Biomedical subjects

T Pillar

Publications and source records attributed to T Pillar.

At least 19 recordsLinked to original sources

PubMed1996

An ultrasonic-operated kinematic measurement system for assessment of stance balance in the clinic.

This study describes the application of a kinematic measurement system based on ultrasonic technology to enable the assessment of stance balance in the clinic. The system is composed of 1-8 ultrasonic transducer markers which transmit ultrasonic waves, and three ultrasonic receivers. The spatial position of each marker is monitored by calculation of the time interval between transmission and reception of the wave. Sway data from the waist of 44 healthy subjects and 15 hemiparetic patients were collected during quiet stance. The results distinguished between data collected with and without vision, between patients and controls, and between the two sides of the body. The findings were found to be valid and reliable in repeated measurements. RELEVANCE:--Assessment of stance balance in the clinic is a requisite for quantifying disability and measuring improvement in patients with postural control deficits. Due to high costs and complexity of operation, the use of prevailing equipment for these purposes is mainly confined to research facilities. This paper describes a unique kinematic measurement system whose low price and ease of operation make it feasible for clinical use.

Journal Article↗

PubMed1996

Somatosensory evoked potentials in aphasic patients.

The purpose of this study was to employ evoked potentials to evaluate the function of the somatosensory system in a group of right hemiplegic aphasic patients in whom conventional physical examination was inapplicable. Bilateral somatosensory evoked potentials (SEPs) in response to stimulation of the median nerve were recorded in 20 patients, and unilateral recordings were performed with 20 healthy, aged, matched controls. The major abnormality, present in 13 patients, was absence or reduction of the amplitude of the cortical components N19 and P22 in the lesioned side of the brain. Consequently, the only significant difference between the lesioned versus nonlesioned brain side in patients, and between patients and control subjects was in the amplitude of the cortical components. Since a strong correlation exists between the detected abnormality and impaired somatosensory function, it is concluded that it is highly probable that many aphasic patients suffer somatosensory deficits which, being difficult to assess, are overlooked by the medical personnel.

Aged↗

PubMed1995

Effect of donor age on response of skin grafts to gamma-interferon.

BACKGROUND: Failure of aged human epidermis to induce HLA-DR antigens after intradermal administration of gamma-interferon (IFN-gamma) has recently been observed. OBJECTIVE: The purpose of the study was to find out whether this observation reflects an intrinsic impairment in the aged skin or is rather due to an environmental factor. METHODS: Aged and young human skin grafted onto nude mice were injected with IFN-gamma, and the induction of HLA-DR, intercellular adhesion molecule-1 (ICAM-1) and Langerhans cell (LC) migration patterns were studied. RESULTS: Increased surface expression of both HLA-DR and ICAM-1 molecules by epidermal cells was observed in all grafts, after IFN-gamma injections, whereas a decrease in LC was found only in the young grafts. CONCLUSION: This study may indicate that the lack of response of aged skin to IFN-gamma is due to both intrinsic impairment in epidermal cell function and changes in function of cells outside the epidermis such as lymphocytes and endothelial cells.

Adult↗

PubMed1995

Possible role of cytokines in cellular proliferation of the skin transplanted onto nude mice.

BACKGROUND AND DESIGN: In recent studies on the behavior of aged skin transplanted onto nude mice, the epidermis of aged and young skin showed an increase in proliferation and thickness following engraftment, and became almost identical. The aim of this study was to ascertain a possible role for the release of local cytokines in this phenomenon. Grafted human skin was injected intradermally with anti-interleukin-6 (IL) and anti-IL-1 alpha, and comparisons of epidermal thymidine incorporation and thickness were made. Grafts injected with irrelevant antibodies served as control. RESULTS: Interleukin-6 and IL-1 alpha expression were studied in grafts by immunoperoxidase staining. Only IL-6 expression was found in the 1-month grafts. Intradermal injections of anti-IL-1 alpha and anti-IL-6 showed an inhibitory effect on cellular proliferation in the epidermis. A significant difference in the response of epidermal proliferation and, consequently, in thickness was found in samples injected with anti-IL-1 alpha and anti-IL-6 compared with those injected with irrelevant antibodies. CONCLUSIONS: These data may indicate that local cytokines released by the keratinocytes are involved in the cellular proliferative activity in skin engrafted onto the mice.

Aged↗

PubMed1994

Effect of antiinsulin-like growth factor 1 on epidermal proliferation of human skin transplanted onto nude mice treated with growth hormone.

Recently it has been demonstrated that long-term administration of GH leads to increase of skin thickness. The aim of the present study was to determine whether this effect of GH is mediated by insulin growth factor 1 (IGF-1), which enhances epidermal proliferation. In order to address this question, human split-thickness grafts obtained from aged skin were grafted onto nude mice. One group of mice was treated systemically with GH, whereas a second group was treated with intradermal graft injections of anti-IGF-1 in addition to GH. A third group received distilled water and served as a control group. Histological and autoradiographic analyses were performed before and after engraftment. The GH-treated mice showed a significant increase in epidermal proliferation measured by epidermal thickness (analysis of variance with repeated measurements, P < 0.01) and labeled index (analysis of variance, P < 0.01) as compared to the control group. The intradermal injections of anti-IGF-1 reduced significantly the proliferative stimulatory effect of GH (P < 0.01). The present study emphasizes the role of IGF-1 in the increased skin thickness observed after GH administration and provides a useful model for determining the effect of various compounds, including GH, on human skin.

Aged↗

PubMed1993

[Survival and mortality in amputees with dysvascular lower limbs].

Survival and mortality in 248 cases of lower limb amputation for vascular disease, after prosthetic rehabilitation, were assessed. Mean survival time was 3.5 years, with survival in women less than in men. Survival was shorter in those with peripheral vascular disease as compared to diabetics, and also shorter in above-knee than below-knee amputations.

Aged↗

PubMed1993

Reaction and movement times in patients with hemiparesis for unilateral and bilateral elbow flexion.

BACKGROUND AND PURPOSE: This work was designed to study the effects of bilateral elbow flexion on the reaction and movement times of the impaired upper extremity of patients with hemiparesis. SUBJECTS: The subjects consisted of an experimental group of patients with hemiparesis (n = 25) and a control group of age-matched healthy volunteers (n = 26). METHODS: Each subject performed three sets of 16 elbow flexion trials. Two of these sets required unilateral movements, one for each upper extremity. The third set of movements required simultaneous elbow flexions of both upper extremities. In each trial, subjects were instructed to flex their elbows in response to an auditory signal from a supported initial position of 150 degrees through a goal orientation of 120 degrees. "Reaction time" was defined as the time between the auditory signal and movement initiation. "Movement time" was defined as the time between movement initiation and the completion of 30 degrees of elbow flexion. RESULTS: When subjects were asked to bilaterally flex their elbows, the reaction and movement times increased in both extremities. CONCLUSION AND DISCUSSION: It was speculated that in patients with hemiparesis, movement time of the nonparetic extremity in the bilateral task is limited by the rate of performance of the paretic extremity. The decrease in speed of these performance-determining variables in the bilateral task warrants consideration during physical therapy intervention for patients with hemiparesis.

Aged↗

PubMed1993

The role of cyclosporine on Ia antigen expression on gut epithelium in nude mice.

Increased expression of class II antigens (HLA-DR, human:Ia murine) on epithelial cells (EC) such as keratinocytes and gut EC suggests a role of the epithelium in the inflammatory response. It has been shown that injection of normal mouse serum (NMS) into nude mice caused an induction of Ia antigen by keratinocytes of the nude mice. The aim of the present study was to determine whether such induction could be observed in gut EC and whether it can be inhibited by cyclosporine A (CyA). Forty nude mice were divided into 4 groups of 10 each, designated A-D. Group A was injected with 0.1 ml of NMS; groups B and C were also injected with NMS and treated with oral CyA for 10 days. The dosage in group B was 30 g/ml and in group C 60 g/ml of drinking water. Group D was injected with serum of nude mice and served as a control group. Biopsies of small intestine and colon were obtained from each mouse and analyzed by indirect immunoperoxidase to identify Ia expression. Small intestine and colon EC were induced to express Ia antigen in most of the mice in groups A and B. A striking reduction in Ia expression was noted in group C. The differences between groups A and C concerning Ia expression on small intestine and colon EC were statistically significant. Our results demonstrate that the nude mouse may serve as a model for the study of Ia expression on gut EC, and that CyA can suppress the expression of Ia antigen also in the gut.

Animals↗

PubMed1992

Self-propelled weight-relieving walker for gait rehabilitation.

This paper describes a novel walking aid, the weight relieving walker (WRW), which partially relieves the body weight of an ambulating patient. The device incorporates a pneumatic weight relief mechanism, a restraint mechanism and a forward propulsion mechanism. Weight relief facilitates stance on an affected lower limb as well as the swing of that same limb. Restraint of the patient by the walker adds to trunk stability thereby facilitating walking movements of the lower extremities. A motorized, self-propelled walker neutralizes the effect of the walker's own weight on patient's locomotion. Additionally, it contributes to step symmetry. Data gathered from 26 patients with severe locomotion problems, point to a substantial contribution of the device to ambulation.

Adult↗

PubMed1992

Response of aged versus young skin to intradermal administration of interferon gamma.

BACKGROUND: Interferon gamma (IFN-gamma) induces the interaction of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen type 1 expression, and of HLA-DR antigens by keratinocytes. OBJECTIVE: The aim of the present study was to determine the potential ability of aged versus young skin to respond to intradermal administration of IFN-gamma, as an in vivo immunologic stimulus. METHODS: For 3 consecutive days elderly and young volunteers were injected with 10 micrograms of recombinant IFN-gamma diluted in 0.1 ml of sterile water. On day 5, punch biopsy specimens were obtained from the injected sites. Histologic and immunohistochemical stainings were performed on all sections. RESULTS: ICAM-1 was expressed by keratinocytes in both aged and young skin. An impairment was manifested mainly by the reduced accumulation of mononuclear cells throughout the dermis, the absence of HLA-DR expression by keratinocytes in 7 of 10 elderly volunteers, and the absence of an effect on the Langerhans cell population. CONCLUSION: This observation shows a diminished immune response in aged skin.

Adult↗

PubMed1992

Failure of passive transfer of serum from patients with alopecia areata and alopecia universalis to inhibit hair growth in transplants of human scalp skin grafted on to nude mice.

We have previously demonstrated regrowth of hair in scalp skin grafts taken from patients with alopecia areata (AA) and alopecia universalis (AU) following engraftment on to nude mice. This present study was to determine whether serum from patients with AA and AU, has a role in the process of hair loss and the role of antibodies and complement. Forty mice were grafted with transplants obtained from seven patients. One group of the grafted mice was given patients' serum and another group normal serum. The mice were treated topically with cyclosporin (CyA), or olive oil. Hair growth was noted in most grafts and intravenous injections of serum did not prevent or inhibit this process. Immunofluorescence studies before grafting showed deposition of immunoglobulins and complement in hair follicles in both normal and affected scalp skin, but a more striking deposition was noted in the affected skin. Deposition of immunoreactants after grafting was observed only after the injection of serum from the patients but not with normal serum. Thus the sera from patients with AA or AU, when injected into nude mice with hair transplants from the scalp skin of patients with these disorders, does not alter the hair growth despite deposition of immunoreactants around the hair follicles.

Alopecia↗

PubMed1992

Evaluation of the degree of effectiveness of biobeam low level narrow band light on the treatment of skin ulcers and delayed postoperative wound healing.

Twenty-one patients with 31 postoperative delayed open wounds resistant to conventional therapy were randomly allocated to three groups. Group 1 was treated with red low level narrow band (LLNB) light (660 nm); group 2 was treated with infrared LLNB light (940 nm); and group 3 was treated with a placebo such as the Biobeam machine (no light irradiation). Group 1 showed a significant improvement compared to groups 2 and 3 (t-test).

Aged↗

PubMed1991

Effect of cyclosporine A on the regulation of Ia antigen keratinocytes expression.

Since many skin diseases characterized by positive Ia keratinocytes show improvement with cyclosporine therapy, the purpose of this study was to determine whether cyclosporine A (CyA) alters the expression of Ia keratinocytes. Nude mice were injected with normal mouse serum (NMS) to induce keratinocyte expression of the Ia antigen. The injected mice were then divided into four groups: one was treated with oral CyA; the second was treated topically with CyA twice a day; the third was treated topically with olive oil; and the fourth was injected with nude mouse serum. The third and fourth groups served as Ia positive and Ia negative controls, respectively. The mice were treated during the first 10 days after the injections. On Day 10, epidermal sheets were analyzed for Ia expression. Analysis was made by an indirect immunoperoxidase staining method using monoclonal antibodies specific for Ia determinants. Quantitation of the number of Langerhans cells was analyzed on epidermal sheets using immunodiagnostic reagents, anti-MHC-Ia, and surface ectoenzyme, ATPase. A significant reduction of Ia-positive keratinocytes was noted in the oral CyA group vs topical and olive oil groups (64.9 +/- 29.9% vs 20.1 +/- 18.7%, respectively, P less than 0.01). In a second set of experiments mice were injected with NMS, but treatment was started only on Day 10 after injections, for 10 days. The results showed that CyA failed to down-regulate Ia expression. Topical and systemic CyA did not modify Langerhans cell population. The present study showed that systemic administration of CyA significantly reduced Ia induction by keratinocytes of nude mice that were injected with NMS.

Animals↗

PubMed1991

Melanocytes and Langerhans cells in aged versus young skin before and after transplantation onto nude mice.

Previous studies have demonstrated decreased numbers of melanocytes and Langerhans cells (LC) in aged skin. In the present study, we employed dopa and indirect immunoperoxidase techniques in epidermal sheets to determine the fate of melanocytes and LC of aged versus young donors after skin transplantations onto nude mice. The detection of positive homologous leucocytic antibody reaction of degeneration (HLA-DR) of LC indicates an age-associated reduction in sun-protected thigh skin in aged versus young subjects (263 +/- 63 versus 589.25 +/- 142.643, p less than 0.001). The mean number of LC four weeks after transplantation remained almost constant. Prior to skin engraftment, a decreased number of melanocytes was found in aged versus young epidermis (160.77 +/- 51.7 versus 255.83 +/- 81.2, respectively, p less than 0.05). A significantly increased number of melanocytes was noted four weeks following engraftment in epidermis from aged (307.44 +/- 174, p less than 0.05) and young human donors (402.16 +/- 139, p less than 0.02). The marked increase in density of dopa-positive melanocytes following engraftment onto nude mice may indicate the existence of circulating factors in nude mice that perhaps both stimulates and enhances proliferation and activity of these cells.

Adult↗

PubMed1991

Aged versus young skin before and after transplantation onto nude mice.

The behaviour of aged skin transplanted onto nude mice was investigated to determine whether the skin maintains its histological features. Split-thickness skin grafts obtained from the unexposed skin on the thighs of healthy aged and young volunteers were grafted onto nude mice. A significant difference between the mean thickness of young versus aged epidermis was noted before transplantation (P less than 0.001). The epidermis of aged and young skin showed an increase in thickness following engraftment with a mean increase in epidermal thickness of 18.8% in the young (P less than 0.01) and 142.5% in aged skin (P less than 0.001). The number of blood vessels in the aged skin was significantly lower than in the young skin, but a remarkable increase was found post-transplantation. These findings indicate that part of the typical histological changes of unexposed aged skin are reversible.

Adult↗

PubMed1991

Sleep-wake cycles in multi-infarct dementia and dementia of the Alzheimer type.

We monitored by actigraphs minute-by-minute activity of 10 patients with multi-infarct dementia (MID), 15 patients with dementia of the Alzheimer type (DAT), and 11 control volunteers for eight consecutive 24-hour periods to assess sleep-wake cycles and sleep quality. MID patients had disrupted sleep-wake cycles associated with decreased sleep quality. In contrast, ambulatory DAT patients maintained a relatively normal sleep-wake cycle that did not differ significantly from controls. There was no correlation between the severity of intellectual deterioration and the degree of sleep-wake cycle disintegration in either group of dementia patients.

Aged↗

PubMed1991

Walking reeducation with partial relief of body weight in rehabilitation of patients with locomotor disabilities.

This study was undertaken to investigate the contribution of a weight-relieving system on the gait of patients with severe locomotor disabilities. Temporal parameters of gait and subjective evaluations of the effect of the system were studied in 24 patients and 6 healthy subjects. Partial weight relief was accomplished through a pneumatic system mounted in the ceiling over a conductive walkway which was placed between parallel bars. Subjects were tested in three walking trials: free walking, walking while harnessed to the system but without weight relief, and walking with relief of 20 percent of their body weight. Temporal measurements indicated a positive effect of the system on duration of the stance and swing phases. The percentage of the stance period of the involved lower limb relative to the uninvolved one increased by 148 percent; at the same time, the swing period of the involved limb relative to the sound one decreased to 68 percent of that value in free ambulation. A substantial increase in gait symmetry and velocity were also noted. Subjective information from the patients and observers also pointed to a facilitative effect of the system on the patients' ambulation. Conversely, natural gait velocity of the healthy subjects was impeded by weight relief through the system.

Adult↗

PubMed1990

Topical cyclosporine in male pattern alopecia.

We previously demonstrated a systemic and topical effect of cyclosporine on hair growth in an experimental model composed of human scalp skin transplanted onto nude mice. The aim of this study was to determine whether topical cyclosporine affects male pattern alopecia. For 4 months in a double-blind study, 10 subjects were treated with cyclosporine and three were treated with olive oil. Hair growth was evaluated by photographs and hair counts. Significant hair growth was observed in two of the eight patients who completed the study. In one the hair growth was cosmetically satisfactory. No systemic or cutaneous side effects were noted.

Administration, Topical↗