Riding into battle without a pharm.D. degree.
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Clinical Competence↗
Biomedical subjects
B L Roberts
Publications and source records attributed to B L Roberts.
Dopaminergic and GABAergic cerebrospinal fluid-contacting neurons along the central canal of the spinal cord of the eel and trout.
In anamniote vertebrates the central region of the spinal cord has been implicated in its regeneration. This is a complex region and so as a first step in understanding its possible regenerative role we have examined the organization of the cells that contact the lumen of the spinal cord in two teleost fishes, eel and trout, using immunohistochemical procedures and light and electron microscopy. Cell bodies immunoreacting positively with antibodies for tyrosine hydroxylase and for dopamine were located at the ventral rim of the central canal, whereas cell bodies reacting for an antibody for gamma-aminobutyric acid were more laterally located. None of the canal-contacting cells were positively immunoreactive for choline acetyltransferase. All immunopositive cells have a similar morphology: the amphora-shaped perikaryon is bipolar and has a single process that extends to the lumen of the canal, and another that branches and forms extensive lateral and ventral plexuses. Electron microscopic investigations of the ventral dopaminergic cells showed that the apical processes bear one or more cilia, which protrude into the canal lumen and which originate from within a superficial rosette of nonciliated processes. The ventral process was occasionally seen to form synapses; the cell body was also the target of synapses.
Animals↗
Cadmium disposition in the earthworm Eisenia fetida.
The disposition of cadmium was examined in the earthworm Eisenia fetida using two exposure media, filter paper, and artificial soil. Uptake and elimination rates were estimated to be 0.03039 and 0.00895 hr-1, respectively, for 1.25 micrograms Cd/cm2 filter paper exposure and 0.00512 and 0.00029 hr-1, respectively, for 10 micrograms Cd/g artificial soil exposure. The distribution of cadmium was examined using whole body autoradiography, tissue distribution, and subcellular localization. Cadmium tissue distribution was exposure-dependent, while cadmium subcellular localization apparently was not exposure-dependent. Acid-soluble thiol levels, examined as an index of cadmium exposure, were too variable in nonexposed earthworms to serve as an indicator of cadmium exposure.
Animals↗
A polyclonal antibody against mammalian FOS can be used as a cytoplasmic neuronal activity marker in a teleost fish.
A polyclonal antibody raised against a conserved region of a mammalian FOS sequence was tested for its use as an activity marker in the rainbow trout. The FOS-like expression in the trout is entirely cytoplasmic and appears in a Nissl-like pattern. The reaction is specifically induced by both orthodromic and antidromic electrical stimuli and during motor responses evoked by natural stimulation, although some positive neurons are found at locations that are not obviously related to the presented stimuli. Following spinal nerve stimulation, antidromically activated motoneurons were found to be positive in the ipsilateral spinal cord. Orthodromic driving of spinal moto- and interneurons by stimulation of the medial longitudinal fasciculus (MLF) in the hindbrain evoked FOS-like immunoreactivity throughout the motor column in the spinal cord, but not in regions lying caudal to a lesion of the MLF-axons. Evoking about 25 startle responses by natural auditory stimulation gives FOS-like immunoreactivity in the Mauthner cell, which initiates the response, whereas positive Mauthner cells were never observed in control fish. The stimulation protocols that were used strongly activated the stimulated cells and so the observed FOS-like immunoreactivity might be related to an increase protein synthesis needed to restore their depleted transmitter levels.
Acoustic Stimulation↗
An investigation of pain experience and management following gynecological day surgery: differences between open and closed surgery.
This study aimed to investigate the pain and activity levels of patients for a 5-day period following gynecological day surgery. Patients recorded their degree of pain and activity on visual analogue scales in a diary; completed diaries were returned by 54.9% of the patients approached (106 of 193). The median age of the women was 28.5 years (range, 15-55 years). Each procedure was classified as either open or closed surgery, depending upon whether an incision was necessary. Most (63.2%) of the patients required analgesics on the first morning after their surgery. Open surgery patients experienced significantly more pain for at least 3 postoperative days and were less active until the fifth day (P < 0.05 by Mann-Whitney tests). Drowsiness (47.2%), nausea (30.2%), and headache (30.2%) were the most common adverse effects experienced in the first postoperative morning. The incidence of adverse effects declined over the five days, but a minority of patients still suffered with headache (14.2%), drowsiness (9.4%), sore throat (7.5%), and nausea (5.3%) on the fifth day following surgery. The percentage of patients who experienced constipation peaked at 19.8% on the second day, most likely reflecting the consumption of codeine-containing analgesics on the first and second postoperative days. While day surgery has an important role in many forms of gynecological surgery, the potential discomfort and recovery time following day surgery should not be underestimated.
Adolescent↗
Margin in life among hospitalized and non-hospitalized elderly persons.
This study compared six dimensions of adult life among 39 hospitalized elders with a mean age of 72.1 years and 44 elders with a mean age of 75.7 years living in the community. The dimensions of life were physical function, work, spirituality, family, community and self concept. Multivariate analysis of variance revealed that the patterns of the subscales did not significantly differ between the groups. Except for the outside interest factor of the community subscale, univariate analysis of variance revealed no significant differences between hospitalized and community elders.
Aged↗
Coexistence of calcitonin gene-related peptide and choline acetyltransferase in eel efferent neurons.
We applied choline acetyltransferase, (ChAT) and calcitonin gene-related peptide (CGRP) immunocytochemistry to the efferent neurons that innervate the lateral line and the ear of the eel. Strong immunoreactivity to the ChAT antiserum was observed in neurons located within the octavolateralis efferent nucleus that could be distinguished, on the basis of their form, location and dendritic organization, from the ChAT-immunopositive motoneurons of the adjacent facial motor nucleus. Both facial motoneurons and efferent neurons were found to be immunopositive for CGRP, although the reaction was always stronger in the motoneurons. Double labelling experiments established the presence of both ChAT and CGRP in many efferent neurons. The results are evidence that cholinergic efferent neurons supplying end organs of different modalities may also produce calcitonin gene-related peptide.
Anguilla↗
Physical, psychological, and social resources as moderators of the relationship of stress to mental health of the very old.
The purpose of this pilot study was to assess the attenuating effects of physical, psychological, and social resources on the relationship between stress and mental health among the oldest old. Physical resources include perceived health and independence in functional and instrumental activities of daily living, while psychological resources include mastery, self-esteem, and coping. Social resources are measured by frequency of social interaction and size of the social network. Among the 124 women and 31 men (M = 89 years), greater independence in IADLs and greater perceived control of events significantly attenuated the adverse effects of strain on psychological well-being.
Activities of Daily Living↗
The size and number of neurons descending to the spinal cord in relation to body length in the European eel (Anguilla anguilla).
Cells of origin of descending spinal pathways in eels of different body lengths (15-59 cm) were identified by labelling them retrogradely with horseradish peroxidase from the rostral spinal cord. The aim was to determine whether changes in size, number and distribution of these neurons take place in line with changes in the size of the spinal targets that occur with increasing body length. The somal cross-sectional areas of the labelled cells were measured from horizontal frozen sections and counts were made of the axons within the ventral funiculus in 1 micron transverse sections of the pectoral spinal cord. The distributions and numbers of labelled cells in the brain, and the number of axons in the ventral funiculus in the pectoral spinal cord, were similar for all lengths of fish studied. The somata of most of the labelled cells in the brain increase in size in fish up to a length of 40 cm. Some reticulospinal neurons are individually identifiable and most of these show a distinct increase in size; however, the cells that have relatively large somata in small fish show no change in size as the fish lengthen.
Anguilla↗
Choline acetyltransferase immunoreactive neurons innervating labyrinthine and lateral line sense organs in amphibians.
The goal of the present study was to investigate aspects of the central organization of the neurons belonging to the octavolateralis efferent system of amphibians. The perikarya of three genera, Pleurodeles, Xenopus, and Discoglossus, were located in the brainstem by applying retrograde tracers to the appropriate cranial nerves and choline acetyltransferase immunohistochemistry was used to identify cholinergic neurons. The efferent neurons supplying lateral line (Pleurodeles, Xenopus) and labyrinthine (Pleurodeles, Xenopus, and Discoglossus) end organs were found to intermingle in a single octavolateralis efferent nucleus. The neurons lie bilateral to the labelled nerves in Pleurodeles and ipsilateral in Xenopus and Discoglossus. Separate labelling of the anterior and posterior octavus rami provided no evidence for distinct groupings of efferent neurons that could be associated with auditory and vestibular end organs. In all three species many if not all octavolateral efferent neurons displayed immunoreactivity for choline acetyltransferase. They could be distinguished from the cholinergic facial motoneurons, with which they sometimes intermingle, on the basis of either their distinctive size and shape (Pleurodeles, Xenopus) or their location (Discoglossus). Double labelling in Xenopus confirmed the cholinergic nature of the efferent neurons.
Animals↗
Is a stay in an intensive care unit a risk for falls?
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Accidental Falls↗
Pilot study results. Falls among institutionalized elderly.
Increased cognitive impairment relates to poorer balance, to greater dependence in activities in daily living (ADL), and to perceptions of greater balance. Also, greater depression relates to better balance, to less dependence in ADL, and to perceptions of poorer balance. Those who fell were significantly younger and more dependent in ADL than residents who did not fall. However, there were no significant differences between these two groups for sex, length of institutionalization, depression, cognitive impairment, balance, or perceptions of balance. The findings that actual balance and perceptions of balance may not be congruent among cognitively impaired and depressed elderly has important implications for assessment and intervention. Perceptions are central to the decision of a person to ambulate or transfer and engage in other activities, and discrepancies between actual and perceived abilities may lead them to perform activities that they are unable to do safely.
Accidental Falls↗
Protease inhibitor display M13 phage: selection of high-affinity neutrophil elastase inhibitors.
We report display of the complete protease inhibitor (Kunitz) domain, BPTI, on the surface of bacteriophage M13 as a fusion to the gene III product. Phage that display BPTI bind specifically to anti-BPTI antibodies, trypsin and anhydrotrypsin. A point mutation of BPTI [Lys15-->Leu(K15L)] alters the binding specificity of fusion phage such that a human neutrophil elastase-binding phenotype is conferred while a trypsin-binding phenotype is eliminated. Phage were eluted from an immobilized protease with step gradients of decreasing pH. Phage that display Kunitz domains having higher affinity for the immobilized protease exhibit characteristic pH elution phenotypes, indicating that bound display phage can be selectively recovered from an affinity matrix. Utilization of this technology should enable the selection of remodeled protease inhibitors exhibiting novel binding specificities.
Amino Acid Sequence↗
Differences in the dopaminergic innervation of the electroreceptive and mechanoreceptive medullary lateral line nuclei of the ray, Raja radiata.
An immunohistochemical study was made of the octavolateral centres in the medulla of a cartilaginous fish, using an antibody specific for dopamine. No immunopositive cell bodies were observed but dopaminergic fibres were present in parts of the region. The overlying cerebellar crest was devoid of dopamine; the dorsal (electroreceptive) nucleus was poorly innervated, but the medial (mechanoreceptive) nucleus received a rich dopaminergic innervation comprising very fine, varicose fibres.
Animals↗
Directed evolution of a protein: selection of potent neutrophil elastase inhibitors displayed on M13 fusion phage.
Inhibitors of human neutrophil elastase were engineered by designing and producing a library of phage-displayed protease inhibitory domains derived from wild-type bovine pancreatic trypsin inhibitor and fractionating the library for binding to the target protease. The affinity of one of the engineered variants for human neutrophil elastase (Kd = 1.0 pM) is 3.6 x 10(6)-fold higher than that of the parental protein and exceeds the highest affinity reported for any reversible human neutrophil elastase inhibitor by 50-fold. Thus the display phage method has allowed us to obtain protein derivatives that exhibit greatly increased affinity for a predetermined target. The technology can be applied to design high-affinity proteins for a wide variety of target molecules.
Amino Acid Sequence↗
Metabolic profiles of spinal motoneurons in fish as established by quantitative enzyme histochemistry.
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Animals↗
Brainstem neurons projecting to different levels of the spinal cord of the dogfish Scyliorhinus canicula.
Neurons in the brain that project to different levels of the spinal cord in the dogfish Scyliorhinus canicula have been identified by retrograde labelling with horseradish peroxidase. Injections have been made at four different levels, namely, cervical (segments 3-6), pectoral (segments 16-18), pelvic (segments 34-36) and caudal (segments 60-80). Labelled neurons were located in the diencephalon, mesencephalon and rhombencephalon. Twenty nuclei contained labelled cells following cervical injections. Fourteen of these contained labelled cells following pectoral injections as did nine following pelvic injections and only seven after caudal injections. Of the three diencephalic nuclei projecting to the cord only nucleus thalamus ventralis pars medialis projected further than cervical regions. From the mesencephalon, the tectospinal projection, which arises from tectal and tectotegmental regions, reaches only as far as the cervical cord. The reticulospinal system, arising from cell groups in both the mesencephalon and rhombencephalon, provides the major descending pathway and reaches the most caudal levels. From the octaval region a vestibulospinal pathway arises from nucleus octavus magnocellularis, to reach all levels of the cord, and from nucleus octavus descendens, to project only as far as the pectoral cord. Other rhombencephalic cell groups--the trigeminal nuclei and nuclei B, F and G--project at least as far as the pectoral cord. We conclude that few brainstem nuclei can directly affect the whole spinal cord, whereas many nuclei may have an impact on its most rostral regions; here we have found labelled spinal interneurons with long descending axons that reach the most caudal cord levels.
Animals↗
The influence of cerebellar lesions on the swimming performance of the trout.
The influence of partial cerebellar ablation on the performance of rainbow trout, Oncorhynchus mykiss, swimming in a water tunnel was studied. Before surgery, all fish maintained a steady position in the water tunnel at all speeds tested. A linear relationship was found between the specific velocity (body length s-1) and the tail-beat frequency. After partial cerebellectomy, the fish swam well in the tunnel at low speeds, retaining the relationship between tail-beat frequency and specific velocity, but they were unable to maintain a steady position at water speeds requiring tail-beat frequencies above 3.5 s-1 and were swept backwards. Two sham-operated fish swam at all water speeds tested. Post mortem histological investigation showed that the lesions were restricted to the cerebellar corpus. We conclude that the cerebellum plays no role in the generation of motor programmes but may be essential for their selection and implementation.
Animals↗