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Biomedical subjects

G Baio

Publications and source records attributed to G Baio.

12 recordsLinked to original sources

Magnetic resonance imaging at 1.5 T with immunospecific contrast agent in vitro and in vivo in a xenotransplant model.

OBJECT: Demonstrating the feasibility of magnetic resonance imaging (MRI) at 1.5 T of ultrasmall particle iron oxide (USPIO)-antibody bound to tumor cells in vitro and in a murine xenotransplant model. METHODS: Human D430B cells or Raji Burkitt lymphoma cells were incubated in vitro with different amounts of commercially available USPIO-anti-CD20 antibodies and cell pellets were stratified in a test tube. For in vivo studies, D430B cells and Raji lymphoma cells were inoculated subcutaneously in immunodeficient mice. MRI at 1.5 T was performed with T1-weighted three-dimensional fast field echo sequences (17/4.6/13 degrees ) and T2-weighted three-dimensional fast-field echo sequences (50/12/7 degrees ). For in vivo studies MRI was performed before and 24 h after USPIO-anti-CD20 administration. RESULTS: USPIO-anti-CD20-treated D430B cells, showed a dose-dependent decrease in signal intensity (SI) on T2*-weighted images and SI enhancement on T1-weighted images in vitro. Raji cells showed lower SI changes, in accordance to the fivefold lower expression of CD20 on Raji with respect to D430B cells. In vivo 24 h after USPIO-anti-CD20 administration, both tumors showed an inhomogeneous decrease of SI on T2*-weighted images and SI enhancement on T1-weighted images. CONCLUSIONS: MRI at 1.5 T is able to detect USPIO-antibody conjugates targeting a tumor-associated antigen in vitro and in vivo.

Animals↗

Pharmacoutilization and costs of osteoarthritis: changes induced by the introduction of a cyclooxygenase-2 inhibitor into clinical practice.

OBJECTIVE: To establish whether the introduction of a cyclooxygenase-2 inhibitor has led to changes in pharmacoutilization in the treatment of osteoarthritis (OA) in clinical practice. METHODS: Administrative and general practice databases were cross-linked to analyse the use of non-steroidal anti-inflammatory drugs (NSAIDs) and gastroprotective agents (GPAs) before and after the introduction of rofecoxib. Costs of treatment and costs of hospitalization for gastrointestinal events were also considered. RESULTS: A total of 3090 patients were evaluated. A significant reduction in the use of GPAs in the rofecoxib group was observed, corresponding to reductions of 64 and 59.7% compared to NSAIDs among patients in incident and prevalent cases respectively. The weighted mean daily cost of therapy with rofecoxib in incident cases was 1.88 euro, 7.4% lower than that of NSAIDs (2.03), and in prevalent cases it was 1.87 euro, 28.1% higher than that of NSAIDs (1.46). Although the rate of hospitalization was similar, there was an additional daily cost per patient of 186.6 for patients being treated with NSAIDs and 21.6 euro for those being treated with rofecoxib. CONCLUSIONS: The cyclooxygenase-2 inhibitor rofecoxib determined substantial changes in the pharmacoutilization and costs of OA.

Aged↗

Long-term persistence with antihypertensive drugs in new patients.

The objective of this study was to investigate stay-on-therapy patterns over 3 years among patients prescribed different classes of antihypertensive drugs for the first time. A retrospective analysis of information recorded in the drugs database of the Local Health Unit of Ravenna (Italy) was carried out on 7312 subjects receiving a first prescription for diuretics, beta-blockers, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors or angiotensin II antagonists between 1 January and 31 December 1997. Patients were followed up for 3 years. All prescriptions of antihypertensive drugs filled during the follow-up periods were considered. The patients continuing or discontinuing the initial treatment, the duration of treatment, and the doses taken were all calculated, as well as main factors influencing the persistence rate. The drugs prescribed were predominantly ACE-inhibitors, followed by calcium channel blockers, diuretics, beta-blockers and angiotensin II antagonists. A total of 57.9% of patients continued their initial treatment during the 3-year follow-up period, 34.5% discontinued the treatment, whilst 7.6% were restarted on a treatment in the third year. Persistence with treatment was influenced by: age of patient (persistence rate increasing proportionately with advancing years), type of drug first prescribed (persistence rate higher with angiotensin II antagonists, progressively lower with ACE-inhibitors, beta-blockers, calcium channel blockers and diuretics), gender of patient (persistence was better in males), age of general practitioner (GP) (the younger the GP, the better the persistence rate) and gender of GP (better stay-on-therapy rate with male GP prescribing). In the case of patients treated continuously, mean daily dose increased progressively over the 3 years. With adequate markers, helpful data can be collected from prescription claims databases for the purpose of monitoring the persistence of patients in continuing their medication, and the quality of antihypertensive treatment in a general practice setting.

Antihypertensive Agents↗

Retinal laser photocoagulation in diabetic patients causes prolactin, growth hormone and cortisol release.

Stress of many kinds (psychological, physical, metabolic) is able to induce endocrine modifications in humans, such as growth hormone (GH), prolactin (PRL), luteinizing hormone (LH), glucagon and cortisol release. Argon laser photocoagulation of the retina (RP), the treatment of choice for diabetic retinopathy, is a painful and stressful maneuvre and represents a direct injury onto a nervous tissue. Therefore it was decided to evaluate the possible endocrine modifications induced by RP in diabetic patients affected by retinopathy. In 19 insulin-dependent diabetic patients (12 men and 7 women), RP induced cortisol release in all cases, GH and PRL release in men, but not in women, and no modification of LH and glucagon plasma levels; in 12 similar patients receiving saline infusions without RP, no endocrine modifications were observed. It is concluded that RP elicits GH, PRL and cortisol release in diabetic patients.

Adult↗

Glucose metabolism alterations in Friedreich's ataxia.

We have characterized the abnormalities of glucose metabolism associated with Friedreich's ataxia (FA) by studying plasma glucose, insulin, growth hormone (GH), and glucagon before and after an oral glucose tolerance test (OGTT), an IV glucose load, and an IV arginine load, in 21 patients and in controls. Twelve patients were normotolerant (NT) to glucose, five glucose-intolerant (IT), and four diabetic (DM). Insulin secretion of IT patients was increased and delayed during OGTT. Interestingly, the insulin release during arginine load was significantly decreased in NT and IT as well as in DM patients. The GH response to OGTT was altered in IT patients. Plasma glucagon after an arginine load was significantly higher in patients than in controls. The results indicate that FA is associated with insulin resistance, beta-cell deficiency, and type I diabetes. These alterations might be genetically linked or metabolically related to the primary defect in FA. Their interplay or independent effects are responsible for abnormalities of glucose metabolism in FA.

Adolescent↗

Sulfonylureas enhance in vivo the effectiveness of insulin in type 1 (insulin dependent) diabetes mellitus.

Indirect evidence suggests that sulfonylureas, in addition to stimulating insulin release, exert additional effects at extrapancreatic levels which are of value in the management of type 2 diabetes. In order to characterize in vivo some of these effects, insulin sensitivity was studied in 9 type 1 diabetics with no residual insulin secretory activity, during treatment with chlorpropamide (250 mg b.i.d. for 8 days) and with glipizide (5 mg t.i.d. for 8 days). Employing the glucose clamp technique with the aid of an artificial pancreas (Biostator), glucose disposal during insulin infusion (0.1 U/kg in 60 min) was calculated by the amount of glucose required to keep the blood glucose at preinfusion levels. Chlorpropamide and glipizide administration was accompanied by a significant increase of the amount of glucose required to clamp blood glucose levels, while serum (free) insulin levels were superimposable during the different clamping studies. In the absence of endogenous insulin release, these data strongly suggest that the two sulfonylureas employed enhance in vivo the peripheral sensitivity to insulin. Further studies are required to indicate a preferential site of action (liver, muscle, adipose tissue) of sulfonylureas.

Adolescent↗

Effects of naloxone on prolactin, luteinizing hormone, and cortisol responses to surgical stress in humans.

To evaluate the possible involvement of endogenous opioid peptides in the responses of PRL, LH, and cortisol to surgical stress, we have studied the effect of naloxone on these hormones in otherwise normal subjects of both sexes undergoing cholecystectomy for gallstones. In 24 subjects (12 males and 12 females), premedication consisted of atropine sulfate (0.007 mg/kg BW); general anesthesia (30 min later) was induced by thiopental (7 mg/kg) and maintained constant by 1% ethrane in a 70%:30% nitrous oxide-oxygen mixture. In 6 males and 6 females, naloxone (0.4 mg) was injected iv before anesthesia induction. After skin incision, a clear PRL release was observed in all subjects; this was more evident in females than in males. PRL release was significantly lower in naloxone-pretreated subjects. LH release was observed only in males and was significantly higher in naloxone-pretreated subjects. Cortisol release occurred in both sexes in a similar way and was not significantly different in naloxone-pretreated subjects. Cortisol release occurred in both sexes in a similar way and was not significantly different in naloxone-pretreated subjects. These results indicate that endogenous opioid peptides are involved in stress-induced PRL and LH release in humans.

Adult↗

The effect of histamine and H1 and H2 receptors on prolactin and luteinizing hormone release in humans: sex differences and the role of stress.

The present experiments were performed to investigate the possible role of histamine and its receptors, H1 and H2, in the control of PRL and LH release in normal adult humans of both sexes. Histamine infusion (200 microgram, iv, in 15 min) induced PRL and LH release in men; in women, histamine inhibited LH release without affecting PRL release. Two H1 antagonists, dexchlorpheniramine (10 mg, iv) and promethazine (50 mg, im), reduced PRL release in both sexes, stimulated LH release in men, and inhibited LH release in women. Cimetidine, an H2 antagonist (400 mg, iv), elicited PRL release in both sexes, more consistently in females than in males, and was without effect on LH release in either sex. These data suggest that in humans, the effect of histamine on PRL release is linked to H1 and H2 receptors, which respectively stimulate and inhibit PRL release independently of sex. The effect of histamine on LH release appears to depend on sex and to be mediated only by H1 receptors. To rule out the possibility that the effects of histamine are merely due to a nonspecific stress reaction, we have evaluated PRL and LH release in otherwise normal men and women undergoing surgery for gallstones. Surgery was accompanied by PRL release in both sexes, more evident in women, and by LH release only in men. These results indicate that the effect of histamine on PRL and LH release in humans is linked to sex and H1 and H2 receptors and is not due to stress; further studies are required to clarify the possible mechanism and site of action of histamine in modifying PRL and LH release in humans.

Adult↗

Cognitive processes in insulin-dependent diabetes.

Cognitive processes in a group of neurologically asymptomatic patients with relatively severe but uncomplicated insulin-dependent diabetes mellitus (IDDM) were studied. In comparison with a homogeneous group of normoglycemic controls, the diabetic group performed significantly worse in global memory, abstract reasoning, and eye-hand coordination tests. The two groups scored similarly in intelligence, concentration and attention, spatial, visual, and psychomotor tests. The neuropsychological deficits did not correlate with the duration or the severity of the disease. Whether these mild neuropsychological deficits are transient or stable or whether they are caused by central nervous system vascular or metabolic dysfunctions or by the emotional influence of the chronic illness on the intellectual and educational development of patients remains unclear. Our findings need to be cautiously interpreted and perhaps could not be extended to diabetic patients with better metabolic control.

Adolescent↗

[Evaluation model of the effect of Rofecoxib on the co-prescription of gastroprotective agents observed during the treatment of osteoarthritis].

OBJECTIVE: This study was conducted to define an evaluation model to estimate changes in the co-prescription of gastroprotective agents (GPAs) induced by rofecoxib in the treatment of osteoarthritis (OA). METHODS: On the basis of a cross-linking information, which were stored in different administrative and clinical databases, a multivariate regression analysis was used to develop the model. Data were collected by 30 general practitioners of the Local Health Unit of Ravenna (middle-north of Italy). RESULTS: The study population consisted of 2,944 patients treated with non-steroidal anti-inflammatory drugs (NSAIDs) and 487 treated with rofecoxib. Patients treated with rofecoxib generally presented a higher number of gastrointestinal damage risk factors and also a lower level of GPAs co-prescription compared to those treated with NSAIDs. Including in the model variables such as type of anti-inflammatory treatment (NSAIDs or rofecoxib), gender, age by class, previous hospital admissions due to gastrointestinal complications, number of different NSAIDs used, and prescription of corticosteroids, the regression equation and its coefficients were identified. A non-linear relationship between the percentage of patients treated with rofecoxib and the relative reduction of GPAs co-prescription was found. It has been estimated the basis of the registered percentage of patients treated with rofecoxib (17,6%) adjusting for gastrointestinal damage risk factors, and on a 63% (CI95%: 55%-70%) relative reduction of GPA use with rofecoxib with respect to NSAIDs was estimated. CONCLUSIONS: Based on data collected in the clinical practice after the introduction of rofecoxib, a model evaluating the relationship between the frequency of its use in the OA population and the expected reduction of GPAs, has been developed.

Aged↗