Biodegradation of petroleum sludge and petroleum polluted soil by a bacterial consortium: a laboratory study.

This article presents a study of the efficiency and degradation pattern of samples of petroleum sludge and polluted sandy soil from an oil refinery. A bacterial consortium, consisting of strains from the genera Pseudomonas, Achromobacter, Bacillus and Micromonospora, was isolated from a petroleum sludge sample and characterized. The addition of nitrogen and phosphorus nutrients and a chemical surfactant to both the samples and bioaugmentation to the soil sample were applied under laboratory conditions. The extent of biodegradation was monitored by the gravimetric method and analysis of the residual oil by gas chromatography. Over a 12-week experiment, the achieved degree of TPH (total petroleum hydrocarbon) degradation amounted to 82-88% in the petroleum sludge and 86-91% in the polluted soil. Gas chromatography-mass spectrometry was utilized to determine the biodegradability and degradation rates of n-alkanes, isoprenoids, steranes, diasteranes and terpanes. Complete degradation of the n-alkanes and isoprenoids fractions occurred in both the samples. In addition, the intensities of the peaks corresponding to tricyclic terpenes and homohopanes were decreased, while significant changes were also observed in the distribution of diasteranes and steranes.

The impact of Schiff bases on antibiotic production by Streptomyces hygroscopicus.

A media consisting of isatin-Schiff bases (isatin-3-thiosemicarbazone, isatin-3-semicarbazone, and isatin-3-phenylhydrazone) was developed to maximize the production of antibiotics Hexaene H-85 and Azalomycine B by Streptomyces hygroscopicus. The media isatin-3-thiosemicarbazone resulted in the maximum antibiotics concentration of 372 mug cm(-3) for Hexaene H-85 and 118 mug cm(-3) for Azalomycine B. The impact of modified media on soil morphology also was investigated.

Production of levan by Bacillus licheniformis NS032 in sugar beet molasses-based medium.

The production of levan by Bacillus licheniformis NS032 in a medium based on sugar beet molasses was studied. High polysaccharide yields were produced by using diluted molasses (100-140 g/L of total sugars) with the addition of commercial sucrose up to 200 g/L of total sugars, as well as K2HPO4. A levan yield of 53.2 g/L was obtained on a medium optimized by response surface methodology, containing 62.6% of sugar originating from molasses, and 4.66 g/L of phosphate, with initial pH value of 7.2. In comparison to the media with 200 and 400 g/L sucrose, in the molasses optimized medium, the observed bacterial growth was faster, while the maximum production of polysaccharide was achieved over a shorter time interval (48 h). The polysaccharide produced in molasses medium had a weight average molecular weight of 5.82 × 106 Da, degree of branching 12.68%, viscosity of 0.24 dL/g, and based on methylation analysis and NMR data, it did not significantly differ from levan obtained in the medium with 200 g/L sucrose.

Total ghrelin levels during acute insulin infusion in patients with polycystic ovary syndrome.

Controversial data were reported concerning fasting ghrelin (decreased, normal or elevated) in polycystic ovary syndrome (PCOS). The aim of our study was to clarify ghrelin levels in non-obese, overweight, and obese PCOS patients; to investigate the effect of acute insulin infusion on ghrelin in PCOS as a chronic insulin-resistant state, with and without the impact of obesity, and to examine ghrelin-androgen interaction. In that order, we evaluated 1) ghrelin levels among 8 nonobese patients with PCOS [body mass index (BMI): 20.52+/-1.31 kg/m2], 8 overweight and obese patients with PCOS (BMI: 34.36+/-6.53 kg/m2) and their respective controls, 2) ghrelin suppression during euglycemic hyperinsulinemic clamp, and 3) ghrelin-androgen interrelationship. After overnight fast, 2-h euglycemic hyperinsulinemic clamp, was performed in all investigated women. Fasting ghrelin was significantly lower in non-obese PCOS than in controls (64.74+/-25.69 vs 108.36+/-52.60; p<0.05) as well as in overweight and obese PCOS in comparison with controls (38.71+/-14.18 vs 98.77+/-40.49; p<0.05). Insulin infusion significantly suppressed ghrelin in all subgroups of investigated women. Analysis of variance for repeatable measures confirmed that there was no significant difference in pattern of response between PCOS and controls. In conclusion, women with PCOS had lower fasting ghrelin and decreased insulin sensitivity independently of their BMI, compared to the controls. In addition, there were no differences between fasting ghrelin levels among non-obese, overweight, and obese women with PCOS. During euglycemic hyperinsulinemic clamp, ghrelin decreased in all studied groups to a similar extent, implying that, compared to chronic hyperinsulinemia, acute hyperinsulinemia reduces ghrelin levels independently of the degree of insulin resistance.

The effect of parathyroidectomy on insulin sensitivity in patients with primary hyperparathyroidism - an never ending story?

Previous studies demonstrated insulin resistance and increased prevalence of impaired glucose tolerance and type 2 diabetes mellitus in patients with primary hyperparathyroidism (PHPT). The effect of curative parathyroidectomy on insulin sensitivity was associated with conflicting results depending on which method for measuring the insulin sensitivity has been used. There was no improvement using HOMA and QUICKI while minimal model demonstrated significant improvement in insulin sensitivity. The aim of our study was to evaluate the insulin sensitivity before and after parathyroidectomy in patients with PHPT using a euglycemic clamp. 44 patients with PHPT and 11 age and body mass index matched healthy controls participated in study protocol. Before surgery M values and HOMA IR suggest insulin resistance in patients with PHPT. There was no difference in M index (3.74±1.89 vs. 4.62±2.27, p>0.05), HOMA IR (2.94±1.39 vs. 3.29±0.81, p>0.05), AUC glucose (863.0±261.3 vs. 842.3±165.5, p>0.05), AUC insulin (7068.7±4159.0 vs. 7229.6±2581.7, p>0.05), ISI (4.73±2.77 vs. 4.25±2.94, p>0.05) and AIR (47.89±32.05 vs. 38.96±21.20, p>0.05) between patients with PHPT and HC. There was significant improvement in insulin sensitivity after parathyroidectomy but both preoperative and postoperative M values were not significantly different in comparison to HC. There were no significant changes in HOMA IR, AUC glucose, AUC insulin, ISI and AIR before and after therapy. In conclusion, we observed significant improvement in insulin sensitivity after parathyroidectomy in patients with PHPT. There was no difference in parameters of insulin secretion before and after parathyroidectomy in patients with PHPT.

High levan production by Bacillus licheniformis NS032 using ammonium chloride as the sole nitrogen source.

In this study, levan production by Bacillus licheniformis NS032 isolated from a petroleum sludge sample was investigated. High levan yield was obtained in a wide range of sucrose concentrations (up to 400 g/L) and, contrary to most levan-producing strains, using ammonium chloride as the sole N source. Interaction between sucrose, ammonium chloride, and initial pH of the medium in a low sucrose (60-200 g/L) and a high sucrose (300-400 g/L) system was analyzed by response surface methodology. According to the calculated model in the low sucrose system, maximum predicted levan yield was 47.8 g/L (sucrose 196.8 g/L, ammonium chloride 2.4 g/L, pH 7.0), while in the high sucrose system, levan yield was 99.2 g/L (sucrose 397.6 g/L, ammonium chloride 4.6 g/L, pH 7.4). In addition, protective effect of microbial levan against copper toxicity to Daphnia magna is observed for the first time. The acute toxicity (48 h EC50) of copper decreased from 0.14 to 0.44 mg/L by levan in concentration of 50 ppm.

Cardiovascular risk in adolescent and young adult obese females with polycystic ovary syndrome (PCOS).

Women with polycystic ovary syndrome (PCOS) could have associated risk for cardiovascular disease. The aim of the present study was to investigate the relationship between age and metabolic factors on cardiovascular risk in obese women with PCOS. Obese patients with PCOS were divided into an adolescent group (n=11; age 16.90 +/- 0.45 yr; BMI 35.04 +/- 1.70 kg/m2), and an adult group (n=18; age 29.66 +/- 1.31; BMI 34.57 +/- 1.46). We determined basal values of glucose, insulin, lipid and fibrinolytic parameters from blood samples taken in all patients and matched controls. Significantly different concentrations between the groups with PCOS were obtained for glucose, total cholesterol, triglycerides, LDL-cholesterol and Apo-B. Elevated concentrations of insulin (20.63 mU/l), both insulin sensitivity indexes--G:I ratio (7.52 mg/10(-4) U) and HOMA model (4.11 mmol/l x U/l(2))--and PAI-1 (5.49 U/ml) were obtained in the adolescent group with PCOS compared to controls, with further increase in the adult group with PCOS. It seems that the youngest obese population with PCOS represents a cohort with potential cardiovascular disease in adulthood.

Growth hormone replacement normalizes impaired fibrinolysis: new insights into endothelial dysfunction in patients with hypopituitarism and growth hormone deficiency.

BACKGROUND: Cardiovascular morbidity in adult patients with growth hormone deficiency (GHD) and hypopituitarism is increased. Clustering of cardiovascular risk factors leading to endothelial dysfunction and impaired fibrinolysis has also been reported and may account for progression to overt vascular changes in these patients. However, effect of long lasting GH replacement therapy on fibrinolytic capacity in GH deficient patients has not been investigated so far. OBJECTIVE: To investigate fibrinolysis before and after challenge with venous occlusion in GHD patients with hypopituitarism before and during one year of growth hormone replacement. DESIGN: Hospital based, interventional, prospective study. INVESTIGATED SUBJECTS: Twenty one patient with GHD and fourteen healthy control subjects matched for age, sex and body mass index (BMI). METHODS: Anthropometric, metabolic and fibrinolytic parameters were measured at the start and after three, six and twelve months of treatment with human recombinant GH. RESULTS: At baseline GHD patients had significantly impaired fibrinolysis compared to healthy persons. During treatment with GH, significant changes were observed in insulin like growth factor 1(IGF-1) [from baseline 6.9(2.4-13.5) to 22.0(9.0-33.0) nmol/l after one month of treatment; p<0.01] and fibrinolysis. Improvement in fibrinolysis was mostly attributed to improvement of stimulated endothelial tissue plasminogen activator (t-PA) release in response to venous occlusion [from baseline 1.1(0.4-2.6) to 1.9(0.5-8.8) after one year of treatment; p<0.01]. CONCLUSION: Growth hormone replacement therapy has favorable effects on t-PA release from endothelium and net fibrinolytic capacity in GHD adults, which may contribute to decrease their risk of vascular complications.

Effect of 12 months of recombinant human growth hormone replacement therapy on insulin sensitivity in GH-deficient adults as determined by different methods.

BACKGROUND: Controversial results have been obtained in measuring insulin sensitivity (S(I)) during recombinant human growth hormone (rhGH) treatment in adult growth hormone deficient (GH-deficient) patients. AIMS: The aim of our study was to estimate S(I) before and during treatment using three different methods for quantifying insulin sensitivity in GH-deficient adults treated with rhGH. SETTINGS AND DESIGN: Twenty-one GH-deficient adults were treated with rhGH during 12 months. S(I) was estimated using Minimal model analysis, Homeostatic Model of Assessment (HOMA) and Quantitative Insulin Sensitivity Check Index (QUICKI) before and after 3, 6, 9 and 12 months of rhGH therapy. MATERIAL AND METHODS: Oral Glucose Tolerance Test (OGTT) and Frequently Sampled Intravenous Glucose Tolerance Test (FSIGT) were performed in each patient at respective time intervals. QUICKI and HOMA were calculated using basal values of glucose and insulin from FSIGT. Minimal model computer analysis was calculated from glucose and insulin data obtained during FSIGT. STATISTICAL ANALYSIS: Area under the curve for glucose, insulin and C-peptide were calculated using trapezoidal rule from OGTT data. Differences and correlations were tested using ANOVA for repeated measures, Wilcoxon's matched-paired test, paired t-test, Pearson's correlation and Bland Altman plot. RESULTS: There were no significant changes in S(I) using Minimal model analysis and QUICKI during rhGH treatment. On the contrary, HOMA analysis indicated significant deterioration in S(I) after 12 months of therapy. CONCLUSION: Our study did not demonstrate any changes in S(I) using Minimal model and QUICKI analysis, while there was significant increase in insulin resistance using HOMA model. We suggest that the choice of method for the determination of S(I) may influence the interpretation of results concerning the effect of rhGH therapy on S(I) in GH-deficient adults.

Ovulation induction and early pregnancy loss in a woman susceptible to autoimmune diseases: a possible interrelationship.

We report a 34-year-old woman with sequentially occurring autoimmune diseases that are possibly triggered by numerous ovulation inductions. At the ages of 26-32 years, she experienced 27 uncontrolled ovulation induction cycles using clomiphene citrate (CC) or CC plus human menopausal gonadotropin plus human chorionic gonadotropin. She became pregnant at the ages of 27, 30 and 31 with subsequent pregnancy loss in the 28th, 8th and 10th week of gestation, respectively. Insulin-dependent diabetes mellitus (IDDM) developed at the age of 28. During the second year of ovulation induction, at the age of 27, she developed arthralgia that worsened and became migratory from the age of 31. Thrombocytopenia appeared at the age of 33. The diagnosis of systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) was established at the age of 34. To the best of our knowledge, this is the first case of concurrent IDDM, SLE and APS in a patient associated with ovulation inductions. Excessive levels of estradiol achieved during the ovulation inductions could play a role in the expression of multiple autoimmune diseases in the susceptible woman.

Growth-hormone response to combined stimulation with GHRH plus GH-releasing peptide-6 in obese patients with polycystic ovary syndrome before and after short-term fasting.

Controversial data were reported on GH response to different provocative stimuli in obese patients with polycystic ovary syndrome (PCOS). The objective of our study was to assess the effect of short-term fasting on GH response to combined stimulus with GHRH+GH-releasing peptide-6 (GHRP-6) in obese patients with PCOS and possible relation with leptin and insulin changes during fasting. Twelve obese PCOS women and nine obese control women participated in 3-day fasting. GH response, IGF-I, insulin and leptin were measured after GHRH+ GHRP-6, before and after short-term fasting. Obese PCOS patients had significantly greater GH peak after GHRH+GHRP-6 before fasting. Enhanced response to GH stimulation was found after fasting without substantial differences between obese PCOS and obese controls. Insulin and leptin significantly decreased, while insulin sensitivity significantly improved in both groups during fasting. In conclusion, obese PCOS patients have peculiar type of GH response to GHRH+GHRP-6 before fasting, possibly due to enhanced sensitivity of somatotrophs. Observed changes in insulin and leptin may participate in modulation of enhanced GH response after short-term fasting to GHRH+GHRP-6 in PCOS and obese controls.

Effect of 12 months of recombinant human growth hormone replacement therapy on insulin sensitivity in GH-deficient adults as determined by different methods.

BACKGROUND: Controversial results have been obtained in measuring insulin sensitivity (S(I)) during recombinant human growth hormone (rhGH) treatment in adult growth hormone deficient (GH-deficient) patients. AIMS: The aim of our study was to estimate S(I) before and during treatment using three different methods for quantifying insulin sensitivity in GH-deficient adults treated with rhGH. SETTINGS AND DESIGN: Twenty-one GH-deficient adults were treated with rhGH during 12 months. S(I) was estimated using Minimal model analysis, Homeostatic Model of Assessment (HOMA) and Quantitative Insulin Sensitivity Check Index (QUICKI) before and after 3, 6, 9 and 12 months of rhGH therapy. MATERIAL AND METHODS: Oral Glucose Tolerance Test (OGTT) and Frequently Sampled Intravenous Glucose Tolerance Test (FSIGT) were performed in each patient at respective time intervals. QUICKI and HOMA were calculated using basal values of glucose and insulin from FSIGT. Minimal model computer analysis was calculated from glucose and insulin data obtained during FSIGT. STATISTICAL ANALYSIS: Area under the curve for glucose, insulin and C-peptide were calculated using trapezoidal rule from OGTT data. Differences and correlations were tested using ANOVA for repeated measures, Wilcoxon's matched-paired test, paired t-test, Pearson's correlation and Bland Altman plot. RESULTS: There were no significant changes in S(I) using Minimal model analysis and QUICKI during rhGH treatment. On the contrary, HOMA analysis indicated significant deterioration in S(I) after 12 months of therapy. CONCLUSION: Our study did not demonstrate any changes in S(I) using Minimal model and QUICKI analysis, while there was significant increase in insulin resistance using HOMA model. We suggest that the choice of method for the determination of S(I) may influence the interpretation of results concerning the effect of rhGH therapy on S(I) in GH-deficient adults.