Sequential change of heterogeneous cerebral blood blow patterns after diffuse brain ischemia

In order to provide an insight into the basic nature of ischemic brain injury, we sequentially studied cerebral blood flow with [99mTc]hexamethylpropyleneamine oxime single photon emission computed tomography (CBF imaging) in a patient with diffuse brain ischemia due to prolonged cardiac arrest. On the 10th postarrest day, concentrated blood flow over superior-medial portion of the occipital lobe was demonstrated. On the 18th postarrest day, the same region became high density on a CT scan, while the concentrated flow on the CBF imaging had diminished. Thus, an abnormal cerebral blood flow (CBF) pattern preceded the density change on CT scan. On the 23rd postarrest day, remarkably concentrated flow over the brainstem was demonstrated. This might have illustrated the reduced metabolic demand of the damaged tissue over the cerebral and cerebellar hemispheres with relative preservation of brainstem perfusion. In patients with diffuse brain ischemia, a CBF imaging may be a useful tool for clarifying pathological process and prognosis.

Cerebral infarction in a heterozygote with variant antithrombin III

BACKGROUND

We report a heterozygous case of familial qualitative deficiency of antithrombin III associated with cerebral infarction.

CASE DESCRIPTION

A 33-year-old man had a history of recurrent transient ischemic attacks from the age of 28. Cerebral computed tomography at age 29 disclosed a low-density area in the left frontal lobe, and an internal carotid angiogram showed branch occlusion of the right anterior cerebral artery and stenosis of the left middle cerebral artery. Occlusion of the right middle cerebral artery developed thereafter. The plasma antithrombin III antigen concentration and progressive antithrombin activity were normal, but plasma heparin cofactor activity was low in the patient and his father. Nucleotide sequence analysis of the proband's deoxyribonucleic acid showed no mutation in exons II and VI of antithrombin III.

CONCLUSIONS

We conclude that abnormal antithrombin III with defective heparin binding, even though heterozygous, may cause ischemic stroke in young adults. We named this antithrombin III variant "Antithrombin III Nagasaki."

Papillary craniopharyngioma of the third ventricle--case report

A papillary craniopharyngioma localized in the third ventricle occurred in a 45-year-old male. The clinical presentation was unusual and the neuroradiological appearance resembled a choroid plexus papilloma of the third ventricle. The tumor originated from the right anterolateral wall of the third ventricle, forming a discrete mass with prominent papillae formation. The tumor was totally removed by a transcallosal approach without neurological or endocrinological sequelae.

[Changes in sulfated proteoglycans in alkali injured rabbit cornea]

Morphological changes of sulfated proteoglycans (S-PGs) in the stroma of alkali injured rabbit corneas were examined electron-histochemically following cuprolinic blue (CB) dye binding. The injured eyes were followed for 2 months by slitlamp microscope and photographs. At 1 hour, 3 days, 1 week, 2 weeks, 1 month, and 2 months after the injury, the eyes were enucleated and studied. After 1 hour, while both collagen fibrils and the filaments of S-PGs had already become disarranged; the number of S-PGs appeared to decrease. From 3 days to 1 week after, the number as well as the electron-density of S-PGs were markedly decreased in all areas. After 2 weeks, CB-positive large filaments appeared in anterior stroma. These became larger, more abnormal in shape, and displayed a higher electron density 1 month later. Normally arranged S-PGs can be seen at 2 months later. It was concluded that S-PGs were diminished in alkali-injured corneas. Once they were replaced by abnormal filaments, they gradually recovered normal morphology. Further more the time course of S-PG change correlated with that of corneal transparency after alkali injury.

[Two cases of the brachiocephalic artery avulsion due to blunt chest trauma]

Two young adult patients with brachiocephalic avulsion due to blunt trauma are reported. Both of them were brought to the emergency room of St. Marianna University Hospital with the blunt chest trauma and lung contusion due to the traffic accident. A widening of the superior mediastinum and mediastinal hematoma surrounding the major branches of the aortic arch were demonstrated on chest roentgenogram and contrast enhanced CT scan, however, these evidences were not valuable for the diagnosis. Aortogram revealed an aneurysmal dilatation at the origin of the brachiocephalic artery in the first case and at its distal portion in the second case. Emergency operation was performed under the simple cross clamp of the brachiocephalic artery without any adjunct means. In the first case, 10 mm knitted Dacron graft was interposed between the ascending aorta and distal segment of the brachiocephalic artery. In the second case, the brachiocephalic artery was replaced with 10 mm knitted Dacron graft. The postoperative course was uneventful and no neurological deficit was noted in these cases.

[Fourier analysis of pattern visual evoked potentials and changes of the harmonic component in longstanding optic neuritis]

To determine the clinical usefulness of Fast Fourier Transform (FFT) for the detection of abnormal pattern visual evoked potentials (P-VEPs), the P-VEPs were recorded using a checkerboard pattern (check size: 14.4') which was reversed ranging from 4 to 16 per second. Fourteen eyes of 7 patients with longstanding optic neuritis and 15 eyes of age-matched normal controls were examined. Means and the standard deviation of the square root of the FFT power as a function of spectral frequency (1.953 x fHz, f = 1-17) were calculated and statistically significant levels between the two groups were studied for each reversal rate. When the reversal rate was more than 8/sec, The 1st or 2nd harmonic components decreased significantly in optic neuritis and the significant levels (p) of the 1st harmonic component were lower than that (p) of 2nd or 3rd harmonic component. When the reversal rate was 6/sec, the 1st and 2nd harmonic components decreased significantly and 1st harmonic component had the same level of significance as the 2nd harmonic component. When the reversal rate was 4/sec, the 2nd, 3rd, 5th and 6th harmonic components decreased significantly but 1st harmonic component did not. The level of significance of the 3rd harmonic component was the lowest followed by that of 2nd harmonic component.(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of cerebral blood circulation using fast magnetic resonance imaging (turbo-FLASH)]

In its initial stage of development, poor time resolution was supposed to be inevitable for magnetic resonance imaging (MRI). The development of the gradient echo technique, however, has made an opening for a breakthrough to a fast MRI technique. However, conventional gradient echo technique is not fast enough to disclose the cerebral blood circulation. A new technique (turbo-FLASH), which combines gradient echo and preparation pulse, has opened the door to a true dynamic (high time resolution) MRI. The authors performed a basic study of this new fast imaging technique (Turbo-FLASH) for the evaluation of cerebral blood circulation. Using this dynamic MRI, the conventional Gd-DTPA administration (0.1mmol/kg, intravenous manual administration) has produced sufficient contrast to reveal a difference of the extent of enhancement between normal gray matter and white matter. In patients of cerebral infarction, the infarcted brain does not show any significant increase of signal intensity after the administration of contrast medium, whereas the normal brain shows a sharp increase of signal intensity after the administration of contrast medium. Indeed, many puzzling questions remain to be solved for clinical application of this new dynamic MRI. For example, the optimal quantity of contrast medium and optimal parameters for this sequence (T1 weighted or T2 weighted?) are still unknown. But, in any case, this dynamic MRI is expected to be a clinically powerful tool for the evaluation of cerebral blood flow.

Ocular convergence-related neuronal responses in the lateral suprasylvian area of alert cats

Neuronal spike discharges were recorded from the lateral suprasylvian (LS) area while ocular convergence was elicited in five alert cats. Ocular convergence was elicited by presenting a visual target moving in depth. Cats were rewarded for convergence eye movement. In 9 out of 426 cells sampled in the caudal postero-medial LS area, the number of spikes was positively correlated with the peak eye velocities during ocular convergence. Significant correlation was found mostly within 400 ms preceding the moment at which the maximum velocity of ocular convergence was obtained. The result favors the hypothesis that the LS area plays an important role in the integrative control of ocular convergence.

In vivo administration of tolmetin in hyaluronic acid modulates protease levels in postsurgical macrophage-conditioned media

Tolmetin sodium in a hyaluronic acid carrier (tolmetin-HA) was previously shown to reduce adhesion formation and alter the kinetics and levels of cellular influx into the peritoneal cavity after surgery. In this study, the effect of tolmetin-HA on the level of protease activity in macrophage-conditioned media was determined. The level of collagenase activity in macrophage-conditioned media was suppressed at 12 and 24 h after administration of tolmetin-HA. Alternatively, the peak level of elastase activity measured in macrophage-conditioned media was unchanged after tolmetin-HA treatment, but the kinetics of expression of maximal protease activity was delayed from 12 h in the control surgical rabbits to 24 h in tolmetin-HA-treated rabbits. Elevated plasminogen activator activity was detected in acid-treated conditioned media from the tolmetin-HA-treated rabbits when compared to control levels. However, no alteration in the level of plasminogen activator inhibitor activity was present in conditioned media of macrophages harvested from tolmetin-HA-treated rabbits compared to controls. These data suggest that tolmetin-HA treatment altered the levels of neutral protease activity secreted by postsurgical macrophages and may therefore elevate the fibrinolytic potential of the peritoneal cavity after surgery.

[Clinical application of phase contrast angiography]

"Phase Contrast Angiography" is a new technique of Magnetic Resonance Angiography as reported by Dumoulin CL et al. Using this technique, we can obtain images of vessels (angiograms) without injection of contrast medium. We present the results of phase contrast angiography on cerebral and spinal vascular disease. We utilized the General Electric SIGNA, 1.5 tesla NMR. One hundred and ninety-one cases of cerebral and spinal vascular diseases were scanned using phase contrast angiography. Included were 90 cases of occlusive vascular disease, 16 cases of moyamoya disease, 39 cases of arteriovenous malformation, and 28 aneurysms. The phase contrast angiography uses flow encoding gradient pulses, which impart a velocity-dependent phase shift to the transverse magnetization of moving spins. The resulting image contains only information from the moving spins; while information from stationary tissue remains suppressed. In cases using 3-D angiogram, we made 32 images 6 degrees apart in their projection direction and displayed them on a video terminal. We were able to visualize occlusions of vessels, aneurysms, bypassed vessels, and abnormal vessels of arteriovenous malformations. Retrospective evaluation comparing phase contrast angiography with conventional angiography of the stenotic findings on the horizontal portion of middle cerebral arteries (64 vessels of 32 patients), resulted in a false positive ratio of 39.1%. We obtained clinically valuable results regarding the hydrodynamics of patients using "phase contrast angiography" non-invasively. These results reveal not only "anatomical" images of vessels, but also "functional" images, which are sensitive to the pattern of the blood flow. This study would strongly suggest that phase contrast angiography presents a valuable tool for the clinical diagnosis of cerebral and spinal vascular diseases.

Electrophysiologic changes before onset of ventricular tachyarrhythmias during partial reperfusion following severe myocardial ischemia in dogs

We examined the electrophysiologic changes before an onset of ventricular tachyarrhythmia during partial reperfusion following severe myocardial ischemia. The left anterior descending coronary artery was occluded and cannulated below the occluded portion in 26 dogs. To deplete collateral flow into the ischemic myocardium, retrograde blood flow was induced for 20 min. Then, in all dogs except 7 with ventricular fibrillation during retrograde blood flow, partial reperfusion through collateral flow into the ischemic myocardium was produced by stopping the retrograde flow. Within 2 min of partial reperfusion, sustained ventricular tachycardia (VT) occurred in 7 dogs (group A) and non-sustained VT degenerating ventricular fibrillation occurred in 11 dogs (group B) of the remaining 12 dogs. In 6 dogs of group A and 9 of group B, epicardial conduction block appeared 5.0 +/- 2.2 and 3.5 +/- 1.3 min after ischemia. This was followed by fractionated electrical activities 15.2 +/- 3.2 and 11.7 +/- 3.3 min after ischemia. In group A, the fractionation had a slight change in configuration and a small increase in amplitude before the onset of VT during reperfusion; in group B, new deflections with large amplitude emerged before it. There was a significant difference in the amplitude (0.38 +/- 0.2 vs 0.67 +/- 0.3 mV, p < 0.025) between the 2 groups, although there was no significant difference in the amplitude (0.33 +/- 0.2 vs 0.23 +/- 0.1 mV) of the fractionation just before reperfusion. Our results show that slight improvement in fractionation induces sustained VT, and new deflections induce non-sustained VT degenerating ventricular fibrillation, even during partial reperfusion.

Developmental changes in expression of a calcium-binding protein (spot 35-calbindin) in the Nervus terminalis and the vomeronasal and olfactory receptor cells

The detailed localization of spot 35-calbindin and its ontogenic change were studied in Nervus terminalis, the vomeronasal organ and the olfactory epithelium of the rat by immunohistochemistry. At the embryonic days 12 and 13 (E 12-13), calbindin-immunoreactive cells were found in the outermost layer of the presumptive olfactory bulb and within the olfactory placode. At E 14 to the postnatal day 1 (P 1), intense calbindin-immunoreactivity was localized in ganglionated fiber bundles of Nervus terminalis coursing through the mesenchymal spaces on both sides of the nasal septum. Nervus terminalis decreased the immunoreactivity abruptly after P 1 and it showed no distinct immunoreactivity for calbindin at P 7 and thereafter. On the other hand, numerous receptor cells in the olfactory epithelium and the thicker vomeronasal epithelium exhibited weak to moderate immunoreactivity for calbindin at E 18-P 1. Their immunoreactivity decreased in intensity progressively after P 7 and no distinct immunoreactivity for calbindin was detected in most of the receptor cells, whereas moderate immunoreactivity was detected in most of the vomeronasal and olfactory nerves at P 28 and P 63.

[Pseudocoarctation associated with dissecting aneurysm of the aorta: a case report]

A case of pseudocoarctation with dissecting aneurysm of the ascending aorta and arch is reported. A 49-year-old man was admitted with chest pain and loss of consciousness. Angiogram showed kinking of the aortic isthmus and dissecting aneurysm of the ascending aorta. There was no pressure gradient between arms and legs. Prosthetic graft replacement of the ascending aorta was successfully performed by the use of total cardiopulmonary bypass with moderate hypothermia. Etiology of the development of pseudocoarctation is unknown, however, hypothesis that embryological abnormality of the aortic arch is one of the contributing factors has been widely accepted. This case was accompanied by bicuspid aortic valve. It is suggested that the developmental etiology of this case seems to be similar to that of classical coarctation of the aorta. Development of the dissecting aneurysm is supposed to be due to hypertension of the upper body during exercise, even though there is no pressure gradient at rest.

Cavernous angioma of the cerebellum and cerebellar atrophy--case report

A cavernous angioma of the cerebellum occurred in a 55-year-old female presenting with a 3-year history of slowly progressive cerebellar signs and symptoms. Computed tomography and magnetic resonance imaging revealed a lesion in the left cerebellar nuclei and atrophic change of the affected cerebellar hemisphere. The final diagnosis was made at operation. The cerebellar nuclei and white matter were probably affected by the slowly expanding lesion, with repeated hemorrhage leading to degeneration of the afferent and efferent fibers, and subsequent atrophy of the affected cerebellar hemisphere.

Magnetic resonance findings in spontaneous dissection of the cervical internal carotid artery--case report

The magnetic resonance (MR) appearance of a spontaneous dissection of the cervical internal carotid artery (ICA) in a 53-year-old male is described. Cerebral angiograms demonstrated a long-segment stenosis of the left cervical ICA beginning above the common carotid bifurcation and extending to the skull base ("string sign"). T1-, T2-, and proton density-weighted MR images of the upper neck revealed a high-intensity crescent mass expanding the arterial wall and narrowing the arterial lumen of the left ICA. This high-intensity mass was considered to represent the mural hematoma of the involved ICA. Gradual improvement of the dissection was confirmed by both angiography and MR imaging. Cerebral angiograms have shown pathognomonic findings such as double lumen and intimal flap in only some patients with ICA dissection. Our experience suggests that MR demonstration of the mural hematoma is specific and important for diagnosis and follow-up in cases of spontaneous dissection of the cervical ICA.

Acute depressor effect of alcohol in patients with essential hypertension

To investigate the time course of the effects of alcohol on blood pressure, we studied the response of ambulatory blood pressure, neurohumoral variables, and hemodynamics to a single moderate dose of alcohol in hypertensive patients. Sixteen Japanese men (22-70 years old) with essential hypertension who were habitual drinkers were examined under standardized conditions. On the alcohol intake day, they ingested 1 ml/kg ethanol (vodka) at dinner, and on the control day they consumed a nonalcoholic beverage. The order of the two periods was randomized. Mean ambulatory blood pressure was lower in the alcohol intake period than in the control period (125 +/- 3/74 +/- 2 versus 132 +/- 4/78 +/- 2 mm Hg, p less than 0.05), and the significant depressor effect of alcohol lasted for up to 8 hours after drinking. Blood pressure on the next day did not differ with or without alcohol intake. The acute hypotensive effect of alcohol was associated with an increase in heart rate and cardiac output and with a decrease in systemic vascular resistance as determined by echocardiography. Plasma catecholamine levels and renin activity rose significantly at 2 hours after dinner, whereas vasopressin and potassium levels fell on the alcohol day. Blood glucose and serum insulin levels were comparable between the two periods. Three patients with marked alcohol-induced flush had greater hypotensive and tachycardiac responses than those who did not show an alcohol-induced flush. The change in mean blood pressure induced by alcohol was negatively correlated with age, the baseline blood pressure, and the change in plasma norepinephrine. These results indicate that the major effect of acute alcohol intake is to lower blood pressure through systemic vasodilatation in hypertensive subjects. Ambulatory blood pressure monitoring may be useful for assessing blood pressure in habitual drinkers.

Production of antiserum to [D-Ala2]deltorphin I and its immunohistochemical application to the mouse brain

Antiserum to haptenic [D-Ala2]deltorphin I (DADTI: Tyr-D-Ala-Phe-Asp-Val-Val-Gly.NH2), a highly selective ligand for delta opioid receptors, was produced in rabbits. By immunospot assay, the antiserum recognized 62.5 pmol DADTI but failed to react even with 4 nmol carrier protein of the immunogen. Although the antiserum reacted equally with an isomer [L-Ala2]deltorphin I, virtually no cross-reaction occurred with other analogues such as [D-Ala2]deltorphin II (Tyr-D-Ala-Phe-Glu-Val-Val-Gly.NH2) and similar peptides lacking the C-terminal glycine amide. Therefore, the major epitope for immunorecognition appeared to be in the C-terminal region which is known to be the specific domain for delta opioid receptor selectivity. Immunohistochemical study using this antiserum revealed positive neuronal structures in some specific systems of the mouse brain.

Argyrophilic glial intracytoplasmic inclusions in multiple system atrophy: immunocytochemical and ultrastructural study

Argyrophilic intracytoplasmic inclusions in oligodendrocytes (AGCIs) were seen in all of 15 cases of multiple system atrophy (MSA), and none in other neurodegenerative diseases, including 9 cases of Menzel-type olivopontocerebellar atrophy and 4 cases of Joseph's disease. The inclusions were widespread, not only in the olivopontocerebellar and striatonigral systems but also among fibers connecting their affecting lesions of MSA. Immunohistochemically, they were closely associated with tau, tubulins and microtubule-associated protein 5. Ultrastructurally, they consisted of 30- to 50-nm filaments (not tubules) and electron-dense granules, in varying proportions, and their formation is discussed. The specific occurrence of AGCIs could be a key to approach the pathogenesis of MSA.

Localization of gene expression of calreticulin in the brain of adult mouse

The localization of gene expression of calreticulin, a calcium-binding protein in the endoplasmic reticulum, was examined throughout the entire brain of adult mice by in situ hybridization. Calreticulin mRNA is expressed widely and heterogeneously in discrete neurons throughout the brain, but the white matters expressed it weekly or faintly. In the olfactory bulb, the mRNA is expresses moderately in the mitral cells, but weakly in the periglomerular cells and internal granule cells. In the cerebrum, the gene is expressed intensely in the piriform cortex, but weakly in neocortex, the entorhinal cortex and the amygdaloid nuclei. In the hippocampal formation, calreticulin mRNA is expressed intensely in the CA1-CA3 regions but less intensely in the granule cells of the dentate gyrus. The caudate-putamen, thalamic and hypothalamic nuclei, and mammillary nuclei express the mRNA weakly or faintly. In the mesencephalon, pons and medulla, moderate expression of the mRNA is detected in the pontine nuclei and the locus ceruleus. Weak expression of the mRNA is detected in several discrete nuclei and zones such as the substantia nigra, the superior colliculus and the central gray. Expression signals of calreticulin mRNA are faint in the inferior olive. In the cerebellum, calreticulin mRNA is expressed moderately in the Purkinje cells whereas no significant expression is detected in the granule cells. The plexus choroideus of the lateral, third and fourth ventriculi express calreticulin mRNA intensely although no distinct expression of the mRNA is discerned in the ependyma.

Incidence of Paneth cells in minute tubular adenomas and adenocarcinomas of the large bowel

This study attempted to demonstrate the incidence of Paneth cells within large bowel tubular adenoma and adenocarcinoma according to location and macroscopic appearance using minute tumors (up to 5 mm in size). We have shown that Paneth cells were sometimes seen in the early stage of the development of large bowel epithelial neoplasia. According to the macroscopic appearance (elevated or depressed type), in large bowel epithelial neoplasia, there was a statistical difference between the depressed type (32.5%, 14 of 40 cases) and the elevated type (16.6%, 24 of 145 cases) (Chi square analysis, p < 0.05) in the incidence of Paneth cells. Paneth cells were seen more frequently in adenocarcinoma (45.8%, 11 of 24 cases) than in tubular adenoma (16.8%, 27 of 161 cases), with a significant statistical difference (Chi square analysis, p < 0.01). According to location, in both tubular adenoma and adenocarcinoma, Paneth cells were more frequently observed in the proximal colon (tubular adenoma: p < 0.01, adenocarcinoma: p < 0.05, Chi square analysis).

Mouse mammary tumor virus gene expression is suppressed by oligomeric ellagitannins, novel inhibitors of poly(ADP-ribose) glycohydrolase

Oligomeric ellagitannins (nobotanins B, E, and K) were found to be potent inhibitors of poly(ADP-ribose) glycohydrolase purified from mouse mammary tumor 34I cells. Kinetic analysis revealed that the inhibition of nobotanin B (dimer) was competitive with respect to the substrate poly(ADP-ribose), whereas nobotanin E (trimer) and nobotanin K (tetramer) exhibited mixed-type inhibition. These results suggest that the dimeric structure of ellagitannin may have a functional domain that competes with poly(ADP-ribose) on the poly(ADP-ribose) glycohydrolase molecule. To determine the inhibitory effects of oligomeric ellagitannins on poly(ADP-ribose) glycohydrolase in vivo, we examined their effects on de-poly(ADP-ribosyl)ation of some chromosomal proteins in intact 34I cells that was induced by glucocorticoid treatment. Nobotanin B caused concentration-dependent inhibition of glucocorticoid-induced de-poly(ADP-ribosyl)ation of HMG 14 and 17 and histone H1 in intact 34I cells. Interestingly, this inhibition was associated with suppression of the glucocorticoid-sensitive mouse mammary tumor virus (MMTV) mRNA synthesis. In contrast, nobotanin E and K had little inhibitory effect on either de-poly(ADP-ribosyl)ation of these proteins or induction of MMTV transcription after glucocorticoid treatment. Nobotanin B but not E and K was taken into 34I cells. These results may suggest that the suppression of glucocorticoid-sensitive MMTV transcription results from in vivo inhibition of poly(ADP-ribose) glycohydrolase by nobotanin B. These results also indicate the importance of de-poly(ADP-ribosyl)ation of HMG 14 and 17 and histone H1 in regulation of transcription of the glucocorticoid-sensitive MMTV gene.

The efficiency of new leukocyte removal filters. CF-1 and CF-2

Two new leukocyte removal filters, Nipro CF-1 and CF-2 (Nipo Medical Industries, Osaka, Japan), were evaluated. These non-woven polyester filters, which are gravity flow devices that require no priming and no rinsing after use, were developed for preparing 400 ml of whole blood or red cell concentrates from 400 ml of whole blood. A flow cytometric technique was developed to measure extremely low white blood cell (WBC) counts. To evaluate the efficiency of these filters, leukocyte counts were measured by three techniques: 1) electronic, 2) visual, and 3) flow cytometry. Flow cytometric counting was done using a Coulter EPICS-C cytometer (Coulter Corp., Hialeah, FL). Nipro CF-1 removed 99.97 +/- 0.01% (mean +/- SD, n = 14) of leukocytes measured by flow cytometry, and CF-1 recovered 90.7 +/- 4.47% (n = 21) of red blood cells. After filtration through CF-2, more than a 6 log10 (> 99.9999%) depletion of WBCs was detected in six samples, a 6 log10 (99.9999%) depletion of WBCs was detected in two samples, a 5 log10 (99.999%) depletion was detected in five samples, and a 4 log10 (99.99%) depletion was detected in one sample. CF-1, in which size and priming volume was smaller than other commercial leukocyte removal filters, accomplished a 3 log10 reduction in WBC count, compared with other commercial filters. CF-2 achieved a 4-6 log10 depletion of WBCs assayed by flow cytometry.