Anti-microbial activity of human CAP18 peptides

BACKGROUND

CAP18 derived from rabbit leukocytes is a 142-amino acid protein recently demonstrated to have Lipopolysaccharide (LPS) binding and anti-microbial activity. The C-terminal 37 amino acids of rabbit CAP18 (CAP18(106-142) comprise the LPS-binding and anti-microbial domain. The homologous domain of human CAP18 (huCAP18(104-140) was identified from the recently cloned human CAP18 cDNA.

OBJECTIVES

To evaluate the antimicrobial activity of C-terminal peptides derived from human CAP18.

STUDY DESIGN

Prepare synthetic human CAP18(104-140) and study anti-microbial activity versus various gram-negative and gram-positive bacteria.

RESULTS

Synthetic human CAP18(104-140) has broad anti-microbial activity versus both gram-positive (IC50 = 2.5 micrograms/ml) and gram-negative bacteria (IC50 = 0.5-5 micrograms/ml). Susceptible strains include Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium. A 32-amino acid peptide lacking five amino acids from the C-terminus of CAP18(104-140) has higher activity. Unlike previously characterized anti-microbial peptides derived from granulocyte proteins, CAP18(104-140) is active in serum.

CONCLUSIONS

Human CAP18(104-140) or a derivative peptide may have therapeutic potential for bacterial sepsis.

A novel big defensin identified in horseshoe crab hemocytes: isolation, amino acid sequence, and antibacterial activity

Hemocytes of the horseshoe crab (limulus) contain a family of arthropodous peptide antibiotics, termed the tachyplesin family, and antibacterial protein, called anti-LPS factor, of which the former is located in the small (S) granules and the latter in the large (L) granules of the hemocytes. In our ongoing studies on granular components, we have identified here a novel defensin-like substance present in both L- and S-granules. This substance strongly inhibits the growth of Gram-negative and -positive bacteria, and fungi, such as Candida albicans. The isolated substance, tentatively termed "big defensin," consists of 79 amino acid residues, of which the COOH-terminal 37 residues have a sequence similar to those of mammalian neutrophil-derived defensins, especially rat defensin. Characterization of the disulfide motif in big defensin indicated that the disulfide array is identical to that of beta-defensins from bovine neutrophils. One clear structural difference is that the limulus hemocyte-derived big defensin has an extension of the NH2-terminal hydrophobic sequence with 35 amino acid residues followed by the COOH-terminal cationic defensin portion. This amphipathic nature of big defensin seems likely to be associated with its potent antibacterial activity. Furthermore, antibacterial activities of the NH2-terminal hydrophobic region and the COOH-terminal defensin portion separated by tryptic digestion are significantly different: the former displays a more potent activity against Gram-positive bacteria, whereas the latter is more potent against Gram-negative bacteria. Big defensin, therefore, may prove to represent a new class of defensin family possessing two functional domains with different antimicrobial activities.

Human CAP18: a novel antimicrobial lipopolysaccharide-binding protein

CAP18 (18-kDa cationic antimicrobial protein) is a protein originally identified and purified from rabbit leukocytes on the basis of its capacity to bind and inhibit various activities of lipopolysaccharide (LPS). Here we report the cloning of human CAP18 and characterize the anti-LPS activity of the C-terminal fragment. Oligonucleotide probes designed from the rabbit CAP18 cDNA were used to identify human CAP18 from a bone marrow cDNA library. The cDNA encodes a protein composed of a 30-amino-acid signal peptide, a 103-amino-acid N-terminal domain of unknown function, and a C-terminal domain of 37 amino acids homologous to the LPS-binding antimicrobial domain of rabbit CAP18, designated CAP18(104-140). A human CAP18-specific antiserum was generated by using CAP18 expressed as a fusion protein with the maltose-binding protein. Western blots (immunoblots) with this antiserum showed specific expression of human CAP18 in granulocytes. Synthetic human CAP18(104-140) and a more active truncated fragment, CAP18(104-135), were shown to (i) bind to erythrocytes coated with diverse strains of LPS, (ii) inhibit LPS-induced release of nitric oxide from macrophages, (iii) inhibit LPS-induced generation of tissue factor, and (iv) protect mice from LPS lethality. CAP18(104-140) may have therapeutic utility for conditions associated with elevated concentrations of LPS.

[Modification of vancomycin nephrotoxicity by other antibiotics in rats]

Vancomycin (VCM) was intravenously administered to rats for 14 days at doses of 150 mg/kg/day and 250 mg/kg/day alone or in combination with 1,000 mg/kg/day of latamoxef (LMOX), flomoxef (FMOX) or cefpirome (CPR) or 250 mg/kg/day of fosfomycin (FOM), and the influences of combined antibiotics on the VCM-induced renal damage were studied. The renal impairment caused by VCM alone was, morphologically, demonstrated mainly as regeneration of tubular epithelium: slight regeneration was observed in a half of rats administered 150 mg/kg/day and slight to extensive regeneration in all the rats administered 250 mg/kg/day. Clinical examinations found apparent increases in urinary LDH and MDH activities in rats administered 250 mg/kg/day, thus showing a good correlation with renal pathological changes. In addition, increase in kidney weight and increase in urinary NAG activity were noted, while changes in plasma urea-N and creatinine were mild, and gamma-GTP activity and protein in urine could not be used as a parameter of the renal impairment. The slight renal impairment as noted in rats administered VCM 150 mg/kg/day alone was not observed at all when LMOX or FMOX was administered concomitantly, and less pronounced even when FOM was administered concomitantly. When CPR was administered concomitantly, the changes were the same as those observed with VCM alone. The renal impairment in rats administered VCM 250 mg/kg/day was apparently less severe when combined with LMOX, FMOX and FOM than that in rats administered VCM alone, and this was supported by apparent reduction of clinical examination values as the parameter of VCM-induced nephrotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of cytochrome P-450 isoenzymes in cultured monkey hepatocytes

The effect of phenobarbital (PB), beta-naphthoflavone (beta-NF) and rifampicin (Rif) on the drug-metabolizing activity of cultured squirrel monkey hepatocytes was examined. The drug metabolizing activity (e.g. alkoxycoumarin dealkylase or steroid hydroxylase) gradually decreased during the culture period with 40-70% activity remaining at 72 hr. When 0.5 mM PB was added to the culture, the activities of 7-methoxycoumarin O-demethylase (MCOD) and 7-ethoxycoumarin O-deethylase (ECOD) increased to 6-7 fold higher level than those of control at 72 hr. Testosterone 6 beta-hydroxylase (6 beta-OH-T) and testosterone 16 beta-hydroxylase (16 beta-OH-T) activities were approx. 3-fold higher than those of the control. Addition of beta-NF significantly increased the activities of 7-ethoxyresorufin O-deethylase (EROD) and ECOD. Though statistically insignificant, Rif slightly increased 6 beta-OH-T activity. Western blot analysis indicated PB induced production of the CYP 2B and 3A subfamilies, while beta-NF and Rif induced that of the CYP 1A and the CYP 3A subfamily, respectively.

Sexual transmission of human T-lymphotropic virus type I among female prostitutes and among patients with sexually transmitted diseases in Fukuoka, Kyushu, Japan

The authors investigated the prevalence of antibody to human T-lymphotropic virus type I (anti-HTLV-I) in 409 female prostitutes, 446 patients with an episode of sexually transmitted diseases, and 17,345 control blood donors. All subjects were Japanese and all studies were done in Fukuoka, Kyushu, Japan, in 1989. The prevalence of anti-HTLV-I was significantly higher in the prostitutes (5.1%, p < 0.001), in the male patients (2.8%, p < 0.05), and in the female patients (5.7%, p < 0.05) than in the controls (males 1.4%, females 2.2%). Prevalence of anti-HTLV-I in the prostitutes increased with the number of years spent in prostitution, but the increase was not statistically significant. Among the subjects with sexually transmitted diseases, female prostitutes with syphilis, male patients with non-gonococcal urethritis, female patients with syphilis, and female patients with gonorrhea had a significantly higher prevalence of anti-HTLV-I than did the controls. A longitudinal study was done on the 168 prostitutes. Two (1.3%) of the 158 initially seronegative subjects seroconverted over the period of 2 years. These data suggest that the risk of male-to-female transmission of HTLV-I through sexual contact is high among high risk groups in Japan, and they support the possibility of female-to-male transmission of HTLV-I.

Chronic toxicity of tar from heavy-duty diesel exhaust following intratracheal instillations to the lungs of hamsters

Chronic toxicity of tar from heavy-duty diesel exhaust (HD tar) was studied in male Syrian golden hamsters which received 15 mg, 7.5 mg or 1.5 mg of HD tar as the total dosages by intratracheal instillations once a week for 15 weeks. As a control group, hamsters were treated with the 0.1 ml of Tween 60: ethanol: phosphate buffer (pH 6.88, 0.25 M) solution (5.8: 8.7: 100 by volume) once a week in the same manner. The survival rate during the instillation period in the group given 15 mg of HD tar, the high-dose group of HD tar, was the lowest, and the effect was dose-dependent. However, the survival rates during the subsequent observation period showed no marked differences among HD tar treated groups. During their total life span, one papilloma in the larynx was seen in the 44 hamsters in the group given 1.5 mg of HD tar, one papilloma in the larynx was appeared in the 59 hamsters in the group given 1.5 mg of HD tar and one lung adenoma was developed in the 58 hamsters in the control group. There were no tumors in the respiratory tract in the group given 7.5 mg of HD tar. Concerning the histopathological findings of the lung, the incidence of alveolar cell or bronchiolar cell hyperplasia in the group given 1.5 mg of HD tar was significantly higher than that in the control group. From these results, although we could not observe any tumorigenicity or carcinogenic effect of HD tar, it would seem that HD tar caused weak but positive damage to the lungs of hamsters.

Evaluation of radioiodinated iodoclorgyline as a SPECT radiopharmaceutical for MAO-A in the brain

An in vivo estimation of the newly synthesized MAO-A specific inhibitor, [125I]-labeled N-[3(2,4-dichloro-6-iodophenoxy)propyl]-N-methyl-2- propynylamine ([125I]-iodoclorgyline), was performed. Retention of the radioactivity of this radioligand was observed in the brain from 1 h post-injection. Pretreatments with clorgyline and l-deprenyl showed selective binding of [125I]-iodoclorgyline to MAO-A in the brain at 24 h post-injection. Moreover, a good correlation (r = 0.907) between the uptake of [125I]-iodoclorgyline and MAO-A enzyme activity in the cortex was observed in the pretreatment study with several doses of clorgyline. Although improvement to increase the brain/blood ratio is desirable because of slow blood clearance of the radioactivity, radioiodinated iodoclorgyline may serve as a useful SPECT radiopharmaceutical for quantitative analysis of MAO-A in the brain.

Digital nerve conduction velocity for evaluation of peripheral nerve impairments in vibration syndrome

In order to evaluate peripheral nerve impairments in vibration syndrome, sensory nerve conduction velocity (SCV) in the digital segment of the median nerve was measured by applying electrical stimulation to the wrist and recording from two pairs of electrodes attached to the middle finger. Fractionated SCVs were also measured in the palm-to-finger, wrist-to-palm, and elbow-to-wrist segments of the median nerve. Subjects were 65 patients with vibration syndrome and 48 healthy controls of similar age. SCVs in the digital nerve segment were significantly slower in the patients than in the controls. Significant slowing was also found in the wrist-to-palm segment. SCVs in the palm-to-finger and elbow-to-wrist segments did not differ between the two groups. Slowed SCVs were most frequently encountered in the digital segment (38% of the patients). The slowing in the wrist-to-palm segment was found in 20% of the patients. Present findings indicate that the digital segment is most frequently affected in vibration-induced neuropathy, and measurement of SCVs in the digital segment would serve to evaluate the peripheral neuropathy in vibration syndrome.

Nerve conduction velocities in the lower extremities among patients with vibration syndrome

In order to clarify the effect of vibration syndrome (VS) on the peripheral nervous system (PNS) in the lower extremities, 59 patients with VS (age 58.5 +/- 5.1 years) and 49 age-matched controls (age 57.0 +/- 5.1 years) were examined for sensory nerve conduction velocities (SCV) in the sural nerve (SSCV) and the medial plantar nerve (PSCV) in the summer of 1993 and 1994. They had not been suffering from diseases and injuries which might have affected the SCV in the lower extremities. These patients were divided into two subgroups, one with past vibration exposure to chainsaw (N = 22) and the other with past vibration exposure to rock drills and other tools (N = 37). SCVs corrected by skin temperature were subjected to statistical analysis. In PSCV a significant reduction among all patients (40.8 +/- 4.24 m/s, p < 0.01) including two subgroups (chainsaw, 39.7 +/- 4.7 m/s, p < 0.01; rock drill and others, 41.0 +/- 4.6 m/s, p < 0.01) was observed compared with those of the controls (43.2 +/- 4.31 m/s), but there was no significant reduction in SSCV. Significantly more subjects with PSCV below the standard of PSCV (ten percentile value of those of the controls) were observed among all patients (17/59, 28.8%, p < 0.05) including two subgroups (chainsaw, 7/22, 31.8%, p < 0.05; rock drill and others, 10/37, 27.0%, p < 0.05) than in the controls (4/49, 8.2%). These findings suggested that VS affected the PNS function in the lower extremities and that its mechanism was considered to mediate a circulatory disturbance, and to differ from SCV reduction in the finger.

D-myo-inositol 1,4,5-trisphosphate binding domain of phospholipase C-delta 1

D-myo-Inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) binding domain of phospholipase C-delta 1 (PLC-delta 1) was determined by examining binding activity of the synthetic peptide corresponding to residues 30-43 of PLC-delta 1. The peptide coupled with carrier proteins such as keyhole limpet hemocyanin or bovine serum albumin bound Ins(1,4,5)P3, whereas a scrambled peptide with the same amino acids did not do so. Polyclonal antibody against the peptide was examined to determine whether it would cause inhibition of the Ins(1,4,5)P3 binding to PLC-delta 1. Fab fragment of antibody to the peptide did inhibit binding to PLC-delta 1, in a dose-dependent manner. Thus it seems likely that the region of residues 30-43 of PLC-delta 1 is responsible for the binding of Ins(1,4,5)P3.

Molecular characterization of a mouse prostaglandin D receptor and functional expression of the cloned gene

Prostanoid receptors belong to the family of G protein-coupled receptors with seven transmembrane domains. By taking advantage of nucleotide sequence homology among the prostanoid receptors, we have isolated and identified a cDNA fragment and its gene encoding a mouse prostaglandin (PG) D receptor by reverse transcription polymerase chain reaction and gene cloning. This gene codes for a polypeptide of 357 amino acids, with a calculated molecular weight of 40,012. The deduced amino acid sequence has a high degree of similarity with the mouse PGI receptor and the EP2 subtype of the PGE receptor, which together form a subgroup of the prostanoid receptors. Chinese hamster ovary cells stably expressing the gene showed a single class of binding sites for [#H]PGD2 with a Kd of 40 nM. This binding was displaced by unlabeled ligands in the following order: PGD2 > BW 245C (a PGD agonist) > BW A868C (a PGD antagonist) > STA2 (a thromboxane A2 agonist). PGE2, PGF2 alpha, and iloprost showed little displacement activity at concentrations up to 10 microM. PGD2 and BW 245C also increased cAMP levels in Chinese hamster ovary cells expressing the receptor, in a concentration-dependent manner. BW A868C showed a partial agonist activity in the cAMP assay. Northern blotting analysis with mouse poly(A)+ RNA identified a major mRNA species of 3.5 kb that was most abundantly expressed in the ileum, followed by lung, stomach, and uterus.

Mechanically assisted intraoperative peritoneal lavage for generalized peritonitis as a result of perforation of the upper part of the gastrointestinal tract

BACKGROUND

The efficiency of intraoperative peritoneal lavage (IOPL) and peritoneal drainage in patients with generalized peritonitis remains controversial. The benefit of large volume IOPL, using a newly designed device, and of peritoneal drainage were evaluated in 101 patients with generalized peritonitis.

STUDY DESIGN

Patients were divided into two groups, one treated by mechanically assisted IOPL (group 1), and the other treated by manual IOPL (group 2). They were further divided into two groups, one undergoing drainage (DR group) and the other undergoing no drainage (ND group). Based on data in the progress notes, patients in these groups were compared with each other with respect to disease process, volume of IOPL fluid, incidence of infectious complications, and other prognostic factors.

RESULTS

In group 1, the incidence of infectious complications was significantly lower than in group 2 (10.8 versus 62.9 percent, p < 0.01). Patients who underwent operative treatment 12 hours or more after onset of peritonitis had a lower incidence of infection following high volume IOPL (greater than or equal to 30 L) compared with those patients who underwent low volume IOPL. The incidence of infectious complications was significantly higher in the DR group (32.8 versus 12.9 percent).

CONCLUSIONS

A large volume of saline (greater than or equal to 30 L) was needed for IOPL. The new device for IOPL proved to be very successful and efficient. When IOPL was successful, it seemed that peritoneal drainage did not provide any additional benefits to the treatment of generalized peritonitis.

Pheophorbide a, a potent endothelin receptor antagonist for both ETA and ETB subtypes

Many crude drugs were screened for their capacity to inhibit the binding of endothelin-1 (ET-1) to ET receptors; several crude drugs showed significant binding inhibitory activity. Pheophorbide a (1), a potent non-peptide ET receptor antagonist, was isolated from Altemisiae capillaris Flos ("Inchinko" in Japanese), which has been utilized as a remedy for hepatitis in Oriental medicine. In receptor binding experiments, compound 1 inhibited ET-1 binding specifically to both the ETA receptor (ETAR) and ETB receptor (ETBR), with IC50 values of 8.0 x 10(-8) and 2.1 x 10(-7) M, respectively. Thus, compound 1 is an ET-1 binding inhibitor; however, it exhibited no affinity for the other receptors of angiotensin II and atrial natriuretic peptide. We also evaluated the inhibitory activity of porphyrin compounds, and found that some exhibited moderate activity.

Expression and characterization of an inositol 1,4,5-trisphosphate binding domain of phosphatidylinositol-specific phospholipase C-delta 1

It was previously found that the 85-kDa protein purified from rat brain using an inositol 1,4,5-trisphosphate (Ins(1,4,5)P3)-immobilized matrix was the delta 1 isoform of phosphatidylinositol-specific phospholipase C (PLC). We expressed rat PLC-delta 1 in Escherichia coli as a fusion protein with glutathione S-transferase, and found that the bacterial lysate shows a significant amount of Ins(1,4,5)P3 binding. The lysate was applied to Ins(1,4,5)P3-immobilized column chromatography and the eluate with 2 M NaCl solution containing only a 100-kDa protein showed high Ins(1,4,5)P3 binding. The lysate was also purified to near homogeneity using a glutathione-Sepharose 4B affinity system. Bacterially-expressed enzyme thus purified showed essentially the same inositol phosphate binding characteristics as the brain-derived enzyme. PLC-delta 1 consists of the amino-terminal nonconserved region and two well-conserved regions among isozymes, designated as X and Y, which are thought to constitute a catalytic core of the enzyme. Using a combination of deletion mutants and proteolytic products of the enzyme, we were able to locate an Ins(1,4,5)P3 binding domain in the molecule. Deletion of 223 residues from the amino terminus completely abolished the binding activity, while deletion of X region only partially inhibited the binding and deletion of Y region did not affect the binding. A 76-kDa proteolytic product of the expressed PLC-delta 1 which lacked 60 amino acids at the amino terminus showed a minimal Ins(1,4,5)P3 binding activity. A peptide consists of 14 amino acids corresponding to residues 30-43 of PLC-delta 1, which contains 6 basic amino acids, binds to an Ins(1,4,5)P3-immobilized matrix. Moreover, Ins(1,4,5)P3 binding was blocked by phospholipid vesicles containing phosphatidylinositol 4,5-bisphosphate. These results, taken together, indicate that the amino-terminal domain of PLC-delta 1 is important for the binding of both Ins(1,4,5)P3 and phosphatidylinositol 4,5-bisphosphate.

Anti-inflammatory effect of 22-oxa-1 alpha,25-dihydroxyvitamin D3 on carrageenin-induced inflammation in rats

The anti-inflammatory effect of 22-oxa-1 alpha,25-dihydroxyvitamin D3 [22-oxa-1 alpha,25(OH)2D3], an analogue of the active form of vitamin D3, was studied regarding carrageenin-induced inflammation in rats. In the early phase of the inflammation, the formation of granulation tissue and the weight of exudate were significantly suppressed by both oral and local administrations of 22-oxa-1 alpha,25(OH)2D3 daily for 4 d (day 0-3) after carrageenin injection, though the local injection of 22-oxa-1 alpha,25(OH)2D3 (7 and 10 micrograms/kg) into the carrageenin-air-pouch was much more effective than the oral administration of the compound (20 micrograms/kg). Similarly, oral and local administrations of 22-oxa-1 alpha,25(OH)2D3 from day 4 to 7 significantly suppressed the increase in exudate and the proliferation of granulation tissue in the late phase of carrageenin-induced inflammation in rats. The results suggest that 22-oxa-1 alpha,25(OH)2D3 has an anti-inflammatory activity on both the acute and proliferative phases of inflammation in rats.

Increased lactic dehydrogenase (LDH)-linked immunoglobulin associated with interferon-alpha therapy in a case of chronic hepatitis C

A 47-year-old man diagnosed as having chronic hepatitis C was admitted to our hospital where he was treated with interferon (IFN)-alpha. After initiation of this treatment, his serum LDH became elevated, and when the drug was stopped, it decreased gradually to within the normal range. The histopathological findings and the liver function were not aggravated. The administration of IFN-alpha showed a correlation to LDH-linked immunoglobulin, a complex of LDH and immunoglobulin, often causing high levels of LDH. In patients on IFN therapy with elevated LDH, LDH-linked immunoglobulin should be tested.

Study of new prognostic factors of esophageal variceal rupture by use of image processing with a video endoscope

BACKGROUND

We studied new prognostic factors of esophageal variceal rupture by analyzing electronic video images of esophageal varices in 30 patients with portal hypertension.

METHODS

Fifteen of the patients were emergency or elective cases (bleeders), and the remaining 15 were prophylactic cases (nonbleeders). A comparison was made between the bleeders and nonbleeders in terms of endoscopic findings and the image processing data, especially variceal color tone and red color sign.

RESULTS

Endoscopic findings based on the general rules prepared by the Japanese Research Society for Portal Hypertension showed no significant difference between the two groups. However, with regard to the image processing data, both the ratio of red signal and the ratio of value were significantly lower in bleeders than in nonbleeders. In addition, the area ratio of red color sign was significantly higher in the former than in the latter. A follow-up study of nonbleeders also indicated that image processing data were more reliable than traditional endoscopic rules.

CONCLUSIONS

By adding these image processing data to the traditional general rules for recording endoscopic findings, it is possible to select patients with varices that have a higher risk of rupture.

Dose-dependent testicular toxicity of propylene oxide in rats induced by repeated intraperitoneal injections

The dose-dependent testicular toxicity of propylene oxide (PO) was evaluated in male Wistar rats when administered by intraperitoneal injections. In 23 mg/kg, 47 mg/kg, and 93 mg/kg groups, PO was given three days a week for six weeks, while PO was given three days a week for two weeks plus once a week after the third week in a 186 mg/kg group. In the 186 mg/kg group, the epididymal weight and sperm count in the body plus tail of the epididymis decreased, while the rate of sperm with morphological abnormalities increased significantly. The number of sperm with an immature head increased slightly, although significantly, even in the 47 mg/kg group and a dose-dependent effect could be seen. The serum testosterone concentration did not change significantly and there were no apparent histopathological changes in Leydig cells in any of the treatment groups. This is the first detailed study concerning the dose-dependent testicular toxicity of PO.

The role of angiography in the assessment of blunt liver injury

Angiography and therapeutic embolism (TE) were studied retrospectively in cases of blunt liver injury with regard to their indications and usefulness. The management of patients fell into three groups distinguished by the clinical evidence of the severity of the liver injuries. The most severe 42 cases (39.6 per cent) were managed surgically and promptly, the least severe 38 cases were not subjected to angiography and the intermediate group (26 cases; 24.5 per cent) underwent angiography and 12/26 cases underwent TE. However, haemodynamic stability on admission was not significantly different between these groups. In addition, all patients who underwent angiography and TE had more severe parenchymal injury on imaging studies while their haemodynamic instability was not identified on admission. Angiography and TE for blunt liver injury were most strongly indicated in patients with good haemodynamic responses to intravenous fluid administration during the acute phase and/or in cases of severe parenchymal injury on imaging.