Effectiveness of Laser Photoradiation Therapy following Hematoporphyrin Derivative Administration in the Experimental MS-2 Tumor Model

The effectiveness of laser photoradiation therapy with hematoporphyrin derivative sensitization was tested in the MS-2 sarcoma. This solid tumor, transplanted into the pad of the hind leg of BALB/c mice, was found to be a sensitive experimental model for a quantitative evaluation of response to phototherapy and for determination of critical parameters in laser phototherapy treatment. Under our experimental conditions, optimal therapeutic effects appeared to be critically dependent on drug dose, number of treatments, light intensity, and irradiation of the peripheral border of the tumor.

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.

Trend of Total and District Activity in Patients Subjected to Intralymphatic Radiotherapy

The aim of this paper is to determine the dose received by every organ of patients subjected to intralymphatic radiotherapy with Lipiodol F181I. For this purpose external counting techniques have been devised for determining the effective half-life (Te). The determination of the initial concentration (Co) will be considered in a subsequent paper. Systematic checks were carried out on 9 patients with a Nukab scanner by means of sectorial counts, total body scanning and body profiles. By measuring the areas of successive profiles in the same patient, the effective half-life of the radioactive substance in the different body sections could be exactly determined. No shifting of the medium from the abdominal to the thoracic region by direct lymphatic route could be detected from the first day after lymphography until almost total decay of 131I. The trend of radioactivity accumulation in the lung was studied during injection and during the first few hours after lymphography. Some hypotheses as to the trend of activity in the various body districts and the possible metabolic routes of the medium in the body are advanced.

Laser Phototherapy following HpD Administration in Superficial Neoplastic Lesions

We report our preliminary clinical experience with hematoporphyrin derivative (HpD) injection and argon or dye laser irradiation for the treatment of 61 surface neoplastic lesions in 7 patients. Forty-three sites were multiple basal cell carcinoma in 5 patients, and the remaining 18 were cutaneous and subcutaneous recurrent breast carcinoma after mastectomy in the thoracic wall. The patients were selected on the basis of the lack of indication for conventional therapeutic modalities. The selection of irradiation procedures and laser source was based on the thickness of the lesion and extension of the disease. The photochemical reaction between HpD injected i.v. at a dose of 3 mg/kg body weight and the laser beam at a dose of 60 to 120 J/cm2 resulted in 75 % favorable responses at the treated sites. Optimal therapeutic effects appeared to be critically dependent on total light dose and tumor infiltration patterns. The phototherapeutic technique proved to be effective in selected cases of neoplastic lesions, especially when conventional treatment modalities were poorly indicated or contraindicated.

Radioactivity in the Lungs after Intralymphatic Radiotherapy with Lipiodol F 131I

A follow-up to earlier studies on the biological behavior of Lipiodol F 131I injected into lymph vessels of the foot for intralymphatic radiotherapy. A series of investigations on the trend of the activity in the lungs was conducted using various external measurements. It was found that the radioiodide accumulation was considerable and that it was eliminated more rapidly than from the lymph nodes. An explanation of the build-up of radioactivity in the lungs is suggested.

Topical Administration of Tetrasodium-Mesotetraphenyl-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 am, 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.

KRAS and BRAF mutations and MSI status in precursor lesions of colorectal cancer detected by colonoscopy

Colorectal cancer (CRC) is one of the most frequent cancers worldwide. Adenoma is the main precursor lesion and, recently, the serrated polyps were described as a group of colorectal lesions with malignant potential. The morphologic and biologic characterizations of serrated polyps remain limited. The aim of the present study was to determine the frequency of KRAS and BRAF mutations and microsatellite instability (MSI) in CRC precursor lesions, to evaluate the association between molecular, pathologic and morphologic alterations in precursor lesions and to compare with the alterations detected in CRC. A series of 342 precursor lesions were removed from 155 patients during colonoscopy. After morphologic classification, molecular analysis was performed in 103 precursor lesions, and their genetic profile compared with 47 sporadic CRCs. Adenomas were the main precursor lesions (70.2%). Among the serrated polyps, the main precursor lesion was hyperplastic polyps (HPs) (82.4%), followed by sessile serrated adenomas (12.7%) and traditional serrated adenomas (2.0%). KRAS mutations were detected in 13.6% of the precursor lesions, namely in adenomas and in HPs, but in no serrated adenoma. BRAF mutations were found in 9 (8.7%) precursor lesions, mainly associated with serrated polyps and absent in adenomas (P<0.001). High MSI (MSI-H) was absent in precursor lesions. In the 47 CCR cases, 46.8% exhibited KRAS mutation, 6.5% BRAF mutations and 10.6% MSI-H. This study confirms the role of KRAS and BRAF mutations in CRC carcinogenesis, a crucial step in implementing CRC screening strategies.

Assessment of airborne soy-hull allergen (Gly m 1) in the Port of Ancona, Italy

BACKGROUND

Epidemic asthma outbreaks are potentially a very high-risk medical situation in seaport towns where large volumes of soybean are loaded and unloaded Airborne allergen assessment plays a pivotal role in evaluating the resulting environmental pollution.

OBJECTIVE

The aim of this study was to measure the airborne Gly m 1 allergen level in the seaport of Ancona in order assess the soybean-specific allergenic risk for the city.

METHODS

Allergen and PM10 were evaluated at progressive distances from the port area. Allergen analysis was performed by monoclonal antibody-based immunoassay on the sampled filters. Daily meteorological data were obtained from the local meteorological station. For estimating the assimilative capacity of the atmosphere, an approach based on dispersive ventilation coefficient was tried.

RESULTS

The allergen concentrations detected were low (range = 0.4-171 ng/m3). A decreasing gradient of the airborne allergen from the unloading area (22.1 +/- 41.2 ng/m3) to the control area (0.6 +/- 0.7 ng/m3) was detected. The concentration of the airborne Gly m 1 was not coupled with the presence of the soy-carrying ships in the port. A statistically significant relationship between airborne allergen, PM10 and local meteorological parameters quantifies the association with the atmospheric condition.

CONCLUSION

Airborne Gly m 1 is part of the atmospheric dust of Ancona. The low level of this allergen seems consistent with the absence of asthma epidemic outbreak.

Completely isolated enteric duplications cysts: a survey of four cases

Enteric duplication cysts are uncommon congenital abnormalities with epithelial lining. They are cystic or tubular structures intimately attached to a portion of the gastrointestinal tract; they are usually located on the mesenteric site of the digestive tract sharing common blood supply. Isolated cystic duplications are an extremely rare variant with their own blood supply: in literature only five cases have been reported. We present our four cases series of this uncommon anomaly.

Exendin-4, a glucagon-like peptide 1 receptor agonist, protects cholangiocytes from apoptosis

BACKGROUND AND AIMS

Progression of chronic cholestatic disorders towards ductopenia results from the dysregulation of cholangiocyte survival, with cell death by apoptosis prevailing over compensatory proliferation. Currently, no therapy is available to sustain cholangiocyte survival in the course of those disorders. It was recently shown that cholangiocytes express the glucagon-like peptide-1 receptor (GLP-1R); its activation results in enhanced proliferative reaction to cholestasis. The GLP-1R selective agonist exendin-4 sustains pancreatic beta cell proliferation and prevents cell death by apoptosis. Exendin-4 is now employed in humans as a novel therapy for diabetes. The aim of the present study was to verify whether exendin-4 is effective in preventing cholangiocyte apoptosis.

METHODS

In vitro, tests were carried out to determine if exendin-4 is able to prevent apoptosis of cholangiocytes isolated from normal rats induced by glycochenodeoxycholic acid (GCDCA); in vivo, animals subjected to 1 week of bile duct ligation and to a single intraperitoneal injection of CCl(4) were treated with exendin-4 for 3 days.

RESULTS

Exendin-4 prevented GCDCA-induced Bax mitochondrial translocation, cytochrome c release and an increase in caspase 3 activity. Phosphatidylinositol 3-kinase, but not cAMP/protein kinase A or Ca(2+)/calmodulin-dependent protein kinase inhibitors, neutralised the effects of exendin-4. In vivo, exendin-4 administration prevented the increase in TUNEL (terminal deoxynucleotidyl transferase-mediated triphosphate end-labelling)-positive cholangiocytes and the loss of bile ducts observed in bile duct-ligated rats treated with CCl(4).

CONCLUSION

Exendin-4 prevents cholangiocyte apoptosis both in vitro and in vivo; such an effect is due to the ability of exendin-4 to counteract the activation of the mitochondrial pathway of apoptosis. These findings support the hypothesis that exendin-4 may be effective in slowing down the progression of cholangiopathies to ductopenia.

Human cholangiocarcinoma development is associated with dysregulation of opioidergic modulation of cholangiocyte growth

BACKGROUND/AIMS

Incidence of cholangiocarcinoma is increasing worldwide, yet remaining highly aggressive and with poor prognosis. The mechanisms that drive cholangiocyte transition towards malignant phenotype are obscure. Cholangiocyte benign proliferation is subjected to a self-limiting mechanism based on the autocrine release of endogenous opioid peptides. Despite the presence of both, ligands interact with delta opioid receptor (OR), but not with microOR, with the consequent inhibition of cell growth. We aimed to verify whether cholangiocarcinoma growth is associated with failure of opioidergic regulation of growth control.

METHODS

We evaluated the effects of OR selective agonists on cholangiocarcinoma cell proliferation, migration and apoptosis. Intracellular signals were also characterised.

RESULTS

Activation of microOR, but not deltaOR, increases cholangiocarcinoma cell growth. Such an effect is mediated by ERK1/2, PI3K and Ca(2+)-CamKIIalpha cascades, but not by cAMP/PKA and PKCalpha. microOR activation also enhances cholangiocarcinoma cell migration and reduces death by apoptosis. The anti-apoptotic effect of microOR was PI3K dependent.

CONCLUSIONS

Our data indicate that cholangiocarcinoma growth is associated with altered opioidergic regulation of cholangiocyte biology, thus opening new scenarios for future surveillance or early diagnostic strategies for cholangiocarcinoma.

[Intestinal intussusception: easy diagnosis in the 21st Century? Outcome of five years experiences]

Intussusception is an entity well codify in pediatric surgery, with guidelines well defined since years in terms of imaging and procedures.

MATERIAL

From January '99 to Dec. '03, 25 children were admitted to the Department of Pediatric Surgery of the Children's Hospital of Milan. All the aspects related to the pathology have been evaluated in the study.

RESULTS

25 patients have been studied. 23/25 presented severe pain, 19/25 normal bowel movements in the last 3 hours and in 9/25 a mass were detected at clinical examination.19/25 were submitted to laparotomy after failure of reduction through barium enema, and in 17/19 a manual reduction were performed. Only 2 patients required a bowel resection with primary anastomosis. The analysis of the delay of diagnosis, the delta-T between beginning of the symptoms and first medical evaluation was of 16,23 h. (3-72), and the delta-T between the first evaluation and diagnosis was 18,7 h. The interval between diagnosis and surgery was of 4,3.

CONCLUSION

Authors believe that intussusception still represent a challenge for medical and surgical emergency team, supported by the data in literature. Imaging procedures must not be constricted in case of minimal suspicions of intestinal intussusception.

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.

[Small bowel overgrowth: a frequent complication after abdominal surgery in newborns]

BACKGROUND/PURPOSE

Surgery for congenital or acquired gastroenterological disorders, and particularly that associated with short bowel, is not infrequently complicated by Small Bowel Bacterial Over growth (SBBO). Aim of this study is to evaluate the clinical course of children undergoing bowel surgery in the newborn period, assessing the development of SBBO and the response to intensive treatment with a "bowel cocktail" of gentamycin, metronidazole and cholestyramine.

METHODS

17 children with various conditions were studied clinically and by Breath Hydrogen Test (fasting and after glucose). 14 children underwent more than one procedure. All children were treated with overall "bowel cocktail" of gentamycin, metronidazole and cholestyramine.

RESULTS

5 children recovered after one course of treatment and 11 children relapsed at least once and required further courses of therapy. One child died from TPN related liver failure and another following a liver and small bowel transplant for short bowel syndrome. A third child required total intestinal tube splinting according to Sauer and another one required a tapering of the preatretic enlarged jejunal loop.

CONCLUSIONS

Our study suggests that children undergoing bowel surgery in the neonatal period and those having more than one procedure are at greater risk of developing small bowel bacterial overgrowth postoperatively. Interestingly, loss of the ileocecal valve was not associated with an increased risk of bacterial overgrowth.

[Chronic idiopathic gastric volvulus in children]

OBJECTIVE

We report clinical, radiograpic and instrumental data about 18 cases of gastric chronic idiopathic volvulus observed since 1997 to june 2000.

METHOD

All cases diagnosed by barium meal, performed for vomiting or after a pHmetric esophageal monitoring, in cases of atipical symptoms of gastroesophageal reflux disease.

RESULTS

All patients underwent a conservative treatment (antireflux position and procinectics): 5 recovered after 1 year of treatment and 13 were operated on because they did not improve during medical therapy or relapsed after the end of conservative treatment.

CONCLUSION

Abnormal position of the stomach is not an absolute indication for surgical treatment. When medical treatment does not obtain improvement in symptoms, surgical option has to be discussed.

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.

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.

[Synchronous renal carcinoma and urothelioma of the contralateral renal pelvis]

A case characterized by a rare synchronous occurrence of transitional cell carcinoma of the renal pelvis and renal cell carcinoma in the contralateral kidney is presented. The simultaneous occurrence of renal adenocarcinoma and transitional cell carcinoma of the renal pelvis in the opposite kidney is unusual.

[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.

[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.

[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.

[Duodenocolonic fistula. Report of a case and review of the literature]

Malignant duodenocolic fistula due to carcinoma of the colon is an infrequent condition. The authors describe a case treated by right hemicolectomy associated with gastrectomy and partial duodenectomy. After a review of the literature, they discuss the surgical possibilities.

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.

[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.

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.

A comparison of efficacy of photoradiation therapy and other conventional treatment modalities on experimental MS-2 sarcoma

The therapeutic efficacy of photoradiation therapy (PRT) following hematoporphyrin derivative (HpD) administration was compared in the experimental MS-2 tumour model to that of conventional treatment methods for local control of neoplastic diseases. The therapeutic effects of PRT and surgical removal of primary tumour were comparable in these experiments. However, optimal effects were critically dependent on the stage of tumour development. In addition, the therapeutic advantage of PRT over radiotherapy suggest an interesting role of a new approach in tumours resistant to this conventional treatment.

Laser oncology in Italy: experimental research and clinical applications at the National Cancer Institute, Milan

CO2, Nd:YAG, and argon lasers have been used for 5 years for experimental and clinical procedures at the National Cancer Institute of Milan under the auspices of the National Research Council. Experimental data regarding tumor cell spread through lymphatic and hematic channels and cell viability in the fumes after CO2 laser irradiation are reported. New advantages in the combined treatment modalities have been demonstrated, since the synergism between the low power argon laser beam and chemotherapeutic agents (anthracyclines) was assessed on cell cultures and the least toxic and the most effective doses of the drugs were identified. Due to the optical properties of the laser beam, physical measurements of the delivered energy and mathematical calculation of the energy per tissue volume unit to be ablated increase the precision in microsurgery especially when conservative managements are indicated. Main applications in surgical oncology, and comparison versus conventional methods, both with vaporization and excisional techniques, according to specific therapeutic protocols, in general surgery, otolaryngology, gynecology, and endoscopy, even on an outpatient basis, are finally illustrated in a series of 600 cases.

CO2 lasers: beam patterns in relation to surgical use

According to surgeons operating with a variety of CO2 lasers available at the National Cancer Institute of Milan (Coherent, Sharplan, Valfivre), these lasers have different cutting and coagulation properties. To identify what physical parameters might corroborate the subjective impression of the surgeons, a comparative study of the crater forms in perspex samples was performed. Perspex was chosen for its thermal properties (in fact, its thermal conductivity and diffusivity are similar to those of organic tissue) and because it allowed good visualization and measurement of crater characteristics. Depth of penetration, crater diameter, and extension of thermal damage were measured against power, focal length, and exposure time for each CO2 laser model. These results can be used as an index of behaviour of different surgical lasers. It appears that for fully characterizing the interaction of surgical lasers with the sample, it is necessary to specify either power, focal length, exposure time, or beam mode.

[Anatomo-pathologic and therapeutic considerations on the Papineau method]

The authors study the treatment of bone infections through Papineau's technique, and emphasize the element they consider essential in the process restoring the loss of substance: the "bouton" according to the French School. On the basis of the experience deriving from the treatment of 22 patients, they subsequently point out the importance of local antibiotic therapy and, on the contrary, the inefficacy of the administration of antibiotics by general way, at least as far as the not strictly surgical period is concerned.

[Incidence of painful pronation in pediatric traumatology]

After examining the traumatic mechanism responsible for the lesion and considering the possible pathogenetic interpretations, the Authors pass to a description of the clinical picture and the simple but effective reduction manoeuvre. The attached cases tend to emphasize the by no means negligible frequency of painful pronation among childhood traumatisms, a condition often misunderstood and a source of wrong diagnostic interpretations.