Biomedical subjects

J Eng

Publications and source records attributed to J Eng.

227 records · Page 13Linked to original sources

PubMedDate not supplied

Cholecystokinin octapeptide purified from brains of Australian marsupials.

Cholecystokinin octapeptides (CCK8s) have been purified from methanol extracts of two brains from each of two Australian marsupials, Tammar Wallaby and Eastern Quoll, containing 3 nmol and 2 nmol of the peptides, respectively. Immunoreactive CCK was concentrated on QMA SepPak cartridges and purified by two successive HPLC steps on Nova C18 radial-pak cartridges. The sequence of each of the peptides is identical with that previously reported for Old World mammals (DYMGWMDF). This is in contrast to the previously reported sequence for CCK8 from the South American hystricomorphs, guinea pig and chinchilla, which differs in a substitution of valine for methionine in position 3 from the NH2-terminus. Although evolutionary history suggests that marsupials migrated from South America into Australia before the two continents separated, this peptide resembles that found in Old World mammals rather than that of South American hystricomorphs. Such molecular data are useful in assessing phylogenetic relationships among taxa.

Amino Acid Sequence↗

PubMedDate not supplied

Opossum insulin, glucagon and pancreatic polypeptide: amino acid sequences.

Pancreatic hormones have been purified from the opossum, a New World marsupial. Opossum insulin contains a Leu substitution at the N-terminus of the B-chain in place of the Phe that is generally present in mammalian insulins. In addition, there are two other amino acid substitutions in the opossum insulin A-chain (positions 8 and 18) compared to pig insulin. Opossum glucagon is identical to chicken glucagon with both differing from the usual mammalian glucagon by Ser in place of Asn at its penultimate C-terminal position. Opossum PP differs from the porcine peptide in only 3 sites (position 3, 19 and 30).

Amino Acid Sequence↗

PubMedDate not supplied

Purification of peptide hormones from chinchilla pancreas by chemical assay.

Glucagon was purified from chinchilla pancreas and its biological activity determined. It was isolated using a chemical assay to identify peptides with a histidyl residue at the N-terminus. Chinchilla glucagon has the amino acid sequence HSQGTFTSDYSKHLDSRYAQEFVQWLMNT. It differs from the usual mammalian glucagon by amino acid substitutions at positions 13, 18 and 21 from the N-terminus. Despite these sequence changes, its biological activity is conserved. Chinchilla glucagon has approximately the same potency as pig glucagon in stimulating liver membrane adenyl cyclase activity. Pancreatic polypeptide was also purified from chinchilla pancreas based on its Ala1 signal and has the sequence APLEPVYPGDNATPEQMAQYAAEMRRYINMLTRPRY#.

Adenylyl Cyclases↗

PubMedDate not supplied

Ethanol-induced free radical injury to the hepatocyte glucagon receptor.

Plasma membrane receptors are essential in cellular homeostasis. Free radical generation and catalytic iron have been implicated in alcohol-induced liver injury; damage to plasma membrane receptors may be one important mechanisms of injury. The effect of ethanol-induced free radicals on hepatocyte receptor dysfunction was investigated in rodent models of free radical injury due to chronic alcohol administration. Receptors for glucagon and their postreceptor signal transduction pathway (cyclic AMP production [cAMP]) were investigated as sites of free radical injury in isolated perfused livers. Glucagon-stimulated cAMP decreased (15%-80%) over a range of physiological (submaximal) doses of glucagon after 6 weeks of ethanol feeding, while free radical generation (alkane evolution) increased greater than three to fourfold over baseline (ethane; 2.04 +/- 0.36 vs. 0.58 +/- 0.08 pmole/10(6) cell/hr, p < 0.01; pentane 3.15 +/- 0.30 vs. 0.91 +/- 0.16, p < 0.01). Iron loading (125 mg/kg IP) potentiated this inhibition of cAMP production (40%-95%) and further increased alkane production twofold (ethane 4.29 +/- 0.78, pentane 5.76 +/- 0.71). Scatchard analysis revealed decreased numbers of glucagon receptors paralleling cAMP responses. Free radical damage to hepatocyte cell membrane receptors may be an important mechanism of alcohol-induced liver injury.

Alkanes↗

PubMedDate not supplied

Homology between the cDNAs encoding phosphoprotein p19 and SCG10 reveals a novel mammalian gene family preferentially expressed in developing brain.

We have isolated and sequenced a rat testis cDNA encoding p19, a 19-kD cytosolic phosphoprotein that is abundant in immature brain, testis, and neuroendocrine tumor cells. The cDNA was identified using bovine brain p19 peptide sequences, which indicate that the gene encoding p19 has been highly conserved during mammalian evolution. Using Northern blot analysis on rat tissues, p19 mRNA was readily detected in brain and testis and showed a 15-fold greater abundance in newborn than in adult brain. Low levels of p19 mRNA were observed in spleen, kidney, and heart, but not in liver. Thus, the expression of the gene encoding p19 shows a strong tissue preference and is developmentally regulated. The predicted amino acid sequence of p19 is highly homologous to that of SCG10, another protein expressed in the developing rat nervous system, suggesting that the two proteins serve similar functions. Based on a comparison of the two cDNAs, we conclude that p19 and SCG10 are encoded by distinct but related genes constituting a novel gene family.

Aging↗

PubMedDate not supplied

Normal enhancement of the small bowel: evaluation with spiral CT.

PURPOSE: The purpose of this work was to determine normal contrast enhancement of the small bowel with biphasic spiral CT, using water as oral contrast agent. METHOD: Biphasic spiral CT was performed in 50 healthy patients undergoing evaluation as potential renal donors. All patients received 500 ml of water as oral contrast agent and 150 ml of Omnipaque 350 administered by mechanical injector at a rate of 3 ml/s. Dual phase CT of the abdomen was performed in each patient. Acquisition of early phase images began 30 s after the start of the intravenous injection, and portal phase images were obtained 60 s after initiation of the contrast agent injection. Attenuation measurements (in Hounsfield units) were obtained from the wall of the small bowel (duodenum, jejunum, ileum) in both the arterial and the portal phases. RESULTS: During the arterial phase, the mean (95% confidence interval) attenuation of the duodenum, jejunum, and ileum was 120 (+/- 5), 119 (+/- 5), and 118 (+/- 5) HU, respectively. During the portal phase, the average attenuation of the duodenum, jejunum, and ileum was 111 (+/- 4), 111 (+/- 3), and 107 (+/- 3) HU, respectively. There was no statistically significant difference between the attenuation of the duodenum, jejunum, or ileum within either the arterial or the portal venous phases. There was a statistically significant difference in small bowel enhancement between the arterial and portal venous phases. CONCLUSION: There is no important variation in small bowel attenuation during the 30 and 60 s scanning phases. This study serves as a normal reference that may be helpful when spiral CT is used to evaluate ischemic bowel or inflammatory small bowel diseases.

Administration, Oral↗

PubMedDate not supplied

Improving the interactivity and functionality of Web-based radiology teaching files with the Java programming language.

Java is a programming language that runs on a "virtual machine" built into World Wide Web (WWW)-browsing programs on multiple hardware platforms. Web pages were developed with Java to enable Web-browsing programs to overlay transparent graphics and text on displayed images so that the user could control the display of labels and annotations on the images, a key feature not available with standard Web pages. This feature was extended to include the presentation of normal radiologic anatomy. Java programming was also used to make Web browsers compatible with the Digital Imaging and Communications in Medicine (DICOM) file format. By enhancing the functionality of Web pages, Java technology should provide greater incentive for using a Web-based approach in the development of radiology teaching material.

Computer Communication Networks↗

PubMedDate not supplied

Enhancing Web applications in radiology with Java: estimating MR imaging relaxation times.

Java is a relatively new programming language that has been used to develop a World Wide Web-based tool for estimating magnetic resonance (MR) imaging relaxation times, thereby demonstrating how Java may be used for Web-based radiology applications beyond improving the user interface of teaching files. A standard processing algorithm coded with Java is downloaded along with the hypertext markup language (HTML) document. The user (client) selects the desired pulse sequence and inputs data obtained from a region of interest on the MR images. The algorithm is used to modify selected MR imaging parameters in an equation that models the phenomenon being evaluated. MR imaging relaxation times are estimated, and confidence intervals and a P value expressing the accuracy of the final results are calculated. Design features such as simplicity, object-oriented programming, and security restrictions allow Java to expand the capabilities of HTML by offering a more versatile user interface that includes dynamic annotations and graphics. Java also allows the client to perform more sophisticated information processing and computation than is usually associated with Web applications. Java is likely to become a standard programming option, and the development of stand-alone Java applications may become more common as Java is integrated into future versions of computer operating systems.

Algorithms↗

PubMedDate not supplied

Left thoracotomy approach for resection of carcinoma of the oesophagus and cardia.

Oesophagogastrectomy is the best available treatment for patients with carcinoma of the oesophagus or cardia. It provides better longevity than other types of therapy and remains the standard against which combined modality treatment should be compared. Our experience with two hundred and twenty-four patients who underwent surgical exploration performed transdiaphragmatically by way of a left thoracotomy formed the basis of this report. Of these 224 patients, 201 (89.7%) underwent resection, 15 were bypassed and the remaining 5 patients were intubated. Of those resected, 79 patients required a two-rib thoracotomy. The postoperative mortality rate was 3.57%, and morbidity, mainly caused by respiratory complications occurred in 36 patients (16.1%), with no patients requiring ventilatory support. Surgical bypass without resection carried a higher mortality rate (8.3%) than those for resection (2.5%). All anastomosis were hand sewn. There were no anastomotic leaks. Adequate analgesia was provided by continuous extrapleural intercostal nerve block. Five year survival for squamous carcinoma was 36% while that adenocarcinoma was 18.7%. The left thoracotomy provides an effective method for undertaking oesophageal resections with low mortality and morbidity rates. This techniques has advantages and should be more widely used in the surgical management of patients with carcinoma of the oesophagus or cardia.

Adenocarcinoma↗

PubMedDate not supplied

Primary anorectal malignant melanoma. A case report.

A case of primary anorectal malignant melanoma in a 66-year-old lady is presented and the clinical, radiological and surgical features reviewed. The presenting symptoms similar to the more commonly encountered haemorrhoids led to a delay in the eventual diagnosis and treatment, resulting in limited post-operative survival. The relevant literature is reviewed and an emphasis made on the accurate histological diagnosis of anorectal growths.

Aged↗

PubMedDate not supplied

Hysterosalpingography: value in estimating tubal function, and risk of infectious complications.

A prospective study of 80 patients referred for hysterosalpingography (HSG). In 74 patients HSG was performed as part of an infertility investigation. Samples taken from the cervix were cultured for N. gonorrhoeae, Chl. trachomatis and M. hominis. Serum specimens were examined for antibodies against Chl. trachomatis and M. hominis. Two of our patients (2,5%) developed clinical signs of pelvic inflammatory disease following the procedure. Both had negative cultures for pathogenic microbes. The value of pre-HSG microbial culturing seemed negligible. Most patients had antibodies against Chl. trachomatis and M. hominis. Occlusion in one or both tubes was seen in 22 patients while possible pelvic adhesions were found in 15. It is concluded that HSG seems to have a relatively high risk of infectious complications, and we propose to do laparoscopy with chromopertubation as the primary step for evaluation of tubal function in infertile women.

Cervix Uteri↗