Biomedical subjects

E Raposio

Publications and source records attributed to E Raposio.

At least 19 recordsLinked to original sources

PubMed2006

Characterization and induction of human pre-adipocytes.

Human processed lipoaspirate is a source of multipotent adult stem cells that are able to differentiate between mesenchymal and neurogenic lineage. We characterized PLA cells by cytometry and then they were cultured to induce differentiation into myogenic and neurogenic lineage. Lipoaspirates were digested with collagenase to obtain the pellet, which was labelled with anti-CD44, anti-CD45, and anti-CD90. We used BD FACS Calibur flow cytometer to acquire cellular events. Some cells were cultured at 37 degrees C and 5% CO(2) in neurogenic or myogenic medium and analysed by immunocytochemistry, using Neuron specific enolase, Vimentin, Glial fibrillary acidic protein, Tau, MAP2 to confirm neurogenic differentiation, MyoD1, Myosin heavy chain, Actin smooth muscle, vimentin to confirm myogenic differentiation. The cytometry results suggest that a part of the cells are of a mesenchymal origin, among which there are progenitor endothelial cells and leucocytes. Microscopy observation already reveals neuronal morphology and longitudinal multinucleated cells compared to control cells. Neurogenic cells only express NSE (early neuronal progenitor marker), but not GFAP, Tau, MAP2 (mature neuron and glial markers); myogenic cells are positive for MyoD1 and Myosin heavy chain. This demonstrates that lipoaspirate cells are capable of differentiating in vitro over a short period of time, and could be employed in biological and clinical research, like mesenchymal adult stem cells.

Adipocytes↗

PubMed2006

Characterization of multipotent cells from human adult hair follicles.

Recent works demonstrated the presence of a multipotent epithelial cell population in the bulge region of adult human hair follicles. These cells can be cultured in vitro, thus leading to the preparation of dermal-epidermal substitutes which are applicable in the treatment of burns and ulcers. We evaluated the main marker expression in cells obtained from stripped human hair follicles. A pool of hair follicles were incubated at 37 degrees C and 5% CO(2) in a growth medium. The cells were then labelled with antibodies (anti-CD34, anti-CD38, anti-CD45, anti-CD90, anti-CD133, anti-CD146) and analysed by cytometry. We also used hair follicles for immunohistochemical studies, employing antibodies such as CD34, Actin Smooth Muscle, Filaggrin, Desmin, Vimentin, Glial Fibrillary Acidic Protein, Ki-67, PanCytokeratin, CK15, CK19. The cytometry results revealed that a part of bulge cells were CD34+ (1-2%). CD34+ population comprises both large, CD45-, CD133-, CD146- cells and small, CD45+, CD133+, CD146+ cells. Thus, a part of CD34+ cells present a mature endothelial marker (CD146). An expression of the proliferation marker Ki-67 and the stem cell marker CD34 is present in the follicle bulge region. In conclusion, we observed that the stripped hair follicle has the same multipotent cell population as adult and fetal scalp hair follicles.

Adult↗

PubMed2004

In vivo experimental testing and model identification of human scalp skin.

A comprehensive experimental/numerical procedure is formulated and validated for the in vivo characterization of the mechanical properties of human skin and the simulation of reconstructive surgery. The procedure uses in vivo experimental tests on undermined skin flaps, which can be performed during surgery, a numerical model formulated within the framework of nonlinear finite strain elasticity and a nonlinear parameter identification technique for the calibration of the model from indirect measurements. The procedure is applied to characterize the scalp skin tested in Raposio and Nordström (Skin Res. Technol. 4 (1998) 94). The skin is treated as a time independent, isotropic and hyperelastic membrane and the problem is solved through a finite element discretization. The study highlights that the model parameters can be determined with good accuracy using displacement measurements of a few points in the domain.

Biomechanical Phenomena↗

PubMed2002

[Experimental model for the evaluation of topical application of a solution to help myocutaneous flap transposition].

The aim of this article is the evaluation of the topical application of a solution of hydrogen peroxide (H2O2) 8% and dimethyl sulphoxide (DMSO) 50% in order to reduce ischaemic failure in random skin flaps. This study was performed using a rabbit model. Two parallel, cephalad-based para-midline random cutaneous flap (10 cm x 2.5 cm) were elevated and resutured in place on the dorsum of 40 New Zealand rabbits. The 80 flaps thus obtained were then randomly divided into one control group and three experimental groups of 20 flaps each. Flaps from the control group (group A) were topically treated with saline, while flaps from experimental group B were treated with H2O2 8%, flaps from experimental group C with DMSO 50%, and flaps from experimental group D with a solution of 50% DMSO + 8% H2O2. Each solution was topically applied, 20 cc per three times a day, on the flaps for seven days, starting on the immediate postoperative period. Transcutaneous oxygen tension (Ptc O2) measurements were carried out in all flaps, 72 h after flap elevation. The percentage of surviving skin area of each flap was determined by planimetry 7 days after flap elevation. The mean surviving area of the group A (control) flaps was 71%. The mean surviving area of the group B (H2O2-treated) flaps was 72%. The mean surviving area of the group C (DMSO-treated) flaps was 76%, and that of the group D (DMSO + H2O2-treated) flaps was 92%. While no statistically significant differences were found between the survival rates of both the flaps treated with H2O2 or DMSO alone and that of the control group, the mean surviving rate of the DMSO + H2O2 treated flaps (+20%) was statistically higher than that of the control flaps. Similarly, a statistically significant difference has been found between the mean Ptc O2 values of the DMSO + H2O2 flaps and those of the other three groups of flaps.

Administration, Topical↗

PubMed2002

[Computer-based preoperative planning for breast reconstruction in the woman with unilateral breast hypoplasia].

BACKGROUND: Aim of this paper is to describe a computer program which can provide objective and quantitative data useful for the selection of the proper implant in order to obtain the symmetry with the contralateral breast in case of unilateral breast reconstruction by tissue expansion, especially for the surgeon without experience or for the occasional operator. METHODS: Our C++ program provides the final implant volume using the measurements of the semi-circumference and projection of the contralateral breast performed on the supine patient. The aim is the symmetry of the two breasts. RESULTS: According to our experience in breast reconstruction by tissue expanders, this program allows non invasive and simple measurements of the breast volume, useful to obtain the mammary symmetry. CONCLUSIONS: In case of breast reconstruction by tissue expansion, the preoperative evaluation is usually based on the surgeon's experience and on empirical observations without knowing the correct volume to reach. For this reason our program is useful to know the necessary volume for breast reconstruction, and therefore it allows the surgeon to obtain a better plastic result.

Adult↗

PubMed2001

The "Nordstrom suture" to enhance scalp reductions.

The authors compared the results of 10 scalp reductions using the "Nordstrom suture" with the earlier published results of scalp reductions without a device to prevent stretch-back and of reductions with extenders. At 1 month postoperatively, the Nordstrom suture eliminated the stretch-back of 8.3 mm seen in earlier studies and, in fact, it shrank the bald area. The average shrinking achieved with the Nordstrom suture was 16.9 mm (i.e., 143 percent improvement over scalp reductions alone). Scalp extenders shrank the bald area, but the Nordstrom suture shrank the area about three times more than extenders at 1 month postoperatively.

Alopecia↗

PubMed2001

[Minimally-invasive endoscopic transthoracic sympathectomy of the upper limbs. A new method].

OBJECTIVE: Indications for endoscopic transthoracic upper dorsal sympathectomy are axillary and palmar hyperhidrosis, upper extremities ischemia (due to, e.g., Raynaud s disease), and upper extremities causalgia. METHODS: At present, this methodology relies on (at least) double trocar insertion (per side) and/or carbon dioxide insufflation. Thus, although this approach, compared with the traditional open sympathectomy techniques, it guarantees the smallest number of postoperative complications, it still determines a certain amount of postoperative discomfort as well as a risk of complications related to carbon dioxide insufflation, as intraoperative profound bradycardia and hypotension due to mediastinal shift, and postoperative subcutaneous emphysema. From December 1995, we are using a minimally-invasive endoscopic transthoracic sympathectomy technique, performed by a single-entry specifically modified thoracoscope and without the need for carbon dioxide insufflation, with the aim to reduce the drawbacks associated with the above-mentioned currently adopted endoscopic techniques. After general anesthesia with double-lumen endotracheal tube, with the patient placed in a half-sitting position with both arms abduced to 90 degrees, a 1 cm incision is performed, along the midclavear line (in male patients) or the anterior axillary line (in female patients), in the second or third intercostal space. RESULTS: The effects of sympathectomy are immediate, and the patients wake up with warm and dry hands and axillae. CONCLUSIONS: In personal opinion, this single-entry technique, compared with other reported approaches, should minimize any damage to the intercostal neurovascular bundle, while avoiding the complications connected with carbon dioxide insufflation.

Arm↗

PubMed2001

[Computer planning for postmastectomy breast reconstruction by tissue expansion].

Aim of this paper is to present a computer program able to provide objective and quantitative data useful to guarantee the selection of the proper implant in order to obtain symmetry with the contralateral breast, in case of unilateral breast reconstruction by tissue expansion, especially for surgeons without experience or for occasional operators. Our C++ program provides the final implant volume using the measurements of the semi-circumference and projection of the contralateral breast performed on the supine patient. The aim is the symmetry of the two breasts. According to personal experience in breast reconstruction by tissue expanders, this program allows non invasive and simple measurements of the breast volume, useful to obtain the mammary symmetry. In case of breast reconstruction by tissue expansion, the preoperative evaluation is usually based on the surgeon experience and on the empirical observation without knowing the correct volume to reach. Since this program is useful to know the precise necessary volume for breast reconstruction, it allows the surgeon to obtain a better plastic result.

Breast Implants↗

PubMed2001

[Computer-aided preoperative planning of tissue expansion].

OBJECT: The aim of this paper is to introduce a computer program developed to provide objective and quantitative data useful to provide proper expander selection when a rectangular tissue expander has to be used. METHODS: The program has been developed to calculate the volume of a rectangular tissue expander to obtain the exact amount of yield necessary to allow for reconstruction of a determined defect. The only data to be supplied are the length and the width of the defect to be reconstructed. RESULTS: The accuracy of the results obtained by the computer program was tested clinically comparing preoperative data with volume measurements obtained at the end of the expansion procedure. In our study the resulting data did not show any statistically significant difference (p<0,05) between the two groups. CONCLUSIONS: In our opinion, although its use is not aimed at replacing clinical judgment based on experience and careful observation, this program may be considered a simple and useful adjunct for the inexperienced surgeon (or the occasional operator) planning to use a rectangular tissue expander.

Humans↗

PubMed2000

Quantitative benefits provided by acute tissue expansion: a biomechanical study in human cadavers.

The aim of this study was to test the ex vivo biomechanical properties of acutely expanded cutaneous flaps to quantitatively assess the efficacy of intraoperative tissue expansion. A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (15 x 8 cm), proximally based flap was designed on each side of the body, in three different locations: lateral arm, anterior thorax, anterior thigh. In each cadaver, one randomly selected flap per each body region underwent acute-intermittent expansion, whereas the contralateral flap served as control. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force-transducer. The obtained data showed that the biomechanical benefits provided by acute tissue expansion were statistically different (P< 0.05) from those obtained by simple subcutaneous undermining. While no changes of length have been observed in the acutely expanded skin flaps as compared to control cutaneous flaps, a statistically significant gain in the compliance of the former has been recorded as compared to the biomechanical behaviour of the latter.

Adult↗

PubMed2000

[Intraoperative expansion of scalp flaps. Quantitative assessment].

BACKGROUND: The aim of this study was to test the ex-vivo biomechanical properties of acutely expanded scalp flaps, in order to quantitatively assess the efficacy of acute scalp expansion. METHODS: A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (4 x 10 cm), laterally-based flap was designed on each side of the scalp, starting from the superior margin of the external auditory canal. One randomly-selected flap per each scalp underwent acute-intermittent expansion (3-minute expansion-3-minute rest cycle per three times with the maximal expansion achievable), while the contralateral flap served as control. After the expansion process, the acutely-expanded flaps were measured to assess if the applied biomechanical stress have determined any changes in their dimensions. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force-transducer. RESULTS: The obtained data showed that the biomechanical benefits provided by acute scalp expansion were not statistically different (p < 0.05) from those obtained by simple subgaleal undermining. Neither any change of length nor any gain in the compliance have been observed in the acutely-expanded flaps as compared to control scalp flaps. CONCLUSIONS: In our opinion, a possible explanation (to be further validated) for the lack of effect of acute scalp expansion might be that inelastic galea aponeurotica did not allow the mechanical creep to exploit the inherent elastic properties of the overlying scalp skin.

Adult↗

PubMed1999

Serial scalp reductions: a biomechanical approach.

BACKGROUND: Several technical aspects of scalp-reduction procedures still need to be clearly elucidated: in particular, (a) the quantitative effects provided by different amounts of subgaleal undermining, (b) the immediate gains provided by increasing amount of tension when advancing a scalp flap, and (c) the eventual benefits provided by galeotomies. OBJECTIVE: The aim of the present paper is to report on some biomechanical properties of scalp flaps as related to serial scalp reduction procedures for correction of male pattern baldness. METHODS: Data were collected by stepwise loading of 20 scalp flaps, obtained by a reversed-Y scalp incision, after increasing amounts of undermining, as well as after performing three galeotomies. RESULTS: Increasing amounts of tension (while advancing a scalp flap) affect the compliance of a scalp flap in a non-linear fashion; increasing amounts of undermining permit obtaining significant, but not proportional, gains; performing galeotomies is a useful adjunct to decrease the amount of closing tension when performing scalp-reduction procedures. CONCLUSION: When performing serial scalp reductions, to take into account the biomechanics of scalp flaps may be of some utility in obtaining an optimal result.

Adult↗

PubMed1999

Scalp extension--a quantitative study.

The authors have compared the results of scalp reductions with extenders with their earlier results of scalp reductions without extenders. The extenders seem to prevent "stretch-back" and provide 30 to 86% more effectiveness when a second reduction is performed 4 weeks later.

Alopecia↗

PubMed1999

Effects of cooling micrografts in hair transplantation surgery.

BACKGROUND: When isolating hair grafts in hair transplantation procedures, it is generally recommended to preserve the grafts at a low temperature (1 degrees C- 4 degrees C) in order to enhance the survival rate of the grafted hairs. This study was carried out to test the real benefits provided by cold-storing hair grafts. OBJECTIVE: The aim of this study was to evaluate, in an in vitro model, the effects of cooling micrografts during hair transplantation procedures to experimentally assess the soundness of this approach to enhance the survival and growth rates of hair micrografts. METHODS: A total of 240 anagen hair follicles were obtained from 10 healthy male patients. Follicles were thus randomly assigned to one of the following groups: group A (control; n = 120 follicles), or group B (experimental; n = 120 follicles). Follicles from group A were preserved for 5 hours at room temperature (26 degrees C), and follicles from group B were preserved for 5 hours at 1 degrees C. Immediately after that 5-hour period, follicles from both groups were then cultured for 10 days. The length of each follicle was measured immediately following the 5-hour test period and at the end of the 10-day culture period. RESULTS: No statistically significant differences were found between the survival and growth rates of follicles from the control (survival rate = 87%, mean 10-day growth rate = 2.68 mm) and experimental (survival rate = 88%, mean 10-day growth rate = 2.54 mm) groups. CONCLUSION: Although, at present, it is generally assumed that lowering the metabolism of grafts by reducing their temperature may be of some utility for enhancing their survival rate, our data indicate of that there are no effects when performing hair transplantation surgery.

Adult↗

PubMed1999

Topical application of DMSO as an adjunct to tissue expansion for breast reconstruction.

The aim of this study was to evaluate the effectiveness of topical 60% dimethyl sulphoxide (DMSO) prior to tissue expansion for breast reconstruction in reducing expander pressure and length of treatment. Forty patients undergoing immediate breast reconstruction with tissue expanders following modified radical mastectomy were consecutively divided into two groups of 20 subjects each: group A (control) and group B (experimental). Patients from group A underwent traditional tissue expansion, while, to patients of group B, before each filling session, topical 60% DMSO was applied to the skin overlying the expander by soaking-wet surgical sponges left in place for 30 min. The average inflated volume was 395 cc (range 250-580 cc) in group A, and 410 cc (range 240-620 cc) in group B; no statistically significant difference was found between these values. A statistically significant difference was found between the expansion time of group A (mean 6 sessions; range 4-10 sessions with one filling session per week) and group B (mean 4 sessions; range 2-6 sessions with one filling session per week). A statistically significant difference was also found between the average inflated volume per session of group A (90 cc; range 60-130 cc) and group B (120 cc; range 90-160 cc). According to the data obtained by tonometry, a statistically significant difference was found between the average pre-filling and post-filling pressures of group A (28.4 and 66.5 mmHg, respectively) and group B (22.1 and 64.3 mmHg, respectively). Clinical benefits of pre-filling topical applications of 60% DMSO observed in our trial were an enhancement of the total volume inflatable per session and a significant shortening of the total expansion period.

Administration, Cutaneous↗

PubMed1999

Fetal unilateral cleft lip and palate: detection of enzymic anomalies in the amniotic fluid.

Aims of this study were to evaluate whether it is possible to determine, by means of isoelectric focusing, an enzymic differentiation in human amniotic fluid, and whether the onset of fetal cleft lip and palate is accompanied by a pathologic enzymatic differentiation pattern in amniotic fluid. From January of 1993 to June of 1996, amniotic fluid samples from 315 healthy pregnant women (ages 22 to 43 years, mean 37 years; gestational age 14 to 22 weeks, mean 17 weeks) were examined. The normality of all pregnancies was confirmed at birth. Moreover, amniotic fluid samples were examined from three pregnancies (ages 36, 35, and 30 years; gestational ages 16, 18, 24 weeks) with fetal unilateral cleft lip and palate (confirmed at birth), diagnosed by ultrasound. The authors have tested as "metabolic" markers the enzymes lactate dehydrogenase and creatine phosphokinase. For the concentration rates of both the tested enzymes, a statistically significant difference (p = 0.003) was found between amniotic fluid samples obtained from normal and affected pregnancies. These data, in the authors' opinion, corroborate the hypothesis that a local metabolic impairment is somehow involved in the pathogenesis of cleft lip and palate.

Adult↗

PubMed1999

Ineffectiveness of acute scalp expansion.

The aim of this study was to test the ex vivo biomechanical properties of acutely expanded scalp flaps to quantitatively assess the efficacy of acute scalp expansion. A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (4 x 10 cm), laterally based flap was designed on each side of the scalp, starting from the superior margin of the external auditory canal. One randomly selected flap per scalp underwent acute intermittent expansion (a 3-minute expansion/3-minute rest cycle was performed three times with the maximum expansion achievable); the contralateral flap served as a control. After the expansion process, the acutely expanded flaps were measured to assess whether applied biomechanical stress caused any changes in flap dimensions. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force transducer. The obtained data showed that the biomechanical benefits provided by acute scalp expansion were not statistically different (p < 0.05) from those obtained by simple subgaleal undermining. No change of length nor gain in compliance was observed in the acutely expanded flaps as compared with control scalp flaps. In the authors' opinion, a possible explanation (to be further validated) for the lack of effect of acute scalp expansion might be that the inelastic galea aponeurotica did not allow mechanical creep to exploit the inherent elastic properties of the overlying scalp skin.

Adult↗

PubMed1999

Two modified techniques for flexor tendon repair.

The aim of this article is to present two new techniques for digital flexor tendon repair: a modification to the conventional Kessler technique (wrap core suture) and tendon splints (H-shaped splint). These techniques were aimed at enhancing the biomechanical properties of such repairs as related to resistance to both gap formation and repair failure. Comparing (in an ex vivo study) the tensiometric properties (gap formation and failure strengths) of 24 flexor digitorum profundus tendons repaired with the described techniques (12 repairs per each technique) and the conventional Kessler repair (24 repairs), we found that the former provided significantly stronger repairs than the latter in vitro. A statistically significant difference (p < 0.001) was found between each of the two presented techniques and the Kessler repair. The wrap core suture increased the load at which a visible (1 mm) gap formed by 22.6 percent when compared with the conventional Kessler suture. The mean gap strength of the wrap core repair was 6.5 N, whereas that of the conventional Kessler was 5.3 N. The failure loads (ultimate strength) of the wrap core suture were 33.8 percent higher than those of the conventional Kessler. The mean breaking load of the wrap core repair was 19.4 N, whereas that of the conventional Kessler was 14.5 N. The H-splint repair increased the load at which a visible gap formed and the failure loads (ultimate strength) by 158.5 and 333.1 percent, respectively, when compared with the conventional Kessler suture. The mean gap strength of the H-splint repair was 13.7 N, and its mean breaking load was 62.8 N.

Biomechanical Phenomena↗