Novel protein candidates for serodiagnosis of African animal trypanosomosis: Evaluation of the diagnostic potential of lysophospholipase and glycerol kinase from Trypanosoma brucei.

African trypanosomosis, a parasitic disease caused by protozoan parasites transmitted by tsetse flies, affects both humans and animals in sub-Saharan Africa. While the human form (HAT) is now limited to foci, the animal form (AAT) is widespread and affects the majority of sub-Saharan African countries, and constitutes a real obstacle to the development of animal breeding. The control of AAT is hampered by a lack of standardized and easy-to used diagnosis tools. This study aimed to evaluate the diagnostic potential of TbLysoPLA and TbGK proteins from Trypanosoma brucei brucei for AAT serodiagnosis in indirect ELISA using experimental and field sera, individually, in combination, and associated with the BiP C-terminal domain (C25) from T. congolense. These novel proteins were characterized in silico, and their sequence analysis showed strong identities with their orthologs in other trypanosomes (more than 60% for TbLysoPLA and more than 82% for TbGK). TbLysoPLA displays a low homology with cattle (<35%) and Piroplasma (<15%). However, TbGK shares more than 58% with cattle and between 45-55% with Piroplasma. We could identify seven predicted epitopes on TbLysoPLA sequence and 14 potential epitopes on TbGK. Both proteins were recombinantly expressed in Escherichia coli. Their diagnostic potential was evaluated by ELISA with sera from cattle experimentally infected with T. congolense and with T.b. brucei, sera from cattle naturally infected with T. congolense, T. vivax and T.b. brucei. Both proteins used separately had poor diagnostic performance. However, used together with the BiP protein, they showed 60% of sensitivity and between 87-96% of specificity, comparable to reference ELISA tests. In conclusion, we showed that the performance of the protein combinations is much better than the proteins tested individually for the diagnosis of AAT.

Hypertriglyceridaemia unresponsive to multiple treatments.

A 52-year-old man with a longstanding history of hypertriglyceridaemia (approximately 7 mmol/L (600 mg/dL)), unresponsive to treatment, presented to a lipid-specialty clinic. Additional triglyceride-lowering therapies were added with no effect. It was then noted that despite the apparent hypertriglyceridaemia, his serum sample was clear. A 'glycerol blank' was then requested from an advanced lipid laboratory, which reported a triglyceride value of 0.7 mmol/L (62 mg/dL). These findings suggest isolated asymptomatic glycerol kinase deficiency (GKD) or 'pseudohypertriglyceridaemia'. The falsely elevated triglyceride values in such individuals are a result of excess serum glycerol and clinical laboratories measuring glycerol to report triglyceride concentrations. After discontinuation or modification of the patient's primary triglyceride-lowering agents, the lipid panels and triglyceride values remained comparable to previous readings. Recognition of asymptomatic GKD is important to prevent unnecessary treatment and overestimated cardiovascular risk.

Glucagon response to oral glucose challenge in type 1 diabetes: lack of impact of euglycemia.

OBJECTIVE Previous studies have demonstrated aberrant glucagon physiology in the setting of type 1 diabetes (T1D) but have not addressed the potential impact of ambient glycemia on this glucagon response. Thus, our objective was to evaluate the impact of euglycemia versus hyperglycemia on the glucagon response to an oral glucose challenge in T1D. RESEARCH DESIGN AND METHODS Ten adults with T1D (mean age 56.6 ± 9.0 years, duration of diabetes 26.4 ± 7.5 years, HbA1c 7.5% ± 0.77, and BMI 24.1 kg/m(2) [22.6-25.4]) underwent 3-h 50-g oral glucose tolerance tests (OGTTs) on two separate days at least 24 h apart in random order under conditions of pretest euglycemia (plasma glucose [PG] between 4 and 6 mmol/L) and hyperglycemia (PG between 9 and 11 mmol/L), respectively. RESULTS Glycemic excursion on the OGTT was similar between the euglycemic and hyperglycemic tests (P = 0.72 for interaction between time postchallenge and glycemic setting). Interestingly, glucagon levels increased in response to the OGTT under both glycemic conditions (P < 0.001) and there were no differences in glucagon response between the euglycemic and hyperglycemic days (P = 0.40 for interaction between time postchallenge and glycemic setting). In addition, the incretin responses to the OGTT (glucose-dependent insulinotropic polypeptide, glucagon-like peptide-1, glucagon-like peptide-2) were also not different between the euglycemic and hyperglycemic settings. CONCLUSIONS In patients with T1D, there is a paradoxical increase in glucagon in response to oral glucose that is not reversed when euglycemia is achieved prior to the test. This abnormal glucagon response likely contributes to the postprandial hyperglycemia in T1D irrespective of ambient glycemia.

Pseudohypertriglyceridemia: two cases of probable glycerol kinase deficiency.

The National Cholesterol Educational Program Adult Treatment Panel's third report define borderline-high, high, and very high triglycerides as serum levels of 150-199 mg/dL, 200-499 mg/dL, and ≥500 mg/dL, respectively. Hypertriglyceridemia (HTG) is generally very responsive to both therapeutic lifestyle changes (TLC), and drug therapy, with niacin, omega-3 fatty acids, fibrates, and statins, each reducing levels by ~10-50%. This paper presents two cases of patients who were aggressively treated for significant HTG with little response to therapy. Although most measured triglyceride (TG) values in these patients were markedly elevated, periodic concentrations were reported as normal. When this occurs, the clinician must immediately think of the diagnosis 'pseudohypertriglyceridemia' or as it is more aptly termed 'glycerolemia' secondary to glycerol kinase deficiency (GKD).

Comparison of triglyceride concentration with lipemic index in disorders of triglyceride and glycerol metabolism.

BACKGROUND: In plasma, triglycerides (TG) are transported in lipoprotein particles (mainly chylomicrons, very low-density and low-density lipoprotein). Turbidimetry (bichromatically at 660 and 700 nm) allows measurement of the lipemic (L) index. We explored the use of this index, in combination with a TG assay, to detect errors due to non-fasting, to assess abnormalities in TG metabolism and to detect patients with glycerol kinase deficiency (GKD). METHODS: We collected 2441 patient samples. Normolipidemic (n=2347), type IV hyperlipidemic (n=80), postprandial samples (n=22) and serial dilutions of Intralipid with saline (n=6) were selected. One patient presenting with GKD was included, as well as two patients with type I and type V hyperlipoproteinemia, respectively. RESULTS: We introduced the use of the ratio between the logarithm of serum triglycerides and that of the L-index (TG/L ratio). CONCLUSION: Although the proposed TG/L-index ratio cannot be regarded as an alternative for the accurate diagnosis of lipid disorders, it provides additional information about TG-containing particles.

[Monitoring oxypurines levels in women with pregnancy induced hypertension and in women with physiological pregnancy]. / Monitorowanie stezenia oksypuryn u kobiet z nadcisnieniem indukowanym ciaza i w ciazy fizjologicznej.

In this paper the concentration of oxypurines in the plasma taken from women with PIH, regular pregnancies and control group was determined. In comparison to the other groups very high concentration of HX and low X in the plasma of women with PIH was found. Such a result allows for the conclusion proving the exsistance of hypoxia in the group of women with PIH. To confirm the claim the clinical evaluation of pregnant women, fetuses and newborns was used. The values of most parameters proved that fetuses and newborns coming from the pregnancies of women with complicated PIH are weak, in the clinical evaluation, than those coming from the regular pregnancies.

Isolated glycerol kinase deficiency in a neonate.

Glycerol kinase deficiency occurs either as a relatively benign isolated enzyme deficiency, or as part of a syndrome resulting from a microdeletion in the p21 region of the X chromosome associated with congenital adrenal hypoplasia and/or Duchenne muscular dystrophy. Developmental delay is a consistent feature of the microdeletion syndrome but not of the isolated enzyme defect. We report a case of isolated glycerol kinase deficiency in a neonate presenting with hypotonia, apnea, mild developmental delay, and glyceroluria, without evidence of adrenal insufficiency or myopathy. A mild communicating hydrocephalus was noted on magnetic resonance imaging brain scan. It is important, therefore, to exclude glyceroluria in infants being investigated for apnea and hypotonia.

[New enzymatic and endocrinological aspects in two cases of Werner's syndrome (author's transl)]. / Nuevos aspectos enzimáticos y endocrinológicos en dos casos de síndrome de Werner.

Results of endocrinological studies and of the investigation of intraerythrocytic glycolytic pathway carried out in two patients with Werner's syndrome are presented. An increase of glyceraldehyde 3-phosphate and 3-phospho-glycerokinase has been observed, but the significance of these original findings is still unknown. An hyperinsulinism after oral glucose overload has been demonstrated too. This finding, which has been reported by other authors, probably reflects a peripheral resistance to insulin action. Other endocrinological abnormalities were a decrease in the T3:T4 quotient and a slight delay in the FSH-LH peak to LH-RH.