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Biomedical subjects

C D Smith

Publications and source records attributed to C D Smith.

At least 253 records · Page 14Linked to original sources
PubMed1986

Alternative cell line for virus isolation.

A human lung carcinoma cell line (A549) was compared with various other cell lines to determine susceptibility to viral growth. In the first phase of the study, A549 cells were compared with human embryonic kidney (HEK) and cynomolgus monkey kidney (CMK) cells for isolation of upper-respiratory disease viruses by using 1,248 throat swab specimens from basic-combat trainees. Of the 552 virus isolates, 507 were adenoviruses, 41 were polioviruses, and 4 were herpes simplex viruses (HSV). Of the isolates, 518 (93.8%) were isolated in A549 cells, 480 (87.0%) were isolated in HEK cells, and 262 (47.5%) were isolated in CMK cells (P less than 0.001). In the second phase of the study, A549 cells were compared with a human diploid fibroblast cell strain (MRC-5) and Vero monkey kidney (VMK) cells for the isolation of HSV from 1,157 specimens submitted for culture. Of the 227 HSV isolates, 210 (92.5%) were isolated in A549 cells, 202 (89.0%) were isolated in VMK cells (P greater than 0.1 for A549 versus VMK cells), and 167 (73.6%) were isolated in MRC-5 cells (P less than 0.001 for A549 versus MRC-5 cells). These results suggest that A549 cells are more susceptible to adenovirus infection and at least as susceptible to HSV infection compared with the other cell cultures evaluated. Detracting factors for the use of A549 cells were a slight loss of sensitivity to adenovirus at passage 120 and a concurrent change in the morphology of the cells. The A549 cell line proved to be an efficient, practical, and economical alternative cell system for the isolation of adenovirus and HSV in particular. Initial indications are that other clinically significant viruses may be grown in A549 cells; however, additional studies need to be performed.

Adenoviruses, Human↗
PubMed1986

Diaphragmatic paralysis and eventration in infants.

Twenty-six children with eventration (congenital in 10, resulting from birth trauma in four, and resulting from operative phrenic nerve injury in 12) under 15 months of age were evaluated at a single institution in a 5 year period. There was a high incidence of significant associated anomalies and prematurity. All operative phrenic nerve injuries occurred in patients under 3 months of age, and they were most common in patients undergoing Blalock-Taussig shunt. Plication (12 thoracic, nine abdominal) was performed in 21 patients, 19 of whom had respiratory distress or were ventilator dependent. Repeat plication was required in four patients. All long-term survivors were extubated within 1 week of plication. Of 21 patients undergoing plication, 14 (67%) died. Death was attributed directly to complications of eventration in three patients and was a contributing factor in nine patients. We reached the following conclusions: The incidence of operative phrenic nerve injury in infants undergoing lateral thoracotomy, particularly for Blalock-Taussig shunt, is higher than generally appreciated; plication is a safe procedure as performed by either an abdominal or thoracic approach; failure to achieve extubation within a week of plication is an ominous prognostic sign; mortality in patients with eventration in the presence of major associated conditions may be high despite plication.

Diaphragmatic Eventration↗
PubMed1985

Chemoattractant receptor-induced hydrolysis of phosphatidylinositol 4,5-bisphosphate in human polymorphonuclear leukocyte membranes. Requirement for a guanine nucleotide regulatory protein.

Incubation of plasma membranes from human polymorphonuclear leukocytes (PMNs) with [gamma-32P]ATP in the presence of MgCl2 resulted in the formation of 32P-labeled phosphatidic acid (PA), phosphatidylinositol 4-phosphate (PIP), and phosphatidylinositol 4,5-bisphosphate (PIP2). Membranes from PMN specific and azurophil granules synthesized only PIP, suggesting that PIP2 metabolism is confined to the plasma membrane in PMNs. Further incubations of the labeled plasma membranes for 60 s in the presence of 1 mM CaCl2 resulted in the hydrolysis of approximately 40 and 50% of the labeled PIP and PIP2, respectively. In the presence of 2 microM added CaCl2, PIP and PIP2 levels were unchanged by incubation with either the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe) at 0.1 microM or by 10 microM GTP; however, addition of fMet-Leu-Phe plus GTP together resulted in a 11 and 28% decrease in PIP and PIP2, respectively. These treatments had no effect on PA levels. No additional radiolabeled organic-soluble products were detected after treatment with fMet-Leu-Phe plus GTP. Incubation of intact PMNs, with the Bordetella pertussis toxin (islet-activating protein) eliminated the ability of fMet-Leu-Phe plus GTP to promote PIP2 breakdown in the isolated plasma membranes, but did not inhibit PIP2 degradation in the presence of 1 mM CaCl2. These results provide the first direct evidence that the fMet-Leu-Phe receptor in PMN membranes is coupled to polyphosphoinositide hydrolysis through an islet-activating protein-sensitive guanine nucleotide regulatory protein.

Bacterial Toxins↗
PubMed1985

Potential role for a guanine nucleotide regulatory protein in chemoattractant receptor mediated polyphosphoinositide metabolism, Ca++ mobilization and cellular responses by leukocytes.

Islet activating protein from Bordetella pertussis toxin which ribosylates certain guanine nucleotide regulatory proteins causes a marked reduction of chemoattractant-elicited responses such as chemotaxis, O2 production and cAMP elevations in human polymorphonuclear leukocytes. The toxin appears to exert its effects by preventing the rapid breakdown of phosphatidylinositol 4,5-bisphosphate induced by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine, thereby inhibiting the increase in intracellular [Ca++] which normally follows chemoattractant stimulation. Responses of leukocytes exposed to Concanavalin A, the Ca++ ionophore A23187, or phorbol myristate acetate were not affected by the toxin. Thus the chemoattractant receptor appears to be coupled to a phosphoinositide specific phospholipase C through a guanine nucleotide regulatory protein. We propose that this complex of receptor-guanine nucleotide regulatory protein-phospholipase C may be applicable to the class of receptors which mobilize intracellular Ca++ by stimulating polyphosphoinositide breakdown.

Bacterial Toxins↗
PubMed1985

Bronchial laceration in a newborn with persistent posterior pneumomediastinum.

A large posterior pneumomediastinum that compromised the respiratory status and reaccumulated promptly after needle aspiration, aroused the suspicion of airway laceration. Tracheogram was consistent with laceration of the right bronchus. Evacuation of air with chest tube resulted in complete resolution of pneumomediastinum and healing of bronchial tear with no recurrence following removal of chest tube after seven days.

Bronchi↗
PubMed1985

Lung abscesses in children: diagnostic and therapeutic needle aspiration.

Three children aged 17 months to 17 years developed right-sided peripheral lung abscesses. Clinical signs were fever and cough. Laboratory cultures were negative, and the patients did not respond to appropriate antibiotic coverage. Under fluoroscopic guidance, purulent material was removed from the abscesses by needle aspiration. The patients became afebrile within 24 hours; none suffered complications of bleeding or pneumothorax. Cultures of the aspirate were positive for microorganisms sensitive to the prescribed treatments. A simple aspiration technique is described and proposed as useful for selected patients when surgical drainage is recommended. There was no morbidity in our cases, and recovery from a typically prolonged course was shortened by the procedure.

Adolescent↗
PubMed1984

Solubilization and reconstitution of a nuclear envelope-associated ATPase. Synergistic activation by RNA and polyphosphoinositides.

Treatment of isolated rat liver nuclear envelopes with 1% Triton X-100 solubilized 20-30% of the nuclear envelope protein and 85% of the ATPase activity. Chromatography on DEAE-Sepharose in 1% Triton X-100 at pH 7.5 removed all of the chemically measurable phospholipid from the bound ATPase activity; however, endogenously synthesized phosphatidylinositol [4-32P]phosphate (PIP) co-chromatographed with the ATPase activity on this column. Further purification by chromatography on heparin-agarose removed all of the [32P]PIP and RNA from the ATPase; however, the recovery of ATPase activity from this column was very low. RNA, polyadenylic acid, and polyguanylic acid stimulated the delipidated ATPase activity 4-6-fold. This activity was not further stimulated by the addition of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, or phosphatidic acid, but was stimulated 2-fold by the addition of phosphatidylinositol. Addition of 40 microM PIP and 50 micrograms of RNA/ml resulted in a 25-fold stimulation of basal ATPase activity. Phosphatidylinositol 4,5-bisphosphate, in the presence of RNA, was also able to stimulate ATPase activity but to a lower extent than that of PIP. Therefore, the nuclear envelope-associated ATPase appears to require interaction with a polynucleotide and PIP to express full activity. PIP, which is actively metabolized in the nuclear envelope, may therefore be involved in the regulation of the activity of this enzyme.

Adenosine Triphosphatases↗
PubMed1984

Crystallization and preliminary x-ray investigation of a protein neurotoxin from the sea anemone Anthopleura xanthogrammica.

Neurotoxic protein AX-I isolated from the sea anemone Anthopleura xanthogrammica has been crystallized. Two crystal forms were obtained. One form is tetragonal, space group P41 or P43 , with cell dimensions a = b = 40.74(2) A and c = 34.13(3) A. The second crystal form is hexagonal, space group P622 , with cell dimensions a = b = 72.23(2) A and c = 39.16(2)A. Density measurements indicate that the tetragonal crystals contain one toxin molecule/asymmetric unit. Both crystal forms diffract to high resolution.

Animals↗
PubMed1984

A long-term longitudinal study of anticentromere antibodies.

A longitudinal retrospective study of 37 patients previously tested for anticentromere antibodies (ACA) in 1982 was carried out. No ACA were found in stored sera from 22 ACA-negative patients including 1 patient with CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia). All ACA-positive patients, with 1 exception, were found to have ACA in their sera over prolonged periods of time. One patient developed ACA for the first time when the third feature of the CREST syndrome (Raynaud's phenomenon) was noted. Anticentromere antibodies were IgG, and no consistent change in titer over time was found.

Antibodies, Antinuclear↗
PubMed1984

The clinical utility of the lupus band test.

In order to determine the clinical utility of the lupus band test, the presence of dermal-epidermal junction (DEJ) deposits of IgG, IgM, IgA, C3, C4, Clq, and properdin were studied in biopsies of clinically normal deltoid area skin from 102 patients with systemic lupus erythematosus (SLE) and 151 patients with other rheumatic diseases. One or more proteins were detected at the DEJ in 72.6% (74 of 102) of patients with SLE and in 36.4% (55 of 151) of the other patients, yielding a specificity of 64% and a predictive value of 57%. The predictive value for the diagnosis of SLE was greatest with C4 (100%), properdin (91.3%), and IgA (86.2%) and lowest with IgM (59%). Specificity and predictive value increased with the number of proteins detected at the DEJ. The results suggest that more rigid criteria are required before diagnostic significance is attached to a positive result on the lupus band test.

Biopsy↗
PubMed1984

Characterization of a phosphatidylinositol 4-phosphate-specific phosphomonoesterase in rat liver nuclear envelopes.

Incubation of rat liver nuclear envelopes with [gamma-32P]ATP resulted in the synthesis of phosphatidylinositol-[4-32P]phosphate (PIP). Degradation of endogenously labeled PIP was observed upon the dilution of the labeled ATP with an excess of unlabeled ATP. This degradation was most rapid in the presence of EDTA, and was inhibited by MgCl2 and CaCl2. To further characterize the degradative activity, phosphatidylinositol[4-32P]phosphate and phosphatidylinositol [4,5-32P]bisphosphate (PIP2) were synthesized and isolated from erythrocyte plasma membranes. The 32P-labeled phospholipids were then resuspended in 0.4% Tween 80, a detergent that did not inhibit degradation of endogenously labeled PIP, and mixed with nuclear envelopes. [32P]PIP and [32P]PIP2 were degraded at rates of 2.25 and 0.04 nmol min-1 mg nuclear envelope protein-1, respectively. Only 32P was released from phosphatidyl[2-3H]inositol-[4-32P]phosphate, indicating that hydrolysis of PIP was due to a phosphomonoesterase activity (EC 3.1.3.36) in nuclear envelopes. Similarly, anion-exchange chromatographic analysis of the water-soluble products released from [32P]PIP indicated that inorganic phosphate was the sole 32P-labeled product. Hydrolysis of PIP was most rapid at neutral pH, and was not affected by inhibitors of acid phosphatase or alkaline phosphatase. Hydrolysis of PIP was also not inhibited by nonspecific phosphatase substrates, such as glycerophosphate, p-nitrophenylphosphate, AMP, or glucose 6-phosphate. Hydrolysis was stimulated by putrescine, and was inhibited by inositol 2-phosphate, spermidine, spermine, and neomycin.

Animals↗
PubMed1984

A technique for immediate manual external aortic counterpulsation during cardiac surgery.

Intraaortic balloon pump counterpulsation is well established as a lifesaving measure. Aortic counterpulsation may be achieved externally as well as internally. A simple technique for manual external aortic counterpulsation during cardiovascular surgical procedures is presented. This technique is available on immediate demand and identical in effect to intraaortic balloon pumping, and it may be lifesaving in patients with acute cardiovascular decompensation since it allows time for institution of necessary emergency therapy.

Aorta↗
PubMed1984

Skeletal muscle differentiation in Wilms' tumor. Antibody identification and explant culture.

We studied a case of Wilms' tumor with focal areas of well-differentiated skeletal muscle by immunoperoxidase staining using anti-skeletal muscle myosin and by tissue culture explant of the tumor. Strong immunostaining occurred in areas of well-differentiated muscle but also occurred in focal areas where the cells were undifferentiated. The primary explant of this tumor was attempted using standard serum-containing culture media and a serum-free hormonally defined culture medium. While serum-containing culture media gave rise to a fibroblastlike cell population, the serum-free hormonally defined medium produced cells of myoid origin. Ultrastructurally, all stages of early myogenesis from myoblasts to myotubules were observed in this primary explant grown in serum-free medium.

Antibodies↗