Setting the record straight.

Replies to comments by H. W. Marsh and L. A. Roche (see record 1997-43129-003) on the author's article (Educational Policy Analysis Archives, 1997) on student evaluation and academic freedom. The author expresses his dismay that Marsh and Roche misrepresented (not misinterpreted) the article without documenting their misrepresentation. A documented response to this undocumented misrepresentation is provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The distribution of HBV, HCV and HGV among livers with fulminant hepatic failure of different aetiology

BACKGROUND/AIMS: The aim of the study was to assess the impact factor of HCV and HGV in fulminant hepatic failure. METHODS: The 5'-untranslated regions of HCV RNA and HGV RNA and a segment of the core antigen sequence of HBV were amplified after extracting the nucleic acids from snap-frozen tissue aliquots from explanted livers of 26 consecutive patients undergoing orthotopic liver transplantation for fulminant hepatic failure preoperatively diagnosed as either autoimmune (n=2), HAV/HBV (n=8), toxic (n=4) or aetiologically unknown (n=12). RESULTS: HCV RNA was detected in five of 26 (19.2%) livers with fulminant hepatic failure. All five HCV RNA-positive livers belonged to the group of non-toxic, non-autoimmune liver failure (n=20), three of them were found in the group of liver failure with unknown aetiology (n=12) and two in the group of HBV-associated liver failure (n=7), making an HCV incidence of 25%, 25% and 28.6%, in the different groups, respectively. HGV RNA was detected in 10 of 17 (58.8%) explants and in all four groups of fulminant hepatic failure as defined preoperatively. HBV DNA was identified in six livers of 26 patients (23.1%) with fulminant hepatic failure. Neither HCV RNA nor HBV DNA was detected in the livers of patients with toxic or autoimmune fulminant hepatic failure. CONCLUSIONS: These results indicate that HBV and HCV, but not HGV, play an aetiologic role in fulminant hepatic failure. HCV-positive cases were concentrated either in the group of otherwise unexplained fulminant hepatic failure or in the group of HBV fulminant hepatic failure. HGV-positive cases, on the other hand, were found within all four preoperatively defined groups, indicating a role as cofactor rather than as single aetiologic agent.     

Membrane-bound calmodulin in Xenopus laevis oocytes as a novel binding site for melatonin

Melatonin has been suggested as a physiological antagonist of calmodulin. In this work, we have characterized melatonin binding sites in Xenopus laevis oocyte membranes. Binding of [125I]melatonin by X. laevis oocyte membranes fulfills all criteria for binding to a receptor site. Binding was dependent on time, temperature, and membrane concentration and was stable, reversible, saturable, and specific. The binding site was also pharmacologically characterized. Stoichiometric studies showed a high-affinity binding site with a Kd of 1.18 nM. These data are in close agreement with data obtained from kinetic studies (Kd=0.12 nM). In competition studies, we observed a low-affinity binding site (Kd=63.41 microM). Moreover, the binding site was characterized as calmodulin. Thus, binding was dependent on calcium and blocked by anti-CaM antibodies in a concentration-dependent manner. Calmodulin inhibitor chlorpromazine also inhibited binding of the tracer. From these results, it is suggested that membrane-bound calmodulin acts as a melatonin binding site in Xenopus laevis oocytes, where it might couple cellular activities to rhythmic circulating levels of melatonin. This hypothesis correlates with the previous findings describing melatonin as a physiological antagonist of calmodulin.     

The mechanics of compressive kinking in unidirectional fiber reinforced ductile matrix composites

Three distinct stages of kink band formation and propagation exist in ductile matrix composites subjected to compressive loading. These stages are called incipient kinking, transient kinking and kink band broadening. Each stage involves a different deformation mode. The mechanics governing each stage are discussed. Incipient kinking, where the peak load is attained, and kink band broadening, where the load attains a steady-state, are important in structural design. Two design philosophies are presented. References to pertinent literature are made throughout.     

Differential therapy of cerebral arteriovenous malformations. An analysis with reference to personal microsurgery experiences

A total of 126 patients (63 female, 63 male) underwent microsurgical removal of their cerebral arteriovenous malformations (AVMs) by the same surgeon. The mean age at surgery was 34.7 (6-72) years. The symptoms were intracerebral hemorrhage (37.3%), seizure disorder (34.9%) or focal neurological deficits and minor symptoms. According to the Spetzler/Martin scale, 20.6% of the AVMs were grade I, 28.6% grade II, 32.5% grade III, 14.3% grade IV and 4% grade V. In all, 78 AVMs (61.9%) were located in functionally important brain regions. The series was split into three different groups: small AVMs under 3 cm in diameter (n = 62/49.2%), medium-sized AVMs (n = 58/46%) and large AVMs (n = 6/4.8%). Seventeen patients had preoperative embolization of their AVM. All patients had postoperative angiographic control and 3- and 6-month follow-up. One patient died (0.8%), and another one (0.8%), in whom the AVM was incompletely resected, suffered a secondary hemorrhage. Seventeen (27.4%) of the patients with small AVMs developed transient neurological worsening post-operatively, which remained permanently significant in 3.2%. The respective numbers for the patients with medium-sized AVMs were 48.3% and 10.3% and for the large AVMs 83.3% and 33.3%. The results of microsurgical removal of cerebral AVMs can still be considered superior to the results of stereotactic radiosurgical treatment available from the literature-even for small AVMs. This is due to immediate exclusion of the AVM under direct local control of the angioarchitecture and thereby a reduced risk of secondary hemorrhaging and a decreasing morbidity rate with increasing time after the operation. Radiosurgical treatment requires a 2-year latency period for obliteration and carries a mortality rate of up to 12.5% and a rate of unexpected side effects of up to 20%. This treatment should be reserved for small, deep, surgically inaccessible AVMs or used as part of a multimodality treatment regimen consisting of partial embolization, partial excision and consecutive radiation of the residual nidus in initially very large AVMs. Embolization therapy-such as radiosurgery-carries a significant risk of morbidity (8%) and a mortality rate of up to 6%. It should only be considered for AVMs that are expected to be fully obliterated afterwards, or for primary inoperable AVMs that are to be changed into operable ones by embolization. Size reduction of otherwise operable AVMs does not justify the additional risk of embolization. Close collaboration of the specialties involved is desirable.     

Expert statement and assessment of medical impairment in work-related pulmonary disease

The Norwegian Societies of Thoracic Medicine and Occupational Medicine established a working group to standardise diagnostic procedures and evaluation of work-related respiratory disorders. In cases of suspected work-related diseases the physician may be asked by the National Insurance Administration or an insurance company to make a statement which will be one of the documents used to decide the patient's right to compensation benefit. We discuss the role of the physician as an independent expert. This is different from his role as clinician. The statement should include a balanced presentation of information from different sources, including health and occupational history, and the employer's information about the work environment (quantitative and qualitative exposure data). The statement must also include the results of a clinical examination and an assessment of functional status based on objective tests. The paper contains recommendations for evaluation of permanent impairment in light of the present Norwegian laws and regulations.     

Manufacture of films displaying liquid-crystalline structure

Reported is an attempt to attain orientation of macromolecules during extrusion of films of cellulose derivatives that led to the liquid-crystalline state of a polymer and resulted in enhanced film strength.     

Development of improved methods for type testing present day mediumvoltage circuit breakers for outdoor service

Type testing for fault currents for medium-voltage circuit breakers rated at 15 kV to 72.5 kV is addressed. The ANSI designation of a new class of definite-purpose circuit breakers capable of switching transformer secondary faults and the introduction of the requirement for short-line-fault tests for breakers rated 72.5 kV and below have increased the difficulty of performing type tests in a testing laboratory. It is concluded that synthetic testing using the parallel current injection circuit is described in ANSI C37.081 provides the best available method for proving these complex requirements for medium-voltage circuit breakers