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Biomedical subjects

G Fava

Publications and source records attributed to G Fava.

At least 19 recordsLinked to original sources
PubMed2005

Leaching and mechanical behaviour of concrete manufactured with recycled aggregates.

The reuse of debris from building demolition is of increasing public interest because it decreases the volume of material to be disposed to landfill. This research is focused on the evaluation of the possibility of reusing recycled aggregate from construction or demolition waste (C&D) as a substitute for natural aggregate in concrete production. In most applications, cement based materials are used for building construction due to their cost effectiveness and performance; however their impact on the surrounding environment should be monitored. The interstitial pore fluid in contact with hydrated cementitious materials is characterized by persistent alkaline pH values buffered by the presence of hydrate calcium silicate, portlandite and alkaline ions. An experimental plan was carried out to investigate concrete structural properties in relation to alkali release in aqueous solution. Results indicate that the presence of recycled aggregate increases the leachability of unreactive ions (Na, K, Cl), while for calcium the substitution resulted in a lower net leaching. In spite of the lower mechanical resistance (40% less), such a waste concrete may be suggested as more environmentally sustainable.

Conservation of Natural Resources↗
PubMed2001

A rare anorectal malformation: a very large H-type fistula.

A very large H-type rectovaginal fistula was observed in a 9-year-old girl. The diameter of the abnormal opening was about 15 mm. The fistulous tract originated from the stenotic segment 1 cm above the pectinate line of the anus and was connected to the back wall of the vagina. The patient underwent posterior sagittal transrectal surgery with a protecting colostomy. At present, she has good bowel function and sphincter control without recurrence of the fistula.

Child↗
PubMed2000

Paradoxical effects of contralateral white noise on evoked otoacoustic emissions in ears with acoustic neuroma.

A contralateral suppression effect on evoked otoacoustic emissions (EOAEs) is usually present in normally hearing subjects and in patients with sensorineural hearing loss, while it is absent or reduced in ears to which the vestibular nerve has been cut and in ears with acoustic neuroma (AN). To date, a paradoxical effect, that is an increase in EOAE amplitude during contralateral stimulation, has been described in one ear with sensorineural hearing loss of unknown aetiology and in three ears with AN (two in the present paper). Evidence has been provided that the contralateral suppression effect on EOAEs is accomplished largely, if not entirely, via the medial olivocochlear bundle (OCB). According to clinical data the absence or the reduced amount of contralateral suppression effect on EAOEs may be attributed to a totally, or partially, damaged or malfunctioning medial OCB. The way in which a contralateral noise may increase EOAE amplitude is more difficult to explain. One attractive hypothesis is that this paradoxical effect is a result of some pathological adaptive process in the medial OCB.

Acoustic Stimulation↗
PubMed1998

[Low-level laser therapy in osteoarticular diseases in geriatric patients].

INTRODUCTION: Laser light absorption through the skin causes tissue changes, targeting the nervous, the lymphatic, the circulatory and the immune systems with an antalgic, anti-inflammatory, anti-edemic effect and stimulating tissue repair. Therefore low level laser therapy is now commonly used in numerous rehabilitation centers, including the "Istituto Gerontologico Pio Albergo Trivulzio", Milan, Italy. However, to activate the treatment program, the basic medical research results must always be considered to choose the best optical wavelength spectrum, technique and dose, for rehabilitative laser therapy. We analyzed the therapeutic effects of different wavelengths and powers in various treatment schedules. In particular, a protocol was designed to test such physical parameters as laser type, doses and individual schedule in different pathologic conditions. We report the results obtained with low level laser therapy in the rehabilitation of geriatric patients, considering the various physical and technical parameters used in our protocol. MATERIAL AND METHODS: We used the following laser equipment: an HeNe laser with 632.8 nm wavelength (Mectronic), a GaAs Laser with 904 nm wavelength (Mectronic) and a CO2 Laser with 10,600 nm wavelength (Etoile). To evaluate the patient clinical status, we use a different form for each involved joint; the laser beam is targeted on the region of interest and irradiation is carried out with the sweeping method or the points technique. Irradiation technique, doses and physical parameters (laser type, wavelength, session dose and number) are indicated on the form. The complete treatment cycle consists of 5 sessions per week--20 sessions in all. At the end of the treatment cycle, the results were scored on a 5-grade semiquantitative scale--excellent, good, fair, poor and no results. We examined 3 groups of patients affected with gonarthrosis (149 patients), lumbar arthrosis (117 patients), and algodystrophy (140 patients) respectively. RESULTS: In gonarthrosis patients, the statistical analysis of the results showed no significant differences between CO2 laser and GaAs laser treatments (p = .975), but significant differences between CO2 laser and HeNe laser treatments (p = .02) and between GaAs laser and HeNe laser treatments (p = .003). In lumbar arthrosis patients treated with GaAs or HeNe laser, significant differences were found between the two laser treatments and the combined sweeping-points techniques appeared to have a positive trend relative to the sweeping method alone, especially in sciatic suffering. In the algodystrophy syndrome, in hemiplegic patients, significant differences were found between CO2 and HeNe laser treatments (p = .026), between high and low CO2 laser doses (p = .024), and between low CO2 laser dose and high HeNe laser dose (p = .006). CONCLUSIONS: Low level laser therapy can be used to treat osteoarticular pain in geriatric patients. To optimize the results, the diagnostic picture must be correct and a treatment program defining the physical parameters used (wavelength, dose and irradiation technique) must also be designed.

Age Factors↗
PubMed1996

[Electrocochleography by extra- and transtympanic methods: the results in a group of normal subjects].

Electrocochleography (ECoG) is an electrophysiologic approach to the study of hearing. In ECoG, electrical activity that originates within the cochlea or the auditory nerve is recorded. ECoG represents an evoked or stimulus dependent measure. The electrical potentials which can be analyzed in ECoG are: the cochlear microphonic potential (CM), the summating potential (SP) and the acoustic nerve potential (AP). Two major types of electrocochleography electrodes can be used, transtympanic and extratympanic. Transtympanic ECoG is performed by inserting a long needle electrode, placed through the tympanic membrane onto the promontory. Extratympanic ECoG is recorded by using electrodes placed within the external meatus near the tympanic membrane. At the ENT Department of the University of Parma, ECoG was performed in 10 normal hearing subjects (4 males and 6 females. Their ages ranged from 21 to 29 years (mean 26 years). All subjects underwent ECoG recording simultaneously with extratympanic and transtympanic technique.

Adult↗
PubMed1996

[Brainstem auditory evoked potentials in neonatology: the method and results in a group of normal newborns].

Brainstem evoked responses audiometry was performed on 10 newborn infants. They ranged in postnatal age from 19 hours to 5 days and in estimated gestational age from 39 to 42 weeks. Clicks of 0.1 msec duration were presented at a rate of 11.4 per second. Measurements were made at 50, 80 and 100 dB. Wave V latencies were evaluated at 50, 80 and 100 dB HL in order to measure the auditory threshold. The latency of wave V is the datum of interest. Wave V responses were obtained bilaterally at 50 dB HL. Waves I and III latencies were measured at 100 dB HL.

Acoustic Stimulation↗
PubMed1995

[The time parameters of the stapedius reflex. The normal results].

The evaluation of the temporal characteristics of the acoustic stapedius reflex is one the fundamental aspects of the impedance audiometry, since significant biological information to be used as sensitive indicators of distinctive pathologies can be obtained. At the Audiology Service of the E.N.T. Department of Parma four parameters of the acoustic stapedius reflex have been studied (onset latency, latency at 10% of the maximum amplitude, rise time, offset latency) in a group of people having normal ears without previous otological problems, with the aim to establishing some rules. The equipment used is the Madsen Impedenzometro ZO 174 which enables to obtain an average among a desired number of reflex responses. The report shows the value of the four parameters of the stapedius reflex obtained from the study of 10 normoacusic patients totalling 20 ears. The resulting guidelines can make up the basis for further research in pathological cases with cochlear, neural and central lesions.

Acoustic Impedance Tests↗
PubMed1987

Topical administration of tetrasodium-meso-tetraphenyl-porphinesulfonate (TPPS): correlation between drug penetration and depth of necrosis in skin of nude mice following red light irradiation.

The main side effect in photodynamic therapy is photosensitization of the patient's skin following systemic administration of the photosensitizing agent. In the case of superficial lesions, this problem can be avoided by topically applying the drug: in this way a local treatment can be performed. We tested the photosensitizing properties of a 2% solution of TPPS (tetrasodium-tetraphenylporphinesulfonate) in a vehicle containing a penetration enhancer, Azone, on skin of nude mice. An aliquot of 0.1 ml/cm2 of the solution was painted on the skin overlying an s.c. implanted NMU-1 tumor. Subsequently, animals were sacrificed at different times after application. Fluorescence microscopy revealed that TPPS penetration depth was related to time elapsed after application and to painting modalities. Solution penetration was enhanced by wiping with ether immediately before painting. Irradiation at 80 mW/cm2 for 20 min with a dye laser emitting at 640 nm, 4 h after TPPS application, produced necrosis of the upper skin layers, up to 0.2 mm in depth. These findings suggest that topical TPPS administration, followed by laser irradiation, may be a suitable treatment modality for skin lesions involving epithelial layers, even though several aspects of this metodology need further investigation.

Adenocarcinoma↗
PubMed1986

A study on the possible involvement of nonlinear mechanism of light absorption by HpD with Nd:YAG laser.

The purpose of this study was to investigate whether excitation of porphyrin could be related to nonlinear mechanisms of absorption of porphyrin itself or of the medium in which porphyrin is embedded. This possibility was proposed as an explanation for results of previous experiments where a Nd:YAG laser was used. An MS-2 sarcoma transplanted into the hind pad of BALB/c mice was used as the experimental tumor model. Mice were given HpD i.v. (25 mg/kg) 24 h before exposure to light delivered from an IR laser (1,060 nm). Since at dose-rates ranging between 600 and 1,200 mW/cm2 the thermal effect tended to mask the nonlinear effect, the temperature of the limb of mice was kept cold by running water. Irradiation performed under cooling conditions did not show any tumor growth inhibition. Experiments in vitro performed on HT-29 cells by a continuous wave (CW) or pulsed (Q-switch) Nd:YAG laser indicated no appreciable difference in DNA synthesis between irradiated and nonirradiated cells. Our results did not evidence nonlinear mechanisms of absorption by HpD with Nd:YAG laser both in CW and pulsed (nanosecond range) modes. Whether this effect should occur, in any case it is unlikely to be suitable to induce a photodynamic effect due to its low efficiency. Nd:YAG laser could induce a heating related effect, which can improve the therapeutic efficacy of PDT.

Animals↗
PubMed1985

Temperature rise in biological tissue during Nd:YAG laser irradiation.

Few data are available about temperature distribution in tissue during Nd:YAG laser irradiation. To study the heat distribution that produces tissue coagulation, we used a thermographic camera aimed orthogonally to the laser beam axis to obtain thermal maps. Immediately after surgical resection, specimens of human stomach were irradiated near the resected edge, and the heat emitted sideways was detected by an infrared image system. A magnifying lens mounted on the camera enabled us to obtain 0.1 mm spatial resolution of the isothermic curves. The thermal analysis showed that the maximum depth where the increase in temperature reached 25 degrees C (corresponding to a coagulation temperature of about 60 degrees C) was never greater than 3 mm, irrespective of the power and exposure time used. Moreover, the bidimensional thermal maps showed that the temperature did not decrease in a purely exponential fashion along the beam axis, but reached a maximum at about 1 mm beneath the surface. This fact, which confirms the decrepitation theorem, could explain the explosion inside the tissues observed in surgical application of the Nd:YAG laser.

Body Temperature↗
PubMed1985

[1 year of traumatologic activity in the Emergency Orthopedic Unit of the G. Pini Institute (statistical data)].

The Authors have considered one year's traumatological activity in the G. Pini Institute's S.T.U. by drawing some statistical results. The data refer to the traumas ambulatorium-treated and to all those which required hospitalization during 1979. The total of the traumas surveyed in 1979 is 33335 of which 1812 required urgent hospitalization (5.44%). Previous statistics show 6679 patients in 1961 and 3209 in 1956. We can realize how these figures have increased in a few years (and in this abstract the different kinds of traumas are also highlighted) without any adjustment to the existing structures and equipment which are completely insufficient.

Contusions↗
PubMed1984

Hyperthermal effects in phototherapy with hematoporphyrin derivative sensitization.

Although the photochemical reaction of hematoporphyrin derivative (HpD) appears to play a major role in cytotoxic activity, the hyperthermal contribution to tumor destruction has not yet been clarified. We investigated its role in the effectiveness of laser photoradiation therapy using MS-2 sarcoma transplanted into the hind pad of BALB/c mice as the experimental model. Mice received HpD i.v., 25 mg/kg - 24 h before exposure to light delivered from a dye laser or Nd-YAG laser, or before warming in a thermostated bath. Since our aim was not to cure the tumor, the treatment response was evaluated only as inhibition of tumor growth at different days after treatment. Our results support the view that in laser photochemotherapy the hyperthermia produced by irradiation and the photodynamic effect mediated by HpD could contribute to tumor destruction. Moreover, a synergistic interaction between the photodynamic effect and heat was observed in this experimental model.

Animals↗