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Biomedical subjects

K Johansen

Publications and source records attributed to K Johansen.

At least 91 records · Page 5Linked to original sources
PubMed1991

Aortic sepsis: is there a role for in situ graft reconstruction?

Conventional extraanatomic reconstruction for aortic sepsis is associated with a significant risk of operative death, as well as frequent late complications. We evaluated in situ aortic grafting in the treatment of primary or graft-related aortic infection. Eleven selected patients underwent in situ aortic graft reconstruction in the setting of mycotic aneurysm (n = 5), secondarily infected aortic aneurysm (n = 1), primary aortoenteric fistula (n = 1), and secondary aortoenteric fistula (n = 4). All patients survived: follow-up from 10 to 130 months reveals no evidence for graft thrombosis, pseudoaneurysm, new or recurrent aortoenteric fistula, or subsequent aortic operations in any patient. A literature review produced 110 cases of aortic sepsis managed by in situ aortic reconstruction during the last decade. Thirty-two patients (29%) either died in the operative period or suffered a lethal late complication associated with their aortic reconstruction. This mortality rate declined to 21% if patients undergoing incomplete removal of a contaminated graft were excluded, and to 19% with the addition of our 11 patients. Both our experience and that described in the literature suggest that, in properly-selected patients, in situ aortic graft replacement may be a rational treatment option for localized or circumscribed aortic sepsis.

Adult↗
PubMed1991

Complex cellular and subcellular regulation of notch expression during embryonic and imaginal development of Drosophila: implications for notch function.

The Notch gene in Drosophila encodes a transmembrane protein with homology to EGF that appears to mediate cell-cell interactions necessary for proper epidermal vs. neural fate decisions. In this study, we examine Notch expression in detail throughout embryonic and imaginal development using confocal laser-scanning microscopy and specific mAb probes. We find that Notch is expressed in a tissue-specific manner as early as the cellular blastoderm stage, when cells of the presumptive mesoderm clearly express less Notch than adjacent ectodermal precursors. Notch is abundantly expressed during the initial determination of neuronal lineages, such as the embryonic neuroblasts and the precursors of sensory neurons in the imaginal disc epithelia, but expression quickly decreases during subsequent differentiation. These changing patterns of Notch expression do not correlate well with cell movements, and thus do not appear to support the notion that the major function of Notch is to maintain epithelial integrity via adhesive mechanisms. Our data suggest instead that Notch may act as a cell-surface receptor, perhaps functioning in the lateral inhibition mechanism that is necessary for proper spacing of neuronal precursors.

Animals↗
PubMed1991

Can Doppler pressure measurement replace "exclusion" arteriography in the diagnosis of occult extremity arterial trauma?

Although highly accurate, contrast arteriography is a costly, invasive, and time-consuming method to rule out occult arterial damage in injured extremities. Accordingly the authors assessed the sensitivity and specificity of Doppler-derived arterial pressure measurements in trauma victims undergoing evaluation for possible extremity arterial damage. Arterial pressure index (API) was calculated (Doppler arterial pressure distal to injury/Doppler arterial pressure in uninvolved arm), but not used in clinical decision making in 100 consecutive injured limbs in 93 trauma victims. All patients then underwent contrast arteriography. Twenty limbs had an API less than 0.90 and an abnormal arteriogram, whereas 75 had both a normal API and a normal contrast study. One limb had a significant angiographic abnormality with an API greater than 0.90; two others had API less than 0.90 but normal arteriograms. Two limbs with a normal API had false-positive arteriograms. When compared with arteriography, an API less than 0.90 had a sensitivity of 87% and a specificity of 97% for arterial disruption in this series. Sensitivity and specificity rose to 95% and 97% when API was compared with clinical outcome. In the absence of obvious signs of arterial injury, API may be a reasonable substitute for screening arteriography in the traumatized extremity, particularly if close follow-up observation can be assured.

Adolescent↗
PubMed1991

Coronary artery disease and apolipoprotein A-I/C-III gene polymorphism: a study of Saudi Arabians.

The infrequent band of 3.2-kb of the apolipoprotein A-I/C-III polymorphic region has previously been found to be associated with coronary artery disease and with hypertriglyceridaemia in Caucasians. We studied the apolipoprotein A-I/C-III gene cluster polymorphism in 97 Saudi Arabians in relation to coronary artery disease. Patients were categorized as being with or without coronary artery disease on the basis of coronary angiography. Genomic blotting of Sac I-digested chromosomal DNA with the use of an apolipoprotein A-I gene probe revealed 4.2-kb and 3.2-kb hybridization bands. The genotype frequency of patients with and without coronary artery disease was not different. The frequency of the 3.2-kb allele occurred in 16% of patients with coronary artery disease and in 21% of patients with normal coronary arteries (non-significant). In conclusion, we have not been able to confirm in Saudi Arabians associations previously reported in Caucasians of the 3.2-kb band and coronary artery disease.

Apolipoprotein A-I↗
PubMed1991

Coenzyme Q10, alpha-tocopherol and free cholesterol in HDL and LDL fractions.

Twenty-three randomly selected plasma samples from apparently healthy, middle aged men were analysed for coenzyme Q10 (CoQ10), alpha-tocopherol (AT) and free cholesterol (FC) in: 1) whole plasma, 2) the HDL lipoprotein fraction after LDL precipitation (VLDL + LDL). CoQ10, AT and FC in plasma averaged 0.69 +/- .11, 6.74 +/- 1.78 micrograms x ml-1 and 0.59 +/- .11 mg x ml-1 and in HDL 0.17, 3.24 micrograms x ml-1 and 0.17 mg x ml-1 or 29, 48 and 29% of plasma values. Amounts of CoQ10 and AT were correlated to that of FC in all pools. The amount of HDL-CoQ10 but not of HDL-AT fell, with the HDL-FC expressed as the fraction of plasma FC. In all pools, N-AT versus AT initially increased and then levelled off, indicating saturation like conditions in contrast to CoQ10. Thus, CoQ10 and AT are differently allocated in HDL and LDL. This might have a bearing both on the suggested lipoprotein protection against peroxidation by these two antioxidants, but also on the distribution and allocation in different organs of CoQ10 and AT by HDL and LDL transportation.

Cholesterol↗
PubMed1991

Traumatic scapulothoracic dissociation: case report.

A 23-year-old man suffered traumatic scapulothoracic dissociation (TSD) in a car-vs.-bicyclist accident. TSD is a devastating forequarter injury characterized by brachial plexus damage, major upper extremity musculoskeletal disruption, and exsanguinating hemorrhage: our patient survived a hematocrit of 7. Prompt recognition and aggressive management of TSD's multiple injuries are crucial.

Accidents, Traffic↗
PubMed1991

Ruptured abdominal aortic aneurysm: the Harborview experience.

During the last decade (1980 to 1989) 186 patients with ruptured abdominal aortic aneurysm were admitted to a single urban hospital. Ninety-six percent of these patients had a prehospital systolic blood pressure less than 90 mm Hg. Management included paramedic field resuscitation and transport, an emergency department diagnostic protocol completed in an average of 12 minutes, rapid transport to a dedicated emergency operating room, aneurysmorrhaphy by general surgery chief residents under the supervision of specialist vascular surgeons, and skilled postoperative intensive care unit care. Nevertheless, 130 (70%) patients died in the first 30 postoperative days--3% in the emergency department, 13% in the operating room, 51% in the intensive care unit, and 3% on the ward or at home. Certain features--age greater than 80 years, female gender, persistent preoperative hypotension despite aggressive crystalloid and blood replacement, admission hematocrit less than 25, transfusion requirements exceeding 15 units--were associated with a greater than 90% likelihood of death. No patient with preoperative cardiac arrest survived more than 24 hours. From this experience we conclude that, although "optimal" prehospital, emergency department, operating room, and postoperative care can improve the outcome of patients with ruptured abdominal aortic aneurysms in shock, most such patients will die. Certain clinical features predict such excessive mortality rates after ruptured abdominal aortic aneurysms that withholding operation may be reasonable. Screening of patients at high risk for abdominal aortic aneurysm, followed by elective aneurysmorrhaphy, is clearly indicated.

Aged↗
PubMed1991

Comparison of 1073 MBq and 3700 MBq iodine-131 in postoperative ablation of residual thyroid tissue in patients with differentiated thyroid cancer.

In a randomized prospective study, we compared the efficacy of low dose (1073 MBq) and high dose (3700 MBq) iodine-131 administration in postoperative ablation of residual functioning thyroid tissue in 63 patients with differentiated thyroid cancer. We were unable to demonstrate any difference between the low- and the high-dose of radioactive iodine in scintigraphic ablation of remnant tissue. In 81% (21/26) of the patients, 1073 MBq ablated after the first dose, 77% (21/26 + 3/5 = 24/31) after the first plus second dose, and 69% (24/31 + 0/4 = 24/35) after the first, second, and third dose. Radioiodine (3700 MBq) ablated in 84%, 73%, and 69% of the patients after respectively 1., 1. plus 2., and 1. plus 2. plus 3. dose. Forty percent of the patients ablated with the low dose and 44% ablated with the high dose had elevated thyroglobulin levels at the time of complete scintigraphic ablation. In conclusion, we did not find any difference between 3700 MBq and 1073 MBq iodine-131 as regard to number of doses needed for complete scintigraphic ablation of residual functioning thyroid tissue.

Adult↗
PubMed1991

Non-invasive vascular tests reliably exclude occult arterial trauma in injured extremities.

We evaluated the ability of noninvasive vascular tests to exclude clinically significant occult arterial damage in injured extremities. In a preliminary study, a Doppler arterial pressure index (API) (the systolic AP in the injured extremity divided by the AP in an uninvolved arm) of less than 0.90 was found to have sensitivity and specificity of 95% and 97%, respectively, for major arterial injury. The negative predictive value for an API greater than 0.90 was 99%. Because these values suggested that noninvasive vascular tests might effectively be substituted for "exclusion" arteriography in patients at risk for silent extremity arterial injuries, we then conducted a trail in which arteriography was performed in extremity trauma victims only when the API was less than 0.90. Among 100 traumatized limbs (84 penetrating, 16 blunt) in 96 consecutive patients, 16 of 17 limbs (94%) with an API less than 0.90 had positive arteriographic findings, and seven underwent arterial reconstruction. Among 83 limbs with an API greater than 0.90, followup (including duplex scanning in 64 limbs) revealed five minor arterial lesions (four pseudoaneurysms, one arteriovenous fistula) but no major injuries. Arteriograms for extremity trauma fell from 14% to 5.2% of all angiographic studies performed (p less than 0.001, Chi-square). These studies suggest that noninvasive vascular tests can reliably exclude major occult arterial damage in injured extremities. Screening for such injuries with Doppler arterial pressure measurements, reserving arteriography for limbs in which the API is less than 0.90, is safe, accurate, and cost effective.

Adolescent↗
PubMed1990

Determination of water-soluble vitamins in blood and plasma by coupled-column liquid chromatography.

A method is described for the simultaneous determination of riboflavin and the coenzymes related to pyridoxine and thiamine. Pyridoxal-5'-phosphate (PLP) bound to proteins as a Schiff base was liberated and stabilized by reaction with semicarbazide. Blood or plasma proteins were precipitated with acid and the supernatant formed was injected into a liquid chromatographic system consisting of one precolumn and two analytical reversed-phase columns. Riboflavin was detected by its native fluorescence with a separate detector while post-column reactions based on the fluorescence of PLP semicarbazone in alkaline solution and the oxidation of thiamine to thiochrome were combined in the same reaction detector. Chromatographic separation was achieved within 7 min and normal endogenous levels were quantified with a precision of 2-5% (relative standard deviation).

Chromatography, Liquid↗
PubMed1990

[Hyperlipidemia in diabetes mellitus. Pathogenesis, diagnosis and drug therapy--a review].

Atherosclerosis is the most prevalent long-term diabetic complication. The increased mortality and morbidity in diabetics caused by atherosclerosis has been related to the frequent occurrence of hyperlipidaemia in diabetes. Insulin regulates many processes in lipid metabolism via control of enzyme activity and receptor binding. It is important to establish a precise diagnosis of the lipid abnormalities before commencing treatment. The treatment begins with control of blood glucose, followed by dietary treatment of hyperlipidaemia. Hypolipidaemic drugs are first introduced when the dietary response is unsatisfactory. Optimal therapy with antidiabetic drugs should precede hypolipidaemic drug therapy.

Cholesterol↗
PubMed1990

Can duplex scanning replace arteriography for lower extremity arterial disease?

This preliminary study was undertaken to determine if surgeons would choose different intervention for lower extremity occlusive disease when given basic clinical information and data from either a duplex scan or arteriogram. Information on degree of stenosis from duplex scans and arteriograms of 29 patients was indicated on an anatomical line drawing along with the ankle blood pressures and a brief clinical description. Based on these data sheets, six vascular surgeons chose a clinical plan in a blinded fashion for each patient. Each plan was placed into one of eight possible categories for comparison using the kappa statistic. Intraobserver agreement between surgeons' decisions based on duplex scanning versus those based on arteriography was very good (mean kappa .70 with exact agreement in 76%). Interobserver agreement between different surgeons' decisions based on the same studies was significantly less (mean kappa 0.56, p less than .05). Significant disparity in clinical approach occurred in 43% of the patients with nearly identical duplex scan and arteriogram reports, suggesting that much of the discrepancy lies in the clinical decision-making process. Clinical decisions made using duplex scans are very similar to those made using arteriograms. This technique can limit the need for arteriography in assessing patients with lower extremity arterial occlusion disease.

Angiography↗
PubMed1990

Duplex ultrasonography of the portal vein.

Although the ability of ultrasonography to provide anatomic detail and physiologic information about the arterial system is well established, its applicability for the venous system and the splanchnic circulation has only recently been recognized. We have found duplex scanning, which is non-invasive, rapid, inexpensive, and reproducible, to be highly accurate in (1) establishing or confirming the diagnosis of portal hypertension, (2) demonstrating portal and splenic vein patency and direction of flow, (3) assessing portosystemic shunt patency, and (4) providing novel anatomic and physiologic information regarding the normal and diseased splanchnic venous system. These ultrasonographic techniques also have a significant role to play in the surveillance of patients who have undergone liver transplantation or massive liver resection. To a great extent, ultrasonography may supplant the invasiveness, discomfort, and expense of contrast angiography in the evaluation of many patients with advanced liver disease.

Humans↗
PubMed1990

St. Anthony's fire: successful reversal of ergotamine-induced peripheral vasospasm by hydrostatic dilatation.

A 60-year-old trauma victim developed severe ischemia of all four extremities following administration of heparin-dihydroergotamine as prophylaxis against deep venous thrombosis. Despite cessation of heparin-dihydroergotamine and infusion of intraarterial papaverine into the right femoral artery, both lower extremities progressed to frank gangrene and amputation (above-knee on the left and below-knee on the right). However, both ischemic upper extremities were salvaged following intraoperative hydrostatic dilatation with balloon catheters. Ergotism is an avoidable and potentially treatable cause of peripheral gangrene in the critically-ill patient.

Catheterization↗
PubMed1990

Objective criteria accurately predict amputation following lower extremity trauma.

MESS (Mangled Extremity Severity Score) is a simple rating scale for lower extremity trauma, based on skeletal/soft-tissue damage, limb ischemia, shock, and age. Retrospective analysis of severe lower extremity injuries in 25 trauma victims demonstrated a significant difference between MESS values for 17 limbs ultimately salvaged (mean, 4.88 +/- 0.27) and nine requiring amputation (mean, 9.11 +/- 0.51) (p less than 0.01). A prospective trial of MESS in lower extremity injuries managed at two trauma centers again demonstrated a significant difference between MESS values of 14 salvaged (mean, 4.00 +/- 0.28) and 12 doomed (mean, 8.83 +/- 0.53) limbs (p less than 0.01). In both the retrospective survey and the prospective trial, a MESS value greater than or equal to 7 predicted amputation with 100% accuracy. MESS may be useful in selecting trauma victims whose irretrievably injured lower extremities warrant primary amputation.

Adult↗