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D Gal

Publications and source records attributed to D Gal.

At least 55 records · Page 3Linked to original sources
PubMed1989

Pulsed ultraviolet laser irradiation produces endothelium-independent relaxation of vascular smooth muscle.

Recent studies have shown that continuous wave laser irradiation induces contraction of vascular smooth muscle, except at powers far below the threshold for tissue ablation. To determine the corresponding effects of pulsed laser irradiation on vascular smooth muscle tone, vascular rings of rabbit thoracic aorta were mounted isometrically with 1 g tension in Krebs-bicarbonate buffer and irradiated with 308 or 351 nm from an excimer laser through a 400-microns optical fiber. A total of 250 exposures were performed with 1-6.5 mJ/pulse (fluence = 0.8-5.5 J/cm2), 10-50 Hz, and cumulative exposures of 10-120 seconds. Excimer laser irradiation in combinations of pulse energy (PE), repetition rate (RR), and cumulative exposure below, at, or above threshold for tissue ablation consistently produced relaxation unassociated with contraction in each of the 250 exposures. For the total 250 exposures, the magnitude of relaxation (reduction in recorded tension, Rmax) was 55 +/- 4% (mean +/- SEM) of maximum vasomotor reactivity recorded in the specimen in response to administration of serotonin. Rmax varied directly with both PE and RR. When PE was increased from 1 to 5 mJ/pulse (n = 13), Rmax increased from 57 +/- 19% to 80 +/- 19% (p less than 0.0001); when RR was increased from 10 to 50 Hz (n = 10), Rmax increased from 27 +/- 8 to 46 +/- 8 (p less than 0.0001). Rmax varied independently of endothelial integrity (assessed anatomically and pharmacologically) and wavelength (308 vs. 351 nm). Simultaneously recorded tissue-temperature profiles disclosed that during pulsed laser irradiation, tissue temperature rise did not exceed 5 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Effect of pulsed excimer laser on arterial smooth muscle].

The effect of pulsed lasers on vasomotricity was measured on 22 segments of isolated rabbit thoracic aorta. The segments were isometrically suspended in a bath of Krebs-bicarbonate buffer and irradiated with two excimer lasers (XeCl and XeF) emitting at 308 and 351 nm respectively and coupled with a 400 mu optical fibre. The 10 to 120 seconds irradiations were performed at frequencies ranging from 10 to 100 Hz and pulse energies comprised between 1 and 7 mJ. These parameters were on both sides of the tissue ablation threshold. On the 22 segments studied the irradiation induced in every case (n = 118) relaxation of the vascular smooth muscle. The presence or absence of an anatomically and functionally intact endothelium was checked by scanning electron microscopy and by induction of relaxation with acetylcholine. Identical results were observed on specimens that had been subjected to deliberate endothelial abrasion. Relaxation was increased by drug-induced precontraction. The rise in arterial wall temperature, as measured by thermistor microprobe, never exceeded 5 degrees C, and histological examination of the specimens never showed thermal damage. It is concluded that on the isolated rabbit aorta pulsed excimer laser irradiation induces an endothelium-independent smooth muscle relaxation most probably due to photorelaxation combined with a lack of significant heating of the arterial wall. These experimental data support the use of pulsed sources for laser angioplasty.

Acetylcholine↗
PubMed1989

[Effects of continuous laser on arterial vasomotoricity in vitro].

The effects of a continuous-wave argon laser irradiation on arterial vasomotricity were studied isometrically on 19 aortic segments obtained from rabbits. The segments had a resting tension of 1 g and were suspended in a perfusion chamber filled with a Krebs-bicarbonate buffer solution at 37 degrees C gassed with 95 p. 100 O2 and 5 p. 100 CO2. Irradiation was performed with an argon laser emitting principally at 488-514 nm, via a flexible optical fibre 200 microns in diameter. The tension of each specimen, measured with a strain gauge, was recorded at the same time as the arterial wall temperature, measured by a thermistor probe. The integrity of the endothelium was checked by scanning electron microscopy and acetylcholine test. The endothelium of 5 specimens was deliberately abrased, and this was checked by the same methods. Laser irradiations of more than 1 watt regularly (n = 34) induced a contraction the kinetics of which were parallel to those of the arterial wall heating and usually reversible after the end of irradiation. With irradiations of less than 0.1 watt, the parietal temperature never rose by more than 5 degrees C, and the vasomotor response always (n = 41) was a relaxation which was reversible after irradiation. At intermediate levels of power, the vasomotor response was biphasic and of low amplitude (n = 100). At all levels, similar responses were given by specimens whose endothelium had been removed. Thus, at the powers used for angioplasty, irradiation of the arterial wall by continuous-wave argon laser induces and intense vasoconstriction which is independent of the endothelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Transmissibility and treatment failures of different types of human papillomavirus.

In order to evaluate the transmissibility and treatment failures of different types of human papillomavirus (HPV), we obtained biopsy specimens from genital lesions related to HPV in 113 women prior to laser therapy. Sixty-eight had condylomata acuminata, 14 had flat condyloma, and 31 had cervical intraepithelial neoplasia with or without condylomata. Of 76 male sexual partners examined colposcopically, 58 (76%) had HPV-related lesions. All biopsy specimens were analyzed for specific type of HPV DNA by Southern blot hybridization with probes for HPVs 6, 11, 16, and 18. Sixty-one women had HPV 6 or 11 (6/11), 40 had HPV 16 or 18 (16/18), and in 12 the analysis was negative for these types of viral DNA. Deoxyribonucleic acid analysis of biopsy specimens from recurrent lesions showed the same type of viral DNA as in the primary lesion. Significantly more male partners (28 of 47) with the same HPV type were found among women with HPV 6/11 than among women with HPV 16/18 (P less than .005). Patients with HPV 16/18 had significantly more recurrences (14 of 40) after laser therapy than patients with HPV 6/11 (six of 60) (P less than .001).

DNA, Viral↗
PubMed1989

Management of imperforate hymen with the carbon dioxide laser.

A method for the management of imperforate hymen using carbon dioxide laser is described. In four patients presenting with imperforate hymen, the hymen was excised by CO2 laser under local anesthesia. No bleeding or wound infection occurred, and healing was prompt and satisfactory. Two out of four patients became sexually active and experienced no introital dyspareunia. We conclude that the CO2 laser may be an alternative method of treatment for this rare congenital abnormality.

Adolescent↗
PubMed1988

Percutaneous, in vivo excimer laser angioplasty: results in two experimental animal models.

Pulsed ultraviolet light from an excimer laser was successfully transmitted via conventional fused silica optical fibers and used to accomplish recanalization of stenotic or totally occluded arteries in an intact, flowing blood field of two atherosclerotic animal models. The fibers, 300-600 micron in diameter, were delivered percutaneously in wire-guided multilumen catheters and then used to transmit wavelengths of 308 or 351 nm from excimer lasers with pulse durations of 12 nsec or less. Lesions from 70-100% diameter narrowing, and 0.6 to 5.5 cm in length were successfully recanalized (less than 50% residual diameter narrowing) in eight animals, using 3-4 J/cm2/pulse, 10-50 Hz, and 48-370-sec cumulative exposure. Necropsy examination in six of the eight animals disclosed no signs of thermal injury. Perforations were observed in four of eight animals. Thus, while use of an excimer laser power source did not obviate vascular perforation as a complication of laser angioplasty, these preliminary results indicate that energies of pulsed ultraviolet light sufficient to ablate atherosclerotic plaque can be both transmitted via conventional fused silica optical fibers and used successfully within an intact, flowing blood field. It may therefore be possible to use pulsed ultraviolet light from an excimer laser to accomplish percutaneous ablation of atherosclerotic arterial obstructions in humans.

Angiography↗
PubMed1988

Carbon dioxide laser effect on platelet function and surface ultrastructure in vitro.

Platelet aggregation may be an important factor in the feasibility of transcatheter laser angioplasty. The in vitro effects of increasing doses of CO2 laser irradiation on platelet number, function, and surface ultrastructure were examined. Results indicated a progressive dose-response reduction of both platelet number and function following laser irradiation. By scanning electron microscopy the irradiated platelets showed dose-related changes in pseudopods as well as progressive damage of the cell membrane.

Adult↗
PubMed1988

Mechanism of laser ablation in an absorbing fluid field.

Selection of a laser source for intravascular applications has frequently been predicated upon assumptions involving transmissibility in blood of the wavelength of light emitted by a given laser. Standard absorption curves for ultraviolet radiation in blood and infrared radiation in water would suggest that transmission of ultraviolet radiation through a blood field and infrared radiation through any aqueous fluid field would be insufficient for tissue ablation. The present series of experiments was undertaken to determine whether these theoretical predictions would in fact obviate the use of these wavelengths in a blood field. Specimens of normal human myocardium and/or polyvinylchloride were submerged under blood and water and irradiated with ultraviolet radiation (351 nm) delivered as a focused beam and via an optical fiber and infrared radiation (10,600 nm) delivered as a focused beam. Ablation of myocardium was successfully accomplished with a focused beam of both ultraviolet and infrared radiation under as much as 5 mm of blood and with ultraviolet radiation via an optical fiber with the fiber tip up to 3 mm distant from the tissue specimen. High-speed cine recordings of ablation carried out using a focused beam of laser radiation demonstrated that formation of a dynamic optical cavity is the basis for successful pulsed ultraviolet and infrared laser transanguineous tissue ablation. These results thus demonstrate that prediction of wavelength transmission through fluid media based on optical properties of a static fluid does not predict ability to accomplish ablation under dynamic circumstances of laser irradiation.

Blood↗
PubMed1988

The use of carbon dioxide fiberoptic laser catheter for atrial septostomy.

The development of optical fibers capable of transmitting laser energy has encouraged the experimental use of laser irradiation for the treatment of acquired cardiovascular disorders. One of the key questions is which combination of laser source, energy parameters, and transmitting fiberoptic would be best suited for intravascular use. In most experiments argon, neodymium-YAG, and excimer lasers, coupled to suitable optical fibers, have been used. We now describe the use of a carbon dioxide fiberoptic laser catheter for the creation of an atrial septal defect. Silver halide infrared transmitting fibers were inserted into standard 6 French cardiovascular catheters. This laser catheter system, capable of transmitting several watts of pulsed CO2 laser energy, was initially used to create atrial septal defects in isolated dog hearts to determine the best energy parameters. Atrial septostomy was later performed successfully in four of five anesthetized dogs. The thermal damage extended 50 to 60 micron beyond the "holes" created by the laser irradiation in the interatrial septum. Thus, pulsed CO2 laser irradiation, delivered through optical fibers, can create an atrial septal defect.

Animals↗
PubMed1988

Papillomaviruses in lesions of the lower genital tract in Israeli patients.

Human papillomaviruses (HPVs) have been strongly associated with benign lesions of the genital tract (condylomata) and with genital cancer of the vulva and cervix. Since the incidence of these lesions in Israel is considered to be low, we have studied the presence of HPV 6, 11, 16 and 18 DNAs in benign, premalignant and malignant tissue samples or gynecological swabs of the lower genital tract. HPV sequences were detected in 48 out of 66 condylomatous lesions (72%), 5/11 grades I-II intraepithelial neoplasia (45%), 4/6 grade III intraepithelial neoplasia (carcinoma in situ) (66.6%) and 8/22 invasive carcinoma (36%). The latter included six cases of vulvar carcinoma which were all negative for HPV sequences. No additional HPV types could be detected in any of the tissue biopsies examined. HPV 18 DNA has been found in one vulvar condyloma where it persisted as an episomal molecule, this being the first report of that specific viral DNA in a condylomatous lesion. In all the benign and premalignant lesions containing HPV, the viral sequences were maintained in an episomal state. In two cases of invasive carcinoma, the HPV 16/18 related sequences were integrated in the cellular genome, but in five cases (three containing HPV 16/18 related DNAs and two containing HPV 6/11 related DNAs) the viral sequences were episomal. HPV 16/18 related sequences detected in one out of three cases of vaginal carcinoma were also found to be episomal. This data indicates that human papillomavirus sequences are indeed found in genital lesions of Israeli patients, although to a lesser extent than in other countries, especially for benign lesions and invasive carcinomas. Although HPVs may have a causative role in the development of genital lesions, also in this low tumor incidence area, other factors should be also considered in the etiology of these lesions.

Condylomata Acuminata↗
PubMed1988

Mullerian adenosarcoma of the uterine cervix.

The management of cervical adenosarcoma in a 14-year-old girl is described. The tumor had an exceptionally violent biological nature and did not respond to a variety of customary and unorthodox therapeutic measures. These included conventional intravenous chemotherapy, radiation therapy, surgery, intraarterial chemotherapy, colostomy, and peritoneovenous shunt for untreatable ascites. The patient died within 16 months of diagnosis. This is the fifth case of cervical adenosarcoma in the English literature. This tumor usually has a better prognosis and none of the previous four cases succumbed to the disease. The unusual virulence of the present case is discussed and the literature reviewed.

Adolescent↗
PubMed1988

Effect of argon laser irradiation on rabbit aortic smooth muscle: evidence for endothelium independent contraction and relaxation.

To study the effect of argon laser irradiation on vascular smooth muscle reactivity, ring segments of rabbit thoracic aorta were mounted isometrically in Krebs bicarbonate buffer. Laser irradiation was performed via a 200-micron core optical fibre interfaced with an argon ion gas laser. Laser irradiation at powers greater than 1.0 watt (W) (n = 34) produced contraction in each case, regardless of the duration of exposure. Conversely, irradiation at powers less than 0.1 W (n = 41) consistently produced relaxation. When the power employed ranged from 0.1 to 1.0 W (n = 100), the typical response consisted of a combination of low amplitude contraction and relaxation. At each power level, the responses observed were independent of the presence or absence of intact endothelium, assessed functionally by the response to acetylcholine and anatomically by scanning electron microscopy. Recordings of tissue temperature profiles performed during continuous-wave laser irradiation suggest that the findings observed in this study may be explained by a combination of heat induced contraction and light induced relaxation. At powers greater than 1.0 W, heat generated by laser irradiation is predominant, causing contraction. At powers less than 0.1 W, light predominates over heat, causing relaxation. When the power range is intermediate between these values, the heterogeneous response recorded reflects the combination of light and heat. In all cases, contraction and relaxation are endothelium independent.

Animals↗
PubMed1988

Concomitant endometrial adenoacanthoma and bilateral (inguinal) lymph node endometriotic adenoacanthomas or nodal metastases of the endometrial adenoacanthoma? A case report with a literature survey of the histogenetic aspects of endometriotic foci in pelvic lymph nodes.

This case report depicts an interesting association of well-differentiated adenocarcinoma of the endometrium with benign squamous metaplastic foci confined to the fundus uteri, superficially invading the myometrium and with concomitant bilateral pelvic lymph node endometriotic adenoacanthomas. Right inguinal lymphadenopathy was detected during the first hospitalization. A lymph node biopsy from the right groin, carried out at Nahariyya, revealed apparent metastatic adenoacanthoma regarded most probably as endometrial in origin. Fractionated curettage later showed a stage Ia G1 adenocarcinoma of the endometrium with benign squamous metaplastic elements (adenoacanthoma). At Rambam Hospital, Haifa, left groin node enlargement was noted as well. The Gynecologic Oncology Unit confirmed the previous histologic findings. At exploratory laparotomy total abdominal hysterectomy and bilateral salpingo-oophorectomy, paraaortic, and bilateral pelvic lymph node sampling as well as appendectomy were performed. Bilateral groin node dissection was then carried out. Out of 37 nodes examined tumor was found in only one node, namely that of the left groin. The paper includes an extensive survey of the literature on the subject of the histopathogenesis of endometriotic foci in pelvic lymph nodes and the discussion is designed to elucidate the diagnostic problem involved in this case report.

Adenocarcinoma↗
PubMed1987

Splenomegaly and solitary spleen metastasis in solid tumors.

Metastasis to the spleen from various neoplasms is very rare. Most of the splenic metastases are found at autopsy, and are part of a widespread disease. Four patients had cervical cancer (1 patient), endometrial cancer (1 patient), lung carcinoma (1 patient), and malignant melanoma (1 patient). All patients had splenic involvement without pathologic evidence of lymph node metastasis, and all underwent splenectomy. Three of the four presented with painful splenomegaly. The time from diagnosis to the development of splenic metastasis varied from 20 to 24 months. Two of the four patients had postoperative radiotherapy, one patient received intraperitoneal chemotherapy, and the patient with the melanoma received adjuvant chemotherapy. The rarity of solitary spleen metastasis from solid tumors and the treatment modalities are discussed.

Adult↗
PubMed1987

Keloid scars as a result of CO2 laser for molluscum contagiosum.

Molluscum contagiosum is an infectious disease of the skin, found primarily on the thighs and genitalia. It is a sexually transmitted disease of increasing prevalence. The traditional treatment of this condition is surgical ablation, although CO2 laser has been advocated recently as an alternative mode of therapy. Six patients with molluscum contagiosum were treated by either continuous or intermittent CO2 laser. Four of the six have developed severe keloid scars. Removal of lesions by cold knife, however, was not followed by keloid scars. In the same patient, areas affected by human papillomavirus that were treated with CO2 laser did not develop keloid scars. Our results question the use of CO2 laser therapy for molluscum contagiosum.

Adult↗
PubMed1986

The effects of varying lengths and powers of CO2 laser pulses transmitted through an optical fiber on atherosclerotic plaques.

We have studied the changes induced in atherosclerotic arteries by a CO2 laser beam delivered through a silver halide optical fiber. We found that the crater depth and diameter correlate with the total energy delivered and with the mode of delivery. Short-duration high-power pulses caused shallower and narrower craters and less damage to the arterial wall compared to the same energy delivered as low-power pulses of long duration. Thus, high-power pulses for short periods may be an effective and safe procedure for evaporization of atherosclerotic plaques.

Arteriosclerosis↗