The fitting of logistic curves by means of a nomograph.
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Biometry↗
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On the best choice of sample sizes for a t-test when the ratio of variances is known.
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Biometry↗
Note on some errors in the evidence of periodicity in short time series.
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Biometry↗
The role of prolidase activity in the diagnosis of uremic bone disease.
The derangements in bone metabolism in patients with chronic renal failure (CRF) are summarized as uremic bone disease (UBD). In this study, we planned to determine the serum prolidase to compare it with the other biochemical markers. This study was performed on 44 patients (19 females, 25 males, mean age = 56.8 +/- 15.6 years) with endstage renal disease (ESRD). The patients were divided into three groups according to serum bone alkaline phosphatase (bAP) levels. The patients whose bAP was > or =77 U/L were accepted as having high-turnover UBD (n=18), the patients whose bAP was < or =50 U/L were accepted as having low-turnover UBD (n=14), and the patients whose bAP levels were between these two values were accepted as having bone disease with normal turnover (n=12). The serum prolidase levels did not increase in patients with ESRD. There were no significant differences between the serum prolidase levels of patients according to types of the UBD (p > 0.05). Kidney is the most prolidase-rich tissue of the human body. The serum prolidase activity is low in all patients with ESRD, irrespective of the type of UBD. Therefore, we concluded that prolidase had no value in the diagnosis of UBD.
Acid Phosphatase↗
Body posture photographs as a diagnostic aid for musculoskeletal disorders related to temporomandibular disorders (TMD).
The purpose of this study was to test the hypothesis that body posture could be an etiologic factor in patients with temporomandibular disorders. "Faculty" body posture has been considered to be an initiating and perpetuating etiologic factor in some temporomandibular disorders (TMD). Although in patients with temporomandibular disorders a significant craniocervical dysfunction has been established, a causal relationship between posture and TMD has not yet been proved. Two samples of 40 subjects each were selected, age and gender matched. The experimental group consisted of 40 patients, who were not previously treated for temporomandibular dysfunction. TMD of these patients was diagnosed on the basis of a questionnaire and a thorough intra- and extraoral examination. The clinical symptoms of TMD were confirmed with transcranial x-rays and the condylar tracings of the performed axiography. A clinical examination was done to confirm the good health of the control group. In addition, symptoms of craniocervical dysfunction within the experimental group were evaluated to make a proper referral to a physical therapist. Four photographs of the orthostatic posture were taken. In accordance with anthropometric guidelines, the following anatomical landmarks were palpated and applied on the skin with a dark lipstick on forehand: both acromiones of the scapula and the anterior (ASIS) and posterior superior iliac spine (PSIS). Statistical testing was performed to confirm the data fit a normal distribution. The differences between the experimental group and the control group were tested with Student's two sample T-test. Within the experimental group, a significant correlation existed between the shoulder line and the pelvis line, on the frontal as well as on the dorsal photograph. The results suggest a somatic basis for the observed postural imbalances in patients with temporomandibular disorders. The results, however, must be interpreted with reservation.
Adolescent↗
Effect of arthrocentesis on TMJ disturbance of mouth closure with loud clicking: a preliminary study.
The objective of this study was to evaluate the short-term effect of arthrocentesis on temporomandibular joint disturbance of mouth closure with loud clicking compared to the effect of one-time pumping into the joint space previous to arthrography. Twenty-one consecutive patients (22 joints) with loud clicking during mouth closure were enrolled. All were unable to smoothly close the mouth without effort. Eleven patients (12 joints) were examined using magnetic resonance imaging (MRI) to determine disk position. They then underwent arthrocentesis. Ten patients (10 joints) underwent arthrography alone as controls. Six months later, changes in clicking and temporomandibular joint movement were analyzed and the disk position was re-examined. There was improvement of mouth closing and clicking occurred in nine joints from the arthrocentesis group and two joints from the control group, with a significant difference between the two groups. Arthrocentesis may be indicated for patients with temporomandibular joint dysfunction and loud clicking when mouth closing.
Adolescent↗
Long-term outcome after treatment of temporomandibular joint osteoarthritis with exercise and manual therapy.
In a previous study, exercise and manual therapy demonstrated a 90% success rate in patients with osteoarthrosis of the temporomandibular joints in the short-term. The aim of this follow-up study was to assess the long-term effect of these treatment modalities. Seventeen patients were evaluated. All patients suffered from osteoarthrosis of the temporomandibular joints with pain in the temporomandibular joint at baseline and were treated successfully in a prior short-term study. The parameters were pain at rest and at chewing, impairment in daily life, and mouth opening. At follow-up, 11 patients (65%) experienced no pain and 13 patients (76%) had no pain at rest (Fisher's Exact Test: p<0.02). Thirteen patients (76%) had a normal incisal edge clearance, and ten patients (59%) felt no impairment due to the disease (Fisher's Exact Test: p=0.01). Thirteen patients (76%), who had been treated once successfully, have not needed treatment within the three years after cessation of their therapy. Exercise therapy is an effective tool to treat osteoarthrosis of the temporomandibular joints.
Activities of Daily Living↗
Asymptomatic cervical spine dysfunction (CSD) in patients with internal derangement of the temporomandibular joint.
Patients with temporomandibular disorders (TMDs) frequently show symptoms related to the cervical spine. It is however unknown whether patients with TMD who have no symptoms in the neck region often have signs of cervical spine dysfunction (CSD) and whether there is a predominant localization of these asymptomatic CSDs. In a prospective and controlled examiner-blinded clinical trial, the prevalence and localization of asymptomatic CSD in patients with TMD was examined. Thirty patients with internal derangement of the temporomandibular joint but without any neck problems were compared with 30 age and gender matched healthy controls. Significantly more asymptomatic dysfunctions of the vertebral joints and increased muscle tenderness were found in the patient group. The difference between patents and nonpatients for vertebral joint dysfunction and muscle tenderness was greatest in the upper cervical spine. These findings support the thesis that a complementary examination of this area should be performed, even when TMD patents do not report any neck problems.
Adult↗
A randomized controlled trial of therapeutic exercise for clicking due to disk anterior displacement with reduction in the temporomandibular joint.
Therapeutic exercise is a new concept of treatment for patients with clicking due to anterior disk displacement with reduction (ADDWR). In order to investigate the efficacy of the exercise, we designed a randomized controlled clinical trial to compare with no-treatment controls. The subjects were patients who complained of painless unilateral reciprocal clicking and were diagnosed as having ADDWR by Magnetic Resonance Imaging (MRI). Forty-two patients were randomly assigned. Three months after the randomization, the success rate was 61.9% (13/21 joints) in the exercise group and 0% (0/21 joints) in the control group, with a significant difference between the two groups (p=0.0001). However, captured disks in the successful cases were seen in only 23.1% on MRI examination. In conclusion, the therapeutic exercise for clicking due to ADDWR is significantly effective in reducing the clicking, and thought to be much more conservative and cost-effective than splint therapy or surgery.
Adolescent↗
Variants of ossification in the stylohyoid chain.
The purpose of this study was to evaluate the age-related differences in the incidence, length and topographic location of ossification in the stylohyoid chain. Panoramic radiographs of 420 patients (795 reviewed stylohyoid-chains), subdivided into 4 age groups (20 years and under, 21 to 40 years, 41 to 60 years, older than 60 years) were reviewed and examined for the incidence, length and topographic location of stylohyoidal ossification. 245 (30.8%) out of 795 reviewed stylohyoidal chains showed radiological variabilities (elongation of the styloid process and/or ossification of the stylohyoid ligament). With increasing age, there was an increase in the incidence and length of stylohyoidal ossifications (p<0.01). A significant linear correlation between the length of the stylohyoidal ossifications and age was only found in the young age group (under 20 yrs.; p<0.01). In the young age group (under 20 yrs), there was also a higher prevalence of isolated locations in the superior stylohyoidal segment. With increasing age, there was a pronounced presence of ossifications in the middle and inferior stylohyoid segments and combinations of ossified variabilities. Stylohyoidal ossifications show age-related differences in incidence, length and topographical location. Stylohyoid ossifications gain a different importance in adult patients than in juvenile patients.
Adolescent↗
Increased platelet reactivity in unstable angina patients is not related to C-reactive protein levels.
Platelets are a major component of thrombi, and coronary thrombosis plays a key role in the pathogenesis of unstable angina (UA). Whether platelet aggregability is increased in UA patients however, is not known. Furthermore, no study has investigated the relationship between platelet reactivity and inflammation in UA patients In this study, venous blood samples were collected at admission in coronary care unit in 37 patients with unstable angina (Braunwald class IIIB) and in 37 sex- and age-matched patients with chronic stable angina (CSA). Patients taking thienopyridine or anticoagulant drugs were excluded from the study, as also were excluded patients with a history of acute myocardial infarction in the previous 12 months. Platelet aggregability was measured on flowing blood as time to occlude a ring coated with collagen-adenosine diphosphate (ADP), using the platelet function analyzer (PFA-100) system. By this method, the time to occlusion (closure time) is taken as a measure of platelet adhesion/aggregability, with shorter times indicating greater platelet reactivity. There were 23 men and 14 women in both groups, and age was 67.7 +/- 8 and 67.5 +/- 8 years in UA and SA, respectively (P = 0.93). Closure time was significantly reduced in UA patients (78.8 +/- 14 s), compared to SA patients (93.3 +/- 19 s, P < 0.001). Among UA patients, serum C-reactive protein (CRP) levels had a median value of 5.1 mg/l (bottom and top quartile levels, 1.50-7.95). There was no significant correlation between closure time and CRP levels (r = 0.22, P = 0.29). Our data show that, in patients with unstable angina there is an increase of platelet reactivity in response to ADP/collagen stimulation, which is not related to inflammation.
Adenosine Diphosphate↗
Dose response studies. I. Some design considerations.
A critical aspect of biomedical research is the characterization of the dose response relationship of a compound. This is true in laboratory experiments and clinical trials and pertains to efficacy, safety, and the resulting benefit/risk ratio. Presented here is Part I of this article, which deals with some clinical trial design issues surrounding dose response studies. Some additional comments are made about trials for identifying the minimum effective dose, randomized concentration controlled trials, and the use of one-sided hypotheses in designing such trials. Part II is a separate paper reviewing some analysis strategies for dose response studies.
Cross-Over Studies↗
A sequential trial of pain killers in arthritis: issues of multiple comparisons with control and of interval-censored survival data.
A large clinical comparison of pain killers used in the treatment of arthritis was conducted using a sequential design. The trial presented two major challenges: there were three treatments to be compared, and patients were assessed annually for up to 7 years. Treatment comparisons were made by selecting appropriate pairwise comparisons, to which standard theory could be applied. Rules concerning actions to take in the event of each stopping criterion being reached were evaluated by simulation. The annual assessments were used to create an interval-censored survival time: the year during which "disease progression" first occurred.
Analgesics↗
A multiple comparison procedure to control the strong stagewise family error rate in comparing test treatments and a control.
Multiple comparisons are commonly seen in clinical trials and many other fields. An example, which is the focus of this paper, is the comparison of several test treatments (possibly different doses of a compound) with placebo (control). It is well known that steps must be taken to control the type I error rate when multiple testing is performed. We introduce the concept of the strong stagewise family error rate and propose a multiple comparison procedure to control this error rate. The proposed procedure is compared to Dunnett's step-down procedure when there are two test treatment groups and a placebo group.
Clinical Trials as Topic↗
The use of generalized tests in medical research.
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Humans↗
Problems in the collection of opinion-research data.
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Humans↗
Binary analysis and optimization-based normalization of gene expression data.
MOTIVATION: Most approaches to gene expression analysis use real-valued expression data, produced by high-throughput screening technologies, such as microarrays. Often, some measure of similarity must be computed in order to extract meaningful information from the observed data. The choice of this similarity measure frequently has a profound effect on the results of the analysis, yet no standards exist to guide the researcher. RESULTS: To address this issue, we propose to analyse gene expression data entirely in the binary domain. The natural measure of similarity becomes the Hamming distance and reflects the notion of similarity used by biologists. We also develop a novel data-dependent optimization-based method, based on Genetic Algorithms (GAs), for normalizing gene expression data. This is a necessary step before quantizing gene expression data into the binary domain and generally, for comparing data between different arrays. We then present an algorithm for binarizing gene expression data and illustrate the use of the above methods on two different sets of data. Using Multidimensional Scaling, we show that a reasonable degree of separation between different tumor types in each data set can be achieved by working solely in the binary domain. The binary approach offers several advantages, such as noise resilience and computational efficiency, making it a viable approach to extracting meaningful biological information from gene expression data.
Algorithms↗