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Biomedical subjects

C C Chuang

Publications and source records attributed to C C Chuang.

At least 19 recordsLinked to original sources

Enhancement of drug sensitivity of human malignancies by epidermal growth factor.

We have previously shown that epidermal growth factor (EGF) enhances the in vitro and in vivo sensitivity of human ovarian carcinoma 2008 cells to cisplatin. EGF was found to enhance selectively the in vivo toxicity of cisplatin to 2008 cell xenografts without altering the toxicity of cisplatin to non-malignant target tissues such as the kidney or bone marrow. We now show that recombinant human EGF (rhEGF) enhances the cisplatin sensitivity of cell lines representative of many other types of malignancies in addition to ovarian carcinoma, including cancers of the head and neck, cervix, colon, pancreas and prostate, as well as non-small-cell carcinoma of the lung. In addition, rhEGF was found to sensitise cells to other platinum-containing drugs and several other classes of chemotherapeutic agents. rhEGF sensitised 2008 cells not only to cisplatin, but also to carboplatin and tetraplatin, as well as taxol, melphalan and 5-fluorouracil. We conclude that modulation of drug sensitivity by rhEGF is observed in cell lines representative of many human malignancies and for multiple classes of chemotherapeutic agents, indicating that it alters one or more components of the cellular damage response that are both common between cell lines and classes of drugs and fundamental to survival.

Antineoplastic Agents

Double-rib composite free transfer to reconstruct a single-spared lower extremity defect.

The case of a 43-year-old man is reported in which a 15-cm defect of the tibia sustained 8 months previously was treated by the double-rib composite microvascular free transfer. The fracture site united, and the grafted ribs showed some hypertrophy at 1 year. He returned to his job. At 5 years follow-up, the x-ray film showed good hypertrophy of the grafted ribs.

Adult

[Impact of exercise on athlete's cardiac muscle evaluated by Troponin T test].

Twenty-four nursing college students ages 16 to 17 Year were selected as research subjects and divided into two group. Group A comprised 12 individuals who were trained for short distance running (5KM/day) over a five week period, while Group B was trained for middle distance running (7KM/day) during the same period. Breathing frequency, blood pressure, pulse rate and body surface skin temperature were measured at rest (before training) and after exercise every week. Troponin T (TnT). Creatin kinase (CK), Creatine kinase -MB (CK-MB), and Lactate Dehydrogenase (LDH) tests were performed using blood samples and were used as indicators of the impact on heart muscle during exercise. There were no significant differences in breathing frequency, blood pressure, pulse rate or body surface skin temperature between groups A and B before or after training. After one week, the CK levels in both group were higher after exercising than before the training program had begun, and there were significant differences (P < 0.05) between the two groups. Thenceforth, the CK levels in group A decreased to the normal values and stayed the same throughout the fifth week. The CK levels in group B decreased to the normal value after training for three weeks, and there were significant differences between the values before exercising and those for the forth and fifth weeks of training. Although the levels of CK-MB, LDH, and Troponin-T increased after training, all were within the normal range, and no significant difference was observed before or after five weeks of training.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Torsion of an ovarian borderline tumor with extreme serum tumor markers: a case report.

A postmenopausal woman with torsion of the left ovarian mucinous cystadenoma with borderline malignancy is reported. Extremely elevated serum tumor markers such as carcinoembryonic antigen (CEA) (398.0 ng/mL, normal < 3.0 ng/mL), carbohydrate antigen 19-9 (CA 19-9) (240 U/mL, normal < 37 U/mL) and tissue polypeptide antigen (TPA) (1,918 U/L, normal < 110 U/L) were found preoperatively. Imaging studies such as ultrasound and computed tomogram favored a diagnosis of ovarian malignancy, and advanced ovarian cancer was suspected prior to operation. Diagnosis of borderline malignancy was first made by frozen section during laparotomy. The patient recovered following simple total hysterectomy and bilateral salpingo-oophorectomy. Serum levels of the tumor markers became normal gradually following operation. To present knowledge, this is the first reported case with extremely high serum tumor markers in a postmenopausal woman with torsion of a stage-Ia ovarian mucinous cystadenoma of borderline malignancy. Rapid release of these tumor markers into circulation secondary to necrosis and degeneration of the tumor cells following torsion might account for such an unusual finding.

Aged

Distal phalanx replantation.

Microsurgical replantation has been attempted in the distal phalanx of the digits. Twenty-three complete, single digit amputations are reviewed. The patients' ages ranged from 9 months to 48 years. Viability was 78%. Sensory recovery averaged 7 mm static two-point discrimination. Range of motion in the distal interphalangeal joint of the finger and the interphalangeal joint of the thumb averaged 64 and 51 degrees, respectively. Eight of the 17 successfully replanted digits had mild to moderate atrophy. Eighty-two percent of patients were able to use the replanted digit successfully in their daily work. We feel that distal digital replantation is rewarding. In successful cases, it always preserves acceptable function and good appearance at a price of an average of 2.3 months off work.

Adolescent

Selection of recipient vessels for free flaps to the distal leg and foot following trauma.

The recipient vessels are of prime importance in free flap transfers to the lower limbs. To determine the incidence and pattern of vascular trauma, a study was carried out in 126 patients who had Gustillo Type III open fractures of the distal legs and feet that required free flaps for wound coverage. In comparison with the posterior tibial artery, the anterior tibial artery has a much higher incidence of injury with more extensive damage. It can be injured at a more proximal level than estimated from gross inspection during surgery. This should be borne in mind when the anterior tibial artery is selected as the recipient artery in order to prevent reexploration and failure of the flaps. However, the posterior tibial artery is much less vulnerable to damage in most injuries and is more reliable as the recipient artery. In this series there was no problem in finding proper recipient veins in the legs. A general principle is proposed for selecting recipient vessels in crushed legs, with a warning against the pitfalls that have been encountered.

Adolescent

Miniature plates and screws in acute complex hand injury.

Thirty-six patients with 72 metacarpal and phalangeal fractures with associated injuries to the neurovascular bundle, tendon, soft tissue, or bone following acute complex hand injury were treated with miniature plates and screws and reconstruction of the disrupted and missing structures. The results were judged according to the criteria of the American Society for Surgery of the Hand. The overall results were good in 46.3%, fair in 32.2%, and poor in 21.5%. Although traditional wiring techniques are certainly useful in complex hand injuries, internal osteosynthesis with miniature plates and screws has definite indications in cases requiring stable and rigid internal fixation.

Adult

Microsurgical thumb reconstruction with toe transfer: selection of various techniques.

Microsurgical toe transfer is an established method for reconstruction of missing thumbs. However, there is little agreement on which of the various techniques represents the ideal transfer. Basically, selection of technique requires balancing the patient's functional needs, appearance of the reconstructed thumb, and donor-site cosmesis. Based on our experience with 103 toe-to-thumb transfers performed over the past 9 years, this paper attempts to provide guidelines for appropriate selection among the four most commonly employed toe transfer techniques (e.g., second toe, total great toe, great toe wrap-around, trimmed great toe) so that optimal results and patient's acceptance can both be achieved.

Adolescent

[Physiological changes in the metabolism of football trainees following a match under high temperature].

The effects of a football match on the muscle metabolism of long-term football players were studied. Twenty-two senior high school students (Age: 16.95 +/- 0.82 y/o) were divided into two groups. Group A, included the subjects with longer histories of playing football (7 years) and group B were those with a shorter histories (6 years). There was no statistical difference between the two groups (p > 0.05). The temperature of all muscles tested showed statistical differences after exercise (p < 0.05). After 24 hours, all muscles except the gluteus maximus returned to the normal state while the skin temperature of the latissimus dorsi did not have any change. Body temperature, pulse rate, respiratory rate, and diastolic pressure all significantly increased immediately after the match (p < 0.05) and they all returned to their normal resting rate within one hour, except the body temperature, which required two hours to return to normal. A comparison between groups A and B showed a significant difference (p < 0.01) in creatine kinase level immediately and one hour after the match. It is inferred that energy is derived from the aerobic system.

Adolescent

Reconstruction of four damaged or destroyed ipsilateral fingers with free toe-to-hand transplantations.

Three patients with traumatic partial or complete loss of all ipsilateral digits, excluding the thumb, were reconstructed with free microvascular toe transplantations for all involved digits. In two cases, two pairs of combined second and third toe transplantations were utilized; in the third case, four separate toes were employed. Clinical follow-up was 8 1/2 years, 2 years, and 1 2/3 years. Detailed functional analysis was performed. All patients except the first had initially undergone reconstruction of only two digits and had requested a second procedure to transfer two additional toes. While reconstruction of the thumb and two opposing digits is adequate in most cases, selected patients may benefit from the additional two digits, especially with respect to improving hook grip.

Adolescent

Functional and esthetic reconstruction of a mutilated hand using multiple toe transfers and iliac osteocutaneous flap: a case report.

With reconstructive microsurgical techniques, some previously hopelessly mutilated hands have become reconstructable. The functional and esthetic results of such hands can be improved to an acceptable degree with through prereconstruction evaluation and planning. This case report demonstrates the approach to reconstruction of a mutilated hand using the following: a pedicle groin flap for soft tissue reconstruction of the first web space and the amputation stump of the thumb; a combined second and third toe transfer for reconstruction of opposable fingers at the amputated index and middle finger stumps; a single second toe for reconstruction of the thumb, and an iliac osteocutaneous flap for reconstruction of the ulnar border of the palm.

Accidents, Occupational

Microsurgical reconstruction of distal digits following mutilating hand injuries: results in 121 patients.

From 1982-1989, 152 mutilated distal digits were reconstructed with microsurgical foot tissue transfers in 121 patients. These various foot tissues included wrap-around flaps or pulp from the great toe, second toe, or third toe, as well as partial toe, nail, web space skin, and other portions of the foot. The reconstructions were carried out primarily and secondarily in 78 and 74 patients respectively. The immediate success rate was 98%. Most of the patients were satisfied with both the cosmetic appearance and the functional result. This relatively minor microsurgical foot tissue transfer proved to be an ideal reconstructive option for distal digital defects.

Adolescent

[Reconstructive microsurgery in the elderly].

Between 1989 and 1990, 20 patients older than 60 years underwent reconstructive microsurgery in our hospital. The procedures consisted of 6 digital replantations in 5 patients and 17 free tissue transfers in 15 patients. The success were 5 out of 6 digital replantations and 16 out of 17 free tissue transfers. This success rate had no significant difference compared with other age groups of our reconstructive microsurgery series. There was no additional complications which might always be considered to encounter with elder patients after prolonged anesthesia. We conclude that with good preoperative work up, careful intraoperative or postoperative care as well as meticulous operative technique, the operative risk remains low and the success rate is comparable to other age groups.

Age Factors

Emergency free-flap transfer for reconstruction of acute complex extremity wounds.

Nine patients with complex extremity injuries were treated with emergency free-flap transfers over a 3 1/2-year period. The transferred emergency free flaps were performed to cover exposed vital structures. All flaps survived without infection. Complete and careful assessment of the systemic condition of the patient and the nature of the injured extremity is mandatory. Emergency free-flap transfers may salvage the limb or finger and may improve the functional and aesthetic results with the shortest possible hospital stay.

Accidents

Molecular cloning of a member of a new class of low-molecular-weight GTP-binding proteins.

We report the cloning of a low-molecular-weight GTP-binding protein that appears to be the first member of a new class of G proteins. This G protein was cloned from the HT4 neural cell line and has the closest homology to the rab, sec4, and ypt1 members of the low-molecular-weight (LMW) G-protein family. The amino acid sequence identity is only 30% with these other LMW G proteins, but in the four conserved GTP-binding domains, amino acid identity increases to 50-100%. A unique feature that distinguishes this G protein from other LMW G proteins is its carboxy-terminal amino acid sequence -Cys-Cys-Pro. In keeping with the current nomenclature for other members of the ras superfamily, we will designate this new class as rah (ras-related homolog). On the basis of sequence homology, rah may function in vesicular trafficking and possibly in neurotransmitter secretion.

Amino Acid Sequence

Combined second and third toe transfer.

Historically, restoration of hand function following multiple digital amputation has been unsatisfactory. The evolution of digital reconstruction with toe transfer has enabled surgeons to reestablish prehension in these severely injured hands. A 4-year experience with 26 consecutive combined second and third toe transfers to replace missing adjacent fingers was reviewed in order to delineate the indications and technical considerations and to emphasize prevention of donor-site complications. Combined second and third toe transfer is reserved for adjacent finger amputations proximal to the digital web space with remaining fingers no longer than the small finger. Radial amputations are replaced with contralateral combined toe units, while ipsilateral toes are more ideal for ulnar amputations. Limited dorsal and plantar skin flaps extending only to the midpoint of the first and third digital web spaces allow for direct donor-site closure and uncomplicated healing. Maintenance of the plantar metatarsal arch by avoiding metatarsal shaft osteotomies or bone grafting-shortened metatarsals eliminates potential gait disturbances. When properly applied in selected patients, this single-stage microsurgical procedure can restore prehensile function, improve the appearance of the hand with multiple digital amputations, and preserve near-normal donor-foot function.

Adolescent

Simultaneous multiple toe transfers in hand reconstruction.

Our experience with simultaneous transfer of two or more toe units to the same hand where multiple digits were missing is presented. Forty-six toes from 38 feet were transferred to reconstruct 19 hands in 19 patients. The transfers consisted of 7 combined second and third toe units and 32 single toes. Three patients had a primary and 16 patients had a secondary reconstruction. There was one complete and one partial failure. The two-point discrimination ranged from 6 mm to protective sensation. Total active movement averaged 57 degrees in the thumb and 127, 93, 71, and 68 degrees, respectively, in the fingers reconstructed at middle phalanx, proximal phalanx, metacarpophalangeal joint, and metacarpal head. Pulp-to-pulp pinch averaged 2.4 kg in patients who had thumbs reconstructed and averaged 3.0 kg in patients who had normal thumbs. There was no cold intolerance, and no significantly disabled foot occurred except one with scissoring deformity. Simultaneous multiple toe transfer in hand reconstruction is feasible without increased complications both in primary and secondary wound conditions. It is time-effective and cost-effective.

Accidents, Occupational