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Biomedical subjects

R Carminati

Publications and source records attributed to R Carminati.

At least 19 recordsLinked to original sources

Coherent thermal antenna using a photonic crystal slab.

We show that a photonic crystal film can emit coherent thermal radiation. We demonstrate the key role of leaky waves existing at the air-photonic crystal interface. The frequency and direction of emission depend on the lattice parameters. This paves the way towards the design of coherent infrared antennas.

Journal Article↗

Highly directional radiation generated by a tungsten thermal source.

We report the design of a tungsten thermal source with extraordinarily high directivity in the near infrared, comparable to the directivity of a CO2 laser. This high directivity is the signature of the long-range correlation of the electromagnetic field in the source plane. This phenomenon is due to the resonant thermal excitation of surface-plasmon polaritons.

Journal Article↗

In vitro IFN-gamma production by goat blood cells after stimulation with somatic and secreted Corynebacterium pseudotuberculosis antigens.

Corynebacterium pseudotuberculosis is the causal agent of caseous lymphadenitis, a chronic illness that attacks goats and sheep characterized by pyogranulomas formation in lymph nodes and organs. Regarding the current knowledge of the pathogenesis of the caseous lymphadenitis, there is evidence that besides the humoral response the induction of a durable cellular response is fundamental for its control. In this sense, research on antigens of C. pseudotuberculosis that are capable to inducing cellular immunity is an important step for the development of diagnosis tests and more efficient vaccines. In the present study, the interferon-gamma production in cultures of whole blood from infected goats stimulated with secreted bacterial antigen or somatic antigen were used to evaluate the cellular response. The results demonstrated a significant difference in the ability of the two antigens to induce a cellular response. That is, IFN-gamma production was high with cells from infected animals in response to the secreted antigen while IFN-gamma production was low when somatic antigen was used. The concomitant use of these antigens with PWM also showed differences. That is, the secreted antigen increased the IFN-gamma production induced by PWM, while the somatic antigen seems not to have altered the response to PWM.

Animals↗

Beyond the diffusing-wave spectroscopy model for the temporal fluctuations of scattered light.

We extend the theory of diffusing-wave spectroscopy using a random-walk approach and a numerical solution of the radiative transfer equation. The theory is not restricted to the diffusive regime and allows one to describe the crossover between the single-scattering and the diffusive regimes, which has been observed experimentally. It also predicts a lower bound of the scattered-field correlation time at long paths. This extended theory should have broad experimental applications in the field of imaging through biological tissues.

Journal Article↗

Three-phase partitioning as an efficient method for extraction/concentration of immunoreactive excreted-secreted proteins of Corynebacterium pseudotuberculosis.

The three-phase partitioning (TPP) technique was used upstream to isolate/concentrate secreted proteins from Corynebacterium pseudotuberculosis cultured in a complex liquid medium. Several parameters of the TPP technique (15, 30, or 60% ammonium sulfate concentration; 4.0, 5.5, or 7.0 pH; and primary (n) or tertiary (t)-butanol solvent isomer) were varied to determine the optimal recovery of serologically and cellularly immunoreactive extracted proteins. A TPP extraction made with 30% ammonium sulfate and an initial pH of 4.0 gave the best humoral and cellular immunoreactivity of caseous lymphadenitis infected goats. In particular, two immunogenic secreted (16 and 125 kDa) proteins, which had not been found by other extraction methods, were identified.

Ammonium Sulfate↗

Experimental Corynebacterium pseudotuberculosis primary infection in goats: kinetics of IgG and interferon-gamma production, IgG avidity and antigen recognition by Western blotting.

Corynebacterium pseudotuberculosis is the cause of caseous lymphadenitis (CLA) in small ruminants, a chronic granulomatous disease that provokes significant zootechnics losses to ovine and goat breeders in northern Brazil. The present work was conducted to analyse aspects of humoral and cellular immune responses after experimental infection. Eight goats were infected intradermally with a single dose of virulent C. pseudotuberculosis strain and specific IgG, interferon-gamma (IFN-gamma) production as well as IgG avidity and antigens pattern recognition dynamics against an excreted-secreted antigen were recorded during 20 weeks. At the end of the follow-up, animals were slaughtered and necropsied. Although no animals showed apparent clinical signs of infection at the end of the trial, IFN-gamma response, even more so than the humoral response, differentiated animals into two groups of high or medium/low response. The time-course of IFN-gamma production presented a short-lived primary response on day 5 after infection of animals of both groups, and a strong and long lasting secondary response starting on day 16 after infection in the high response group. The indirect ELISA used was able to detect a positive antibody titre between 6 and 11 days after infection in the two groups. IgG avidity index oscillated initially between 15 and 45%, and showed approximately 5% units increment during the 20 follow-up weeks. With only one individual exception, the qualitative antigens pattern recognition showed on day 11 after infection remained constant through the experiment. IgG avidity is highly correlated with IgG production, but could not be related with specific immunodominant bands. Both humoral and cellular responses kinetics presented a similar pattern of activation/deactivation but necropsy results suggested that the IFN-gamma test would be a very specific marker of CLA status.

Animals↗

Systematic pelvic and aortic lymphadenectomy in elderly gynecologic oncologic patients.

BACKGROUND: Retroperitoneal lymph node dissection is a fundamental step in the surgical management of patients with pelvic gynecologic malignancies, but its applicability to geriatric patients is controversial. The objective of this study was to evaluate whether pelvic and aortic lymphadenectomy in elderly patients with gynecologic malignancies can be a safe procedure in terms of morbidity and mortality. METHODS: In a retrospective case-control study, the authors compared morbidity, mortality, and surgical data in a series of elderly patients (age > 70 years) with endometrial and ovarian carcinoma who underwent surgery. Patients were divided into two groups: Cases were 36 elderly patients who underwent surgery and pelvic and/or aortic lymphadenectomy and were matched with 72 controls, who were patients who underwent surgery without lymphadenectomy. RESULTS: Cases showed a significantly longer median operative time than controls (median, 162 minutes [range, 85-330 minutes] vs. median, 100 minutes [range 20-310 minutes], respectively; P = 0.003). No significant difference between the two groups in terms of blood loss, blood transfusions, intraoperative complications, duration of ileus, reintervention required, or postoperative hospital stay were observed. One patient in the control group died. The type and frequency of severe postoperative complications in the two groups were not substantially different. CONCLUSIONS: Pelvic and aortic lymphadenectomy was performed safely in elderly patients age > or = 70 years with endometrial and ovarian carcinoma without an increase in morbidity and mortality. Advanced chronologic age alone should not be considered a contraindication to full surgical treatment in these patients.

Age Factors↗

Kirchhoff approximation for diffusive waves.

Quantitative measurements of diffuse media, in spectroscopic or imaging mode, rely on the generation of appropriate forward solutions, independently of the inversion scheme employed. For complex boundaries, the use of numerical methods is generally preferred due to implementation simplicity, but usually results in great computational needs, especially in three dimensions. Analytical expressions are available, but are limited to simple geometries such as a diffusive slab, a sphere or a cylinder. An analytical approximation, the Kirchhoff approximation, also called the tangent-plane method is presented for the case of diffuse light. Using this approximation, analytical solutions of the diffusion equation for arbitrary boundaries and volumes can be derived. Also, computation time is minimized since no matrix inversion is involved. The accuracy of this approximation is evaluated on comparison with results from a rigorous numerical technique calculated for an arbitrary geometry. Performance of the approximation as a function of the optical properties and the size of the medium is examined and it is demonstrated that the computation time of the direct scattering model is reduced at least by two orders of magnitude.

Journal Article↗

Near-field spectral effects due to electromagnetic surface excitations

We demonstrate theoretically that the spectra of electromagnetic emission of surface systems can display remarkable differences in the near and the far zones. The spectral changes occur due to the loss of evanescent modes and are especially pronounced for systems which support surface waves.

Journal Article↗

Scattering theory of Bardeen's formalism for tunneling: new approach to near-field microscopy

We propose a new theoretical approach to near-field microscopy, which allows one to deal with scanning tunneling microscopy and scanning near-field optical microscopy with a unified formalism. Under the approximation of weak tip-sample coupling, we show that Bardeen's perturbation formula, originally derived for electron tunneling, can be derived from a scattering formalism which extends its validity to electromagnetic vector fields. This result should find broad applications in near-field imaging and spectroscopy.

Journal Article↗

[The coronal approach in maxillofacial surgery. Notes on the surgical anatomy].

INTRODUCTION: In the light of personal experience and of the modern advances in surgical anatomy, the surgical approach and practice in coronal access is described. For a long time this approach has been considered unusual owing to the risk of damaging the frontal branch of the facial nerve. ANATOMY: The SMAS includes the galea capitis which in temporal region is named superficial temporal fascia; under the galea there are the subaponeurotic avascular plane by Merkel and the periosteum. In the temporal space the periosteum (named temporal fascia) is composed of the superficial fold and deep fold. The frontal branch of the facial nerve lies under the superficial temporal fascia, and where it crosses the zygomatic arch is separated only by the superficial fold of the temporal fascia and by areolar tissue. SURGICAL APPROACH: The incision is made deeply to the subaponeurotic areolar tissue following, about 4 cm posterior to the hairline. The periosteum is incised at 2 cm above the superior orbital margin. Four cm above the bony lateral canthus and at 7 cm on the tangential to the zygomatic arch, the incision is made deeply to the superficial fold of the temporal fascia and the interfascial vascular fat. CONCLUSIONS: If the approach is correct, the coronal access is considered an easy and very safe way. In personal experience important complications have not been observed, while the esthetic results have been remarkable and with no visible scars.

Face↗

A combined technique for correction of the prominent ear.

PURPOSE: The literature illustrates a large number of different techniques for the correction of the prominent ear, and the great variety available is indicative of how difficult it is to achieve satisfactory results in all cases. This report describes a procedure for successfully treating such patients. PATIENTS AND METHODS: Forty patients were treated with a surgical procedure creating a new anthelical plica based on the Stenström and Mustardé method and producing an anatomic cavity in the mastoid region where the concha can be repositioned according to the Furnas method. The tension of the "cartilage spring," which is a likely cause of relapse, was relieved by dissecting a triangular portion of cartilage from the root of the inferior crus. RESULTS: No major complications were observed with this technique and a good esthetic result was achieved in all cases. CONCLUSIONS: This surgical technique is suitable for correction of all cases of prominent ear.

Adolescent↗

[Myositis ossificans of the pterygoid and temporal muscles with metachronous contralateral involvement].

After reviewing the literature, the authors report a case of myositis ossificans of the right pterygoid and temporalis muscles in a patient undergoing surgery to remove the left medial pterygoid muscle owing to the same pathology. The metachronous localisation in contralateral masticatory muscles compared to the primary site leads the authors to emphasize the post-traumatic and iatrogenic etiology of this rare pathology. In the light of their experience, they underline the importance of a precise diagnosis and surgical exeresis, followed by cautious rehabilitation with the least trauma, if necessary backed by appropriate medical treatment.

Adult↗

Laparoscopically assisted vaginal removal of ovarian dermoid cysts.

Dermoid cysts were diagnosed by transvaginal sonography in 19 patients who subsequently underwent laparoscopy to confirm the nature and extent of the lesion and the mobility of the adnexa. Eighteen patients underwent surgery after the ovary was exteriorized through a posterior colpoceliotomy. No intraoperative complications were observed, and sonographic follow-up at 3 and 6 months after surgery showed a normal sonographic ovarian pattern. Laparoscopically assisted vaginal removal of dermoid cysts should be considered as an alternative to laparotomy and operative laparoscopy in cases when adnexal mobility is proven and vaginal extraction is feasible.

Adult↗