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Biomedical subjects

L Miro

Publications and source records attributed to L Miro.

At least 19 recordsLinked to original sources
PubMed2005

Late outcome of Senning and Mustard procedures for correction of transposition of the great arteries.

OBJECTIVES: To evaluate late mortality and morbidity after an atrial switch procedure for correction of transposition of the great arteries (TGA) and to assess predictive factors for adverse outcome. SETTING: Tertiary referral centre. DESIGN AND PATIENTS: Retrospective follow up study of 137 patients surviving hospitalisation for TGA atrial switch procedure (Mustard or Senning) in a single institution and divided into two groups (simple and complex) depending on presurgical anatomy. Several surgical and follow up factors were evaluated during 16.7 (5.6) years' follow up. RESULTS: Late mortality was 5.1% (95% confidence interval 1.37% to 8.84%) with sudden death as the most common cause. No significant difference was found between Mustard and Senning procedures and between the complex and simple groups in terms of mortality. Independent predictive factors for late mortality were a history of supraventricular tachyarrhythmias and advanced New York Heart Association (NYHA) functional class during follow up. A very common finding was development of sinus node dysfunction (47.6%), which had no influence on mortality. There was little need for reintervention (5.1%) and relatively few cases of right ventricular systolic dysfunction (14.6%). During follow up, most patients (96.2%) were in NYHA functional class I-II. CONCLUSIONS: Overall long term outcomes of patients with atrial repair of TGA in the present era are encouraging in terms of late mortality and quality of life. Nevertheless, better outcomes may be offered through improved diagnostic methods for right ventricular function and better management of supraventricular tachyarrhythmias.

Adolescent↗
PubMed1999

Evaluation in humans of the effects of radiocellular telephones on the circadian patterns of melatonin secretion, a chronobiological rhythm marker.

A decrease in melatonin secretion has been observed in small mammals under exposure to extremely low frequency electromagnetic fields. As there is some concern about possible health effects of the increasing use of radiocellular telephones emitting radiofrequency electromagnetic fields, we examined whether such fields would alter melatonin levels in the human. Volunteers were two groups totalling 38 men, 20-32 yr old. Exposures were to commercially available cellular telephones of the GSM 900 type (Global System for Mobile communication at 900 MHz) or DCS 1800 type (Digital Communication System at 1800 MHz), for 2 hr/day, 5 days/wk, for 4 wk, at their maximum power. Attention of the volunteers was sustained by TV projection of movies. Blood samples were collected hourly during the night and every 3 hr in the daytime. Four sampling sessions were performed at 15-day intervals: before the beginning of the exposure period, at the middle and the end of the exposure period, and 15 days later to evaluate the persistence or late appearance of potential effects. Evaluated parameters were the maximum serum concentration, the time of this maximum, and the area under the curve of the hormone profile. Melatonin circadian profile was not disrupted in 37 young male volunteers submitted to a typical pattern of exposure to the electromagnetic fields generated by two common types of cell phones.

Adult↗
PubMed1998

GSM radiocellular telephones do not disturb the secretion of antepituitary hormones in humans.

It is known that the endocrine system of experimental animals is susceptible to perturbation by radiofrequency (RF) radiation. Because of the recent interest in health and safety issues of cellular telephones, an experiment was designed to evaluate the effect of a 900 MHz RF radiation emitted by a Global System for Mobile radiotelephone (217 Hz impulses, one-eighth duty cycle, 2 W peak power) on human endocrine functions. Twenty healthy male volunteers aged from 19 to 40 were inducted in the present experiment. Each subject was exposed to RF radiation through the use of a cellular phone 2 h/day, 5 days/wk, for 1 month. Subjects were their own control. End points were serum adrenocorticotropin, thyrotropin, growth hormone, prolactin, luteinizing hormone, and follicle stimulating hormone concentrations. These end points were determined in nine weekly blood samples obtained starting 3 weeks before the commencement of the exposure and ending 2 weeks after exposures. All but one blood sample was drawn 48 h after each weekly session. The seventh drawing was performed the morning after the last weekly exposure. Within each individual, the preexposure hormone concentration was used as a control. Results indicated that all hormone concentrations remained within normal physiologic ranges. A difference was not noted among the nine weekly samples in five of six hormones studied. There was a significant change only in thyrotropin concentration, showing a 21% decrease on the seventh sampling. Because this change recovered fully during the postexposure period, it is concluded that 1 month of intermittent exposures to RF radiation from a cellular telephone does not induce a long-lasting or cumulative effect on the hormone secretion rate of the anterior pituitary gland in humans.

Adrenocorticotropic Hormone↗
PubMed1997

Effect of laser irradiation on latency of herpes simplex virus in a mouse model.

Low power Laser irradiation is used in medical practice for different indications. Several firms which commercialise Laser claim that Laser irradiation may be beneficial towards Herpes virus pathogenicity. We observe that, in the ear experimental model of HSV latency [3], repeated exposure to infrared Laser radiation of cervical ganglia following HSV inoculation appears to specifically hinder the establishment of virus latency in mouse.

Animals↗
PubMed1992

Hypertrophic cardiomyopathy in mucopolysaccharidoses: regression after bone marrow transplantation.

Mucopolysaccharide storage disease (MPS) presents clinically with a broad spectrum of abnormalities, among which cardiovascular involvement has been described. The echocardiographic findings have recently been reported for the various types of MPS. Among these, asymmetric septal hypertrophy (ASH) has been documented. We present a case of a 9-year-old girl suffering from type I MPS, atypical variant, with echocardiographic signs of ASH. She was given a bone marrow transplant after which the hypertrophic cardiomyopathy regressed.

Bone Marrow Transplantation↗
PubMed1990

[Scanning electron microscope view of dentin exposed to CO2 laser radiation].

In order to better define the effects of CO2 Laser rays on dentine, 10 healthy human teeth to be removed and 64 recently removed healthy human teeth were prepared and irradiated according to the classic protocol used in clinical periodontics, and observed with a scanning electron microscope. The examination of these samples confirms the phenomena of dentin fusion and recrystallization. But these alterations result in the appearance of a reorganized superficial layer consisting of unevenly juxtaposed craters formed by the pin-point action of the laser beam. These craters present numerous fissures and openings of variable diameter. They do not form a homogeneous surface, since chips may be raised, demonstrating the fragility of the reorganized layer and a lack of cohesion of the underlying dentine. The modified dentine layer also disappears when a curette is used, revealing a very uneven surface crossed with small cracks and where the tubule openings become visible. Our results, unlike many more optimistic studies, still prompt us to exert caution in the systematic use of CO2 lasers in Periodontics.

Adult↗
PubMed1982

Experimental comparative study on morphological effects of different lasers on the liver.

Three types of laser radiation were compared as to their capabilities in hepatic surgery using 17 New Zealand rabbits. In four animals, subtotal scalpel lobectomy was performed, the hepatic pedicle being clamped. Hemostasis is obtained by means of argon or Nd YAG laser as long as the internal diameter of the vessels encountered is less than 4.5 mm. Nd YAG laser requires a power output four times higher than argon laser to obtain hemostasis. In six animals limited resection was performed by means of Nd YAG and CO2 lasers. CO2 radiation supplied insufficient hemostasis whenever the vessel diameter was more than 1 mm despite an excellent cutting power. Nd YAG radiation created an important necrosis zone due to thermal diffusion. In seven animals various focal hepatic lesions produced by the three types of laser were compared. Argon laser induced superficial and regularly round lesion, Nd YAG laser deeper, cauliflower-like lesions with thermal diffusion following especially vessels. Veins presented thrombosis of their blood content and coagulation necrosis of their wall. The amount of glycogenic granulation decreased. The CO2 laser induced very sharp punctual lesion without necrosis. Electron-microscopic sections revealed faint shadowy liver cells closet to the thermal source and bubbled mitochondria containing disrupted critea around the lesion. In later lesions Nd YAG laser produced more extensive fibrosis than argon or CO2 laser. After first clinical trials we believe that laser irradiation is actually an adjuvant safety factor in current hepatic surgery, whereas the Nd YAG laser could be of real interest in metastatic carcinoma destruction in liver.

Animals↗
PubMed1970

Current status of French research on the biological effects of heavy ions in cosmic radiation as observed in high-altitude balloons.

On casual inspection, cosmic rays may not be considered to pose a biological hazard. Nevertheless, the heavy ion component does produce a significant but very local irradiation. This has been confirmed by the hair whitening in black-haired animals. Experiments with black C 57 mice in balloons at 30,000 m altitude show white-haired tufts along the tracks of heavy ions. Histological and radioautographic studies were carried out; the results are reported. Similar investigations on black rabbits gave similar results and confirm those obtained previously with black mice. In the discussion, we report that tissue damage is amplified. This fact is not yet explained, but suggests reconsideration of the calculation of radiation dosage. The ionization distribution induced by heavy ions is analyzed. We point out that along their tracks the dosage is very important; therefore it is necessary to investigate their biological action, particle by particle, according to their energy and their charge.

Animals↗