Bacterial endocarditis due to Haemophilus parainfluenzae

We have evaluated three patients with Haemophilus parainfluenzae endocarditis. Two of the three had underlying heart disease. All presented with fever, chills and malaise of less than two weeks' duration. Mitral valve involvement led to congestive heart failure in two of three cases. Treatment proved difficult, despite normally adequate dosages of antibiotics to which the pathogens were sensitive in vitro (ampicillin, 12-20 gm/dag; gentamicin, 3-5 mg/kg/day). Two patients were cured; one died. There was a suggestion of an inverse correlation between vegetation mass and favorable clinical response. Review of the English literature disclosed 22 documented cases of H parainfluenzae endocarditis, including 12 in the antibiotic era.     

Visual receptive-field properties of single neurons in cat's ventral lateral geniculate nucleus

1. Visual receptive-field characteristics were determined for 154 cells in the ventral lateral geniculate nucleus (VLG) of cats anesthetized with nitrous oxide. All cells were verified histologically to be within the VLG. Responses of 182 cells from laminae A and A1 of the dorsal lateral geniculate nucleus (DLG) were tested for comparison. 2. The VLG cells could be grouped into one of seven classes according to their responses to light stimulation. Twenty-seven percent of the cells had uniform receptive fields. They responded maximally to stationary stimuli flashed on or off anywhere within the receptive field and showed no evidence for antagonistic surround mechanisms. About 19.5% of the VLG cells had concentric receptive fields. They were similar to the uniform type, with the addition of a concentric inhibitory surround. Eight percent of the VLG cells had ambient receptive fields. These cells were characterized by an unusually regular maintained discharge which varied in rate in relation to the level of receptive-field illumination or of full-field ambient illumination. About 4% of the VLG cells were movement sensitive. They gave little or no response to stationary stimuli flashed on or off in the receptive field, and responded best to a contour moving across the receptive field in any direction. An additional 2.5% of the VLG cells were direction sensitive. Their response was dependent on the direction of stimulus movement through the receptive field. Sixteen percent of the VLG cells had indefinite receptive fields. They responded to whole-eye illumination or to localized visual-field stimulation; however, specific receptive-field properties could not be adequately defined. Approximately 23% of the VLG cells studied gave no convincing response to visual stimulation. 3. Responses of DLG cells agreed with those reported in previous studies. Almost all (97%) had concentric receptive fields, and a few (3%) had uniform receptive fields with no apparent antagonistic surround. None of the DLG cells had receptive fields like those in the other classes found for VLG cells. 4. The VLG cells tended to have large receptive fields; mean diameter was 10.6 degrees of visual arc. This was substantially larger than the diameter of receptive fields for DLG cells. In addition, VLG cells generally required larger stimuli than DLG cells to respond. There was no consistent relationship between receptive-field size and visual-field eccentricity for VLG cells, in contrast to the DLG. Most (57%) VLG cells were driven only by the contralateral eye, 30% were binocularly driven, and 13% were driven only by the ipsilateral eye. 5. A systematic visuotopic organization was present in the VLG. The lower visual field was represented anteriorly in the nucleus and the upper visual field posteriorly. The vertical meridian was represented along the dorsomedial border of the VLG where it abuts the DLG, and the temporal periphery was represented ventrolaterally. 6. Responses to electrical stimulation of the optic chiasm were studied for 55 VLG cells...     

A tilt and roll device for automated correction of rotational setup errors

A tilt and roll device has been developed to add two additional degrees of freedom to an existing treatment table. This device allows computer-controlled rotational motion about the inferior-superior and left-right patient axes. The tilt and roll device comprises three supports between the tabletop and base. An automotive type universal joint welded to the end of a steel pipe supports the center of the table. Two computer-controlled linear electric actuators utilizing high accuracy stepping motors support the foot of table and control the tilt and roll of the tabletop. The current system meets or exceeds all pre-design specifications for precision, weight capacity, rigidity, and range of motion.     

Initial evaluation of human recombinant interleukin-1 receptor antagonist in the treatment of sepsis syndrome: a randomized, open-label, placebo-controlled multicenter trial

OBJECTIVES: To evaluate the safety, pharmacokinetics, and efficacy of human recombinant interleukin-1 receptor antagonist (IL-1ra) in the treatment of patients with sepsis syndrome. DESIGN: Prospective, open-label, placebo-controlled, phase II, multicenter clinical trial using three different doses of human recombinant IL-1ra. SETTING: Twelve academic medical center intensive care units in the United States. PATIENTS: Ninety-nine patients with sepsis syndrome or septic shock who received standard supportive care and antimicrobial therapy, in addition to infusion with escalating doses of IL-1ra or placebo. INTERVENTIONS: Patients received an intravenous loading dose of either human recombinant IL-1ra (100 mg) or placebo, followed by a 72-hr intravenous infusion of either one of three doses of IL-1ra (17, 67, or 133 mg/hr) or placebo. All patients were evaluated for 28-day, all-cause mortality. MEASUREMENTS AND MAIN RESULTS: A dose-dependent, 28-day survival benefit was associated with IL-1ra treatment (p = .015), as indicated by the following mortality rates: 11 (44%) deaths among 25 placebo patients; eight (32%) deaths among 25 patients receiving IL-1ra 17 mg/hr; six (25%) deaths among 24 patients receiving IL-1ra 67 mg/hr; and four (16%) deaths among 25 patients receiving IL-1ra 133 mg/hr. A dose-related survival benefit was observed with infusion of IL-1ra in patients with septic shock at study entry (n = 65; p = .002) and in patients with Gram-negative infection (n = 45; p = .04). Patients with an increased circulating interleukin-6 (IL-6) concentration of > 100 pg/mL at study entry demonstrated a dose-related survival benefit with IL-1ra treatment (p = .009). In patients with an increased IL-6 concentration at study entry, the magnitude of the decrease in IL-6 concentration 24 hrs after the initiation of therapy was correlated with increasing the IL-1ra treatment dose (p = .052). A significant dose-related reduction in the Acute Physiology and Chronic Health Evaluation (APACHE II) score was achieved by the end of infusion (p = .038). A renal elimination mechanism for IL-1ra was suggested by the positive correlation between IL-1ra plasma clearance and estimated creatinine clearance (p = .001; r2 = .51). Human recombinant IL-1ra was well tolerated. CONCLUSIONS: This initial evaluation suggests that human recombinant IL-1ra is safe and may provide a dose-related survival advantage to patients with sepsis syndrome. A larger, definitive clinical trial is needed to confirm these findings.     

Effects of calcium channel entry blockers on cocaine and amphetamine-induced motor activities and toxicities

The effects of calcium channel entry blockers on cocaine and amphetamine-induced behavioral responses were investigated. Cocaine and amphetamine produced dose-dependent increases in locomotor activity and stereotyped behavior with a maximum response at 40 and 1.2 mg/kg, respectively. The 1,4-dihydropyridine nimodipine and the benzothiazepine diltiazem were more effective in inhibiting cocaine (20 mg/kg)-induced responses than amphetamine (0.6 mg/kg)-induced responses. At doses of cocaine and amphetamine that caused seizures and death, nimodipine, nitrendipine and diltiazem did not offer any protection; rather, they potentiated the toxicities produced by these psychomotor stimulants.     

Gas chromatographic determination of chloramphenicol residues in shrimp: interlaboratory study

An interlaboratory study of a gas chromatographic method for determining chloramphenicol (CAP) residues in shrimp was conducted. An internal standard (Istd), the meta isomer of CAP, was added to the shrimp, and the treated shrimp were homogenized with ethyl acetate. The ethyl acetate extract was defatted with hexane, and the CAP was partitioned into ethyl acetate from an aqueous salt solution. The ethyl acetate was evaporated, and the dried residue was treated with Sylon, a trimethylsilyl derivatizing agent, to yield the trimethylsilyl derivative of CAP. A portion of the solution containing the derivative was injected into a gas chromatograph equipped with an electron capture detector. Levels of fortified and incurred CAP were calculated from the peak area ratio of standard CAP to Istd. Recoveries of CAP from tissue directly fortified at 5 ppb were 102% (within-laboratory relative standard deviation [RSDr] = 5.6%), 104% (RSDr = 5.5%), and 108% (RSDr = 6.3%) from Laboratories 1, 2, and 3, respectively. Incurred-CAP residues at 5 and 10 ppb levels were also determined, with the following results: Laboratory 1: composite A, 4.56 ppb (RSDr = 14.0%); composite B, 8.38 ppb (RSDr = 11.6%); Laboratory 2: composite A, 4.17 ppb (RSDr = 12.5%); composite B, 8.90 ppb (RSDr = 5.60%); Laboratory 3: composite A, 4.66 ppb (RSDr = 14.9%); composite B, 11.0 ppb (RSDr = 11.8%).