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Biomedical subjects

S C Kao

Publications and source records attributed to S C Kao.

At least 37 records · Page 2Linked to original sources

Role of M-line proteins in sarcomeric titin assembly during cardiac myofibrillogenesis.

A rat polyclonal anti-M-line protein antiserum and three mouse monoclonal anti-titin antibodies (E2, F3, and A12) were used to study the spatiotemporal relationship between M-line proteins and titin during myofibril assembly in cultured chicken cardiomyocytes by immunofluorescence microscopy. In day 2 cultures, M-line proteins and titin were detected as punctate staining in most cardiomyocytes, which possessed many nonstriated fibrils. At a late stage (day 3 cultures), M-line proteins were incorporated into dot-like structures along nonstriated fibrils, while titin staining was continuous on these structures. As development progressed, M-line proteins were registered in periodic pattern in the mid-A band. In cardiomyocytes from day 5 cultures, the titin bands were separated by an unstained region, and achieved their adult doublet pattern. Thus, the organization of titin in the sarcomere appears to occur later than that of M-line proteins in the M-line. Our morphological data indicate that the early registration of M-line proteins in primitive myofibrils may guide titin filament alignment via interaction between M-line proteins and titin. In order to investigate the role of M-line proteins in the assembly of titin filaments, anti-M-line protein or anti-titin antibodies were introduced into cultured cardiomyocytes by electroporation to functionally bind the respective proteins, and the profile of myofibril assembly was examined. Cardiomyocytes from day 2-3 cultures with incorporated anti-M-line protein antibodies became shrunk, and exhibited defective myofibrillar assembly, as shown by the failure of titin to assemble into a typical sarcomeric pattern. Incorporation of anti-titin antibody E2, which recognizes the M-line end domain of titin, resulted in the failure of M-line proteins organized into the M-line structure, as shown by random, sporadic staining with anti-M-line protein antibody. These studies confirm the essential role of M-line proteins in the organization of titin filaments in the sarcomere and that the interaction between titin and M-line proteins is crucial to the formation of the M-line structure.

Animals↗

Cervical spine abnormalities and instability with myelopathy in warfarin-related chondrodysplasia: 17-year follow-up.

A patient with warfarin embryopathy developed progressive cervical spinal myelopathy owing to bony cervical spinal damage. While there are several descriptions of warfarin embryopathy, the long-term complication of cervical spinal instability has not been reported. This cervical instability may, as in our patient, cause severe neurological dysfunction or even sudden death; therefore, it is important that pediatric radiologists should be alert to this condition.

Abnormalities, Drug-Induced↗

Radiologic volumetry on a personal computer with a stereologic method.

RATIONALE AND OBJECTIVES: There is no universally accepted way to estimate organ and tumor volumes, and manual tracing of the outline of an organ or tumor is tedious, time-consuming, and therefore not widely used. The authors developed a stereologic method for estimating organ and tumor volumes with a personal computer and evaluated its accuracy and efficiency with computed tomographic images. MATERIALS AND METHODS: CT images were obtained of a 200-cm3 phantom sphere, a normal liver, a normal spleen, a brain tumor, and a large abdominopelvic tumor. Volumes were estimated with a computer program developed on a personal computer. The estimated volumes were compared with those found with the manual tracing method, which was used as a standard of reference. The time to complete each procedure was recorded. RESULTS: When approximately 200 grid points were used, the volumes estimated with the computer were varied from the reference by 1.9%-4.5%. The volumes ranged from 51 to 2,679 cm3, and the time to estimate these ranged from 42 to 96 seconds. CONCLUSION: Stereologic estimation of organ and tumor volumes from cross-sectional images with a personal computer can be accurate and efficient at a relatively low cost.

Abdominal Neoplasms↗

Oncocytic adenomatous hyperplasia of the lacrimal sac: a case report and review of the literature.

Oncocytic tumors of the lacrimal sac are very rare, with only 21 cases documented in the world literature. The authors report a 75-year-old woman who sought treatment for recurrent dacryocystitis and a palpable mass in the left medial canthal area. The patient underwent surgery for removal of a suspected lacrimal sac cancer, but pathologic findings indicated benign oncocytic adenomatous hyperplasia. Complete removal of the tumor and long-term follow-up are necessary in patients with lacrimal sac oncocytic lesions. The authors discuss the characteristic features of ocular adnexal oncocytic lesions and review the literature.

Adenocarcinoma↗

Gastric volvulus and wandering spleen.

Although rare in childhood, gastric volvulus and wandering spleen share a common etiology: congenital absence of intraperitoneal visceral attachments. We report an unusual case of a patient who presented with three episodes of intractable vomiting and abdominal mass but no abdominal pain. A diagnosis could not be made until the third episode because the gastric volvulus resolved each time on placement of a nasogastric (NG) tube before any further tests could be done. During the third episode, diagnostic imaging was performed before inserting an NG tube, and the diagnosis of a mesenteroaxial gastric volvulus and an abnormally positioned spleen was made. Although both conditions are caused by abnormalities of fixation, the association of gastric volvulus and wandering spleen has been reported only once before.

Child, Preschool↗

A quick method to extract DNA from paraffin-embedded tissues.

BACKGROUND: The amplification power of the polymerase chain reaction (PCR) technique has had great impact in molecular analysis, and DNA extraction is a common requirement in retrospective studies utilizing PCR as a tool. Conventional methods used in deparaffinization, harvesting and purification of DNA from paraffin-embedded tissue are time consuming and cause a significant loss in the yield of DNA. METHODS: We utilized heating-melting-cooling removal of paraffin, digestion of the sample with proteinase K and purification of the extracted DNA by a microconcentrator. The products, after PCR amplification of the p53 gene exon 8, were used to make a comparison between our method and the conventional xylene-phenol-choloform method. RESULTS: The amplified products from our method were superior to that of the conventional method. CONCLUSION: The method we propose has a better recovery of DNA and is more time efficient.

DNA↗

A review of ocular emergencies in a Taiwanese medical center.

BACKGROUND: Ocular injury is one of the most common problems in the Emergency Department (ED), but a general survey of ocular injuries has rarely been reported in the literature. This article reviews cases of ocular injury collected in the ED of a medical center over a 12-month period. METHODS: A retrospective analysis was done on 1,314 consecutive patients who presented with eye complaints to the ED of the Veterans General Hospital-Taipei between November 1993 and October 1994. Common ocular diagnoses and their associated variables were assessed separately. RESULTS: Ocular injuries occurred in a male to female ratio of about 1.9:1 with a peak age in the third decade. Diagnoses were grouped as trauma (43.8%) and non-trauma (56.2%). Corneal abrasion was the most common trauma reported. The main circumstances of eye trauma were play (50.0%) in children (< 15 years), work (37.1%) in the age group of 16 to 59 years and domestic activity (45.8%) in patients over 60 years of age. Blunt objects and contusions (hits or falls) caused nearly 50% of all ocular injury cases. Most of the non-traumatic cases were due to acute conjunctivitis (19.1%), followed by contact lens (CL)-related disorders (11.4%). Three cases of CL-induced corneal ulcer resulted in permanent visual morbidity. There was a trend toward an increase in acute conjunctivitis in the summer, corneal ulcer in the spring and acute glaucoma in the winter. CONCLUSIONS: Young males were found to run a higher risk of ocular accidents, especially at work. Penetrating injuries with or without a retained intraocular foreign body were the leading cause of poor visual outcomes and often occurred in patients without protective eyeglasses. With the widespread use of CLs, many potentially serious complications were noted in the ED, which deserve attention.

Adolescent↗

Astigmatic change following congenital ptosis surgery.

BACKGROUND: High astigmatism is frequently associated with congenital ptosis. Ptosis surgery itself may also induce astigmatic refractive change that will cause amblyopia in young children. The purpose of this study was to assess postoperative astigmatic change and the effect of different ptosis surgical procedures on astigmatism. METHODS: An analysis of 63 consecutive surgical cases of congenital ptosis was conducted. The preoperative incidences of anisometropia, amblyopia, strabismus and high astigmatism were evaluated. All patients underwent levator resection or received frontalis sling. The postoperative astigmatic change after the follow-up period of 12 months was assessed in 28 patients. It included a total of 40 ptotic eyelids from 12 bilateral and 16 unilateral cases of ptosis. The eyes on the contralateral side in unilateral cases served as the control group. RESULTS: In 63 cases of congenital ptosis, 30.2% (19/63) were associated with anisometropia and 39.7% (25/63) with amblyopia, and 11.1% (7/63) were combined with strabismus. Most cases of amblyopia were associated with high astigmatism (64%). The incidence of high astigmatism (> 2.5 diopters, D) in congenital ptosis was 25.3%. Of 40 ptotic eyelids included for the study of postoperative astigmatism change, 15% showed an increase of more than 0.5 D, whereas 27.5% showed a decrease of more than 0.5 D, and no significant change was observed in 57.5%. An average decrease of 0.18 D in astigmatism was observed, while no statistical difference was found between the study group and the control group for astigmatic change. Moreover, both the levator resection and frontalis sling groups showed a decrease in average cylinder, and again, demonstrated no statistically significant difference in astigmatic change. CONCLUSIONS: A high incidence of amblyopia was associated with astigmatism in congenital ptosis. Postoperative astigmatic study also revealed some change in astigmatic power, but no new cases of amblyopia developed after ptosis surgery. Patients with congenital ptosis should have cycloplegic refraction as soon as possible, and long-term postoperative refraction check-up is also recommended.

Adolescent↗

Dacryocystorhinostomy with intraoperative mitomycin C.

PURPOSE: To observe the effect of intraoperative mitomycin C on the size of the osteotomy site after dacryocystorhinostomy.: METHODS: A total of 15 eyes of 14 patients diagnosed with primary acquired nasolacrimal duct obstruction were assigned randomly to either a mitomycin C group or a control group. The surgical procedures in both groups were exactly the same, except that in the patients in the mitomycin C group, a piece of neurosurgical cottonoid soaked with 0.2 mg/ml mitomycin C was applied to the osteotomy site and then after 30 minutes was removed transnasally. Nasoendoscopic findings were recorded at the completion of the surgery and at 1 month, 3 months, and 6 months after surgery for the two groups. A computer-aided digitizer was used to calculate the surface area of the osteotomy site, and a Student's t test was used to compare the difference between the two groups. RESULTS: All patients in the mitomycin C group remained symptom free after removal of their silicone tube (100% success), and there was one patient in the control group who had recurrent epiphora (87.5% success). Septo-osteotomy adhesion was found in two patients in the control group (25%), but there was no such adhesion found in the patients in the mitomycin C group. In the mitomycin C group, the average final surface area of the osteotomy at the end of the sixth postoperative month was 27.10 +/- 5.78 mm2, whereas that of the control group was only 10.83 +/- 3.37 mm2. Although the immediate postoperative surface area of the osteotomy showed no significant difference between the two groups, a statistically significant difference was noted at 6 months. CONCLUSION: Intraoperative mitomycin C is effective in maintaining a larger osteotomy size. This modification may possibly improve success rates over the traditional dacryocystorhinostomy procedure.

Chemotherapy, Adjuvant↗

Relationships of orbital computed tomographic findings and activity scores to the prognosis of corticosteroid therapy in patients with Graves' ophthalmopathy.

To elucidate the relationships of orbital computed tomographic findings and activity scores to the prognosis of corticosteroid therapy in patients with Graves' ophthalmopathy, 22 cases were treated with corticosteroid. Orbital computed tomographic was performed before treatment and the maximal muscle areas of rectus muscle bellies were calculated from the coronal images. Activity scores were calculated according to the recommendations of an international ad hoc committee. The clinical severity of the eye disease was based on the NOSPECS classification. Observation of the effectiveness of treatment at 6 months allowed patients to be classified into good responders or poor responders. Twelve of 22 patients (54.5%) belonged to the good responders. The total muscle areas were less in good responders. Although the total muscle areas were significantly correlated with the activity scores, no difference in the activity scores was noted between these two groups. We concluded that although activity score seems to be a predictor of initial responsiveness to anti-inflammatory drugs, the maximal muscle area is a prognostic factor of corticosteroid therapy in patients with Graves' ophthalmopathy.

Adult↗

Skeletal injuries in the pediatric patient.

Immature skeleton is different from adult skeleton with unique vulnerability to acute and chronic injuries at the growth plate. Recognition and differential diagnosis of inflicted skeletal injury are important. Familiarity with the dynamic changes of growing skeleton in normal children is key to the recognition of pathologic states.

Acute Disease↗

Imaging techniques in the diagnosis of gastrointestinal and hepatic disease.

Abdominal imaging continues to grow in importance for diagnosis, anatomic staging, and functional analysis of gastrointestinal ailments. In this review, we attempt to delineate those publications, both original investigations and summary articles, that have advanced our understanding of abdominal imaging in infants and children. Special attention is given to the newer modalities that provide previously unavailable methods to analyze abnormalities. These include Doppler ultrasonography and magnetic resonance imaging as well as CT for abdominal trauma. Interventional radiology techniques useful for treatment of gastrointestinal diseases are also discussed.

Child↗

Postoperative care following single-stage laryngotracheoplasty.

Single-stage laryngotracheoplasty (SSLTP) provides a method of correcting mild-to-moderate laryngotracheal stenosis while avoiding the risks of prolonged laryngeal stenting. Pediatric patients are orally intubated for 5 to 7 days postoperatively to ensure an adequate airway while edema resolves and healing begins. During this period, continuous neuromuscular blockade has been advocated in infants and young children to avoid endotracheal tube trauma to the fresh graft and potentially life-threatening accidental decannulation. Pulmonary atelectasis is the most common morbidity associated with prolonged neuromuscular blockade. Neuromuscular weakness also may follow prolonged paralysis and prolong hospitalization. This paper compares the postoperative course of 17 patients who underwent 18 SSLTP procedures by the senior author. The first 8 patients received continuous neuromuscular blockade in the early postoperative period. To reduce perceived morbidity, the last 9 patients were managed with a protocol that incorporated daily 4- to 8-hour "interruptions" of paralysis. Seven patients tolerated this protocol modification. As a group, these patients had less postoperative pulmonary atelectasis prior to extubation (p < .05) and were extubated sooner than patients receiving continuous neuromuscular blockade (p<.05) without compromising the surgical success of the procedure. Intermittent paralysis permitted for more accurate assessment of pain control and protected against accidental drug accumulation. Although self-extubation did not occur, diligent nursing care with adequate sedation and analgesia is necessary to avoid the risk of accidental extubation.

Child↗

Duplex Doppler sonography of changes in portal vein flow in healthy term newborn infants after feeding.

To establish reference values for changes in portal venous diameter, angle- corrected maximal flow velocity, and flow in healthy term newborn infants after formula feeding, we studied 20 subjects using duplex Doppler sonography. After feeding, portal venous diameter increased from 3.6 +/- 0.1 (mean +/- standard error of the mean) to 3.9 +/- 0.1 mm at 15 min and decreased to 3.8 +/- 0.1 at 60 min. Maximal flow velocity increased from 24.1 +/- 1.3 cm/s to a maximum of 35.9 +/- 2.4 cm/s at 15 min and decreased to 28.8 +/- 1.5 cm/s at 60 min. Flow increased from 85.0 +/- 7.5 ml/min to a maximum of 153.6 +/- 14.9 ml/min at 15 min with decrease similar to the maximal flow velocity curve. We conclude that formula feeding produces peak portal blood flows of nearly twice the fasting values at 15 min after feeding and returns almost to fasting value by 60 min.

Eating↗