Regeneration of hypoglossal nerve axons following blockade of the axotomy-induced microglial cell reaction in the rat

The aim of the present study was to examine whether inhibition of the microglial cell reaction around axotomized motoneurons affects the subsequent regeneration process of the injured axons. The microglial cell reaction in the hypoglossal nucleus of the rat was blocked by infusion of cytosine-arabinoside (ARA-C) into the ventricular system. Axon regeneration was evaluated by determining the number and size distribution of myelinated axons at a defined level distal to the crush site, the number of neurons which could be retrogradely labelled from the distal stump as well as the number of motor endplates in the tongue at various times following injury. No significant difference was observed for any of these parameters between ARA-C-treated and untreated animals. Therefore, it is concluded that the microglial cell reaction is not necessary for peripheral nerves to regenerate and restore target contact at a normal rate and to a normal extent.

The response of central glia to peripheral nerve injury

Microglial and astroglial cells undergo prompt responses to peripheral motor and sensory axon injury. These responses include proliferation of microglial cells as well as hypertrophy and increased levels of glial fibrillary acidic protein around the axotomized motoneurons and in the central projection territories of peripherally axotomized sensory ganglion cells. Proliferating microglial cells migrate towards reacting motoneurons, however, without directly apposing their cell membrane. Astroglial cells, on the other hand, increase their structural interrelationship with reacting motoneurons, seemingly at the expense of some presynaptic terminals. In sensory projection areas, microglial cells phagocytose degenerating axons and terminals. Beyond these observations, the functional role of the central glial cell response to peripheral nerve injury is obscure.

The influence of surgically induced acute liver failure on the intestine in the rat

The influence of acute liver failure induced by 90% hepatectomy on the intestine was evaluated in the rat. Small-intestinal mucosal mass decreased 2 h after hepatectomy. Microvillous height decreased significantly from 1 h and on, and villous height and area in the distal small intestine from 2 h after operation. Ninety per cent hepatectomy resulted in a decrease in systemic arterial blood pressure and an increase in portal venous pressure. Subserosal microcirculation and small-arterial circulation in the proximal and distal small intestine and colon decreased significantly after 90% hepatectomy. Overgrowth and colonization of Escherichia coli occurred in the distal small intestine from 1 h and on after hepatectomy. Protein content in enterocytes and bile secretion from the liver remnant were markedly reduced in hepatectomized rats. Thus, the present study shows evidence of alterations in intestinal morphology and function that can contribute to explain the enteric bacterial translocation after surgically induced acute liver failure.

Isomerase and chaperone activity of prolyl isomerase in the folding of carbonic anhydrase

Several proteins have been discovered that either catalyze slow protein-folding reactions or assist folding in the cell. Prolyl isomerase, which has been shown to accelerate rate-limiting cis-trans peptidyl-proline isomerization steps in the folding pathway, can also participate in the protein-folding process as a chaperone. This function is exerted on an early folding intermediate of carbonic anhydrase, which is thereby prevented from aggregating, whereas the isomerase activity is performed later in the folding process.

Evidence for activation of the complement cascade in the hypoglossal nucleus following peripheral nerve injury

Following hypoglossal nerve transection in adult rats, immunoreactivity for complement factor C3 and one of its degradation products C3d as well as C4d and immunoglobulin G (IgG) was observed in the ipsilateral hypoglossal nucleus. Double-labelling experiments indicated that these antigens were present in perineuronally located reactive microglial cells. In addition, increased levels of complement factor C3-mRNA was found in perineuronally located cells ipsilateral to nerve lesion. These results suggest that the complement cascade is locally activated in the vicinity of axotomized neuronal perikarya and that microglial cells have a key role in this process, alternatively that C3, C3d, C4d and IgG are involved in other so far unknown processes.

The effect of axon injury on microtubule-associated protein MAP2 mRNA in the hypoglossal nucleus of the adult rat

High molecular weight microtubule-associated protein 2 (HW MAP2) is heavily concentrated in mature dendrites and may be critical for dendritic stability. Motor axon injury results in retraction of the dendritic tree which is associated with a decrease in MAP 2-like immunoreactivity (-LIR). Here we have shown with in situ hybridization that motor axon injury results in reduced expression of HW MAP2 mRNA in affected neurons. We conclude that axotomy induces a down-regulation of HW MAP2 synthesis.

Interleukin-6 response of epithelial cell lines to bacterial stimulation in vitro

This study demonstrated that epithelial cell lines secrete interleukin-6 (IL-6) in response to stimulation with gram-negative bacteria. Human epithelial cell lines of urinary tract origin (A-498 and J82) and of intestinal origin (HT-29 and Caco-2) were analyzed for the secretion of IL-6 by using the B9 bioassay. The supernatants from cells maintained with culture medium were used to assess the constitutive production of IL-6. The supernatants from cells exposed to Escherichia coli strains, lipopolysaccharide, lipid A, and isolated fimbriae were used to quantitate the IL-6 response to these stimulants. The urinary tract epithelial cell lines were found to constitutively secrete IL-6. The IL-6 activity in the supernatants of the bladder cell line (J82) increased above constitutive levels after 2 h of stimulation by most of the bacterial strains tested. The IL-6 activity in the supernatants of the kidney line (A-498) accumulated at a constant rate over the 24-h assay period. The role of bacterial adherence for the induction of IL-6 production was investigated by comparing the responses to recombinant E. coli strains expressing different fimbriae. In addition, isolated P and S fimbriae with and without the receptor binding domain were also used as stimulants. The IL-6 activity in the supernatants of the bladder cell line increased after exposure to bacteria and bacterial products regardless of their adhesive properties. In contrast, the kidney cell line was stimulated to secrete significantly more IL-6 by adhering bacteria and by adhesin-positive P fimbriae than by nonadhering bacteria or adhesin-negative P fimbriae. The S-fimbrial preparations had no specific effects on the IL-6 activity of the cell supernatants. These results are consistent with our hypothesis that epithelial cells can be a major source of IL-6 when stimulated by bacteria and that the adhesive properties of the bacteria can influence this response.

The effect of axon injury on microtubule-associated proteins MAP2, 3 and 5 in the hypoglossal nucleus of the adult rat

Microtubule-associated proteins appear to be critical elements in the stabilization of microtubules during neurite development. Axon injury results in a new burst of axonal growth activity as well as in partial dendritic involution. With this background we have examined the immunocytochemical staining pattern for microtubule-associated proteins 2, 3 and 5 in the hypoglossal nucleus of adult rats following unilateral hypoglossal nerve resection. From four days to six weeks postlesion a significant reduction in microtubule-associated protein 2-like immunoreactivity was observed in the neuropil and neuronal perikarya of the hypoglossal nucleus ipsilateral to nerve transaction. Microtubule-associated protein 5-like immunoreactivity was reduced in neuronal perikarya and neuropil four days to two weeks after injury. After six weeks microtubule-associated protein 5-like immunoreactivity had returned to normal levels. Microtubule-associated protein 3-like immunoreactivity, which was observed in glial cell perikarya and axons, but not neuronal perikarya or dendrites, appeared to be essentially unaltered. The reduced levels of microtubule-associated proteins 2 and 5 may be factors contributing to previously documented axotomy-induced dendritic retraction. The decrease in microtubule-associated protein 5 staining and absence of microtubule-associated protein 3 expression in axotomized neurons contrast with the situation in developing neurons, and demonstrate that the neuronal reaction to axon injury in mature mammals involves a specific series of events distinct from the developmental process.

Cis-trans isomerization is rate-determining in the reactivation of denatured human carbonic anhydrase II as evidenced by proline isomerase

The refolding of human carbonic anhydrase II is a sequential process. The slowest step involved is the recovery of enzymic activity (t1/2 = 9 min). Kinetic data from 'double-jump' measurements indicate that proline isomerization might be rate determining in the reactivation of the denatured enzyme. Proof of this is provided by the effect of proline isomerase on the reactivation kinetics: the presence of isomerase during reactivation lowers the half-time of the reaction to 4 min, and inhibition of proline isomerase completely abolishes this kinetic effect. A similar acceleration of the refolding process by proline isomerase is also observed for bovine carbonic anhydrase II, in contrast to what has previously been reported. In human carbonic anhydrase II there are two cis-peptidyl-Pro bonds at Pro30 and Pro202. Two asparagine single mutants (P30N and P202N) and a glycine double mutant (P30G/P202G) were constructed to investigate the role of these prolines in the rate limitation of the reactivation process. Both in the presence and absence of PPIase the P202N mutant behaved exactly like the unmutated enzyme. Thus, cis-trans isomerization of the Pro202 cis-peptidyl bond is not rate determining in the reactivation process. The mutations at position 30 led to such extensive destabilization of the protein that the refolding reaction could not be studied.

Long-term effects of glipizide on insulin secretion and blood glucose control in patients with non-insulin-dependent diabetes mellitus

Of 23 patients with non-insulin-dependent diabetes mellitus (NIDDM), whose fasting blood glucose had not reached less than or equal to 6.0 mmol.l-1 after 10 weeks of dietary regulation, 15, who had had a weight reduction of -2.8 kg by dietary control, did achieve a fasting blood glucose less than or equal to 6.0 mmol.l-1 after addition of less than or equal to 20 mg glipizide daily. They had a sustained (greater than or equal to 2 years) increase in meal-induced insulin secretion (32% increase in postprandial C-peptide AUC), and a sustained reduction in postprandial hyperglycaemia (34% reduction in AUC). Ten of the patients took a mean daily dose less than 5 mg (4.8 mg) and had a sustained increase in insulin secretion rate (increased C-peptide slope). The 15 patients had no elevation of basal insulin secretion and no impairment of weight reduction. The remaining 8 subjects, who showed little or no weight reduction on dietary control, had little or no reduction in fasting blood glucose despite long-term treatment with 20 mg glipizide daily, a less sustained increase in meal-induced insulin secretion, a smaller reduction of postprandial hyperglycaemia, and an increase in body weight. On diagnosis the 8 subjects did not differ from the other 15 subjects in age, body weight, blood glucose, HbA1c, C-peptide or insulin, nor in their glucose and insulin responses to a test dose of glipizide; the main reason for the apparent drug failure appeared to be deficient compliance with dietary regulation rather than a primary inability to respond to sulphonylurea treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

The impact response of the seated subject

An impact method for establishing the dynamic response of the seated subject is introduced. The method employs a pendulum to apply the impact to the suspended seat. Pins are placed in the spinous process at L3. Highly reproducible results are obtained. The results were not affected by the amplitude of impact, implying a linear system. A marked peak of transmissibility is found in the 4-5 Hz range and an attenuation peak is found close to 8 Hz. Both muscle contraction and postural changes affect the dynamic response. A relaxed posture shows greater gain and attenuation peaks. A valsalva stiffens the system and reduces the effective damping. The vertical response of the body probably shows in the 5-6 Hz peak, while the rotational response is probably encompassed in the 8 Hz attenuation peak.

Home service costs: the Swedish experience

This article will show that the annual cost of service and care for a receiver of home service in Sweden ranges from SEK 5,000 to SEK 435,000 according to individual disability. In our sample, the average annual cost amounts to slightly less than SEK 100,000. Furthermore, the cost of service and care for pensioners of good mental health is about SEK 50,000 higher than for the group of mentally disabled (everything else being the same). Not quite unexpectedly, the annual cost of service and care decreases when assistance from relatives increases. Without help from relatives, the annual cost increases by approximately SEK 16,000 per individual. The average annual cost is higher for home service receivers who live at home and have an alarm telephone than for those who have not got an alarm telephone (everything else being the same). Alarm telephone systems which require staff for supervision and home visits account for half of the recorded difference in cost. Both living in one's own home with handicap adjustment and living in a service flat mean a lower cost of service and care than living in one's own home without handicap adjustment (everything else being the same). For persons who are in great need of daily help, living at home implies a cost that is slightly more than 20 per cent higher than the cost for living in a service flat.

Isometric muscle strength and quantitative electromyography of back muscles in wrestlers and tennis players

The isometric motor performance of the trunk muscles was studied in 10 male wrestlers and 9 male tennis players, all of whom were elite athletes. Isometric flexion, extension, and lateral bending were performed. The motor output, including fatigue, was studied by means of a load cell and using electromyography. The wrestlers were found to have symmetrical strength and were stronger in all measured directions, especially in side bending (flexion, 852 N; extension, 951 N; right and left side bending, 759 N and 744 N, respectively), than the tennis players and normal subjects of any published study. The development of fatigue in the erector spinae muscles, as evaluated by spectral analysis of the myoelectric signal, was not symmetrical and was significant bilaterally at the lumbar level and on the right side at the thoracic level. As expected, the tennis players had asymmetrical isometric strength. They were stronger in left side bending than right side bending (643 N compared with 557 N, P less than 0.01), and stronger in extension than flexion (835 N compared with 638 N, P less than 0.01). The development of fatigue in the erector spinae muscles was significant bilaterally at the lumbar level and on the left side at the thoracic level. The development of fatigue in the tennis players was less than that of the wrestlers except for the left thoracic measurement site. Our conclusions are that tennis players appear to be relatively weak in trunk flexion. The wrestlers displayed a development of fatigue that was asymmetrical and was of nearly the same degree as the tennis players, but on the opposite side.

Treatment of asthma in pre-school children with inhalation of terbutaline in Turbuhaler compared with Nebuhaler

The aim of this study was to evaluate the efficacy, safety and preference of pre-school children with regard to two different devices for treatment of bronchial asthma with terbutaline. Turbuhaler, a powder inhaler preloaded with pure terbutaline for inhalation, was compared with a pressurized metered dose inhaler, attached to a Nebuhaler. The study had an open, cross-over randomized design. Each treatment period consisted of 2 weeks. Diary cards were filled in every morning and evening by the parents regarding PEF, asthma symptoms, extra inhalations of terbutaline, and side effects. Twenty-one children (mean age 3.9 years) were included in the study. A highly significant (P less than 0.001) increase in peak expiratory flow (PEF) was obtained after inhalation with both devices. The PEF values in the mornings after inhalation of terbutaline with Turbuhaler were significantly higher (P = 0.046) than those with Nebuhaler. Further, the PEF baseline values in the evenings before inhalation were also significantly higher (P = 0.03) with Turbuhaler. No difference was found in asthma symptoms and extra medication between the two devices. Side effects were mild and few with both devices. The parents found Turbuhaler easier to handle and 19 of 21 preferred this device for future use.

Efficacy of dietary regulation in primary health care patients with hyperglycaemia detected by screening

The efficacy of dietary regulation was examined in 38 consecutive primary health care patients with hyperglycaemia detected on screening. Ten weeks of dietary regulation reduced overall mean fasting blood glucose from 8.2 to 6.5 mmol l-1. Fasting blood glucose fell more (from 12.3 to 7.6 mmol l-1 and from 8.4 to 6.6 mmol l-1) in the two quartiles initially above the median (7.15 mmol l-1), than in the lower quartiles (6.7 to 6.1 mmol l-1 and 5.7 to 5.8 mmol l-1), even though weight reduction was similar. The reduction in blood glucose correlated (r = 0.87) with the degree of fasting hyperglycaemia before treatment. Sixteen patients (42%) reached or maintained fasting blood glucose less than or equal to 6.0 mmol l-1, and they had a milder degree of glucose intolerance, a higher insulin response to a meal and a greater reduction in weight than the 22 patients (58%) who did not reach less than or equal to 6.0 mmol l-1. Nine patients (24%) maintained fasting blood glucose less than or equal to 6.0 mmol l-1 for greater than 5 years, and showed a considerable improvement of insulin action. Dietary regulation improved glucose control mainly by reducing fasting hyperglycaemia; neither the delay in early insulin release nor the associated elevation and prolongation of the post-prandial glucose excursions were reduced.

Measurement of global and regional left ventricular performance with isotope technique in coronary heart disease

In order to evaluate the left ventricular function in coronary artery disease, radionuclide measurements of global and regional ejection fraction (EF), regional wall motion and phase analyses of the left ventricular contraction were performed by equilibrium technique. One group of patients with angina pectoris and one group with myocardial infarction were compared with a control group. All the above-mentioned parameters significantly separated the infarction group from the reference group both at rest and during work, while the group of patients with angina pectoris showed disturbances mainly during work, such as impaired ability to increase global and regional ejection fraction and regional wall motion. Adding regional analysis and phase analysis to the global EF determination increases the possibility of studying the left ventricular function. However, this addition has a limited value in detecting impaired left ventricular function compared to the determination of just global EF in patients with angina pectoris and in patients with myocardial infarction.

Effect on the rat hypoglossal nucleus of vinblastine and colchicine applied to the intact or transected hypoglossal nerve

The possibility that interruption of axonal transport in otherwise intact axons induces retrograde neuronal and nonneuronal reactions was examined. In addition, the proposal that blockade of axonal transport proximal to nerve injury might inhibit or delay the axon reaction was examined. Cuffs containing various doses of vinblastine were applied to the intact hypoglossal nerve. Colchicine was applied in a similar way to the intact hypoglossal nerve, injected directly into the intact nerve, or administered proximal to the site of hypoglossal nerve transection. The effect on retrograde axonal transport in the nerve was evaluated in the vinblastine experiments by the retrograde horseradish peroxidase (HRP) technique following injection of HRP or wheat germ agglutinin-conjugated HRP into the tongue. A dose of 0.01% caused an almost complete, but transient, blockade of the retrograde transport of the tracer, and induced a clearcut chromatolytic reaction in hypoglossal neurons. The chromatolytic changes were accompanied by a significant increase in the number of glial cells, many of which were identified as microglia. Similar results were obtained with colchicine alone or in combination with nerve transection. Signs of Wallerian degeneration after vinblastine treatment (0.01%) were observed only in a small number of myelinated fibers. The findings are compatible with the view that depletion of retrogradely transported factors from the peripheral innervation territory (including the distal nerve stump) to the perikaryon and/or a premature return of anterogradely transported substances at the site of drug exposure are factors inducing retrograde neuronal and nonneuronal changes.

Treatment of prostatic cancer by monthly injections of an LHRH-analogue depot

Thirty-six patients with advanced prostatic cancer were treated by monthly depot injections of a luteinizing-hormone releasing hormone analogue (LHRH-a). Five of these patients were also pretreated for 14 days with cyproterone acetate (CPA) in order to counteract initial increase in testosterone concentration. Two weeks after the initial depot injection the serum testosterone had been reduced to and was maintained at castrate level. Luteinizing hormone and follicle stimulating hormone were also significantly reduced. Of the 31 patients 23 showed objective regression at 3 months, 9 had stable disease and none showed progression. At 3 months 22 patients reported subjective improvement. At 12 months 18 showed objective regression, 7 had withdrawn from therapy and 6 showed progression. Side effects were acceptable and comparable to those following surgical castration. It is shown that CPA counteracts the initial increase in testosterone concentration at initiation of LHRH-a treatment. We conclude that depot preparations of LHRH-analogues, both with and without pretreatment with CPA, are useful in the treatment of patients with advanced prostatic cancer.

Exogenous GM1 ganglioside and thyrotropin-releasing hormone do not affect survival rate of spinal motorneurons and number of ventral root myelinated fibers following early postnatal sciatic nerve transection

Treatment with gangliosides or thyrotropin-releasing hormone has been shown to stimulate structural and functional recovery that follows mechanical or chemical lesions in the nervous system. We studied the possible effects of the ganglioside GM1 and thyrotropin-releasing hormone on the survival rate of spinal motorneurons after sciatic nerve transection at the age of 1 week in the rat. GM1 (30 mg/kg body weight, i.p.) was administered 24 and 1 h before and once daily for 2 weeks after transection. TRH (2 mg/kg body weight, i.p.) was administered 1 h before, at 2, 16, and 24 h, and thereafter once daily for 7 days after transection. Nine weeks postlesion, the number of motorneuron profiles labeled by retrograde transport from the proximal stump of the sciatic nerve was counted and measured using a computerized image analysis system, and the number of myelinated axons in ventral roots L4 and L5 was estimated. Compared with controls, no significant effects of GM1 or hormone treatment were observed with regard to the number, diameter, and area of motorneuron profiles and the number of ventral root myelinated axons ipsilateral to sciatic nerve injury. The results may indicate principal differences between various lesions and/or metabolic reactions following a lesion of developing and adult neurons. The present lesion model with an intense axon reaction and extensive nerve cell death does not seem to respond to administration of exogenous GM1 or thyrotropin-releasing hormone.

The response of the seated human to sinusoidal vibration and impact

Low back pain has been shown to occur more frequently among vehicle drivers than in representative control groups. Thus the response of the human to vibration and impact is of interest. This study investigated the response of the spine to both impact and sinusoidal excitation in either a relaxed or erect seated posture. The sinusoidal testing apparatus used was a resonating system consisting of two parallel wooden beams, simply supported, and the impact testing apparatus a bearing-guided, spring-suspended platform, struck from below. Ten subjects (5 males, 5 females) were evaluated using both methods. Transfer functions were compared at 2-4 Hz, 4-8 Hz and 8-16 Hz intervals using a sign test. Although in 24 comparisons of either test method (vibration or impact) or posture (erect or relaxed) where eleven showed differences significant at the p less than .05 level, only 2 out of 24 comparisons were the differences distinct enough to be significant (at the p less than .01 level). Both of these latter differences were due to test method while the subjects were sitting erect. In those instances where there were no significant differences due to test method, the impact method may be a viable replacement for the vibration test method. Where the levels of significance are higher (p less than .01 or p less than .05), further study of the magnitude of the differences is indicated and may reveal further insight into the seated individual as a system.