PubMed Health⌕ Search

Biomedical subjects

D C Watson

Publications and source records attributed to D C Watson.

At least 73 records · Page 4Linked to original sources
PubMed1988

The amino acid sequence of a gonococcal growth inhibitor from Staphylococcus haemolyticus.

A gonococcal inhibitor produced by Staphylococcus haemolyticus was separated into three components by reverse-phase h.p.l.c. The amino acid composition analysis of each of the three components indicated extensive similarities. N-Terminal sequence analysis of all three components allowed the identification of the first 27-30 residues of each. The complete primary structure of each component was determined from the sequence analysis of trypic peptides and peptides generated by mild acid hydrolysis. Each component is composed of 44 amino acid residues, with evidence suggesting the presence of an N-terminal formylmethionine residue in each. The components I, II and III have respectively 33, 29 and 33 identical amino acid residues in their sequences, which represents 75%, 65.9% and 75% homology. These components contain a high proportion of hydrophobic amino acids, and their hydrophobicity profiles are closely related. Also, each of the three components contains a positively charged residue (lysine) as the third residue, followed by a core of hydrophobic residues. These results suggest that the three components are possible signal sequences of one or more secreted or membrane-associated proteins.

Amino Acid Sequence↗
PubMed1988

Sputum wax-worms after plombage.

Paraffin wax plombage was one of several plombage operations used for pulmonary tuberculosis about 40 years ago, and Shepherd included seven patients treated with wax plombage in her review of plombage in 1985. We describe another patient with wax plombage who coughed up wax 28 years after plombage, followed by much larger amounts of wax 15 years later. The pieces of wax were like worms and spirals, and we discuss possible causes for these shapes.

Aged↗
PubMed1988

Reexpansion pulmonary edema.

Unilateral reexpansion pulmonary edema (RPE) is a rare complication of the treatment of lung collapse secondary to pneumothorax, pleural effusion, or atelectasis. Although RPE generally is believed to occur only when a chronically collapsed lung is rapidly reexpanded by evacuation of large amounts of air or fluid, in this review 15 of 47 cases of RPE available for assessment occurred when the pulmonary collapse was of short duration or when the lung was reexpanded without suction. The pathogenesis of RPE is unknown and is probably multifactorial. Implicated in the etiological process of RPE are chronicity of collapse, technique of reexpansion, increased pulmonary vascular permeability, airway obstruction, loss of surfactant, and pulmonary artery pressure changes. Since the outcome of RPE was fatal in 11 of 53 cases reviewed (20%), physicians treating lung collapse must be aware of the possible causes and endeavor to prevent the occurrence of this complication.

Adult↗
PubMed1987

Cloning and gene expression of Schistosoma mansoni protease.

Schistosomes utilize proteases (termed hemoglobinases) for degradation of host globin. cDNA clones encoding Schistosoma mansoni protease were isolated by immunologically screening an expression cDNA library with antisera raised against purified hemoglobinase. Confirmation of the identities of the clones was obtained immunologically and biochemically. The bacterially produced fusion protein encoded by one clone, lambda Hb2, degraded hemoglobin in vitro. The sequence of this clone suggested that this S. mansoni protease is synthesized in a precursor form in vivo. Gene titrations indicated that S. mansoni contains multiple genes corresponding to this cDNA. The expression of these genes may be regulated during the organism's life cycle since adult, female worms contained the highest abundances of homologous mRNA and protein compared to other stages.

Amino Acid Sequence↗
PubMed1986

The purification and complete amino acid sequence of the 9000-Mr Ca2+-binding protein from rat placenta. Identity with the vitamin D-dependent intestinal Ca2+-binding protein.

A 9000-Mr Ca2+-binding protein was isolated from rat placenta and purified to homogeneity by h.p.l.c. procedures. The complete amino acid sequence was established for the 78-residue placental protein. A sequence analysis of a minor component of the rat intestinal Ca2+-binding protein (residues 4-78) and a tryptic peptide (residues 55-74), both purified by h.p.l.c., showed both proteins to be identical. Thus this placental 9000-Mr Ca2+-binding protein is the same gene product as the intestinal Ca2+-binding protein whose synthesis is dependent on vitamin D.

Amino Acid Sequence↗
PubMed1986

Pediatric digital subtraction angiography: intraarterial and intracardiac applications.

Intraarterial digital subtraction angiography (IA-DSA) was performed in 80 pediatric patients. Forty-four underwent arterial injections with digital filming techniques. Of the 130 injections, DSA imaging was good or excellent in 121, often allowing resolution of vessels 1 mm in size. Thirty-six of the 80 patients underwent cardiac evaluation with intra-cardiac injections. Improved contrast resolution with IA-DSA allowed the use of smaller catheters (3-4F) and smaller amounts of contrast material. Immediate availability of subtracted images (no film processing delay) resulted in shorter total procedure time. Outpatient studies are possible. IA-DSA provides several notable advantages for the pediatric patient.

Adolescent↗
PubMed1986

Management of broncholithiasis: is thoracotomy necessary?

Endoscopic treatment of broncholithiasis is controversial. From 1953 through 1984, 66 operations were performed on 40 patients with broncholithiasis in an endemic area for histoplasmosis. They are reviewed here retrospectively. All patients had cough; wheeze, hemoptysis, and lithoptysis were present in 60%, 45%, and 26%, respectively. Bronchoscopic stone removal was successful in 19%, whereas 21% of patients required no treatment. The 25 patients who were affected more severely required thoracotomy and operations varying from simple lung wedge resection to repair of a bronchoesophageal fistula. Optimum preservation of lung function was a major treatment guideline. All survived, and most have returned to normal preoperative activity. For selected patients, bronchoscopy and stone removal may be all that is required for broncholithiasis.

Adult↗
PubMed1986

Costs and results of cardiac operations in infants less than 4 months old. Are they worthwhile?

From 1979 through 1983, 328 of 1,388 pediatric cardiac operations involved patients undergoing their first procedure at less than 4 months of age. Of these, 220 patients had 265 nonductal procedures, and their case histories are reviewed for results and total hospital cost. Initial operative mortality was 20% (43 patients). Infants with lower operative age and operative weight tended to have closed procedures. Mortality and cure were not related to gestational age, birth weight, age at operation, number of operations, or type of operation. Lower operative weight was associated with a greater mortality. Evaluated survivors (142 patients) were followed for a mean of 24 months. Fifteen percent (33 patients) died during follow-up. Of survivors, 80% (114 patients) had optimized general health; a subset of 29% had normal cardiac function, and 17% were cured. Lower birth weight was associated with curable lesions and normalcy (p less than 0.04). Longer preoperative hospital stay and lower weight at operation were associated with higher hospital cost (p less than 0.05). Hospital cost was not related to type of operation, gestational age, birth weight, age at operation, mortality, cure, or normalcy. Acquired neurologic dysfunction and long-term disability were uncommon. The mean hospital cost for surviving infants was +80,000 (1984 dollars). Effective hospital cost per survivor was +110,000. Mortality, cure, and normal function after cardiac operations in infants less than 4 months of age were not related to gestational age, birth weight, or age at operation. Mortality was higher in patients with a lower weight at operation. Separation into distinct fiscal cost groups is not reasonable in this series. Because most survivors are in normal or optimized cardiac health, intensive cardiovascular care in this population is justified.

Age Factors↗
PubMed1985

Anticoagulation therapy in children with mechanical prosthetic cardiac valves.

From 1980 through 1984, 28 children younger than 19 years (mean 7.9) underwent cardiac valve replacement with 30 mechanical prostheses. Patients were followed for a total of 471 months (mean 15.7) and received either warfarin (mean 0.16 mg/kg/day) or acetylsalicylic acid and dipyridamole (mean 6.1 and 1.9 mg/kg/day, respectively) as thromboembolism prophylaxis. The frequency and incidence of thromboembolism and hemorrhage were compared. Warfarin-treated patients were at increased risk of hemorrhage (5 of 20 [25%], or 22 per 100 patient-years, vs 0 of 10 [0%], or 0 per 100 patient-years, p less than 0.05). Three of the 5 hemorrhagic episodes were mild, and in no case was hemorrhage life-threatening. Patients who did not receive warfarin had a greater risk of thromboembolism (2 of 10 [20%], or 12 per 100 patient-years, vs 0 of 20 [0%], or 0 per 100 patient-years, p less than 0.05). Both episodes of thromboembolism were life-threatening and necessitated emergency valve replacement. Although warfarin is associated with greater risk of hemorrhage than is acetylsalicylic acid and dipyridamole, warfarin is better than antiplatelet drugs in thromboembolism prophylaxis and is indicated for anticoagulation therapy in children with mechanical cardiac prostheses.

Aspirin↗
PubMed1985

Rat skin calcium-binding protein is parvalbumin.

Only one major low-Mr calcium-binding protein could be isolated by h.p.l.c. procedures from aqueous extracts of homogenized adult rat skin. This was shown by tryptic peptide mapping and independent amino acid sequence analysis to be identical in all 109 residues with the parvalbumin from rat skeletal muscle. This calcium-binding protein was not in skin epidermis, but was confined to the dermal layer. Skin calcium-binding protein is therefore parvalbumin.

Amino Acid Sequence↗