The effects of long-term treatment with metrifonate, a cholinesterase inhibitor, on cholinergic activity, amyloid pathology, and cognitive function in APP and PS1 doubly transgenic mice

Recent studies in cell cultures have shown that modulating the cholinergic activity can influence the processing and metabolism of amyloid precursor protein (APP). To investigate whether acetylcholinesterase inhibitors (ChEIs) could decrease production of amyloid beta-peptide (A(beta)) and slow down the accumulation of A(beta) also in vivo, we chronically administered metrifonate (100 mg/kg, po), a second-generation ChEI, to 7-month-old doubly transgenic APP+PS1 mice and their nontransgenic littermate controls for 7 months. Behavioral studies, including open field test, T maze, and water maze, were conducted after 6 months treatment with metrifonate, and the mice were sacrificed at the age of 14 months for biochemical and histological analyses. The long-term treatment with metrifonate failed to inhibit the marked overproduction and deposition of A(beta) in the APP+PS1 mice; in contrast, it increased both A(beta)40 and A(beta)42 levels in the hippocampus. However, the A(beta)42 to 40 ratio was significantly reduced by the treatment. In addition, the number of amyloid plaques in the hippocampus did not differ between the treatment and the control groups. Tolerance to cholinesterase inhibition might be induced in the mouse brain because the inhibition rate of AChE was attenuated from about 80 to 50% during the experiment in both APP+PS1 and nontransgenic mice. The metrifonate treatment did not affect cognitive testing parameters but reduced swimming speed and locomotor activity in both genotypes. Our results do not support the idea that ChEIs would slow down the progression of amyloid pathology in Alzheimer's disease.

Does training in a virtual reality simulator improve surgical performance?

BACKGROUND

The development of computerized surgical simulators in a virtual reality environment demands models for proper validation. Recent investigations have shown that a virtual reality simulator (MIST-VR) is a reliable tool for the assessment of laparoscopic psychomotor skills and that it improves the automation of the so-called fulcrum effect. Therefore, we set out to determine whether training with the MIST-VR would improve the surgical performance of surgically inexperienced medical students and to see if results obtained in the simulator would correlate with surgical performance.

METHODS

A total of 29 medical students were randomized into two groups. One group received preoperative MIST-VR training. Both groups then performed a simulated laparoscopic appendectomy in a pig. The operations were videotaped and examined by three independent observers.

RESULTS

There was no significant difference in performance between the two groups. The performance with the MIST-VR correlated with the results in surgery.

CONCLUSION

A method that can measure surgical skill, based on the scoring of independent observers who view videotaped performances, seems to be reliable. MIST-VR did not improve the surgical skills of the subjects, but the results with MIST-VR did predict surgical outcome.

Hip fractures in Finland and Great Britain--a comparison of patient characteristics and outcomes

All hip fracture patients (age <50 years, pathological and subtrochanteric fractures excluded) were registered at admission to hospital and at 4 months (mortality up to 1 year) between 1989 and 1997 in Peterborough District Hospital (2083 patients) and Oulu University Hospital (1702 patients). The mean age at fracture was 80.3 years in Peterborough and 78.3 years in Oulu. Respectively, 69% and 62% of the patients had been living in their own homes, 50% and 54% had been able to walk alone unassisted. In Oulu, the patients were discharged after a mean stay of 7.1 days, most of them to health care centre hospitals (71%) and only 21% to their original place of residence. In Peterborough 81% were discharged to their original place of residence after a mean stay of 15.6 days. At 4 months, 54% were living at their own homes in Peterborough and 44% in Oulu. The overall mortality at 1 year was 27.1% in Peterborough and 24.9% in Oulu.

Spatial working memory improvement by an alpha2-adrenoceptor agonist dexmedetomidine is not mediated through alpha2C-adrenoceptor

1. Aged alpha2C-adrenoceptor knockout and wild type mice were used to investigate whether alpha2C-adrenoceptors are involved in mediating the beneficial effects of alpha2-adrenoceptor agonist, dexmedetomidine, on spatial working memory. 2. A win-stay task in the radial arm maze was used to dissociate the effects of dexmedetomidine on working vs. reference memory. In addition, the animals were tested in simple response habit learning in the T-maze. 3. Knockout mice made more working memory errors after the change of the baited arm in radial arm maze, but after training reached again as accurate level of performance as wild type controls. Dexmedetomidine 5 and 10 microg/kg alleviated the increase in spatial working memory errors after the change of the baited arm in knockout mice. Knockout and wild type mice performed equally well in T-maze, and dexmedetomidine had no effect on this simple response learning. 4. The present results indicate that alpha2-adrenoceptor agonists have a selective effect on spatial working memory not only in monkeys but also in mice. Further, this study confirms our earlier finding that the presence of alpha2C-adrenoceptors is not necessary for the spatial working memory enhancing effect of alpha2-adrenoceptor agonists.

Tooth eruption symmetry in functional lateralities

Dental casts and oral photographs from a cross-sectional sample of 2092 young North Americans with detailed information on functional lateralities (eyedness, handedness and footedness) were examined to compare the proportions of symmetrical and asymmetrical eruption of the antimeric (left-right, contralateral pair) permanent teeth using a four-grade eruption scale. The proportion of symmetrically erupting antimeric teeth was higher for some teeth in those with non-right-sidedness of the feet and eyes, but not significantly so in the case of handedness. Left-footedness was significantly (95% confidence interval) associated with an increased proportion of symmetrical pairs of the maxillary first molar and mandibular lateral incisor, and non-right-eyedness with an increased proportion of symmetrical eruption and left/right non-balanced proportions of asymmetrical eruption in maxillary central incisors. True right-sidedness (hand, foot and eye) was significantly (P< or =0.05) associated with advanced eruption of the left mandibular first molar. It is suggested that while the timing of antimeric tooth emergence and clinical eruption is primarily programmed before crown mineralization, starting approximately at the 30th gestational week in the case of first permanent molars, symmetrical/asymmetrical tooth emergence and eruption may provide information a posteriori on prenatal and early postnatal growth and development.

Outpatient laparoscopic cholecystectomy. A prospective study with 100 consecutive patients

One hundred patients with cholelithiasis were included in a prospective consecutive follow-up study to evaluate laparoscopic cholecystectomy in a day surgical setting. The median operating time was 70 min. In 96% of the patients, it was possible to perform peroperative cholangiography. The median time off work was 7 days and the median time to full recovery was 14 days. Five patients were admitted due to weakness/nausea. Six patients were admitted due to conversion to open surgery or choledocholithiasis. Eighty-nine patients were treated in ambulatory surgery. We conclude that laparoscopic outpatient cholecystectomy can be performed safely with a low unplanned admission rate.

Permanent tooth crown dimensions in prematurely born children

AIM

The aim was to examine the effect of preterm birth on permanent tooth crown dimensions.

MATERIALS AND METHODS

The data consisted of 328 prematurely born white and black children and 1804 control children who participated in the cross-sectional study of the Collaborative Perinatal Project (USA) in the early 1960s and 1970s. The dental examinations were carried out in a standardized fashion at ages varying from 6 to 12 years in 95% of cases. Tooth crown size measurements were performed on the dental casts with an electronic measuring device and readout by two experienced observers according to precise definitions generally quoted in the anthropological and genetic literature. The preterm and control groups were divided by sex and race.

RESULTS

The results show both increased and decreased tooth crown dimensions in the prematurely born children. Significantly increased dimensions were found in the means of the intercuspal distances of the first permanent molars in the white boys and in the mesiodistal dimensions (MD) of the lower lateral incisors and the upper left first molar in the black girls. By contrast, there were decreased intercuspal distances, MD and labiolingual (LL) tooth crown dimensions in the white girls and black boys. The statistical method used was the Mann-Whitney's U-test (Willcoxon Rank-Sums test).

CONCLUSIONS

The findings partly support previous reports of decreased tooth crown dimensions in preterm infants, but the increased dimensions found in the preterm white boys and black girls differ from earlier reports. Our results indicate the importance of environmental factors including neonatal factors in determining permanent tooth crown dimensions. Growth patterns, the buffering capacity and the timing of sensitive moments in tooth crown volume gain may vary between the sexes and ethnic groups and the possible effect of the accelerated growth period in preterm infants (catch-up growth) may influence the determination of permanent tooth crown dimensions.

Is a dissection balloon beneficial in totally extraperitoneal endoscopic hernioplasty (TEP)? A randomized prospective multicenter study

BACKGROUND

Laparoscopic hernioplasty has been criticized because of its technical complexity and increased costs. Disposable dissection balloons can be used to facilitate the creation of the initial working space in totally extraperitoneal endoscopic hernioplasty (TEP), but their use adds to the cost of the operation.

METHODS

A total of 322 men with unilateral, primary, or recurrent inguinal hernias were randomized to undergo TEP with or without a dissection balloon.

RESULTS

In the group with the balloon, three of 161 patients (2.5%) required conversion to transabdominal preperitoneal hernioplasty (TAPP), or open herniorraphy, whereas 17 of 161 patients (10.6%) were converted to TAPP or open herniorraphy in the group without the balloon (p = 0.002). The mean operation time was 55 min in the group with the balloon and 63 min in the group without the balloon (p = 0.004). There was no difference between them in postoperative morbidity, and there were no major complications in either group. The recurrence rate was 3.1% in the group with the balloon and 3.7 % in the group without the balloon (p = 0.8).

CONCLUSION

The use of a dissection balloon in TEP reduces the conversion rate and may be especially beneficial early in the learning curve.

Transplacental transfer of amitriptyline and nortriptyline in isolated perfused human placenta

RATIONALE

Although tricyclic antidepressants (TCAs) have gained wide acceptance for use in the treatment of depression in pregnant women, their pharmacokinetics during pregnancy have been poorly characterized. The aim of the present study was to investigate the transplacental transfer of amitriptyline (AMI) and its main active metabolite nortriptyline (NOR) in isolated perfused human placenta.

METHODS

Nine term human placentae were obtained immediately after delivery with maternal consent and a 2-h non-recirculating perfusion of a single placental cotyledon was performed. AMI (200 ng/ml) and NOR (150 ng/ml), with antipyrine as a reference compound, were added to the maternal reservoir and their appearance to the fetal circulation was followed for 2 h. AMI and NOR concentrations were measured by high performance liquid chromatography (HPLC) and antipyrine concentrations spectrophotometrically.

RESULTS

The mean (SD) transplacental transfers (TPT(SS)%) for AMI and NOR were 8.2 (2.3)% and 6.5 (1.8)%, respectively, calculated as the ratio between the steady-state concentrations in fetal venous and maternal arterial sides. The TPTs of AMI and NOR were 81% and 62% of the freely diffusable antipyrine. The absolute fraction of the dose that crossed the placenta (TPT(A)) was moderately, but significantly higher for AMI (7.7%) than for NOR (5.7%) (P=0.037). In all perfusions, steady state at the fetal side was reached by 30 min for AMI and by 50 min for NOR in the fetal side. The viability of the placentae was retained during the 2-h perfusion, as evidenced by unchanged pH of the perfusate and by stable perfusion pressures in fetal artery and stable antipyrine transfer.

CONCLUSIONS

Both AMI and NOR cross the human placenta. However, the fetal exposure with NOR may be somewhat smaller compared with AMI, probably due to the higher lipophilicity of AMI.

Effect of chemical pollution on forms of 137Cs, 90Sr and 239,240Pu in arctic soil studied by sequential extraction

The aim of the present study was to determine the forms of 137Cs, 90Sr and 239,240Pu occurring in different soil horizons using sequential extraction of samples taken from four sites located along a pollution gradient from the copper-nickel smelter at Monchegorsk in the Kola Peninsula, Russia, and from a reference site in Finnish Lapland in 1997. A selective sequential-leaching procedure was employed using a modification of the method of Tessier, Cambell and Bisson ((1979). Analytical Chemistry, 51, 844-851). For 137Cs the organic (O) and uppermost mineral (E1) layer were studied, for 90Sr and 239,240Pu only the uppermost organic layer (Of). The fraction of 137Cs occurring in readily exchangeable form in the organic layer was about 50% at the reference site and decreased as a function of pollution, being 15% at the most polluted site in the Kola Peninsula. There was a clear positive correlation in the O layer between the distance from the smelter and the percentage of 137Cs extracted in the readily exchangeable fraction (Spearman correlation rsp = 0.7805, p = 0.0001), whereas in the E1 layer no correlation was evident. The distribution of 90Sr in the Of layer was similar at all sites, with the highest amounts occurring in exchangeable form and bound to organic matter, whereas stable Sr showed a somewhat different distribution with the highest amount in the oxide fraction. Most of the 239,240Pu was bound to organic matter. Chemical pollution affected the exchangeable fraction of 239,240Pu, which was about 1% at the most polluted site and 4-6% at the other sites.

The role of respiratory viruses in otitis media

Evidence derived from numerous studies ranging from animal experiments to extensive clinical trials supports a crucial role for respiratory viruses in acute otitis media. Viral infection of the upper respiratory tract initiates the whole cascade of events that ultimately leads to development of acute otitis media, and viruses contribute to the pathogenesis of this disease by several mechanisms. Recent data indicate that at least some types of viruses actively invade the middle ear and may also interfere with the outcome of otitis media. The availability of effective vaccines against the principal viruses predisposing to acute otitis media could be expected to result in a substantial reduction in the incidence of this disease.

Validity of ultrasonography in diagnosis of acute maxillary sinusitis

BACKGROUND

Accurate diagnosis of maxillary sinusitis is difficult on the basis of clinical examination only because the signs and symptoms of sinusitis are nonspecific. A simple, rapid, and readily available method for diagnosing maxillary sinusitis in primary care would increase the accuracy of the diagnoses and thus reduce unnecessary antibiotic treatment.

OBJECTIVE

To investigate the validity of ultrasonography compared with radiography and magnetic resonance imaging (MRI) in detection of maxillary sinusitis.

DESIGN

Ultrasonography and plain-film radiography of the paranasal sinuses were performed on all patients and MRI was performed on 40 randomly selected patients on day 7 of the study.

SETTING

Study office at the Department of Pediatrics of Turku University Hospital, Turku, Finland.

PATIENTS

One hundred ninety-seven young adults who contacted the study office within 48 hours of the onset of symptoms of the common cold.

MAIN OUTCOME MEASURES

Detection rates of maxillary sinusitis by ultrasonography, radiography, and MRI.

RESULTS

Acute maxillary sinusitis was diagnosed in 24% of the sinuses by radiography and in 28% by MRI. Compared with MRI findings, the sensitivity of ultrasonography for detection of maxillary sinusitis was 64% (specificity, 95%). Using a 2-step diagnostic approach in which radiological findings were additionally considered in cases of negative ultrasound findings, a sensitivity of 86% (specificity, 95%) was observed.

CONCLUSIONS

The high specificity of ultrasonography indicates that a positive ultrasound finding can be regarded as evidence of maxillary sinusitis. The addition of plain-film radiography in cases of negative ultrasound findings increases the diagnostic sensitivity to clinically acceptable levels without loss in specificity. Active use of ultrasonography would substantially decrease the need for radiological imaging of the sinuses and also help reduce unnecessary antibiotic treatment in primary care. Arch Otolaryngol Head Neck Surg. 2000;126:1482-1486

A single intramuscular dose of ceftriaxone changes nasopharyngeal bacterial flora in children with acute otitis media

The increasing prevalence of drug-resistant bacteria is attributed to the extensive use of antibiotics, which causes selective pressure on the nasopharyngeal bacterial flora. Shortened courses of antibiotics have been proposed to decrease the development of resistant strains. We determined the effect of a single intramuscular dose of ceftriaxone (50 mg/kg) on the nasopharyngeal bacterial flora in 167 children (median age 13 mo) with acute otitis media. Nasopharyngeal samples for bacterial culture were obtained before and 5 d after treatment with ceftriaxone. Before treatment, Moraxella catarrhalis was isolated in 99 (59%) children, Streptococcus pneumoniae in 87 (52%), and Haemophilus influenzae in 53 (32%). After treatment, M. catarrhalis was found in 62 (37%) children, which constitutes a 37% decrease in the colonization rate by this pathogen (p < 0.001). S. pneumoniae was isolated in 50 (30%; 43% decrease) and H. influenzae in 17 (10%; 68% decrease) children after treatment (p < 0.001 for both). Before treatment, 60% of pneumococcal isolates were sensitive to penicillin, 26% were of intermediate susceptibility, and 14% were penicillin-resistant. Eradication of S. pneumoniae occurred mainly in children with penicillin-sensitive isolates. As a consequence, only 24% of pneumococcal isolates that remained after treatment were sensitive to penicillin, 59% were penicillin-intermediate, and 16% were penicillin-resistant. A single dose of ceftriaxone resulted in significant changes in the nasopharyngeal bacterial flora, increasing the relative prevalence of pneumococcal strains with decreased susceptibility to penicillin.

Intranasal fluticasone propionate does not prevent acute otitis media during viral upper respiratory infection in children

BACKGROUND

Acute otitis media (AOM) is the most common complication of a viral upper respiratory infection (URI) in children. The virus-induced host inflammatory response in the nasopharynx plays a key role in the pathogenesis of AOM. Suppression of this inflammatory process might prevent the development of AOM as a complication.

OBJECTIVE

We sought to assess the effect of intranasally administered fluticasone propionate on prevention of AOM during a viral respiratory infection.

METHODS

A total of 210 children (mean age, 2.1 years; range, 0.7-3.9 years) with normal middle ear status and URI of 48 hours' duration or less were randomly allocated to receive either fluticasone (100 microg twice daily) or placebo for 7 days. The specific viral cause of the infection was determined from nasopharyngeal aspirates obtained at the first visit. The children were re-examined at the end of the 7-day medication period.

RESULTS

In the fluticasone group AOM developed in 40 (38.1%) of 105 children compared with 29 (28.2%) of 103 children receiving placebo (P =.13). The viral cause of the respiratory infection was determined in 167 (86.1%) of 194 children from whom a nasopharyngeal aspirate was obtained. In children with rhinovirus infection, AOM developed significantly more often in the fluticasone group (45.7%) than in the placebo group (14.7%, P =.005).

CONCLUSION

Intranasally administered fluticasone does not prevent the development of AOM during URI but may increase the incidence of AOM during rhinovirus infection.

The transplacental transfer of the macrolide antibiotics erythromycin, roxithromycin and azithromycin

OBJECTIVE

To investigate the transplacental transfer of the macrolide antibiotics erythromycin, roxithromycin and azithromycin.

METHODS

Twenty-one term placentas were obtained with maternal consent immediately after delivery and a two-hour nonrecirculating perfusion of a single placental cotyledon was performed. Erythromycin (2 microg/mL), roxithromycin (2 microg/mL) and azithromycin (0.3 microg/mL) were infused to the maternal inflow at a constant rate, with antipyrine as a reference compound, and their appearance in the fetal circulation was followed. Drug concentrations were measured by high performance liquid chromatography for 120 min.

RESULTS

The mean transplacental transfers (TPT(SS)) for erythromycin, roxithromycin and azithromycin were 3.0%, 4.3% and 2.6%, respectively, calculated as the ratio between the steady state concentrations in fetal venous and maternal arterial sides. Similar results were obtained when the TPT was calculated as the absolute amount of drug transferred across the placenta during 2-hour perfusion (TPT(A)). No significant differences were found among the three macrolides in TPT(SS) (P = 0.39) or TPT(A) (P = 0.35). The TPT(SS) of erythromycin, roxithromycin and azithromycin were 41%, 35% and 32% of the freely diffusable reference compound antipyrine, respectively. Steady state was reached in 60 minutes in each perfusion indicating sufficient perfusion time.

CONCLUSION

The limited transplacental transfer of erythromycin, roxithromycin and azithromycin suggests compromised efficacy in the treatment of fetal infections. On the other hand, the placenta seems to produce an effective barrier reducing the fetal exposure when these three macrolides are used to treat maternal infections.

Role of viruses in the pathogenesis of acute otitis media

To date there is ample evidence suggesting a crucial role for respiratory viruses in the pathogenesis of AOM. Respiratory viral infection appears to initiate the cascade of events that finally leads to development of AOM (Fig. 1). The pathogenesis of AOM is complicated, involving a network of factors, some probably not yet identified, which affect each other in a time-dependent manner. Increased knowledge of the detailed mechanisms of viral infection, the host inflammatory response during URI and the interaction between viruses and bacteria could lead to major advances in the prevention of AOM.

Increasing importance of viruses in acute otitis media

Acute otitis media is generally considered a simple bacterial infection that can be effectively treated with antibiotics. However, despite the extensive use of broad-spectrum antibiotics, poor clinical response to treatment of acute otitis media is common in children. Numerous studies ranging from animal experiments to extensive clinical studies have clearly demonstrated that respiratory viruses play a crucial role in the aetiology and pathogenesis of acute otitis media. Viral infection of the upper respiratory tract initiates the whole cascade of events that finally leads to the development of acute otitis media as a complication. Respiratory viruses induce a release of inflammatory mediators in the nasopharynx, increase bacterial colonization and adherence, and have a suppressive effect on the host's immune defense. Recent data indicate that at least some types of viruses actively invade the middle ear. Viruses also seem to enhance the inflammatory process in the middle ear and impair the outcome of the disease. Vaccines against the major viruses predisposing to acute otitis media hold a great promise for the prevention of this disease. Major advances in the management of acute otitis media will require further research into the mechanisms of viral infection, viral-bacterial interaction and the host inflammatory response during viral infection.

Estrogen and NMDA receptor antagonism: effects upon reference and working memory

Since both estrogen and NMDA receptor antagonists act on the hippocampus CA1 region and behaviorally affect hippocampal memory tasks, we examined how estrogen depletion (ovariectomy) and NMDA receptor antagonism interact upon spatial memory of the mouse. After ovariectomy or sham operation, mice were given a 2-week recovery before behavioral tests began under the influence of vehicle or (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP 2, 5 and 10 mg/kg) intraperitoneal injections. CPP is a competitive, full NMDA receptor antagonist. Spatial reference memory was tested by the water maze, spatial working memory was tested by the radial arm maze, while overall locomotive activity was monitored by the Y-maze. Results from the water maze and the Y-maze did not show any spatial reference memory or activity differences between sham-operated and ovariectomized mice. The radial arm maze, however, highlighted some working memory differences between intact and ovariectomized mice. CPP treatment impaired dose dependently--the performance of ovariectomy and sham-operated mice equally on both water maze and radial arm maze, while the drug had no effect on Y-maze performance. These results suggest that short term estrogen deprivation has no effect upon spatial-reference memory, while it impairs spatial working memory. This effect is probably not mediated by NMDA receptors.

Oral prednisolone is an effective adjuvant therapy for acute otitis media with discharge through tympanostomy tubes

OBJECTIVE

To determine the efficacy of a short course of oral prednisolone as an adjuvant therapy for acute otitis media draining through tympanostomy tubes.

STUDY DESIGN

In a randomized, double-blind, placebo-controlled study, children with acute discharge (<48 hours) through tympanostomy tubes received either prednisolone (2 mg/kg/d; n = 23) or placebo (n = 27) for 3 days. All children received amoxicillin/clavulanate (40/10 mg/kg/d) for 7 days. The children were examined daily at the study clinic until the drainage ceased.

RESULTS

The median duration of otorrhea in the prednisolone group was 1.0 days (25% to 75% range, 1.0 to 2.0 days), compared with 3.0 days (25% to 75% range, 2.0 to 4.0 days) in the children receiving placebo (P <.001). The duration of otorrhea was </=2 days in 21 (91%) children in the prednisolone group, compared with 8 (30%) children in the placebo group (P <.001).

CONCLUSIONS

Oral prednisolone appears to be modestly effective adjuvant therapy for acute otitis media with discharge through tympanostomy tubes in children. Further studies seem warranted to determine whether short-term use of steroids early during the course of acute otitis media would also reduce the duration of middle ear effusion in children with intact tympanic membranes.

Quantification of cytokines and inflammatory mediators in samples of nasopharyngeal secretions with unknown dilution

In the study of inflammatory mechanisms in the upper respiratory tract, the unknown dilution of collected samples of nasal secretions poses a serious problem for interpretation of the measured concentrations of various substances in the specimens. We investigated the magnitude of the dilution problem in a true clinical research situation and determined the validity of using the levels of total protein, albumin, and secretory IgA in nasal secretions to correct for the unknown dilution. The study samples consisted of simultaneously obtained nasopharyngeal aspirates and nasal lavage specimens from 52 children with upper respiratory tract infection. The dilution factors of the nasal lavage specimens varied widely between 1.8 and 432 (median, 11.2). Of the three proteins studied, total protein had the narrowest inter-subject variation in the nasal secretions of the children and thus seemed to provide the best standardization method for comparing levels of substances between individuals. Concentrations of IL-6 standardized with total protein correlated significantly better with the true IL-6 concentrations in the nasal secretions than did IL-6 levels measured in the nasal lavage specimens without standardization (p = 0.049). These findings suggest that the most common current practice of measuring substances in nasopharyngeal specimens, i.e. measuring without correction for the dilution, may produce "false-negative" results. Potentially important information on inflammatory mechanisms may be undetected if false-negative results mask real differences between groups. The use of exogenous markers of dilution might improve the accuracy of quantifying substances in nasal secretions.

Free secretory component as a standardization protein for nasopharyngeal specimens from children with upper respiratory tract infection

Free secretory component (FSC) has been recommended as a reliable protein for correction of the unknown dilution in tracheal aspirate samples from preterm infants. To investigate whether FSC would also provide a valid standardization protein for samples of nasopharyngeal secretions, this study determined the intersubject variation and the alteration over time in the concentrations of FSC in nasal secretions from 35 children (median age 14 months) who participated in an antibiotic efficacy trial. Nasopharyngeal aspirates were obtained at enrolment and after 2-3 d. FSC in the specimens was quantified by a direct enzyme immunoassay. The concentrations of FSC in the nasal secretions ranged from 0.08 to 189.6 microg ml(-1) (median 12.3 microg ml(-1); the ratio of the highest to the lowest concentrations was 2370, the difference between the 90th and 10th percentile concentrations was 189-fold and the difference between the 75th and 25th percentile values was 26. FSC concentrations were significantly lower in children aged < or =12 months (median 2.2 microg ml(-1) than in the older children (median 21.5 microg ml(-1); p = 0.035). Between the first and the follow-up specimens, 65% of the children had > or =2-fold difference in the levels of FSC in the secretions. Because an optimal standardization protein should show minimal variation between individuals and over time, FSC may not be a suitable protein for correction of the unknown dilution of nasopharyngeal specimens from children with upper respiratory tract infection.

Prevalence of various respiratory viruses in the middle ear during acute otitis media

BACKGROUND

Vaccines against respiratory viruses may be able to reduce the frequency of acute otitis media. Although the role of respiratory viruses in the pathogenesis of acute otitis media is well established, the relative importance of various viruses is unknown.

METHODS

We determined the prevalence of various respiratory viruses in the middle-ear fluid in 456 children (age, two months to seven years) with acute otitis media. At enrollment and after two to five days of antibiotic therapy, specimens of middle-ear fluid and nasal-wash specimens were obtained for viral and bacterial cultures and the detection of viral antigens. The viral cause of the infections was also assessed by serologic studies of serum samples obtained during the acute illness and convalescence.

RESULTS

A specific viral cause of the respiratory tract infections was identified in 186 of the 456 children (41 percent). Respiratory syncytial virus was the most common virus identified in middle-ear fluid: it was detected in the middle-ear fluid of 48 of the 65 children (74 percent) infected by this virus (P< or =0.04 for the comparison with any other virus). Parainfluenza viruses (15 of 29 children [52 percent]) and influenzaviruses (10 of 24 children [42 percent]) were detected in the middle-ear fluid significantly more often than enteroviruses (3 of 27 children [11 percent]) or adenoviruses (1 of 23 children [4 percent]) (P< or =0.01 for all comparisons).

CONCLUSION

Respiratory syncytial virus is the principal virus invading the middle ear during acute otitis media. An effective vaccine against upper respiratory tract infections caused by respiratory syncytial virus may reduce the incidence of acute otitis media in children.

Serum interleukin-6 in bacterial and nonbacterial acute otitis media

BACKGROUND

Increasing prevalence of antibiotic-resistant bacteria is a serious clinical problem that calls for reduction of unnecessary use of antibiotics. Acute otitis media (AOM) is the most common reason for antibiotic therapy in the United States. Approximately 30% of AOM cases do not have a bacterial etiology. Rapid identification of these cases could help withhold unnecessary antibiotic treatment.

OBJECTIVE

To determine the usefulness of serum levels of interleukin-6 (IL-6), an acute phase cytokine shown to be a reliable marker of neonatal bacterial infection, in differentiation between bacterial and nonbacterial AOM in children.

STUDY DESIGN

IL-6 was measured in stored serum samples from 184 children (mean age, 22 months) with AOM who were enrolled in antibiotic efficacy trials at our department. The samples were obtained at enrollment and at 9 to 12 days after initiation of antibiotic therapy. Sera from 21 uninfected children (mean age, 23 months) were used as controls. The etiology of AOM was determined by bacterial and viral cultures as well as respiratory syncytial virus antigen detection in the middle ear fluids obtained by tympanocentesis.

RESULTS

Bacterial etiology of AOM was confirmed in 125 children (68%), whereas in 59 children (32%) no bacterial pathogen could be detected in the middle ear fluid. Children with bacterial AOM had significantly higher IL-6 levels than those with nonbacterial AOM (median, 11.5 vs 3.7 pg/mL). However, this difference was almost entirely attributable to pneumococcal AOM specifically. IL-6 levels in children with AOM caused by Streptococcus pneumoniae were significantly higher (median, 40.1 pg/mL) than in AOM caused by Haemophilus influenzae (7.3 pg/mL) or Moraxella catarrhalis (6.8 pg/mL). At the cutoff value of 30 pg/mL, the specificity of IL-6 for detection of pneumococcal AOM was 91% with a sensitivity of 61%, but its sensitivity for detection of bacterial AOM in general was only 27%.

CONCLUSIONS

Low levels of IL-6 do not rule out bacterial etiology of AOM in general; therefore, IL-6 is not sensitive enough as a marker of bacterial AOM. Surprisingly, serum IL-6 levels in pneumococcal AOM were significantly higher than the levels associated with other bacterial AOM, and serum IL-6 levels of >30 pg/mL were highly specific for pneumococcal AOM. These findings suggest a distinctive role for S pneumoniae in the pathogenesis of AOM.

Intranasally administered immunoglobulin for the prevention of rhinitis in children

OBJECTIVE

To determine the efficacy of intranasally administered immunoglobulin in preventing symptoms of rhinitis in children.

METHODS

Forty children ages 1 to 4 years who attended day-care centers in Turku, Finland, were enrolled in the double blind, placebo-controlled study. The children were randomly assigned to receive treatment with immunoglobulin, composed mainly of immunoglobulin A, or placebo, both administered as nasal sprays twice daily for 8 weeks. During this medication period and an additional 8-week follow-up period, the parents recorded the symptoms of the children daily in the diaries provided. One child who met an exclusion criterion was withdrawn from the study after a few days of medication.

RESULTS

During the 8-week medication period the 19 children in the immunoglobulin group had 42% fewer days with rhinitis than the 20 children receiving placebo (mean, 10.8 vs. 18.7 days; P=0.004). The total numbers of episodes of rhinitis in the immunoglobulin and placebo groups were 33 and 51, respectively. No significant differences were observed between the groups during the postmedication follow-up period.

CONCLUSIONS

Intranasal administration of immunoglobulin appears to be an effective method to prevent symptoms of rhinitis in children, and further studies of this approach are needed.

Otitis media

Despite extensive research on various aspects of otitis media, this disease remains an important health care problem of childhood. The rapid increase in resistance to penicillin and several other drugs among strains of Streptococcus pneumoniae will most likely have a great impact on the antibiotic treatment of acute otitis media. The increasing antimicrobial resistance has once again brought up the question of whether antibiotics are really needed in the treatment of acute otitis media. Further, the resistance problem underscores the great need for effective methods to prevent otitis media. In the current situation, the common practice of using antimicrobial prophylaxis for prevention of otitis media should be seriously reconsidered.

Role of viruses in middle-ear disease

Taken together, there is ample evidence suggesting a role for viruses in the pathogenesis of OM. This evidence comes from numerous studies performed in animals and in vitro cell cultures, as well as in adults and children with URI and OM. Viruses induce host immune and inflammatory responses that result in pathology of the ET and the middle ear, and predispose the host in various ways to secondary bacterial infection. A suggested mechanism for the pathogenesis of OM following respiratory viral infection is presented in Figure 1.

Maternal smoking and tooth formation in the foetus. III. Thin mandibular incisors and delayed motor development at 1 year of age

Dental casts from 2159 black and white Americans with detailed neurological data available from the Collaborative Perinatal Study were examined to investigate the relationship of maternal smoking during pregnancy and delayed motor development at 1 year of age to morphological traits in the dentition. Earlier results have indicated that maternal smoking during pregnancy may cause selected tooth size metric reductions in the deciduous dentition and at least in some of the permanent teeth with prenatal crown formation, these features being influenced by sex and race differences. The present results suggest that a thinning of the incisal parts of the permanent mandibular incisors is associated with heavy maternal smoking during pregnancy, and those white girls, in whom this dental variant is found, have probably experienced more severe central damage during the smoking sensitive gestational months, as is also seen in a delayed motor development at the age of 1 year.

Total costs of laparoscopic and lichtenstein inguinal hernia repairs: a randomized prospective study

In a prospective, randomized study, laparoscopic (n = 20) and Lichtenstein (n = 18) inguinal hernia repairs were compared in relation to operative time, operative costs, hospital stay, postoperative pain, return to work, patient satisfaction, complications, and total costs. All the operations were performed with the patient under general anesthesia. The median operative times in the laparoscopic and Lichtenstein groups were 71.5 (range, 43-140) and 45 (16-83) min, respectively (p < 0.001). Postoperative pain and use of analgesics was less in the laparoscopic group. The median time to return to work was 14 (8-26) days in the laparoscopic group and 19 (5-40) days in the Lichtenstein group. More complications occurred in the Lichtenstein group. The median of the operative costs, in U.S. dollars, was $1,395 and $878, respectively, and the median total costs (including community expenses resulting from lost workdays) were $4,796 in the laparoscopic and $5,320 in the Lichtenstein groups.

New prospects in the prevention of otitis media

Otitis media is the most common bacterial infection in children, accounting for a substantial economic burden to the health care system. Together with concern for long-term developmental sequelae, prevention of otitis media has become a high priority area of research. A wide range of factors has been associated with an increased risk of acute otitis media. Most of these factors, however, predispose to upper respiratory tract infection which, in turn, can be considered the most important risk factor for acute otitis media. Conventionally, antimicrobial prophylaxis, tympanostomy tubes and adenoidectomy have been used for prevention of otitis media. At present, the vaccine approach seems to hold the greatest promise for ultimate prevention of otitis media. In addition to the bacterial vaccines, vaccines against the most common viruses predisposing to acute otitis media may also prove valuable in the prevention of otitis media.

Incidence of acute otitis media associated with group A and B respiratory syncytial virus infections

The comparative association of respiratory syncytial virus group A and B infections with acute otitis media was determined by analysing the hospital records of children with community-acquired respiratory syncytial virus infection during three successive outbreaks from 1987 to 1992. Of 326 episodes analysed, 192 (59%) were caused by group A and 134 (41%) by group B infections. Acute otitis media was diagnosed in 101 (75%) children with group B infection, compared with 119 (62%) with group A infection (p = 0.01). Group A infections were more often associated with wheezing (71% versus 59% in group B; p = 0.02) and oxygen therapy in inpatients (48% versus 31%, respectively; p = 0.008). The higher incidence of acute otitis media associated with group B infections was observed both after adjustment for potential confounding variables and during each outbreak.

Short-term use of amoxicillin-clavulanate during upper respiratory tract infection for prevention of acute otitis media

We performed a randomized, double-blind, placebo-controlled study to determine whether acute otitis media could be prevented by antibiotic therapy initiated promptly after the appearance of symptoms of upper respiratory tract infection. One hundred four children aged 1 to 4 years received a 7-day course of either amoxicillin-clavulanate or placebo. Acute otitis media developed in 9 (18%) of the 50 children receiving amoxicillin clavulanate and in 12 (22%) of the 54 children receiving placebo (p = 0.59).

Signs and symptoms predicting acute otitis media

OBJECTIVE

To determine whether acute otitis media can be distinguished from an uncomplicated upper respiratory tract infection by the symptoms of the children.

DESIGN

Prospective cohort study.

SETTING

Urban, pediatric primary care center in Turku, Finland.

PATIENTS

Three hundred two children younger than 4 years (mean age, 2.1 years) attending day-care centers were followed up and examined during episodes of upper respiratory tract infection. The signs and symptoms of the children were recorded daily by the parents.

MAIN RESULTS

The specificity and positive predictive value of earache for acute otitis media were 92% and 83%, respectively. However, 40% of the children with acute otitis media had no apparent earache. Restless sleeping had a specificity of 51% and a positive predictive value of 46% for acute otitis media. Thirty-one percent of the children with acute otitis media had no fever. Continuation of respiratory symptoms for several days after the first examination was significantly related with later development of acute otitis media.

CONCLUSIONS

Earache in children with upper respiratory tract infection is indicative of acute otitis media, but the absence of earache does not preclude acute otitis media. Therefore, even in the absence of any signs and symptoms localized to the ear, all children at risk for acute otitis media should be examined during upper respiratory tract infection, and if respiratory symptoms persist for several days after the initial visit, a reexamination should be performed. Restless sleeping and fever are of no value in distinguishing acute otitis media from an uncomplicated upper respiratory tract infection.

Maternal smoking and tooth formation in the foetus. II. Tooth crown size in the permanent dentition

Altogether 2159 pregnancies among black and white Americans in the Collaborative Perinatal Study and dental casts from their children at the age of 6-12 years were studied to determine the effect of maternal smoking on permanent tooth crown dimensions. A trend of reduction, similar to that observed in the deciduous second molars, was found in the permanent first molars and also in the mesio-distal dimension of permanent incisors in relation to sex and race of the children and smoking habits of the mother. In terms of peak in their mitotic growth, the results can be interpreted to indicate a sensitive period of intra uterine development from the 24th to 28th gestational weeks. Comparisons of postnatal body size and differential correlation patterns in affected tooth dimensions with early postnatal body and head size between smokers and non-smokers, suggests that maternal smoking during pregnancy may have an effect on basic growth of the head and body and/or the developmental process that impacts tooth development at some specific sensitive period also during the postnatal formation of these tooth crowns.

Relationship of difficult forceps delivery to dental arches and occlusion

This study examined the relationship between the extensive use of forceps procedures during delivery and later occlusal characteristics. The work uses data collected in National Collaborative Perinatal Research Project (USA), in which more than 60,000 pregnancies and the children's health were followed by regular medical tests and examinations. Of these, a subsample of 2,074 children participated in dental examinations, including the production of dental casts with wax bites to register occlusion. A total of 84 children, 55 boys and 29 girls, were coded as having undergone difficult or very difficult forceps deliveries. A control group was matched by age, sex, race, and site of dental examination. The results show a significant increase in asymmetric molar occlusion (P < 0.005) and canine relations (P < 0.001) in the study group. The sagittal length of the mandibular arch was increased in the difficult forceps delivery group (P < 0.01). In conclusion, difficult forceps procedures are associated with a later asymmetric occlusion.

Maternal smoking and tooth formation in the foetus. I. Tooth crown size in the deciduous dentition

Altogether 2159 pregnancies among black and white Americans in the Collaborative Perinatal Study and dental casts from the children at the age of 5-12 years were studied to find out the effect of maternal smoking on deciduous tooth crown growth. Minor crown size reduction (2-3%) in some dimensions was found in children whose mothers had smoked during pregnancy. The possible change in dimensions seems to be influenced by sex, race and smoking habit. The critical time periods of the gestational development (16th to 19th) weeks would possibly appear from these data to be targeted by the detrimental effect of maternal smoking. It is concluded that deciduous tooth sizes seem to be greatly unaffected when compared to reduction in birthweight.

Influenza vaccination in the prevention of acute otitis media in children

We studied a new approach to the prevention of acute otitis media through the administration of influenza vaccine to 187 day-care center children aged 1 to 3 years before the influenza A epidemic of 1988-1989. The control group consisted of 187 unvaccinated children of similar age and background. During the 6-week study period, influenza A infection was diagnosed in five (3%) of 187 vaccinees and in 29 (16%) of 187 controls. Acute otitis media developed in three (60%) of five vaccinees with an influenza A infection compared with 18 (67%) of 27 controls (excluded were two children with a double viral infection). The incidence of acute otitis media associated with influenza A was reduced by 83% in the vaccinees. The total number of children with acute otitis media in the vaccine group was 35, compared with 55 in the control group, disclosing a 36% reduction among the vaccinees. We conclude that influenza vaccination decreases the incidence of acute otitis media in children during an influenza A epidemic, suggesting also that other vaccines against respiratory viruses may be an effective way to reduce the incidence of acute otitis media.