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W H Castro

Publications and source records attributed to W H Castro.

At least 19 recordsLinked to original sources
PubMed2004

Investigation of the GSalpha gene in the diagnosis of fibrous dysplasia.

Fibrous dysplasia is a benign fibro-osseous disease of bone and its etiology has been previously established. Activating mutations in the gene that encodes the alpha subunit of stimulatory G protein (G(S)alpha) has been described in monostotic and polyostotic fibrous dysplasia and in the McCune-Albright syndrome. The present report describes a patient with monostotic fibrous dysplasia which diagnosis was confirmed by sequencing of the G(S)alpha gene, demonstrating a heterozygous missense mutation on codon 201 (201C --> T). Due to the high prevalence of G(S)alpha gene mutations in fibrous dysplasia in contrast to other benign and malignant fibrous-osseous lesions, mutational analysis are an additional and helpful parameter for the diagnosis of fibrous dysplasia in selected cases.

Adolescent↗
PubMed2001

No stress--no whiplash? Prevalence of "whiplash" symptoms following exposure to a placebo rear-end collision.

Volunteer studies of experimental, low-velocity rear-end collisions have shown a percentage of subjects to report short-lived symptoms, but the cause of these symptoms remains unknown. It is unclear whether the symptoms arise from biomechanical stress causing injury or from psychological stress causing symptom expectation and anxiety. Similarly, the cause of symptoms remains obscure in virtually all "whiplash" patients because it is impossible to identify acute pathology in many cases. In this study subjects were exposed to placebo collisions that almost completely lacked biomechanical stress. It was highly probable that if the symptoms reported following low-velocity collisions were not due to injury but to other factors (including misattribution of symptoms from other sources), then the proportion of subjects reporting symptoms would be similiar to that reported for volunteers in true (experimental) low-velocity, rear-end collisions. A total of 51 volunteers (33 males and 18 females, mean age 32.4 years) were recruited through local newspaper advertisements. An experimental set-up for a placebo collision was constructed using two standard European cars. At time T0, prior to the placebo collision, a history and physical examination was performed, including a psychological analysis (Freiburger Personality Inventory). A symptom history and physical examination were also performed at time T1, immediately after the placebo collision, and the subjects completed symptom questionnaires 3 days (time T2) and 4 weeks (time T3) after the placebo collision. Data analysis included a determination of the predictive value of psychological data for the presence of symptoms following exposure to a placebo collision. At time T1, 9 out 51 participants (17.6%) indicated symptoms. Within 3 days (time T2) after the placebo collision, 10 (19.6%) of the subjects had symptoms, and within 4 weeks (time T3) 5 subjects (9.8%) had symptoms. Of the last group, two of the five did not relate these symptoms to the "collision". Subjects who endorsed symptoms at time T1 had significantly higher scores on the psychological scale of psychosomatic disorders (measured at time T0). Subjects endorsing symptoms at time T2 had significantly higher scores on emotional instability. There was also a tendency to higher scores on this sub-scale for subjects with whiplash-associated disorders (WAD) at time T3. A discriminant analysis using all four psychological scales from time T0 had a power of 87%, 83% and 92% for correct classification of subjects as asymptomatic times T1, T2 and T3, respectively. Approximately 20% of subjects exposed to placebo, low-velocity rear-end collisions will thus indicate WAD, even though no biochemical potential for injury exists. Certain psychological profiles place an individual at higher risk for phenomenon.

Accidents, Traffic↗
PubMed2001

Glandular odontogenic cyst: absence of PTCH gene mutation.

Glandular odontogenic cyst (GOC) is a rare jawbone cyst of odontogenic origin. Human patched (PTCH) is a tumour suppressor gene that has been recently associated with signalling pathways during odontogenesis. Recently alterations of this gene were found on sporadic odontogenic keratocysts. This evidence, together with the biological behaviour similarities of both lesions, and the absence of reports on molecular analysis of GOC, led us to hypothesize that PTCH gene mutations may underlie the tumorigenesis of GOC. Therefore the aim of this study was to report one additional case of GOC and investigate the PTCH gene of the cyst. No mutations were found in the splicing and coding regions of the PTCH gene. In conclusion, the PTCH gene does not seem to be involved in GOC pathogenesis.

Aged↗
PubMed2001

Juvenile xanthogranuloma: case report with immunohistochemical identification of early and late cytomegalovirus antigens.

Juvenile xanthogranuloma (JXG) is a dermatological condition of unknown etiology that rarely affects the oral mucosa. There are conflicting reports suggesting that it may represent a reactive virally-induced lesion associated with cytomegalovirus (CMV) infection. The present paper reports an additional case of oral JXG and discusses its possible association with CMV infection. The biotin-streptavidin system was used to detect early and late CMV antigens. Positive immunolabelling for both antigens was demonstrated in some histiocytes in the lesion. These findings suggest that JXG may be associated with CMV infection.

Antigens, CD↗
PubMed2000

Noninvasive three-dimensional analysis of cervical spine motion in normal subjects in relation to age and sex. An experimental examination.

STUDY DESIGN: Experimental examination in vivo. OBJECTIVES: To determine the precision of the ultrasound-based Coordinate Measuring System (CMS 50; Zebris Medizintechnik GmbH, D-88316, Isny, Germany) and then to establish a reference range for the active range of motion of the cervical spine in normal test subjects grouped according to age and sex. SUMMARY OF BACKGROUND DATA: Many different devices such as inclinometers, goniometers, potentiometers, computer-aided devices, and radiographic procedures have been developed to examine the range of motion of the cervical spine. All of them have more or less inherent limitations. METHODS: To assess the precision of this examination method, preliminary experiments were performed including intraobserver retest and two-observer repeatability, intraindividual variability, a daily profile, and a comparison between active and passive motions. In the subsequent main experiment 157 persons (86 women and 71 men) were examined during active motion. The sex groups were further subdivided into age groups of 10 years each. A comparison of weight and athletic activity was also performed. RESULTS: The range of motion decreased with increasing age, increasing body weight, and decreasing athletic activity. The rotation in the upper cervical spine increases with age to compensate for the reduced range of motion in the lower levels. Women showed significantly better mobility than men of the same age, only above the age of 70. CONCLUSIONS: The CMS 50 device provides precise reproducible measurements of the active range of motion of the cervical spine in all three planes. Criteria such as age, sex, body weight, and athletic activity influence the range of motion of the cervical spine.

Adult↗
PubMed2000

Pediatric cervicofacial actinomycosis: a case report.

Cervicofacial actinomycosis in children is a rare disorder. This article reports a case in a 7-year-old-girl. The importance of cervicofacial actinomycosis in the differential diagnosis of cervical masses in young patients is emphasized.

Actinomycosis, Cervicofacial↗
PubMed1999

Regional odontodysplasia: an unusual case with a conservative approach.

A case of a 14-year-old male with regional odontodysplasia is reported. In this presentation many atypical clinical and radiographical features of this condition are present. The chief complaint of the patient was the enlargement of the gingiva and, according to the literature, inflammatory processes are the main reason why patients look for care. Moreover, there was no radiographic evidence of unerupted teeth in this report. The functional and psychological benefits of the conservative approach are emphasised.

Adolescent↗
PubMed1999

Cell cycle-associated proteins in melanotic neuroectodermal tumor of infancy.

OBJECTIVE: The purpose of the present study was to compare the immunohistochemical expression of cell cycle-associated proteins in neuroblastic and melanocytic cell populations of melanotic neuroectodermal tumor of infancy. STUDY DESIGN: Three cases of melanotic neuroectodermal tumor of infancy were selected. The immunohistochemical expression of MDM-2, p53, proliferating cell nuclear antigen, cyclin D1, and cyclin A was assessed through use of the streptavidin-biotin-peroxidase complex technique. RESULTS: Positive immunostaining for MDM-2, proliferating cell nuclear antigen, cyclin D1, and cyclin A was occasionally observed in the large melanin-containing epithelioid cells. CONCLUSIONS: These data suggest that MDM-2 expression may be important for the development of melanotic neuroectodermal tumor of infancy and that the melanocytic cell population, not the neuroblastic one, is the proliferative component of the tumor.

Cell Cycle Proteins↗
PubMed1998

Interobserver variance in diagnostic arthroscopy of the knee.

The diagnostic interindividual variance of 91 German and Dutch arthroscopists has been assessed by the Kappa Cohen interobserver variation analysis using a videotape with three complete knee arthroscopies with different pathologies. Non-pathological conditions show a moderate to excellent interobserver correlation, whereas pathological changes often show very little correlation, especially the synovial membrane of the suprapatellar recess, the cartilage of the femuropatellar groove, and the posterior cruciate ligament. The patella alignment also shows a high interobserver variability. There are no apparent differences between German and Dutch arthroscopists. When comparing arthroscopic findings with other imaging techniques the above results should be taken into account because the use of arthroscopy as golden standard is challenged. Furthermore, these results will influence the meaningfulness of medical expert witness based only on pictures. Also the medical cost balance based on arthroscopic findings has to take into account that a wrong diagnosis is possible and therefore charged wrong.

Adult↗
PubMed1998

Immunocytochemistry of fine-needle aspirates from central giant cell granuloma.

Fine needle aspiration biopsy (FNAB) is an important technique in the diagnosis of oral and maxillofacial conditions. We describe here the cytological and immunocytological findings in four patients with central giant cell granuloma. All the aspirates showed mononuclear cells associated with many giant cells. We conclude that immunocytochemical examination of FNAB specimens helps to confirm the provisional clinical diagnosis of central giant cell granuloma.

Adolescent↗
PubMed1998

Multiple calcifying hyperplastic dental follicles.

Multiple calcifying hyperplastic dental follicles is a rare condition characterized by multiple unerupted teeth with abundant calcifications and rests of odontogenic epithelium in their enlarged dental follicles. This article describes an additional example of this condition.

Adolescent↗
PubMed1998

Congenital absence of parotid glands and lacrimal puncta.

Bilateral parotid aplasia and lacrimal puncta are a rare disorder. A case is presented in which the clinical diagnosis was confirmed by ultrasonography. The importance to dentists in early recognition of bilateral parotid aplasia and lacrimal puncta is emphasized.

Child↗
PubMed1997

Do "whiplash injuries" occur in low-speed rear impacts?

A study was conducted to find out whether in a rear-impact motor vehicle accident, velocity changes in the impact vehicle of between 10 and 15 km/h can cause so-called "whiplash injuries". An assessment of the actual injury mechanism of such whiplash injuries and comparison of vehicle rear-end collisions with amusement park bumper car collisions was also carried out. The study was based on experimental biochemical, kinematic, and clinical analysis with volunteers. In Europe between DM 10 and 20 billion each year is paid out by insurance companies alone for whiplash injuries, although various studies show that the biodynamic stresses arising in the case of slight to moderate vehicle damage may not be high enough to cause such injuries. Most of these experimental studies with cadavers, dummies, and some with volunteers were performed with velocity changes below 10 km/h. About 65% of the insurance claims, however, take place in cases with velocity changes of up to 15 km/h. Fourteen made volunteers (aged 28-47 years; average 33.2 years) and five female volunteers (aged 26-37 years; average 32.8 years) participated in 17 vehicle rear-end collisions and 3 bumper car collisions. All cars were fitted with normal European bumper systems. Before, 1 day after and 4-5 weeks after each vehicle crash test and in two of the three bumper car crash tests a clinical examination, a computerized motion analysis, and an MRI examination with Gd-DTPA of the cervical spine of the test persons were performed. During each crash test, in which the test persons were completely screened-off visually and acoustically, the muscle tension of various neck muscles was recorded by surface electromyography (EMG). The kinematic responses of the test persons and the forces occurring were measured by accelerometers. The kinematic analyses were performed with movement markers and a screening frequency of 700 Hz. To record the acceleration effects of the target vehicle and the bullet vehicle, vehicle accident data recorders were installed in both. The contact phase of the vehicle structures and the kinematics of the test persons were also recorded using high-speed cameras. The results showed that the range of velocity change (vehicle collisions) was 8.7-14.2 km/h (average 11.4 km/h) and the range of mean acceleration of the target vehicle was 2.1-3.6 g (average 2.7 g). The range of velocity change (bumper car collisions) was 8.3- 10.6 km/h (average 9.9 km/h) and the range of mean acceleration of the target bumper car was 1.8-2.6 g (average 2.2 g). No injury signs were found at the physical examinations, computerized motion analyses, or at the MRI examinations. Only one of the male volunteers suffered a reduction of rotation of the cervical spine to the left of 10 degrees for 10 weeks. The kinematic analysis very clearly showed that the whiplash mechanism consists of translation/extension (high energy) of the cervical spine with consecutive flexion (low energy) of the cervical spine: hyperextension of the cervical spine during the vehicle crashes was not observed. All the tests showed that the EMG signal of the neck muscles starts before the head movement takes place. The stresses recorded in the vehicle collisions were in the same range as those recorded in the bumper car crashes. From the extent of the damage to the vehicles after a collision it is possible to determine the level of the velocity change. The study concluded that, the "limit of harmlessness" for stresses arising from rear-end impacts with regard to the velocity changes lies between 10 and 15 km/h. For everyday practice, photographs of the damage to cars involved in a rear-end impact are essential to determine this velocity change. The stress occurring in vehicle rear-end collisions can be compared to the stress in bumper car collisions.

Accidents, Traffic↗
PubMed1997

Peripheral dentinogenic ghost-cell tumor: a case report.

The dentinogenic ghost-cell tumor is a rare solid variant of the calcifying odontogenic cyst. Few peripheral cases of this tumor with clinical and radiographic documentation have been reported. A case of peripheral dentinogenic ghost-cell tumor is presented and the literature is reviewed.

Aged↗
PubMed1997

[Interobserver variation in diagnostic arthroscopy of the knee joint. "How really objective are arthroscopic findings?"].

UNLABELLED: We assessed the interindividual diagnostic variance of 39 experienced arthroscopists by the Kappa Cohen interobserver variation analysis using videotapes of eight different patients with different diagnoses. Arthroscopically normal findings showed a relatively acceptable interobserver correlation. Pathological changes, in contrast, often showed very little correlation, especially in the synovial membrane of the suprapatellar recess, in the cartilage of the femoropatellar groove and the posterior cruciate ligament. In patellar alignment there was also great interobserver variation. CLINICAL RELEVANCE: When comparing arthroscopic findings with other imaging techniques the above results should be taken into account. Furthermore, these results will affect the significance of medical expertise based only on pictures. In addition, medical cost billing, which is based on arthroscopic findings, has to take into account that a wrong diagnosis is possible and therefore charges will be wrong.

Adolescent↗
PubMed1996

Accuracy of pedicle screw placement in lumbar vertebrae.

STUDY DESIGN: The location of pedicle screws (n = 42) in four human specimens of the lumbar spine and in 30 patients (n = 131 screws) after lumbar spinal fusion was assessed using computed tomography. OBJECTIVES: To determine the accuracy of pedicle screw placement in lumbar vertebrae and the reproducibility and repeatability of the computed tomography examination. SUMMARY OF BACKGROUND DATA: Failures in the placement of transpedicular screws for lumbar fusion are reported. The evaluation of such screws using computed tomography examination has not been investigated. METHODS: After surgery, the specimens were dissected in transversal slices to observe macroscopically the location of the pedicle screw and to correlate these observations with the computed tomography images. All patients were examined by one observer. To determine the reproducibility and repeatability of the computed tomography examination, two observers studied computed tomography images of 12 patients (n = 58 screws) twice within 3 months. RESULTS: In the specimens, 10 screws were observed to penetrate the medial wall of the pedicle. This correlated fully with the images. In the patients' group, 40% of all screws penetrated the cortex of the vertebra. Of all screws, 29% penetrated the medial wall of the pedicle. From the computed tomography images, it appeared that a deviation of more than 6 mm medially was a high risk for nerve root damage. Three months after his first examination, Observer 1 documented a different position in three of 58 screws (kappa = 0.90). Observer 2 found a different position in eight screws (kappa = 0.65). The comparison between the reviews of the two observers showed a different opinion for the first evaluation, four disagreements (2-4 mm) and 17 disagreements (0-2 mm; kappa = 0.34), and for the second evaluation, four disagreements (2-4 mm) and 12 disagreements (0-2 mm; kappa = 0.43). CONCLUSIONS: Correct placement of transpedicular screws for spinal fusion seems to be more difficult than it looks. The computed tomography scanning is useful for differential diagnosis of postoperative radicular syndromes after lumbar transpedicular fixation.

Bone Screws↗