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Abstract Medication is the predominant method for the management of patients with movement disorders. However, there is a fraction of patients who experience limited relief from pharmaceuticals or experience bothersome side-effects of the drugs. Deep brain stimulation (DBS) and surgical lesioning of the thalamus and basal ganglia are respected neurosurgical procedures, with valued success rates and a very low incidence of complications. Despite these positive outcomes, DBS and surgical lesioning procedures are contraindicated for some patients. Stereotactic radiosurgery with the Gamma Knife (GK) has been used as a lesioning technique for patients seeking a non-invasive treatment alternative and for medication-intolerable patients, who are unable to undergo DBS or lesioning due to comorbid medical conditions. Tremors of various etiologies are treated using GK thalamotomy, which targets the ventralis intermedius nucleus. GK thalamotomy produces favorable outcomes when treating tremors, with success rates ranging from 80-100%. In contrast, GK pallidotomy targets the internal globus pallidus, and is used in treating bradykinesia, rigidity, and dyskinesia. Although radiosurgery has proven beneficial for tremors, radiosurgical pallidotomy for bradykinesia, rigidity, and dyskinesia remains questionable, with mixed success rates in the literature that ranges from 0-87%. We suggest that GK thalamotomy be offered along with other neurosurgical approaches as a feasible treatment option to patients who prefer the non-invasive nature of radiosurgery and to those who are unqualified candidates for the neurosurgical alternatives. Also, we advise that patients with bradykinesia, rigidity, and dyskinesia be educated about the variability in the literature pertaining to GK pallidotomy before proceeding with treatment.

Abstract Approximately 5 million people in America are affected by essential tremors (ET), which are classified as a type of benign movement disorder. This disease manifests as tremors that usually occur in the hands, but they may also be present in the head, face, tongue, and lower limbs. Radiofrequency thalamotomy (RF) and deep brain stimulation (DBS) are common invasive procedures with proven track records that are used to treat ET. Although these procedures have high success rates, they still put patients at risk of potential side effects and are invasive by nature. Thalamotomy using the gamma knife (GK) also produces favorable outcomes in treating tremors, without the complications associated with invasive neurosurgery procedures. This report describes the presenting symptoms and extended treatment outcome for a patient with an advanced case of ET, who received GK thalamotomy treatment six years ago. Because of this non-invasive treatment, she regained the ability to paint and live with an improved quality of life. We also discuss and review the relevant literature regarding the risks and benefits of this treatment modality. GK thalamotomy is one effective option for the treatment of ET, and due to its noninvasive nature, it has a different risk profile than neurosurgery. We suggest that GK thalamotomy should be presented as one viable treatment option to all ET patients, and should be recommended to those who would be best served by less invasive treatment techniques.

Presents a summary of studies on carbon measurements made by the World Ocean Circulation Experiment/Joint Global Ocean Flux Study/Ocean Atmosphere Carbon Exchange Study in the Pacific Ocean. Analytical and statistical methods; Results of statistical analysis; Recommended adjustments in the development of unified data sets on Pacific carbon measurements.

Objective: Multitasking is an essential part of everyday functioning often not formally assessed by traditional neuropsychological tests. Although individuals with Parkinson's disease (PD) experience both motor and cognitive difficulties, previous research has demonstrated more pronounced functional difficulties with the presence of mild cognitive impairment (PD-MCI). The current study compared individuals with PD-MCI, PD with normal cognition (PD-NC), and healthy controls on a naturalistic task of multitasking, the Day Out Task (DOT). Method: Participants were 38 healthy older adults (HOA), 23 individuals with PD-NC, and 15 individuals with PD-MCI. Participants completed a battery of neuropsychological tasks and the DOT. Informants also completed a self-reported questionnaire of participants' everyday executive functioning. Results: Compared to PD-NC and HOA, participants with PD-MCI were less accurate and efficient and took longer to complete the DOT. After controlling for motor performance, only DOT accuracy remained worse, with poorer accuracy resulted from more subtasks being left incomplete or being completed inaccurately by the PD-MCI group. DOT sequencing was a significant predictor of informant reported everyday dysexecutive symptoms. Conclusions: The findings highlight that individuals with PD-MCI are likely to experience difficulties completing complex everyday tasks due to both motor and cognitive impairments. Clinicians may therefore recommend strategies to support efficiency and accuracy in complex tasks of everyday functioning in treatment considerations.

Several infections have been associated with motor neuron diseases resembling ALS, including species of viruses, bacteria, and parasites. Mycobacterium avium subspecies paratuberculosis (MAP), most known for its probable etiologic association with Crohn's disease, has been suggested as another possible infectious cause of motor neuron disease. Two published case reports describe the successful treatment of ALS-like symptoms with antimycobacterial antibiotics. Both cases had atypical features. Based on these, we believe it would be reasonable to begin performing chest imaging in PALS who have features of their history or exam that are atypical for ALS such as pain, fevers, or eye movement abnormalities. If the chest imaging is abnormal, more specific testing for mycobacteria may be indicated. Until there is more clear evidence of an association between mycobacteria and ALS, we cannot endorse the widespread use of potentially toxic antimycobacterial antibiotics for PALS.

Objective: This study used multiple assessment methods to examine instrumental activities of daily living (IADLs) performance in individuals with Parkinson's disease with mild cognitive impairment (PD-MCI) compared to individuals with mild cognitive impairment (MCI) and cognitively healthy older adults (HOA). Associations between functional performance and cognition were also examined., Methods: Eighteen individuals with PD-MCI, 48 individuals with MCI, and 66 HOAs were assessed with multiple IADL measures, including direct observation, a performance-based measure, and self- and informant-report questionnaires. Performance on the direct-observation measure was further characterized by coding for four error types: omissions, substitutions, and inefficient and irrelevant/off-task actions., Results: Both the PD-MCI and MCI groups performed more poorly on the overall score for all IADL measures relative to HOAs. Although the PD-MCI and MCI groups did not differ in overall performance, on the direct-observation measure, the PD-MCI group took longer and made more inefficient and irrelevant/off-task errors relative to the HOA and MCI groups, whereas the MCI group made more omission and substitution errors relative to HOAs. Further, the pattern of cognitive correlates that associated most strongly with the functional measures varied across groups and functional assessment methods., Conclusion: Compared to HOAs, PD-MCI and MCI groups demonstrated increased difficulties performing everyday activities, and cognitive and motor abilities differentially contributed to the everyday task difficulties of these two groups.

The abundances of free-living species have changed dramatically in recent decades, but little is known about change in the abundance of parasitic species. We investigated whether populations of several parasites have shifted over time in two shore crab hosts, Hemigrapsus oregonensis and Hemigrapsus nudus, by comparing the prevalence and abundance of three parasite taxa in a historical dataset (1969-1970) to contemporary parasite abundance (2018-2020) for hosts collected from 11 intertidal sites located from Oregon, USA, to British Columbia, Canada. Our data suggest that the abundance of the parasitic isopod Portunion conformis has varied around a stable mean for the past 50 years. No change over time was observed for larval acanthocephalans. However, larval microphallid trematodes increased in prevalence over time among H. oregonensis hosts, from a mean of 8.4-61.8% between the historical and contemporary time points. The substantial increase in the prevalence of larval microphallid trematodes could be owing to increased abundances of their bird final hosts, increased production of parasite infective stages by snail intermediate hosts or both. Our study highlights the variability among parasite species in their temporal trajectories of change.

Seawater Mg:Ca and Sr:Ca ratios are biogeochemical parameters reflecting the Earth-ocean-atmosphere dynamic exchange of elements. The ratios' dependence on the environment and organisms' biology facilitates their application in marine sciences. Here, we present a measured single-laboratory dataset, combined with previous data, to test the assumption of limited seawater Mg:Ca and Sr:Ca variability across marine environments globally. High variability was found in open-ocean upwelling and polar regions, shelves/neritic and river-influenced areas, where seawater Mg:Ca and Sr:Ca ratios range from ∼4.40 to 6.40 mmol:mol and ∼6.95 to 9.80 mmol:mol, respectively. Open-ocean seawater Mg:Ca is semiconservative (∼4.90 to 5.30 mol:mol), while Sr:Ca is more variable and nonconservative (∼7.70 to 8.80 mmol:mol); both ratios are nonconservative in coastal seas. Further, the Ca, Mg, and Sr elemental fluxes are connected to large total alkalinity deviations from International Association for the Physical Sciences of the Oceans (IAPSO) standard values. Because there is significant modern seawater Mg:Ca and Sr:Ca ratios variability across marine environments we cannot absolutely assume that fossil archives using taxa-specific proxies reflect true global seawater chemistry but rather taxa- and process-specific ecosystem variations, reflecting regional conditions. This variability could reconcile secular seawater Mg:Ca and Sr:Ca ratio reconstructions using different taxa and techniques by assuming an error of 1 to 1.50 mol:mol, and 1 to 1.90 mmol:mol, respectively. The modern ratios' variability is similar to the reconstructed rise over 20 Ma (Neogene Period), nurturing the question of seminonconservative behavior of Ca, Mg, and Sr over modern Earth geological history with an overlooked environmental effect., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)

Ocean acidification (OA) along the US West Coast is intensifying faster than observed in the global ocean. This is particularly true in nearshore regions (<200 m) that experience a lower buffering capacity while at the same time providing important habitats for ecologically and economically significant species. While the literature on the effects of OA from laboratory experiments is voluminous, there is little understanding of present-day OA in-situ effects on marine life. Dungeness crab (Metacarcinus magister) is perennially one of the most valuable commercial and recreational fisheries. We focused on establishing OA-related vulnerability of larval crustacean based on mineralogical and elemental carapace to external and internal carapace dissolution by using a combination of different methods ranging from scanning electron microscopy, energy dispersive X-ray spectroscopy, elemental mapping and X-ray diffraction. By integrating carapace features with the chemical observations and biogeochemical model hindcast, we identify the occurrence of external carapace dissolution related to the steepest Ω calcite gradients (∆Ω cal,60 ) in the water column. Dissolution features are observed across the carapace, pereopods (legs), and around the calcified areas surrounding neuritic canals of mechanoreceptors. The carapace dissolution is the most extensive in the coastal habitats under prolonged (1-month) long exposure, as demonstrated by the use of the model hindcast. Such dissolution has a potential to destabilize mechanoreceptors with important sensory and behavioral functions, a pathway of sensitivity to OA. Carapace dissolution is negatively related to crab larval width, demonstrating a basis for energetic trade-offs. Using a retrospective prediction from a regression models, we estimate an 8.3% increase in external carapace dissolution over the last two decades and identified a set of affected OA-related sublethal pathways to inform future risk assessment studies of Dungeness crabs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The range of the mosquito Aedes aegypti continues to expand, putting more than two billion people at risk of arboviral infection. The sterile insect technique (SIT) has been used to successfully combat agricultural pests at large scale, but not mosquitoes, mainly because of challenges with consistent production and distribution of high-quality male mosquitoes. We describe automated processes to rear and release millions of competitive, sterile male Wolbachia-infected mosquitoes, and use of these males in a large-scale suppression trial in Fresno County, California. In 2018, we released 14.4 million males across three replicate neighborhoods encompassing 293 hectares. At peak mosquito season, the number of female mosquitoes was 95.5% lower (95% CI, 93.6-96.9) in release areas compared to non-release areas, with the most geographically isolated neighborhood reaching a 99% reduction. This work demonstrates the high efficacy of mosquito SIT in an area ninefold larger than in previous similar trials, supporting the potential of this approach in public health and nuisance-mosquito eradication programs.

Background: Covering the instrument table during surgery may decrease contamination. We hypothesized that (1) covering the instrument table in an operating room (OR) during static periods of nonuse and dynamic periods of active use would dramatically decrease the bacterial bioburden on the table, and (2) the use of sterile plastic table covers would be equivalent to sterile impervious paper covers in reducing the bioburden in a dynamic environment., Methods: Bacterial contamination of the instrument table was evaluated by settle plates in static and dynamic ORs. Airborne particulate and bacterial contaminants were sampled throughout the room. Tested groups included instrument tables covered with sterile impervious paper covers, sterile plastic covers, or no covers., Results: Covering the instrument table during static and dynamic operating room conditions resulted in a significantly decreased bacterial load on the instrument table. No differences were seen between paper and plastic covers., Conclusions: A significant decrease in bacterial bioburden on the instrument table when the table was covered during static and dynamic periods was observed, suggesting the utility for covering the instrument table during periods of nonuse and during active surgeries., (Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Background: The use of long sleeves by nonscrubbed personnel in the operating room has been called into question. We hypothesized that wearing long sleeves and gloves, compared with having bare arms without gloves, while applying the skin preparation solution would decrease particulate and microbial contamination., Methods: A mock patient skin prep was performed in 3 different operating rooms. A long-sleeved gown and gloves, or bare arms, were used to perform the procedure. Particle counters were used to assess airborne particulate contamination, and active and passive microbial assessment was achieved through air samplers and settle plate analysis. Data were compared with Student's t-test or Mann-Whitney U, and P < .05 was considered to be significant., Results: Operating room B demonstrated decreased 5.0- µm particle sizes with the use of sleeves, while operating rooms A and C showed decreased total microbes only with the use of sleeves. Despite there being no difference in the average number of total microbes for all operating rooms assessed, the use of sleeves specifically appeared to decrease the shed of Micrococcus., Conclusion: The use of long sleeves and gloves while applying the skin preparation solution decreased particulate and microbial shedding in several of the operating rooms tested. Although long sleeves may not be necessary for all operating room personnel, they may decrease airborne contamination while the skin prep is applied, which may lead to decreased surgical site infections., (Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Background: Hospitals face growing pressure to meet the dual but often competing goals of providing a safe environment while controlling operating costs. Evidence-based data are needed to provide insight for facility management practices to support these goals., Methods: The quality of the air in 3 operating rooms was measured at different ventilation rates. The energy cost to provide the heating, ventilation, and air conditioning to the rooms was estimated to provide a cost-benefit comparison of the effectiveness of different ventilation rates currently used in the health care industry., Results: Simply increasing air change rates in the operating rooms tested did not necessarily provide an overall cleaner environment, but did substantially increase energy consumption and costs. Additionally, and unexpectedly, significant differences in microbial load and air velocity were detected between the sterile fields and back instrument tables., Conclusions: Increasing the ventilation rates in operating rooms in an effort to improve clinical outcomes and potentially reduce surgical site infections does not necessarily provide cleaner air, but does typically increase operating costs. Efficient distribution or management of the air can improve quality indicators and potentially reduce the number of air changes required. Measurable environmental quality indicators could be used in lieu of or in addition to air change rate requirements to optimize cost and quality for an operating room and other critical environments., (Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Background: The effectiveness of operating room headgear in preventing airborne contamination has been called into question. We hypothesized that bouffant style hats would be as effective in preventing bacterial and particulate contamination in the operating room compared with disposable or cloth skull caps, and bouffant style hats would have similar permeability, particle penetration, and porosity compared with skull caps., Study Design: Disposable bouffant and skull cap hats and newly laundered cloth skull caps were tested. A mock surgical procedure was used in a dynamic operating room environment. Airborne particulate and microbial contaminants were sampled. Hat fabric was tested for permeability, particle transmission, and pore sizes., Results: No significant differences were observed between disposable bouffant and disposable skull caps with regard to particle or actively sampled microbial contamination. However, when compared with disposable skull caps, disposable bouffant hats did have significantly higher microbial shed at the sterile field, as measured by passive settle plate analysis (p < 0.05). When compared with cloth skull caps, disposable bouffants yielded higher levels of 0.5 μm and 1.0 μm particles and significantly higher microbial shed detected with passive analysis. Fabric assessment determined that disposable bouffant hats had larger average and maximum pore sizes compared with cloth skull caps, and were significantly more permeable than either disposable or cloth skull caps., Conclusions: Disposable bouffant hats had greater permeability, penetration, and greater microbial shed, as assessed by passive microbial analysis compared with disposable skull caps. When compared with cloth skull caps, disposable bouffants yielded greater permeability, greater particulate contamination, and greater passive microbial shed. Disposable style bouffant hats should not be considered superior to skull caps in preventing airborne contamination in the operating room., (Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Sufficient quantities of quality air and controlled, unidirectional flow are important elements in providing a safe building environment for operating rooms., Methods: To make dynamic assessments of an operating room environment, a validated method of testing the multiple factors influencing the air quality in health care settings needed to be constructed. These include the following: temperature, humidity, particle load, number of microbial contaminants, pressurization, air velocity, and air distribution. The team developed the name environmental quality indicators (EQIs) to describe the overall air quality based on the actual measurements of these properties taken during the mock surgical procedures. These indicators were measured at 3 different hospitals during mock surgical procedures to simulate actual operating room conditions. EQIs included microbial assessments at the operating table and the back instrument table and real-time analysis of particle counts at 9 different defined locations in the operating suites. Air velocities were measured at the face of the supply diffusers, at the sterile field, at the back table, and at a return grille., Results: The testing protocol provided consistent and comparable measurements of air quality indicators between institutions. At 20 air changes per hour (ACH), and an average temperature of 66.3°F, the median of the microbial contaminants for the 3 operating room sites ranged from 3-22 colony forming units (CFU)/m 3 at the sterile field and 5-27 CFU/m 3 at the back table. At 20 ACH, the median levels of the 0.5-µm particles at the 3 sites were 85,079, 85,325, and 912,232 in particles per cubic meter, with a predictable increase in particle load in the non-high-efficiency particulate air-filtered operating room site. Using a comparison with cleanroom standards, the microbial and particle counts in all 3 operating rooms were equivalent to International Organization for Standardization classifications 7 and 8 during the mock surgical procedures., Conclusions: The EQI protocol was measurable and repeatable and therefore can be safely used to evaluate air quality within the health care environment to provide guidance for operational practices and regulatory requirements., (Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Background: We report the interim results from XCiDaBLE, a large, prospective, observational "naturalistic" study evaluating Xeomin® (incobotulinumtoxinA) for Cervical Dystonia or BLEpharospasm in the United States., Methods: Subjects (≥ 18 years old) with cervical dystonia (CD) are followed for two treatment cycles and monitored via Interactive Voice/Web Response. The subject's physician must have chosen to treat with incobotulinumtoxinA prior to and independent of enrollment in this study. Subject-reported scales include the Subject Global Impression-Severity and Improvement and Cervical Dystonia Impact Profile (CDIP-58), and Work Productivity and Quality of Life (QoL) are assessed by means of an employment questionnaire and work history and the SF-12v2 Health Survey (SF-12v2). Subjects are seen by the investigator for three visits, which include a baseline visit (including the first injection), a second injection visit, and a final study visit (12 weeks after the second injection)., Results: This ongoing study includes 145 subjects with a diagnosis of CD. The majority were female (82.3%) and white (91.0%) and had previously been treated with botulinum toxins (77.2%). There were 106 employed at the time of disease onset, but 12.6 years later only 44% were still employed at the time of enrolment into the study, and 20% were either receiving or seeking disability benefits. The mean total dose/treatment of CD was 225.2 units for the first injection. The CDIP-58 total score was significantly improved 4 weeks after the first injection compared to baseline (p≤0.0001). Most subjects noted improvement in their global impression assessment. No new or unexpected adverse events occurred., Discussion: The results from these interim analyses confirm previous controlled, single-dose studies of incobotulinumtoxinA in terms of efficacy and safety.

Objective: 6002-US-051 was a 12-week, double-blind study evaluating the safety and efficacy of istradefylline, a selective A(2A) adenosine receptor antagonist, as monotherapy in patients with Parkinson's disease (PD)., Methods: Patients with Hoehn-Yahr stages 1-2.5 who had not received dopaminergic drugs in the past 30 days or levodopa for >30 days at anytime were randomized to 40 mg/day istradefylline or placebo. The primary efficacy outcome was the change from Baseline to Endpoint in the Unified Parkinson's Disease Rating Scale (UPDRS) Subscale III score. Safety was assessed by physical examination, laboratory tests, electrocardiograms, and adverse event monitoring., Results: 176 patients comprised the intent-to-treat population. Although istradefylline showed numerically greater improvements in UPDRS Subscale III at each time point and reached statistical significance at Week 2 (LS mean difference = -1.47), it did not show statistically significant improvement from placebo for the primary endpoint (least square [LS] mean difference = -1.11). Similar proportions of patients in each group experienced treatment-emergent adverse events (63% istradefylline, 65% placebo)., Conclusions: Istradefylline, as monotherapy in patients with PD, is safe and well tolerated. However, efficacy in improving motor symptoms in early PD was not statistically demonstrated by this study.

Objective: This multicenter, cross-sectional study was conducted to determine the sensitivity and specificity of a 9-item Wearing-off Questionnaire (WOQ-9) compared with assessment by a clinician., Methods: Patients with a diagnosis of Parkinson's disease (PD) for 5 or=90 days, completed the WOQ-9 before independent evaluation by the physician., Results: One hundred fifty-seven patients reported WO using the WOQ-9; only 79 had been previously diagnosed with WO by a physician. The most frequent items used by physicians to diagnose WO included type of symptoms (69.6%), symptom response (63.3%), and timing of symptom response (58.2%) to medication. Physician assessment of WO and WOQ-9 results corresponded in 76 of 79 cases; physicians disagreed with WO identification in 81 of 157 cases. Sensitivity of the WOQ-9 was 96.2% and specificity was 40.9%., Conclusion: The WOQ-9 is a useful screening tool to aid diagnosis of WO in PD patients.

Most lipomas occurring in the scrotum originate and develop in the spermatic cord. In rare cases, however, lipomas originate in the fat cells of the subcutaneous tissues of the scrotal walls themselves. These primary lipomas of the scrotum vary in size. We describe a patient with a scrotal mass that, to our knowledge, is the largest scrotal lipoma originating in the tunica dartos reported in the English literature.

In vertebrate rod cells, the activated alpha-subunit of rod transducin interacts with the gamma (regulatory) subunits of phosphodiesterase to disinhibit the catalytic subunits. A 22-amino acid long region of rod transducin involved in phosphodiesterase activation has recently been identified. We have used peptides from this region of rod transducin and from several other G protein alpha-subunits to study the nature and specificity of the G protein alpha-effector interaction. Although peptides derived from rod transducin, cone transducin and gustducin are similar, only the rod peptide is capable of activating rod phosphodiesterase. Using substituted peptides we have identified five residues on one exposed face of rod transducin as important to phosphodiesterase activation. These results disagree with previous models which propose that loop regions of rod transducin interact with phosphodiesterase gamma.

Solution structures were determined for a linear analogue of growth hormone releasing factor (GRF), and cyclic and dicyclic analogues in which the side chains of aspartyl and lysyl residues spaced at positions i-(i + 4) were joined to form a lactam. The four analogues were [Ala15]-GRF-(1-29)-NH2 and its cyclo8-12, cyclo21-25, and dicyclo8-12;21-25 derivatives. The peptides were studied in two solvent systems: 75% methanol/25% water at pH 6.0; and 100% water at pH 3.0. CD spectroscopy was used to assess the overall alpha-helical content. Nuclear magnetic resonance spectroscopy was used to determine the structures in more detail. Nearly complete proton resonance assignments were made for each of the peptides, in both solvents. Nuclear Overhauser effects were converted into distance constraints and applied in the molecular dynamics program CHARMM to evaluate the range of low-energy structures that satisfied the nmr data. In 75% methanol, all of the peptides are comprised of a single alpha-helical segment with fraying of one to three residues at each end. The linear analogue has a tendency to kink. In water, the analogues have two helical segments with flexible regions between them and at the termini of the peptides. The linear analogue is helical at residues 7-14 and 21-28. In the cyclo8-12 analogue, the N-terminal helical region extends to include residues 7-19, while the other helical region is slightly shortened. In the cyclo21-25 analogue, the C-terminal helical region is extended to include residues 19-28, while the N-terminal helical region is destabilized. The dicyclic analogue has the largest N-terminal helix, spanning residues 7-20, but its helical segment at residues 21-28 is not well ordered. All of the analogues exhibit substantial biological activity. The cyclic and dicyclic analogues show dramatically increased resistance to degradation during incubation with human plasma. The i-(i + 4) lactam, therefore, appears to be a synthetic means of stabilizing a local alpha-helical conformation, which may be of general use in the design of active, stable peptides.

Until now mass media smoking cessation studies have relied almost exclusively on self-reports of smoking cessation because biochemical confirmation has not seemed practical. This study investigated the reliability of mailed salivary cotinine specimens for the determination of smoking status. Two simultaneous saliva specimens were obtained from 10 smokers and 10 nonsmokers. One of each pair was frozen immediately. The other was sent through the local U.S. mail and then subjected to additional physical agitation and heat before being frozen. All specimens were subsequently analyzed for cotinine. No cotinine was detectable in any of the nonsmokers' specimens. There was excellent correlation between the paired smokers' specimens. These results show that the mailing of saliva specimens for cotinine analysis is practical and provides accurate data on smoking status. It is an approach which could easily be used in mass media smoking cessation studies to biochemically confirm smoking behavior.