Differences in aerodynamic characteristics of new and dysfunctional Provox®2 voice prostheses in vivo

Tracheoesophageal voice prostheses need to be replaced due to increased airflow resistance or retrograde leakage of fluid into the trachea as a consequence of biofilm formation. Previous in vitro studies show a change of aerodynamic features of biofilm covered voice prostheses after removal of the prostheses out of the patient. To assess these changes in an in situ situation, aerodynamic characteristics were measured within 45 patients at the beginning and at the end of the wearing process of the Provox 2 voice prosthesis. As a consequence, the influence of biofilm formation on aerodynamic characteristics can be evaluated. In the majority of cases, leakage through the prosthesis was the reason for replacement. No differences were found in the total flow, volume range and intratracheal pressure (ITP) of the voice prostheses measured. The airflow resistance of biofilm covered prostheses was significantly reduced compared to new clean prostheses. However, no correlation was found between the extent of biofilm and the different aerodynamic features measured. Biofilm formation on the Provox 2 is responsible for both reduction in airflow resistance and leakage through the prosthesis by deterioration of the silicone rubber material.     

Inter-NICU variation in rates and management of thrombocytopenia among very low birth-weight infants.

OBJECTIVES: To investigate variation among neonatal intensive care units (NICUs) in prevalence and management of thrombocytopenia in infants <1500 g. STUDY DESIGN: In total 1283 infants &<1500 g admitted to six NICUs over 21 months were prospectively analyzed. Illness severity was measured by the Score for Neonatal Acute Physiology (SNAP). Platelet counts in the first 12 hours after birth and on day 3 of life were abstracted from the infants' medical records. Thrombocytopenia was determined from the lowest platelet count in each of these time periods. RESULTS: There was variability in rates of thrombocytopenia among NICUs, even after controlling for risk factors (e.g., SNAP, small for gestational (SGA) age and maternal hypertension). One site had a high prevalence of thrombocytopenia, but the lowest percentage of infants with thrombocytopenia who received platelet transfusions. After controlling for SNAP, GA, SGA, Apgar score and incidence of thrombocytopenia, the odds of receiving platelets at this site, relative to the site with the highest transfusion rate, was 0.10 (95% CI 0.02 to 0.43). CONCLUSIONS: This multicenter study finds a 10-fold variation among NICU in the administration of platelets to their thrombocytopenic infants that cannot be explained by presence of thrombocytopenia or illness severity.     

Avidin-biotin enzyme immunoassay of osteocalcin in serum or plasma.

We describe a competitive enzyme immunoassay, the ExtrAvidin-biotin system, for determining osteocalcin in human serum or plasma. Antibodies were raised against bovine osteocalcin. Binding of the antibodies to osteocalcin was calcium-dependent. Limit of detection is 0.07 nmol/L (0.4 microgram/L). The standard curve for method is linear between 0.3 and 17.6 nmol/L (1.9 and 100 micrograms/L). Interassay CV over the range 0.9 to 14.8 nmol/L (5.3 to 84 micrograms/L) is 7.5% to 11.7%. Analytical recovery is 105% +/- 5% (mean +/- SD). The measurement, which is adapted to microtiter plates, requires only 20 microL of serum and 5 h. The coefficient of correlation between the concentrations measured by this method and by a commercially available radioimmunoassay kit (CIS Biointernational) is 0.91. Osteocalcin can be measured in serum or heparinized plasma. Hemolysis (174 mumol/L hemoglobin) reduces osteocalcin concentration by 54%. High concentrations of triglycerides (7 mmol/L) give an overestimation of 63%. Serum concentrations of osteocalcin measured in 130 healthy subjects (ages 15-64 years) and 86 children (ages 4-14 years) were 1.4 +/- 0.8 and 4.0 +/- 1.5 nmol/L (8.1 +/- 4.6 and 22.5 +/- 8.6 micrograms/L), respectively (mean +/- SD).     

Planned lesbian families: their desire and motivation to have children

BACKGROUND: There is no information about the desire and motivation for children among planned lesbian families. The overall aim of this research was to examine whether planned lesbian families differ from heterosexual families in desire and motivation to have a child. The reason for studying this is that desire and motivation to have children are characteristics that are supposed to effect parenting and the parent-child relationship. METHODS: A total of 100 lesbian two-mother families were compared with 100 heterosexual families. All data were collected by means of questionnaires. RESULTS: Lesbian parents and heterosexual parents rank their parenthood quite similarly; however, happiness is significantly more important for lesbian mothers than it is for heterosexual parents and identity development is less important for lesbian mothers than it is for heterosexual parents. Furthermore, compared with heterosexual parents, lesbian parents had spent more time thinking about their motives for having children, and their desire to have a child was stronger. CONCLUSIONS: Lesbian parents especially differ from heterosexual parents in that their desire to have a child is much stronger. The study's findings may be helpful for counsellors in their work to inform and assist lesbian couples in their decision to have a child.     

Infrared-spectrometric determination of D2O in biological fluids

The determination of D₂O in biological fluids by means of infrared spectrometry was reinvestigated. When the temperature of a solution, containing D₂O in the range from natural abundance to 5 ml·1^–1 increases, its absorbance decreases and the wavenumber of maximum absorption shifts to a higher value. Both changes are linearly related to the change in temperature. Storage for 17 d in either glass or polyethylene tubes does not affect the D₂O concentration. Purification of biological fluids by vacuum-sublimation removes all substances which also absorb at the O-D vibration band and the recovery of D₂O from plasma and urine is complete. The partition ratio of D₂O between plasma water and red cell water equals unity, and the same holds for plasma water and urine water over a wide range of urine flows and osmolalities. The arterial and urinary disappearance curves of D₂O, measured over several days, both permit the calculation of the total amount of body water (V ^bw), the daily water turn-over (F) and the half-time of water in the body (t _1/2), but the data derived from arterial disappearance curves are more precise. In 16 male mongrel dogs (25–32 kg body mass) the following results were obtained:V ^bw=626±28 ml·kg^–1,F=12.0±3.2% andt _1/2=6.21±1.78 d.     

The effect of pentobarbital anaesthesia upon the extracellular fluid volume in the dog,studied by continuous infusion and single injection methods

The effect of pentobarbital anaesthesia on the volume and ionic composition of the extracellular space was studied in adult male mongrel dogs with permanent catheters in aorta and pulmonary artery. The extracellular fluid volume (Q ^ec ) was determined with: a) methods based on equilibration of the indicator throughoutQ ^ec by continuous infusion; b) methods based on the assumption that after a single injection of indicator the plasma indicator concentration equals extracellular indicator concentration as long as the log plasma indicator concentration-time curve is linear; c) a single injection method based on a closed flow system model with a single inflow and a single outflow orifice. The measurements were made before and 30 and 90 min after induction of anaesthesia. Thirty minutes after induction of anaesthesiaQ ^ec as determined with the method sub a, had decreased by about 10% and remained so during the following 60 min. The values ofQ ^ec as calculated by the method sub c fairly agreed withQ ^ec as determined with the method sub a and also showed a decrease ofQ ^ec during pentobarbital anaesthesia. The procedures sub b overestimatedQ ^ec and yielded a seemingly higherQ ^ec during anaesthesia, because the boundary conditions for these procedures do not apply. The haemoglobin concentration decreased by about 10% and the lactate concentration by about 50%. The phosphate concentration increased by about 25% while the other electrolyte concentrations (Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl^–, HCO ₃ ^– ) did not change. A respiratory acidosis developed during the first 30 min and almost disappeared in the following 60 min. Possible explanations for the pentobarbital-induced concentration ofQ ^ec are discussed.     

Mental Health Screening Practices Among Primary Care Providers in High HIV Burden Areas of the South: Does Having Patients with HIV Matter?

The Journal of Behavioral Health Services & Research - Mental health (MH) disorders are associated with HIV-related risk and health outcomes. Primary care providers (PCPs) conducting MH...     

Accumulation and effects of lead and cadmium on wood ducks near a mining and smelting complex in Idaho

A study of wood ducks (Aix sponsa) was conducted along the Coeur d'Alene River system in northern Idaho in 1986 and 1987. Most of this area has been subjected to severe contamination from lead and other metals from mining and smelting since the 1880s. In 1986, a preliminary study of wood duck nesting was conducted in the contaminated area; incubating hens captured in nest boxes were bled and weighed. Blood samples were used to determine lead and cadmium concentrations and physiological characteristics. In 1987, an intensive study of wood ducks involved trapping and monitoring nest boxes in the contaminated area. Blood and tissue samples were also taken from wood ducks from a reference area without known contamination from metals. Lead levels in blood and tissues of most wood ducks from the contaminated area frequently exceeded those considered hazardous to birds; maximum levels (wet weight) of lead were 8 g g^–1 in blood and 14 g g^–1 in liver. Changes in physiological characteristics constituted the only evidence of potentially adverse effects from lead. In the contaminated area, nesting success (55% unadjusted, 35% Mayfield estimate) was less than in other areas where predation was low and nest boxes were used; but lead concentrations and physiological characteristics of blood were similar in successful and unsuccessful hens.Values of ALAD, hemoglobin, and body mass were negatively correlated with blood concentrations of lead, whereas protoporphyrin was positively correlated with lead levels in the blood. Some of the protoporphyrin values (1,091 g dl^–1 in a male and 756 g dl^–1 in a female) equalled those associated with lead toxicosis in experimental birds. ALAD activity was low in most birds from the contaminated area; values of 0 were obtained from 11 birds. Lead levels in blood, ALAD, protoporphyrin, and hemoglobin were significantly different between birds from the contaminated and reference areas. Concentrations of lead in ingesta of wood ducks ranged from 0.9 to 610 g g^–1 in the contaminated area and 0.2 to 0.6 g g^–1 in the reference area. Levels of cadmium in kidneys of wood ducks ranged from 1g g^–1 to 20 g g^–1 in the contaminated area and from only to 0.1 g g^–1 to 1 g g^–1 in the reference area. Cadmium concentrations were less than known effect levels.