Tip-enhanced Raman spectroscopy of bradykinin and its B2 receptor antagonists adsorbed onto colloidal suspended Ag nanowires

The tip-enhanced Raman scattering (TERS) spectra of bradykinin (BK) and its potent B2 BK receptor antagonists, [d-Arg(0),Hyp(3),Thi(5,8),l-Pip(7)]BK and [d-Arg(0),Hyp(3),Thi(5),d-Phe(7),l-Pip(8)]BK, approximately with a size of about 40 nm, adsorbed onto colloidal suspended Ag nanowires with diameter in the range of 350-500 nm and length of 2-50 μm were recorded. The metal surface plasmon resonance and morphology of the Ag nanowires were studied by ultraviolet-visible (UV-Vis) spectroscopy and scanning electron microscopy (SEM). Briefly, it was shown that two C-terminal amino acids of BK and [d-Arg(0),Hyp(3),Thi(5,8),l-Pip(7)]BK are involved in the interaction with the colloidal suspended Ag nanowire surface, whereas three last amino acids of the [d-Arg(0),Hyp(3),Thi(5),d-Phe(7),l-Pip(8)]BK sequence attached the Ag surface. Thus, BK adsorbs on the colloidal suspended Ag nanowires mainly through the Phe(5/8) ring (tilted orientation) and the one oxygen atom of the carboxylate group and the H2N-C-NH-CH2- fragment of Arg(9). In the case of [d-Arg(0),Hyp(3),Thi(5,8),l-Pip(7)]BK, the Thi(8) ring (through the lone electron pair on the sulfur atom) and the both oxygen atoms of the carboxylate group and the amine group of Arg(9) mainly participated in the interaction with the Ag nanowire surface. For [d-Arg(0),Hyp(3),Thi(5),d-Phe(7),l-Pip(8)]BK, the d-Phe(7) ring, the Pip(8) ring, and the Arg(9) side-chain assisted in the peptide interaction with the Ag surface. The obtained results emphasize the importance of the C-terminal part of these peptides in the adsorption process onto the colloidal suspended Ag nanowires.

Current practice of management of bacteremic sepsis: a study in a tertiary care teaching hospital in Japan

OBJECTIVE

To investigate how patients with bacteremic sepsis are managed in a tertiary care teaching hospital.

PATIENTS AND METHODS

Prospective observational study on patients with bacteremic sepsis. Clinical and microbiological characteristics of bacteremic sepsis were analyzed in relation to prognosis. Severity of the illness was quantitatively analyzed by the APACHE (Acute Physiology, Age, Chronic Health Evaluation) III scoring system. Also investigated was how closely physicians paid attention to acute physiological alterations in patients.

RESULTS

The 28-day mortalities in fifty hemodynamically stable patients and in twenty-three septic shock patients were 26% and 52%, respectively (p=0.028). Gram-positive organisms accounted for 54% of all organisms, with the mortality and incidence of septic shock being the same as with Gram-negative infections. The mean APACHE III score was 42.9 in survivors, and 76.5 in non-survivors (p < 0.001). Although serum levels of C-reactive protein and acute physiology score (APS) was significantly higher in non-survivors than in survivors, the correlation with APACHE III score was more prominent in APS. The number of vital signs recorded was 1.67 in physicians and 3.6 in nurses (p < 0.001).

CONCLUSIONS

The present study proved that the APACHE III score accurately discriminates between survivors and non-survivors of patients with sepsis. By addressing the need for an objective evaluation of severity of illness, it strongly recommends that physicians should be made aware of physiologically defined sepsis and that they should pay closer attention to patients' physiological alterations to identify the development of sepsis in critically ill patients.

[A trial of infection control measure by clinical microbiology laboratory]

In 1998, we developed a Total Infection Control System in Saga Medical School Hospital, and would like to introduce it for the practical use. This system was named "Dr. FLEMING" (Flexible Microbiological Test & Information System for the New Generation) and is expected to help physicians by providing highly valuable test results and useful information. For example, bacterial identification and drug susceptibility test can be completed within 4-6 hrs after bacterial colony is isolated, and the test report the contains full-colored pictures to enhance understanding. In addition, we have made an information center for infectious disease, where physicians can have access to various data bases outside our hospital. Furthermore, we offer many kinds of useful information to physicians working at other medical facilities to assist their clinical practice of infectious diseases.

Prevalence and genetic diversity of cagD, cagE, and vacA in Helicobacter pylori strains isolated from Japanese patients

BACKGROUND

Although cagD and cagE (cagDE) identified upstream of cagA have been shown to be involved in the induction of interleukin (IL)-8 expression, the relationship between cagDE status and gastroduodenal diseases still remains to be examined. Thus we investigated prevalence and genetic diversity of cagD, cagE, and vacA in Helicobacter pylori strains isolated from patients with peptic ulcer or gastritis.

METHODS

We analyzed 73 H. pylori strains isolated from Japanese patients (gastritis (GA), 15; gastric ulcer (GU), 28; duodenal ulcer (DU), 23; GU and DU, 7). The presence of cagDE was evaluated by polymerase chain reaction (PCR) and Southern hybridization. The vacA genotype was examined by PCR, using type-specific primers.

RESULTS

cagDE was present in 13 (86.7%) of 15 patients with GA, 26 (92.9%) of 28 patients with GU, 21 (91.3%) of 23 patients with DU, and 6 (85.7%) of 7 patients with GU and DU (P = 0.89). vacA signal sequence type s1 was found in 14 (93.3%) of 15 patients with GA, 26 (92.9%) of 28 patients with GU, 22 (95.7%) of 23 patients with DU, and 6 (85.7%) of 7 patients with GU and DU (P = 0.84). Sequences of cagDE and vacA in our Japanese strains were highly homologous with one another, and there were no disease-specific mutations.

CONCLUSIONS

Most of the H. pylori strains in Japan were cagDE-positive, vacA s1 type, regardless of clinical outcome. The present study also indicated that these genes were conserved well among our H. pylori isolates.

Evaluation of anti-herpesvirus activity of (1'S,2'R)-9-[[1',2'-bis(hydroxymethyl)cycloprop-1'-yl]methyl]- guanine (A-5021) in mice

The anti-herpesvirus activity of (1'S,2'R)-9-[[1',2'-bis(hydroxymethyl)cycloprop-1'-yl]methyl]guani ne (A-5021) was evaluated in murine cells and in several murine models of herpes simplex virus (HSV) infection. Against HSV type 1 (HSV-1), A-5021 was 15-30- and 30-60-fold more active, and against HSV type 2 (HSV-2), it was 2- and 8-fold more active than acyclovir and penciclovir in Balb/3T3 cells, respectively. When antiviral compounds were administered orally (once daily) to mice infected intraperitoneally with HSV-1 (Tomioka), A-5021 was more active than acyclovir or famciclovir in spite of its relatively low oral bioavailability. A-5021 was as active as penciclovir when the antiviral compounds were given intravenously (three times daily) to mice infected intraperitoneally with HSV-2 (186). In mice with a cutaneous HSV-1 (KOS) infection, three times daily oral therapy with A-5021 at 25 mg/kg per day produced more significant reduction in severity of skin lesions than equivalent treatment with acyclovir or famciclovir. In mice infected intracerebrally with HSV-1 (Tomioka), complete survival was observed in the group treated intravenously with A-5021 at 25 mg/kg per day (three times daily), while more than 50% of mice died in the groups treated intravenously with acyclovir of up to 100 mg/kg per day (three times daily). Moreover, A-5021 was more effective than acyclovir in clearing infectious virus from the brain. These findings demonstrate that A-5021 has potent anti-HSV activity in several murine models.

[Patients also desire standard therapies]

Insured health care in Japan has to date lacked quality controls and checks, and treatments provided by medical institutions and doctors are found to be widely varied. Today, quality control is commonplace among commercial products and services, but the field of health care clearly lags behind in this area. Standard medical treatments are a significant step toward quality control and improvements. The progress made in developing standard treatments for stomach cancer, the most common form of cancer among Japanese, is thus much welcomed by all citizens.

Education as a means of reducing medical expenses

In treating patients with infectious diseases, key knowledge and experience are essential in making appropriate clinical decisions. Medical students in Japan receive limited tuition in clinical pharmacology and microbiology in their undergraduate curriculum. Education and guidance in these fields are not always provided, even during postgraduate training. To help overcome this problem, we have devised a quick medical reference system to support antimicrobial chemotherapy, and this has been operating in our hospital since May 1994. This system is integrated in order to convey the maximal significance of test results by providing detailed information on various kinds of pathogens and antibiotics immediately on every computer display. This is a unique system in Japan, and aims to help doctors provide effective therapy. Using this system, we have succeeded in reducing medical expenditure for antimicrobials by around 10%.

Anionic properties of beta-lactam-enhancing factor on methicillin-resistant Staphylococcus aureus

We found a Factor (factor T) in aged mixtures of tungstate and phosphate which greatly enhanced the antibacterial effects of beta-lactams upon methicillin-resistant Staphylococcus aureus (MRSA). Factor T suppressed penicillinase production and the amount of penicillin-binding protein-2' in the membrane fraction, thus sensitizing MRSA strains to beta-lactams. In addition, Factor T caused a metachromatic reaction and prolonged the blood coagulation time, indicating that it is a heparin-like polyanion. Since Factor T becomes ineffective in the presence of a polycation, a charge interaction may play an important role in the enhancing effect. One possibility is that Factor T non-specifically inhibits several anion-sensitive enzymes. Factor T inhibited several nucleotide-interacting enzymes, but not most serum enzymes.

[Clinical bacteriological analysis of Vibrio vulnificus infection--a report of five case]

Clinical features in Vibrio infection are generally represented by gastrointestinal involvements such as food poisoning, and its prognosis is usually good. However, Vibrio vulnificus infection not uncommonly causes serious problems including sepsis, necrotizing fasciitis of the extremities, and other conditions, sometimes resulting in fatal outcome. In the present study, we analyzed clinical microbiological aspects of five cases with V. vulnificus infection. All the strains of V. vulnificus isolated in five patients are oxidase-positive Gram negative rods presenting comma-like configuration, which were yielded on TCBS agar forming green colonies; they were grayish-white in color and viscous in texture on 5% sheep blood agar, identification of bacteria were done using VITEK AMS (BioMérieux). Piperacillin and third-generation cephalosporins were found to have bactericidal activities against these strains. All five cases we experienced have primary ailments, and three cases out of the five had taken perishable sea-food before showing disease symptoms. V. vulnificus has two infection channels; one is external wound and the other is oral intake. The latter is said that it may become serious. This has a rather short period from the starting the symptoms to death, and there is high death rate. For life-saving, it is inevitably necessary to dose an effective antibacterial medicine in the early stage. If we suspect this bacteria in the test laboratory, it is important to report this to the clinical doctor. In other words, this is one of the bacteria that needs prompt treatment and further microbiology testing.

Possible mechanism of action of beta-lactam-enhancing factor on methicillin-resistant Staphylococcus aureus

We have recently found a factor (Factor T) in aged mixtures of tungstate and phosphate which greatly enhances the antibacterial effects of beta-lactams on methicillin-resistant strains of staphylococcal species such as methicillin-resistant Staphylococcus aureus (MRSA), but shows only weak effects on methicillin-susceptible S. aureus and bacterial strains other than staphylococci. Factor T alone did not strongly inhibit cell metabolism and bacterial growth unless an excess amount was added. When Factor T was added to the culture medium beforehand, the growth of MRSA cells was rapidly suppressed just after addition of oxacillin (MPIPC). However, the growth of the cells was inhibited gradually when these two reagents were added in reverse order. For full expression of the enhancing effect, it seemed necessary for cells of MRSA strains to be incubated with Factor T for at least 2-3 hr. When the cells were washed after being sensitized by incubating them for 5 hr with Factor T, it took approximately 1 hr for the cells to recover their resistance to MPIPC. Factor T reduced the amount of penicillin-binding protein-2' (PBP 2'), and thus sensitized the MRSA strains to beta-lactams.

[Isolation of penicillin-resistant Streptococcus pneumoniae in Saga Medical School Hospital]

A recent nationwide increase in beta-lactams-resistant Streptococcus pneumoniae has attracted a great deal of attention. We studied the drug sensitivity of S. pneumoniae isolated from various clinical specimens in Saga Medical School Hospital between April 1988 and December 1991. To determine the drug sensitivity of the strains, we used a micro-dilution method and determined the MIC. Drug resistance was evaluated using MIC of ampicillin (ABPC) as a reference MIC, and the results were roughly classified into the following three groups: sensitive (< or = 0.1 microgram/ml), moderately resistant (0.2-3.13 micrograms/ml) and highly resistant (> or = 6.25 micrograms/ml). The isolation frequency was calculated on the basis of one strain from one patient. No strain of S. pneumoniae with high resistance against ABPC was found in 1988 (94 strains of S. pneumoniae were isolated) and 1990 (115 strains isolated), but one such strain (0.8%) was found among 129 strains isolated in 1989, and 2 such strains (2.4%) among 84 strains isolated in 1991. Moderately resistant strains were isolated at the frequencies of 12.8%, 15.5%, 22.6%, and 21.4% respectively, in 1988, 1989, 1990, and 1991. A sum of the frequencies of "moderately resistant" and "highly resistant" (2.4%) strains was 23.8% in 1991. The frequency of resistant strains is increasing and the intensity of resistance is also being elevated.

[Hospital infection with methicillin-resistant Staphylococcus aureus (MRSA) in Saga Medical School Hospital, a rapid increase in coagulase type-VIII strains]

Hospital infection with MRSA has increased in Saga Medical School Hospital. The causative MRSA consisted predominantly of coagulase type-II strain before 1989, but after 1990, coagulase type-VII MRSA increased rapidly. This type-VII strain has marked multiple drug-resistance, and the pattern of drug sensitivity of MRSA in this hospital was different from that of MRSA detected in other facilities, which are clinically serious problems, therefore, we conducted an etiological study of the background of the increase in MRSA infection in our hospital. The results of the study are summarized as follows: 1) The proportions of MRSA (on strain from one patient) to all types of S. aureus detected in the hospital were 26% for 1986, 23% for 1988, 37% for 1989, 30% for 1990 and 60% for 1991. The proportion increased greatly in 1991. 2) Coagulase type VII-MRSA was first detected only in 5 patients in 1989, then it tended to spread, and this type (probably derived from the same strain) accounted for 47% of MRSA infection in patients examined in 1991. 3) The study of the drug sensitivity pattern and etiological survey of the infection showed that coagulase type VII-MRSA prevalent in the hospital consisted of two types: CLDM, and EM-sensitive, IPM/CS, and MINO-resistant and TSST-1 non-producing and enterotoxin non-producing type, and CLDM, and EM-sensitive, IPM/CS, and MINO-resistant and TSST-1 non-producing type with enterotoxin serotype A. 4) Coagulase type VII-MRSA (Probably derived from the same strain) was detected in physicians and nurses working in affected wards and also in the patients's room.(ABSTRACT TRUNCATED AT 250 WORDS)

An improved method for the serotyping of free coagulase from Staphylococcus aureus

The serotyping of free coagulase, one of the most reliable ways to identify strains of Staphylococcus aureus, and widely employed in Japan, has been improved by adding magnetite sand to the reaction mixture. Culture medium supernatant and a type-specific antibody are mixed in a well of a microtiter plate, and plasma-enriched bovine fibrinogen is treated with magnetite sand. The use of tranexamic acid and gum arabic in the reaction mixture also increases the sensitivity of the reaction. Finally, the plate is placed on a magnetic stirrer. If the type of the coagulase corresponds to that of the antibody, no clot formation will occur, and this is easily confirmed by the movement of the sand. Although the amount of reaction mixture required is much less than that for the conventional tube method, our new method is able to detect slight increases in viscosity of the reaction mixture due to fibrin formation even before complete clotting occurs, thus providing very high sensitivity. Clot formation can also be judged by observing a turbid mass of fibrin in the well (Hwang's method), but this approach is a little slower than our method involving immobilization of magnetite sand.

Palliative laser therapy

Endoscopic laser treatment has been tried for hemostasis, relief of stenosis and reduction of tumor volume in advanced upper gastrointestinal cancer. This form of treatment was found to be effective for each purpose, but success was usually only temporary. Thus, it was considered that endoscopic laser therapy for problems of advanced upper GI cancer could perhaps be improved by modifying the technique and/or developing new methods, such as the combination of the laser with other therapies.

Effect of disinfectants on variola virus in cell culture

Twenty kinds of disinfectants were examined for ability to inactivate variola virus. Cytopathic effect and plaque formation on monolayer cultures of an established monkey kidney cell line were used as indicators of virus inactivation. A micromethod using microplate cultures, and not requiring a CO2 incubator, was adopted. The procedures were straightforward, showing good reproducibility. Among the compounds tested, several were found to be superior because of the minimum concentrations required for complete inactivation of virus. The purified viruses were shown to be more sensitive to the compounds than were the crude samples. The virus inactivation kinetics curves were determined by plaque counting. The usefulness of this method for quantitative analysis of disinfecting effect is suggested.