Comparison of monochromatic ocular aberrations measured with an objective cross-cylinder aberroscope and a Shack-Hartmann aberrometer.

Repeated measures of wavefront aberrations were taken along the line-of-sight of seven eyes using two instruments: an objective, cross-cylinder aberroscope (OA) and a Shack-Hartmann (SH) aberrometer. Both instruments were implemented on the same optical table to facilitate interleaved measurements on the same eyes under similar experimental conditions. Variability of repeated measures of individual coefficients tended to be much greater for OA data than for SH data. Although Zernike coefficients obtained from a single measurement were generally larger when measured with the OA than with the SH, the averages across five trials were often smaller for the OA. The Zernike coefficients obtained from the two instruments were not significantly correlated. Radial modulation-transfer functions and point-spread functions derived from the two sets of measurements were similar for some subjects, but not all. When average Zernike coefficients were used to determine optical quality, the OA indicated superior optics in some eyes, but the reverse trend was true if Zernike coefficients from individual trials were used. Possible reasons for discrepancies between the OA and SH measurements include difference in sampling density, quality of data images, alignment errors, and temporal fluctuations. Multivariate statistical analysis indicated that the SH aberrometer discriminated between subjects much better than did the objective aberroscope.     

Cervical Cancer with Paraaortic Metastases: Significance of Residual Paraaortic Disease after Surgical Staging

Cervical carcinoma frequently metastasizes to the paraaortic region, necessitating extended field radiotherapy to effect a cure. As imaging modalities are unreliable in identifying all cases of paraaortic nodal metastases (PAN), surgical staging is often utilized prior to radiotherapy. This study was aimed at identifying factors predictive of survival in women with cervical carcinoma and paraaortic metastases. In particular, survival based on extent of paraaortic disease was examined. The study group consisted of 43 women (stages IB–IVB) identified between 1982 and 1993 who were treated with extended field radiation for cervical carcinoma with histologically confirmed paraaortic metastases. The estimated 5-year survival for the study population was 24% with a median survival of 18 months. Pelvic tumor size had a significant impact on survival with the median survival being 34 months if the primary lesion was <6 cm compared to 14 months if ≥6 cm (P= 0.01). Eight of the 26 (31%) women without residual PAN disease after surgical staging remain alive and disease free (mean follow-up, 74 months). In contrast, only 1 of the 17 (6%) women with gross residual PAN is alive 71 months after treatment (P= 0.05). However, a comparison of Kaplan–Meier survival curves did not show a statistically significant advantage to the surgical excision of grossly involved PAN (P= 0.98). Although long-term survival among women with grossly involved, unresected paraaortic metastases is uncommon, further study is necessary to elucidate the role of surgical excision of bulky aortic disease in women with cervical cancer.     

The assessment of pain in rheumatoid arthritis: disease differentiation and temporal stability of a behavioral observation method

An observation method for the assessment of pain behaviors in patients with rheumatoid arthritis (RA) has been developed. We investigated the extent to which the frequencies of pain behaviors differentiated patients with RA and patients with chronic low back pain from depressed and nondepressed, pain free, control subjects. The reliability of the pain behavior frequencies of patients with RA across 2 observation sessions also was determined. Total pain behavior scores clearly differentiated patients with RA and low back pain from depressed and nondepressed, pain free, control subjects. Pain behavior observed in patients with RA showed a high degree of stability over time. The results of our study suggest that the behavioral observation method will prove useful in the assessment of RA pain in clinical and research settings.     

Inhibition of cis-diamminedichloroplatinum (II) — induced renal toxicity in the rat

Summary The hydroxyl-containing dithiocarbamates, sodium (di(hydroxyethl)-dithiocarbamate (NaY) and sodium N-methyl, N-dithiocarboxy-D-glucamine (NaG), appear to possess definite advantages over sodium diethyldithiocarbamate (DDTC) in reducing the cis-dichlorodiammineplatinum (Cis-Pt)-induced renal damage in rats given Cis-Pt as an IV bolus of 7.5 mg/kg 1 h before the IP administration of the dithiocarbamate. Renal damage, as estimated by blood urea nitrogen (BUN) values and serum creatinine levels, was less at all times up until sacrifice in animals given naY or NaG than in those given DDTC.An even more effective method for suppression of Cis-Pt renal toxicity is to use a combination of procedures. The most efficacious combination involves a 24-h pretreatment with DDTC or NaG plus acetazolamide and normal saline hydration 30 min before administration of Cis-Pt, followed by post-treatment with NaG. With this combination therapy renal function can be almost completely spared. Although DDTC or NaG pretreatment is highly effective when used in conjunction with NaG post-treatment, DDTC or NaG pretreatment alone has no renal sparing effect on renal function or renal platinum accumulation.In experiments in which antidotes were given 1 h after Cis-Pt and the animals were followed up for 75 days, a chronic interstitial nephritis at 75 days, suggesting a persistent cell-mediated immune response to Cis-Pt-induced renal damage, may be the basis for chronically abnormal renal function resulting from Cis-Pt. Treatment with all three dithiocarbamates, NaY, NaG, and DDTC, reduced the intensity of this cellular reaction and also reduced platinum levels in the kidneys.Although NaY and NaG are effective heavy metal chelators and renal function is spared and kidney platinum levels are substantially reduced by the dithiocarbamates, no parallel loss of antineoplastic activity by Cis-Pt on the rat Walker carcinoma was observed. Since the dithiocarbamates have no known human toxicity that would disqualify their clinical use, phase 1 clinical trials are indicated.This work was supported in part by the Natural Sciences Committee of the College of Arts and Sciences, Vanderbilt University     

Sample size considerations when groups are the appropriate unit of analysis.

This article discusses issues to be considered by nurse researchers when groups should be used as the unit of randomization. Advantages and disadvantages are presented, with statistical calculations needed to determine the effective sample size. Examples of these concepts are presented using data from the Black Cosmetologists Promoting Health Program. Different hypothetical scenarios and their impact on sample size are also presented. Given the complexity of calculating the sample size when using groups as the unit of randomization, it is advantageous for researchers to work closely with statisticians when designing and implementing studies that anticipate the use of groups as the unit of randomization.     

Computer-assisted assignment of functional domains in the nonstructural polyprotein of hepatitis E virus: delineation of an additional group of positive-strand RNA plant and animal viruses.

Computer-assisted comparison of the nonstructural polyprotein of hepatitis E virus (HEV) with proteins of other positive-strand RNA viruses allowed the identification of the following putative functional domains: (i) RNA-dependent RNA polymerase, (ii) RNA helicase, (iii) methyltransferase, (iv) a domain of unknown function ("X" domain) flanking the papain-like protease domains in the polyproteins of animal positive-strand RNA viruses, and (v) papain-like cysteine protease domain distantly related to the putative papain-like protease of rubella virus (RubV). Comparative analysis of the polymerase and helicase sequences of positive-strand RNA viruses belonging to the so-called "alpha-like" supergroup revealed grouping between HEV, RubV, and beet necrotic yellow vein virus (BNYVV), a plant furovirus. Two additional domains have been identified: one showed significant conservation between HEV, RubV, and BNYVV, and the other showed conservation specifically between HEV and RubV. The large nonstructural proteins of HEV, RubV, and BNYVV retained similar domain organization, with the exceptions of relocation of the putative protease domain in HEV as compared to RubV and the absence of the protease and X domains in BNYVV. These observations show that HEV, RubV, and BNYVV encompass partially conserved arrays of distinctive putative functional domains, suggesting that these viruses constitute a distinct monophyletic group within the alpha-like supergroup of positive-strand RNA viruses.     

The Discriminative Stimulus Properties of Acute Ethanol Withdrawal (Hangover) in Rats

Twenty male Sprague-Dawley rats were trained to discriminate pentylenetetrazole (PTZ, 15 mg/kg, intraperitoneally) from saline (SAL) under a drug discrimination procedure. Test sessions were conducted with 10 randomly selected subjects. Tests with various doses of PTZ resulted in a dose-dependent increase in the percentage of total session responses emitted on the PTZ-appropriate lever without a significant change in response rates across a wide range of test PTZ doses. Rats did not generalize the PTZ stimulus to ethanol (ETOH) up to ETOH test doses that completely suppressed responding. High acute ETOH doses (2, 3, and 4 g/kg) administered at various time points prior to discrimination test sessions engendered responding on the PTZ-appropriate level in a quantitative fashion, that was dose- and time-dependent. This acute ETOH delayed effect from these high doses replicates our previously published study using a Drug 1-Drug 2 discrimination task with Chlordiazepoxide and PTZ. More importantly, we suggest that the present behavioral assay may be a sensitive animal analogue of human "hangover" phenomena.