A new epoxynaphthoquinol from Rumex japonicus

A new epoxynaphthoquinol derivative, 3-acetyl-2-methyl-1, 5-dihydroxy-2,3-epoxynaphthoquinol (I), was isolated from the root of Rumex japonicus. The structure was elucidated by high field 1D and 2D NMR techniques.

Matching for private or public HLA epitopes reduces acute rejection episodes and improves two-year renal allograft function

BACKGROUND

The current role of HLA matching in renal transplantation is controversial. Public HLA epitope matching has been suggested to be as advantageous as private HLA matching, with the added benefit of increasing recipients' access to well-matched grafts.

METHODS

In this single-center study of 105 renal transplant recipients, we examined the association of HLA matching with early (0-3 months) and late (4-6 months) rejection episodes (RE), as well as renal allograft function up to 2 years after transplant.

RESULTS

Poor HLA-DR, but not HLA-A or -B, matching was associated with early RE (0 DR matches, RE=2.7+/-0.19, 1 DR match, RE=2.37+/-0.18, vs. 2 DR matches, RE=1.5+/-0.38; P < 0.01). In contrast, poor HLA-B, but not HLA-A or -DR, matching was associated with late rejections (0 HLA-B matches, RE=1.1+/-0.51 vs. 1-2 HLA-B matches, RE=0.51+/-0.1; P < 0.004). HLA-B matching was also associated with a significantly lower serum creatinine (SCr) level at 24 months (0 HLA-B matches, SCr=178+/-20 micromol/L vs. SCr=132+/-6 micromol/L for 1-2 HLA-B matches; P < 0.025). Matching for 10 supertypic HLA-A and -B cross-reactive groups was associated with reduced late graft rejection (0-2 residue matches, RE=1.15+/-0.18 vs. RE=0.62+/-0.12 for 3 to 7 residue matches; P < 0.013) as well as a significantly lower SCr level at 24 months (0-2 residue matches, SCr=205+/-29 micromol/L vs SCr=131+/-6 micromol/L for 3 to 7 residue matches; P < 0.001) after transplantation.

CONCLUSIONS

HLA-DR matching was associated with a reduced frequency of early rejection episodes, whereas HLA-B or residue/cross-reactive group matching was associated with a reduced frequency of late rejection episodes and improved graft function at 2 years.

Two new monogalactosylacylglycerols from Hydrocotyle ramiflora

Two new monogalactosylmonoacylglycerols ( 1, 2) and two known compounds ( 3, 4) were isolated from Hydrocotyle ramiflora. Based on physicochemical evidence and spectral data, the structures of 1, 2, 3, and 4 were determined as (2 S)-1- O-(7 Z,10 Z,13 Z-hexadecatrienoyl)-3- O-beta-galactopyranosylglycerol, (2 S)-1- O-(9 Z,12 Z-octadecadienoly)-3- O-beta-galactopyranosyl-glycerol, alpha-spinasterol, and capsidiol 3-acetate, respectively.

Comparison of microparticle enzyme and fluorescence polarization immunoassays in pediatric patients not receiving digoxin

Previously, investigators have measured endogenous digoxin-like immunoreactive substances (DLIS) in pediatric patients. Digoxin-like immunoreactive substances may cross-react with digoxin assays to produce false-positive digoxin concentrations; hence, the validity of digoxin concentrations in pediatric patients is questionable. The authors compared the presence and magnitude of apparent DLIS using the microparticle enzyme immunoassay (MEIA) AxSYM Digoxin II and the fluorescence polarization immunoassay (FPIA) TDx Digoxin II, in the serum of 80 pediatric patients who were hospitalized with normal serum creatinine but had not been administered digoxin. Patients ranged in age from 1 day to 16 years (mean age, 4.96 +/- 5.17 years). Serum creatinine and total bilirubin were 0.5 +/- 0.18 mg/dl and 1.3 +/- 0.17 mg/dl, respectively. Forty-eight percent of MEIA samples and 79% of FPIA samples had measurable DLIS values. Digoxin-like immunoreactive substance concentrations for the MEIA (0.07 +/- 0.09 ng/ml) and FPIA assays (0.1 +/- 0.1 ng/ml) were statistically different (p = 0.01); however, no sample had a DLIS value >0.38 ng/ml. A poor correlation was noted between patient age, serum creatinine, total bilirubin, and DLIS concentration. The MEIA and FPIA assays effectively minimized DLIS cross-reactivity making both technologies clinically acceptable for serum digoxin measurement in pediatric patients with normal serum creatinine and total bilirubin.

Cytologic correlates of papillary immature metaplasia (immature condyloma) of the cervix

Papillary immature metaplasia (PIM) of the cervix (immature condyloma) is a variant of low-grade squamous intraepithelial lesions (LSIL). It is frequently associated with human papillomavirus (HPV) types 6 and 11. The purpose of this study was to characterize the cytologic changes associated with this lesion. We analyzed 10 cases of PIM from our files and reviewed the Papanicolaou smears taken proximate to the time of the biopsy. Four cases had either reactive epithelial changes (2 cases) or cytologic findings typical of low-grade SIL, with koilocytosis (2 cases). Six cases displayed a spectrum of metaplastic cells with varying maturation that ranged from atypical reactive cells to atypical immature metaplastic cells. Binucleation was common. Some cells exhibited features characteristic of SIL, although the degree of nuclear atypia generally was less than that associated with high-grade SIL. Papanicolaou smears from all cases were interpreted as atypical (ASCUS) metaplasia or low-grade SIL. Follow-up biopsy in one case revealed a PIM in association with a high-grade SIL, the latter undiagnosed by smear alone. PIM is a distinct histologic entity that can present with a spectrum of cytologic findings. Its recognition histologically can resolve some cytologic/histologic discrepancies. Confusion with an immature HSIL or atypical immature metaplasia can occur in some instances and the diagnosis of PIM by cytology alone is not recommended, unless the diagnosis is qualified.

Adenocarcinoma in situ in cervical smears with a small cell (endometrioid) pattern: distinction from cells directly sampled from the upper endocervical canal or lower segment of the endometrium

Adenocarcinoma in situ (AIS) with small, endometrioid cells in cervicovaginal smears, is a source of false-negative diagnoses because of the difficulty in distinguishing these cells from endometrial cells of the lower uterine segment or benign cells from the upper endocervical canal. This study was designed to elucidate the most useful criteria for this distinction. Three observers blinded to the actual diagnoses reviewed 29 preselected cases (AIS, 17; benign, 12) that had originally caused diagnostic difficulty. Each observer made a diagnosis and evaluated 15 preselected diagnostic criteria. All 3 observers agreed on the correct diagnosis in 19 (66%) of 29 cases, and at least 2 observers agreed on the correct diagnosis in 27 (93%) of 29 cases. No case was misdiagnosed by all 3 observers. The most useful criteria for the diagnosis of AIS are a predominance of groups with marked crowding, focal feathering, nuclear hyperchromatism with coarsening of chromatin, and occasional mitotic figures. Sheets of cells, endometrial tubules, and endometrial stroma favor a benign diagnosis. Although 12 (14%) of 87 possible diagnoses were erroneous, well-preserved, small, endometrioid AIS cells can be identified correctly on cervical smears and distinguished from epithelium from the lower uterine segment and high endocervical canal in most cases using the aforementioned criteria.

Isolation of a multidrug resistance inhibitor from Aconitum pseudo-laeve var. erectum

To overcome multidrug resistance (MDR) in cancer chemotherapy, we prepared various plant extracts and searched for a component which is effective for inhibition of MDR. MDR inhibition activity was determined by measuring cytotoxicity to MDR cells using multidrug resistant human fibrocarcinoma KB V20C, which is resistant to 20 nM vincristine and expresses high level of mdr1 gene. Of various plant extracts, the MeOH extract of the root of Aconitum pseudo-laeve var. erectum was found to have potent inhibitory activity on MDR. The bioassay-guided fractionation of the MeOH extract of the plant led to the isolation of an alkaloid, lycaconitine, as an active principle. And the IC50 of lycaconitine for KB V20C cells was 74 micrograms/ml.

Qualifying the cytologic diagnosis of "atypical squamous cells of undetermined significance" affects the predictive value of a squamous intraepithelial lesion on subsequent biopsy

OBJECTIVE

To evaluate whether different qualifications of a cytologic diagnosis of "atypical squamous cells of undetermined significance" predict a greater or lesser likelihood of cervical pathology.

DESIGN

Comparison of different cytologic qualifications of atypical squamous cells of undetermined significance with the frequency of significant cervical disease as documented by tissue biopsy.

PARTICIPANTS AND SETTING

Four hundred, fifty-two consecutive Papanicolaou smears showing atypical squamous cells of undetermined significance (diagnosed by nine cytopathologists) in women who had undergone cervical biopsy within the previous 90 days at Brigham and Women's Hospital, Boston, Mass (January-June 1995).

MAIN OUTCOME MEASURE

The histopathologic diagnosis of squamous intraepithelial lesion of the cervix.

RESULTS

The 452 smears were qualified as "favor reactive" (22%), "not otherwise specified" (42%), "favor squamous intraepithelial lesion" (29%), and "favor high-grade squamous intraepithelial lesion" (6%). High-grade squamous intraepithelial lesions and total squamous intraepithelial lesions were pathologically confirmed by cervical biopsy in 3.6% and 6% of the favor reactive smears, in 11% and 21% of the not otherwise specified smears, in 12% and 30% of the favor squamous intraepithelial lesion smears, and in 53% and 59% of the favor high-grade squamous intraepithelial lesion smears. Significant associations were seen between a favor reactive smear and a benign finding on cervical biopsy (94%, P = .04) and between a favor high-grade squamous intraepithelial lesion smear and a biopsy that showed a high-grade squamous intraepithelial lesion (53%, P = .00001).

CONCLUSIONS

Qualifying atypical squamous cells of undetermined significance stratifies women into different risk groups for squamous intraepithelial lesion. It is reasonable for physicians to make patient management decisions based, at least in part, on such qualifications.

Evaluation of vancomycin use in a pediatric teaching hospital based on CDC criteria

This study was performed to determine whether vancomycin use at our pediatric hospital was consistent with modified Centers for Disease Control and Prevention guidelines. Vancomycin use was inappropriate in 54% of patients. Inappropriate use briefly decreased by 14% after educational efforts. Further education regarding vancomycin use was deemed necessary and is continuing.

Four new cytotoxic germacranolides from Carpesium divaricatum

In a bioassay-guided search for cytotoxic compounds from higher plants of South Korea, four new sesquiterpenes of the germacranolide type, named cardivins A (1), B (2), C (3), and D (4), have been isolated from the aerial parts of Carpesium divaricatum. Structures of these compounds were elucidated on the basis of spectroscopic techniques. Compounds 1, 2, 3, and 4 showed cytotoxicity to the human tumor cells, A-549 (nonsmall cell lung), SK-OV-3 (ovary), SK-MEL-2 (skin), XF-498 (central nervous system), and HCT-15 (colon).

Total hip arthroplasty with an uncemented femoral component. Excellent results at ten-year follow-up

We followed 138 patients (145 hips) who had had uncemented total hip arthroplasty using the Taperloc femoral component for a mean of ten years (8 to 12.5). No patient was lost to follow-up; 31 (31 hips) died before the minimum time of eight years for inclusion in the study, and 30 of these still had their femoral component in place. One well-fixed prosthesis had been exchanged at the time of acetabular revision. Of the remaining 114 hips, one femoral component required revision for aseptic loosening and one for sepsis. Three other well-fixed femoral components were removed during acetabular revision. Complete clinical and radiological follow-up was obtained in the 109 hips which had not had revision. Clinically, 94 (87%) were rated good or excellent, eight (7%) fair and seven (6%) poor. The average Harris hip score increased from 48 before operation to 88 at the time of the last follow-up. Radiologically, 103 hips (94%) had fixation by bone ingrowth, three (3%) showed stable fibrous ingrowth and three (3%) were unstable. Osteolysis of the fomoral cortex was seen in seven hips (6%), with major lysis in only one. At a mean follow-up of ten years, the results of the Taperloc femoral component are comparable with those of modern techniques of cementing in primary total hip arthroplasty.

Artekeiskeanin A: a new coumarin-monoterpene ether from Artemisia keiskeana

A new coumarin-monoterpene ether, artekeiskeanin A (1) and two known coumarins, dracunculin (2) and scopoletin (3) were isolated from the aerial parts of Artemisia keiskeana. The structure of 1 was determined to be 7-(trans-8-oxogeranyloxy)-6-methoxycoumarin on the basis of spectroscopic studies.

Use of statistical analysis of cytologic interpretation to determine the causes of interobserver disagreement and in quality improvement

BACKGROUND

Disagreements in cytologic interpretation can have several causes, including differences in diagnostic threshold and diagnostic accuracy. These can be distinguished by a combination of statistical analyses.

METHODS

For demonstration purposes, a nonrandom collection of 80 cervicovaginal smears, the majority of which (74) were originally diagnosed as atypical cells of undetermined significance (ASCUS), were reviewed by 3 separate observers and classified as either negative, negative and reactive, ASCUS favor reactive, ASCUS not otherwise specified, ASCUS suggestive of a squamous intraepithelial lesion (SIL), low grade SIL, or high grade SIL. The results were compared with corresponding biopsies and analyzed with distribution analysis, the kappa statistic, threshold analysis, and receiver operating characteristic (ROC) curve analysis.

RESULTS

Distribution analysis of diagnoses from the three observers demonstrated statistically significant differences in how cases were classified and a low level of agreement. Kappa analysis confirmed a very poor interobserver agreement. Threshold analysis revealed that one observer used a threshold between negative and ASCUS that was statistically more specific but less sensitive than the other observers. ROC curve analysis showed that another observer was more accurate than this observer.

CONCLUSIONS

Variation in cytologic interpretation may have several causes. Distribution, threshold, and ROC analysis allow distinction between differences in diagnostic accuracy and diagnostic thresholds. This approach to analyzing cytologic interpretation may be useful for quality improvement efforts.

Comparison of conventional Papanicolaou smears and a fluid-based, thin-layer system for cervical cancer screening

OBJECTIVE

To compare the cytologic diagnoses and specimen adequacy of a fluid-based, thin-layer preparation and conventional Papanicolaou tests.

METHODS

A total of 7360 women from six separate sites-three screening centers and three hospitals-participated in split-sample/matched-pair, double-masked clinical trials. A conventional Papanicolaou test was performed, after which residual material on the sampling device was rinsed into a fluid preservative from which a thin-layer slide (ThinPrep) was prepared using the ThinPrep 2000 automated slide processor (Cytyc Corp., Boxborough, MA). Conventional and ThinPrep slides were read independently. Cytologic diagnoses and specimen adequacy were classified using the Bethesda system.

RESULTS

For the three screening centers, 65% more diagnoses of low-grade squamous intraepithelial lesions and higher were made on the ThinPrep slides (P < .001); for the three hospital centers, 6% more of these diagnoses were made with the ThinPrep method (P = .294). Comparison of specimen adequacy showed a significant increase in satisfactory specimens and a reduction in the number of "satisfactory but limited by" specimens using the ThinPrep method (P < .001).

CONCLUSION

The fluid-based, ThinPrep method of sample preparation resulted in a statistically significant increase in cytologic diagnosis of cervical cancer precursors and in specimen adequacy compared with the conventional Papanicolaou testing method.

Seizures induced by intracerebral injection of thrombin: a model of intracerebral hemorrhage

The coagulation cascade plays an important role in brain edema formation caused by intracerebral blood. In particular, thrombin produces brain injury via direct brain cell toxicity. Seizures and increased cerebral electrical activity are commonly associated with intracerebral blood and are possible effects of thrombin leading to cell injury in the brain. In this study, artificial clots containing concentrations of thrombin found in hematomas were infused intracerebrally in rats. The animals were observed clinically for seizure activity, behavior, and neurological deficits. Several animals underwent video electroencephalographic (EEG) monitoring during intracerebral infusion and for 30 minutes postinfusion. All animals were killed 24 hours after injection, and brain water and ion contents were measured to determine the amount of brain edema. Clinically, thrombin produced focal motor seizures in all animals. None of the control animals or those receiving N[alpha]-(2-Naphthalenesulfonyl-glycyl)-4-amidino-DL-phenylalanine -piperidide (alpha-NAPAP), a thrombin inhibitor added to the thrombin, showed clinical evidence of seizures. Of the rats undergoing EEG monitoring, all animals receiving thrombin showed electrical evidence of seizure activity, whereas none of the control animals exhibited seizure activity. There was no evidence of seizure activity on EEG monitoring when alpha-NAPAP was injected along with the thrombin. In addition, the artificial clots containing thrombin produced agitation and a circling tendency in the rats, along with brain edema. These results indicate that the coagulation cascade is involved in seizure production and increased brain electrical activity, which contribute to the neurological deficits and brain edema formation that are seen with intracerebral hemorrhage.

Accuracy of fine needle aspiration in distinguishing subtypes of renal cell carcinoma

OBJECTIVE

To evaluate the cytologic features of each subtype of renal cell carcinoma (RCC) for separating the various subtypes.

STUDY DESIGN

Thirty-eight renal fine needle aspiration (FNA) specimens with surgical resection follow-up were retrospectively reviewed and classified without knowledge of the resection specimen diagnosis. These included 18 clear cell RCCs, 8 papillary RCCs, 4 oncocytomas, 2 chromophobe RCCs, 2 sarcomatoid RCCs and 4 metastases to the kidney.

RESULTS

Seventy-four percent of the primary renal lesions were correctly classified. All 4 oncocytomas and the 2 chromophobe tumors were correctly classified, while both sarcomatoid RCCs and 3 of 8 papillary RCCs were misclassified as clear cell RCC. One clear cell RCC was misclassified as papillary type. Two clear cell and one papillary RCC were nondiagnostic; in each case the tumor had a prominent cystic component. All four metastases were correctly identified.

CONCLUSION

Subclassification of RCC by FNA is relatively accurate. In this study, the most common error was to misclassify papillary and sarcomatoid RCC as clear cell RCC.

Wear of polyethylene acetabular components in total hip arthroplasty. An analysis of one hundred and twenty-eight components retrieved at autopsy or revision operations

We evaluated the rates of volumetric wear and the patterns of wear of 128 acetabular components retrieved during an autopsy or a revision operation between one and twenty-one years after total hip arthroplasty. Twenty-two all-polyethylene components were retrieved at autopsy from hips that had been functioning well at the time of death (Group A). The remaining 106 components--eighty-four all-polyethylene components (Group B) and twenty-two metal-backed components (Group C)--were retrieved during revision operations. All 128 components had been inserted with cement. The mean rate of volumetric wear, determined directly with a fluid-displacement method, was thirty-five cubic millimeters per year (range, eight to 116 cubic millimeters per year) for Group A, sixty-two cubic millimeters per year (range, eight to 256 cubic millimeters per year) for Group B, and ninety-four cubic millimeters per year (range, twelve to 284 cubic millimeters per year) for Group C. Multivariate regression analysis showed a significant relationship (p < 0.05) between the size of the femoral head and the calculated mean annual rate of volumetric wear. The rate of volumetric wear was highest in association with thirty-two-millimeter femoral heads and lowest in association with twenty-two-millimeter heads; according to linear regression analysis, this represented a 7.5 per cent increase (Group A) or a 10 per cent increase (Group B) in the rate of wear for every one-millimeter increase in the size of the head. Linear regression analysis also showed a significant relationship between the duration that the implant had been in situ and the rate of wear (p < 0.05), with the rate being highest initially after the operation and decreasing with an increasing duration in situ. With the numbers available, the patient's age and gender and the side of the arthroplasty did not have a significant relationship to the annual rate of volumetric wear. Increased thickness of the polyethylene was related to a decreased rate of wear (p < 0.05) in the group of metal-backed components, which had a 25 per cent increase in the rate of wear for every one-millimeter decrease in thickness, but not in the other groups. The estimated median annual rates of wear, after adjustment of confounding variables to a hypothetical constant set of median values for the parameters (duration in situ, 132 months; diameter of the femoral head, twenty-six millimeters; and thickness of the polyethylene, eight millimeters), were significantly different among the three groups of components (p < 0.05). Histological evaluation of the worn surfaces showed the predominant mechanisms of wear to be abrasion and adhesion rather than fatigue-cracking or delamination. The highly worn areas were polished to a glassy finish on gross examination, but scanning electron microscopy showed numerous multidirectional scratches along with fine, drawn-out fibrils with a diameter of one micrometer or less oriented parallel to each other. These fibrils are the most likely source of submicrometer wear particles. Thus, wear appeared to occur mostly at the surface of the components and to be due to large-strain plastic deformation and orientation of the surface layers into fibrils that subsequently ruptured during multidirectional motion.

Koilocytotic atypia in Papanicolaou smears. Reproducibility and biopsy correlations

BACKGROUND

It would be useful if cervical smears containing koilocytes alone could be reliably separated from those containing other forms of nuclear atypia within the spectrum of low grade squamous intraepithelial lesions (LSIL) and that this separation was predictive of differences in biopsy follow-up. In this article, the authors sought to test this possibility.

METHODS

Consecutive smears diagnosed as LSIL from 140 patients who had follow-up colposcopic biopsies were reviewed independently by three observers. The inter- and intraobserver reproducibility in diagnosing smears with koilocytes alone was assessed by the kappa statistic. Comparison of each reviewer's cytologic diagnosis with a reviewed biopsy diagnosis was assessed using chi-square analysis. The quantity of abnormal cells was compared with the presence or absence of a lesion on biopsy.

RESULTS

Kappa values for any 2 observers agreeing on koilocytosis as a separate category ranged from 0.22-0.47 (poor to good). Intraobserver reproducibility across all cytologic categories ranged from 0.35-0.62 (poor to good). A cytologic diagnosis of koilocytosis predicted a lower rate of high grade SIL (HSIL) on initial biopsy for one of the observers, but not for the other two. Koilocytosis did not predict a lower rate of LSIL on initial biopsy or HSIL in follow-up biopsies for any observer. The quantity of cells on the initial smear did not correlate with a lesion on biopsy.

CONCLUSIONS

Separation of LSIL into two diagnostic categories is not feasible because of its poor cytologic reproducibility and inability to predict differences in biopsy diagnosis. The quantity of abnormal cells in LSIL is not predictive of the detection of a lesion on biopsy.

Mechanisms of edema formation after intracerebral hemorrhage: effects of thrombin on cerebral blood flow, blood-brain barrier permeability, and cell survival in a rat model

Recently, the authors showed that thrombin contributes to the formation of brain edema following intracerebral hemorrhage. The current study examines whether the action of thrombin is due to an effect on cerebral blood flow (CBF), vasoreactivity, blood-brain barrier (BBB) function, or cell viability. In vivo solutions of thrombin were infused stereotactically into the right basal ganglia of rats. The animals were sacrificed 24 hours later; CBF and BBB permeability were measured. The actions of thrombin on vasoreactivity were examined in vitro by superfusing thrombin on cortical brain slices while monitoring microvessel diameter with videomicroscopy. In separate experiments C6 glioma cells were exposed to various concentrations of thrombin, and lactate dehydrogenase release, a marker of cell death, was measured. The results indicate that thrombin induces BBB disruption as well as death of parenchymal cells, whereas CBF and vasoreactivity are not altered. The authors conclude that cell toxicity and BBB disruption by thrombin are triggering mechanisms for the edema formation that follows intracerebral hemorrhage.

Papanicolaou smear sensitivity for adenocarcinoma in situ of the cervix. A study of 34 cases

The sensitivity of cervical smears for adenocarcinoma in situ (AIS) is not known, nor is it known whether false-negative smears are due to sampling or to screening or interpretive errors. In 16 of 34 patients with AIS, 38 negative smears were reported 2 weeks to 7 years before biopsy. Thirty-one of these negative smears were rescreened, and 17 (55%) were retrospectively diagnosed as abnormal. Ten of the 17 had numerous well-preserved AIS cells: 5 with very small, crowded AIS cells, possibly originally mistaken for endometrial cells, and 5 with large groups in which AIS cells resembled reactive endocervical cells. Four smears were confirmed sampling errors. The sensitivity of cervical smears for AIS was 55% to 72%. Improved sampling of the endocervical canal offers cytologists the opportunity to diagnose AIS. This study demonstrates that this opportunity may not be fully exploited. Small "endometrioid" AIS cells and AIS cells resembling reactive endocervical cells may be mistaken for benign cells, thus decreasing sensitivity.

Hemodynamic response to intentionally altered flow continuity of dobutamine and dopamine by an infusion pump in infants

STUDY OBJECTIVE

To evaluate the effect of an intentional alteration in infusion pump flow continuity on the hemodynamic stability of infants receiving either dobutamine or dopamine.

DESIGN

Prospective, open-label study.

SETTING

A university-affiliated children's hospital.

PATIENTS

Ten hemodynamically stable infants (age 2 wks-10 mo) in intensive care receiving dobutamine (5) or dopamine (5). Three patients received both agents and were studied at independent times.

INTERVENTIONS

Dobutamine and dopamine were administered using the Flo-Gard VP pump that delivers an intentional alteration of flow continuity (rate pulse). Heart rate and mean arterial pressure (MAP) were recorded every second. Analysis was based on the measurements obtained from the first 5 minutes on the study pump and the 2 minutes before and after the rate pulse.

MEASUREMENTS AND MAIN RESULTS

Although hemodynamic changes in pre- and post-rate pulses were statistically significant (p < 0.05) in some individuals, only one infant had a greater that 10% change in MAP 2 minutes after the rate pulse. Alterations in hemodynamics were not consistent among or within patients.

CONCLUSION

In infants requiring dobutamine or dopamine, no clinically significant pharmacodynamic effects were associated with alteration in continuity of drug delivery caused by the single positive rate pulse. Therefore, we conclude there is no contraindication to the use of this infusion pump in hemodynamically stable infants receiving these drugs.

Evaluation of the ThinPrep processor for fine needle aspiration specimens

OBJECTIVE

To test the ThinPrep Processor for fine needle aspiration.

STUDY DESIGN

One hundred unfixed, surgically removed specimens were aspirated. One pass was directly smeared, fixed and stained with the Papanicolaou technique. The other pass was rinsed in a proprietary fixative, and a single ThinPrep slide was made. Smears were diagnosed without knowledge of the histologic diagnosis.

RESULTS

Cellularity and architectural integrity of cell groups were superior on the conventional slides. Preservation and detail of both epithelial and stromal cells were superior with the ThinPrep Processor. Preservation of background material, such as mucus and colloid, was slightly superior on the ThinPrep slides. Diagnostic sensitivity and specificity for malignancy and unsatisfactory rates were all slightly better on the ThinPrep slides.

CONCLUSION

The ThinPrep Processor offers an alternative to direct smears in situations in which expertise in slide preparation is not available.

Thrombin-soaked gelatin sponge and brain edema in rats

Previous work from this laboratory has shown that injection of thrombin into rat basal ganglia causes brain edema. This study investigates the effect on rat brain of thrombin-soaked gelatin sponge (used for intraoperative hemostasis in clinical situations) at a concentration similar to that used in humans. Three models were developed to evaluate this effect. In the first model, a gelatin sponge soaked with vehicle or thrombin (100 U/cm3) was placed on the intact pia of the right frontal lobe in rats without cortical lesions. In the second model, frontal cortex was excised (3 mm3) and the exposed brain was cauterized with electrocoagulation. Gelatin sponge was soaked with vehicle or thrombin (1000, 100, 10, or 1 U/cm3) and placed in the lesion site. In the third model, hirudin, a specific thrombin antagonist, was added to the thrombin-soaked gelatin sponge and placed in a similar cortical lesion to determine if the observed effects were specific to thrombin. The dose-response range for thrombin was determined qualitatively by magnetic resonance (MR) imaging and quantitatively by brain edema formation 24 hours after exposure. We found no edema in the cortically intact rats. The rats given cortical lesions developed significant edema when subjected to 1000, 100, and 10 U/cm3 thrombin as seen on MR imaging and at 100 and 10 U/cm3 thrombin as revealed by wet/dry weight and ion studies of brain tissue. Topical hirudin prevented thrombin-induced edema. It is concluded that thrombin-soaked gelatin sponges cause or enhance significant brain edema in rats at concentrations typically used for human neurosurgery.

The role of the coagulation cascade in brain edema formation after intracerebral hemorrhage

The coagulation cascade has a potential role in brain edema formation due to intracerebral hemorrhage. In this study blood and other solutions were injected stereotactically into the right basal ganglia in rats. Twenty-four hours following injection, brain water and ion contents were measured to determine the amount of brain edema. Intracerebral blood resulted in an increase in brain water content. The amount of brain edema surrounding the intracerebral hematoma was reduced by a thrombin inhibitor N alpha-(2-Naphthalenesulfonylglycyl)-4-amidino-DL-phenylalaninep iperidide, (alpha-NAPAP) infused into the hematoma after the clot had been allowed to solidify. The inhibitor did not alter the actual size of the clot mass. An artificial clot composed of fibrinogen, thrombin, and styrene microspheres also produced brain edema. A fibrin clot led to edema formation even in the absence of mass effect provided by the microspheres. The single component responsible for production of brain edema in all these models was thrombin. The edema was formed in response to a fibrinogen-independent pathway. These results indicate that the coagulation cascade is involved in brain edema that develops adjacent to an intracerebral hematoma.