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Biomedical subjects

J Walsh

Publications and source records attributed to J Walsh.

At least 181 records · Page 10Linked to original sources

Infective endocarditis with inflammatory lesions in the peripheral nervous system.

A 64-year-old woman developed septicemia and a generalized peripheral neuropathy while being ventilated postoperatively. No cause for the neuropathy could be found during life. At autopsy she was found to have infective endocarditis and multifocal inflammatory lesions in the central and peripheral nervous systems, consistent with damage due to septic emboli. Infective endocarditis may be a cause of a generalized polyradiculoneuropathy and could be responsible for a proportion of cases of "critical illness polyneuropathy".

Endocarditis, Bacterial↗

Intraoperative ultrasound of the liver affects operative decision making.

The surgeon operating upon patients with primary or metastatic hepatic cancers must determine if resection is feasible and, if it is, the magnitude of required resection. In an attempt to determine which tests best aid the surgeon in these determinations, the authors prospectively compared preoperative computed tomography (CT) of the liver and intraoperative ultrasound (IOU) in 42 patients with liver tumors who underwent 45 exploratory operations. The primary diseases included colorectal cancer metastases in 27 patients, hepatoma in 11 patients, and metastatic cancers of other origins in 4 patients. In the 42 patients there were 89 identified hepatic lesions that were confirmed to be malignant by resection, biopsy, or continued growth on follow-up CT. The sensitivity of either test for detecting these lesions was 69/89 (77%) for CT and 87/89 (98%) for IOU. Resection was not feasible in 13 patients. Five had extrahepatic disease, 4 had more nodules discovered by IOU, 3 were found by IOU to have involvement of all three hepatic veins by tumor and 1 patient had portal-vein invasion. Alternatively, in four patients tumors thought to involve all three hepatic veins by CT were shown to be free of at least one hepatic vein, thereby permitting resection. In one patient who had been previously operated upon, a tumor thought to involve the remaining right hepatic vein was seen to be free of the vein, also permitting resection. Regarding the extent of resection, IOU was also helpful. Lesser procedures than anticipated were proved possible by IOU in seven patients. A more extensive resection was shown to be necessary by IOU in two patients. Thus, IOU affected the operative management in 22 of 45 operative episodes (49%). It was conclude that IOU is superior to both preoperative CT and surgical exploration in assessing both the feasibility and the extent of resection required for primary and secondary hepatic cancers. In the authors' experience, IOU is the most sensitive indicator of number of lesions present in the liver. In addition, the ability of IOU to determine hepatic venous anatomy is a helpful adjunct in determining resectability of liver tumors.

Adult↗

Direct detection of Neisseria gonorrhoeae with monoclonal antibodies characterized by serotyping reagents.

A panel of monoclonal antibodies (MAbs) directed to outer membrane protein I were generated with the ultimate aim of detecting Neisseria gonorrhoeae in patient samples by a direct immunofluorescence (IF) test. In an initial evaluation of the sensitivity of these reagents, a cocktail of six IF MAbs recognized 491 (91%) of 540 gonococci isolates from several centers in Sydney, Australia. IF MAbs designated 185 and 228 recognized serovars of WI serogroup and IF MAbs 208, 210, and 312 recognized serovars of WII/III serogroup. IF MAb 198 recognized serovars within both serogroups. Three additional IF MAbs, designated 322, 323, and 330, were then generated by using strains which failed to react with the original MAb cocktail and which belonged to particular serovars. The new cocktail of nine IF MAbs recognized 96% of the gonococcal isolates, which incidentally contained representatives of serovars shown to have a worldwide distribution in previous studies. Although subtle differences were apparent in the reaction patterns found with coagglutination (serotyping) and IF, there nonetheless seems to be merit in the approach of continually evaluating the sensitivity of diagnostic reagents such as MAbs. This is especially true with an organism such as N. gonorrhoeae, which has the capacity to regularly alter the antigenic structure of its outer membrane proteins.

Antibodies, Monoclonal↗

A subpopulation of dopaminergic neurons in rat ventral mesencephalon contains both neurotensin and cholecystokinin.

The coexistence of the neuropeptides neurotensin and cholecystokinin and the catecholamine-synthesizing enzyme tyrosine hydroxylase within neurons of the ventral mesencephalon was analyzed using an immunofluorescence triple-labeling technique. Virtually all of the neurotensin-positive cell bodies in the ventral tegmental area, medial substantia nigra pars compacta, retrorubral field, and rostral and caudal linear raphe nuclei were found to contain both cholecystokinin and tyrosine hydroxylase immunoreactivities. The degree of colocalization was lower and more variable in other regions including the ventral and central periaqueductal grey matter and dorsal raphe nucleus. It appeared that immunoreactivities for these 3 neuroactive substances were not contained within the same axonal-like fibers and terminals in the ventral midbrain. These results demonstrate that a subpopulation of dopaminergic neurons, which presumably comprise part of the ascending mesotelencephalic system, contains the two peptides neurotensin and cholecystokinin. Thus, the data suggest a morphological basis for some of the reported functional interactions of these 3 putative neurotransmitters/neuromodulators within this system.

Animals↗

Comparison of lorazepam and flurazepam as hypnotic agents in chronic insomniacs.

Hypnotic efficacy and safety of 3 weeks of daily doses of 2 mg lorazepam or 30 mg flurazepam were compared in a double-blind cross-over study in eight chronic insomniacs between the ages of 29 and 60 years. Subjects were monitored in the sleep laboratory twice weekly for a total of 25 nights. Also, subjective estimates of sleep, vigilance tests, and adverse effects were recorded throughout the study. Findings indicated lorazepam performed better than flurazepam in most sleep parameters. With lorazepam there was improvement from baseline in percentage of sleep time (P less than .05); in total wake time after sleep onset (P less than .01) and in last third of night (P less than .05); in percentage of stage 2 (P less than .05) (weeks 1, 2, 3) and in percentage of night in stage 4 (weeks 2 and 3). Only total wake time from baseline improved (P less than .05) with flurazepam (week 2). Objective and subjective sleep parameters did not correlate well for either drug. Neither drug impaired REM sleep or vigilance test performance. Side effects (grogginess, lethargy; flurazepam only) were few and none was unexpected; neither rebound insomnia nor early morning insomnia occurred with either drug. In summary, both lorazepam 2 mg at bedtime and flurazepam 30 mg at bedtime were found to be effective and safe for treating chronic insomnia, as measured by parameters of sleep and daytime functioning. Lorazepam had more favorable effects on sleep than did flurazepam.

Adult↗

TRH-like immunoreactivity in endocrine cells and neurons in the gastro-intestinal tract of the rat and guinea pig.

By use of the indirect immunofluorescence technique, the cellular localization of thyrotropin-releasing hormone (TRH) was studied in the gastrointestinal tract of rats and guinea pigs of different ages. TRH-like immunoreactivity (LI) was observed in many pancreatic islet cells of young rats and guinea pigs but only in single cells of 6-month-old rats. In aged guinea pigs, a reduction in the number of TRH-positive cells was evident; however, numerous strongly fluorescent cells were still present. In the guinea pig, TRH-LI was in addition observed in gastrin cells in the stomach. TRH-positive nerve fibers occurred in the myenteric plexus of the oesophagus, stomach and intestine of the rat, and in the muscle layers of the guinea pig. These results suggest a functional role of TRH both as hormone and neuroactive compound in various portions and sites of the gastro-intestinal tract of the rat and guinea pig.

Animals↗

Further analysis of presence of peptides in dopamine neurons. Cholecystokinin, peptide histidine-isoleucine/vasoactive intestinal polypeptide and substance P in rat supramammillary region and mesencephalon.

Double-labeling combined with elution-restaining immunofluorescence techniques were used to analyze the extent of coexistence among the peptides cholecystokinin (CCK), peptide histidine-isoleucine (PHI)/vasoactive intestinal polypeptide (VIP), substance P and the catecholamine-synthesizing enzyme tyrosine hydroxylase in neurons of the supramammillary region and mesencephalon of the rat. Approximately 50% of the PHI/VIP-containing perikarya and about 25% of the CCK-positive cell bodies in the supramammillary region exhibited coexistence of both peptides. Only a very minor portion of these double-labeled neurons were also found to contain immunostaining for tyrosine hydroxylase (indicative of dopamine in these cells). A low percentage of the neurons contained the enzyme plus either CCK- or PHI/VIP-like immunoreactivity. A low proportion of the tyrosine hydroxylase-positive neurons in this region contained substance P-like immunoreactivity and vice versa. In other areas, small numbers of neurons in periventricular and periaqueductal regions were found to be immunostained for CCK, PHI/VIP and tyrosine hydroxylase. Single examples of triple-labeled (CCK-PHI/VIP-TH) somata were infrequently observed in the ventral tegmental area. These data provide further evidence of peptide/peptide and peptide/monoamine coexistence in the central nervous system. The demonstration of CCK-PHI/VIP colocalization (possibly including a minor dopaminergic component) and of substance P and tyrosine hydroxylase coexistence within neurons of the supramammillary region, which has widespread projections to many areas of the forebrain, suggests that these neuropeptides may coexist in some of these pathways and perhaps be co-released in several different regions of the brain.

Animals↗

Morphological and electrophysiological properties of cat lumbar paravertebral neurones.

The morphological and electrophysiological properties of neurones in the 3rd, 4th and 5th cat lumbar paravertebral ganglia were studied in vitro utilising intracellular injection of horseradish peroxidase (HRP) and intracellular electrophysiological recording techniques. Projections of neurones (T13-L5) were determined by in vivo HRP techniques. Two distinct soma morphologies were noted in all ganglia. Those whose long and short axes were approximately equal in length were designated as being 'spherical' and had a mean cross sectional area of 730 micron2. The remainder, whose long axis was at least 1.5 times the length of their short axis were called 'fusiform' and had a mean soma area of 540 micron2. The two cell types occurred in an approximate 2:1 ratio, respectively. The mean numbers of primary, secondary and tertiary dendrites for the population studied were 6.5, 6.3 and 3.4, respectively. Spherical cells had significantly more of each than fusiform cells as well as having a greater number of branch points and overall length of dendritic arbor. Neither cell type could be distinguished from the other based on the estimated number of fast excitatory postsynaptic potentials, the duration of the afterspike hyperpolarization or the duration of action potential discharge in response to 8-10-s depolarizing current pulses. The estimated number of synaptic potentials associated with both types of neurones (mean 10.6 +/- 1.6) correlated inversely only with the soma diameters (see Materials and Methods). It is concluded that while cat lumbar paravertebral neuronal soma may be classified into two morphologically distinct types, this is not reflected in their electrophysiological profiles. In addition, these data suggest that cat lumbar paravertebral neurones have a dendritic appearance and a degree of convergence of synaptic input previously shown to occur in this system.

Animals↗

Analysis of 18 recent cases of penetrating injuries to the common and internal carotid arteries.

Penetrating injuries to the common and internal carotid artery carry the unique potential for irreversible neurologic damage, respiratory collapse, and exsanguination. This study analyzes a recent 4 year experience with 18 cases of penetrating injury to the carotid artery to identify the factors influencing surgical decision-making, perioperative complications, and mortality. Sixteen patients with acute respiratory distress required emergent airway intubation. Three patients in hemorrhagic shock were brought directly to the operating room; the remaining 15 underwent emergency carotid arteriography. Three patients with multiple intramediastinal vascular injuries exsanguinated on the operating table before hemorrhage could be controlled. There were no deaths or neurologic complications in the 14 surviving patients who had an operation on the carotid artery, including 2 patients treated by internal carotid artery ligation. Early control of the airway was the most common initial requirement in this group of patients. Judicious use of preoperative arteriography was thought to facilitate the operative approach in selected patients. A flexible surgical approach to the damaged carotid artery is essential based on the patient's hemodynamic status, degree of neurologic impairment, and nature and extent of arterial damage.

Adolescent↗

Costs of spinal cord injury in Australia.

Available data on spinal cord injury in Australia has been synthesised. An investigation and discussion has been made into the major financial costs involved in the acute management and ongoing life support systems required by people who have sustained spinal cord injury. The costs are projected to give an estimate of the potential for dollar savings in Australia in reducing the impact of spinal cord injury, either by lowering its incidence or by reducing the resulting devastation. Allowance has been made in these projections for severity of disability, rates of survival, re-employment, hospitalisation and relative use of various aids and appliances. It is estimated that based on an incidence rate of 25 new cases of spinal cord injury per million of population per annum the annual cost by the year 2006 will exceed $250m. As the spinal cord injury population ages the propensity of cost is expected to move from acute and medical care to less acute, community based care. Mention is also made of the non-economic human costs which cannot be quantified in terms of dollars and cents.

Australia↗

Antiserum raised against residues 159-168 of the guanine nucleotide-binding protein Gi3-alpha reacts with ependymal cells and some neurons in the rat brain containing cholecystokinin- or cholecystokinin- and tyrosine 3-hydroxylase-like immunoreactivities.

Antibodies raised against a synthetic deca-peptide corresponding to a specific sequence of Gi3-alpha protein (an inhibitory guanine nucleotide-binding protein) were used to analyze Gi3-alpha-like immunoreactivity in brain sections from colchicine-treated rats by indirect immunofluorescence histochemistry. Gi3-alpha-peptide-positive cell bodies were found in the ventral tegmental area and substantia nigra, and these cells were also cholecystokinin (CCK)- and tyrosine 3-hydroxylase-positive. Gi3-alpha-peptide staining was observed in perikarya in the hippocampus and in fibers in the nucleus accumbens, tuberculum olfactorium, bed nucleus of stria terminalis, and a spino-thalamic tract, where it coexisted with CCK-like immunoreactivity as well. No coexistence with CCK occurred in Gi3-alpha-peptide-positive ependymal cells outlining the aqueduct and ventricles. Preadsorption of Gi3-alpha antibodies with CCK-8 or CCK-33 did not alter Gi3-alpha-peptide staining. The occurrence of Gi3-alpha-peptide-like immunoreactivity in CCK-containing neurons may indicate the presence of Gi3-alpha protein and in CCK/dopamine neurons may indicate an association of this Gi protein with dopamine autoreceptors.

Animals↗