Evaluation of a newly developed first aid training programme adapted for older people.

BACKGROUND: Older people need to acquire knowledge and skills at first aid (FA) training tailored to them. Our research aimed to evaluate an FA training programme adapted for older people. We assumed that satisfaction with FA training, as well as knowledge of FA, would be higher among older people who received training according to an adapted programme compared to those who received training according to the existing programme for the general public. METHODS: We trained older people according to the existing FA programme for the general public and according to a new FA training programme adapted for older people. The new training program is shorter and focuses on FA contents that are more relevant for older people. We evaluated participants with a general assessment questionnaire (consisting of items regarding satisfaction, comprehensibility, length, and physical difficulty), a test on theoretical FA knowledge, and a test on practical cardiopulmonary resuscitation (CPR) knowledge. To ensure the homogeneity of the groups and to verify the impact on the results of the test of practical CPR knowledge, we also tested the participants regarding their psychophysical capabilities. RESULTS: A total of 120 people completed the free FA training sessions. The general assessment questionnaire score of participants who were trained based on the new FA training program was 19.3 (out of 20), which was statistically significantly (p < 0.05) higher than that of those trained based on the old program (general assessment score of 17.1). Participants who were trained based on the new program scored an average of 8.6 points on the theoretical FA knowledge test, while those who were trained based on the old program scored an average of 7.1 points, which was statistically significantly (p < 0.05) lower. In both programs, the same average scores (7.5 out of 10 points) on the practical CPR knowledge test was achieved. However, participants who participated in the FA course adapted for the older people gained practical CPR knowledge in a shorter time. Older people with a greater psychophysical capacity were more successful in performing CPR, regardless of which FA training programme they received. CONCLUSIONS: The effectiveness of FA training is greater if older people are trained in accordance with a targeted programme adapted to the psychophysical limitations of the older people.

The importance of elderly people knowing basic first-aid measures.

BACKGROUND: In the event of a sudden illness or injury, elderly individuals are often dependent on self-help and mutual assistance from partners. With poor access to medical services during natural and other disasters, the importance of first aid knowledge of elderly individuals increases even more. We assessed the opinions of different generations of Slovenian population regarding the importance of knowing the basic first aid measures. In addition, we aimed to examine the knowledge of first aid in the most common emergencies that threaten elderly people's health and lives, focusing on the knowledge of elderly. METHODS: A structured questionnaire was conducted with a representative Slovenian adult population (n = 1079). Statistically significant differences in average ratings of the importance of first aid knowledge were compared among different age groups with one-way ANOVA followed by a post hoc test. Significant differences in percentages of correct answers in particular cases of health conditions between different age groups were determined using the χ 2 test followed by post hoc tests. RESULTS: Slovenes are well aware of the importance of first aid knowledge and feel personally responsible for acquiring this knowledge. The general opinion is that older retirees need less first aid knowledge than individuals in younger populations. We found a high level of knowledge about symptoms and first aid measures for some of the most common health conditions that occur in old age. The level of knowledge in the group of the oldest respondents was comparable with that of younger age groups. However, their recognition of health conditions was also somewhat worse, especially when recognising the symptoms and signs of hypoglycaemia and heart attack. Most of the tested knowledge did not depend on a person's age but on the time since that person was last educated in first aid. CONCLUSIONS: The knowledge of people older than 80 years is somewhat poorer than that in the younger population, mainly because too much time has passed since they were last educated in first aid. Public awareness of first aid needs to be increased and appropriate guidelines should be given with a focus on the elderly population.

Engineered combinatorial cell device for wound healing and bone regeneration.

Growth factors are the key regulators that promote tissue regeneration and healing processes. While the effects of individual growth factors are well documented, a combination of multiple secreted growth factors underlies stem cell-mediated regeneration. To avoid the potential dangers and labor-intensive individual approach of stem cell therapy while maintaining their regeneration-promoting effects based on multiple secreted growth factors, we engineered a "mix-and-match" combinatorial platform based on a library of cell lines producing growth factors. Treatment with a combination of growth factors secreted by engineered mammalian cells was more efficient than with individual growth factors or even stem cell-conditioned medium in a gap closure assay. Furthermore, we implemented in a mouse model a device for allogenic cell therapy for an in situ production of growth factors, where it improved cutaneous wound healing. Augmented bone regeneration was achieved on calvarial bone defects in rats treated with a cell device secreting IGF, FGF, PDGF, TGF-ß, and VEGF. In both in vivo models, the systemic concentration of secreted factors was negligible, demonstrating the local effect of the regeneration device. Finally, we introduced a genetic switch that enables temporal control over combinations of trophic factors released at different stages of regeneration mimicking the maturation of natural wound healing to improve therapy and prevent scar formation.

The needs and opportunities of older laypeople to acquire first aid skills.

We aimed to determine the needs and opportunities of older lay people to obtain first aid skills. We determined the level of theoretical knowledge of performing first aid with a structured questionnaire, performed on the sample of 842 adult inhabitants of Slovenia. The method of sampling was balanced by using a system of sampling weights in order to correct deviations in the structure of the sample to the level of the population structure. We also checked their attitude regarding the renewal of first aid knowledge. The level of self-assessment of first aid knowledge and actual theoretical knowledge of proper first aid measures typically decreased with age. The percentage of those who had attended first aid courses at any time was statistically significantly lower among respondents over the age of 60; 38% of elderly respondents thought they needed to renew their first aid knowledge, and 44% would attend a suitable first aid course. None of the 29 European Red Cross and Red Crescent Societies member states that responded have a developed a formally adopted first aid program to train the elderly. A tailored first aid training program for the elderly could be one of the many steps that should be taken to ensure adequate health care for the elderly population.

The Relationship between Autonomic Regulation of Cardiovascular Function and Body Composition.

BACKGROUND: We investigated whether the results of autonomic function tests correlate with body composition and shape in healthy young people. METHODS: We conducted cardiovascular reflex tests (heart rate [HR] and blood pressure [BP] responses to the Valsalva maneuver and HR response to deep breathing) and the tilt table test with 32 subjects (19 males; mean age, 22.1±1.9 years). Participants also completed an anthropometric measurement sequence (weight; height; upper arm, hips, and waist circumference; triceps and subscapular skinfold), bioelectric impedance testing, and hand grip strength measurements. RESULTS: Markers of obesity, other anthropometric measures, functional measures, and the basal metabolic rate (BMR) were significantly positively correlated with systolic BP (SBP) and diastolic BP (DBP) in both the supine and tilted positions. There was a positive correlation between the difference in HR (ΔHR) between the tilt and supine body positions and markers of obesity, the functional marker of dominant handgrip strength, and BMR. Participants with a body mass index (BMI) <25 kg/m2 had significantly lower median values of ΔHR, DBP in the tilt-test, SBP at rest, and SBP in the tilt-test than participants who had a BMI ≥25 kg/m2 (10.55 vs. 21.95 bpm, P=0.003; 77.55 vs. 90.05 mmHg, P=0.045; 113.45 vs. 140.55 mmHg, P=0.013; 117.00 vs. 135.25 mmHg, P=0.006, respectively). Body fat percentage was identified as an independent positive predictor (ß=0.993; 95% confidence interval [CI], 0.070 to 1.916; P=0.036) and body water percentage was an independent negative predictor of tilted SBP (ß=-1.370; 95% CI, -2.634 to 0.106; P=0.035). CONCLUSION: High sympathetic activity, as evaluated by cardiovascular regulation, correlates with a high share of adipose tissue in young healthy persons.

Effect of aging on recovery of cutaneous nociception after end-to-side nerve repair in the rat.

Age-related differences in the recovery of cutaneous mechanonociception after end-to-side nerve repair were examined in rats. Recovery of the dorsal foot skin nociception, determined by pinch test 19 weeks after the end-to-side coaptation between the recipient peroneal and the donor sural nerves, was about 20% larger in young adult rats. It was found in 66% and 16% of young and aged rats, respectively. The presence of nociceptive axons in the recipient nerve was determined by pinch test in 75% and 25% of young and aged rats, respectively (P = 0.039). The number of myelinated (but not of unmyelinated) axons was significantly larger in young than in aged rats, and the majority of them in both age groups were thin fibers. Functional recovery of cutaneous mechanonociception after end-to-side nerve repair is less extensive in aged rats because of severely reduced sprouting into the end-to-side coapted nerve compared with young adult rats.

Unilateral ligature-induced periodontitis influences the expression of neuropeptides in the ipsilateral and contralateral trigeminal ganglion in rats.

OBJECTIVES: Expression of neuronal neuropeptides in inflammatory conditions is altered. The changes in expression of substance P (SP) and calcitonin gene-related peptide (CGRP) in ipsilateral and contralateral trigeminal ganglion (TG) neurons were investigated by immunohistochemistry one week after unilateral ligature-induced periodontitis in rats. DESIGN: A retrograde nerve tracer Fluorogold (FG) was applied into the gingival sulcus of the second maxillary molar to identify the neurons in TG that specifically innervate the inflamed gingivomucosa. In addition, neurons from the corresponding maxillary and the adjacent mandibular-ophthalmic regions in TG were analysed. RESULTS: Statistically significantly higher frequencies of CGRP-positive neurons, regardless of their size, were found in TG ipsilateral to the periodontitis (83% and 73% in FG-labelled and maxillary regions, respectively) than in the control group without periodontitis (52% and 42% in FG-labelled and maxillary regions, respectively). The frequency of small FG-labelled SP-positive neurons in the ipsilateral TG (60%) was significantly higher than in the control TG (25%). In the contralateral TG the frequency of CGRP-positive neurons in maxillary region (66%) was significantly higher than in the control group. Surprisingly, the number of SP-positive neurons in all regions of contralateral TG decreased when compared to control and ipsilateral TGs. CONCLUSIONS: Taken together, these results implicate a role of neurogenic component in the pathogenesis of periodontitis. The contralateral response in the TG could be mediated through the transmedian neurological pathways crossing in the trigeminal nuclear complex or through the systemic inflammatory reaction and the activation of the so called "neuro-immune axis".

Expression of TrkA receptor for neurotrophins in trigeminal neurons innervating the rat gingivomucosal tissue.

The purpose of this study was to characterize and evaluate the expression of TrkA receptor in trigeminal ganglion (TG) neurons that innervate the rat gingivomucosal tissue. A retrograde nerve tracer Fluorogold (FG) was injected into the gingiva (group 1) or applied into the gingival sulcus (group 2) of the first right maxillary molar to identify the neurons in TG that innervate the gingivomucosa. After 10 days TG were dissected and FG fluorescence in neurons was observed under UV light microscope. To draw a comparison, approximately 1000 neurons per ganglion from the entire TG (group 3) and approximately 350 neurons per ganglion from the maxillary region in TG (group 4), were analyzed. Expression of TrkA receptor in TG neurons was investigated by immunohistochemistry. About 70% of neurons in groups 1 and 2 contained TrkA receptor, which was statistically significantly more than in groups 3 (41%) and 4 (38%). FG-labeled TrkA-immunopositive neurons were predominantly small or medium-sized (less than 1200microm(2)). However, the neurons innervating the rat gingivomucosa were on average larger than the neurons in the entire TG or in the maxillary region. In conclusion, the majority of neurons in TG that innervate the rat gingivomucosa are small or medium-sized, contain TrkA receptor and are most probably nociceptive.

Identification and neuropeptide content of trigeminal neurons innervating the rat gingivomucosal tissue.

OBJECTIVES: The purpose of this study was to identify and characterise the neuropeptide content and the size of trigeminal ganglion (TG) neurons innervating the rat gingivomucosal tissue. DESIGN: Retrograde nerve tracer Fluorogold (FG) was injected into the gingiva (group 1, n=5) or applied into the gingival sulcus (group 2, n=5) of the first right maxillary molar. After 10 days, the ganglia were dissected and FG fluorescence was observed under UV light microscope. Expression of calcitonin gene-related peptide (CGRP) and substance P (SP) in FG-labelled neurons was investigated by immunohistochemistry. Cross-sectional areas of neuron cell bodies containing FG were determined. As a control group, approximately 1000 neuron cell bodies representing the entire TG neuron population was evaluated in five trigeminal ganglia. RESULTS: In group 1, the percentages of neurons containing CGRP (median 63%, range 48-72%) and SP (median 64%, range 54-64%) were significantly greater than in the control group (CGRP: median 43%, range 42-47% and SP: median 23%, range 21-27%). In group 2, only the percentage of neurons containing SP (median 50%, range 40-56%) was significantly greater than in the control group. FG-labelled neurons were predominantly small or medium sized (less than 1200 microm2). The neurons in the group 1 were significantly smaller than in group 2. In both experimental groups, immunopositive neurons were significantly smaller than immunonegative neurons. CONCLUSIONS: The majority of neurons in TG that innervate the rat gingivomucosa are small or medium sized and contain CGRP and SP.

Toll-like receptor 4 expression in trigeminal neurons is increased during ligature-induced periodontitis in rats.

BACKGROUND: Periodontitis, activated by oral bacteria and orchestrated by innate immune response, is regulated by primary nociceptive neurons, which are generally considered to have small- to medium-sized perikaryons. Bacterial byproducts (e.g., lipopolysaccharides) activate primary nociceptive neurons directly through Toll-like receptors (TLRs). Therefore, this study aims to morphometrically characterize rat trigeminal neurons, which express TLR4, and to investigate the changes in the TLR4 expression in neurons during periodontal inflammation. METHODS: Trigeminal neurons innervating gingivomucosa were identified by application of the retrograde tracer hydroxystilbamidine into the gingival sulcus of the maxillary molar in 14 rats. Periodontitis was induced by ligature around the same molar in seven rats. TLR4 expression was investigated by immunohistochemistry on paraffin sections of the trigeminal ganglia (TG). Semiquantitative method was used to identify the intensity of TLR4 expression. RESULTS: In the control group without the ligatures, TLR4 was detected in 19% of the neurons in the maxillary region of TG and in 29% of neurons innervating gingivomucosa. Expression of TLR4 was more frequent and intensive in small- to medium-sized neurons than in large-sized neurons. One week after ligature-induced periodontitis, the percentage of TLR4-positive neurons in the maxillary region and among the neurons innervating inflamed gingivomucosa significantly increased statistically to 32% and 41%, respectively. CONCLUSIONS: TLR4 is predominantly, but not exclusively, expressed in smaller trigeminal nociceptive neurons in the rat. Experimental periodontitis upregulates TLR4 expression in the trigeminal neurons. The hypothesis that bacterial byproducts regulate the pathogenesis of periodontitis by activation of trigeminal nociceptors through TLR4 should be explored.

Dental pulp and gingivomucosa in rats are innervated by two morphologically and neurochemically different populations of nociceptors.

OBJECTIVES: Difference in phenotypes of sensory neurons innervating dental pulp or gingivomucosa may be responsible for intense pain sensations in pulpitis in contrast to relatively painless chronic periodontitis. Therefore, we classified these neurons according to their size and two neurochemical characteristics of nociceptors, their TrkA expression and isolectin IB4 binding. DESIGN: In rats (n=6) fluorescent tracers Fluorogold and TrueBlue were simultaneously applied into the standard-sized tooth cavity and nearby gingival sulcus, respectively. After the fluorescence on paraffin trigeminal ganglia (TG) sections was identified and photographed, immunohistochemistry for TrkA expression and IB4 binding was performed on the same sections. RESULTS: The average sizes of TG neurons projecting to the gingivomucosa and dental pulp were 894±441µm(2) and 1012±381µm(2), respectively. The proportions of small-sized gingival and pulpal neurons were 14% and 5%, respectively (p<0.05). The proportions of TrkA-positive neurons among all gingival or pulpal neurons were 76% and 86%, respectively (p<0.05). Among all gingival or pulpal neurons the proportions of IB4-positive neurons were 46% and 3% (p<0.001), respectively, and the majority of them were small-medium sized. CONCLUSIONS: Dental pulp and gingivomucosa are richly innervated by nociceptive TrkA-expressing neurons. However, while great majority of pulpal neurons are larger NGF-dependent A-fibre nociceptors without affinity to bind IB4, almost half of the gingival neurons are smaller IB4 binding C-fibre nociceptors. The difference in phenotype of sensory neurons might partially explain the different sensitivity of both tissues during normal and pathological conditions.

Influence of breaching the connective sheaths of the donor nerve on its myelinated sensory axons and on their sprouting into the end-to-side coapted nerve in the rat.

The influence of breaching the connective sheaths of the donor sural nerve on axonal sprouting into the end-to-side coapted peroneal nerve was examined in the rat. In parallel, the effect of these procedures on the donor nerve was assessed. The sheaths of the donor nerve at the coaptation site were either left completely intact (group A) or they were breached by epineurial sutures (group B), an epineurial window (group C), or a perineurial window (group D). In group A, the compound action potential (CAP) of sensory axons was detected in ~10% and 40% of the recipient nerves at 4 and 8 weeks, respectively, which was significantly less frequently than in group D at both recovery periods. In addition, the number of myelinated axons in the recipient nerve was significantly larger in group D than in other groups at 4 weeks. At 8 weeks, the number of axons in group A was only ~15% of the axon numbers in other groups (p<0.05). Focal subepineurial degenerative changes in the donor nerves were only seen after 4 weeks, but not later. The average CAP area and the total number of myelinated axons in the donor nerves were not different among the experimental groups. In conclusion, myelinated sensory axons are able to penetrate the epiperineurium of donor nerves after end-to-side nerve coaption; however, their ingrowth into recipient nerves is significantly enhanced by breaching the epiperineurial sheets at the coaptation site. Breaching does not cause permanent injury to the donor nerve.

Aging impairs collateral sprouting of nociceptive axons in the rat.

Sprouting of uninjured nociceptive axons was examined in young adult, middle aged and aged rats. Axon sprouting from the spared sural nerve, both into adjacent denervated skin and into end-to-side coapted nerve graft, was significantly higher in young rats than in aged rats. Cross-transplantations of the end-to-side coapted nerve grafts between young and aged rats demonstrated that axon sprouting from young recipient nerves into aged donor nerve grafts was significantly deteriorated, whereas the axon sprouting from aged recipient nerves into young donor nerve grafts was not statistically significantly affected. The levels of laminin polypeptides in peripheral nerves were 50-100% higher in young adult than in aged rats. However, the levels of peripherin, NGF isoforms and TrkA in skin, peripheral nerves and DRG, respectively, were not significantly reduced in aged rats. Therefore, impaired sprouting of nociceptive axons in aged rats is due rather to the alterations in peripheral neural pathways, than to the limited sprouting capacity of aged sensory neurons. Decreased levels of extracellular matrix components might be important in this respect.

Sex-related differences in recovery of cutaneous nociception after end-to-side nerve repair in the rat.

Sex-related differences in the recovery of cutaneous nociception after end-to-side nerve repair were examined in rats. Recovery of nociception in the dorsal foot was determined by skin pinch test 19 weeks after the proximal end of the distal stump of the transected peroneal nerve was sutured to the side of the adjacent intact sural nerve (end-to-side nerve coaptation). Axon sprouts in the recipient peroneal nerve were counted by light and electron microscopy. Recovery of nociception due to axon sprouting through the end-to-side coaptation was found in 87% of females and in 60% of males. The area of nociception was not significantly different (P=0.59) between females and males (13+/-8% and 11+/-9%, respectively). The number of myelinated axons in the recipient peroneal nerve (but not of unmyelinated axons) was significantly larger (P=0.028) in females (median=512, 25th and 75th percentiles: 467 and 594) than in males (median=322, 25th and 75th percentiles: 239 and 468). The majority of these axons in females and males were thin fibres, and recipient nerves in both groups were responsive to nerve pinch test. In conclusion, collateral sprouting of thin myelinated nociceptive axons into the end-to-side coapted nerve is more abundant in female than in male rats. However, recovery of cutaneous mechano-nociception due to sprouting of these axons was not different between the two sexes. Possible reasons are discussed.

Chapter 26: Age-related differences in the reinnervation after peripheral nerve injury.

Numerous and extensive functional, structural, and biochemical changes characterize intact aged peripheral nervous system. Functional recovery after peripheral nerve injury depends on survival of injured neurons and functional reinnervation of target tissue by regeneration of injured axons and collateral sprouting of uninjured (intact) adjacent axons. The rate of axonal regeneration becomes slower and its extent (density and number of regenerating axons) decreases in aged animals. Aging also impairs terminal sprouting of regenerated axons and collateral sprouting of intact adjacent axons, thus further limiting target reinnervation and its functional recovery. Decreased survival of aged noninjured and injured neurons, limited intrinsic growth potential of neuron, alteration in its responsiveness to stimulatory or inhibitory environmental factors, and changes in the peripheral neural pathways and target tissues are possible reasons for impaired reinnervation after peripheral nerve injury in old age. The review of present data suggests that this impairment is mostly due to the age-related changes in the peripheral neural pathways and target tissues, and not due to the limited intrinsic growth capacity of neurons or their reduced responsiveness to trophic factors. Age-related alterations in the soluble target derived neurotrophic factors, like nerve growth factor, and nonsoluble extracellular matrix components of neural pathways, like laminin, might be important in this respect.

Collateral sprouting of sensory axons after end-to-side nerve coaptation--a longitudinal study in the rat.

The end-to-side nerve coaptation is able to induce collateral sprouting of axons from the donor nerve and to provide functional reinnervation of the target tissue. Sensory axon sprouting and its effects on the donor nerve up to 9 months after the end-to-side nerve coaptation were studied in the rat. Peroneal, tibial and saphenous nerves were transected and ligated, and the distal stump of the transected peroneal nerve was sutured to the side of the uninjured sural nerve. The average skin area of the residual sensitivity to pinch due to the axons sprouting through the recipient peroneal nerve did not change statistically significantly between 4 and 9 months after surgery. Axon counting, measurements of compound action potentials and retrograde neuron labeling indicate that the sprouting of the myelinated sensory axons and unmyelinated axons through the recipient nerve was largely completed by 2 months and 4 months after the end-to-side nerve coaptation, respectively, and remained stable thereafter for at least 9 months. A decrease in the amplitude and area of the CAP of myelinated fibers, observed in the donor nerve up to 4 months after surgery, was probably due to mild degeneration of nerve fibers and a tendency of the diameter of myelinated axons to decline. However, no significant changes in functional, electrophysiological or morphological properties of the donor nerve could be observed at the end of the observational period, indicating that end-to-side nerve coaptation has no detrimental effect on the donor nerve on a long-term scale.

Sex-related differences in the regeneration of sensory axons and recovery of nociception after peripheral nerve crush in the rat.

Sex-related differences regarding the regeneration of nociceptive axons and the recovery of nociception after sural nerve crush injury were examined in rats. The elongation rate of the fastest regenerating sensory axons in females started to increase after the first 6 days. This resulted in about 15% greater axon elongation distance at 8 days after crush in female than in male rats as determined by the nerve pinch test. The number of regenerating sensory axons in female and male rats, however, was not different. The recovery of nociception in the instep started earlier and was more extensive in females than in males during the entire 24-week recovery period, so that the pain sensitive area was finally about 20% larger in females than in males. Although ovariectomy significantly reduced plasma estradiol concentration in female rats, it did not change the elongation distance of regenerating nociceptive axons, which remained significantly greater than in male rats. Elimination of the cells in the distal nerve segment by freezing revealed that a more effective cell support in the distal nerve segment is probably responsible for faster regeneration of nociceptive axons in females than in males, rather than the circulating female sex hormones.