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Biomedical subjects

Y C Chang

Publications and source records attributed to Y C Chang.

At least 289 records · Page 16Linked to original sources
PubMed1990

Clinicopathologic comparisons between estrogen receptor-positive and -negative hepatocellular carcinomas.

During the past 8 years, estrogen receptors (ERs) in the cytosol of hepatocellular carcinoma (HCC) were assayed in 66 unselected patients without preceding treatments on whom radical hepatic resection was performed. Twenty-six patients had ERs of 0.9 to 13.4 fmol/mg protein with a mean dissociation constant of 7.8 x 10(-10) M. The remaining 40 patients had no detectable amount of the receptor. There were no substantial differences between the ER-positive and ER-negative groups in preoperative clinical and laboratory data such as sex, age, alcohol abuse, underlying liver disease, and hepatic functions. Large tumors were more common in the ER-negative group and therefore the incidence of major hepatic resection was significantly higher in this group. Histopathologic studies revealed no substantial differences between the two groups. Operative mortality rate was 11.5% in the ER-positive and 12.5% in the ER-negative group. Excluding eight operative deaths, the rate of tumor recurrence in the residual liver and long-term survival rate were identical for the two study groups. The current results may indicate that the presence or absence of ERs in human HCC does not correlate to either biologic or pathologic characteristics of this tumor, but the true role of ERs in human HCC remains to be elucidated.

Carcinoma, Hepatocellular↗
PubMed1990

Subclinical lithium neurotoxicity: correlation of neural conduction abnormalities and serum lithium level in manic-depressive patients with lithium treatment.

Nerve conduction velocities (NCVs) and multimodality evoked potentials were studies in 28 manic-depressive patients under lithium prophylaxis with serum lithium levels between 0.320 and 0.980 mEq/L. Slowing of motor and sensory NCVs and prolonged central neural conduction times obtained from somatosensory and brainstem auditory evoked potentials were found to correlate with serum lithium levels. Lithium-induced changes in cell membrane conductivity and in the synaptic transmission are considered responsible for the neurotoxic effects of lithium.

Adult↗
PubMed1990

Acute triphenyltin intoxication: a case report.

A 23 year old male developed abdominal pain, diarrhoea, and vomiting several hours after poisoning with acute triphenyltin intoxication in a suicide attempt. Severe ataxia, dysmetria, nystagmus, and blurring of vision soon supervened. Disturbance of consciousness and confusion developed 12 days later and lasted for two months. A delayed sensorimotor polyneuropathy was shown by electrophysiological studies to be due to axonal degeneration and demyelination. The neuropathy rapidly recovered after consciousness was regained.

Adult↗
PubMed1990

Patients with n-hexane induced polyneuropathy: a clinical follow up.

The prognosis of hexacarbon induced polyneuropathy is usually good, though its clinical course after the cessation of exposure has not been described in detail. Eleven patients with moderate to severe n-hexane induced polyneuropathy due to occupational exposure were regularly followed up for a period of four years at the neurological department of the National Taiwan University Hospital. Sensorimotor neuropathy was diagnosed in nine patients and motor neuropathy in two. All were removed from further exposure to n-hexane after aetiological confirmation, but motor disturbance continued to worsen in five cases. Sensory functions were regained earlier than motor functions. All the patients, including one who was tetraplegic and confined to a wheelchair in the early stages, regained their full motor capabilities within one to four years. Three patients with severe neuropathy had residual muscle atrophy in the intrinsic foot and hand muscles. Signs of damage to the central nervous system, including increased tendon reflexes in two patients and leg tightness in six patients, emerged as muscle power was nearing complete recovery. The tightness of the legs gradually disappeared, but muscle cramps of the calves developed and these were still present at the end of follow up. Two patients had mild abnormal colour vision, and the abnormality was still detectable four years later. It is concluded that n-hexane induced neuropathy has a good prognosis, and that spasticity due to damage to the central nervous system is functionally reversible; muscle cramps and dyschromatopsia persist much longer.

Adolescent↗
PubMed1990

Cervical incompetence: preliminary evaluation with MR imaging.

The ability of magnetic resonance (MR) imaging to demonstrate cervical incompetence in nonpregnant women was investigated in a prospective study of 41 volunteers referred in random order. These included 20 patients with normal cervices, 11 with cervical incompetence of traumatic or congenital origin, and 10 with clinically small cervices due to in utero diethylstilbestrol (DES) exposure. On MR images of the normal patients, cervical length was 33.0 mm +/- 1.0 (mean +/- standard error of the mean) and the width of the internal cervical os was 3.3 mm +/- 0.1. In patients with cervical incompetence, the cervical length did not significantly differ from those in the normal group. However, the internal cervical os was significantly wider (4.5 mm +/- 0.3, P less than .001), and localized irregularity of the endocervical canal was demonstrated in two patients. The MR appearance of the cervical stroma varied from normal, uniformly low signal intensity (n = 4) to uniformly (n = 3) or partially (n = 4) medium-to-high signal intensity on T2-weighted images. In the patients with in utero DES exposure, the mean length of the cervical canal (22.9 mm +/- 1.7) was significantly shorter than that of the normal group. The width of the internal cervical os and the MR signal intensity of the cervical stroma were normal. In summary, MR findings of a cervical length shorter than 3.1 mm (95% confidence limit), an internal cervical os wider than 4.2 mm (95% confidence limit), or abnormal signal intensity in the cervical stroma are highly suggestive of incompetent cervix and should assist in planning further therapeutic decisions.

Cervix Uteri↗
PubMed1990

Assessment of pattern and treatment of intrahepatic recurrence after resection of hepatocellular carcinoma.

From 1980 to 1988, 161 patients underwent total extirpation of primary hepatocellular carcinoma. There were 18 operative or hospital deaths. Recurrence of tumor was diagnosed in 69 of the remaining 143 patients during follow-up treatment with monthly serum alpha-fetoprotein measurements and imaging studies that were performed every three months. There were 61 men and eight women whose ages ranged from 33 to 78 years. The histologic factors noted were cirrhosis of the liver in 60 patients and chronic hepatitis in nine. There were multiple or diffuse recurrences (Type A) in 34 instances, one to three nodular recurrences (Type B) in 21, marginal recurrences (Type C) in 11 and a mixed form of the latter two in three instances. Two-thirds of the recurrences were found within 1.5 years and the second peak was noted between 2.0 and 2.5 years. Sex of patient, hepatitis B virus, type of tumor, capsule, extent of hepatic resection and postoperative chemotherapy did not influence the rate of recurrence, but cirrhotic livers had a significantly higher recurrence rate. A second hepatic resection was performed upon 20 patients with a five year survival rate of 26.8 per cent. Good results were obtained by chemoembolization of the hepatic artery. Prevention and adequate treatment of intrahepatic recurrence are of paramount importance in achieving better surgical results for hepatocellular carcinoma.

Adult↗
PubMed1990

Clinicopathologic features and long-term results of alpha-fetoprotein-producing gastric cancer.

During a 10-yr-period, 24 cases of alpha-fetoprotein-producing gastric cancer were experienced in our department. The mean age was 62.5 yr, and the sex ratio of males to females was 3:1. Borrmann II and III types of gastric cancer were predominant (83.3%). The prognosis was dismal. Most of the patients, including three radically operated cases of early gastric cancer, died from liver metastasis within 2 yr. The 1-, 3-, and 6-yr survival rates were 37.5%, 8.3%, and 8.3%, respectively, for all cases and 75.0%, 25.0%, and 25.0% for radically operated cases. The incidences of synchronous and metachronous liver metastasis were 31.8% and 40.9%, significantly higher than the incidences of AFP-negative gastric cancer (p less than 0.91). Despite radical gastrectomy, metachronous liver metastasis occurred in 75.0% of the cases. Two radical hepatic resections, including extended right lobectomy, were performed in one patient with early gastric cancer who had repeated metachronous liver metastasis. However, the tumor recurred immediately. Apparently, radical gastrectomy or hepatic resection alone may not suffice for this particular type of cancer. The methods of treatment and follow-up considered should be different from that for other types of gastric cancer.

Adult↗
PubMed1990

[The characters of AFP-producing early gastric cancer].

During the last decade, we have experienced 525 cases of gastric cancer. Within these, 195 were early gastric cancer (37.1%). Five and eight year survival rates were 86.9 and 77.2%. There were seven cases of recurrence, all of which were liver metastasis of submucosal cancers. Two combined with pulmonary metastasis. Three of the recurrent cases had serum AFP raised (greater than 20ng/ml) before or after partial gastrectomy. When these gastric specimens were reviewed, AFP positive cells were stained by PAP method. Compared with the AFP negative group of 168 early gastric cancers, invasion of lymphatic and venous vessels of the stomach and incidence of the liver metastasis were significantly higher in the stained group. 1.3 and 4.5 year survival rates of the cases (including ours) of AFP producing early gastric cancer, which had been reported in Japanese literatures, were 76.1, 45.7 and 22.9%, respectively. Liver metastasis was found in 7 of 12 cases (58.3%). It is clear that AFP producing early gastric cancer has the same tendency for liver metastasis as the AFP producing advance gastric cancer does. To prevent its recurrence, early diagnosis by PAP method for specimens with hepatic picture and aggressive adjuvant chemotherapy are mandatory.

Aged↗
PubMed1990

Decremental propagation of reflex spikes along giant axons of the earthworm Amynthas hawayanus.

The constant-velocity conduction of an action potential evoked by stimulating the isolated nerve cord of the earthworm Amynthas hawayanus differs from the propagation of a reflex spike evoked by stimulating the epithelium of an epithelio-muscular-nerve-cord (EMNC) preparation and recorded between pairs of microelectrodes spaced every 10 segments along either giant axon. The reflex spike is decremental and lasts for no more than 20 segments before it eventually disappears. Secondary and tertiary spikes sometimes arise even before the disappearance of the primary spike, and disappear after propagating for a short distance. This decremental propagation is tentatively attributed to the summation of excitatory postsynaptic potentials from the synaptic impingings of afferent interneurons in a polysynaptic reflex arc.

Action Potentials↗
PubMed1990

Outbreak of type A botulism caused by a commercial food product in Taiwan: clinical and epidemiological investigations.

In late September 1986, we found 7 patients from a printing factory in Chang-Hwa city who developed an endemic disease manifested by general malaise, ptosis, double vision, dysarthria, dysphagia, and proximal limb weakness. After clinical, epidemiological, microbiological, and toxicological investigations, an outbreak of botulism was confirmed 2 weeks later, Commercially canned peanuts made by an unlicensed cannery were identified as the vehicle of botulinum toxin transmission. Antitoxin was given to 2 patients who needed ventilator support. One of the 7 victims died from medical complications and the remaining 6 patients recovered. Several administrative problems exposed in this outbreak were the poor governmental supervision of canned food, the inadequate quantities of "orphan drugs" stored in this country, the inefficient system for recalling the problem products, and the delayed broadcasting of warnings to the public. Since commercially processed food is increasingly popular with modernization, the possibility of future botulism outbreaks should not be overlooked.

Adolescent↗
PubMed1989

Androgen and estrogen receptors in hepatocellular carcinoma and the surrounding liver in women.

Androgen receptors (AR) and estrogen receptors (ER) were consecutively assayed for hepatocellular carcinoma (HCC) and the surrounding liver was removed surgically from 19 female patients. Patient age ranged from 43 to 79 years, with an average of 61 +/- 9 years. All patients had underlying liver disease (liver cirrhosis in 16, liver fibrosis in two, and chronic hepatitis in one). Seven (37%) of 19 HCC had AR ranging from 2.3 to 82.6 fmol/mg of cytosol protein. The AR titer was higher in the HCC than in the liver in these cases. Three cases also had ER. ER existed in seven (37%) tumors (range, 2.4 to 25.6 fmol/mg of protein). AR and ER were detected in 11 (65%) and ten (58%) of 17 nonneoplastic liver tissues, respectively. Serum alpha-fetoprotein (AFP) level, hepatitis B virus markers, or histopathologic types of HCC had no correlation with the presence or absence of AR or ER and their titers. Also, there was no correlation between the AR and ER positivities. Further studies are mandatory to determine the genuine role of sex hormone receptors in the development and growth of HCC in humans.

Aged↗
PubMed1989

Phylogenetic relationships between the chlorophyll a/b binding protein (CAB) multigene family: an intra- and interspecies study.

The genome of Glycine max (L.) Merr. cv. "Dare" contains a chlorophyll a/b binding (Cab) protein gene family consisting of 10 genes. The primary structures of two linked Cab genes (Cab 4 and Cab 5) were determined. A comparison of the nucleic acid and predicted amino acid sequences of Cab 4 and Cab 5 revealed a high degree of similarity (96% and 98%, respectively). Phylogenetic inferences drawn from sequence comparisons between previously characterized soybean Cab 1, 2, and 3 and Cab 4 and 5 suggested that soybean Cab 3 was an evolutionarily distant member within this family. We further investigated the molecular evolution of the Cab gene family by comparing nucleotide sequences from 25 different Cab genes representing diverse phylogenetic taxa including monocot and dicot species. Phylogenetic inferences from these data support existing morphological phylogenies in that all species within one family clustered together. These data suggested that the Solanaceae were more evolutionarily distant from the monocots than the Fabaceae and Brassicacea. In addition, these data supported the theory that Cab Type I and II genes originated prior to divergence of the monocots and dicots.

Amino Acid Sequence↗
PubMed1989

Duodenal stenosis caused by ruptured aneurysms of the pancreaticoduodenal artery--a case report.

A case reported herein is a patient with ruptured minute pancreaticodudenal arterial aneurysms that proved difficult to distinguish from malignant tumors of the pancreas or duodenum. A 61-year-old woman was admitted to our hospital complaining of abdominal fullness, epigastralgia, nausea, and vomiting. Pre-operative examinations demonstrated duodenal stenosis, mass formation in the head of the pancreas, and three tiny aneurysms in the branches of the gastroduodenal artery. At surgery, an orange-sized mass was revealed in the head of the pancreas, which had adhered fibrously to the duodenum, inferior vena cava, and transverse mesocolon. Thus, pancreaticoduodenectomy was performed with a tentative diagnosis of a malignant tumor of the pancreas or duodenum. Subsequent histopathologic examinations, however, demonstrated the presence of a hematoma between the pancreas and duodenum, extensive fibrosis around the hematoma and dissecting aneurysms in the branches of the pancreaticoduodenal artery. In this case, it was considered that fibrosis around the ruptured aneurysms extending to the surrounding organs made it difficult to distinguish the aneurysms from a malignant tumor.

Aneurysm↗
PubMed1989

Intraoperative ultrasonography in resection of small hepatocellular carcinoma associated with cirrhosis.

Preoperative detectability rates of hepatocellular carcinoma smaller than 5 cm in 113 cirrhotic patients were 91 percent by ultrasonography, 93 percent by computed tomography, and 92 percent by selective angiography. The combination of two methods produced detectability rates of 97 to 99 percent. One hundred three patients underwent various types of hepatic resection with the aid of intraoperative ultrasonography. Forty-four tumors (43 percent) were embedded in the liver, and these tumors were not detected by conventional surgical exploration. The detectability rates were 38 percent for hepatocellular carcinomas smaller than 2 cm, 57 percent for 2 to 3.5 cm tumors, and 71 percent for 3.5 to 5 cm tumors. All undetectable hepatocellular carcinomas were identified by intraoperative echography. The overall detection rate by this method was 98 percent, which was substantially higher than the preoperative rate. Intraoperative ultrasonography is a useful and indispensable method for performing atypical minor hepatectomy for the treatment of small hepatocellular carcinomas associated with liver cirrhosis.

Carcinoma, Hepatocellular↗
PubMed1989

Transformation of human epidermal cells by transfection with plasmid containing simian virus 40 DNA linked to a neomycin gene in a defined medium.

A human epidermal cell culture was transformed by transfection with a recombinant plasmid containing simian virus 40 DNA with a deletion at the origin and an antibiotic (neomycin or G418) marker. A calcium phosphate-mediated DNA transfection method was optimized for introducing exogenous DNA into cells maintained in a fully defined medium. The transformed cells were propagated for more than 200 population doublings and did not appear to go through a "crisis" period. The growth characteristics of the transformed cells were similar to those of untransformed cells. Major keratins synthesized in the transformed cells were similar to those found in normal epidermal cells. Transformed cells initially transfected with the recombinant plasmid could be propagated for more than 30 passages. Actively growing cells could then be repeatedly selected from cell populations based upon their neomycin (G418)-resistant phenotype for at least another 30 passages. Simian virus 40 T-antigen and extrachromosomal DNA containing plasmid- and SV40-specific DNA sequences were detected in the transformed cells. Because of their nononcogenic phenotype and defined growth requirements, the transformed cells provide a model for examining structural changes during cell proliferation and differentiation, and for exploring the multistage carcinogenesis of human epithelial cells.

Antigens, Polyomavirus Transforming↗
PubMed1989

Androgen receptor in hepatocellular carcinoma as a prognostic factor after hepatic resection.

Androgen receptors (AR) in the cytosol of hepatocellular carcinoma (HCC) were assayed in 45 unselected patients in whom radical hepatic resection was performed. Thirty-one patients had detectable amounts of ARs in tumors, ranging from 2.3 to 82.6 fmol/mg protein with the dissociation constants (Kd) of 4.1 - 30.9 x 10(-10) M. The receptor was not found in the remaining 14 cases. AR negative HCCs were significantly more common among women and nonalcoholic patients. Otherwise, there were no significant difference in the clinicopathologic background between patients with AR positive HCCs and those with AR negative tumors. Three patients died of liver failure in the former group, whereas two died in the latter; one patient died of liver failure and the other died of pneumonia (results were not statistically significant). Excluding those five operative deaths, the recurrence rates were 67.9% in the group of patients with AR positive HCCs and 33.3% in the group of patients with AR negative tumors (0.1 less than p less than 0.05). The 5-year survival rate was significantly better (p less than 0.05) in patients with AR negative HCCs (62.2%) than in those with the positive tumors (17.3%). In light of the current results and previous experimental works by others, it is likely that testosterones enhance the growth and invasiveness of human HCC, which is mediated by AR in the tumor.

Carcinoma, Hepatocellular↗
PubMed1989

Radiation-induced uterine changes: MR imaging.

To assess the capability of magnetic resonance (MR) imaging to demonstrate postirradiation changes in the uterus, MR studies of 23 patients who had undergone radiation therapy were retrospectively examined and compared with those of 30 patients who had not undergone radiation therapy. MR findings were correlated with posthysterectomy histologic findings. In premenopausal women, radiation therapy induced (a) a decrease in uterine size demonstrable as early as 3 months after therapy ended; (b) a decrease in signal intensity of the myometrium on T2-predominant MR images, reflecting a significant decrease in T2 relaxation time, demonstrable as early as 1 month after therapy; (c) a decrease in thickness and signal intensity of the endometrium demonstrable on T2-predominant images 6 months after therapy; and (d) loss of uterine zonal anatomy as early as 3 months after therapy. In postmenopausal women, irradiation did not significantly alter the MR imaging appearance of the uterus. These postirradiation MR changes in both the premenopausal and postmenopausal uteri appeared similar to the changes ordinarily seen on MR images of the nonirradiated postmenopausal uterus.

Adult↗