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Biomedical subjects

T Lee

Publications and source records attributed to T Lee.

At least 271 records · Page 15Linked to original sources
PubMed1991

Support systems, facilities and staffing of clinics in Mhala, Gazankulu--are they adequate?

A study comprising in-depth interviews of sisters in all 15 rural clinics in the Mhala district of Gazankulu showed them to experience major problems with support systems: radiophone communication was unreliable (and even absent in 3 clinics); transport was inadequate; the cold chain was not well maintained and essential drugs and equipment were absent (only 1 clinic had all the equipment to manage a neonatal resuscitation adequately). There were also serious deficiencies in facilities, lack of running water and electricity posing the most serious problems (resulting in deliveries and suturing of episiotomies by candlelight). Other pressing problems include inadequate waiting space and patient privacy. Staffing at the clinics fell well below what is required, yet the commitment of staff was often inspiring. The state of the clinics must be seen within the constraints of 'homeland' policy and the unequal distribution of the country's health care resources. Despite these limitations the clinic service can be improved. Recommendations are made for this, concentrating on improving support structures rather than on the more costly improvement of facilities.

Ambulatory Care Facilities↗
PubMed1991

Micellar electrokinetic capillary chromatographic separation and laser-induced fluorescence detection of 2'-deoxynucleoside 5'-monophosphates of normal and modified bases.

Micellar electrokinetic chromatography is used to separate dansylated nucleotides, both normal and modified species. The high separation power allows detection of minor components present in less than 1 part per thousand of the major components. Laser-excited fluorescence is used to detect the separated components at the 6 x 10(-18) mol level or 10(-9) M injected material. Combined with high-performance liquid chromatographic enrichment prior to labeling, this technique can be used to assess DNA damage in carcinogenesis studies.

Animals↗
PubMed1991

Identification of mutations that occurred on the genome of Japanese encephalitis virus during the attenuation process.

The total nucleotide sequences of the genomes of two Japanese encephalitis virus (JEV) strains, the attenuated vaccine strain SA14-14-2 and its parental virulent strain SA14, were determined by using the molecular cloning technique. The sequence analysis revealed that both virion RNA molecules were 10,976 nucleotides long with 95 and 585 flanking bases at the 5' and 3' untranslated sequences, respectively. A single, long open reading frame spanning 10,296 nucleotides was observed to encode a polyprotein of 3432 amino acid residues. When these sequences were compared with each other, 57 nucleotide substitutions were found to be scattered all over the genome. Of these, 24 resulted in amino acid changes within viral proteins. Structural proteins C and E contain one and eight amino acid changes, respectively. Of the nonstructural proteins, NS1 contains three, NS2a two, NS2b two, NS3 four, NS4a one, NS4b one, and NS5 two amino acid substitutions. The 5'- and 3'-terminal untranslated regions contain one- and two- point mutations, respectively. These data and comparative studies with other JEV strain genomes provide a molecular basis for investigating attenuation mechanisms of JEV.

Amino Acid Sequence↗
PubMed1991

Post-myelogram headache--physiological or psychological?

Psychological aspects of post-lumbar puncture headache have hitherto received little attention. A hundred consecutive patients admitted for elective myelography were studied. Post-myelogram headache was assessed by an independent observer and found to be strongly associated with normality of the test (P less than 0.001). Psychological testing showed a trend between Hospital Anxiety Depression score and normality of myelogram as well as development of headache, although this did not achieve statistical significance. This study suggested that there is a large psychological as well as organic component to post-myelogram headache.

Adolescent↗
PubMed1991

Preparation of Japanese encephalitis virus nonstructural protein NS1 obtained from culture fluid of JEV-infected Vero cells.

The Japanese encephalitis virus (JEV) nonstructural protein NS1 was released efficiently into culture fluid of JEV-infected Vero cells. The JEV NS1 protein in the infected culture fluid was found almost as a high-molecular-weight form, probably a dimer form of NS1, and was converted to a monomer by boiling. Large amounts of NS1 protein were accumulated in the infected culture fluid. The NS1 protein, separated from JE virions by centrifugation through sucrose layer, could be obtained in large quantities.

Animals↗
PubMed1991

Primary structure of gonadotropin-releasing hormone from the brain of a holocephalan (ratfish: Hydrolagus colliei).

Gonadotropin-releasing hormone (GnRH) in the ratfish brain has been isolated and purified using reverse-phase high performance liquid chromatography. Amino acid composition and sequence analysis indicate that the primary structure is pGlu-His-Trp-Ser-His-Gly-Trp-Tyr-Pro-Gly-NH2. The presence of the amino terminal pyroglutamic acid has been confirmed by degradation studies with pyroglutamyl aminopeptidase. The amidated carboxy terminus and molecular weight were confirmed using mass spectrometry. Moreover, sequence comparison and coelution studies with one of the synthetic forms of GnRH (chicken GnRH II) indicate that the ratfish and chicken GnRH II molecules are identical. This represents the first sequence data of a GnRH molecule from a cartilaginous fish (class: Chondrichthyes). It is argued that the ratfish GnRH molecule has been retained for over 400 million years of evolution and is expressed in most vertebrate classes.

Amino Acid Sequence↗
PubMed1991

Ossification of posterior longitudinal ligament of the cervical spine in non-Japanese Asians.

"The Japanese disease," ossification of the posterior longitudinal ligament, is not confined to the Japanese only. A similar incidence of 0.8% was found in this study among non-Japanese Asians. Of 5167 patients who attended the Mount Elizabeth Hospital in Singapore for cervical spine complaints, 43 patients were found to have ossification of the posterior longitudinal ligament, forming the largest non-Japanese series. All but one patient were of Mongolian origin, and males were affected four times more commonly than females. Diabetes mellitus was present in 16%. There was a significant association between ossification of the posterior longitudinal ligament and calcification of other cervical paraspinal ligaments. It is suggested that a generalized tendency to calcification may be an important etiological factor in ossification of the posterior longitudinal ligament. Four of the patients required surgery, and in our experience, anterior spinal fusion with removal of the ossified ligament or multilevel laminoplasty gives satisfactory results.

Adult↗
PubMed1991

Social isolation and cohabitation with haloperidol-treated partners: effect on density of striatal dopamine D2 receptors in the developing rat brain.

The influence of the social environment on striatal dopamine D2 receptor density in the developing rat brain was investigated. Social isolation of rats from 20 to 60 days of age was associated with a decrease in the density of striatal dopamine receptors. Daily handling of the animals did not attenuate this effect. Chronic haloperidol treatment increased striatal dopamine receptor density to normal control values. Cohabitation with haloperidol-treated rats from 20 to 60 days of age was also associated with a decrease in the density of striatal dopamine D2 receptors in nondrugged animals similar to that seen in animals housed in isolation. The contribution of early life experiences to the development of normal receptor functioning is discussed.

Age Factors↗
PubMed1991

Investigation of striatal dopamine D2 receptor acquisition following prenatal neuroleptic exposure.

To test the hypothesis that neuroleptic blockade impairs the development of striatal dopamine D2 receptors, pregnant rats were given haloperidol, thiothixene, or trifluoperazine for gestational days 15-18 (short-term exposure) or days 5-20 (long-term exposure). All of the drugs were demonstrated to cross the placenta and enter the fetal brains equally well. Striatal dopamine D2 receptors of the pups were assayed on postnatal day 14. Neither receptor density nor receptor affinity was altered significantly by the short- or long-term prenatal neuroleptic treatment.

Animals↗
PubMed1991

Calvarial thinning in low grade intracerebral gliomas presenting with epilepsy.

Intracranial gliomas can erode or thin the skull. These changes are detectable on conventional radiographs but they appear to be rare. Only a few examples of the appearances on computed tomography (CT) are recorded in the literature. This paper describes the CT appearances of 11 cases. All of the patients presented with epilepsy. In most the tumours were small and indolent. Some went undetected or misdiagnosed for several years because of a lack of familiarity with the appearances.

Adolescent↗
PubMed1991

Supratentorial masses: stereotactic or freehand biopsy?

CT-guided stereotactic biopsy is now an accepted method of tissue sampling in intracranial mass lesions but many surgeons still practise freehand burrhole biopsy. This study compares two groups of patients who had either stereotactically guided (n = 153) or freehand (n = 217) biopsy. Stereotactic biopsy has a lower incidence of both mortality (2.6%) and morbidity (1.3%) than freehand (7.8 and 7.8%) while diagnostic accuracy is 92.1 and 64.9%, respectively. The success rate for stereotactic biopsy is independent of the size and depth of the lesion while freehand biopsy is most successful for large, superficial lesions but its success never exceeds 88%. The stereotactic technique is superior to the freehand for all intracranial biopsies regardless of size or site.

Adult↗
PubMed1991

[High resolution real-time sonographic evaluation of superficial lesions].

One hundred and thirty-one cases of suspected superficial soft tissue lesions, excluding parotid, thyroid, parathyroid, breast and scrotum, were collected in 7-year-period in Veterans General Hospital-Taichung. High resolution (10MHz transducer) real-time ultrasound was applied as imaging modality. Among them, 46 cases were proved pathologically or clinically. We retrospectively evaluated the sonographic features and divided them into five major patterns. I. Cystic lesion with smooth margin, II. Cystic lesion with blurred margin, III. Solid lesion with smooth margin, IV. Solid lesion with blurred margin, V. Diffuse infiltrative lesion. In addition, gas or calcification in the lesion and the echogenicity were included in the evaluation. Some of the lesions considered to be of vascular origin were evaluated with doppler. Ultrasonography can accurately recognize cystic, solid, or infiltrative lesions. In spite of the fact that most of the findings are non-specific, several lesions do have characteristic sonographic patterns that can easily be diagnosed, especially in conjunction with the anatomical location, ie. Backer's cyst, branchial cyst, lymphangioma, and abscess. Lesions with cystic or hyperechoic solid patterns can be considered as benign, if the margin is smooth. Lesions with hypoechoic solid pattern and blurred margin, however except for abscess, can be considered as malignant. We conclude that high resolution real-time sonography is a good imaging modality for evaluating superficial soft tissue lesions.

Female↗
PubMed1991

Evaluation of anorectal malformations using magnetic resonance imaging.

Demonstration of the anatomy of the anal sphincter muscles in patients with anorectal malformations is important. The information can help us in preoperative planning for surgical repair and in predicting a patient's prognosis. For patients with postoperative incontinence, the anatomic imaging is especially useful. Magnetic resonance imaging (MRI) is a relatively new diagnostic tool that generates images of sections of the body taken in any plane. From Oct. 1989 to Dec. 1990, twelve patients received MRI examination, imaging the pelvis and lumbosacral spine in the sagittal, transverse, and coronal planes. Normal anorectum in 2 cases was recorded for comparison. The other ten cases included three of postoperative incontinence, three of cloacal anomaly, and four of questionable level of anorectal anomaly before MRI evaluation. Our experience proved that MRI is a useful examination in selected patients with anorectal malformation. To be cost-effective, we suggest that MRI is performed only in patients with postoperative incontinence and some questionable cases.

Anal Canal↗
PubMed1991

[Castleman's disease: 6 cases report].

The authors present six cases of Castleman's disease. One was located in the left middle lung near the lung root, one in the right posterior mediastinum, one in the gallbladder fossa, one in the left perinephric space, and the last two in the mesenteric region. All the hyaline-vascular type showed good enhancement after contrast medium injection. The only one case of plasma cell type located in mesentery was not enhanced after contrast injection. Ultrasound of abdomen was performed in one of the six patients, which showed homogeneous and hypoechoic in echo-pattern.

Adolescent↗
PubMed1990

Effect of a new computed tomographic image transfer system on management of referrals to a regional neurosurgical service.

A computed tomographic image transfer system ('Image Link') was used to link scanners within the Oxford region, UK, to the regional neurosurgical service. 100 consecutive neurosurgical referrals were examined by this system; 43% of the emergency referrals did not require transfer, 31% were transferred electively, and 26% urgently. Most of the patients defined as potentially hazardous for transfer (10/11) did not require neurosurgical intervention. The delay by the use of the system was negligible and early detection of intracranial haematoma contributed to good outcome in some head injured patients. Overall, 3,170 miles of ambulance journey were avoided. Use of image link has led to substantial improvements in management of neurosurgical emergency referrals, cost-effectiveness of neurosurgical and ambulance facilities, and interhospital communication between doctors.

Adolescent↗