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Biomedical subjects

G T Ho

Publications and source records attributed to G T Ho.

14 recordsLinked to original sources

Predicting the outcome of severe ulcerative colitis: development of a novel risk score to aid early selection of patients for second-line medical therapy or surgery.

BACKGROUND: The failure rate of medical therapy in severe ulcerative colitis is high. A risk index, to aid the identification of patients of not responding at an early stage to intravenous corticosteroid therapy, would be useful to facilitate second-line treatment or surgery. METHODS: We recruited 167 consecutive patients with severe ulcerative colitis between January 1995 and March 2002; and employed multiple logistic regression to analyse parameters within the first 3 days of medical therapy. We applied statistical modelling to formulate a risk score according to the likelihood of medical failure. RESULTS: Sixty-seven (40%) patients failed to respond to medical therapy. Multiple logistic regression analysis identified mean stool frequency and colonic dilatation within the first 3 days and hypoalbuminaemia as independent predictors of outcome (P < 0.001, 0.001 and 0.002 respectively). A numerical risk score was formulated based on these variables. Patients with scores of 0-1, 2-3 and > or =4 had a medical therapy failure rate of 11%, 43% and 85% respectively. Receiver-operator characteristic analysis of this score yielded area under curve of 0.88, with a sensitivity of 85% and specificity of 75% using score > or =4 in predicting non-response. CONCLUSION: This risk score allows the early identification of patients with severe ulcerative colitis who would be suitable for second-line medical therapy or surgery.

Adult↗

Peyronie's disease: current management.

Peyronie's disease is an acquired inflammatory condition of the penis associated with penile curvature and,in some cases, pain. It primarily affects men between 45 and 60 years of age, although an age range of 18 to 80 years has been reported. If left untreated, Peyronie's disease may cause fibrotic, nonexpansile thickening of relatively discrete areas of the corpora tunica, typically resulting in focal bend, pain or other functional or structural abnormalities of the erect penis. Many cases resolve without treatment. Medical therapies, including antioxidants (such as vitamin E and potassium aminobenzoate) and corticosteroids injected directly into the plaque, lack adequate scientific support. Surgery remains a mainstay when conservative measures fail.

Humans↗

Anatomic bases of the vascularized hepatic teres ligament flap.

The hepatic ligamentum teres was investigated in 30 adult specimens. The ligament represents a fibrous remnant of the umbilical v. and a small irregular lumen still exists in the ligament in adult life. The ligament is supplied by one set of independent round ligament a. and paraumbilical vv. Since the proximal segment of the ligament is easily mobilised and since the ligamentous a. originates from the right hepatic a. near the hilum, a proximal vascularized pedicle flap of the ligamentum teres has been recommended. Surgical repair of the extrahepatic bile duct using a vascularized pedicle flap of the ligamentum teres has been carried out successfully in 12 patients.

Adolescent↗

The utility of patient age in evaluating prostate cancer.

The utility of age in examining patients for prostate cancer was assessed. Of the 462 patients in the study, 138 had prostate cancer. The age distribution of the patients with cancer was similar to that found in patients with prostate cancer in the US population, and a correlation between age and the serum prostate-specific antigen (PSA) value was noted (r = .4, P < .002). Selection of reference intervals had a significant effect on test performance. Using an interval of 0 to 4.0 ng/mL, sensitivity of the PSA assay was 90% overall and varied from 78% (patients aged 50-59 years) to 94% (patients aged 70-79 years). In contrast, age-adjusted reference ranges yielded corresponding sensitivities of 84%, 78%, and 88%. With a single, fixed reference range, specificity decreased with advancing patient age (P < .001). This trend was eliminated by adjusting the cutoff in different age groups. In addition, age-adjusted reference ranges improved specificity by 10%, and by using the results of examination of a biopsy specimen as the "gold standard," the total number of patients classified correctly by PSA increased from 226 to 250 (49%-54%). For staging before treatment, patient age, clinical stage, and Gleason score were combined to yield a single probability estimate for organ-confined disease (P < .001). The use of age-adjusted reference ranges is supported by this study, which demonstrates that assay efficiency and specificity improve and sensitivity, although decreased overall, becomes more uniform across age groups. In this patient population, age was useful in determining the probability of organ-confined prostate cancer. Use of this model in clinical decision making should await evaluation in a prospective trial.

Age Distribution↗

Further study on the vascular basis for the reimplantation of the hand amputated through the palm.

Based on the anatomic data obtained from earlier studies on the vascular anatomy of the hand, the vascular architecture in the palm of the hand was studied on 60 sides of unembalmed adult upper extremities. Each palm was divided into 64 squares by 8 sagittal and 8 transverse sections. The vascular architecture in these squares and the arterial relations between them were observed and measured by angiography, operative microscopic dissection and computerised three-dimensional reconstruction. According to the pattern of the blood-vessels, the amputated palms can be classified into 4 types. The anatomic basis for the vascular anastomosis in each type is defined. There are three key-areas for the blood-supply of the palm and their significance is discussed. Apart from the 4 types of transversely amputated palms, the repair program of the blood-vessels in 4 types of common obliquely amputated palms are also discussed.

Amputation, Traumatic↗

Prostate cancer screening: role of the digital rectal examination and prostate-specific antigen.

BACKGROUND: This study was designed to determine the efficacy of digital rectal examination (DRE) and serum prostate-specific antigen (PSA) for early detection of prostate cancer in men > or = 50 years of age. METHODS: A prospective single-center clinical trial was conducted to screen 644 asymptomatic men, who were elicited by newspaper and radio advertisements, with DRE and PSA. Quadrant biopsy examinations of the prostate were performed if PSA > 4 ng/ml or if DRE was suspicious. RESULTS: Thirty-seven percent of the men (n = 241) had an abnormality of DRE or elevated PSA. Of the 163 patients who underwent transrectal ultrasound and quadrant biopsies of the prostate, 77% had normal biopsies, 14 (8%) had prostatic intraepithelial neoplasia, and 24 (15%) had carcinoma of the prostate. PSAs ranged from 0.3 to 65.5 ng/ml, with a mean of 2.35 and a median of 1.6. Ninety-five patients had a PSA > 4 ng/ml, of whom 17 had a PSA > 10 ng/ml. Sensitivity of PSA was 75% and specificity 87%; for DRE the sensitivity was 75% and the specificity 69%. Clinical stage of patients who underwent radical prostatectomy was B1 in 15 and B2 in five. Fifteen of 20 patients (75%) had organ-confined disease; the other five had specimen-confined disease. No patient was found to have nodal involvement. CONCLUSION: The combination of PSA and DRE seems to improve the stage of diagnosis of patients with prostate cancer. Larger, randomized studies will be necessary to evaluate the effect of screening on overall survival.

Aged↗

The effect of testicular nongerm cell tumors on local spermatogenesis.

OBJECTIVE: To assess ipsilateral spermatogenesis in men with malignant and benign nongerm cell tumors of the testis. DESIGN, PATIENTS: Histologic review of radical orchiectomy specimens performed for 20 men with malignant nongerm cell tumors and 15 with benign testicular lesions, including five Leydig cell tumors with benign clinical features. MAIN OUTCOME MEASURES: Degree of spermatogenesis was determined on a 1 to 10 scale, with 10 representing mature sperm within a seminiferous tubule. For each patient "near" and "far" scores were determined by obtaining the mean score of 50 tubules adjacent (< 3 mm) to the tumor and 50 tubules distant (> 3 mm) from the tumor, respectively. RESULTS: Total, near, and far scores were all lower for malignant tumors than for benign lesions. Scores for Leydig cell tumors were similar to benign lesions. Malignant tumors demonstrated a gradient effect, with greatest impairment of spermatogenesis occurring adjacent to tumor. In contrast, a distinction between near and far scores was not observed for benign lesions or Leydig cell tumors. CONCLUSIONS: Malignant nongerm cell tumors of the testis were associated with significant impairment of ipsilateral spermatogenesis, particularly in areas adjacent to tumor. These findings are similar to those observed for testicular germ cell tumors, suggesting a generalized negative influence on ipsilateral spermatogenesis by malignant tumors.

Adult↗

Efficacy of endoscopic hydrocele ablation.

We describe a new endoscopic technique that was used for the treatment of symptomatic scrotal hydroceles in 10 men. Through a small skin incision, the parietal surface of the tunica vaginalis was ablated endoscopically using either electrocautery or the KTP:YAG laser. This approach permitted visual inspection of the scrotal contents with minimal manipulation and was performed using monitored local anesthesia with bilateral spermatic cord blocks. With a mean follow-up interval of 6.1 months, no hydrocele recurrences, wound infections, or hematomas have been detected. The mean operative time was comparable (53 minutes) to that in a historical control group consisting of 15 men who had undergone open hydrocelectomy at our institution (46 minutes). Postoperative scrotal discomfort was minimal, with 6 of the 10 patients requiring no analgesics. Patients were able to resume their preoperative lifestyles an average of 2 days after surgery. In contrast, 11 of the 15 men in the control group was still complaining of scrotal pain, requiring oral analgesics, at their 2-week follow-up visit. Thus, endoscopic hydrocele ablation appears to be an effective and well-tolerated alternative to treat hydroceles with minimal postoperative discomfort.

Adult↗

Influence of testicular carcinoma on ipsilateral spermatogenesis.

A histological review of radical orchiectomy specimens was performed to assess the impact of testicular cancer on spermatogenesis. Slides from 28 patients with testicular cancer were available for review, consisting of 14 pure seminomas, 12 embryonal carcinomas and 2 mixed tumors. For each specimen tubules adjacent (less than 3 mm.) to the tumor and distant (more than 3 mm.) from the tumor were evaluated. This study indicates that marked impairment of ipsilateral spermatogenesis is associated with testicular carcinoma, particularly in the vicinity of the tumor. The quality of distant spermatogenesis appears to be influenced by tumor type and not by elevation of known serum tumor markers, such as human chorionic gonadotropin and alpha-fetoprotein, nor by the presence of carcinoma in situ.

Adult↗

Endoscopic hydrocele ablation.

A new technique for the treatment of hydroceles by percutaneous drainage and endoscopic ablation under direct vision is described. The possible benefits and drawbacks of this treatment modality for symptomatic hydroceles are discussed.

Catheter Ablation↗

Mathematical representation with graphic reconstruction on a microcomputer for an arterial tree.

The branching arterial tree is considered as a collection of numerous points and lines. When treated with vertex analysis, it can be expressed with a new mathematical representation, and graphical reconstruction can be carried out on a microcomputer. This new method is useful for recording an arterial tree precisely on anatomical books or comparing arteries under hypertension with those under normotension in order that the early morphological changes of hypertensive vascular disease can be revealed.

Animals↗

Blood supply of the flexor digital tendon in the hand and its clinical significance.

An anatomical study on the blood sources and vascularity of the flexor digital tendon was conducted in the upper extremities of fresh cadavers by means of arterial injection and meticulous dissection of the transparent tendon under the microscope. According to whether or not synovial membrane surrounded the tendon, the flexor digital tendon can be divided into 2 regions: non-synovial and synovial. The major intrinsic blood supply of the digital tendon was in the form of longitudinal vascular bundles, while the transverse anastomotic branches were short and sparse. The non-synovial region of the tendon was covered by paratenon and the vascular distribution of this region was uniform. In the synovial sheath, the blood vessels distributed only on the dorsal side, while the volar side was devoid of vessels. The profundus and superficialis tendons had an avascular zone at the proximal interphalangeal and metacarpophalangeal joints respectively. It was considered that the difference of the vascular architecture might be related to the mechanical force to which the tendon was subjected. The nutrition of tendon was discussed and the selection of tendon graft at operation was suggested.

Hand↗

Basic vascular anatomy and the reimplantation of the amputated hand through the palm.

Thirty adult upper extremities were used to study the blood vessels of the hand by angiography, cross-sectional measurement and operative microscopic dissection. The arteries in the middle segment of the palm are arranged in three planes, while in the upper or lower segment there are two planes only. The division of the territories of the radial and ulnar arteries are not same in the three different layers. There are three main anastomotic pathways between the radial and ulnar arteries in the radial-ulnar direction, while in the palmar-dorsal direction there are three anastomotic zones between the palmar and dorsal planes. According to the rate of appearance, sources, cross-sectional area, irrigation territories and anastomoses of the arteries in the three segments, the clinical significance in the reimplantation of the amputated hand through the palm has been discussed.

Amputation, Traumatic↗