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Biomedical subjects

A Kourti

Publications and source records attributed to A Kourti.

12 recordsLinked to original sources
PubMed2004

Estimates of gene flow from rare alleles in natural populations of medfly Ceratitis capitata (Diptera: Tephritidae).

Gene flow based on the spatial distribution of rare alleles at 25 gene loci was estimated in 15 populations of Ceratitis capitata (Wiedemann) from different parts of the world. Estimates of Nm, the number of migrants exchanged per generation among populations in different regions of the world, appeared to be quite similar, ranging from 3.36 in tropical Africa to 2.94 in the New World and 2.72 in Mediterranean basin populations. This suggests that gene flow among neighbouring populations of medfly is quite extensive. The genetic differentiation in American, Mediterranean and African populations was related to major climatic differences between North and South. These differences arise mainly from five loci that showed gene frequency patterns suggestive of latitudinal clines in allele frequencies. The clinal variation was such that tropical-subtropical populations were more heterozygous than temperate populations. It was concluded that gene flow, counteracting the forces of natural selection and genetic drift, determines the extent to which geographical populations of C. capitata are differentiated.

Alleles↗
PubMed1997

Comparison of mtDNA variants among Mediterranean and New World introductions of the Mediterranean fruit fly Ceratitis capitata (Wied.).

Restriction enzyme cleavage sites of mitochondrial DNA (mtDNA) from the Mediterranean fruit fly (Ceratitis capitata) were found to vary among Mediterranean and New World populations. A restriction map for six populations (one from Greece and five from the New World) is constructed for the Mediterranean fruit fly. Six diagnostic restriction enzymes (EcoRI, EcoRV, HaeIII, HindIII, SstI, XbaI) are assigned three geographically distinct main types, CI, CII, and CIII.

Animals↗
PubMed1996

Ambulatory blood pressure measurement in type-II diabetic patients with autonomic neuropathy.

The aim of our study was to access the 24-hr ambulatory blood pressure (BP) in diabetic patients with autonomic neuropathy (AN). Twenty-two NIDDM patients without hypertension, being treated with sulfonylureas, were studied. The 24-hr ambulatory blood pressure recordings were performed using portable non-invasive automatic system. Autonomic neuropathy was assessed by standard cardiovascular reflex tests. There were ten patients with and 12 without AN, matched for age, body mass index, duration of diabetes and glycemic control. Mean BP increased at night in four of the subjects with AN and decreased in the remaining 18 patients. The group of subjects with nocturnal increases in BP had more severe autonomic nerve dysfunction compared with those with decreases in nocturnal BP. No significant difference between clinical and ambulatory day-time measurements was found. In three patients with AN after 5 weeks intensified therapy. 24-hr BP did not show any significant difference.

Autonomic Nervous System Diseases↗
PubMed1994

Effect of an acute oral protein load on microalbuminuria in uninephrectomized patients in relation to the time since nephrectomy.

To evaluate the effect of an acute oral protein load (OPL) on urinary albumin excretion (UAE) in uninephrectomized subjects with a negative Albustix test, in relation to the time since nephrectomy, the UAE was determined by a double-antibody 125I radioimmunoassay in 3-hour urine collections before and after 150 g OPL under conditions of moderate physical activity in 18 subjects who underwent unilateral nephrectomy more than 10 years (346.5 +/- 178.60 months) before evaluation and had a mean basal creatinine clearance (CCr) of 45.3 +/- 14 ml/min (group 1), in 21 subjects who underwent unilateral nephrectomy less than 10 years (31.5 +/- 28 months) before evaluation and had a mean basal CCr of 76.0 +/- 22 ml/min (group 2), and in 16 normal volunteers (controls) with a mean basal CCr of 103.1 +/- 12 ml/min. The UAE was higher in group 1 as compared with either group 2 or controls at both basal state (90.8 +/- 65, 19.6 +/- 17, and 11.0 +/- 5 micrograms/min/100 CCr for groups 1 and 2 and controls, respectively; p < 0.001) and after OPL (92.0 +/- 65, 43.6 +/- 24, and 12.0 +/- 5 micrograms/min/100 CCr for groups 1 and 2 and controls, respectively; p < 0.001). However, the increase in UAE following OPL was significant (p < 0.001) only in group 2 patients. In all patients, the basal UAE was negatively correlated with basal CCr (r = 0.63; p < 0.001) and positively correlated with the time since nephrectomy (r = 0.73; p < 0.001) and with both systolic (r = 0.57; p < 0.001) and diastolic blood pressures (r = 0.69; p < 0.001). CCr calculated using 3-hour urine collections increased more in controls (11.2 +/- 44.2%) than in patient groups 1 (1.6 +/- 0.89) and 2 (7.7 +/- 3.7%; p < 0.001). Basal CCr calculated using 24-hour urine collections the day before the test was negatively correlated with the time since nephrectomy in group 1 (r = -0.69; p < 0.001) and positively correlated with the time since nephrectomy in group 2 (r = 0.89; p < 0.001). Multiple regression analysis revealed that the relationship between CCr and duration of uninephric state was independent of age or systolic and diastolic blood pressures in both patient groups. These results suggest that UAE increase significantly after an OPL in subjects who have been nephrectomized less than 10 years before the study and have basal CCr values higher than 50% of normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1994

The prevalence of peripheral vascular disease in type 2 diabetic patients with and without proteinuria.

It has been reported that albumin excretion rate may reflect not only an indication of renal disease but also a widespread vascular damage. We studied the relationship between overnight albumin excretion rate (AER) and peripheral vascular disease (PVD), using Doppler ultrasound, and its major risk factors in 80 Type 2 (non-insulin-dependent) diabetic patients. Thirty-eight of these patients had normoalbuminuria (AER < 30 micrograms/min), 22 had microalbuminuria (30-200 micrograms/min) and 20 had macroalbuminuria (> 200 micrograms/min). Patients with macroalbuminuria were older than those with normoalbuminuria (p < 0.01) and they also had a longer duration of diabetes (p < 0.05). Patients with elevated albumin excretion rates had elevated prevalence of PVD (macroalbuminuric 40%, p < 0.01; microalbuminuric 27.2%, p < 0.05; vs normoalbuminuric 7.8%). Among the risk factors analysed, hypertension and triglyceride concentrations were higher in the proteinuric diabetics (macroalbuminuric p < 0.001, p < 0.01; microalbuminuric p = NS, p < 0.01 respectively), while HDL-C levels were found to be significantly lower in this group (p < 0.05). In the diabetic group as a whole, raised AER was correlated with PVD (p < 0.05), duration of diabetes and systolic blood pressure (p < 0.01). We conclude that the prevalence of PVD was significantly higher in Type 2 diabetic patients with elevated albumin excretion rate. Furthermore, these patients had higher blood pressure and low HDL-C.

Aged↗
PubMed1993

Effect of intravenous calcium infusion on indices of activity of the parathyroid glands and on urinary calcium and sodium excretion in normotensive and hypertensive subjects.

The effect of an intravenous calcium gluconate load (10 mg/kg over 5 min) on plasma ionized calcium concentration, parathyroid hormone (PTH), and the rate of urinary excretion of calcium, sodium, and nephrogenous cyclic adenosine monophosphate (NcAMP) was examined in 26 patients with essential hypertension and 27 age- and sex-matched normotensive subjects. Prior to calcium administration hypertensives had lower plasma ionized calcium concentration (P < .01) and higher PTH levels (P < .001) and excreted more calcium (P < .05) and NcAMP (P < .001) in the urine compared to normotensives. Following calcium infusion, plasma ionized calcium did not differ significantly between the two groups, but PTH levels remained higher in the hypertensive subjects at both 60 min (P < .001), and at 120 min (P = .02) post-load. Post-load values for both urinary calcium excretion and urinary sodium excretion were significantly higher in the hypertensive subjects than in the control group. Both before and after calcium infusion, urinary calcium excretion was positively correlated with urinary sodium excretion in each of the two groups, but for the same level of sodium excretion, hypertensives excreted more calcium in the urine, compared to normotensives, both before (P < .05) and after calcium infusion (P < .001). A positive correlation between basal plasma renin activity (PRA) values and plasma ionized calcium values obtained before (r = 0.42, P = .03) or at 60 min (r = 0.41, P = .03) and 120 min (r = 0.42, P = .03) after calcium infusion existed only in the hypertensive subject group. Post-load urinary sodium excretion values were negatively correlated to basal PRA values in both groups (r = -0.55, P < .01 and r = -0.58, P < .01 for hypertensives and normotensives, respectively), but a similar negative correlation between post-load urinary calcium excretion values and basal PRA values existed only in the hypertensive subject group (r = -0.50, P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Urine calcium excretion, nephrogenous cyclic-adenosine monophosphate and serum parathyroid hormone levels in patients with essential hypertension.

To evaluate the role of calcium and the parathyroid gland in the pathophysiology of essential hypertension, creatinine clearance, urinary excretion of sodium, calcium and nephrogenous cyclic adenosine monophosphate (NcAMP) and serum parathyroid hormone (PTH) levels were measured in 25 newly diagnosed essentially hypertensive patients before institution of any treatment and in 25 age- and sex-matched normal volunteers. While no significant differences in creatinine clearance, serum total calcium levels or 24-hour sodium excretion existed between the two groups, hypertensives had a higher mean (+/- SD) 24-hour calcium excretion rate (199.0 +/- 44.7 vs. 152.8 +/- 33.6 mg, p less than 0.001), a higher mean NcAMP excretion rate (2.54 +/- 0.8 vs. 1.87 +/- 0.5 nmol/100 ml glomerular filtrate, p less than 0.001) and a higher mean serum PTH concentration (1.87 +/- 0.6 vs. 1.53 +/- 0.4 ng/ml, p less than 0.001) than the normotensives. A significant positive correlation existed between calcium and sodium excretion in both hypertensives (r = 0.66, p less than 0.001)) and normotensives (r = 0.67, p less than 0.001), but given the same levels of creatinine clearance and sodium excretion, hypertensives excreted more calcium than normotensives (p less than 0.001)). In both hypertensives and normotensives, serum PTH levels were positively correlated with NcAMP excretion (r = 0.42, p less than 0.05, and r = 0.41, p less than 0.05, respectively) and the ratio of urinary sodium to urinary calcium excretion (r = 0.59, p less than 0.001, and r = 0.75, p less than 0.001), respectively). The above results suggest that in essential hypertension, increased activity of parathyroid glands may occur as a consequence of increased urinary calcium losses which are presumably due to an intrinsic defect in renal calcium handling.

Adult↗
PubMed1991

Nephrobronchial fistula. Case report.

A 26-year-old woman presented with a six-year history of right staghorn calculus and pyonephrosis. Intravenous pyelography showed a non-functioning right kidney and chest radiography, an elevated right hemidiaphragm and fluid in the right costaphrenic space. At operation a nephrobronchial fistula was found, and nephrectomy and subdiaphragmatic drainage of the lung abscess was carried out. Culture of the pus grew Proteus mirabilis. The patient made an uneventful recovery and was discharged on the sixteenth day after operation.

Adult↗
PubMed1988

Plasma lipid and lipoprotein response to carbohydrate feeding in cirrhotic patients.

Serum lipids and lipoproteins, and glucose and insulin, were measured after an overnight fast, and during 3 days of a eucaloric diet rich in carbohydrate, in 15 patients with cirrhosis and seven normal subjects. Following the high-carbohydrate diet triglyceride rose in all groups but the increase in cirrhotics was lower than in normals. In normals and in cirrhotics with good liver function most of the triglyceride increment was carried in VLDL; in cirrhotics with poor liver function only 31% of the increment was found in VLDL, and 56% in triglyceride-rich LDL. In an earlier study on fat feeding, our cirrhotic patients with poor liver function had an impaired chylomicron and VLDL response; they also carried most of the triglyceride increment in triglyceride-rich LDL. The markedly impaired response of triglyceride-rich lipoproteins to both carbohydrate and fat feeding suggests that sick cirrhotics may have a problem with storage of dietary energy and that this contributes to loss of their adipose tissue.

Adult↗
PubMedDate not supplied

Peripheral vascular disease in newly diagnosed non-insulin-dependent diabetic.

The aim of this study was to assess the prevalence of peripheral vascular disease (PVD) in newly diagnosed diabetic patients and the possible relationship to various risk factors. One hundred and twenty non-insulin-dependent diabetics (NIDDs) aged 50-70 years and 93 non-diabetic subjects, matched for age and sex, were studied using Doppler ultrasound. None had a history of alcoholic abuse, while 12 diabetic and 8 non-diabetic subjects were smokers. There were 6 male subjects with PVD (5 NIDDs, 1 control subject) and 2 female diabetic subjects with PVD (p: No SD). In group of male diabetics with PVD, HDL-C levels were found to be lower and triglyceride levels higher, than in those without diabetes, but the difference was not significant. Hypertension, body mass index and smoking were not associated with the presence of PVD in either female or male diabetic subjects. It is concluded that, although PVD tended to be more common in men with newly diagnosed diabetes, the overall findings support the view that macrovascular disease is related to duration of diabetes.

Age Factors↗
PubMedDate not supplied

The prevalence of peripheral vascular disease in sulfonylurea treated diabetic patients with proteinuria.

The aim of this study was to assess the prevalence and the possible risk-factors for the development of peripheral vascular disease (PVD) in sulfonylurea-treated diabetic patients with proteinuria. Fifty non-insulin-dependent diabetics (NIDDs) with proteinuria (greater than 500 mg/24 h), with age less than or equal to 75 years and duration of diabetes greater than or equal to 5 years, and forty-eight NIDDs without proteinuria, matched for age, sex, body mass index (BMI), duration of diabetes and glycaemic control, were studied using Doppler ultrasound. Risk factors analysed included smoking, hypertension and metabolic indices (cholesterol, HDL-C, triglycerides). The prevalence of PVD was 44% in the proteinuric disease group compared to 14.6% in those without proteinuria (p less than 0.01). Among the risk factors analysed, hypertension and triglyceride concentration were significantly higher in the proteinuric diabetics (p less than 0.01), while HDL-C levels were found to be significantly lower in this group (p less than 0.05). We conclude that the prevalence of PVD was significantly higher in NIDDs with proteinuria. Furthermore, proteinuric patients had higher blood pressure and low HDL-C.

Aged↗