Comparison of the effects of gelatin,Ringer’s solution and a modern hydroxyl ethyl starch solution after coronary artery bypass graft surgery

Objective

The aim of this study was to compare the effect of 6% hydroxyl ethyl starch solution with 4% gelatin and Ringer’s solutions on the haemodynamic stability of patients after coronary artery bypass graft (CABG) surgery and immediately after discontinuation of cardiopulmonary bypass (CPB).

Methods

This was a randomised, double-blind clinical trial of 92 patients who were candidates for on-pump CABG. After discontinuation of CPB, all patients were transferred to the intensive care unit (ICU) and divided randomly into three groups. The first group received Ringer’s solution, the second group 4% gelatin, and the third 6% hydroxyl ethyl starch (HES) solution (Voluven). Haemodynamic parameters such as heart rate, mean arterial pressure, systolic blood pressure, diastolic blood pressure, central venous pressure, cardiac output and the presence of arrhythmias were documented.

Results

The volume needed for maintaining normal blood pressure and central venous pressure in the range of 10–14 mmHg was less in the HES group than in the other groups. The volume was similar however in the gelatin and Ringer’s groups in the first 24 hours after surgery. Urinary output in the first four and 24 hours after surgery were significantly higher in the HES group than in the other two groups. Mean creatinine levels were significantly lower in the HES group.

Conclusion

HES (6%) had a better volume-expanding effect than gelatin (4%) and Ringer’s solutions, and its short-term effects on renal function were also better than gelatin and Ringer’s solutions.     

Cryptosporidium Spp. Infection in Human and Domestic Animals

Background

Cryptosporidium spp. is a coccidian parasite infected humans and animals. Prevalence rate of Cryptosporidium spp. infection associated with is some parameters such as sampling, age, season, country and contact to domestic animals. This study aimed to determine Cryptosporidium spp. Infection in humans and some animals in rural areas of Shushtar district from Khuzestan Province, south- west of Iran.

Methods

In this study, Stool specimens were randomly collected from 45 cattle, 8 buffalos, 35 calves, 22 turkeys, 3 sheep, 2 geese as well as 62 humans in different seasons selected from rural areas of Shushtar district located in Khuzestan in the south- west of Iran from August 2009 to April 2011. The collected stool samples were examined by modified Ziehl-Neelsen staining method.

Results

Altogether, 68/115 (59.1%) domestic animals and 9/62 (14.5%) of humans were showed Cryptosporidium spp. infection in the study areas.

Conclusion

In this study we found the high frequency of Cryptosporidium spp. infection in the studied areas.     

Assessment of Trace-Metal Concentrations in Western Reef Heron (Egretta gularis) and Siberian Gull (Larus heuglini) From Southern Iran

The objective of the present study was to investigate the levels of heavy metals, namely, chromium, copper, cobalt, nickel, and iron, in Western Reef heron (Egretta gularis) (n = 15) and Siberian gull (Larus heuglini) (n = 15) to (1) compare metal concentrations between two bird species with different trophic level, molting pattern, and life strategy; (2) examine species- and sex-related variations in trace-metal accumulation; and (3) determine the significance between heavy-metal concentrations in kidney, liver, and pectoral muscle. Bird samples were collected from November to December 2010 throughout the Hara Biosphere Reserve, and heavy metals were assayed by using a Shimadzu AA 680 flame atomic absorption spectrophotometer; the results were given as μg/g dry weight. Metal concentrations were different between the bird species as well as among bird tissues, but there was no difference (except chromium and iron in kidney) between sex (male vs. female). Mean levels in kidney of Western Reef heron and Siberian gull were chromium (0.96, 2.32 μg/g), copper (6.31, 10.55 μg/g), cobalt (0.12, 0.14 μg/g), nickel (1.13, 1.32 μg/g), and iron (37.92, 39.64 μg/g), respectively, whereas in liver they were chromium (1.05, 2.75 μg/g), copper (8.93, 12.63 μg/g), cobalt (0.09, 0.17 μg/g), nickel (1.1, 2.27 μg/g), and iron (34.03, 44.21 μg/g), respectively. Results showed that heavy-metal concentrations in Western Reef heron were decreased in the sequence iron > copper > nickel > chromium > cobalt, whereas in Siberian gull they were decreased in the sequence iron > copper > chromium > nickel > cobalt. Results also showed that in both species, the highest chromium and nickel concentrations were measured in female birds and the lowest in male birds, whereas the highest copper, cobalt, and iron (except iron in liver) concentrations were measured in male birds and the lowest in female birds.     

Differential effects of pentaerythritol tetranitrate and nitroglycerin on the development of tolerance and evidence of lipid peroxidation: a human in vivo study

OBJECTIVES: We investigated the development of nitrate tolerance after continuous exposure to nitroglycerin (GTN) as compared with pentaerythritol tetranitrate (PETN) in humans. BACKGROUND: Sustained therapy with GTN causes tolerance and has been associated with increased production of free oxygen radicals by the endothelium. Pentaerythritol tetranitrate is an organic nitrate that has been used in the therapy of angina. There have been no investigations concerning the development of tolerance to PETN in humans. Animal investigations suggested that continuous therapy with PETN does not cause increased free radical production or hemodynamic tolerance. METHODS: We randomized 30 healthy volunteers to continuous GTN (0.6 mg/h/24 h), long-acting PETN (60 mg orally three times a day) or no treatment (control group) for seven days. We studied systemic blood pressure responses and venous volume responses to GTN with strain-gauge plethysmography. The levels of cytotoxic aldehydes and isoprostanes were measured as markers of free radical-mediated lipid peroxidation. RESULTS: Tolerance, as demonstrated by blood pressure and forearm plethysmography, developed in the GTN group and was absent in the PETN group (p < 0.05). Therapy with GTN was associated with a significant increase in plasma markers of lipid peroxidation. This response was not observed in those treated with PETN (isoprostanes: control: 38 +/- 5; GTN: 59 +/- 6; PETN: 38 +/- 3 microg/ml; p < 0.005). CONCLUSIONS: Treatment with PETN does not cause tolerance and is not associated with evidence of increased free radical production.     

Effect of liposome size on peritoneal retention and organ distribution after intraperitoneal injection in mice

Peritoneal carcinomatosis is a serious concern when treating digestive or ovarian tumors. Treatment with systemic chemotherapy suffers from poor penetration of cytotoxic agents into the peritoneal cavity and is not quite effective. Local delivery of drugs, especially as controlled-release delivery systems like liposomes, could provide sustained and higher drug levels and reduce systemic toxicity.In order to investigate the effect of liposome size on peritoneal retention, liposomes composed of distearoylphosphatidylcholine and cholesterol (DSPC/CHOL, molar ratio 2:1) were prepared at four sizes of 100, 400, 1000 and 3000 nm. Subsequently, these liposomes were labeled with ^99mTc complex of hexamethylpropyleneamineoxime (^99mTc-HMPAO) and injected into mouse peritoneum. Then, mice were sacrificed at eight different time points and the percentage of injected radiolabel in the peritoneal cavity and the organ distribution in terms of percentage injected dose/gram tissue (%ID/g) were obtained.Results showed that the free label (^99mTc-HMPAO) was cleared very rapidly from the cavity so that after 5 min and 7 h only 6.89 ± 2.51% and 0.91 ± 0.51% of the injected dose was recovered, respectively. However, for the liposomal formulations, this recovery value ranged from 8.47 ± 1.62% to 29.99 ± 12.06% at 7 h. Peritoneal retention of the vesicles was increased with their size, and the highest retention rate was obtained with 1000 nm liposomes with an AUC value 15.51 times that of ^99mTc-HMPAO. In blood, as expected, 100 nm liposomes showed much higher levels because of their greater stability. Their greater blood concentration also caused increased levels in the heart and kidneys, although their organ to blood AUC ratio was the lowest.Overall, among the different sized neutral liposomes investigated, the 1000 nm vesicles seemed to be the most optimal, achieving a greater peritoneal level and retention.     

Bioaccumulation of Heavy Metals in Freshwater Fish Species,Anzali, Iran

The main objectives of study were to monitor the metals concentrations, in freshwater fish species, Carassius gibelio and Esox lucius; and to identify any relationships between species and bioaccumulation of metals. The highest concentration of metals (cadmium, 1.96; copper, 24.2; zinc, 49.6; lead, 5.4; chromium, 4.4) between the fish species and tissues was in the liver of Esox lucius, while the lowest (cadmium,0.21; copper,7.2; zinc,19.4; lead,0.9; chromium,0.6 μg/g) found in the muscle of Carassius gibelio. Results showed that the metal concentrations were in fishes in descending order of zinc > copper > lead > chromium > cadmium, similarly in the tissue liver > kidney > gill ~ intestine > muscle.