioids modulate stress-induced proenkephalin gene expression in the hypothalamus of transgenic mice: a model of endogenous opioid gene regulation by exogenous opioids.

Stressful stimuli strongly induce proenkephalin gene expression within the paraventricular nucleus (PVN) of the hypothalamus. A human proenkephalin-beta-galactosidase fusion gene has previously been shown to give correct phenotypic expression and appropriate stress regulation within the hypothalamus of transgenic mice; this model provides high sensitivity, cellular resolution, and ready quantification of levels of proenkephalin gene expression. Here we describe use of this transgenic model to study modulation of stress-regulated gene expression in the PVN by opiates. Acute or subacute morphine administration prior to a hypertonic saline stress produced marked superinduction of transgene expression compared with hypertonic saline stress alone. In contrast, chronic morphine administration decreased basal expression of the transgene, and inhibited stress-induced expression of the transgene. The endogenous proenkephalin mRNA was induced in parallel with the transgene as demonstrated by in situ hybridization; the immediate-early gene c-fos was also regulated in parallel with the transgene. These data suggest that acute or subacute morphine administration sensitizes proenkephalin neurons within the PVN and other regions of the hypothalamus to stress and that chronic morphine administration desensitizes this response. Because the molecular mechanisms regulating the expression of the transgene are well understood, this model provides a useful tool for investigating cellular and molecular effects of opioids on the hypothalamus.

Animals↗

Anti-CD11b antibody prevents immunopathologic changes in viable moth-eaten bone marrow chimeric mice.

The effect of in vivo treatment with anti-CD11b (MAC-1) antibody (Ab) was examined in an inflammatory disease model, the viable moth-eaten (mev) mutant mouse. The autosomal recessive mev gene occurred spontaneously as a point mutation of the hematopoietic cell protein tyrosine phosphatase in C57BL/6 mice. Homozygotes (mev/mev) develop a chronic myelomonocytic inflammation, involving accumulation of myelomonocytic cells in lungs and skin, resulting in interstitial pneumonitis and severe edema in the paws. These mice also exhibit abnormalities in lymphoid development, thymic atrophy, with T cell and NK cell dysfunction. These inflammatory changes are transferrable by bone marrow cells of mev/mev mice, indicating that mev mutation is due to a stem cell defect in the myelomonocytic pathway. An anti-CD-11b (5C6) Ab inhibited the immunopathologic changes in the bone marrow chimeras, when the Ab treatment was initiated on day -1 or day 0 of the bone marrow transplant. The lungs, paws, and thymus all remained normal after treatment. Furthermore, the Ab also delayed the onset of the mev syndromes when the Ab was given 10 days after the bone marrow transfer. Therefore anti-CD11b Ab inhibited inflammation both prophylactically and therapeutically, and restored normal function of T and NK cells in this disease model. These results support the contention that CD11b molecules expressed in the myelomonocytic cells play a critical role in this naturally occurring inflammatory disease.

Animals↗

Formation of eosinophilic and monocytic intradermal inflammatory sites in the dog by injection of human RANTES but not human monocyte chemoattractant protein 1, human macrophage inflammatory protein 1 alpha, or human interleukin 8.

Equilibrium binding studies on canine mononuclear and granulocytic cells allow the identification of a single high affinity receptor for the human C-C chemokine RANTES (dissociation constant, 14 +/- 8 pM), that, in contrast to the human RANTES receptor, has no affinity for human macrophage inflammatory protein 1 alpha (hMIP-1 alpha). A single intradermal injection of hRANTES in dog resulted in eosinophil- and macrophage-rich inflammatory sites within 4 h. Cell infiltration peaked at 16-24 h after hRANTES injection. There was histological evidence of intravascular activation of eosinophils at 4 h, although eosinophils in the vasculature and interstitium contained apparently intact granules. Monocytes were the predominant cells adherent to venular endothelium at 16-24 h. Human MIP-1 alpha elicited no response in canine dermis, whereas monocyte chemoattractant protein 1 caused mild perivascular cuffing with monocytes. In contrast, human interleukin 8 induced a neutrophilic dermal infiltrate that was maximal by 4 h after challenge. This provides the first direct evidence in vivo that RANTES has significant proinflammatory activity and, in addition, could be a mediator in atopic pathologies characterized by eosinophilic and monocytic inflammatory responses.

Animals↗

A phase I-II study of epirubicin, 5-fluorouracil, and leucovorin in advanced adenocarcinoma of the stomach.

BACKGROUND: To determine the maximum tolerated dose of epirubicin for use in combination with 5-fluorouracil (5-FU) and low-dose leucovorin (LV), a Phase I-II trial was conducted in 37 patients with advanced gastric carcinoma. METHODS: The doses of 5-FU (425 mg/m2) and LV (20 mg/m2), both given intravenously on days 1-5, were held constant while the dose of epirubicin was escalated in cohorts of patients (beginning dose, 50 mg/m2 on day 1). Cycles were repeated every 4 weeks. RESULTS: Significant gastrointestinal symptoms and myelosuppression were observed infrequently at the initial dose level. At a dose of 60 mg/m2 of epirubicin on day 1, however, five of eight patients had significant mucosal toxic effects during the first cycle of therapy. In addition, two patients treated at this dose level had Grade 4 granulocytopenia with insufficient recovery to permit a second course by day 28, and one patient each had severe diarrhea and nausea and vomiting. Among 37 patients with assessable disease, there were 3 complete and 11 partial responses (response rate, 38%). CONCLUSIONS: LV modulation of 5-FU can be incorporated safely into combination chemotherapy with epirubicin and provides a relatively active regimen for treatment of disseminated gastric cancer.

Adenocarcinoma↗

Randomised comparison of combination chemotherapy plus supportive care with supportive care alone in patients with metastatic colorectal cancer.

OBJECTIVES: To compare the length of survival and quality of life in patients given combination chemotherapy in addition to supportive care and in patients given only supportive care. DESIGN: Randomised study. SETTING: Gastrointestinal oncology departments. PATIENTS: 40 previously untreated patients with histologically confirmed, measurable colorectal cancer that was locally recurrent or metastatic. INTERVENTIONS: Patients were allocated randomly to receive chemotherapy or only supportive care in a ratio of 2:1 according to performance status, metastatic disease of the liver, and weight loss in the six months before entering the study. Chemotherapy consisted of four week cycles of intravenous leucovorin (200 mg/m2/day) followed by 5-fluorouracil (550 mg/m2/day) and cisplatin (20 mg/m2/day), each drug being given on the first four days of the cycle. MAIN OUTCOME MEASURES: Length of survival and quality of life score with an optimised functional living index-cancer scale. RESULTS: Overall survival was significantly longer for patients given chemotherapy (11.0 months) than for those receiving supportive care alone (5.0 months; p = 0.006). Despite common association of chemotherapy with mild to moderate gastrointestinal symptoms, there was no significant difference between the two groups in global or subgroup quality of life scores. In patients with abnormal scores before treatment, quality of life seemed better in the chemotherapy arm. CONCLUSIONS: In this sample of patients with disseminated colorectal cancer the chemotherapy regimen was an effective form of palliative treatment.

Adenocarcinoma↗

Characterization and species distribution of high affinity GTP-coupled receptors for human rantes and monocyte chemoattractant protein 1.

Equilibrium binding studies with recombinant human chemoattractant cytokines Rantes and monocyte chemoattractant protein 1 (MCP-1) on monocytic THP-1 cells have allowed the functional identification of two distinct receptors for C-C chemokines. One is a novel oligospecific receptor with high affinity for Rantes (50% maximal inhibitory concentration [IC50], 0.68 nM) and low affinity (IC50, 35 nM) for MCP-1, while the other is the previously described specific receptor for MCP-1 (IC50, 0.5 nM). Receptor affinity for Rantes is enhanced on preparation of isolated membranes with a 12-fold decrease in receptor Kd. The basis of this enhancement is not understood. The Rantes receptor appears to be G protein linked, as binding activity is abolished by guanosine 5'-O-(3-thiotriphosphate) (IC50, 7.3 nM). In contrast to the consequences of MCP-1 binding, we were unable to demonstrate ligand-dependent calcium fluxes on binding of Rantes to human monocytes or THP-1 cells. The binding of Rantes and MCP-1 to mononuclear cells from dog, rabbit, and rat were tested. While high affinity binding could be demonstrated in dog and rabbit, differences in ligand-induced Ca2+ fluxes could be shown between species. This suggests that receptor-ligand interactions and receptor coupling is best examined with autologous receptors and cytokine.

Animals↗

Immunohistochemical and biochemical measurement of estrogen and progesterone receptors in primary breast cancer. Correlation of histopathology and prognostic factors.

OBJECTIVE: The authors investigated correlations of estrogen-receptor and progesterone-receptor with conventional risk factors as well as histopathology in patients with primary breast cancer. SUMMARY BACKGROUND DATA: Immunohistochemically determined hormone receptors have gained importance as prognosticators in primary breast cancer, but their definitive role has not yet been evaluated. METHODS: Tumor samples from 299 patients were examined for estrogen and progesterone receptors by biochemical and immunohistochemical assay. Correlations with established risk factors (tumor size, lymph node status, menopausal status, grading including subfactors) and histopathology were analyzed. RESULTS: The estrogen receptor, determined by immunohistochemical method revealed positivity in 80.6% of patients; biochemical measurement yielded 76.2% positive results. The progesterone receptor measured by immunohistochemistry yielded 61.3% positivity versus 55.8% detected by biochemical analysis. Invasive lobular, tubular, and ductal invasive carcinoma with prominent stroma content ("scirrhous carcinoma") rather than ductal invasive carcinoma was more frequently estrogen-receptor positive with immunohistochemistry than with biochemical assay. For progesterone receptor, the same pattern of positivity was seen with immunohistochemical assay. With progesterone receptor determined biochemically, "scirrhous" and lobular carcinoma showed positive results in a lower proportion than invasive ductal and tubular carcinoma. Significant correlations were observed between the estrogen-receptor status, the histologic grade of malignancy, nuclear polymorphism, and the rate of mitosis with both methods (p < 0.001 respectively). Different correlations were found between tumor size, menopausal status and estrogen receptor status with both assays respectively. For the progesterone receptor status, immunohistochemistry yielded significant correlations with the histologic grade of malignancy, nuclear polymorphism, rate of mitosis (p < 0.001 respectively) as well as growth pattern (p < 0.01), while biochemical analysis revealed a correlation with nuclear polymorphism (p < 0.05). The correlation analysis of both components of the immunoreactive score revealed a more significant impact of percentage of positive cells than of staining intensity. CONCLUSIONS: Immunohistochemistry detected a closer correlation between prognostic factors and receptor data than biochemical analysis.

Adult↗

Effector role of blood monocytes in experimental visceral leishmaniasis.

In BALB/c mice, liver granulomas provoked by visceral infection with intracellular Leishmania donovani are rapidly populated by influxing blood monocytes. To determine the host defense effector role of these mononuclear phagocytes, we treated three populations of infected animals with 5C6, an anti-type 3 complement receptor monoclonal antibody (MAb), which inhibits monocyte recruitment into inflamed tissues. In naive BALB/c mice, injections of 5C6 impaired the initial acquisition of antileishmanial resistance and arrested the development of mature liver granulomas. In sensitized mice with established immunity, both resistance to rechallenge and accelerated granuloma formation were similarly inhibited by MAb administration. Finally, in naive mice, 5C6 MAb also abolished the antileishmanial activity induced by treatment with the macrophage-activating lymphokine gamma interferon. Together, these results suggest a key effector role for the influxing blood monocyte in both initial and established antileishmanial defense and granuloma assembly and in the infected liver as the mononuclear phagocyte target for the antimicrobial effects of gamma interferon.

Animals↗

Endocarditis caused by Rochalimaea quintana in a patient infected with human immunodeficiency virus.

Rochalimaea quintana and Rochalimaea henselae are closely related, fastidious, gram-negative rickettsiae. Thus far, the spectrum of human Rochalimaea sp. infections has not included endocarditis. We describe a 50-year-old human immunodeficiency virus-positive man who developed endocarditis caused by R. quintana. DNA relatedness studies, which compared our patient's blood culture isolate with known Rochalimaea species, identified the organism as R. quintana. Our report expands the spectrum of Rochalimaea sp. infections and identifies a new infectious cause of endocarditis.

DNA, Bacterial↗

Effective treatment of the pulmonary fibrosis elicited in mice by bleomycin or silica with anti-CD-11 antibodies.

We treated two types of experimental pulmonary fibrosis elicited in mice by the intratracheal instillation of bleomycin or silica with monoclonal antibodies (mAbs) specific for the leukocytic integrins CD-11a or CD-11b. This treatment completely prevented collagen deposition, as measured by lung hydroxyproline content on Day 15 after instillation. Furthermore, anti CD-11a mAb was also effective when given on Days 20 and 25 and the lung hydroxyproline content determined on Day 30 after instillation, i.e., in the treatment of an established pulmonary fibrosis. Histologic studies indicated that anti CD-11 mAbs attenuated the fibrosing alveolitis induced by silica or bleomycin and in addition markedly decreased the lymphoid infiltration and platelet microthrombi associated with both types of alveolitis. In contrast, these mAbs had little or no effect on the cellularity of the bronchoalveolar lavage, mainly composed of macrophages. In normal mice, anti CD-11 mAbs also decreased the number of interstitial lymphocytes and the lung collagen content. These observations may lead new to therapies for pulmonary fibrosis.

Animals↗

Intrapleural streptokinase as adjunctive treatment for persistent empyema in pediatric patients.

Successful treatment of persistent empyema by intrapleural streptokinase is described in five pediatric patients. Their ages ranged from 18 months to 7 years. All experienced dramatic improvement in the resolution of their empyemas following intrapleural streptokinase. Improved chest tube drainage occurred concurrently with clinical improvement. Intrapleural instillation of streptokinase appears to be a safe adjunctive therapeutic tool to facilitate drainage of persistent empyema in the small number of pediatric patients in whom it has been employed. Additional study will be required to further assess the long-term therapeutic efficacy and consequences of intrapleural streptokinase therapy.

Chest Tubes↗

Monoclonal antibody against CD11b/CD18 inhibits endotoxin-induced uveitis.

PURPOSE: To examine the serial expression of cell adhesion molecules in C3H/HeN mice with endotoxin-induced uveitis, and to study the effect of treatment with a monoclonal antibody against Mac-1 on the development of endotoxin-induced uveitis. METHODS: Immunohistochemical staining was used to document the serial expression of Mac-1, intercellular adhesion molecule-1 (ICAM-1), and lymphocyte function-associated antigen-1 (LFA-1) in eyes of C3H/HeN mice with endotoxin-induced uveitis. Then, in two separate experiments, endotoxin-induced uveitis was produced in a total of 48 mice by injecting Salmonella typhimurium endotoxin into one hind footpad. At the time of endotoxin injection, 24 mice received an intraperitoneal injection of anti-Mac-1 antibody and 24 control mice received an intraperitoneal injection of rat IgG. Histopathologic sections of eyes taken 24 hours after endotoxin injection were graded by two masked observers on a scale of 0 to 4. RESULTS: Intercellular adhesion molecule-1 was first expressed on the ciliary body epithelium 6 hr after endotoxin injection and Mac-1 and LFA-1 were expressed on infiltrating inflammatory cells 12 hr after endotoxin injection. Treatment with anti-MAC-1 antibody significantly inhibited the development of ocular inflammation when compared with treatment with control IgG (P < 0.001). CONCLUSION: Intercellular adhesion molecule-1 is expressed in the eye before clinical or histologic signs of inflammation. Furthermore, treatment with antibody against Mac-1 significantly inhibits the development of endotoxin-induced uveitis in mice and suggests that anti-Mac-1 antibody may be useful for treating acute ocular inflammation.

Animals↗