Biomedical subjects

M Y Tseng

Publications and source records attributed to M Y Tseng.

9 recordsLinked to original sources

PubMed2005

Cerebral blood flow augmentation in patients with severe subarachnoid haemorrhage.

Following aneurysmal subarachnoid haemorrhage (SAH), cerebral blood flow (CBF) may be reduced, resulting in poor outcome due to cerebral ischaemia and subsequent stroke. Hypertonic saline (HS) is known to be effective in reducing intracranial pressure (ICP). We have previously shown a 20-50% increase in CBF in ischaemic regions after intravenous infusion of HS. This study aims to determine the effect of HS on CBF augmentation, substrate delivery and metabolism. Continuous monitoring of arterial blood pressure (ABP), ICP, cerebral perfusion pressure (CPP), brain tissue oxygen (PbO2), middle cerebral artery flow velocity (FV), and microdialysis was performed in 14 poor grade SAH patients. Patients were given an infusion of 23.5% HS, and quantified xenon computerised tomography scanning (XeCT) was carried out before and after the infusion in 9 patients. The results showed a significant increase in ABP, CPP, FV and PbO2, and a significant decrease in ICP (p < 0.05). Nine patients showed a decrease in lactate-pyruvate ratio at 60 minutes following HS infusion. These results show that HS safely and effectively augments CBF in patients with poor grade SAH and significantly improves cerebral oxygenation. An improvement in cerebral metabolic status in terms of lactate-pyruvate ratio is also associated with HS infusion.

Adult↗

PubMed2001

Endoscopic extraperitoneal lumbar sympathectomy for plantar hyperhidrosis: case report.

A right sided endoscopic retroperitoneal lumbar sympathectomy was performed on a 23 year old female who had plantar hyperhidrosis. After the operation, the right foot temperature increased and the plantar hyperhidrosis was relieved. During the follow up period, both feet were warm and dry, although only the right side lumbar sympathectomy had been performed. The outcome appeared to be compatible with that of an open procedure but with minimal invasiveness.

Adult↗

PubMed2001

Thoracoscopic sympathectomy for palmar hyperhidrosis: effects on pulmonary function.

Palmar hyperhidrosis, probably caused by an over-reactivity of sympathetic nerves passing through the second and the third thoracic sympathetic ganglia (T2 & T3 ganglia), can only be cured by sympathectomy. Such sympathetic denervation may also alter pulmonary function. Previous studies have shown that open sympathectomy can cause significant deterioration in pulmonary function, however, the surgical procedure itself may contribute to the change. Recently thoracoscopic sympathectomy has been developed as a minimally invasive but effective treatment for palmar hyperhidrosis. In order to investigate the effect of sympathectomy, pulmonary function was compared before and four weeks after operation in 20 patients. Forced vital capacity (FVC) (-2.3%), forced expiratory volume in one second (FEV1) (-6.1%), and FEV1/FVC (-4.6%) were all slightly but significantly decreased four weeks after thoracoscopic sympathectomy. Also the instantaneous forced expiratory flow at 75%, 50% and 25% of the FVC (Vmax25, Vmax50, Vmax75) in flow-volume curves were decreased (-1.6%, -8.4%, and -20% respectively). Therefore, thoracoscopic sympathectomy minimises pulmonary restrictive effects but allows subclinical small airway obstructive effects to become more evident.

Adolescent↗

PubMed2000

Experience in surgical management of tumours involving the cavernous sinus.

Potential injury to the neurovascular structures within the cavernous sinus often prohibits aggressive removal of tumours involving it, however, fully understanding the anatomy and selecting an appropriate surgical approach can often resolve this problem with acceptable morbidity. Moreover, a tumour may originate from different anatomical structures of the cavernous sinus which will influence the difficulty and outcome of the surgery. In general, tumours in this region can be classified as intradural, intracavernous and invasive types. The strategy of surgical treatment varies among these different anatomical types. Therefore, preoperative evaluation of tumours in the cavernous sinus is critical for the selection of an appropriate microsurgical approach. During the past 5 years, 12 tumours involving the cavernous sinus have been operated upon which included four neuromas, three meningiomas, three cavernous haemangiomas, one plasmacytoma and one chondroma. Nine of these twelve tumours were totally resected after one or two operations. There was no surgical mortality and the most common morbidity was transient cranial nerve palsy. At 2 months after surgery there was no additional postoperative cranial nerve deficit in all the patients; however, one patient developed a postoperative middle cerebral artery infarct due to accidental injury to the internal carotid artery during surgery. The respectability of the tumour mostly depends on its consistency and the involvement of the adjacent anatomy. The pathoanatomical features of the tumours and the clinicoradiological findings, as well as the selection of the microsurgical approach, are discussed.

Adolescent↗

PubMed2000

Recurrent intracerebral hemorrhages in cerebral amyloid angiopathy: a case report.

Cerebral amyloid angiopathy frequently causes recurrent intracerebral hemorrhages in elderly patients who do not have systemic hypertension. Surgery should be reserved for conditions which cannot be controlled by medical treatment. When surgery is needed, potential complications (such as bleeding near the operation site or remote area) should be kept in mind. A case study of a 66-year-old woman with cerebral amyloid angiopathy and recurrent intracerebral hemorrhages is presented.

Aged↗

PubMed1999

Isolated leptomeningeal tuberculoma.

Intracranial leptomeningeal tuberculoma without evidence of systemic tuberculosis is rarely encountered and is often difficult to diagnose because there are no specific signs or symptoms. A 49-year-old woman, without any past history of tuberculosis, presented with weakness and focal seizures in the right hand. Cranial magnetic resonance imaging revealed a leptomeningeal lesion in the left frontoparietal region. All conventional examinations demonstrated no evidence of tuberculous infection. The patient underwent biopsy, and histopathologic examination showed caseating granulomas compatible with tuberculomas. The culture of the surgical specimen grew Mycobacterium tuberculosis 4 weeks later. The patient was then actively treated with antituberculous agents for 1 year. Subsequent clinical features and image studies showed the intracranial lesion in resolution. The findings of this case argue in favor of surgical biopsy when intracranial tuberculosis is clinically suspected, even without evidence of systemic tuberculous infection.

Culture Techniques↗

PubMed1997

A novel role of ImmE7 in the autoregulatory expression of the ColE7 operon and identification of possible RNase active sites in the crystal structure of dimeric ImmE7.

Site-specific cleavage of mRNA has been identified in vivo for the polycistronic colicin E7 operon (ColE7), which occurs between G and A nucleotides located at the Asp52 codon (GAT) of the immunity gene (ceiE7). In vitro, this specific cleavage occurs only in the presence of the ceiE7 gene product (ImmE7). The crystal structure of dimeric ImmE7 has been determined at 1.8 A resolution by X-ray crystallographic analysis. We found that several residues located at the interface of dimeric ImmE7 bear surprising resemblance to the active sites of some RNases. These results suggest that dimeric ImmE7 may possess a novel RNase activity that cleaves its own mRNA at a specific site and thus autoregulates translational expression of the downstream celE7 gene as well as degradation of the upstream ceaE7 mRNA.

Bacterial Proteins↗

PubMed1994

Expression of the crystal protein gene under the control of the alpha-amylase promoter in Bacillus thuringiensis strains.

The expression of an insecticidal crystal protein gene of Bacillus thuringiensis under the control of the alpha-amylase gene promoter was investigated. The cryIC gene, which encodes a protein known to have a unique activity against Spodoptera (armyworm) species, was used in this investigation. The cryIC gene was placed, along with the alpha-amylase promoter from B. subtilis, in a B. thuringiensis-derived cloning vector, generating a pair of recombinant plasmids, pSB744 and pSB745. The cloning vector that contains the minimal replicon of B. thuringiensis subsp. kurstaki HD73 is stably maintained in a variety of B. thuringiensis strains, as previously reported by Gamel and Piot (Gene 120:17-26, 1992). The present study confirmed that the recombinant plasmids are also stably maintained in B. thuringiensis subsp. kurstaki Cry-B and HD73 growing in media without selection pressure for at least 48 h. The cryIC gene on the recombinant plasmids were notably expressed at high levels in both recombinant strains. Expression of the introduced cryIC gene on the recombinant plasmid in B. thuringiensis subsp. kurstaki HD73 did not impair expression of the resident cryIA(c) gene. The CryIA(c) protein is known to have a high level of activity against loopers such as Trichoplusia ni (the cabbage looper). As a result of coexpression of the introduced cryIC gene and the resident cryIA(c) gene, recombinant strain HD73 acquired an additional insecticidal activity against Spodoptera exigua (the beet armyworm) whereas the original activity level against T. ni was maintained.

Animals↗

PubMed1994

Determination and Distribution of cry-Type Genes of Bacillus thuringiensis Isolates from Taiwan.

Using PCR with a set of specific oligonucleotide primers to detect cryI-type genes, we were able to screen the cry-type genes of 225 Bacillus thuringiensis soil isolates from Taiwan without much cost in time or labor. Some combinations of cry genes (the cry-type profile) in a single isolate were unique. We identified five distinct profiles of crystal genes from the B. thuringiensis soil isolates from Taiwan. The cry genes included cryIA(a), cryIA(b), cryIA(c), cryIC, cryID, and cryIV. Interestingly, 501 B. thuringiensis isolates (93.5% of the total number that we identified) were isolated from areas at high altitudes. The profiles of cry-type genes were distinct in all isolation areas. The distribution of cry-type genes of our isolates therefore depended on geography. Using PCR footprinting to detect cryIC-type genes, we identified two distinct cryIC footprints from some of our isolates, indicating that these isolates may contain novel cryIC-type genes. B. thuringiensis isolates containing cryIA(a)-, cryIA(b)-, and cryIA(c)-type genes exhibited much greater activity against Plutella xylostella than did other isolates, indicating that multiple cry-type genes may be used as markers for the prediction of insecticidal activities.

Journal Article↗