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Biomedical subjects

K Johansen

Publications and source records attributed to K Johansen.

At least 73 records · Page 4Linked to original sources
PubMed1993

Critical appraisal of the angiographic portacaval shunt (TIPS).

The transjugular intrahepatic portacaval shunt (TIPS) is a novel angiographic method for achieving portal decompression without operation. Fifty-nine consecutive patients underwent a total of 80 consecutive TIPS procedures. The procedure was unsuccessful in 4 patients (7%) and initially succeeded in 55 (93%). Eighteen patients (30%) underwent 2 or more TIPS procedures during the same hospitalization due to technical difficulties, early rebleeding, shunt stenosis, or thrombosis. Early TIPS occlusion occurred in seven patients (12%) and led to recurrent variceal hemorrhage in five. Forty-two percent of the cases of persisting or recurrent bleeding were nonvariceal. Procedure-related complications occurred in 10% of TIPS procedures or 14% of patients. Twenty-three patients (39%) were actively bleeding at the time of the procedure, and, in 6 of these (26%), bleeding was never controlled. In-hospital mortality (25%) was related only to the presence of bleeding at the time of TIPS (56% for emergent versus 5.5% for non-emergent, p < 0.0001). Mortality was not related to the Child-Pugh classification. Hemodynamic stabilization, vasoconstrictor therapy, balloon tamponade, and sclerotherapy were underutilized in 30% to 40% of patients prior to TIPS. Aggressive medical management should be used to stop variceal hemorrhage prior to TIPS in all patients, regardless of the Child-Pugh classification. Prospective trials comparing TIPS with sclerotherapy and surgical shunt are required to demonstrate the proper role of this procedure in the management of portal hypertension and variceal hemorrhage.

Adult↗
PubMed1993

Symmetrical peripheral gangrene (purpura fulminans) complicating pneumococcal sepsis.

Bacterial sepsis is only infrequently accompanied by peripheral ischemia. However, we have managed 10 patients with symmetrical peripheral gangrene (purpura fulminans) accompanying pneumococcal sepsis (Streptococcus pneumoniae) during the past 15 years at a single institution. In only two (20%) of these patients could vasoconstrictor administration be implicated as contributory to gangrene. The clinical scenario was characterized by pneumococcal bacteremia, admission to the medical intensive care unit, normal proximal arterial perfusion, and symmetrical full-thickness digital and distal extremity ischemia leading to cutaneous gangrene. Three (30%) of these patients died. The failure of anticoagulant and antiplatelet agents as therapy and the successful reversal of impending digital gangrene in one patient by sympathetic blockade suggest that the initial underlining pathophysiology is vasoconstrictive rather than thrombotic in nature. Effective management includes appropriate antibiotic therapy, avoidance of early operative intervention, conservative local débridement, and secondary skin grafting.

Adrenal Cortex Hormones↗
PubMed1993

Stroke following rottweiler attack.

A previously healthy 50-year-old man suffered a major right cerebral infarction shortly after receiving head and neck bites in an attack by two rottweilers. Arteriography revealed occlusion of the right middle cerebral artery, an intimal flap and pseudoaneurysm in the high right internal carotid artery just proximal to the skull base, and an obstructed right vertebral artery. The powerful jaw mechanism of rottweilers and other large mastiff-type dogs makes their bites particularly destructive. The predilection of these animals for attacking the head and upper body makes occult crush injury to the extracranial cerebral vessels an important diagnostic consideration following such attacks.

Animals↗
PubMed1993

Analytical performance evaluation of EMIT II monoclonal amphetamine/methamphetamine assay: more specificity than EMIT d.a.u. monoclonal amphetamine/methamphetamine assay.

We evaluated a new EMIT II monoclonal amphetamine/methamphetamine assay for screening human urine by comparing it with the EMIT d.a.u. monoclonal amphetamine/methamphetamine assay and a fluorescence polarization assay. The EMIT II assay has a cutoff of 1 mg/L d-methamphetamine. The EMIT II and EMIT d.a.u. assays were run on a BM/Hitachi 704 analyzer; for the fluorescence polarization assay we used a TDx analyzer. All EMIT II positive samples were also analyzed by the fluorescence polarization assay. We used gas chromatography/mass spectrometry (GC/MS) for confirmation of the presence of amphetamine or methamphetamine. Within-run CVs for the Level 1 (1 mg/L) and Level 2 (3 mg/L) calibrators for the EMIT II assay were 0.47% and 0.53%, respectively. Corresponding between-run CVs were 1.48% and 1.60%, respectively. Of the 1007 samples screened for amphetamines, 50 were positive by the EMIT d.a.u. assay; 21 samples (not a subset of the 50 samples) were positive by the EMIT II assay. However, 19 samples that tested positive by EMIT II also tested positive by the EMIT d.a.u. assay. Subsequent testing of the EMIT II positive samples by the fluorescence polarization assay detected in six positive samples. By means of chiral derivatization wer identified two specimens containing primarily l-isomers of amphetamine and methamphetamine. Sympathomimetic amines were identified in several of the samples not containing amphetamine or methamphetamine.

Amphetamine↗
PubMed1992

[Arteriosclerosis of the lower extremities--patients' contacts with alternative therapists].

During the period July 1987-April 1988, ninety-one patients with arterial insufficiency in the lower limbs were referred to the Department of Thoracic and Vascular Surgery at Aalborg Hospital. The mean delay between contact with the general practitioner and the vascular surgeon was nine months. Twenty-nine of the patients contacted alternative therapists before referral to the vascular surgeon. Twenty-five of these patients had suffered from intermittent claudication for at least two years and the total cost of treatment was 76,013 Danish crowns (900 Danish crowns or approximately pounds 75 per patient).

Adult↗
PubMed1992

Circulatory changes induced by portal venous diversion and mesenteric hypertension in rats.

We studied the hemodynamics in four groups of rats with combinations of mesenteric hypertension and portal diversion. Operations created three groups with mesenteric hypertension and different degrees of portal venous diversion: mesenteric vein stenosis, portal vein stenosis and end-to-side portacaval anastomosis with mesenteric vein stenosis, the fourth group had only portacaval anastomosis. A control group had sham operations. Cardiac output, splanchnic blood flows and portosystemic shunt indices were measured with radioactive microspheres. Mesenteric venous pressures in the mesenteric-stenosed, portal-stenosed, portacaval-shunted and end-to-side portacaval anastomosis with mesenteric vein stenosis rats were, respectively, 13.5 +/- 0.6, 15.3 +/- 0.7, 4.3 +/- 0.5 and 13.0 +/- 0.9 mm Hg, which were all significantly different from controls: 8.3 +/- 0.3 mm Hg. Portosystemic shunt indices were also significantly different from each other: controls, 0.4% +/- 0.02%; mesenteric-stenosed, 5.9% +/- 2.3%; and portal-stenosed, 52.1% +/- 4.9%. Cardiac output and splanchnic visceral blood flows were significantly increased in the portal-stenosed rats and the two groups with portacaval anastomoses, with the latter two groups having the highest values. The addition of mesenteric stenosis did not change the blood flows because mesenteric-stenosed rats did not differ from controls and end-to-side portacaval anastomosis with mesenteric vein stenosis rats did not differ from rats with portacaval anastomosis alone. These results suggest that mesenteric venous hypertension per se does not affect hemodynamics but that diversion of portal venous blood from the liver is a critical factor in the development of hyperkinetic circulation in portal hypertension.

Abdomen↗
PubMed1992

N-acetylation polymorphism and diabetes mellitus among Saudi Arabians.

The acetylator phenotypes of 200 Saudi diabetics and an equal number of control subjects of the same origin were determined by measuring the peak height ratio of two urinary caffeine metabolites, 5-acetylamino-6-formylamino-3-methyluracil (AFMU) and 1-methylxanthine (1MX), using a simplified high-performance liquid chromatographic method. Urine samples were collected from the diabetics and the control subjects who regularly drink coffee, tea, or caffeinated beverages as part of their normal daily diet. The patients were classified as either type 1 (insulin-dependent) (28 patients) or type 2 (insulin-independent) diabetics (172 patients) according to standard criteria. The reproducibility of acetylator phenotype was established by examining the peak height ratio of AFMU/1MX in 18 diabetics and 6 control subjects on different days. Significant differences in the proportion of rapid acetylators were observed between type 1 (53.6%) and type 2 (33.7%) diabetics (P < or = .0436), and between the control group (26%) and the overall diabetics (36.5%) (P < or = .024) or those with type 1 disease (P < or = .0028). Also, there was a significant (P < or = .0436) association between rapid acetylator status and type 1 diabetes mellitus.

Acetylation↗
PubMed1992

Portal hypertension and bleeding esophageal varices.

Bleeding from esophageal varices exacts a high mortality and extraordinary societal costs. Prophylaxis--medication, sclerotherapy, or shunt surgery to prevent an initial bleeding episode--is ineffective. In patients who have bled from varices, endoscopic injection sclerotherapy can control acute bleeding in more than 90% of patients. Because recurrent bleeding frequently occurs and survival without definitive therapy is dismal, selection of a permanently effective treatment is mandatory once variceal bleeding has been controlled. Long-term injection sclerotherapy can be performed in compliant patients; it is relatively safe but is associated with a 30-50% rebleeding rate. Beta-blockers significantly reduce portal pressure and recurrent bleeding but have not been shown to diminish mortality from BEV. Portal decompressive surgery permanently halts bleeding in more than 90% of patients; the risk of operative mortality is high in decompensated cirrhotics, and long-term complications of encephalopathy and accelerated liver failure may limit indications for shunt surgery to good-risk cirrhotics who are not liver transplant candidates. Devascularization procedures have a low operative mortality and encephalopathy rate but unacceptably high rates of recurrent bleeding. Liver transplantation is curative therapy for bleeding esophageal varices and the associated underlying hepatic dysfunction; cost and availability of donor organs generally limit its use in this setting to variceal bleeders with end-stage liver disease not associated with active alcoholism.

Esophageal and Gastric Varices↗
PubMed1992

Neurologic consequences of cerebrovascular injury.

Because of ongoing controversy, the issue of vascular repair or ligation for patients with cerebrovascular injuries and preoperative central neurologic deficits is frequently debated. A total of 133 patients with penetrating cerebrovascular injuries were analyzed. The frequency of preoperative neurologic deficit was 20% (27 patients). The common carotid and internal carotid arteries were the most frequently injured structures, with a 29% and 15% incidence of preoperative neurologic deficits, respectively. The results of carotid repair in all patients whose preoperative deficit was limited to weakness or paralysis were favorable (seven patients normal or improved, two patients unchanged). The results of repair in patients whose preoperative deficit was characterized by obtundation were variable (four patients improved, four patients worsened or died). The results of carotid ligation were also variable (one improved, one unchanged, three worsened or died). Limited numbers of patients with preoperative neurologic deficits and the retrospective nature of this review prohibit definite conclusions. Therefore a multicenter, prospective, randomized trial of ligation or vascular repair for comatose patients with cerebrovascular injuries is proposed.

Carotid Artery Injuries↗
PubMed1992

Comparison of thyroglobulin and radioiodine scintigraphy during follow-up of patients with differentiated thyroid carcinoma.

OBJECTIVES: To compare serum thyroglobulin concentration and radioiodine scintigraphy during follow-up after thyroidectomy and radioiodine ablation for differentiated, non-medullary thyroid carcinoma. METHODS: One hundred fifty-eight patients received radiation ablation after thyroidectomy every 3-4 months until no pathological radioiodine uptake was seen on the scintigraphy. Simultaneously performed postablation scintigraphy and serum thyroglobulin measurement were related to clinical characteristics and mutually compared using kappa statistics (observed agreement not accounted for by chance divided by possible agreement not accounted for by chance). RESULTS: After three ablation doses, serum thyroglobulin concentration had fallen to below detection limit (5 micrograms/L) in 71% of the patients and 70% of the patients had achieved negative scintigraphy after a median radioiodine dose of 3700 MBq I-131 and a median follow-up time of 5 months. The observed agreement between serum thyroglobulin and scintigraphy after the third ablation dose was 62%. The chance agreement was 50% giving a kappa value of only 24%. The size of the thyroid cancer at admission was larger in patients with a positive scintigraphy after first ablation compared with patients with a negative scintigraphy (p = 0.005) and was correlated to thyroglobulin concentration (p = 0.05). Among patients with thyroglobulin level > 5 micrograms/L after thyroidectomy and first ablation dose, there were more patients who at admission had palpable lymph nodes in the neck (p = 0.06) and microscopically verified neck metastasis (p = 0.03) compared with the group with thyroglobulin < 5 micrograms/L. These differences were not seen when comparing patients with positive and negative scintigraphies. CONCLUSION: The low agreement between the two markers for thyroid cancer emphasizes the value of complementary use of thyroglobulin and scintigraphy in the follow-up of thyroid cancer patients. Patients with large tumours and neck metastasis probably need higher radioiodine doses for complete ablation.

Adenocarcinoma, Follicular↗
PubMed1992

Prospective comparison of partial versus total portal decompression for bleeding esophageal varices.

Eighty-six patients underwent portacaval shunt (PCS) to treat bleeding esophagogastric varices during a period of four years. Twenty-eight patients (group 1) underwent emergency total portal decompression, while 58 patients (group 2) underwent elective partial PCS. Age, gender, preshunt and postshunt alcohol consumption and modified Child-Pugh classification at the time of operation, and at latest follow-up evaluation, did not differ significantly between the two groups. Early mortality was higher after emergency shunts than after elective operation (p < 0.01). However, partial portal decompression, when compared with total shunt, resulted in a significantly lower likelihood of late mortality (13 versus 39 percent) (p < 0.05), as well as portasystemic encephalopathy (8 versus 56 percent) (p < 0.0005). All shunts remained patent postoperatively and no patient had variceal rebleeding during follow-up evaluation averaging 2.2 years. Duplex sonography demonstrated hepatofugal portal flow in all patients in both groups. The results of the current study suggest that partial portal decompression is technically feasible, prevents further variceal hemorrhage and confers significant protection against late mortality and the development of postshunt neuropsychologic dysfunction.

Adult↗
PubMed1991

Clean-up of plasma extracts by gel permeation chromatography during analysis of isosorbide nitrates by capillary gas chromatography.

This work describes how gel permeation chromatography (GPC) can be used for sample clean-up to reduce the fouling of the column in an automated on-column injector. The analytes were isolated from plasma together with the internal standard (isomannide dinitrate) by liquid-liquid extraction on Extrelut silica columns. The extracts were evaporated and reconstituted in tetrahydrofuran for separation of the analytes from non-volatile plasma components by GPC on a styrene-divinylbenzene column with 100 A pore size. A programmable autosampler with an additional three-way valve was used for injection and fraction collection. The molecular weight fraction between 100 and 700 a.m.u. was collected and transferred to the on-column autosampler for capillary gas chromatography on a 30-m column butt-connected to a 0.2-m pre-column. The pre-column was replaced after 50 sample injections. When the GPC purification was excluded from the work-up procedure a deposit of non-volatile components was formed at the injection zone of the pre-column which resulted in excessive peak-tailing after only five or six injections of plasma extract. The limit of determination was 0.2 ng/ml plasma for isosorbide dinitrate and 0.4 ng/ml for the mononitrates.

Blood↗
PubMed1991

Duplex scanning for arterial trauma.

Duplex sonography was evaluated as a potential screening examination for arterial trauma in 89 patients with 93 injuries, mostly to the extremities (n = 74) or the cervicothoracic region (n = 17). Among 60 scans performed solely because of wound proximity to nearby vascular structures, 4 (6.7%) were positive. Thirteen of 19 (68%) scans performed for clinical indications were positive. Six of 12 (50%) postoperative studies were abnormal, and each of 4 arterial injuries followed serially remained stable. Four false-negative duplex scans (4.3%) were recorded; no major arterial injuries were missed, and no false-positive studies were noted. Duplex sonography is rapid, noninvasive, inexpensive, and portable. Since it also appears to be reliable in diagnosing and localizing sites of arterial disruption, duplex scanning may be of value in screening patients with trauma for the presence of occult vascular injuries.

Adolescent↗