Thiamine Levels Research Articles

Increase in lake trout reproduction in Lake Huron following the collapse of alewife: Relief from thiamine deficiency or larval predation?

In the Great Lakes there is still uncertainty as to the population level effects of a thiamine deficiency on salmonines caused by high consumption of alewives Alosa pseudoharengus. A resurgence of lake trout Salvelinus namaycush reproduction in Lake Huron following the crash of alewife stocks between 2002 and 2004 provided an opportunity to evaluate the relative effects of this crash on reproduction through relief from either alewife mediated thiamine deficiency or alewife predation on larval lake trout relative to possible changes in the size of the lake trout spawning stock. Changes in mean lake trout egg thiamine concentration post crash at one spawning reef in Parry Sound, where mean thiamine concentration increased by almost two-fold, were consistent with diet switching from alewives to rainbow smelt Osmerus mordax, the next most abundant prey fish in Lake Huron. Although thiamine levels for lake trout collected at a second reef in Parry Sound did not change post-crash, levels both pre- and post-crash were consistent with a rainbow smelt diet. A reef specific fry emergence index was found to be positively related to reef specific egg thiamine concentration but negatively related to reef specific occurrence of EMS, a thiamine deficiency related mortality syndrome. We found little evidence for overlap between the timing of spring shoreward migration of alewives and lake trout emergence, suggesting that relief from alewife predation effects had relatively little effect on the observed increase in lake trout recruitment. Numbers of spawners in the north, north-central, and southern zones of the lake increased from 2000 onwards. Overall the abundance post-2003 was higher than from pre-2004, suggesting that spawner abundance may also have contributed to increased lake trout reproduction. However, predicted numbers of spawners and measured abundance of wild recruits in assessment gear were poorly correlated suggesting that the increase in reproduction was not totally spawner dependent and hence relief from thiamine deficiency was also likely involved. We conclude from this that eliminating the effects of an alewife diet mediated thiamine deficiency can have positive effects on lake trout reproduction but more research is required to understand the effect of spawner number and the role of spawning habitat availability.

Coronary artery bypass graft surgery depletes plasma thiamine levels

Objective Thiamine is an essential component of cellular metabolism, and lack of this vitamin results in a potentially life-threatening biochemical lesion. The stress of surgery and critical disease depletes electrolytes, minerals, and essential biochemical substrates. We hypothesized that critical illness (represented by major surgery) would result in decreased thiamine levels over time. Methods We performed a prospective, observational study of serial thiamine levels of 15 patients who underwent non-emergent coronary artery bypass graft surgery. The primary endpoint was change in thiamine levels from before to immediately after surgery. Secondary endpoints included change in thiamine levels from presurgical to 6- and 24-h time points. Results Of the 15 study patients, 1 did not have a plasma thiamine measurement at time 0 because of laboratory error and could not be accounted for in paired comparisons over time. Plasma thiamine levels decreased significantly from before to after coronary artery bypass grafting ( P = 0.0004). In addition, there was a statistically significant decrease in thiamine levels from before surgery to 24 h ( P = 0.003). Conclusion Our data suggest that major surgery (as a surrogate for the stress of critical illness) depletes thiamine levels; further study is needed to determine whether routine replacement of thiamine in the critically ill is warranted.

Linking Egg Thiamine and Fatty Acid Concentrations of Lake Michigan Lake Trout with Early Life Stage Mortality

The natural reproduction of lake trout Salvelinus namaycush in Lake Michigan is thought to be compromised by nutritional deficiency associated with inadequate levels of thiamine (vitamin B1) in their eggs. However, mortality driven by thiamine deficiency (commonly referred to as early mortality syndrome [EMS]) is not the only significant cause of low lake trout survival at early life stages. In this study, we sought to better understand the combined effects of variable levels of thiamine and fatty acids in lake trout eggs on prehatch, posthatch, and swim-up-stage mortality. We sampled the eggs of 29 lake trout females from southwestern Lake Michigan. The concentrations of free thiamine and its vitamers (e.g., thiamine monophosphate [TMP] and thiamine pyrophosphate [TPP]) as well as fatty acid profiles were determined in sampled eggs. Fertilized eggs and embryos were monitored through the advanced swim-up stage (1,000 degree-days). Three distinct periods of mortality were identified: prehatch (0-400 degree-days), immediately posthatch (401-600 degree-days), and swim-up (601-1,000 degree-days). Stepwise multiple regression analysis revealed (1) that cis-7-hexadecenoic acid in both neutral lipids (NL) and phospholipids (PL) correlated with prehatch mortality, (2) that docosapentaenoic acid in PL and docosahexaenoic acid in NL correlated with posthatch mortality, and (3) that total lipids, TPP, and palmitoleic acid in NL, linoleic acid, and palmitic acid in PL correlated with the frequency of EMS. These results indicate the complexity of early life stage mortality in lake trout and suggest that inadequate levels of key fatty acids in eggs, along with variable thiamine content, contribute to the low survival of lake trout progeny in Lake Michigan.

Thiamine tetrahydrofurfuryl disulfide improves energy metabolism and physical performance during physical-fatigue loading in rats

Impaired energy metabolism is considered a possible cause of fatigue. The thiamine derivative, thiamine tetrahydrofurfuryl disulfide (TTFD), is prescribed and is also an over-the-counter drug for the attenuation of fatigue. It is readily absorbed from the intestinal tract and converted into thiamine pyrophosphate (TPP), which plays an important role as a cofactor for enzymes of metabolic pathways involved in the production of adenosine triphosphate (ATP). We postulated that TTFD has an anti-fatigue effect by improving energy metabolism during physical-fatigue loading. Here, we initially used the forced swimming test to determine whether daily TTFD or thiamine for 5 days has anti-fatigue effects on weight-loaded rats. The swimming duration of TTFD-, but not of thiamine-treated rats, was significantly longer than that of control rats (P < .05). Based on these findings, we examined changes in the levels of thiamine and its phosphate esters in various organs and the effect of TTFD on ATP levels in skeletal muscle after forced swimming, to determine the cellular mechanisms of the anti-fatigue effect of TTFD. Daily TTFD resulted in a characteristic distribution of thiamine and its phosphate esters in rat skeletal muscle, liver, kidney, heart, brain, and plasma. Furthermore, daily TTFD attenuated the decrease in ATP content in the skeletal muscle caused by forced swimming with a weight load for a defined period (150 s). These results indicate that TTFD exerts anti-fatigue effects by improving energy metabolism during physical fatigue.

Gizzard Shad Thiaminase Activity and Its Effect on the Thiamine Status of Captive American Alligators Alligator mississippiensis

Adult mortality and low egg hatch rate were observed among American alligators Alligator mississippiensis in Lake Griffin, Florida, between 1998 and 2003. Previous studies show that the alligator mortality is due to neurological impairment associated with thiamine (vitamin Bt) deficiency. This study determined the rate of thiaminase activity in gizzard shad Dorosoma cepedianum, a fish often eaten by alligators, and examined the thiamine status of captive adult alligators fed only gizzard shad. We found that the thiaminase activity of gizzard shad in Lake Griffin is 16,409 +/- 2,121 pmol/g/min (mean +/- 2SEs). This high rate of thiaminase activity was present in most months and across a wide range of shad sizes. Seven alligators were captured in the wild from Lake Griffin and Lake Woodruff, held in captivity, and fed gizzard shad. We monitored blood and muscle thiamine levels throughout the experiment and liver thiamine at the end. Over a period of 6-12 months, all of the alligators maintained weight but blood and muscle thiamine levels decreased to 25-50% of the original (healthy) values. Three animals with the greatest reduction in thiamine died, demonstrating mobility impairment and neural histopathology similar to those seen in wild alligators in Lake Griffin. Two alligators were fed shad for 10 months but then treated with thiamine. These animals showed a reduction in thiamine while eating shad, but treatment restored their thiamine levels to the initial values, which were comparable to those of normal wild Lake Griffin alligators. We demonstrated that thiamine deficiency can be induced by a diet of gizzard shad and cause neurological signs and death in alligators in captivity. We conclude that the thiaminase activity in gizzard shad is high enough to cause thiamine deficiency in wild alligators when shad are a major part of their diet.

Nutrient and Organochlorine Pesticide Concentrations in American Alligator Eggs and Their Associations with Clutch Viability

Since the early 1900s, the lakes of the Ocklawaha basin in central Florida have experienced ecological degradation due to anthropogenic development. One species affected by this degradation is the American alligator Alligator mississippiensis, which has suffered from poor clutch viability and embryo mortality. Although some studies indicate that organochlorine pesticides (OCPs) may be involved, OCPs do not account for all of the variation seen in hatch rates. Indeed, nutrition and non-OCP contaminants have been associated with developmental problems in fish and birds. Our study evaluated embryo mortality in alligators at reference and OCP-contaminated sites as a function of exposure to OCPs, polychlorinated biphenyls (PCBs), and polyaromatic hydrocarbons (PAHs), along with egg nutrients (Zn, Se, and vitamins A, E, and B1). The four-pronged study consisted of a case-control cohort study, an expanded field study, a topical egg treatment thiamine amelioration experiment, and a topical egg treatment thiamine antagonist experiment. The results from the two field studies suggested that the total thiamine levels in the eggs were positively associated with clutch viability and negatively associated with the lipid content and certain OCPs measured in egg yolks. In addition, PCBs, PAHs, Zn, Se, and vitamins A and E were not found to be associated with the observed clutch viability defects. The thiamine levels in the eggs explained 38% of the variation in clutch survival in the case-control cohort study and 27% in the expanded field study. The topical egg treatment experiments were successful in elevating the thiamine concentrations in the albumin but not the yolk. No significant differences were noted among treatment groups in either egg treatment experiment with respect to clutch survival. In summary, thiamine egg concentrations explain some of the variation in the clutch viability of free-ranging alligators, but the cause-effect relationships are still unclear.

Effects of Vitamin B1 (Thiamine) Deficiency in Lake Trout Alevins and Preventive Treatments

The objectives of this study were to examine the effect of thiamine immersion of fish from a population known for compromised survival as a result of early mortality syndrome (EMS) and to investigate the cause-response relationship between thiamine concentration and lesions in tissues in swim-up-stage lake trout Salvelinus namaycush alevins. Lake trout eggs from 14 fish from Lake Michigan were artificially fertilized and the progeny divided into two groups based on the thiamine concentration (low [< 0.73 nmol/g] or high [> 0.85 nmol/g]) in the unfertilized eggs. Progeny were treated or not with a thiamine solution (2,000 mg/L for 2 h) at hatching or the swim-up stage. The survival of progeny in control groups at the swim-up stage correlated with thiamine concentration. The low thiamine-treated groups had significantly higher survival between the swim-up stage (812.0 degree-days) and 16 d after swim-up (963.3 degree-days) than the control groups; the survival of the high thiamine-treated groups did not differ between treated and control fish, regardless of the treatment at hatching and the swim-up stage. Control alevins that had low thiamine levels showed EMS, which resulted in 94.9-100% mortality 16 d after the swim-up stage. No pathological changes were observed in the brain, olfactory lobe, eye, liver, or muscle in alevins of high thiamine-treated group. Glycogen deposits in the liver of alevins from the low control group were variable, no glycogen being observed in the hepatocytes of 7 of the 24 fish. We demonstrate that thiamine treatment at swim-up enhances the survival of EMS-affected lake trout relative to treatment at hatching.

Impaired cellular contractile function in thiamine‐deficient rat cardiomyocytes

Background Thiamine (vitamin B1) is an essential cofactor of important metabolic enzymes. 1,2 Studies have demonstrated that thiamine deficiency (TD) leads to changes in cardiac morphological, electrophysiological and mechanical properties, as well as in cardiac metabolism. 3 - 9 Clinical studies have indicated that the use of loop diuretics can induce TD and eventually cause heart dysfunction. The most important reported clinical manifestation of TD involves high-output heart failure. In humans, TD damages the cardiovascular system causing heart failure. 10-12 The altered excitation-contraction coupling that characterizes cardiac failure occurs due to changes in Ca 2+ dynamics, action potential duration, global Ca 2+ transient, and contraction and relaxation rates. 13 Oliveira et al. 8 found that thiamine deprivation decreased the global Ca 2+ release from the sarcoplasmic reticulum (SR) due to the lower SR Ca 2+ load without changes in Ca 2+ current density. Aim According to data in the literature, TD may elicit deregulation of SR Ca 2+ handling in the heart, with implications on cellular cardiac contractility. However, it is unknown whether TD would cause contractile dysfunction at the cellular level. In this study, we sought to determine if TD affects cellular contractility. Methods Male Wistar rats (200-250 g) were randomly allocated to receive a diet containing thiamine (control, n = 6) or a TD diet (TD, n = 6) for 35 days as described previously by our group. 8,9 All experimental procedures were conducted in accordance with international guidelines (Declaration of Helsinki). Cell isolation Ventricular cardiomyocytes from age-matched control and TD rats were enzymatically isolated as described previously. 8,9 Briefly, the heart was mounted on a custom-designed Langendorff system, perfused for ∼3-5 min with calcium-free solution following perfusion with 1 mg/mL collagenase type II (Worthington, USA). After 10-15 min, single cells were isolated by mechanical dispersion and stored in Dulbecco's modified Eagle's medium. The average cell yield under these conditions is 60-70%. Measurement of cellular contractility Cellular contractility was measured as described previously. 14 Briefly, isolated cells were placed in an experimental chamber with a glass cover-slip base mounted on the stage of an inverted microscope. Cells were perfused with Tyrodes solution containing 1.8 mM CaCl 2 and field stimulated at frequencies of 1 and 3 Hz (20 V, 5 ms duration square pulses). Cells were imaged using a NTSC camera in a partial scanning mode. Cell shortening in response to electrical stimulation was measured with a video-edge detection system at 240 Hz frame rate (lonoptix). All parameters were evaluated using customized software developed in MatLab ® platform. 14 Experiments were performed at room temperature (∼25°C). Only calcium-tolerant, quiescent, rod-shaped myocytes showing clear cross striations were studied. Statistical analysis All results are expressed as mean ± standard error of the mean. For statistical analysis, we used Student's t-test and ANOVA for repeated measurements with Bonferroni post hoc testing. Values of P < 0.05 were considered significant. Results After 35 days of thiamine deprivation, cellular ATP availability decreases, leading to impairment of heart contraction as we reported in a previous study. 8 Thus, we hypothesized that a reduction in circulating thiamine levels would affect cardiomyocyte.

Diabetic acido-ketosis revealing thiamine-responsive megaloblastic anemia

Thiamine-responsive megaloblastic anemia (TRMA) is a rare autosomal recessive disorder characterized by megaloblastic anemia, diabetes mellitus and progressive sensorineural deafness. We report the cases of two infants, aged 4 and 5 months, hospitalized for diabetic ketoacidosis requiring insulin therapy. Laboratory tests revealed megaloblasic anemia, thrombocytopenia and normal thiamine level. Neurosensorial investigations showed bilateral deafness and ophthalmic involvement. Treatment with oral thiamine normalized hematological disorders and controlled diabetes; however, thiamine therapy had no impact on neurosensorial disorders.

Impaired Intestinal Vitamin B 1 (Thiamin) Uptake in Thiamin Transporter-2–Deficient Mice

Intestinal thiamin uptake process is vital for maintaining normal body homeostasis of the vitamin; in vitro studies suggest that both thiamin transporter-1 (THTR-1) and -2 (THTR-2) are involved. Mutations in THTR-1 cause thiamin-responsive megaloblastic anemia, a tissue-specific disease associated with diabetes mellitus, megaloblastic anemia, and sensorineural deafness. However, in patients with thiamin-responsive megaloblastic anemia, plasma thiamin levels are within normal range, indicating that THTR-2 (or another carrier) could provide sufficient intestinal thiamin absorption. We tested this possibility and examined the role of THTR-2 in uptake of thiamin in the intestine of mice. THTR-2-deficient mice were generated by SLC19A3 gene knockout and used to examine intestinal uptake of thiamin in vitro (isolated cells) and in vivo (intact intestinal loops). We also examined intestinal thiamin uptake in THTR-1-deficient mice. Intestine of THTR-2-deficient mice had reduced uptake of thiamin compared with those of wild-type littermate mice (P < .01); this reduction was associated with a decrease (P < .01) in blood thiamin levels in THTR-2-deficient mice. However, intestinal uptake of thiamin in THTR-1-deficient mice was not significantly different from that of wild-type littermate animals. Level of expression of THTR-1 was not altered in the intestine of THTR-2-deficient mice, but level of expression of THTR-2 was up-regulated in the intestine of THTR-1-deficient mice. THTR-2 is required for normal uptake of thiamin in the intestine and can fulfill normal levels of uptake in conditions associated with THTR-1 dysfunction.

Thiamine Level in Hospitalized Elderly Egyptian Patients with Congestive Heart Failure and Left Ventricular Systolic Dysfunction

Thiamine Level in Hospitalized Elderly Egyptian Patients with Congestive Heart Failure and Left Ventricular Systolic Dysfunction

Physiological and molecular changes in Oryza meridionalis Ng., a heat-tolerant species of wild rice

Oryza meridionalis Ng. is a wild relative of Oryza sativa L. found throughout northern Australia where temperatures regularly exceed 35 °C in the monsoon growing season. Heat tolerance in O. meridionalis was established by comparing leaf elongation and photosynthetic rates at 45 °C with plants maintained at 27 °C. By comparison with O. sativa ssp. japonica cv. Amaroo, O. meridionalis was heat tolerant. Elongation rates of the third leaf of O. meridionalis declined by 47% over 24 h at 45 °C compared with a 91% decrease for O. sativa. Net photosynthesis was significantly higher in O. sativa at 27 °C whereas the two species had the same assimilation rates at 45 °C. The leaf proteome and expression levels of individual heat-responsive genes provided insight into the heat response of O. meridionalis. After 24 h of heat exposure, many enzymes involved in the Calvin Cycle were more abundant, while mRNA of their genes generally decreased. Ferredoxin-NADP(H) oxidoreductase, a key enzyme in photosynthetic electron transport had both reduced abundance and gene expression, suggesting light reactions were highly susceptible to heat stress. Rubisco activase was strongly up-regulated after 24 h of heat, with the large isoform having the largest relative increase in protein abundance and a significant increase in gene expression. The protective proteins Cpn60, Hsp90, and Hsp70 all increased in both protein abundance and gene expression. A thiamine biosynthesis protein (THI1), previously shown to act protectively against stress, increased in abundance during heat, even as thiamine levels fell in O. meridionalis.

Severe anasarca due to beriberi heart disease and diabetic nephropathy

A 40-year-old man was transferred to our hospital because of severe anasarca. He was a heavy drinker for more than 20 years, and diagnosed with diabetes mellitus 8 years earlier and treated with retinal photocoagulation 8 months earlier. He reported loss of appetite after divorce 10 months prior to admission. On admission, he presented with systemic edema and dyspnea. Chest radiography showed massive pleural effusion and cardiomegaly. Serum total protein was 5.6 g/dl, albumin 2.6 g/dl, and urinary protein excretion was 5.3 g/day. Glucose tolerance test showed normal pattern. Ultrafiltration and continuous hemofiltration resulted in loss of 40 kg body weight in 5 days. Echocardiography revealed high-output heart failure and blood tests showed low serum thiamine level of 12 ng/ml (normal, >28 ng/ml). Accordingly, the diagnosis was established as beriberi heart disease complicated with nephrotic syndrome. Treatment with 50 mg/day thiamine intravenously and 80 mg/day furosemide resulted in increase in urine output, decrease in cardiac output, resolution of pulmonary effusion, and about 70 kg body weight loss. Percutaneous renal biopsy showed nodular glomerulosclerosis, mesangial matrix expansion, and thickening of glomerular basement membrane (GBM). Immunofluorescence study showed no glomerular deposition of immunoglobulin or complement. Electron microscopy showed GBM thickening and mesangial matrix deposition without electron-dense deposits or fibrils. These findings were compatible with diabetic glomerulosclerosis. In this patient, extreme malnutrition altered glucose tolerance but, on the other hand, nephrotic syndrome associated with diabetic nephropathy made the diagnosis of beriberi heart disease difficult.

Clinical Presentation of Beriberi After Roux-en-Y Gastric Bypass (RYGB) Surgery

Purpose: RYGB is the most common surgical procedure performed for medically-complicated obesity. We previously reported a high prevalence of thiamine deficiency associated with small intestinal bacterial overgrowth (SIBO) after RYGB (Nutrition Res, 2008). Clinical manifestations of Beriberi include: 1) Neuropsychiatric; 2) High output cardiovascular disease (wet Beriberi); 3) Neurological/Neuropathies (dry Beriberi); or 4) Gastrointestinal (nausea/emesis/megajejunum or constipation/megacolon). The purpose of this study is to estimate the prevalence of and subtypes of Beriberi after RYGB. Methods: Prospective study performed in an urban community hospital. Consecutive RYGB patients seen at a new joint Medical/Surgical Bariatric Clinic from February 1, 2008 to May 1, 2009 were included in this study. Data included date of and type (open or laparoscopic) of RYGB, sex, age, thiamine diphosphate levels, Beriberi symptoms (Types 1-4), thiamine supplementation, and potential resolution with thiamine treatment. Beriberi is defined in this study by: 1) consistent clinical symptoms and examination and 2) either low blood thiamine level (n=22), or resolution of consistent clinical symptoms after intramuscular (IM) thiamine (n=5). Results: Of 151 patients evaluated, 25 females and 2 males met the criteria for Beriberi (estimated prevalence of 18%); age range is 30-68 years (mean age: 50 years); 4 patients had laparoscopic while 23 had open RYGB. Symptoms were noted 2 months to 9 years (mean: 5.0 years) after RYGB. In these 27 RYGB patients, 12 have one symptom consistent with Beriberi while 15 have symptoms consistent with multiple subtypes. Among these patients, 52% had Type 1 Beriberi, 67% had Type 2, 11% had Type 3, and 48% had Type 4 (GI) Beriberi. Of 20 patients with symptoms of Beriberi prior to treatment with IM thiamine, all 20 (100%) noted post-treatment symptomatic improvement. In 3 patients, a symptom of Beriberi returned after replacing IM thiamine therapy with oral thiamine supplements. Conclusion: In our patient population, a high prevalence of Beriberi was identified on average 5.0 years after RYGB. The most common Beriberi identified was Type 2 (wet Beriberi). General gastroenterologists are seeing an increasing number of bariatric patients. For symptoms of nausea, emesis or constipation, GI Beriberi should be considered. However, other types of Beriberi may be present. Oral thiamine alone may be an ineffective treatment in these patients, supporting malabsorption. If there is a clinical suspicion of Beriberi in a RYGB patient, therapy with IM thiamine should be started. Further studies are required to determine whether treating SIBO in RYGB patient prevents Beriberi or may be effective as an adjuvant therapy in patients with Beriberi.

Thiamine-deficient encephalopathy due to excessive intake of isotonic drink or overstrict diet therapy in Japanese children

Aim: To report on two children with encephalopathy caused by dietary thiamine deficiency due to newly developing nutritional problems in contemporary Japan. Subjects: A 1-year-old boy who had consumed 1 l of isotonic drinks per day for 4 months after an episode of diarrhea, and presented with ocular movement disorder, dystonia, and unconsciousness. The other subject was an 11-month-old boy who suffered from vomiting and somnolence; he and his mother had atopic dermatitis, and he had been on a low-allergen diet that strictly restricted intake of eggs, dairy products, meat, and fish since his early infancy. Results: Both patients showed decreased blood thiamine levels and magnetic resonance imaging revealed striatal and thalamic lesions. Thiamine administration yielded prompt improvement of symptoms, but cavitiform lesions in the bilateral putamen persisted in the first patient, accompanied by residual generalized dystonia. Marked elevation of blood/cerebrospinal lactate levels and severe hyponatremia were present in this patient. Conclusion: Thiamine-deficient encephalopathy in Japanese children due to excessive intake of sports drink or overstrict diet therapy for atopic dermatitis has been increasingly reported during the last decade, but is still not broadly recognized. These children may visit hospitals due to persistent vomiting as a symptom of thiamine deficiency, but glucose infusion without thiamine supplementation can aggravate their condition. Knowledge of these facts in medical and public settings is necessary to correct the erroneous impression that nutritional options given to ill children are necessarily beneficial for health, and promote awareness that they can be harmful when consumed in excess.

Effects of vitamin B 1 (thiamine) deficiency in lake trout (Salvelinus namaycush) alevins at hatching stage

The objectives of this study were to examine the relationship between thiamine concentrations in unfertilized eggs and yolksac individuals of lake trout (Salvelinus namaycush), along with any associated histopathological changes in the tissues of alevins at the hatching stage. We address these questions in a lake trout population from different spawning grounds of Lake Michigan (North and South), known for compromised survival due to early mortality syndrome (EMS). However, a dichotomous forage base of lake trout spawning stocks, with a dietary thiaminase-rich alewife in the North, and dietary low-thiaminase round goby in the South, provides the basis for the assumption that different diets may lead to differences in severity of EMS between different stocks. Lake trout eggs of 18 females were collected and fertilized individually with the sperm of several males. The eggs, eyed embryos and newly-hatched alevins were sampled to examine thiamine utilization during embryogenesis. Progenies of females with low (< 0.73 nmol/g) and high (> 0.85 nmol/g) levels of thiamine were chosen for histological studies. The obtained results showed that total thiamine levels in the body and yolk of eyed embryos and alevins at hatching were influenced by thiamine levels of unfertilized eggs and it decreased during embryogenesis (to 51% in eyed embryos and 28% in newly-hatched alevins in comparison to unfertilized eggs). The survival of lake trout until hatching stage does not correlate with the thiamine level, however it was affected by collection site and was significantly higher in fish from the South site (Julian's Reef). At the hatching stage, no pathological changes were observed in the brain, olfactory lobe, retina or liver in embryos regardless of thiamine concentrations in unfertilized eggs. It has been concluded that an enhanced thiamine requirement for the fast muscle mass growth near the swim-up stage is responsible for overt and histopathological signs of EMS. Current study confirms earlier findings that lake trout suffering from EMS can be successfully treated by immersion in thiamine solution as late as at the swim-up stage.

Thiamine supplementation increases serum thiamine and reduces pyruvate and lactate levels in burn patients

The importance of vitamins for optimal metabolism is well established. However, currently little is known about the optimal vitamin levels required for burn patients. As a consequence, current practice both for macronutrient supplementation and vitamin supplementation varies widely between burn units. A better understanding of the effects of vitamins on metabolism may lead to better nutrition and subsequently improved outcomes for burn patients. Thiamine is an important co-factor required for multiple enzymes involved in carbohydrate metabolism. We have examined the levels of thiamine (B1) in burn patients as well as the effects of thiamine supplementation on the levels of serum thiamine, pyruvate and lactate. Twenty patients had blood samples taken on the day of admission, then on days 1, 3, and 7 post-admission and weekly thereafter until discharge. Of these, nine received enteral feeding. Six patients received thiamine supplementation. Serum thiamine, pyruvate and lactate levels were measured at each time point. Serum thiamine levels increased significantly with thiamine supplementation ( p < 0.001). Serum thiamine levels also increased with time of supplementation ( p < 0.001). Serum thiamine level was closely associated with pyruvate and lactate levels, with a decrease in both pyruvate and lactate associated with increased serum thiamine. Lastly, pyruvate and lactate levels appear closely associated in a linear relationship. This study suggests thiamine supplementation increases serum thiamine and that this increase is associated with a decrease in pyruvate and lactate levels. Further study of changes in metabolic flux associated with thiamine supplementation and a randomised control trial of thiamine supplementation are required to establish whether thiamine supplementation is beneficial to burn patients’ metabolism and recovery.

Pancreatic beta cells and islets take up thiamin by a regulated carrier-mediated process: studies using mice and human pancreatic preparations

Thiamin is essential for the normal function of the endocrine pancreas, but very little is known about uptake mechanism(s) and regulation by beta cells. We addressed these issues using mouse-derived pancreatic beta-TC-6 cells, and freshly isolated primary mouse and human pancreatic islets. Results showed that thiamin uptake by beta-TC-6 cells involves a pH (but not Na+)-dependent carrier-mediated process that is saturable at both the nanomolar (apparent K(m) = 37.17 +/- 9.9 nM) and micromolar (apparent K(m) = 3.26 +/- 0.86 microM) ranges, cis-inhibited by thiamin structural analogs, and trans-stimulated by unlabeled thiamin. Involvement of carrier-mediated process was also confirmed in primary mouse and human pancreatic islets. Both THTR-1 and THTR-2 were found to be expressed in these mouse and human pancreatic preparations. Maintaining beta-TC-6 cells in the presence of a high level of thiamin led to a significant (P < 0.01) decrease in thiamin uptake, which was associated with a significant downregulation in level of expression of THTR-1 and THTR-2 at the protein and mRNA levels and a decrease in transcriptional (promoter) activity. Modulators of intracellular Ca2+/calmodulin- and protein-tyrosine kinase-mediated pathways also altered thiamin uptake. Finally, confocal imaging of live beta-TC-6 cells showed that clinical mutants of THTR-1 have mixed expression phenotypes and all led to impairment in thiamin uptake. These studies demonstrate for the first time that thiamin uptake by the endocrine pancreas is carrier mediated and is adaptively regulated by the prevailing vitamin level via transcriptional mechanisms. Furthermore, clinical mutants of THTR-1 impair thiamin uptake via different mechanisms.

Wernicke's Encephalopathy Presenting as Acute Psychosis after Gastric Bypass

Background and Objectives: Patients frequently present to the Emergency Department (ED) with psychiatric complaints. The differential diagnosis for acute psychosis is extensive, and determining a possible etiology requires a thorough history and physical. Small details can help the physician in differentiating organic disease from non-organic disease. Many times patients are thought to be “crazy” without a thorough history and physical being done. Case Report: In this case, the diagnosis hinged on the history of having gastric bypass surgery. A thorough physical examination was performed, and the patient had neurologic findings suggestive of severe thiamine deficiency. The patient's thiamine level was low. The patient was started on i.v. thiamine and slowly began to recover. Conclusion: Cerebral beriberi, more commonly known as Wernicke's encephalopathy, is a difficult diagnosis to make in the ED. A thorough neurologic examination is difficult to perform in the ED environment, but it is necessary when trying to determine the etiology of the patient's altered mental status. The number of patients with Wernicke's encephalopathy may increase with bariatric surgery becoming more common. This disease can present with a wide variety of findings, and the classic triad is not very common. With this in mind, the physician should have a low threshold for administering thiamine intravenously.

Influence of Diet of Double-Crested Cormorants on Thiamine, Lead, and Mineral Contents of Their Eggs

ABSTRACT Throughout much of the Great Lakes basin, reproduction of several fish species is impaired by deficiency of thiamine in their eggs, an effect attributed to consumption of thiaminase-containing forage species, primarily alewife (Alosa pseudoharengus.) Because the double-crested cormorant (Phalacrocorax auritus) nesting on islands in Lake Ontario is known to consume considerable amounts of alewife, we examined cormorant food habits and measured thiamine content in eggs collected in 1999 from six separate nests of cormorants from colonies near Lake Ontario and contrasted them with food habits and eggs of cormorants from Oneida Lake where the alewife is rare. Thiamine concentrations in eggs varied between 4.31 and 11.24 nmoleslg with no significant (P>0.18) difference between mean concentrations for Lake Ontario and Oneida Lake (8.08 vs 8.36 nmoles/g) even though alewife comprised approximately 65 vs 0 % of their diets, respectively. Consumption of other thiaminase-containing species was minor in both lakes. Therefore, consumption of alewife and other thiaminase containing fishes by cormorants on Lake Ontario did not appear to significantly impair the levels of thiamine in their eggs. However, we found that the concentration of thiamine in eggs (T; nmoles/g) was inversely related (P<0.02) to lead (Pb) concentration (μg/g) according to the equation: T = −3.142 Pb + 16.25. This relationship may reflect the known ability of thiamine to chelate lead and increase its excretion.