Biodegradable Cellulose/Polycaprolactone/Keratin/Calcium Carbonate Mulch Films Prepared in Imidazolium-Based Ionic Liquid

Ionic liquid 1-butyl-3-methylimidazolium chloride [BMIM][Cl] was used to prepare cellulose (CELL), cellulose/polycaprolactone (CELL/PCL), cellulose/polycaprolactone/keratin (CELL/PCL/KER), and cellulose/polycaprolactone/keratin/ground calcium carbonate (CELL/PCL/KER/GCC) biodegradable mulch films. Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) spectroscopy, optical microscopy, and Field-Emission Scanning Electron Microscopy (FE-SEM) were used to verify the films' surface chemistry and morphology. Mulch film made of only cellulose regenerated from ionic liquid solution exhibited the highest tensile strength (75.3 ± 2.1 MPa) and modulus of elasticity of 944.4 ± 2.0 MPa. Among samples containing PCL, CELL/PCL/KER/GCC is characterized by the highest tensile strength (15.8 ± 0.4 MPa) and modulus of elasticity (687.5 ± 16.6 MPa). The film's breaking strain decreased for all samples containing PCL upon the addition of KER and KER/GCC. The melting temperature of pure PCL is 62.3 °C, whereas that of CELL/PCL film has a slight tendency for melting point depression (61.0 °C), which is a characteristic of partially miscible polymer blends. Furthermore, Differential Scanning Calorimetry (DSC) analysis revealed that the addition of KER or KER/GCC to CELL/PCL films resulted in an increment in melting temperature from 61.0 to 62.6 and 68.9 °C and an improvement in sample crystallinity by 2.2 and 3.0 times, respectively. The light transmittance of all studied samples was greater than 60%. The reported method for mulch film preparation is green and recyclable ([BMIM][Cl] can be recovered), and the inclusion of KER derived by extraction from waste chicken feathers enables conversion to organic biofertilizer. The findings of this study contribute to sustainable agriculture by providing nutrients that enhance the growth rate of plants, and hence food production, while reducing environmental pressure. The addition of GCC furthermore provides a source of Ca²⁺ for plant micronutrition and a supplementary control of soil pH.

[Acceptance of generic prescribing in general practice: effect of patient education and reference prices]

AIMS

To assess patient acceptance of the substitution of brand-name drugs for generic equivalents in the context of repeat prescriptions for chronic diseases.

METHODS

A prospective multicenter study of drug use was performed. Of the 31 centers included in the study, 8 were randomized to the intervention group and 23 to the control group. For 1 year, patients in the intervention group who visited the center to collect repeat prescriptions received verbal and written information on the advantages and disadvantages of generic and brand name drugs. Data on the number of patients taking brand-name drugs for which generic equivalents were available, as well as the reasons and variables related to refusal of generic drugs (age, gender, education, primary care centre, general practitioner, type of drug and total number of repeat prescriptions) were collected. The percentage of generic drugs among the total number of drugs prescribed was calculated at 2-monthly intervals.

RESULTS

A total of 98.9% of the 4620 patients in the intervention group agreed to change to a generic formulation. The percentage of patients accepting generic drugs was significantly associated with the primary care centre, the class of drug, doctors' influence, and patient satisfaction with the drug. Generic prescriptions represented 5.9% in the intervention practices compared with 2.8% in controls. After the intervention, and before the application of reference prices, the percentages were 6.7% and 3.9%, respectively. Immediately after application of the reference prices, the percentages were 8.6% and 6.3%, respectively.

CONCLUSIONS

Direct patient education is an effective strategy in increasing the prescription of generic equivalents. General practitioners' motivation and knowledge of generic drugs influenced their use. The application of reference prices increased the use of generic equivalents.

Familial progressive sensorineural deafness is mainly due to the mtDNA A1555G mutation and is enhanced by treatment of aminoglycosides

Hearing loss involves both genetic and environmental factors. A mutation (A1555G) in the mtDNA has been associated with aminoglycoside-induced and nonsyndromic sensorineural deafness. The pathological significance of this mutation in Caucasoid families has not been established, and its relationship with antibiotic treatment is not well understood. We studied 70 Spanish families with sensorineural deafness (36 congenital and 34 late onset) for the mtDNA A1555G mutation. The A1555G mutation was found in 19 families with maternally transmitted deafness but not in the other 51 families or in 200 control subjects. In 12 families all the patients with the A1555G mutation who received aminoglycosides became deaf, representing 30.3% of the deaf patients in these families. None of the deaf patients from seven other families received aminoglycosides. Overall, only 17.7% of the patients with deafness and the A1555G mutation had been treated with aminoglycosides. The age at onset of deafness was lower (median age 5 years, range 1-52 years) in those treated with aminoglycosides than in those who did not receive antibiotics (median age 20 years, range 1-65 years) (P < .001). The mtDNA of these families belongs to haplotypes common in Europeans. These data indicate that the A1555G mutation accounts for a large proportion of the Spanish families with late-onset sensorineural deafness, that the A1555G mutation has an age-dependent penetrance for deafness (enhanced by treatment with aminoglycosides), and that mtDNA backgrounds probably do not play a major role in disease expression.

[Specificity of CK-MB enzyme in the diagnosis of acute myocardial infarction in the postoperative period following non-cardiac surgery]

OBJECTIVES

1) To determine plasma concentrations of creatinphosphokinase-MB (CK-MB) enzyme during non-cardiac surgery for detecting postoperative myocardial infarction or ischemia. 2) To assess the specificity of CK-MB levels for the diagnosis of acute myocardial infarction (AMI) in patients undergoing non-cardiac surgery.

PATIENTS AND METHOD

Three hundred twenty-eight patients were studied prospectively. Inclusion criteria were as follows: 1) presenting cardiac risk factors; 2) major surgery; and 3) presence of associated pathology, unrelated to cardiac pathology. All patients were given an electrocardiogram and CK-MB levels were determined every 8 hours over the first 24 hours and on the second and third days. Total CK was measured at 24 hours.

RESULTS

AMI was detected by electrocardiogram in 3.3% of the patients. ST-segment/T-wave changes were detected in 5.7% and myocardial ischemia was found in 14.7%. Mean levels of CK-MB in patients with postoperative AMI were significantly higher than in patients without AMI. Total CK levels in patients with electrocardiographic changes were not significantly different from those of other patients. Thoracic surgery produced a significant increase in total CK but no increase in CK-MB. Patients undergoing esophageal surgery presented high initial levels of CK-MB that became normal.

CONCLUSIONS

1) The CK-MB/total CK ratio is highly specific for detection AMI after surgery. 2) Type of surgery affects total CK levels. 3) Detection of high levels of MB fraction should lead to a suspicion of myocardial damage. 4) Total CK level is not a good marker of myocardial necrosis in the postoperative period.

[Peroperative myocardial infarction and myocardial ischemia in non cardiac surgery: prevalence and predictive factors]

BACKGROUND

The decrease in the prevalence of infarction in the population has not been accompanied by a reduction in postinfarct mortality, particularly in the population segment which does not present major symptoms of coronary disease. The aim of the present study was to determine the incidence and predictive factors of cardiac complications in patients undergoing non cardiac surgery.

METHODS

Eight hundred seventy-five patients undergoing elective surgery from May 1990-1991 had some of the following criteria: history of heart disease, major surgery, and medical risk other than cardiac. A sample of 328 patients was selected to whom an ECG an CK-MB isoenzyme test were performed on admission, every 8 h, and at the second and third days. Infarction or ischemia were diagnosed by electrocardiographic and enzymatic criteria. Minimum follow up was 72 hours.

RESULTS

IAM was diagnosed in 10 cases (3%, confidence interval 95%, 2 to 4%) and ischemia in 47 cases (14%, CI 95%, 11 to 18%). Operative mortality of cardiac origin was 4% (CI 95%, 2 to 6%). Arrhythmia not preoperatively present was detected in 11%, hemodynamic instability in 25%, and sinusal tachycardia in 21%. Other complications were: abdominal 12%, respiratory 14%, neurologic 6% and renal 4%. The appearance of cardiac complications was related with: ASA classification (p < 0.05), previous history of heart disease (p < 0.01), cardiovascular drug administration (p < 0.01) and changes in preoperative electrocardiogram (p < 0.001).

CONCLUSIONS

The present study suggests that patients with changes of the ST-T segment in the preoperative ECG should undergo examination to determine the degree of cardiac involvement. A strict peroperative hemodynamic control may reduce the prevalence of cardiac complications in those patients at high risk.