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Biomedical subjects

P Woo

Publications and source records attributed to P Woo.

At least 181 records · Page 10Linked to original sources
PubMed1978

Combined genetic deficiency of C6 and C7 in man.

By routine screening of sera, a subject was discovered who showed a sub-total deficiency of C6 and C7. No clinical disease was associated with this deficiency which was transmitted through the subject's family as a single genetic characteristic, the C6 deficiency being associated with a silent allele at the structural locus. The propositus was found to have low quantities of an abnormal C6 which was both antigenically deficient and smaller in size than normal C6 (110,000 daltons compared with 140,000 daltons) and small quantities of apparently normal C7. It is concluded that the most likely explanation for this defect is that the subject has a structural mutation in his C6 gene which produces hyopsynthesis not only of C6 but also of the closely linked gene for C7. These findings suggest the possibility that C6 and C7 may function as a single genetic unit and that the primary transcript copied from the genome includes information for both proteins.

Aged↗
PubMed1970

Trypanosomes in cattle in southern Ontario.

Trypanosomes were found in the blood of 155 out of 274 Holstein cows of various ages from southern Ontario. The incidence varied from about 8% in one herd to about 85% in another herd. Two species of trypanosomes were found in cattle in the Guelph area. One was Trypanosoma theileri. The other was a much smaller trypanosome which morphologically resembles T. uniforme of the Salivaria. This is the first report of such a trypanosome in cattle in North America. Epimastigotes from blood agar slants of both trypanosomes, when inoculated into chick embryos, produced blood forms morphologically identical to those found in the blood of the cows. T. theileri survived at least two weeks in blood kept at 4-5 degrees C.

Agar↗
PubMedDate not supplied

Prehospital delay and emergency department management of ischemic stroke patients in Taiwan, R.O.C.

OBJECTIVE: To determine the magnitude of prehospital delay and how much time elapses between emergency department (ED) presentation and ED clinical investigations in ischemic stroke patients. Factors associated with prehospital delay were also correlated with demographic characteristics and clinical variables. METHODS: A prospective, observational study was conducted simultaneously in five community teaching hospitals in Taiwan from October 1997 to April 1998. Included were all patients presenting with acute ischemic stroke. In each case, diagnosis was confirmed by cranial CT scanning. The main outcomes measured were the number of patients presenting at the ED more than two hours after the onset of symptoms (T(prehospital) > 2 hr) and the time spent at the ED for ED physician evaluation, cranial CT scanning, laboratory examinations, and neurologic consultation. Chi-square testing was used to compare the characteristics of patients with T(prehospital) > 2 hr and those with T(prehospital)< or = 2 hr. Independent predictors of T(prehospital) > 2 hr were determined using multiple logistic regression. RESULTS: Of 157 patients observed, 105 (67%) arrived at the hospital more than 2 hr after the onset of symptoms. Average time from ED presentation to examination by ED physician, completion of CT scanning, and laboratory investigations was 3, 58, and 61 minutes, respectively. Mean time from ED presentation to neurologic consultation was 174 minutes for 38 patients [24%, (38/157)]. The factor associated with T(prehospital) > 2 hr was interhospital transfer (p < 0.05). CONCLUSION: This study reveals that delayed management of stroke patients is mainly due to delayed ED presentation and to difficulties in obtaining neurologic consultation. Ideally, a stroke center may be incorporated within the EMS system to overcome delays due to interhospital transfer and to difficulties in obtaining neurologic consultation.

Adult↗
PubMedDate not supplied

Dynamics of venturi jet ventilation through the operating laryngoscope.

Venturi jet ventilation with the oxygen injector needle placed within the lumen of the laryngoscope was studied systematically in two dogs undergoing repeated general anesthesia suspension laryngoscopy. Using a total body plethysmograph, the effect of changes of needle angle, position and its effect on tidal volume delivery were measured. The changes of pressure regulator, flow rate and needle size were correlated with the volume delivery. Intratracheal pressure during Venturi ventilation was measured. Correlation of arterial blood gases and minute ventilation with the system was done. While ventilatory capacity is able to be achieved predictably, there are many variables. Optimal placement of the needle tip for maximum safety and efficiency appears to be at the midthird or lower third of the laryngoscope. It is important to center the needle axis to the laryngoscope axis. Other parameters subject to choice are the selection of needle size, regulator pressure setting and flow rate setting. By first selecting the correct needle size that will hyperinflate the subject, the pressure regulator can then be reduced to achieve ventilatory volumes similar to spontaneous tidal volumes. In prolonged use, the Venturi system was able to provide excellent ventilation safely and predictably.

Animals↗
PubMedDate not supplied

Congenital laryngeal atresia. Histopathologic study of two cases.

Two specimens of laryngeal atresia were studied. In the first case stenosis was hard due to noncanalization of the anterior cricoid cartilage. In the second case there was a soft stenosis from limited canalization of the endoluminal soft tissue. Additionally, the first case had a posterior cleft with a persistent pharyngotracheal duct. The stenotic soft-tissue elements in both cases contained striated muscle fibers that interdigitated across the midline. The mucosa on the inferior surface of the hard stenosis was grossly thickened and contained large mucous glands. The embryologic significance of these anomalies is discussed. Presumably these cases represent anomalies caused by different embryologic events.

Epiglottis↗
PubMedDate not supplied

Venturi jet ventilation through the metal endotracheal tube: a nonflammable system.

In an effort to design a fireproof and reliable method of ventilation during CO2 laser laryngoscopies, a new Venturi jet endotracheal tube coupler has been designed. This allows microdirect laryngoscopy. Its design features are described. Sixteen clinical cases of various laryngeal pathologies treated with direct laryngoscopy and laser excision are ventilated using this system. The clinical data and experiences are discussed. The arterial blood gases done at 20 minutes after muscular paralysis showed a median value of pH 7.45/PO2 252/PCO2 36. No complications or adverse effects were noted. The Venturi jet endotracheal tube coupler allows for jet ventilation through a metal endotracheal tube with reliable ventilation. This is an alternate, reliable, and fire-safe method during laser use.

Adult↗
PubMedDate not supplied

Histochemical study of posterior cricoarytenoid muscle reinnervation by a nerve-muscle pedicle in the cat.

Reinnervation of the posterior cricoarytenoid (PCA) muscle with a nerve-muscle pedicle (NMP) has been proposed for patients with bilateral abductor vocal cord paralysis. Since its success has been controversial, a glycogen depletion histochemical technique was used to examine reinnervation. An ansa cervicalis NMP was implanted into the denervated PCA in nine cats. Eight months later, vocal cord activity was evaluated. The NMP nerve was stimulated extensively in seven cats (experimental group). Optical densities of NMP-supplied PCA muscle fibers from experimental and control groups were compared to detect differences in glycogen content. The results demonstrated quantitative evidence of reinnervation in two experimental animals. Electrical stimulation of the NMP produced abduction in one of these two animals, but was never observed during spontaneous respiration or airway occlusion. These observations indicate that reinnervation can occur but abduction requires electrical stimulation. The NMP technique may be more successful with an electrical pacer.

Animals↗
PubMedDate not supplied

Phonatory airflow analysis in patients with laryngeal disease.

Phonatory airflow was recorded in 150 patients with various laryngeal diseases and in 60 persons with normal voices. All subjects produced several sustained vowels at different loudness levels. Disturbances of voice due to laryngeal disease may be manifested as variations of mean flow (DC), alternating flow (AC), or as a variation in the amplitude of the frequency components of the airflow signal (frequency spectra). The quantification of airflow characteristics is important if the clinician is to have a better understanding of laryngeal disease. Furthermore, preoperative and postoperative analysis can serve to document therapeutic effectiveness.

Adult↗
PubMedDate not supplied

Cytokine polymorphisms and inflammation.

Cytokines and chemokines are important mediators of inflammation. The numbers are still expanding. It is clear that these mediators act in positive and negative feedback loops in a complex network to allow inflammation as well as repair to take place. The fact that many of these molecules and their receptors are polymorphic with functional consequences is becoming clear. Such genetic polymor phisms will impact on the network to produce a variety of inflammatory responses, both acute and chronic.

Acute Disease↗