Evidences of microplastics in Hawassa Lake, Ethiopia: A first-hand report.

Investigation on freshwater MPs has increased gradually across the world, since they are main trajectory for the transportation of MPs from inland to ocean. The present study aims to identify the presence, distribution and the type of MPs in the lake Hawassa, Ethiopia. Twenty-five shoreline surface sediments were separated using ZnCl2 solution and was microphotographed using SEM and type of MP was identified using FTIR spectra. The abundance of MPs was in range of 11-74 items/m3 near the catchment area of the lake in the eastern side. Fiber (90%), fragments (5%) and pellets (5%) were the commonly observed form with varied colour such as white, black, blue, red and others. Our results infer that the common polymer detected in the study area were polyester (82%), polyethylene (15%) and polystyrene (3%) infer their origin from fishing nets, ropes and plastics bags. The industries near the lake contributes more MPs, where the waste water effluents are drained directly into the lake. Spearman's correlation matrix applied among the MPs characters endorses the fate of MPs in the lake environment indicating the weathering process (especially due to bleaching process). Comparative studies with other lake regions around the globe indicate higher values which is entirely and it depends on various factors surrounding the study area. Being, highly polluted lake in Ethiopia, this study extremely acclaims that some monitoring studies in fresh water components in the lake Hawassa helps to mitigate the prevailing MPs pollution.

Assessment of groundwater quality and hydrogeochemistry of Manimuktha River basin, Tamil Nadu, India.

Groundwater quality assessment study was carried out around Manimuktha river basin, Tamil Nadu, India. Twenty six bore well samples were analyzed for geochemical variations and quality of groundwater. Four major hydrochemical facies (Ca-HCO(3), Na-Cl, Mixed CaNaHCO(3), and mixed CaMgCl) were identified using a Piper trilinear diagram. Comparison of geochemical results with World Health Organization, United States Environmental Protection Agency, and Indian Standard Institution drinking water standards shows that all groundwater samples except few are suitable for drinking and irrigation purposes. The major groundwater pollutions are nitrate and phosphate ions due to sewage effluents and fertilizer applications. The study reveals that the groundwater quality changed due to anthropogenic and natural influence such as agricultural, natural weathering process.

Obesity and the metabolic response to severe multiple trauma in man.

In the obese state profound metabolic disturbances exist and it is not known how this disrupted metabolism in obese subjects (body mass index greater than 30) may change their ability to respond to the superimposed, injury-induced stress. Understanding the mechanisms that modify the metabolic parameters in traumatized obese patients is essential in their nutritional assessment and further treatment. We have investigated in 7 obese and 10 nonobese multiple trauma patients, on a whole-body level, the energy metabolism, protein kinetics, and lipolysis in the early catabolic "flow phase" of severe injury when they were receiving maintenance fluids without calories or nitrogen. Traumatized obese patients mobilized relatively more protein and less fat compared with nonobese subjects. A relative block both in lipolysis and fat oxidation is experienced by injured obese patients that results in a shift to preferential use of proteins and carbohydrates. Reduced endogenous protein synthetic efficiency observed in obese patients implies increased protein recycling. Thus obese patients could not effectively use their most abundant fat fuel sources and have to depend on other fuel sources. The nutritional management of obese trauma victims should therefore be tailored towards provision of enough glucose calories to spare protein.

Tumor necrosis factor and the acute metabolic response to tissue injury in man.

Tumor necrosis factor (cachectin), a protein produced by monocytes and macrophages, has been implicated as an important mediator of the lethal effects of endotoxic shock and the cachexia of chronic infection. Recombinant human tumor necrosis factor alpha (rTNF) was given intravenously to patients as part of an antineoplastic trial. Fever, tachycardia, and at higher doses, hypotension occurred after a single injection of rTNF. Metabolic effects after rTNF administration were dose related and included enhanced energy expenditure with elevated CO2 production, increased whole body protein metabolism and peripheral amino acid efflux from the forearm, and decreased total arterial amino acid levels associated with a significant increase in plasma cortisol. Elevated serum triglycerides, as well as increased glycerol and free fatty acid turnover were seen, suggesting increased whole body lipolysis and fat utilization after rTNF. These findings indicate that administration of TNF in man reproduces many of the acute physiologic and metabolic responses to tissue injury, including energy substrate mobilization.

Basal glucagon replacement in chronic glucagon deficiency increases insulin resistance.

To evaluate the role of glucagon in insulin-mediated glucose metabolism, we studied four men and four women, ranging in age from 30-73 yr (mean +/- SEM, 54 +/- 5) who had undergone complete pancreatic resection for cancer or chronic pancreatitis 16-58 mo previously. The patients had undetectable C-peptide levels and established lack of biologically active 3500 mol wt glucagon. Euglycemic insulin clamp studies were performed with a 40 mU X m-2 X min-1 insulin infusion in the basal, post-absorptive, insulin-withdrawn state, before and during the last 3 h of a 72-h glucagon replacement-dose infusion (1.25 ng X kg-1 X min-1). In four patients, hepatic glucose production was determined by a primed-constant infusion of 3-[3H]glucose. Monocyte insulin-binding studies, pre- and postglucagon, were performed in all patients. The 72-h glucagon infusion, resulting in mean plasma glucagon levels of 124 +/- 7 pg/ml, caused a significant rise in the mean plasma glucose level (249 +/- 8 versus 170 +/- 13 mg/dl preglucagon) and a sixfold increase in mean 24-h glucose excretion. Both with and without glucagon, euglycemic hyperinsulinemia achieved identical and complete suppression of hepatic glucose production. The mean glucose utilization rate (4.70 +/- 0.36 mg X kg-1 X min-1 preglucagon) was significantly decreased by glucagon replacement (3.83 +/- 0.31 mg X kg-1 X min-1, P less than 0.02). Mean glucose clearance was also diminished with glucagon (4.49 +/- 0.32 versus 5.73 +/- 0.45 ml X kg-1 X min-1 preglucagon, P less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetics of intravenously administered 15N-L-alanine in the evaluation of protein turnover.

After a pulse injection of 15N-L-alanine to a healthy male subject, the distribution of 15N in the various components of blood and urine were determined as function of time. The rapid appearance of the isotope both in the urinary urea and ammonia and in the plasma amide and urea suggests that transamination (and not deamination) may be the key step in the interaction. After 30 to 60 min postinjection, the tracer dynamics represents the overall metabolic pool characteristics and does not reflect the metabolism of alanine only. The nitrogen of alanine is used effectively in the synthesis of body protein.

Metabolism and recycling of urea in man.

The rate of breakdown and reutilization of urea in man has been measured in five normal and two septic patients using 15N and 13C labeled ureas. The labeled molecules of the 15N urea dose were distinguished from the labeled molecules of the recycled urea by analyzing in a mass spectrometer the isotopic nitrogens produced when the recrystalized urine urea was treated with a hypobromite solution. In a normal subject with regular nitrogen intake, it was found that only 4/5 of the produced urea was excreted in urine and the rest was endogenously degraded. Seventy percent of the nitrogen and 63% of the carbon of the degraded urea were returned to the urea pool. On a nitrogen-free diet or after neomycin treatment with regular diet in the normal, the extent of urea splitting is considerably reduced. In the septic patients, breakdown, as well as recycling of urea was almost eliminated. It appears that the reate of endogenous catabolism of urea depends mainly on the activity of the gut flora which may be affected by dietary intake and clinical status of the subject. The method developed here could be applied for the quantitation of urea dynamics under different physiological and pathological conditions.

Mild orotic aciduria and uricosuria in severe trauma victims.

Hypermetabolic responses with respect to pyrimidine and purine kinetics in trauma victims were investigated during the catabolic phase before and after nutritional support. Orotic acid and uric acid excretions were measured in 32 adult, severely traumatized, hypermetabolic, and highly catabolic patients while they were receiving fluids with no calories or nitrogen. Patients were then fed intravenously amino acids and glucose or glucose alone or fed enterally for 5-6 d. Daily excretions of orotic acid, uric acid, urea, nitrogen, and creatinine were monitored. Mild orotic aciduria and uricosuria with hypouricemia were the basal-trauma responses. The significant (P = 0.001, r = 0.70) positive correlation between orotic and uric acid excretion demonstrates the parallelism between pyrimidine and purine metabolism. Feeding for 5-6 d could decrease but not readily abolish the injury-induced metabolic changes in nitrogen, pyrimidine, and purine metabolism. Glucose infusion alone may be sufficient to counteract the metabolic effects of trauma in the early flow phase of injury.

Evaluation of whole body nitrogen kinetics in acute metabolic acidosis.

The data obtained after a pulse dose of L-[15N] alanine and [13C] urea in control and acidotic conscious dogs were analyzed to compute the whole body nitrogen turnover rates. Acute acidosis was induced and maintained by continuous HCl infusion. On the basis of a four pool model, the mean daily protein synthesis rate in the normal dog was calculated to be 10.8 g/kg compared to 7.6 g/kg in acidosis. Since all dogs were in negative nitrogen balance, the daily catabolic rate of protein was greater than the synthetic rate and the mean daily catabolic rate was 14.4 g protein/kg in normal dogs compared to 10.5 g protein/kg in acidotic dogs. The body urea pool size and excretion rates were decreased by 24 and 27%, respectively, due to acute acidosis, without any change in the fractional turnover rate. Thus the adaptive response to the induced acid challenge appears to be a reduction in the synthesis and breakdown rates of protein and also a decrease in the production and excretion rate of urea.

Whole body protein synthesis and catabolism in septic man.

The protein catabolic response to sepsis has been measured in three patients and in two normal subjects using a pulse injections of L-[15N]alanine. In addition, the urea kinetics were measured using a pulse administration of [15N]urea. Several nitrogen models which simulated the metabolic pathways of nitrogen-labeled compounds were tried. Best curve fits and acceptable confidence limits were obtained with a four-pool model containing two metabolic pools and two urea pools. Using this model, synthesis and catabolism rates were calculated for a fast and slow protein turnover pool. The mean daily total protein synthesis rate in the normal was 3.695 g/kg compared to 4.479 g/kg in sepsis. Because all subjects were in negative nitrogen balance, the mean total protein catabolic rate in the normal was 4.379 g/kg, compared to 5.298 g/kg in sepsis. These data suggest an increase in both protein synthesis and catabolism during sepsis.

Effect of major trauma on plasma free amino acid concentrations in geriatric patients.

Age-associated decrease in lean body mass may lead to varied responses to severe trauma. Hypoaminoacidemia is generally common among trauma victims. We measured the plasma free amino acids in the early "flow," ie, catabolic, phase of injury in 9 elderly (aged 61-81 y) and 13 young (aged 20-38 y) traumatized patients. Postabsorptive control samples were obtained from 8 elderly and 10 young volunteers. The results were analyzed for age-related responses to major trauma. Older healthy control subjects showed a decrease in total amino acids, essential amino acids, proline, histidine, taurine, and cystine. The hypoaminoacidemia was less pronounced in geriatric trauma, mainly because of a larger decrease in nonessential amino acids in young trauma victims. Significant decreases in arginine and methionine and increases in ornithine and citrulline concentrations were seen in geriatric trauma. These results suggest a sluggish protein metabolic response to trauma in elderly individuals, which should be considered in their nutritional management.

Aminoaciduria of severe trauma.

Plasma and urine levels of free amino acids were measured in 15 severely traumatized adult patients while they were receiving fluids free of calories and nitrogen. Endogenous plasma clearance and the relative rates of reabsorption of free amino acids from renal tubules were calculated. These data were compared with similar studies of eight control subjects. Multiple injury provoked distinct patterns of free amino acids in plasma and urine. Hypoaminoacidemia and hyperaminoaciduria were seen in severe trauma. There was a marked depletion of nonessential amino acids in plasma of trauma victims. In contrast, the urinary loss of all amino acids was increased 5-10 times. This enhanced loss in patients, however, represented only 2.1% of total N excreted compared with 0.7% in control subjects. Considerable variations were seen in the selectivity with which various amino acids were reabsorbed by renal tubules. This may partly be due to the abnormal pattern of amino acids presented to renal tubules.

Relative nutritional efficacy of arginine and ornithine salts of alpha-ketoisocaproic acid in traumatized rats.

The relative dietary efficacy of arginine alpha-ketoisocaproate (AKIC) and ornithine alpha-ketoisocaproate (OKIC) is evaluated in a rat (Sprague-Dawley) trauma (bilateral femur fracture) model. Both control and traumatized rats were starved for 2 d and then pair-fed for 2 or 4 d one of three liquid diets: diet 1 was a basic casein diet; diets 2 and 3 were the basic diet in which 10% of nitrogen was replaced by AKIC or OKIC nitrogen, respectively. Irrespective of the diet, the protein-efficiency ratio, defined as the gain in body weight per grams nitrogen consumed, was 27% less in traumatized rats than in control rats. More improvement in apparent nitrogen balance, particularly in traumatized rats, was seen with the AKIC supplement. Plasma amino acid patterns demonstrated stimulation of net protein synthesis with AKIC and not with OKIC. Dietary supplementation with AKIC may be beneficial to promote nitrogen economy in trauma victims.

Protein synthesis in the tumor-influenced hepatocyte.

Total body protein turnover is elevated in the Fischer 344 rat bearing a subcutaneous transplantable methylcholanthrene-induced sarcoma. To assess the contribution of the liver, we have measured protein synthesis by hepatocytes freshly isolated from tumor-bearing animals over a range of tumor burdens and from sham-inoculated nontumor bearers. Synthetic rates of total hepatocyte protein were more than twofold greater in hepatocytes from tumor-bearing animals (P less than 0.005) and the increase was proportional to the tumor burden in individual animals (n = 19; r = 0.68; p less than 0.005). When compared with pair-fed nontumor bearers, the differences in rates of total hepatocyte protein synthesis reached statistical significance only when the tumor burden exceeded 5% of total body weight. The stimulation in synthetic rates applied equally to secretory and nonsecretory hepatocyte protein. Furthermore, a lack of net protein accrual in the livers of tumor-bearing animals suggests a concomitant increase in the rate of hepatic protein degradation.

Extremity blood flow in man: comparison between strain-gauge and capacitance plethysmography.

Metabolic studies with substrate limb flux determinations require an accurate and simple method for measuring blood flow through the extremity. Two common, noninvasive methods used in recent studies are strain-gauge and capacitance venous occlusion plethysmography. The values obtained for forearm blood flow by these two methods are highly correlated in normal resting and seriously ill patients. The use of a fixed percentage of cardiac output as a measure of extremity flow was not indicative of the measured flow by either capacitance or strain-gauge plethysmography. Capacitance and strain-gauge plethysmography are comparable, noninvasive indicators of change in extremity blood flow in humans.

Pulsatile nature of growth hormone levels in critically ill trauma victims.

BACKGROUND: Circulating growth hormone (GH) levels in normal persons fluctuate widely because of pulsatile GH secretion. It is not known whether this pulsatile nature and rhythmicity exist in severe injury. These data become necessary to decide the timing of supplementary GH administration for its optimal utilization. The purpose of this study was to investigate the GH circadian variation with respect to that of insulin-like growth factor-1 (IGF-1), insulin, C-peptide, and cortisol in the early flow phase of injury. METHODS: Plasma GH, IGF-1, insulin, C-peptide, and cortisol levels were measured at 1-hour intervals during 24 hours (8 AM to 8 AM) in 10 severely injured adults with multiple trauma during the early catabolic flow phase 24 to 48 hours after injury, when patients received maintenance fluids without calories or nitrogen. RESULTS: The 24-hour integrated GH concentration is not different from either 12-hour mean diurnal or 12-hour mean nocturnal or mean 8 AM GH concentration. Pulsatile GH bursts persist in injured patients during both day and night. Pulsatile bursts do not exist for IGF-1, insulin, and C-peptide. The plasma levels of cortisol show time-dependent daily maximum and minimum levels. CONCLUSIONS: Pulsatile GH bursts persist in injured patients but less frequently than seen in normal persons. The time of bolus administration of GH to augment the anabolic GH action in patients with trauma does not matter; however, for convenience morning administration may be preferable for patients in the intensive care unit.

Decreased growth hormone levels in the catabolic phase of severe injury.

BACKGROUND: Human growth hormone (hGH) is a potent anabolic agent, which has profound effects on protein, carbohydrate, and lipid metabolism. The role of this primarily anabolic hormone in the severe catabolic state of trauma is not known. METHODS: In a group of young, obese, and elderly patients with multiple traumas, plasma hGH levels were measured in the catabolic "flow" phase of injury, once before and then after 4 to 6 days of nutritional support sufficient to match their initial loss of calories and nitrogen. RESULTS: A decreased hGH level was noted in the hyperglycemic and hypercatabolic injured state, particularly in victims of trauma who were young and not obese, compared to respective volunteers. A significant (p = 0.025) inverse relationship was observed between age and plasma hGH levels in this group of patients who had experienced trauma. Nutritional therapy improved the protein and fat metabolism but could not reverse to the normal state. In young patients who had experienced trauma and who were not obese, the hGH levels were significantly improved because of dietary intake, whereas in elderly patients or patients who were obese no change was noted. CONCLUSION: These results are consistent with less lipid mobilization and inefficient utilization of fatty acids in the elderly patients or patients who were obese who had abundant fat sources to spare. Elevation of hGH level by exogenous administration may improve the nitrogen economy and lipid mobilization, particularly so in the elderly patients or patients who were overweight. Our study supports the view that provision of adequate nutrition with daily administration of human hGH in the first week after trauma would enhance the metabolic status of the patient, resulting in reduced morbidity and earlier discharge from the hospital.

Gluconeogenesis in tumor-influenced hepatocytes.

The growth of a tumor leads to alterations in host carbohydrate metabolism. In this study we examined gluconeogenic capacity and amino acid transport in tumor-influenced and control rat hepatocytes. Serum glucose level decreased with increasing tumor burden and a significant correlation (r = -0.80) was observed. Hepatic glycogen content was similar in both groups after an overnight fast. Endogenous glucose production was 27% higher in tumor-influenced hepatocytes. The presence of 10mM of alanine led to 72% stimulation of gluconeogenesis in tumor-influenced hepatocytes as compared to 48% stimulation in control hepatocytes. The same trends were present when lactate was used as a substrate. Alanine transport into the cells was increased in tumor-influenced hepatocytes by 55% +/- 5% at a physiologic level of substrate. In conclusion, gluconeogenesis from alanine and lactate is significantly increased in tumor-influenced hepatocytes despite decreased serum glucose levels. This is associated with increased gluconeogenic capacity and accelerated alanine transport.

Impaired metabolic response to endotoxin in obstructive jaundice.

Surgical management of extrahepatic cholestasis is frequently complicated by sepsis, which can be explained in part by diminished function of the reticuloendothelial system. We have explored the possibility that the metabolic response to infection may also be abnormal. Fischer 344 rats underwent either bile duct ligation (BDL) or sham operation and were studied 3 days after operation. Hepatic amino acid uptake measured in vivo by the accumulation of 14C-alpha-aminoisobutyric acid or in vitro by the rate of transport of 14C-alanine by isolated hepatocytes was unaltered in the BDL animals, while gluconeogenesis from alanine by viable hepatocytes from BDL rats was actually enhanced. However, the expected increase in hepatic amino acid uptake in response to endotoxin was diminished in the BDL animals. In addition, we observed impaired responses of the jaundiced animals to glucagon and interleukin-1, two mediators of the hepatic acute phase response to endotoxin. These data suggest that while hepatic amino acid transport is normal in the basal state, the rat with extrahepatic biliary obstruction does not respond appropriately to stress and that this defect cannot be explained solely on the basis of altered handling of endotoxin by the reticuloendothelial system.

Energy expenditure, nitrogen balance, and norepinephrine excretion after injury.

In this study we examine the effect of different hypocaloric nutritional regimens on nitrogen balance in patients following total hip replacement and compare it to that of normal subjects on strict bed rest. The interrelationship between nitrogen balance, energy expenditure, and urinary free norepinephrine excretion is analyzed with emphasis on the effects of nutrition on these relationships. Amino acid infusions following major elective orthopedic surgery had no nitrogen-sparing effect above that of 5% dextrose. Optimum nitrogen balance was obtained by administration of both 5% dextose and 3.5% amino acids. Patients receiving 5% dextrose showed no increase in resting energy expenditure in postoperative period compared to the preoperative control value. However, patients receiving amino acid infusions showed a 14% rise in energy expenditure postoperatively. Failure to administer 5% dextrose was associated with a high urinary norepinephrine excretion postoperatively. In normal subjects on bed rest either 5% dextrose or total starvation resulted in a marked fall in resting energy expenditure, whereas amino acid infusions isocaloric to the carbohydrate intake prevented any fall in resting energy expenditure. Nitrogen balance was improved with amino acid infusions in normal subjects. This study suggests the effect of amino acid infusions is highly dependent on the metabolic state of the patient.