Ultrasonography-Derived Elasticity Estimation of Live Porcine Oral Mucosa

OBJECTIVES

To investigate the biomechanical properties of porcine oral tissues with in vivo ultrasonography and to compare the difference between oral alveolar mucosa and gingival tissue concerning compressional and tensile mechanical strain.

MATERIALS AND METHODS

Sinclair minipigs (6 females and 4 males, 6 to 18 months of age) were anesthetized for ultrasonography. In vivo high-frequency tissue harmonic ultrasound (12/24 MHz) cine-loops were obtained while inducing mechanical tissue stress (0 to 1 N). Post-processing strain analysis was performed in a cardiac speckle tracking software (EchoInsight®). Region of interest (ROI) was placed for gingival and alveolar mucosa tissues for longitudinal (compressional) and tensile strain analyses. A calibrated gel pad was employed to determine the absolute force (pressure) for the measured tissue strain response function. The resulting elasticity data was statistically analyzed using custom Matlab scripts.

RESULTS

In total, 38 sonography cine-loops around the third premolars were included in the investigation. The longitudinal strain of alveolar mucosaε AM L was found to be significantly (P < .05) larger than that of gingivaε G L . Across the measured force range,ε AM L  ~ 1.7 × ε G L . Significant differences between alveolar mucosa and gingiva tissues were found for all forces. The tensile strain of the alveolar mucosaε AM T was found to be ~2 × ε G T (on the epithelial surface of the gingiva). Both were statistically significantly different for forces exceeding ~0.08 N. At depth, that is, 500 and 1000 μm below the epithelial surface, the gingiva was found to have less ability to stretch contrary to the alveolar mucosa. Gingival tissue at 500 μm depth has significantly less tensile strain than at its surface and more than at 1000 μm depth. In contrast, the tensile strain of alveolar mucosa is largely independent of depth.

CONCLUSION

Ultrasonography can reveal significant differences in oral alveolar mucosal and gingival elastic properties, such as compressional and tensile strain. Under minute forces equivalent to 10 to 40 g, these differences can be observed. As dental ultrasound is a chairside, and noninvasive modality, obtaining real-time images might soon find clinical utility as a new diagnostic tool for the objective and quantitative assessment of periodontal and peri-implant soft tissues in clinical and research realms. As ultrasound is a safe modality with no known bioeffects, longitudinal monitoring of areas of concern would be particularly attractive.

Anatomy-driven complexity classification for soft-tissue tunneling procedures

BACKGROUND

The tunnel technique (TUN) preserves the integrity of the papilla by creating envelope flaps that allow for the insertion of a connective tissue graft, and/or biomaterials.

METHODS

(1) A comprehensive overview of tunneling flap procedures in the treatment of gingival recessions (GRs) for soft tissue coverage is presented and (2) A classification system for soft and hard tissue anatomy of GR sites which may aid the clinician in determining the surgical complexity is being introduced.

RESULTS

A novel clinical classification system is proposed to illustrate complexity levels determined by soft and hard tissue anatomy of GR sites such as the mucogingival junction proximity to the gingival margin, bone morphotype, and mucosal margin thickness.

CONCLUSIONS

TUN is highly effective in treating single/multiple GRs. Its limitations are related to variability in surgical site anatomy and operator expertise. A classification system based on anatomical soft and hard tissue variations has been proposed to help identify complexity levels encountered during tunneling procedures.

KEY POINTS

Site-related factors directly impact the surgical variables related to tissue trauma, flap tension, soft tissue management, muscle pull, and wound stability during the healing of gingival recessions (GRs). The achievement of expedited and favorable wound healing is crucial to obtaining quantitative and qualitative success in the treatment of GR and the long-term stability of root coverage. A classification system based on anatomical soft and hard tissue variations has been proposed to facilitate tunneling procedures while respecting surgical principles.

Aging leads to inferior Achilles tendon mechanics and altered ankle function in rodents

Spontaneous rupture of the Achilles tendon is increasingly common in the middle aged population. However, the cause for the particularly high incidence of injury in this age group is not well understood. Therefore, the objective of this study was to identify age-specific differences in the Achilles tendon-muscle complex using an animal model. Functional measures were performed in vivo and tissues were harvested following euthanasia for mechanical, structural, and histological analysis from young, middle aged, and old rats. Numerous alterations in tendon properties were detected across age groups, including inferior material properties (maximum stress, modulus) with increasing age. Differences in function were also observed, as older animals exhibited increased ankle joint passive stiffness and decreased propulsion force during locomotion. Macroscale differences in tendon organization were not observed, although cell density and nuclear shape did vary between age groups. Muscle fiber size and type distribution were not notably affected by age, indicating that other factors may be more responsible for age-specific Achilles tendon rupture rates. This study improves our understanding of the role of aging in Achilles tendon biomechanics and ankle function, and helps provide a potential explanation for the disparate incidence of Achilles tendon ruptures in varying age groups.

Effects of a respiratory functional training program on pain and sleep quality in patients with fibromyalgia: A pilot study

OBJECTIVE

To evaluate the effect of 8-week respiratory functional training program on pain tolerance, sleep, and urinary antioxidant and cortisol levels in 18 patients with fibromyalgia.

METHODS

Participants underwent a 12-week intervention: 4 weeks as control and 8 weeks of breathing exercises. Pain tolerance assay was done by using an algometer, whereas sleep quality was evaluated by actigraphy and by the Pittsburgh Sleep Quality Index. Cortisol and antioxidant levels were determined using commercial assay kits.

RESULTS

Increases in the pain tolerance threshold were detected in the occiput point after one month of intervention as well as in the low cervical and second rib points after one and two months. Actigraphy revealed a decrease in sleep latency, whereas sleep questionnaire showed improvements in sleep quality, sleep duration and sleep efficiency. No changes in cortisol and antioxidant levels were detected.

CONCLUSION

The 8-week breathing exercise intervention reduced pain and improved sleep quality.

Melatonin increases the survival time of animals with untreated mammary tumours: Neuroendocrine stabilization

The aim of this study was to evaluate the therapeutic effect of melatonin, the main hormone of the pineal gland, on rats with advanced and untreated mammary tumours. Mammary tumours were chemically induced in Sprague-Dawley rats with the carcinogen 9,10-dimethyl-1,2-bezanthracene (DMBA). After the appearance of tumours the effect of melatonin (5 mg/ml per rat per day) was then evaluated on the survival time, tumour multiplicity, and tumour volume until the death of the animals. In addition, the variations in prolactin, noradrenaline and adrenaline concentrations, and in the percentage of NK cells were evaluated after one month of the treatment with melatonin. Daily administration of melatonin increased significantly the survival time of tumour-bearing animals (p<0.05 with respect to the control non-melatonin-receiving rats). The increased survival time did not correlate, however, with changes in either tumour multiplicity or tumour growth rate. Animals with mammary tumours exhibited an increase (p<0.05 with respect to healthy animals) in prolactin and catecholamine concentrations. The administration of melatonin stabilized the hormone levels, returning them to those in the basal-healthy animals. Rats with mammary tumours also presented lower percentages of NK cells, which were not increased by the administration of melatonin. The results strongly suggest that melatonin per se is beneficial during advanced breast cancer. It increases survival time, maybe by improving the homeostatic and neuroendocrine equilibrium which is imbalanced during advanced breast cancer.

Physiological concentrations of melatonin and corticosterone in stress and their relationship with phagocytic activity

The aim of the present work was to investigate the possible connection between melatonin, corticosterone and the nonspecific immune response under both basal and stressed conditions. The concentrations used in the present study were as determined in an earlier work, and corresponded to the minimum and maximum concentrations of the hormones melatonin and corticosterone over one circadian cycle in mice subjected to stress and in a basal group of mice. The concentrations were 15 pg/ml and 90 pg/ml of melatonin and 50 ng/ml and 200 ng/ml of corticosterone for incubations of the basal group macrophages, and 15 pg/ml and 70 pg/ml and 200 ng/ml and 500 ng/ml of melatonin and corticosterone, respectively, for incubations of macrophages from the group of stressed mice. The results indicate that corticosterone stimulates antigen ingestion at all physiological doses tested in the macrophages from the unstressed mice. The greatest phagocytic stimulation was obtained in macrophages from mice in a basal situation, and which had been incubated with the diurnal concentrations of the two hormones (maximum corticosterone 200 ng/ml; minimum melatonin 15 pg/ml). When the macrophages were from stressed mice, neither corticosterone nor melatonin led to any change in their phagocytic activity.

Melatonin and aging: in vitro effect of young and mature ring dove physiological concentrations of melatonin on the phagocytic function of heterophils from old ring dove

We have studied the circadian rhythm of melatonin in the ring dove (Streptopelia risoria) for different age groups: young (1-1.5 years), mature (3-4 years) and old animals (>8 years). Melatonin levels were determined by radioimmunoassay. Results showed a significant decline in plasma melatonin levels in old animals when compared with the concentrations observed in the other two age groups, in which maximum (nocturnal) concentrations were 300 pg/ml and minimum (diurnal) concentrations were 50 pg/ml. We analyzed the in vitro effect of the physiological concentrations found in young and mature animals on the heterophils obtained from old animals, evaluating the capacity for ingestion and destruction of Candida albicans, and the oxidative metabolism associate to phagocytosis by determining the superoxide anion levels. Melatonin induced an increase in both the phagocytosis index and the candidicide capacity. This effect was dose-dependent. In relation with the oxidative metabolism, a decline in superoxide anion levels after incubation with both concentrations of the hormone was observed. Thus our results corroborate in this avian species the decline in plasma melatonin levels with advanced age, as well as the enhancing effect of physiological concentrations of melatonin on the phagocytic function.

Enhanced chemotaxis of macrophages by strenuous exercise in trained mice: thyroid hormones as possible mediators

Exercise modulates the macrophage activity via 'stress hormones'. Three experiments were performed. (1) The effect of strenuous exercise performed by trained mice on macrophage chemotactic capacity was evaluated; (2) peritoneal macrophages from control mice were incubated with plasma from exercised mice or control mice and the differences in chemotaxis were measured; (3) changes in plasma T3 and T4 levels after exercise were measured, and the effect of incubation with the post-exercise levels of plasma T3 and T4 on chemotaxis was then studied in vitro. A 10(4)-fold higher concentration of each hormone was also evaluated. Exercise provoked an increase in chemotaxis (104 +/- 35 vs. 47 +/- 11 in controls). Incubation with plasma from exercised mice led to an increased level of chemotaxis. Incubation with concentrations of T3 and T4 similar to those observed in post-exercise plasma (T3, 2.3 nmol l(-1); T4, 84 nmol l(-1)) enhanced chemotaxis with respect to incubation with the basal concentrations of the hormones in control animals. A 10(4)-fold concentration of T4 reversed this effect. It is concluded that thyroid hormones stimulate macrophage chemotaxis. Also, these data support the hypothesis that thyroid hormones may be involved in exercise-induced stimulation of chemotaxis.

Suppression of both basal and antigen-induced lipid peroxidation in ring dove heterophils by melatonin

There have been several findings recently concerning melatonin as a free radical scavenger and general antioxidant. For instance, in bird heterophils we found that 100 microM of melatonin decreases superoxide anion levels and modulates superoxide dismutase activity. This paper sought to study the effect of melatonin upon induced oxidative damage in heterophils of the ring dove (Streptopelia risoria). The concentration of malonaldehyde (MDA) as an index of induced oxidative damage to lipid membranes was tested by colorimetric assay. A heterophil suspension was co-incubated with and without inert particles (latex beads) as material to be phagocytosed, both alone and in combination with 100 microM of melatonin. Measurements were made at the basal time (0 min), as well as at 15, 30, 45, and 60 min. Protein concentrations were determined by a standardized method using bovine serum albumin as standard. Results are expressed as nmol MDA/mg prot. Melatonin clearly reduced the production of MDA, an index of lipid peroxidation. It also annulled the enhancement of MDA levels produced by latex beads. Both effects were observed at all the times studied. In conclusion, our findings again show that the neurohormone melatonin could be useful as an effective pharmacological antioxidant.

Serum hemolytic and bactericidal activity in breast and formula-fed infants

Whether formula or breast feeding influences the functional activity of the complement system from birth to three months of age has been studied. The classical pathway was evaluated by assessing hemolytic activity, based on the capacity of the intact complement system to lyse sheep erythrocytes when coated with specific antibodies. The bactericidal activity of the serum against Staphylococcus aureus and Escherichia coli was used to evaluate the alternative complement pathway. Sera were obtained from neonates (40 +/- 2 weeks of gestation), and one-month or three-month old infants, fed either breast or formula. Control serum was obtained from healthy adults between 22 and 30 years of age. The hemolytic capacity of serum from breast-fed infants of one month and three months of age was significantly greater than that of the serum from infants which had been fed formula milk.

A study of the role of corticosterone as a mediator in exercise-induced stimulation of murine macrophage phagocytosis

1. It is generally accepted that physical activity provokes changes in the immune system. Previous studies have demonstrated that the stress of physical activity (swimming until exhaustion) increases the phagocytic activity of peritoneal macrophages. However, the precise mechanisms remain unknown. 2. Two experiments were performed in the present study. (A) Peritoneal macrophages from control mice were incubated with plasma from three different groups of mice: (1) mice subjected to swimming until exhaustion with no previous training, (2) mice subjected to the same activity but with 1 month of training (30 min day-1), and (3) a control (non-exercised) group. The differences in the resulting phagocytic (attachment and ingestion) capacity were measured. (B) Changes in the concentration of plasma corticosterone after exercise were also measured, and the effect of incubation with the postexercise plasma corticosterone level on the phagocytic activity of peritoneal macrophages was then studied in vitro. 3. The results were: (A) incubation with plasma from both groups of exercised mice (with and without previous training) led to increased levels of phagocytic capacity (number of C. albicans cells ingested per 100 macrophages). (B) Incubation with a corticosterone concentration of 0.72 mumol l-1 (similar to that observed in plasma immediately after exercise) raised the phagocytic capacity (144 +/- 12 after incubation with 0.72 mumol l-1 vs. 93 +/- 19 after incubation with 0.24 mumol l-1). This increase was also significantly greater than that observed with 7.2 mumol l-1 corticosterone. 4. It is concluded that corticosterone may mediate the increased phagocytic function of peritoneal macrophages induced by exercise.

Intracellular activity of both teicoplanin and vancomycin against Staphylococcus aureus in human neutrophils

The effects in vitro of both teicoplanin and vancomycin of blood peripheral human neutrophils have been studied by assays of antibiotic uptake and intracellular killing of previously phagocytosed Staphylococcus aureus. The effects of vancomycin and teicoplanin (a novel glycopeptide antibiotic), at the therapeutic concentrations reached in plasma (10, 25, 50, 75 and 100 mg/l) and at different times of incubation (5, 15, 30 and 60 min) were studied. The results indicate that: (1) the bactericidal effect of neutrophils increases with incubation time, (2) in the presence of both teicoplanin and vancomycin, the number of CFU/ml of intraphagocytic S. aureus declines with both increasing incubation time and exposure dose of the antibiotics and (3) at 100 mg/l of teicoplanin there is a significant increase in the percentage inhibition of S. aureus growth at all the times studied.

Increased phagocytic activity of polymorphonuclear leukocytes during pregnancy

Many immunological parameters are depressed during pregnancy. For this reason, an evaluation was made of the phagocytic activity, representing non-specific immunity, of polymorphonuclear leukocytes from pregnant women. The cells were isolated from heparinized venous human blood of pregnant women of 10 or more weeks' gestation and non-pregnant women (controls), 20-30 years old. The results indicate that the phagocytosis of inert particles (latex beads) does not significantly change in pregnancy. However, the attachment, ingestion and digestion of Candida albicans significantly increased in pregnancy, with the greatest difference from controls being in the second trimester. These findings suggest that the phagocytic activity in pregnant women is enhanced and that this increased non-specific immunity may compensate in part for weakened specific immunity of the maternal host.

Effect of age on adherence and chemotaxis capacities of peritoneal macrophages. Influence of physical activity stress

The aim of the present research was to study the effects of age on the adherence and chemotaxis capacities of macrophages. Macrophages were obtained from the peritoneum of young and old mice (young, 12 +/- 4 weeks; old, 68 +/- 6 weeks) and young and mature guinea pigs (young, 12 +/- 1 weeks; mature, 108 +/- 2 weeks). Adherence of macrophages was evaluated with a plastic adherence technique, and chemotaxis in a Boyden chamber. The macrophages from old animals showed a higher adherence capacity (studied at 10, 40 and 60 min of incubation), and lower chemotaxis capacity in both mice and guinea pigs. The effect of physical activity stress (swimming until exhaustion) was also studied, both with and without a previous training program, on the adherence and chemotaxis of macrophages from young and old mice. While the physical activity stress (detected by the increase of the serum corticosterone concentration) did not induce changes in adherence or chemotaxis of peritoneal macrophages from young mice, in the old mice, there was a decrease in adherence and an increase in chemotaxis.

In vitro effect of cefoxitin on phagocytic function and antibody-dependent cellular cytotoxicity in human neutrophils

The effects in vitro of Cefoxitin, a beta-lactam antibiotic, at a concentration of 50 micrograms/ml (similar to a therapeutic level in plasma) on each step of the phagocytic process, in addition to antibody-dependent cellular cytotoxicity (ADCC) of blood peripheral human neutrophils have been studied. The antibiotic produced a significant stimulation of adherence capacity, chemotaxis, attachment of Candida albicans to neutrophils and phagocytosis of Candida albicans (with serum, decomplemented serum or without serum), ingestion of inert particles (latex beads), microbicidal activity, and digestion capacity of the ingested material [measured by nitroblue tetrazolium (NBT) reduction]. Moreover, cefoxitin (50 micrograms/ml) demonstrated chemoattractant activity for neutrophils. ADCC was also increased by this antimicrobial agent. These results therefore suggest that a therapeutic concentration of cefoxitin may enhance microbicidal and cytotoxic functions of a pivotal human phagocytic cell: the neutrophil.

Stimulation of phagocytic processes and antibody-dependent cellular cytotoxicity of human neutrophils by cefmetazole

Interactions between antimicrobial agents and phagocytic cells, especially neutrophils, have a potential role in the treatment of infections. The in vitro effects of cefmetazole, a novel beta-lactam antibiotic, at a therapeutic concentration reached in plasma (50 micrograms/ml) on phagocytic and cytotoxic functions of human neutrophils have been studied. In human neutrophils, adherence capacity to nylon fiber and to substrate, chemotaxis, attachment to and ingestion of Candida albicans (with serum, with decomplemented serum and without serum), ingestion of inert particles (latex beads), candidicidal activity and superoxide anion production were all stimulated by cefmetazole. Cefmetazole at this dose was a chemotactic agent for neutrophils. Antibody-dependent cellular cytotoxicity (ADCC) was also increased by this anti-microbial agent.

Phagocytic function of blood neutrophils in sedentary young people after physical exercise

The effect of exhaustive running exercise on the phagocytic function of blood polymorphonuclear neutrophils in sedentary young men and women has been studied. Adherence capacity to the endothelium, spontaneous mobility, chemotaxis and ingestion of Candida albicans were not modified after physical exercise. However, opsonization of Candida albicans as well as candidicide power increased significantly in men and women after exercise. The immediate advantages of physical exercise on the phagocytic immune response is discussed.

Mechanisms of action involved in the chemoattractant activity of three beta-lactamic antibiotics upon human neutrophils

The effects produced by three beta-lactamic antibiotics (N-formimidoyl thienamycin or imipenem, cefmetazole and cefoxitin) in vitro on protein carboxylmethylation, cAMP and cGMP levels in human polymorphonuclear neutrophils were studied. These antibiotics (50 micrograms/mL) exhibited chemoattractant activity for phagocytic cells and produced a fast (0.5 min) and significant stimulation of protein carboxylmethylation. They also increased intraphagocytic cGMP levels although no changes in cAMP levels were observed. Since the involvement of the above-mentioned mechanisms in leukotaxis have been established, the stimulation of neutrophil chemotaxis by the three antibiotics studied could possibly be mediated by one or more of these mechanisms.

Phagocytic function and antibody-dependent cellular cytotoxicity of human neutrophils in the presence of N-formimidoyl thienamycin

The efficacy of an antibiotic in the treatment of bacterial infections depends upon the interactions of the drug, bacteria and phagocytes. We have studied "in vitro" the effect of N-formimidoyl thienamycin (Imipenem), a novel beta-lactamic antibiotic, on the phagocytic function and antibody-dependent cellular cytotoxicity of human neutrophil leukocytes. The incubation of these cells with 50 micrograms/ml of Imipenem similar to the therapeutic levels reached in plasma results in an increase of their adherence capacity to nylon fiber and to substrate, induced mobility or chemotaxis, opsonization, phagocytosis of Candida albicans (with serum, with decomplementarized serum and without serum) and latex beads, candidicidal power and the capacity of NBT reduction. Imipenem at this dose also presents chemoattractant power for neutrophils and enhances the antibody-dependent cellular cytotoxicity (ADCC).

In vitro and in vivo effects of Imipenem on phagocytic activity of murine peritoneal macrophages

Imipenem, a new antibiotic beta-lactam, and Tienam (an Imipenem/Cilastatine combination) have been studied in vitro and in vivo respectively, in the phagocytic function of macrophages. In this paper we have seen the variations produced by 50 mg/l of Imipenem and 120 mg/kg of Tienam in the adherence, spontaneous mobility, chemotaxis, opsonization, phagocytosis of Candida albicans and latex beads, candidicid effect and nitroblue tetrazolium (NBT) reduction in peritoneal macrophages from BALB/C mice. This antibiotic significantly increases in vitro and in vivo the adherence, spontaneous mobility and chemotaxis, phagocytosis of latex beads and the digestion of ingested material (nitroblue tetrazolium reduction) in the above-mentioned cells. The number of Candida albicans opsonized and ingested by the macrophages is not modified in the presence of Imipenem, and neither is the candidicid effect.

Effects of acetylsalicylic acid on the phagocytic function of human polymorphonuclear leukocytes in vitro

1. In this paper acetylsalicylic acid (aspirin), an anti inflammatory drug, was studied in vitro at doses of 50, 100, 200 and 500 mg/l to see its effects on adherence, chemotaxis, spontaneous mobility, phagocytosis, candidicide power, nitrobule tetrazolium (NBT) reduction as well as the incorporation and metabolism of arachidonic acid in human polymorphonuclear neutrophils (PMNns). 2. Aspirin significantly stimulated neutrophil adherence to nylon fiber at all the doses used, with a correlation between the doses used and the adherence indices found. 3. At the therapeutic dose (100 mg/l) aspirin brings about a significant increase of chemotaxis, but reduces this property at the highest dose (500 mg/l). On the other hand, spontaneous mobility is not altered except with the 500 mg/l dose of aspirin which produces a significative decrease. 4. The ingestion of Cándida albicans by PMNns is significant at the therapeutic dose; the candidicide power is not modified with any of the doses used with 100 mg/l of aspirin nitroblue tetrazolium (NBT) reduction is significantly increased. 5. No changes are observed in the incorporation of arachidonic acid or in the release of its metabolites.

Effects of cefmetazol, cefoxitin and imipenem on polymorphonuclear leukocytes

1. We have investigated the effects produced in vitro by Cefmetazol, Cefoxitin and Imipenem on the chemotaxis, spontaneous mobility, adherence, phagocytosis and candidicide power of human polymorphonuclear neutrophils (PMNs). 2. The three antibiotics tested significantly stimulated the adherence of neutrophils to nylon fibre at doses either equal (50 mg/l) or superior (500 mg/l) to the therapeutic one. 3. Cefmetazol, Cefoxitin and Imipenem bring about a maximum increase of chemotaxis at the therapeutic dose, whereas the spontaneous mobility diminishes with any one of the doses used. 4. The capacity of the PMNs to phagocytize and produce lysis of Candida albicans is increased in Cefmetazol with therapeutic doses. Cefoxitin produced an increased lysis of candidas.