PubMed HealthSearch

Biomedical subjects

J K Huang

Publications and source records attributed to J K Huang.

At least 19 recordsLinked to original sources

A novel cereal storage protein: molecular genetics of the 19 kDa globulin of rice.

A lambda gt11 cDNA library, constructed from poly(A)+ RNA isolated from immature rice seed endosperm, was screened with affinity-purified antibodies against the rice storage protein called alpha-globulin (previously), or the 19 kDa globulin (our term). A positive clone was isolated and sequenced and shown to encode a 21 kDa precursor for the 19 kDa globulin, based on the identity of portions of the inferred amino acid sequence and the sequence of three cyanogen bromide peptides of the 19 kDa globulin. Analysis of genomic DNA by Southern blotting using the cDNA clone probe revealed one hybridizing band in Eco RI, Hind III, and Bam HI digests. This strongly suggests that the 19 kDa globulin is encoded by a single-copy gene. Because of its single-copy nature and its abundance of Arg and lack of Lys, the 19 kDa rice globulin appears to be a particularly attractive target for genetically engineering increased Lys content in rice seeds.

Amino Acid Sequence

Acupuncture in the treatment of renal colic.

A prospective randomized study was performed to compare the effect of acupuncture and intramuscular Avafortan injection in the treatment of renal colic. Our results showed that acupuncture is as effective in relieving renal colic as Avafortan but it had a more rapid analgesic onset (3.14 +/- 2.88 minutes versus 15.44 +/- 7.55 minutes, p less than 0.05). Of the patients in the Avafortan group 7 (43.8%) had side effects, including skin rash in 3, tachycardia in 2, drowsiness in 1 and facial flush in 1. No side effects were noted in the acupuncture group. During 2 hours of observation acupuncture and Avafortan seemed to be ineffective in promoting stone passage. However, patients receiving Avafortan treatment were more likely to have paralytic ileus. In summary, acupuncture can be a good alternative for the treatment of renal colic.

Acupuncture Therapy

Determinant role of testosterone in the pathogenesis of urolithiasis in rats.

By using an ethylene glycol-induced urolithiasis model, we assessed the role of testosterone in the pathogenesis of urolithiasis. The intact and castrated male and female rats were fed with 0.5% ethylene glycol in drinking water for four weeks. The renal excretions of oxalate, citrate and other electrolytes were measured, and the stone and crystal deposit were examined microscopically. The results showed that drinking a loading of 0.5% ethylene glycol for four weeks produced hyperoxaluria in all rats, but the intact male rats excreted more urinary oxalate than any other groups of rats. The ethylene glycol-fed rats exhibited hypocitraturia except the castrated male rats. However, urolithiasis occurred in intact male but not female rats. Castration in male rats fed with ethylene glycol dramatically decreased the incidence of renal stone from 71.4% (5/7) to 14.3% (1/7). On the other hand, there was still no renal stone formed in the oophorectomized female rats which received ethylene glycol treatment. These data indicate that serum testosterone level plays a determinant role in urolithiasis formation.

Animals

Uninephrectomy enhances urolithiasis in ethylene glycol treated rats.

Uninephrectomy (uNX) usually induces compensatory hyperfunction of the remaining kidney in an attempt to preserve the homeostasis of body fluid composition. The present study used uninephrectomized Sprague-Dawley rats on a lithogenic diet (0.5% ethylene glycol, EG) to evaluate the influence on urinary stone formation and calcium oxalate crystal deposition of compensatory excretion of lithogenic substances in the remnant kidney. The results showed that there were no urinary stones or calcium oxalate crystal deposits in the intact or uNX rats fed a normal diet. In the EG feeding groups, the incidence of massive (grade 3) crystal deposits was significantly higher in the uNX rats (87.5%) than that in the intact rats (37.5%; P less than 0.05). The incidence of urinary stone formation was also higher in the uNX rats as compared to that of the intact rats, although the difference did not achieve statistical significance. The serum magnesium, phosphorus and creatinine increased significantly, whereas creatinine clearance (CCr), 24-hour urinary excretions of citrate, sodium, potassium and chloride decreased significantly in the uNX rats fed EG. These data indicate that uninephrectomy increases the vulnerability of the contralateral remnant kidney to urolithiasis and crystal deposition when the lithogenic risk factors are present. Furthermore, once the remnant kidney forms urolithiasis or massive calcium oxalate crystal deposits, the renal function is severely compromised.

Animals

Simultaneous bilateral adrenal metastases from renal cell carcinoma. Surgical implications and review of the literature.

We report a case of left-side renal cell carcinoma with contemporary bilateral adrenal involvement discovered preoperatively with computerized tomography and other imaging techniques. Surgical treatment consisted of radical nephrectomy with a nearly total contralateral adrenalectomy and the unroofing of a lower pole renal cyst. Postoperative cortisone acetate replacement was instituted. The surgical implications of renal cell carcinoma with metastasis are also discussed.

Adrenal Gland Neoplasms

Comparison of effective renal plasma flow (ERPF) and endogenous creatinine clearance (Ccr) in evaluation of the differential kidney function: an in vivo study.

Eleven patients with obstructive uropathy were inserted with a pigtail catheter either for urinary diversion, endopyelotomy or percutaneous nephrolithotomy. Differential kidney functions were obtained by single-sample technique with I-131 orthoiodohippurate (OIH) and separate endogenous creatinine clearance (Ccr). Good linear correlation was noted between effective renal plasma flow (ERPF) and Ccr (r = 0.84, p less than 0.005), but there was still some discrepancy between these two examinations, chiefly found in two severely obstructed kidneys. Determination of ERPF by I-131-OIH single-sample technique is a simple, rapid, inexpensive and relative accurate test to measure the differential kidney function. But if the ERPF is at extremely low level, further investigations such as sonography of kidney and separate endogenous creatinine clearance should be done to avoid unnecessary nephrectomy.

Adolescent

Early CT findings of acute cerebral infarction in the middle cerebral artery territory.

For an early and definitive diagnosis of acute cerebral infarction by computed tomography (CT), we retrospectively analyzed the initial CT findings of 14 patients with proven acute middle cerebral artery (MCA) infarction within 4 hours after stroke onset. The following results were obtained: (a) abnormal CT findings could be recognized quite early in 13 patients (92.9%), (b) the most common and earliest finding was loss of defination of the gray-white interface at the lateral margins of the insula. This sign was recognized in 12 patients (85.7%) and could be detected as early as 1 hour after stroke onset, (c) the next common finding was narrowing or blurring of the Sylvian fissure in 10 patients (71.4%) and could be detected 1.5 hours after stroke onset, (d) an obscured outline or partial disappearance of the lentiform nucleus was recognized in 7 patients (50%) and could be detected 1.5 hours after stroke onset, (e) effacement of the cerebral sulci was found in 6 patients (42.9%) and could be detected 2.5 hours after stroke onset, (f) increased density in MCA or its major branches was not seen in our patients.

Acute Disease

[Intracellular effect of the ventral prostate in zinc deficient rats].

Concentration of androgens, binding-sites of androgen-receptors as well as the activity of 5 alpha-reductase of the ventral prostates have been studied in the zinc-deficient rats. Eight-week-old Sprague-Dawley rats were housed individually in cages and divided into two groups, I. Experimental group, redivided into 2 sub-groups: (a) maintained on a zinc-deficient diet for 3 and 6 weeks, (b) zinc-deficient diet for 3 weeks then re-fed normal diet, II. Control group fed with normal diet. The ventral prostates were dissected free and homogenized after the rats sacrificed. Androgens and androgen-receptor were quantified by RIA and "exchange assay" respectively. The result obtained from the zinc-deficient rats were significantly different (P less than 0.05) from those of the control group 1. The zinc-deficient 3 and 6 weeks rats showed the plasma testosterone concentration decreased by 18% and 15%. 2. The cytosolic (fmo1/mg protein) dihydrotestosterone and its binding receptor were decreased by 10-15% and 28-30%, respectively. 3. The nuclear (fmo1/mg DNA) dihydrotestosterone and its receptor protein were ony 2-3% and 3-3.6% of the control group respectively. 4. Studies on the androgen metabolism showed that the metabolite, dihydrotestosterone (fmo1/mg protein) of rats with zinc-deficient 6 weeks was only 48% of the control group. 5. The prostate weight (mg) of zinc-deficient rats was 45-50% of the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Structure of the human gene for monoamine oxidase type A.

Monoamine oxidases, type A and type B, are principal enzymes for the degradation of biogenic amines, including catecholamines and serotonin. These isozymes have been implicated in neuropsychiatric disorders. Previously, cDNA clones for both MAO-A and MAO-B have been sequenced and the genes encoding them have been localized to human chromosome Xp11.23-Xp11.4. In this work, we isolated human genomic clones spanning almost all the MAOA gene from cosmid and phage libraries using a cDNA probe for MAO-A. Restriction mapping and sequencing show that the human MAOA gene extends over 70 kb and is composed of 15 exons. The exon structure of human MAOA is similar to that described by others for human MAOB. Exon 12 (bearing the codon for cysteine, which carries the covalently bound FAD cofactor) and exon 13 are highly conserved between human MAOA and MAOB genes (92% at the amino acid level). Earlier work revealed two species of MAO-A mRNA, 2.1 kb and 4.5-5.5 kb. We now report on further cDNA isolation and sequencing, which demonstrates that the longer message has an extension of 2.2 kb in the 3' noncoding region. This extended region is contained entirely within exon 15. The two messages therefore appear to be generated by the use of two alternative polyadenylation sites. Results from the present work should facilitate the mutational analysis of functional domains of MAO-A and MAO-B. Knowledge of the gene structure will also help in evaluating the role of genetic variations in MAO-A in human disease through the use of genomic DNA, which is more accessible than the RNA, as a template for PCR-amplification and sequencing.

Amino Acid Sequence

Reduction of calcium excretion in the stone-forming kidney in unilateral ureteral obstruction.

Thirteen urolithiasis patients with unilateral obstructive uropathy were treated with percutaneous nephrostomy (PCN) either for urinary diversion, endopyelotomy, nephrolithtotmy or chemolysis. After percutaneous nephrostomy, the individual urine volume, creatinine clearance (Ccr), urinary absolute and fractional excretions of sodium, potassium, calcium, magnesium and inorganic phosphate were measured separately in timed urine collections from a pigtail catheter and from the urethra. The data showed that Ccr and the absolute urinary excretions of sodium, potassium, calcium, magnesium and inorganic phosphate were significantly lower in the PCN kidney immediately or 2 days after relief of obstruction. The ratio of total urinary calcium excretion to urinary creatinine excretion in the obstructed kidney was significantly greater than that in the contralateral kidney. The fractional excretions of calcium and magnesium increased as renal function decreased. The results showed that when the total Ccr is below normal, the apparent excretion of urinary calcium will be underestimated. However, when the total Ccr of patients is within normal range, hypercalciuria may be detected adequately and thus favors early implementation of an appropriate therapeutic strategy.

Calcium

Association of hepatitis B viral precore mutations with fulminant hepatitis B in Japan.

We studied the precore DNA sequences of hepatitis B viral genomes in five patients with fulminant hepatitis B and in five with acute self-limited hepatitis B from Japan. Using the polymerase chain reaction, three to four independent HBV DNA clones from each patient were obtained and analyzed. We demonstrated that patients with fulminant hepatitis B carried HBV genomes with a G to A mutation at nucleotide positions 1898 (five of five patients; 18 of 18 clones, 100%) and 1901 (five of five patients; 12 of 18 clones, 66%) in the precore region. The first mutation results in an in-phase stop codon (TAG) in the precore open reading frame and the absence of HBeAg production. In contrast, a G to A mutation was found in 6 of 16 clones (37%) in position 1898 and in 0 of 16 clones (0%) in position 1901 from patients with acute self-limited hepatitis. We concluded that both of the precore mutations are commonly associated with fulminant hepatitis B and may contribute to the pathogenesis of fulminant hepatitis. A hypothetical model for the biological significance of these two mutations is proposed.

Adult

The incidence and prognostic significance of humoral hypercalcemia in renal cell carcinoma.

This retrospective study was conducted to evaluate the incidence and prognostic significance of humoral hypercalcemia in 218 renal cell carcinoma patients during the last 20 years. Of 218 patients 20 (9.2%) were hypercalcemic, with serum calcium levels ranging from 10.7 to 16.0 mg./dl. The respective incidence of humoral hypercalcemia was 3% in patients with stage I, 5.9% with stage II, 14.1% with stage III and 18.9% with stage IV disease without bone metastasis. The survival curves between the hypercalcemic and eucalcemic groups among stages I to III cancer patients showed no statistical significance (p greater than 0.05). The survival curve deteriorated significantly in stage IV cancer patients with humoral hypercalcemia (p less than 0.005), with a median survival of 45.0 +/- 39.7 days versus 286.4 +/- 27.6 days in eucalcemic patients. No specific correlation was found between pathological cell type and humoral hypercalcemia.

Carcinoma, Renal Cell

Serum iron as a tumor marker in renal cell carcinoma.

To evaluate the feasibility of using serum iron as a tumor marker for renal cell carcinoma, a retrospective review of serum iron, hemoglobin, hematocrit, mean corpuscular volume and pathology in patients with renal cell carcinoma was carried out. From January 1985 to December 1989, preoperative serum iron was obtained in 82 patients; 27 had stage I, 5 stage II, 23 stage III and 27 had stage IV disease. The serum iron levels (micrograms/dl) were 81.6 +/- 33.2 in stage I, 57.8 +/- 18.9 in stage II, 59.6 +/- 34.6 in stage III and 45.6 +/- 32.7 in stage IV disease, which were significantly lower as compared with the data (114.6 +/- 38.9) of a control group. Postoperative serum iron levels were available in 31 patients following nephrectomy and all showed an increase as compared with preoperative data except 2: 1 with recurrence and the other with progression of disease. It was concluded that the serum iron level may be used as a useful tumor marker in staging and follow-up of renal cell carcinoma.

Biomarkers, Tumor

Experience with percutaneous nephrostomy, extracorporeal shock wave lithotripsy and chemolysis in the treatment of obstructive uric acid stones.

Intravenous pyelography (IVP), retrograde ureteral catheterization and percutaneous nephrostomy (PCN) have been used to locate radiolucent stones during ESWL in an X-ray localization system lithotripter. We also used an alternative method combining PCN, ESWL and chemolysis to treat 8 obstructive uric acid stones. The average number of shock wave pulses was 1,725 (range 1,000-2,000), the generator voltage of the HM-3 Dornier lithotripter was 20-22 kV, and the local chemolysis lasted 4 days (range 2-7). All radiolucent uric acid stones were successfully disintegrated. Of the 8 patients treated, 5 were completely free of stones and the other 3 had insignificant residual stones after 3 months. Three patients who developed fever during local chemolysis with 0.1 M sodium bicarbonate solution were managed conservatively without severe sequelae. Only 1 patient retained a PCN tube after discharge. Because PCN can provide a path for local chemolysis and better localization, it is especially helpful in treating obstructive uric acid stones.

Bicarbonates

Factors influencing radiation exposure during the extracorporeal shock wave lithotripsy.

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Adult