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B Soong

Publications and source records attributed to B Soong.

10 recordsLinked to original sources

Fetal endoscopic telesurgery using an Internet Protocol connection: clinical and technical challenges.

Until recently, fetoscopic laser surgery to seal the placental anastomoses that cause severe twin-to-twin transfusion syndrome has been available in only a few centres worldwide. The technique typically takes a long time to learn. We have used a dedicated Internet Protocol (IP) connection for tele-education to assist the introduction of fetoscopic laser surgery to Australia. During the implementation of the international telemedicine link, there were multiple clinical and technical problems, which were eventually overcome. The quality of images and of video-sequences was comparable to that supported by an ISDN connection. Pictures of live surgery performed by an expert in Florida, USA, were transmitted and viewed by a novice team in Brisbane, Australia. The Australian team has performed 19 fetoscopic laser operations to date. Preliminary results are comparable to those from centres that have performed over 100 procedures.

Australia↗

Randomized comparison of the quality of realtime fetal ultrasound images transmitted by ISDN and by IP videoconferencing.

We compared the quality of realtime fetal ultrasound images transmitted using ISDN and IP networks. Four experienced obstetric ultrasound specialists viewed standard recordings in a randomized trial and rated the appearance of 30 fetal anatomical landmarks, each on a seven-point scale. A total of 12 evaluations were performed for various combinations of bandwidths (128, 384 or 768 kbit/s) and networks (ISDN or IP). The intraobserver coefficient of variation was 2.9%, 5.0%, 12.7% and 14.7% for the four observers. The mean overall ratings by each of the four observers were 4.6, 4.8, 5.0 and 5.3, respectively (a rating of 4 indicated satisfactory visualization and 7 indicated as good as the original recording). Analysis of variance showed that there were no significant interobserver variations nor significant differences in the mean scores for the different types of videoconferencing machines used. The most significant variable affecting the mean score was the bandwidth used. For ISDN, the mean score was 3.7 at 128 kbit/s, which was significantly worse than the mean score of 4.9 at 384 kbit/s, which was in turn significantly worse than the mean score of 5.9 at 768 kbit/s. The mean score for transmission using IP was about 0.5 points lower than that using ISDN across all the different bandwidths, but the differences were not significant. It appears that IP transmission in a private (non-shared) network is an acceptable alternative to ISDN for fetal tele-ultrasound and one deserving further study.

Computer Communication Networks↗

Metabolic characterization of spinocerebellar ataxia type 6.

BACKGROUND: Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disorder characterized by slowly progressive ataxia and dysarthria. The mutational basis is an expanded CAG repeat sequence within the coding regions of the CACNL1A4 gene. Basic clinical, neuroimaging, and pathological, and epidemiological features have been described in the literature. However, the metabolic features of SCA6 have not been elucidated. OBJECTIVE: To investigate the metabolic features of SCA6. PATIENTS AND METHODS: Seven patients with SCA6 and 7 healthy individuals underwent positron emission tomography using fluorodeoxyglucose F 18. RESULTS: Cerebral glucose utilization in the 7 patients with SCA6 was characterized by significant hypometabolism in widespread structures, including cortical regions and basal ganglia, as well as the cerebellar hemispheres and brainstem. CONCLUSIONS: The results of the multiple-regional brain hypometabolism suggest that brain dysfunction associated with SCA6 may not be limited to the cerebellum and inferior olive, as previously suggested by the results of other pathologic studies.

Adult↗

Realtime fetal ultrasound by telemedicine in Queensland. A successful venture?

We have established a realtime fetal tele-ultrasound consultation service in Queensland, which has been integrated into our routine clinical practice. The service, which uses ISDN transmission at 384 kbit/s, allows patients in Townsville to be examined by subspecialists in Brisbane, 1500 km away. For the 90 tele-ultrasound consultations performed for the first 71 patients, 90% of the babies have been delivered, and outcome data have been received on all the pregnancies. All significant anomalies and diagnoses have been confirmed. The referring clinicians would have physically referred 24 of the 71 patients to Brisbane in the absence of telemedicine. A crude cost-benefit calculation suggests that the tele-ultrasound service resulted in a net saving of A$6340, and at the same time enabled almost four times the number of consultations to be carried out.

Cost-Benefit Analysis↗

Paroxysmal kinesigenic dyskinesia and infantile convulsions: clinical and linkage studies.

OBJECTIVE: To clinically characterize affected individuals in families with paroxysmal kinesigenic dyskinesia (PKD), examine the association with infantile convulsions, and confirm linkage to a pericentromeric chromosome 16 locus. BACKGROUND: PKD is characterized by frequent, recurrent attacks of involuntary movement or posturing in response to sudden movement, stress, or excitement. Recently, an autosomal dominant PKD locus on chromosome 16 was identified. METHODS: The authors studied 11 previously unreported families of diverse ethnic background with PKD with or without infantile convulsions and performed linkage analysis with markers spanning the chromosome 16 locus. Detailed clinical questionnaires and interviews were conducted with affected and unaffected family members. RESULTS: Clinical characterization and sampling of 95 individuals in 11 families revealed 44 individuals with paroxysmal dyskinesia, infantile convulsions, or both. Infantile convulsions were surprisingly common, occurring in 9 of 11 families. In only two individuals did generalized seizures occur in later childhood or adulthood. The authors defined a 26-cM region using linkage data in 11 families (maximum lod score 6.63 at theta = 0). Affected individuals in one family showed no evidence for a shared haplotype in this region, implying locus heterogeneity. CONCLUSIONS: Identification and characterization of the PKD/infantile convulsions gene will provide new insight into the pathophysiology of this disorder, which spans the phenotypic spectrum between epilepsy and movement disorder.

Adolescent↗

Clinical value of real-time tertiary fetal ultrasound consultation by telemedicine: preliminary evaluation.

Congenital fetal abnormalities are major causes of perinatal mortality and morbidity. The performance of ultrasound in the diagnosis and assessment of fetal anomalies varies enormously between tertiary referral centers and general units. Telemedicine offers a chance for tertiary realtime ultrasound consultations using standard telephone lines for remote sites. Preliminary investigations by our group have shown that real-time transmission of fetal ultrasound images over long distances via telephone (integrated systems digital network [ISDN]) lines is technically feasible. A live link of up to 2 Mb/s was established between Mater Mothers Hospital in Brisbane and Kirwan Hospital for Women in Townsville, which are 1,500 km apart. The objective of the current study was to evaluate the clinical value of a tertiary teleultrasound consultation service. Patients requiring tertiary ultrasound consultations were recruited from North Queensland. Clinicians from the referral site established an initial diagnosis and management plan. Using standard ISDN lines, the real-time ultrasound images were transmitted to the maternal fetal medicine subspecialists in Brisbane. The ultrasound examination was completed under the direction of the subspecialist. The subspecialist explained the findings to the patient at the end of the session, and discussed the diagnosis and management plans with the clinicians involved. Any diagnosis and management variations were classified into minor and major upon agreement by the two teams of clinicians involved. The clinicians and patients in Townsville rated the value of the consultation, and the subspecialists rated the confidence of their diagnoses on five-point scales. Pregnancy outcomes were obtained and the data analyzed. Over a 3-month period, 24 teleultrasound consultations were carried out. The indications for referral were: assessment of growth restriction/fetal wellbeing in the third trimester (6); detailed assessment for high-risk patients (5); evaluation of markers for anomalies (5); isolated fetal anomalies (1); and complex fetal problems such as twin/twin transfusion, multiple anomalies, etc. (7). Overall, the consultations resulted in some modifications to the clinical diagnosis in 45.8% of the cases, and modifications to the management plan in 33.3% of the cases (about half of which were minor variations). The clinicians rated the teleconsultations highly (mean rating 4.7, SD 0.44). The patients also rated the consultations highly, and were comfortable that their privacy and confidentiality were maintained during the consultation. The subspecialists were confident in making their diagnoses by telemedicine (mean score for confidence 4.2, SD 0.43). All the pregnancies have now been completed, with all antenatal diagnoses confirmed to be correct postnatally. Tertiary real-time ultrasound consultation by telemedicine is not only technically feasible, it is welcomed by the clinicians and patients involved. It also contributes to diagnostic and management differences. Larger scale clinical trials are needed to evaluate the true benefits and costs involved. The social benefits in bridging the healthcare gap between the country and the city, and in enabling patients in remote areas to stay close to their family under times of stress is well recognized by all involved.

Congenital Abnormalities↗

The development of clinical indicators--the impact on midwifery practice in Queensland in the future.

Perineal trauma is the most frequently reported complication of labour and delivery in the Qld Perinatal Data Collection. It is documented that some individual accoucheurs seem to be particularly skillful in assisting at birth in a way that minimises perineal trauma. Recent trends within the Qld health industry have emphasised the importance of quality improvement activities focussing on health outcomes. Midwives accoucheur most of the "normal" deliveries in public hospitals, thus it is important that midwives play a leading part in the development and improvement of tools which identify quality outcomes and pinpoint areas for improvement. This study aims to benchmark current practices regarding perineal outcomes. Moreover, the authors aim to initiate discussion towards the development of the first clinical indicators appropriate to midwifery care.

Adult↗

Minimum requirements for remote realtime fetal tele-ultrasound consultation.

We studied the transmission bandwidth required for accurate diagnoses when performing realtime fetal tele-ultrasound consultations. The study was divided into three phases. In phase I, three experienced clinicians evaluated the quality of ultrasound images transmitted at various bandwidths (internally looped back within Brisbane) using eight commercially available codecs at random. The two codecs that performed best proceeded to phase 2, in which a realtime video-link of up to 2 Mbit/s was set up between Brisbane and Townsville (1,500 km apart). Testing with a standard video-tape was performed at seven different bandwidths selected at random, with four clinicians (who were blinded to the equipment and bandwidths used). The optimum line rates for transmission were determined, and testing was then performed using these line rates for fetuses with various anomalies (phase 3). The results showed significant differences in performance according to bandwidths used, but not according to observers. Bandwidths were grouped into three levels. At level I (256 kbit/s) the performance was significantly worse than at level II (384, 512 or 768 kbit/s), which was in turn worse than that at level III (1, 1.5 or 2 Mbit/s). However, within each level, performance at one bandwidth was not significantly different from that at the others. The most cost-effective transmission rates therefore appeared to be 384 kbit/s and 1 Mbit/s. Further testing with fetuses affected by various anomalies confirmed that the majority could be diagnosed using a 384 kbit/s link, with slight improvement in evaluation when the bandwidth was increased to 1 Mbit/s.

Analysis of Variance↗

Machado-Joseph disease: clinical, molecular, and metabolic characterization in Chinese kindreds.

Machado-Joseph disease, an autosomal dominant multisystem motor degeneration, has been described mainly in people of Portuguese descent. Our report documents the presence of Machado-Joseph disease in the Chinese population, based on the specific molecular marker of a CAG repeat array in the 3' end of the MJD gene. We screened 21 Chinese families with dominant spinocerebellar ataxia. The results showed that Machado-Joseph disease with CAG expansion accounted for 52% of families with autosomal dominant cerebellar ataxia in this series. The clinical characteristics, besides the well-documented cerebellar ataxia, dysarthria, nystagmus, corticospinal dysfunctions, a variable degree of facial muscle fasciculation, and proprioceptive loss, included loss of optokinetic nystagmus and autonomic nervous system dysfunction. The CAG repeat number in the MJD gene ranged from 14 to 39 among normal alleles, and from 63 to 81 among MJD alleles. There was a strong inverse correlation (gamma = -0.77) between number of CAG repeats and age at symptom onset, accounting for 60% of the variance of age at onset. A strong clinical anticipation of age at onset existed in successive generations. Mild instabilities of expanded CAG repeat numbers during meiotic transmission occurred, with no significant difference according to the gender of the transmitting parent. Finally, brain metabolism in Machado-Joseph disease, studied with positron emission tomography, was characterized by significant progressive regional hypometabolism in the occipital cortex, as well as the cerebellar hemispheres, vermis, and brainstem.

Adult↗

Clinical spectrum of Niemann-Pick disease type C.

Analysis of the neurologic symptomatology in 22 patients with Niemann-Pick disease type C revealed 3 phenotypes: (1) an early-onset, rapidly progressive form associated with severe hepatic dysfunction and psychomotor delay during infancy and later with supranuclear vertical gaze paresis, ataxia, marked spasticity, and dementia; (2) a delayed-onset, slowly progressive form heralded by the appearance, usually in early childhood, of mild intellectual impairment, supranuclear vertical gaze paresis, and ataxia, and later associated with dementia and, variably, seizures and extrapyramidal deficits; (3) a late-onset slowly progressive form distinguished from the 2nd pattern by later age of onset (adolescence or adulthood) and a much slower rate of progression. The existence of the 1st and 2nd phenotypes within the same sibship suggests that they are variant expressions of the same clinicopathologic disorder. Niemann-Pick disease type C should be considered not only in infants and children who present with organomegaly and a progressive neurodegenerative course, but also in adolescents and adults who have insidiously progressive neurologic dysfunction and only slight organomegaly. Associated with the disease is a marked deficiency in the ability of cultured fibroblasts to esterify exogenously supplied cholesterol. Assay of this deficiency is particularly useful for confirming the diagnosis in patients with atypical presentation.

Adolescent↗