Omega-3 fatty acid regulates inflammatory cytokine/mediator messenger RNA expression in Porphyromonas gingivalis-induced experimental periodontal disease.

INTRODUCTION: Porphyromonas gingivalis is strongly implicated in the etiology of adult periodontitis by inducing inflammatory cytokines, resulting in gingival and periodontal tissue inflammation and alveolar bone resorption. This study tested the hypothesis that supplementing the diet with omega-3 fatty acid (omega-3 FA; i.e. fish oil) would exert anti-inflammatory effects in the gingival tissues of P. gingivalis-infected rats. METHODS: Rats were fed either fish oil or corn oil diets ad libitum for 22 weeks and infected with P. gingivalis strain 381 or strain A7A1-28. After sacrifice, rat gingival tissues were excised and the RNA was isolated and analyzed for proinflammatory mediators [interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), IL-6], T helper type 1 and type 2 cytokines [interferon-gamma (IFN-gamma), IL-4, IL-10), antioxidant enzymes [catalase (CAT), superoxide dismutase (SOD)], and genes critical for eicosanoid mediator production [cyclo-oxygenase-2 (COX-2), 5-lipoxygenase (5-LO)] by reverse transcription-polymerase chain reaction using rat-specific primers. RESULTS: Rats on the omega-3 FA diet exhibited decreased proinflammatory cytokine gene expression (IL-1beta, TNF-alpha) and enhanced IFN-gamma, CAT and SOD messenger RNA expression compared to rats fed a corn oil diet, supporting a diet-induced modulation of host inflammatory reactions. Analyses of alveolar bone resorption in the rats related to gene expression profiles demonstrated significant positive correlations with IL-1beta, IL-6 and COX-2 and negative correlations with CAT and SOD. CONCLUSION: These findings suggest that diets enriched for omega-3 FA modulate the local gingival inflammatory milieu of the host following oral P. gingivalis infection, which impacts on alveolar bone resorption in rats.

Omega-3 fatty acid effect on alveolar bone loss in rats.

Gingival inflammation and alveolar bone resorption are hallmarks of adult periodontitis, elicited in response to oral micro-organisms such as Porphyromonas gingivalis. We hypothesized that omega (omega)-3 fatty acids (FA) dietary supplementation would modulate inflammatory reactions leading to periodontal disease in infected rats. Rats were fed fish oil (omega-3 FA) or corn oil (n-6 FA) diets for 22 weeks and were infected with P. gingivalis. Rats on the omega-3 FA diet exhibited elevated serum levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), documenting diet-induced changes. PCR analyses demonstrated that rats were orally colonized by P. gingivalis; increased IgG antibody levels substantiated this infection. P. gingivalis-infected rats treated with omega-3 FA had significantly less alveolar bone resorption. These results demonstrated the effectiveness of an omega-3 FA-supplemented diet in modulating alveolar bone resorption following P. gingivalis infection, and supported that omega-3 FA may be a useful adjunct in the treatment of periodontal disease.

CFTR: covalent modification of cysteine-substituted channels expressed in Xenopus oocytes shows that activation is due to the opening of channels resident in the plasma membrane.

Some studies of CFTR imply that channel activation can be explained by an increase in open probability (P(o)), whereas others suggest that activation involves an increase in the number of CFTR channels (N) in the plasma membrane. Using two-electrode voltage clamp, we tested for changes in N associated with activation of CFTR in Xenopus oocytes using a cysteine-substituted construct (R334C CFTR) that can be modified by externally applied, impermeant thiol reagents like [2-(trimethylammonium)ethyl] methanethiosulfonate bromide (MTSET+). Covalent modification of R334C CFTR with MTSET+ doubled the conductance and changed the I-V relation from inward rectifying to linear and was completely reversed by 2-mercaptoethanol (2-ME). Thus, labeled and unlabeled channels could be differentiated by noting the percent decrease in conductance brought about by exposure to 2-ME. When oocytes were briefly (20 s) exposed to MTSET+ before CFTR activation, the subsequently activated conductance was characteristic of labeled R334C CFTR, indicating that the entire pool of CFTR channels activated by cAMP was accessible to MTSET+. The addition of unlabeled, newly synthesized channels to the plasma membrane could be monitored on-line during the time when the rate of addition was most rapid after cRNA injection. The addition of new channels could be detected as early as 5 h after cRNA injection, occurred with a half time of approximately 24-48 h, and was disrupted by exposing oocytes to Brefeldin A, whereas activation of R334C CFTR by cAMP occurred with a half time of tens of minutes, and did not appear to involve the addition of new channels to the plasma membrane. These findings demonstrate that in Xenopus oocytes, the major mechanism of CFTR activation by cAMP is by means of an increase in the open probability of CFTR channels.

Perceptions of labour pain by mothers and their attending midwives.

AIMS: The aim of the current study was to examine the perception of pain by labouring women and their attendant midwife, from the onset of labour to delivery. RATIONALE: Accurate measurement and appropriate management of pain is a significant problem for attendant medical and nursing personnel. Both the experience and perception of pain are regarded as subjective and are therefore difficult to measure objectively. Indeed, much of the literature reports that pain is often under- or over-estimated by nursing staff who as a consequence consistently fail to administer adequate analgesia. Few studies have specifically examined the ability of midwives to assess the pain of labouring women. DESIGN: The short form McGill Pain Questionnaire (SF-MPQ), routinely used to assess pain in obstetric environments, was used to determine pain perception. Thirteen labouring women and nine midwives completed the SF-MPQ every 15 minutes beginning at the time of admittance to the delivery suite. Peak pain ratings for the preceding 15 minutes were obtained without reference to prior ratings or each other's scores. Further, midwives in the maternity unit of The Queen Elizabeth Hospital (TQEH), Adelaide, South Australia completed a survey investigating the cues they use to assess pain during labour. RESULTS: On each measure of pain on the SF-MPQ, the midwives scores correlated with the mothers' scores across the entire pain range. Further analysis showed that mothers' and midwives' pain scores were similar at mild-moderate pain levels, but midwives significantly underestimated pain intensity at levels that mothers described as severe. The survey responses indicated that midwives rely on both verbal and nonverbal cues to assess pain levels. CONCLUSIONS: The cues used by midwives to differentiate pain intensities and qualities are similar to those used in other clinical settings, but may have limited discriminatory value as pain levels become severe.

Activation of HIV in human skin by ultraviolet B radiation and its inhibition by NFkappaB blocking agents.

To determine whether ultraviolet B (UVB) irradiation leads to activation of HIV in human skin, we conducted prospective and controlled studies in two academic medical centers in Texas from July 1995 to April 1999. HIV-positive patients with UV-treatable skin diseases were enrolled at each center, 18 subjects at one and 16 at the other. In one center, specimens from lesional and nonlesional skin biopsies were taken before and after sham- or UVB-irradiation administered in vivo or in vitro. In the other center, UVB phototherapy was administered three times weekly and specimens from skin biopsies were taken before and after 2 weeks (six treatments). Cutaneous HIV load was assessed using reverse transcriptase-polymerase chain reaction and reverse transcriptase-polymerase chain reaction in situ hybridization. UVB irradiation led to a 6-10-fold increase in the number of HIV in skin. To ascertain a role for nuclear factor kappa B (NFkappaB) in UVB-inducible HIV activation, two types of blockers, NFkappaB oligonucleotide decoy and sodium salicylate, were tested; each inhibited UVB-inducible HIV activation in skin partially. We conclude that UVB irradiation leads to increased numbers of HIV in human skin via processes that include release of cytoplasmic NFkappaB.

Craniosacral rhythm: reliability and relationships with cardiac and respiratory rates.

Craniosacral rhythm (CSR) has long been the subject of debate, both over its existence and its use as a therapeutic tool in evaluation and treatment. Origins of this rhythm are unknown, and palpatory findings lack scientific support. The purpose of this study was to determine the intra- and inter-examiner reliabilities of the palpation of the rate of the CSR and the relationship between the rate of the CSR and the heart or respiratory rates of subjects and examiners. The rates of the CSR of 40 healthy adults were palpated twice by each of two examiners. The heart and respiratory rates of the examiners and the subjects were recorded while the rates of the subjects' CSR were palpated by the examiners. Intraclass correlation coefficients were calculated to determine the intra- and inter-examiner reliabilities of the palpation. Two multiple regression analyses, one for each examiner, were conducted to analyze the relationships between the rate of the CSR and the heart and respiratory rates of the subjects and the examiners. The intraexaminer reliability coefficients were 0.78 for examiner A and 0.83 for examiner B, and the interexaminer reliability coefficient was 0.22. The result of the multiple regression analysis for examiner A was R = 0.46 and adjusted R2 = 0.12 (p = 0.078) and for examiner B was R = 0.63 and adjusted R2 = 0.32 (p = 0.001). The highest bivariate correlation was found between the CSR and the subject's heart rate (r = 0.30) for examiner A and between the CSR and the examiner's heart rate (r = 0.42) for examiner B. The results indicated that a single examiner may be able to palpate the rate of the CSR consistently, if that is what we truly measured. It is possible that the perception of CSR is illusory. The rate of the CSR palpated by two examiners is not consistent. The results of the regression analysis of one examiner offered no validation to those of the other. It appears that a subject's CSR is not related to the heart or respiratory rates of the subject or the examiner.

Effect of melatonin and corticosteroid on in vitro cellular immune function in humans.

It is well accepted that the immune system shows circadian rhythmicity and that circadian disruption can significantly alter indices of immune function. Recently, a functional link between the endocrine and immune systems has been proposed to explain circadian rhythms in immune activity. Of particular interest is the finding that hormones such as melatonin and corticosteroid are able to exert modulating effects on lymphocyte proliferation. Previous research examining the effects of melatonin in vitro, however, has produced equivocal results. The aim of this study, therefore, was to examine the effects of melatonin and corticosteroid, both separately and together, on mitogen-stimulated human lymphocyte proliferation. Purified human lymphocytes were stimulated with concanavalin A (Con A, 4 micrograms/mL). Melatonin and/or corticosteroid were added to the culture medium during incubation. All cultures were done in quadruplicate. As expected, corticosteroid (25-1,000 ng/mL) significantly reduced proliferation by between 30 and 60% in a dose-related manner (P < 0.0001). Melatonin alone (10-1,000 fmol/mL) did not significantly affect lymphocyte proliferation. However, when lymphocytes were cultured in the presence of melatonin and corticosteroid, a significant decrease in proliferative function of 50-85% was observed (P < 0.0001). Hence, the effect of melatonin and corticosteroid combined was significantly greater than that observed with corticosteroid alone (P < 0.0001). Therefore, it appears that the in vitro effect of corticosteroid on immune function may be modulated by melatonin in physiological to pharmacological concentrations.

Chronobiotics--drugs that shift rhythms.

A chronobiotic is defined and levels of action within the mammalian circadian pacemaker system, such as the retina, retinohypothalamic tract, geniculohypothalamic tract, suprachiasmatic nuclei, output and feedback systems are identified. Classes of drug that include the indoleamines, cholinergic agents, peptides, and benzodiazepines, which might act as chronobiotics within these levels, are evaluated. Particular emphasis is placed on the indole, melatonin (MLT). The clinical circumstances for use of chronobiotics in sleep disturbances of the circadian kind, such as jet lag, shift work, delayed sleep-phase syndrome, advanced sleep-phase syndrome, irregular and non-24-hr sleep-wake cycles, are described under reorganized headings of disorders of entrainment, partial entrainment, and desynchronization. Specific attention is given to the blind and the aged. Both human and animal studies suggest that MLT has powerful chronobiotic properties. MLT shows considerable promise as a prophylactic and therapeutic alternative or supplement to the use of natural and artificial bright light for resetting the circadian pacemaker. Throughout this discussion, the hypnotic and hypothermic versus the chronobiotic actions of MLT are raised. Finally, problems in the design of delivery systems for MLT are discussed.

Malnutrition: folate and cobalamin deficiency.

Malnutrition of folate and cobalamin occurs on a world-wide scale. Millions of individuals, for a variety of cultural, religious and socio-economic reasons, ingest less than the daily amounts required to maintain body stores. Assessment of intake depends on the population under study, method of food preparation and assay technique. Up to 90% of folate may be destroyed by cooking and, although less, significant amounts of cobalamin can also be lost in this way. Estimates of the proportion of both vitamins absorbed from a mixed diet vary, but may be as little as 50%. The need for supplementation is more common with folate than cobalamin. However, recent advances have highlighted subtle sub-clinical metabolic changes in some groups, particularly the elderly. Further investigation into their requirements is indicated. New assays for metabolites of cobalamin and folate are highly sensitive but lack specificity and are not readily available.

Increased cytotoxicity of squamous cell carcinoma of the head and neck by combining cisplatin with VP-16 and ciprofloxacin.

Chemotherapeutic treatment of squamous cell carcinoma (SCC) of the head and neck has been largely ineffective because of tumor cell resistance. This study examined combinations of cisplatin, 4' demethylepipodophyllotoxin ethylidene D-glucoside (VP-16), and ciprofloxacin, a quinolone antibiotic. VP-16 and ciprofloxacin were used in an effort to inhibit DNA repair and increase cytotoxicity. Chemotherapeutic agents often have a direct damaging effect on cellular DNA. Cytotoxicity may be the result of incomplete DNA repair mechanisms; whereas tumor cell resistance to drugs may be due to efficient DNA recovery. A nuclear enzyme especially important to DNA repair and cell growth is topoisomerase II (topo II). Targeted inhibition of topo II by VP-16 and ciprofloxacin may cause increased cisplatin cytotoxicity. SCC cell lines of head and neck origin were treated with a combination of cisplatin, VP-16, and/or ciprofloxacin with cell viability being assessed by the MTT colorimetric assay. Four of five SCC lines examined demonstrated significant augmentation of cisplatin cytotoxicity with the addition of both VP-16 and ciprofloxacin. These in vitro data suggest methods may exist for improving the chemotherapeutic treatment of SCC of the head and neck.

Alleviation of sleep maintenance insomnia with timed exposure to bright light.

OBJECTIVE: Half of the population over 65 suffers from chronic sleep disturbance. As a consequence, almost 40% of hypnotic medications are prescribed to people over age 60. Yet, hypnotics are often of little benefit in this population. As such, an effective non-drug alternative could prove important in the management of age-related sleep maintenance insomnia. The current study sought to evaluate the efficacy of bright light exposure in the treatment of sleep maintenance insomnia. DESIGN: Following baseline sleep and circadian rhythms assessment, subjects with sleep-maintenance insomnia were treated with timed exposure to either bright white light or dim red light for 12 consecutive days. Sleep and circadian rhythms recordings were subsequently obtained and measures of sleep quality were compared to assess efficacy of the treatments. SETTING: Baseline and post-treatment sleep and circadian rhythms assessments took place in the Laboratory of Human Chronobiology, Department of Psychiatry, Cornell University Medical College. The treatment phase of the study was conducted in participants' homes. PARTICIPANTS: Sixteen men and women between the ages of 62 and 81 years were studied. All subjects were free of hypnotic medication, and all had experienced sleep disturbance for at least 1 year prior to entering the study. RESULTS: Exposure to bright light resulted in substantial changes in sleep quality. Waking time within sleep was reduced by an hour, and sleep efficiency improved from 77.5% to 90%, without altering time spent in bed. Increased sleep time was in the form of Stage 2 sleep, REM sleep, and slow wave sleep. The effects were remarkably consistent across subjects. CONCLUSIONS: The findings demonstrate the effectiveness of timed exposure to bright light in the treatment of age-related sleep maintenance insomnia. With further refinement of treatment regimens, this non-drug intervention may prove useful in a large proportion of sleep disturbed elderly.

Melatonin and sleep in humans.

Early studies on the physiological effects of melatonin typically reported hypnotic 'side-effects'. Later studies, specifically addressing this action, failed to reliably replicate hypnotic effects using standard polysomnography. This difference may be related to differences in the basic physiological action of melatonin compared with more conventional hypnotics. It is suggested that melatonin exerts a hypnotic effect through thermoregulatory mechanisms. By lowering core body temperature, melatonin reduces arousal and increases sleep-propensity. Thus, in humans, one role of melatonin is to transduce the light-dark cycle and define a window-of-opportunity in which sleep-propensity is enhanced. As such, melatonin is likely to be an effective hypnotic agent for sleep disruption associated with elevated temperature due to low circulating melatonin levels. The combined circadian and hypnotic effects of melatonin suggest a synergistic action in the treatment of sleep disorders related to the inappropriate timing of sleep and wakefulness. Adjuvant melatonin may also improve sleep disruption caused by drugs known to alter normal melatonin production (e.g., beta-blockers and benzodiazepines). If melatonin is to be developed as a successful clinical treatment, differences between the pharmacological profile following exogenous administration and the normal endogenous rhythm should be minimized. Continued development as a useful clinical tool requires control of both the amplitude and duration of the exogenous melatonin pulse. There is a need to develop novel drug delivery systems that can reliably produce a square-wave pulse of melatonin at physiological levels for 8-10 hr duration.

The effect of hyperbaric oxygen on growth of human squamous cell carcinoma xenografts.

Hyperbaric oxygen is an important adjunct to the treatment of patients with head and neck cancer with existing or recurrent wound healing problems. Anecdotal clinical observations and a recent study of chemically induced oral cancer in hamsters have raised concern that hyperbaric oxygen therapy may accelerate tumor growth in such patients. This study evaluated the effect of hyperbaric oxygen therapy on the growth of human squamous cell carcinoma xenografts in a proved animal model. Fresh tumor specimens from three patients with head and neck squamous cell carcinoma of varying degrees of differentiation were first subcutaneously transplanted into a nude mouse host. Growing xenografts were then transplanted into one of three mouse groups. Half of the mice in each group were given hyperbaric oxygen therapy. The transplant volume as an index of tumor growth was measured in controls and mice given hyperbaric oxygen therapy six times during the 3-week course. Xenograft growth was almost linear in all mice. No statistical difference in overall group mean growth rates was observed in mice given hyperbaric oxygen or control mice regardless of the degree of tumor differentiation. Xenograft tissue from all mice was microscopically examined for tumor mitotic indices and degree of differentiation. This study suggests that hyperbaric oxygen therapy has no effect on established tumor xenograft growth.

A controlled trial of psychological treatment for the irritable bowel syndrome.

One hundred two patients with irritable bowel syndrome were studied in a controlled trial of psychological treatment involving psychotherapy, relaxation, and standard medical treatment compared with standard medical treatment alone. Patients were only selected if their symptoms had not improved with standard medical treatment over the previous 6 months. At 3 months, the treatment group showed significantly greater improvement than the controls on both gastroenterologists' and patients' ratings of diarrhea and abdominal pain, but constipation changed little. Good prognostic factors included overt psychiatric symptoms and intermittent pain exacerbated by stress, whereas those with constant abdominal pain were helped little by this treatment. This study has demonstrated that psychological treatment is feasible and effective in two thirds of those patients with irritable bowel syndrome who do not respond to standard medical treatment.

Bright light treatment: are we keeping our subjects in the dark?

Bright light treatments for seasonal affective disorder (SAD) and phase-disturbed circadian rhythms show considerable interindividual variation in response. Many studies have explained this variation in terms of traditional explanations of response variance, i.e., poor diagnostic criteria, poor compliance, etc. This study examined proximity and gaze behavior during illumination as a source of variance in response. Distance from the light source and gaze were varied systematically in order to quantify the discrepancy between perceived and transmitted light. The results indicate that the discrepancy between perceived and transmitted light increases rapidly as a function of distance and gaze. At best, subjects exposed to a transmitted illuminance of 10,000 lux perceived only 20% of the transmitted light, and this dropped rapidly to between 1 and 2% when subjects were more than 3 feet away and not gazing directly at the light source. These results suggest that light treatment protocols may be compromised by lack of attention to compliance and administration factors. These issues may account for much of the response variance observed previously.

Magnetic resonance imaging in multiple sclerosis: decreased signal in thalamus and putamen.

High-field strength (1.5 Tesla) magnetic resonance imaging in 15 patients with multiple and extensive white-matter lesions and clinically definite multiple sclerosis delineated a previously undescribed finding of abnormally decreased signal intensity on T2-weighted images in the thalamus and putamen. The decreased signal intensity (preferential decreased T2 relaxation time) is most likely to be related to abnormally increased iron accumulation causing local magnetic field heterogeneities.

Reduced signal intensity on MR images of thalamus and putamen in multiple sclerosis: increased iron content?

High-field-strength (1.5-T) MR imaging was used to evaluate 47 patients with definite multiple sclerosis and 42 neurologically normal control patients. Abnormal, multiple foci of increased signal intensity on T2-weighted images, most prominent in the periventricular white matter, were apparent in 43 of 47 MS patients and in two of 42 control patients. A previously undescribed finding of relatively decreased signal intensity most evident in the putamen and thalamus on T2-weighted images was seen in 25 of 42 MS patients and correlated with the degree of white-matter abnormality. In the normal control patients a prominently decreased signal intensity was noted in the globus pallidus, as compared with the putamen or thalamus, correlating closely with the distribution of ferric iron as determined in normal Perls'-stained autopsy brains. The decreased signal intensity (decreased T2) is due to ferritin, which causes local magnetic field inhomogeneities and is proportional to the square of the field strength. The decreased T2 in the thalamus and striatum in MS may be related to abnormally increased iron accumulation in these locales with the underlying mechanism remaining speculative.

Changes in erythroblast morphology as an index of response to cyanocobalamin in patients with megaloblastic anaemia.

Fifty-three patients with megaloblastic anaemia treated with cyanocobalamin and folic acid have been studied. Repeat marrow examination was found to be of value in assessing response to treatment. The early improvement in marrow morphology in patients with pernicious anaemia was greater with 1000 mug than with 5 mug doses of cyanocobalamin. The effect of folate deficiency in delaying marrow response to cyanocobalamin in patients with pernicious anaemia is described and combined cyanocobalamin and folic acid treatment was found to be more effective than either alone. The response to large doses of cyanocobalamin in folate deficient patients was unrelated to the initial serum vitamin B12 level.