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Biomedical subjects

R Oren

Publications and source records attributed to R Oren.

At least 91 records · Page 5Linked to original sources
PubMed1991

Follicular lymphoma: a model of lymphoid tumor progression in man.

Human follicular lymphoma can be viewed as a malignancy in evolution. Since this disease is composed of a clonal population of B lymphocytes all expressing a given immunoglobulin light chain and heavy chain, it seems possible that the initial transforming event, the t(14; 18) chromosomal translocation, occurs in a cell already committed to the expression of a particular VH and VL gene. A panel of antibodies has been assembled which define a set of idiotypes expressed repeatedly by B-cell lymphomas. Nonetheless, VH gene usage in follicular lymphoma tumors appears to reflect the normal B-cell repertoire. Growth of follicular lymphoma appears to be partially under normal regulatory control. The expanding malignant B-cell clone grows in follicles with particular apposition to follicular dendritic cells and heavy infiltration with CD4+ T cells. Interaction with T cells can induce the proliferation of follicular lymphoma cells. This tumor eventually evolves into a diffuse large-cell lymphoma which is highly aggressive and lethal. It is now clear that the malignant progression occurs from a single cell within the expanding follicular lymphoma clone. A panel of monoclonal antibodies to cell surface molecules has been generated that inhibit proliferation of diffuse lymphoma cell lines, and some of the target molecules have been partially characterized. Therapeutic application of anti-idiotype monoclonal antibodies has shown a high degree of tumor responsiveness, but ultimately escape of idiotype-negative variant cells occurs. These variants arise as a result of extensive somatic point mutation in the VH and VL genes of follicular lymphoma. Active immunization can result in an immune response by patients directed against the idiotype expressed on their own B-cell tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Communication↗
PubMed1991

Oral contraceptive-induced esophageal ulcer. Two cases and literature review.

Two patients with esophageal ulcers following ingestion of oral contraceptives are presented. Without discontinuing the drug, but providing that the pills were correctly ingested, the ulcers completely healed. This new adverse side effect of oral contraceptive emphasizes once more what appears to be a never-ending problem due to the lack of awareness of the prescribing physician.

Adult↗
PubMed1991

Visceral leishmaniasis: a difficult diagnosis and unusual causative agent.

In a young man who had a prolonged fever of unknown origin, hepatosplenomegaly, and progressive pancytopenia, stained smears, blood-agar cultures of bone marrow, and serologic testing for antileishmanial antibodies were negative. Biopsies from liver and bone marrow were uninformative. Visceral leishmaniasis was diagnosed only after splenectomy, when amastigotes were finally cultured from the spleen. The parasite was shown to be an unusual leishmanial parasite, possessing a mixture of intrinsic biochemical and serologic characteristics displayed independently by Leishmania tropica and Leishmania donovani sensu lato, the latter being the usual cause of visceral leishmaniasis. After splenectomy, parasites were also demonstrated in stained bone marrow aspirate smears. Recovery was uneventful after treatment with antimony for 28 days. Visceral leishmaniasis can be a cause of fever of unknown origin and should be considered in its differential diagnosis in endemic areas.

Adult↗
PubMed1991

Undetectable caeruloplasmin values in a patient with autoimmune chronic active hepatitis.

Caeruloplasmin is an alpha 2 protein produced in the liver that is responsible for transporting copper in the blood. Caeruloplasmin values are usually high in patients with chronic liver diseases, including chronic active hepatitis: low values, however, are characteristic of Wilson's disease. The case of a 17 year old woman with very low caeruloplasmin values and chronic active hepatitis of the lupoid type is described. Steroid treatment resulted in an increase in the caeruloplasmin concentration and clinical improvement.

Adolescent↗
PubMed1991

Localized primary sclerosing cholangitis mimicking a cholecystectomy stricture relieved by an endoprosthesis.

Primary sclerosing cholangitis presenting as a localized stricture affecting a segment of the extrahepatic biliary tree is rarely found. We describe the case of a 39 year old woman with obstructive jaundice, in whom this diagnosis was proven by endoscopic retrograde cholangiography. An endoprosthesis was endoscopically introduced through the stenotic area which led to a dramatic improvement enabling a successful liver transplantation after 2 years.

Adult↗
PubMed1991

Etiology, treatment, and prognosis of large pericardial effusions. A study of 34 patients.

During the last 20 years, only a few studies have been published concerning large pericardial effusion. We recently reviewed 34 patients who presented with large pericardial effusion not associated with trauma. Our analysis revealed that half of the patients (52 percent) had pericardial effusion of unknown origin. Four patients had postmyocardial infarction pericardial effusion, three had associated malignant neoplasms, three suffered from collagen diseases, and two had infectious agents. Uremia and irradiation accounted for a single case each. Twenty-seven (79 percent) of the patients underwent pericardiocentesis and two (5.8 percent) had a pericardial window operation. The overall prognosis of the patients was excellent.

Adult↗
PubMed1991

Acute pericarditis: etiology, treatment and prognosis. A study of 115 patients.

One hundred and 15 hospitalized patients with acute pericarditis were analyzed retrospectively for their etiology, management and long-term prognosis. It was found that most of the patients had either idiopathic or viral etiologies (60%), collagen disease (16.4%) or malignancy (6.9%). Most of the patients were treated with non-steroidal anti-inflammatory drugs (NSAID). Twenty-six patients (22%) required corticosteroids following NSAID treatment failure. Only one patient underwent pericardiocentesis for tuberculous pericarditis. The long-term prognosis was good, although 21.9% of the patients suffered from recurrent episodes of pericarditis. It is concluded that in hospitalized patients with pericarditis, an extensive workup may not reveal the major etiologies, and the disease may be more complicated than previously thought.

Acute Disease↗
PubMed1991

Elevated creatine phosphokinase and creatine phosphokinase-MB in acute laryngitis.

Elevated creatine phosphokinase (684 mU/ml) and creatine phosphokinase-MB (3.5%, 23.9 mU/ml) were observed in a 66 year old female with acute laryngitis. The patient had received L-thyroxine because of hypothyroidism for 10 years and her T3 and TSH levels were normal. Acute myocardial infarction was denied by repeated EKG findings. The mechanisms of the enzyme abnormality were discussed.

Aged↗
PubMed1990

Autonomous replication sequences in an extrachromosomal element of a pathogenic Entamoeba histolytica.

Entamoeba histolytica possesses a 24.5 kilobase plasmid-like molecule which encodes for the organism's ribosomal RNAs. Sequence analysis of this extrachromosomal element revealed the presence of AT rich sequences which show homology to the origin of replication of other lower eucaryotes. An 802 bp fragment containing these sequences was cloned into a yeast shuttle vector lacking the origin of replication and the construct tested for its ability to replicate autonomously in yeast. Mitotic stability tests as well as evidence for plasmid maintenance indicate that the transformed cells contained self-replicating episomes and not stably integrated molecules. The nucleotide sequence of this ARS-containing fragment is presented.

Animals↗
PubMed1990

Postpartum Budd-Chiari syndrome with prolonged hypercoagulability state.

Budd-Chiari syndrome after pregnancy is an extremely rare disease. Reported here is a case of postpartum Budd-Chiari syndrome with unusual features of prolonged hypercoagulability state. The disease occurred 2 weeks after delivery and despite massive anticoagulation treatment the patient developed severe hepatic vein occlusion, renal vein thrombosis, inferior vena cava thrombosis, and femoral artery thrombosis.

Adult↗
PubMed1990

TAPA-1, the target of an antiproliferative antibody, defines a new family of transmembrane proteins.

A murine monoclonal antibody was identified by its ability to induce a reversible antiproliferative effect on a human lymphoma cell line. Immunoprecipitation studies revealed that the antibody reacted with a 26-kilodalton cell surface protein (TAPA-1). A diverse group of human cell lines, including hematolymphoid, neuroectodermal, and mesenchymal cells, expressed the TAPA-1 protein. Many of the lymphoid cell lines, in particular those derived from large cell lymphomas, were susceptible to the antiproliferative effects of the antibody. TAPA-1 may therefore play an important role in the regulation of lymphoma cell growth. A cDNA clone coding for TAPA-1 was isolated by using the monoclonal antibody to screen an expression library in COS cells. Analysis of the deduced amino acid sequence indicated that the protein is highly hydrophobic and that it contains four putative transmembrane domains and a potential N-myristoylation site. TAPA-1 showed strong homology with the CD37 leukocyte antigen and with the ME491 melanoma-associated antigen, both of which have been implicated in the regulation of cell growth.

Amino Acid Sequence↗
PubMed1990

Non A, non B hepatitis in the aged.

In order to study the clinical picture of non A, non B hepatitis in the elderly, a retrospective study was carried out in the two main hospitals in Jerusalem. Thirty-six patients with acute viral hepatitis, older than 65, have been hospitalized between the years 1982-1988. Seventy-two percent were diagnosed as non A, non B hepatitis. All patients were symptomatic and the main symptoms were abdominal pain, fever and jaundice. Thirty percent of the patients had marked cholestasis, while the disease was uneventful in 96% of the cases. Non A, non B hepatitis is the main type of viral hepatitis in the aged and should be suspected in patients with abdominal pain, fever and cholestasis.

Aged↗
PubMed1990

Prolonged course of a cutaneous T-cell lymphoma with late systemic involvement.

The clinical course of cutaneous T-cell lymphomas is known to be extremely variable. The disease may be present for up to 50 years, although it has a median survival of four to ten years. Clinical manifestations may range from cutaneous involvement alone to widespread systemic involvement. Described here is a patient with an unusually prolonged course of a cutaneous T-cell lymphoma with systemic involvement which reappeared ten and 18 years after the initial presentation. The patient developed Sjögren's syndrome, bone marrow and peripheral nerve involvement late in the course of her disease.

Adult↗
PubMed1990

Vasculitis and cryoglobulinemia associated with persisting cholestatic hepatitis A virus infection.

Extrahepatic manifestations are rarely found in hepatitis A viral (HAV) infection. Only a single case of HAV infection associated with cutaneous vasculitis and cryoglobulinemia has been reported. Described here is a patient with a persisting cholestatic type of HAV infection who developed cutaneous vasculitis and cryoglobulinemia during the third month of her illness. Analysis of the cryoglobulins revealed IgM anti-HAV antibodies.

Adult↗
PubMed1990

Pulmonary alveolar proteinosis associated with recurrence of Hodgkin's disease in the lung.

We report the case of a 36-year-old woman who presented with the clinical and histological features of pulmonary alveolar proteinosis (PAP) 13 years after the diagnosis of Hodgkin's disease. The PAP preceded the recurrence of Hodgkin's disease in the lung by a few weeks. To the best of our knowledge this patient is the first documented case of recurrent Hodgkin's disease in the lung associated with pulmonary alveolar proteinosis.

Adult↗
PubMed1989

Detection of hepatitis A virus RNA in serum from patients with acute hepatitis.

Hepatitis A virus (HAV) RNA was extracted from the sera of patients with acute hepatitis and then detected by molecular hybridization using cloned HAV complementary DNA (cDNA). HAV RNA was detected in 20 of 85 patients with acute HAV infection, mainly during the prodromal stage, or early during the icteric phase of the disease; it was detected as long as 21 days after its initial detection. Patients with HAV RNA in the serum had a significantly higher titer of anti-HAV IgM.

Acute Disease↗