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Biomedical subjects

T J Lin

Publications and source records attributed to T J Lin.

At least 37 records · Page 2Linked to original sources

Calcium oxalate is the main toxic component in clinical presentations of alocasis macrorrhiza (L) Schott and Endl poisonings.

Alocasia macrorrhiza (L) Schott and Endl is called Hai Yu, Tien Ho, Shan Yu, Kuan Yin Lien, Tu Chiao lien, Lao Hu Yu and Lang Du in Chinese. Its common English name is Giant Elephant's Ear. The toxic effects of A macrorrhiza arise from sapotoxin and include gastroenteritis and paralysis of the nerve centers. From 1985 to 1993 all individuals who called the Poison Control Center asking for information regarding macrorrhiza were included in this retrospective study. A questionnaire filled out by the Poison Control Center staff collected the demographic data of the victim, the reason for consumption, the prescribed part, clinical symptoms and signs of the victim, and medical outcome of poisonings. Among 27 cases of A macrorrhiza poisoning, the age was 1.5 to 68 y with 12 females and 15 males. One had skin contact and 1 had eye contact. In the 25 cases that consumed the plant leaf or tuber either raw or cooked, the primary symptom was in injected sore throat and the secondary symptom was numbness of the oral cavity. Some patients had salivation, dysphonia, abdominal pain, ulcers of the oral cavity, difficulty in swallowing, thoracodynia, chest tightness and swollen lips. We believe the presence of sapotoxin alone is not sufficient to explain the injected swollen and ulcerative lesions. Calcium oxalate is reported distributed in the entire plant and results in inflammation of the oral cavity and mucous membranes just as our patients had.

Adolescent↗

Differential regulation of mast cell function by IL-10 and stem cell factor.

In the development of rodent mast cells (MC), IL-10 significantly enhances the growth factor activity of stem cell factor (SCF). The differential effects of IL-10 and SCF on function of rat peritoneal MC (PMC) are investigated in this study. IL-10 inhibits both constitutive and Ag-induced nitric oxide production by PMC in a dose-dependent manner, whereas SCF does not affect nitric oxide production by PMC. Short term (20-min) incubation with IL-10 does not affect Ag-induced histamine secretion, whereas long term (24-h) incubation with IL-10 significantly potentiates Ag-induced histamine secretion, an effect similar to those reported for IL-3 and IL-4 in mouse MC. By contrast, SCF significantly potentiates Ag-induced histamine secretion in both short term (20-min) and long term (24-h) experiments. Both constitutive and Ag-induced TNF-alpha production by PMC are dose-dependently inhibited by IL-10, whereas they are not affected by SCF at all doses tested (2-500 ng/ml) and incubation times observed (3-24 h). Interestingly, rat PMC constitutively express IL-10 mRNA and proteins, as tested by reverse transcription-PCR and immunocytochemistry. In addition, it was found by flow cytometry that 23.5% PMC express surface IL-10. Moreover, treatment of PMC with anti-IL-10 Ab for 6 h significantly potentiates constitutive and Ag-induced TNF-alpha production by rat PMC. Thus, IL-10 and SCF exert different regulatory effects on MC secretory function. IL-10 produced by MC has the potential to regulate MC function in an autocrine manner, an effect that may be highly relevant to responses involving MC activation.

Animals↗

A novel CD8 molecule expressed by alveolar and peritoneal macrophages stimulates nitric oxide production.

Macrophages play an essential role in host defense, and we have identified a novel CD8 molecule, on alveolar and peritoneal macrophages, that may be involved in regulating this function. Flow cytometric analysis of bronchoalveolar lavage from normal rats identified a large number of CD8-positive cells that could not be accounted for by T lymphocytes. Within the scatter profile region in which the majority of cells were alveolar macrophages (OX41; 89 +/- 1%), 63 +/- 5% of the cells stained positively for CD8alpha (OX8) and 52 +/- 3% for CD8beta (341). Double-staining of lavage cells confirmed the presence of CD8 on alveolar macrophages. Interestingly, flow cytometry showed differences between CD8 on alveolar macrophages and on T lymphocytes within the ligand binding domain for MHC class I. Reverse transcription-PCR analysis on FACS-enriched alveolar macrophages showed the presence of CD8alpha mRNA, determining that macrophages synthesize CD8. Further studies identified both the alpha (49 +/- 8%)- and beta (37 +/- 4%)-chains of CD8 on peritoneal lavage cells (86 +/- 3% macrophages (OX42, CD11b)). As with alveolar macrophages, there were differences within the ligand-binding domain of CD8 on peritoneal macrophages compared with T lymphocytes. Functional studies determined that anti-CD8alpha (OX8) stimulated a dose-dependent release of nitric oxide, indicating that CD8 can directly regulate macrophage function. Thus, macrophages express an unusual CD8 molecule that differs within its ligand-binding domain, compared with T lymphocytes, and these findings suggest hitherto unknown ligand(s) for CD8. These findings will lead to a greater understanding of macrophage function and regulation.

Animals↗

Traumatic brainstem deafness with normal brainstem auditory evoked potentials.

A 48-year-old woman became totally deaf after a head injury. Magnetic resonance imaging showed bilateral contusions around the inferior colliculi and the brainstem auditory evoked potentials (BAEP) failed to show any abnormality. This case demonstrates that small, symmetrical, bilateral lesions around the inferior colliculi may cause deafness and may still be associated with a normal BAEP.

Auditory Pathways↗

The difficulty in handling poisonings associated with Chinese traditional medicine: a poison control center experience for 1991-1993.

The purpose of this prospective case series was to outline the characteristics of Chinese traditional medicine poisonings and develop essential information for poison prevention and management. All phone inquiries made to the Poison Center related to Chinese traditional medicines from January 1, 1991 to December 31, 1993 were included. Standardized questionnaires were used to capture relevant information. Among the 318 phone inquiries about Chinese traditional medicines, 273 cases were classified as poisonings; and 22 mortalities occurred (6.9%). All of the poisonings occurred because of suicide attempts, accidents, or erroneous or improper use or processing. In our study, 47% of the potential toxic effects of Chinese traditional medicines were either unknown or could not be found in the literature. There existed undefinable uncertainty in attributing the clinical effects to the exposures to Chinese traditional medicines. We recommend that the strategy in handling Chinese traditional medicine poisonings to decrease mortality should be comprised of confirmation of the generic name of the substances and the specific part of the plant used, awareness of improper processing methods, maintenance of records on a broad review of systems and laboratory data, identification of active principles and potential interactions among the individual active agents; verification of histopathologic effects of the toxins; development of information on toxicodynamics and toxicokinetics; intensive supportive care for poisoned patients, and investigation of potential antidotes. There are several regulatory options available to health authorities to control the unrestricted use of these potentially toxic medicines and to help safeguard the public.

Adult↗

Effects of salvianolic acid A on oxygen radicals released by rat neutrophils and on neutrophil function.

Salvianolic acid A (Sai A) has demonstrated potent antioxidant activity in previous studies. In the present study, the effects of Sai A on oxygen radicals released by rat neutrophils and on neutrophil function were investigated. Superoxide anion assayed by the nitroblue tetrazolium test and hydrogen peroxide detected with redox of scopoletin were scavenged concentration dependently by Sai A in n-formyl-methionyl-leucylphenylalanine (fMLP)- and phorbol myristate acetate (PMA)-stimulated rat neutrophils. Hydroxyl radicals generated in PMA-stimulated neutrophils, measured by HPLC, also were scavenged significantly by Sai A, whereas Sai A showed no significant effects on chemotaxis toward fMLP and phagocytosis of latex beads by rat neutrophils. In addition, the intracellular free calcium and cyclic nucleotide levels of neutrophils, when stimulated by fMLP, were not affected by Sai A. These results suggest that Sai A could significantly scavenge oxygen radicals released by activated neutrophils without affecting their functional ability.

Animals↗

Stem cell factor potentiates histamine secretion by multiple mechanisms, but does not affect tumour necrosis factor-alpha release from rat mast cells.

The effect of stem cell factor (SCF) on histamine and tumour necrosis factor-alpha (TNF-alpha) release from rat peritoneal mast cells (PMC) was determined and the intracellular pathways involved in the potentiation of histamine secretion were investigated. The effects of SCF (2-100 ng/ml) were examined following both short-term (0 and 20 min) and long-term (up to 24hr) preincubations with SCF. Pretreatment of PMC with SCF for 0 min (concurrent) or 20 min did not induce histamine secretion directly, but significantly increased antigen (Ag)-induced histamine secretion. SCF potentiated Ag-induced intracellular Ca2+ increase and calcium ionophore A23187-induced histamine secretion. Pertussis toxin (PT) inhibited SCF-induced potentiation of IgE-dependent histamine secretion, indicating that PT-sensitive G-proteins are involved in the immediate effects of SCF. In long-term incubation experiments, SCF pretreatment for 18-24 hr significantly enhanced Ag-induced histamine secretion, but did not affect Ag-induced intracellular Ca2+ levels. The effects of long-term incubation with SCF, but not the short-term effects, were blocked by cycloheximide. Interestingly, spontaneous and Ag-induced TNF-alpha release from rat PMC were not affected by pretreatment with SCF (2-500 ng/ml) for 1 to 24 hr. Thus, through immediate and delayed mechanisms, SCF potentiates histamine release from PMC, but has not effect on TNF-alpha release. The regulation of MC by SCF may be important in allergic and other inflammatory diseases.

Animals↗

Outbreak of obstructive ventilatory impairment associated with consumption of Sauropus androgynus vegetable.

BACKGROUND: Forty four individuals, suffering from temporary insomnia and poor appetite followed by progressive difficulty breathing after four weeks or more ingestion of the Sauropus androgynus or Sabah vegetable, were reported to the National Poison Center of Taiwan by physicians between August 23, 1994 and August 25, 1995. OBJECTIVE: A telephone questionnaire survey was designed and conducted to collect demographic data, information about use of the vegetable, past medical history and clinical presentation. Laboratory data were obtained from their physicians as available. RESULTS: Forty one patients, predominantly women, 43 +/- 11 years old, were identified in our survey. They reported a variety of sources and preparation methods for the vegetable. Difficulty breathing, identified in 36 cases, was the clinical hallmark. Twenty people gave a history of dyspnea delayed until 44 +/- 40 days after discontinuing vegetable consumption. Laboratory evidence of obstructive ventilatory impairment (FEV1/FVC 56 +/- 12%, FEV1 31 +/- 6%, PaO2 71 +/- 15%) was observed in 12 cases tested. An open lung biopsy performed in a demonstration case disclosed bronchiolitis obliterans organizing pneumonia. CONCLUSION: In this case series of 41 victims, we have identified a severe pulmonary effect and hypothesize that it is related to consumption of sauropus androgynus vegetable. Papaverine has been previously identified in this vegetable but is unlikely to be responsible for the full range of toxicity seen.

Adult↗

Two outbreaks of acute Tung Nut (Aleurites fordii) poisoning.

OBJECTIVE: Aleurites fordii, widely distributed in the Southeastern US, Taiwan, mainland China, Japan and India, is commonly known as Tung Nut, Tung Oil Tree or Chinawood Oil Tree. The seeds are the most toxic part. CASE REPORTS: We report two outbreaks of Aleurites fordii poisoning, occurring on November 27, 1992 and November 29, 1994. Thirty-five elementary school students and 29 senior high school students misidentified Aleurites fordii seeds as chestnuts and ingested variable amounts. METHODS: We conducted a survey by questionnaire to supplement the hospital record information. Simple descriptive statistics and Chi-square (Fisher's exact) tests were calculated. RESULTS: The three most common symptoms of the patients were vomiting, abdominal pain and diarrhea. The more serious clinical presentations occurred in younger victims. Our information suggests that food attenuates intestinal irritation perhaps by delaying absorption of the toxic principle. With symptomatic treatment, all of the symptoms and signs subsided within one to two days. CONCLUSIONS: Aleurites fordii can be cultivated and is easily accessible to the community and schools. Public education about the toxicity of Tung Nut seeds in areas of ready availability may reduce the chance of misidentification and subsequent poisoning.

Adolescent↗

Acute isoniazid intoxication: a case report.

Since its introduction in 1952, isoniazid has remained one of the drugs of choice in the treatment and prophylaxis of tuberculosis. In populations with a high prevalence rate of tuberculosis or suicide rate, acute ingestion of isoniazid has occasionally been reported. Acute intoxication by isoniazid is known to cause symptoms of seizures, metabolic acidosis, coma, and even death. These clinical symptoms, however, are not well recognized by physicians in Taiwan, even though the prevalence rate of tuberculosis is relatively high here. This report concerns the case of a 25-year-old female with a past history of tuberculosis who presented with the symptoms of refractory seizures, metabolic acidosis and deep coma after intentional ingestion of some unknown drug. Although implicating agents were not recognized initially, she was successfully revived with basic resuscitation, anticonvulsants and correction of metabolic acidosis. A review of her history revealed that her ingestion of five grams of isoniazid in this case was responsible for the entire clinical spectrum. Given easy access to isoniazid in Taiwan, a diagnosis of isoniazid poisoning should always be considered in patients who present with the classical symptoms of refractory seizures, metabolic acidosis and coma.

Acidosis↗

An outbreak of tetrodotoxin poisoning following gastropod mollusc consumption.

Tetrodotoxin, a violent neurotoxin, is present in puffer fish and may occur in a variety of marine animals. Outbreaks of human tetrodotoxin poisoning, following consumption of marine organisms other than puffer fish, has been rare. We here report an outbreak of tetrodotoxin poisoning following ingestion of gastropod molluscs and its clinical features are discussed. A 71-year-old woman was admitted with hypertension and other neurological symptoms developing after ingestion of some molluscs. A further 16 cases were also found to have typical symptoms of tetrodotoxication after mollusc consumption. Clinical features in these 17 cases were similar to those conventionally found in tetrodotoxin poisoning, except that there was hypertension in eight cases (47%). All except one case had mild poisoning and recovered well. The molluscs consumed comprised two different species: Nassarius castus and Nassarius conoidalis, both of which were shown to contain various amounts of tetrodotoxin. It is concluded that tetrodotoxin poisoning following mollusc consumption is a possibility. Hypertension, as an unusual feature in tetrodotoxication, is frequent in this outbreak, and should be looked for in future cases. The explanation of hypertension in tetrodotoxication may come either from an exaggerated response to sympathetic stimuli, or due to various responses of the vasomotor centre to a small dose of tetrodotoxin. Further studies are required to answer this question.

Adolescent↗

Effect of schisanhenol on function and surface shape of rat neutrophils.

AIM: To study the regulatory effect of Schisanhenol (Sal) on function of rat neutrophils. RESULTS: It was found that Sal (1, 10, and 100 mumol.L(-1)) inhibited neutrophil activities such as chemotaxis, phagocytosis, and superoxide anion production in vitro in a concentration-dependent manner. Changes of surface morphology of neutrophils were observed by scanning electron microscopy, showing that the ruffles and pseudopods on neutrophil surface increased under the stimulation by chemotactic peptide N-formyl-Met-Leu-Phe (FMLP). When pretreated with Sal 100 mumol.L(-1), the ruffles and pseudopods disappeared and the surface became smooth. Sal 100 mumol.L(-1) decreased the cytosolic calcium concentration of neutrophils and increased the intracellular cAMP level. CONCLUSION: These data suggested that Sal could inhibit the function of rat neutrophils through affecting the cytosolic free calcium and cAMP level besides its anti-oxidant activity.

Animals↗

Features of centipede bites in Taiwan.

In order to define characteristics that would help differentiate a centipede bite from a viper bite, we designed a prospective study using the data collection system of a Poison Control Center. The clinical goal is to rapidly distinguish envenomations for which antitoxin may be indicated (viper) from those for which palliative care only is appropriate (centipede). During a year period, 31 cases, including two cases receiving double bites in each event, were reported. Centipede lengths were estimated to range from 3 to 20 cm. Ninety-two per cent of the bite marks were pointed in shape. A local reaction developed at the bitten site, but usually remaining localized to a 10 x 10 cm area of involvement. The length of the biting animal, the bite mark characteristics, the presence of haemorrhagic vesicles, the wound size and the progression of local reactions are useful in the rapid clinical differentiation between centipede bites and viper bites.

Adolescent↗

Survival of paraquat intoxication complicated with mediastinal emphysema: a case report.

Paraquat intoxication is a common medical problem in this country. The mortality is high, particularly in the cases of high dose ingestion. Mediastinal emphysema observed in paraquat intoxication always means mortality, however, we experienced a survivor. A 29 y/o female ingested about 10-15 c.c. of 24% (2.4-3.6 gm) paraquat to attempt suicide. Nausea and protracted vomiting occurred shortly after. During hospitalization, mediastinal emphysema developed on the 7th day and subsided 10 days later. Serum paraquat level determination revealed 185 ng/ml in 20 hours after ingestion and 34 ng/ml on the 6th day. She received general supportive treatments with the augmentation of sodium thiosulfate. Hypokalemia had been observed for 11 days and was intractable until hypomagnesemia was identified and corrected. So far, she had returned back to her work for more than 1 year, although the chest x-ray revealed slight pulmonary fibrosis. The high ingested dose, oral ulcers, high serum level and mediastinal emphysema of this patient all implicate a poor prognosis of paraquat intoxication; however, these contradict the observed survival of our patient. In conclusion, mediastinal emphysema observed in paraquat intoxication is not related to the serum level of paraquat. It does not absolutely lead to death and may simply come from the esophageal rupture after vigorous vomiting in paraquat intoxication.

Adult↗

Protection by salvianolic acid A against adriamycin toxicity on rat heart mitochondria.

It was found that salvianolic acid A (Sai A) has potent antioxidant activity. The effects of Sai A on adriamycin-induced heart mitochondrial toxicity of rats in vitro and on adriamycin antitumor activity are investigated in this article. Malondialdehyde (MDA) formation and membrane rigidification of rat heart mitochondria intoxicated with adriamycin were significantly reduced by Sai A. In the electron spin resonance (ESR) studies, Sai A has no significant effect on the formation of adriamycin semiquinone radicals (AQ.), while hydroxyl radicals generated by electron transfer from AQ. to H2O2 were scavenged by Sai A dose-dependently. On the other hand, Sai A was shown to have no effects on the antitumor activity of adriamycin in cultured L1210 ascitic tumor cells and in mice with P388 ascite tumor. These results indicate that Sai A protects against adriamycin induced heart mitochondrial toxicity of rats, while Sai A has no antagonizing effect on the antitumor activity of adriamycin.

Animals↗

Protection by schisanhenol against adriamycin toxicity in rat heart mitochondria.

The effects of schisanhenol (Sal) on Adriamycin (ADM)-induced rat heart mitochondrial toxicity in vitro were investigated. Malondialdehyde formation, lysis, disintegration and membrane rigidification in mitochondria treated with ADM were reduced significantly by Sal. In the electron spin resonance studies, Sal did not affect significantly the formation of ADM semiquinone radicals (AQ.), whereas hydroxyl radicals generated by electron transfer from AQ.to H2O2 were scavenged by Sal dose dependently. These results indicate that Sal could protect against ADM-induced rat heart mitochondrial toxicity.

Animals↗