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Biomedical subjects

J Henkel

Publications and source records attributed to J Henkel.

At least 19 recordsLinked to original sources
PubMed2001

The highly conserved protein methyltransferase, Skb1, is a mediator of hyperosmotic stress response in the fission yeast Schizosaccharomyces pombe.

The p21-activated kinase, Shk1, is required for cell viability, establishment and maintenance of cell polarity, and proper mating response in the fission yeast, Schizosaccharomyces pombe. Previous genetic studies suggested that a presumptive protein methyltransferase, Skb1, functions as a positive modulator of Shk1. However, unlike Shk1, Skb1 is not required for viability or mating of S. pombe cells and contributes only modestly to the regulation of cell morphology under normal growth conditions. Here we demonstrate that Skb1 plays a more significant role in regulating cell growth and polarity under conditions of hyperosmotic stress. We provide evidence that the inability of skb1Delta cells to properly maintain cell polarity in hyperosmotic conditions results from inefficient subcellular targeting of F-actin. We show that Skb1 localizes to cell ends, sites of septation, and nuclei of S. pombe cells. Hyperosmotic shock results in substantial delocalization of Skb1 from cell ends and nuclei, as well as stimulation of Skb1 protein methyltransferase activity. Taken together, our results demonstrate a new role for Skb1 as a mediator of hyperosmotic stress response in fission yeast. We show that the protein methyltransferase activity of the human Skb1 homolog, Skb1Hs, is also stimulated by hyperosmotic stress in fission yeast, providing evidence for evolutionary conservation of a role for Skb1-related proteins as mediators of hyperosmotic stress response, as well as mechanisms involved in regulating this novel class of protein methyltransferases.

Carrier Proteins↗
PubMed2001

Bob1, a Gim5/MM-1/Pfd5 homolog, interacts with the MAP kinase kinase Byr1 to regulate sexual differentiation in the fission yeast, Schizosaccharomyces pombe.

The MAPKK Byr1 is an essential component of a Ras-dependent MAPK module required for sexual differentiation in the fission yeast, Schizosaccharomyces pombe. Here we describe the genetic and molecular characterization of a highly conserved protein, Bob1, which was identified from a two-hybrid screen for Byr1-interacting proteins. Byrl and Bobl proteins coprecipitate from S. pombe cell lysates, and both proteins localize to the tips and septa of S. pombe cells. S. pombe bob1 null (bob1delta) mutants lack obvious growth defects but exhibit a significant mating deficiency, which can be suppressed by overexpression of Byrl. Overexpression of Bob1 also leads to inhibition of mating in S. pombe, and this defect is likewise suppressed by Byrl overexpression. Bob1 is highly homologous in structure to the mammalian MM-1/Pfd5 and budding yeast Gim5/Pfd5-Sc proteins, which have been implicated as regulators of actin and tubulins. Similar to budding yeast gim5/pfd5-Sc mutants, S. pombe bob1delta cells have cytoskeletal defects, as judged by hypersensitivity to cytoskeletal disrupting drugs. byr1delta mutants do not share this characteristic with bob1delta mutants, and byr1delta bob1delta mutants are not significantly more sensitive to cytoskeletal disrupting drugs than cells carrying only the bob1delta mutation. Taken together, our results suggest that Bob1 has Byr1-related function(s) required for proper mating response of S. pombe cells and Byrl-independent function(s) required for normal cytoskeletal control. We show that the human MM-1/Pfd5 protein can substitute for its counterpart in fission yeast, providing evidence that the functions of Bob1-related proteins have been highly conserved through evolution. Our results lead us to propose that Bob1-related proteins may play diverse roles in eukaryotic organisms.

Amino Acid Sequence↗
PubMed2000

Long term outcome after cervical foraminotomy.

We recently demonstrated the effectiveness of dorsal foraminotomy in lateral herniated cervical disc after 1 year follow-up in a prospective study.(1) The goal of this paper is to confirm these results concerning long term outcome. We carried out a prospective, consecutive study on 54 patients, operated on for lateral herniated cervical disc. We analysed demographic data, the case history, the neurological examination on admission and imaging data. Ninety per cent were followed up for 3.5 years postoperatively. According to their ratings on a pain scale the group were divided into favourable and unfavourable outcomes. These groups were analysed in relation to the patient's initial condition. At follow up, 90% of patients showed complete recovery or improvement. A long standing preoperative neurological deficit seems to be an important prognostic factor for unfavourable long term outcome after cervical foraminotomy.

Adult↗
PubMed1997

A solid-phase enzyme linked immunosorbent assay using monoclonal antibodies, for the detection of African swine fever virus antigens and antibodies.

An improved solid-phase enzyme linked immunosorbent assay (ELISA) using monoclonal antibodies was developed to detect an African swine fever virus protein (VP73) in pig samples. The use of monoclonal antibodies against VP73 allowed a sensitive and specific sandwich ELISA. This assay detected a limiting antigen concentration of 0.05 microgram/ml of VP73, lower than the detection limit of 0.6 microgram/ml obtained by using polyclonal antibodies by the same ELISA. The whole virus particle was detected with this method to a limit of 2.3 x 10(2) PFU/ml. At the same time, an indirect ELISA was developed to detect ASFV antibodies. The results also indicate that this method may be a useful technique for epidemiological surveys.

African Swine Fever↗
PubMed1994

Safeguarding human tissue transplants.

Transplants of human tissues, such as cornea and bone, can be modern miracles. But they can also transmit disease such as HIV and hepatitis. FDA has tightened controls of transplanted human tissue to minimize risks, and is considering additional action.

Humans↗
PubMed1994

[Is prevention of thromboembolism in ambulatory and conservative therapy of rupture of the fibular ligament of the upper ankle joint necessary?].

In a prospective clinical study, 111 outpatients with tears of the lateral ankle ligaments were investigated for the occurrence of deep venous thrombosis (DVT). All patients had been treated by a plaster cast for 1 week and had not received any form of DVT prophylaxis. After removal of the plaster cast (mean 7.1 days), colour flow imaging of the veins of the injured leg was performed. A phlebography was undertaken whenever there was any suspicion of DVT. Risk factors for thrombosis [3, 10] were documented in all patients. Besides injury and immobilisation, a median of 1.2 (0-4) risk factors for DVT was involved. Only 31 patients had no additional risk factors at all. Median age of the patients was 26.1 years (16-53 median range). Only 1 patient over 40 years of age was diagnosed as having DVT, and none under 40. Therefore, medicamentous prophylaxis of DVT is not considered necessary in outpatients younger than 40 years with ankle ligament tears treated by bi-valved casts in cases when there are no additional risk factors (Table 4) for DVT.

Adolescent↗
PubMed1992

Atypical herpes simplex encephalitis: clinical, virologic, and neuropathologic evaluation.

An atypical form of herpes simplex encephalitis produced by HSV-1 documented in the present article demonstrates that (1) prominent EEG abnormality may correlate with subtle increase in signal intensity on MRI; (2) the disease may start with prominent involvement of the cingulate gyri; and (3) viral infection of the brainstem may cause early onset of severe neurologic dysfunction and coma.

Brain Stem↗
PubMed1991

Clinostatic rotation decreases crossover frequencies in the fungus Sordaria macrospora Auersw.

Two-factor crosses between the non-allelic spore colour mutants r2 and lu of the fungus Sordaria macrospora were used to investigate the effect of clinostatic rotation (= simulated weightlessness) on crossover frequencies. The experiment was carried out with different rotary directions at a rotary rate of 4 rpm. Second-division segregations of the gene lu, which result from crossover between the gene locus and centromere, are significantly smaller in the clinostat experiments than in the static controls. No differences were found between the two rotary directions. A similar influence of clinostatic rotation was not observed for the gene r2 which in contrast to the lu locus is located very close to the centromere. The suitability of this approach for the investigation of the effect of space flight conditions on cytogenetic processes is pointed out.

Chromosome Mapping↗
PubMed1990

Referral tracking system shows accurate bottom-line assessment.

Rose Medical Center in Denver, Colo., needed a way to track referrals from its many offsite care centers to determine their impact on revenue. Programmers at Rose developed a microbased system, eventually bought by SMS, that measures profitability against investment to become a true decision support tool for hospital executives.

Colorado↗
PubMed1980

The oxygen-dependent deactivation and reactivation of spinach ribulose-1,5-bisphosphate carboxylase.

Ribulose-1,5-bisphosphate carboxylase-oxygenase (3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39) is deactivated by the removal of oxygen, and reversibly reactivated by its readdition to the enzyme solution. A short pulse of oxygen to the anaerobic enzyme solution is sufficient to trigger the reactivation process; the Ka value for this reaction was estimated as 0.12 mM oxygen. The enzyme could not be reactivated under anaerobic conditions by an organic oxidant (benzoylperoxide) or by sulfhydryl group reducing reagents (dithiothreitol or beta-mercaptoethanol), suggesting that the process of reactivation was oxygen specific. Furthermore, the inhibition of the reactivation by superoxide anion scavengers such as Tiron (1,2-dihydroxybenzene-3,5-disulfonic acid), copper penicillamine, hydroxylamine, nitroblue tetrazolium, and ascorbate, indicated that the monovalent reduced oxygen was involved as the reacting species in this process. The deactivation of the enzyme associated with the removal of oxygen was also sensitive to the presence of scavengers of O2(-), suggesting that superoxide anion was also involved in the deactivation process. Both the carboxylase and the oxygenase activities were similarly affected under all the experimental conditions studied. On the basis of these results it is argued that the enzyme molecules are able to reduce oxygen and that superoxide anion causes the deactivation or reactivation of the enzyme.

1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium ↗