Lateral intervertebral disk extrusion causing lameness in a dog.
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Animals↗
Biomedical subjects
J E Alexander
Publications and source records attributed to J E Alexander.
What is your diagnosis? Septic arthritis of the coxofemoral joint in a dog.
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Animals↗
P300 from an auditory oddball task: inter-laboratory consistency.
Event-related potentials (ERPs) were recorded from normal subjects for the purpose of evaluating measurement consistency among six laboratories located in different cities within the United States. At each laboratory location 15 male subjects were tested using a simple auditory stimulus discrimination task and identical electrophysiological equipment and recording methods. Assessment of the N1, P2, N2, and P3(00) potentials from both the target and standard stimuli resulted in no reliable differences among laboratories for component amplitudes, latencies, and scalp distributions. Quantitative evaluation of overall waveform and specific component morphology yielded good to excellent agreement across laboratories. The findings suggest that large-scale inter-laboratory human electrophysiological studies are feasible and may prove of value when using ERPs to evaluate cognitive function in humans.
Adult↗
Concurrent finger-tapping in mathematically gifted males: evidence for enhanced right hemisphere involvement during linguistic processing.
O'Boyle and Benbow (1990) have suggested that enhanced involvement of the right hemisphere (RH) during basic information processing is a neuropsychologic characteristic of the gifted brain. To provide converging evidence for this hypothesis, the present study was conducted using a concurrent finger-tapping paradigm. Specifically, 24 mathematically precocious and 16 average ability adolescent males were required to tap a key as quickly as possible while sitting silently (baseline condition), concurrently reading a paragraph aloud (verbal load), or encoding a random form into memory (spatial load). For average ability subjects, the concurrent verbal load reduced tapping rate for the right but not the left hand, reflecting a division of LH resources between linguistic processing of the paragraph and motor control of the contralateral hand. In contrast, for gifted subjects, both their left- and right-hand tapping rates were significantly reduced, suggesting that both hemispheres were engaged during verbal processing. The concurrent spatial task produced a small but reliable reduction in finger-tapping rate for both the left and right hand in each group. These findings provide additional support for the notion that enhanced reliance on RH functioning is a physiological correlate of mathematical precocity in gifted males.
Adolescent↗
Immunization of mice with pneumolysin toxoid confers a significant degree of protection against at least nine serotypes of Streptococcus pneumoniae.
Pneumolysin is the thiol-activated cytolysin produced by Streptococcus pneumoniae. Mice were immunized with a genetically engineered toxoid version of pneumolysin, which was derived from a serotype 2 pneumococcus. The toxoid carried the mutation Trp-433-->Phe. Alum was used as the adjuvant. Immunized mice had significantly increased levels of anti-pneumolysin antibodies, principally immunoglobulin G1. Mice were challenged intraperitoneally or intranasally with 12 strains covering capsular serotypes 1 to 6, 7F, 8, and 18C. Following challenge, the survival rate and/or the time of death of nonsurvivors (survival time) was significantly greater than that of sham-immunized mice for all nine serotypes. However, differences in the degree of protection were noted between different strains. The route of challenge also appeared to influence the degree of protection. Nevertheless, the significant, albeit in some cases partial, protection provided against all nine pneumococcal serotypes supports the conclusion that pneumolysin toxoids warrant consideration for inclusion in a human vaccine.
Adjuvants, Immunologic↗
Cerebral lateralization in homosexual males: a preliminary EEG investigation.
A preliminary investigation was conducted to determine whether hemispheric patterns of electrophysiological activation in male homosexuals differ from that of male and female heterosexuals. Electroencephalographic (EEG) activity was recorded over left and right cerebral hemispheric locations while subjects performed verbal and spatial cognitive tasks. Male homosexuals demonstrated different patterns of alpha power compared to heterosexual males and females during baseline recording. Different hemispheric patterns of alpha activity also were observed between homosexual and heterosexual males during affective judgments of both verbal and spatial stimuli, but not between homosexual males and heterosexual females. These results provide further evidence of biologically-mediated functional differences between homosexuals and heterosexuals.
Adult↗
Characterization of an aromatic amino acid-dependent Listeria monocytogenes mutant: attenuation, persistence, and ability to induce protective immunity in mice.
A transposon insertion mutant of Listeria monocytogenes was shown to be deficient in prephenate dehydratase, an enzyme acting late in the pathway for biosynthesis of phenylalanine. This mutant had reduced virulence in mice. The mutant and parent strains persisted to the same extent in the tissues of infected mice and elicited similar degrees of splenomegaly. Mice vaccinated with the mutant were protected significantly from subsequent challenge with virulent L. monocytogenes.
Animals↗
Characterization of posttranslational modifications in neuron-specific class III beta-tubulin by mass spectrometry.
Class III beta-tubulin, isolated from adult bovine brain, is resolved into at least seven charge variants on isoelectric focusing gels. To identify the posttranslational modifications responsible for this heterogeneity, a mixture of brain tubulins was treated with cyanogen bromide and the C-terminal fragments from the class III beta-tubulin isoforms were then isolated by binding them to the monoclonal antibody TuJ1. Combined use of tandem mass spectrometry and both subtractive and automated Edman degradation chemistry on the isolated peptides indicates that many of the isoforms differ by phosphorylation at Ser-444 plus attachment of one to six glutamic acid molecules to the side chain of the first glutamate residue, Glu-438, in the C-terminal sequence Tyr-Glu-Asp-Asp-Glu-Glu-Glu-Ser-glu-Ala-Gln-Gly-Pro-Lys.
Amino Acid Sequence↗
Enhanced right hemisphere activation in the mathematically precocious: a preliminary EEG investigation.
A preliminary electroencephalographic (EEG) investigation was conducted to determine if the pattern of hemispheric activation in mathematically precocious youth differs from that of average math ability subjects. Alpha activity at four brain sites (frontal, temporal, parietal, and occipital lobes) over the left and right cerebral hemispheres (LH/RH) was monitored while 12- to 14-year-old, right-handed males: (a) looked at a blank slide (baseline condition), (b) judged which of two chimeric faces was "happier," and (c) determined if a word was a noun or a verb. At baseline, the LH of the precocious group was found to be more active at all four brain sites relative to that of the average ability group. During chimeric face processing, the gifted subjects exhibited a significant reduction in alpha power over the RH, primarily at the temporal lobe, while no such alpha suppression was observed in the average ability subjects. For noun/verb determinations, no significant alpha power reductions were obtained for either group. These electrophysiological data generally corroborate the behavioral findings of O'Boyle and Benbow (1990a) and support their contention that enhanced RH involvement during cognitive processing may be a correlate of mathematical precocity. Moreover, the pattern of activation observed across tasks suggests that the ability to effectively coordinate LH and RH processing resources at an early age may be linked to intellectual giftedness.
Adolescent↗
Cardiovascular effects of halothane anesthesia after diazepam and ketamine administration in beavers (Castor canadensis) during spontaneous or controlled ventilation.
Fourteen adult beavers (Castor canadensis) weighing 16.5 +/- 4.14 kg (mean +/- SD) were anesthetized for surgical implantation of radio telemetry devices. Beavers were anesthetized with diazepam (0.1 mg/kg) and ketamine (25 mg/kg) administered IM, which provided smooth anesthetic induction and facilitated tracheal intubation. Anesthesia was maintained with halothane in oxygen via a semiclosed circle anesthetic circuit. Values for heart rate, respiratory rate, esophageal temperature, direct arterial blood pressure, end-tidal halothane concentration, and end-tidal CO2 tension were recorded every 15 minutes during the surgical procedure. Arterial blood samples were collected every 30 minutes to determine pH, PaO2, and PaCO2. Values for plasma bicarbonate, total CO2, and base excess were calculated. Ventilation was spontaneous in 7 beavers and controlled to maintain normocapnia (PaCO2 approx 40 mm of Hg) in 7 others. Vaporizer settings were adjusted to maintain a light surgical plane of anesthesia. Throughout the surgical procedure, all beavers had mean arterial pressure less than 60 mm of Hg and esophageal temperature less than 35 C. Mean values for arterial pH, end-tidal CO2, PaO2, and PaCO2 were significantly (P less than 0.05) different in spontaneously ventilating beavers, compared with those in which ventilation was controlled. Respiratory acidosis during halothane anesthesia was observed in spontaneously ventilating beavers, but not in beavers maintained with controlled ventilation. All beavers recovered unremarkably from anesthesia.
Acid-Base Equilibrium↗
Change in haloperidol level due to carbamazepine--a complicating factor in combined medication for schizophrenia.
Serum haloperidol levels were measured in patients who received haloperidol alone and, subsequently, haloperidol in combination with carbamazepine or lithium carbonate. Haloperidol levels and the level- dose ratios dropped about 50% in patients receiving carbamazepine. They remained the same in most patients receiving lithium carbonate. One patient receiving added carbamazepine experienced worsening of symptoms; this was associated with a drop in serum haloperidol level. Two other patients receiving added carbamazepine showed significant symptom reduction, although they also sustained drops in serum haloperidol levels. It is not clear whether these two individuals benefited from a primary antipsychotic effect of carbamazepine or from reduction of "toxic" haloperidol levels. Serum levels of antipsychotic medication should be monitored carefully when these medications are prescribed in combination with carbamazepine.
Carbamazepine↗
Development of an optimized system for electroporation of Listeria species.
Electroporation was used to facilitate transformation of Listeria species with plasmid DNA. Optimal conditions for transformation of L. monocytogenes were a field strength of 8.5 kV/cm, 200 Ohms resistance, 25 microF capacitor with a time constant of 5 ms. With these conditions, 3.9 x 10(6) transformants/micrograms DNA were obtained. Under the same conditions, L. innocua and L. ivanovii exhibited a frequency of transformation similar to that of L. monocytogenes but a somewhat lower level was obtained with L. seeligeri.
Cell Membrane Permeability↗
High-resolution hip ultrasound in the limping child.
Hip ultrasound was performed on 44 children (114 exams) presenting with a painful hip or a limp thought to be due to hip disease. Effusions were found in 20 patients (21 hips). Hip ultrasound in combination with aspiration of the joint was found to be useful in diagnosis of osteomyelitis and septic joints, transient synovitis, trauma, and traumatic synovitis. We had no false positives or false negatives for hip effusions by ultrasound. In previous reports, absolute measurements have been relied upon for determination of hip effusions. We present a characteristic appearance of a capsule with and without abnormal joints fluid. The results of these 44 patients are summarized.
Arthritis, Infectious↗
Memory deficits in compulsive checkers: replication and extension in a clinical sample.
Thirteen checkers and twelve noncheckers, identified on the basis of their responses to the checking subscale of the Maudsley Obsessional-Compulsive Inventory (MOCI; Rachman and Hodgson, 1980), were recruited from a sample of 99 consecutive admissions to the outpatient department of a community mental health center. Consistent with our previous research with nonclinical samples of college students (Sher et al., 1983, 1984), checkers were found to show deficits in memory, especially recall for recently completed actions, compared to noncheckers. This result demonstrates the replicability of our previous findings across different types of samples and implicates deficits in memory for actions as a potentially important determinant of checking behavior. Assessment of spontaneous imagery associated with the anamnestic process suggested that checkers utilized less imagery, especially visual imagery, when recalling biographical information. Additional measures collected at the time of testing indicated that checkers were more neurotic and reported more psychological distress than noncheckers.
Adult↗
Pseudosarcomatous stromal reaction in primary and metastatic urothelial carcinoma. A source of diagnostic difficulty.
We report five urothelial carcinomas (one primary and four metastatic) with pseudosarcomatous stromal reaction. The exuberant stromal reaction led to a histologic misdiagnosis in three of the original small biopsy specimens. The differential diagnoses of primary spindle cell lesions of urinary tract include spindle cell carcinoma, carcinosarcoma, sarcoma, and benign pseudosarcomatous lesions. The distinction between those conditions and urothelial carcinomas with pseudosarcomatous stromal reaction is obviously of great clinical significance. In an initial small biopsy specimen, it may be difficult to make such a distinction. Immunostaining for cytokeratin and examination of more material should be performed. In our study of metastatic urothelial carcinomas with pseudosarcomatous stromal reaction, clinicopathologic correlations along with immunostaining for keratin proved to be useful. The stromal inductive capability of transplanted urothelium, which has been established in animal experiments, has occasionally also been reported in humans. The malignant urothelium in humans similarly appears to be capable of inducing stromal reaction.
Aged↗
Prognostic factors for healing of bone lesions in histiocytosis X.
Healing characteristics and rates of resolution were retrospectively reviewed in 38 bone lesions in 18 patients with histiocytosis X. Signs which tended to indicate future healing were a change from a nontrabecular pattern to a trabecular pattern by 10 weeks, a nonsclerotic lesion to one with sclerosis by 13 weeks, and loss of distinct margins by 24 weeks. Complete healing then occurred within 36 to 40 weeks after development of these favorable signs. The earliest occurrence of a favorable sign was 6 weeks. A trabecular pattern was found in 90% of the lesions, outside the skull, which eventually healed. Fifty-eight percent (22 of 38) of the lesions completely healed in an average of 13.6 months. Five months was the most rapid occurrence of healing in any of our cases.
Bone Diseases↗
The ultrasonographic diagnosis of typhlitis (neutropenic colitis).
Typhlitis is a necrotizing inflammatory disease of the cecum, usually with secondary infection. It is most often found in acute leukemia patients on chemotherapy but has also been reported in other patients on chemotherapeutic drugs. Diagnostic features of typhlitis have been reported on plain radiographs, barium enema, angiography, CT, and one other reported case with ultrasound. We report three cases of typhlitis with a characteristic echogenic thickening of the mucosa on ultrasound. The sonographic findings in the one previous report were identical to those of our three cases. We believe that the sonographic findings of typhlitis are unique and that ultrasound offers an easy noninvasive method of diagnosing this potentially lethal disease.
Adolescent↗
A protocol of plain radiographs, hip ultrasound, and triple phase bone scans in the evaluation of the painful pediatric hip.
A useful protocol for the evaluation of hip pain in the pediatric patient, using a combination of plain radiographs, hip ultrasound (US), and triple phase radionuclide bone scans is presented. Patients with hip pain were initially evaluated by plain radiographs of the pelvis and hips. If no diagnosis was reached, the hips were studied for effusions by real-time hip ultrasonography. If an effusion was present, the joint was aspirated for diagnosis. If no effusion was present by US or if no diagnosis was reached by aspiration, triple phase radionuclide bone scans were performed. Fifty patients were evaluated by this prospective protocol, and the diagnosis was reached in 48 of the 50 cases (10 by plain radiographs, 16 by US, and aspiration of the joint, and 22 by triple phase bone scans). Hip effusions were found in 20 patients by US, with no false positives or false negatives. Previous studies for detecting effusions by US have emphasized absolute measurements of the capsular width, but we report a typical appearance of the hip capsule when fluid is present (a bulging convex capsule). When no effusion is present, the capsule is concave and parallels the long axis of the femoral neck.
Child↗