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Biomedical subjects

E Squires

Publications and source records attributed to E Squires.

10 recordsLinked to original sources

Criterion-based validity of an intracarotid amobarbital recognition-memory protocol.

PURPOSE: We tested whether the behavioral components of an Intracarotid Amobarbital Protocol (IAP) had criterion validity. It was hypothesized that a recognition-memory test designed for intracarotid injections and used to predict the risk of global amnesia before an elective temporal lobectomy should also identify persons who are severely amnesic due to other neurologic causes. Divergent validity predicts that speech tasks would be unaffected by amnesia. Test-retest reliability also was measured. METHODS: Fifteen persons with severe amnesia were administered four alternate forms of a yes/no recognition-memory protocol and a speech protocol. No drug injection occurred. Standardized neuropsychological tests were used to divide the amnesic group into those with Global Amnesia (i.e., retain no ongoing memories), Severe Amnesia (i.e., memory impaired), and Amnesia Plus (severe amnesia plus other neuropsychologic deficits). RESULTS: Two persons with Global Amnesia obtained scores at or below chance (i.e., failed) on the memory protocol. Unexpectedly, 12 of 13 severely amnesic persons obtained near-perfect memory scores. Amnesia had no impact on the speech protocol. Pass/Fail outcomes were highly correlated across all four sets. CONCLUSIONS: A four-item IAP memory protocol showed good reliability and criterion validity in identifying the rare condition of Global Amnesia, but it was insensitive to other disabling, severe amnesic disorders. This IAP memory protocol might have validity in predicting a postsurgical Global Amnesic disorder, but it did not identify and therefore could not predict other more common severe amnesic disorders.

Adolescent↗

Ultrasonographic detection of chronic epididymitis in a stallion.

Clinical signs of chronic epididymitis in a stallion included recurrent signs of inguinal pain--retraction of the right testis into the inguinal area, resentment of palpation of the right testis, and right-sided scrotal swelling. The tail of the right epididymis was firm and seemed to be adhered to the testis. The tail of the left epididymis felt firmer than normal. Ultrasonographically, the diameter of the head of the epididymis was considered larger than normal, was hyperechoic in relation to the right testis, and had an irregular border. Several bright 1- to 5-mm-diameter echogenic areas that alternated with less echogenic areas were seen in the head of the right epididymis. Ultrasonographic findings were interpreted as fibrosis attributable to chronic inflammation. Unilateral castration (right-sided) was performed, but the prognosis was guarded because of presumed involvement of the left epididymis.

Animals↗

Collaborative clinical laboratory study of a broth-disk test for determination of bacterial susceptibility to beta-lactams in combination with amdinocillin.

Methodology for the performance of synergistic antibiotic susceptibility studies has not been standardized. We addressed this problem collaboratively with combinations of amdinocillin and select other beta-lactam antibiotics by using a simple broth-disk test compared with a microdilution approach. Each method used the same drugs singly and in combination. The broth-disk test evaluated each agent and the combinations at concentrations that reflected the breakpoints for each drug; the same ratios of beta-lactam to amdinocillin were used in doubling dilutions with the microdilution method. Initially, each participant studied the same 50 members of the family Enterobacteriaceae; each bacterium was studied on three occasions. Thereafter, 500 representatives of Enterobacteriaceae isolated recently from clinical specimens were studied. Designated strains served as controls. Reproducibility between the two approaches studied in phase 1 of the investigation indicated good agreement between the methods, ranging from 87 to 100%. Agreement between the microdilution and broth-disk tests for the 2,551 clinical isolates ranged from 86 to 95%, with slightly better correlations between combination results than with the single agents. The findings indicate that antibiotic disks used routinely in the clinical laboratory can be used in a simple elution test to determine susceptibility of organisms to beta-lactam antibiotics alone and in combination with amdinocillin.

Amdinocillin↗

Interpretation of susceptibility testing of ceftriaxone.

Susceptibility of a variety of bacterial isolates to ceftriaxone was determined by Kirby-Bauer assays using 30 micrograms ceftriaxone disks and by microdilution (MIC) assays using standard procedures. The relation between zones of inhibition and MICs was expressed by the following regression equation: zone diameter = 22.98-2.653 In (MIC). Using this regression line and the breakpoints estimated from ceftriaxone concentrations in plasma 12 to 24 hours after 1- and 2-g doses, the susceptibility of a pathogen to ceftriaxone was classified as follows: susceptible-zone 16 mm or greater, MIC 16 micrograms/ml or less; moderately susceptible-zone 13 to 15 mm, MIC 17 to 63 micrograms/ml; resistant-zone 12 mm or less, MIC 64 micrograms/ml or greater. These breakpoints were used to determine the susceptibility of organisms isolated during clinical studies in the United States. The correlation between the in vitro results and the bacteriologic outcomes achieved in the clinical cases was analyzed to assess the suitability of the chosen breakpoints. The results of the disk assays were correctly predictive of bacteriologic responses with 1,388 of 1,513 organisms (91.7 percent), whereas the results of dilution assays correctly predicted the response with 897 of 941 organisms (95.3 percent). The correlation between in vitro results and bacteriologic outcome in patients treated with ceftriaxone was equivalent or superior to that achieved in patients treated with the comparative agents cefamandole and cefazolin. Thus, the chosen cutoff points for indicating susceptibility and resistance to ceftriaxone appear to be suitable and highly predictive of clinical success.

Bacteria↗

Antimicrobial activity of ceftriaxone: a review.

Ceftriaxone possesses potent activity, both in vitro and in vivo, against a broad range of bacteria. MIC50 and MIC90 geometric means were calculated using the results of broth and agar dilution assays performed worldwide. The MIC90 for ceftriaxone overall was 8 micrograms/ml or less for Enterobacteriaceae and 0.024 microgram/ml or less for Neisseria and Hemophilus species. Moderate activity was noted against Pseudomonas and Acinetobacter species (MIC50 12 to 28 micrograms/ml). Ceftriaxone was extremely active against nonenterococcal streptococci (MIC90 0.07 microgram/ml or less) and quite active against methicillin-susceptible Staphylococcus aureus (MIC90 5 micrograms/ml or less). Ceftriaxone generally was inactive against enterococci and methicillin-resistant staphylococci. Activity against anaerobes was good, except for many strains of Bacteroides fragilis and B. thetaiotaomicron (MIC greater than 64 micrograms/ml). Ceftriaxone exhibited excellent stability to beta-lactamases. The effect of medium and inoculum on in vitro testing was minimal. Excellent activity was demonstrated in vivo. Against Enterobacteriaceae, nonenterococcal streptococci, and H. influenzae, the PD50 in mice generally was less than 1 mg/kg. S. aureus strains responded moderately (mean PD50 6.5 mg/kg), whereas against most P. aeruginosa strains, PD50s ranged from 5 to greater than 250 mg/kg. The superior pharmacokinetic profile of ceftriaxone compared with that of other new cephalosporins was demonstrated by use of a prophylactic treatment schedule. The ability of ceftriaxone to penetrate the cerebrospinal fluid and provide excellent therapeutic coverage was confirmed in experimental meningitis models.

Aminoglycosides↗

Enhanced activity of beta-lactam antibiotics with amdinocillin in vitro and and in vivo.

An important advantage of antibiotic combinations which can be determined is the increase in spectrum of activity. Ad hoc combinations of amdinocillin with ampicillin, ticarcillin, piperacillin, azlocillin, cefazolin, cefamandole, cefoxitin, and moxalactam in ratios similar to those in serum after parenteral administration of normal dosages of these agents were tested in vitro against over 200 strains of bacteria, including Staphylococcus aureus, Streptococcus faecalis, representative genera of the Enterobacteriaceae, and Pseudomonas aeruginosa. Independent of amdinocillin's activity, it was possible to show marked enhancement of the spectrum of all the beta-lactam agents tested, except moxalactam, against members of the Enterobacteriaceae. Little or no enhancement or antagonism of activity was seen against gram-positive bacteria or P. aeruginosa. The enhancing activity of amdinocillin on three beta-lactam antibiotics, ampicillin, cefazolin, and cefoxitin, was also demonstrated in experimental mouse infections with gram-negative bacteria.

Amdinocillin↗

Late wound separation after cataract extraction.

Many years after cataract extraction, blunt trauma ruptured limbal wounds in five eyes. Filtrations followed minor trauma in three patients, and occurred spontaneously in two others. Limbal wounds do not regain the tensile strength of adjacent normal stroma and may be further weakened by tissue incarcerations, vascularization, and other defects. Histologic studies after cataract extraction also reveal minimal collagen bridging of the stromal wound in some human eyes. Diagnosis and clinical significance are discussed.

Aged↗