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Biomedical subjects

J B Chen

Publications and source records attributed to J B Chen.

At least 55 records · Page 3Linked to original sources
PubMed1999

Ischemic bowel disease in chronic dialysis patients.

BACKGROUND: Ischemic bowel disease, especially acute mesenteric ischemia, carries high morbidity and mortality rates. Any delay in diagnosis or treatment aggravates the patient's outcome. Owing to the scarcity of reports concerning ischemic bowel disease in chronic dialysis patients, we investigated the ischemic bowel disease in chronic dialysis patients. METHODS: From January 1986 through April 1997, medical records of 2416 chronic dialysis patients at our hospital were reviewed. Among them, 5 patients with surgically documented ischemic bowel disease were enrolled. The clinical manifestations, laboratory findings, operative findings, pathologic test results and prognoses of these patients are reported. RESULTS: Abdominal pain, abdominal distension and bloody stool were major initial presentations. The mean age of the patients was 62.4 years at the time of diagnosis of ischemia. All patients had hypertension, 3 patients had hyperlipidemia, three patients had diabetes mellitus and three patients had history of shunt occlusion. Four patients had leukocytosis. Image studies revealed dilatation of bowel loops in four patients. Peritonitis made exploratory laparotomy necessary. The findings during operation showed turbid ascites and variable degrees of bowel ischemia or gangrene. The methods of surgical intervention depended on the severity of the disease. Only one patient died due to extensive ischemic bowel involvement and subsequent sepsis. CONCLUSION: It is mandatory to have an index suggestive of ischemic bowel disease in chronic dialysis patients with unexplained abdominal pain or discomfort. Early diagnosis and aggressive surgical intervention is the cure modality for patients with acute ischemic bowel disease.

Aged↗
PubMed1999

Hyperglycemic hyperosmolar non-ketotic syndrome in hemodialysis patients.

BACKGROUND: Hyperglycemic hyperosmolar non-ketotic syndrome (HHNK) is an emergency complication of diabetes mellitus. The conventional treatment modality often includes massive fluid supplementation. In maintenance hemodialysis patients, dehydration via the renal route may not occur, and fluid management is rather complicated. In this study, we investigated the precipitating factors, treatment modalities, clinical course and prognosis of HHNK patients who received maintenance hemodialysis. METHODS: From January 1988 through August 1998, 16 diabetic patients who had developed HHNK were enrolled. Eight of them were end stage renal disease (ESRD) patients on maintenance hemodialysis, and another group included 8 acute renal failure (ARF) diabetes mellitus patients who received their first hemodialysis during the HHNK episode. We retrospectively reviewed their medical charts and recorded each patient's age, treatment modalities, especially fluid supplementation, predisposing factors, and biochemical data during the HHNK episode. Complications and the final outcome were also recorded. RESULTS: There were no significant differences in biochemical data and patients' ages between the two groups (p > 0.05). The major predisposing factor for the ARF patients was infection, but irregular use of or discontinuing oral hypoglycemic agents (OHA) or insulin was the major predisposing factor for the ESRD patients. Less fluid supplementation was given in the ESRD group as compared to the ARF group and no deaths occurred in the ESRD group of patients. However, 6 patients expired in the ARF group of patients. CONCLUSION: Regular medical care, early diagnosis and recognition, and easier management of fluid administration explain the rather smooth course and better prognosis in the ESRD group of patients.

Acute Kidney Injury↗
PubMed1999

Acute fish liver intoxication: report of three cases.

The livers of some larger fish such as shark, tuna and seabass have been reported to be responsible for a peculiar poisoning causing headaches and desquamation. This type of poisoning can also be induced by ingestion of the livers of the sea whale, the polar bear and the seal. Since these animals contain an extremely large quantity of vitamin A in their livers and the symptoms of poisoning in the patients resembled those of patients with acute hypervitaminosis A, the poisoning was believed to have been caused by excessive vitamin A intake. We observed an episode of acute fish liver intoxication in which 3 man experienced dizziness, headache, blurred vision, nausea, vomiting, fever, and desquamation after ingesting the liver of the grouper fish Cephalopholis boenak (C. boenak). One of the patients had full-blown symptoms and presented with a high fever, headache, dizziness, generalized aching pain, and superficial vesicles and bullae of the skin. The treatment was mainly supportive. In the follow-up period, he subsequently developed hair loss and diffuse peeling of the skin on his palms and soles. Acute fish liver intoxication is rare, especially in subtropical regions. Symptomatologically, the clinical pictures of these patients were comparable to acute hypervitaminosis A or retinoid intoxication. The average vitamin A content in the grouper (C. boenak) is high enough to cause acute vitamin A intoxication. Moreover, ethanol may play a potentiating role in this type of event.

Acute Disease↗
PubMed1998

Comparison of the types of mutations induced by 7,12-dimethylbenz[a]anthracene in the lacI and hprt genes of Big Blue rats.

An important question regarding the use of transgenic reporter genes to detect mutation in rodents is how the types of mutations recovered in transgenes compare with the types of mutations found in endogenous genes. In this study, we examined mutations induced by 7,12-dimethylbenz[a]anthracene in the lacI transgene and the endogenous hprt gene of lymphocytes from Big Blue rats and in the hprt gene of lymphocytes from nontransgenic Fischer 344 rats. The overall mutation profiles found in these genes were remarkably similar: the majority of mutations were base pair substitutions, with the most common mutation being A:T-->T:A transversion. Differences were found for the mutational profiles in the endogenous gene and transgene with respect to the location of the mutations and the orientation of basepair substitutions in the DNA strands. In most cases, these differences could be explained by the nature of the target genes. The results support the use of the lacI transgene for detecting in vivo mutation.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1998

The significance of syphilis serology tests on long-term hemodialysis patients.

BACKGROUND: Syphilis is a sexually transmitted disease. Blood transfusion and blood contact are also routes of infection. Patients on long-term hemodialysis are at risk during their therapy. The aim of this study is to investigate the incidence of syphilis in hemodialysis patients, possible nosocomial infection and methods of treatment. MATERIALS AND METHODS: A total of 556 uremic patients on maintenance hemodialysis at our hospital on June 1996 were enrolled in the study. They all received syphilis screening tests. The rapid plasma reagin (RPR) test was used as the primary screening tests and Treponema pallidum hemagglutination assay (TPHA) test as the confirmation test. According to the test results, patients were classified into false and true-positive groups. The titer of both tests were recorded. The patients in the true-positive group were further divided into the untreated and treated group depending on whether they had already received treatment. The serial change of RPR test titer of the treated group was reviewed. RESULTS: Thirty-one patients (5.6%) had positive RPR test results and 10 patients (1.8%) had false-positive results. The titers of both RPR and TPHA tests were rather low in the positive groups. Most of the confirmed syphilis patients were asymptomatic and diagnosed serologically. In the treated group, the RPR test titer did not show significant decline and no seroconversion was noted after treatment. CONCLUSION: We observed that infectious syphilis patients exist in our hemodialysis unit and survey for this disease is necessary. The titers of both positive RPR and TPHA tests are low. Most diagnosed patients had latent syphilis, and serologic response to treatment is probably the same as in general population.

Aged↗
PubMed1998

Spontaneous cellulitis in adults with idiopathic nephrotic syndrome.

BACKGROUND: Susceptibility to infection is a common problem in a patient with nephrotic syndrome. The spontaneous cellulitis is not uncommon in pediatric patients with nephrotic syndrome, whereas there have been few cases reported in adults. In order to clarify the clinical course of this complication, we present 17 adult idiopathic nephrotic patients with spontaneous cellulitis. MATERIALS AND METHODS: A series of 17 adult idiopathic nephrotic patients with spontaneous cellulitis were retrospectively reviewed in Chang Gung Memorial Hospital, Kaohsiung from 1986 through 1996. We analyzed their physical conditions, clinical manifestations, and outcome. All patients received renal biopsies and had pathologic diagnoses. RESULTS: The medical records of 17 patients were collected, 12 men and 5 women, with ages ranging from 16 to 63 years (mean 29.5 years). The pathologic diagnoses of renal biopsies included minimal change disease (13/17), membranous glomerulonephritis (2/17), mesangioproliferative glomerulonephritis (1/17) and focal/segmental glomerulosclerosis (1/17). All patients had generalized edematous state. The clinical presentations of these patients were variable. The mean serum albumin and daily urinary protein excretion were 1.28+/-0.64 g/dl and 8.75+/-5.16 g, respectively. The results of blood cultures were E. coli (3/17), Gram-negative bacilli (1/17), Streptococcus viridans (1/17), Streptococcus pneumoniae (1/17) and no growth (11/17). All patients responded to antibiotic treatment except one patient who died due to overwhelming sepsis. CONCLUSION: The related factors of spontaneous cellulitis in patients with nephrotic syndrome are edematous skin, hypoalbuminemia, immunosuppressive drugs and defective immunity. Our patients had accordant conditions. The prognosis was good if diagnosis and treatment are made early.

Adolescent↗
PubMed1998

Sensitivity of the phiX174 am3 allele in relation to the endogenous Hprt gene for detecting mutation in transgenic mice.

Transgenic mice have been developed containing multiple, chromosomally integrated copies of the phiX174 am3 allele that serve as reporters for in vivo mutation at a single A:T basepair. In this study, we examined the relative sensitivity of the am3 transgene for detecting the in vivo mutagenicity of N-ethyl-N-nitrosourea (ENU). Three-week-old male phiX174 mice were treated with 0, 40, and 160 mg/kg of ENU. After 1, 3, 6, and 9 weeks, animals were killed, their spleens removed, and isolated splenocytes were used to measure mutant frequencies (MFs) in both the am3 allele and the endogenous Hprt gene. For animals treated with 40 mg/kg of ENU, the Hprt assay detected an average 22-fold increase over background, while the am3 MFs averaged threefold above background. With the 160 mg/kg dose, the Hprt assay detected a 54-fold average increase, while a sixfold average increase above background was found for the transgenic locus. We conclude that the sensitivity of the am3 assay to ENU was compromised by the presence of ex vivo mutations. Adjustment of am3 MFs to exclude these ex vivo mutants could enhance the sensitivity of the assay.

Animals↗
PubMed1997

Acute renal failure after snakebite: a report of four cases.

There is risk of acute renal failure (ARF) after snakebite. Four patients are reported who developed ARF after bites by Vipera russelli formosensis. The four patients were all male, of ages ranging from 26 to 55 years old. Their clinical features were mainly hemorrhage including hemoptysis, hematemesis, gross hematuria and hypotension. The abnormal laboratory data were thrombocytopenia, prothrombin time (PT) and activated partial thromboplastin time (APTT) prolongation, disseminated intravascular coagulation (DIC), hemolysis and rhabdomyolysis. The onset of ARF occurred within 24 hours after the snakebite, and lasted for 17 to 26 days. All patients received conservative treatment including hemodialysis and antivenin therapy. One patient, with massive gastrointestinal bleeding, died. It was concluded that the factors contributing to ARF following Vipera russelli formosensis bit are hemorrhage, hypotension, DIC, hemolysis and rhabdomyolysis. To prevent development of ARF, the early administration of antivenin cannot be too strongly emphasized.

Acute Kidney Injury↗
PubMed1997

Clinical treatment in colonoscopic perforation: a comparison of surgical and conservative management.

BACKGROUND: Successful management of colonoscopic perforation by conservative treatment has been reported, but management remains controversial. Delayed surgery in some situations may lead to an irretrievable result. How to make the best decision? A retrospective study was designed to address this challenge. METHODS: From the period October 1982 and December 1995, 9214 consecutive colonoscopic examinations at Taichung Veterans General Hospital were reviewed. RESULTS: Twenty perforations (0.22%) related to the procedure were found. Of those 16 occurred during diagnostic colonoscopies, and four, during therapeutic colonoscopies. Fifteen perforations caused by diagnostic colonoscopies were treated by surgery, one perforation caused by diagnostic colonoscopy and the four by therapeutic colonoscopies were treated by non-surgical methods. CONCLUSIONS: A standard text on large bowel surgery recommends laparotomy for most cases of colonoscopic perforations. In experience here, however, non-operative management was indicated if the perforation was small with no signs of general peritonitis, and the patient's condition was good. However, if the patients deteriorated with non-operative treatment, immediate laparotomy is indicated.

Adult↗
PubMed1996

Molecular analysis of lacI mutations in Rat2 cells exposed to 7,12-dimethylbenz[a]anthracene: evidence for DNA sequence and DNA strand biases for mutation.

The Rat2 cell line carries 50-70 stably integrated copies per cell of a lambda/lacI shuttle vector as a target for mutagenicity testing. Rat2 cells were exposed to 1 and 10 micrograms/ml of 7,12-dimethylbenz[a]anthracene (DMBA) for 24 h at 37 degrees C in the presence of primary rat hepatocytes, and grown to confluence. The shuttle vector was rescued from untreated and mutagen-treated cells and mutant frequencies were determined. The low and high doses of DMBA induced mutant frequencies that were 7-fold (25 +/- 4.9 x 10(-5)) and 33-fold (127 +/- 19.9 x 10(-5)) higher, respectively, than the spontaneous mutant frequency (3.8 +/- 0.7 x 10(-5)). DNA sequence analysis of the DMBA-induced lacI- mutants indicated that they contained mainly basepair substitution mutations at A:T and G:C, and that A:T-->T:A and G:C-->T:A transversions were the predominant types. In addition, 23 of 28 (82%) A:T basepair substitution mutations occurred with the mutated dA, the putatively adducted base, on the coding strand. Furthermore, 20 of the 28 (71%) A:T mutations had the mutated dA flanked 5' by a dC, and 17 of these were A:T-->T:A transversions, suggesting a sequence preference for this mutation. Except for a higher proportion of G:C-->A:T transitions in the low dose data, the mutational profiles from low and high doses of DMBA were similar. These results indicate that DMBA mutagenesis in the lacI gene of Rat2 cells displays distinct DNA sequence and DNA strand preferences.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1996

QTc prolongation indicates a poor prognosis in patients with organophosphate poisoning.

This study reviewed emergency department electrocardiograms of 223 patients with organophosphate poisoning from January 1982 to June 1994: 97 (43.5%) had QTc prolongation and were placed in group A; 126 patients without QTc prolongation were designated as group B. Compared with group B, group A patients had a higher mortality (19.6% v 4.8%, P < .001) and a higher incidence of respiratory failure (56.7% v 20.6%, P < .001). Serum cholinesterase levels were determined in the 223 patients: 92 (41.3%) were classified as severe poisoning. 32 (14.3%) as moderate, 41 (18.1%) as mild, and 58 (25.7%) as very mild. The severe group had a high incidence of QTc prolongation (P < .001), a high incidence of respiratory failure (P < 0.001), and a higher mortality rate (P < 0.001) than the other groups. Of the QTc prolongation patients, 59.8% (55/92) had a high incidence of respiratory failure (78.2% v 35.1%, P < .0001) and a higher mortality rate (29.1% v 8.1%, P < 0.05) compared with 40.2% (37/92) of the patients without QTc prolongation in the severe group. In conclusion, a complete electrocardiogram at the emergency department is important and of prognostic value.

Adolescent↗
PubMed1996

Rheumatoid nodules affecting both heels with surgical debulking: a case report*.

The presence of subcutaneous nodules in association with rheumatoid arthritis is well documented. In most cases, these nodules occur in association with severe rheumatoid disease. Treatment should be initiated with conservative measures such as custom-molded shoes, nonweightbearing, and oral antibiotic therapy to control infection. The goals of surgery were to alleviate pain, improve function and cosmesis, remove infected bone, and prevent further infection. The surgical sites are completely healed without complications 2 years postoperatively.

Arthritis, Rheumatoid↗
PubMed1996

[Clinical experience of automated double filtration plasmapheresis].

Double filtration plasmapheresis, one kind of fractionation plasmapheresis, was developed from membrane type plasmapheresis to remove only the pathogen and return the normal protein back to the patient. We started our automated double filtration plasmapheresis since December 1993. There were 13 patients who received one hundred treatments totally during one year period. And they are myasthenia gravis (8 patients); acute inflammatory demyelinating polyneuropathy (1 patient), multiple myeloma (1 patient); acquired factor VIII inhibitor (1 patient); autoimmune hemolytic anemia (1 patient); systemic lupus erythematous (1 patient). Technically double filtration plasmapheresis is easy to perform and time-saving. It also makes necessity of replacement fluid less frequent. Incidence of complication is rare, and this includes hypotension 2%, palpitation 1%, headache 1%, hemolysis 4%, air emboli 1%, high secondary pressure 2%, and no motality during our treatment. Clinical response is documented in cases of myasthenia gravis; acute inflammatory demyelinating polyneuropathy and acquired factor VIII inhibitor in our study. In conclusion, double filtration plasmapheresis is a time-saving, convenient, and safe therapeutic modality with rare complication. Because its effectiveness on limited kinds of diseases and costs relatively high price, thus plasmapheresis should be used in selected cases and treat aggressively if indicated.

Adolescent↗
PubMed1995

A clinical study of colorectal cancer accompanied by cancer of other organs.

BACKGROUND: The incidence of double primary neoplasms has increased in recent decades. The etiologies and epidemiologies of double primary neoplasms are under investigation, and relationships between some cancers are well established. A group of patients with double primary cancers was studied to determine the relationships between certain cancers. METHODS: From November 1982 to September 1993, 48 patients with colorectal cancer accompanied by cancer of another organ (double primary cancers) were treated here. The male-to-female ratio was 31 to 17. According to Warren's definitions, the patients were classified into two groups: synchronous and metachronous. Data collection was done on the basis of locations, pathological staging and interval between cancers. RESULTS: Among the 48 patients, extracolonic cancers were mainly found in the cervix (8), stomach (7), prostate (5), lung (5), urinary bladder (4), and breast (4). In the female patients, 88.2% (15/17) of extracolonic cancers were in the female reproductive organs. In male patients, 45% (14/31) of extracolonic cancers were GI tract neoplasms, and 35.5% (11/31) were cancers of the GU tract. Nearly half of the patients expired within two years after diagnosis of the second primary cancer. CONCLUSIONS: Cancers of the cervix, stomach, prostate, lung, urinary bladder and breast may have some etiologic factors in common with that of colorectuim. Thus, attention should be paid to these sites during the period of post-operative follow-up of the first primary cancer.

Adult↗
PubMed1993

A single gene change can extend yeast life span: the role of Ras in cellular senescence.

The budding yeast Saccharomyces cerevisiae has a limited life span (reproductive capacity), which is measured by the number of times an individual cell divides. There is evidence for the involvement of a senescence factor that affects cell cycle traversal in older yeast cells. Distinct alterations in the abundance of a handful of transcripts have been identified during the life span of this organism, and the genes that specify these mRNAs have been cloned. This raises the question whether the activity of one or more genes can alter the yeast life span. Indeed, the controlled expression of the transforming gene of Harvey murine sarcoma virus (v-Ha-ras) was found to extend the life span nearly two-fold. The normal homologs of this oncogene, RAS1 and RAS2, play a central role in the integration of cell growth and the cell cycle in yeast. Expression of v-Ha-ras appears to impinge on this integration. We suggest that it is the relative levels of the senescence factor and the Ras protein that determine whether a cell ceases to divide and senesces. We liken the senescence factor to the product of an anti-oncogene or tumor suppressor gene that neutralizes Ras.

Cell Cycle↗