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C Huh

Publications and source records attributed to C Huh.

14 recordsLinked to original sources
PubMed2003

A review of US anthropometric reference data (1971-2000) with comparisons to both stylized and tomographic anatomic models.

Two classes of anatomic models currently exist for use in both radiation protection and radiation dose reconstruction: stylized mathematical models and tomographic voxel models. The former utilize 3D surface equations to represent internal organ structure and external body shape, while the latter are based on segmented CT or MR images of a single individual. While tomographic models are clearly more anthropomorphic than stylized models, a given model's characterization as being anthropometric is dependent upon the reference human to which the model is compared. In the present study, data on total body mass, standing/sitting heights and body mass index are collected and reviewed for the US population covering the time interval from 1971 to 2000. These same anthropometric parameters are then assembled for the ORNL series of stylized models, the GSF series of tomographic models (Golem, Helga, Donna, etc), the adult male Zubal tomographic model and the UF newborn tomographic model. The stylized ORNL models of the adult male and female are found to be fairly representative of present-day average US males and females, respectively, in terms of both standing and sitting heights for ages between 20 and 60-80 years. While the ORNL adult male model provides a reasonably close match to the total body mass of the average US 21-year-old male (within approximately 5%), present-day 40-year-old males have an average total body mass that is approximately 16% higher. For radiation protection purposes, the use of the larger 73.7 kg adult ORNL stylized hermaphrodite model provides a much closer representation of average present-day US females at ages ranging from 20 to 70 years. In terms of the adult tomographic models from the GSF series, only Donna (40-year-old F) closely matches her age-matched US counterpart in terms of average body mass. Regarding standing heights, the better matches to US age-correlated averages belong to Irene (32-year-old F) for the females and Golem (38-year-old M) for the males. Both Helga (27-year-old F) and Donna, however, provide good matches to average US sitting heights for adult females, while Golem and Otoko (male of unknown age) yield sitting heights that are slightly below US adult male averages. Finally, Helga is seen as the only GSF tomographic female model that yields a body mass index in line with her average US female counterpart at age 26. In terms of dose reconstruction activities, however, all current tomographic voxel models are valuable assets in attempting to cover the broad distribution of individual anthropometric parameters representative of the current US population. It is highly recommended that similar attempts to create a broad library of tomographic models be initiated in the United States and elsewhere to complement and extend the limited number of tomographic models presently available for these efforts.

Adult↗
PubMed2001

Influences of parameter uncertainties within the ICRP 66 respiratory tract model: particle deposition.

Risk assessment associated with the inhalation of radioactive aerosols requires as an initial step the determination of particle deposition within the various anatomic regions of the respiratory tract. The model outlined in ICRP Publication 66 represents to date one of the most complete overall descriptions of not only particle deposition, but of particle clearance and local radiation dosimetry of lung tissues. In this study, a systematic review of the deposition component within the ICRP 66 respiratory tract model was conducted in which probability density functions were assigned to all input parameters. These distributions were subsequently incorporated within a computer code LUDUC (LUng Dose Uncertainty Code) in which Latin hypercube sampling techniques are used to generate multiple (e.g., 1,000) sets of input vectors (i.e., trials) for all of the model parameters needed to assess particle deposition within the extrathoracic (anterior and posterior), bronchial, bronchiolar, and alveolar-interstitial regions of the ICRP 66 respiratory tract model. Particle deposition values for the various trial simulations were shown to be well described by lognormal probability distributions. Geometric mean deposition fractions from LUDUC were found to be within approximately +/- 10% of the single-value estimates from the LUDEP computer code for each anatomic region and for particle diameters ranging from 0.001 to 50 microm. In all regions of the respiratory tract, LUDUC simulations for an adult male at light exertion show that uncertainties in particle deposition fractions are distributed only over a range of about a factor of approximately 2-4 for particle sizes between 0.005 to 0.2 microm. Below 0.005 microm, uncertainties increase only for deposition within the alveolar region. At particle sizes exceeding 1 microm, uncertainties in the deposition fraction within the extrathoracic regions are relatively small, but approach a factor of 20 for deposition in the bronchial region. Deposition fractions for particles above 1 microm become very uncertain within the deeper regions of the lungs (bronchiolar and alveolar-interstitial).

Body Height↗
PubMed2000

Genomic structure and chromosome location of the mouse RelA p65 gene (Rela).

The RelA (p65) subunit of transcription factor NF-kappaB plays a critical role in development, and rela(-/-) knockout mice die in utero from massive liver apoptosis. Only partial sequences of the mouse Rela gene are available. We have determined the genomic structure of mouse Rela and promoter, and have mapped the gene to chromosome 19B1-3.

Animals↗
PubMed1996

Mouse and rat cystatin C: Escherichia coli production, characterization and tissue distribution.

Recombinant mouse (Mus musculus) and rat (Rattus norvegicus) cystatin C were produced by expression in Escherichia coli, isolated and functionally characterized. The mouse and rat inhibitors were both fully active in titrations of papain. Determination of equilibrium constants for dissociation (Ki) for their complexes with the target proteinase, cathepsin B, produced values not largely different from that for human cystatin C (Ki 0.07-0.13 nM). Rabbit antisera against mouse and rat cystatin C were produced and used for improved affinity purification of the recombinant inhibitors. Affinity purified immunoglobulins isolated from the antiserum against mouse cystatin C were used for construction of a sensitive enzyme-linked immunosorbent assay. The assay was used to demonstrate a high degree of immunological cross-reactivity between mouse and rat cystatin C and could be used for cystatin C quantification in mouse and rat tissue homogenates. All tissues analyzed contained cystatin C, with a relative content very similar to that of human tissues. For all species, brain tissue contained the highest cystatin C amounts and liver the lowest, whereas kidney, spleen and muscle tissues were intermediate in content. In the mouse, a notable high cystatin C content in parotid gland tissue was observed. The high degree of similarity in distribution pattern and functional properties for mouse, rat and human cystatin C indicates that a murine model should be relevant for studies of the human disease, hereditary cystatin C amyloid angiopathy.

Amino Acid Sequence↗
PubMed1996

Postterm pregnancy: putting the merits of a policy of induction of labor into perspective.

BACKGROUND: Several randomized, controlled trials compared the policies of induction of labor and expectant management for women who reach 41 weeks' gestation, and although they suggest a better outcome for mothers and infants with such a policy in place, controversy continues as to which is the better form of care. The Canadian Multicenter Postterm Pregnancy Trial (CMPPT) enrolled 3407 women, of whom 1701 were randomized to a policy of induction of labor (induced group) and 1706 were randomized to a policy of expectant management (expectant group). Secondary analyses of data from the CMPPT were undertaken to explore a number of controversial issues. METHODS: We used data from the CMPPT to explore further the timing of delivery for women enrolled between 41 0/7 and 41 6/7 weeks' gestation, the potential impact of more liberal use of prostaglandins on cesarean section rates, and the relative merits of induced versus spontaneous labor in the two groups. RESULTS: Most women in the CMPPT (89%) were enrolled at 41 0/7 to 41 6/7 weeks' gestation, of whom 86.2 percent in the induced group and 63.6 percent in the expectant group gave birth before 42 weeks' gestation. Assuming that administration of prostaglandins would reduce the likelihood of cesarean section by 12 to 15 percent, cesarean section rates were reduced in the induction group from 21.2 percent to 20.8 to 20.9 percent, and in the expectant group from 24.5 percent 23.3 to 24.2 percent. If labor was induced as part of a policy of expectant management, the cesarean section rate was much higher (33.5%) than if labor was either spontaneous or induced as part of a policy of induction (18.5%, 22.4%). CONCLUSIONS: Women should be informed of the benefits and risks associated with the policies of induction of labor and expectant management, and their preferences regarding these policies should be respected.

Adult↗
PubMed1995

Structural organization, expression and chromosomal mapping of the mouse cystatin-C-encoding gene (Cst3).

Cystatin C (CstC) is a potent cysteine-proteinase inhibitor. The structure of the mouse CstC-encoding gene (Cst3) was examined by sequencing a 6.1-kb genomic DNA containing the entire gene, as well as 0.9 kb of 5' flanking and 1.7 kb of its 3' flanking region. The sequence revealed that the overall organization of the gene is very similar to those of the genes encoding human CstC and other type-2 Cst, with two introns at positions identical to those in the human gene. The promoter area does not contain typical TATA or CAAT boxes. Two copies of a Sp1-binding motif, GGGCGG, are present in the 5' flanking region within 300 bp upstream from the initiation codon. A hexa-nucleotide, TGTTCT, which is a core sequence of the androgen-responsive element (ARE), is found in the promoter region. This region also contains a 21-nucleotide sequence, 5'-AGACTAGCAGCTGACTGAAGC, which contains two potential binding sites for the transcription factor, AP-1. The mouse Cst3 mRNA was detected in all of thirteen tissues examined by Northern blot analysis. Cst3 was mapped in the mouse to a position on distal chromosome 2.

Amino Acid Sequence↗
PubMed1995

A study of the safety and clinical efficacy of flexible sigmoidoscopy and colonoscopy after recent colonic surgery in 52 patients.

OBJECTIVE: Our objective was to evaluate the safety of lower endoscopy after colonic surgery, which has been unstudied and unknown. Endoscopy could promote suture breakdown at sites of colonic anastomoses, ostia, or repair by colonic abrasion or stretch from endoscopic intubation, torque, and insufflation. METHODS: Risks versus benefits of lower endoscopy performed within 3 wk of colonic surgery were retrospectively analyzed at five medical centers in 36 patients undergoing sigmoidoscopy and 72 age-and-sex-matched controls, and in 16 patients undergoing colonoscopy and 32 age-and-sex-matched controls. RESULTS: Sigmoidoscopy indications included rectal bleeding in 14, distal colonic obstruction in 12, and other in 10. Sigmoidoscopy provided the diagnosis in 18 (54%) of 33 cases (excluding three therapeutic sigmoidoscopies, control rate = 30%, p < 0.01, X2, including colon cancer in six and benign stricture in five. Sigmoidoscopy led to colonic surgery in nine and medical therapy changes in four. Colonoscopy indications included colonic bleeding in seven, colonic obstruction in five, and other in four. Colonoscopy provided the diagnosis in nine (56%, control rate = 56%, NS, X2). Colonoscopy led to colonic surgery in three and chemotherapy in one. Two endoscopic complications, unrelated to suture breakdown, occurred: An acutely ill patient developed hypotension during sigmoidoscopy which resolved with intravenous fluid resuscitation. A contained sigmoid diverticular perforation became a free perforation (requiring laparotomy) after colonoscopy. Both control groups had no endoscopic complications (NS, Fisher's exact test). CONCLUSION: In this study, the benefits outweighed the risks of postoperative sigmoidoscopy and colonoscopy. Clinicians should use discretion and perform colonoscopy or sigmoidoscopy after colonic surgery, particularly bowel anastomosis, only for clinically important indications. Endoscopy is contraindicated when colonic wound dehiscence or bowel perforation is suspected.

Colon↗
PubMed1995

A study of the safety and clinical efficacy of esophagogastroduodenoscopy after esophageal, gastric, or duodenal surgery in 60 patients.

OBJECTIVES: Our purpose was to evaluate the safety of esophagogastroduodenoscopy (EGD) after esophageal, gastric, or duodenal surgery, a previously unstudied subject. EGD could promote suture breakdown at sites of anastomoses, ostia, or repair by abrasion or stretch from endoscopic intubation, torque, or insufflation. METHODS: Risks versus benefits of EGD performed within 24 days of upper gastrointestinal surgery were analyzed at five medical centers in 60 study patients and were compared with 120 controls matched for age, sex, and EGD indication. RESULTS: Of 13,170 hospitalized patients undergoing EGD, 60 patients (0.46%) had EGD within 24 days of upper gastrointestinal surgery. EGD indications in study patients included gross upper gastrointestinal bleeding in 24, nausea and vomiting in 23, bright red blood per rectum in four, dysphagia in three, abdominal pain in three, and "other" in three. EGD was performed on average 14.7 +/- 7.2 (SD) days after surgery. EGD provided the diagnosis in 45 (75%) study patients (control rate = 77%, not significantly different, chi 2). In particular, postoperative EGD provided the diagnosis in 20 (83%) of 24 patients with upper gastrointestinal bleeding (control rate = 92%, not significantly different, Fisher's exact test). Thirteen study patients (22%) had upper gastrointestinal lesions directly related to surgery including: anastomotic ulcers in six, anastomotic erosions in six, and an excessively tight Nissen fundoplication in one. One additional patient at EGD had extrinsic duodenal compression attributed to postoperative adhesions. EGD led to surgery in nine and to successful endoscopic therapy in six. No study patient experienced an endoscopic complication. The control group had one endoscopic complication (not significantly different rates, Fisher's exact test). CONCLUSION: In this study, the benefits outweighed the risks of postoperative EGD when performed more than 7 days after surgery: the diagnostic yield was high and the complication rate was low. Indeed, the yield and risks were similar to that of other EGDs. Postoperative EGD identified a surgical complication in about 20% of cases. Clinicians should use discretion and perform postoperative EGD for clinically important indications. EGD is contraindicated when wound dehiscence or bowel perforation is suspected.

Case-Control Studies↗
PubMed1994

The use of a paraspinal field block before epidural analgesia for labour.

The purpose of this study was to determine whether paraspinal field block (PSFB) reduced the pain of epidural needle insertion and the incidence of prolonged post partum back pain in patients receiving epidural analgesia for labour. Patients were randomly assigned to receive local infiltration only with 1-1.5 ml of 1.5% lidocaine (group C, N = 27) or PSFB consisting of an additional 1 ml of 1.5% (group S, N = 30) through the midline skin wheal, on either side of the midline (total 2 ml), near the lamina, before needle insertion. Back pain was measured at the time of needle insertion, before discharge from hospital and 6 weeks post partum, by a blinded observer. There were no differences between groups in maternal or neonatal demographic data. There was no difference in back pain at any of the times measured. The incidence of severe back pain 6 weeks post partum was 0% in group C and 6.6% in group S (combined incidence group C+group S = 3.5%). The cause of post partum back pain is multifactorial and is not dependent on technique of epidural insertion. We conclude that PSFB is ineffective in reducing the pain of epidural needle insertion in labouring patients. Although this study was too small to detect a difference in incidence of late post partum back pain, it appears to be less common than previously reported.

Journal Article↗
PubMed1993

Uterine incision and maternal blood loss in preterm caesarean section.

The purpose of this study was to compare maternal blood loss, as reflected by the perioperative changes in haemoglobin (Hgb), the incidence of severe bleeding (estimated blood loss > 1000 ml) at operation, and the need for blood transfusion, between patients who had classical caesarean section (CCS) and lower segment caesarean section (LSCS) at 34 weeks gestation or less. The data from 31 women delivered by CSS between 25 and 34 weeks gestation were compared, in a retrospective case-control fashion, to another 31 women delivered by LSCS. Patients were matched for gestational age at delivery, the type of anaesthesia, and the prior use of tocolytic therapy. Excluded from the study were patients who had an antepartum haemorrhage or placenta praevia. There was a significantly greater reduction in maternal Hgb and an higher incidence of severe bleeding in the CSS group compared to the LSCS group (P < 0.05). The results of this study suggest that for preterm caesarean sections, the classical incision is associated with increased blood loss compared to the lower segment incision.

Blood Loss, Surgical↗
PubMed1993

Spinal subdural haematoma in a parturient after attempted epidural anaesthesia.

We report a case of spinal subdural haematoma with neurological deficit in a 36-yr-old woman following Caesarean section for severe preeclampsia and placental abruption. She had been taking chronic trifluoperazine treatment for depression. Her activated partial thromboplastin time (aPTT) was 49 sec (normal = 26-36) but all other tests of coagulation were normal. Epidural anaesthesia was attempted but, despite a negative test dose, injection of local anaesthetic resulted in a generalized seizure and general anaesthesia was induced. Seventy-two hours after delivery, she was found to have bilateral leg weakness, urinary incontinence, absent rectal sphincter tone and asymmetrical leg reflexes. The diagnosis of spinal haematoma was confirmed by magnetic resonance imaging. She underwent emergency laminectomy and made a full neurological recovery.

Adult↗
PubMed1977

Double-blind, controlled study of clemastine fumarate, chlorpheniramine and placebo in the symptomatic treatment of seasonal allergic rhinitis in desensitized and nondesensitized patients.

In double-blind trials clemastine fumarate 2.68 mg. chlorpheniramine 4 mg and placebo were randomly assigned to two groups of patients with seasonal allergic rhinitis. Thirty-nine desensitized patients were given one of the three test drugs in a parallel design; 67 nondesensitized patients each received two of the three drugs in a crossover design. Assessment of drug activity in each study was by whole body plethysmography and intranasal color photography as well as by subjective methods. Objective measurements showed clemastine fumarate was significantly superior to placebo and often better than chlorpheniramine in decreasing true nasal resistance and relieving nasal congestion. High placebo responses characterized the subjective evaluations, although the active drugs were clearly better. Responses varied somewhat between desensitized and nondesensitized patients. The number of reports of sedative effect, high in all groups, seemed to be more closely related to these antihistamine conditioned patients than to activity of the drugs themselves, based on previous reports of low sedation with clemastine fumarate. The techniques described proved very useful in distinguishing relative activity of antihistamines. Clemastine fumarate, the new antihistamine studied, appears to offer certain advantages over the older drug, chlorpheniramine.

Airway Resistance↗