Search PubMed⌕ Search

Biomedical subjects

K Johansen

Publications and source records attributed to K Johansen.

At least 109 records · Page 6Linked to original sources

Apolipoprotein A-I/C-III gene cluster polymorphism in Saudi Arabians, Filipinos and Caucasians.

We studied the polymorphic locus in the A-I/C-III gene cluster on the long arm of chromosome 11 in 147 Saudi Arabian, in 84 Filipino and in 69 Caucasian blood donors. Digestion of DNA yielded two fragments 4.2 kb and 3.2 kb long. The genotype distribution was the same in Arabs and Filipinos, but both were significantly different from Caucasians (p = 0.005 and 0.0005). The 3.2-kb allele occurred in 18% of the Saudi Arabians, in 23% of the Filipinos and in 4% of Caucasians. The frequency of the 3.2-kb allele was significantly higher in Arabs and Filipinos compared to Caucasians (p = 0.0005).

Alleles↗

Mesenteric venous stenosis reduces hyperammonemia in the portacaval-shunted rat.

Hyperammonemia is a constant finding following portacaval anastomosis (PCA), and has been incriminated in the neurologic deterioration observed following portasystemic shunt in humans. We developed a rat model for mesenteric venous hypertension by modification of a commonly used technique for studying extrahepatic portal hypertension. We then examined serum ammonia levels in rats undergoing sham operation, mesenteric vein stenosis (MVS) alone, PCA alone, and MVS plus PCA. All MVS animals had a significant (p less than 0.05) elevation in mesenteric venous pressures 2-3 weeks after operation. Serum ammonia levels were normal in rats undergoing sham operation and MVS, and were significantly elevated (p less than 0.001) in rats with PCA. However, a significant (p less than 0.01) reduction in serum ammonia levels was realized when PCA and MVS were combined. These data suggest that intestinal ammonia absorption is a function of splanchnic venous pressure. These findings may be relevant to the management of the neuropsychiatric deterioration seen following PCA in man.

Ammonia↗

Limb salvage versus amputation. Preliminary results of the Mangled Extremity Severity Score.

Objective criteria can predict amputation after lower-extremity trauma. The authors examined the hypothesis that objective data, available early in the evaluation of patients with severe skeletal/soft-tissue injuries of the lower extremity with vascular compromise, might discriminate the salvageable from the unsalvageable limbs. The Mangled Extremity Severity Score (MESS) was developed by reviewing 25 trauma victims with 26 severe lower-extremity open fractures with vascular compromise. The four significant criteria (with increasing points for worsening prognosis) were skeletal/soft-tissue injury, limb ischemia, shock, and patient age. (There was a significant difference in the mean MESS scores; 4.88 in 17 limbs salvaged and 9.11 in nine limbs amputated; p less than 0.01). This scoring system was then prospectively evaluated in 26 lower-extremity open fractures with vascular injury over a 12-month period at two trauma centers. Again, there was a significant difference in the mean MESS scores; 4.00 for the 14 salvaged limbs and 8.83 for the 12 amputated limbs (p less than 0.01). In both the prospective and retrospective studies, a MESS score of greater than or equal to 7 had a 100% predictable value for amputation. This relatively simple, readily available scoring system of objective criteria was highly accurate in acutely discriminating between limbs that were salvageable and those that were unsalvageable and better managed by primary amputation.

Adult↗

[The effect of systemic N-acetylcysteine on postoperative expectoration. A prospective, randomized double-blind study].

A material of 110 consecutive patients submitted to elective upper abdominal laparotomy participated in a randomized double-blind investigation of the effect of N-acetylcysteine (Mucomyst) administered systemically in the recommended dosage on postoperative expectoration. As an effect variable the quantity of expectorate and the viscosity as assessed subjectively by the physiotherapists in the department on a visual analog scale was employed. N-acetyl-cysteine was not found to have any effect on the postoperative expectoration as assessed by the quantity and the viscosity.

Clinical Trials as Topic↗

Partial portal decompression for variceal hemorrhage.

To test the hypothesis that partial portal decompression in the treatment of variceal hemorrhage will diminish subsequent encephalopathy, 50 consecutive patients were studied after construction of a small-stoma (10 to 12 mm) side-to-side portacaval shunt, with the goal of a postoperative portacaval pressure gradient of 10 mm Hg. During follow-up averaging 26 months, six patients (12 percent) died. Four patients (8 percent) had episodes of rebleeding, only one from varices. All patients had patent shunts at subsequent angiography or ultrasonography. Despite consistent (100 percent) postoperative reversal or stagnation of portal flow on duplex scan, encephalopathy on clinical and psychometric grounds was observed in only three patients (6 percent). This study suggests that small-stoma portacaval shunt can be performed with reliably low rates of rebleeding and encephalopathy. That encephalopathy was rare despite loss of hepatic portal perfusion incriminates other factors besides portal flow in the genesis of postshunt hepatic failure.

Adult↗

A twelve-year survey of cervicothoracic vascular injuries.

This study of a large series of victims of trauma to the cervicothoracic great vessels confirms the lethal potential of these injuries: more than half of victims of such injuries died. The optimal management of patients potentially harboring such vascular damage appears to include skilled prehospital resuscitation and rapid transport to a trauma center, a high index of diagnostic suspicion, a low threshold for the performance of contrast arteriography, aggressive surveillance for associated neurologic and aerodigestive tract injuries, and timely technical repair, including liberal indications for sternotomy or thoracotomy to assure vascular control.

Adolescent↗

Treatment options for aneurysms in high-risk patients.

The increasing prevalence of aneurysms in an aging population bears with it increasing numbers of patients who are less than optimal candidates for resection. It is likely that the majority of such patients can undergo standard resection, either by referral to a center where the management of the elderly chronically ill is commonplace or by providing intensive preoperative metabolic, cardiac, pulmonary, and nutritional resuscitation. Such preoperative preparation might well include coronary revascularization or carotid endarterectomy. For the occasional patient in whom medical comorbidity is advanced and fixed, or in whom rapid aneurysm expansion or worsening symptoms mandate immediate management, yet operative risk for standard aneurysm resection seems inordinately high, several nonresective options have been identified and tested. Among these options, aneurysm exclusion appears to have significantly better results (in terms of lower rates of operative mortality and subsequent aneurysm rupture) than distal aneurysm ligature. A more recent technique, aneurysm bypass, may have potential but has not been tested for a long enough period, or by an adequate number of surgeons, to have established itself as a nonresective option. Clinical judgment, technical expertise, and a willingness to seek assistance and consultation remain the hallmarks of the optimal management of the patient with an abdominal aortic aneurysm.

Aged↗

Intestinal permeability assessed with polyethylene glycols in children with diarrhea due to rotavirus and common bacterial pathogens in a developing community.

Intestinal permeability was assessed with different-sized polyethylene glycols (PEG 400 and PEG 1,000) in small children with acute diarrhea. All children with acute diarrhea absorbed and excreted less PEG of all molecular sizes into the urine when compared with healthy control children (p less than 0.001). Children with acute rotavirus infection excreted significantly less PEG of all sizes than children with Shigella, Salmonella, and enteropathogenic Escherichia coli (EPEC) infection (p less than 0.001-0.01), suggesting a more severe mucosal lesion caused by rotavirus. In patients with severe malnutrition there was also a significant decrease in absorption of PEGs observed. In addition, malnourished patients with rotavirus diarrhea showed a pronounced decrease of PEGs in comparison with well-nourished patients. The ratio between the recovery of a large PEG molecule, 1,074 Da, and a small molecule, 370 Da, was utilized to assess the absorption of large molecules in relation to that of smaller ones. On applying this ratio, it was noted that the intestine in children with Shigella and EPEC infection was relatively more permeable to larger molecules than in healthy controls, while in rotavirus and Salmonella infection it was less permeable to larger molecules. In this study significant differences in the permeability characteristics were observed, suggesting etiology-specific effects on the mucosal barrier.

Child, Preschool↗

Coronary artery disease, HDL cholesterol, and insulin-gene flanking sequences.

The relationship between coronary artery disease, HDL cholesterol, and the hypervariable region flanking the human insulin gene was studied in Saudi Arabian non-diabetic subjects (n = 68) and in patients with Type 2 diabetes (n = 35). A locus of insulin-gene-linked DNA polymorphism with three average size classes of alleles was found: a small class 1, a rare medium size class 2, and a large class 3 allele. In the total group of subjects (n = 103), those with the class 3 allele had a lower plasma HDL cholesterol concentration than those without the class 3 allele (0.93 +/- 0.26 vs 1.12 +/- 0.30 mmol l-1, 2p less than 0.003). No difference in genotype and allelic frequency was found between patients with and without coronary artery disease in the combined group of subjects, with and without diabetes. Similarly the genotype distribution was not different between non-diabetic subjects and patients with Type 2 diabetes in the combined group of subjects, both with and without coronary artery disease. In conclusion, the study did not confirm a previous study showing an association between the class 3 allele and atherosclerosis in a Caucasian population. However, the class 3 allele was associated with a low plasma HDL cholesterol concentration.

Alleles↗

Identification of Moraxella bovis by using a monoclonal antibody to a lipopolysaccharide epitope.

A monoclonal antibody to the lipopolysaccharide of Moraxella bovis is described. In an indirect fluorescent-antibody test, this monoclonal antibody reacted with 39 of 39 strains of M. bovis tested and did not react with 26 nonfermenting gram-negative coccobacilli other than M. bovis. When used in an indirect fluorescent-antibody test, it proved useful for rapid and easy identification of M. bovis.

Animals↗

A comparison of the toxicity and efficacy of cisplatin and carboplatin in advanced ovarian cancer. The Swons Gynaecological Cancer Group.

Eighty-eight patients with stage IIB-III epithelial ovarian cancer were randomised to receive first line single agent cisplatin (100 mg/m2) monthly or carboplatin (400 mg/m2) monthly for up to 5 cycles. Crossover to the opposite analogue occurred with progression or lack of response. All patients were premedicated with i.v. methylprednisolone (500 mg at 0 hours and 250 mg at 3 hours) and the first 20 patients in both groups received lorazepam and prochloperazine for nausea and vomiting. The median number of vomiting episodes per cycle with cisplatin was 16 and with carboplatin 2 (p less than 0.001). In the cisplatin arm 27/40 (67.5%) developed mild renal toxicity, 9/40 (22.5%) WHO grade I neurotoxicity and 18/40 (45%) evidence of ototoxicity at audiometry. To date we have seen no neuro- or ototoxicity with carboplatin and 1/40 (2.5%) have developed WHO grade I renal toxicity. Myelosuppression and anaemia was more common with carboplatin but only 1 episode of grade IV thrombocytopenia has been seen with first line carboplatin. The clinical response rate (CR+PR) for cisplatin was 19/40 and for carboplatin 27/40. Actuarial survival for cisplatin group at 24 months was 50% and for carboplatin group 58% with no significant difference. Carboplatin appears less toxic than cisplatin producing to date similar survival and response as a single agent.

Antiemetics↗

Beneficial effects of intra-arterial reserpine after upper-extremity embolectomy: a prospective randomised trial.

Persistent ischaemia occasionally follows technically-successful arterial embolectomy, and has generally been ascribed to small-vessel thrombosis in the distal vascular bed. Because of the possibility that distal vasospasm might be a contributory cause, we conducted a prospective randomised trial of vasodilator therapy in this setting. In 50 consecutive patients presenting with their first episode of upper-extremity arterial embolism, we compared the results of the intra-arterial instillation of 0.5 mg reserpine with those of saline alone following embolectomy. Among 29 patients receiving saline only, 13 (44.8%) suffered persistent or recurrent limb ischaemia requiring reoperation, while three (14.3%) of 21 patients receiving reserpine had continuing ischaemia (P = 0.02). Three patients in each group required a second re-operation; all three in the reserpine group were ultimately found to have a proximal axillo-subclavian artery stenosis as the cause for their persistent or recurrent limb ischaemia. Although its underlying pathophysiology remains obscure, peripheral vasospasm appears to accompany acute embolic arterial occlusion. Manoeuvres to prevent or reverse such distal vasoconstriction may be useful in avoiding persistent or recurrent ischaemia following arterial embolectomy.

Aged↗

Duplex sonography accurately assesses portacaval shunt patency.

Among 42 patients who had undergone portacaval shunt (PCS) to treat bleeding esophageal varices, shunt patency was assessed with duplex sonography 1 month to 5 years postoperatively. Patency was confirmed in all patients (100%). Correlative angiograms confirming the sonographic findings were obtained in 24 patients. Duplex scanning showed hepatofugal or stagnant flow in the distal portal vein in all 42 patients. Very low rates of liver-failure-related mortality (6%) and morbidity (6% incidence of encephaloparthy) in this series despite loss of portal perfusion of the liver in patients incriminate factors other than magnitude and direction of portal vein flow as the cause of complications occurring after PCS. Duplex sonography offers accurate and relevant clinical and physiologic data about shunt hemodynamics in patients who have undergone PCS.

Humans↗

Skeletal muscle adaptations to physical training in type II (non-insulin-dependent) diabetes mellitus.

Seven middle-aged men with manifest type II diabetes mellitus underwent an endurance training programme for 10-15 weeks. The maximal aerobic capacity, as well as the endurance capacity, was improved by 10% (p less than 0.05). The intramuscular glycogen store increased by more than 80% (p less than 0.05) from 350 mumol/g dw (dry weight), and the activities of citrate synthase and 3-hydroxy-acyl-CoA dehydrogenase increased by more than 50% (p less than 0.05) and 30% (p less than 0.05). The activity of glycogen synthase was decreased by approximately 20% (p less than 0.05), whereas lactate dehydrogenase remained unchanged. Capillaries/fibre and fibre area increased by more than 50% (p less than 0.05) and 30% (p less than 0.05) leaving the area of supply constant. Training did not influence fasting blood lipids and glucose, glycosylated hemoglobin, oral glucose tolerance, and insulin response to an oral glucose load measured 72 hours post-exercise. It is concluded that patients with manifest type II diabetes, as normoglycaemic individuals, adapt to physical training. However, no persistent effect on glucohomeostasis and lipaemia is produced by short-term training in the diabetic patients.

Adaptation, Physiological↗

Lung carcinoid with Cushing's syndrome: control of serum ACTH and cortisol levels using SMS 201-995 (sandostatin).

Two patients with Cushing's syndrome due to lung carcinoid tumours were given the long-acting somatostatin analogue SMS 201-995 (Sandostatin). One received a single 50 micrograms dose which produced a 50% reduction in circulating ACTH levels within 4 h. The other has been maintained in clinical and biochemical remission for 10 weeks on 100 micrograms tid. This is the first report of the successful use of SMS 201-995 in carcinoid-induced Cushing's syndrome, and suggests that this hormone analogue could be valuable in the long term medical management of such patients.

Adrenocorticotropic Hormone↗

Gas exchange during high-frequency ventilation in the pigeon (Columba livia).

We studied the effect of high-frequency ventilation (HFV) on the gas exchange of tracheotomized pigeons. The pigeons were artificially ventilated using a piston pump, which alternately connected the pigeons' airways to a constant-flow source. Two-minute periods of HFV were interposed between long periods of normal ventilation. The effect of HFV was assessed by the recorded changes in the PO2, PCO2 and pH of arterial blood and from the changes in the composition of the gas in the interclavicular air sacs. The results showed that HFV can augment gas exchange when the tidal volume (VT) is less than the volume of the anatomical dead space (VD). However, normal arterial gas composition can only be maintained if respiratory frequency is high (greater than 20 Hz). At the normal panting frequency of pigeons (7.8 Hz), gas exchange can thus only be maintained if tidal volume is approximately 125% of the dead space. When panting the VT must be greater than the VD. This finding agrees with the results of recent work showing flush-out- or compound-panting in birds: i.e. if, during panting, VT approaches close to the VD, intermittent interruptions, by taking deeper breaths in order to ensure a supply of fresh air to the lungs, are necessary.

Animals↗