Oxidative stress response induced in rat primary hepatocyte monolayers by mechanical removal of adherent cells.

We show that mechanical separation of adherent rat primary hepatocytes after the monolayer-forming stage causes the induction of the oxidative stress genes HO-1 (haem oxygenase) and MnSOD (manganese superoxide dismutase). The procedures for enzymatically breaking up liver tissue structure and isolating hepatocytes do not cause HO-1 and MnSOD activation. Only after a 3-h incubation, during which hepatocytes form a monolayer on culture dishes, does the hydrodynamic shearing away of necrotic cells sticking to the monolayer surface activate these two genes. Analysis of this injury-response pathway shows that oxidative stress and mitochondrial dysfunction play a role, as activation can be repressed by antioxidants and by respiratory inhibitors. Recovery of the cells takes a further 24-h incubation during which HO-1 and MnSOD expression returns to basal levels.

Thyroid hormone and gene expression in the regulation of mitochondrial respiratory function.

Thyroid hormone has a profound effect on cellular respiration. Abnormally high levels of this hormone accelerate respiration in conjunction with a general increase in metabolism while pathologically low amounts cause low levels of respiration with a general slowing of metabolic activity. The affect on respiration is primarily the result of changes in the expression of respiratory genes and modulation of inner membrane structure. This review focuses on the regulation of respiratory gene expression by thyroid hormone. Respiratory genes are encoded in both the nucleus and the mitochondrion, the products of which are required in stoichiometric amounts for proper assembly of the respiratory chain. Thyroid hormone influences the expression of a number of nuclear encoded respiratory genes at the level of mRNA and enhances expression of mitochondrially encoded respiratory genes. Therefore, thyroid hormone appears to affect gene regulation in two different cell compartments. The current evidence for a direct thyroid hormone/thyroid receptor regulation of these respiratory genes and possible indirect pathway(s) mediating the thyroid effect is discussed.

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.

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.

Electromyographic activity of the biceps brachii muscles and elbow flexion during associated reactions in hemiparetic patients.

Activity of the biceps brachii muscles and movements of the elbows were studied during associated reactions in hemiparetic patients and in healthy volunteers. Onset time and increase in electromyographic (EMG) activity during associated reactions and onset of elbow flexion and its maximal magnitude were measured. Testing was performed while standing with a footswitch attached to the sole of the nonparetic foot in patients and to the sole of the right foot in controls. Lifting of that foot generated a trigger signal that served to time the dependent variables. Bilateral EMG activity associated with one foot stance appeared in the two upper extremities in both patients and controls. Elbow flexion occurred in the majority of patients bilaterally, whereas in controls it frequently took place on one side only. There was a significant difference between patients and controls in onset of EMG activity and elbow flexion. This difference indicates an earlier preparatory activity to one foot stance in the upper limbs of patients than in healthy controls. The greatest excursion into flexion was measured in the paretic upper extremity of patients; it significantly exceeded both the flexion angle measured in controls and increase in flexion angle on the nonparetic side. Further understanding of the nature of associated reactions seems to be required for their adequate treatment by physical procedures.

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.

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.

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.

Cloning and characterisation of the cytochrome c gene of Aspergillus nidulans.

The cytochrome c gene (cycA) of the filamentous fungus Aspergillus nidulans has been isolated and sequenced. The gene is present in a single copy per haploid genome and encodes a polypeptide of 112 amino acid residues. The nucleotide sequence of the A. nidulans cycA gene shows 87% identity to the DNA sequence of the Neurospora crassa cytochrome c gene, and approximately 72% identity to the sequence of the Saccharomyces cerevisiae iso-1-cytochrome c gene (CYC1). The S. cerevisiae CYC1 gene was used as a heterologous probe to isolate the homologous gene in A. nidulans. The A. nidulans cytochrome c sequence contains two small introns. One of these is highly conserved in terms of position, but the other has not been reported in any of the cytochrome c genes so far sequenced. Expression of the cycA gene is not affected by glucose repression, but has been shown to be induced approximately tenfold in the presence of oxygen and three- to fourfold under heat-shock conditions.

[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.

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.

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.

Isolation and nucleotide sequence of the 5-aminolevulinate synthase gene from Aspergillus nidulans.

The structural gene for 5-aminolevulinate (ALA) synthase has been cloned and sequenced from the filamentous fungus Aspergillus nidulans using an oligonucleotide probe based on a highly conserved-amino-acid sequence found in ALA synthase genes of a wide range of species. The cloned gene, hemA, has a 5' untranslated mRNA of 92 nucleotides (nt) and one intron (64 nt). The deduced protein sequence (648 amino acids) shows 64% identity to the yeast ALA synthase in the C-terminal region of 453 amino acids. The N-terminal region is typical of ALA synthase proteins in that the specific amino-acid sequence is not conserved but consists of a "leader" region rich in basic amino acids, believed to be involved in mitochondrial targeting, followed by a stretch of largely hydrophobic residues which may allow interaction with the inner mitochondrial membrane. Under the conditions used the transcription of hemA was unaffected by dextrose repression, heat shock, or oxygen levels.

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.

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).

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.

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.

Isolation and nucleotide sequence of the ribosomal protein S16-encoding gene from Aspergillus nidulans.

A genomic clone has been isolated from Aspergillus nidulans which is homologous to the ribosomal (r) protein S16-encoding gene of Saccharomyces cerevisiae (S16A) and the r-protein S19-encoding gene of rat (S19). The amino acid (aa) sequences, deduced from nucleotide (nt) sequence analysis, show that in both cases more than 63% of the aa are conserved. The proposed A. nidulans r-protein S16 gene (rps16) differs from that of S. cerevisiae in that it occurs as a single copy in the haploid genome (rather than two copies as in yeast) and contains two putative introns (rather than one). The mRNA leader is long compared to many Aspergillus genes, commencing 293 nt upstream from the coding region, and contains an open reading frame of 13 codons.

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.

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.