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T Antoniou

Publications and source records attributed to T Antoniou.

7 recordsLinked to original sources
PubMed2006

Assay of HIV gp41 amino acid sequence to identify baseline variation and mutation development in patients with virologic failure on enfuvirtide.

In this study, we retrospectively assessed a gp41 genotypic assay in 404 enfuvirtide-naïve individuals (340 clade B, 64 non-B clade) to determine the prevalence of baseline polymorphisms and in 41 patients virologically failing enfuvirtide to determine correlates of resistance to this agent. Conserved and polymorphic regions of gp41 were identified in clade B isolates, with 127 of 328 codons (38.7%) being highly conserved (<1.0% variation) and 74 of 328 codons (22.6%) being partially conserved (1.0-5.0% variation). Polymorphisms were observed throughout gp41 in non-B clade virus sequences compared to the clade B reference strain, ranging from 53 natural substitutions in clade D to 76 in clade A. Insertions were common at positions 3, 105, 215 and 276. In the patients failing enfuvirtide, mutations were detected in the 10 amino acid region at positions 36-45 in all plasma virus sequences. Six additional mutations were selected outside of the common region which may be clinically significant at positions 33, 73, 75, 126, and 138. Two or three mutations at positions 36-45 were observed in the majority of plasma virus sequences from patients with virologic failure following the use of enfuvirtide. Further study is required to determine the clinical relevance of the clade related polymorphisms and the new mutations identified in the patients with virologic failure.

Adult↗
PubMed2006

Inhaled iloprost in eight heart transplant recipients presenting with post-bypass acute right ventricular dysfunction.

BACKGROUND: During heart transplantation, weaning from cardiopulmonary bypass may be particularly laborious as a result of superimposed acute right ventricular dysfunction in the setting of pre-existing pulmonary hypertension. Research in recent years has focused on inhaled vasodilatory treatment modalities which selectively target the pulmonary circulation. METHODS: We present a series of eight patients in whom inhaled iloprost, a synthetic prostacyclin analog, was used to treat pulmonary hypertension and right ventricular dysfunction detected by transesophageal echocardiography during a heart transplant procedure. In addition to conventional inotropic support, 20 mug of inhaled iloprost was administered via nebulized aerosol for a 20-min period. Complete sets of hemodynamic measurements were obtained before inhalation and during and after cessation of the inhalation period. RESULTS: Inhaled iloprost decreased the transpulmonary gradient at the end of the inhalation period relative to baseline (8.2 +/- 1.6 mmHg vs. 11.2 +/- 0.9 mmHg, P < 0.05). The mean pulmonary artery pressure to systemic artery pressure ratio decreased over this period (0.24 +/- 0.07 vs. 0.44 +/- 0.09, P < 0.05). A statistically significant decrease in the pulmonary vascular resistance to systemic vascular resistance ratio was also observed (0.10 +/- 0.02 vs. 0.19 +/- 0.02, P < 0.05). Improved indices of right ventricular function were observed in echocardiographic monitoring. CONCLUSION: During heart transplantation procedures, episodes of pulmonary hypertension can be successfully treated with inhaled iloprost administration, without untoward side-effects or significant systemic impact.

Administration, Inhalation↗
PubMed2005

Incidence of and risk factors for tenofovir-induced nephrotoxicity: a retrospective cohort study.

OBJECTIVES: Despite the recent publication of case reports describing various manifestations of tenofovir-related nephrotoxicity, data regarding the incidence of and risk factors for this adverse effect are currently lacking. METHODS: A retrospective cohort study of patients from four centres in Toronto, Canada, enrolled in the tenofovir expanded access programme with a minimum of 3 months follow up, was carried out. RESULTS: A total of 172 patients receiving tenofovir disoproxil fumarate (TDF) for a median of 16 months (range 3-25 months) were included in the study. Seven (4%) patients developed grade 1 (>44 micromol/L from baseline) increases in serum creatinine (SCr) during follow up; no patient developed grade 2 or higher nephrotoxicity. Fifteen (8.7%) patients had an increase in SCr of greater than 1.5 times baseline values during follow up. Four (2.3%) patients discontinued TDF because of an increase in SCr and/or abnormal urinalysis. Of 62 patients with a urinalysis, grade 1 or higher proteinuria (< 3 g/L) was observed in 27 (43%) patients. Only baseline SCr [odds ratio (OR)=0.51 per 10 micromol/L increase; P=0.0005] and baseline creatinine clearance (1.26 per 10 mL/min increase; P=0.01) were significantly associated with ever having a 1.5-fold increase in serum creatinine. Twenty-eight (16%) and 11 (6%) patients developed grade 1 (serum phosphorus < or = 0.71 mmol/L) and grade 2 (serum phosphorus < or = 0.61 mmol/L) hypophosphataemia during follow-up, respectively. CONCLUSIONS: Although slight increases in SCr did occur after starting TDF, clinically significant nephrotoxicity was rare. The clinical significance of TDF-related hypophosphataemia and proteinuria requires further study.

Adenine↗
PubMed1980

The utilization of rye by growing chicks as influenced by calcium, vitamin D3, and fat type and level.

Four experiments were conducted with growing chicks to study the effects of feeding rye and wheat diets supplemented with different calcium levels, two types and two levels of fat, and increasing levels of vitamin D3 and to study the interrelationships of these dietary ingredients on chick performance. In Experiment 1, feed conversion efficiency was reduced to a much greater extend (10% vs. 1%) when tallow replaced soybean oil in a rye-based diet containing only .6% calcium compared to a wheat-based diet. When the dietary calcium was increased to 1.1% the replacement of tallow by soybean oil resulted in only a small reduction in feed efficiency for chicks fed either the rye-(3%) or wheat- (1%) based diets. The retention of fat, particularly tallow, was depressed in rye as compared to wheat-fed birds. Fat retention was also influenced by calcium levels. Increasing the dietary calcium from .6 to 1.1% improved tallow (16%) and depressed (7%) soybean oil retention in rye-based diets, whereas in wheat-based diets the retention for both fats was slightly decreased. Experiment 2 showed that the efficiency of utilization of rye diets containing 7.5% tallow was improved by 10% when the level of dietary calcium was increased from .6 to 1.1% while the corresponding improvement in similarly formulated wheat diets was only 1%. The improvement of 2.5% fat, however, was only about 3% for both wheat and rye diets. The results from Experiment 3 showed that in the presence of a large excess of vitamin D3, the depression in the efficiency of utilization of the wheat diet was 13% but was less than 1% for the rye diet. This indicates that rye contains a factor that depresses vitamin D3 absorption. In Experiment 4, when dietary calcium was increased from .80 to 2.00% or when penicillin (200 mg/kg) was added, the improvement in efficiency of feed utilization was greater in chicks fed a rye diet (7%) compared to those fed a wheat diet (1%). The rye diets, however, were always less efficiently utilized than the corresponding wheat diets. Vitamin D supplementation, in contrast, did not affect chick performance. These results show that the performance of chicks fed rye diets is markedly influenced by type and level of dietary fat and the level of dietary calcium.

Animal Nutritional Physiological Phenomena↗