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Biomedical subjects

M T Chen

Publications and source records attributed to M T Chen.

At least 127 records · Page 7Linked to original sources
PubMed1990

Recognition of altered shapes by hearing and hearing-impaired subjects.

In the present study, we explored whether mental transformation or feature detection is involved in visual processing of shape recognition; another purpose was to compare the visual processing of hearing subjects with that of hearing-impaired subjects. Deprivation of hearing, according to Myklebust (1964), impedes perceptual functioning in some respects and enhances such functioning in other respects. An experiment was conducted using two-dimensional random shapes under similarity transformations in Euclidean space. Reaction time served as the behavioral measure. The analysis of variance results showed significant main effects of orientations, isometries, and shapes, but not of groups and sizes. There were significant linear trends for orientations and sizes. Both groups demonstrated mental isometric transformation.

Adult↗
PubMed1990

Management of painful caliceal stones by extracorporeal shock wave lithotripsy.

One hundred and seven patients with caliceal stones causing flank pain were treated by extracorporeal shock wave lithotripsy (ESWL), followed up and reviewed. The total stone-free rate 3 months after ESWL was 38.8%. The total pain-free rate was 50.5%. The pain-free rate was 85% in the stone-free group and 29% in the group with residual stones. No significant differences between the stone-free rate and the duration of pain or age was noted. Patients with abnormal intravenous pyelography (IVP) had a lower stone-free rate than patients with normal IVP (16 vs. 45%, p less than 0.05). The complications included: 6 cases of stone street formation with spontaneous passage; 1 case of stone street formation needing percutaneous nephrolithotomy for drainage; 1 perirenal hematoma; 9 cases of severe colic pain following ESWL; 3 cases of fever following ESWL, and 4 cases of hydronephrosis due to a stone in the ureterovesicle junction. These results show that ESWL is an effective, noninvasive treatment for painful caliceal stones.

Adult↗
PubMed1990

Prophylactic bladder neck incision in the treatment of small benign prostatic hyperplasia.

From May 1986 to January 1989, a total of 178 patients with small prostate (less than 20 grams) received transurethral resection for benign prostatic hyperplasia. Twenty-two patients (12.4%) developed bladder neck contracture with an average interval of 247 days. The prophylactic bladder neck incision was performed concomitantly with transurethral resection of the prostate on 72 patients. Although smaller adenoma (average weight: 11.4 grams) was resected in this group, the bladder neck contracture occurred in 4 patients (5.6%), compared to 18 contractures in 106 patients (16.9%) who underwent transurethral resection of the prostate alone for larger adenoma (14 grams), P value less than 0.05. The operation time, peri-operative morbidity and hospital stay were similar in these two groups. It appeared that prophylactic bladder neck incision could protect against the formation of bladder neck contracture in patients with small obstructing prostatic adenoma.

Chi-Square Distribution↗
PubMed1990

Giant hydronephrosis: report of 4 cases with review of the literature.

Giant hydronephrosis is uncommon. In 1939, Stirling defined it as the presence of more than 1,000 ml of fluid in the collecting system [1]. We herein report 4 cases of giant hydronephrosis containing 1,900 ml, 3,400 ml, 2,100 ml and 3,200 ml, respectively. Only 6 cases with a malignant tumor have been reported in the literature. Our second case with multiple foci of transitional cell carcinoma with squamous metaplasia is presented. This is the first report of this kind of pathological morphology with giant hydronephrosis. An erroneous diagnosis is often made in cases of giant hydronephrosis. For example, 3 of our 4 patients were first diagnosed as ovarian cyst, retroperitoneal hamartoma and hepatic cyst, respectively. We have found 523 cases reported in the literature. It is seen more often in males than in females (2.4:1) and more often on the left side than on the right side (1.8:1). The amount of fluid in the hydronephrotic sac is often between 1 and 2 liters. It is usually secondary to ureteropelvic junction obstruction, stones or congenital abnormality. Nephrectomy is often performed due to severe impairment of renal function. Acute renal failure and cardiopulmonary distress developed in our second case after the operation. The reason may be the sudden decompression of the huge hydronephrotic sac, which resulted in a change in the hemodynamic balance. Therefore, a two-stage procedure with slow decompression by percutaneous nephrostomy before the nephrectomy is preferred in the compromised patient.

Adolescent↗
PubMed1990

Analysis of urinary calculi by infrared spectroscopy.

In the past 4 years, we used infrared spectroscopy to analyze 728 urinary calculi. The most common component of pure urinary calculi was calcium oxalate (whewellite and weddellite) 8.65%, followed by calcium phosphate (carbonate apatite, brushite and amorphous calcium phosphate) 6.87%, uric acid 5.91% and struvite 2.75%. The majority of urinary calculi had mixed components: whewellite/apatite 28.98%, weddellite/apatite 24.31% and whewellite/weddellite/apatite 14.42%. Only 3 cystine stones were found (0.41%). Good correspondence (82.7%) was noted when the results of 110 urinary calculi analyzed by infrared spectroscopy were compared with the results of polarization microscopy. The advantages and disadvantages of infrared spectroscopy are also discussed.

Adolescent↗
PubMed1990

Retroperitoneal abscesses.

Abscesses developing within the retroperitoneal spaces are complicated serious surgical infections marked by an insidious, occult process lead to considerable mortality and morbidity. In a retrospective review of 39 retroperitoneal abscesses in our hospital. Attention is directed to clinical presentation, diagnosis and treatment. On average, 19.2 days was required to establish the diagnosis and overall mortality is 7.7%. Two patients suffered from complications of discharged sinus and recurrent abscess respectively. Computed tomography (CT) is thought to be the best diagnostic modality of retroperitoneal abscesses. Only 2 patients (5.3%) shows bilateral lesions. Detailed anatomic reviews detailing the pathogenesis of bilateral retroperitoneal abscess are also discussed.

Abscess↗
PubMed1989

Urodynamic and clinical outcome of Kock pouch continent urinary diversion.

Urodynamic studies of the Kock pouch were conducted in 20 patients 3 to 36 months after radical cystectomy and urinary diversion for invasive bladder cancer. Functional pouch capacity, intrapouch pressure, maximal nipple pressure, maximal nipple closure pressure and functional nipple length with the pouch filled to capacity were measured. Intermittent involuntary pressure spikes resembling bowel peristaltic waves occurred in 5 patients (25 per cent). The mean functional pouch capacity was 280.0 +/- 119.2 ml. (standard deviation) and mean maximal intra-pouch pressure was 41.0 +/- 11.0 cm. water in patients with involuntary pressure spikes. In patients without involuntary pressure spikes these values were 332.7 +/- 114.5 ml. and 11.6 +/- 4.8 cm. water, respectively. For all patients the mean maximal nipple pressure was 72.1 +/- 24.6 cm. water, the mean maximal nipple closure pressure was 58.8 +/- 23.1 cm. water and the mean functional nipple length was 3.4 +/- 0.9 cm. A functional nipple length of less than or equal to 2.5 cm. and/or a low maximal nipple closure pressure (less than 40 cm. water) correlated with a small functional pouch capacity (less than 200 ml.) in 5 patients. Clinically, these 5 patients also required frequent catheterization to provide continence. A maximal nipple closure pressure greater than 60 cm. water and an adequate functional nipple length (greater than 3.0 cm.) correlated with a rather large functional pouch capacity (more than 350 ml.). The degree of continence provided by the Kock pouch appeared to be determined by functional nipple length, maximal nipple closure pressure, functional pouch capacity and maximal intrapouch pressure.

Aged↗
PubMed1989

Electrohydraulic lithotripsy for stones in Kock pouch.

During endoscopy of the Kock pouch, we found rather large stones in the pouches of 3 male patients 14-23 months after operation. The size of the stones varied from 1.5 to 3.5 cm. Because the stones in the pouch were too large to be extracted using forceps, for fear of damaging the efferent nipple valve, electrohydraulic lithotripsy (EHL) was applied and all stones could be broken down and removed easily. No complication occurred during or after EHL. Topical anesthesia was not necessary in all 3 patients. Usually the stones formed around staples. The major component of the stones was struvite. Urease-secreting bacteria as well as alkaline urine were found in all 3 patients. This result suggested that though EHL was used in an intestinal milieu (instead of urothelial bladder), it was an easy, safe and effective procedure for the removal of rather large stones (greater than 1.5 cm) from the Kock pouch. We suggest endoscopy of the Kock pouch at least once every 6 months or when stones have been demonstrated on plain X-ray of the abdomen. Stones in the pouch larger than 1.5 cm could be removed using EHL to avoid damaging the efferent nipple valve.

Humans↗
PubMed1989

[Oral tramadol for extracorporeal shock wave lithotripsy].

Two hundred patients undergoing shock wave lithotripsy for renal calculi with the improved version of Dornier HM3 lithotripter system were randomly divided into group A and group B with 100 patients in each. Patients in group A were orally given tramadol 100 mg and lorazepam 1 mg and those in group B flunitrazepam 1 mg was given. Those in group A, who did not need supplemental medication during ESWL were subdivided in group A while those who needed an adjuvant of 100 micrograms intravenous fentanyl were subdivided in group A2. Like group A, those in group B, who did not need supplemental drug and those who needed 100 micrograms intravenous fentanyl were respectively subcategorized into groups B1 and B2. Drugs were given with 15 mL water 30 min prior to ESWL. Pre-operatively, an intravenous line and monitoring system which included noninvasive blood pressure and pulse oximeter were established. The entire course was divided into 5 stages i.e. stage I (prior to oral medication), stage II (10 min after medication), stage III (10 min following ESWL), stage IV (5 min following 100 micrograms intravenous fentanyl) and stage V (10 min after ESWL). The mean blood pressure, heart rate and SpO2, pain scale, sedation scale and side effects were recorded in various stages. The results showed that in group A 68 patients passed the ESWL smoothly (A1) and 32 patients needed supplemental fentanyl (A2). In group B 70 patients successfully underwent the ESWL (B1) while 30 patients needed supplemental fentanyl (B2). Ther were no significant changes in both groups in various stages regarding heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

[Experience in using modified HM-3 Dornier lithotripter to treat urinary tract stones].

Low pressure generator has been developed mainly to reduce pain and kidney injury while at the same time maintain an equally effective stone-free rate. Our experience in using Modified HM-3 Dornier lithotripter to treat urinary tract stones has given an average of stone-free rate (58.88%) quite similar to what the conventional one can give. Compared with the conventional intervention, the modified one might increase by 52.07% (2281 vs 1500 pulses) in the average frequency of shock wave and by 26.52% (38.40 vs 30.35 minutes) in average operation time. However, low pressure may contribute to less complications and overall smoother procedure under oral analgesic use.

Adolescent↗
PubMed1989

Extracorporeal shock wave lithotripsy in the management of upper third ureteral stones.

From January 1986 to March 1988, 177 patients with 180 upper third ureteral stones (located at L3, L4, or L5 level) received extracorporeal shock wave lithotripsy (ESWL) in Veterans General Hospital-Taipei. The average size of stones was 10.4 mm. Seventy-seven percent of patients received one session of ESWL, twenty percent two sessions and three percent three sessions. One hundred and thirty-four cases (74.4%) had preoperative reposition of stones. The over-all success rate, being 78.3%, was significantly related to the size of stones, result of reposition, and severity of hydronephrosis and renal function impairement (Pearson's coefficient less than 0.05). For more rational use of ESWL, we suggest that if the failure in the reposition of the ureteral stone happens in company with other poor prognostic factors such as the stone size larger than 15 mm, severe hydronephrosis or renal function impairement other regimens should be tried instead.

Humans↗
PubMed1989

[Use of double-J in extracorporeal shock wave lithotripsy of large renal calculi].

Treatment of large renal calculi by extracorporeal shock wave lithotripsy alone has not been accepted yet as the treatment of choice because of the high incidence of complications such as stone street inducing obstructive uropathy. From Sep. 1987 to Nov. 1987, Thirty four patients had received double-J catheter in ureter before E.S.W.L. to prevent ureteral obstruction. The age distribution was from 29 to 66 years old (mean = 49.1 Y/O) and male to female ratio was 3:1. All the stone size was larger than 20mm in its longest axial length. Each patient was followed at least 3 months, and the results indicated that 8 patients (23.53%) had stone free, 11 patients (32.35%) had sandy stone in kidney, and 15 patients (44.12%) had stone street in ureter. The additional treatments for significant residual stone included 3 patients needing ureteroscopy, 8 patients needing more than one session of E.S.W.L. and 4 patients having spontaneous stone passage after removal of double-J. Although the necessity of external diversion and the incidence of colic pain after E.S.W.L. would reduce so as to improve patients' quality of life, double-J does not increase the stone free rate, and ureteral obstruction was still possible to induce the renal function impairment. We suggest that double-J be removed as soon as possible if the stone fragments have no change in position after 2-4 weeks of followup and adjuvant treatment be necessary.

Adult↗