Outcome following pulmonary haemorrhage in very low birthweight neonates treated with surfactant

AIM

To determine if pulmonary haemorrhage after surfactant treatment increases short and long term morbidity and mortality in neonates weighing <1500 g at birth.

METHODS

Neonates weighing <1500 g at birth who developed pulmonary haemorrhage after surfactant treatment were identified from a database. Based on the change in FIO2, pulmonary haemorrhage was classified as mild, moderate, or severe. Controls were matched for birthweight, gestational age, Apgar scores and hospital. Chronic lung disease (CLD) was defined as the need for supplemental oxygen at 36 weeks of corrected gestational age.

RESULTS

From January 1990 to May 1994, 94 of 787 (11.9%) neonates treated with surfactant developed pulmonary haemorrhage. Ten were excluded because of incomplete data or lack of controls. Eighty four were included for further analysis; two acceptable matches were found in 75, while only one match was possible in nine. For the pulmonary haemorrhage group, the mean (SD) birthweight was 917 (238) g, gestational age 27 (1.9) weeks. Pulmonary haemorrhage was severe in 39 (46%), moderate in 22 (26%), and mild in 23 (27%). Moderate and severe pulmonary haemorrhage were associated with chronic lung disease or death, OR 4.4 (confidence interval 1.3-15.7) and OR 7.8 (CI 2.6-28), respectively, while mild pulmonary haemorrhage was not, OR 1.8 (CI 0.55-5.8). pulmonary haemorrhage was associated with major intraventricular haemorrhage (IVH), OR 3.1 (CI 1.5-6.4), but not with minor IVH, OR 1.3 (CI 0.6-2. 6). In the survivors who could be assessed at >/=2 years, the differences in neurodevelopmental outcome among the two groups were not significant.

CONCLUSIONS

In neonates treated with surfactant moderate and severe pulmonary haemorrhage is associated with an increased risk of death and short term morbidity. Pulmonary haemorrhage does not seem to be associated with increased long term morbidity.

Developing outcome measures in orthodontics that reflect patient and provider values

During the past decade, emphasis in orthodontics has been directed toward the development of outcome measures from both the patient and clinician perspectives. New methodological standards of rigor have been introduced into research design to eliminate bias and test well-defined questions. Sample size calculations and established exclusion and inclusion criteria define sample populations and the ability to statistically accept or reject hypothesis-driven clinical studies. Although advances in our understanding of evidence-based medicine and dentistry from the provider perspective have been productive, the emerging value placed on patient perspective has not been as forthcoming. The emphasis placed on patient-oriented clinical research has resulted in new constructs of surveys and questionnaires in which the items are derived and tested from the patient's point of view. Because orthodontics is a condition without the natural history of a disease process for which no intervention has predictable consequences, new strategies have been developed to estimate need and demand for orthodontic treatment. Studies to measure seekers and nonseekers of orthodontic treatment are reported, as well as sex and cross-cultural issues in the use of established process and outcome measures. The design of clinical studies is discussed in the context of future directions for clinical research, and the usefulness of the information generated will directly relate to providing patients with the necessary information to make decisions and hence knowledgeably give informed consent for treatment interventions.

Extracellular and intracellular actions of azadirachtin on the electrophysiological properties of cultured rat DRG neurones

The distinct electrophysiological actions of extracellular and intracellular azadirachtin (type A) were investigated using cultured dorsal root ganglion neurones from neonatal rats and the whole cell variant of the patch clamp technique. The cultured mammalian neurones were relatively insensitive to azadirachtin compared with some invertebrate preparations, such as insect chemosensory systems. Insect preparations have been found to respond to 1-100 nM azadirachtin. However, at concentrations of azadirachtin between 10 and 100 microM significant changes in the electrophysiological properties of cultured DRG neurones were seen. Extracellular application of azadirachtin prolonged the late repolarization phase of evoked action potentials and consistent with this produced modulation of voltage-activated K+ currents. This modulation involved an initial transient increase in K+ current followed by reversible inhibition when azadirachtin was applied at a concentration of 10 microM. Higher concentrations of azadirachtin (50 and 100 microM), had only inhibitory effects on voltage-activated K+ currents. Azadirachtin produced a degree of voltage-dependent inhibition, with a greater level of K+ current inhibition observed when neurones were held at -90 mV compared with -40 mV. Prolonged application of azadirachtin for 24 h reversibly reduced action potential amplitude. In contrast intracellular application of 100 microM azadirachtin via the patch pipette solution had no significant effects on action potentials but produced an increase in conductance. Intracellular azadirachtin activated several conductances including a TEA-sensitive K + current and an inward current that had an estimated reversal potential close to 0 mV. In conclusion, data showed that azadirachtin had different effects when it was applied inside and outside the neurones and that azadirachtin at high concentrations reversibly altered neuronal excitability mainly by modulating potassium conductances. It appears that rat cultured DRG neurones are less affected by azadirachtin than some insect sensory systems.

Consistency of orthodontic treatment planning decisions

OBJECTIVE

(i) To analyse the consistency of a group of orthodontists' treatment decisions and (ii) to identify factors that may influence this consistency.

DESIGN

Cross-sectional observational study.

SUBJECTS

Ten orthodontists.

METHODS

The orthodontists examined 60 case vignettes and recorded their treatment decisions on two separate occasions.

MAIN MEASURE

Inter- and intra-examiner agreement was evaluated with the Kappa statistic.

RESULTS

The consistency within each orthodontist was moderate. However, between-orthodontist consistency was poor.

CONCLUSION

It appears that there is marked variation between orthodontists in treatment planning decisions and this may reflect the lack of evidence for the effectiveness of competing treatments.

Analgesic efficacy of paracetamol and diclofenac in children receiving PCA morphine

We studied 80 children, aged 5-13 yr, who received PCA with morphine after appendicectomy using a standardized tracheal general anaesthetic. All patients received morphine 0.1 mg kg-1 before surgical incision and all had wound infiltration with bupivacaine 1 mg kg-1 at the end of surgery. Patients were allocated randomly to receive postoperative analgesia with PCA morphine alone, morphine plus diclofenac 1 mg kg-1, morphine plus paracetamol 15-20 mg kg-1 or morphine plus a combination of both diclofenac and paracetamol. Cumulative morphine consumption was significantly reduced by concurrent administration of diclofenac but no additive effect of paracetamol was demonstrable with the doses used in the study. Analgesia, as assessed by movement pain scoring, was significantly improved by the addition of diclofenac despite lower morphine consumption. Adverse effects and duration of PCA were comparable in the four groups.

Complications associated with surgically placed central venous catheters in low birth weight neonates

OBJECTIVE

To determine the incidence of complications in low birth weight neonates with surgically inserted central venous catheters (CVCs).

STUDY DESIGN

Retrospective chart review of all neonates < or = 1500-gm birth weight from three tertiary care neonatal intensive care units who required CVC insertion.

RESULTS

A total of 112 CVCs was inserted in 104 neonates with birth weight of 798 (490 to 1380) gm, age 16 (3 to 179) days, for a duration of 21 (1 to 130) days. The birth weights of 85 neonates were < or = 1000 gm. One or more complications associated with the CVC occurred in 59 patients (57%). Sepsis was the commonest complication, with 43 episodes in 38 patients, at a rate of 14.5 episodes/1000 catheter days. Using regression analysis, sepsis was associated with birth weight, male sex, and the duration for which the CVC remained in place. Five of the nine who developed superior vena cava syndrome and/or pleural effusions died.

CONCLUSION

CVCs can provide venous access that is durable. However, in the LBW neonate, and especially in those of < or = 1000 gm, there is a high incidence of associated complications.

Penetrating sledding injuries to the lower torso--2 case reports

Sledding accidents are frequent and vary in severity. Penetrating sledding injuries are uncommon but may be devastating. Snow-racers--sleds with both steering and braking devices--may be associated with an increased rate of injury. The authors present 2 cases of lower-torso penetrating trauma associated with the use of snow-racers. Both cases involved penetration--of the perineum in one case and the inguinal area in the other--by wooden sticks. Both patients recovered fully after prompt surgical intervention. The authors suggest that the absence of a protective panel at the front of the snow-racer may result in the sledder's lower torso being more exposed to objects encountered while sledding. The injuries reported raise concerns about the safety of modern sleds and the possibility that design changes are needed.

Tracheal intubation without neuromuscular blockade in children: a comparison of propofol combined either with alfentanil or remifentanil

Forty healthy children, aged between two and 12 years of age undergoing elective surgery where the anaesthetic technique involved tracheal intubation followed by spontaneous ventilation were studied. Induction of anaesthesia was with either alfentanil 15 micrograms.kg-1 or remifentanil 1 microgram.kg-1 followed by propofol 4 mg.kg-1 to which lignocaine 0.2 mg.kg-1 had been added. Intubating conditions were graded on a four point scale for ease of laryngoscopy, vocal cord position, degree of coughing, jaw relaxation and limb movement. All children were successfully intubated at the first attempt. There were no significant differences in the assessments of intubating conditions between the two groups. Arterial blood pressure and heart changes were similar in the two groups with both alfentanil and remifentanil attenuating the haemodynamic response to tracheal intubation. The time taken to resumption of spontaneous ventilation was similar in both groups.

Cloning, expression, purification, and characterization of the acid alpha-mannosidase from Trypanosoma cruzi

The acid alpha-mannosidase of Trypanosoma cruzi is a broad-specificity hydrolase involved in the catabolism of glycoconjugates, presumably in the digestive vacuole. We have cloned the alpha-mannosidase gene from a T.cruzi epimastigote genomic library. The alpha-mannosidase gene was determined to be single copy by Southern analysis, and similar sequences were not detected in genomic digests of either Trypanosoma brucei or Leishmania donovani. The coding region was subcloned into the Pichia pastoris expression vector pPICZ, and alpha-mannosidase activity was detected in the medium of induced cultures. The recombinant alpha-mannosidase demonstrated a pH optimum, inhibition by swainsonine, Km, and substrate specificity consistent with the characteristics of the alpha-mannosidase previously purified from T.cruzi epimastigotes. The recombinant enzyme was purified 103-fold from the culture medium of Pichia pastoris and had a native molecular mass of 359 kDa by gel filtration. A combination of SDS-PAGE, deglycosylation with endo H, and NH2-terminal sequencing indicates that the enzyme is originally synthesized as a homodimeric polypeptide that is subsequently cleaved to form a heterotetramer composed of 57 and 46 kDa subunits. A polyclonal antibody raised to the recombinant enzyme was shown to immunoprecipitate the alpha-mannosidase from T.cruzi cell extracts and will be used in future immunolocalization studies.

Orthodontic process and outcome: efficacy studies--strategies for developing process and outcome measures: a new era in orthodontics

The development of process and outcome measures in orthodontics lends itself to retrospective clinical studies. Once valid and reliable measures have been tested, prospective studies may utilize these measures to assess the quality of orthodontic treatment outcome and the duration and process of treatment. The findings from two retrospective studies comparing the quality of outcome using the peer assessment rating (PAR) occlusal index and duration of treatment are reported. Class I and Class II treatment comparisons indicate the duration of treatment time is increased on average 5 months in Class II, division 1 patients. In the second study, the effect of extraction/non-extraction treatment in a sample that included all types of malocclusion indicates that, on average, treatment time is increased by approximately 5 months when extractions are included as part of the orthodontic treatment plan.

Effect of ex vivo hyperthermia on radiation-induced micronuclei in lymphocytes of cancer patients before and during radiotherapy

To investigate the effect of ex vivo hyperthermia (HT) and 137Cs-irradiation on micronucleus (MN) production in cytokinesis-blocked lymphocytes, we obtained the peripheral blood samples from the same cancer patients (n=6) before and during fractionated partial-body radiotherapy (xRT). The whole blood cultures were heated at 43.5 degrees C for 60 min, followed by 137Cs irradiation (0-4 Gy). The control cultures from the same patients were incubated at 37 degreesC after being exposed to radiation. The lymphocytes were then stimulated with PHA. Cytochalasin B was applied at 44 h, and lymphocytes were harvested at 72 h. MN frequency was determined on Giemsa-stained slides. We found that in patients before xRT, HT (43.5 degrees C) significantly increased the MN yield (mean+/-SEM) in unirradiated lymphocytes from 15.6+/-2.8 (37 degrees C) to 39.7+/-10.9. Further, in patients either before or during xRT, when the lymphocytes were treated with HT (43.5 degrees C) and combined with ex vivo irradiation, the MN yield (Y) could be estimated by a linear equation Y=C+alphaD. Our findings indicate that as measured by the MN production in cytokinesis-blocked lymphocytes, HT alone at 43.5 degrees C++ induced DNA damage. Moreover, it enhanced the radiation-induced cytogenetic damage. Therefore, the application of HT may impair the T-cell function in cancer patients who are receiving radiotherapy. 1998 Elsevier Science B.V.

MerMade: an oligodeoxyribonucleotide synthesizer for high throughput oligonucleotide production in dual 96-well plates

We have designed and constructed a machine that synthesizes two standard 96-well plates of oligonucleotides in a single run using standard phosphoramidite chemistry. The machine is capable of making a combination of standard, degenerate, or modified oligos in a single plate. The run time is typically 17 hr for two plates of 20-mers and a reaction scale of 40 nM. The reaction vessel is a standard polypropylene 96-well plate with a hole drilled in the bottom of each well. The two plates are placed in separate vacuum chucks and mounted on an xy table. Each well in turn is positioned under the appropriate reagent injection line and the reagent is injected by switching a dedicated valve. All aspects of machine operation are controlled by a Macintosh computer, which also guides the user through the startup and shutdown procedures, provides a continuous update on the status of the run, and facilitates a number of service procedures that need to be carried out periodically. Over 25,000 oligos have been synthesized for use in dye terminator sequencing reactions, polymerase chain reactions (PCRs), hybridization, and RT-PCR. Oligos up to 100 bases in length have been made with a coupling efficiency in excess of 99%. These machines, working in conjunction with our oligo prediction code are particularly well suited to application in automated high throughput genomic sequencing.

Measuring beliefs about orthodontic treatment: a questionnaire approach

OBJECTIVES

Few studies have examined what parents and orthodontists expect from and value about orthodontic treatment. In this study, we designed and tested a questionnaire to outline what drives consumer demand for children's orthodontic care. Further, we present data from the questionnaire to illustrate how expectations and values pertaining to orthodontic treatment relate to sociodemographic variables.

METHODS

Subjects were 220 Pennsylvania orthodontists and 220 parents at a university orthodontic clinic who were administered a questionnaire designed to assess what parents and orthodontists value about and expect from orthodontic treatment. Items for the questionnaire were developed via a qualitative, telephone interview process. Data were analyzed using factor analysis and reliability analysis for scale development, and analysis of variance for preliminary validity assessment.

RESULTS

Through factor analysis, the questionnaire was reduced from 84 to 52 items, and eight scales were examined: expected treatment benefits, expected treatment risks (short- and long-term), expected treatment inconveniences, value of treatment benefits, value of risks (short- and long-term), and value of treatment inconveniences. For parents, the reliability for all scales was in the acceptable range. For orthodontists, only the "short-term risks" scale failed to attain an acceptable reliability. Preliminary validity was assessed through examining relationships between demographic variables and subscale scores. For parents, income, father's education level, and sex of respondent were related to treatment expectations and values. For orthodontists, age, sex, and patient volume were related to treatment values.

CONCLUSIONS

The questionnaire developed in the present study was found to be practical and reliable for use with providers and consumers of orthodontic care and can be used to explore factors affecting the demand for orthodontic care. Implications of possible unrealistic treatment expectations on the part of orthodontists and parents also are discussed.

Induction and emergence in infants less than 60 weeks post-conceptual age: comparison of thiopental, halothane, sevoflurane and desflurane

We have studied 40 infants with a post-conceptual age of less than 60 weeks undergoing general anaesthesia for herniotomy. Patients were anaesthetized with 1 MAC equivalent values for age and agent and allocated randomly to receive halothane, savoflurane or thiopental for induction, and halothane, sevoflurane or desflurane for maintenance of anaesthesia. At induction, both time to acceptance of a face mask and loss of eyelash reflex were recorded. Emergence times were noted by a blinded observer. Induction and emergence times were similar between the halothane and sevoflurane groups but were consistently shorter in the desflurane group compared with the halothane or sevoflurane groups. There were no problems at extubation or significant apnoea in any group. Induction of anaesthesia in this population was no quicker with sevoflurane than with halothane and the method used for induction did not influence recovery time. Maintenance of anaesthesia with desflurane resulted in a shorter recovery time in infants in whom anaesthesia was induced with halothane or thiopental. Desflurane maintenance may be particularly beneficial in the neonate.

Sevoflurane compared with halothane for tracheal intubation in children

We have studied 40 healthy children, aged 3-10 yr, undergoing adenotonsillectomy, in a double-blind, randomized study. Intubating conditions were assessed when the pupils had become small and central after inhalation induction with either 5% halothane and 60% nitrous oxide in oxygen or 8% sevoflurane and 60% nitrous oxide in oxygen. The quality of tracheal intubation was graded according to ease of laryngoscopy, position of the vocal cords, coughing, jaw relaxation and movement of limbs. Fewer children had significant vocal cord movement on laryngoscopy (P < 0.01) and more had ideal intubating conditions when halothane was used (12 of 20 compared with seven of 20; ns). Time to reach the clinical end-point for intubation was reached sooner with halothane (P = 0.015). In all children the trachea was intubated successfully at the first attempt and all remained haemodynamically stable throughout induction.

Assessing oral health outcomes for orthodontics--measuring health status and quality of life

This paper considers the rationale behind the use of quality of life measures for orthodontic treatment. Current quality of life measures that have been developed for dentistry are not always applicable for orthodontic treatment. Possible methods using preliminary data for the development of these measures for orthodontics are described.

The atmospheric cosmic- and solar energetic particle radiation environment at aircraft altitudes

Galactic cosmic rays interact with the solar wind, the earth's magnetic field and hadron, lepton and photon fields at aircraft altitudes. In addition to cosmic rays, energetic particles generated by solar activity bombard the earth from time to time. These particles, while less energetic than cosmic rays, also produce radiation fields at aircraft altitudes which have qualitatively the same properties as atmospheric cosmic rays. We have used a code based on transport theory to calculate atmospheric cosmic-ray quantities and compared them with experimental data. Agreement with these data is seen to be good. We have then used this code to calculate equivalent doses to aircraft crews. We have also used the code to calculate radiation doses from several large solar energetic particle events which took place in 1989, including the very large event that occurred on September 29th and 30th of that year. The spectra incident on the atmosphere were determined assuming diffusive shock theory.

Polycystic ovarian condition in the dehydroepiandrosterone-treated rat model: hyperandrogenism and the resumption of meiosis are major initial events associated with cystogenesis of antral follicles

BACKGROUND

The purpose of this study was to elucidate the early effects of dehydroepiandrosterone (DHEA) in the polycystic rat model by charting cytological changes in the early antral follicle of the ovary and constructing a serum hormonal profile. Histological examinations of ovaries from DHEA-treated rats for ten consecutive days revealed that the oocyte of antral follicles, ranging from 1.5 mm to 3.4 mm in diameter, had become activated, i.e., had resumed meiosis. Tabulation and statistical analysis revealed a highly significant difference in the percentage of oocyte activation between the ovaries of DHEA-treated and control rats. Granulosa cells associated with those antral follicles included in our statistical analysis showed no evidence of atresia. A few follicles not included in our analysis contained oocytes that had resumed meiosis and whose associated granulosa cells were atretic. The observed resumption of meiosis occurred in the absence of surges of follicle stimulating hormone (FSH) and luteinizing hormone (LH). During meiosis, a period when many oocytes become activated, levels of serum androgens (DHEA, testosterone, and androstenedione) were high, while FSH, LH, and prolactin (PRL) levels did not differ significantly from those in the controls. Follicles that resume meiosis may be members of a group of follicles that produces a signal(s) when the oocyte becomes uncoupled from the granulosa cell. This signal(s) permit(s) a reprogramming of the accompanying granulosa cells of the follicle to engage in certain developmental processes of cystogenesis. Just what cascade of signals is necessary to achieve this selection remains elusive at this time and is the subject of our continuing investigations.

A clinical evaluation of the effectiveness of including fluoride into an orthodontic bonding adhesive

A clinical trial was undertaken to assess the value of incorporating fluoride released from a commercially available bonding adhesive (Rely-a-Bond) to determine the extent of any protection provided against enamel decalcification. Fifty patients undergoing fixed appliance therapy were included in the trial. Contralateral quadrants were used as controls where no fluoride was present in the adhesive. Enamel decalcification after treatment and bond failure rates during treatment were investigated. A total of 366 experimental and 371 control teeth were included in the study. The results showed that 50 per cent of patients and 13.5 per cent of teeth exhibited post-treatment decalcification. The addition of fluoride to the adhesive did not significantly reduce the incidence of enamel decalcification. Bond failure rates were satisfactory for both experimental and control teeth (all under 5 per cent).

Balance and skeletal alignment in a group of elderly female fallers and nonfallers

The purpose of this study was to determine whether sagittal plane posture differed between fallers and nonfallers and to explore the relationship between skeletal alignment and balance in elderly females. Forty-eight women > 65 years of age were recruited from various medical and senior citizen centers. Thirteen of these women were classified as fallers. Spinal posture was measured in standing using an inclinometer, and lower extemity joint angles were assessed in standing using a universal goniometer. The Berg Balance Scale, the Functional Reach Test, end a modified Timed Get Up and Go Test were used to measure balance. Spinal alignment did not differ significantly between fallers and nonfallers; however, knee joint angle was significantly greater in fallers compared to nonfallers. Significant, but low, correlations were found between the inclination of the upper thoracic spine and all three balance measures. Lower thoracic slope and knee joint angle in standing were also weakly related to two of the three balance measures. This study supports the hypothesis that a significant but weak relationship exists between balance and skeletal alignment in elderly females.

High bone mass as a marker for breast cancer risk

Postmenopausal women in the highest quartile for metacarpal bone mass were found to have an increased risk of developing breast cancer, after adjusting for age and other variables known to influence breast cancer risk. Although the mechanisms responsible for this relationship have not been identified, postmenopausal bone mass may serve as an indicator of cumulative estrogen exposure.

Biochemical evidence for a novel low molecular weight 2-5A-dependent RNase L in chronic fatigue syndrome

Previous studies from this laboratory have demonstrated a statistically significant dysregulation in several key components of the 2',5'-oligoadenylate (2-5A) synthetase/RNase L and PKR antiviral pathways in chronic fatigue syndrome (CFS) (Suhadolnik et al. Clin Infect Dis 18, S96-104, 1994; Suhadolnik et al. In Vivo 8, 599-604, 1994). Two methodologies have been developed to further examine the upregulated RNase L activity in CFS. First, photoaffinity labeling of extracts of peripheral blood mononuclear cells (PBMC) with the azido 2-5A photoaffinity probe, [32P]pApAp(8-azidoA), followed by immunoprecipitation with a polyclonal antibody against recombinant, human 80-kDa RNase L and analysis under denaturing conditions. A subset of individuals with CFS was identified with only one 2-5A binding protein at 37 kDa, whereas in extracts of PBMC from a second subset of CFS PBMC and from healthy controls, photolabeled/immunoreactive 2-5A binding proteins were detected at 80, 42, and 37 kDa. Second, analytic gel permeation HPLC was completed under native conditions. Extracts of healthy control PBMC revealed 2-5A binding and 2-5A-dependent RNase L enzyme activity at 80 and 42 kDa as determined by hydrolysis of poly(U)-3'-[32P]pCp. A subset of CFS PBMC contained 2-5A binding proteins with 2-5A-dependent RNase L enzyme activity at 80, 42, and 30 kDa. However, a second subset of CFS PBMC contained 2-5A binding and 2-5A-dependent RNase L enzyme activity only at 30 kDa. Evidence is provided indicating that the RNase L enzyme dysfunction in CFS is more complex than previously reported.

Limb defects in homozygous alpha-thalassemia: report of three cases

Homozygosity for the South-Asian alpha-thalassemia (--SEA/) deletion is a serious hematological condition that results, in most cases, in intrauterine or postnatal death due to anemia and severe hypoxia of prenatal onset. A relationship between congenital abnormalities and intra-uterine hypoxia has been postulated. However, since homozygosity for the (--SEA/) deletion is most common in underdeveloped countries where detailed autopsies are lacking, the incidence of congenital abnormalities among these babies has not been well delineated. We report on three newborn infants, homozygous for the (--SEA/) deletion, who were born with limb defects. We postulate that this combination is the result of prenatal hypoxia which may affect other fetal body organs. This should be taken into consideration when prenatal treatment of affected fetuses, with intrauterine blood transfusion, is suggested.

Construction and characterization of a one-plasmid system for the controlled expression of genes in mammalian cells by tetracycline

The two-plasmid system of Gossen and Bujard [Gossen and Bujard (1992) Proc. Natl. Acad. Sci. USA 89, 5547-5551] to express mammalian genes in a tetracycline-repressed fashion was combined into a single-plasmid system. Two variants of this single-plasmid system that differ in the multiple cloning site (MCS) region are described. These vectors were used to stably transfect raf kinase domain into the normal rat kidney epithelial cell line (NRKE) to obtain a conditionally transformed cell line. These vectors were also used to stably transfect wild-type and mutant human p53 into the human osteosarcoma cell line, SAOS-2. Tetracycline repressed gene expression in both cell lines; about 12-fold in NRKE and about 80-fold in SAOS-2 cell line.

Influence of demographic variables in prehospital treatment of patients with chest pain

OBJECTIVE

To determine whether the number of interventions requested by EMS personnel for patients with acute, nontraumatic chest pain varied with the patient's gender or race.

METHODS

The authors conducted a retrospective chart review of the care requested for patients 17 years old or older complaining of acute, nontraumatic chest pain by one EMS squad in a city of 50,000 people over a six-month period. Interventions recorded for each patient included oxygen administration, artificial airway placement, intravenous fluid administration, defibrillation, and use of lidocaine and nitroglycerin.

RESULTS

Of the 169 patients in this study, 54% (n = 92) were white and 56% (n = 95) were female. Age was missing for two patients; of the remainder, 75% (n = 127) were 40 years old or older. The numbers of interventions requested ranged from 0 to 4. EMS personnel requested supplemental oxygen for 163 patients. 81% of the females had i.v. lines placed or attempted, compared with 70% of the males; EMS personnel requested orders for nitroglycerin for 43% of the females and 29% of the males. Whites were more likely than nonwhites to have requests for i.v. lines or nitroglycerin. Overall, the numbers of interventions were similar among young females and among older patients, regardless of race or gender. The pattern for young males was different, with significantly more requests for interventions for young white males than for young non-white males (1.89 vs 1.34).

CONCLUSIONS

Among older patients and among young females, EMS personnel requested similar numbers of interventions for patient complaining of acute, nontraumatic chest pain regardless of patients race. Patterns of care appeared to differ for young males, a finding that warrants further study.

Index of Orthodontic Treatment Need, its use in a dental epidemiology survey calibration exercise

The Index of Orthodontic Treatment Need (IOTN) was included in a pre-survey calibration exercise of 18 dental epidemiologists. Nine months later 16 of the epidemiologists were re-calibrated in the IOTN. The Index was readily accepted by the experienced dental epidemiological examiners and each examination was estimated to be extended by, on average, less than two minutes. The inter-examiner agreement of the dental health component using the weighted kappa statistic improved from a mean of 0.53 (moderate agreement) for the first calibration to 0.66 (good agreement) at the second calibration. The mean inter-examiner agreement on the aesthetic component using the weighted kappa statistic reduced from 0.52 for the first calibration to 0.49 at the second. Using sensitivity and specificity to measure agreement on the dichotomous decision of those defined as having a definite treatment need, mean sensitivity rose from 0.72 to 0.79 and specificity from 0.90 to 0.97. It is concluded that dental examiners for epidemiological surveys can be trained to use the IOTN by using a pre-calibration exercise and that agreement on the dental health component improves after the index has been used for some months.

Factors influencing the uptake of orthodontic treatment

The aim of this investigation was to evaluate the factors that influenced the uptake of orthodontic treatment for patients who were referred for orthodontic treatment to two types of orthodontic treatment provider; a fee per item and hospital service. The following data were collected: (i) basic demographic data; (ii) the need for orthodontic treatment as measured by IOTN; and (iii) the outcome of the consultation. The data analysis with logistic regression revealed that the following variables had a predictive effect on the uptake of treatment: (i) the need for orthodontic treatment; and (ii) the patient's gender. Most of the patients that were referred and accepted for treatment had a definite need for orthodontic treatment.

Perceptions of orthodontic treatment need: Receiver Operating Characteristic analysis

This study aimed to investigate the variations in dentists' perception of need for orthodontic treatment. Sixteen dentists viewed forty clinical vignettes and recorded their decisions according to the certainty with which they would offer treatment for each case. Receiver Operating Characteristic (ROC) analysis was performed on this data, using the Index of Orthodontic Treatment Need (IOTN) as the "gold standard'. The data suggest that dentists treatment decisions do not concur with current guidelines in use in the UK.

Health gain in orthodontics: a comparison of the general dental services and the hospital service in England and Wales

The aim of this paper was to assess the health gain in orthodontics achieved by practitioners in the General Dental Service (GDS) and Hospital Dental Service (HDS) and the relative probabilities in achieving health gain in relation to the presenting occlusal trait. In a sample of 1225 patients in the GDS in England and Wales and 1365 cases in the HDS different levels of health gain were found. Occlusal traits are most likely to be treated more successfully in the HDS. Seven out of every ten patients in the HDS were likely to achieve health gain as opposed to four out of every ten patients in the GDS.

Do dentists refer orthodontic patients inappropriately?

One concern to both providers and consumers of orthodontic treatment is the length of new patient consultation waiting lists. A possible reason for the excessive length of these lists could be unnecessary referral of patients. This research project aimed to identify whether inappropriate referrals for new patient orthodontic consultations were a significant problem. The study was carried out in two FHSA areas in the north of England in two stages. The first part of the study involved an evaluation of GDP referral patterns to orthodontic secondary care providers. In the second part, information on the patients referred by the dentists was collected. We concluded that there was a marked variation in referral rates between the dentists and many patients were referred unnecessarily. Importantly, there was no association between dentists' referral rate and the number of inappropriate referrals made. It appears that referral guidelines for orthodontic treatment are necessary and they should be directed at all general dental practitioners.

Consistency of orthodontic extraction decisions

Ten orthodontists having completed specialist training, examined on two occasions 1 month apart, the complete pre-treatment records of 60 Class II division 1 patients representing the full range of dental malocclusion severity. At each session the orthodontist recorded whether their proposed treatment involved extractions. The level of agreement both between and within the orthodontists was evaluated with the Kappa statistic. Data analysis revealed that the level of agreement within the examiners was good, however the between examiner agreement was poor. It appeared that the orthodontists were applying different criteria in terms of the extraction decision and this has implications for orthodontic patients.