RF-EMF EXPOSURE LEVELS IN SENSITIVE LAND USE IN GREECE: EDUCATIONAL UNITS CENSUS IN THE MUNICIPALITY OF KORYDALLOS

BACKGROUND

The growing popularity of mobile phones and the expansion of network infrastructure in Greece have raised concerns about the possible negative health effects on sensitive groups, such as children, from exposure to long-term radiofrequency electromagnetic fields (RF-EMFs).

AIMS

The objective of this study is to estimate mean RF-EMF exposure levels of primary and secondary education schools located in the municipality of Korydallos, Athens, Greece.

METHODS

We performed measurements to all the schools units ($n=62$) in the region in order to calculate the mean value for RF-EMF exposure in the range of 27 MHz-3 GHz, which covers the whole spectrum of RF-EMF sources.

RESULTS

At the $97.5\%$ of schools found in Korydallos region, the exposure level is at least 2200 times below the Greek exposure limits.

CONCLUSION

The exposure levels in the locations tested are both below $60\%$ of the highest limit set by the International Commission on Non-Ionizing Radiation Protection regarding school exposures.

EXTREMELY LOW FREQUENCY ELECTROMAGNETIC FIELD EXPOSURE MEASUREMENT IN THE VICINITY OF WIND TURBINES

BACKGROUND

There is an exponential growth of public concern worldwide regarding the exposure to electromagnetic fields (EMF) generated by wind turbines. The high concern of the general population enhances the fact that EMF exposure remains a crucial issue that demands specific actions and reliable data to evaluate possible health hazards.

MATERIALS AND METHODS

EMF exposure measurements were conducted in two wind farm (W/F) areas in Greece. The magnetic field strength concentrated in the proximity of 22 wind turbines (20 type of Gamesa Eolica Siemens of total power of 17 MW and 2 type of E53 Enercon, 800 KW each). Measurements were conducted using a Narda-NBM-550 basic unit (Narda Safety Test Solutions Company) using EHP-50F probe. The EMF exposure measurements were processed applying the weighted peak method (WPM), according to the 2013/35/EU Directive. WPM provides correction of the measured value of pulse signals, taking into account the phases of the various frequency components. The data were classified under two scenarios of EMF exposure: 'high wind' and 'low wind' conditions.

RESULTS

The variation of the magnetic field strength was calculated between 1.13 and 1.42% (WPM). Measurements indicate that the intensity of the emitted magnetic field at the base of the wind turbines, in both high and low wind conditions, was relatively low (mean = 0.146 μT), while decreasing rapidly with increasing distance and reaching background values 6 m from the base.

CONCLUSION

The results of the present study indicate that EMF levels are similar or even lower compared to those in urban areas and well below the national and international safety limits.

Biocontrol efficacy of Trichoderma asperellum-enriched coconut fibre against Fusarium wilts of cherry tomato

AIMS

Agro-based wastes were evaluated as a medium for mass micropropagule production and optimal efficacy of Trichoderma asperellum B1092 in controlling Fusarium oxysporum f. sp. lycopersici and promoting tomato growth. This study focused on biological control because pathogen persistence in the soil makes the disease difficult to control.

METHODS AND RESULTS

Rice bran, biochar, empty fruit bunches, coconut fibres, compost, top soil and mixed soil were evaluated as media for mass multiplication of T. asperellum, which is effective in controlling plant pathogens. Yielding the most colony forming units (CFU) among the media, coconut fibre was deemed most suitable for promoting sporulation. After 120 days on the medium, T. asperellum B1902 produced 9·053 × 10⁵  CFU per gram coconut fibre; oil palm empty fruit bunches was second highest (7·406 × 10⁵  CFU per gram). In field tests of T. asperellum B1092 against F. oxysporum f. sp lycopersici (causing Fusarium wilt of cherry tomato), B1092 significantly promoted plant growth compared to the control. The efficacy of this formulation resulted in increased growth of roots and shoots tomato plants and total lycopene, sugar, K, N, Ca, P and Mg content after 120 days.

CONCLUSIONS

Trichoderma asperellum B1092 showed great field potential for improving productivity and quality of tomatoes and in controlling Fusarium wilt of cherry tomato.

SIGNIFICANCE AND IMPACT OF THE STUDY

This innovative approach using a cheap agro-waste to control the persistent soil-borne Fusarium pathogen of cherry tomato should increase soil survival rate of Trichoderma and has potential for upscaling in the field for other crops.

Changes in gene expression in the rumen and colon epithelia during the dry period through lactation of dairy cows and effects of live yeast supplementation

The objectives of this study were (1) to use endoscopy to collect biopsies from the rumen and colon epithelia to describe changes in gene expression in these 2 tissues as cows move from a dry to a lactation ration and (2) to evaluate the potential influence that supplementation of live yeast could exert on these 2 epithelia. Twenty-one Holstein cows were split into 2 treatments and received either 300 g/d of corn containing 1 × 10¹⁰ cfu/d of live yeast (LY; n = 10) or 300 g/d of corn with no supplementation (control; n = 11) starting 21 ± 2.6 d (average ± SD) before until 21 d after calving. At 14 ± 2.6 d before the expected calving date, and exactly at 7 and 21 d after calving, rumen and colon biopsies were obtained from each cow using an endoscope. Total RNA was extracted from rumen and colon tissues, and the expression of IL10, TNFA, TLR4, IL1B, PCNA, MKI67, SGLT1, BAX, CASP3, OCLN, CLDN4, HSPA1A, HSPB1, DEFB1, and MCT1 (the latter only in rumen samples) was quantified by quantitative PCR. Overall, fluctuations in expression of the selected genes in the colon between the 2 stages of production and the 2 treatments were smaller than those found in the rumen. In the rumen epithelium, expression of TLR4 and DEFB1 was greatest before calving, with LY cows having a greater expression of TLR4 than control cows. Similarly, expression of IL10 was greatest in LY cows before calving. Expression of TNFA in the rumen epithelium of control cows was lowest at 21 DIM but in LY cows was kept steady among production stages. The expression of PCNA and MKI67 in the rumen epithelium was greatest at 7 DIM, indicating a high proliferation rate of this epithelium after calving. In the colon mucosa, expression of TLR4 and DEFB1 was greater than in the rumen, and DEFB1 expression was greater in LY cows than in control cows. The use of an endoscope allowed us to study the dynamics of rumen epithelium adaptation to increased supply of concentrate after calving, consisting of increased epithelia remodeling, reduction of the TLR4, and increased IL10 expression. Furthermore, the rumen epithelium of dry cows responded rapidly to live yeast, with changes in the expression of genes involved in the immune response becoming evident after 7 d of exposure to yeast. The expression of genes related to the immune response (mainly TLR4 and DEFB1) in the colon mucosa was greater than in the rumen, and the expression of DEFB1 was further stimulated by live yeast. It is concluded that the use of an endoscope allows the study of gene expression patterns in the rumen and hindgut epithelia. We report marked changes in the rumen wall and more modest changes in the colon when transitioning from a dry to a lactation ration. Furthermore, supplementation of live yeast fostered and increased expression of genes regulating inflammation and epithelial barrier in the rumen, and in the colon it increased the expression of DFEB1 coding for an antimicrobial peptide.

Effects of forage provision to young calves on rumen fermentation and development of the gastrointestinal tract

Fifteen Holstein male calves were randomly assigned to 1 of 3 dietary treatments according to age and body weight (BW) to determine the effects of feeding different forages sources on rumen fermentation and gastrointestinal tract (GIT) development. Treatments consisted of a starter (20% crude protein, 21% neutral detergent fiber) fed alone (CON) or supplemented with alfalfa (AH) or with oat hay (OH). All calves received 2L of milk replacer (MR) at 12.5% dry matter twice daily until 49 d of age. Calves received 2L of the same MR from 50 to 56 d of age and were weaned at 57 d of age. Individual starter, forage, and MR intakes were recorded daily and BW was recorded weekly. A rumen sample was taken weekly to determine rumen pH and volatile fatty acid concentrations. Three weeks after weaning, animals were harvested and each anatomical part of the GIT was separated and weighed with and without contents. Rumen pH was lower in CON than in OH and AH calves. Furthermore, acetate proportion in the rumen liquid tended to be greater in AH than in CON and OH treatments. Total GIT weight, expressed as a percentage of BW, tended to be greater in AH compared with the other 2 treatments. Rumen tissue tended to weigh more in CON than in OH animals. Animals with access to forage tended to have a greater expression of monocarboxylate transporter 1 than CON calves. In conclusion, calves supplemented with oat hay have a better rumen environment than calves offered no forage and do not have an increased gut fill.

Effects of an extract of plant flavonoids (Bioflavex) on rumen fermentation and performance in heifers fed high-concentrate diets

To study the effects of an extract of plant flavonoids [Bioflavex (FL)] in cattle fed high-concentrate diets, 2 experiments were designed. In the first experiment, the effects of Bioflavex on the development of rumen acidosis was evaluated in 8 Holstein-Friesian crossbreed heifers (451 kg; SEM 14.3 kg of BW) using a crossover design. Each experimental period lasted 22 d; from d 1 to 20, the animals were fed rye grass, on d 21 the animals were fasted, and on d 22, rumen acidosis was induced by applying 5 kg of wheat without [

CONTROL

(CTR) heifers who did not receive Bioflavex] or with flavonoids [heifers who received FL; 300 mg/kg DM] through a rumen cannula. Rumen pH was recorded continuously (from d 19 to d 22). On d 22, average rumen pH was significantly (P < 0.01) higher in the FL animals (6.29; SEM = 0.031) than it was in the CTR heifers (5.98; SEM = 0.029). After the wheat application, the rumen VFA concentration increased (P < 0.01), the proportion of acetic acid decreased (P < 0.01), and lactate concentration (mmol/L) increased, but the increase was not as great (P = 0.09) in the FL as it was in the CTR heifers (0.41 to 1.35 mmol/L; SEM = 0.24). On d 22, Streptococcus bovis and Selenomonas ruminantium titers increased after the wheat application, but Megasphaera elsdenii titers increased (P < 0.05) only in the FL heifers. In the second experiment, the effect of Bioflavex on the performance and rumen fermentation in finishing heifers was evaluated. Forty-eight Fleckvieh heifers (initial BW = 317 kg; SEM = 5.34) were used in a completely randomized design. Heifers were assigned to 1 of 4 blocks based on their BW and, within each block, assigned to 1 of 2 pens (6 heifers/pen). In addition, 16 heifers (2/pen) were rumen cannulated. Individual BW and group consumption of concentrate and straw were recorded weekly until the animals reached the target slaughter weight. Supplementation with FL did not affect ADG, feed consumption, or feed conversion ratio. Rumen pH and molar proportions of propionate were greater (P < 0.01) and acetate proportion was less in the FL (P < 0.01) than they were in the CTR heifers. Flavonoid supplementation might be effective in improving rumen fermentation and reducing the incidence of rumen acidosis. This effect of flavonoids may be partially explained by increasing the numbers of lactate-consuming microorganisms (e.g., M. elsdenii) in the rumen.

Optimizing the coagulation process in a drinking water treatment plant -- comparison between traditional and statistical experimental design jar tests

In this study of coagulation operation, a comparison was made between the optimum jar test values for pH, coagulant and coagulant aid obtained from traditional methods (an adjusted one-factor-at-a-time (OFAT) method) and with central composite design (the standard design of response surface methodology (RSM)). Alum (coagulant) and polymer (coagulant aid) were used to treat a water source with very low pH and high aluminium concentration at Sri-Gading water treatment plant (WTP) Malaysia. The optimum conditions for these factors were chosen when the final turbidity, pH after coagulation and residual aluminium were within 0-5 NTU, 6.5-7.5 and 0-0.20 mg/l respectively. Traditional and RSM jar tests were conducted to find their respective optimum coagulation conditions. It was observed that the optimum dose for alum obtained through the traditional method was 12 mg/l, while the value for polymer was set constant at 0.020 mg/l. Through RSM optimization, the optimum dose for alum was 7 mg/l and for polymer was 0.004 mg/l. Optimum pH for the coagulation operation obtained through traditional methods and RSM was 7.6. The final turbidity, pH after coagulation and residual aluminium recorded were all within acceptable limits. The RSM method was demonstrated to be an appropriate approach for the optimization and was validated by a further test.

Effects of ring castration with local anesthesia and analgesia in Holstein calves at 3 months of age on welfare indicators

Forty-seven Holstein calves (130 +/- 3.43 kg of BW and 95 +/- 1.5 d of age) were randomly assigned to 2 treatments [intact (INT), n = 23; or castrated (CAS), n = 24] to evaluate the effect of ring castration at 3 mo of age on welfare indicators. Castration was performed with local anesthesia (2% lidocaine, 3 mL in each testis and 2 mL in the scrotum) and analgesia (flunixin meglumine, intramuscularly, 3 mg/kg of BW). No local anesthesia or analgesia was used with INT calves. Serum cortisol concentration was determined at -120, 0, 30, 60, 90, and 180 min with respect to castration. At d 0, 1, 3, 7, 14, 21, 28, 35, 42, and 49, serum haptoglobin concentration was determined, rectal body and scrotal temperatures were measured, lesions at the castration site were scored, and the activity and behavior of 18 calves (9 INT and 9 CAS) were recorded continuously for 24 h. Weekly BW and concentrate and straw DMI were recorded. To evaluate humoral immunity, at 14 d after castration, ovalbumin was injected subcutaneously and serum antibody titers against ovalbumin before the injection and at d 35 were determined. At d 49 after castration, calves were intravenously injected with ACTH, and at 0, 1, 2, and 4 h thereafter, serum cortisol and testosterone concentrations were determined. Average daily gain was greater (P < 0.001) in INT than CAS calves (1.36 vs. 1.16 +/- 0.038 kg/d, respectively). Area under the curve of cortisol at castration day was reduced (P < 0.05) in CAS calves compared with INT calves (18 vs. 33 +/- 5.2 nmol/L per hour, respectively). The main scrotal lesion score observed in CAS calves throughout the study was 0, corresponding to no visible swelling, inflammation, or infection. However, scrotal lesion scores classified as 1 (swelling) were greater (P < 0.01) at 21 and 28 d after castration than at 1, 3, 7, and 14 d. Abnormal standing occurred more frequently (P < 0.001) in CAS than INT calves (2.6 vs. 0.5 +/- 0.03%, respectively) from 3 to 14 d after castration. Head turning tended (P = 0.06) to be greater at d 14 of the study in CAS than INT calves (3.0 vs. 2.6 +/- 0.04%, respectively). At d 49, 100% of CAS calves had no testes and no serum testosterone was detected. In summary, ring castration of Holstein calves performed at 3 mo of age with local anesthesia and analgesia decreased ADG and affected some behavioral traits during the first 14 d after castration. However, intake, serum cortisol and haptoglobin concentrations, rectal temperature, and humoral immunity were not altered.

Characteristics of developed granules containing selected decolourising bacteria for the degradation of textile wastewater

Textile wastewater, one of the most polluted industrial effluents, generally contains substantial amount of dyes and chemicals that will cause increase in the COD, colour and toxicity of receiving water bodies if not properly treated. Current treatment methods include chemical and biological processes; the efficiency of the biological treatment method however, remains uncertain since the discharged effluent is still highly coloured. In this study, granules consisting mixed culture of decolourising bacteria were developed and the physical and morphological characteristics were determined. After the sixth week of development, the granules were 3-10 mm in diameter, having good settling property with settling velocity of 70 m/h, sludge volume index (SVI) of 90 to 130 mL/g, integrity coefficient of 3.7, and density of 66 g/l. Their abilities to treat sterilised raw textile wastewater were evaluated based on the removal efficiencies of COD (initial ranging from 200 to 3,000 mg/L), colour (initial ranging from 450 to 2000 ADMI) of sterilised raw textile wastewater with pH from 6.8 to 9.4. Using a sequential anaerobic-aerobic treatment cycle with hydraulic retention time (HRT) of 24 h, maximum removal of colour and COD achieved was 90% and 80%, respectively.

Antinociceptive, anti-inflammatory and antipyretic effects of Solanum nigrum aqueous extract in animal models

The present study was carried out to evaluate the antinociceptive, anti-inflammatory and antipyretic effects of the aqueous extract of Solanum nigrum leaves using various animal models. The extract, at concentrations of 10, 50 and 100%, was prepared by soaking (1:20; w/v) air-dried powdered leaves (20 g) in distilled water (dH2O) for 72 h. The extract solutions were administered subcutaneously in mice/rats 30 min prior to the tests. The extract exhibited significant (P < 0.05) antinociceptive activity when assessed using the abdominal constriction, hot plate and formalin tests. The extract also produced significant (P < 0.05) anti-inflammatory and antipyretic activities when assessed using the carrageenan-induced paw edema and brewer's yeast-induced pyrexia tests, respectively. Overall, these activities occurred in a concentration-dependent manner, except for the 50% concentration of the extract, which was not effective in the abdominal constriction test. In conclusion, the present study demonstrated that S. nigrum leaves possessed antinociceptive, anti-inflammatory and antipyretic effects and thus supported traditional claims of its medicinal uses.

Potential biomarkers of preeclampsia: inverse correlation between hydrogen peroxide and nitric oxide early in maternal circulation and at term in placenta of women with preeclampsia

Preeclampsia (PE) is a pregnancy-specific disease that has been associated with future cardiovascular disease for the mother and her child. The etiology of PE is unclear but oxidative stress seems to play a major role in endothelial dysfunction and permanent systemic vasoconstriction shown in PE. Hydrogen peroxide (H(2)O(2)), a terminal metabolite of the cellular oxidative stress cascade, is also revealed as a component of oxidative ischemia/reperfusion stress in placenta. We were the first to show an increase in the levels of H(2)O(2) in the serum of preeclamptic women at term. H(2)O(2) is already known to reduce the production of NO by increasing the metabolism of arginases. The objective of this study was to investigate a possible correlation between nitric oxide (NO), a potent vasodilator, and H(2)O(2) throughout pregnancy. Thus, we simultaneously assessed the levels of NO and H(2)O(2) in the serum of normal and preeclamptic women at 10-15 and 37-40 weeks of pregnancy, and in placentas at delivery. Our findings showed an inverse correlation between increased levels of H(2)O(2) and decreased levels of NO early in maternal circulation and at term in placenta. This relationship is confirmed by our in vitro experiments which demonstrate that H(2)O(2) inhibits NO synthesis of cytotrophoblasts. In conclusion, our findings highlight an inverse correlation between H(2)O(2) and NO early in maternal circulation and in placenta of women with preeclampsia, paving the way for further studies examining the potential use of NO and H(2)O(2) as biomarkers in the prediction of preeclampsia.

Influence of initial dissolved oxygen concentration on Fenton's reagent degradation

The effect of initial dissolved oxygen concentration (IDOC) on Fenton's reagent degradation of a dyestuff, Reactive Black 5 was explored in this study. The study was designed, conducted and analysed based on Central Composite Rotatable Design using a 3-1 lab-scale reactor. The participation of O2 in the process was experimentally observed and appears to be affected by the dosage of the reagents used in the study. The IDOC was found to have a significant influence on the process. Reducing the IDOC from 7.5 mg l(-1) to 2.5 mg l(-1) increased the removal of TOC by an average of about 10%. Reduction of IDOC from 10 mg l(-1) to 0 mg l(-1) enhanced the TOC removal by about 30%. The negative influence of IDOC is likely to be caused by the competition between the O2 and the reagents for the organoradicals. A model describing the relationship between initial TOC removal, reagent dosage and IDOC has also been developed.

Fenton oxidation of Reactive Black 5: effect of mixing intensity and reagent addition strategy

This study investigates the effect of mixing intensity and reagents addition strategy on Fenton's reagent degrading a common reactive diazo type dyestuff, Reactive Black 5. Within the experimental conditions used in the study, the effect of mixing intensity on TOC removal was observed to be both significant and complex. Using factorial analysis, it was found that if the reagents are added near to each other, higher mixing intensity will enhance the effectiveness of the degradation process. However, a very, high mixing level may cause reduction in performance. It was also observed that the mixing intensity effect interacts with Fe2+ or/and H2O2 dosage. The benefit of increasing mixing intensity appears to be higher for lower reagents dosage. The effect of reagents addition strategy was found to be inter-dependent with mixing intensity level. It was also deduced that proper chemical addition strategy could be used to reduce the mixing intensity requirement of the process.

Characterization of effects of selected organic substances on decomposition of hydrogen peroxide during Fenton reaction

This study aims to investigate the effects of selected organic substances on the degradation of hydrogen peroxide during the Fenton reaction. Since the presence of organic substances can strongly affect the mechanism of the Fenton reaction, the information on effects of organic substances on the reaction would be a vital guide to the success of its application to the destruction of organics in wastewater. Several organic compounds having different structures were selected as model pollutants: 4-chlorophenol, 1,4-dioxane, chloroform, a dye (reactive black-5), and EDTA. Oxidation of 4-chlorophenol and reactive black-5 resulted in enormously fast degradation of hydrogen peroxide, while others such as 1,4-dioxane and chloroform showed much slower degradation. These experimental data were compared to simulation results from a computational model based on a simple *OH-driven oxidation model. Modelling results for chloroform and 1,4-dioxane were in relatively good agreement with the experimental data, while those for 4-chlorophenol and reactive black-5 were very different from the experimental data. The results for EDTA showed a different trend to those for other compounds. From these results, classification of organic substances into several sub-groups was tried.

Dentine hypersensitivity in subjects recruited for clinical trials: clinical evaluation, prevalence and intra-oral distribution

Relatively few studies have reported on the frequency, distribution and severity of dentine hypersensitivity (DH) in subjects recruited for clinical trials of desensitizing agents. Potential subjects (n= 48 M, 81 F, mean age 35.1 years) for inclusion into such a study were screened to determine the extent of the problem. 117 subjects (41 M, 76 F) mean age 24.9 years were clinically examined. Evaluation by questionnaire indicated that the prevalence of DH was proportionately higher in the 20-29.9 years (34.9%), and 30-39.9 years groups (33.3%), respectively. Sensitivity to cold was the main presenting symptom. Tactile (probe) and cold air (dental air syringe) stimuli were used to clinically evaluate DH. Of the teeth eligible for evaluation 1561/3136 (49.8%) responded to either one or both of the test stimuli; 274/3136 (8.7%) responded to tactile only stimulation, 779/3136 (24.8%) to thermal only stimulation and 508/3136 (16.2%) to both tactile and thermal stimulation. Of those teeth responding to the stimuli, 477 (30.6%) were premolars, 437 (28%) incisors, 415 (26.8%) molars and 232 (14.9%) canines. The results agree with those of previously reported studies in that DH is most frequently observed on premolars and that proportionately more teeth are sensitive to evaporative than to tactile stimulation. Furthermore it would appear from the results of the study that tactile is less effective than thermal/evaporative stimulation in the evaluation of DH.

Influence of varying reacting conditions in the degradation of azo dye using immobilized TiO2 photocatalyst

In Malaysia, most colored wastewater from dyeing factories is discharged to the environment causing serious problems. In this paper the influence of several reacting conditions, i.e. H2O2, pH, Ultraviolet (UV) intensity and dye concentration, on the performance of the immobilized system is discussed. The pH of the solution was varied from 3 to 11 while H2O2 concentration tested was from 10(-4) M to 5 x 10(-2) M. UV was tested at 365 nm and 254 nm, while dye concentration ranged from 2.5 x 10(-4) M to 10(-3) M. The influence of the reacting conditions was assessed based on absorbance. Using an OG concentration of 10(-3) M, the degradation increases from 17.8% to 49.7%. Optimum concentration of H2O2 was found to be 5 x 10(-3) M for degradation. Increasing the intensity of the UV light via shorter light wavelength also improves the performance of the system. Increasing the concentration of the dye reduces the overall performance of the system. Using the dye concentration of 2.5 x 10(-4) M (H2O2 = 10(-2) M, lambda = 254 nm, pH = 11), gives a degradation of 93.2%. At dye concentration of 10(-3) M, the performance was reduced to 53.1%.

Multiple intracardiac lesions after blunt chest trauma

Closed chest trauma can cause rupture of intracardiac structures. We report the case of a 17-year-old boy whose chest was trodden by a horse. He sustained rupture of tricuspid and aortic valve leaflets and rupture of the interventricular septum. He underwent surgical repair of these lesions, but aortic insufficiency developed 2 years later and the aortic valve was replaced with a mechanical prosthesis.

Pulmonary function following aortic valve replacement: a comparison between ministernotomy and median sternotomy

BACKGROUND AND AIM OF THE STUDY

Minimally invasive aortic valve replacement (AVR) has several theoretical advantages over standard median sternotomy, but the effects of these techniques on postoperative pulmonary function have not been determined.

METHODS

Twenty-six patients undergoing AVR through either a ministernotomy (group M; n = 12) or a median sternotomy (group S; n = 14) underwent pulmonary function tests. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), PaO2 and PaCO2 were determined preoperatively and before hospital discharge (at a mean of five days). Data regarding time to extubation, degree of pain and opening of the pleura were collected prospectively. Both groups had similar preoperative characteristics.

RESULTS

There was a significant decrease in FVC, FEVJ, PaO2 and PaCO2 during the postoperative period in all patients, though differences between the groups were not significant. Patients in group M referred less pain than those in group S. In this group, the fall in FVC and FEV1 correlated with the degree of pain, while preoperative FVC correlated with early extubation. Pleurotomy did not affect pulmonary function or pain.

CONCLUSION

FVC, FEV1, PaO2 and PaCO2 are reduced significantly following AVR, but a minimally invasive approach does not prevent postoperative pulmonary dysfunction.

Reversed "C" ministernotomy for aortic valve replacement

The technique of aortic valve replacement through a reversed "C" sternotomy incision is described. The sternal incision extends between the second and the fifth intercostal space and provides excellent exposure of the ascending aorta, the aortic root, and the right atrial appendage. The procedure can be performed with standard cannulation for cardiopulmonary bypass and conventional surgical instruments.

Ministernotomy versus median sternotomy for aortic valve replacement: a prospective, randomized study

BACKGROUND

Minimally invasive aortic valve replacement reduces surgical trauma and, supposedly, postoperative pain, blood loss, and length of stay. A prospective, randomized study was designed to prove these theoretical advantages.

METHODS

Forty patients undergoing isolated, elective aortic valve replacement were randomized into two equal groups. Patients in group M underwent aortic valve replacement through a ministernotomy (reversed L or reversed C). In group S, a median sternotomy was used. The anesthetic and surgical protocol was identical for both groups. Pain was evaluated on a daily basis. Pulmonary function tests were performed preoperatively and before hospital discharge in all patients.

RESULTS

There were two deaths in each group. Cross-clamp time was longer in group M: 70 +/- 19 minutes versus 51 +/- 13 minutes in group S (p = 0.005). There were no statistically significant differences between groups M and S in pump time (95 +/- 20 minutes versus 83 +/- 19 minutes), extubation time (9.9 hours in both groups), chest drainage (479 +/- 274 mL/L 24 hours versus 355 +/- 159 mL/24 hours), transfusion requirements (27% in both groups), pain evaluation (1.34 +/- 1.3 versus 2.15 +/- 1.5), length of stay (6.2 +/- 2.3 days versus 6.3 +/- 2.5 days), and cosmetic appraisal. Forced vital capacity decreased 26% from preoperative reference values in group M and 33% in group S (p = not significant). Forced expiratory volume in 1 second decreased 22% and 35%, respectively (p = not significant).

CONCLUSIONS

This study has failed to prove the theoretical advantages of minimally invasive aortic valve replacement. With this technique, cross-clamp time is longer than with a median sternotomy.

Repair of aortic coarctation in patients more than 50 years of age

BACKGROUND

Most patients with uncorrected coarctation of the aorta die before reaching age 50 years. In those who survive, the beneficial effect of surgical repair on systolic hypertension has been questioned.

METHODS

Surgical repair of aortic coarctation was performed in 8 patients aged 51 to 73 years (mean, 58+/-9 years). Preoperative mean systolic pressure was 185+/-34 mm Hg and systolic gradient, 70+/-11 mm Hg. In addition, 3 patients had significant coronary artery disease. Severe calcification of the aortic arch and left subclavian artery was found in 3 patients. The surgical technique involved bypass of the coarctation with a Dacron tube graft (16 or 18 mm) in all patients. One patient underwent concomitant coronary artery bypass grafting.

RESULTS

There were no operative or late deaths during a mean follow-up of 4.3 years. Mean systolic blood pressure decreased significantly in the postoperative period to 128+/-16 mm Hg (p < 0.001). At the last visit, systolic blood pressure was a mean of 127+/-9 mm Hg. Five patients were not taking antihypertensive medication.

CONCLUSIONS

Surgical repair of aortic coarctation in patients more than 50 years of age with a Dacron tube bypass graft reduces systolic hypertension and the need of antihypertensive medication.

Technique of mitral valve replacement with the Monostrut prosthesis preserving the posterior leaflet

BACKGROUND AND AIM OF THE STUDY

Techniques of mitral valve replacement with leaflet and chordal preservation normally involve the use of a bioprosthesis or bileaflet valve to reduce the risk of obstruction of the prosthesis by the retained subvalvular apparatus.

METHODS

The technique of mitral valve replacement with the Monostrut prosthesis and with preservation of the posterior leaflet is described. The stitches are placed in such a manner that the posterior leaflet is folded under the posterior aspect of the prosthetic ring.

RESULTS AND CONCLUSIONS

The technique allows safe implantation of the Monostrut valve. The excellent performance of this prosthesis can be therefore combined with the beneficial effects of chordal preservation on left ventricular function.

Francisco Romero, the first heart surgeon

Francisco Romero, a Catalonian physician, became the first heart surgeon when he performed an open pericardiostomy to treat a pericardial effusion in 1801. He presented his work at the Society of the School of Medicine in Paris in 1815, but the procedure was considered too aggressive and his work was silenced for many years. Proper credit should be given to Romero as the first man who directly approached the heart by incising the pericardium.

The 20 mm Medtronic Hall prosthesis in the small aortic root

BACKGROUND AND AIMS OF THE STUDY

The choice of prosthesis becomes crucial in the narrow aortic annulus. The 20 mm Medtronic Hall valve has a reduced sewing ring that fits in an annulus where only a 19 mm valve would fit. This study assesses the hemodynamic performance of this prosthesis at rest and at exercise, and compares it with two 19 mm mechanical prostheses.

MATERIALS AND METHODS

Forty-two patients were studied by Doppler echocardiography, a mean of 34 months following surgery. Twenty-six had a 19 mm prosthesis implanted (12 standard St. Jude Medical and 14 Monostrut valves) and 16 had a 20 mm Medtronic Hall. Parameters studied were peak velocity and transvalvular gradient, both at rest and at exercise, effective orifice area and valve index.

RESULTS

No differences were found between the two 19 mm valves, but when compared with the Medtronic Hall valve at rest, this valve showed significantly lower peak velocity and gradient (2.9 vs. 3.3 m/sec, p < 0.01, and 17 vs. 23 mmHg, p < 0.003, respectively) and higher effective orifice area and valve index (1.3 vs. 1.0 cm2, p < 0.01 and 0.81 vs. 0.62 cm2, p < 0.006, respectively). There were also significant differences under exercise.

CONCLUSIONS

The 20 mm Medtronic Hall prosthesis shows a significantly better hemodynamic performance, both at rest and under exercise, than other, 19 mm mechanical prostheses and represents a superior choice in valve replacement with a small aortic root.

The Spanish Monostrut Study Group: a ten-year experience with 8,599 implants

BACKGROUND

The Monostrut valve is a pyrolytic carbon, tilting-disc prosthesis with no welds. After the first implantation in Spain in May 1983, the Spanish Monostrut Study Group was established to evaluate prospectively the performance of the valve using uniform protocols.

METHODS

During a 10-year period, 8,599 Monostrut valves were implanted in 7,317 patients in 22 centers. Mean age was 53.3 +/- 11 years. Of the total group, 3,229 underwent aortic valve replacement, 2,806 had mitral valve replacement, and 1,282 had double valve replacement. Follow-up was 96% complete, with a mean period of 4.3 years and a total of 29,155 patient-years.

RESULTS

The operative mortality rate was 7.2%. The 10-year probability of freedom from valve-related complications and linearized rates (event/100 patient-years in parentheses) were as follows: structural deterioration, 100% (0); nonstructural dysfunction, 96% +/- 0.5% (0.51); thromboembolism, 82.9% +/- 1.5% (1.32); anticoagulant-related hemorrhage, 87.6% +/- 1.4% (0.98); and prosthetic valve endocarditis, 96.1% +/- 0.5% (0.48). There were five obstructive valve thromboses (0.017/100 patient-years). Actuarial freedom from reoperation was 95% +/- 0.5% at 10 years. Actuarial freedom from all valve-related morbidity was 70.2% +/- 1.6%; freedom from all valve-related morbidity and mortality (including operative and sudden deaths) was 62.6% +/- 2% (70.1% +/- 2% for aortic valve replacement, 56.9% +/- 2% for mitral valve replacement, and 59.8% +/- 3% for double valve replacement; p < 0.0001). Clinically, 5,988 patients (94%) are in New York Heart Association class I-II.

CONCLUSIONS

The Monostrut valve has shown no structural failures and a low rate of valve-related complications over a 10-year period in a large patient population.

As originally published in 1988: Long-term results of mitral valve surgery in patients with severe pulmonary hypertension. Updated in 1996

Mitral valve surgery was performed in 88 patients with severe pulmonary hypertension (average systolic pulmonary artery pressure, 94.7 +/- 22 mm Hg; range, 70-180 mm Hg) over a 10-year period. Sixty-four patients (73%) were in New York Heart Association Functional Class III or IV. There were 64 valve replacements and 24 open mitral commissurotomies. Operative mortality was 5.6% (5 patients) and was not related to the degree of pulmonary hypertension, surgical procedure performed, or type of valve lesion. A 100% follow-up was obtained, ranging from nine months to 10 years, with a mean of 44 months. Six late cardiac deaths (7.2%) occurred, 5 in patients with valve replacement and 1 in a patient who underwent a commissurotomy. Actuarial survival was 86 +/- 3% at five years and 83 +/- 4% at 10 years. Fourteen patients underwent right ventricular catheterization a mean of 24 months following operation. Systolic pulmonary artery pressure had decreased from a mean preoperative value of 101 +/- 22 to 40.5 +/- 7 mm Hg (p < 0.001). Cardiac index increased by 55% of the preoperative values. Functional status improved markedly; 71 survivors (93%) were in New York Heart Association Class I or II. These results indicate that, in patients with mitral valve lesions and severe pulmonary hypertension, (1) surgical procedures can be performed with an acceptable operative mortality; (2) excellent long-term survival and functional results can be obtained; and (3) pulmonary hypertension decreases significantly after operation. Patients with mitral valve disease may benefit from surgical treatment regardless of the degree of pulmonary hypertension.

Retrograde strut embolization in a fractured Björk-Shiley mitral prosthesis

The case of the minor strut fracture of a Björk-Shiley convexo-concave mitral valve, with retrograde embolization to a pulmonary vein is presented. Migration probably occurred during ventricular systole and the strut became anchored to the pulmonary vein wall. The patient underwent emergency mitral valve replacement with event free recovery. The strut was located by computed tomography postoperatively, and it has remained in the same location for over one and a half years.

[Massive endobronchial hemorrhage due to pulmonary artery rupture caused by a Swan-Ganz catheter]

We present the case of a 69-year-old male bearing a Swan-Ganz catheter while undergoing aortic and mitral valve replacement. Massive hemorrhage through the endotracheal tube began after closure of the sternotomy. Selective endobronchial intubation was performed and the thorax immediately reopened to reveal a tear in the right pulmonary artery at the level of the middle lobar branch. The tear was sutured, and throughout the early postoperative hours the patient presented signs of active bleeding through thoracic drains, with persistent slight hemoptysis in the right branch of the endotracheal tube. Ventilation was controlled artificially with two synchronized respirators and positive end-expiratory pressure (PEEP) up to 10 cm H2O in the right lung. The double-lumen tube was removed after 15 days with no complications and the patient was released two months after surgery. Massive endobronchial hemorrhage resulting from perforation of the pulmonary artery or its tributaries caused by Swan-Ganz catheters requires early diagnosis and treatment based on airway protection and immediate location and control of the point of hemorrhage. Selective endobronchial intubation with double-lumen tubes, direct arterial surgery and use of PEEP may constitute a valid alternative for management of these patients, making resection unnecessary.

Cardiopulmonary bypass in HIV-positive patients

To prove the hypothesis that cardiopulmonary bypass may accelerate the development of acquired immunodeficiency syndrome (AIDS) in the human immunodeficiency virus carrier, the clinical course of 40 patients positive for human immunodeficiency virus who underwent cardiac operations between 1986 and 1992 was analyzed, especially in regard to the progression to AIDS. Mean age was 30 years (range, 19 to 61 years). Thirty-four patients (85%) were intravenous drug abusers; in 4 (10%) transmission of infection was sexual, and in 2 (5%) it was through a contaminated blood transfusion. Valve procedures were performed in 38 patients (95%), mostly for endocarditis in drug addicts. Hospital mortality was 20% (8 patients). The 32 survivors have been followed up a mean of 21 months (range, 4 months to 6 years). Four patients (12.5%) experienced progression to AIDS during the follow-up period. Actuarial progression to AIDS is 5% (+/- 5%) at 1 year, 20% (+/- 10%) at 2 years, and 40% (+/- 19%) at 5 years. There have been 8 late deaths (5 due to recurrent endocarditis, 2 due to AIDS, and 1 due to overdose). Actuarial survival is 79% (+/- 8%) at 1 year, 60% (+/- 11%) at 2 years, and 48% (+/- 14%) at 5 years. The results indicate that progression to AIDS in the patient positive for human immunodeficiency virus is not accelerated by the use of cardiopulmonary bypass. The poor prognosis in these patients is mainly related to the particular pathological conditions that often affect the drug addict population.

Subacute cardiac rupture: repair with a sutureless technique

Thirteen patients with ages between 53 and 74 years had development of free wall left ventricular rupture after a myocardial infarction (mean interval, 3.8 days). All patients showed clinical signs of cardiac tamponade. Diagnosis was established by bedside multiple pressure monitoring and echocardiography, which showed pericardial effusion with compression of the right ventricle. Cardiac catheterization was not performed. A new surgical technique was employed for the repair. After the pericardium was opened and cardiac tamponade was relieved, the myocardial tear was identified. A Teflon patch was applied over the area and glued to the heart surface with a surgical glue (cyanoacrylate). Cardiopulmonary bypass was not used except in a patient with a posterior tear. The method was consistently effective in controlling bleeding from the myocardial tear. All patients survived the operation and were discharged from the hospital a mean of 15 days after the operation. Follow-up extending up to 5 years (mean, 26 months) shows a 100% survival, 11 asymptomatic patients, and 2 patients with mild exertional angina. The technique is a simple, effective, and safe method for repair of subacute cardiac rupture and obviates the need for suturing on an infarcted ventricle.

Hemodynamic effects of prostaglandin E1 and isoproterenol early after cardiac operations for mitral stenosis

Patients with mitral stenosis and some degree of right ventricular failure may benefit from inotropic or pulmonary vasodilator drugs in the early postoperative period. Thirty patients undergoing an operation for mitral stenosis were randomized into three groups. In group I (n = 10), isoproterenol (5 micrograms/kg/min) was started in the immediate postoperative period. In group P (n = 10), prostaglandin E1 (0.08 microgram/kg/min) was given, and in group C, the control group (n = 10), no drugs were used. After the operation and before drug therapy was begun, basal measurements of cardiac index, mean pulmonary arterial and mean arterial pressures, and pulmonary vascular resistance were taken. Measurements were repeated at 6, 12, and 24 hours. Mean measurements of cardiac index (basal up to 24 hours) were as follows: 1.39 +/- 0.3, 1.92 +/- 0.4, 2.4 +/- 0.5, and 2.34 +/- 0.3 L/min/m2 for group C; 1.54 +/- 0.5, 2.64 +/- 0.4, 2.68 +/- 0.7, and 2.2 +/- 0.6 L/min/m2 for group I, and 1.57 +/- 0.3, 2.2 +/- 0.6, 2.72 +/- 0.7, and 2.27 +/- 0.4 L/min/m2 for group P (p less than 0.05 between groups C and I at 6 and 12 hours). Mean pulmonary artery pressures were as follows: 19.5 +/- 3.2, 24.8 +/- 7, 27.7 +/- 7.3 and 28.8 +/- 5.7 mm Hg in group C; 21.4 +/- 8.7, 25.7 +/- 7.2, 26.4 +/- 7, and 29.4 +/- 8.6 mm Hg in group I, and 19.1 +/- 4, 19.2 +/- 3, 20.4 +/- 6, and 20.7 +/- 5 mm Hg in group P (p less than 0.05, group P versus groups C and I at 6, 12, and 24 hours). Mean pulmonary vascular resistances were as follows: 3.9 +/- 2.4, 3.9 +/- 1, 3.36 +/- 2, and 3.2 +/- 1.4 Wood units in group C; 4.84 +/- 4, 3.37 +/- 2.2, 3.69 +/- 3, and 4.69 +/- 4.1 Wood units in group I, and 3.29 +/- 1.3, 1.71 +/- 0.5, 1.61 +/- 0.5, and 1.96 +/- 0.8 Wood units in group P (p less than 0.05, group P versus groups C and I at 6, 12, and 24 hours). There was no difference in mean systemic arterial pressure among the three groups. Our results indicate that patients subjected to mitral valve operations have a low cardiac index. Isoproterenol increases cardiac index but has little effect on pulmonary resistance. At low doses, prostaglandin E1 effectively decreases pulmonary vascular resistance without altering systemic arterial pressure or heart rate.

The Monostrut Björk-Shiley valve. Seven years' experience

The results of cardiac valve replacement with the Monostrut Björk-Shiley prosthesis (Shiley, Inc., Irvine, Calif.) during a 7-year period are presented. A total of 984 valves were implanted in 820 patients from May 1983 to April 1990. Aortic valve replacement was performed in 378 patients, mitral replacement in 294, and multiple replacement in 148. In addition, 180 patients (22%) underwent associated procedures. Mean age was 52.6 +/- 11 years. Operative (30 days) mortality was 5.9% (49 patients): 3.9% (15 patients) for aortic, 7.8% (23 patients) for mitral, and 7.4% (11 patients) for multiple valve replacement. All patients were given long-term anticoagulation therapy. Follow-up was 99% complete (eight patients were lost to follow-up), with a closing interval of 3 months, and totaled 2422 patient-years. Valve-related complications, expressed as percentage event-free (+/- standard error) at seven years were as follows: structural deterioration, 100%; nonstructural dysfunction, 98.3% +/- 0.6%; thromboembolism, 90.2% +/- 1.7%; anticoagulant-related hemorrhage, 88.7% +/- 2.8%; and prosthetic valve endocarditis, 98.1% +/- 0.8%. There were no cases of valve thrombosis. Actuarial survival (free from operative, valve-related, and sudden death) was 88.4% +/- 1.2% at 7 years. Freedom from reoperation was 96.8% +/- 0.1%. Probability of being free from all valve-related morbidity and mortality was 70% +/- 3%, and 708 (93%) of the survivors were in New York Heart Association class I or II. Serial Doppler echocardiograms were done prospectively in 243 patients (with 154 aortic and 120 mitral prostheses), both postoperatively and at regular intervals up to 3 years. Mean prosthetic gradients ranged from an average of 20.9 to 7 mm Hg in the aortic prostheses (21 to 29 mm) and from 6.1 to 4.8 mm Hg in the mitral prostheses (25 to 31 mm). The gradients in each patient did not change significantly during the follow-up period. Our 7 year's experience with the Monostrut valve shows a low rate of valve-related complications, a durable design, and good hemodynamic and functional results.

[Membranous obstruction of the inferior vena cava in its drainage portion in the left atrium. Presentation of a case]

A child with a membranous obstruction of the inferior vena cava (MOIVC) is presented. The diagnosis was confirmed by angiography. The clinic significance, the evolution, the surgical treatment and the possible complications are described.

Fertility in a case of progeria

A 32-year-old woman with Hutchinson-Gilford disease (progeria) is described. The absence of complete sexual maturation has been considered characteristic of the syndrome, but this woman delivered a normal child at the age of 23.