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Biomedical subjects

M Papadakis

Publications and source records attributed to M Papadakis.

At least 19 recordsLinked to original sources
PubMed2001

Standardized patients' perceptions about their own health care.

BACKGROUND: There have been detailed descriptions on standardized patients (SP) programs' effects on students, curricula, and faculty, yet little attention has been paid to the consequences of participating on the SP's. PURPOSE: This study explored the perceptions of SPs toward their own health care in the context of having served as SPs. METHOD: All 180 SPs participating in Department of Medicine programs at 5 medical schools were surveyed. They completed the survey during SP activities, or it was mailed to them. SPs indicated their level of agreement or disagreement with 11 attitude statements related to their own health care after serving as an SP using a Likert scale, with 1 reflecting the most positive attitude and 5 the least positive. RESULTS: Responses to the attitudinal questions were obtained from 164 SPs (91%). SPs perceived that because of their participation as SPs they had a better understanding about medical history taking and physical examinations (1.9 +/- 0.9), communicated more effectively with their health care provider (1.8 +/- 0.9), and were more comfortable with both health care visits and physical examinations (2.2 +/- 0.9). There were no significant differences in results based on gender, age, race, or school. CONCLUSIONS: As a consequence of their participation, the SPs indicated a change in attitudes about their personal health care. They perceived improved understanding and ability to communicate and comfort with their own health care. Participation in SP programs seems to influence SPs by improving perceptions about their own health care interactions.

Adolescent↗
PubMed1998

Combination chemotherapy with docetaxel, vinorelbine and cisplatin as first-line treatment of advanced non-small-cell lung cancer: a multicenter phase II study of the Greek Cooperative Group for Lung Cancer.

Vinorelbine, docetaxel and cisplatin have documented single-agent activity in non-small-cell lung cancer (NSCLC); a multicenter phase II trial was initiated in order to evaluate the tolerance and efficacy of their combination. A total of 24 chemotherapy-naive patients with measurable stage IIIB or IV NSCLC and performance status (PS; WHO) 0-2 entered the study. Vinorelbine (20 mg/m2 i.v.) was given on days 1 and 15, cisplatin (60 mg/m2) on day 1, and docetaxel (100 mg/m2) on day 16, in cycles of 28 days. Recombinant human granulocyte colony-stimulating factor (150 microg/m2 s.c.) was administered prophylactically from day 17 to day 27. One pathological complete (4%) and six partial responses (25%) were documented (overall response 29%; 95% CI 11.6-49.2%). A total of five patients (21%) had stable and 12 (50%) progressive disease. The median duration of response was 28 weeks and the median time to tumor progression 36 weeks; the median survival was 20 weeks. Grade 3-4 neutropenia occurred in 16 patients (67%) while 13 of them (54%) developed febrile neutropenia. Grade 4 mucositis occurred in two patients (8%) and one of them also presented grade 4 diarrhea. There were four treatment-related deaths: two from sepsis, one from massive hemoptysis due to a pulmonary abscess and one from acute myocardial ischemia 7 days post-chemotherapy. In conclusion, the high incidence of neutropenic episodes and treatment-related deaths led to an early discontinuation of patient enrollment. This combination, in the schedule and the doses used, could not be recommended for off protocol treatment of patients with advanced NSCLC.

Adult↗
PubMed1997

delta-Thalassemic phenotype due to two "novel" delta-globin gene mutations: CD11[GTC-->GGC (A8)-HbA2-Pylos] and CD 85[TTT-->TCT(F1)-HbA2-Etolia].

delta-Thalassemia reduces the expected HbA2 percentage, altering the normal as well as the beta-thalassemia trait phenotype. An attempt to elucidate the molecular basis of delta-thalassemia in the Greek population, revealed two cases with unknown molecular defects that presented low levels of HbA2 (about 1.5%). DNA sequence analysis of delta-globin gene identified two "novel" mutations in the coding regions of the gene; the cd11 (GTC-->GGC) resulting in the substitution of valine for glycine (:HbA2-Pylos) and the cd85(TTT-->TCT) resulting in the substitution of phenylalanine for serine (:HbA2-Etolia). Because these mutations are localized at the helical positions A8 and F1 of the HbA2 respectively, they potentially cause molecular instability of the tetramer, thus leading to reduced HbA2 percentage.

Adult↗
PubMed1997

Scanning method to identify the molecular heterogeneity of delta-globin gene especially in delta-thalassemias: detection of three novel substitutions in the promoter region of the gene.

A scanning strategy for the detection of delta-globin gene mutations and polymorphisms is presented. This procedure is based on the denaturing gradient gel electrophoresis (DGGE) of four different artificially amplified DNA fragments which cover the promoter, the exons, as well as IVS I of the reported gene. To estimate the efficiency and sensitivity of the proposed procedure, we analysed the appropriate controls of delta-thalassemic carriers, uncharacterised delta-thalassemias and cases with normal hematological phenotype, but slightly increased (up to 3.5%) HbA2. DGGE results permitted the identification of delta-globin gene mutations and the polymorphism -199 (T-->C). Three novel base substitutions inside the promoter region of the gene [-65 (A-->G), -55 (T-->C), -36 (C-->A)], were also revealed. These changes are either linked in cis with other mutations or are responsible for thalassemias or for positive regulatory effect in delta-globin gene expression. The proposed experimental strategy consists of an accurate, rapid, safe and inexpensive screening procedure for establishing the molecular basis of delta-globin gene defects, suitable for the application for both research and diagnostics.

Electrophoresis, Polyacrylamide Gel↗
PubMed1995

Hb Lepore (Pylos)/Hb S compounds heterozygosity in two Greek families.

We have studied three compound heterozygotes for Hb Lepore ("Pylos")/HbS hemoglobin, a combination quite uncommon in the literature. It is of interest that while two of these cases are clinically similar to those thus far reported, the third one is free of symptoms and the diagnosis was put incidentally. This mild condition may be due to the high level of fetal hemoglobin produced.

Adult↗
PubMed1992

Pulmonary perfusion during lung transplant rejection and experimental pneumonia.

Six left lung allotransplants were performed in healthy mongrel dogs. Immunosuppression was established with cyclosporine (15 mg/kg/day p.o.) from the day of transplantation for 30 days. Another group of animals (n = 3) was used to produce acute experimental pneumonia by instilling 4-6 ml of a 10(8) CFU suspension of Pseudomonas aeruginosa into the right lower lobe. Dynamic perfusory lung scintigraphy (DPLS) was performed before transplant/pneumonia (control), during acute rejection/pneumonia as detected radiologically, and after treatment with methylprednisolone (1 g/day for 3 days i.v.) (transplant group) or antibiotics (pneumonia group). Seroalbumin macroaggregates (5-8 McI) marked with 99-mTc were injected into the cephalic vein and the percentage of perfusion to each lung was determined. Eight acute rejection episodes were detected. DPLS showed similar perfusion to each lung, whereas during acute rejection perfusion was significantly reduced by almost 30%. Perfusion was reestablished to control levels after treatment with methylprednisolone. Reduction in perfusion correlated with radiological rejection grading. No reduction in left lung perfusion was detected in pneumonia animals. In conclusion, acute rejection reduces perfusion to the transplanted lung as measured by DPLS. Treatment restores normal perfusion.

Animals↗
PubMed1988

Effects of fasting and diabetes on some enzymes and transport of glutamate in cortex slices or synaptosomes from rat brain.

Phosphate-activated glutaminase (PAG) and glutamic acid decarboxylase (GAD) were assayed in homogenates and synaptosomes obtained from starved (48 hr or 120 hr) and diabetic (streptozotocin) rat brain cortex. Glutamine synthetase (GS) was assayed in homogenates, microsomal and soluble fractions, from brain cortex of similarly treated rats. L-Glutamate uptake and exit rates were determined in cortex slices and synaptosomes under the same conditions. The specific activity (s.a.) of PAG, a glutamate producing enzyme, decreased (50%) in the homogenate after 120-hr starvation. In synaptosomes it decreased (25%) only after 48-hr starvation. The s.a. of GAD and GS, which are glutamate-consuming enzymes, were progressively increased with time of starvation, reaching 39% and 55% respectively after 120 hr. GS in the microsomes or the soluble fraction and GAD in the synaptosomes showed no change in s.a. under these conditions. Diabetes increased (40%) microsomal GS s.a. and decreased GAD s.a. (18%) in the homogenate. The L-glutamate uptake rate was decreased (48%) by diabetes in slices but no in synaptosomes. It is suggested that a) enzymes of the glutamate system respond differently in different subcellular fractions towards diabetes or deprivation of food and b) diabetes may affect the uptake system in glial cells but not in neurons.

Animals↗
PubMed1985

The predictive value of physical examinations for ascites.

To determine the predictive value of physical signs for ascites, we compared the results of physical examination with those of abdominal sonography in 90 men in hospital with liver disease. The positive predictive values of shifting dullness and prominent fluid waves were low (51% and 73%). We divided the patients into two groups: those with prolonged prothrombin times (72% prevalence of ascites by sonogram), and those with normal prothrombin times (15% prevalence). In patients with prolonged prothrombin times, a prominent fluid wave had a very high positive predictive value for ascites (96%). Many patients with prolonged prothrombin times had ascites despite negative physical signs. In contrast, in those with normal prothrombin times, both shifting dullness and prominent fluid waves were usually falsely positive. Patients with normal prothrombin times and no shifting dullness rarely (2%) had ascites. The predictive value of physical signs for ascites depends on the prevalence of ascites in groups of patients that are examined. The prothrombin time is a useful index for identifying inpatients with a high or low prevalence of ascites and the predictive value of physical signs is enhanced by interpreting them in combination with a patient's prothrombin time.

Ascites↗
PubMed1984

Relationships between phosphoenolpyruvate synthesis and glutamine formation in isolated chicken liver mitochondria.

The rate of phosphoenolpyruvate (PEP) and glutamine (Gln) formation was measured under different conditions in isolated chicken liver mitochondria. Glutamate (Glu) added as a sole substrate in high concentrations (30 mM) to the incubated mitochondria is preferentially metabolized to Gln, but Asp and PEP are also formed. Glu (10 mM) inhibited the rate of PEP formation from malate by about 25%. The effect was potentiated by NH4Cl (10 mM). Neither Glu nor NH4Cl affected the rate of PEP formation from malate by isolated guinea-pig liver mitochondria. Methionine S-sulfoximine, an inhibitor of Gln synthetase, did not reverse the inhibitory effect of Glu of PEP formation from malate in chicken liver mitochondria. The data are discussed in terms of possible interrelationships between uricogenesis and gluconeogenesis in chicken liver.

Aminooxyacetic Acid↗
PubMed1983

Rifaprim in urinary tract infection: a comparison with co-trimoxazole.

Two regimes of rifaprim (RPM), a 3.75 to 1 combination of rifampicin (RIF) and trimethoprim (TMP), were compared with co-trimoxazole (CO-T) for the treatment of urinary tract infection in 60 patients. Dosages were: A, 450 mg RIF + 120 mg TMP twice daily; B, 600 mg RIF + 160 mg TMP at bedtime and C, 800 mg sulphamethoxazole (SMZ) + 160 mg TMP twice daily. Clinical results were similar but CO-T treatment was accompanied by a greater number of late bacteriological failures. In none of 40 patients receiving RPM did resistance to any of the components develop, while in three of 20 patients receiving CO-T resistance to TMP or SMZ emerged during treatment. There were no side effects in the patients receiving RPM, but three patients developed transient laboratory abnormalities. One patient receiving CO-T had a rash and one further transient laboratory abnormalities. Satisfactory concentrations of RIF and TMP were measured in urine up to 24 h after a dose of 600 mg RIF + 160 mg TMP. RIF may be a better companion to TMP than the sulphonamides for the treatment of urinary tract infection.

Adult↗