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Biomedical subjects

P Woo

Publications and source records attributed to P Woo.

At least 163 records · Page 9Linked to original sources
PubMed1987

Tracheobronchial abnormalities in infants with bronchopulmonary dysplasia.

Twelve preterm infants with bronchopulmonary dysplasia underwent bronchoscopy to determine if airway abnormalities were contributing to persistent pulmonary problems. Indications for bronchoscopy were persistent atelectasis, lobar hyperinflation, or both on chest radiograph (11 patients), unexplained respiratory distress (three patients), and aspiration of tissuelike material from a tracheostomy (one patient). Bronchoscopy revealed abnormalities of the trachea, bronchi, or both in all infants, including partial or near total airway occlusion by abnormal growth of tissue (10 patients); tracheomalacia, bronchomalacia, or both (three patients); and inspissated secretions (two patients). Seven infants died during initial hospitalization. Tracheobronchial abnormalities should be considered as a cause of persistent pulmonary problems in infants with bronchopulmonary dysplasia.

Bronchi↗
PubMed1987

Prevalence, natural history and surgical treatment of exophthalmos.

The 95% confidence limits of exophthalmometer measurements have been defined by a single observer in 105 individuals who had no known thyroid disease, and found to be 10.5-18.8 mm. Measurements in 308 patients with thyrotoxicosis have shown that exophthalmos (greater than 19 mm) of one or both eyes was present in 21.3% of the patients. Among the 122 thyrotoxic patients whose exophthalmometer measurements could be performed annually for 3-19 years after correction of the thyrotoxicosis (usually with 131I), exophthalmos remained stable in 78.7%, worsened in 15.6% and became less severe in 5.7% of the patients. Transantral decompression of the orbits was performed in 15 patients with rapid subjective improvement in all and reduction in exophthalmometer measurements of 3.6 +/- 0.5 (mean +/- SEM) mm, and no serious side-effects. In view of these findings, transantral decompression should be considered more frequently in the treatment of severe or cosmetically damaging exophthalmos.

Adolescent↗
PubMed1986

Trauma center verification.

Sanctioned trauma center designation began in the late 1970's to improve hospital capabilities to care for injured patients. Guided by criteria established by the American College of Surgeons Committee on Trauma and led by surgeons dedicated to improving trauma care, many states focused early on the quality of care issue only to later struggle with the political consequences that followed the designation process. Institutional commitment to trauma care was often stated but seldom measured. Unlike the designation process with its strong emphasis on capabilities assessment, the verification process focused on performance documentation. Confirmation was sought in response time of key personnel, completeness of registry database, and trauma death audits. Trauma Committee minutes were reviewed and prehospital personnel interviewed to confirm institutional involvement in paramedic education and overall EMS system design. Other areas of documentation included trauma education at all levels, research, nursing audits, and outreach programs. We conclude that trauma center designation and verification are both essential and complementary. Effective trauma system performance requires trauma center designation plus a verification process to confirm institutional commitment of these resources for optimal care of the injured patient.

Accreditation↗
PubMed1986

Phonatory volume velocity recording by use of hot film anemometry and signal analysis.

Phonatory airflow volume velocity signal was recorded from nine normal adult males and eight hoarse patients with laryngeal carcinoma; hot film anemometry and computer-aided signal analysis were used. Marked differences in phonatory flow signal were seen in the two groups. The normal phonatory flow signal is quasiperiodic, with excellent cycle-to-cycle repetition at the frequency of vocal fold vibration. The signal's spectral energy is dominated by the fundamental and its harmonics. The phonatory flow signal in cancer is characterized by random and aperiodic fluctuations. There is decreased AC-to-DC signal ratio. The phonatory signal spectra reveal little harmonic power. The loss of periodic flow signal is consistent with clinical observation of aperiodic vocal fold vibration in cancer. The analysis of airflow signal is a potentially valuable method for monitoring airflow during phonation in conditions affecting the larynx.

Adult↗
PubMed1986

The effect of tracheostomy on posterior cricoarytenoid muscle.

It has been reported previously that the amount of electromyographic (EMG) potential of the posterior cricoarytenoid (PCA) decreases after prolonged tracheostomy. It is, therefore, reasonable to assume that a significant alteration of the biochemical characteristics of this muscle would also occur. In addition to histochemical analysis, endoscopic and EMG data were recorded to give a direct comparison in each subject. Seven male beagles were used for this study. Four were tracheostomized and three served as controls. They were examined immediately before and after surgery and again after 4 weeks by EMG and endoscopic techniques. Histochemical staining was performed on each subject. All three modalities failed to demonstrate a substantial difference between the controls and the experimental dogs.

Airway Obstruction↗
PubMed1985

Characterization of genomic and complementary DNA sequence of human C-reactive protein, and comparison with the complementary DNA sequence of serum amyloid P component.

Complementary and genomic DNA clones corresponding to the human C-reactive protein (CRP) mRNA and structural gene have been analyzed and compared. Nucleotide sequencing of the coding regions of both cDNA and genomic DNA revealed an additional 19 amino acid peptide not described in the published CRP amino acid sequence. The CRP gene contains a single 278 base pair intron within the codon specifying the third residue of mature CRP. The intron contains a repetitive sequence (GT)15G(GT)3 which is similar to structures capable of adopting the Z-DNA form. A comparison of CRP coding and amino acid sequences with those of serum amyloid P component revealed striking overall homology which was not uniform: a region of limited conservation is bounded by two highly conserved regions.

Amino Acid Sequence↗
PubMed1985

Controlled comparison of short-wave diathermy treatment with osteopathic treatment in non-specific low back pain.

The effectiveness of spinal manipulation carried out by a non-medical qualified osteopath was compared with that of short-wave diathermy (SWD) and a placebo (detuned SWD) in 109 patients with low back pain. More than half the subjects in each of the 3 treatment groups benefited immediately from therapy. Significant improvements were observed in the 3 groups at the end of 2 weeks' treatment, and these were still apparent at 12 weeks. The outcome of treatment was unrelated to the initial severity or duration of pain or to the trend of pain towards deterioration or improvement. It is, therefore, unlikely that the results simply reflect the natural history of low back pain. Benefits obtained with osteopathy and SWD in this study may have been achieved through a placebo effect.

Adult↗
PubMed1985

Simultaneous turnover of normal and dysfunctional C1 inhibitor as a probe of in vivo activation of C1 and contact activatable proteases.

Simultaneous turnover of normal and dysfunctional C1-inhibitor (C1-INH) was carried out in 10 normal subjects and 13 patients with rheumatoid arthritis as a measure of the in vivo activation of C1 and the contact activatable enzymes. In the first series of experiments, dysfunctional protein We was used in simultaneous turnover studies in five normal subjects and nine patients. The fractional catabolic rate of the dysfunctional C1-INH, We, (FCR(d)) was unchanged in both groups but the fractional catabolic rate of the normal C1-INH (FCR(n)) was faster in the patients compared to the controls, in particular patients with vasculitis. The enzyme-dependent catabolism defined as FCR(n-d) X concentration of C1-INH X plasma volume, was raised in the patient group, and correlated with disease activity score (r = 0.83, P less than 0.05). Neither FCR(n) nor FCR(d) was dependent on C1-INH concentration. The latter was higher in the patients (206 mg/l compared with 155 mg/l) indicating a very high synthetic rate in the patients (280.81 micrograms/kg/h compared with 179.77 micrograms/kg). In the second series of turnovers in six patients and five normal subjects, another dysfunctional C1-INH, at, was used. The FCR of C1-INH was slower than C1-INH (We) (1.88%/h compared with 2.7%/h). Enzyme-dependent catabolism of C1-INH in these patients were raised and also correlated with disease activity score (r = 0.82, P less than 0.05).

Adult↗
PubMed1984

Persistent immunoglobulin deficiency after prednisolone and antiepileptic therapy in a C2 deficient patient with lupus-like syndrome.

A homozygous C2 deficient patient with a lupus-like syndrome developed hypogammaglobulinemia soon after treatment with prednisolone together with phenytoin, replaced subsequently by carbamazepine. She suffered from recurrent chest infections and her lupus symptoms continued unabated. In vitro tests of immunoglobulin production by her Epstein Barr virus transformed B cells showed typical patterns of reduced IgA and IgG production seen in common variable hypogammaglobulinemia. An opsonisation defect to Hemophilus influenzae was also demonstrated which could be reversed by the addition of pooled human gammaglobulin. Serum IgM and IgG levels returned to normal 2 years after withdrawal of phenytoin and prednisolone, but 3 years later, she remained IgA deficient and the in vitro abnormalities persisted.

Adult↗
PubMed1983

A safe, nonflammable, all-metal, cuffless endotracheal Venturi ventilation system for use in laser surgery.

In this preliminary study with seven dogs, ventilation with a Sanders bronchoscope attachment coupled to the Norton metal endotracheal tube and use of a jet O2 injector system proved adequate for sustained oxygenation and acid-base balance. This system is shown to be superior to the conventional anesthesia volume ventilator when used with the cuffless metal endotracheal tube. The ventilatory capability can be easily adjusted upward and downward by changing the driving pressures of the reducing valve. Peak intratracheal and transtracheal pressure measurements show the pressures encountered to be similar to those of conventional volume ventilation techniques. The use of the all-metal endotracheal tube in endolaryngeal laser surgery is discussed. The advantages of such a system lie in the elimination of a flammable endotracheal tube during laser endolaryngeal surgery while preserving adequate and stable ventilation.

Animals↗
PubMed1983

The effects of intravenous pulse methylprednisolone on immunological and inflammatory processes in ankylosing spondylitis.

Acute phase reactants, serum immunoglobulins and immune complexes and T cell function were measured in eight patients with active ankylosing spondylitis (AS) before and up to 3 months after three pulses of 1 g methylprednisolone. There was a two stage effect. The first stage was an early anti-inflammatory event with a fall in clinical disease activity mirrored by changes in acute phase reactants particularly prealbumin. The second stage occurred later and was an immunological event with a fall in serum IgA and IgG and a rise in mitogenic response, mixed lymphocyte response and delayed cutaneous hypersensitivity. Most of these changes returned towards pre-treatment levels by 3 months. This study has shown that pulse methylprednisolone has an immediate anti-inflammatory and a prolonged immunological effect in AS.

C-Reactive Protein↗
PubMed1982

Complement-mediated inhibition of immune precipitation. I. Role of the classical and alternative pathways.

This study has examined the mechanisms involved in complement-mediated inhibition of immune precipitation using radiolabelled BSA and rabbit anti-BSA. Purified proenzyme C1 was capable of maintaining the complexes in soluble form during the first few minutes of reaction whereas immune precipitation was immediate in the presence of purified C1q or C1 + EDTA (ethylenediamine tetra-acetate). In C1q deficient serum, initial immune aggregation was followed by partial solubilization of the formed precipitate similar to that obtained with normal human serum in the presence of Mg EGTA. In C2 deficient serum precipitation occurred at a slow rate. Repletion of the deficient component (C1q or C2 respectively) restored fully inhibition of precipitation. These experiments establish a critical role for the classical pathway, in this phenomenon. By contrast the role of the alternative pathway in maintaining complexes in solution was less important; only partial and delayed precipitation occurred in sera depleted of factor D (RD) or factor B (RB). B and D restored normal complement activity to depleted sera. No precipitation was detected in a reagent depleted of properdin (RP). The mechanisms of inhibition of precipitation are therefore distinct from those responsible for solubilization of an immune precipitate, which is largely dependent on the alternative pathway.

Animals↗
PubMed1981

The detection and characterization of a membrane protein with Factor B-like activity on human lymphoid cells.

Factor B-like activity associated with human peripheral blood lymphocytes was first described by Halbwachs & Lachmann (1976), who employed a functional assay. In this present study, clones of B cells from patients with chronic lymphatic leukaemia (CLL) and lymphoblastoid 'Raji' cells were used. The surface of these cells was labelled with 125I by the lactoperoxidase technique and the cell membrane proteins solubilized with the detergent NP40. A single polypeptide chain of molecular weight 103K was precipitated with F(ab')2 anti-serum Factor B, and not with a control antibody. This 103K protein was also found if Raji cells were biosynthetically labelled with [14C]-leucine. When the radiolabelled cells were incubated with cobra venom factor (CVF) and Factor D, two specific polypeptides were precipitated by F(ab')w anti-Factor B. Moreover, the larger fragment forms a complex with CVF, since it could be precipitated by anti-CVF. These events are similar to those involving serum Factor B and CVF.

Autoradiography↗