Removal of Pb(II) ions from aqueous solutions by sulphuric acid-treated wheat bran

Sulphuric acid-treated wheat bran (STWB) was used as an adsorbent to remove Pb(II) ions from aqueous solution. It was observed that the adsorption yield of Pb(II) ions was found to be pH dependent. The equilibrium time for the process was determined as 2h. STWB gave the highest adsorption yield at around pH 6.0. At this pH, adsorption percentage for an initial Pb(II) ions concentration of 100mg/L was found to be 82.8 at 25 degrees C for contact time of 2h. The equilibrium data obtained at different temperatures fitted to the non-linear form of Langmuir, Freundlich and Redlich-Peterson and linear form of Langmuir and Freundlich models. Isotherm constants were calculated and compared for the models used. The maximum adsorption capacity (q(max)) which was obtained linear form of Langmuir model increased from 55.56 to 79.37mg/g with increasing temperature from 25 to 60 degrees C. Similar trend was observed for other isotherm constants related to the adsorption capacity. Linear form of Langmuir isotherm data was evaluated to determine the thermodynamic parameters for the process. Thermodynamic parameters show that adsorption process of Pb(II) ions is an endothermic and more effective process at high temperatures. The pseudo nth order kinetic model was successfully applied to the kinetic data and the order (n) of adsorption reaction was calculated at the range from 1.711 to 1.929. The values of k(ad) were found to be 5.82x10(-4) and 21.81x10(-4)(min(-1))(mg/g)(1-n) at 25 and 60 degrees C, respectively. Activation energy was determined as 29.65kJ/mol for the process. This suggest that the adsorption Pb(II) ions by STWB is chemically controlled.

Expression of proteins associated with cell-matrix adhesion in proliferative vitreoretinopathy designed by Dispase model

PURPOSE

During recent years, the interaction of cell surface molecule, extracellular matrix proteins, and cytoskeletal elements has been a topic for research for the purpose of understanding the mechanisms of pathologic conditions. This study aims to evaluate the expression of CD44, as a cell surface adhesion molecule; fibronectin (FN), as an extracellular and a cell surface protein; vinculin and actin/á-smooth muscle actin (alfa-SMA), as cytoskeletal elements; and the interactions of these proteins in the microenvironment of proliferative vitreoretinopathy (PVR).

METHODS

This experimental study was designed by the intravitreal Dispase model in rabbits and proteins' expression were evaluated via immunohistochemical staining.

RESULTS

As a cell surface protein, CD44 expression was determined in only four eyes focally and weakly, but in a small number of cells. Among the cytoskeletal proteins, vinculin expression was the most extensive and the strongest in intensity in epi- and subretinal membranes. Alpha-SMA expression was mostly present within small foci of cells. Fibronectin expression was determined in some of the eyes only faintly.

CONCLUSIONS

Vinculin seems to be involved in PVR pathogenesis. Variability in co-distribution of the expression of vinculin, FN, and alfa-SMA reflects the dynamic interactions evolving between cell and extracellular matrix during the epi- and subretinal membrane formations. The results of this study were determined not to be in support of the assumption that CD44 has a functional role in the pathogenesis of PVR.

Acro-cardio-facial syndrome associated with neuroepithelial cyst: a case report

Acro-cardio-facial syndrome (ACFS) is a very rare genetic syndrome. Only 5 patients have been reported in the literature so far. A female neonate presented with limb abnormalities, cleft palate and congenital heart disease was diagnosed as ACFS. Her cranial magnetic resonance imaging revealed a huge cerebral neuroepithelial cyst. To our knowledge, this is the first case of ACFS in the literature associated with a neuroepithelial cyst in the brain.

The adsorption of Cd(II) ions on sulphuric acid-treated wheat bran

The adsorption of Cd(II) ions which is one of the most important toxic metals by using sulphuric acid-treated wheat bran (STWB) was investigated. The effects of solution pH and temperature, contact time and initial Cd(II) concentration on the adsorption yield were studied. The equilibrium time for the adsorption process was determined as 4 h. The adsorbent used in this study gave the highest adsorption capacity at around pH 5.4. At this pH, adsorption capacity for an initial Cd(II) ions concentration of 100 mg/L was found to be 43.1 mg/g at 25 degrees C for contact time of 4 h. The equilibrium data were analysed using Langmuir and Freundlich isotherm models to calculate isotherm constants. The maximum adsorption capacity (qmax) which is a Langmuir constant decreased from 101.0 to 62.5 mg/g with increasing temperature from 25 to 70 degrees C. Langmuir isotherm data were evaluated to determine the thermodynamic parameters for the adsorption process. The enthalpy change (deltaH(o)) for the process was found to be exothermic. The free energy change (deltaG(o)) showed that the process was feasible. The kinetic results indicated that the adsorption process of Cd(II) ions by STWB followed first-order rate expression and adsorption rate constant was calculated as 0.0081 l/min at 25 degrees C. It was observed that the desorption yield of Cd(II) was highly pH dependent.

A study on the reduction of hexavalent chromium in aqueous solutions by vinasse

Hexavalent chromium introduced to the water ecosystem is an important issue due to the toxic effect it poses. The first step of conventional treatment of wastewaters containing hexavalent chromium is its reduction to chromium (III) which is less toxic. The use of industrial waste material for the reduction of chromium (VI) may be a new cost-effective alternative. In this study, Cr(VI) reduction characteristics of vinasse which is a waste material of alcohol production from sugar beet molasses was investigated. The parameters of pH, temperature, concentrations of initial Cr(VI) and vinasse on the reduction of Cr(VI) were examined as a function of time by applying batch tests. Cr(VI) was almost completely reduced within about 270 min in the concentrations of Cr(VI) and vinasse of 80 mg l(-1) and 200 ml l(-1), respectively, at pH 3.0 and 25 degrees C. The results showed that reduction time can be shortened by increasing acidity and vinasse concentration or decreasing Cr(VI) initial concentration. Cr(VI) reduction process was found be obey first order kinetic model of homogenous phase reactions. The temperature was found to have a positive effect on the reduction process and the activation energy of process was calculated as 46.07 kJ mol(-1). Although the detoxification of wastewaters containing Cr(VI) via reducing it to Cr(III) by using vinasse seems to be cost-effective, the resulting effluent to be produced necessitates a further treatment to reduce organic pollution.

The adsorption of Cr(VI) on sulphuric acid-treated wheat bran

Wheat bran, a by-product of wheat milling industries, was converted into a cheap and efficient material by treating with sulphuric acid and used for the adsorption of Cr(VI) from aqueous solution. Effects of various parameters such as initial pH of solution, contact time, initial Cr(VI) concentration and temperature were studied. The sulphuric acid-treated wheat bran (STWB) gave the highest adsorption efficiency at pH 1.5. The equilibrium data were fitted better to Langmuir isotherm model compared to Freundlich model at all the temperatures studied. The adsorption capacity increased from 91 to 133 mg gl(-1) with an increase in temperature from 20 degrees C to 50 degrees C. The adsorption process was found to be endothermic and Langmuir isotherm data were evaluated to determine the thermodynamic parameters for the process. Thermodynamic parameters showed that the process was feasible. The results indicated that the chromium removal process by STWB followed first-order rate expression and adsorption rate constants increased with increasing temperature.

Cr(VI) reduction in aqueous solutions by using synthetic iron sulphide

This study was carried out to reduce Cr(VI) in aqueous solutions by using synthetic iron sulphide. For that purpose, the effects of acid content, contact time, initial Cr(VI) concentration, temperature of the solution, particle size and dosage of iron sulphide on the Cr(VI) reduction were investigated. Reduction extent of Cr(VI) is, to a great extent, dependent on the amount of acid. The Cr(VI) in the solution containing two times the H2SO4 with respect to stoichiometric amount of Cr(VI) was completely reduced within 45 min by using 2.5 g litre(-1) iron sulphide at 25 degrees C. The reduction efficiency of Cr(VI) was increased with temperature of solution. The variation in particle size of iron sulphide did not affect the reduction yield of Cr(VI). The total reduction capacity of synthetic iron sulphide was found to be 237.6 mg Cr(VI) g(-1). The results related to shrinking particle model showed that the reduction reaction was chemically controlled and activation energy for theprocess was calculated as 38.4 kJ mol(-1).

17Beta-estradiol modulates endothelin-1 expression and release in human endothelial cells

OBJECTIVE

In this study the role of 17beta-estradiol (E2) in the regulation of endothelin-1 (ET-1) mRNA expression and secretion was investigated in cultured human umbilical vein endothelial cells (HUVECs).

METHODS

Endothelial cells were either deprived of or treated with 17beta-estradiol (10(-9), 10(-7) M) for 48 h. After the incubation, the effect of E2 on ET-1 gene expression was evaluated by Northern blot analysis. ET-1 release into the media was measured by radioimmunoassay after 6 h of incubation under basal conditions and upon stimulation with thrombin (4 U/ml). In addition, the cyclic guanosine 5'-monophosphate (cGMP) content of cells was assayed by immunoassay. In order to exclude the role of nitric oxide (NO) in E2-induced effects on endothelin-1 gene expression and secretion, nitric oxide synthase (NOS) inhibitor, N-nitro L-arginine methyl ester (1 mM) (L-NAME) was added to the media of some cultures.

RESULTS

Incubation of HUVECs with 10(-9) and 10(-7) M E2 for 48 h resulted in a 30 and 47% inhibition of ET-1 mRNA expression, respectively. Incubation with E2 also decreased the basal and thrombin-stimulated ET-1 release while increasing the cGMP content of cells significantly. NOS inhibitor L-NAME increased the release of ET-1 from E2-incubated cells but did not alter the ET-1 release from hormone-deprived cells. However, ET-1 secretion of E2-treated cells were significantly less than the deprived ones. Northern blot analyses also demonstrated that inhibition of NOS only partly attenuated the effect of E2 on ET-1 gene expression. In the presence of L-NAME, treatment with 10(-7) M E2 caused a 12% decrease in ET-1 gene expression.

CONCLUSION

The results demonstrate that E2 may play both direct and indirect role in regulation of ET-1 gene expression and production in human endothelial cells. E2-induced increase in NO but decrease in ET-1 production may partly explain the mechanism of the protective effects of the hormone on the cardiovascular system.

The life cycle of Sphaerospora truttae (Myxozoa: Myxosporea) and some features of the biology of both the actinosporean and myxosporean stages

A previously undescribed echinactinomyxon type actinosporean was shown experimentally to be the alternate stage of Sphaerospora truttae. The echinactinomyxon type spores were found to be released from Lumbriculus variegatus and occasionally Tubifex tubifex. Overall infection prevalence of the echinactinomyxon was 0.14%. Peak release was in March-May each year. S. truttae spores developed in experimentally infected salmon 4.5 mo post-exposure to echinactinomyxon spores. Extrasporogonic stages of S. truttae first appeared in naturally infected salmon in early July and persisted for 8 to 10 wk. Correlation between peak release of echinactinomyxon spores and appearance of extrasporogonic stages of S. truttae is discussed.

Effects of treatment with FK409, a nitric oxide donor, on collar-induced intimal thickening and vascular reactivity

Intimal thickening in arteries is considered a site of predilection for atherosclerosis. In a rabbit model of early atherosclerosis, a silastic collar was placed around the carotid artery, which resulted in the formation of intimal thickening. We investigated whether the oral application of FK409 ((+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide , 10 mg kg(-1) day(-1), p.o.), a nitric oxide donor, inhibited the collar-induced intimal thickening as well as accompanying reactivity changes in rabbit carotid artery. The intimal thickening was significantly inhibited by FK409. The collar treatment increased the pD2 value of 5-hydroxytryptamine (5-HT) whereas it decreased those of phenylephrine and acetylcholine and did not significantly alter that of nitroglycerine. Maximal contractile force development in response to potassium chloride (KCl), 5-HT and phenylephrine was decreased in collared arteries. The collar did not alter the maximal relaxant effects of acetylcholine and nitroglycerine. Despite the significant reduction of intimal thickening, FK409 treatment did not affect these collar-induced modifications in vascular reactivity.

Effects of nicardipine on collar-induced intimal thickening and vascular reactivity in the rabbit

The effects of nicardipine treatment on collar-induced intimal thickening and on accompanying reactivity changes in rabbit carotid artery have been investigated. Treatment for three weeks with subcutaneous nicardipine (20 mgkg(-1) per day) significantly inhibited the intimal thickening caused by perivascular application of a silicone rubber collar. Potassium chloride (KCl), phenylephrine and 5-hydroxytryptamine (5-HT) induced concentration-dependent contractions in both sham-operated and collared arteries. Collar-induced attenuation of maximum KCl-, phenylephrine- and 5-HT-induced contraction was not affected by nicardipine. Collaring caused the means of pD2 values (the negative logarithm of EC50 values, 50% effective concentration) of 5-HT and phenylephrine to increase and decrease, respectively. Nicardipine did not affect the altered sensitivity to these agonists. Neither collar implantation nor nicardipine treatment altered the pD2 values for acetylcholine- and nitroglycerine-induced relaxations. These results demonstrate that nicardipine inhibits collar-induced intimal thickening in rabbit carotid artery without affecting the accompanying changes in vascular reactivity, indicating a possible lack of association between the development of intimal thickening and altered reactivity.

Molecular and population genetic analyses of beta-thalassemia in Turkey

In this report we describe the molecular analysis of 795 chromosomes derived from unrelated Turkish beta-thalassemia and sickle cell anemia carriers identified in hematology clinics in Istanbul, Ankara, Izmir, Adana, and Antalya. The determination of the molecular pathology of 754 beta-thalassemia and 42 abnormal hemoglobin genes and analysis of the frequency distribution in six distinct regions of Turkey was accomplished. The experimental strategy, based on PCR amplification of the beta-globin gene, included dot-blot hybridization with 18 probes specific for the Mediterranean populations, denaturing gradient gel electrophoresis, and genomic sequencing. When the regional results are compared with the overall frequency of mutations in the country, it is observed that the frequencies in the western and southern parts of Turkey are in good accordance with the overall distribution, whereas the northern and eastern parts have a more region/population-specific profile with some rare mutations having a significantly high occurrence in these regions. Further evaluation of the data with respect to region- or population-dependent differences will contribute to a better understanding of the mechanisms leading to the marked genetic heterogeneity in Turkey, but could also be extremely valuable in facilitating rapid identification of mutations in families at risk for different hemoglobinopathies.

A study on the Cr(VI) removal from aqueous solutions by steel wool

The reduction of Cr(VI) by steel wool and the precipitation of reduced chromium by CaCO(3) powder and NaOH solution were investigated in continuous and batch systems, respectively. The effects of acid and initial Cr(VI) concentrations, volumetric rate and temperature of solution on Cr(VI) reduction were studied. The results showed that the reduction of Cr(VI), to a large extent, depended on, and increased with, acid concentration. The Cr(III) and iron ions in the reduced solution were completely precipitated by using NaOH solution at appropriate alkaline conditions. It was concluded that CaCO(3) powder could be used as a cheap precipitant for Cr(III) ions. But the iron ions in the reduced solution could not be fully removed by using this precipitant.

Effect of verapamil on intimal thickening and vascular reactivity in the collared carotid artery of the rabbit

1. Intimal thickening is a common site for atherosclerosis. Therefore, we investigated whether the calcium entry blocker verapamil (10 mg kg-1 body weight day-1, s.c.) can retard intimal thickening and changes in vascular reactivity induced by a non-occlusive, silicone collar positioned around the left carotid artery of rabbits. The contralateral carotid artery was sham-operated and served as a control. 2. Verapamil and placebo (saline 0.1 ml kg-1, day-1, s.c.) treatments were initiated 7 days before placing the collar and lasted 3 weeks. Thereafter, segments were cut from collared and sham-treated arteries for histology and isometric tension recording. 3. The intima/media (I/M ratio increased after 14 days of collar treatment, but intimal thickening was not inhibited by verapamil (I/M ratio placebo 0.31 +/- 0.07, verapamil 0.32 +/- 0.09). 4. The collar decreased the capacity to develop force, as indicated by the response to a supramaximal concentration of KCl, decreased the sensitivity (pD2) to acetylcholine (ACh) and phenylephrine (Phe), but increased the sensitivity to 5-hydroxytryamine (5-HT). 5. Although verapamil did not affect intimal thickening, it normalized the hypersensitivity to 5-HT in collared arteries. 6. The contraction to the supramaximal concentration of KCl was not affected by verapamil. Verapamil decreased the Emax of ACh, but this was only seen in collar-treated arteries. Verapamil also decreased the sensitivity to ACh and Phe, in both sham- and collar-treated arteries. 7. We conclude that verapamil, without preventing thickening of the intima, can modify collar-induced changes in vascular reactivity.

Effect of hepatocyte proliferation and cellular DNA synthesis on hepatitis B virus replication

BACKGROUND & AIMS

Interrelationship between hepatitis B virus (HBV) replication and the stage of hepatocyte proliferation and differentiation may play an important role in the pathogenesis of HBV infection. The aim of this study was to assess the effect of hepatocyte proliferation and/or cell arrest on HBV replication.

METHODS

Hepatoblastoma cells transfected with HBV were subjected to serum deprivation or treatment with aphidicolin or camptothecin. Cell cycle analysis was performed using flow cytometry, and cellular DNA synthesis was analysed by assessing 5-bromo-2'-deoxyuridine incorporation. Distribution of episomal HBV DNA and proliferating cell nuclear antigen in liver specimens was assessed by simultaneous in situ hybridization and immunohistochemistry.

RESULTS

Serum deprivation inhibited cellular DNA synthesis and increased levels of HBV messenger RNA (mRNA). Aphidicolin treatment resulted in cell arrest in C1, with concomitant increases in levels of HBV mRNA and viral DNA. Cell entry into S phase inhibited expression of HBV mRNA. Camptothecin induced G2 cell arrest and inhibited cellular DNA synthesis with increased amounts of viral replication and levels of HBV mRNA. In vivo studies showed an inverse correlation between expression of proliferating cell nuclear antigen and presence of episomal HBV DNA in individual hepatocytes.

CONCLUSIONS

HBV replication is cell cycle dependent, supporting the concept of enhanced viral replication in quiescent hepatocytes. The results may explain the mechanism of viral elimination during cell regeneration.

Leiomyosarcoma of the parotid gland

A 36-year-old patient with a primary leiomyosarcoma of the left parotid gland is presented. To our knowledge this is only the second case of a parotid leiomyosarcoma in the world according to the literature review.

Prenatal diagnosis of beta-thalassaemia and sickle cell anaemia in Turkey

This paper reports our experience of molecular analysis and diagnosis of beta-thalassaemia and sickle cell anaemia (HbS) in 70 prospective parents of Turkish descent and their fetuses. Molecular screening was carried out by allele-specific oligonucleotide (ASO) hybridization of amplified DNA to the 12 most common mutations in the Turkish population. By using this approach, we were able to define the mutation in 95 per cent of chromosomes investigated. Genomic sequencing led to the additional detection of three rare mutations: Cd 44 (-C), IVS-I-5 (G-C), and IVS-I-116 (T-G). All diagnoses were successfully accomplished and no misdiagnosis occurred. Consanguineous marriage appears to contribute significantly to the frequency of affected births in Turkey. Out of the 14 homozygous fetuses, six were the result of close consanguinity. This study indicates that fetal diagnosis of beta-thalassaemia and HbS may be obtained in practically all cases, even in a heterogeneous population like the Turkish population, when early methods of fetal sampling are combined with polymerase chain reaction (PCR)-based techniques. Until gene therapy becomes a reality, the only approaches to the control of haemoglobinopathies are prevention and avoidance. The most relevant and common aspects of the programmes, which have been very effective in reducing the birth rate of beta-thalassaemia major in several at-risk areas of the Mediterranean basin, are the continuous educational campaigns directed at the population at large, the voluntary basis, and non-directive counselling. The most important challenge for the eradication of the haemoglobinopathies in Turkey is the organization of a nation-wide and comprehensive genetic preventive programme based on DNA technology.

Induction of senescent cell-derived inhibitor of DNA synthesis gene, SDI1, in hepatoblastoma (HepG2) cells arrested in the G2-phase of the cell cycle by 9-nitrocamptothecin

BACKGROUND

Recent studies have demonstrated that the plant-derived alkaloid camptothecin (CPT) and its derivative, 9-nitro-CPT (9NC), are cytotoxic in tumorigenic cells but cytostatic in nontumorigenic cells in vitro and in vivo. Also, CPT induces differentiation of human leukemia cells in vitro along specific lineages. In this study, we have investigated the effects of 9NC on nontumorigenic HepG2 cells derived from human hepatoblastoma. A newly discovered senescent cell-derived inhibitor (SDI1) plays a critical role in the cell cycle, so we evaluated the effect of 9NC on the expression of the SDI1 gene.

EXPERIMENTAL DESIGN

The effects of 9NC on HepG2 cells were evaluated by monitoring DNA synthesis, morphologic and ultrastructural changes of cells, and perturbation in the cell cycle and by assessing the levels of p53 protein and SDI1 mRNA.

RESULTS

Treatment of HepG2 cells with 9NC results in a dose-dependent inhibition of cell proliferation and DNA synthesis. Flow cytometric analysis of DNA content showed that 9NC-treated HepG2 cells are arrested in the G2-phase of the cell cycle. Light and electron microscopic examination revealed that 9NC at low concentrations induces morphologic and growth features that resemble properties highly differentiated or senescent cells, i.e., increased cell size and decreased nuclear/cytoplasmic ratio, as well as enlarged numbers of lysosomes, mitochondria, and lipid in the cytoplasm. No significant alteration in the p53 protein level was noted in 9NC-treated cells. In contrast to untreated, logarithmically grown HepG2 cells, 9NC-treated cells arrested at the G2-phase of the cell cycle and contained increased levels of SDI1 mRNA. Kinetic studies revealed gradual increases in SDI1 mRNA synthesis.

CONCLUSIONS

Induction of SDI1 mRNA by 9NC represents the first documentation that the SDI1 gene can be overexpressed in the G2-phase of the cell cycle and provides a valuable cell culture system to dissect the events controlling the G2 checkpoint. In addition, this finding corroborates the hypothesis that genes up-regulated in senescent cells can also be induced in tumor-derived immortalized cells.

Sustained-release dosage form of nitrofurantoin. Part 2. In vivo urinary excretion in man

The in vivo absorption of crystalline nitrofurantoin and the dosage forms of nitrofurantoin prepared with microcapsules were carried out in man by determination of urinary excretion of unchanged nitrofurantoin. The cumulative amount of drug excreted and the duration of the therapeutic urine levels were compared. The microcapsule administration showed that the peak reached during the excretion of nitrofurantoin in urine, decreased significantly when compared to the pure drug. This could be an explanation for the decrease in side-effects of nitrofurantoin such as nausea and vomiting. Experiments in male albino rats showed that the microcapsules did not produce gastric haemorrhage seen with the same doses of the pure drug.

The molecular basis of β-thalassemia in Turkey

By using oligonucleotide hybridization, restriction endonuclease analysis and direct sequencing of amplified genomic DNA, we have been able to characterize 18 different mutations in the beta-globin genes of 161 beta-thalassemia homozygotes and 107 beta-thalassemia heterozygotes from Turkey (429 beta-thalassemia chromosomes). Previous studies dealing with beta-thalassemia in Mediterranean countries have shown that, in most Mediterranean populations, only a few mutations are prevalent. In contrast, beta-thalassemia in Turkey does not seem to be associated with a few predominant mutations. The six most frequent alleles, IVS-I-110 (G----A), IVS-I-6(T----C), FSC-8 (-AA), IVS-I-1(G----A), -30(T----A) and FSC-5 (-CT), account for only 69.3% of the disease genes; indeed, all 26 mutations assayed represent 85.8% of the disease genes, confirming the considerable molecular heterogeneity of beta-thalassemia among Turks, and indicating the possible presence of rare, previously undefined, mutations in the population. Two mutations observed in this study, IVS-I-116 (T----G) and Cd44(-C), have not been reported in the Turkish population to date. Since preventive medical services, such as genetic counseling and prenatal diagnosis, are greatly improved by detailed knowledge of the molecular pathology of beta-thalassemia, we strongly believe that the presented data will facilitate the intended establishment of a prenatal diagnosis center, based on DNA analysis, in Turkey.

The effect of cigarette smoke on the plasma piroxicam concentrations in rats

The plasma concentration of unchanged piroxicam has been determined at 15, 30, 60 and 90 min after 10 mg kg-1 oral administration of the drug to rats exposed to cigarette smoke or pretreated with phenobarbitone, 3,4-benzpyrene or ethanol. Plasma piroxicam concentrations decreased in rats pretreated with phenobarbitone, 3,4-benzpyrene and ethanol and in rats 24 h after exposure to cigarette smoke.

[Microscopic studies of the skin of the Turkish Angora goat. I. Skin layers]

The study describes basic structural aspects of the integumental layers (epidermis, dermis, hypodermis) of the Turkish Angora goat. The results have been obtained by light- and electronmicroscopical methods. Central topics are measurements of layer thickness as related to annual season and life period, as well as typical criteria of integumental layer construction as connected with the hair cycle. Remarkable is a trimerous organization of the dermis and cyclic changes in the thickness of the stratum adiposum of the hypodermis. The findings are discussed with regard to comparable observations from other domestic mammals.

The effect of a single treatment with cigarette smoke on the blood levels and hemodynamic effects of propranolol in rats

The effect of a single treatment with cigarette smoke on the blood levels and hemodynamic effects of propranolol in rats was studied. Pentobarbital sleep time was not affected whereas zoxazolamine paralysis time was shortened 72% in rats, 24 h after the cigarette smoke exposure. The beta-adrenoceptor blocking effect of propranolol observed at 10 and 20 min time intervals was abolished in rats exposed to cigarette smoke 24 h after the exposure. The blood propranolol concentrations were decreased in rats pretreated with phenobarbital, 3,4-benzpyrene and ethanol as well as in cigarette smoke exposed rats. Among several factors that could influence propranolol metabolism, in this study, enzyme induction is suggested to be dominant.

Contraction induced by (-)-tartaric acid on rat isolated gastric fundus and its inhibition with indomethacin

Tartaric acid-evoked contractions of the rat isolated fundus could not be antagonized by atropine sulphate or methysergide hydrogen maleate, but were partially reduced by mepyramine hydrochloride. The contractions were prevented by indomethacin (25 micrograms ml-1) although the tissue remained sensitive to PGE2.

Isolation and identification of two isomeric trihydroxy octadecenoic acids with prostaglandin E-like activity from onion bulbs (Allium cepa)

Two fractions with prostaglandin E-like activity were isolated from onion (Allium cepa) by using XAD-2 adsorption, silicic acid column chromatography and thin layer chromatography. The fractions were analyzed by gas chromatography/mass spectrometry and were characterized as isomeric mixtures of 9,10,13-trihydroxy-11-octadecenoic and 9,12,13-trihydroxy-10-octadecenoic acid, which are lipoxygenase metabolites of linoleic acid. Bio-assay, for which cascade superfusion was used and the rabbit coeliac and mesenteric arteries and the rat fundus strip were employed as assay organs, was utilized to monitor the bio-active profile throughout the isolation procedures. The activity of 1 microgram of the pharmacologically active fractions T1 and T2 was found to be equivalent to that of respectively 1.33 and 0.63 ng of prostaglandin E2.

Adenylate cyclase and phosphodiesterase activity in the platelet release abnormality

11 patients with histories of clinical bleeding were selected as examples of platelet release abnormality. Mean bleeding time was 18 +/- 2.6 min (normal +/- SEM; 6 +/- 0.44); mean platelet adhesiveness was 9.9 +/- 4.3% (normal +/- SEM; 30 +/- 2.2). Clot retraction and platelet factor 3 were normal. Platelet aggregation with adenosine diphosphate (ADP), epinephrine and collagen was decreased, as was 14C-serotonin release. Electron microscopic studies of platelets exposed to epinephrine showed 2 subgroups: one which failed to aggregate or have centralization of organelles and a second which developed pseudopodia and centralization of organelles, but rarely aggregated or degranulated. Measurements of activity of adenylate cyclase and phosphodiesterase under basal conditions were performed on platelets from patients and control subjects. Adenylate cyclase activity was significantly lower and phosphodiesterase activity significantly higher in the patient group. Prostaglandin E1 was a potent stimulator of adenylate cyclase in both groups, as was NaF. It was concluded that the causative defects with "platelt release abnormality" do not reside in either the activity of adenylate cyclase or of phosphodiesterase. Changes in formation and destruction of cyclic adenosinemonophosphate (AMP) may instead be regarded as a compensatory response to a defect in another effector system.