Spatial memory deficits in mice induced by chemotherapeutic agents are prevented by acetylcholinesterase inhibitors.

PURPOSE: These studies determined whether the acetylcholinesterase inhibitors, donepezil and galantamine, both of which are approved for the treatment of cognitive deficits in Alzheimer's disease, can prevent or reverse spatial memory deficits in mice induced by cyclophosphamide and doxorubicin, cytotoxic agents commonly used to treat breast cancer. METHODS: Female BALB/C mice were trained in the Morris water maze to identify the location of a submerged platform, and, following baseline assessment of spatial memory, received injections of cyclophosphamide and doxorubicin once per week for 4 weeks to impair spatial memory. Saline or acetylcholinesterase inhibitors were administered daily either concurrent with the chemotherapy injections (prevention) or beginning 1 week following the final chemotherapy injections (reversal), and spatial memory was assessed weekly. RESULTS: Spatial memory declined during and following weekly injections of cyclophosphamide and doxorubicin, and was unaltered when the acetylcholinesterase inhibitors were administered following the manifestation of chemotherapy-induced deficits. In contrast, spatial memory of mice receiving the acetylcholinesterase inhibitors concurrent with chemotherapy did not differ from that at baseline. CONCLUSIONS: Results indicate that chemotherapy-induced spatial memory deficits in mice can be prevented, but not reversed by the use of acetylcholinesterase inhibitors concomitant with chemotherapy, suggesting that these agents should be investigated further for the prevention of chemobrain.

3-Acetylpyridine neurotoxicity in mice.

3-acetylpyridine (3-AP) is a metabolic antagonist used in research to decrease levels of nicotinamide (niacinamide) in laboratory animals. The administration of 3-AP followed by nicotinamide to rats leads to the selective destruction of neurons in the medial inferior olive, resulting in a loss of climbing fibers innervating cerebellar Purkinje cells and a consequent ataxia manifest by alterations in both balance and gait. Although 3-AP has also been administered to mice to destroy neurons in the inferior olive, there are limited studies quantifying the consequent effects on balance, and no studies on gait. Further, the relationship between 3-AP-induced lesions of the inferior olive and behavior has not been elucidated. Because 3-AP continues to be used for experiments involving mice, this study characterized the effects of this toxin on both balance and gait, and on the neuronal integrity of several brain regions involved in motor coordination. Results indicate that C57BL/6 mice are less sensitive to the neurotoxic effects of 3-AP than rats, and a dose more than 6.5 times that used for rats produces deficits in both balance and gait comparable to those in rats. This dose led to a significant (p<0.05) loss of NeuN(+) neurons in several subregions of the inferior olive including the rostral medial nucleus, dorsomedial cell column, ventrolateral protrusion, and cap of Kooy. Further, the number of NeuN(+) neurons in these subregions, with the exception of the dorsomedial cell column, was significantly (p<0.05) related to rotorod performance, implicating their involvement in this behavior.

Analysis of gait in rats with olivocerebellar lesions and ability of the nicotinic acetylcholine receptor agonist varenicline to attenuate impairments.

Studies have demonstrated that administration of the neuronal nicotinic receptor agonist varenicline to rats with olivocerebellar lesions attenuates balance deficits on a rotorod and balance beam, but the effects of this drug on gait deficits have not been investigated. To accomplish this, male Sprague-Dawley rats were trained to walk on a motorized treadmill at 25 and 35 cm/s and baseline performance determined; both temporal and spatial gait parameters were analyzed. A principal component analysis (PCA) was used to identify the key components of gait, and the cumulative gait index (CGI) was calculated, representing deviations from prototypical gait patterns. Subsequently, animals either remained as non-lesioned controls or received injections of 3-acetylpyridine (3-AP)/nicotinamide to destroy the climbing fibers innervating Purkinje cells. The gait of the non-lesioned group was assessed weekly to monitor changes in the normal population, while the gait of the lesioned group was assessed 1 week following 3-AP administration, and weekly following the daily administration of saline or varenicline (0.3, 1.0, or 3.0mg free base/kg) for 2 weeks. Non-lesioned animals exhibited a 60-70% increased CGI over time due to increases in temporal gait measures, whereas lesioned animals exhibited a nearly 3-fold increased CGI as a consequence of increases in spatial measures. Following 2 weeks of treatment with the highest dose of varenicline (3.0mg free base/kg), the swing duration of lesioned animals normalized, and stride duration, stride length and step angle in this population did not differ from the non-lesioned population. Thus, varenicline enabled animals to compensate for their impairments and rectify the timing of the gait cycle.

Gait analysis and the cumulative gait index (CGI): Translational tools to assess impairments exhibited by rats with olivocerebellar ataxia.

Deviations from 'normal' locomotion exhibited by humans and laboratory animals may be determined using automated systems that capture both temporal and spatial gait parameters. Although many measures generated by these systems are unrelated and independent, some may be related and dependent, representing redundant assessments of function. To investigate this possibility, a treadmill-based system was used to capture gait parameters from normal and ataxic rats, and a multivariate analysis was conducted to determine deviations from normal. Rats were trained on the treadmill at two speeds, and gait parameters were generated prior to and following lesions of the olivocerebellar pathway. Control (non-lesioned) animals exhibited stable hindlimb gait parameters across assessments at each speed. Lesioned animals exhibited alterations in multiple hindlimb gait parameters, characterized by significant increases in stride frequency, braking duration, stance width, step angle, and paw angle and decreases in stride, stance, swing and propulsion durations, stride length and paw area. A principal component analysis of initial hindlimb measures indicated three uncorrelated factors mediating performance, termed Rhythmicity, Thrust and Contact. Deviation in the performance of each animal from the group mean was determined for each factor and values summed to yield the cumulative gait index (CGI), a single value reflecting variation within the group. The CGI for lesioned animals increased 2.3-fold relative to unlesioned animals. This study characterizes gait alterations in laboratory rats rendered ataxic by destruction of the climbing fiber pathway innervating Purkinje cells and demonstrates that a single index can be used to describe overall gait impairments.

Modelling the impact of HIV prevention and treatment for men who have sex with men on HIV epidemic trajectories in low- and middle-income countries.

Little is known about the impact of combination HIV prevention interventions for men who have sex with men (MSM) and the impacts on the wider epidemics. Modelling analyses of MSM-specific interventions across varied HIV epidemics may inform evidence-based responses. The Goals model was adapted to project the impacts of providing HIV interventions for MSM and access to expanded coverage of antiretroviral therapy (ART) for adults to measure the effects on the MSM and adult epidemics in Peru, Ukraine, Kenya and Thailand. Positive impacts were observed in all four countries. Across epidemics, 14-25% of infections among MSM may be averted between 2012 and 2016 when MSM interventions are brought to scale and MSM have equal access to expanded ART for adults. Among adults, MSM interventions may avert up to 4000 new infections, in addition to the benefits associated with increased ART. Greatest impacts from expanded interventions were observed in countries where same sex transmission contributes significantly to the HIV epidemic. While significant benefits are observed among the adult and MSM populations with expansion of ART, consideration should be given to the synergies of combining ART expansion with targeted interventions to reach hidden, high-risk populations for HIV testing and counselling and linkages to care.

Simple high-performance liquid chromatographic method to analyze serum creatinine has several advantages over the Jaffé picric acid reaction as demonstrated with a cimetidine dose response in rhesus monkeys.

A simple method for creatinine determination was developed using high-performance liquid chromatography (HPLC) to more accurately monitor serum creatinine levels in experimental animal models when compared to the Jaffé method. The new HPLC procedure will replace the traditional Jaffé method for rhesus monkey kidney function studies. We developed an isocratic method using a polymeric, hydrophilic, silica-based strong cation-exchange bed with a 5.0 mmol/l lithium acetate matrix, pH 4.9, which isolates creatinine with no detectable impurities as determined by three-dimensional ultraviolet-visible spectral analysis. Sample preparation includes deproteination with acetonitrile, evaporation, and resolubilization in mobile phase followed by quantitation with UV detection at 234 nm. Extraction efficiency across the measured range was 96 +/- 2%. From numerous extracted rhesus monkey creatinine curves (n=38) a slope of 251,100 +/- 756 (95% CI) and an intercept of 675.6 +/- 712.7 (95% CI) was calculated. Extraction efficiency and peak purity tests with human plasma were cross-compared with rhesus monkey serum producing equivalent results. An average of 120 samples can be run daily.

Immunocontraception of white-tailed deer with GnRH vaccine.

PROBLEM: Reduction of excess numbers of white-tailed deer (Odocoileus virginianus) is an example of a potential use for immunocontraception as a means of wildlife population management. METHOD OF STUDY: A 4 year multifaceted study was conducted to determine the long term effects of gonadotropin releasing hormone (GnRH) contraceptive vaccine on the fertility and behavior of female and male white-tailed deer. Deer were monitored for breeding behavior, hormone levels, pregnancy, fawning and GnRH specific antibody levels. RESULTS: Treatment lead to reduced fawning rates, altered estrus behavior, reduced concentrations of progesterone, contraception and failure to maintain pregnancy following conception. GnRH immunized does bred to untreated bucks had an 88% reduction in fawning caused by either immunocontraception or immunocontragestion. The vaccine effect is reversible, directly related to the antibody titer. Infertility lasted up to two years without boosting. GnRH immunized bucks demonstrated no interest in sexual activity when paired with control females. Depending on the immunization schedule, antlers either dropped early or remained in velvet. CONCLUSIONS: The results of this study demonstrate that GnRH vaccine is effective in inducing a reversible infertility in white-tailed deer, the infertility lasting up to two years without boosting.

Immunocontraception of white-tailed deer using native and recombinant zona pellucida vaccines.

We conducted a 2-year feasibility study with native porcine zona pellucida (PZP) vaccine and three recombinant rabbit zona pellucida vaccines (RC55, RC75a and a combination of RC55, RC75a and RC75b) as an initial phase of developing a recombinant immunocontraceptive vaccine to control reproduction in overpopulated herds of white-tailed deer (Odocoileus virginianus). Forty captive white-tailed does were divided into five groups (one sham and four treated), of eight each and injected with a 500microg prime dose of vaccine. Each prime dose was followed by a 300microg booster dose at 3-7 weeks post prime. The frequency and number of months of observed breeding were higher in PZP immunized does than in sham controls. Although the antibody titers of the three recombinant groups were 1000 or less, as compared with the PZP group with titers often over 128,000, the fawning rates of the two recombinants were significantly lower than that of the control group. The combined antigen group did not have a significantly lower fawning rate.

Stereoselective synthesis of C5-C20 and C21-C34 subunits of the core structure of the aplyronines. Applications of enantioselective additions of chiral allenylindium reagents to chiral aldehydes.

The stereoselective synthesis of a C5-C20 and a C21-C34 subunit of the aplyronine family of polyketide marine macrolides has been achieved. These subunits contain all 15 stereocenters of the core structure. Six of the 15 stereocenters were introduced through enantioselective and diastereoselective additions of chiral allenylindium reagents to alpha-methyl-beta-oxygenated propionaldehydes. The products of these additions were further transformed by reactions involving the terminal alkynyl substituent produced in the addition reactions. Unlike previous applications of this methodology, the present synthesis employs Pd(0)-catalyzed transmetalations of chiral allenylpalladium intermediates to generate the chiral allenylindium reagents in situ.

Racial/ethnic variations of practicing dentists.

BACKGROUND: In recent years, the dental school population has changed from being predominantly white male to a more diverse racial and ethnic makeup. Noting this change in the student population, the American Dental Association undertook an in-depth study of the various racial/ethnic groups. METHODS: Questionnaires were sent to approximately 8,000 dentists nationwide. Samples were drawn for each of the following racial/ethnic groupings: white, black, Hispanic, Native American and Asian. The survey instrument asked questions about personal characteristics, work and private practice issues, household and practice income, and patient characteristics; it also asked for dentists' opinions. A final adjusted response rate of 57.0 percent was achieved. RESULTS: The majority of all dentists responded that they were "very satisfied" with their profession, but the survey found variations in patient mix, employment history and provision of free or discounted care. CONCLUSIONS: The survey examined dentists by race/ethnicity to identify differences and similarities. Cultural and ethnic minorities are the fastest growing segment of the U.S. population. As the profession becomes more diverse, practice patterns will affect the overall dental profession. PRACTICE IMPLICATIONS: Dentists' racial/ethnic backgrounds may change the provision of care as patient mix varies, with each dentist group treating a specific group of patients in regard to family income, racial/ethnic background and subgroups for whom they offer free or reduced-rate dental care.

Tunable and frequency-stabilized diode laser with a Doppler-free two-photon zeeman lock.

We describe frequency locking of a diode laser to a two-photon transition of rubidium using the Zeeman modulation technique. We locked and tuned the laser frequency by modulating and shifting the two-photon transition frequency with ac and dc magnetic fields. We achieved a linewidth of 500 kHz and continuous tunability over 280 MHz with no laser frequency modulation.

Long-term effects of PZP immunization on reproduction in white-tailed deer.

A 6-year study was conducted to determine the long-term effects of porcine zona pellucida (PZP) vaccine on the immune and hormonal responses, and reproduction of the white-tailed deer. The first 2 years of active immunization resulted in an 89% reduction in fawning. Vaccination with PZP produced reversible infertility lasting 1-4 years. Infertility was directly related to immune titers to PZP. Doe fertility was restored when the antibody titer dropped to minimal levels, but following re-immunization, infertility was reestablished. Reduction in fawning throughout the 6-year study was 76%. It was also observed that immune responses among deer were variable, especially in the first year of treatment. Variability was also observed among deer for the duration of infertility following the initial vaccination.

Oral vaccination of white-tailed deer using a recombinant Bacillus Calmette-Guérin vaccine expressing the Borrelia burgdorferi outer surface protein A: prospects for immunocontraception.

PROBLEM: Reduction of excess numbers of white-tailed deer (Odocoileus virginianus) is a prime example of a potential use for immunocontraception as a means of wildlife population management. Oral vaccination appears to be the most pragmatic way to deliver immunocontraceptive vaccines to free-roaming populations of deer, but there was little, if any, prior evidence that oral vaccination is a viable concept in deer. METHOD OF STUDY: We used live Bacillus Calmette-Guérin (BCG) in a recombinant form (rBCG), which expressed Borrelia burgdorferi outer surface protein A, to test whether deer vaccinated orally with a specific antigen expressed in a live vector produce detectable antibody titers. RESULTS: The data indicate that oral vaccination of deer with an expressed antigen is feasible, as demonstrated by peak antibody titers to the expressed antigen. Also, peak titers measured by enzyme-linked immunosorbent assay were highest in orally vaccinated deer: 1600 in deer vaccinated by injection and 6400 in those vaccinated orally. CONCLUSIONS: The results of this study demonstrate that it is feasible to vaccinate deer orally with a live vector.

'Out-of-hospital cardiac arrests' treated by the West Midlands Ambulance Service over a 2-year period.

We aimed to determine whether our results were any better or worse than other published reports and to examine the efficacy of the West Midlands Ambulance Service (WMAS) policy of applying cardiopulmonary resuscitation (CPR) and manual ventilation to all unwitnessed cardiac arrests in preference to immediate defibrillation. All cardiac arrests were studied from October 1994 to September 1996. In all unwitnessed arrests, crews undertook CPR and manually ventilated the lungs via a mask or an endotracheal tube with a bag and valve or a mechanical resuscitator using an FIO2 of 1 or 0.21 for at least 2 min before defibrillation was attempted. There were 3403 diagnosed cardiac arrests but, in these, the diagnosis was not certain. CPR and advanced life support (ALS) were applied in 3380 patients and return of spontaneous circulation (ROSC) was obtained in 554, giving a success rate of 16.4%. A total of 364 patients were accepted into hospital, 90 patients died in A&E but 274 patients were admitted to ICU/CCU. Seventy died within 24 h, 69 died after 24 h and 135 were discharged alive and well without cerebral damage. The final success to discharge rate was 49.27%. Of those discharged, 69 had a circulatory arrest period of more than 4 min but in only 10 was a bystander available to start CPR. The European Resuscitation Council Guidelines recommending immediate defibrillation for unwitnessed arrests are not supported by these results. The apparent lack of cerebral damage and the percentage success suggests that resuscitation considerations should be as brain orientated as they are heart orientated. The elapsed time periods reported challenge several shibboleths.

Comparative efficacy of two immunocontraceptive vaccines.

As part of our research program to develop immunocontraception as a wildlife management tool, we compared the physiological responses of wild Norway rats (Rattus norvegicus) to two immunocontraceptive vaccines; one involved mouse zona pellucida peptide (MZPP); the other involved gonadotropin releasing hormone (GnRH). Efficacy was monitored by immune, hormonal, and natality responses. Both vaccines were effective, but GnRH was much more effective (100% sterility of both sexes vs. 50% sterility of MZPP-treated females). Breeding success of control rats was 88% with litters of 5-9 pups; breeding success of MZPP rats was 50% with litters of 2-8; GnRH rats produced no young. In GnRH-treated male rats monitored for up to 17 months, testosterone was nondetectable and testes were atrophied to about 10% of their original volume for 10-13 months. There were no notable differences in mortality or body weights among groups, and, with the exception of testicular regression, there were no changes in general appearance. The GnRH vaccine is potentially a good rat reproductive control agent that may be effective over the normal lifespan of a rat under natural conditions in the wild.

The development of a medication reminder card for elderly persons.

This paper describes the development and testing of a medication reminder card specifically designed for elderly persons on complex drug regimens. The need for such a system was confirmed by a survey of approximately 100 Canadian hospital pharmacy departments where no system provided at discharge by respondents met with our criteria for the "ideal" card. The new medication reminder card was tested in 29 ambulatory and 16 institutionalized elderly persons. Over 75 percent of patients continued to use the card two weeks post enrollment and a majority of ambulatory elderly were still using the card at six weeks. In addition to organizing medications and providing a reminder for patients to take drugs, the card facilitated communication with the pharmacist (a mean of 20 minutes) and with other health care professionals. Patients found the card easy to read and the system easy to understand. Despite time constraints, eight of nine participating community pharmacists indicated they would continue to use the system for select patients. A major obstacle to the use of the card was patient reluctance, for a variety of reasons. Although the card will require further modification in design, it provides a useful alternative as a compliance aid for ambulatory and hospitalized patients on chronic, complex drug regimens.

An improved spiral electrode applicator system for fetal heart rate monitoring.

A new fetal scalp electrode applicator system uses a guide tube with increased curvature and a plunger mechanism to advance, rotate, and release the spiral electrode. Results of a preliminary survey among house staff who used the system in 51 patients indicated a favorable impression, with 96.1% of the applications rated as "much better," "better," or "same" as compared with the conventional system. The rate for a subset of 26 patients with limited cervical dilatation (1-3 cm) or high station of the presenting part (-1 to -3) was similarly good (92.3%). The characteristics found most favorable were the increased curvature for facilitating applications to high presenting parts, the plunger mechanism for applying the electrode, and better control of the guide tube.

Rat venule mechanical characteristics during venous pressure elevation.

The purpose of this study was to compare the in vivo mechanical characteristics during venous pressure elevation of two sizes of venules in the intestinal muscularis of anesthetized Wistar rats. The two venules studied were the first-order venule (1V), ID = 71.2 +/- 3.3 microns [12] (means +/- SE [n]) and the small collecting vein (SCV), ID = 134.4 +/- 9.1 microns [12]. Vessel diameters and servonull pressures were measured as venous pressure was elevated with a snare about the vein of the isolated segment. The distension characteristics of the two vessels were significantly different, with the 1V evidencing greater strains (percent change from control diameter) and in vivo distensibilities [D = (delta lumen area/lumen area)/delta pressure] than the SCV at all pressure elevations above control. The 1V and SCV mean wall elastic moduli (calculated using Rhodin's measurements of venule control wall thickness) reflected these differences: the initial 1V wall Young's modulus was low and changed little during the vessel distension, whereas the SCV modulus was greater at control and increased sharply with strain in a nonlinear fashion. Although a portion of these differences can be attributed to different initial hoop wall stress levels, the SCV elastic modulus was significantly greater than the 1V modulus at comparable levels of wall stress. Both active and passive factors may contribute to these in vivo differences in elastic modulus, but this experiment does not distinguish between them.