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Biomedical subjects

J S Berg

Publications and source records attributed to J S Berg.

13 recordsLinked to original sources
PubMed2005

Evaluation of a novel method for measuring tissue blood flow and gases.

In clinical practice a method for assessment of tissue vitality is a sought-after tool. We have developed a new sensor principle, which is able to register changes in tissue concentration of O2 and tissue flow. The technique is based on diffusion of inert gases and mass spectrometer detection of gaseous metabolites. It was hypothesized that the new sensor could register changes in vital parameters after induction and release of an ischaemic insult to muscular tissue. The sensor performance was evaluated in ten anaesthetized pigs subjected to local muscular ischaemia. Preliminary data from this study indicate the validity of registered hypoxia and reduction in tissue flow as a consequence of compromised blood supply. It was concluded that although precise calibration of the technique is not yet established, it holds promise as a technique that can be used to monitor changes in tissue vitality.

Animals↗
PubMed2001

Myosin-I nomenclature.

We suggest that the vertebrate myosin-I field adopt a common nomenclature system based on the names adopted by the Human Genome Organization (HUGO). At present, the myosin-I nomenclature is very confusing; not only are several systems in use, but several different genes have been given the same name. Despite their faults, we believe that the names adopted by the HUGO nomenclature group for genome annotation are the best compromise, and we recommend universal adoption.

Animals↗
PubMed2001

[Coronary bypass surgery without heart-lung-machine. First experiences and results after two years].

Results and experiences two years after the introduction of off-pump coronary artery bypass (OPCAB) are presented. The material includes 95 patients, where 24 patients had a high preoperative risk due to unstable angina, concomitant diseases or relative contraindications to conventional bypass surgery. Per- and postoperative course was characterized by low morbidity with ultra fast track recovery, no detectable levels of coronary enzyme release in the majority of patients, no reoperations for bleeding and early discharge from the hospital. There were two in-hospital deaths, both patients from the high risk group, where one patient died due to a preoperative myocardial infarction, while the other death was not related to cardiac disease. Follow-up results were fully satisfactory, where 86% of the patients were free from anginal symptoms three months after surgery. As a consequence of these positive experiences, OPCAB surgery is offered to an increasing number of patients, currently 25% of our CABG procedures.

Adult↗
PubMed2001

A millennial myosin census.

The past decade has seen a remarkable explosion in our knowledge of the size and diversity of the myosin superfamily. Since these actin-based motors are candidates to provide the molecular basis for many cellular movements, it is essential that motility researchers be aware of the complete set of myosins in a given organism. The availability of cDNA and/or draft genomic sequences from humans, Drosophila melanogaster, Caenorhabditis elegans, Arabidopsis thaliana, Saccharomyces cerevisiae, Schizosaccharomyces pombe, and Dictyostelium discoideum has allowed us to tentatively define and compare the sets of myosin genes in these organisms. This analysis has also led to the identification of several putative myosin genes that may be of general interest. In humans, for example, we find a total of 40 known or predicted myosin genes including two new myosins-I, three new class II (conventional) myosins, a second member of the class III/ninaC myosins, a gene similar to the class XV deafness myosin, and a novel myosin sharing at most 33% identity with other members of the superfamily. These myosins are in addition to the recently discovered class XVI myosin with N-terminal ankyrin repeats and two human genes with similarity to the class XVIII PDZ-myosin from mouse. We briefly describe these newly recognized myosins and extend our previous phylogenetic analysis of the myosin superfamily to include a comparison of the complete or nearly complete inventories of myosin genes from several experimentally important organisms.

Animals↗
PubMed2000

Developmental regulation of sensory neuron number and limb innervation in the mouse.

Although used widely in studies of naturally occurring cell death, systematic descriptions of the time course of changes in sensory neuron number and of limb innervation in the mouse are not available. The development of sensory innervation to the mouse forelimb was traced using the lipophilic carbocyanine dye, DiI, and correlated with neuron number in dorsal root ganglia contributing to the cervical enlargement. Axon invasion of the forelimb began at E10.5. Sensory axons reached the distal margin of the forelimb by E13.5. The difficulty of identifying immature neurons precluded estimating neuron numbers during the period of limb innervation. Neuron numbers in dorsal root ganglia (DRGs) C5-C8 increased from E14 to E16 and from E18 to P4. No evidence of a decline in neuron numbers was found during the developmental periods studied. Neuron number was compared in neonates and adults to determine if sensory neurons are added as body size increases as found in the frog [J. Comp. Neurol. 314 (1991) 106] and the rat [J. Comp. Neurol. 386 (1997) 8]. In contrast to previous findings, no difference was found in sensory neuron number between neonate and adult mice in either cervical or lumbar DRGs.

Animals↗
PubMed2000

Myosin-X, a novel myosin with pleckstrin homology domains, associates with regions of dynamic actin.

Myosin-X is the founding member of a novel class of unconventional myosins characterized by a tail domain containing multiple pleckstrin homology domains. We report here the full-length cDNA sequences of human and bovine myosin-X as well as the first characterization of this protein's distribution and biochemical properties. The 235 kDa myosin-X contains a head domain with <45% protein sequence identity to other myosins, three IQ motifs, and a predicted stalk of coiled coil. Like several other unconventional myosins and a plant kinesin, myosin-X contains both a myosin tail homology 4 (MyTH4) domain and a FERM (band 4.1/ezrin/radixin/moesin) domain. The unique tail domain also includes three pleckstrin homology domains, which have been implicated in phosphatidylinositol phospholipid signaling, and three PEST sites, which may allow cleavage of the myosin tail. Most intriguingly, myosin-X in cultured cells is present at the edges of lamellipodia, membrane ruffles, and the tips of filopodial actin bundles. The tail domain structure, biochemical features, and localization of myosin-X suggest that this novel unconventional myosin plays a role in regions of dynamic actin.

Actins↗
PubMed2000

Early menopause presenting with mood symptoms in a student aviator.

The clinical presentation of menopause can resemble the symptoms of a mood disorder. We describe the case of a 31-yr-old student helicopter pilot who presented to the Aviation Psychiatry Department with a several-month history of inconsistent training performance, mood lability, tearfulness, anxiety, insomnia, fatigue, and decreased concentration. Symptoms persisted despite stress management training and resolution of family stressors, and further evaluation revealed other symptoms consistent with early menopause. Symptoms responded to estrogen/progesterone therapy, and patient returned to flight training. The clinical presentation, differential diagnosis, treatment, and aeromedical disposition of perimenopause and menopause are discussed.

Adult↗
PubMed1999

Tails of unconventional myosins.

In addition to the conventional myosins (class II) required for processes such as muscle contraction and cytokinesis, the myosin superfamily of actin-based motor proteins includes at least 14 'unconventional' classes. These unconventional myosins are defined by myosin-like head (motor) domains attached to class-specific tail domains that differ greatly from those of myosin-II. The unconventional myosins account for almost two-thirds of the 28 or more myosin genes currently believed to be expressed in humans and 80-90% of the approximately 10 or more myosin genes expressed in a typical nonmuscle cell. Although these members of the myosin superfamily have not been as intensively investigated as the conventional myosins, unconventional myosins are known or believed to power many forms of actin-based motility and organelle trafficking. The presence of signaling domains such as kinase domains, SH3 domains, PH domains or GTPase-activating domains in the tails of unconventional myosins indicates that these proteins can also be components of signal transduction pathways. Since several classes of the myosin superfamily have been found only in lower eukaryotes or plants (VIII, XI, XIII and XIV), in this review we will focus on the structures and properties of the unconventional myosins found in multicellular animals (excluding classes I and V, which have been reviewed elsewhere recently). Special attention will be focused on the three classes of unconventional myosins that can cause deafness in mouse or humans when mutated. In addition, we discuss the discovery of a pair of intriguing domains, the Myosin Tail Homology 4 (MyTH4) and FERM (band 4.1, Ezrin, Radixin, Moesin) domains, that are present in the tails of otherwise very different myosins as well as a plant kinesin-like protein. Recent progress in the identification of novel unconventional myosins will also be summarized.

Amino Acid Sequence↗
PubMed1998

Compulsive sexual behaviors--difficult aeromedical disposition.

Axis I psychiatric disorders generally are considered incompatible with both the issuance and subsequent maintenance of aeromedical clearance certificates. Little doubt exists as to the impact that conditions such as anxiety disorders, mood disorders, or substance-related disorders have on the conduct of safe flight. Nevertheless, different compulsive sexual behaviors (CSBs), which now are thought to share similar origins and associated comorbidity, can similarly affect impulse control, judgment, concentration, and insight. Yet, these conditions frequently are handled administratively (if not legally). Moreover, in practice CSBs fall within a spectrum of behaviors from "normative" nonparaphilic sexuality to more deviant paraphilic behavior. Through the presentation of five selected cases seen at the Naval Operational Medicine Institute, this article explores examiner difficulty in establishing a diagnosis, discusses models useful in understanding the origins of these disorders, and highlights critical elements in establishing aeromedical disposition. The authors conclude that CSBs may be associated with anxiety, dysphoria, a pattern of increased risk taking, a high threshold for arousal, and poor judgment, which may impact the safety of flight. A comprehensive psychiatric evaluation is essential in determining aeromedical disposition, and consideration should be given to reviewing these cases from a medical perspective prior to any administrative disposition.

Adult↗
PubMed1996

A case of "eating disorder NOS": aeromedical implications of DSM-IV diagnostic criteria.

The authors describe a case of intermittent fasting and self-induced vomiting in a student aviator whose symptoms do not meet the full criteria for either anorexia or bulimia. The range of symptomatology and differential diagnosis of eating disorders is discussed. New DSM-IV diagnostic criteria for eating disorders, including Eating Disorder Not Otherwise Specified (NOS), and associated therapeutic alternatives are reviewed. The case demonstrates the importance of comprehensive physical and psychiatric evaluation of those patients with complex or atypical presentations. Issues pertaining to the aeromedical disposition of such patients are discussed, with emphasis on the role of the flight surgeon in the early recognition of eating disorders.

Adult↗
PubMed1989

Calculi in female urethral diverticulum.

A case of two calculi found in the same urethral diverticulum in a 41-year-old woman with recurrent urinary tract infections is reported. The diagnostic procedures are discussed.

Adult↗