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Biomedical subjects

B Yoffe

Publications and source records attributed to B Yoffe.

At least 19 recordsLinked to original sources
PubMed2006

Malignant phyllodes tumor with heterologous liposarcomatous differentiation and tubular adenoma-like epithelial component.

Phyllodes tumor of the breast is a biphasic fibroepithelial neoplasm. A 30-year-old woman presented with a 1-year history of a palpable, asymptomatic right breast mass without axillary lymphadenopathy and family history of breast carcinoma. Malignant phyllodes tumor was diagnosed. The authors present not previously described histological appearance of this tumor where an epithelial component was identical to that of a tubular adenoma of the breast, with the review of the literature. This is in addition to very rare liposarcomatous stromal differentiation in the malignant phyllodes tumor.

Journal Article↗
PubMed2004

Signet ring cell infiltration in tubular adenoma of ascending colon.

We present a case of signet ring cell infiltration in an adenomatous polyp of the ascending colon and review the literature. The patient had undergone resection of a mucin-producing adenocarcinoma of the proximal sigmoid colon seven months before the findings were reported. We presume that the signet ring cell aggregates are of metastatic origin.

Adenocarcinoma↗
PubMed2002

Treatment of obstetric hemorrhage with recombinant activated factor VII (rFVIIa).

Recombinant activated factor VII (rFVIIa, NovoSeven) was used in three patients with massive obstetric hemorrhage due to placenta previa accreta, rupture of the uterus and pre-eclampsia with HELLP. Administration of the drug markedly decreased the bleeding and enabled control of the hemorrhage. rFVIIa seems to be an adjunctive hemostatic measure for the treatment of severe obstetric hemorrhage.

Blood Transfusion↗
PubMed2002

Role of alpha-1-antichymotrypsin deficiency in promoting cirrhosis in two siblings with heterozygous alpha-1-antitrypsin deficiency phenotype SZ.

BACKGROUND: Alpha-1-antitrypsin (A1AT) deficiency is the most common inherited metabolic disorder with the potential to cause injury in the lung and liver. Recent reports suggested that alpha-1-antichymotrypsin (A1AC) deficiency may also be a possible cause of chronic liver disease. However, it has received little attention and is rarely investigated in the clinical setting. AIMS: To assess the role of A1AC deficiency in the pathogenesis of chronic liver disease in two siblings with heterozygous A1AT phenotype Pi SZ. PATIENTS: Two adult siblings with an A1AT Pi SZ phenotype and reduced levels of A1AC consistent with heterozygosity who developed cirrhosis and underwent liver transplantation. METHODS AND RESULTS: A1AT and A1AC levels in plasma measured by electroimmunoassay were 74 mg/dl and 90 mg/dl (140-470) and 0.12 mg/ml and 0.14 mg/ml (0.173-0.46), respectively. Immunohistochemistry revealed an apparent accumulation of both A1AT and A1AC in hepatocytes. A previously reported point mutation in exon III (Pro(229) to Ala substitution) of the A1AC gene was not detected by polymerase chain reaction amplification and a single strand conformation polymorphism analysis. CONCLUSIONS: Our report represents the first case of two siblings with A1CA phenotype Pi SZ who developed cirrhosis and underwent liver transplantation. Both siblings were heterozygous for A1AT and A1AC deficiency suggesting that combined deficiency of these two major serine protease inhibitors may enhance the risk of developing liver disease.

Adult↗
PubMed2001

Hepatitis C virus infection-related morbidity and mortality among patients with human immunodeficiency virus infection.

Hepatitis C virus (HCV) has emerged as a major pathogen among patients with human immunodeficiency virus (HIV). Morbidity and mortality were compared among 263 patients with HIV alone, 166 patients with HIV and HCV, and 60 patients with HCV alone (mean duration of follow-up, 2 years and 10 months). No differences in HIV loads and CD4 cells counts were observed between the HIV and HIV/HCV groups. Alanine aminotransferase levels were higher (52 U/L versus 35 U/L; P<.05) and albumin levels were lower (3.5 g/dL versus 3.8 g/dL; P <.02) among coinfected patients than they were among patients with HIV alone. Liver decompensation developed in 10% of patients with HIV/HCV coinfection. In contrast, no liver-related deaths or decompensation occurred in patients without coinfection (P<.05). Of the patients with HIV alone, 7% died, compared with 11% of the coinfected patients (P<.02); 47% of the deaths in the latter group were due to liver-related causes. In summary, HCV infection causes increased morbidity and mortality in patients with HIV infection.

AIDS-Related Opportunistic Infections↗
PubMed2001

Povidone-iodine related burns.

Skin preparation burns associated with chemical agents are uncommon. They occur most frequently in patients placed in the lithotomic position undergoing gynaecologic or urologic operations, the burn being on the buttocks, and in those undergoing orthopaedic operations, the burn being on the extremities and under a tourniquet. The basic mechanism involves irritation coupled with maceration and pressure. If the betadine solution has not been allowed to dry and has been trapped under the body of the patient in a pooled dependent position, such as the buttocks or under a tourniquet, the solution may irritate the skin and result in a skin burn. The irritation coupled with pressure leads to a situation analogous to that seen in the development of an acute accelerated decubitus ulcer; irritation, maceration, friction and pressure compounding each other to result in a skin burn or superficial ulcer in the skin. Our experience with three illustrative patients who presented with various burns following exposure to povidone-iodine (betadine) is described below.

Administration, Topical↗
PubMed2001

Garlic burns.

A patient with a second-degree burn of the forehead, induced by topical application of crushed garlic is reported. The literature on garlic burns is reviewed.

Asthma↗
PubMed2001

Diagnosis and treatment of strictures and kinks in salivary gland ducts.

PURPOSE: This article describes the use of sialoendoscopy for diagnosis and treatment of strictures and kinks in the major salivary glands ducts. PATIENTS AND METHODS: Thirty-four salivary glands with obstruction were diagnosed as having ductal kinks or strictures. Strictures were diagnosed by sialography and sialoendoscopy, kinks were diagnosed mainly by sialography, whereas endoscopy was used to rule out other pathology and to locate the kink. There were strictures in 25 salivary glands (14 male and 11 females; aged 25 to 60 years), 14 in the parotid and 11 in the submandibular gland, and kinks in 9 salivary glands (5 males 4 females; aged 40 to 55 years). Seven kinks were found in the submandibular gland and 2 in the parotid. Treatment of strictures was performed by dilatation procedures with saline under pressure, balloon techniques, and forced manipulation. After these procedures, a polyethylene stent was inserted for 2 weeks. Kinks were treated by advancement ductoplasty and balloon contouring to overcome the acute angle. RESULTS: Twenty of 25 cases of stricture became completely asymptomatic in a follow-up of 8 to 36 months after treatment. In 4 cases, further revisional dilatation was needed, and in 1 case treatment failed and the gland had to be removed. All 9 cases of kinks became completely asymptomatic in a follow-up of 6 to 24 months after treatment. CONCLUSION: Strictures and kinks should be considered when salivary gland obstruction is present without sialolithiasis.

Adult↗
PubMed2001

Huge renal arteriovenous malformation mimicking a simple para-pelvic cyst.

The presenting symptoms of renal arteriovenous malformation are usually gross hematuria and hypertension. Herein we present an unusual case of a huge renal arteriovenous malformation without these signs, but with an ultrasound picture mimicking a simple para-pelvic cyst. Other imaging tests, including duplex ultrasound, computerized tomography and aortography, demonstrated the vascular lesion. We suggest that duplex ultrasound should accompany routine renal ultrasound in order not to miss such cases, especially when the physical examination suggests an intra-abdominal vascular lesion or bleeding.

Angiography↗
PubMed2001

Microarray analysis of genes differentially expressed in HepG2 cells cultured in simulated microgravity: preliminary report.

Developed at NASA, the rotary cell culture system (RCCS) allows the creation of unique microgravity environment of low shear force, high-mass transfer, and enables three-dimensional (3D) cell culture of dissimilar cell types. Recently we demonstrated that a simulated microgravity is conducive for maintaining long-term cultures of functional hepatocytes and promote 3D cell assembly. Using deoxyribonucleic acid (DNA) microarray technology, it is now possible to measure the levels of thousands of different messenger ribonucleic acids (mRNAs) in a single hybridization step. This technique is particularly powerful for comparing gene expression in the same tissue under different environmental conditions. The aim of this research was to analyze gene expression of hepatoblastoma cell line (HepG2) during early stage of 3D-cell assembly in simulated microgravity. For this, mRNA from HepG2 cultured in the RCCS was analyzed by deoxyribonucleic acid microarray. Analyses of HepG2 mRNA by using 6K glass DNA microarray revealed changes in expression of 95 genes (overexpression of 85 genes and downregulation of 10 genes). Our preliminary results indicated that simulated microgravity modifies the expression of several genes and that microarray technology may provide new understanding of the fundamental biological questions of how gravity affects the development and function of individual cells.

Cell Culture Techniques↗
PubMed2000

Induction of hepatitis B virus gene expression at low temperature.

There is a limited understanding of the cellular regulation of HBV gene expression in differentiated hepatocytes. We previously demonstrated that HBV replication inversely correlates with cell proliferation and DNA synthesis. In this report, temperature-induced modulation of cell growth was used as a novel approach to study HBV gene expression in the absence of indirect effects from drugs or serum deprivation. We observed markedly elevated levels of hepatic HBV mRNA expression from integrated and episomal HBV DNA at 32 degrees C. Additionally, hepatoblastoma cells cultured at 32 degrees C expressed increased levels of albumin mRNA and decreased levels of c-myc mRNA, which demonstrates that liver-derived cells cultured at low temperature exhibit characteristics of functional and differentiated hepatocytes. In transiently transfected HepG2 cells cultured at 32 degrees C, the HBV enhancer 1 activated the X promoter and core/pregenomic promoter by 7.3- and 28-fold, respectively. In the absence of enhancer 1, core/pregenomic promoter activity was 2.4-fold higher than the X promoter in HepG2 cells at 32 degrees C. In contrast, enhancer 1 exclusively activated the X promoter in transfected non-liver cells at 32 degrees C. Therefore, the core/pregenomic promoter exhibits strict liver-specificity at low temperature. This work supports the hypothesis that HBV replication and gene expression are optimal in non-activated hepatocytes, and provides a novel system for delineating molecular aspects of the HBV replication process.

Cells, Cultured↗
PubMed1999

Induction of three-dimensional assembly of human liver cells by simulated microgravity.

The establishment of long-term cultures of functional primary human liver cells (PHLC) is formidable. Developed at NASA, the Rotary Cell Culture System (RCCS) allows the creation of the unique microgravity environment of low shear force, high-mass transfer, and 3-dimensional cell culture of dissimilar cell types. The aim of our study was to establish long-term hepatocyte cultures in simulated microgravity. PHLC were harvested from human livers by collagenase perfusion and were cultured in RCCS. PHLC aggregates were readily formed and increased up to 1 cm long. The expansion of PHLC in bioreactors was further evaluated with microcarriers and biodegradable scaffolds. While microcarriers were not conducive to formation of spheroids, PHLC cultured with biodegradable scaffolds formed aggregates up to 3 cm long. Analyses of PHLC spheroids revealed tissue-like structures composed of hepatocytes, biliary epithelial cells, and/or progenitor liver cells that were arranged as bile duct-like structures along nascent vascular sprouts. Electron microscopy revealed groups of cohesive hepatocytes surrounded by complex stromal structures and reticulin fibers, bile canaliculi with multiple microvilli, and tight cellular junctions. Albumin mRNA was expressed throughout the 60-d culture. A simulated microgravity environment is conducive to maintaining long-term cultures of functional hepatocytes. This model system will assist in developing improved protocols for autologous hepatocyte transplantation, gene therapy, and liver assist devices, and facilitate studies of liver regeneration and cell-to-cell interactions that occur in vivo.

Albumins↗
PubMed1999

Cultures of human liver cells in simulated microgravity environment.

We used microgravity-simulated bioreactors that create the unique environment of low shear force and high-mass transfer to establish long-term cultures of primary human liver cells (HLC). To assess the feasibility of establishing HLC cultures, human liver cells obtained either from cells dissociated by collagenase perfusion or minced tissues were cultured in rotating vessels. Formation of multidimensional tissue-like spheroids (up to 1.0 cm) comprised of hepatocytes and biliary epithelial cells that arranged as bile duct-like structures along newly formed vascular sprouts were observed. Electron microscopy revealed clusters of round hepatocytes and bile canaliculi with multiple microvilli and tight junctions. Scanning EM revealed rounded hepatocytes that were organized in tight clusters surrounded by a complex mesh of extracellular matrix. Also, we observed that co-culture of hepatocytes with endothelial cells stimulate albumin mRNA expression. In summary, a simulated microgravity environment is conducive for the establishment of long-term HLC cultures and allows the dissection of the mechanism of liver regeneration and cell-to-cell interactions that resembles in vivo conditions.

Albumins↗
PubMed1999

Does aflatoxin B1 play a role in the etiology of hepatocellular carcinoma in the United States?

Previous research showed that risk factors associated with hepatocellular carcinoma (HCC) include infection with hepatitis B (HBV) and hepatitis C (HCV) viruses, exposure to aflatoxin B1 (AFB1), and liver cirrhosis, due primarily to alcohol consumption. To determine whether AFB1 may play a role in HCC in the United States, a search for AFB1 adducts and p53 alterations, potentially induced by AFB1, was conducted in the United States in 23 HCC patients with available tissue samples. The presence of AFB1 tumor-DNA and -serum lysine adducts and mutant p53 product was determined by immunoassays and codon 249 p53 mutation by restriction enzyme analysis. HBV and HCV serology and serum HBV-DNA were also determined. Thirteen patients were positive for HBV by HBs antigen or anti-HBc antigen or by polymerase chain reaction for HBV-DNA sequences. Nine patients were free of HBV and HCV markers; 5 of 22 sera tested were anti-HCV positive. p53 Protein expression, determined by immunohistochemical staining, was present in 5 of the 23 tumor tissues, whereas p53 codon 249 mutations were not observed in the 5 cases in which tissue was available for study. AFB1 tumor-DNA adducts were present in 3 of 19 tumor tissues, and in 1 of these 3 samples p53 protein was also detected. Sera from only 5 of the patients were tested for AFB1-lysine adducts, and all were positive. In these five patients, neither p53 protein nor a mutation on codon 249 was detected. The demonstration that AFB1-DNA and -lysine adducts are present in HCC patients in the United States is intriguing but requires further substantiation because of the small number of subjects in this pilot study. To elucidate the pathogenetic significance of these findings, further investigation, including studies in larger patient cohorts and properly selected controls, is warranted.

Adult↗
PubMed1998

Microsatellite instability in human hepatocellular carcinoma: relationship to p53 abnormalities.

AIMS/BACKGROUND: Microsatellite instability was sought in 10 human hepatocellular carcinomas (HCCs) to determine whether defective DNA mismatch repair might be implicated in the multiple genetic alterations observed in the p53 tumor suppressor gene in some of these patients' tumors. METHODS: Genomic DNA from HCCs and adjacent nontumorous livers was subjected to PCR with primers for nine microsatellites, and PCR products were resolved in a denaturing gel. Microsatellite instability was defined as the presence of band shifts or additional bands for at least two microsatellite sequences in an HCC compared to the nontumorous liver tissue from the same patient. RESULTS: Microsatellite instability was detected in four of ten HCCs. Three of these four HCCs did not have p53 exon mutations. However, one HCC had microsatellite instability as well as multiple p53 exon mutations and multiple intron alterations. Four other patients with multiple p53 intron alterations in HCC (compared to their own nontumorous liver), three of whom also had a mutation in the exons, had no microsatellite instability. CONCLUSIONS: Defective DNA mismatch repair, as indicated by microsatellite instability, might have played a role in hepatocarcinogenesis in four of the ten patients, but in general it was not associated with p53 alterations. In one of the ten patients, defective DNA mismatch repair might have been the cause of multiple mutations in both the coding and intron sequences of the p53 gene.

Adolescent↗