Description of a Colocated Comprehensive Care Model for People With Sickle Cell and Comorbid Pulmonary Disease

Comorbid pulmonary complications in people with sickle cell disease (pwSCD) are associated with high rates of morbidity and mortality, and poor access to care contributes to poor outcomes among this particularly high-risk pwSCD. Our purpose was to describe the population served and the resources required for hematology, pulmonary, nursing, respiratory therapy, social work, genetics, psychology, and school liaison providers to see these patients in an integrated clinic. We abstracted demographic, medication, clinical, and diagnostics data of the pwSCD seen at least once in this clinic from February 1, 2014 to December 10, 2020 from the electronic medical record and identified 145 unique pwSCD. Abnormal lung function and bronchodilator responsiveness were detected in 31% and 42% of participants respectively. Sleep abnormalities were found in over two-thirds of those screened and 65% had ≥1 previous acute chest syndrome episode. This clinic also allowed for direct provider communication and required relatively limited resources to serve a large number of severely affected pwSCD. Given the degree of abnormal respiratory variables detected and the limited resources required to implement this model, studies are warranted to evaluate whether it has the potential to improve outcomes in high-risk populations.

Tumor lysis Syndrome in a Patient with Metastatic Breast Cancer Treated with Alpelisib

Purpose:

Tumor lysis syndrome (TLS) is a rare but life-threatening phenomenon that occurs mainly in patients with aggressive hematologic or highly chemotherapy sensitive solid tumors such as high-grade neuroendocrine carcinoma or testicular cancer. Tumor lysis syndrome is exceedingly rare in hormone receptor-positive, HER2-negative breast cancer. Furthermore, TLS following treatment with alpelisib, a novel phosphatidylinositol 3-kinase (PI3K) inhibitor used to treat PIK3CA-mutated (gene encoding p110α subunit of PI3K), hormone receptor positive advanced breast cancer, has never been described in patients with nonhematologic malignancies.

Methods:

In the following case, we present a patient with hormone receptor-positive, HER2-negative, PIK3CA-mutated metastatic breast cancer who developed TLS 12 days after starting fulvestrant and alpelisib.

Results:

Patient was promptly treated with improvement in her renal function to baseline without requiring renal replacement therapy. Alpelisib was resumed at a reduced dose with no further complications.

Conclusion:

Through this case, we discuss the potential complications of TLS and the importance of prompt recognition and treatment.

Novel protein pathways in development and progression of pulmonary sarcoidosis

Pulmonary involvement occurs in up to 95% of sarcoidosis cases. In this pilot study, we examine lung compartment-specific protein expression to identify pathways linked to development and progression of pulmonary sarcoidosis. We characterized bronchoalveolar lavage (BAL) cells and fluid (BALF) proteins in recently diagnosed sarcoidosis cases. We identified 4,306 proteins in BAL cells, of which 272 proteins were differentially expressed in sarcoidosis compared to controls. These proteins map to novel pathways such as integrin-linked kinase and IL-8 signaling and previously implicated pathways in sarcoidosis, including phagosome maturation, clathrin-mediated endocytic signaling and redox balance. In the BALF, the differentially expressed proteins map to several pathways identified in the BAL cells. The differentially expressed BALF proteins also map to aryl hydrocarbon signaling, communication between innate and adaptive immune response, integrin, PTEN and phospholipase C signaling, serotonin and tryptophan metabolism, autophagy, and B cell receptor signaling. Additional pathways that were different between progressive and non-progressive sarcoidosis in the BALF included CD28 signaling and PFKFB4 signaling. Our studies demonstrate the power of contemporary proteomics to reveal novel mechanisms operational in sarcoidosis. Application of our workflows in well-phenotyped large cohorts maybe beneficial to identify biomarkers for diagnosis and prognosis and therapeutically tenable molecular mechanisms.

Guillain-Barré syndrome hyponatremia: is it SIADH or pseudohyponatremia?

Approximately 5% of hospitalized patients with Guillain–Barré syndrome (GBS) experience SIADH; but pseudohyponatremia has also been reported in patients treated with IVIG. We present a case of a 51-year-old male with GBS who developed acute hyponatremia the day after initiation of IVIG; his sodium levels began to improve within 24 h of completion of IVIG. Differentiating between pseudohyponatremia caused by the IVIG treatment and SIADH caused by GBS was the key to successfully treating this patient. This case exemplifies the importance of pursuing further studies to determine the exact cause of hyponatremia in GBS in order to prevent further neurologic damage to the patient.

Whole-exome sequencing is a valuable diagnostic tool for inherited peripheral neuropathies: Outcomes from a cohort of 50 families

The inherited peripheral neuropathies (IPNs) are characterized by marked clinical and genetic heterogeneity and include relatively frequent presentations such as Charcot-Marie-Tooth disease and hereditary motor neuropathy, as well as more rare conditions where peripheral neuropathy is associated with additional features. There are over 250 genes known to cause IPN-related disorders but it is estimated that in approximately 50% of affected individuals a molecular diagnosis is not achieved. In this study, we examine the diagnostic utility of whole-exome sequencing (WES) in a cohort of 50 families with 1 or more affected individuals with a molecularly undiagnosed IPN with or without additional features. Pathogenic or likely pathogenic variants in genes known to cause IPN were identified in 24% (12/50) of the families. A further 22% (11/50) of families carried sequence variants in IPN genes in which the significance remains unclear. An additional 12% (6/50) of families had variants in novel IPN candidate genes, 3 of which have been published thus far as novel discoveries (KIF1A, TBCK, and MCM3AP). This study highlights the use of WES in the molecular diagnostic approach of highly heterogeneous disorders, such as IPNs, places it in context of other published neuropathy cohorts, while further highlighting associated benefits for discovery.

Pharmacokinetics of fluticasone propionate multidose, inhalation-driven, novel, dry powder inhaler versus Diskus and metered-dose inhalers

BACKGROUND

A novel inhalation-driven multidose dry powder inhaler (MDPI) that eliminates the need for the patient to coordinate device actuation with inhalation has been developed for delivery of inhaled asthma medications.

OBJECTIVE

To characterize the pharmacokinetics of single-dose fluticasone propionate (Fp) MDPI compared with single doses of Fp Diskus (a dry powder inhaler) and a metered-dose inhaler (MDI) in healthy subjects.

METHODS

This was a single-center, open-label, randomized, three-period crossover, single-dose pilot study in healthy adults ages 18 to 45 years. Eligible subjects (N = 18) were randomized to one of six treatment sequences that contained three treatment arms: Fp MDPI 400 micrograms/inhalation X two inhalations (800 micrograms total dose); Fp Diskus 250 micrograms/inhalation X four (1000 micrograms total dose); and Fp MDI 220 micrograms/inhalation X four (880 micrograms total dose). Pharmacokinetics (area under concentration-versus- time curve [AUC], maximum plasma concentration [Cmax], time to Cmax [tmax], and elimination half-life [t1⁄2]), safety, and tolerability were assessed for each treatment.

RESULTS

Plasma Fp concentration-versus-time curves were comparable across treatments. Geometric mean AUC 0-t and Cmax for Fp MDPI 800 micrograms were 19% and 18% higher, respectively, compared with Fp Diskus 1000 micrograms, and 47% and 82% higher, respectively, compared with Fp MDI 880 micrograms. Median tmax (60.0-60.6 minutes) and median t1/2 (9.1-9.8 hours) were comparable across the three treatments. Single-dose Fp was well tolerated, with no new safety issues noted.

CONCLUSION

Single-dose administration of Fp MDPI 800 micrograms produced systemic exposure comparable with those for Fp Diskus 1000 micrograms and Fp MDI 880 micrograms.

p38 Mitogen-Activated Protein Kinase in beryllium-induced dendritic cell activation

Dendritic cells (DC) play a role in the regulation of immune responses to haptens, which in turn impact DC maturation. Whether beryllium (Be) is able to induce DC maturation and if this occurs via the MAPK pathway is not known. Primary monocyte-derived DCs (moDCs) models were generated from Be non-exposed healthy volunteers as a non-sensitized cell model, while PBMCs from BeS (Be sensitized) and CBD (chronic beryllium disease) were used as disease models. The response of these cells to Be was evaluated. The expression of CD40 was increased significantly (p<0.05) on HLA-DP Glu69+ moDCs after 100 μM BeSO₄-stimulation. BeSO₄ induced p38MAPK phosphorylation, while IκB-α was degraded in Be-stimulated moDCs. The p38 MAPK inhibitor SB203580 blocked Be-induced NF-κB activation in moDCs, suggesting that p38MAPK and NF-κB are dependently activated by BeSO₄. Furthermore, in BeS and CBD subjects, SB203580 downregulated Be-stimulated proliferation in a dose-dependent manner, and decreased Be-stimulated TNF-α and IFNγ cytokine production. Taken together, this study suggests that Be-induces non-sensitized Glu69+ DCs maturation, and that p38MAPK signaling is important in the Be-stimulated DCs activation as well as subsequent T cell proliferation and cytokine production in BeS and CBD. In total, the MAPK pathway may serve as a potential therapeutic target for human granulomatous lung diseases.

Exogenous and endogenous virus interactions in head and neck cancer immunity (105.34)

We report that two common tumor viruses etiologically associated with head and neck cancer, Epstein-Barr virus (EBV) with undifferentiated nasopharyngeal carcinoma, and human papillomavirus (HPV) with oropharyngeal squamous cell carcinoma, transactivate an endogenous retrovirus (HERV-K18), which encodes a superantigen that activates TCRBV13 T cells. EBV LMP-2 transactivated the HERV-K18 superantigen in nasopharyngeal epithelial cells, and EBV-associated nasopharyngeal carcinomas expressed the superantigen. HPV type-16 E6 and E7 proteins also transactivated the HERV-K18 superantigen in oropharyngeal epithelial cells, and superantigen expression was significantly increased in HPV16-associated carcinomas. Serum cytokine levels in head and neck carcinoma patients indicated that there were distinct inflammatory profiles associated with exogenous and endogenous viruses. HPV-associated patients had increased levels of serum IL-8, while HPV-negative patients had higher serum IL-6 and G-CSF levels. Interestingly, HERV-K18 superantigen levels correlated independently with serum levels of the Th2 cytokine IL-13. Among HPV+ tumors, gene expression array analyses indicated that B cell specific genes were significantly upregulated in the superantigen high group. Our results suggest that endogenous superantigen expression in HPV+ tumors was associated with a Th2 immune response, demonstrating that chronic and endogenous viruses comprising the virome affect both host and tumor immunity.

Cutaneous amyloidosis

Amyloidosis is generally classified as either systemic or cutaneous, with both primary and secondary forms. There are also heredofamilial and hemodialysis-associated varieties of amyloidosis, all with specific amyloid fibril derivatives. Nodular cutaneous amyloidosis is the most rare form of primary cutaneous amyloidosis. Lesions typically present as a crusted nodule on the face, extremities, or acral sites. The amyloid fibrils are immunoglobulin-derived and either kappa or lambda light chains. Systemic involvement is dependent on plasma cell amyloid protein deposition. Lesions may otherwise be classified as a local plasma cell clone or cutaneous plasmacytoma. Recent reports state that there is <10% risk of systemic progression. Workup should include at least a full history and physical examination; serum protein electrophoresis and urine protein electrophoresis; and gingival, rectal, or abdominal fat pad biopsies to rule out the presence of extracutaneous amyloid deposition. Management of nodular cutaneous amyloidosis is challenging, as there is no consistently effective treatment and local recurrence is common.

CC chemokine receptor 5 gene polymorphisms in beryllium disease

CC chemokine receptor 5 (CCR5) is expressed on type-1 T-helper cells, which are involved in the pathogenesis of the granulomatous lung disease chronic beryllium disease (CBD). CCR5 gene (CCR5) polymorphisms are associated with sarcoidosis severity. The present study explores associations between CCR5 polymorphisms and CBD and its disease progression. Eight CCR5 polymorphisms were genotyped in CBD (n = 88), beryllium sensitisation (BeS; n = 86) and beryllium-exposed nondiseased controls (n = 173) using PCR with sequence-specific primers. Pulmonary function and bronchoalveolar lavage data were examined for associations with genotypes. There were no significant differences in genotype and allele frequency between CBD, BeS individuals and controls. In CBD, associations were found with decline in forced expiratory volume in 1 s and forced vital capacity and the CCR5 -3458 thymidine (T)T genotype (p<0.0001), and an increase in alveolar-arterial oxygen tension difference at rest (p = 0.003) and at maximum exercise (p = 0.01) and the -5663 adenine allele. Increased bronchoalveolar lavage lymphocyte numbers were associated with CCR5 -2459 guanine/-2135T (p = 0.01) only in the combined CBD and BeS group. This is the first study showing that CCR5 polymorphisms are associated with worsening pulmonary function over time in CBD, suggesting that CCR5 is important in the progression of pulmonary function in CBD. Further studies would be useful to clarify the mechanism whereby CCR5 polymorphisms affect progression of CBD.

Mortality of geese as a result of collision with the ground

Two incidents are reported in which groups of migrating wild geese were found dead in agricultural fields in southern Manitoba during spring. In each case, the birds died overnight and poisoning was suspected; however, the birds had lesions of severe traumatic injury. The first incident, in 1985, involved about 150 lesser snow geese (Anser caerulescens caerulescens); the second, in 2003, involved 62 Canada geese (Branta canadensis). Both incidents occurred on dark, moonless nights. One possible explanation is that the birds became disoriented in a manner analogous to spatial disorientation described in aircraft pilots and flew as a flock directly into the earth. In the first incident, geese might have been frightened by sonic booms from aircraft; in the second, there was a thunderstorm with strong gusty winds in the area.

Donepezil for dementia in Parkinson's disease: a randomised, double blind, placebo controlled, crossover study

OBJECTIVE

To study the safety and efficacy of a cholinesterase inhibitor, donepezil hydrochloride, for the treatment of dementia in Parkinson's disease (PD).

METHODS

This was a randomised double blind, placebo controlled, crossover study in 22 subjects with PD and dementia. Participants were randomised to receive either donepezil followed by identical placebo, or placebo followed by donepezil. Donepezil was administered at 5-10 mg/day. Treatment periods were 10 weeks with a washout period of 6 weeks between the two periods. The primary outcome measure was the Alzheimer's Disease Assessment Scale Cognitive Subscale (ADAScog).

RESULTS

Donepezil was well tolerated and most adverse events were mild. There was no worsening of PD symptoms as measured by the total or motor sections of the Unified Parkinson's Disease Rating Scale.There was a 1.9 point trend toward better scores on the ADAScog on treatment compared with placebo that was not statistically significant. The secondary cognitive measures showed a statistically significant 2 point benefit on the Mini Mental Status Examination and no change on the Mattis Dementia Rating Scale (MDRS). The Clinical Global Impression of Change (CGI) showed a significant 0.37 point improvement on donepezil. No improvement was observed on the MDRS or the Brief Psychiatric Rating Scale. Carryover between treatment periods was observed but was not statistically significant.

CONCLUSIONS

Donepezil was well tolerated and did not worsen PD. There may be a modest benefit on aspects of cognitive function. The possible clinical benefit measured by CGI was reflected in only one of the cognitive scales used in this study.

Reactome: a knowledgebase of biological pathways

Reactome, located at http://www.reactome.org is a curated, peer-reviewed resource of human biological processes. Given the genetic makeup of an organism, the complete set of possible reactions constitutes its reactome. The basic unit of the Reactome database is a reaction; reactions are then grouped into causal chains to form pathways. The Reactome data model allows us to represent many diverse processes in the human system, including the pathways of intermediary metabolism, regulatory pathways, and signal transduction, and high-level processes, such as the cell cycle. Reactome provides a qualitative framework, on which quantitative data can be superimposed. Tools have been developed to facilitate custom data entry and annotation by expert biologists, and to allow visualization and exploration of the finished dataset as an interactive process map. Although our primary curational domain is pathways from Homo sapiens, we regularly create electronic projections of human pathways onto other organisms via putative orthologs, thus making Reactome relevant to model organism research communities. The database is publicly available under open source terms, which allows both its content and its software infrastructure to be freely used and redistributed.

Adenosine A(2A) receptor antagonist treatment of Parkinson's disease

BACKGROUND

Observations in animal models suggest that A(2A) antagonists confer benefit by modulating dopaminergic effects on the striatal dysfunction associated with motor disability. This double-blind, placebo-controlled, proof-of-principle study evaluated the pathogenic contribution and therapeutic potential of adenosine A(2A) receptor-mediated mechanisms in Parkinson disease (PD) and levodopa-induced motor complications.

METHODS

Fifteen patients with moderate to advanced PD consented to participate. All were randomized to either the selective A(2A) antagonist KW-6002 or matching placebo capsules in a 6-week dose-rising design (40 and 80 mg/day). Motor function was rated on the Unified PD Rating Scale.

RESULTS

KW-6002 alone or in combination with a steady-state IV infusion of each patient's optimal levodopa dose had no effect on parkinsonian severity. At a low dose of levodopa, however, KW-6002 (80 mg) potentiated the antiparkinsonian response by 36% (p < 0.02), but with 45% less dyskinesia compared with that induced by optimal dose levodopa alone (p < 0.05). All cardinal parkinsonian signs improved, especially resting tremor. In addition, KW-6002 prolonged the efficacy half-time of levodopa by an average of 47 minutes (76%; p < 0.05). No medically important drug toxicity occurred.

CONCLUSIONS

The results support the hypothesis that A(2A) receptor mechanisms contribute to symptom production in PD and that drugs able to selectively block these receptors may help palliate symptoms in levodopa-treated patients with this disorder.

Huntington's disease: a randomized, controlled trial using the NMDA-antagonist amantadine

OBJECTIVE

To examine the acute effects of the NMDA receptor antagonist amantadine on motor and cognitive function in Huntington's disease (HD).

BACKGROUND

Chorea in HD and in the levodopa-induced dyskinesias of PD may be clinically indistinguishable. In PD, hyperphosphorylation of NMDA receptors expressed on striatal medium spiny neurons contributes to peak-dose dyskinesias, and drugs that block these receptors can diminish chorea severity. Because these spiny neurons are the primary target of the neurodegenerative process in HD, sensitization of NMDA receptors on residual striatal neurons might also participate in the generation of motor dysfunction in HD.

METHODS

To evaluate this possibility, 24 patients with HD entered a double-blind placebo-controlled crossover study of amantadine with two 2-week arms.

RESULTS

Chorea scores were lower with amantadine (usually 400 mg/d) than placebo, with a median reduction in extremity chorea at rest of 36% (p = 0.04) for all 22 evaluable patients and of 56% in the 10 individuals with the highest plasma drug levels. Improvement correlated with plasma amantadine concentrations (p = 0.01) but not CAG repeat length. Parkinsonian rating scores did not worsen and there was no consistent change in cognitive measures. Adverse event profile was benign.

CONCLUSIONS

Results suggest that NMDA receptor supersensitivity may contribute to the clinical expression of choreiform dyskinesias in HD and that selective antagonists at that site can safely confer palliative benefit.

Continuous transdermal dopaminergic stimulation in advanced Parkinson's disease

The objective of the study was to determine the safety and efficacy of increasing doses of Rotigotine CDS in patients with advanced Parkinson's disease. The development of motor complications in Parkinson's disease has been linked to intermittent stimulation of dopamine receptors. Continuous, noninvasive, dopaminergic stimulation has not been available to date. Rotigotine CDS is a lipid-soluble D2 dopamine agonist in a transdermal delivery system that could fill this void. This inpatient study consisted of a 2-week dose escalation phase followed by a 2-week dose maintenance phase at the highest dose (80 cm2). Each individual's L-Dopa dose was back-titrated as feasible. The primary outcome measure was L-Dopa dose, and secondary outcome measures included early morning "off"-L-Dopa Unified Parkinson's Disease Rating Scale motor scores by a blinded evaluator and motor fluctuation data obtained from patient diaries ("on" without dyskinesia, "on" with dyskinesia, and "off"). Seven of 10 subjects provided data that could be evaluated. There were two administrative dropouts, and one individual was eliminated from the study because of recrudescence of hallucinations. The median daily L-Dopa dose decreased from 1,400 to 400 mg (p = 0.018, Wilcoxon test). Unified Parkinson's Disease Rating Scale motor scores were unchanged. Although diary variables improved in most individuals, only the reduction in "off" time attained statistical significance. Adverse effects were mild and consisted mainly of dopaminergic side effects and local skin reactions. The data suggest that Rotigotine CDS is an effective treatment for advanced Parkinson's disease and permits patients to substantially lower L-Dopa doses without loss of antiparkinsonian efficacy. Full-scale controlled clinical trials are warranted. In addition to potential therapeutic benefits, this drug can be used to test the hypothesis that continuous dopaminergic stimulation from the initiation of Parkinson's disease therapy will limit the development of motor complications.

Bupropion overdose: a potential problem with the new 'miracle' anti-smoking drug

Bupropion (Zyban) has recently been launched in the UK as an aid to smoking cessation. As a result of the considerable publicity, there has been unprecedented demand for this new drug in primary care. Within a few weeks of its launch, four patients presented to our A&E department having taken bupropion as an intentional overdose. Three recovered with simple supportive measures; one one was critically ill and required admission to the intensive care unit. There are several case reports on bupropion overdose in the US but none so far in the UK.

Role of hypertension, diabetes, obesity, and race in the development of symptomatic myocardial dysfunction in a predominantly minority population with normal coronary arteries

BACKGROUND

Hypertension, diabetes, and obesity have been reported as risk factors for both vascular and myocardial disease. Myocardial disease may be manifest as systolic or diastolic dysfunction. The development of coronary artery disease frequently obscures or confounds the myocardial disease. Our purpose was to study the effect of these risk factors and race on the frequency and severity of myocardial disease in the absence of coronary artery disease.

METHODS AND RESULTS

We studied patients referred to the cardiac catheterization laboratory. We selected 233 patients with normal coronary arteries and excluded patients with other structural cardiac disorders and other causes of myocardial disease. Systolic function and diastolic function were determined. We gathered demographic, risk factor, clinical, and hemodynamic data on each patient. A multivariate analysis was performed to determine factors important to the development of myocardial disease in the absence of coronary artery disease. Diastolic dysfunction (44%) and systolic dysfunction (25%) were common findings. The 3 risk factors were found most often in black and Hispanic patients, but hypertension and obesity were most severe (P <.001) in black patients. Multivariate analysis indicated that a prior diagnosis of hypertension, level of systolic blood pressure, and severe obesity were the 3 factors independently associated with myocardial disease.

CONCLUSIONS

Systolic dysfunction and diastolic dysfunction are common in patients with normal coronary arteries who have hypertension, diabetes, and/or obesity. Because these risk factors are so frequent and severe in the black population, myocardial disease is significantly more common in this segment of the population.

Chronic intermittent stimulation of the thyroarytenoid muscle maintains dynamic control of glottal adduction

Patients with laryngeal motor control disorders need improved dynamic glottal closure for speech and swallowing. To evaluate the functional outcome of intermittent chronic thyroarytenoid muscle stimulation in an animal model, 6 canines were implanted with bilateral Medtronic Xtrel systems containing Peterson-type electrodes in the inferior and superior portions of the thyroarytenoid muscle. Stimulation was on one side only at 60 Hz, for 5 s on and 5 s off, over 8 h, 5 days per week, up to 8 months. Monthly videorecordings were done under anesthesia to measure the voltage threshold for detectable movement on each side, and vocal fold displacement and velocity during maximal stimulation of each side. Movement thresholds were lower in the inferior portion of the thyroarytenoid muscle (P </= 0.0005). Movement velocity was greater on the stimulated than on the nonstimulated side after 3 to 8 months (P = 0.039). No differences in the percentage distribution of different myosin heavy chain types were found between the stimulated and nonstimulated muscle samples. Sustained dynamic glottal adduction with no alteration in thyroarytenoid muscle function or fiber type was achieved with intermittent stimulation over 8 months. The results suggest that chronic intermittent thyroarytenoid stimulation has good potential for improving airway protection in dysphagia.

Laryngeal long latency response conditioning in abductor spasmodic dysphonia

Previously, we demonstrated that patients with adductor spasmodic dysphonia (ADSD) have a disinhibition of laryngeal responses to sensory input. In this study, sensorimotor responses to stimulation of the superior laryngeal nerve were compared between 10 subjects with abductor spasmodic dysphonia (ABSD) and 15 normal volunteers. The groups had similar latency and frequency characteristics of their unconditioned adductor responses (p>.05). The conditioned R1 (early) responses of the subjects with ABSD were greater and more variable in amplitude than those of the normal volunteers (p< or =.008). Similar R2 (late) conditioning effects were found in both groups, with a nonsignificant trend toward reduced inhibition of contralateral R2 responses at lower interstimulus intervals (p = .01) in the patient group. Thus, inhibitory mechanisms that modulate the R1 laryngeal sensorimotor pathway in the brain stem may be abnormal in subjects with ABSD. Abnormal modulation of laryngeal sensorimotor responses seems present in both types of spasmodic dysphonia.

Effects of the full dopamine D1 receptor agonist dihydrexidine in Parkinson's disease

The contribution of dopamine D1 receptor stimulation to the motor effects of dopaminergic drugs in patients with Parkinson's disease remains undetermined. The authors of this article studied the clinical efficacy, pharmacokinetics, and tolerability of the full D1 receptor agonist dihydrexidine, (+/-)-trans-10,11-dihydroxy-5,6,6a,7,8,12b-hexahydrobenzo[a] phenanthridine hydrochloride in a double-blind, placebo-controlled trial in four patients with Parkinson's disease. Single intravenous doses were carefully titrated according to a fixed schedule ranging from 2 mg to the highest tolerated dose (or a maximum of 70 mg) infused over either 15 or 120 minutes. The only patient to achieve a plasma drug concentration greater than 100 ng/ml had a brief but definite motor improvement accompanied by choreic dyskinesias similar to the response to levodopa. Dose-limiting adverse effects, including flushing, hypotension, and tachycardia, were observed in all cases, especially with rapid infusions. No nausea or emesis occurred. Pharmacokinetic studies yielded a plasma half-life < 5 minutes. These preliminary data suggest that dihydrexidine has a marginal therapeutic window for providing an antiparkinsonian effect, although it remains uncertain how much of this effect is attributable to pure D1 receptor stimulation.

Type II SLAP lesions: three subtypes and their relationships to superior instability and rotator cuff tears

One hundred two type II SLAP lesions without associated anterior instability, Bankart lesion, or anterior inferior labral pathology were surgically treated under arthroscopic control. There were three distinct type II SLAP lesions based on anatomic location: anterior (37%), posterior (31%), and combined anterior and posterior (31%). Preoperatively, the Speed and O'Brien tests were useful in predicting anterior lesions, whereas the Jobe relocation test was useful in predicting posterior lesions. Rotator cuff tears were present in 31% of patients and were found to be lesion-location specific. In posterior and combined anterior-posterior lesions, a drive-through sign was always present (despite absence of anterior-inferior labral pathology or a Bankart lesion) and was eliminated by repair of the posterior component of the SLAP lesion. We conclude that SLAP lesions with a posterior component develop posterior-superior instability that manifests itself by a secondary anterior-inferior pseudolaxity (drive-through sign), and that chronic superior instability leads to secondary lesion-location-specific rotator cuff tears that begin as partial thickness tears from inside the joint.

A case of paraquat poisoning and subsequent fatality presenting to an emergency department

Paraquat (1,1'-dimethyl-4,4'-dipyridylium) is an herbicide associated with both accidental and intentional ingestion, leading to severe and often fatal toxicity. Prognosis is largely dependent on the amount of paraquat absorbed. Rapid identification of the symptoms of paraquat toxicity (burns or ulceration at the site of ingestion or injection, acute respiratory distress, and renal failure) can facilitate early treatment intervention to limit absorption. We report a case of a 71-year-old man with a suicidal ingestion of paraquat 2 days prior to presentation. Serum paraquat levels, time elapsed since ingestion, and clinical symptoms all indicated poor prognosis. The patient developed severe respiratory distress and progressive renal failure, and died 6 days after admission to the hospital.

Maximizing internal opportunities for healthcare facilities facing a managed-care environment

The primary theme of this article concerns the pressures on healthcare facilities to become efficient utilizers of their existing resources. This acute need for efficiency has been extremely obvious since the changing reimbursement patterns of managed care have proliferated across the nation.

Lung angiotensin receptor binding characteristics during the development of monocrotaline-induced pulmonary hypertension

Alterations in lung angiotensin converting enzyme (ACE) activity in monocrotaline (MCT)-induced pulmonary hypertension in rats have suggested a pathophysiologic role for angiotensin II (AII) in pulmonary vascular remodeling. ACE inhibitors suppress MCT-induced pulmonary hypertension; however, losartan, an angiotensin type 1 (AT1) receptor antagonist, was without impact. The present study examined AII receptor binding characteristics by radioligand binding during the development of MCT-induced pulmonary hypertension. Saturation binding isotherms for [125I]AII binding to membrane preparations from rat lung were performed at 4, 10, and 21 days following a single injection of MCT (60 mg/kg) or saline vehicle. Right ventricular hypertrophy, an index of pulmonary hypertension, increased at 21 days post-MCT. Saturation binding isotherms revealed a single, high affinity site for [125I]AII binding in lung membranes from MCT-treated and control rats, with no change in receptor affinity or density during the development of pulmonary hypertension. Competition displacement binding demonstrated that the AT1 receptor predominates in lung membranes from control rats, with no alterations in AII receptor subtype distribution following MCT treatment. In summary, these results suggest that the AT1 receptor subtype predominates in rat lung and does not contribute to the development of MCT-induced pulmonary hypertension.

Consumption of deoxynivalenol-contaminated wheat by mallard ducks under experimental conditions

Captive mallards (Anas platyrhynchos) were fed wheat containing 5.8 ppm deoxynivalenol (DON, vomitoxin) from an outbreak of Fusarium graminearium head-blight that occurred on grain crops in Manitoba, Canada, during 1993. There was no evidence of taste aversion to this grain during a 10-day palatability trial. No significant differences were detected in serum protein, calcium, glucose, creatinine kinase, aspartate aminotransferase or uric acid levels, blood packed cell volume, or body or organ weight, between ducks fed contaminated wheat and those fed uncontaminated wheat during a 14-day feeding trial. No gross or microscopic lesions were detected in birds fed contaminated wheat for 14 days. Based on these results, ducks will consume grain containing moderate levels of DON and short-term exposure to this grain will not result in obvious adverse effects.

Rescue of the fission yeast snRNA synthesis mutant snm1 by overexpression of the double-strand-specific Pac1 ribonuclease

The Schizosaccharomyces pombe temperature-sensitive mutant snm1 maintains reduced steady-state quantities of the spliceosomal small nuclear RNAs (snRNAs) and the RNA subunit of the tRNA processing enzyme RNase P. We report here the isolation of the pac1+ gene as a multi-copy suppressor of snm1. The pac1+ gene was previously identified as a suppressor of the ran1 mutant and by its ability to cause sterility when overexpressed. The pac1+ gene encodes a double-strand-specific ribonuclease that is similar to RNase III, an RNA processing and turnover enzyme in Escherichia coli. To investigate the essential structural features of the Pac1 RNase, we altered the pac1+ gene by deletion and point mutation and tested the mutant constructs for their ability to complement the snm1 and ran1 mutants and to cause sterility. These experiments identified four essential amino acids in the Pac1 sequence: glycine 178, glutamic acid 251, and valines 346 and 347. These amino acids are conserved in all RNase III-like proteins. The glycine and glutamic acid residues were previously identified as essential for E. coli RNase III activity. The valines are conserved in an element found in a family of double-stranded RNA binding proteins. Our results support the hypothesis that the Pac1 RNase is an RNase III homolog and suggest a role for the Pac1 RNase in snRNA metabolism.

Cytokines and metabolic dysfunction after severe head injury

Patients with head injury must overcome central as well as peripheral metabolic insults. In addition to specific tissue damage to the brain, a cellular biochemical cascade occurs that can negatively affect organ function, cause a systemic response to injury, and may cause secondary tissue injury. The metabolites involved in this cascade are numerous and complex. Cytokines are important cell-to-cell communication mediators during injury. It is speculated that cytokines, such as interleukin 1 (IL-1), interleukin 6 (IL-6), tumor necrosis factor (TNF), and interleukin 8 (IL-8), which are found in elevated amounts in both human and basic trials after head injury, play a role in the cellular cascade of injury. Some of the metabolic events produced by small doses of cytokine infusion in animals, as well as humans, include fever, neutrophilia, muscle breakdown, altered amino acid metabolism, depression of serum zinc levels, production of hepatic acute phase reactants, increased endothelial permeability, and expression of endothelial adhesion molecules. These are all known sequelae of severe head injury. Cytokines have also been implicated in organ failure. Infusion of cytokines in basic science trials revealed that organ functions of the gut, liver, and lung are negatively altered by high-dose cytokine infusion. Infusion of certain cytokines has been shown to cause death of brain cells, increase blood-brain barrier permeability, and cause cerebral edema. This suggests that cytokines may also play a role in the sequelae of organ demise. These effects of cytokines have been attenuated in basic trials by blocking the initial signaling system of cytokines or by decreasing serum cytokine activity. We hypothesize that cytokines that are elevated after head injury play a role in the pathology of injury, including altered metabolism and organ demise.

Molecular deletion of 9p sequences in non-small cell lung cancer and malignant mesothelioma

Previously we have reported non-random cytogenetic abnormalities involving the short arm of chromosome 9 (9P) in the majority of primary non-small cell lung cancer (NSCLC) patient samples, which indicated loss of DNA sequences. In another lung tumor, pleural malignant mesothelioma (MM), cytogenetic changes also include apparent deletions of 9p. To define the location and extent of deletions of 9p in NSCLC and MM, Southern blot analyses on six NSCLC and five MM cell lines using molecular probes to 9p loci (IFNA, IFNB1, D9S3, and D9S19) were performed, and DNA dosage was determined by densitometry. Our data demonstrated reduced dosage of 9p sequences in three of six NSCLC and four of five MM lines. A homozygous deletion of D9S3 was found in one NSCLC and one MM cell line. The region of common loss overlapped the D9S3 locus and was flanked by the IFNB1 and D9S19 loci. IFNB as previously been localized to 9p22, and the D9S3 and D9S19 loci have been mapped in this study by in situ hybridization to 9p21 and 9p13, respectively. We hypothesize the existence of one or more tumor suppressor genes on 9p with a role in the development or progression of NSCLC and MM.

Effect of aging and dopaminomimetic therapy on mitochondrial respiratory function in Parkinson's disease

Oxygen consumption and enzyme activity were evaluated in platelet mitochondria from 17 patients with Parkinson's disease. In comparison with age-matched controls, no consistent abnormality could be discerned in complex I, complex II-III, or complex IV oxygen consumption, or in the enzyme activity of these respiratory chain complexes. Neither chronic therapy with levodopa/carbidopa alone nor in combination with deprenyl significantly affected any measure of mitochondrial respiratory function. There was no discernible relationship between patient age or disease severity and any parameter of mitochondrial respiration. Moreover, blood lactate levels following glucose loading were not different in patients and controls. These results fail to support the occurrence of a generalized defect in any mitochondrial respiratory function in Parkinson's disease.

Failure of buspirone and verapamil to improve spasmodic torticollis

The effects of buspirone and verapamil on spasmodic torticollis were investigated in two double-blind, placebo-controlled crossover studies. Buspirone was given in doses of 20-100 mg/day for 4 weeks to 14 patients; verapamil was given in doses of 40-100 mg/day for 3 weeks to 8 patients. Neither drug improved symptoms of the movement disorder (posture, motility, rigidity, tremor), pain, perceived stress, or mood, either in the whole group or in any individual patient.

Bilirubin as an antioxidant: effect on group B streptococci-induced pulmonary hypertension in infant piglets

Bilirubin scavenges toxic oxygen radicals in vitro, but it is not known whether this potential salutary effect can be extended to the intact animal. Accordingly, the present experiments tested the hypothesis that bilirubin protects against oxygen radical-dependent pulmonary hypertension and arterial hypoxemia in piglets infected with group B streptococci (GBS). Piglets ranging in age and weight from 7 to 14 days and 1.5 to 2.0 kg, respectively, were infused for 60 min with 108 cfu GBS/kg/min. One group of 7 animals was pretreated with a bolus infusion of 15 mg/kg of bilirubin followed by a continuous bilirubin infusion. A second group of 7 animals was given the vehicle. While plasma bilirubin levels in control animals were negligible, administration of exogenous bilirubin was associated with plasma levels of 13.0 +/- 0.74 mg%. Piglets treated with exogenous bilirubin exhibited GBS-induced increases in pulmonary arterial pressure and decreases in PaO2 of 16.1 +/- 2.0 and 46.5 +/- 4.3 torr, respectively. In control animals, GBS increased pulmonary arterial pressure and decreased PaO2 by 17.5 +/- 1.6 and 47.9 +/- 3.2 torr, respectively. Neither the peak changes in pulmonary arterial pressure or PaO2 nor the time courses of these alterations differed between treatment groups. These observations indicate that bilirubin fails to prevent GBS-induced pulmonary hypertension and arterial hypoxemia in infant piglets and suggests that in this particular model bilirubin does not exhibit appreciable oxygen radical scavenging activity.

Schizosaccharomyces U6 genes have a sequence within their introns that matches the B box consensus of tRNA internal promoters

The gene for the U6 small nuclear RNA (snRNA) in the fission yeast Schizosaccharomyces pombe is interrupted by an intron whose structure is similar to those found in messenger RNA precursors (pre-mRNAs) (1). This is the only known example of a split snRNA gene from any organism--animal, plant, or yeast. To address the uniqueness of the S. pombe U6 gene, we have investigated the structures of the U6 genes from five Schizosaccharomyces strains and three other fungi. A fragment of the U6 coding sequence was amplified from the genomic DNA of each strain by the polymerase chain reaction (PCR). The sizes of the PCR products indicated that all of the fission yeast strains possess intron-containing U6 genes; whereas, the U6 genes from the other fungi appeared to be uninterrupted. The sequences of the Schizosaccharomyces U6 gene fragments revealed that each had an intron of approximately 50 base pairs in precisely the same position. In addition to the splice sites and putative branch point regions, a sequence immediately upstream of the branch point consensus was found to be conserved in all of the Schizosaccharomyces U6 genes. This sequence matches the consensus for the B box of eukaryotic tRNA promoters. These results raise the interesting possibility that synthesis of U6 RNA in fission yeast might involve the use of internal promoter elements similar to those found in other genes transcribed by RNA polymerase III.

Physostigmine treatment of progressive supranuclear palsy

Cognitive and extrapyramidal effects of cholinomimetic therapy were evaluated in 8 patients with progressive supranuclear palsy. Each was randomized to a 10-day double-blind crossover trial of physostigmine and placebo. Physostigmine treatment was associated with marginal and inconsistent changes in long-term memory, suggesting that cholinergic therapy alone is insufficient to restore cognitive function. Motor scores remained unchanged.