A revised lower estimate of ozone columns during Earth's oxygenated history

The history of molecular oxygen (O₂) in Earth's atmosphere is still debated; however, geological evidence supports at least two major episodes where O₂ increased by an order of magnitude or more: the Great Oxidation Event (GOE) and the Neoproterozoic Oxidation Event. O₂ concentrations have likely fluctuated (between 10^-3 and 1.5 times the present atmospheric level) since the GOE ∼2.4 Gyr ago, resulting in a time-varying ozone (O₃) layer. Using a three-dimensional chemistry-climate model, we simulate changes in O₃ in Earth's atmosphere since the GOE and consider the implications for surface habitability, and glaciation during the Mesoproterozoic. We find lower O₃ columns (reduced by up to 4.68 times for a given O₂ level) compared to previous work; hence, higher fluxes of biologically harmful UV radiation would have reached the surface. Reduced O₃ leads to enhanced tropospheric production of the hydroxyl radical (OH) which then substantially reduces the lifetime of methane (CH₄). We show that a CH₄ supported greenhouse effect during the Mesoproterozoic is highly unlikely. The reduced O₃ columns we simulate have important implications for astrobiological and terrestrial habitability, demonstrating the relevance of three-dimensional chemistry-climate simulations when assessing paleoclimates and the habitability of faraway worlds.

Airway events in obese vs. non-obese elective surgical patients: a cross-sectional observational study

Obesity is an increasingly prevalent comorbidity within the UK population. The aim of this study was to determine the proportion of obese patients in an elective surgical population. The second aim was to determine the choice of airway equipment and incidence of airway events in obese vs. non-obese patients. We conducted a cross-sectional observational study over two 24-h periods in March 2018 across 39 hospitals in the greater London area. Data were collected regarding 1874 patients. The incidence of obesity was 32% in the study population compared with 26% in the general UK population (p < 0.0001). Minor airway events were defined as: desaturation to S_p O₂ < 90%; failed mask ventilation; supraglottic airway device problem; aspiration; airway trauma and difficult intubation; or recognised oesophageal intubation. Major airway events were defined as: unrecognised oesophageal intubation; a 'cannot intubate cannot oxygenate' emergency; the need for unplanned front-of-neck airway; cardiac arrest; or unplanned intensive care unit admission due to an airway event. In total, 89 minor and two major airway events were recorded. Obese patients were more likely to experience a minor airway event (RR 2.39, 95%CI 1.60-3.57), the most common being desaturation (S_p O₂ < 90%). The use of a supraglottic airway device in obese vs. non-obese patients was associated with increased airway events (RR 3.46 [1.88-6.40]). Tracheal intubation vs. supraglottic airway device use increased with obesity class but was not associated with a decrease in airway events (RR 0.90 [0.53-1.55]). Our data suggest that obesity is more common in the elective surgical vs. general population and minor airway events are more common in obese vs. non-obese elective patients.

Attitudes toward advance care planning among persons with dementia and their caregivers

OBJECTIVES

To examine factors that influence decision-making, preferences, and plans related to advance care planning (ACP) and end-of-life care among persons with dementia and their caregivers, and examine how these may differ by race.

DESIGN

Cross-sectional survey.

SETTING

13 geographically dispersed Alzheimer's Disease Centers across the United States.

PARTICIPANTS

431 racially diverse caregivers of persons with dementia.

MEASUREMENTS

Survey on "Care Planning for Individuals with Dementia."

RESULTS

The respondents were knowledgeable about dementia and hospice care, indicated the person with dementia would want comfort care at the end stage of illness, and reported high levels of both legal ACP (e.g., living will; 87%) and informal ACP discussions (79%) for the person with dementia. However, notable racial differences were present. Relative to white persons with dementia, African American persons with dementia were reported to have a lower preference for comfort care (81% vs. 58%) and lower rates of completion of legal ACP (89% vs. 73%). Racial differences in ACP and care preferences were also reflected in geographic differences. Additionally, African American study partners had a lower level of knowledge about dementia and reported a greater influence of religious/spiritual beliefs on the desired types of medical treatments. Notably, all respondents indicated that more information about the stages of dementia and end-of-life health care options would be helpful.

CONCLUSIONS

Educational programs may be useful in reducing racial differences in attitudes towards ACP. These programs could focus on the clinical course of dementia and issues related to end-of-life care, including the importance of ACP.

Cost-Effective Care Coordination for People With Dementia at Home

Background and Objectives

People with dementia (PWD) represent some of the highest-need and highest-cost individuals living in the community. Maximizing Independence (MIND) at Home is a potentially cost-effective and scalable home-based dementia care coordination program that uses trained, nonclinical community workers as the primary contact between the PWD and their care partner, supported by a multidisciplinary clinical team with expertise in dementia care.

Research Design and Methods

Cost of care management services based on actual time spent by care management personnel over first 12 months of MIND at Home intervention was calculated for 342 MIND at Home recipients from Baltimore, Maryland and surrounding areas participating in a Centers for Medicare and Medicaid Services (CMS) funded Health Care Innovation Award demonstration project. Difference-in-differences analysis of claims-based Medicaid spending of 120 dually-eligible MIND at Home participants with their propensity score matched comparison group (n = 360).

Results

The average cost per enrollee per month was $110, or $1,320 per annum. Medicaid expenditures of dually-eligible participants grew 1.12 percentage points per quarter more slowly than that of the matched comparison group. Most savings came from slower growth in inpatient and long-term nursing home use. Net of the cost of the 5-year MIND at Home intervention, 5-year Medicaid savings are estimated at $7,052 per beneficiary, a 1.12-fold return on investment.

Discussion and Implications

Managed care plans with the flexibility to engage community health workers could benefit from a low-cost, high-touch intervention to meet the needs of enrollees with dementia. Limitations for using and reimbursing community health workers exist in Medicare fee-for-service, which CMS should address to maximize benefit for PWD.

COMMON UNMET NEEDS OF DEMENTIA CAREGIVERS AND HOW THESE DIFFER BY DISEASE STAGE AND RACE

This presentation (co-presentation Samus and Sloan) will use combined cross-sectional, baseline data from two intervention studies (n=-642) conducted in Maryland evaluating the impact of dementia care coordination model (MIND at home) to provide a detailed description of common modifiable unmet care needs of family caregivers of community-living persons with dementia (PWD), explore how care needs may differ by the disease stage of the PWD, and presence of racial disparities in care needs. Unmet caregiver needs were identified based on comprehensive in-home assessments using a standardized tool (JHDCNA 2.0) with 6 care domains and 18 items covering caregiver needs. Family caregivers were 77% women; 63 years old (mean); 60% White; and 52% adult children. The most prevalent needs were for education/resources (98%), legal (74%), mental health (44%), and informal support (43%). Needs varied based on dementia severity. African American caregivers (vs. white) had significantly more unmet caregiver needs at baseline (p<.001).

MAKING ENGAGEMENT MEANINGFUL THROUGH ORGANIZED ROUTINE INTERACTION (MEMORI) CORPS TRIAL: AN INTRODUCTION

This presentation will review the design, methods, and early lessons learned from the Making Engagement Meaningful through Organized Routine Interaction (MEMORI) Corps trial recently funded by NIA. This trial is evaluating the feasibility and efficacy of the MEMORI Corps program, a novel 12-week activity-based companion care model designed to mobilize and equip senior volunteers to deliver individualized, evidence-based activity programming to persons with dementia PWD living at home and offer family CGs needed respite. The intervention synthesizes and adapts prior evidence-based work from the Tailored Activities Program® (an activity-based intervention persons with dementia), Experience Corps® (an intergenerational civic engagement program that engages senior volunteers to work in elementary schools), and MIND at Home® (a home-based dementia care coordination program) to simultaneously address unmet respite care needs of family CGs, provide PWD structured meaningful activities and social engagement, and provide meaningful engagement and peer support opportunities for senior volunteers.

Describing readmissions to an Ebola case management centre (CMC), Sierra Leone, 2014

Case management centres (CMCs) are part of the outbreak control plan for Ebola virus disease (EVD). A CMC in Sierra Leone had 33% (138/419) of primary admissions discharged as EVD negative (not a case). Fifteen of these were readmitted within 21 days, nine of which were EVD positive. All readmissions had contact with an Ebola case in the community in the previous 21 days indicating that the infection was likely acquired outside the CMC.

Describing readmissions to an Ebola case management centre (CMC), Sierra Leone, 2014

Case management centres (CMCs) are part of the outbreak control plan for Ebola virus disease (EVD). A CMC in Sierra Leone had 33% (138/419) of primary admissions discharged as EVD negative (not a case). Fifteen of these were readmitted within 21 days, nine of which were EVD positive. All readmissions had contact with an Ebola case in the community in the previous 21 days indicating that the infection was likely acquired outside the CMC.

Neuronal beacon

The controlled navigation of the axonal growth cone of a neuron toward the dendrite of its synaptic partner neuron is the fundamental process in forming neuronal circuitry. While a number of technologies have been pursued for axonal guidance over the past decades, they are either invasive or not controllable with high spatial and temporal resolution and are often limited by low guidance efficacy. Here, we report a neuronal beacon based on light for highly efficient and controlled guidance of cortical primary neurons.

Fiber-optic two-photon optogenetic stimulation

Optogenetic stimulation of genetically targeted cells is proving to be a powerful tool in the study of cellular systems, both in vitro and in vivo. However, most opsins are activated in the visible spectrum, where significant absorption and scattering of stimulating light occurs, leading to low penetration depth and less precise stimulation. Since we first (to the best of our knowledge) demonstrated two-photon optogenetic stimulation (TPOS), it has gained considerable interest in the probing of cellular circuitry by precise spatial modulation. However, all existing methods use microscope objectives and complex scanning beam geometries. Here, we report a nonscanning method based on multimode fiber to accomplish fiber-optic TPOS of cells.

The effects of perineural and intrasynovial anaesthesia of the equine foot on subsequent magnetic resonance images

REASONS FOR PERFORMING STUDY

Artefacts caused by regional anaesthesia can influence image interpretation of ultrasonography and nuclear scintigraphy. Perineural and intrasynovial anaesthesia are commonly performed prior to magnetic resonance imaging (MRI); and the effects on MR images, if any, are unknown.

OBJECTIVES

To determine if perineural and intrasynovial anaesthesia of structures in the equine foot cause iatrogenic changes detectable with MRI.

METHODS

A baseline MRI examination of both front feet was performed on 15 horses, 2-6 days prior to mepivacaine injection adjacent to the lateral and medial palmar digital nerves, and into the podotrochlear bursa, digital flexor tendon sheath and distal interphalangeal joint of one randomly assigned forelimb. Magnetic resonance imaging was repeated at 24 and 72 h post injection; then qualitative and quantitative assessments of MRI findings were performed.

RESULTS

Magnetic resonance imaging findings associated with the palmar digital nerves, podotrochlear bursa and distal interphalangeal joint at 24 and 72 h after mepivacaine injection did not alter significantly from those at baseline. Compared with baseline, a significant increase in synovial fluid volume of the digital flexor tendon sheath was detected with MRI at 24 and 72 h post injection.

CONCLUSIONS

Perineural anaesthesia of the palmar digital nerves and intrasynovial anaesthesia of the podotrochlear or distal interphalangeal joint did not interfere with the interpretation of MR images acquired at 24 or 72 h after injection. However, intrasynovial anaesthesia of the digital flexor tendon sheath caused an iatrogenic increase in synovial fluid, detectable on MR images for at least 72 h.

POTENTIAL RELEVANCE

Although a definite time frame for resolution of digital flexor tendon sheath distension was not determined, we recommend waiting more than 3 days between intrasynovial anaesthesia of the digital flexor tendon sheath and evaluation with MRI.

A follow-up study of change in quality of life among persons with dementia residing in a long-term care facility

BACKGROUND

Dementia is a major public health problem. Increased attention is being paid to the quality of life (QOL) of people with this chronic disease. There have been no longitudinal studies of QOL change in dementia.

METHOD

Longitudinal study of a cohort of 47 persons with dementia residing in a long-term care facility. The QOL of participants was assessed at baseline using the Alzheimer's Disease Related Quality of Life (ADRQL) scale. At this time participants were also assessed on a series of other clinical measures. QOL was reassessed on the ADRQL scores two years later.

RESULTS

There was small but significant mean decline in ADRQL over the two-year study interval. However, for 49% of participants, ADRQL scores did not change or improved. Small but significant declines occurred in all ADRQL domains, with the exception of 'feelings and mood'. Of the baseline variables assessed, only a lower baseline ADRQL score was associated with greater decline in ADRQL score at follow-up. There was no association between sociodemographic variables, baseline ratings of dementia severity (MMSE), ADL impairment, behavioral impairment, and depression, or MMSE change during follow-up and ADRQL decline.

CONCLUSIONS

Among long-term care residents with dementia there is a small decline in QOL ratings over two years. However, for nearly half, QOL ratings stay the same or improve. The ADRQL is a sensitive measure of change in QOL and is appropriate for use as an outcome measure in intervention studies. The predictors of QOL change are complex and require further study.

In vacuo esterification of carboxyl groups in lyophilized proteins

A new method is described for the esterification of carboxyl groups in proteins by reaction of the lyophilized protein in vacuo with gaseous alcohol and HCI catalyst. Carboxyl groups are rapidly esterified with no protein degradation. 13C-Methyl or 13C-ethyl esters of the alpha-, gamma- and delta-carboxyl groups could be distinguished by the distinct chemical shifts of their resonances. Within the class of gamma- or delta-esters, the chemical shifts have little variation; however, the chemical shift of a C-terminal esterified alpha-carboxyl group shows a strong dependence on the nature of the C-terminal amino acid and sequence. Iodomethane reacts with deprotonated carboxyl groups in lyophilized proteins to form methyl esters, but unlike the reaction with gaseous methanol/HCI, it does not selectively methylate carboxyl groups. The procedure permits the cost-effective incorporation of isotopic labels and provides a new approach using 13C-NMR spectroscopy for determining the number of different C-termini present in a protein preparation.

The neuropathic postural tachycardia syndrome

BACKGROUND

The postural tachycardia syndrome is a common disorder that is characterized by chronic orthostatic symptoms and a dramatic increase in heart rate on standing, but that does not involve orthostatic hypotension. Several lines of evidence indicate that this disorder may result from sympathetic denervation of the legs.

METHODS

We measured norepinephrine spillover (the rate of entry of norepinephrine into the venous circulation) in the arms and legs both before and in response to exposure to three stimuli (the cold pressor test, sodium nitroprusside infusion, and tyramine infusion) in 10 patients with the postural tachycardia syndrome and in 8 age- and sex-matched normal subjects.

RESULTS

At base line, the mean (+/-SD) plasma norepinephrine concentration in the femoral vein was lower in the patients with the postural tachycardia syndrome than in the normal subjects (135+/-30 vs. 215+/-55 pg per milliliter [0.80+/-0.18 vs. 1.27+/-0.32 nmol per liter], P=0.001). Norepinephrine spillover in the arms increased to a similar extent in the two groups in response to each of the three stimuli, but the increases in the legs were smaller in the patients with the postural tachycardia syndrome than in the normal subjects (0.001+/-0.09 vs. 0.12+/-0.12 ng per minute per deciliter of tissue [0.006+/-0.53 vs. 0.71+/-0.71 nmol per minute per deciliter] with the cold pressor test, P=0.02; 0.02+/-0.07 vs. 0.23+/-0.17 ng per minute per deciliter [0.12+/-0.41 vs. 1.36+/-1.00 nmol per minute per deciliter] with nitroprusside infusion, P=0.01; and 0.008+/-0.09 vs. 0.19+/-0.25 ng per minute per deciliter [0.05+/-0.53 vs. 1.12+/-1.47 nmol per minute per deciliter] with tyramine infusion, P=0.04).

CONCLUSIONS

The neuropathic postural tachycardia syndrome results from partial sympathetic denervation, especially in the legs.

Interaction of carbon dioxide and sympathetic nervous system activity in the regulation of cerebral perfusion in humans

Recent studies suggest that activation of the sympathetic nervous system either directly or indirectly influences cerebrovascular tone in humans even within the autoregulatory range. In 6 healthy subjects (aged 29+/-4 years), we used transcranial Doppler sonography to determine cerebral blood flow velocity during sympathetic activation elicited through head-up tilt (HUT) and sympathetic deactivation through ganglionic blockade. PaCO(2) was manipulated through hyperventilation and CO(2) breathing (5%). With subjects in the supine position and during HUT, mean arterial pressure was not influenced by PaCO(2). During ganglionic blockade, mean arterial pressure decreased markedly with hyperventilation (-13+/-1.9 mm Hg). Manipulation of sympathetic tone elicited only mild changes in cerebral blood flow (64+/-5.8 cm/s supine, 58+/-4.9 cm/s upright, and 66+/-6.2 cm/s during ganglionic blockade; P:=0.07 by ANOVA). The slope of the regression between PaCO(2) and mean velocity was 1.6+/-0.18 cm/(s. mm Hg) supine, 1.3+/-0.14 cm/(s. mm Hg) during HUT, and 2.3+/-0.36 cm/(s. mm Hg) during ganglionic blockade (P:<0.05). Spontaneous PaCO(2) and ventilatory response to hypercapnia were also modulated by the level of sympathetic activity. Changes in sympathetic tone have a limited effect on cerebral blood flow at normal PaCO(2) levels. However, the sympathetic nervous system seems to attenuate the CO(2)-induced increase in cerebral blood flow. This phenomenon may indicate a moderate direct effect of the sympathetic nervous system on the cerebral vasculature. Furthermore, sympathetic activation tends to increase ventilation and thus can indirectly increase cerebrovascular tone.

Use of the pH memory effect in lyophilized proteins to achieve preferential methylation of alpha-amino groups

It is demonstrated that the pH memory effect can be used to control the ionization state of amino groups in lyophilized proteins and hence their chemical reactivity toward modifying reagents. When proteins were lyophilized from aqueous solutions at pH values between 6 and 7 and reacted in vacuo with iodomethane, the alpha-amino groups were found to be either preferentially or selectively trimethylated. Reaction with 13C-labeled iodomethane permitted detection and identification of individual trimethylated alpha-amino groups by 13C-NMR spectroscopy as distinct peaks in the spectral region between 52 and 57 ppm. There was adequate sensitivity to detect minor resonances of free alpha-amino groups arising from proteolysis of the major protein or from protein impurities. The resonances of the trimethylated alpha-amino groups in standard amino acids and peptides are sufficiently close to those in the derivatized protein to make a tentative identification of the N-terminal amino acid. It is also demonstrated that advantage can be taken of the pH memory effect to use the preferential 13C-methylation of amino groups to verify whether a protein has a free or blocked amino terminus.

Mastoidectomy elimination: obliterate, reconstruct, or ablate?

OBJECTIVE

This study aimed to evaluate a chronology of techniques used to manage troublesome open mastoid cavities, with emphasis on the selection of the mastoidectomy elimination technique most appropriate to the case at hand.

STUDY DESIGN

The study design was a retrospective review of techniques used in 465 consecutive elimination cases.

SETTING

The study was conducted at a single surgeon's private otologic practice.

PATIENTS

Patients with mastoidectomy elimination who were treated from 1974-1996, including 55 patients with obliterations (cavity fill-in), 372 patients with reconstructions (canal wall repair), and 38 patients with ablations (external canal closure), requiring 823 procedures, were examined.

MAIN OUTCOME MEASURES

Clinical success and complication rates of the techniques studied were measured.

RESULTS

Optimal outcomes (89% successful) were recorded from hydroxylapatite reconstruction cases managed with canal revascularization (middle temporal flap) and cholesteatoma prevention (staging and composite grafts).

CONCLUSIONS

Obliteration is recommended only over noncholesteatomatous sites because of the risk of residual disease and the difficulty re-exploring these cases. Ablation is effective in selected, severely damaged cases. All ablation cases remained disease-free after surgery. Reconstruction is the preferred method when hearing restoration is required. Canal wall reconstruction required modifications to avoid complications from poor tissue vitality and cholesteatoma. These are outlined and discussed below.

The use of vascular flaps in middle ear surgery

OBJECTIVE

This study aimed to evaluate improved surgical outcomes from middle and external ear surgery using local vascular flaps to enhance tissue healing.

STUDY DESIGN

The study design was a review of the design and clinical trials of three soft tissue flaps: the middle temporal flap (MTF), the middle temporal canal flap (MTCF), and the wing flap. All derive axial vascular supply from the middle temporal vessels.

SETTING

The study was performed at a single surgeon's private otologic practice.

PATIENTS

A total of 319 patients were treated from 1991-1996: MTF in 223, MTCF in 38, and wing flap in 58. The average case maturity was 2.25 years. Most cases were mastoidectomy reconstruction or intact canal wall mastoidectomy.

INTERVENTION

The flaps are used to introduce an improved blood supply to key repair sites in the middle and external ear.

MAIN OUTCOME MEASURES

Canal skin breakdown, chronic myringitis, and chronic otitis externa were measured.

RESULTS

Dehiscence rates fell from 15-5% and myringitis rates fell from 15-4%. Thicker, vascular canal skin was the usual result.

CONCLUSIONS

The flaps provide the optimal method of revascularizing the external canal during mastoidectomy reconstructions and possibly canal defect repairs during intact canal wall mastoidectomy. Further studies are required to evaluate the efficacy of the wing flap and the MTCF.

Heat shock treatment releases Penicillium phosphoglycopeptide

Filtrates of heat (54 degrees) treated day-5 Penicillium fellutanum cultures contained 70 mg of peptidophosphogalactomannan-II; an unheated control contained 30 mg. The polymer contained up to 60 phosphodiesters, and 5-O-beta-D-galactofuranosyl, mannopyranosyl, amino acyl and 2-aminoethanol residues. Its 13C NMR spectrum was nearly identical with that of the control polymer. The major 31P NMR signal was phosphocholine phosphodiester at delta 0.22 ppm: significant phosphodiester signals occurred at delta 1.15, 1.33 and 1.47. Dilute mineral acid released galactofuranosyl residues from the mannan. Signals at delta 1.15-1.47 ppm were associated with molecules of mass less than 3500 and contained galactose, 2-aminoethanol and peptide(s). After this acid treatment, signals at delta 1.0-0.22 remained associated with the mannan. Heat released up to 4-fold more of peptidophosphogalactomannan-III compared with the untreated control; carbohydrate and phosphate content, per mg polymer, were reduced by 4- and 2-fold, respectively. A galactofuranosyl-, phosphoryl- and amino acyl-containing polymer of Mr greater than 14,000 was solubilized by alkali treatment of P. fellutanum cell walls.

Treating tuberculosis: the essential role of social work

The resurgence of tuberculosis gives cause for alarm. Compliance with an effective medication regimen leads to cure; yet, many patients fail to comply. This paper discusses factors affecting compliance and the essential role of social work, from an ecological perspective, when intervening to increase compliance. The authors relate comments made by patients at the only hospital originally and still serving as a TB sanatorium in relation to literature on compliance. Changes at the hospital include the development of a social work department which uses the ecological perspective in working with patients whose histories include non-compliance, as well as alcoholism, homelessness, loneliness, joblessness, and AIDS. The content of interviews with patients reveal and identify problems for future research.

Differentiating recruitment strategies for direct patient care, clerical, and fundraising hospice volunteers

A survey of direct patient care and nondirect patient care volunteers in two hospice programs generated information about various aspects of their volunteer experience. This paper focuses on the effectiveness of identified recruitment strategies for direct patient care, clerical, and fundraising volunteers. People learned about the opportunity to volunteer at hospice most frequently from personal experiences, friends, and newspapers. Significantly more direct patient care volunteers learned about the volunteer opportunity through newspaper feature stories than did nondirect volunteers. Friends recruited significantly more fundraising volunteers than direct patient care or clerical volunteers. The events triggering direct care and clerical volunteers to serve were most often personal experiences, whereas friends appear to have triggered direct care and fundraising volunteers to serve.

Effects of volume loading and pressor agents in idiopathic orthostatic tachycardia

BACKGROUND

Idiopathic orthostatic tachycardia (IOT) is characterized by an increase in heart rate (HR) with standing of > or = 30 bpm that is associated with elevated catecholamine levels and orthostatic symptoms. A dynamic orthostatic hypovolemia and alpha1-adrenoreceptor hypersensitivity have been demonstrated in IOT patients. There is evidence of an autonomic neuropathy affecting the lower-extremity blood vessels.

METHODS AND RESULTS

We studied the effects of placebo, the alpha1-adrenoreceptor agonist midodrine (5 to 10 mg), the alpha2-adrenoreceptor agonist clonidine (0.1 mg), and I.V. saline (1 L) in 13 patients with IOT. Supine and upright blood pressure (BP) and HR were measured before and at 1 and 2 hours after intervention. Midodrine decreased both supine and upright HR (all HR values are given as bpm) at 2 hours (from 78+/-2 supine to 108+/-5 upright before treatment and from 69+/-2 supine to 95+/-5 upright after treatment, P<.005 for supine and P<.01 for upright). Saline decreased both supine and upright HR (from 80+/-3 supine to 112+/-5 upright before infusion and from 77+/-3 supine to 91+/-3 upright 1 hour after infusion, P<.005 for supine and P<.001 for upright). Clonidine decreased supine HR (from 78+/-2 to 74+/-2, P<.03) but did not affect the HR increase with standing. Clonidine very significantly decreased supine systolic BP (from 109+/-3 at baseline to 99+/-2 mm Hg at 2 hours, P<.001), and midodrine decreased supine systolic BP mildly.

CONCLUSIONS

IOT responds best acutely to saline infusion to correct the underlying hypovolemia. Chronically, this can be accomplished with increased salt and water intake in conjunction with fludrocortisone. The response of patients to the alpha1-agonist midodrine supports the hypothesis of partial dysautonomia and indicates that the use of alpha1-agonists to pharmacologically replace lower-extremity postganglionic sympathetics is an appropriate overall goal of therapy. These findings are consistent with our hypothesis that the tachycardia and elevated catecholamine levels associated with IOT are principally due to hypovolemia and loss of adequate lower-extremity vascular tone.

Driver fatigue in the city

The current survey investigates the features of driver fatigue incidents (accidents, near accidents and unintentional drifting-out-of-lane events) which occurred in cities. The results show similar patterns to previous surveys, with incident trips tending to be short, and prior sleep loss and late night driving featuring as factors. Work trips feature very strongly among city fatigue incident trips and work is also a common reason for sleep loss before a fatigue incident. Consistent with the high representation of work trips, there are peaks in incident occurrence at commuter travel times. Shiftworkers are prominent amongst fatigue incident-involved drivers. Social trips also feature amongst fatigue incident trips but are likely to be more difficult to address with countermeasures.

The prevalence of psychiatric disorders in elderly residents of public housing

BACKGROUND

This study estimates lifetime and one-month prevalence of psychiatric disorders among elderly public housing residents.

METHOD

Nine hundred forty-five residents of six public housing developments for the elderly were administered the General Health Questionnaire (GHQ), the Mini-Mental State Examination (MMSE), and the CAGE by lay interviewers. Residents screening positive and a 10% random sample of screen negatives were administered the Structured Clinical Interview for DSM-III-R (SCID) and a DSM-III-R derived algorithm for dementia and delirium. Prevalence rates were estimated based on weighted data from 298 subjects.

RESULTS

Thirty-six percent of participants screened positive on at least one instrument. Based on the case identification interview, estimated lifetime prevalence of psychiatric disorders was 57.6%, and one-month prevalence was 27.9%. Cognitive disorder (10.5%), mood disorder (8.0%), psychotic disorder (4.6%), and substance abuse/dependence (4.4%) were the most common current disorders. Mood disorders (26.6%) and substance abuse/dependence (23.0%) were the most prevalent lifetime disorders. Compared to data from the Epidemiologic Catchment Area, public housing residents have higher current rates of mood disorder, schizophrenia, and substance use disorder.

CONCLUSIONS

Elderly residents of public housing suffer higher rates of psychiatric morbidity than older people living independently in the community. The high prevalence of psychiatric disorders in this growing population of low-income elderly presents a challenge to the delivery of mental health service.

The deep branch of the ulnar nerve in Guyon's canal: branching and innervation of the hypothenar muscles

Thirty-seven embalmed, unpaired cadaver hands were dissected to delineate and classify the innervation of the hypothenar musculature. The deep branch of the ulnar nerve passed between the abductor digiti minimi and flexor digiti minimi and then pierced the opponens in all specimens. All branching occurred on the ulnar aspect of the deep branch of the ulnar nerve. A classification based on proximity of the different branches is prepared. Five different patterns have been noted.

Mastoidectomy elimination

Surgery that eliminates the open radical cavity takes three forms: obliteration (cavity fill-in, reconstruction (canal wall defect repair), or ablation (external canal closure). The evolution of each variety is reviewed in detail and a personal series of 240 cases is discussed. These included obliterations and reconstructions employing porous hydroxylapatite ceramic implants. Larger defects required Grote implants, but high facial ridge cases were managed with attic defect plates and limited canalplasty. Canal repair success rates improved with the use of the middle temporal flap to improve canal wall vascularity Residual cholesteatoma has been prevented by staged surgery, and recurrent disease has been virtually abolished by aggressive prevention techniques which employ drum reinforcement with finely shaven cartilage-perichondrium composite grafts. Ossiculoplasty procedures included 85 Plastipore columellas, 107 Oval-Top hydroxylapatite/Teflon columellas and, more recently, 17 Spanner malleus-stapes/footplate assemblies. Earlier poor results have been succeeded by more satisfactory levels. Since 1990, the air-bone gap has been closed to within 10 dB in 33% of cases and to within 20 dB in 66% of cases. Studies using SPITE (surgical, prosthetic, infection, tissues, and eustachian) adverse indicators have demonstrated high levels of pathology in elimination cases, when compared with nonelimination series. The SPITE studies have also demonstrated the reduction of pathology levels by staged surgery. Elimination surgery now provides permanent relief from the problem cavity in all but a few cases.

Anxiety disorders in children and adolescents

Anxiety disorders are common in children and adolescents and may be associated with significant suffering, disruptions of normal psychosocial and academic development, disruption of family functioning, and increased utilization of medical services. They are frequently chronic disorders. Effective early interventions for children and adolescents with anxiety disorders may reduce or eliminate potentially life-long suffering and impairment.

Psychiatric characteristics of children with selective mutism: a pilot study

OBJECTIVE

To ascertain characteristics of children with selective mutism.

METHOD

Subjects with selective mutism were evaluated by means of parent and teacher rating scales and structured diagnostic interviews.

RESULTS

Thirty children were evaluated. Mutism severity varied markedly in different environmental settings. Ninety-seven percent of the subjects were diagnosed with social phobia or avoidant disorder of childhood or adolescence or both and 30% with simple phobia. No other psychiatric disorders were common. Parent and teacher rating scales showed high levels of anxiety symptoms, especially social anxiety, and low levels of all other psychiatric symptoms. Anxiety and social anxiety severity correlated with mutism severity. First-degree family history of social phobia and of selective mutism, obtained by family history method, was present in 70% and 37% of families, respectively. There was no evidence of a causal relationship between psychologically or physically traumatic experiences and development of selective mutism.

CONCLUSIONS

Selective mutism may be a symptom of social anxiety, rather than a distinct diagnostic syndrome. Further study of the characteristics of children with selective mutism and their families is warranted.