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Biomedical subjects

J E Oliver

Publications and source records attributed to J E Oliver.

At least 19 recordsLinked to original sources

Pudendal reflexes and effects of conditioning stimuli in cats.

Evaluation of pudendal reflexes and effects of pudendal branch conditioning on those reflexes was carried out in 2 studies. In the first study of pudendal reflexes, 20 adult male and female mixed-breed cats underwent surgical isolation of the anal branch, urethral branch, and distal trunk (consisting primarily of the dorsal nerve of the penis/clitoris) of the pudendal nerve. Reflexes were tested in all possible ipsilateral and contralateral test-response combinations. Latency values and effects of increasing stimulus rate on response amplitude were recorded. Reflexes were detected in all combinations, with response latencies between 6.3 and 13.0 ms. Response amplitudes were diminished at stimulus rates of 3 to 5 Hz, and responses were apparently abolished at 4 to 16 Hz, suggesting that pudendal reflexes are polysynaptic. In the second study of conditioning effects, 9 adult male and female mixed-breed cats underwent preparation similar to that for study 1. A train of conditioning stimuli was applied to branches of the pudendal nerve prior to attempting to induce reflex responses, as performed in study 1. Conditioning completely abolished reflex responses for a period of 70 to 130 ms. Reflex responses were diminished in amplitude, compared with those observed during preconditioning trials, for 180 to 300 ms after conditioning.

Anal Canal

Comparison of genitoanal and bulbospongiosus reflexes and measurement of penile nerve conduction velocity in cats.

The bulbospongiosus reflex, genitoanal reflex, and nerve conduction velocity of the dorsal nerve of the penis were evaluated in cats. Seven adult sexually intact or castrated male mixed-breed cats underwent surgical isolation of the bulbospongiosus (analagous to bulbocavernosus) branch, anal branch, and distal trunk of the pudendal nerve. The bulbospongiosus and genitoanal reflexes were recorded from the bulbospongiosus and anal branches, respectively, by electrical stimulation, in turn, of the distal pudendal trunk and the penis itself. Nerve conduction velocity of the dorsal nerve of the penis was calculated by measuring response latency differences in the anal branch after stimulation of 2 sites on the extruded penis. The bulbospongiosus reflex had response latencies of 8.1 to 10.3 ms (distal trunk stimulation) and 11.0 to 13.0 ms (penile stimulation). The genitoanal reflex had latencies of 8.1 to 10.5 ms (distal trunk stimulation) and 11.2 to 13.2 ms (penile stimulation). Response amplitudes diminished at stimulus rates of 5 to 10 Hz; responses were abolished at rates of 12 to 15 Hz, suggesting that the reflexes are polysynaptic. There was no significant difference between latency values for the bulbospongiosus and genitoanal reflexes. Mean +/- SD nerve conduction velocity in the dorsal nerve of the penis was calculated to be 3.8 +/- 0.34 m/s, which was considerably slower than that found in human beings. This may represent technical difficulties in performing the test in cats, but could also indicate a difference between cats and human beings in the predominant population of cutaneous sensory fiber types of the penis.

Anal Canal

Measurement of anal and genitoanal reflexes in cats.

Noninvasive determination of anal and genitoanal reflexes was evaluated in clinically normal cats. Thirty adult mixed-breed cats (15 sexually intact or castrated males, 15 sexually intact or spayed females) were sedated by IV administration of ketamine, acetylpromazine, and atropine. Anal reflexes were recorded from the anal sphincter muscle after ipsilateral and contralateral electrical stimulation of the perineal skin. Genitoanal reflexes were recorded from the anal sphincter muscle after electrical stimulation of the penis or clitoris. An anal sphincter response to tibial nerve stimulation was attempted. Anal reflexes from ipsilateral and contralateral stimulations and a genitoanal reflex were detected in all cats. Anal sphincter responses to tibial nerve stimulation were inconsistent (4/30) and were not included in any analyses. Anal reflexes had response latencies of 7.5 to 12.0 ms (ipsilateral stimulation) and 6.5 to 13 ms (contralateral stimulation). Genitoanal reflexes had latencies of 9.0 to 13.0 ms (males) and 6.5 to 9.0 ms (females). Anal reflex latencies were significantly (P less than 0.05) longer for contralateral, opposed to ipsilateral, stimulation and were significantly (P less than 0.05) longer in males than in females. Genitoanal reflex latencies were also significantly (P less than 0.05) longer in males than in females, reflecting the more peripheral stimulation site in males. Anal reflex responses could be recorded in 2 feline clinic patients with such severe perineal trauma that pudendal nerve function could not be manually evaluated A potentially favorable prognosis was given in each instance on the basis of detection of the response. One cat eventually recovered.(ABSTRACT TRUNCATED AT 250 WORDS)

Anal Canal

Nuclear factors interact with conserved A/T-rich elements upstream of a nodule-enhanced glutamine synthetase gene from French bean.

The gln-gamma gene, encoding the gamma subunit of glutamine synthetase in French bean (Phaseolus vulgaris), is strongly induced during nodule development. We have determined the nucleotide sequence of a 1.3-kilobase region at its 5' end and have identified several sequences common to the promoter regions of late nodulin genes from other legume species. The 5'-flanking region was analyzed for sequence-specific interactions with nuclear factors from French bean. A factor from nodules (PNF-1) was identified that binds to multiple sites between -860 and -154, and a related but distinct factor (PRF-1) was detected in extracts from uninfected roots. PNF-1 and PRF-1 bound strongly to a synthetic oligonucleotide containing the sequence of an A/T-rich 21-base pair imperfect repeat found at positions -516 and -466. The same factors also had a high affinity for a protein binding site from a soybean leghemoglobin gene and appeared to be closely related to the soybean nodule factor NAT2, which binds to A/T-rich sequences in the lbc3 and nodulin 23 genes [Jacobsen et al. (1990). Plant Cell 2, 85-94]. Comparison of NAT2/PNF-1 binding sites from a variety of nodulin genes revealed the conservation of the short consensus core motif TATTTWAT, and evidence was obtained that this sequence is important for protein recognition. Cross-recognition by PNF-1 of a protein binding site in a soybean seed protein gene points to the existence of a ubiquitous family of factors with related binding affinities. Our data suggest that PNF-1 and PRF-1 belong to an evolutionarily conserved group of nuclear factors that interact with specific A/T-rich sequences in a diverse set of plant genes. We consider the possible role of these factors in coregulating the expression of gln-gamma and other late nodulin genes.

Amino Acid Sequence

In vitro inhibition of prostaglandin H synthase by compounds from the exocrine secretions of lace bugs.

1. Selected lace bug-derived and related compounds were shown to be in vitro inhibitors of mammalian and insect derived prostaglandin H synthase. 2. Two compounds, 2,6-dihydroxyacetophenone and 2,4,6-trihydroxyacetophenone, were significantly better inhibitors of prostaglandin synthesis than aspirin, whereas 2-nonyl-5,7-dihydroxychromone and 1-(2,6-dihydroxyphenyl) dodecan-1-one were equivalent to aspirin. 3. 2,4-Dihydroxyacetophenone was less effective in inhibiting the prostaglandin H synthase and 2-nonyl-5-hydroxychromanone showed no inhibition. 4. Three compounds, 2,6-dihydroxyacetophenone, 2,4,6-trihydroxyacetophenone and 1-(2,6-dihydroxyphenyl) dodecan-1-one were equal to aspirin in PSI inhibition with fat body preparations of the American cockroach Periplaneta americana L.

Animals

Two glutamine synthetase genes from Phaseolus vulgaris L. display contrasting developmental and spatial patterns of expression in transgenic Lotus corniculatus plants.

The gln-gamma gene, which specifies the gamma subunit of glutamine synthetase in Phaseolus vulgaris L., has been isolated and the regulatory properties of its promoter region analyzed in transgenic Lotus corniculatus plants. A 2-kilobase fragment from the 5'-flanking region of gln-gamma conferred a strongly nodule-enhanced pattern of expression on the beta-glucuronidase reporter gene. Parallel studies on the promoter of another glutamine synthetase gene (gln-beta) showed that a 1.7-kilobase fragment directed 20-fold to 140-fold higher levels of beta-glucuronidase expression in roots than in shoots. Histochemical localization of beta-glucuronidase activity in nodules of the transgenic plants indicated that the chimeric gln-gamma gene was expressed specifically in the rhizobially infected cells; expression of the gln-beta construct was detected in both cortical and infected regions of young nodules, and became restricted to the vascular tissue as the nodule matured. We conclude that gln-beta and gln-gamma genes are differentially expressed both temporally and spatially in plant development and that the cis-acting regulatory elements responsible for conferring these contrasting expression patterns are located within a 2-kilobase region upstream of their coding sequences.

Amino Acid Sequence

Insulin-like growth factor I gene expression in the rat ovary is confined to the granulosa cells of developing follicles.

The in vivo intraovarian synthesis of insulin-like growth factor-I (IGF-I) has been studied in the rat by Northern blot, dot blot hybridization, and in situ hybridization histochemistry. Ovarian IGF-I mRNA transcript sizes (7.0 kilobases (kb), 1.6 kb, and a group from 0.4-0.9 kb) were similar to those in liver and other tissues. The proportion of ovarian IGF-I to tubulin messenger RNA (mRNA) was increased to 176% of control values by treatment with diethylstilbestrol, while the ratio in liver was decreased to 64.4%. In situ hybridization identifies the major in vivo site of IGF-I synthesis in the ovary as the granulosa cells of developing follicles. IGF-I mRNA was present in the granulosa cells of developing preantral and antral follicles, but was not seen in atretic follicles or corpora lutea. In preovulatory follicles high levels of IGF-I mRNA were confined to the antral cell layers and to the cells of the cumulus oophorus. High levels of tubulin gene expression within follicles were seen in a similar distribution to that for IGF-I but 80-90% of corpora lutea also strongly expressed the tubulin gene. Interstitial cells, including thecal cells, express the tubulin gene at low levels but do not express the IGF-I gene. The distribution of IGF-I mRNA is the same as that previously observed for mitotically active granulosa cells, and therefore offers strong support for the view that IGF-I in the ovary acts by an autocrine-paracrine mechanism to promote granulosa cell replication.

Animals

Arterial supply to the spinal cord of dogs and cats.

The blood supply patterns to the spinal cord were examined and compared in 15 dogs and 10 cats by use of dissection and radiographic visualization. The lowest percentages of radicular contributions and the smallest diameter vessels were found in the thoracic part of the spinal cord. The central arteries were fewest in number in the thoracic region and unilaterally or bilaterally supplied the gray matter. The percentage of bilaterally distributed central arteries increased from the cervical to the lumbar regions. The anastomotic plexus on the surface of the spinal cord was found to be most dense in the cervical and lumbar regions.

Animals

Neurologic manifestations associated with hypothyroidism in four dogs.

Hypothyroidism was believed responsible for peripheral and central neurologic abnormalities in 4 dogs. Clinical signs consisted of abnormalities of gait and postural reactions and dysfunction of multiple cranial nerves in all 4 dogs. Circling, hypermetria, and spontaneous verticle nystagmus were observed in some of the dogs. Hypothyroidism was diagnosed in all 4 dogs on the basis of low resting serum thyroxine concentration and inadequate response to thyroid stimulating hormone. After thyroid hormone supplementation, resolution of neurologic abnormalities was complete in 2 dogs and partial in the other 2 dogs.

Animals

Stability and substrate specificity of a beta-glucosidase from the thermophilic bacterium Tp8 cloned into Escherichia coli.

A facile isolation of beta-glucosidase (EC 3.2.1.21) from Escherichia coli containing the recombinant plasmid pNZ1001 carrying a beta-glucosidase gene from the extremely thermophilic anaerobic bacterium Tp8 is reported. The enzyme was purified to homogeneity by anion-exchange chromatography and steric exclusion HPLC following thermal denaturation/precipitation of heat-labile E. coli proteins. The enzyme had a broad specificity for beta-D-glucosides, galactosides, fucosides, and xylosides. Action on aryl-beta-D-glycosides of glucose, galactose, and fucose was characterized by low Km and high Kcat/Km values compared with disaccharide substrates for which specificity decreased in the order laminaribiose, sophorose, cellobiose, beta-gentiobiose, lactose. Galactono-1-4-lactone, glucono-1-5-lactone, and 1-O-methyl-beta-D-glucose were competitive inhibitors with Ki values of 1.6, 0.09, and 17.5 mM, respectively. The enzyme was remarkably stable to detergents, urea, and organic solvents. Thermostability was greatest at the pH activity optimum (pH 6.0-6.5) and half-life (t1/2) values were 11 min at 90 degrees C, 105 min at 85 degrees C, and 900 min at 80 degrees C. Activity was destabilized by Sr2+, Co2+, Ca2+, Mg2+, and Mn2+, but t1/2 increased in the presence of substrates or competitive inhibitors. Activation energy, Ea, was 54.3 kJ.mol-1. A free thiol group(s) was required for full activity, this being rapidly lost in the presence of Hg2+ or N-ethyl maleimide.

Bacteria, Anaerobic

Glucosylations of pregn-5-ene-3 beta,20R-diol.

The four possible monoglucosides of the pregn-5-ene-3 beta,20R-diol were synthesized along with a mixture of the four possible 3,20-diglucosides. The glucosides were characterized by HPLC and mass spectrometry.

Chemical Phenomena

Successive generations of child maltreatment. The children.

Families were identified, in north-east Wiltshire (UK), (population 200,000), in which there was a pattern of two or more generations of child maltreatment and where there were also two or more children maltreated in the current generation (born between 1960 and 1980). These children had high rates of mental handicap, backwardness, and antisocial behaviour, and there were also characteristic patterns of emotional disturbance. The post-neonatal death rate for the 294 index children was very high, but higher still for their brothers and sisters. Some of the deaths, and at least 11 cases of violence-induced mental handicap (VIMH), were caused by characteristic types of child abuse - particularly violent shaking and throwing of infants, and secret suffocatory practices. There were very strong indications that larger numbers of children than the 11 proven VIMH cases had also suffered blunting of the intellect, physical complications such as epilepsy, and educational problems, as well as emotional and social maladjustment as the consequence of ill-treatment and neglect. Within the families, for children remaining at home, forms of ill-treatment and poor quality care persisted and ultimately affected most, or all, of the children in each family unit. Many families were chaotic, and within each family unit there were children frequently in care who suffered multiple placements, and who needed sustained specialist support throughout their childhood, encompassing a huge range of professional and other social support services. Such detail was generally underplayed or not accessible, and its full significance for children in each family could only be assessed by combining direct personal clinical involvement with record linkage methods, depending in turn on good co-operation from all agencies concerned wholly or partly with child protection.

Adolescent

Chronic polyneuritis in a Rottweiler.

A 2-year-old male Rottweiler was examined because of progressive weakness and muscular atrophy in the 4 limbs. Neurologically, the disease was characterized by hypoactive segmental reflexes without ataxia. Function of the cranial nerves was maintained. Electromyographic findings, nerve conduction velocity measurements, recordings of somatosensory-evoked potentials, and results of histologic examination of nerve and muscle biopsy specimens indicated a peripheral neuropathy. Rapid progression of the disease over a 4.5-month period was observed before the dog was euthanatized. Necropsy was performed, and the histopathologic findings confirmed peripheral neuropathy, which appeared to involve the peripheral myelin. An immune-mediated process was suspected.

Animals

Cystometrography and urethral pressure profiles in healthy horse and pony mares.

Cystometrography and urethral pressure evaluations were performed in 7 horse mares and 5 pony mares before and after sedation with xylazine. Before sedation, mean (+/- SD) maximal bladder contraction pressure was 91.4 +/- 16.5 cm of H2O in horses and was 86.0 +/- 14.4 cm of H2O in ponies, and maximal urethral closure pressure was 49.1 +/- 19.4 cm of H2O in horses and 37.7 +/- 14.4 cm of H2O in ponies. A significant difference was not found between values of nonsedated vs sedated animals. Only values for threshold volume were significantly different (P less than 0.05) between nonsedated horses (1,982 +/- 1,241 ml) and ponies (825 +/- 412 ml).

Animals

Biosynthesis of a C21 steroid conjugate in an insect. The conversion of [14C]cholesterol to 5-[14C]pregnen-3 beta,20 beta-diol glucoside in the tobacco hornworm, Manduca sexta.

Following injection into Manduca sexta (L.) female pupae (day 16), [14C]cholesterol was converted to a C21 steroid conjugate, 5-[14C]pregnen-3 beta,20 beta-diol glucoside. The conjugate was isolated from ovaries and eggs and contained three glucose units at least one of which is attached to C-20. The distribution of the other two glucose units remains to be determined. Other than the dealkylation of C-24 alkane or alkene substituents, side-chain cleavage of sterols is uncommon to insects. Here we report the first definitive proof of the biosynthesis of a C21 steroid conjugate from cholesterol in an insect species. The capability of M. sexta to so readily convert cholesterol to a C21 steroid suggests a physiological role for 5-pregnen-3 beta,20 beta-diol in this species.

Animals

Successive generations of child maltreatment: social and medical disorders in the parents.

Sustained attempts were made to identify all families in which there was a pattern of two or more generations of child maltreatment and multi-agency involvement in North-East Wiltshire (population 200,000) and where there were also two or more children maltreated in the current generation (born between 1960 and 1980). One hundred and forty-seven families were discovered. Disorders of behaviour of the parents of the 1960-1980 children are described. Collating information laboriously from at least 34 different agencies revealed very high levels of disturbance. Such detail was generally inaccessible, and its full significance for each family could only be assessed by using family medical record linkage methods. In the parents and antecedents, mental and personality disorders, suicidal attempts, mental handicap, dependence on drugs (mothers) or on alcohol (fathers), epilepsy and criminality were conspicuous features.

Adolescent