Does Perioperative Radiation Affect Implant Survivorship of Primary Total Hip Arthroplasty in the Setting of Metastatic Bone Disease?

Background

Metastatic bone disease (MBD) commonly affects the hip and surgical intervention including total hip arthroplasty (THA) is often indicated to treat the joint and improve function. Patients with metastatic cancer often receive radiotherapy, and orthopaedic oncologists must consider surgical risks with operating on irradiated bone and soft tissue. We evaluated surgical outcomes and implant survival (IS) of titanium acetabular components and femoral components in patients treated for MBD in the setting of perioperative radiation.

Methods

This was a retrospective review of patients who underwent THA for MBD at 3 institutions between 2017 and 2021. Outcomes included rates of reoperation, complications, IS, and overall survival.

Results

Forty-six patients who received primary THA for MBD were included in the study. Twenty patients (43.5%) received perioperative radiation for MBD. Six postoperative complications including one superficial wound infection, 2 dislocations, 2 pathologic fractures, and one aseptic acetabular component loosening led to 5 reoperations. There were no significant differences in postoperative outcomes, reoperation after THA, and IS based on radiotherapy status.

Conclusions

To our knowledge, this is the first paper evaluating primary THA outcomes and IS between patients who receive perioperative radiation for MBD to the hip and those who do not. As surgical management is a crucial part of the treatment in alleviating pain and disability in patients with MBD, we continue to recommend THA for patients who received radiation at the operative site.

Opiate use after total hip arthroplasty for metastatic bone disease

OBJECTIVES

To investigate post-operative opioid use following a total hip arthroplasty (THA) in metastatic bone disease (MBD) patients and identify factors associated with post-operative opioid use at 6 weeks and 90 days.

BACKGROUND

MBD commonly affects the hip, and surgical intervention including THA may be indicated for pain relief or to improve function. Following THA, patients are often prescribed short courses of opioids for post-operative pain relief. No study has evaluated opiate use following THA in patients for MBD.

METHODS

This was a retrospective review of patients using opioids preoperatively who underwent primary THA for MBD at two institutions between 2009 and 2022. Preoperative and post-operative opioid usages, respectively, at 6 weeks and 90 days were quantified through calculating daily morphine milligram equivalents (MMEs) and compared using the sign test. Factors associated with post-operative opioid use at 6 weeks and 90 days were compared using χ2 test or Fisher's exact test as appropriate.

RESULTS

Nineteen THA and 11 THA with complex acetabular reconstruction were included. At 6 weeks, 26 (86.7 percent) patients were utilizing opiates, and at 90 days, 23 (76.7 percent) patients were utilizing opiates. There was a statistically significant difference between median daily preoperative MME compared to daily MME at 90 days (p < 0.001). The only statistically significant association with opioid use at 90 days was opioid use at 6 weeks.

CONCLUSION

To our knowledge, this is the first paper evaluating post-operative opioid use following primary THA in MBD patients. After THA in the setting of MBD, patients exhibit decreased post-operative opioid use. Future studies with larger cohorts should be conducted to characterize post-operative opioid use following joint arthroplasty in MBD patients.

Building Approachable Surgical Experiences (BASE) in High School Populations

OBJECTIVE

Pipeline programs are often set up to bring more diverse candidates to medical schools with the goal of diversifying the physician workforce in the years to come. All too often, these programs begin in college, long after many students of diverse backgrounds have been left behind through a myriad of barriers that exist between entering high school and matriculating to medical school. The Building Approachable Surgical Experiences (BASE) outreach program was designed to showcase healthcare careers, with an emphasis on surgical subspecialties, to historically underserved high school students. This pilot program's goal was to increase high school students' interest and confidence in pursuing future medical and surgical careers and provide a platform to initiate mentorship.

DESIGN

Local high school students from underrepresented in medicine (URiM) populations or medically underserved communities were invited to spend the day at an academic medical school campus. These students engaged in hands-on clinical and basic operative skill workshops led by third- and fourth-year medical students. They also engaged in small group conversations centered on mentorship with surgical residents and faculty.

SETTING

Program implementation took place at an academic medical center school of medicine in an urban city.

PARTICIPANTS

Forty high school students, 16 medical students, and 2 surgery faculty participated in this pilot program.

CONCLUSIONS

This event allowed early exposure for high school students to surgical and medical specialties, clinical techniques, and surgical mentorship. From the connections made, students have developed mentorship relationships and have felt comfortable reaching out with questions regarding the steps required to seek entrance to medical school. Mentors are currently resident or attending physicians, which provides students from underrepresented populations an opportunity for direct insight and guidance to and through the path to becoming a physician. Based on qualitative feedback from students, their high school teachers, and administrators, this pilot program succeeded in providing a window into healthcare, using a format that was encouraging to students long beyond their time on the school of medicine campus.

Diagnosing Laryngopharyngeal Reflux: A Comparison between 24-hour pH-Impedance Testing and Pharyngeal Probe (Restech) Testing, with Introduction of the Sataloff Score

OBJECTIVE

The purpose of this study was to compare the diagnostic utility of pH monitoring using 24-hour esophageal pH-Impedance (HEMII-pH) testing versus pharyngeal pH (Restech) testing (Respiratory Technology Corporation, Houston, Texas) for diagnosing laryngopharyngeal reflux (LPR).

METHODS

Retrospectively, patients were reviewed who had completed a Reflux Symptom Index (RSI) survey and stroboscopy within 60 days before or after undergoing simultaneous esophageal pH-Impedance monitoring and Restech testing. Reflux Finding Score (RFS) was determined by 4 blinded observers. 80.45% of patients were on anti-reflux medications at the time of study and had incomplete response to treatment for reflux. Improvement on reflux treatment was determined by evaluating presenting pre-pH monitoring RFS, post treatment RFS, and improvement of symptoms. Pearson correlation coefficients were calculated to assess relationships among RSI, RFS, and test results from HEMII-pH and Restech tests.

RESULTS

Eighty-seven patients were included in the analysis. The inter-rater reliability of the RFS determination was 74.57%, and the intra-rater reliability was 67.00%. Subjects who had a positive RYAN Score had a significant correlation with RFS (r of 0.222 and p-value of 0.0492). There was no correlation between RFS and number or percent time of reflux events, longest event, total number of events, or percent of time at alkaline pH for either HEMII-PH or Restech test. RSI correlated better with HEMII-pH test than with Restech for percent time spent in both upright (r of 0.226 and p-value of 0.029) and supine position (r of 0.261 and a p-value of 0.032). Restech correlated better with total patient symptom Scores including cough, heartburn, burping, and throat clearing, with a r of 0.242 and a p-value of 0.048. Restech detected more percent time in reflux for total reflux, supine reflux, and upright reflux (p-value less than 0.0001). Restech also detected longer event times than Impedance (p-value of less than 0.0001). When diagnosis of LPR is based on the definition of CRC, the Sataloff Score test had 70.45% sensitivity and 80.95% specificity. The RYAN Score had a sensitivity of 72%, and a specificity of 56.45%, and the Wu Score had a sensitivity of 62.16%, and specificity of 54.05%. When the Sataloff and Wu Score were used together, the sensitivity was 71.45%, specificity 100%, positive predictive value of 100%, and a negative predictive value of 59.46%.

CONCLUSION

The amount of time of reflux events correlates with symptoms better than the number of events. The HEMII-pH test was able to detect more events of pH<4 than Restech, possibly because there might have been more acid events below than above the upper esophageal sphincter, while Restech detected more total events. Restech recorded longer event times than HEMII-pH test. Since length of time correlates with RFS (probably reflecting laryngeal inflammation), and since laryngeal clearance of acid is more similar to pharyngeal than esophageal clearance, this finding might prove valuable clinically. The Sataloff Score has a sensitivity of 70.45%, and a specificity of 80.95% and appears useful clinically to detect mild to moderate that is missed by the RYAN Score. A combination of Sataloff Score and Wu Score may be clinically valuable to identify LPR with an increased sensitivity of 71.45% and increased specificity of 100%. The Wu Score is not yet available for the general clinical use, but the Sataloff Score is.

Perioperative allogenic blood transfusions are associated with increased fracture related infection rates, but not nonunion in operatively treated distal femur fractures

INTRODUCTION

Distal femur fractures are common injuries that remain difficult for orthopedic surgeons to treat. High complication rates, including nonunion rates as high as 24% and infection rates of 8%, can lead to increased morbidity for these patients. Allogenic blood transfusions have previously been identified as risk factors for infection in total joint arthroplasty and spinal fusion surgeries. No studies have explored the relationship between blood transfusions and fracture related infection (FRI) or nonunion in distal femur fractures.

METHODS

418 patients with operatively treated distal femur fractures at two level I trauma centers were retrospectively reviewed. Patient demographics were collected including age, gender, BMI, medical comorbidities, and smoking. Injury and treatment information was also collected including open fracture, polytrauma status, implant, perioperative transfusions, FRI, and nonunion. Patients with less than three months of follow up were excluded.

RESULTS

366 patients were included in final analysis. One hundred thirty-nine (38%) patients received a perioperative blood transfusion. Forty-seven (13%) nonunions and 30 (8%) FRI were identified. Allogenic blood transfusion was not associated with nonunion (13% vs 12%, P = 0.87), but was associated with FRI (15% vs 4%, P<0.001). Binary logistic regression analysis identified a dose dependent relationship between number of perioperative blood transfusions and FRI: total transfusion ≥2 U PRBC RR= 3.47(1.29, 8.10, P = 0.02), ≥3 RR= 6.99 (3.01, 12.40, P<0.001), and ≥4 RR= 8.94 (4.03, 14.42, P<0.001).

DISCUSSION

In patients undergoing operative treatment of distal femur fractures, perioperative blood transfusions are associated with increased risk of fracture related infection, but not the development of a nonunion. This risk association increases in a dose-dependent relationship with increasing total blood transfusions received.

COVID-19: Impact on the Musician and Returning to Singing; A Literature Review

OBJECTIVE

The purpose of this study was to review current literature of the impact of COVID-19 on musicians and returning to singing.

METHODS

A comprehensive search of peer-review articles was completed using PubMed, GoogleScholar, Scopus, and Web of Science. The search was completed using many key terms including voice, hoarseness, dysphonia, aphonia, cough, singers, and public speakers. The bibliography from each article found was searched to find additional articles. The search process revealed 56 peer-reviewed articles, 18 primary articles, ranging from the years 2019 to 2020.

CONCLUSION

COVID-19 has had a major impact on singers and other musicians worldwide. It can affect the voice and can lead to paresis/paralysis of laryngeal nerves to long-term changes in respiratory function. There is a risk from aerosolization/droplet formation transmission with singing, and with playing wind and brass instruments that can be mitigated by following COVID-19 guidelines. Ways to reduce possible transmission during singing and instrument play include virtual rehearsals or performances, mask-wearing, instrument covers, smaller choirs, performing outside, excellent ventilation being socially distanced, shorter rehearsals, regularly cleaning commonly touched surfaces and washing hands, avoiding contact with others, and temperature screening.

The Validity and Reliability of the Reflux Finding Score

Laryngopharyngeal reflux (LPR) disease is common. The incidence of newly diagnosed cases has increased substantially due to awareness and development of new diagnostic measurements. The reflux finding score (RFS) and reflux symptom index (RSI) are believed to be useful in the assessment process, including after the initiation of therapy. However, many authors have suggested concerns about the reliability and validity of the RFS.

OBJECTIVE

To evaluate the validity and reliability of the RFS.

METHODS

Ninety-two patients diagnosed with LPR who had undergone 24-hour pH-Impedance tests were included. All patients underwent stroboscopy and 24-Hour pH-Impedance monitoring within thirty days. Fifty-nine patients filled out a RSI prior to stroboscopic exam. The RFS was determined by four blinded observers: one otolaryngology resident, two laryngology fellows, and one laryngologist. Stroboscopic images were reviewed again one year later to assess intrarater reliability. RFS and RSI were correlated with 24-hour pH Impedance testing.

RESULTS

The Kappa value between reviewers was 0.479. The percent agreement of the four observers for total RFS was 74.04%.The percent agreement between reviewers for subglottic edema was 78.77%; for ventricular obliteration was 65.55%; for erythema/hyperemia was 69.62%, for vocal fold edema was 68.32%; for diffuse laryngeal edema was 66.86%, for posterior commissure hypertrophy was 73.54%; for granuloma/granulation was 96.80%; for thick endolaryngeal mucus was 72.81%. The intrarater reliability of the four observers for total RFS was 67.5% with an intrarater reliability range of 50%-90%. The intrarater reliability for subglottic edema was 85% with a range of 70%-100%; for ventricular obliteration was 77.50% with a range of 70%-90%; for erythema/hyperemia was 65.00% with a range of 50%-90%; for vocal fold edema was 52.50% with a range of 30%-70%; for diffuse laryngeal edema was 62.50% with a range of 20%-80%; for posterior commissure hypertrophy was 52.50% with a range of 10%-80%; for granuloma/granulation was 100%; for thick endolaryngeal mucus was 55.00% with a range of 10%-90%. There was no correlation between RFS and any parameter of the 24-Hr pH-Impedance Test. RSI had a significant correlation with number of upright events (r value of 0.271, R² of 0.0733 and P-value of 0.037), total symptoms experienced (r value of 0.0.267, R² of 0.0715 and P-value of 0.041), and symptom correlation score (r value of -0.297, R² of 0.0884 and P-value of 0.022).

CONCLUSION

Many authors have expressed concerns about the reliability and validity of the RFS. In our study we found a fair/substantial interrater reliability, and a modest intra-rater reliability. We found no correlation between the RFS and 24-Hr pH Impedance testing. This study suggests that the concerns about the validity and reliability of the RFS may be warranted. This widely used clinical score should be interpreted with caution and further research and refinement should be considered.

The Prevalence of Esophageal Disorders Among Voice Patients With Laryngopharyngeal Reflux-A Retrospective Study

OBJECTIVE

The goal of this study was to determine the prevalence of esophageal disorders among voice patients with intractable laryngopharyngeal reflux (LPR) who have undergone 24 pH impedance and esophageal manometry.

METHODS

A retrospective chart review was performed of patients with LPR-associated dysphonia in the absence of subjective dysphagia who presented between January 1, 2007 and June 30, 2019 and underwent 24 pH impedance and esophageal manometry studies after inadequate response to lifestyle modifications, high dose of Proton Pump Inhibitor (PPIs), H2 blockers, alkaline water, and Gaviscon (GlaxoSmithKline, Warren, NJ, USA). The comorbidities, medications, Strobovideolaryngoscopy findings, 24 pH impedance, and esophageal manometry results were analyzed.

RESULTS

The study included 109 patients ages 19 to 80 years old, with a mean age of 51.5 (SD 16.8). About 24.8% of the 109 subjects were found to have peristaltic wave abnormalities indicating esophageal dysmotility (11% with esophageal stasis). Lower esophageal sphincter pressures were normotensive in 56.9% of patients, hypertensive in 24.8%, and hypotensive in 18.4% of patients. In addition, the upper esophageal sphincter pressures were normotensive in 57.8% of patients, hypertensive in 36.7%, and hypotensive in 2.8% of patients. About 12.6% had both lower esophageal sphincter and upper esophageal sphincter dysfunction (hypertensive or hypotensive). The average total reflux events in patients exhibiting dysmotility on manometry 101.81, which was significantly higher compared with the mean total of 61.28 in the group of patients without dysmotility (P= 0.0396). In addition, there was a significantly higher prevalence of total events that were weakly acidic in the group with dysmotility compared with the group without (all patients performed the study on reflux medications, mean of total weakly acidic events 70.2 in dysmotility group vs 44.2 in normal motility group, P= 0.0427).Finally, the average number of total supine reflux events and the total acidic supine events were both significantly higher in the dysmotility group compared with the group without motility problems (P = 0.0199 and P = 0.0213, respectively).

CONCLUSION

Esophageal dysmotility may be a significant cofactor in voice patients with refractory LPR on appropriate reflux medications and lifestyle modifications. Further research is advised.

Paradoxical Vocal Fold Movement: A Retrospective Analysis

BACKGROUND

Paradoxical vocal fold motion (PVFM) is a disorder in which the vocal folds adduct inappropriately during inspiration resulting in episodic dyspnea and sometimes respiratory distress. Diagnosis is obtained through careful history, physical examination, flexible laryngoscopic examination with provocative maneuvers, and laryngeal electromyography. The pathogenesis and clinical findings of this disorder are not known.

OBJECTIVES

To determine characteristics of patients with confirmed PVFM and to evaluate efficacy of current treatments.

METHODS

A retrospective chart review of the patients with PVFM who presented at a quaternary care laryngology office between January 1, 2007 and August 31, 2019 was performed. Comorbidities, laboratories tests, imaging, 24-hours pH impedance testing, and laryngeal EMG results were analyzed. Dyspnea Index questionnaire before and after treatment was used to evaluate the efficiency of treatments for PVFM.

RESULTS

The average age of the 40 patients was 30.25 years. Forty-five percent of patients were under the age of 18, and 80% were female. Twenty-five percent of patients were serious athletes, and 40% of patients were students. Sixty-five percent had a previous diagnosis of asthma. One third of patients had concurrent psychiatric diagnosis. There was no family history of PVFM in the cohort. There were no other common findings. Treatment for laryngopharyngeal reflux (LPR) was used only when there was evidence of LPR; and 93% of our 40 patients received LPR treatment. Ninety percent of patients who received botulinum toxin, voice therapy (VT), and LPR treatment had subjective improvement. Patients with just VT and LPR treatment had a 43% subjective improvement rate; and the difference was statistically significant at P of 0.021. There was no statistical difference between VT and LPR treatment versus VT or LPR treatment alone.

CONCLUSION

Botulinum toxin, VT, and LPR treatment regimen is currently the most effective management for patients with paradoxical vocal fold movement disorder. More research is needed to determine the etiology of this disorder.

Effects of Particle Size of Inhaled Corticosteroid on the Voice

OBJECTIVES

The purpose of this study was to determine if inhaled corticosteroid (ICS) particle size influences the development of laryngitis including candida laryngitis, dysphonia, or vocalis muscle atrophy in asthmatic patients.

STUDY DESIGN

Retrospective analysis.

METHODS

Medical records of patients from a quaternary care laryngology practice who have asthma were reviewed retrospectively. Subjects were divided into two groups determined by the particle size of their ICS, small or standard. Each patient only used one type of inhaler. All subjects had been seen in the office for dysphonia evaluation. Statistical analysis was performed on the collected data using χ2 analysis with Yate's Correction for categorical data and a student t-test for means. A P value of less than 0.05 was considered significant.

RESULTS

There was a significant difference in vocal fold atrophy rate between groups.

CONCLUSION

Routine use of standard particle size ICS is associated with more atrophy than small size ICS.

Diagnostic Value of Acoustic and Aerodynamic Measurements in Vocal Fold Movement Disorders and their Correlation with Laryngeal Electromyography and Voice Handicap Index

OBJECTIVES

Investigate the relationships between the Voice Handicap Index, laryngeal electromyography, and objective acoustic voice testing in order to determine the utility of these measures in the management of vocal fold movement disorders.

METHODS

A retrospective review of patients who had completed a Voice Handicap Index-10 (VHI-10) questionnaire, laryngeal electromyography (LEMG), and objective acoustic measurements (including jitter, relative average perturbation, shimmer, noise-to-harmonic ratio, and standard deviation of fundamental frequency). All three tests had been completed within 30 days of the initial evaluation. All patients' results for acoustic measures were recorded as standard deviations from the norm. LEMG results were converted to grade of paresis (mild, moderate, severe) based on the muscle with the lowest recruitment. Spearman correlation coefficients were calculated to determine the relationship between these three parameters.

RESULTS

A total of 313 subjects were included in the analysis. VHI-10, LEMG (grade of paresis), and objective acoustic measures were, at best, weakly correlated. VHI-10 was better correlated than LEMG to each acoustic parameter including the average acoustic scores; however, the highest correlation observed only reached ρ = 0.349 (P < 0.001). The acoustic variables that correlated best with VHI-10 and LEMG were the standard deviation of the fundamental frequency (ρ = 0.349, P < 0.001) and shimmer (ρ = 0.207, P < 0.001), respectively.

CONCLUSION

This study demonstrates that these measures are, at best, weakly associated. VHI-10 correlated better than LEMG (grade of paresis) to each acoustic voice analysis parameter. However, the maximum correlation coefficient observed was 0.349. Therefore, VHI-10 scores and objective voice acoustic measurements are not useful for predicting the severity of vocal fold movement disorders. Moreover, a given severity of paresis can have different effects on voice handicap and acoustic output in different individuals.

Role of Postoperative Antibiotics in Patients Undergoing Type I Thyroplasty with Gore-Tex Implant

OBJECTIVES

The purpose of this study was to determine the need for postoperative antibiotic administration in patients undergoing type I thyroplasty performed with Gore-Tex implant.

STUDY DESIGN

Retrospective analysis.

METHODS

Medical records of patients from a quaternary care laryngology practice who underwent type I thyroplasty for glottic insufficiency using Gore-Tex (W.L. Gore, Newark, Delaware) implant between the years 2013 and 2019 were reviewed retrospectively. Subjects were divided into two groups determined by those who did or did not receive routine postoperative antibiotics. All patients received two grams of cefazolin IV (for the standard 70-kilogram patient), and 10 mg of dexamethasone as a one-time dose given 10 minutes prior to incision. Patients allergic to cefazoline who received a single preoperative dose of 600 mg of clindamycin IV. All subjects were seen in the office at least three times after the procedure: one day, one week, and approximately six weeks following surgery. Statistical analysis was performed on the collected data using χ² analysis for categorical data and a student t test for means. A P value of less than 0.01 was considered significant.

RESULTS

There was no significant difference in infection rate or other complications between groups.

CONCLUSION

Routine use of antibiotics following type I thyroplasty with Gore-Tex (W.L. Gore, Newark, Delaware) appears unnecessary.

An in vitro demonstration of overcoming drug resistance in SKOV3 TR and MCF7 ADR with targeted delivery of polymer pro-drug conjugates

Drug resistance is a common phenomenon that occurs in cancer chemotherapy. Delivery of chemotherapeutic agents as polymer pro-drug conjugates (PPDCs) pretargeted with bispecific antibodies could circumvent drug resistance in cancer cells. To demonstrate this approach to overcome drug resistance, Paclitaxel (Ptxl)-resistant SKOV3 TR human ovarian- and doxorubicin (Dox)-resistant MCF7 ADR human mammary-carcinoma cell lines were used. Pre-targeting over-expressed biotin or HER2/neu receptors on cancer cells was conducted by biotinylated anti-DTPA or anti-HER2/neu affibody - anti-DTPA Fab bispecific antibody complexes. The targeting PPDCs are either D-Dox-PGA or D-Ptxl-PGA. Cytotoxicity studies demonstrate that the pretargeted approach increases cytotoxicity of Ptxl or Dox in SKOV3 TR or MCF7 ADR resistant cell lines by 5.4 and 27 times, respectively. Epifluorescent microscopy - used to track internalization of D-Dox-PGA and Dox in MCF7 ADR cells - shows that the pretargeted delivery of D-Dox-PGA resulted in a 2- to 4-fold increase in intracellular Dox concentration relative to treatment with free Dox. The mechanism of internalization of PPDCs is consistent with endocytosis. Enhanced drug delivery and intracellular retention following pretargeted delivery of PPDCs resulted in greater tumor cell toxicity in the current in vitro studies.

Measurement of leisure time satisfaction in family caregivers

Caregiving is known to limit participation in a variety of roles. Leisure roles are increasingly recognized as important for the well-being of older adults. Little is known, however, about the impact of caregiving on leisure activities, and existing measures are of limited utility in caregiving research. We developed the Leisure Time Satisfaction (LTS) measure to allow further study of the impact of caregiving on caregivers' leisure time satisfaction, the role of leisure in understanding the caregiving process, and whether caregiving interventions improve leisure time satisfaction. The six-item LTS measure shows excellent psychometric properties, including internal consistency, a single factor structure, and convergent validity. Psychometric features are robust across diverse groups of caregivers, including subgroups varying by race/ethnicity and relationship to the care recipient. The LTS measure appears to be a promising tool for inclusion in caregiving research.

Isotopic constraints on the evolution of metamorphic conditions in the Jijal-Patan complex and the Kamila Belt of the Kohistan arc, Pakistan Himalaya

Pressure-temperature data and Sm-Nd and Rb-Sr garnet ages are presented for retrogressed granulitic rocks of the Jijal-Patan complex and the Kamila Amphibolite Belt. Despite the retrogression and hydration, the two samples contain garnet and hydrous minerals that yield pressures and temperatures similar to previous estimates for pristine granulite facies rocks from the same area. The Sm-Nd and Rb-Sr garnet ages are concordant at 95–100 Ma for the two samples and for both isotopic systems. These ages are interpreted as dating cooling through 700–800 °C following magmatic crystallization and granulite facies metamorphism. In the case of the garnet amphibolites from the Kamila Belt, the garnets retain prograde major element zonation. In addition, the closure temperature for the Rb-Sr system is very close to the recorded temperature. For these reasons, the age of 100 Ma must represent a time close to that when the pressure and temperature preserved in the mineralogy and its chemistry was recorded. The isotopic equilibrium between garnet and paragonite at 90–100 Ma suggests that the regional hydration event that affected the lower crust of the Kohistan arc also occurred at this time. Cooling rates calculated from the Rb-Sr and Sm-Nd ages for the partially retrogressed granulite give a minimum of 3–6°C Ma−1 and imply a different tectonic mechanism for the exhumation of the lower crust than is typical for granulites. This process may be related to early regional decompression following the collision of the Kohistan arc with Eurasia.

Considering olfactory stimulation for adults with age-related dementia

Behavioral interventions and activities for adults with age-related dementias sometimes use olfactory stimulation; however, limitations to the usefulness of such stimulation are suggested by both neurological studies which show a large amount of degeneration in the cells of the olfactory bulb and studies of perception which indicate that adults with Alzheimer's disease and related dementias perform poorly on tests of smell identification and detection. Current approaches to using olfactory stimulation as a component of interventions for adults with age-related dementia may need to be either abandoned or reassessed.

Barriers and aids in conducting research with older homeless individuals

Field notes of a qualitative pilot study of older homeless people in Cincinnati identified several barriers and aids to the study of homeless elders. Identified research barriers were researcher's lack of contextual wisdom (street smarts), locating elders, substance abuse, attrition, victimization, credibility of informants, and xenophobia. Identified research aids were friendliness of certain elders, openness of the researcher, attractive incentives in exchange for interviews, and service providers' willingness to share experiences.

Barriers to use of services by older homeless people

Analysis of responses during participant observation and face-to-face interviews of four homeless elders and six service providers indicated that the four elders comprehended and used the service environment; however, hopelessness (learned helplessness) appears to be the largest personal obstacle to use of such resources by elderly homeless persons to change their situation.

Traits of volunteers preferred by older adults

Face-to-face interviews of 46 people 60 years or older indicated that promptness, friendliness, and kindness were attributes desirable in those who volunteer to perform services for older people.

Modulation of a cloned mouse brain potassium channel

The mouse brain K+ channel (MBK), previously cloned by others, has been independently cloned and shown to express in Xenopus oocytes. This K+ current (IK) inactivated over a time course of seconds and was sensitive to the K+ channel-blocking reagent tetraethylammonium. When the K+ channel was coexpressed with a cloned mouse brain serotonin receptor (5HT1c) in oocytes, activation of the 5HT1c receptor by a brief application of serotonin resulted in a suppression of the IK amplitude over the next 20 min. IK could also be suppressed by activation of G proteins. Suppression was also caused by intracellular Ca2+ injections and was blocked by intracellular injection of EGTA. Calmodulin antagonists block the IK suppression, but a known protein kinase inhibitor did not block suppression. The 5HT1c suppression was reversible; recovery from suppression was blocked by the protein kinase inhibitor H-7. These data suggest that the IK suppression occurs through a novel mechanism independent of A- or C-type protein kinases; suppression is best explained as being due to the action of a Ca2+/calmodulin-activated phosphatase; recovery from suppression is due to the action of a protein kinase.

Rest tremor associated with exposure to Monensin

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Fatty acid synthetase activity in Mycobacterium phlei: regulation by polysaccharides

The multienzyme complex from Mycobacterium phlei which catalyzes the synthesis of long chain fatty acids from acetyl-CoA and malonyl-CoA requires a heat-stable fraction (stimulating factor, SF) for activity. Fractionation of heat-treated M. phlei extracts affords two stimulatory subfractions, one of which (SF(2)) can be replaced by FMN. The other (SF(1)) is further separable into 3 polysaccharides (PS(I), PS(II), and PS(III)). PS(I) contains about 95% 3-O-methylmannose and 5% mannose; the sugar composition of PS(II) and PS(III) is about 55% 6-O-methylglucose and 45% glucose for both. Each of the three purified polysaccharides, in combination with FMN, substitutes for the crude stimulating factor. The polysaccharides exert their effect on the fatty acid synthetase by lowering the K(m) for acetyl-CoA about 50-fold.