Multicenter study of the treatment of erectile dysfunction with transurethral alprostadil (MUSE) in Korea

A Korean multicenter study was conducted to assess the effectiveness of transurethral alprostadil with MUSE in 334 subjects with chronic erectile dysfunction (ED) who were enrolled in 21 clinical centers. Patients with psychogenic impotence comprised about 30% of subjects. Intraurethral alprostadil was titrated in a stepwise fashion in the clinics from 250 to 500 or 1000 mcg based on erectile response and tolerability. The erectile responses were evaluated using an erection assessment scale (score of 1-5). The dose that produced a maximal penile response of score 5 (full rigid erection) or 4 (full tumescence, partial rigidity) was selected for home treatment. Patients who showed partial erection (score of 3) with 1000 mcg were also included in the home-treatment group. In-clinic phase: 198 men (59.3%) had maximal penile responses of score 4 or 5. The rate of maximal responses was not related to patient age, etiology or duration of the ED. A total of 228 (68.3%) men progressed to home treatment. The overall level of comfort of the transurethral alprostadil was rated as uncomfortable or very uncomfortable in 12%. Home phase: During the two-month period of home treatment, 178 (78.1%) men had successful sexual intercourse at least once, and 78.2% of administrations (1976) resulted in successful intercourse. The main causes of drop-out were insufficient erectile response in 27 men (11.8%), adverse reactions (mostly penile or urethral pain) in 7 (3.1%) or both in 7 (3.1%). In conclusion, transurethral alprostadil could be a suitable treatment option for patients with ED regardless of age and etiology of ED. Efficacy in an Asian population (Korea) is comparable to that reported previously in Caucasians.

Resection of a posterior pubic symphyseal protuberance using the electrocautery device

A posterior protuberance of the pubic symphysis can make a radical retropubic prostatectomy difficult. We describe a technique using electrocautery to remove this protuberance, which can be safely and easily performed.

Similarities in function and gene structure of cytohesin-4 and cytohesin-1, guanine nucleotide-exchange proteins for ADP-ribosylation factors

Activation of ADP-ribosylation factors (ARFs), approximately 20-kDa GTPases that are inactive in the GDP-bound form, depends on guanine nucleotide-exchange proteins (GEPs) to accelerate GTP binding. A novel ARF GEP, designated cytohesin-4, was cloned from a human brain cDNA library. Deduced amino acid sequence of the 47-kDa protein contains the same structural components present in cytohesin -1, -2, and -3, including an approximately 200-amino acid Sec7 domain with an approximately 100-residue pleckstrin homology domain near the C terminus. The Sec7 domain sequence is 77% identical to those of other cytohesins. Structures of the cytohesin-4 and cytohesin-1 genes were remarkably similar, except for an extra 3-base pair (GAG) exon present in cytohesin-1. Two mRNAs with and without the 3-base pair sequence were found in brain in different ratios for cytohesin-1, -2, and -3 but not cytohesin-4. Recombinant cytohesin-4 stimulated guanosine 5'-3-O-(thio)triphosphate binding by human ARF1 and ARF5 but not ARF6. Like other cytohesins and unlike the approximately 200-kDa ARF GEPs, it was not inhibited by brefeldin A. A cytohesin-4 mRNA of approximately 3.7 kilobases, abundant in leukocytes, was not detected in most tissues. Among separated populations of blood cells, approximately 90% of CD33(+) (monocytes), 80% of CD2(+) (NK/T), and 10-20% of CD19(+) (B) cells contained cytohesin-4 mRNA by in situ hybridization. Thus, in gene structure and brefeldin A-insensitive GEP activity, cytohesin-4 resembles other cytohesins, but its tissue distribution differs considerably, consistent with a different specific function.

Two carbohydrate recognition domains of Hyphantria cunea lectin bind to bacterial lipopolysaccharides through O-specific chain

We previously identified a novel lectin cDNA from the fall webworm [Shin et al. (1998) Insect Biochem. Mol. Biol. 28, 827-837], which encodes two carbohydrate recognition domains (CRD-N and CRD-C) and is up-regulated following bacterial challenge. The lipopolysaccharide (LPS) binding activities of the recombinant CRD-N and CRD-C (rCRD-N and rCRD-C) were investigated by enzyme-linked immunosorbent assay. The LPS binding of rCRD-N and rCRD-C was pH-dependent: at pH below 6.0, they show a higher binding ability to LPS. The binding of the rCRD-N was inhibited by both D-mannose and N-acetyl-D-glucosamine, whereas the binding of the rCRD-C was inhibited only by D-mannose. The binding of both rCRD-N and rCRD-C to Escherichia coli was mainly mediated through the O-specific chain.

Three cases of pancreas allograft dysfunction

We present dincopathologic features of three cases of biopsy-proven pancreas allograft dysfunction in Korea. All patients had advanced insulin-dependent diabetes mellitus (IDDM). Case 1 was a 30-year-old woman who underwent a simultaneous pancreas-kidney transplantation. Urinary infection developed 6 days after the operation, which remitted and reappeared, when urine amylase level was normal. Since the 55th day after the operation, intermittent hematuria has persisted. Cytomegalovirus inclusions were detected on the urinary bladder and grafted duodenal mucosa. The graft was removed due to perforation of the grafted duodenum and panperitonitis. Case 2 was a 27-year-old man undergoing pancreas transplantation alone (PTA). Ten days after the transplatation, the level of 24 urine amylase decreased and the graft was not delineated by 99mTc DTPA scintigraphy. Allograft needle biopsy revealed multiple acinar cell necrosis and mild lymphocytic infiltration which were compatible with mild acute rejection. Case 3 was a 25-year-old man undergoing cadevaric PTA. Three months after the transplantation, graft was removed due to gastric perforation associated with cytomegalovirus and angiodestructive fungal infection. Various causes of pancreas allograft dysfunction can be diagnosed by needle biopsy, thus appropriate biopsy specimen should be taken using improved biopsy technique.

Structural and functional implications of a proline residue in the antimicrobial peptide gaegurin

Although it is commonly known as a helix breaker, proline residues have been found in the alpha-helical regions of many peptides and proteins. The antimicrobial peptide gaegurin displays alpha-helical structure and has a central proline residue (P14). The structure and activity of gaegurin and its alanine derivative (P14A) were determined by various spectroscopic methods, restrained molecular dynamics, and biological assays. Both P14 and P14A exhibited cooperative helix formation in solution, but the helical stability of P14 was reduced substantially when compared to that of P14A. Chemical-shift analysis indicated that both of the peptides formed curved helices and that P14 showed diminished stability in the region around the central proline. However, hydrogen-exchange data revealed remarkable differences in the location of stable amide protons. P14 showed a stable region in the concave side of the curved helix, while P14A exhibited a stable region in the central turn of the helix. The model structure of P14 exhibited a pronounced kink, in contrast to the uniform helix of P14A. Both peptides showed comparable binding affinities for negatively charged lipids, while P14 had a considerably reduced affinity for a neutral lipid. With its destabilized alpha-helix, P14 exhibited greater antibacterial activity than did P14A. Hence, electrostatic interaction between helical peptides and lipid membranes is believed to be the dominant factor for antibacterial activity. Moreover, helical stability can modulate peptide binding to membranes that is driven by electrostatic interactions. The observation that P14 is a more potent antibacterial agent than P14A implies that the helical kink of P14 plays an important role in the disruption of bacterial membranes.

Comparison of the synergistic effects of tamsulosin versus phentolamine on penile erection: in vitro and in vivo studies

In vitro and in vivo studies were performed to determine the potential use of tamsulosin (TAM) versus phentolamine (PHE) for intracavernosal injection (ICI) therapy when mixed with papaverine (PAP) and/or prostagladin E1 (PGE1) or with vasoactive intestinal polypeptide (VIP) for the treatment of erectile dysfunction. We performed isometric tension studies on rabbit (n = 15), dog (n = 5), and human (n = 10) cavernous smooth muscle strips with TAM, PAP, PHE, VIP, PGE1, and the combinations of PAP and PHE; PAP and TAM; VIP and PHE; VIP and TAM; PAP, PGE1 and PHE; and PAP, PGE1 and TAM. TAM-containing trimix (PAP 18.75 mg, PGE1 6.25 micromg, and TAM 0.875 mg per ml) or PHE-containing trimix (PAP, PGE1, and PHE 0.625 mg per ml) were also injected into the cavernous bodies of ten mongrel dogs. Among the single agents, TAM and PGE1 (only in human) had the strongest effect on the relaxation of cavernous muscles in rabbit, dog, and human strips (P<0.05). Relaxation responses to 2- or 3-drug mixtures containing tamsulosin were also significantly better (P<0.05) than PHE-containing ones in rabbit, dog, and human strips. The increase in intracavernosal pressure with a TAM-containing trimix was higher than with a PHE-containing one (0.03 ml; 81.2 vs. 75.8 mm Hg, 0.04 ml; 103.2 vs. 94.3 mm Hg), although not statistically different. The drop in systemic blood pressure was lower after injection of a TAM-containing trimix than a PHE-containing one, although not statistically different. In conclusion, tamsulosin might be a more efficacious and safer agent to use for ICI therapy than phentolamine.

Altered distribution of Pneumocystis carinii pneumonia during radiation therapy

The radiographic findings of Pneumocystis carinii pneumonia (PCP) are various. The typical findings are diffuse, bilateral, symmetric, finely granular, or reticular infiltrates. In patients taking aerosol pentamidine, atypical findings may be the first manifestation. One interesting radiologic finding of PCP is that the pneumonia may spare the irradiated lung. We report PCP developed in a patient undergoing irradiation for lung cancer. High-resolution CT revealed diffuse, bilateral, and symmetric ground-glass opacities with septal thickening in both lungs; however, the radiation port was spared and appeared as the "photographic negative of post-radiation pneumonia." The distribution of the pneumonic infiltrates was altered by radiotherapy.

Genetic architecture of species differences in annual sunflowers: implications for adaptive trait introgression

Genetic architecture may profoundly influence the ability of adaptive traits to spread between species via introgressive hybridization. Here, we examine the genomic location of quantitative trait loci (QTL) associated with pollen sterility and morphological traits distinguishing two annual sunflowers, Helianthus annuus and H. debilis ssp. cucumerifolius. These species are of particular interest since they hybridize naturally, and the form of H. annuus in Texas (called ssp. texanus) is thought to have arisen through introgression. Analysis of 226 BC(1) progeny from a cross between H. annuus and H. debilis revealed 56 QTL for 15 morphological traits and 2 QTL for pollen sterility. Four morphological QTL are tightly linked (<10 cM) to one or more sterility factors and 7 are closely allied with underrepresented and presumably negatively selected chromosomal blocks. Although these 11 QTL seem unlikely to move between the species, no barrier to introgression was detected for the remaining 45 morphological QTL. In fact, due to widespread pleiotropy (or tight linkage), the introgression of just three small chromosomal blocks appears sufficient to largely recover the phenotype of ssp. texanus. Subsequent work will test for the occurrence and fitness consequences of the identified QTL in natural populations of ssp. texanus.

Adult respiratory distress syndrome in systemic lupus erythematosus: causes and prognostic factors: a single center, retrospective study

OBJECTIVES

To determine the causes and prognostic factors of Adult Respiratory Distress Syndrome (ARDS) in patients with systemic lupus erythematosus (SLE).

METHODS

Among 544 Korean SLE patients, who were followed in the Lupus Clinic of the Catholic Medical Center from 1993 to 1997, patients diagnosed as ARDS were examined retrospectively. During the study period, non-SLE patients with ARDS were investigated and then compared to SLE patients with ARDS in terms of clinical variables.

RESULTS

Nineteen patients with SLE were revealed to have a history of ARDS (3.5%) and 13 (68.4%) of 19 patients died. Death related to ARDS was found in 34.2% of all deaths (n=38) from SLE during the study period. The frequency and causes of ARDS were as follows; 9 sepsis or bacteremia (47.4%), 2 miliary tuberculosis (10.5%), 2 invasive pulmonary aspergillosis (10. 5%), 2 acute pulmonary alveolar hemorrhage syndrome (10.5%), 1 acute lupus pneumonitis (5.3%), 1 massive hemorrhage due to placenta previa (5.3%), 1 aspiration pneumonitis (5.3%), 1 disseminated intravascular coagulation associated with systemic vasculitis (5.3%). The main organisms in sepsis were gram negative bacilli (61.5%) The median steroid dose administered 1 month before ARDS was significantly higher in patients (n=13) with infectious ARDS compared to those (n=6) with ARDS due to other causes (P=0.038). Comparison of the laboratory and clinical variables between the survivors (n=6) and the deceased (n=13) showed that the survivors had lower SLAM indices at presentation (P=0.004) and APACHE (Acute Physiology, Age, Chronic Health Evaluation) III scores within 24 h after diagnosis of ARDS (P=0.024) than the deceased. The APACHE III scores correlated well with the SLAM indices (r=0.615, P=0.007). Non-SLE patients with ARDS during the study period were selected for comparison to SLE patients with ARDS. Age at the onset of ARDS was younger in SLE (n=19) compared to non-SLE (n=190) (P<0.001). Duration from ARDS onset to death was shorter in SLE patients (P<0. 001). The mortality from ARDS tended to be higher in SLE patients (P=NS). The first-day APACHE III score was significantly higher in deceased SLE patients (n=13) compared to deceased non-SLE patients (n=105) (P=0.001).

CONCLUSIONS

ARDS was a common premortem event of SLE and showed a high fatality rate in SLE. The most common cause of ARDS in Korean patients with SLE was sepsis by gram negative bacilli. ARDS in SLE developed at a younger age, and progressed more rapidly compared to ARDS in general. The SLAM index and APACHE III score could be useful to predict the prognosis of ARDS in SLE.

The antioxidative effect of ganhuangenin against lipid peroxidation

The antioxidative effect of ganhuangenin (GHG), isolated from Scutellaria baicalensis Georgi, was examined by measuring its ability to suppress the formation of phospatidylcholine hydroperoxide (PCOOH). The results show that a pretreatment with GHG effectively suppressed PCOOH formation, which was initiated by the peroxyl-generating oxidant, AAPH (2,2'-azobis-2-aminopropane hydrochloride). The protective action of GHG against the formation of the PCOOH was observed in liver, lung, and kidney. When compared with other known antioxidants, we found the antioxidative potency of GHG to be greater than that of alpha-tocopherol. Our data strongly indicate that GHG is a powerful antioxidant against lipid peroxidation and is, therefore, responsible for this prophylactic effect.

Otomastoiditis caused by Rhodococcus equi in a patient with AIDS

Rhodococcus equi is a well-recognized pathogen in veterinary medicine and a rare but well-documented cause of cavitary pneumonia in immunocompromised patients. Most cases of Rhodococcus equi infections in these patients involve the lungs. Otomastoiditis due to Rhodococcus equi is rare, and disseminated Rhodococcus equi with otomastoiditis has never been reported. We report a case of otomastoiditis with systemic dissemination due to Rhodococcus equi in a patient with AIDS.

Molecular analysis of rice plants harboring an Ac/Ds transposable element-mediated gene trapping system

In rice, limited efforts have been made to identify genes by the use of insertional mutagens, especially heterologous transposons such as the maize Ac/Ds. We constructed Ac and gene trap Ds vectors and introduced them into the rice genome by Agrobacterium-mediated transformation. In this report, rice plants that contained single and simple insertions of T-DNA were analysed in order to evaluate the gene-tagging efficiency. The 3' end of Ds was examined for putative splicing donor sites. As observed in maize, three splice donor sites were identified at the 3' end of the Ds in rice. Nearly 80% of Ds elements were excised from the original T-DNA sites, when Ac cDNA was expressed under a CaMV 35S promoter. Repetitive ratoon culturing was performed to induce new transpositions of Ds in new plants derived from cuttings. About 30% of the plants carried at least one Ds which underwent secondary transposition in the later cultures. Eight per cent of transposed Ds elements expressed GUS in various tissues of rice panicles. With cloned DNA adjacent to Ds, the genomic complexities of the insertion sites were examined by Southern hybridization. Half of the Ds insertion sites showed simple hybridization patterns which could be easily utilized to locate the Ds. Our data demonstrate that the Ac/Ds-mediated gene trap system could prove an excellent tool for the analysis of functions of genes in rice. We discuss genetic strategies that could be employed in a large scale mutagenesis using a heterologous Ac/Ds family in rice.

Hybrid weighted-density approximation for nonuniform fluid mixtures

A hybrid weighted-density approximation (HWDA), which is based on both local density and globally averaged density, has been proposed to study the structural properties of nonuniform fluid mixtures. The advantage is that the HWDA is computationally much simpler than the extended weighted-density approximation proposed by Davidchack and Laird. The HWDA has been applied to calculate the density profiles of binary hard-sphere mixtures near a structureless hard wall. Comparison between the theoretical results and simulations for the confined binary hard-sphere mixtures demonstrates the reliable accuracy of the HWDA.

Chronic pruritic papular dermatitis in adult men: a variant of prurigo

Chronic recurrent pruritic papular eruptions in which a specific diagnosis cannot be established becomes a baffling experience to the dermatologist. We have met adult male patients with chronic recurrent pruritic papular eruptions, but their clinicopathological features are not described in English language textbooks. Our purpose was to study the clinical and histological features of this entity and review the various existing taxonomy. We conducted a study of 20 patients over a six year period by taking histories, performing skin biopsies, screening patch tests, and doing immunofluoresence studies. The eruptions occurred exclusively in male adults and had a predilection for the trunk and proximal extremities. The lesions were characterized by severely pruritic, nonfollicular, monomorphic, erythematous urticarial papules. There was no evidence of atopic diathesis or history of insect bite. Most patients had normal levels of serum eosinophils and IgE. The predominant histopathologic finding was a presence of perivascular infiltration of mononuclear cells with eosinophils. The patients followed a chronic course of at least six months with waxing and waning; systemic corticosteroids were the only effective treatment. Finally, all other pruritic erythematous papular dermatoses were ruled out. These cases comprise a distinct entity that has previously been mentioned in a few reports. Clear definition of this entity with an appropriate designation is in order to avoid confusion among dermatologists, and we propose the disease name "chronic papular dermatitis in adult men" as a variant of prurigo.

Fracture at the input tube-cylinder junction of AMS 700 inflatable penile prostheses as a complication of a modified implantation technique in a series of 99 patients

OBJECTIVES

To compare the incidence of a specific failure mode of the penile implant, fracture at the input tube-cylinder junction, with respect to two methods of managing the input tube.

METHODS

AMS 700 series three-piece inflatable penile prostheses were implanted in the first 26 patients using an ordinary technique in which the input tubing runs alongside the cylinder within the corpus and exits through the corporotomy (method A). In the subsequent 73 men, the input tube exited through a separate stab wound in the proximal corpus using a modification of the basic surgical technique (method C). The mean follow-up period was 136.4 months for method A and 69.0 months for method C. The incidence of fracture at the junction of the input tube and cylinder was compared according to the variables of input tube management, prosthesis type, and width of the proximal corpora.

RESULTS

The overall incidence of mechanical failure was 12.1%. Fractures at the input tube-cylinder junction with leaking occurred in 7 patients. The cylinders in these patients were all implanted using method C. The incidence of fracture at the junction was significantly higher (P <0.05) in men with narrow corpora (17.1%) than in the others (0%), regardless of the type of prosthesis implanted. The average functional duration of the failed prostheses was 66.1 months.

CONCLUSIONS

The modified surgical procedure (method C) should be avoided in patients with a narrow-width penis because of an increased likelihood of damage to the input tube-cylinder junction.

Myeloid differentiation of human cord blood CD34+ cells during ex vivo expansion using thrombopoietin, flt3-ligand and/or granulocyte-colony stimulating factor

We investigated the phenotypic changes of human umbilical cord blood (CB) CD34+ cells during ex vivo expansion using thrombopoietin (TPO), flt3-ligand (FL), and/or granulocyte-colony stimulating factor (G-CSF). During ex vivo expansion of CD34+ cells isolated from human CB for up to 5 weeks, surface expression of molecules on the cultured cells including CD64 (Fc gammaRI), CD32 (Fc gammaRII), CD16 (Fc gammaRII), CD11b (MAC-1) and CD18 (beta2-integrin) was analysed by flow cytometry along with simultaneous measurement of apoptosis by 7-aminoactinomycin D staining method. CD64, CD32 and/or CD18 expressing cells appeared in the cultures both with and without the addition of G-CSF until the tenth day. However, without G-CSF, CD16+ fractions did not appear and CD11b+ fractions were not maintained. With G-CSF, the CD16+ or CD11b+ fractions appeared only from the second week. These results suggest that G-CSF is necessary for the late stage of myeloid maturation during which CD16 and CD11b are expressed.

Constitutive activation of extracellular signal-regulated kinase in human acute leukemias: combined role of activation of MEK, hyperexpression of extracellular signal-regulated kinase, and downregulation of a phosphatase, PAC1

Extracellular signal-regulated kinase (ERK) is an important intermediate in signal transduction pathways that are initiated by many types of cell surface receptors. It is thought to play a pivotal role in integrating and transmitting transmembrane signals required for growth and differentiation. Constitutive activation of ERK in fibroblasts elicits oncogenic transformation, and recently, constitutive activation of ERK has been observed in some human malignancies, including acute leukemia. However, mechanisms underlying constitutive activation of ERK have not been well characterized. In this study, we examined the activation of ERK in 79 human acute leukemia samples and attempted to find factors contributing to constitutive ERK activation. First, we showed that ERK and MEK were constitutively activated in acute leukemias by in vitro kinase assay and immunoblot analysis. However, in only one half of the studied samples, the pattern of ERK activation was similar to that of MEK activation. Next, by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblot analysis, we showed hyperexpression of ERK in a majority of acute leukemias. In 17 of 26 cases (65.4%) analyzed by immunoblot, the pattern of ERK expression was similar to that of ERK activation. The fact of constitutive activation of ERK in acute leukemias suggested to us the possibility of an abnormal downregulation mechanism of ERK. Therefore, we examined PAC1, a specific ERK phosphatase predominantly expressed in hematopoietic tissue and known to be upregulated at the transcription level in response to ERK activation. Interestingly, in our study, PAC1 gene expression in acute leukemias showing constitutive ERK activation was significantly lower than that in unstimulated, normal bone marrow (BM) samples showing minimal or no ERK activation (P =.002). Also, a significant correlation was observed between PAC1 downregulation and phosphorylation of ERK in acute leukemias (P =.002). Finally, by further analysis of 26 cases, we showed that a complementary role of MEK activation, ERK hyperexpression, and PAC1 downregulation could contribute to determining the constitutive activation of ERK in acute leukemia. Our results suggest that ERK is constitutively activated in a majority of acute leukemias, and in addition to the activation of MEK, the hyperexpression of ERK and downregulation of PAC1 also contribute to constitutive ERK activation in acute leukemias.

Recent advancement in diagnosis of vasculogenic impotence

Several dynamic tests with vasoactive drugs are available for evaluating penile vascular inflows and outflows, ranging from simple pharmacologic test to more invasive radiologic sets. However, there is still no perfect single test to reflect the penile vascular flow. All possible efforts should be exerted to get the greatest erectile effect to avoid an underestimation of blood flow to the corpora due to incomplete relaxation of the trabecular smooth muscle. Appreciation of the type and frequency of anatomical variations and potential collateral routes is important in interpreting penile arterograms and in evaluating the hemodynamic significance of suspected arterial disease. Choice of the vascular tests should always depend on the purpose of testing.

Not only the nature of peptide but also the characteristics of cell membrane determine the antimicrobial mechanism of a peptide

The mechanisms of antimicrobial actions of magainin 2, buforin II and poly L-lysine against various Escherichia coli strains were studied. Poly L-lysine inhibited BL21, AD 434 and GroE+/DnaK+ growth without lysing the cell. Magainin 2 had a pore-forming activity on BL 21 and AD 434 membrane but could not inhibit the GroE+/DnaK+ growth in a nutrient-rich medium. Buforin II, which killed BL21 and AD 434 without cell membrane damage, lysed GroE+/DnaK+ to death. Once they were introduced into the cell by electroporation, all three peptides were able to inhibit cell growth at concentrations of 10 times lower than their MICs. These results indicate that the nature of the peptide and also the characteristics of the cell membrane determine the antimicrobial actions of a peptide.

CD18-mediated neutrophil recruitment contributes to the pathogenesis of reperfused but not nonreperfused stroke

BACKGROUND AND PURPOSE

Neutrophil (PMN) recruitment mediated by increased expression of intercellular adhesion molecule-1 expression (ICAM-1, CD54) in the cerebral microvasculature contributes to the pathogenesis of tissue injury in stroke. However, studies using blocking antibodies against the common beta2-integrin subunit on the PMN, the counterligand for ICAM-1 (CD18), have demonstrated equivocal efficacy. The current study tested the hypothesis that mice deficient in CD18 would be protected in the setting of reperfused but not nonreperfused stroke.

METHODS

Two groups of mice were studied, those whose PMNs could express CD18 (CD18 +/+) and those mice hypomorphic for the CD-18 gene (CD18 -/-). PMNs obtained from CD18 -/- or CD18 +/+ mice were fluorescently labeled and tested for binding to murine brain endothelial monolayers. Using a murine model of focal cerebral ischemia in which an occluding suture placed in the middle cerebral artery (MCA) is removed after 45 minutes (transient ischemia, reperfused stroke) or left in place (permanent ischemia, nonreperfused stroke), cerebral infarct volumes (% ipsilateral hemisphere by TTC staining), cerebral blood flow (CBF, % contralateral hemisphere by laser-Doppler flowmetry), and survival (%) were examined 24 hours after the initial ischemic event. Adoptive transfer studies used 111In-labeled PMNs (from either CD18 +/+ or CD18 -/- mice) to examine the relative accumulation of PMNs in the ischemic region.

RESULTS

PMNs obtained from CD18 -/- mice exhibit reduced adhesivity (compared with CD18 +/+ PMNs) for both quiescent and cytokine-activated endothelial monolayers. CD18 -/- mice (n=14) subjected to transient focal cerebral ischemia demonstrated a 53% decrease in infarct volumes versus CD18 +/+ mice (n=26, P<0.05), improved penumbral CBF at 24 hours (1.8-fold, P=0.02), and a 3.7-fold decrease in mortality (P=0.02). However, when CD18 -/- mice (n=12) were subjected to permanent focal cerebral ischemia, no differences were noted in infarct volume, mortality, or CBF versus similarly treated CD18 +/+ mice (n=10). There was a greater accumulation of CD18 +/+ PMNs in the ischemic zone of CD18 +/+ animals than CD18 -/- animals subjected to reperfused stroke (82% increase, P=0.02), although there was no difference between groups when subjected to permanent MCA occlusion.

CONCLUSIONS

Deficiency for the CD18 gene confers cerebral protection in a murine model of reperfused stroke, but this benefit does not extend to CD18-deficient animals subjected to permanent MCA occlusion. These data suggest that anti-PMN strategies should be targeted to reperfused stroke and may perhaps be used in conjunction with thrombolytic therapy that establishes reperfusion.

Measurement of leg arterial compliance of normal subjects and diabetics using impedance plethysmography

In this study, compliance, a mechanical characteristic of the lower leg arteries, was measured noninvasively. Changes in blood volume and pressure were measured using impedance plethysmography and a mercury sphygmomanometer, respectively. Compliance was calculated by dividing the change in blood volume by the change in pulse pressure (systolic-diastolic pressure). Subjects were 24 asymptomatic persons ranging from 30 to 58 years and 14 diabetics ranging from 41 to 59 years. Peak compliance, mean pressure, and systolic pressure were statistically analyzed using a t test between the asymptomatic and diabetic groups. The average peak compliance of the asymptomatic and diabetic groups was measured as 2.79 and 1.82 microL/mmHg/cm, respectively, and these were significantly different (p < 0.01). It was also found that compliance is a better parameter in differentiating vascular disease than the mean or systolic blood pressure.