Neonatal vocal cord paralysis following extracorporeal membrane oxygenation

Five cases of unilateral vocal cord paralysis/paresis were diagnosed following extracorporeal membrane oxygenation for newborn respiratory failure. All were right sided and transient in nature. None of the five patients had other findings commonly associated with vocal cord palsy. The extracorporeal membrane oxygenation procedure requires surgical dissection in the carotid sheath on the right side of the neck, an area immediately adjacent to both the vagus and recurrent laryngeal nerve. It is speculated that vocal cord paralysis in these infants was acquired as a result of the extracorporeal membrane oxygenation cannulation. Although the vocal cord paralysis resolved in all cases, two patients had difficult courses after extracorporeal membrane oxygenation. Therefore, laryngoscopic examination should be considered for patients after extracorporeal membrane oxygenation.     

Capsaicin cough sensitivity in allergic asthmatic patients increases during the birch pollen season.

BACKGROUND: A change in neural responsiveness may occur as the result of allergic inflammation in the lower airways as well as in the upper airways. In the lower airways, capsaicin cough sensitivity is known to reflect sensory neural reactivity. OBJECTIVE: The aim of this study was to establish whether allergic inflammation changes airway neural sensory reactivity during prolonged allergen exposure. METHODS: Ten nonsmoking patients with birch pollen-allergic asthma performed a capsaicin inhalation challenge twice, once in the off-pollen season and once during the pollen season. The number of coughs and symptoms induced by capsaicin were recorded and compared with those of healthy control subjects. RESULTS: The response to capsaicin, expressed as number of coughs, increased in a dose-dependent manner during both tests. Before the season, the response was similar to that of healthy control subjects, but during the pollen season, the reactivity was significantly increased. Variations in forced expiratory volume in 1 second were not significant before and after each challenge, and values did not change during the pollen season as compared with the winter season. CONCLUSIONS: Sensory reactivity in allergic asthmatic patients may be increased during prolonged allergen exposure as during the pollen season. This finding suggests that allergic inflammation in the lower and/or upper airways may trigger neurogenic mechanisms of significant clinical importance.     

Use of health care services for psychological distress by immigrants in an urban multicultural milieu.

OBJECTIVE: Research in the United States tends to attribute low rates of use of mental health services by immigrants to economic barriers. The purpose of our study was to examine this issue in the context of Canada's universal health care system. METHODS: A survey of the catchment area of a comprehensive clinic in Montreal interviewed random samples of 924 Canadian-born individuals and 776 immigrants born in the Caribbean (n = 264), Vietnam (n = 234), or the Philippines (n = 278) to assess their health care use for somatic symptoms, psychological distress, and recent life events. RESULTS: Overall rates of use of medical services in the past year were similar in immigrant (78.5%) and nonimmigrant (76.5%) groups. Rates of use of health care services for psychological distress were significantly lower among immigrants (5.5% compared with 14.7%, P < 0.001). This difference was attributable both to a lower rate of use of specialty mental health services by immigrants (2.5% compared with 11.7%, P < 0.001) and to differential use of medical services for psychological distress (3.5% compared with 5.8%, P = 0.02). When level of psychological distress was controlled, Vietnamese and Filipino immigrants were one-third as likely as Canadian-born residents to make use of mental health services. The lower rate of use by immigrants could not be explained by differences in sociodemographics, somatic or psychological symptoms, length of stay in Canada, or use of alternative sources of help. CONCLUSION: Immigrant status is associated with lower rates of use of mental health services, even with universal health insurance. This lower rate of use likely reflects cultural and linguistic barriers to care.     

Karyotypic evolution in Ph-positive chronic myeloid leukemia in relation to management and disease progression

In a prospective study of 32 patients with chronic myeloid leukemia the frequency of chromosome abnormalities in addition to the Philadelphia chromosome (Ph) increased when the disease progressed. Before metamorphosis, 10 patients (31%) had developed additional abnormalities. Such abnormalities were present in three of them at the time of diagnosis; in the other seven, they were detected late in the chronic phase. New clonal abnormalities heralded or accompanied a more malignant phase of the disorder, usually a blastic leukemia. During metamorphosis, 78% of the patients had additional abnormalities, which in 68% of these cases comprised at least one of +8, +22q- or i(17q). Clones with additional abnormalities disappeared in eight cases, either spontaneously or in association with cytostatic therapy during the chronic or blastic phase. Involvement of chromosome #8, usually in the form of a trisomy, was found in 7 of 12 patients treated with busulfan, but was not found in any of the 10 hydroxyurea-treated patients, of whom 8 were splenectomized early during the chronic phase. Cells from the spleen, obtained by fine needle aspiration or splenectomy were cytogenetically examined in 18 cases during the chronic phase, but abnormalities in addition to the Ph were noted in only one patient, who was examined in the late chronic phase. The same abnormalities were present in bone marrow cells of this patient.     

Cytogenetic studies of bone marrow and extramedullary tissues and clinical course during metamorphosis of chronic myelocytic leukemia

Of 33 consecutive patients with chronic myelocytic leukemia, examined during metamorphosis, 82% showed chromosome abnormalities in addition to the Ph1. Aberrations most frequently encountered were +8 (39%), +22q - (30%), and i(17q) (18%). Translocations other than the Ph1 were observed in four cases and - Y clones in four cases. Discrepancies in the cytogenetic pattern between bone marrow and extramedullary tissues or blood were noted in a total of 15 patients. In six cases, transformation occurred in extramedullary organs at a time when it was not present in the marrow. In three cases the bone marrow transformation was preceded by a lymph node blastic infiltrate; in one case, by a skin infiltrate; and in one case, by a subdural blastoma. Clonal abnormalities additional to the Ph1 were identified in the tumor tissue from all these cases. Patients with primary extramedullary transformation tended to have a lower median age at onset of metamorphosis, shorter survival, and higher incidence of chromosome abnormalities than the cases without extramedullary involvement. Patients with only Ph1-positive cells and no other anomalies had a slightly longer duration of metamorphosis and longer total survival. Basophilia and thrombocytopenia were more marked in cases with i(17q) than in the rest of the series.     

siRNA therapy in cutaneous T-cell lymphoma cells using polymeric carriers

Cutaneous T-cell lymphomas (CTCLs) arise from specific molecular aberrations that lead to uncontrolled cell proliferation. RNA interference (RNAi) with short interfering RNAs (siRNAs) is a feasible approach to interrupt aberrant signal processing in CTCL cells, but functional biomaterial carriers are needed to effectively deliver siRNAs intracellularly. Towards this goal, we explored the utility of lipid-substituted polyethylenimines (PEI) carriers in a cell model of CTCL. Using caprylic and linoleic acid substituted 2 kDa PEI (PEI-CA and PEI-LA, respectively), we showed effective delivery of siRNA to T-lymphocyte Hut78 and Jurkat cells, but silencing of a model protein (Green Fluorescent Protein, GFP) was possible only in the Hut78 cells. To enhance siRNA delivery to Hut78 cells, a high siRNA: carrier ratio used to assemble the complexes and centrifugation of cells in the presence of complexes were found effective. The toxicities of PEI-CA and PEI-LA were significantly lower than other commercial carriers, 25 kDa PEI and Lipofectamine^® RNAiMAX. This might have contributed to reduced siRNA delivery efficiency of the latter carriers. Screening several endogenous targets led us to identify phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and cyclin-dependent kinase 18 (CDK18) as viable targets to induce siRNA-mediated cell growth inhibition. The results of this study identified promising polymeric carriers and molecular targets that could control proliferation of CTCL cells based on RNAi therapy.     

Pharmacokinetics of diazepam following multiple-dose oral administration to healthy human subjects

Six healthy subjects between the ages of 21 and 31 years received diazepam tablets orally at a dose of 5 mg t.i.d. atO, 5, and 10hr on days 1–13. On day 14, the dose was 5 mg at 0 and 5 hr and 15 mg at 10 hr. Subsequently, the dose was 15 mg once daily on days 15–24. Numerous plasma samples were obtained during the multiple-dose regimen, and appropriate equations were fitted to all the multiple-dose data. Diazepam absorption was satisfactorily described by a first-order process, with disposition characterized by a linear two-compartment open model. The harmonic mean absorption half-life was 32 min, and the harmonic mean terminal exponential half-life was 57hr. The mean apparent oral total drug plasma clearance was 22.7ml/hr/kg. Steady-state plasma levels of the primary metabolite, desmethyldiazepam, were reached after 5–8 days of dosing. Steady-state diazepam plasma concentration-time profiles suggested that once daily administration of the total daily dose at bedtime might be a satisfactory dosing regimen.