Search PubMed⌕ Search

Biomedical subjects

Y Ullmann

Publications and source records attributed to Y Ullmann.

At least 19 recordsLinked to original sources
PubMed2005

Electrical impedance scanning for melanoma diagnosis: a validation study.

BACKGROUND: A multicenter study was conducted to test the ability of electrical impedance scanning to differentiate between benign and malignant skin lesions. The performance of a dual electrical impedance scanning/image analysis device was also assessed. METHODS: Electrical impedance scanning measurements of 449 preoperative lesions found on 382 patients and including 53 melanomas from the trunk and extremities were performed. Results were correlated with histopathologic findings. In addition, ABCD parameters for the lesions were automatically calculated by the system. RESULTS: Electrical impedance scanning detected melanomas of the trunk and extremities with 91 percent sensitivity and 64 percent specificity. Moreover, sensitivity of electrical impedance scanning was increased to 100 percent for in situ and thin melanomas of smaller size (n = 27). Visual examination identified as malignant only 67 percent of these early tumors (p = 0.002). Clinical examination detected 96 percent of the larger or thicker melanomas (n = 26), whereas electrical impedance scanning detected only 81 percent of them. Combined electrical impedance scanning and image analysis detected 100 percent of the melanomas, independent of their thickness, and with no significant decrease of specificity. Because of electrical differences between the head/neck and the rest of the body, the assessed electrical impedance scanning parameters were not adequate for the diagnosis of melanomas from the head and neck. CONCLUSIONS: A validation study proved the value of electrical impedance scanning as a noninvasive technique for detection of melanoma lesions of the trunk and extremities, specifically, of in situ and thin type. In addition, image analysis was shown to be a valuable, complementary procedure. New parameters should be designed to optimize the performance of electrical impedance scanning for melanomas of the head and neck.

Adult↗
PubMed2004

Ageing of human epidermis: the role of apoptosis, Fas and telomerase.

BACKGROUND: Aged human epidermis is characterized by morphological changes including flattening of the dermal-epidermal junction and a decrease in thickness. OBJECTIVES: To determine the roles of proliferation, apoptosis, Fas (CD95), Fas ligand (FasL) and telomerase in changes of human epidermis during ageing. METHODS: Human epidermis from aged subjects (n = 14; mean age 70.7 years) and young subjects (n = 14; mean age 23.4 years) was studied by histology, immunohistochemistry, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling assay for apoptotic cells and reverse transcription-polymerase chain reaction to determine epidermal thickness, proliferation (Ki-67), apoptosis, expression of Fas and FasL, and telomerase activity. RESULTS: Aged skin was associated with thinning of the epidermis, decreased proliferation, and increased apoptosis below the granular layer. This was associated with increased epidermal expression of Fas and FasL. Telomerase activity was similar in aged and young epidermis. CONCLUSIONS: Fas/FasL-mediated apoptosis, along with decreased proliferation, may have a role in changes of human epidermis during ageing. Telomerase activity did not appear to be limiting in young vs. old human epidermis.

Adolescent↗
PubMed2001

The role of frozen storage in preserving adipose tissue obtained by suction-assisted lipectomy for repeated fat injection procedures.

BACKGROUND: The injection of autologous free fat obtained by suction-assisted lipectomy for the correction of soft tissue defects is a common procedure in plastic surgery. However, unpredictable partial absorption of the injected fat often necessitates repeated procedures. OBJECTIVE: To examine the role of frozen storage as a means of preserving the fat obtained by suction-assisted lipectomy for repeated procedures. METHODS: Human adipose tissue obtained by suction-assisted lipectomy was stored in a domestic refrigerator at -18 degrees C for 2 weeks. After thawing, the fat was injected into nude mice. In the control group, the fat was injected immediately after the harvesting procedure. Grafts were dissected out and compared 15 weeks postinjection. RESULTS: Injected fat survived in both study and control groups. No significant differences were found between fat graft weight and volume, or in any of the histologic parameters examined. CONCLUSION: Fat obtained by suction-assisted lipectomy may be preserved for future use by freezing.

Adipose Tissue↗
PubMed2001

Stimulated healing of recalcitrant wounds by topical application of enriched cell culture medium: a clinical report.

This study was designed to test the efficacy of enriched cell culture medium as a wound dressing. The rationale was to create within the wound space an optimal microenvironment, conducive to cellular proliferation, vascular granulation tissue formation, and epithelialization. This study was performed on various wounds that failed to respond to previous conventional treatments.A total of 288 wounds were within the inclusion criteria, with only contaminated and neoplastic wounds excluded. Most of the patients (80 percent) were ambulatory, and the wounds were examined by the attending physician once every 7 to 14 days at an outpatient clinic. The remaining 20 percent of patients were admitted to the study while hospitalized. Cell culture medium MCDB, supplemented with insulin, thyroxin, and growth hormone, was gelled. The gel was self-applied once a day to freshly washed wounds, covered with a gauze pad, and anchored with netting. Healing started 7 to 14 days after the initiation of treatment with enriched cell culture medium. However, the criterion for success of the treatment was determined on complete wound closure, which was achieved in 189 of 288 wounds (65.6 percent). Wound closure was correlated with the initial wound volume, stage, and origin. The average time required for closure of wounds caused by systemic pathologies (n = 181) and those based on regional status (n = 107) were 12.0 and 4.4 weeks, respectively, compared with 290 and 10.3 weeks of the previous conventional treatment. In 19 extensive wounds, when vascularized granulation tissue was established, a successful surgical closure was attained. Most wounds of patients who did not continue the enriched cell culture medium treatment (34.4 percent) manifested reduced wound volume, ranging from 11 to 98 percent of initial volume. Discontinuation of treatment was associated with difficulties in reaching the clinic for the weekly examination, rather than for reasons directly related to the treatment itself, and occurred significantly earlier during the treatment period.Thus, enriched cell culture medium was effective in stimulating wound healing in recalcitrant wounds. The healing was rapid with minimum scarring and pain. No side effects or allergic reactions were reported or observed.

Administration, Topical↗
PubMed2000

Using the Ilizarov external fixation device for skin expansion.

Addressing war injuries requires tailoring treatment that provides the best functional and aesthetic results within a reasonable period of time. The authors report a young soldier who sustained a gunshot injury that caused an open fracture of the proximal tibia and patella (Gustilo type B-III). A local muscle flap could not be used, and thus the authors decided to use the already applied Ilizarov device for gradual expansion of the wound edge. The expanded skin covered the exposed fracture successfully, and later enabled solid union of the fracture. This reconstructive method seems to be an original solution for the management of open fractures, and additional proof that well-vascularized skin may be equivalent to a muscle flap, and may be considered for selected patients.

Adult↗
PubMed2000

Evaluation and comparison of aesthetic results and patient satisfaction with bilateral breast reduction using the inferior pedicle and McKissock's vertical bipedicle dermal flap techniques.

In the last two decades, McKissock's technique for reduction mammaplasty was largely replaced by Robbins's inferior pedicle technique. However, a substantial number of plastic surgeons still perform McKissock's technique in the belief that it is superior to the inferior pedicle technique in terms of aesthetic results and complication rate. In this study, the authors compared the aesthetic results, complication rates, and patient satisfaction with the two techniques. Numerous studies in the past few years have shown an improvement in physical symptoms in addition to excellent patient satisfaction after breast reduction. However, almost all of these studies have used questionnaires that were mailed to the patients for evaluation. In the present study, aesthetic evaluations by the surgeon and an objective observer were performed in addition to evaluations by the patients themselves, thereby increasing the objectivity and the significance of the patients' evaluations. Two groups of 24 and 27 patients were compared. The groups were almost identical in terms of demographic data and the amount of breast tissue removed. The aesthetic results were good to excellent in both groups, and the groups had similar complication rates. When the patients' evaluations were compared with those of the surgeon and the objective observer, no significant difference was found between the observer and the patients. In one of the groups, the surgeon's evaluations were significantly higher than those of the patients, although they were not significantly higher than the observer's. In terms of aesthetic results, complication rates, and patient satisfaction, no differences existed between the groups. In addition, the patients' evaluations were determined to be a reliable index of aesthetic results and, in these cases, they were often identical to objective evaluations.

Adolescent↗
PubMed2000

The effect of hyperbaric oxygenation on the viability of human fat injected into nude mice.

Autologous free-fat injection for the correction of soft-tissue defects has become a common procedure in plastic surgery. The main shortcoming of this method for achieving permanent soft-tissue augmentation is the partial absorption of the injected fat, an occurrence that leads to the need for both overcorrection and repeated fat reinjection. Improving the oxygenation of the injected fat has been suggested as a means of helping to overcome the initial critical phase that occurs postinjection (when the fat cells are nourished by osmosis), increasing phagocyte activity, accelerating fibroblast activity and collagen formation, and enhancing angiogenesis. In addition, the hyperbaric oxygen-mediated decrement in endothelial leukocyte adhesion will decrease cytokine release, thereby reducing edema and inflammatory responses. The purpose of the present study was to examine the effect of hyperbaric oxygenation on improving the viability of injected fat. Adipose tissue obtained from human breasts by suction-assisted lipectomy was injected into the subcuticular nuchal region in nude mice. The mice were then exposed to daily hyperbaric oxygen treatments, breathing 100% oxygen at 2 atmospheres absolute (ATA) for 90 minutes. The duration of the administered hyperbaric oxygen therapy was 5, 10, or 15 days, according to the study group. Mice exposed to normobaric air alone served as the control group, and each group included 10 animals. The rats were killed 15 weeks after fat injection. The grafts were dissected out, weight and volume were measured, and histologic evaluation was performed. In all of the study groups, at least part of the injected fat survived, giving the desired clinical outcome. No significant differences could be found between the groups regarding fat weight and volume. Histopathologic examination of the dissected grafts demonstrated a significantly better integrity of the fat tissue in the group that received hyperbaric oxygen for 5 days (p = 0.047). This finding was manifested by the presence of well-organized, intact fat cells, along with a normal appearance of the fibrous septa and blood vessels. The worst results were found in animals treated by hyperbaric oxygenation for 15 consecutive days. An inverse correlation was found between an increased dose of the high-pressure oxygen and fat tissue integrity (r = -0.87, p = 0.076). The toxic effects of highly reactive oxygen species on fat cells might explain the failure of an excessively high dose of hyperbaric oxygen to provide any beneficial outcome. The clinical relevance of these results should be further investigated.

Adipose Tissue↗
PubMed1999

Improved vitality of experimental random dorsal skin flaps in rats treated with enriched cell culture medium.

A defined, serum-free cell culture medium supplemented with nonsteroidal anabolic hormones, insulin, thyroxin, and growth hormone was found to accelerate wound healing by stimulating vascularized granulation tissue formation, epithelialization, and angiogenesis. The aim of this work was to study the effect of cell culture medium on the survival rate of cephalically based random dorsal skin flaps in an animal model. A total of 77 Sprague-Dawley rats were randomized into five treatment groups: pharmacologic delay with cell culture medium, flap enhancement with cell culture medium, surgical delay, biological delay with saline, and control. Statistically significant differences in distal flap necrosis were found among all groups (p<0.003). The rats treated with cell culture medium before flap elevation showed a significant increase in flap viability: a survival rate of 83 percent, compared with the control group, which demonstrated a survival rate of only 58 percent (p<0.0001). The surgical delay and the groups treated with cell culture medium yielded similar results with no significant difference between them. This study indicates that preoperative injection of cell culture medium may play a role in decreasing skin flap necrosis.

Animals↗
PubMed1998

Autoimmune hair loss (alopecia areata) transferred by T lymphocytes to human scalp explants on SCID mice.

Alopecia areata is a tissue-restricted autoimmune disease of the hair follicle, which results in hair loss and baldness. It is often psychologically devastating. The role of T lymphocytes in this disorder was investigated with cell transfer experiments. Scalp explants from patients were transplanted to severe combined immunodeficiency (SCID) mice and injected with autologous T lymphocytes isolated from involved scalp. T lymphocytes which had been cultured with hair follicle homogenate along with antigen-presenting cells were capable of inducing the changes of alopecia areata, including hair loss and perifollicular infiltrates of T cells, along with HLA-DR and ICAM-1 expression of the follicular epithelium. Similar changes were not noted in grafts injected with scalp-derived T cells that had not been cultured with follicular homogenate. These data indicate that alopecia areata is mediated by T cells which recognize a follicular autoantigen.

Adult↗
PubMed1998

Cytokine mRNA expression in normal skin of various age populations before and after engraftment onto nude mice.

Whether the impact of skin biological age on cytokine expression is a result of this tissue's proliferation potential or not is an important issue in dermatology. We investigated these questions by monitoring cytokine marker mRNA expression from human skin samples from healthy groups of individuals. The skin samples studied represented three age groups: fetal (17-21 weeks), young (18-35 years) and aged (76-88 years). Furthermore, upon skin transplantation of tissue from different age groups onto nude mice, we investigated whether cytokine marker RNA levels would change or normalize. Interestingly, both TNF-alpha and P53 mRNA showed a similar pattern of expression. Both were significantly higher in fetal skin (p < 0.0001 and p < 0.05, respectively), and no difference was noted between aged versus young skin. In contrast to this, IL1-alpha mRNA was expressed at its lowest and highest levels in fetal and young skin, respectively. Following skin transplantation, cytokines and P53 mRNA expression were normalized to similar levels in all age groups. This study implies that when cytokine expression was determined directly at the mRNA level, post-natal expression was not significantly different at either age group. Furthermore, it seems that the environmental conditions surrounding the grafted human skin found on nude mice encouraged normalization of donor cytokine expression.

Adolescent↗
PubMed1998

Enhancing the survival of aspirated human fat injected into nude mice.

Injection of aspirated fat is now the most commonly used technique for the filling of depressed areas. Partial absorption of the injected fat is the main limitation of this procedure. Cariel T.M. is an enriched serum-free cell culture medium, its ability to enhance the survival of human aspirated fat grafts was investigated in the nude mouse model. A volume of 0.75-cc Cariel preprocessed fat was injected under the scalp skin of 16 nude mice in the experimental group, and the same volume of saline preprocessed fat was injected to 15 control group of mice. Significant maintenance of the weight, 46 percent in the experimental group compared with 29 percent in the control group (p < 0.008), and the volume, 44 percent in the experimental group compared with 31 percent in the control group (p < 0.026), was observed, after 15 weeks, in this newly used model. It seems that addition of the nutrients enriched with anabolic hormones enabled the survival and take of more adipose cells in the graft.

Adipose Tissue↗
PubMed1998

Effect of hyperbaric oxygen on a rat transverse rectus abdominis myocutaneous flap model.

The single-pedicle transverse rectus abdominis myocutaneous (TRAM) flap is frequently associated with partial flap necrosis. Hyperbaric oxygen has previously been shown to increase the survival of skin flaps, although there has been no investigation of possible beneficial effects of hyperbaric oxygen on survival of the TRAM flap. The present study compares the effectiveness of hyperbaric oxygen therapy, normobaric 100% oxygen, a hyperbaric air-equivalent mixture, and no treatment at all (control group), in the prevention of TRAM flap necrosis in a rat model. Forty-eight animals were randomly assigned to one of the four above-mentioned groups. The surviving area of the flap was evaluated 7 days after surgery. The hyperbaric oxygen treatment protocol consisted of five 9-minute sessions breathing 100% oxygen at a pressure of 2.5 atmospheres absolute during the first 48 hours, starting within 1 hour of surgery. The areas of surviving skin paddles ranged from 38.5 percent in the control group to 52.5 percent in the group treated with hyperbaric oxygen. One-way analysis of variance indicated that flap area survival was significantly greater in the hyperbaric oxygen group (F = 2.69, p = 0.05). Tukey's pairwise comparison and the two-sample t test indicated that the group treated with hyperbaric oxygen differed significantly from the control group (Tukey's critical value = 3.8, rejection level = 0.05, t test p = 0.01). Our results suggest that the hyperbaric oxygen treatment protocol used improves survival in the rat TRAM flap. However, the optimal treatment protocol to achieve this objective even in the rat seems to be variable, and further studies are required before extrapolating these data to human applications.

Animals↗
PubMed1997

Urgent delivery, the treatment of choice in term pregnant women with extended burn injury.

Two pregnant patients at term, suffering from major burn wounds, were treated in our burn unit during the year 1995, both were delivered immediately after admission by caesarean section. One of them had smoke inhalation injury which needed mechanical ventilation, both mothers and newborns survived. In spite of low maternal carboxyhaemoglobin the fetal cord blood carboxyhaemaglobin was high, supporting an objective physiological basis for the previous empirical conclusion of early delivery in pregnant patients at term with extensive burn injury (50 per cent TBSA and more). This obvious favourable outcome highlights the importance of urgent delivery in term pregnant women suffering a major burn injury.

Adult↗
PubMed1997

The surgical anatomy of the fat in the upper eyelid medial compartment.

The surgical anatomy of the upper eyelid fat in the medial compartment was investigated in 388 patients and in 12 cadavers. We found two individual fat pads comprising this compartment. The difference among the investigated cases was found to be the extent of their separation. In 16.7 percent of the cadavers' eyelids the fat pads were entirely separated, in 45.8 percent they were separated to about half their length, while in 37.5 percent only the tips were separated. Among the patients in whom only the protruded fat was inspected, 59.8 percent of the fat pads were separated, and in the rest, only the tips were isolated. On histologic examination we could always identify two well-circumscribed fat pads, each surrounded by a fibrocollagenous tissue. At the level of their interconnection, a loose fibroareolar tissue was found. In practice, during blepharoplasty, both fat pads should be addressed in order to achieve the expected results.

Adipose Tissue↗
PubMed1997

Aesthetic results and patient satisfaction with immediate breast reconstruction using tissue expansion: a follow-up study.

Immediate breast reconstruction with the tissue expander is now established as an accepted procedure after mastectomy, and large series have been published concerning the technique and its complications. Unfortunately, only scarce information is available regarding the long-term aesthetic results and patient satisfaction achieved by immediate reconstruction using tissue expansion. In this study, we reviewed 52 patients who had undergone immediate breast reconstruction using the tissue expander with a follow-up of at least 1 year after completion of the reconstruction. We developed an objective assessment of patient satisfaction, aesthetic results, and the factors affecting them. The results show remarkable concordance of assessment by patient, surgeon, and independent observer: All gave good scores for aesthetic appearance (6.4 to 7.4 on a scale of 1 to 10). A total of 92.3 percent of patients rated their satisfaction as good to excellent. Symmetry was the main parameter influencing the patients' score, while the surgeon's score also was affected by the quality of the inframammary fold and capsular contracture. Breast size, chemotherapy, complications, time interval, and additional procedures had no relation to either scoring or patient satisfaction.

Breast Neoplasms↗
PubMed1997

Favourable melanoma prognosis associated with the expression of the tumour necrosis factor receptor and the alpha1beta1 integrin: a preliminary report.

Recently we encountered a patient (p1) with a Clark's level IV melanoma associated with recurrent cutaneous metastasis who subsequently experienced a complete remission after a period of therapy with dichloronitrobenzene (DCNB) and interferon-alpha (IFNalpha). Another patient (p2) with a similar Clark's level of disease but with a fatal prognosis and melanoma cells from the Sk-Mel 28 and MeWo cell lines served as control groups. Since cytokines and members of the alpha1 integrin family have been implicated in the growth and metastatic behaviour of melanomas, we evaluated the cytokine effects and integrins expressed by melanoma cells in the patients' tumours. P1, but not p2 nor MeWo melanoma cells, expressed HLA-DR, alpha1beta1 and the tumour necrosis factor receptor (TNF-R). Culturing p1 melanoma cells with TNFalpha, but not MeWo or p2 melanoma cells, increased their expression of alpha1beta1 integrin and was cytotoxic for the cells. Significant in vivo growth of metastatic p1 and p2 melanoma explants as well as MeWo cells grafted subcutaneously onto nude mice was noted over 36 days. Intralesional injection of TNFalpha induced complete regression of p1 explants, but not of p2 or MeWo explants. Intralesional injection of IFNalpha or anti-alpha1beta1 integrin arrested p1 graft growth. These results suggest that the slow growth of the melanoma cells in nude mice, as well as the susceptibility to tumour killing by TNFalpha and the dependence of the tumour on signals mediated by the alpha1beta1 integrin are features that may have contributed to the beneficial therapeutic response in patient 1.

Aged↗
PubMed1997

T-lymphocyte dependence of psoriatic pathology in human psoriatic skin grafted to SCID mice.

Considerable indirect evidence suggests that T lymphocytes have a role in the pathogenesis of psoriasis. The goal of this study was to directly test the ability of T cells to maintain psoriasis pathology. Psoriatic skin was transplanted onto SCID mice, which were then injected with autologous T cells. T cells were cultured from either psoriatic skin lesions or peripheral blood and injected intradermally or intravenously. Control SCID mice transplanted with psoriasis grafts were not injected with T cells. After 10 wk, control psoriatic skin grafts not injected with T cells lost many of the features of psoriasis. Injection of peripheral blood T cells was not able to maintain these psoriatic features. In contrast, the injection of T cells derived from psoriatic skin was able to maintain the psoriatic phenotype. Psoriatic features that were maintained included epidermal thickness and labeling index and expression of HLA-DR, involucrin, and ICAM-1, as well as loss of expression of filaggrin. Injection of skin infiltrating T cells into skin of normal donors on SCID mice did not induce changes of psoriasis. The ability of T cells from lesional skin, but not peripheral blood, to maintain psoriasis suggests that psoriasis is mediated by an autoantigen reactive T cell, which is present at a higher frequency in the psoriatic lesion.

Adoptive Transfer↗