Insulin-like growth factor-I and bone mineral density

To assess the relationship between insulin-like growth factor-I (IGF-I) and bone mineral density (BMD) 201 healthy postmenopausal women (age 41-68 years) within 10 years of menopause were studied. In all subjects, BMD at the lumbar spine and left hip were measured using dual-energy X-ray absorptiometry and blood samples were obtained. In all subjects, serum IGF-I and parathyroid hormone (PTH) were measured. In a subgroup of these subjects serum concentrations of IGF-binding protein-3 (IGFBP-3), osteocalcin (OC), bone-specific alkaline phosphatase (BALP), tartrate-resistant acid phosphatase (TRAP), and carboxyterminal propeptide of type I procollagen (PICP) were also measured. Serum IGF-I correlated significantly with age (r = -0.159, p = 0.0241), serum OC (r = 0.226, p = 0.0131), BALP (r = 0.259, p < 0.0001), and TRAP (r = 0.261, p < 0.0015), but not with PICP, PTH, or BMD at any site. Although there was a strong correlation between IGF-I and IGFBP-3 (r = 0.559, p < 0.0001), there was no correlation between IGFBP-3 and any of the markers of bone turnover (OC, BALP, TRAP, or PICP) nor with PTH or BMD at any site. We conclude that IGF-I and markers of bone turnover are related, but there is no relationship between IGF-I and BMD.

A bronchoscopic, computer-assisted examination of the changes in dimension of the infant tracheal lumen with changes in head position: implications for emergency airway management

BACKGROUND

Resuscitation guidelines caution against extreme extension or flexion of an infant's head because tracheal obstruction may occur. No data support this recommendation. The authors therefore examined the dimensions of the tracheal lumen in neutral, extended, and flexed head positions in infants undergoing general endotracheal anesthesia for elective surgery.

METHODS

Eighteen healthy full-term infants were studied. A flexible fiberoptic bronchoscope was passed through a previously inserted endotracheal tube and positioned above the cricoid cartilage. Video recordings were taken in each of three head positions. Recordings were analyzed by an investigator blinded to head position. A computer-digitized technique was used to measure anterior-posterior and lateral dimensions and cross-sectional area. Data were analyzed using paired t tests and sign tests.

RESULTS

No significant differences in mean tracheal dimensions with changes in head position were found. No infant had complete tracheal obstruction. Infants were equally as likely to have a small increase as they were to have a small decrease in tracheal dimension with changes in head position.

CONCLUSIONS

Despite the belief that infants and neonates have obstruction at the level of the trachea with extreme positions of the head, the authors were unable to demonstrate this phenomenon.

Alleles of the cholesterol 7 alpha-hydroxylase (CYP7) gene in pigs selected for high or low plasma total cholesterol

Crossbred pigs were selected for high (HTC) or low (LTC) plasma total cholesterol (TC). Pigs from the seventh (n = 51) and eighth (n = 92) generations were used to determine restriction fragment length polymorphisms (RFLP). Using TaqI restriction enzyme digestion, the frequencies of two alleles (2.8- or 5.0-kb fragments) of the cholesterol 7 alpha-hydroxylase (CYP7) gene were determined in the two populations as a potential indicator of TC concentration at 8 weeks of age. Only the 2.8-kb fragment allele was present in the 26 HTC pigs tested in Generation 7. In the LTC pigs both the 2.8- and 5.0-kb alleles were present in 12 pigs, and only the 5.0-kb allele was present in 13 pigs. The allele frequencies of the 2.8 and 5.0 fragments, respectively, were .26 and .74 in LTC pigs and 1.00 and 0 in HTC pigs. There was an association (P < .001) between the 5.0- and 2.8-kb CYP7 alleles, respectively, and low and high TC concentrations. In Generation 8, all HTC pigs were homozygous for the 2.8-kb allele. The 5.0 kb allele was present in all LTC pigs tested and was homozygous in 57% of LTC pigs. Mean plasma TC was 105.0 mg/dl in 30 pigs homozygous for the 2.8-kb allele in Generation 8; means for LTC pigs were 53.5 and 60.4 mg/dl in 35 pigs homozygous for the 5.0-kb allele and in 27 heterozygous pigs, respectively. High TC was associated with the presence of the 2.8-kb allele, and low TC was associated with the presence of the 5.0-kb allele in both Generations 7 and 8. We conclude that TaqI RFLP analysis of the CYP7 gene is a reliable indicator for TC in these swine.

Premedication of pediatric tonsillectomy patients with oral transmucosal fentanyl citrate

We assessed the safety and efficacy of oral transmucosal fentanyl citrate (Fentanyl Oralet; Abbott Laboratories, Abbott Park, IL), administered preoperatively to provide both preoperative sedation and postoperative analgesia, in a randomized, double-blind, placebo-controlled study in 40 children, 2-10 yr of age, scheduled for tonsillectomy. In the preoperative holding area, one group (Group O) received Fentanyl Oralet (fentanyl 10-15 micrograms/kg), and the other (Group IV) received only the candy matrix. Patients in Group O received an i.v. injection of saline, and those in Group IV received an i.v. injection of fentanyl (2 micrograms/kg) after removal of the first tonsil. Except for the opioid, patients received a standard anesthetic. Preoperative sedation and cooperation were assessed. Postoperative pain was evaluated using an objective pain scale. Patients in Group O were more sedated but no more cooperative at the induction of anesthesia compared with those in Group IV. No patient vomited preoperatively or experienced preoperative or postoperative desaturation. Time to postanesthesia care unit (PACU) discharge was not different between groups. There was no significant difference in the number of patients requiring morphine in the PACU (6 of 21 in Group O versus 10 of 19 in Group IV). Plasma fentanyl concentrations were not a reliable indicator of the need for postoperative morphine. Among the patients who required morphine postoperatively, there was an 11-fold variation in plasma fentanyl concentrations at the time of morphine administration. Derived pharmacokinetic parameters were similar to those previously reported in children; bioavailability of the fentanyl in Fentanyl Oralet was 0.33. We conclude that premedication with Fentanyl Oralet did not differ with i.v. fentanyl in regard to the induction of anesthesia and postoperative analgesia.

IMPLICATIONS

In this double-blind, randomized study, we studied the efficacy of Fentanyl Oralet (10-15 micrograms/kg) preoperatively for providing postoperative analgesia in children undergoing tonsillectomy. We found no incidence of preoperative desaturation or vomiting in any patient. This is in contrast to other studies, in which there was a longer time interval between Fentanyl Oralet completion and induction of anesthesia. The bio-availability of the fentanyl in Fentanyl Oralet was estimated to be 33%, which is less than that reported in adults (approximately 50%). There was no difference in postoperative opioid requirements between patients who received 2 micrograms/kg of fentanyl i.v. and those who received Fentanyl Oralet.

Studies of melatonin effects on epithelia using the human embryonic kidney-293 (HEK-293) cell line

The expression of melatonin receptors (MR) of the Mel1a subtype in basolateral membrane of guinea pig kidney proximal tubule suggests that melatonin plays a role in regulating epithelial functions. To investigate the cellular basis of melatonin action on epithelia, we sought to establish an appropriate in vitro culture model. Epithelial cell lines originating from kidneys of dog (MDCK), pig (LLC-PK1), opossum (OK), and human embryo (HEK-293) were each tested for the presence of MR using 2-[125I]iodomelatonin (125I-MEL) as a radioligand. The HEK-293 cell line exhibited the highest specific 125I-MEL binding. By intermediate filament characterization, the HEK-293 cells were determined to be of epithelial origin. Binding of 125I-MEL in HEK-293 cells demonstrated saturability, reversibility, and high specificity with an equilibrium dissociation constant (Kd) value of 23.8 +/- 0.5 pM and a maximum number of binding sites (Bmax) value of 1.17 +/- 0.11 fmol/mg protein (n = 5), which are comparable with the reported Kd and Bmax values in human kidney cortex. Coincubation with GTPgammaS (10 microM) and pertussis toxin (100 ng/ml) provoked a marked decrease in binding affinity (Kd was increased by a factor of 1.5-2.0), with no significant difference in Bmax. Melatonin (1 microM) decreased the forskolin (10 microM) stimulated cAMP level by 50%. HEK-293 cells do not express dopamine D1A receptor. Following transient transfection of HEK-293 cells with human dopamine D1A receptor (hD1A-R), exposure of the cells to dopamine stimulated an increase in the level of cAMP. Similarly, transient transfection of HEK-293 cells with rat glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and PTH type 1 receptors, each resulted in an hormone inducible increase in cAMP levels. Surprisingly, only the stimulatory effect of dopamine could be inhibited by exposure to melatonin. The inhibitory effect of melatonin on dopamine D1-induced increase in cAMP was completely inhibited by pertussis toxin (100 ng/ml, 18 h). Immunoblot and immunocytochemical studies were carried out using two polyclonal antibodies raised against the extra and cytoplasmic domains of Mel1a receptor. Immunoblot studies using antibody against the cytoplasmic domain of Mel1a receptor confirmed the presence of a peptide blockable 37 kDa band in HEK-293 cells. Indirect immunofluorescent studies with both antibodies revealed staining predominantly at the cell surface, but staining with the antibody directed against the cytoplasmic domain required prior cell permeabilization. By RT-PCR, HEK-293 cells express both Mel1a and Mel1b messenger RNAs, but the messenger RNA level for Mel1b is several orders of magnitude lower than for Mel1a. We conclude that HEK-293 cells express MR predominantly of the Mel1a subtype. Our evidence suggests that one of the ways that melatonin exerts its biological function is through modulation of cellular dopaminergic responses.

Muscarinic receptor subtypes and receptor-coupled phosphatidylinositol hydrolysis in rat bladder smooth muscle

BACKGROUND

The purpose of this study was to evaluate the muscarinic receptor subtypes expressed in rat bladder smooth muscle and characterize the muscarinic receptor-coupled phosphatidylinositol (PI) hydrolysis in order to clarify the first step of bladder smooth muscle contraction.

METHODS

Expressions of mRNAs of muscarinic receptor subtypes were examined by Northern blot analysis. Changes in the mass of inositol 1,4,5-trisphosphate (IP3) and the inhibitory effects of muscarinic subtype specific antagonists on PI hydrolysis were determined after carbachol stimulation.

RESULTS

mRNAs of m2 and m3 genes, encoding M2 and M3 receptors, were expressed in rat bladder smooth muscle. Carbachol produced a rapid increase of IP3, which returned to the basal level within 30 seconds. 4-Diphenylacetoxyl-N-methylpiperidine methiodide (4-DAMP; M1 and M3 antagonist) strongly inhibited the PI hydrolysis, but methoctramine (M2 antagonist) partially inhibited it at 10(-4) mol/L. The IC50 value for atropine was 9.5 x 10(-9) mol/L, for pirenzepine 6.4 x 10(-6) mol/L, and for 4-DAMP 1.5 x 10(-7) mol/L.

CONCLUSION

M2 and M3 receptors are expressed in rat urinary bladder. Only M3 receptor was involved in the production of IP3, which might induce the initial phase of contractile response in rat bladder smooth muscle after carbachol stimulation.

Electrocution due to contact of industrial equipment with power lines

Electrocution due to contact of construction equipment with power lines is not uncommon as a source of industrial injury. We report seven such cases. Two patients sustained cardiac arrest and were successfully resuscitated at the scene. Four patients lost consciousness and in two cases, amnesia for the event was encountered. No long-term cardiac or neurologic effects were noted. Surgery including amputation was sometimes required. In all cases, the patient was on the ground touching the machinery or touching cables connected to the machinery at the time of injury. The importance of exercising due care in industrial safety measures is stressed. Prompt CPR was life saving in two cases.

Carboxyfullerenes as neuroprotective agents

Two regioisomers with C3 or D3 symmetry of water-soluble carboxylic acid C60 derivatives, containing three malonic acid groups per molecule, were synthesized and found to be equipotent free radical scavengers in solution as assessed by EPR analysis. Both compounds also inhibited the excitotoxic death of cultured cortical neurons induced by exposure to N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), or oxygen-glucose deprivation, but the C3 regioisomer was more effective than the D3 regioisomer, possibly reflecting its polar nature and attendant greater ability to enter lipid membranes. At 100 microM, the C3 derivative fully blocked even rapidly triggered, NMDA receptor-mediated toxicity, a form of toxicity with limited sensitivity to all other classes of free radical scavengers we have tested. The C3 derivative also reduced apoptotic neuronal death induced by either serum deprivation or exposure to Abeta1-42 protein. Furthermore, continuous infusion of the C3 derivative in a transgenic mouse carrying the human mutant (G93A) superoxide dismutase gene responsible for a form of familial amyotrophic lateral sclerosis, delayed both death and functional deterioration. These data suggest that polar carboxylic acid C60 derivatives may have attractive therapeutic properties in several acute or chronic neurodegenerative diseases.

Relation between insulin-like growth factor-I concentrations, osteoarthritis, bone density, and fractures in the general population: the Chingford study

OBJECTIVE

To assess the association between serum insulin-like growth factor-I (IGF-1) concentrations and osteoarthritis, and bone mineral density, and fractures in a large group of middle aged women from the general population.

METHODS

761 women aged 44-64 years from the Chingford study had serum IGF-I concentrations measured; hand, hip, spine, and anteroposterior weight bearing knee radiographs taken; and dual energy x ray absorptiometry (DEXA) scans of the hip and spine. X rays were scored using the Kellgren and Lawrence system. In addition knee x rays were scored using a standard atlas for individual features of osteophytes and joint space narrowing (both graded 0-3). IGF-I concentrations were adjusted for the effects of age.

RESULTS

In the osteoarthritis analysis results were compared to a constant group of 155 subjects with no evidence of osteoarthritis at any site. There was no significant difference in serum IGF-I between these subjects and 606 subjects with osteoarthritis at any site. When individual sites were analysed, serum IGF-I was higher in those cases with more severe bilateral knee osteoarthritis and in those with distal interphalangeal (DIP) joint disease. There was no significant association between serum IGF-I and other forms of osteoarthritis or milder forms of knee osteoarthritis. There was no correlation between IGF-I concentrations and bone mineral density at the spine or hip, nor any difference between IGF-I concentrations in subjects with and without a history of non-traumatic fracture [22.8 (SD 6.6) v 23.1 (SD 6.6) nmol litre-1, P = 0.6]

CONCLUSIONS

There is a modest association between IGF-I concentrations and the development of DIP osteoarthritis and more severe or bilateral knee joint osteoarthritis in women from the normal population, but no association with other forms of osteoarthritis, bone density, or fractures.

Fat replacers: their use in foods and role in diabetes medical nutrition therapy

The scientific literature demonstrates that fat replacers have a reasonable certainty of no harm. Whether they help produce desired health outcomes, i.e., decreased risk of coronary heart disease and certain types of cancer related to excess fat intake, weight reduction, changes in lipid profile, improved glycemic control, etc., depends on how individuals use these foods to change food choices and eating behaviors. As Miller and Rolls conclude, ...the use of fat-replaced foods alone should not be expected to produce spontaneous improvements in weight management. Such improvements will still be dependent on long-term behavioral changes that include not only modifications in fat, but also modifications in overall energy intake and increase in energy expenditure. (53) Though it has not been studied, one may conjecture that encouraging people with diabetes to use foods with fat replacers to achieve nutrition management goals requires sufficient education, continuous counseling, and an individual's conscientious commitment and readiness to change food habits.

Do latex precautions in children with myelodysplasia reduce intraoperative allergic reactions?

Children with myelodysplasia have an increased incidence of latex allergy, which can lead to severe intraoperative allergic reactions. Despite widespread recommendations to avoid intraoperative latex exposure, little evidence exists to support the efficacy of this practice. We examined the incidence of intraoperative allergic reactions in children with myelodysplasia who underwent 1,025 operations in a 36-month period before and after institution of a standardized latex-avoidance protocol. Risk factors for an intraoperative reaction were found to be a history of latex allergy (p = 0.001) and surgery performed before institution of the latex-avoidance protocol (p = 0.01). The estimate of increased risk for allergic reaction was 3.09 times higher in cases performed without latex avoidance. Recognized violation of the protocol after its institution led to severe allergic reactions in three patients. Our experience suggests that a latex-avoidance protocol reduces intraoperative allergic reactions in children with myelodysplasia. Development of severe allergic reactions with violation of the protocol reinforces the importance of vigilance on the part of all operating room personnel in its implementation.

The Effects of Daflon on Pelvic Pain in Women with Taylor Syndrome

The syndrome of chronic pelvic pain without an obvious pathology has been described as pelvic congestion (Taylor) syndrome. It is frequently associated with continuous bilateral lower abdominal pain and dyspareunia. Pelvic examination reveals tenderness without induration or masses. Although their importance in the pathophysiology of pain is uncertain, prominent enlarged broad ligament veins are observed at laparoscopy. We evaluated the effects of daflon, a venomimetic agent that regulates the circulatory tonus of the venous system, on pelvic pain and investigated the role of enlarged veins in the pathophysiology of Taylor syndrome. Ten women (age 28-35 yrs) with chronic pelvic pain were diagnosed with the syndrome at laparoscopy. They all had prominent broad ligament and ovarian veins without other pathologies such as endometriosis to explain the etiology of pelvic pain. Five women were randomized in a double-blind fashion to receive daflon 500 mg twice/day for 4 months, and five a vitamin pill placebo; they were crossed over for another 4 months. They scored the frequency and severity of lower abdominal pain and dyspareunia on a scale from 0 to 6, and the results were compared with pretreatment values. At the end of the fourth month the frequency and severity of pelvic symptoms began to decrease with daflon compared with pretreatment and placebo. The mean scores were significantly less at the end of 4 months (9.3 &plusmn; 1.1 vs 4.2 &plusmn; 1.4, respectively, p <0.05). Based on our preliminary results, we conclude that venous dysfunction and stasis may be pathophysiologic components of pelvic pain in women with Taylor syndrome. Pharmacologic enhancement of venous tonus may restore pelvic circulation and relieve pelvic symptomatology.

The Fort McMurray Demonstration Project in social marketing: health- and safety-related behaviour among oil sands workers

This is the first round in a series of surveys conducted in Fort McMurray as part of the Fort McMurray Demonstration Project in social marketing. This component of the survey was intended to focus on the most prominent group of employed workers in the community and to compare their patterns of response with the community as a whole. Respondents to the survey were overwhelmingly male (96%), married (72.9%) and living in households of two to five persons (87.9%). They were predominantly aged 30-44 (55%) and graduates of high school (53.5%). Younger male workers (below age 30) were more likely to have a high school diploma (78.3%) or some additional technical or vocational training (21.7% compared to 12.5% overall) and to be unmarried or separated. Attitudes toward safety-related behaviours were stronger than for respondents from the community as a whole. Approximately 70-100% of all age groups and both sexes showed strong agreement with attitudes involving child car seats and the unacceptability of drinking and driving. These attitudes include strong advocacy of vigorous enforcement of occupational health and safety standards. However, they showed a variability similar to the community as a whole in behaviour at home compared to work, generally reporting more consistent use of personal protection on the job than in their own homes, particularly hearing protection. Even so, they were much less likely to perform stretching and warm-up exercises prior to exertion than community residents in general. The potential may exist to transfer the technology and attitudes from workplace health and safety to community safety. One possible strategy to accomplish this is to involve workers in this industry directly in community initiatives. This strategy may be generalizable to any community in which there are major employers who place a heavy emphasis on risk control and occupational health and safety.

Intravenous ondansetron in established postoperative emesis in children. S3A-381 Study Group

BACKGROUND

In pediatric postsurgical patients, postoperative vomiting is a common occurrence that can delay recovery and result in unplanned hospital admissions after outpatient surgery. This randomized, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of ondansetron in the control of established postoperative emesis in outpatients aged 2-12 yr.

METHODS

Screened for the study were 2,720 ASA physical status 1-3 children undergoing outpatient surgery during general anesthesia, which included nitrous oxide. Children experiencing two emetic episodes within 2 h of discontinuation of nitrous oxide were given intravenous ondansetron (n = 192; 0.1 mg/kg for children weighing < or = 40 kg; 4 mg for children weighing > 40 kg) or placebo (n = 183).

RESULTS

The proportion of children with no emetic episodes and no use of rescue medication was significantly greater (P < 0.001) in the ondansetron group compared with placebo for both 2- and 24-h periods after study drug administration (78% of the ondansetron group and 34% of the placebo group for 2 h; 53% of the ondansetron group and 17% of the placebo group for 24 h). Among patients with at least one emetic episode or with rescue medication use, the median time to onset of emesis or rescue was 127 min in the ondansetron group compared with 58 min in the placebo group (P < 0.001). The median time from study drug administration until discharge was significantly shorter (P < 0.01) in the ondansetron group (153 min, range 44-593 min) compared with the placebo group (173 min, range 82-622 min). The incidence of potentially drug-related adverse events was similar in the ondansetron (3% of patients) and the placebo (4% of patients) groups.

CONCLUSION

A single dose of ondansetron (0.1 mg/kg up to 4 mg) is effective and well tolerated in the prevention of further episodes of postoperative emesis in children after outpatient surgery. Administration of ondansetron also may result in a shorter time to discharge.

[High frequency ultrasonography of the gastrointestinal wall]

If an ultrasound probe comes close to the area of interest, high ultrasound frequencies can be applied. Endoscopic ultrasonography is performed by means of echoendoscopes or miniature probes using ultrasound frequencies between 7 and 30 MHz. A high frequency ultrasound image of the normal gastrointestinal wall usually shows five layers corresponding closely to the histological layers of the wall. Corrections have to be made, however, for interface echoes between layers with different acoustic impedances. We describe studies performed with the aim of correlating ultrasound images of the normal and diseased gastrointestinal wall with the histology. Ultrasound images of the normal gastrointestinal wall and pathological changes like ischemia, ulcers, tumours and inflammation are presented.

A randomized controlled trial of oral albuterol in acute cough

BACKGROUND

Beta-agonist agents have been used for bronchospasm and cough in a variety of settings. We sought to evaluate the efficacy of oral albuterol for acute cough in ambulatory adults.

METHODS

We performed a prospective, randomized, controlled, double-blind clinical trial comparing albuterol 4 mg by mouth three times daily for 7 days with placebo in 104 adults. Subjects had cough of less than 4 weeks' duration and no evidence of pneumonia, asthma, or chronic obstructive pulmonary disease. All subjects were enrolled at the walk-in clinic of a rural academic medical center.

RESULTS

There was no significant difference between treated and control subjects in any measure of efficacy including cough severity score, reduction in sleepless nights, utilization of health care, or return to full activity. There were significantly more reports of "shakiness" and "nervousness" among albuterol-treated subjects than among controls.

CONCLUSIONS

Oral albuterol should not be used in unselected patients with acute, nonspecific cough.