PubMed Health⌕ Search

Biomedical subjects

J Wald

Publications and source records attributed to J Wald.

At least 19 recordsLinked to original sources
PubMed2005

Keeping patients active and current in a patient portal.

Maintaining current contact information is crucial to the effectiveness of communication via patient portals. Patients who visit a portal infrequently, or whose contact information is not updated, may miss administrative notices or clinical messages from their doctor's office. We invited patients to review and update their contact information via a broadcast e-mail message sent to all patients in the patient portal, Patient Gateway. We report the effectiveness of the broadcast message approach to reaching registered patients.

Electronic Mail↗
PubMed2001

Unexplained exertional limitation: characterization of patients with a mitochondrial myopathy.

Exercise intolerance is a common complaint, the cause of which often remains elusive after a comprehensive evaluation. In this report, we describe 28 patients with unexplained dyspnea or exertional limitation secondary to biopsy-proven mitochondrial myopathies. Patients were prospectively identified from a multidisciplinary dyspnea clinic at a tertiary referral center. All patients were without underlying pulmonary, cardiac, or other neuromuscular disorders. Patients underwent history, physical examination, complete pulmonary function testing, respiratory muscle testing, cardiopulmonary exercise testing, and muscle biopsy. Results were compared with a group of normal control subjects. The estimated period prevalence was 8.5% (28 of 331). Spirometry, lung volumes, and gas exchange were normal in patients and control subjects. Compared with control subjects, the patient group demonstrated decreased exercise capacity (maximum achieved V O(2) 67 versus 104% predicted; p < 0.0001) and respiratory muscle weakness (PI(max) 77 versus 115% predicted; p = 0.001). These patients have a characteristic exercise response that was hyperventilatory (peak VE/V CO(2); 55 versus 42) and hypercirculatory (maximum heart rate - baseline heart rate/V O(2)max - baseline V O(2)max; 91 versus 41) compared to control subjects. Patients stopping exercise due to dyspnea (n = 16) (as compared with muscle fatigue, n = 11) displayed weaker respiratory muscles (Pdi(max) 61 versus 115 cm H(2)O; p = 0.01) and were more likely to reach mechanical ventilatory limitation (V Emax/ MVV 0.81 versus 0.58; p = 0.02). The sensation of dyspnea was related to indices of respiratory muscle function including respiratory rate and inspiratory flow. We conclude that mitochondrial myopathies are more prevalent than previously reported. The characteristic physiological profile may be useful in the diagnostic evaluation of mitochondrial myopathy.

Adult↗
PubMed2001

Aqueous One-Pot Synthesis of Derivatized Cyclopentadienyl-Tricarbonyl Complexes of (99m) Tc with an In Situ CO Source: Application to a Serotonergic Receptor Ligand.

Instant radiopharmaceuticals-just add [(99m) TcO4 ](-) in water! Half-sandwich complexes of the type [(RCOCp)(99m) Tc(CO)3 ] (e.g. 1) were synthesized in a single step in water from [(99m) TcO4 ](-) . The acidification of the Cp ring by a carbonyl substituent and the use of K2 [H3 BCO2 ] as a reducing agent and in situ source of CO are instrumental in the synthesis.

carbonylation↗
PubMed2001

Zero tolerance: unfair, with little recourse.

This chapter examines racial disparities in the application of zero tolerance, describes legal avenues available to parents and children's advocates, and summarizes recent court decisions issued on school discipline cases.

Adolescent↗
PubMed2001

Psychometric properties of the driVR: a virtual reality driving assessment.

This study provides data on the psychometric properties of the driVR, a virtual reality assessment used to assess driving in persons with brain injury. Several driVR measures were compared to other established indicators of driving performance. Many concurrent validity coefficients over r = 0.3 were identified between driVR measures of lane tracking with on-road, Trail Making Test, and the Driver Performance Test II scores. The results provide further evidence to support the concurrent validity of the driVR. Continued research addressing other aspects of validity and reliability is recommended.

Adult↗
PubMed2000

The use of virtual reality in the assessment of driving performance in persons with brain injury.

In this article, we present the results of a pilot study that examined the driving performance of persons with brain injury using a virtual reality environment, known as the DriVR. Virtual driving performance was examined and compared to on-road, cognitive, visual-perceptual, and driving video test results. The DriVR appeared to be a useful adjunctive screening tool for assessing driving performance. However as with any new assessment tool, will need to undergo further empirical validation.

Automobile Driver Examination↗
PubMed1999

Phenotypic analysis of autosomal dominant hereditary spastic paraplegia linked to chromosome 8q.

OBJECTIVE: To describe clinical, electrophysiologic, neuroimaging, and muscle biopsy features in a hereditary spastic paraplegia (HSP) kindred linked to a new HSP locus on chromosome 8q. BACKGROUND: HSP is a genetically diverse group of disorders characterized by insidiously progressive spastic weakness in the legs. We recently analyzed a Caucasian kindred with autosomal dominant HSP and identified tight linkage to a novel HSP locus on chromosome 8q23-24. METHODS: Clinical analysis, nerve conduction studies, electromyography, somatosensory evoked potentials, MRI of brain and spinal cord, and muscle biopsy for mitochondrial analysis were performed in members of the first HSP kindred linked to chromosome 8q. RESULTS: Fifteen individuals showed insidiously progressive spastic paraparesis beginning between ages 22 and 60 years (average, 37.2 years). Spinal cord MRI in 1 moderately affected subject showed significant atrophy of the thoracic spinal cord as determined by cross-sectional area measurements. Somatosensory evoked potential recording, electromyography, nerve conduction studies, and muscle biopsy, including histochemical and biochemical analysis of mitochondrial function, were normal. CONCLUSIONS: The phenotype in this family is that of typical, but severe, uncomplicated HSP. Other than apparently increased severity, there were no clinical features that distinguished this family from autosomal dominant HSP linked to loci on chromosomes 2p, 14q, and 15q. This clinical similarity between different genetic types of autosomal dominant HSP raises the possibility that genes responsible for these clinically indistinguishable disorders may participate in a common biochemical cascade. Normal results of muscle histochemical and biochemical analysis suggest that mitochondrial disturbance, a feature of chromosome 16-linked autosomal recessive HSP due to paraplegin gene mutations, is not a feature of chromosome 8q-linked autosomal dominant HSP and may not be a common factor of HSP in general.

Adult↗
PubMed1999

Botulinum toxin injection in the treatment of vocal fold paralysis associated with multiple sclerosis: a case report.

Botulinum toxin has been demonstrated clinically to be an effective treatment for a variety of laryngeal problems, most notably spasmodic dysphonia. As in other movement disorders, the theory behind the injection of this substance in the larynx has been a weakening of the vocal fold musculature to relieve uncoordinated and spasmodic movement of the vocal folds, presumably rebalancing the forces within the intralaryngeal musculature. Recently, this concept was applied to help reposition the arytenoid cartilage in acute and longstanding anteromedial cricoarytenoid dislocations. This same concept may apply to the paralyzed vocal fold. In support of this idea, a number of investigators have shown that immobile, clinically paralyzed vocal folds may still have partial voluntary motor unit activity. This voluntary activation may not produce clinically evident movement but may be sufficient to produce tone within the fold. If the voluntary motor units in the abductor musculature of the paralyzed fold are weakened with botulinum toxin, the continued pull of the functioning adductor musculature may be sufficient to medialize the paralyzed fold. This idea has been supported by animal experiments, which have shown that botulinum toxin may affect the ability of the fold to rebalance itself. With this evidence in mind, a patient with fold immobility secondary to multiple sclerosis was treated in an attempt at laryngeal rebalancing, using botulinum toxin to medialize the fold. However, instead of simply having the fold return fixed to the midline, the patient regained normal laryngeal mobility and voice. While it is unclear whether the botulinum toxin alone was responsible, the coincidence of this occurrence certainly requires reporting. This paper is a report of the first successful treatment of vocal fold paralysis using botulinum toxin to treat vocal fold fixation in a patient with multiple sclerosis.

Adult↗
PubMed1999

Respiratory response during arm elevation in isolated diaphragm weakness.

Upper extremity exercise is associated with a significant metabolic and ventilatory cost that is particularly evident in patients with severe chronic airflow obstruction. In these patients abnormal ventilatory muscle recruitment has been hypothesized to relate to impaired diaphragm function resulting from hyperinflation. Similar data have never been reported in patients with isolated diaphragm weakness but without airflow obstruction or hyperinflation, a group that would ideally define the role of diaphragm function during arm elevation (AE). We prospectively studied 15 patients with isolated diaphragm weakness of varying severity (Pdi(sniff), 31.74 +/- 3.75 cm H(2)O) as contrasted with eight normal subjects (Pdi(sniff), 111. 77 +/- 13.35 cm H(2)O) of similar age. Patients with diaphragm weakness demonstrated significant lung volume restriction with normal DL(CO)/VA. There was no difference in resting oxygen consumption (V O(2)), carbon dioxide production (V CO(2)), minute ventilation (V E), and tidal volume (VT) between the two groups; however, a borderline difference in resting breathing frequency (f(b)) (p = 0.056) was evident. Both groups demonstrated a rise in V O(2), V CO(2), and V E during 2 min of AE anteriorly. Normal subjects demonstrated a statistically significant rise in VT but a statistically insignificant rise in f(b) during AE. In contrast, patients with diaphragm weakness demonstrated a statistically significant rise in f(b) during AE but a statistically insignificant rise in VT. In patients the observed rise in VT directly correlated with baseline Pdi(sniff) (r = 0.59, p = 0.02) and Pdi(max) (r = 0.81, p = 0.002). Both groups demonstrated a rise in Pdi during AE. The rise in Pdi during AE directly correlated to Pdi(sniff) in the patients (r = 0.69, p = 0.004). Observed end-expiratory Ppl rose during arm elevation in both the patient group and in the normal control group, but no evidence of a differential response to AE was found. In those patients with greater diaphragm weakness (Pdi(sniff) < 30 cm H(2)O), abnormal respiratory muscle function (lesser rise in Pdi) and a lesser increase in VT during AE were more evident. These data highlight the importance of diaphragm function in determining the metabolic and respiratory muscle response to arm elevation.

Adult↗
PubMed1999

A multiple-dosing, placebo-controlled study of budesonide inhalation suspension given once or twice daily for treatment of persistent asthma in young children and infants.

RATIONALE: Topical antiinflammatory medications such as inhaled corticosteroids are recommended for therapy of asthma, but no formulation suitable for administration to infants and young children is available in the United States. METHODS: This was a 12-week, multicenter, double-blind, randomized, parallel-group study comparing the efficacy and safety of four dosing regimens of bude-sonide inhalation suspension (BIS) or placebo in 480 asthmatic infants and children (64% boys), ages 6 months to 8 years, with moderate persistent asthma. Approximately 30% of children were previously on inhaled corticosteroids that were discontinued before the study. Active treatments were comprised of BIS 0.25 mg once daily (QD), 0.25 mg twice a day (BID), 0.5 mg BID, or 1.0 mg QD. Efficacy was assessed by twice daily recording at home of asthma symptom scores and use of rescue medication, and discontinuation from the study because of worsening asthma and/or a requirement for systemic steroids. Peak flow measurements were recorded twice daily on diary and spirometry was recorded at clinic visits for those children able to perform these tests. Safety was assessed by reported adverse events and by cortisol testing (adrenocorticotropic hormone stimulation) in a subset of patients. RESULTS: Patients enrolled had an average duration of asthma of 34 months; the mean asthma symptom score was approximately 1.3 (scale of 0-3). All dosing regimens with BIS produced statistically significant improvement in various clinical efficacy measures for asthma control compared with placebo. The lowest dose used, 0.25 mg QD, was efficacious but with fewer efficacy parameters than seen with the other doses administered. Separation between active treatment and placebo in daytime and nighttime symptom scores were observed by week 2 of treatment for all BIS treatment regimens. A significant increase in peak flow measurement was observed in most active treatment groups compared with placebo in the subset of children able to do pulmonary function testing. All treatment groups showed numerical improvement in forced expiratory volume in 1 second but only the 0.5-mg BID dose was significantly different from placebo. Adverse events for the entire group and response to adrenocorticotropic hormone in a subgroup of children who underwent cortisol testing before and at the end of the treatment period were no different in budesonide-treated patients in comparison to placebo. CONCLUSION: Results of this study demonstrate that BIS is effective and safe for infants and young children with moderate persistent asthma in a multiple dose range, and that QD dosing is an important option to be considered by the prescribing physician.

Administration, Inhalation↗
PubMed1998

A case of respiratory muscle weakness due to cytochrome c oxidase enzyme deficiency.

Mitochondrial myopathy is a rare cause of dyspnoea and respiratory failure, usually presenting in infancy. We describe a 27 yr old woman with a partial cytochrome c oxidase enzyme deficiency causing respiratory muscle weakness and respiratory failure. The onset was acute, with no preceding respiratory symptoms. The patient was successfully treated with bilevel positive airway pressure therapy.

Adult↗
PubMed1998

Lisofylline causes rapid and prolonged suppression of serum levels of free fatty acids.

Lisofylline (LSF), a novel anti-inflammatory compound that modulates stress-associated changes in lipid metabolism, is under development to modify toxicity for patients undergoing dose-intensive cytotoxic therapy for neoplasia and to prevent multiorgan failure and acute respiratory distress syndrome after oxidative injury. The present investigation, a component of a pharmacokinetics study, was performed to assess the effect of LSF on serum-free fatty acids (FFA). LSF was administered at doses of either 1, 2 or 3 mg/kg every 24 hr for 3 days by 10 min intravenous infusion to 12 healthy volunteers, followed 24 hr later by a single oral dose of 6 mg/kg, which was determined not to be bioavailable. Total serum FFA were quantitated after separation from other lipids by thin-layer chromatography in samples from 10 of 12 subjects, and serum levels of individual fatty acids were measured by high-performance liquid chromatography in samples from 11 of 12 subjects. Six hours after the first LSF dose of 1, 2 or 3 mg/kg, FFA levels decreased from the time zero levels by a mean (+/- S.D.) of 64.7 +/- 7.4% (range, 37-80%; P < .001 vs. time zero levels). Six hours after the third i.v. LSF dose, the FFA reached a nadir of 71.5 +/- 5.5% below the time zero levels (range, 55-88%; P < .001 vs. time zero). Equivalent effects were observed after the first LSF dose regardless of whether patients received LSF at 1, 2 or 3 mg/kg. The decrease in serum FFA was still present 48 hr after the final i.v. dose and 24 hr after the oral dose, with a mean decrease of 34 +/- 9.8% (P < .01 vs. time zero). Serum triglycerides began to increase after the first i.v. LSF dose and were at the highest measured level 6 hr after the third dose, increasing by 74.5 +/- 19.7% from the time zero levels (range, 36-146%; P = .02 vs. time zero). The increase in serum triglycerides also persisted for 36 hr after the final i.v. LSF dose. LSF and its two principal metabolites had plasma clearance t 1/2 values of 0.75 hr, 0.78 hr and 1.17 hr, respectively. Therefore the effects of LSF on lipid metabolism were present for a prolonged period compared with measurable persistence in plasma; this points to unique functions or unknown metabolites of LSF. These alterations in serum lipids may be relevant to the anti-inflammatory activity of LSF and may serve as surrogate markers for the pharmacodynamics of LSF.

Adult↗
PubMed1996

Acute ventilatory failure in Lambert-Eaton myasthenic syndrome and its response to 3,4-diaminopyridine.

Respiratory failure is a common manifestation of myasthenia gravis but is infrequent in Lambert-Eaton myasthenic syndrome (LEMS), where it is often related to the use of paralytic agents or intercurrent pulmonary pathology. Therapies that are effective acutely in myasthenia gravis are usually of minimal benefit in LEMS. We describe a patient with respiratory failure secondary to LEMS who responded to 3,4-diaminopyridine and review the 12 previously reported cases of ventilatory failure in LEMS.

4-Aminopyridine↗
PubMed1994

The natural history of a "benign" rib lesion in a patient with a demyelinating polyneuropathy and an unusual variant of POEMS syndrome.

Patients with POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes) syndrome exhibit great clinical variability and often have osteosclerotic myeloma. We present a patient with an acquired demyelinating polyneuropathy who was eventually diagnosed as having POEMS syndrome. Her long period of observation permitted documentation of the natural history of a plasmacytoma, including its remarkably slow rate of growth and its transformation from a nonsclerotic to a sclerotic bone lesion. Her clinical and laboratory features emphasize the variability of this syndrome. Biopsy of benign-appearing bone lesions should be considered in patients with acquired demyelinating polyneuropathies who do not respond to standard treatment modalities. Serial x-rays may not distinguish benign lesions from plasmacytomas in this treatable condition.

Bone Diseases↗
PubMed1991

Facilitated referral to asthma specialist reduces relapses in asthma emergency room visits.

Facilitated asthma-specialist care delivered by allergists was compared to generalist care on the rate of relapse of asthma emergency room (ER) visits and hospitalizations and on asthma control in a prospective, controlled study of San Diego Kaiser Health Plan members with asthma. Subjects with asthma between the ages of 6 and 59 years presenting for acute ER care for asthma were systematically assigned by alternating, consecutively, the day of their ER visit to receive either (1) facilitated referral to an asthma specialist within the allergy department and concomitant comprehensive ongoing asthma care (intervention group, n = 149) or (2) continued outpatient management from generalist physicians (control group, n = 160). The course of their asthma was evaluated blindly during the subsequent 6 months by review of medical records, initial and follow-up questionnaires, and spirometry. Compared to the control group, the intervention group noted (1) a 75% reduction in the number of, and percent of, subjects with asthma awakenings per night (p less than or equal to 0.0001), (2) an almost 50% reduction in asthma ER relapses (p = 0.017) resulting from a reduction in the frequency of multiple relapse (p = 0.005), and (3) a greater use of inhaled corticosteroids (p less than 0.00001) and cromolyn (p = 0.002). Thus, facilitated referral of subjects with asthma to specialists in asthma therapy after acute ER therapy appears to reduce asthma ER relapses and to improve asthma outcome.

Adult↗
PubMed1986

Incidence of preeclampsia among asthmatic patients lower with theophylline.

The incidence of preeclampsia was reduced among asthmatic patients taking theophylline (one of 85) compared to other asthmatic patients (six of 68, p less than 0.05). Other factors did not appear to account for these results. Theophylline, which is known to inhibit platelet aggregation and alter vascular tone, may reduce the incidence of preeclampsia, at least among asthmatic patients.

Adult↗