Publications by authors named "Berkemeier L"

Background: Adoption and evaluation of contact tracing tools based on information and communications technology may expand the reach and efficacy of traditional contact tracing methods in fighting COVID-19. The Dutch Ministry of Health, Welfare and Sports initiated and developed CoronaMelder, a COVID-19 contact tracing app. This app is based on a Google/Apple Exposure Notification approach and aims to combat the spread of the coronavirus among individuals by notifying those who are at increased risk of infection due to proximity to someone who later tests positive for COVID-19.

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Maturity-onset diabetes of the young 3 (MODY3) is a type of NIDDM caused by mutations in the transcription factor hepatocyte nuclear factor-1alpha (HNF-1alpha) located on chromosome 12q. We have identified four novel HNF-1alpha missense mutations in MODY3 families. In four additional and unrelated families, we observed an identical insertion mutation that had occurred in a polycytidine tract in exon 4.

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The melanocortin-4 receptor (MC4-R) is a G protein-coupled, seven-transmembrane receptor expressed in the brain. Inactivation of this receptor by gene targeting results in mice that develop a maturity onset obesity syndrome associated with hyperphagia, hyperinsulinemia, and hyperglycemia. This syndrome recapitulates several of the characteristic features of the agouti obesity syndrome, which results from ectopic expression of agouti protein, a pigmentation factor normally expressed in the skin.

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The mutated gene responsible for the tubby obesity phenotype has been identified by positional cloning. A single base change within a splice donor site results in the incorrect retention of a single intron in the mature tub mRNA transcript. The consequence of this mutation is the substitution of the carboxy-terminal 44 amino acids with 24 intron-encoded amino acids.

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The survival of developing motor neurons depends on factors secreted from skeletal muscles and from cells within the central nervous system. Although several members of the nerve growth factor protein family [neurotrophins (NTs)] are able to maintain developing rat motor neurons in vitro, only the brain-derived neurotrophic factor has been shown to have significant effects on the survival of motor neurons in vivo. In the present study, we demonstrate that NT-4/5 also prevents injury-induced death of facial motor neurons in neonatal rats.

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Parkinson's disease is a prevalent neurological disease characterized by profound and incapacitating movement disorders. A common pathology in Parkinson's patients is degeneration of substantia nigra dopaminergic neurons that innervate the striatum and a corresponding decrease in striatal dopamine content. We now report that NT-4/5 can prevent the death of rat embryonic substantia nigra dopaminergic neurons in low density, enriched, primary cultures.

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Differentiation, survival, and function of the vertebrate neurons are controlled by multiple, target-derived neurotrophic factors. The best characterized mammalian neurotrophic factors are four structurally related 13 to 14 kDa basic proteins, collectively known as neurotrophins. Here we describe the identification of a gene cluster localized on human chromosome 19 that contains neurotrophin-5 (NT-5) and that may encode three additional acidic members of this protein family.

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In vertebrates, the formation and maintenance of neuronal connections are subject to regulation by multiple target-derived, diffusible (neurotrophic) factors. Here we describe the identification and characterization of a novel neurotrophic factor designated neurotrophin-5 (NT-5). NT-5 is structurally related to nerve growth factor and is expressed in embryonic as well as adult tissues.

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The human osteoinductive proteins BMP-2a and BMP-2b have been cloned and expressed in mammalian cells. In order to improve expression levels we examined the role of the proregion in assembly and export. Use of the BMP-2a proregion combined with the mature region of BMP-2b leads to dramatically improved expression of mature BMP-2b.

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We report here the complete amino acid sequence of the human inhibin beta B-subunit as deduced from the sequence of cDNA and genomic clones. The primary translation product of the beta B mRNA predicts a protein of 407 amino acids, containing a prepro region of 292 amino acids separated by basic amino acids from the mature C-terminal 115 amino acids. Mammalian tissue culture cells transfected with a beta B-subunit expression plasmid secreted an activin B homodimer of approximately 22K mol wt.

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