Esophageal cancer in Iran

Esophageal cancer is among the 10 most frequent cancers in the world. Iran is one of the known areas with a high incidence of esophageal cancer. Most of the patients in Iran have been reported from the north and northeast regions of the country. In one survey by the Iran Cancer Institute, 9% of all cancers and 27% of gastrointestinal cancers were esophageal carcinoma. The male to female ratio was 1.7/1. The distal portion of the esophagus is involved more often than other parts. Consumption of wheat flour, exposure to residues from opium pipes, drinking hot tea, and chewing nass (a mixture of tobacco, lime, ash, and other ingredients) are the suspect etiologic agents for esophageal cancer in Iran. Dysphagia, weight loss, anorexia, abdominal pain, and odynophagia are the common symptoms and signs of Iranian patients with esophageal cancer. For clinical staging, chest computed tomographic scanning is performed. Adenocarcinoma of the esophagus is not as common in Iran as in western countries. Public education, nutritional support, and eradication of opium addiction may decrease the morbidity and mortality that result from esophageal cancer. Surgery has traditionally been the mainstay of esophageal cancer treatment in Iran. Radiotherapy is mainly used postoperatively. The usual combination chemotherapy regimen is cisplatin plus flurouracil (5-Fu). Semin Oncol 28:153-157.

Correction of bone marrow failure in dyskeratosis congenita by bone marrow transplantation

Dyskeratosis congenita is recognized by its dermal lesions and constitutional aplastic anemia in some cases. We report successful allogeneic bone marrow transplantation in two siblings with this disease from their sister, and their long term follow-up. We used reduced doses of cyclophosphamide and busulfan for conditioning instead of total body irradiation. Also, we report late adverse effects of transplantation which are not distinguishable from the natural course of disease.

Prognostic factors in bone marrow transplantation for beta thalassemia major: experiences from Iran

This study concerns the effects of several pre-transplant features on outcome for patients with beta thalassemia major who underwent bone marrow transplantation (BMT). Seventy patients with beta thalassemia major underwent bone marrow transplantation during the period 1991-1997 in Shariati Hospital in Tehran, Iran. The survival and rejection curves levelled off at 8 and 18 months after transplantation at 82.6% and 11.4%, respectively. Pre-transplant clinical features (age, serum ferritin, portal fibrosis, hepatomegaly and quality of chelation therapy) were examined for their effects on survival and recurrence of thalassemia in this group of patients who were less than 16 years old. Increasing age, presence of portal fibrosis and increasing serum ferritin were significantly associated with reduced probability of survival (P = 0.0047, P = 0.016 and P = 0.024, respectively). Hepatomegaly and inadequate pre-transplant chelation therapy which were documented as poor prognostic factors in previous studies, were not evaluable in this study. We also showed the benefits of transplanting more than 5.5 x 10(8)/kg cells in this group of patients with no increase in complications.

Bone marrow transplantation in Iran

Seventy-three BMT procedures (42 allogeneic-BMT, 30 autologous-BMT, 1 syngeneic transplant) were undertaken at the Shariati Hospital in Tehran between March 1991 and November 1993. Allogeneic-BMT was performed for thalassaemia major (n = 23), AML in complete remission (n = 3), severe aplastic anaemia (n = 7), CML (n = 7), dyskeratosis congenita (n = 2) and Fanconi anaemia (n = 1). Conditioning regimens comprised busulphan (BU) plus cyclophosphamide (CY) or CY only. Thirty-two (78%) of the 43 patients remain alive 1-34 months after BMT. Twelve patients died: the causes of death were haemorrhagic cystitis (n = 1), CMV pneumonitis (n = 1), GVHD (n = 3), infection (n = 3), rejection (n = 1), VOD (n = 2) and hepatitis (n = 1). Autologous-BMT was performed for patients with AML in CR (n = 16), ALL in CR (n = 9), lymphoma in relapse (n = 3), Ewing sarcoma (n = 1) and multiple myeloma (n = 1). The median age was 18 years. Conditioning regimens were Ara C plus CY, etoposide plus CY and high-dose melphalan. Sixteen (54%) of the 30 patients survive, 14 in continuous complete remission. The causes of death were relapse (AML (n = 7), ALL (n = 4), lymphoma (n = 1)), VOD (n = 1) and infection (n = 1).

Isolation of high-density lipoproteins by immunoaffinity column chromatography from hog plasma

High density lipoprotein (HDL) was isolated from hog plasma by a simple immunoaffinity column chromatography procedure using immobilized anti-apolipoprotein AI. The composition of HDL isolated by immunoaffinity chromatography was nearly identical to that of a control sample that was isolated by an alternate method utilizing ultracentrifugation and gel chromatography. The HDL isolated by immunoaffinity chromatography had a larger number of polypeptide components that the control as indicated by acrylamide gel electrophoresis in the presence of urea. When the HDL isolated by immunoaffinity chromatography was applied to a heparin-agarose column the amount of protein retained was approximately twice that of the control. These findings indicate that the ultracentrifugation procedure probably induced the loss of apolipoprotein E containing components from the HDL complex.

Characterization of lecithin-cholesterol acyltransferase from human plasma. 3. Chemical properties of the enzyme

The polypeptide molecular weight of lecithin-cholesterol acyltransferase (LCAT) (45000) was obtained by deducting the weight of carbohydrate moiety (25%, w/w) from the total molecular weight of 60000. LCAT was found to have a relatively high content of glutamic acid, aspartic acid, glycine, and leucine residues and four half-cystines. The carbohydrate content was found to be about 25% (w/w): hexoses, 13%; hexosamines, 6.2%; and sialic acid, 5.4%. The total number of 408 amino acid residues per mole and the mean residue weight of 110.3 were found. From fluorescence spectroscopy analysis, 6-7 mol of tryptophan were found per mole of LCAT in 10 mM phosphate (pH 7.4). However, when LCAT was digested by the mixture of chymotrypsin and pronase the tryptophan residues increased to 10-11 mol/mol of LCAT, which agrees well with data obtained previously by ultraviolet absorption spectroscopy. A partial specific volume of 0.707 mL/g was determined by compositional analysis. Human LCAT was found to have a relatively high extinction coefficient (E1%1cm) of 21 at 280 nm and neutral pH. Two residues of cysteine per mole of LCAT were estimated both in the presence or absence of sodium dodecyl sulfate by titration with 5,5'-dithiobis-2-nitrobenzoic acid. The enzyme showed a lower tendency to staining with Coomassie blue R-250 than bovine serum albumin. The enzyme was rapidly inactivated by diisopropyl fluorophosphate (DFP), regardless of whether the free sulfhydryl were blocked or not. The enzyme was also irreversibly inhibited by cysteine above concentrations of 1 mM.(ABSTRACT TRUNCATED AT 250 WORDS)

Study of the lecithin: cholesterol acyltransferase reaction with liposome and high density lipoprotein substrates

The activity of highly purified preparations of human plasma lecithin: cholesterol acyltransferase were stabilized by precipitating the enzyme with ammonium sulfate and using the dilutions of the particulate lecithin: cholesterol acyltransferase suspension for enzyme assays. Ammonium sulfate concentrations in the assay mix up to 0.1 M had no significant effect on lecithin: cholesterol acyltransferase activity. The basic enzymatic properties of lecithin: cholesterol acyltransferase were investigated using liposomes and high density lipoprotein (HDL) substrates. pH optima for both substrates was approximately 8.0. The temperature dependence of lecithin: cholesterol acyltransferase activity resulted in non-linear Arrhenius plots with both substrates. The activity vs. temperature (degrees C) curves showed slight inflections at 30 degrees C, which may have been due to the relatively rapid inactivation of the enzyme above this temperature. HDL3 was found to be a better substrate than HDL or HDL2. HDL3 was also considerably better than egg phosphatidylcholine/cholesterol liposomes as an lecithin: cholesterol acyltransferase substrate. Addition of HDL2 to a reaction mix of enzyme and HDL3 indicated that HDL2 acts as an inhibitor of cholesterol esterification in this system.

A study of the interaction of lecithin: cholesterol acyltransferase with subfractions of high density lipoproteins

High density lipoproteins (HDL) were isolated by a chromatographic procedure and subsequently fractionated on a DEAE cellulose (DE-52) column. Four fractions were separated and analyzed for lipid and protein composition and molecular weight. During ion exchange chromatography, one of the four fractions consistently coincided with lecithin:cholesterol acyltransferase (LCAT) activity. When the HDL fractions were incubated with highly purified LCAT preparations, the LCAT activity showed a dependence on unesterified cholesterol concentrations. The HDL subfraction eluting at the highest ionic strength was found to be the best substrate for LCAT. This subfraction exhibited apoprotein and lipid composition similar to HDL3 and contained 31% of the total apoprotein D present in all the subfractions. A positive correlation was found between LCAT activity and the cholesteryl ester/unesterified cholesterol ratio, and a negative correlation was found between LCAT substrate potential and apparent molecular weight of the HDL subfractions when these subfractions were incubated with LCAT. No correlation was apparent between LCAT activity, and the phospholipid/unesterified cholesterol ratio or with the apoA-I/apoA-II ratio.U

A novel chromatographic method for the preparation of high density lipoproteins

High density lipoproteins (HDL) were isolated by a procedure employing polyanion precipitation and column chromatography. The product polyanion precipitation and column chromatography. The product was free of low denisty lipoproteins (LDL) but serum albumin (HSA) was still present. The remaining HSA was removed by an immunoadsorbent column. The HDL isolated by our method was compared to another HDL preparation isolated from the same plasma sample by the combination of ultracentrifugation and gel chromatgraphy. It was found to have approximately the same lipid and protein composition as the HDL isolated by conventional techniques. Minor differences included a higher phospholipid and apoprotein E content and lower triglyceride and ApoC II content of the HDL isolated by column chromatography. The method described here is considerably less tedious than earlier techniques, can be scaled up without substantial increase in labor and results in an approximately 30% higher yield than the method described by Rudel et al.