Biomedical subjects

J Eng

Publications and source records attributed to J Eng.

At least 91 records · Page 5Linked to original sources

PubMed1991

Tuberculosis of the esophagus.

Tuberculosis of the esophagus is rare. More cases of secondary tuberculosis of the esophagus have been reported compared to primary esophageal tuberculosis. An illustrative case of primary tuberculosis of the esophagus is presented and 54 published cases of esophageal involvement in tuberculosis are reviewed. There were eight primary and 46 secondary cases of esophageal tuberculosis. There were more male than female patients (M/F = 2.6:1) with an average age of 39.2 years (range 6 months to 75 years). Diagnosis can be difficult, being based on clinical, radiological, endoscopic, and histological features and on the response to chemotherapy. Most cases can be successfully treated with antituberculous chemotherapy even in the presence of fistulous tracts. Patients with esophageal tuberculosis in the presence of AIDS do not respond as well to antituberculous chemotherapy.

Adult↗

PubMed1991

Airway complications in relapsing polychondritis.

To analyze the importance of airway involvement in relapsing polychondritis, an illustrative case report is presented and 62 patients reported in the literature with serious airway complications are reviewed. There were 47 female and 17 male patients, with an average age of 40.3 years (range, 2 to 73 years). Patients were seen with hoarseness, breathlessness, cough, stridor, wheezes, and tenderness over laryngotracheal cartilages. Respiratory tract involvement was confirmed by conventional radiography, tomography, computed tomography, dynamic pulmonary function tests, and bronchoscopy. Corticosteroids and antiinflammatory and immunosuppressive agents were used in these patients. Tracheostomy was performed in 18 patients. Death occurred in 13 patients despite tracheostomy or corticosteroid therapy, or both. A detailed analysis of the clinical, radiological, and pulmonary function studies is presented, with emphasis on upper airway mechanics. The medical and surgical management options are reviewed, including the use of endotracheal prosthesis and extraluminal splinting in dynamic airway collapse.

Adolescent↗

PubMed1991

Long-term results of Ionescu-Shiley valve in the tricuspid position.

A retrospective analysis of the long-term results of using the Ionescu-Shiley pericardial bioprosthesis in the tricuspid position was carried out on 73 patients (8 men, 65 women). Of these procedures, ten were tricuspid valve replacement alone and the remainder were in combination with other valve procedures. The mean follow-up was 9.6 years (range, 4 to 18 years). The mean age of the patients was 53 years (range, 27 to 78 years). Seventy-one of the patients suffered tricuspid valve dysfunction from rheumatic heart disease. There were 13 postoperative deaths (within 30 days), giving a mortality rate of 17.8%. The actuarial survival at 10 years was 71% +/- 4.2%. Of the survivors, 49 (79.6%) were in functional class I or II. Primary tissue valve failure in the tricuspid position occurred in 1 patient 12 years after implantation and required reoperation. In another patient bioprosthetic tricuspid valve endocarditis developed. There was no incidence of thromboembolic complications. We conclude that the Ionescu-Shiley pericardial bioprosthesis was a satisfactory prosthesis in the tricuspid position in patients with acquired valvar dysfunction.

Adult↗

PubMed1991

Site of action of continuous extrapleural intercostal nerve block.

Continuous extrapleural intercostal nerve block has been shown in a randomized, controlled study to be effective in reducing postoperative pain after thoracotomy and in restoring pulmonary mechanics. To assess the extent of spread of bupivacaine infused through an extrapleurally placed cannula inserted at thoracotomy, iohexol (Omnipaque) was infused at 5 days postoperatively in 5 patients and computed tomography performed. The contrast medium was confined to the paravertebral space covering on average six intercostal spaces. This study demonstrated that anatomically, the site of action of the bupivacaine infused through an extrapleural cannula was primarily in the paravertebral space.

Autonomic Nerve Block↗

PubMed1991

Coronary ostial stenosis: surgical considerations.

To investigate the clinical significance of coronary ostial stenosis, we reviewed eight patients with such lesions, including three with isolated stenosis at the orifice of the coronary artery. There were five male and three female patients, with an average age of 46.25 years (range 32-69 years). Their symptoms consisted mainly of angina (6 patients), with dyspnoea and palpitation being the presenting features in the remaining two patients. All patients underwent preoperative coronary angiography which confirmed stenosis at the level of the orifice with absence of reflux of contrast medium into the sinus of Valsalva as the main features. Delay in the appreciation of stenosis of the orifice of the right coronary artery resulted in the death of two patients, whose diagnosis was confirmed at post mortem examinations. Stenosis of the orifice of the right coronary artery was present in seven patients, with two patients also having stenosis of the orifice of the left coronary artery. The remaining patient had isolated stenosis of the left coronary arterial orifice. Coronary artery bypass grafting was performed in five patients, including two who had patch angioplasty to the right coronary artery. The patient with isolated stenosis of the orifice of the left coronary artery had patch angioplasty only. Follow-up of up to three years in the surviving patients showed good functional results. The ease with which it is possible to miss right coronary ostial stenosis is emphasized and angiographic features are reviewed.

Adult↗

PubMed1991

Left ventricular outflow tract obstruction from mitral prosthesis.

A case of left ventricular outflow tract obstruction six years following mitral valve replacement is presented. Clinical features, echocardiographic and angiographic studies preoperatively all suggested aortic valve disease. The diagnosis of left ventricular outflow tract obstruction by the strut of the mitral prosthesis was made intraoperatively. Enlargement of the aortic root and aortic valve replacement resulted in good symptomatic and echocardiographic improvement.

Aged↗

PubMed1991

Morbidity following coronary artery revascularisation with the internal mammary artery.

To investigate the morbidity after coronary artery bypass grafting, one hundred and seventy-eight patients were retrospectively studied with a minimum follow-up period of one year. Although there was no difference in the incidence and distribution of pain in hospital, seventy percent of patients who had an internal mammary artery used as one of the bypass conduits experienced chest wound pain after discharge from hospital compared to 51.7% of patients who had vein grafts alone (P less than 0.05). Twenty-three percent of patients who had left internal mammary arteries harvested experienced chronic left-sided chest wall pain compared to 4.5% of patients who had vein grafts only (P less than 0.005). The possible factors responsible are discussed and a review made of the complications which may result from using the internal mammary artery in coronary artery surgery.

Chest Pain↗

PubMed1991

Mediastinal haematoma in Ehlers-Danlos syndrome.

A patient with Ehlers-Danlos syndrome presented acutely with clinical and radiological features suggestive of aortic dissection. Further investigations including computerised tomography and aortography showed mediastinal haematoma with no evidence of aortic dissection. He was treated conservatively with no complications. The typical clinical and radiological features are reviewed and an emphasis is made on accurate diagnosis to allow prompt, appropriate management.

Adult↗

PubMed1991

Magnetization transfer contrast: method for improving contrast in gradient-recalled-echo images.

A method that improves contrast in gradient-recalled-echo magnetic resonance images is described. The increase in contrast is produced by applying low-power radio-frequency irradiation 5-10 kHz from the main water proton resonance frequency to excite macromolecular hydrogen-1 nuclei as part of a conventional gradient-recalled-echo sequence. The contrast so obtained is theoretically different from T1 or T2 contrast and has been termed magnetization transfer contrast. Cat head images were acquired in vivo with this method at 4.7 and 1.5 T. Compared with conventional gradient-recalled-echo images, the magnetization transfer images demonstrate increased contrast between many tissue pairs, such as between white matter and blood and between gray matter and cerebrospinal fluid. The dependence of the magnetization transfer effect on repetition time and preirradiation power were also studied.

Animals↗

PubMed1991

The Norwegian meningococcal serogroup B outer membrane vesicle vaccine protection trials: case tracing, meningococcal antigen detection and serological diagnosis.

A survey is given of the efforts made to inform the general public, the potential vaccinees and their parents, and the health care personnel about meningococcal disease in general and the vaccination trial in particular, as a preparation for the meningococcal outer membrane vesicle serogroup B vaccine (MenB-vaccine "Folkehelsa") trials in secondary school students and military conscripts in Norway. Our case reporting system, supplementing the official notification, concerning even vaguely suspected cases in the age cohorts involved, is described. The efforts made to collect clinical material as well as laboratory and clinical data from 221 registered suspected cases are delineated. We also briefly summarize our cerebrospinal fluid antigen detection methods and diagnostic meningococcal serology work on these suspected cases. The compiled information on findings done at the admitting hospital of the possible cases and the additional diagnostic data provided at the National Institute of Public Health were put at the disposal of the independent Diagnosis Review Committee (DRC) as a basis for their diagnostic decisions before code opening for the meningococcal serogroup B outer membrane vesicle vaccine protection trial 3 June 1991.

Bacterial Capsules↗

PubMed1991

Drug-induced esophagitis.

Drug-induced esophagitis is being recognized increasingly in the past few years. We have reviewed 175 cases with a view to classifying this disease based on pathology. Drug-induced esophageal injury tends to occur at the anatomical site of narrowing, with the middle third behind the left atrium predominating. The disease is classified broadly into two groups. The first group is transient and self-limiting, as exemplified by tetracycline- and emepronium-induced injury (57.3%). The second is the persistent esophagitis group, often with stricture with two distinct entities: 1) patients on nonsteroidal antiinflammatory agents whose injury is aggravated by gastroesophageal reflux (26.2%) (reflux aggravated), and 2) patients with potassium chloride and quinidine sulfate-induced injury (16.2%) (persisting drug injury). We report a case that highlights the pathophysiology (delayed transit, persisting potassium within the stricture) of this type of injury which is not reflux aggravated.

Delayed-Action Preparations↗

PubMed1991

Radiometric and conventional drug susceptibility testing of Mycobacterium tuberculosis.

One hundred and four clinical isolates of M. tuberculosis were susceptibility tested by the radiometric method (RAD) using the BACTEC system in parallel with a conventional modified proportion method (CON). In the latter, the strains were tested against four concentrations of drugs in Lowenstein-Jensen medium (isoniazid (INH), streptomycin (SM) and ethambutol (EMB)) OR 7H10 agar medium (rifampicin (RIF)) and reported as "sensitive", "intermediate" or "resistant" from the minimum inhibitory concentrations observed. The radiometric results were classified in the same three groups in accordance with the BACTEC methodology. The overall agreement between the results obtained by the two methods was 97.4% (INH 95.2%, EMB 96.2%, SM 98.1% and RIF 100%). In addition, the agreement between RAD and each of the drug concentration steps employed in CON was examined and the results discussed in relation to the established critical concentrations of the drugs. The BACTEC technique was found to be a rapid and convenient method for routine use.

Carbon Radioisotopes↗

PubMed1990

Purification and structure of exendin-3, a new pancreatic secretagogue isolated from Heloderma horridum venom.

An amino-terminal histidyl structure (His1) is characteristic of most peptides in the glucagon superfamily. An assay for His1 peptides performed by amino-terminal amino acid sequencing was used to screen venom from the Gila monster lizard, Heloderma horridum. Two His1 peptides were identified: helospectin and a new His1 peptide that has been named exendin-3 to indicate that it is the third peptide to be found in an exocrine secretion of Heloderma lizards which has endocrine activity, the first two being helospectin (exendin-1) and helodermin (exendin-2). In the lot of H. horridum venom tested, exendin-3 was 5-10-fold more abundant in molar concentration than helospectin. The structure of exendin-3 was analyzed by amino acid sequencing and mass spectrometry. Exendin-3 is a 39-amino acid peptide with a mass of 4200. It contains a carboxyl-terminal amide and has a strong homology with secretin at its amino-terminal 12 amino acids. The complete structure of exendin-3 is His-Ser-Asp-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala- Val-Arg - Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro- Ser- amide. It is 32 and 26% homologous with helospectin and helodermin, respectively. It has greatest homology with glucagon (48%) and human glucagon-like peptide-1 (50%). Exendin-3 (3 microM) stimulated increases in cellular cAMP and amylase release from dispersed guinea pig pancreatic acini.

Amino Acid Sequence↗

PubMed1990

Purification of bovine cholecystokinin-58 and sequencing of its N-terminus.

Molecular cloning of cholecystokinin (CCK) mRNA from porcine brain and gut has demonstrated that CCK is synthesized as an identical precursor in both tissues. The sequence for porcine CCK-58 predicted from CCK cDNA was identical with the amino acid sequence of the peptide purified from different lots of animals. However one group did report that there were differences in the N-terminus of CCK-58 purified from the intestines of two different lots of mongrel dogs. In the current report it is demonstrated that the amino acid sequences of CCK-58 purified separately from three bovine brains are identical through the first 19 N-terminal amino acid residues. The peptides were sequenced for ten additional steps and were shown to be identical with the previously reported sequences for the N-terminus of CCK-39. The N-terminus of bovine CCK-58 has the following sequence: AVPRVDDEPRAQLGALLAR.

Amino Acid Sequence↗

PubMed1990

[Hairy cell leukemia and Mycobacterium malmoense infection].

We describe a patient with hairy cell leukemia and protracted fever. The patient's condition deteriorated during treatment with alfa Interferon 2b, and his fever persisted. A slight widening of the upper mediastinum appeared after 2.5 months. Mediastinoscopy with lymph node biopsy revealed granulomatous infiltrates with acid-fast bacilli. Cultures of the lymph node material later showed growth of Mycobacterium malmoense. The patient was treated with rifampicin, doxycycline, etambutol and cycloserin for sixteen months and remains afebrile and is gaining weight. His general condition is still improving. An aggressive diagnostic approach is necessary in febrile patients with hairy cell leukemia.

Adult↗

PubMed1990

Efficacy of continuous extrapleural intercostal nerve block on post-thoracotomy pain and pulmonary mechanics.

To assess the efficacy of continuous extrapleural intercostal nerve block on postoperative pain and pulmonary function, a prospective, randomized, double-blind, placebo-controlled trial was conducted on 56 patients undergoing elective thoracotomy. Infusion was started before closing the chest and was continued for 5 days. Subjective pain relief was assessed on a linear visual analogue scale. Pulmonary function was measured on the day before operation and daily for 5 days. There were 29 patients in a group which received bupivacaine and 27 in a control group which received saline. The bupivacaine group had lower pain scores (P less than 0.01) and required less papaveretum (P less than 0.01) than the control group. Forced vital capacity, forced expiratory volume in 1 s and peak expiratory flow rate were maximally reduced at 24 h to median values of 56, 60 and 57 per cent, respectively, of preoperative control values in the bupivacaine group, and to 25, 30 and 32 per cent in the control group. These differences are highly significant (P less than 0.01). Restoration of pulmonary function was superior in the bupivacaine group (P less than 0.01). There were no infusion-related complications. After thoracotomy, continuous intercostal blockade with bupivacaine is a safe and effective method of pain relief which reduces the early loss of postoperative pulmonary function significantly and more rapidly restores respiratory mechanics.

Adult↗

PubMed1990

NMR spectral analysis of kinetic data using natural lineshapes.

An automated rapid data analysis scheme for NMR spectroscopy time course studies is presented. This method uses a high signal-to-noise reference spectrum collected at the beginning of a time course as a lineshape model to analyze subsequent low signal-to-noise data collected with higher time resolution. The method is fast (approximately 1 s to evaluate two peaks in a 2K spectrum) and easily implemented on NMR spectrometer computers. An application of this method to spectroscopic studies on the heart is provided.

Humans↗

PubMed1990

Renal distribution and metabolism of [2H9]choline. A 2H NMR and MRI study.

Trimethylamines are required as substrates in the biosynthesis of a number of important molecules in the cell. Herein, we describe the use of choline, deuterated in its 9 methyl positions, as an NMR label for following the distribution and metabolism of methyl groups after intravenous choline infusion. Deuterium (2H) NMR spectroscopy of the rabbit kidney in vivo revealed a linear uptake of infused choline that was directly proportional to the rate of infusion. The sensitivity limit for the spectroscopic studies in vivo was in the order of 100 microM for a 2 min data collection. After the infusion, 2H NMR imaging of the kidney in vivo demonstrated high trimethylamine concentrations in both the cortex and inner medulla but not in the outer medulla. The inner medullary fraction, however, was more labile to diuresis induced by furosemide. Companion high resolution 2H NMR studies of extracts revealed a cortex betaine/choline concentration ratio of 0.69 +/- 0.05 (mean +/- SEM, n = 3) before furosemide administration. Following furosemide infusion, the cortex betaine/choline concentration ratio was 3 +/- 1 (n = 6). Thus, 2H renal images following furosemide treatment can be interpreted as metabolic maps of betaine distribution. In addition, extraction studies revealed high concentrations of labelled choline and betaine in the liver. These data demonstrate that 2H-labelled choline is an effective marker of choline methyl metabolism in vivo and should provide a unique tool for the investigation of this important substrate.

Animals↗