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Biomedical subjects

W L Smith

Publications and source records attributed to W L Smith.

At least 235 records · Page 13Linked to original sources
PubMed1989

Ontogeny of the third component of complement in neonatal swine.

Ontogeny of the third component of complement (C3) was monitored in 10 neonatal swine, using a radial immunodiffusion technique. Significant differences in mean serum C3 concentrations, expressed as percentage of C3 concentration in a pooled standard drawn from 15 adult swine, were not observed between serum samples collected before pigs suckled and at 2 days of age (P = 0.2583). Serum C3 concentrations increased significantly between 2 and 7 days of age (P less than 0.0001) and 7 and 14 days of age (P less than 0.0001). Concentrations comparable with those in adults were observed at 14 days of age and significant changes were not observed thereafter. Acquisition of adult concentrations of C3 appeared to be a function of endogenous production by the neonate, rather than by passive colostral transfer.

Animals↗
PubMed1989

Effects of the natural and unnatural isomers and degradation products of enprostil on gastric acid secretion and gastrointestinal motility in the rat.

The gastric antisecretory and gastrointestinal (GI) motility activity of the natural and unnatural allenic isomers and degradation products of enprostil (methyl(+/-)-7-[(1R*,2R*,3R*)-3-hydroxy-2-[(E)-(3R*)-3-hydroxy-4-phenoxy - 1-butenyl]-5-oxocyclopentyl]-4,5-heptadienoate, RS-84135-004) were studied in the rat. The natural R-allenic isomer of enprostil was the most potent antisecretory compound. The 8-iso-enprostil, enprostil free acid, and the 5-acetylene isomer had somewhat less activity while the other compounds were relatively inactive. The natural and unnatural allenic isomers increased intestinal dye transit with the same rank potency as the gastric antisecretory activity. Enprostil, 8-iso-enprostil, prostaglandin A-enprostil and enprostil free acid, all increased intestinal dye transit.

Animals↗
PubMed1989

Sonography of acute appendicitis: a critical review.

In 20% of the cases of acute appendicitis, especially in children, the elderly, and ovulating women, the findings are atypical. The radiographic procedures used to aid in the diagnosis have not been proven reliable. Sonography has often been used to diagnose or rule out appendiceal abscesses, or diseases that can mimic acute appendicitis, such as gynecologic, obstetric, or biliary abnormalities. Recently, high-resolution sonography with graded compression has been shown to be very helpful in the diagnosis of acute appendicitis in several studies. High-resolution 5- to 7.5-MHz transducers are used to compress the bowels, displace the interfering gas in the right lower quadrant, and directly visualize the inflamed appendix with a sensitivity that varies from 80 to 95%, a specificity of 95 to 100%, and an accuracy of 91 to 95%. It is also possible to differentiate acute appendicitis from the gangrenous and perforated appendix. High-resolution sonography is currently the diagnostic method of choice for appendicitis, particularly in patients with equivocal clinical findings. The technique, normal and pathologic anatomy values, and limitations of sonography are discussed.

Acute Disease↗
PubMed1989

Aberrant right hepatic artery vena cava fistula: a case report.

An unusual case of visceral arterial venous fistula between an aberrant right hepatic artery and the inferior vena cava is presented. A critical review of the anatomic relationships in this location offers a plausible explanation to account for the rarity of this type of fistula. The second issue deals with the ligation of the hepatic artery. We caution against hepatic artery ligation, especially when dealing with an aberrant right hepatic artery.

Adult↗
PubMed1989

Ultrastructural morphometry distinguishes Burkitt's-like lymphomas from neuroendocrine neoplasms: useful criteria applied to the evaluation of a poorly differentiated neuroendocrine neoplasm of the nasal cavity masquerading as Burkitt's-like lymphoma.

The present study describes the potential usefulness of ultrastructural morphometry in diagnosis. Ultrastructural morphometric criteria were applied to the evaluation of a poorly differentiated neuroendocrine neoplasm of the nasal cavity that was initially thought to be a Burkitt's-like lymphoma (BLL). Although the nasal lesion in question failed to stain with over 50 cell lineage-relevant antibodies, it did stain for vimentin (an intermediate filament protein) and Ki-67 (a nuclear antigen associated with cell proliferation). Routine electron microscopy revealed a primitive neoplasm with abundant cytoplasmic lipid droplets and sparse dense granules with no intercellular junctions. Treatment options, which included extensive facial surgery, prompted more study. Tissue processed for the uranaffin reaction revealed sparse uranaffin-positive granules indicating the presence of true neurosecretory granules. An ultrastructural morphometric analysis of the neoplastic nuclei of this patient placed the tumor outside the morphometric domains for BLLs (18 cases) and neuroblastomas (11 cases) and within the morphometric domain of neuroendocrine carcinomas (9 cases). A greater mean standard deviation (P less than 0.05) and mean coefficient of variation (P less than 0.02) of nuclear perimeter in the neuroendocrine (NE) group related to the BLL group indicated greater nuclear pleomorphism within the NE group as illustrated in bivariate graphic displays. The possible origin of the neoplasm within the nasal mucosa is discussed.

Burkitt Lymphoma↗
PubMed1988

Regulation of cyclic AMP metabolism in rabbit cortical collecting tubule cells by prostaglandins.

Prostaglandin E1 (PGE1) at 1 nM inhibits arginine-vasopressin (AVP)-induced water reabsorption in the rabbit cortical collecting tubule (RCCT), while 100 nM PGE1, by itself, stimulates water reabsorption (Grantham, J. J., and Orloff, J. (1968) J. Clin. Invest. 47, 1154-1161). To investigate the basis for these two responses, we measured the effects of prostaglandins on cAMP metabolism in purified RCCT cells. In freshly isolated cells, PGE2, PGE1, and 16,16-dimethyl-PGE2 acting at high concentrations (0.1-10 microM) stimulated cAMP accumulation; however, one PGE2 analog, sulprostone (16-phenoxy-17,18,19,20-tetranor-PGE2 methylsulfonilamide), failed to stimulate cAMP accumulation or to antagonize PGE2-induced cAMP formation; PGD2, PGF2 alpha, and a PGI2 analog, carbacyclin (6-carbaprostaglandin I2), also failed to stimulate cAMP synthesis. These results suggest that there is a PGE-specific stimulatory receptor in RCCT cells which mediates activation of adenylate cyclase. Occupancy of this receptor would be anticipated to cause water reabsorption by the collecting tubule. At lower concentrations (0.1-100 nM) PGE2, PGE1, 16,16-dimethyl-PGE2, and, in addition, sulprostone inhibited AVP-induced cAMP accumulation by fresh RCCT cells in the presence of cAMP phosphodiesterase inhibitors. Pertussis toxin pretreatment of RCCT cells blocked the ability of both PGE2 and sulprostone to inhibit AVP-induced cAMP accumulation. In membranes prepared from RCCT cells, sulprostone prevented stimulation of adenylate cyclase by AVP. These results suggest that E-series prostaglandins (including sulprostone) can act through an inhibitory PGE receptor(s) coupled to the inhibitory guanine nucleotide regulatory protein, Gi, to block AVP-induced cAMP synthesis by RCCT cells. Occupancy of this receptor would be expected to cause inhibition of AVP-induced water reabsorption in the intact tubule. Curiously, after RCCT cells were cultured for 5-7 days, PGE2 no longer inhibited AVP-induced cAMP accumulation, but PGE2 by itself could still stimulate cAMP accumulation. In contrast to PGE2, epinephrine acting via an alpha 2-adrenergic, Gi-linked mechanism did block AVP-induced cAMP formation by cultured RCCT cells. This implies that some component of the inhibitory PGE response other than Gi is lost when RCCT cells are cultured.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1988

Imaging evaluation of the human nipple during breast-feeding.

A new real-time ultrasound technique was employed to document in vivo the anatomic characteristics of the human nipple during breast-feeding. The study quantifies human nipple deformation and provides a description of the mechanics of normal sucking derived from 16 normal infants aged 60 to 120 days. This in vivo imaging technique has great potential value in the study of feeding dysfunction.

Adult↗
PubMed1988

U46619 and carbocyclic thromboxane A2-induced increases in tracheal mucous gel layer thickness.

U46619 or carbocyclic thromboxane A2 (CTA2) administered intravenously (IV) to rats produced dose-related increases of tracheal mucous gel layer thickness. Significant gel thickening was observed at doses ranging from 3.5 pg to 35 ng and from 500 pg to 50 ng for U46619 and CTA2, respectively. Intravenous treatment with pinane thromboxane A2 (PTA2), a thromboxane antagonist, prior to injection of U46619 or CTA2 attenuated the mucous gel layer response. The effect of PTA2 on U46619 and CTA2 was dose-dependent over the dosage range of PTA2 tested (1.0-31.6 micrograms/kg). PTA2 was equiactive against U46619 and CTA2 stimulated increases in gel thickness (ED50's 6.64 and 6.43 micrograms/kg respectively) suggesting a similar site of action for U46619 and CTA2. Slow reacting substance (SRS) injected IV into rats stimulated mucous gel layer thickening that was also inhibited by pretreatment with PTA2. These findings lend further support for the role of thromboxane in pathophysiologic conditions in which bronchorrhea contributes to the symptomatology.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1988

Endobronchial metastases from prostatic carcinoma.

Prostatic carcinoma presenting with pulmonary symptoms is unusual. We describe the case of a 59-year-old man whose disseminated prostate cancer was diagnosed with bronchoscopy. To our knowledge, this represents the second reported case of prostate cancer that manifested with endobronchial symptoms. The importance of this entity and clinical and therapeutic aspects are also discussed.

Adenocarcinoma↗
PubMed1988

Primary structure of prostaglandin G/H synthase from sheep vesicular gland determined from the complementary DNA sequence.

Prostaglandin G/H synthase (8,11,14-icosatrienoate, hydrogen-donor:oxygen oxidoreductase, EC 1.14.99.1) catalyzes the first step in the formation of prostaglandins and thromboxanes, the conversion of arachidonic acid to prostaglandin endoperoxides G and H. This enzyme is the site of action of nonsteroidal anti-inflammatory drugs. We have isolated a 2.7-kilobase complementary DNA (cDNA) encompassing the entire coding region of prostaglandin G/H synthase from sheep vesicular glands. This cDNA, cloned from a lambda gt 10 library prepared from poly(A)+ RNA of vesicular glands, hybridizes with a single 2.75-kilobase mRNA species. The cDNA clone was selected using oligonucleotide probes modeled from amino acid sequences of tryptic peptides prepared from the purified enzyme. The full-length cDNA encodes a protein of 600 amino acids, including a signal sequence of 24 amino acids. Identification of the cDNA as coding for prostaglandin G/H synthase is based on comparison of amino acid sequences of seven peptides comprising 103 amino acids with the amino acid sequence deduced from the nucleotide sequence of the cDNA. The molecular weight of the unglycosylated enzyme lacking the signal peptide is 65,621. The synthase is a glycoprotein, and there are three potential sites for N-glycosylation, two of them in the amino-terminal half of the molecule. The serine reported to be acetylated by aspirin is at position 530, near the carboxyl terminus. There is no significant similarity between the sequence of the synthase and that of any other protein in amino acid or nucleotide sequence libraries, and a heme binding site(s) is not apparent from the amino acid sequence. The availability of a full-length cDNA clone coding for prostaglandin G/H synthase should facilitate studies of the regulation of expression of this enzyme and the structural features important for catalysis and for interaction with anti-inflammatory drugs.

Amino Acid Sequence↗
PubMed1988

The emetic activity of centrally administered cisplatin in cats and its antagonism by zacopride.

Cisplatin administered by either the intravenous (i.v.) or intra-cerebroventricular (i.c.v.) route produced emesis in cats. The average time to onset of emesis was decreased significantly (4.0 min versus 100.6 min) when cisplatin was administered i.c.v. Zacopride administered either i.c.v. (0.02 mg) or i.v. (0.1 mg kg-1) completely blocked the emesis due to cisplatin given by either route. Their data show that cisplatin possesses a central emetic component and that this is blocked by zacopride.

Animals↗
PubMed1988

Coronary artery aneurysms due to Kawasaki disease: diagnosis with ultrafast CT.

Coronary artery aneurysms are the most serious complication of Kawasaki disease, and periodic screening examinations are necessary. Two-dimensional (2D) echocardiography represents the standard screening method; however, visualization of the distal coronary arteries is often limited. This report describes the complementary role of ultrafast computed tomography (CT) with 2D echocardiography in the evaluation of coronary artery aneurysms resulting from Kawasaki disease (mucocutaneous lymph node syndrome). Six pediatric patients with coronary aneurysms were examined with 2D echocardiography and ultrafast CT. Ten of 11 lesions were detected with ultrafast CT. The one missed coronary artery aneurysm was one of two contiguous aneurysms. Because of intersection thickness these two discrete aneurysms were interpreted as a solitary aneurysm. Ultrafast CT allowed detection of one aneurysm not initially visualized with echocardiography. In conclusion, ultrafast CT was found to be an effective complementary procedure with 2D echocardiography for noninvasively evaluating coronary artery aneurysms occurring as sequelae of Kawasaki disease.

Adolescent↗
PubMed1988

Congenital anorectal anomalies: MR imaging.

Twenty-one patients with anorectal anomalies were evaluated with magnetic resonance (MR) imaging. In seven preoperative patients, MR imaging demonstrated the level of atresia correctly by showing the rectal pouch and sphincter muscles. The exact location and development of the sphincter muscles were estimated and associated anomalies involving the kidneys and the spine and its contents were evaluated. In 14 postoperative patients, the location of the pulled-through intestine was examined in relation to the sphincter muscles. MR imaging demonstrated operative complications affecting rectal continence--such as a misplaced neorectum, inadvertently pulled-through mesenteric fat, and an implantation mucous retention cyst--and provided objective data for individuals with persistent incontinence after surgery who were under consideration for repeat surgery. The authors recommend MR imaging in all patients being considered for repeat procedures and in any patient without prior surgery who is suspected of having a high anomaly; any degree of sacral agenesis; or spinal, genito-urinary tract, or cloacal anomalies.

Adolescent↗
PubMed1988

Immunodissection of cortical and medullary thick ascending limb cells from rabbit kidney.

A procedure was developed for isolating thick ascending limb cells from either the outer medulla or the inner cortex from rabbit kidneys. Dispersed cells derived from the medulla or cortex were incubated with goat anti-human uromucoid (Tamm-Horsfall glycoprotein) serum, washed, and applied to culture dishes coated with affinity-purified anti-goat immunoglobulin G. Nonadherent cells were removed by washing. Routinely, 10(6) or 7 X 10(4) adherent cells were obtained per gram of rabbit outer medulla or inner cortex, respectively. Greater than 97% of the adherent cells stained for Tamm-Horsfall antigen, and examination of freshly isolated cells by transmission electron microscopy established that they had morphological properties expected for thick limb cells. Freshly isolated medullary thick limb (MTALH) cells consistently accumulated cAMP in response to arginine vasopressin (AVP), thyrocalcitonin, prostaglandin E2 (PGE2), and glucagon. PGE2, thyrocalcitonin, parathyroid hormone, and AVP, but not isoproterenol or glucagon, reproducibly stimulated cAMP accumulation in freshly isolated cortical thick limb (CTALH) cells. MTALH cells produced immunoreactive PGE2 when incubated with 10 microM arachidonic acid. In summary, large numbers of highly purified and hormonally responsive rabbit MTALH and CTALH cells can be obtained by immunodissection using commercially available antibody preparations. Because the Tamm-Horsfall antigen is present as an extracellular determinant on thick ascending limb epithelia from many species, this general approach likely can be used to isolate CTALH and MTALH cells from most mammalian kidneys.

Animals↗