Biomedical subjects

K S Chou

Publications and source records attributed to K S Chou.

8 recordsLinked to original sources

PubMed2005

A novel method to make regenerable core-shell calcium-based sorbents.

A sorbent having a calcium oxide core and a clay shell was prepared and shown to be capable of reusable applications in absorption and desorption processes for carbon dioxide. The novelty of this sorbent is that only calcium carbonate and clay are used for its preparation with water as a binder. A two-step granulation procedure is used to get the core and then another step to coat the shell layer with the clay powder. A repeated wet-and-dry procedure probably makes the core porous yet strong enough to serve as a sorbent. The pellet is then calcined at 1200 degrees C for 2h to reach its final structure. The core-shell pellets have an overall diameter of 4.4mm with average shell thickness of 0.45 mm, crush load of 35 N and attrition index of 0.035 wt%/h. These results indicate that the pellets will probably be capable of withstanding the stress in future applications. Carbon dioxide absorption at or below 300 degrees C showed a maximum weight gain of 38% for our pellets. Finally, desorption in nitrogen at 800 degrees C can restore the pellet to its original state and hence it is ready for re-use as a sorbent.

Absorption↗

PubMed2001

The adsorption of Congo red and vacuum pump oil by rice hull ash.

Rice hull ash (RHA) of large surface area was obtained by acid wash and then calcination at 600 degrees C for 4 h. The white ash was then mixed with kaolin and starch to make pellet adsorbents with reasonable strength to be utilized in a packed column. Both ash and pellet samples showed good adsorption capacities toward the organic substances in wastewater. Furthermore, the surface nature of the white ash and pellet adsorbent could be modified through either hydration or esterification reactions. Corresponding changes in silanol concentrations were successfully correlated to changes in adsorption capacity toward either Congo red or vacuum pump oil molecules.

Adsorption↗

PubMed1996

Preferred nucleotide sequence at the integration target site of human T-cell leukemia virus type I from patients with adult T-cell leukemia.

Human T-cell leukemia virus type I (HTLV-I) is etiologically associated with adult T-cell leukemia/lymphoma (ATL). We cloned and sequenced host DNA adjacent to the long terminal repeats of HTLV-I from uncultured leukemic cells of 4 ATL patients. The region flanking the provirus was generally A/T-rich (60-64% A/T), and a nucleotide composition bias was noticed when sequences within 25 bp on both sides of the integration target site were analyzed. In the 6-bp direct repeat, both end positions are preferentially occupied by G/C, whereas the middle positions are preferentially occupied by A/T. Furthermore, AA or TT dinucleotides are frequently present on each side adjacent to the center of the direct repeat. Our finding suggests preferential integration target sites of HTLV-I in the host genome. Further study is warranted to determine whether each of the target sequence preference is a general property of HTLV-I integration or may be associated with the leukemogenesis of ATL.

Adult↗

PubMed1995

Nucleotide sequence analysis of a full-length human T-cell leukemia virus type I from adult T-cell leukemia cells: a prematurely terminated PX open reading frame II.

Human T-cell leukemia virus type 1 (HTLV-1) is etiologically associated with adult T-cell leukemia/lymphoma (ATL). The prototypic HTLV-1, ATK, is the only full-length provirus cloned from uncultured leukemic cells and completely sequenced prior to this study. We have determined the complete nucleotide sequence of another full-length HTLV-1 provirus cloned directly from leukemic cells. A premature termination codon was found in the second open reading frame (orf II) of the pX region. Our finding indicates that open reading frame II of the HTLV-1 pX region is not required for outgrowth of ATL leukemic clones in vivo.

Amino Acid Sequence↗

PubMed1992

Early diagnosis of a vein of Galen aneurysm: report of a case.

Congenital vascular malformation with an aneurysm of the vein of Galen is rarely seen, particularly in the prenatal period. With the advancement of diagnostic techniques such as ultrasonography, we were able to detect a case prenatally and to diagnose it postnatally.

Cerebral Veins↗

PubMed1989

[Colpocephaly: report of a case].

A 43-year-old G12P4 mother delivered, at 35 weeks of gestation, a girl with a birth weight of 1980 g. Since her last pregnancy 20 years ago, she had had 8 subsequent abortions. Amniocentesis was done at the 18th week of gestation and revealed negative findings. Because of maternal age, the baby was delivered by cesarean section. The family history was not pertinent. After birth, the baby was noted to have a large head girth (34.5 cm) with widened anterior fontanel and mild frontal protrusion. The neurosonography showed symmetric dilatation of the frontal horns and temporal horns of the lateral ventricles, hyperechodensity in the periventricular wall, absence of corpus callosum and cavum septum pellucidum, and a large communicating pear-shaped ventricular cavity on the posterior coronal view. The brain CT scan demonstrated evidence of extreme dilatation of the occipital horns of the lateral ventricles and prominence of the subarachnoid spaces in the supra-Sylvian fissures. Based on these findings, the baby was diagnosed as a case of colpocephaly. Patients with colpocephaly usually have moderate to severe mental retardation, motor deficits, visual abnormalities and seizures. They need speech and physical therapies as early as possible. Therefore, if early diagnosis is confirmed by fetal sonography before the 5th month of gestation, this congenital brain malformation can be prevented by therapeutic abortion.

Brain↗

PubMed1989

[Globus hystericus--reports on 25 ENT cases and literature review].

From October 1987 to March 1988, 25 cases (15 males and 10 females) with the globus hystericus were evaluated at 804 Army General Hospital. All patients underwent complete physical examination, routine laboratory work-up, roentgenographic examination of paranasal sinuses, cervical region and chest, upper G-I series, fiberoptic endoscopy and esophagoscopy. 2.3% of the patients in this study had the globus hystericus, the male to female ratio was 1.5:1, the mean ages were 51 years, the average educational level was low, the endoscopic findings were vallecular cyst in 3 cases (12%), epiglottic cyst in 2 cases (8%), the roentgenographic findings were maxillary sinusitis in 3 cases (12%), cervical osteophytes in 9 cases (36%) gastric ulcer, duodenal ulcer and diverticulum in 1 cases (4%) respectively. We analyzed the positive findings and reviewed the literature.

Adult↗

PubMedDate not supplied

[Nephrotic syndrome complicated with cerebral infarction: report of one case].

A 13-year-old boy was admitted to this hospital for evaluation of pitting edema of both legs. Three years ago, he had been diagnosed to have nephrotic syndrome. Two and half years ago, because of persistent heavy proteinuria, poor response to steroids and frequent relapse of disease, a renal biopsy was done; characteristics of IgM nephropathy was shown. About a year previously, the patient felt dizziness and weakness of the left side of his body upon awakening one morning. Neurologic examination showed loss of muscle tone, muscle power and deep tendon reflexes. Sensory and cranial nerve function were intact. Blood pressure was normal. The CT scan of brain showed a patch of low attenuation area in the right temporal region, obliteration of the right cortical sulci and mild compression of right lateral ventricle. A diagnosis of nephrotic syndrome with right cerebral infarction was made. The patient's condition became stable two days later after mannitol infusion, correction of electrolytes, and supportive therapy. According to literature, most cases of nephrotic syndrome complicate with renal thrombosis, pulmonary emboli, and deep vein thrombosis. Few cases complicate with cerebral thrombosis and infarction. If patient have low plasma albumin and anti-thrombin III level, hyperfunction of platelet aggregability and use long-term diuretic therapy, they may be at higher risk of thromboembolic complications. If thromboembolic complications exist, anticoagulation treatment should be instituted. Prophylactic therapy with aspirin or dicumarol is not currently recommended.

Adolescent↗