The APPLE Tree programme: Active Prevention in People at risk of dementia through Lifestyle, bEhaviour change and Technology to build REsiliEnce-randomised controlled trial

BACKGROUND

Large-scale trials of multidomain interventions show that modifying lifestyle and psychological risk factors can slow cognitive decline. We aim to determine if a lower intensity, personally tailored secondary dementia prevention programme for older people with subjective or mild objective memory decline, informed by behaviour change theory, reduces cognitive decline over 2 years.

METHODS

A multi-site, single-blind randomised controlled trial recruiting 704 older adults at high dementia risk due to mild cognitive impairment (MCI) or subjective cognitive decline (SCD). Participants are randomised using 1:1 allocation ratio to the APPLE Tree intervention versus control arm (dementia prevention information), stratified by site. The intervention explores and implements strategies to promote healthy lifestyle, increase pleasurable activities and social connections and improve long-term condition self-management. Two facilitators trained and supervised by a clinical psychologist deliver ten, 1-h group video call sessions over 6 months (approximately every fortnight), video-call 'tea breaks' (less structured, facilitated social sessions) in intervening weeks and individual goal-setting phone calls every 2 weeks. From 6 to 12 months, participants meet monthly for 'tea breaks', with those not attending receiving monthly goal-setting phone calls. Participants receive a food delivery, pedometer and website access to cognitive training and information about lifestyle modification. Follow-ups for all outcome measures are at 12 and 24 months. The primary outcome is cognition (Neuropsychological Test Battery (NTB) score) at 24 months. Secondary outcomes are quality of life, cost per quality-adjusted life year (QALY) and wellbeing and lifestyle factors the intervention targets (diet, vascular risk, body weight, activity, sleep, anxiety, depression, social networks and loneliness, alcohol intake and smoking). Participants from purposively selected sites participate in qualitative process evaluation interviews, which will be analysed using thematic analytic methods.

DISCUSSION

If effective, the intervention design, involving remote delivery and non-clinical facilitators, would facilitate intervention roll-out to older people with memory concerns.

TRIAL REGISTRATION

ISRCTN17325135 . Registration date 27 November 2019.

Variation in the recall of socially rewarding information and depressive symptom severity: a prospective cohort study

OBJECTIVE

To test the association between recall for socially rewarding (positive) and/or socially critical (negative) information and depressive symptoms.

METHOD

Cohort study of people who had visited UK primary care in the past year reporting depressive symptoms (N = 558, 69% female). Positive and negative recall was assessed at three time-points, 2 weeks apart, using a computerised task. Depressive symptoms were assessed at four time-points using the Beck Depression Inventory (BDI). Analyses were conducted using multilevel models.

RESULTS

Concurrently we found evidence that, for every increase in two positive words recalled, depressive symptoms reduced by 0.6 (95% CI -1.0 to -0.2) BDI points. This association was not affected by adjustment for confounders. There was no evidence of an association between negative recall and depressive symptoms (-0.1, 95% CI -0.5 to 0.3). Longitudinally, we found more evidence that positive recall was associated with reduced depressive symptoms than vice versa.

CONCLUSION

People with more severe depressive symptoms recall less positive information, even if their recall of negative information is unaltered. Clinicians could put more emphasis on encouraging patients to recall positive, socially rewarding information, rather than trying to change negative interpretations of events that have already occurred.

Relative prevalence of Salmonella Sofia on broiler chickens pre- and postprocessing in Australia

A survey was conducted to determine the relative prevalence of Salmonella serovars on whole chicken carcasses before and after processing in 3 Australian poultry abattoirs. Ninety and 180 whole chicken carcasses were tested for Salmonella serovars before and after processing, respectively. Each carcass was subjected to a buffered peptone water rinse according to Australian Standard methodologies and Salmonella prevalence was determined using Australian Standard methodologies. After isolation, Salmonella isolates were serotyped and results were analyzed to determine the relative percentage of each serovar at both processing points. Salmonella Sofia was shown to significantly increase its relative prevalence (P < or = 0.05) after processing and proved to be the dominant serovar accounting for 45/89 (51%) isolations before processing and 51/69 (74%) isolations after processing. The reasons for the increased relative prevalence of Salmonella Sofia are currently unknown and require further investigation but may involve factors related to prevalence and numbers on chickens and the ability of Salmonella Sofia to respond to environmental stressors and attach to surfaces.

Cognition in transmembrane domain neuregulin 1 mutant mice

Neuregulin 1 (NRG1), which has been implicated in the development of schizophrenia, is expressed widely throughout the brain and influences key neurodevelopmental processes such as myelination and neuronal migration. The heterozygous transmembrane domain Nrg1 mutant mouse (Nrg1 TM HET) exhibits a neurobehavioural phenotype relevant for schizophrenia research, characterized by the development of locomotor hyperactivity, social withdrawal, increased sensitivity to environmental manipulation, and changes to the serotonergic system. As only limited data are available on the learning and memory performance of Nrg1 TM HET mice, we conducted a comprehensive examination of these mice and their wild type-like littermates in a variety of paradigms, including fear conditioning (FC), radial arm maze (RAM), Y maze, object exploration and passive avoidance (PA). Male neuregulin 1 hypomorphic mice displayed impairments in the novel object recognition and FC tasks, including reduced interest in the novel object and reduced FC to a context, but not a discrete cue. These cognitive deficits were task-specific, as no differences were seen between mutant and control mice in spatial learning (i.e. RAM and Y maze) for both working and reference memory measures, or in the PA paradigm. These findings indicate that neuregulin 1 plays a moderate role in cognition and present further behavioural validation of this genetic mouse model for the schizophrenia candidate gene neuregulin 1.

Acoustic startle response and sensorimotor gating in a genetic mouse model for the Y1 receptor

Recent research has highlighted a potential role for neuropeptide Y (NPY) and its Y(1) receptor in the development of schizophrenia. Genetic as well as molecular biological studies have demonstrated reduced levels of NPY in schizophrenia patients. Importantly, Y(1) receptors may mediate some of the potential effects of NPY on schizophrenia, as decreased Y(1) receptor expression has been found in the lymphocytes of schizophrenia patients. To clarify NPY's role in schizophrenia, we investigated a genetic animal model for Y(1) deficiency in regard to (i) acoustic startle response (ASR), (ii) habituation to ASR and (iii) sensorimotor gating [i.e. prepulse inhibition (PPI)] using two different PPI protocols. Mutant and wild type-like mice were screened for baseline behaviours and after pharmacological challenge with the psychotropic drugs dexamphetamine (DEX) and MK-801. Y(1) knockout mice (Y(1)(-/-)) showed a moderate reduction of the ASR and an impaired ASR habituation at baseline and after DEX treatment. The baseline PPI performance of Y(1) mutant mice was unaltered their response to DEX and MK-801 challenge was moderately different compared to control mice, which was dependent on the PPI protocol used. MK-801 challenge had a protocol-dependent differential effect in Y(1)(-/-) mice and DEX a more pronounced impact at the highest prepulse intensities. In conclusion, it appears that the Y(1) receptor influences the acoustic startle response and its habituation but does not play a major role in sensorimotor gating. Further explorations into the effects of Y(1) deficiency seem valid.

Prevalence and serotypes of Salmonella associated with goats at two Australian abattoirs

AIMS

This study was carried out to determine the prevalence and serotype of Salmonella in goats presented for slaughter.

METHODS AND RESULTS

A total of 121 goats were examined for the presence of Salmonella in matching rumen, faecal and carcass samples. Samples were analysed for the presence of Salmonella following the Australian Standard AS 1766.2.5-1991. Salmonella was isolated from 56 (46.3%) faecal samples, 55 (45.5%) rumen samples and 35 (28.9%) carcass samples. The dominant serotypes isolated were Salmonella serotype Saintpaul (31%), Salmonella serotype Typhimurium (13%) and Salmonella serotype Chester (11%).

CONCLUSIONS

Salmonella was isolated from at least one of the three sample sites in 68% of animals. Carcase contamination with faeces, compared with rumen liquor, is a greater hazard for Salmonella contamination of goat carcases. Goat meat is a potential source of Salmonella serovars associated with human disease.

SIGNIFICANCE AND IMPACT OF THE STUDY

Goat carcases contaminated with Salmonella during slaughter could be a source of food-borne disease if consumed raw or inadequately cooked, or may be a source of cross-contamination to other foods.

Altered motor activity, exploration and anxiety in heterozygous neuregulin 1 mutant mice: implications for understanding schizophrenia

Human genetic studies have shown that neuregulin 1 (NRG1) is a potential susceptibility gene for schizophrenia. Nrg1 influences various neurodevelopmental processes, which are potentially related to schizophrenia. The neurodevelopmental theory of schizophrenia suggests that interactions between genetic and environmental factors are responsible for biochemical alterations leading to schizophrenia. To investigate these interactions and to match experimental design with the pathophysiology of schizophrenia, we applied a comprehensive behavioural phenotyping strategy for motor activity, exploration and anxiety in a heterozygous Nrg1 transmembrane domain mutant mouse model (Nrg1 HET) using different housing conditions and age groups. We observed a locomotion- and exploration-related hyperactive phenotype in Nrg1 HETs. Increased age had a locomotion- and exploration-inhibiting effect, which was significantly attenuated in mutant mice. Environmental enrichment (EE) had a stimulating influence on locomotion and exploration. The impact of EE was more pronounced in Nrg1 hypomorphs. Our study also showed a moderate task-specific anxiolytic-like phenotype for Nrg1 HETs, which was influenced by external factors. The behavioural phenotype detected in heterozygous Nrg1 mutant mice is not specific to schizophrenia per se, but the increased sensitivity of mutant mice to exogenous factors is consistent with the pathophysiology of schizophrenia and the neurodevelopmental theory. Our findings reinforce the importance of carefully controlling experimental designs for external factors and of comprehensive, integrative phenotyping strategies. Thus, Nrg1 HETs may, in combination with other genetic and drug models, help to clarify pathophysiological mechanisms behind schizophrenia.

Heterozygous neuregulin 1 mice are more sensitive to the behavioural effects of Delta9-tetrahydrocannabinol

RATIONALE

Cannabis use may precipitate schizophrenia especially if the individual has a genetic vulnerability to this mental disorder. Human and animal research indicates that neuregulin 1 (Nrg1) is a susceptibility gene for schizophrenia.

OBJECTIVES

The aim of this study was to investigate whether dysfunction in the Nrg1 gene modulates the behavioural effects of Delta(9)-tetrahydrocannabinol (THC), the major psychotropic component of cannabis.

MATERIALS AND METHODS

Heterozygous Nrg1 transmembrane-domain knockout mice (Nrg1 HET) were treated with acute THC (0, 5 or 10 mg/kg i.p.) 30 min before being tested using open field (OF), hole board (HB), light-dark (LD), elevated plus maze (EPM), social interaction (SI) and prepulse inhibition (PPI) tests.

RESULTS

Nrg1 HET mice showed differences in baseline behaviour with regard to locomotor activity, exploration and anxiety. More importantly, they were more sensitive to the locomotor suppressant actions of THC compared to wild type-like (WT) mice. In addition, Nrg1 HET mice expressed a greater THC-induced enhancement in % PPI than WT mice. The effects of THC on anxiety-related behaviour were task-dependent, with Nrg1 HET mice being more susceptible than WT mice to the anxiogenic effects of THC in LD, but not in the EPM, SI and OF tests.

CONCLUSIONS

Nrg1 HET mice were more sensitive to the acute effects of THC in an array of different behaviours including those that model symptoms of schizophrenia. It appears that variation in the schizophrenia-related neuregulin 1 gene alters the sensitivity to the behavioural effects of cannabinoids.

Growth temperature of four Campylobacter jejuni strains influences their subsequent survival in food and water

AIM

To determine if Campylobacter jejuni grown at 37 and 42 degrees C have different abilities to survive on beef and chicken, and in water.

METHODS AND RESULTS

Beef, chicken and water were separately inoculated with four Camp. jejuni (two poultry and two beef) strains grown at 37 or 42 degrees C. The matrices were stored at approximately 4 degrees C and Camp. jejuni numbers were monitored over time by plate counts. On beef there was a greater decrease in number for two strains (P < 0.05; approximately 0.7 and 1.3 log CFU cm(-2)) grown at 37 degrees C as compared with 42 degrees C. By contrast on chicken there was a decrease in numbers for two strains (P < 0.05; approximately 1.3 and 1 log CFU g(-1)) grown at 42 degrees C as compared with 37 degrees C. In water there was a greater decrease in numbers for all strains (P < 0.05; approximately 3-5.3 log CFU ml(-1)) grown at 42 degrees C as compared with 37 degrees C.

CONCLUSIONS

Growth temperature influences the survival of Camp. jejuni on food and in water.

SIGNIFICANCE AND IMPACT OF THE STUDY

Campylobacter jejuni survival studies need to consider growth temperature to avoid erroneous results. Campylobacter jejuni grown at 37 degrees C, the body temperature of humans and cattle, may represent a greater public health risk in water than those grown at 42 degrees C, the body temperature of poultry.

Results of a search for cold flows of dark matter axions

Theoretical arguments predict that the distribution of cold dark matter in spiral galaxies has peaks in velocity space associated with nonthermalized flows of dark matter particles. We searched for the corresponding peaks in the spectrum of microwave photons from axion to photon conversion in a cavity detector for dark matter axions. We found none and place limits on the density of any local flow of axions as a function of the flow velocity dispersion over the axion mass range 1.98 to 2.17 microeV.

Elevated cytokine and chemokine levels and prolonged pulmonary airflow resistance in a murine Mycoplasma pneumoniae pneumonia model: a microbiologic, histologic, immunologic, and respiratory plethysmographic profile

Because Mycoplasma pneumoniae is hypothesized to play an important role in reactive airway disease/asthma, a comprehensive murine model of M. pneumoniae lower respiratory infection was established. BALB/c mice were intranasally inoculated once with M. pneumoniae and sacrificed at 0 to 42 days postinoculation. All mice became infected and developed histologic evidence of acute pulmonary inflammation, which cleared by 28 days postinoculation. By contrast, M. pneumoniae persisted in the respiratory tract for the entire 42 days studied. Tumor necrosis factor alpha, gamma interferon, interleukin-6 (IL-6), KC (functional IL-8), MIP-1alpha, and MCP-1/JE concentrations were significantly elevated in bronchoalveolar lavage samples, whereas IL-4 and IL-10 concentrations were not significantly elevated. Pulmonary airflow resistance, as measured by plethysmography, was detected 1 day postinoculation and persisted even after pulmonary inflammation had resolved at day 28. Serum anti-M. pneumoniae immunoglobulin G titers were positive in all mice by 35 days. This mouse model provides a means to investigate the immunopathogenesis of M. pneumoniae infection and its possible role in reactive airway disease/asthma.

Dexamethasone facilitates discharge after outpatient anorectal surgery

Corticosteroids can decrease pain and postoperative nausea and vomiting after ambulatory surgery. Therefore, we designed a study to evaluate if the routine use of dexamethasone would facilitate the early recovery process after anorectal surgery. A secondary aim of the study was to determine if dexamethasone would increase the incidence of postoperative wound complications. Eighty adult outpatients undergoing anorectal surgery with a standardized monitored anesthesia care technique were randomly assigned to receive either dexamethasone 4 mg IV or an equal volume of saline before the start of surgery. All patients were premedicated with midazolam 2 mg IV and received ketorolac 30 mg IV as a preemptive analgesic. A propofol infusion, 50 microg. kg(-1). min(-1) IV, was initiated and subsequently titrated to maintain an observer's assessment of alertness/sedation score of 2 or 3 (with 5 = awake/alert to 1 = asleep). Fentanyl 25 microg IV was administered 3-5 min before infiltrating the surgical field with a 30-mL local anesthetic mixture containing 15 mL of lidocaine 1% and 15 mL of bupivacaine 0.25% (with epinephrine 1:200,000 and sodium bicarbonate 3 mL). All patients were fast-tracked directly from the operating room to the step-down recovery area. Even though the incidences of postoperative pain and postoperative nausea and vomiting were small in both treatment groups, the time to "home readiness" was significantly shorter in the dexamethasone group. Importantly, there was no increase in the incidence of wound infections (8% vs 12%) or hematoma formation (3% vs 5%) in the dexamethasone (versus saline) group. We conclude that the administration of dexamethasone, 4 mg IV, shortened the time to home readiness without increasing the incidence of postoperative wound infections in a high-risk outpatient population undergoing anorectal surgery.

IMPLICATIONS

A single dose of dexamethasone (4 mg IV) decreased the time to "home readiness" without increasing the incidence of postoperative wound complications in an outpatient population undergoing anorectal surgery.

Acid resistance of enterohaemorrhagic and generic Escherichia coli associated with foodborne disease and meat

As part of the Australia New Zealand Food Authorities (ANZFA) food standards code, salami manufacturers are required to demonstrate that their process is capable of achieving a 3-log reduction in Escherichia coli. Non-pathogenic E. coli strains with similar or greater acid resistance to enterohaemorrhagic E. coli (EHEC) are needed if industry is to conduct challenge studies to demonstrate compliance with the standard. In the present study, E. coli isolates from sheep and beef carcasses and meat were shown to have wide-ranging acid resistance in broth when preadapted to growth in acidic conditions. Times required for a 3-log reduction in E. coli ranged from less than I day to more than 28 days. Variable acid resistance was observed in both EHEC strains associated with foodborne outbreaks and generic E. coli strains. Generic E. coli strains with the greatest acid resistance were assessed for pathogenicity markers and their survival in fermented meat compared with EHEC strains. It was demonstrated that generic E. coli strains could be used for challenge studies to determine compliance with or validate performance standards designed for the control of EHEC.

Spontaneous recovery profile of rapacuronium during desflurane, sevoflurane, or propofol anesthesia for outpatient laparoscopy

We evaluated the spontaneous recovery characteristics of rapacuronium during desflurane-, sevoflurane-, or propofol-based anesthesia in 51 consenting women undergoing laparoscopic tubal ligation procedures. After the induction of the anesthesia with standardized doses of propofol and fentanyl, 1.5 mg/kg IV rapacuronium was administered to facilitate tracheal intubation. Patients were randomized to receive either 1 minimum alveolar anesthetic concentration of desflurane, 1 minimum alveolar concentration of sevoflurane, or 100 microg. kg(-1). min(-1) propofol infusion in combination with 66% nitrous oxide in oxygen for maintenance of anesthesia. Neuromuscular blockade was monitored at the wrist by using electromyography. The degree of maximum blockade and the times for first twitch recovery (T(1)) to 5%, 25%, 50%, 75%, and 90%, as well as the recovery index, were similar in all three anesthetic groups. However, recovery times for the train-of-four ratio to achieve 0.7 and 0.8 were significantly longer with desflurane (44.4 +/- 18.9 and 53.5 +/- 22.4 min) and sevoflurane (44.8 +/- 15.1 and 53.2 +/- 15.8 min) compared with propofol (31.8 +/- 5.3 and 36.5 +/- 6.5 min). Eight patients (16%) required a maintenance dose of 0.5 mg/kg rapacuronium and reversal of rapacuronium residual block occurred in three (6%) patients. We conclude that spontaneous recovery after an intubating dose of 1.5 mg/kg rapacuronium was significantly prolonged by both desflurane and sevoflurane compared with propofol-based anesthesia. Routine monitoring of neuromuscular activity is recommended even when a single bolus dose of rapacuronium is administered during ambulatory anesthesia.

IMPLICATIONS

When administered for laparoscopic surgery, the duration of action of an intubating dose of rapacuronium was prolonged 40%-50% by desflurane and sevoflurane, respectively, (versus propofol). Monitoring recovery of neuromuscular blockade produced by rapacuronium is particularly important when desflurane or sevoflurane is administered to ensure that an adequate recovery (train-of-four > or = 0.8) is achieved by the end of anesthesia.

Onset/offset characteristics and intubating conditions of rapacuronium: a comparison with rocuronium

We compared onset and offset of action and tracheal intubating conditions after rapacuronium and rocuronium in 60 patients in a randomized, assessor-blinded study. Following induction of anaesthesia with propofol 2.5 mg kg-1, either rapacuronium 1.5 mg kg-1 (n = 30) or rocuronium 0.6 mg kg-1 (n = 30) was administered to facilitate tracheal intubation. Anaesthesia was maintained with either a propofol infusion (100 micrograms kg-1 min-1) or sevoflurane (1% end-tidal) with 66% nitrous oxide (N2O), n = 15 in each subgroup. Neuromuscular monitoring was performed using an electromyographic (EMG) device (Datex Relaxograph). The lag times (mean 42 (SD 11) s and 44 (16) s), maximum block (99 (2)% and 98 (3)%) and intubating conditions at 60 s (good-to-excellent in 86% and 84% of patients) were similar for rapacuronium and rocuronium, respectively. The onset time of rapacuronium was shorter than rocuronium (87 (20) vs 141 (65) s, P < 0.001), and the degree of block at 60 s was greater (69 (26) vs 50 (27)%, P < 0.05). Twenty-five per cent recovery was shorter with rapacuronium than rocuronium during propofol (15.0 (3.2) vs 39.1 (14.2) min, P < 0.001) and sevoflurane (15.1 (4.2) vs 47.8 (19.0) min, P < 0.001) anaesthesia. We conclude that rapacuronium 1.5 mg kg-1 had a more rapid onset, similar intubating conditions, and shorter recovery times than rocuronium 0.6 mg kg-1.

Fast-tracking after immersion lithotripsy: general anesthesia versus monitored anesthesia care

Both monitored anesthesia care (MAC) and general anesthesia (GA) offer advantages over epidural anesthesia for immersion lithotripsy. We compared propofol-based MAC and desflurane-based GA techniques for outpatient lithotripsy. After receiving midazolam 2 mg IV, 100 subjects were randomly assigned to one of two anesthetic treatment groups. In the MAC group, propofol 50-100 microg. kg(-1). min(-1) IV was titrated to maintain an observer's assessment of alertness/sedation score of 2-3 (5 = awake/alert to 1 = asleep). Remifentanil 0.05 microg.kg(-1). min(-1) IV supplemented with 0.125 microg/kg IV boluses, was administered for pain control. In the GA group, anesthesia was induced with propofol 1.5 mg/kg IV and remifentanil 0.125 microg/kg IV and maintained with desflurane (2%-4% inspired) and nitrous oxide (60%). Tachypnea (respiratory rate >20 breaths/min) was treated with remifentanil 0.125 microg/kg IV boluses. In the GA group, droperidol (0.625 mg IV) was administered as a prophylactic antiemetic. Recovery times and postoperative side effects were assessed up to 24 h after the procedure. Compared with MAC, the use of GA reduced the opioid requirement and decreased movements and episodes of desaturation (<90%) during the procedure. Although the GA group took longer to return to an observer's assessment of alertness/sedation score of 5, discharge times were similar in both groups. We conclude that GA can provide better conditions for outpatient immersion lithotripsy than MAC sedation without delaying discharge.

IMPLICATIONS

A desflurane-based general anesthetic technique using the cuffed oropharyngeal airway device was found to be a highly acceptable alternative to propofol-based monitored anesthesia care sedation for outpatient immersion lithotripsy.

A comparison of microbipolar cautery dissection to hot knife and cold knife cautery tonsillectomy

BACKGROUND

Morbidity following tonsillectomy continues to be a major concern to parents, children, and physicians alike. Reduction in post-operative complications, optimal control of pain, and satisfactory return to a normal lifestyle are all important to both family and society. This study compares both the complication and recovery rates after microbipolar dissection (MBPD) technique of tonsillectomy to two well established tonsillectomy techniques: hot knife (HK) and cold knife/cautery (CK/C).

METHODS

A total of 200 consecutive patients presenting for tonsillectomy by the first author (MP) were randomized to either undergo MBPD or HK tonsillectomy. Concurrently, an additional two hundred patients were randomized to undergo MBPD or CK/C tonsillectomy by the second author (LB). Patients were prospectively followed for complications including bleeding and dehydration and multiple indicators of recovery rate.

RESULTS

Postoperative bleeding of any kind was significantly less in the MBPD group than in the CK/C and HK groups (5 vs 12.4 vs 12.5% (P<0.001). The need for post-operative intervention for bleeding, i.e. local control or return to the operating room, was also significantly less in the MBPD group. Return to normal activity occurred 2 days earlier in the MBPD group versus either CK/C or HK (P<0.001). Additionally, earlier recovery was reflected in fewer total doses of pain medication in the MBPD group. Operative time was 3-5 min longer for MBPD (24.2 min) than for CK/C or HK (21.1 and 16.5 min, respectively); blood loss was similar (within 15 cc) among all treatment groups.

CONCLUSION

MBPD tonsillectomy compared most favorably to conventional techniques (CK/C and to HK tonsillectomy). Important clinical outcome differences included a lower bleed rate, earlier recovery and fewer days lost from work and school. The financial impact is estimated to be quite favorable. MBPD tonsillectomy is now our preferred method in children.

Effect of cyclodextrins and polymers on triclosan availability and substantivity in toothpastes in vivo

The aqueous solubility of triclosan is only about 10 microg/mL. This very low solubility can hamper its biological activity in the oral cavity, which could explain the mixed clinical results obtained from triclosan toothpaste trials. Triclosan availability in a silica-based toothpaste was improved through cyclodextrin solubilization. The triclosan in vivo availability was optimized through a series of phase-solubility studies and triclosan release studies. It was found that in toothpastes, natural beta-cyclodextrin (betaCD) was just as good a solubilizer as the more water-soluble betaCD derivatives. Furthermore, the amount of cyclodextrin could be reduced by as much as 60% through the addition of a small amount of carboxymethylcellulose (CMC), without affecting triclosan release from the toothpaste. Optimally, cyclodextrins resulted in an almost 3-fold enhancement of triclosan availability compared to an identical toothpaste containing no cyclodextrin. In vivo studies in humans showed that replacing triclosan with triclosan/betaCD in the toothpaste resulted in only moderate improvement in triclosan substantivity. However, replacing triclosan with triclosan/betaCD/CMC complex resulted in significant improvement in triclosan substantivity. Furthermore, the in vivo studies showed that replacing free triclosan with triclosan/betaCD/CMC complex resulted in an almost 3-fold increase in initial triclosan concentration in saliva after brushing and about 2-fold increase in duration of activity.

Effects of prophylactic nalmefene on the incidence of morphine-related side effects in patients receiving intravenous patient-controlled analgesia

BACKGROUND

Opioid-related side effects associated with intravenous patient-controlled analgesia can be reduced by a low-dose naloxone infusion. The influence of nalmefene, a pure opioid antagonist with a longer duration of action, on opioid-related side effects has not been evaluated. This study was designed to determine the dose-response relation for nalmefene for the prevention of morphine-related side effects in patients receiving intravenous patient-controlled analgesia.

METHODS

One hundred twenty women undergoing lower abdominal surgery were enrolled in the study. General anesthesia was induced using thiopental and rocuronium and maintained with desflurane, nitrous oxide, and fentanyl or sufentanil. All patients received neostigmine and glycopyrrolate to reverse residual neuromuscular blockade. No prophylactic antiemetics were administered. At the end of surgery, patients were randomized to receive saline, 15 microg nalmefene, or 25 microg nalmefene intravenously. The need for antiemetic and antipruritic drugs and the total consumption of morphine during the 24-h study were recorded. The incidences of postoperative nausea, vomiting, pruritus, and pain were recorded 30 min after patients were admitted to the postanesthesia care unit. In addition, patient remembrance of these side effects was noted at 24 h after operation.

RESULTS

The need for antiemetic and antipruritic medications during the 24-h study period was significantly lower in the patients receiving nahmefene compared with those receiving placebo. However, the need to treat side effects was similar in the two nahmefene groups. Prophylactic administration of nalmefene reduced the patients remembrance of nausea and itching as assessed 24 h after operation. Although the total consumption of morphine during the 24-h study period was similar in the three groups, retrospectively patients who received nalmefene characterized their pain as less severe in the previous 24 h.

CONCLUSION

Compared with placebo, prophylactic administration of nalmefene significantly decreased the need for antiemetics and antipruritic medications in patients receiving intravenous patient-controlled analgesia with morphine.

Comparison of adenosine and remifentanil infusions as adjuvants to desflurane anesthesia

BACKGROUND

Because adenosine has been alleged to produce both anesthetic and analgesic sparing effects, a randomized, double-blinded study was designed to compare the perioperative effects of adenosine and remifentanil when administered as intravenous adjuvants during general anesthesia for major gynecologic procedures.

METHODS

Thirty-two women were assigned randomly to one of two drug treatment groups. After premedication with 0.04 mg/kg intravenous midazolam, anesthesia was induced with 2 micro/kg intravenous fentanyl, 1.5 mg/kg intravenous propofol, and 0.6 mg/kg intravenous rocuronium, and maintained with desflurane, 2%, and nitrous oxide, 65%, in oxygen. Before skin incision, an infusion of either remifentanil (0.02 microg x kg(-1) x min(-1)) or adenosine (25 microg x kg(-1) x min(-1)) was started and subsequently titrated to maintain systolic blood pressure, heart rate, or both within 10-15% of the preincision values.

RESULTS

Adenosine and remifentanil infusions were effective anesthetic adjuvants during lower abdominal surgery. Use of adenosine (mean +/- SEM, 166+/-17 microg x kg(-1) x min(-1)) was associated with a significantly greater decrease in systolic blood pressure and higher heart rate values compared with remifentanil (mean +/- SEM, 0.2+/-0.03 microg kg(-1) x min(-1)). Total postoperative opioid analgesic use was 45% and 27% lower in the adenosine group at 0-2 h and 2-24 h after surgery, respectively.

CONCLUSIONS

Adjunctive use of a variable-rate infusion of adenosine during desflurane-nitrous oxide anesthesia was associated with acceptable hemodynamic stability during the intraoperative period. Compared with remifentanil, intraoperative use of adenosine was associated with a decreased requirement for opioid analgesics during the first 24 h after operation.

A sequential treatment regimen with melatonin and all-trans retinoic acid induces apoptosis in MCF-7 tumour cells

Neoplastic events are marked by uncontrolled cell proliferation. One major focus of cancer research has been to identify treatments that reduce or inhibit cell growth. Over the years, various compounds, both naturally occurring and chemically synthesized, have been used to inhibit neoplastic cell proliferation. Two such oncostatic agents, melatonin and retinoic acid, have been shown to suppress the growth of hormone-responsive breast cancer. Currently, separate clinical protocols exist for the administration of retinoids and melatonin as adjuvant therapies for cancer. Using the oestrogen receptor (ER)-positive MCF-7 human breast tumour cell line, our laboratory has studied the effects of a sequential treatment regimen of melatonin followed by all-trans retinoic acid (atRA) on breast tumour cell proliferation in vitro. Incubation of hormonally responsive MCF-7 and T47D cells with melatonin (10(-9) M) followed 24 h later by atRA (10(-9) M) resulted in the complete cessation of cell growth as well as a reduction in the number of cells to below the initial plating density. This cytocidal effect is in contrast to the growth-suppressive effects seen with either hormone alone. This regimen of melatonin followed by atRA induced cytocidal effects on MCF-7 cells by activating pathways leading to apoptosis (programmed cell death) as evidenced by decreased ER and Bcl-2 and increased Bax and transforming growth factor beta 1 (TGF-beta1) expression. Apoptosis was reflected morphologically by an increase in the number of lysosomal bodies and perinuclear chromatin condensation, cytoplasmic blebbing and the presence of apoptotic bodies. The apoptotic effect of this sequential treatment with melatonin and atRA appears to be both cell and regimen specific as (a) ER-negative MDA-MB-231 and BT-20 breast tumour cells were unaffected, and (b) the simultaneous administration of melatonin and atRA was not associated with apoptosis in any of the breast cancer cell lines studied. Taken together, the results suggest that use of an appropriate regimen of melatonin and atRA should be considered for preclinical and clinical evaluation against ER-positive human breast cancer.

Breastfeeding after strenuous aerobic exercise: a case report

There are no documented adverse effects of breastfeeding after long distance running. This case describes an exclusively breastfed baby who cried after being breastfed about 1-2 hours following his mother's 5-mile run. When artificial baby milk was substituted for the postrun feeding only, the inconsolable crying did not occur. Testing the mother's breast milk before and after running showed a similar level of lactic acid; no other component was tested. Further research is needed in this area.

Relationship between nasopharyngeal colonization and the development of otitis media in children. Tonawanda/Williamsville Pediatrics

Streptococcus pneumoniae, nontypeable Haemophilus influenzae, and Moraxella catarrhalis are the predominant bacteria associated with otitis media. A cohort of 306 infants was followed from birth through 12 months to determine frequency and duration of colonization and risk of acute otitis media (AOM) and otitis media with effusion (OME). M. catarrhalis was the most common bacterium isolated. Infants colonized at < or = 3 months of age were at increased risk of AOM and OME. Early colonization with M. catarrhalis revealed the greatest risk (relative risk [RR] = 1.24), especially for OME (RR = 1.57). There was a strong relationship between the frequency of colonization and OM (r = .37, P < .001,) for each pathogen. Although S. pneumoniae, nontypeable H. influenzae, and M. catarrhalis are part of the normal nasopharyngeal flora during infancy, an increased rate of colonization may identify a subpopulation of children that is at increased risk of OM.

Adherence of nontypeable Haemophilus influenzae to respiratory epithelium of otitis-prone and normal children

Three hundred six children were enrolled at birth in a prospective study of otitis media and followed up for 2 years. Adherence of nontypeable Haemophilus influenzae to buccal epithelial cells was compared between otitis-prone children and age- and sex-matched normal controls at birth, 1 year, and 2 years. The mean +/- SD/median percent adherence was similar for the two groups at birth (1.6 +/- 2.3/1.0 versus 1.2 +/- 1.4/1.0; NS) and at 2 years (1.6 +/- 1.7/1.5 versus 2.1 +/- 2.1/1.5; NS). At 1 year of age the adherence rate for the otitis-prone group (2.4 +/- 2.6/1.0) was statistically greater than that for the control group (1.0 +/- 1.3/0.0; p < .02). Because this difference is probably clinically insignificant, other explanations must be sought for the increased colonization rates of nontypeable H influenzae observed in otitis-prone children.

Connecting the Research and Nursing Processes: Making a Difference in Baccalaureate Students' Attitudes and Abilities

Student nurses are often intimidated by the research process. They also frequently have negative attitudes about working with the elderly, especially in long-term care settings. This article describes a clinical project designed to help students improve their attitudes, knowledge, and skills toward research and care of the elderly by connecting the research process and the nursing process. Students implement research-based clinical practice in a long-term care setting. Student evaluations indicate that project goals are achieved. Nursing staff evaluation data indicate that they find student projects interesting and useful in updating resident care plans.

Adherence of nontypable Haemophilus influenzae to respiratory epithelium of otitis prone and normal children

The present study was designed to determine whether nontypable H. influenzae adhered differently to buccal cells from otitis prone compared with normal children. 306 children were enrolled at birth. They were examined at 1-6, 8, 10, 12, 15, 18, 21, and 24 months of age. Buccal cells were collected at 1, 12, and 24 months. 40 children were classified as OP (> or = 4 episodes by age 12 months or > or = 6 episodes by age 24 months). Adherence assays were conducted by incubating 1 x 10(4) buccal cells with 5 x 10(8) colony forming units of radiolabelled nontypable H. influenzae in 1 ml of salt solution with 0.1% gel at 37 degrees C for 60 min. Adherence was expressed as the % of organisms adherent to buccal cells. The adherence of buccal cells from otitis prone children were compared with age and sex matched controls who had not experienced otitis media and had not been colonized with nontypable H. influenzae.

Epidemiology of nasopharyngeal colonization with nontypeable Haemophilus influenzae in the first two years of life

A total of 200 children were followed from birth through 2 years of age with nasopharyngeal (NP) cultures to determine the normal colonization pattern of nontypeable H. influenzae (NTHI) in young children. NP cultures were obtained routinely at 13 scheduled visits. 44% of children became colonized by 2 years; acquisition was greatest in the first year. Colonization with the initial strain, as determined by outer membrane proteins, persisted from 1-5 months, median 2 months. Children carried one predominant strain at a time but became colonized with up to 7 different strains, mean 2.2, over 2 years. Three patterns of colonization were observed: i) rapid elimination of the initial strain, ii) prolonged colonization with the initial strain, and iii) colonization with different strains. Reacquisition of a previously carried strain was rare. Changes in outer membrane protein patterns reflected acquisition of new strains rather than phenotypic changes of old strains. Children colonized with 1 strain for < or = 2 months generated a greater mucosal antibody response, log 2.35, U/ng/ml SIgA, than children colonized with different strains, log 1.89, U/ng/ml SIgA, p <0.01. These data suggest that duration of colonization with one strain and the acquisition of a new strain is regulated by the local specific SIgA.

Microbipolar dissection vs. cold knife/suction cautery tonsillectomy in children: preliminary results of a prospective study

Tonsillectomy and adenoidectomy (T&A) is a common surgical procedure for which many different surgical techniques have been described. However, detailed information is lacking regarding complications or recovery rates for any particular procedure. A newly described technique for T&A, microbipolar dissection (MBPD) is being compared with cold knife dissection with suction cautery of bleeding vessels (CKC) in a prospective study of 200 children aged 2-16 years. Patients are randomly assigned and stratified by age-group into one of two treatment arms. Intraoperative and post-operative measures of T&A effectiveness relative to complications and patient recovery rate are being studied. The preliminary data presented here focus on the reliability of the measures and potential clinical relevance of the findings in 129 of these children, with anticipated confirmation of these tentative results after completion of the larger cohort. Thus far it appears that post-operative bleeding rates are significantly reduced, recovery rate is improved, and return to normal activities are all better in the MBPD patients. Although these data reflect small numbers of children and must be interpreted with caution, it appears that MBPD T&A holds great promise in reducing the morbidity associated with the CKC technique of T&A.

Epidemiology of nasopharyngeal colonization with nontypeable Haemophilus influenzae in the first 2 years of life

Two hundred children were followed from birth through 2 years of age with nasopharyngeal cultures to determine the normal colonization pattern of nontypeable Haemophilus influenzae. Forty-four percent of the children were colonized on one or more occasions; the acquisition rate was greatest in the first year. Monthly prevalence rates were 11%. Colonization with the initial strain persisted 1-5 months (median, 2). Children carried 1 predominant strain at a time but became colonized with up to 7 different strains (mean, 2.2). Children colonized with a single strain for < or = 2 months produced a greater nasopharyngeal secretory IgA to nontypeable H. influenzae response than did children colonized with different strains (log 2.35 +/- 0.68 vs. 1.89 +/- 0.25 U of P6 secretory IgA/ng/mL of total secretory IgA, P < .01). The duration of colonization with a strain and acquisition of a new strain may be affected in part by the local production of specific secretory IgA.

Acclimation of a non-indigenous sub-Arctic population: seasonal variation in thyroid function in interior Alaska

Total, as well as free, T4 and T3 levels were obtained over four seasons for young male infantry soldiers assigned to interior Alaska. Significant seasonal variations were found in both T3 and T4. Total T4 and T3 levels were highest in winter, while free T4 and T3 levels were highest in early spring. Correlations with melatonin levels from a concurrent study showed an association between late day (17.00) mean spot melatonin levels during the preceding summer and T3 levels in winter and spring. Differences in seasonal T4 and T3 levels between indigenous and newly arrived people in the sub-Arctic may be related not only to cold acclimation but also to light.

Growth of Listeria monocytogenes on vacuum-packed cooked meats: effects of pH, aw, nitrite and ascorbate

Slices of cooked meats were inoculated with Listeria monocytogenes strain Murray B, vacuum-packed and stored at either 0 or 5 degrees C. Decreases in pH (6.9-5.9) and aw (0.993-0.960; adjusted with sodium chloride) of the cooked meats increased the lag time and reduced the growth rate at 5 degrees C. The type of meat (beef, pork, chicken or turkey) had no effect on the growth of the organism after allowance was made for pH. Sodium tripolyphosphate (0.3%) increased growth by increasing the pH of the cooked meat. Sodium nitrite reduced the growth rate and increased the lag time. Three microM of residual undissociated nitrite doubled the time taken for a 3 log increase in numbers of L. monocytogenes. The effectiveness of nitrite was significantly increased by sodium ascorbate (0.042%). In the absence of nitrite, ascorbate had no detectable effect on growth. The extent of growth at 0 degree C was similarly influenced by the interaction of pH, aw, nitrite and ascorbate, and was considerably less than at 5 degrees C. Quadratic equations were developed to describe some of the combined effects of pH, aw and residual nitrite on lag, growth rate and time for a 3 log increase in numbers of L. monocytogenes.

Nasopharyngeal colonization with nontypeable Haemophilus influenzae and recurrent otitis media. Tonawanda/Williamsville Pediatrics

The relationship between nasopharyngeal colonization with nontypeable H. influenzae and recurrent otitis media was assessed in 157 children followed prospectively from birth through 12 months of age. Forty-nine (31%) became colonized. Nasopharyngeal secretory IgA (sIgA) reactive with the P6 outer membrane protein was detected in all colonized children. Reduction or elimination of the organism was associated with a better mucosal immune response (560 +/- 864 units/ng/mL of sIgA) than was persistence in the nasopharynx (121 +/- 81; P = .04). Forty colonized children (82%) and 61 noncolonized children (56%) developed otitis media (P = .004); colonized children were four times more likely to be classified as otitis prone (P = .003). The frequency of otitis media episodes was directly related to the frequency of colonization (r = .42, P < .01). These results demonstrate a strong relationship between nasopharyngeal colonization patterns and otitis media. The mucosal immune response may be important in elimination of potential pathogens from the respiratory tract.

Human milk secretory IgA antibody to nontypeable Haemophilus influenzae: possible protective effects against nasopharyngeal colonization

Sixty-eight children fed human milk were followed prospectively from birth to 12 months of age to assess the effect of milk antibody on nasopharyngeal colonization. Human milk secretory IgA antibody to P6, a highly conserved outer membrane protein of nontypeable Haemophilus influenzae, was measured with the use of an enzyme-linked immunosorbent assay. Nasopharyngeal colonization with nontypeable H. influenzae and the occurrence of otitis media were determined. Nasopharyngeal colonization was found in 22 children (32%), and 39 children (57%) had otitis media. Frequency of isolation of nontypeable H. influenzae was directly related to episodes of otitis media (r = 0.35; p = 0.001). The level of human milk anti-P6 secretory IgA antibody was inversely related to frequency of isolation of the organism (r = -0.27; p = 0.026). The average antibody level, expressed as nanograms per 0.1 mg total secretory IgA, in human milk fed to children with no colonization of nontypeable H. influenzae was significantly higher than in milk fed to children in whom colonization occurred on multiple occasions (156 +/- 120 vs 69 +/- 50; p = 0.013). Prevention of colonization was most evident during breast-feeding. These data suggest that the protective effects of human milk against otitis media may be due in part to inhibition of nasopharyngeal colonization with nontypeable H. influenzae by specific secretory IgA antibody.

Memory impairment in schizophrenia--a comparison with that observed in the Alcoholic Korsakoff syndrome

Until very recently, memory impairment was not considered to be a central feature of schizophrenia, except in chronic, deteriorated patients. In this study of a heterogeneous sample of 40 patients with DSM-III-R schizophrenia, episodic memory impairment was found to be prevalent, and in some cases, severe. The degree of memory impairment was not attributable to neuroleptic or anticholinergic medication, or to poor motivation or cooperation. These results, therefore, replicate those reported by McKenna et al. (1990) and Tamlyn et al. (1992), who suggested that the pattern of memory impairment in schizophrenia may conform in important respects to that of the classic amnesic syndrome. However, in a direct comparison of the schizophrenic sample with 18 patients suffering from the Alcoholic Korsakoff Syndrome (AKS), both quantitative and qualitative differences were found to exist between the two groups of patients. In particular, the level of long-term episodic memory impairment was found in the AKS sample to be far greater than that in the schizophrenic group. An interesting possible double-dissociation emerged between the two groups; although demonstrating superior episodic memory functioning, the schizophrenic sample were found to perform significantly more poorly than the AKS sample on a test of semantic memory.

Use of the polymerase chain reaction for detection of Mycoplasma fermentans and Mycoplasma genitalium in the urogenital tract and amniotic fluid

In an attempt to further define the natural history of Mycoplasma genitalium and Mycoplasma fermentans infections in humans, we used cultures and the polymerase chain reaction (PCR) to determine whether these organisms were present in the urethra and cervix of sexually active adults and in the amniotic fluid of women whose membranes were intact and collected at the time of cesarean delivery (to preclude cervical contamination). M. genitalium was detected by PCR but not by culture in 11% of patients with urethritis or cervicitis. It was not detected by either PCR or culture in the 232 amniotic fluid samples analyzed. In contrast, M. fermentans was not detected by either method in patients with urethritis or cervicitis but was detected by PCR in 4 of 232 amniotic fluid samples tested. These results indicate that in these four cases M. fermentans was transferred transplacentally. Histological evidence of chorioamnionitis was present in two of the four patients, a finding suggesting that M. fermentans may be a cause of chorioamnionitis. These results must be confirmed by other investigators, and further studies should be undertaken to determine the potential clinical significance of M. fermentans infection.