Determination of Streptococcus Mutans and Lactobacillus Counts and their Association with Resting pH of Saliva and Dental Caries in Preschool Children in Lagos.

BACKGROUND: Caries is controlled by several factors including exposure to diets rich in carbohydrates, tooth susceptibility, and the presence of some oral flora bacteria such as Streptococcus mutans (S. mutans) and Lactobacilli sp. Tooth demineralisation occurs when the pH in the oral cavity is lower than the critical pH of 5.5 which occurs because of the production of acid by the acidogenic bacteria in the oral flora when they break down sugars (substrate) for energy. OBJECTIVE: The objective of this study was to determine the salivary Streptococcus mutans and Lactobacillus counts and their association with resting pH of saliva and dental caries in pre-school children in Lagos. MATERIALSAND METHODS: Fifty preschoolers with and without caries were recruited from the dental clinic and staff primary school in Lagos University Teaching Hospital, Idi-araba respectively. Saliva was collected in Thioglycollate media. The resting pH of the saliva was measured immediately in the clinic with a pH meter (Jenway pH meter, PHS 25). In the laboratory, the samples were streaked on Mitis salivarius bacitracin agar (MSB) and Rogosa agar for S. mutans and Lactobacillus respectively and incubated anaerobically for 48 hours at 37°C. Biochemical tests and morphological characteristics of colonies were used to identify S. mutans and Lactobacillus. RESULTS: The children were aged between 45 to 71 months with a mean age of 56.66 7.17 months. The mean age of the caries-free group was 55.48 7.57 months and that of caries active group was 57.84 6.76 months. The caries-active subjects recorded significantly higher bacterial counts of S. mutans and Lactobacillus compared to the cariesfree subjects. Streptococcus mutans and Lactobacillus showed a negative and highly significant correlation with resting pH (r = - 0.38 and r = - 0.32 value respectively). CONCLUSION: The resting pH of saliva in both groups was within normal values. Streptococcus mutans and Lactobacillus counts were significantly inversely correlated to the resting pH value of saliva. Streptococcus mutans and Lactobacillus counts were significantly higher in the caries active group. CONTEXTE: La carie est contrôlée par plusieurs facteurs dont l'exposition à des régimes riches en glucides, la sensibilité des dents et la présence de certaines bactéries de la flore buccale telles que Streptococcus mutans (S. mutans) et Lactobacilli sp.. La déminéralisation des dents se produit lorsque le pH dans la cavité buccale est inférieur au pH critique de 5,5 qui se produit à la suite de la production d'acide par les bactéries acidurogènes dans la flore buccale lorsqu'elles décomposent les sucres (substrat) pour l'énergie. BUT ET OBJECTIF: L'objectif de cette étude était de déterminer le nombre de Streptococcus mutans et de Lactobacillus et leur association avec le pH au repos de la salive et des caries dentaires chez les enfants d'âge préscolaire à Lagos. MATÉRIEL ET MÉTHODES: Cinquante enfants d'âge préscolaire avec et sans caries ont été recrutés respectivement à la clinique dentaire et à l'école primaire du personnel de l'hôpital universitaire de Lagos, Idiaraba. La salive a été recueillie dans un milieu au thioglycolate. Le pH au repos de la salive a été mesuré immédiatement en clinique avec un pHmètre (Jenway pH meter, PHS 25).Au laboratoire, les échantillons ont été striés sur gélose bacitracine Mitis salivarius (MSB) et gélose Rogosa pour S. mutans et Lactobacillus respectivement et incubés en anaérobiose pendant 48 heures à 37°C. Des tests biochimiques et des caractéristiques morphologiques des colonies ont été utilisés pour identifier S. mutans et Lactobacillus. RÉSULTATS: Les enfants étaient âgés de 45 à 71 mois avec un âge moyen de 56,66 ± 7,17 mois. L'âge moyen du groupe sans carie était de 55,48 ± 7,57 mois et celui du groupe avec carie active était de 57,84 ± 6,76 mois. Les sujets actifs carieux ont enregistré un nombre de bactéries significativement plus élevé de S. mutans et Lactobacillus par rapport aux sujets sans caries. Streptococcus mutans et Lactobacillus ont montré une corrélation négative et hautement significative avec la valeur du pH au repos (r = - 0.38 et r = - 0.32 respectivement) . CONCLUSION: Le pH au repos de la salive dans les deux groupes était dans les valeurs normales. Les numérations de Streptococcus mutans et de Lactobacillus étaient significativement inversement corrélées à la valeur du pH de la salive au repos. Les numérations de Streptococcus mutans et de Lactobacillus étaient significativement plus élevées dans le groupe actif carieux. Mots-clés: Numération bactérienne, Streptococcus mutans, Lactobacillus, pH delasalive,Enfants d'âgepréscolaire.

L-Arginine supplementation enhanced expression of glucose transporter (GLUT 1) in sickle cell anaemia subjects in the steady state.

L-Arginine may have therapeutic value in the management of sickle cell disease and diabetes mellitus. There is very little information on the interaction of GLUT 1 and L-Arginine in sickle cell disease subjects. This study compared the blood levels of Glut 1, fasting blood glucose (FBG) and fasting insulin (FIns) in non-sickle cell anaemia (HbAA) and sickle cell anaemia (HbSS) subjects in the steady state before and following L-Arginine supplementation (1 g/day for 6 weeks). Nitric oxide metabolites, (NOX), catalase, superoxide dismutase and glutathione peroxidase were also measured in each group of subjects. Correlation coefficients between change (Δ) in Glut 1 and change (Δ) in FBG, Fins, NOX and antioxidant enzymes respectively were calculated. Before supplementation, Glut 1, NOX, GPX and CAT were significantly higher in HbAA subjects while FIns, FBG and MDA were higher in HbSS subjects. In both groups, supplementation significantly increased NOX, Glut 1 and antioxidant enzymes but decreased MDA. Supplementation increased FIns in HbAA but decreased FBG and FIns in HbSS subjects. In both groups of subjects, ΔGLUT 1 correlated positively with ΔNOX, antioxidant enzymes and Δ[R] but negatively with ΔMDA. ΔGLUT 1 correlated negatively with ΔFBG and ΔFins in HbSS but positively in HbAA. Study thus showed that in the steady state HbSS subjects had lower GLUT 1 but elevated FBG and Fins levels than HbAA subjects. Additionally, L-Arginine increased GLUT I and antioxidant enzymes but decreased Fins, FBG and MDA in HbSS subjects.

Blood pressure, hematologic and biochemical changes following L-arginine supplementation in children with sickle cell anaemia already on hydroxyurea therapy.

Hydroxyurea is an approved therapy in the management of children suffering from sickle cell disease (SCD). In adults co-administration of hydroxyurea and L-Arginine in adult sufferers of SCD had shown some benefits. This study examined the effect of co-administration of hydroxyurea (15-35mg/kg/day) and L-Arginine (500 mg/day) for 6 weeks on blood pressure, haematological parameters, liver and antioxidant enzymes levels. The levels of these parameters when the subjects were on hydroxyurea alone were taken as control values. Results showed that the combined therapy (HU + L-Arginine) decreased SBP, DBP, MAP and PP (p <0.01 in each case) but increased %HbF, Hb and PCV (p< o.001 in each case). It elevated CAT, SOD, GPX (p < 0.001 in each case) but depressed MDA, AST, ALT and ALP (p < 0.001 in each case). The study shows that L-Arginine used as an adjunct to hydroxyurea therapy may be beneficial to children suffering from sickle cell anaemia.

Supplementation with l-arginine stabilizes plasma arginine and nitric oxide metabolites, suppresses elevated liver enzymes and peroxidation in sickle cell anaemia.

The effect of l-arginine on liver function in SCD has received little or no attention. The effect of a chronic, oral, low-dose supplementation with l-arginine (1gm/day for 6 weeks) on some liver enzymes, lipid peroxidation and nitric oxide metabolites was studied in 20 normal (non-sickle cell anaemia; NSCA) subjects and 20 sickle cell anaemia (SCA) subjects. Ten milliliters of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and alkaline phosphatase (ALP), plasma total bilirubin concentration [TB], malondialdehyde concentration [MDA] and nitric oxide metabolites concentration [NOx]. Before supplementation, ALT, AST, ALP (p<0.05 respectively) and TB (p<0.001) were higher in SCA subjects than in NSCA subjects. [R] and [NOx] were higher in NSCA subjects (p<0.001 and p<0.05 respectively). Supplementation caused greater percent increases in [R], and [NOX] in SCA than in NSCA subjects (p<0.001 in each case). l-Arginine caused greater percent reductions in ALT and AST in SCA subjects but greater percent reduction in ALP in NSCA subjects (p<0.001 in each case). Changes in [MDA] and [TB] in the two groups were similar. Study shows that chronic, oral, low-dose supplementation with l-arginine improved liver function, oxidative stress, plasma arginine concentration and nitric oxide metabolites levels in NSCA and SCA subjects. Responses in SCA subjects to l-arginine were more sensitive than in NSCA subjects.

l-Arginine supplementation enhances antioxidant activity and erythrocyte integrity in sickle cell anaemia subjects.

The effect of oral, low-dose l-arginine supplementation (1g/day for 6 weeks) on antioxidant activity, haematological parameters and osmotic fragility of red blood cells was investigated in sickle cell disease sufferers. Twenty eight sickle cell anaemia subjects were recruited for the study. Five millilitres of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), total antioxidant enzymes (TAE) activity, malondialdehyde concentration ([MDA]), RBC count, [Hb], PCV, MCHC, MCV, MCH, percent irreversibly sickled cells (%ISC)) and osmotic fragility of red blood cells in the subjects. l-arginine supplementation increased [R] (p<0.001), TAE activity (p<0.05) and MCV (<0.05) but reduced plasma [MDA], MCHC, MCH and %ISC (p<0.001, respectively). Δ[R] correlated positively with ΔTAE (r=0.8) and negatively with Δ[MDA] (r=-0.7) and Δ%ISC (r=-0.5). Also ΔTAE activity correlated negatively with Δ[MDA] (r=-0.7) and Δ%ISC (r=-0.6). Supplementation shifted the osmotic fragiligram to the right and reduced the concentrations of NaCl at which initial and complete lyses of erythrocytes occurred. Study showed that low-dose, oral l-arginine increased antioxidant activity, red blood cell resistance to osmotic lysis but reduced red cell density in SCD.

L-arginine increases nitric oxide and attenuates pressor and heart rate responses to change in posture in sickle cell anemia subjects.

Pressor and heart rate changes following change in posture without or with L-arginine supplementation (1g/day for 6 weeks) were studied in 28 sickle cell anemia (SCA) and 32 non-sickle cell anemia (NSCA) subjects. Change in posture increased HR (p<0.01), RPP (p<0.05) in both groups of subjects, MABP (p<0.05) in SCAS but reduced MABP (p<0.01) in NSCAS and PP (p<0.01) in SCAS. L-Arginine supplementation increased plasma L-Arginine concentration ([R]) in both groups of subjects (p<0.001 in each group) and serum nitric oxide metabolites concentration ([NOx]) (p<0.01 in each group). Change (Δ) [R] correlated positively with Δ [NOx] in both groups (+ 0.7 in each group). L-Arginine supplementation caused greater reduction of MABP (p<0.001) in NSCAS than in SCAS. However, reduction in HR was greater (p<0.001) in SCAS than in NSCAS. After supplementation, MABP and PP responses to change in posture were attenuated in the two groups. However, while HR and RPP responses in SCAS were attenuated, the same responses were enhanced in NSCAS by change in posture after supplementation. In conclusion, study shows that oral, low dose, chronic supplementation with L-arginine increased NO availability and attenuated pressor and heart rate responses to change in posture in sickle cell anemia subjects.

Therapeutic Effects of Exercise Training On Selected Cardio-Pulmonary Parameters and Body Composition of Nigerians with Chronic Heart Failure (A Preliminary Study).

BACKGROUND: The use of exercise training in the management of individuals with chronic heart failure has not been widely accepted by health care providers especially in Sub-Saharan Africa because of the possibility that the failing hearts may have a negative response to the increased workload and stress of exercise. OBJECTIVE: The study aimed to evaluate the effects of exercise training (ET) on selected cardio-respiratory and body composition variables of Nigerians with chronic heart failure (CHF). METHODS: Thirty two Nigerians with CHF (male - 17), aged 30 to 71 years, mean age 54.2 ± 1.9 years and New York Heart Association Functional Class (NYHA) II-III recruited from Cardiology Clinic of Lagos University Teaching Hospital Nigeria participated in the study. They were randomized into exercise (EG) and control groups (CG). Exercise group performed 12-weeks of aerobic and resistance training for 60 minutes, three sessions per week. Selected cardio-respiratory and body composition variables were measured pre and post intervention in both groups. Data was analyzed using SPSS-17 package. Level of significance was set at 0.05. RESULTS: There was no significant difference in the measured variables between the groups at baseline (p > 0.05). Significant improvement was seen in EG in all the measured variables except the systolic (p = 0.29) and diastolic blood pressure (p = 0.45). No adverse effect was observed during the exercise training. No significant improvement was observed in the control group (p > 0.05). CONCLUSION: Exercise training may improve cardiorespiratory and body composition variables in patients with chronic heart failure.

Salt-sensitivity in normotensive and hypertensive Nigerians.

BACKGROUND: Salt-sensitivity increases the risk for the development of high blood pressure in susceptible persons and also increases the risk for cardiovascular events and mortality. OBJECTIVE: The study is to determine the pattern of salt-sensitivity among normotensive and hypertensive Nigerians. METHODS: Twenty-eight (28) hypertensive subjects (HT) and twenty-five (25) age-matched normotensive controls (NT) were given 200 mmol/day salt as sodium chloride for 5 days after control parameters had been determined. Subjects were regarded as salt-sensitive when change in mean arterial blood pressure (cMABP) between baseline levels and that after salt loading was > or = 5 mmHg. RESULTS: Systolic blood pressure and mean arterial blood pressure but not diastolic blood pressure rose significantly (p < 0.05 and p < 0.001 respectively) in NT subjects while all the parameters showed significant increases in hypertensive subjects (SBP p < 0.01; DBP p < 0.001; MABP p < 0.0001). More hypertensive subjects (60.7%) were salt-sensitive compared with normotensive (52.0%) subjects (p < 0.05). CONCLUSION: This study has demonstrated pressor responses to acute salt-loading in normotensive and hypertensive Nigerians and salt-sensitivity was higher in hypertensive subjects.

Exercise training improves walking function in an African group of stroke survivors: a randomized controlled trial.

OBJECTIVE: To evaluate the effects of treadmill walking and overground walking exercise training on recovery of walking function in an African group of stroke survivors. DESIGN: Prospective, randomized controlled study. SETTING: Outpatient stroke rehabilitation unit in a tertiary hospital. SUBJECTS: Sixty patients with chronic stroke (≥3 months). INTERVENTION: All subjects received individual outpatient conventional physiotherapy rehabilitation for 12 weeks. In addition, subjects in Group A (n = 20) received treadmill walking exercise training (TWET) while those in Group B (n = 20) received overground walking exercise training (OWET). Those in Group C (control) (n = 20) received conventional physiotherapy rehabilitation only. MAIN MEASURES: Outcome measures were (i) 10-metre walk time (10MWT) test and (ii) six-minute walk distance (6MWD) test. These were evaluated at entry into the study and at the end of every four weeks. Paired t-tests were used to evaluate the significance of the difference between pre-training and post-training scores on the two measures (P < 0.05). RESULTS: Subjects in the TWET group recorded 22.6 ± 1.5% decrease in 10MWT and 31.0 ± 4.3% increase in 6MWD; those in the OWET group made 26.8 ± 1.3% and 45.2 ± 4.6% improvement in 10MWT and 6MWD respectively. Subjects in the control group made 2.2 ± 0.7% and 2.9 ± 0.8% improvement in the two functions. These changes were significant for the TWET and OWET groups (P < 0.05). CONCLUSION: This study indicated that treadmill and overground walking exercise training programmes, combined with conventional rehabilitation, improved walking function in an African group of adult stroke survivors. Therefore, professionals who conduct stroke rehabilitation programmes should utilize exercise training to optimize patient outcomes.

Liver enzymes and trace elements in the acute phase of sickle cell anaemia.

BACKGROUND: Trace elements are required for the performance of numerous functions of immune cells. It is not clear whether levels of trace elements are elevated and whether there is a relationship between the levels of liver enzymes and trace elements in patients with sickle cell anaemia in crisis. OBJECTIVE: To compare the plasma levels of liver enzymes and trace elements in non sickle cell anaemia (NSCA), sickle cell anaemia subjects in the steady state (SCASS) and sickle cell anaemia patients in crisis (SCAC). METHODS: Haematological parameters, liver enzymes and trace elements were determined in 20 NSCA subjects, 20 SCASS subjects and 18 SCAC subjects. Variables studied included aspartate aminotransferase (AST) , alanine aminotransaminase (ALT), alkaline phosphatase (ALP), and the trace elements copper, zinc, and manganese. RESULTS: Levels of liver enzymes were higher in the SCAC subjects than in the NSCA or SCASS subjects (p<0.001). Plasma Cu++, Zn++ and Mn++ were also higher in the SCAC subjects than in the NSCA or SCASS subjects (p<0.001). Correlationships were high and strong between AST and ALT (r=+0.7; p=0.03), AST and ALP (r=+0.9; p=0.001), Zn++ and Fe++ (r=+0.9; p=0.001) in SCAC. CONCLUSION: During crisis in sickle cell anaemia, liver enzymes, as well as the trace elements of Cu++, Zn++ and Mn++ are increased; levels of aspartate aminotransaminase are strongly correlated with those of ALT and ALP. Levels of liver enzymes do not appear to be related to those of the trace elements in painful sickle cell crisis.

Liver Enzymes and Trace Elements in the Acute Phase of Sickle Cell Anaemia

BACKGROUND: Trace elements are required for the performance of numerous functions of immune cells. It is not clear whether levels of trace elements are elevated and whether there is a relationship between the levels of liver enzymes and trace elements in patients with sickle cell anaemia in crisis. OBJECTIVE: To compare the plasma levels of liver enzymes and trace elements in non sickle cell anaemia (NSCA); sickle cell anaemia subjects in the steady state (SCASS) and sickle cell anaemia patients in crisis (SCAC). METHODS: Haematological parameters; liver enzymes and trace elements were determined in 20 NSCA subjects; 20 SCASS subjects and 18 SCAC subjects. Variables studied included aspartate aminotransferase (AST) alanine aminotransaminase (ALT); alkaline phosphatase (ALP); and the trace elements copper; zinc; and manganese. RESULTS: Levels of liver enzymes were higher in the SCAC subjects than in the NSCA or SCASS subjects (p

Effects of two exercise training techniques on walking function in adult patients with stroke.

BACKGROUND: Patients with stroke usually demonstrate activity limitations manifested by reduced ability to perform daily functions. OBJECTIVE: The purpose of this study was to examine the effects of treadmill walking and overground walking exercise training on walking function in adult patients with stroke. METHODS: Participants were forty (40) patients with stroke comprising 22 males and 18 females. Inclusion criteria included absence of any co-morbidity that could affect rehabilitation. They were randomly assigned to 2 exercise training groups (20 in each group). All study subjects received conventional physiotherapy rehabilitation for 12 weeks. During the same period, subjects in Group A had treadmill walking exercise training (TWET) while those in Group B had overground walking exercise training (OWET) in addition to the conventional physiotherapy. Outcomes were measured as (i) Ten-metre walk time and (ii) Six-minute walk distance. They were evaluated at entry into the study and at the end of every 4 weeks. Results at weeks 0, 4, 8 and 12 were used for analysis. For each of the 2 groups, paired t-tests were used to evaluate the significance of the differences between the pre-intervention (week 0) mean scores on both tests and the mean scores at weeks 4, 8 and 12. RESULTS: With 12 weeks of exercise training, both TWET and OWET produced significant improvement in walking function (P < 0.05). However, OWET resulted in significantly greater reduction (26.8%) in mean walking time over 10 metres than TWET (22.6%); and significantly greater increase (45.2%) in mean walking distance over 6 minutes than TWET (31.0%). CONCLUSION: Exercise training, especially overground walking, could be integrated into the traditional rehabilitation care given to adult patients with stroke.

Electrocardiographic and blood pressure changes in apparently healthy male subjects following oral, chronic, low-dose vitamin C supplementation and/or change in posture.

INTRODUCTION: Studies have shown that oral, chronic, low dose vitamin C reduces blood pressure and forearm blood flow in normal young adults or hypertensive patients. It is not clear how vitamin C affects cardiac function or autonomic control of blood pressure in young apparently healthy adults. AIM: This study was undertaken to examine the effects of a chronic, low dose (300 mg/day for 6 weeks) vitamin C supplementation on the electrocardiogram and autonomic control of blood pressure in apparently healthy male subjects. METHODOLOGY: Electrocardiographic (ECG) and arterial blood pressure (BP) changes were assessed following change in posture with or without oral, chronic low dose vitamin C supplementation in twenty (20) apparently healthy male subjects (mean age 28.2 +/- 2.0 yrs). Blood pressure (BP, mm Hg) and ECG measurements (amplitude, mV; duration or interval, ms) were recorded in the supine position and immediately on assumption of the upright position. Heart rate (HR; beats/min) was calculated from the ECG while rate pressure product (RPP; arbitrary units) was calculated and used as a measure of myocardial oxygen demand. Each subject was then placed on oral vitamin C at a dose of 300 mg/day for 6 weeks. Measurements were made again after the period. RESULTS: Change in posture caused significant reductions in P-wave amplitude, QRS amplitude and duration, T-wave amplitude and systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial blood pressure (MABP) (p < 0.01 respectively). PR and RR intervals also fell (p < 0.05 and p < 0.001 respectively) while HR and RPP increased (p < 0.001) Vitamin C decreased T-wave amplitude (p < 0.01) and QRS duration (p < 0.01). Also, SBP, DBP, MABP and RPP fell (p < 0.01 in each case). After vitamin C supplement ation, change in posture decreased P-wave amplitude, T-wave duration, P-wave duration, QT interval and RR interval (p < 0.05 respectively). BP and HR responses to postural change were attenuated by vitamin C supplementation. SBP fell by 7.4 +/- 1.0 mm Hg (Vs 12.2 +/-0.1 mm Hg pre-supplementation), DBP by 5.4 +/- 0.6 mm Hg (Vs 10.4 +/- 0.1 mm Hg pre-supplementation) and MABP by 6.1 +/- 1.4 mm Hg (Vs 11.0 +/- 0.1 mm Hg pre-supplementation). HR increased by 18.6 +/- 1.0 beats/min (Vs 29.6 +/- 2.5 beats/min pre-supplementation) and RPP by 1385.6 +/- 126.4 units (Vs 2370.0 +/- 105.6 units pre-supplementation). CONCLUSION: Chronic, low dose vitamin C supplementation enhanced cardiovascular autonomic activity in apparently healthy young subjects. It minimized the fluctuations in BP and HR and also reduced myocardial oxygen demand following postural change.

Cardiac and autonomic responses to change in posture or vitamin C supplementation in sickle cell anemia subjects.

Autonomic function following change in posture with or without vitamin C supplementation was studied in ten (10) sickle cell anemia (SCA) and twelve (12) non-sickle cell anemia (NSCA) subjects. Arterial blood pressure and electrocardiographic measurements were taken in the supine position on a couch 80cm high and immediately on assumption of the upright position. Vitamin C was then administered orally (300mg/day for 6 weeks). At the end of the period, blood pressure and ECG measurements were again made in the supine position and in response to change in posture. Change in posture significantly decreased QRS amplitude, QRS duration, PR interval, RR interval and MABP but increased HR and rate pressure product (RPP) in both groups of subjects. The HR and RPP responses were significantly higher in NSCA than in SCA subjects (p<0.001, respectively). Vitamin C caused greater reductions in QRS duration (p<0.01), PR duration p<0.001) in the NSCA subjects than in SCA subjects. It caused, however, greater reduction in RR duration (p<0.001) and MABP in SCA subjects than in NSCA subjects. It also caused significantly greater increases in HR and RPP (p<0.001, respectively) in the SCA subjects than in NSCA subjects. After vitamin C supplementation, change in posture decreased RR interval (p<0.001), QT interval (p<0.01) and MABP (p<0.05) but increased RPP (p<0.01) in NSCA subjects. In SCA subjects, there was a fall in RR interval (p<0.001) and MABP (p<0.01), but elevated RPP (p<0.001). Changes (Delta) in MABP, HR and RPP were similar between NSCA and SCA subjects. In conclusion, these findings indicate a blunted cardiovascular autonomic response to change in posture in sickle cell anemia subjects. Chronic, oral, low-dose vitamin C supplementation equilibrates this response with those of non-sickle cell anemia subjects.

Effect of changes in plasma vitamin E level of vascular responses and lipid peroxidation in sickle cell anaemia subjects.

The effect of vitamin E supplementation (300 mg/day for 6 weeks) on blood pressure, forearm blood flow, forearm vascular resistance, plasma vitamin E level and lipid peroxidation status was investigated in adult sickle cell anaemia subjects. Ten adults whose ages ranged from 19.0 to 25.0 years (mean 22.8+/-0.8 years) were studied. Vitamin E supplementation had little or no effect on arterial blood pressure but significantly increased forearm blood flow (p<0.001) and plasma vitamin E level (p<0.001). However it significantly decreased lipid peroxidation status (p<0.001) and forearm vascular resistance (p<0.001). The change in plasma vitamin E concentration correlated negatively with change in lipid peroxidation status (r=-0.8; p=0.003). However, change in plasma vitamin E concentration correlated positively with change in forearm blood flow (r=0.8; p=0.006). There was an inverse correlation between change in plasma lipid peroxidation and change in forearm blood flow (r=-0.7; p=0.03). The study therefore shows that in sickle cell anaemia subjects, vitamin E supplementation increases forearm blood flow and reduces forearm vascular resistance and lipid peroxidation. The increase in forearm blood flow correlates inversely with the reduction in lipid peroxidation. This suggests that in sickle cell anaemia subjects, vitamin E supplementation could cause an increase in forearm blood flow by decreasing plasma lipid peroxidation level.

Changes in erythrocytes following supplementation with alpha-tocopherol in children suffering from sickle cell anaemia.

INTRODUCTION: Low plasma vitamin E level in children with sickle cell anaemia has been related to elevated level of irreversibly sickled cells which has been implicated in the pathogenesis of painful crisis. In adult patients supplementation with alpha-tocopherol has been shown to reduce irreversibly sickled cell count. In-addition, vitamin E supplementation increases resting forearm blood flow and reduces forearm vascular resistance in adult sickle cell anaemia sufferers. AIM: The aim of the study was to examine the effects of supplementation with alpha-tocopherol on arterial blood pressure, some haematological parameters and osmotic fragility in children suffering from sickle cell anaemia. METHODOLOGY: The effects of supplementation with alpha-tocopherol (100 mg. per day for 6 weeks) on packed cell volume (PCV) haemoglobin concentration ([Hb]), mean corpuscular haemoglobin concentration (MCHC), per cent foetal haemoglobin (% HbF), per cent irreversibly sickled cells (%ISC), erythrocyte osmotic fragility and blood pressure have been assessed in ten (10) children suffering from sickle cell anaemia. Their ages ranged from 4.0 to 10.0 years. RESULTS: Supplementation with alpha-tocopherol significantly increased packed cell volume (p<0.001), haemoglobin concentration (p<0.01) and per cent foetal haemoglobin (p<0.001), but significantly reduced mean corpuscular haemoglobin concentration (p<0.01) and per cent irreversibly sickled cells (p<0.001). alpha-Tocopherol also increased the resistance of the cells to lysis. Supplementation with alpha-tocopherol had little or no effect on arterial blood pressure. CONCLUSION: This study shows that short-term supplementation with alpha-tocopherol may be beneficial to the paediatric sickle cell sufferer.

The effect of warmth or/and vitamin E supplementation on forearm blood flow and forearm vascular resistance in sickle cell and non sickle cell anaemia subjects.

The effects of warmth stimulation and/or supplementation with vitamin E (300 mg/day for 6 weeks) on forearm blood flow (FBF) and forearm vascular resistance (FVR) were measured in 8 sickle cell anaemia (SCA) (mean age = 22.8 + 0.8 years) and 11 non sickle cell anaemia (NSCA) subjects (mean age = 23.2 + 1.1 years) of both sexes. Warmth stimulation was induced by immersing the left foot in warm water at 400C for 2 minutes. Forearm blood flow was measured with the venous occlusion plethysmography method. Warmth increased FBF (p <0.01 in each group) and reduced FVR (p <0.05) in NSCA subjects. The change in FBF was greater (p < 0.05) in the NSCA subjects than in the SCA subjects. Supplementation with vitamin E reduced systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP) (p < 0.001 in each case) in the NSCA subjects but had little or no effect on the SCA subjects. Vitamin E increased FBF in NSCA subjects (p < 0.05) and SCA subjects (p < 0.01) and decreased FVR in both groups (p < 0.05 in NSCA and p < 0.01 in SCA subjects). The change in FVR seen in the NSCA subjects was less (p < 0.01) than the change in SCA subjects. After supplementation with vitamin E, warmth further decreased SBP (p < 0.01 in each group) and FVR (p < 0.01 in each case) and increased FBF in both groups (p < 0.01 respectively). The changes caused by warmth after vitamin E supplementation on the blood pressure parameters, FBF and FVR were similar in the two groups of subjects.

Exercise improves recovery of ventilation in male asthmatic subjects in the steady state.

The effect of a three-minute exercise step test (submaximal) on the recovery of tidal volume (V(T)), respiratory frequency (f(R)) and minute ventilation (V(E)) has been investigated in non-asthmatic subjects, asthmatic subjects that exercise regularly and asthmatics that do not participate in regular exercise. Recovery was observed over twenty minutes at two-minute intervals. Ten male non-asthmatic subjects (NAS) (mean age 20.7+/- 0.4 yr), six male asthmatic subjects (20.5+/- 0.5 yr) that exercised regularly (EAS) and six male asthmatic subjects (20.8+/- 0.5 yr) that did not exercise regularly (NEAS) were studied. Exercise significantly increased all the measured variables in all the groups of subjects (P<0.001 in each case). At the end of the 20th minute, magnitude of recovery of V(T) was 123.3+/- 4.5% in NAS, 102.4+/- 5.1% in EAS (p<0.001) and 87.9+ 5.4% in NEAS (p<0.001). Mean rate of recovery of V(T) was highest (6.3%/min) in NAS and least in NEAS (4.4%/min). At the end of the (T)observation period, recovery of respiratory frequency (f(R)) was 100.0+/- 5.0% in NAS, 100.0+/- 4.5% in EAS and 89.2+/- 3.0 in NEAS. Mean rate of recovery of f(R) was 5.0%/min in NAS and EAS subjects respectively and 4.4%/min in NEAS subjects. Also, at the end of the 20th minute, the magnitude of recovery of V(E) was similar between NAS and EAS (105.1+/- 1.5% and 101.6+/- 1.75% respectively). Recovery of V(E) was significantly less in NEAS (93.9+/- 2.5%; p<0.01). Mean rate of recovery of V(E) was similar between NAS and EAS subjects (5.0%/min in each case) and 4.1%/min in the NEAS subjects. Thus regular exercise improves the recovery of ventilatory parameters in asthmatic subjects.

The effect of vitamin C and/or warmth on forearm blood flow and vascular resistance in sickle cell anaemia subjects.

This study seeks to examine the effects of vitamin C supplementation or/and warmth on forearm blood flow (FBF) and forearm vascular resistance (FVR) in sickle cell anaemia (SCA) subjects in the steady state. Sixteen (16) SCA subjects of both sexes (mean age, 23.4+/-1.5 yrs.) were studied. Blood pressure (BP, mm Hg) and FBF (ml/min) measurements were made at rest, with warmth stimulation, after vitamin C supplementation for 6 weeks at 300 mg per day and with warmth stimulation after vitamin C supplementation. Warmth stimulation was induced by immersing the left foot in a bowl of water at a temperature of 40 degrees C for 2 minutes. Forearm blood flow (FBF) [corrected] was measured by means of a forearm plethysmograph. Forearm vascular resistance (FVR, arbitrary units) was calculated by dividing mean arterial pressure (MAP) with FBF. Warmth stimulation at 40 C significantly decreased systolic blood pressure (SBP) (p<0.05), diastolic blood pressure (DBP) (p<0.01), MAP (p<0.01) and FVR (p<0.01) but significantly increased FBF (p<0.01). Vitamin C supplementation also significantly reduced SBP (p<0.001), DBP (p<0.01), MAP (p<0.01) and FVR (p<0.05) but significantly increased FBF (p<0.01). After vitamin C supplementation, warmth stimulation potentiated the reduction in SBP (p<0.001), DBP (p<0.01), FVR (p <0.01) and increase in FBF (p<0.01). In conclusion, warmth stimulation at 40 [corrected] degrees C or vitamin C supplementation caused a decrease in arterial blood pressure, forearm vascular resistance and increase in forearm blood flow in sickle cell anaemia subjects. Pretreatment with vitamin C enhanced the vasodilator effect of warmth.

Blood pressure, hematologic and erythrocyte fragility changes in children suffering from sickle cell anemia following ascorbic acid supplementation.

The effect of ascorbic acid supplementation (100 mg/day for 6 weeks) on blood pressure, packed cell volume, irreversibly sickled cells, per cent fetal hemoglobin, hemoglobin concentration, and erythrocyte osmotic fragility was assessed in children suffering from sickle cell anemia. Fifteen children whose ages ranged from 4 to 11 years (7.5 +/- 0.75 years) were studied. Ascorbic acid supplementation reduced systolic blood pressure by 10.9 +/- 3.4 mmHg (p < 0.01), diastolic blood pressure by 7.3 +/- 2.0 mmHg (p < 0.01) and mean arterial pressure by 9.4 +/- 2.6 mmHg (p < 0.01). It significantly increased packed cell volume (p < 0.001), hemoglobin concentration (p < 0.001) and per cent fetal hemoglobin (p < 0.001), but reduced per cent irreversibly sickled cells (p < 0.001). Ascorbic acid supplementation also abolished the long tail of the erythrocyte osmotic fragiligram and increased the resistance of the cells to lysis.