β-lipotropin contains two lipolytic sequences

The lipolytic activity of β-lipotropin (β-LPH) is commonly supposed to reside in the heptapeptide sequence, 47–53. However, β-endorphin is also lipolytically active, so a second active sequence must be postulated. In attempts to define this second sequence, porcine β-LPH, β-endorphin, 19 partial sequences of β-LPH, [Leu]enkephalin, and [D-Met², Pro⁵]-enkephalin amide have been examined for glycerol releasing activity in rabbit adipocytes. An N-terminal fragment of β-LPH lacking the 47–53 heptapeptide was inactive. The message within the C-terminal portion of β-LPH could be localized to a C-terminal sequence greater than 87–91, but probably smaller than 78–91.     

Economic repercussions of fisheries-induced evolution

Fish stocks experiencing high fishing mortality show a tendency to mature earlier and at a smaller size, which may have a genetic component and therefore long-lasting economic and biological effects. To date, the economic effects of such ecoevolutionary dynamics have not been empirically investigated. Using 70 y of data, we develop a bioeconomic model for Northeast Arctic cod to compare the economic yield in a model in which life-history traits can vary only through phenotypic plasticity with a model in which, in addition, genetic changes can occur. We find that evolutionary changes toward faster growth and earlier maturation occur consistently even if a stock is optimally managed. However, if a stock is managed optimally, the evolutionary changes actually increase economic yield because faster growth and earlier maturation raise the stock’s productivity. The optimal fishing mortality is almost identical for the evolutionary and nonevolutionary model and substantially lower than what it has been historically. Therefore, the costs of ignoring evolution under optimal management regimes are negligible. However, if fishing mortality is as high as it has been historically, evolutionary changes may result in economic losses, but only if the fishery is selecting for medium-sized individuals. Because evolution facilitates growth, the fish are younger and still immature when they are susceptible to getting caught, which outweighs the increase in productivity due to fish spawning at an earlier age.     

Recurrence of aplastic anemia following cyclophosphamide and syngeneic bone marrow transplantation: evidence for two mechanisms of graft failure

Two patients with aplastic anemia were treated with high-dose cyclophosphamide and marrow transplantation from their normal, genetically identical twin. Both patients rapidly recovered normal marrow function, but marrow failure recurred 13 and 18 months later. Because donor and host pairs were identical twins, these cases of graft failure could not have resulted from the usual cause of graft failure, ie, immunological reactivity of host cells against unshared minor histocompatibility antigens of the donor. These results imply that there are at least two mechanisms responsible for graft failure after marrow transplantation for severe aplastic anemia.     

Cyclosporine as prophylaxis for graft-versus-host disease: a randomized study in patients undergoing marrow transplantation for acute nonlymphoblastic leukemia

Seventy-five patients, 13 to 49 years of age, with acute nonlymphoblastic leukemia in first remission were treated with cyclophosphamide, fractionated total body irradiation, and marrow transplantation from an HLA-identical sibling and randomized to receive either cyclosporine (CSP) (n = 36) or methotrexate (MTX) (n = 39) as prophylaxis for graft-v-host disease (GVHD). All patients engrafted, and 22 who were given CSP and 21 who were given MTX, are alive at 20 to 47 (median, 35) months (P = .5). Engraftment as assessed by granulocyte recovery (P less than .0005) and platelet transfusion requirement (P = .01) was faster in patients on CSP. Twelve patients (33%) on CSP and 22 (56%) on MTX developed acute GVHD of grades II through IV (P = .07) and 15 of 30 on CSP and 14 of 32 on MTX that were at risk developed chronic GVHD. The most frequent causes of death were interstitial pneumonitis and marrow relapse of leukemia, which occurred with similar frequency in both groups. Beneficial effects observed in patients on CSP included less severe mucositis and shorter duration of hospitalization; adverse effects included renal function impairment and hypertension. These data confirm that CSP is a useful immunosuppressant in patients undergoing marrow transplantation but fail to show a significant improvement in survival as compared with the standard regimen of MTX.     

Acute effect of smoking on the functional activity of alpha1-protease inhibitor in bronchoalveolar lavage fluid

To assess the acute effect of smoking on the functional activity of alpha1-protease inhibitor (alpha-Pl) in bronchoalveolar lavage (BAL), we studied 38 smokers (mean age 25 +/- 6.5 yr), who had 2 fiberoptic bronchoscopic lavages in sequence, the first after 8 h of abstinence from smoking, and the second at varying time intervals after smoking. Twenty-two smokers were tested before, and 10 min to 3 h after, smoking 2 medium-tar filter cigarettes; 16 smokers were were tested before, and 2 min to 60 min after, smoking 4 cigarettes. Eight nonsmoking volunteers had 2 BAL performed in sequence as control subjects. Initial BAL from control subjects and from smokers after 8 h of abstinence had similar alpha-Pl activity (mean 0.495 +/- SD 0.017 micrograms of pancreatic elastase/micrograms alpha-Pl, about 90% of the activity of purified alpha-Pl). After smoking, we did not find significant inactivation of alpha-Pl except in the 6 smokers lavaged 1 h after smoking 2 cigarettes, whose alpha-Pl activity decreased slightly to 90.0 +/- SD 10.6% of their initial activity (p less than 0.05). We also obtained BAL from 7 smokers only after smoking, and did not find inactivation of alpha-Pl. We conclude that in young healthy smokers: (1) alpha-Pl in BAL after 8 h of abstinence from smoking is active similar to nonsmoking control subjects, and (2) after smoking 2 to 4 cigarettes, there is no, or very limited, inactivation of alpha-Pl.     

Diagnosis and therapy of spinal stenosis in the elderly

PROBLEM: Spinal stenosis is a common and increasing problem in the elderly population and a diagnostic and therapeutic challenge. METHODS: An overview of etiology, epidemiology, diagnostics and therapy is given based on a literature review of the years 1978-1998 and experiences since 1985. RESULTS: Dealing with spinal stenosis we have to distinguish concerning diagnostics and therapy between cervical and lumbar spinal stenosis. The cardinal symptom of the lumbar spinal stenosis is the claudicatio spinalis and of the cervical spinal stenosis the cervical myelopathy occasionally combined with radiculopathy. The first therapeutic step should be the conservative therapy in nearly all cases, the only exception is a severe cervical myelopathy where an operation is indicated. In case of persistent or progressive symptoms under a sufficient conservative therapy, operative therapy is indicated. The different possible therapy decisions will be based on flow-charts. CONCLUSION: Whereas in lumbar spinal stenosis the indication for operative therapy should be considered with reservation, in cervical spinal stenosis with myelopathy operative therapy should be considered at an early stage.     

Effects of dobutamine on hemodynamics and left ventricular performance after cardiopulmonary bypass in cardiac surgical patients.

BACKGROUND: Dobutamine is commonly used to improve ventricular performance after cardiopulmonary bypass. The authors determined the effect of dobutamine on hemodynamics and left ventricular performance immediately after cardiopulmonary bypass in patients undergoing coronary artery bypass graft surgery. METHODS: One hundred patients received sequential 3-min infusions of dobutamine at 0-40 microg x kg(-1) x min(-1) immediately after cardiopulmonary bypass. Ten additional patients who received no dobutamine served as controls. Hemodynamics and left ventricular performance (fractional area change by transesophageal echocardiography, stroke volume index, and thermodilution cardiac index) were measured. Mixed-effects modeling accounted for repeated-measures data and interindividual differences and allowed for potential effects of covariates. RESULTS: Heart rate increased in a dose-dependent manner. The slope of HR versus dobutamine dose was steeper in individuals in whom peak dobutamine dose was not reached compared with that in the remaining individuals; slope decreased 2.71 +/- 0.68% per year of age. Dobutamine affected blood pressure minimally, but slightly decreased pulmonary capillary wedge pressure and central venous pressure. Systemic vascular resistance initially increased with dobutamine 10 microg x kg(-1) x min(-1) and remained constant with larger doses. Dobutamine produced a dose-dependent increase in left ventricular performance, primarily by increasing heart rate, because stroke volume index decreased with dobutamine dose. CONCLUSION: Our results suggest that the response to graded dobutamine infusion in the post-cardiopulmonary bypass period differs from that previously reported. After cardiopulmonary bypass, the dominant mechanism by which dobutamine improves left ventricular performance is by increasing heart rate. Dobutamine affects blood pressure minimally.     

Nachsorge bei TIPSS Vergleich zwischen Farbdopplersonographie und Portographie

Zusammenfassung Fragestellung: Vergleich zwischen Farbdopplersonographie und Portographie zur Nachsorge von TIPSS-Patienten. Material und Methoden: In einer prospektiven Studie wurde bei 40 konsekutiven TIPSS-Patienten im Rahmen der Nachsorge eine ven?se Portographie und am selben Tag eine Farbdopplersonographie durchgeführt. Innerhalb des TIPSS wurden Flu?werte am Einflu?trakt (portales Segment) und Ausflu?trakt (Lebervenensegment) gemessen. Ergebnisse: Bei 28 Patienten mit unauff?lligem Shunt lag die Flu?geschwindigkeit im Einflu?trakt zwischen 30–120 cm/s (Median 60 cm/s), im Ausflu?trakt zwischen 60–155 cm/s (Median 82 cm/s). Im Ausflu?trakt war die Flu?geschwindigkeit signifikant h?her als im Einflu?trakt (p<0,001). Bei 12 Patienten mit Shuntdysfunktion war die Flu?geschwindigkeit im TIPSS-Einflu?trakt reduziert auf 26±7 cm/s (p<0,0001). Schlu?folgerung: Aufgrund der Beschleunigung der Flu?geschwindigkeit im Ausflu?trakt ist eine getrennte dopplersonographische Beurteilung beider Shuntenden erforderlich. Bei einer Shuntdysfunktion ist die Flu?geschwindigkeit im Einflu?trakt reduziert. Die Farbdopplersonographie ist als nicht invasive Methode zur TIPSS-Nachsorge geeignet.