Enhancing sweat rate using a novel device for the treatment of congestion in heart failure

Background

Current treatment of fluid retention in heart failure (HF) relies primarily on diuretics. However, adequate decongestion is not achieved in many patients.

Purpose

To study the feasibility and short-term performance of a novel approach to remove fluids and sodium directly from the interstitial compartment by enhancing sweat rate.

Methods

We used a device designed to enhance fluid and salt loss via the eccrine sweat glands. Skin temperature in the lower body was increased to 35–38°, where the slope of the relationship between temperature and sweat production is linear. With this wearable device, the sweat evaporates instantaneously, thus avoiding the awareness of perspiration. The primary efficacy endpoint was the ability to increase skin temperature to the desired range without elevating the core temperature above normal range. A secondary efficacy endpoint was a clinically meaningful hourly sweat output, defined as ≥150 mL/h. The primary safety endpoint was any procedure-related adverse events.

Results

We studied 6 normal subjects and 10 HF patients with clinical evidence of congestion and median NT-proBNP of 602 pg/mL [interquartile range 427 to 1719 pg/mL]. Participants underwent 3 treatment sessions of up to 4h. Skin temperature increased to a median of 37.5°C (interquartile range 37.1–37.9°C) with the core temperature remaining unchanged. The median total weight loss during treatment was 219±67 g/h (Figure) with a range of 100–338 g/h. In 77% of cases, the average sweat rate was ≥150 mL/h. Systolic (P=0.25) and diastolic (P=0.48) blood pressure and heart rate (P=0.11) remained unchanged during the procedure. There were no significant changes in renal function and no procedure-related adverse events.

Conclusion

Enhancing sweat rate was safe and resulted in a clinically meaningful fluid removal and weight loss. Further evaluation of this concept is warranted.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): AquaPass Inc Weight loss due to sweat

Ezrin protects bovine spermatozoa from spontaneous acrosome reaction

To interact and penetrate the egg, the spermatozoon must undergo a maturation step called the acrosome reaction (AR) in close proximity to the egg. This process can take place only after a series of biochemical changes to the sperm occur in the female reproductive tract, collectively called capacitation. Spermatozoa can undergo spontaneous-acrosome reaction (sAR) before reaching the vicinity of the egg, preventing successful fertilization. Several mechanisms were shown to protect spermatozoa from undergoing sAR. Here we describe the involvement of the actin cross-linker, Ezrin in the mechanism that protects spermatozoa from sAR. Inhibition of Ezrin stimulates sAR and inhibits actin polymerization. Ezrin is highly phosphorylated/activated during the first hour of the capacitation process, and its phosphorylation rate is subsequently decreased. Ezrin phosphorylation depends on protein kinase A (PKA) and calmodulin kinase II (CaMKII) activities, and to some extent on phosphatidyl-inositol-4-kinase (PI4K) activity. Inhibition of these three kinases stimulates sAR, in which the effect of PI4K inhibition, but not PKA or CaMKII inhibition, can be reversed by increasing p-Ezrin using a phosphatase inhibitor. All together, we showed that three kinases mediate Ezrin activation during spermatozoa capacitation, leading to actin polymerization in a mechanism that prevents sAR.

A possible mechanism for the bactericidal effect of visible light

Visible light at high intensity was found to kill bacteria while low-power light in the visible and near infrared region enhances bacterial proliferation. The present review summarizes evidence demonstrating that the mechanism of visible light- bacteria interaction involves reactive oxygen species (ROS) generation. The ROS are photo induced by bacterial endogenous photosensitizers. Phototoxic effects were found to involve induction of high amounts of reactive oxygen species (ROS) by the bacteria while low amounts of ROS may promote their proliferation. Intense blue light, preferably at 415nm, is better than red light for bacteria killing.

Photodynamic antimicrobial chemotherapy by liposome-encapsulated water-soluble photosensitizers

Photodynamic antimicrobial chemotherapy is an alternative method for killing bacterial cells in view of the increasing problem of multi-antibiotic resistance. We examined the effect of three water-soluble photosensitizers (PhS): methylene blue (MB), neutral red (NR) and rose bengal (RB) on Gram-positive and Gram-negative bacteria. We compared the efficacy of PhS in their free form and encapsulated in liposomal formulations against various bacterial strains, and determined conditions for the effective use of encapsulated PhS. We found that all three PhS were able to eradicate the Gram-positive microbes Staphylococcus aureus and Sarcina lutea; and MB and RB were effective against St. epidermidis. In the case of the Gram-negative species, MB and RB were cytotoxic against the Shigella flexneri, NR-inactivated Escherichia coli and Salmonella para B, and BR was effective in killing Pseudomonas aeruginosa. None of the examined PhS showed activity against Klebsiella pneumoniae. MB and NR enclosed in liposomes gave a stronger antimicrobial effect than free PhS for all tested prokaryotes, whereas encapsulation of RB led to no increase in its activity. We suggest that encapsulation of PhS can increase the photoinactivation of bacteria.

Porin Isolated from the Outer Membrane of Erwinia amylovora and Its Encoding Gene

A major Erwinia amylovora outer-membrane protein (Omp-EA) and the gene encoding for this protein (omp-EA) were isolated and characterized. The native Omp-EA protein forms a trimeric structure of approximately 114 kDa. This protein demonstrated high resistance to detergents such as SDS and octyl-glucopyranoside, but disaggregated to monomers with a molecular weight (MW) of approximately 39 kDa after heating at 95 degrees C for 10 minutes in sample buffer. The pore-forming ability of the oligomeric Omp-EA was determined by the liposome swelling assay, demonstrating that the oligomeric protein formed nonspecific channels with an exclusion limit of approximately 660 Da. On dissociation, the monomers did not exhibit pore-forming ability. The omp-EA gene was cloned and sequenced (GenBank Accession No. DQ184680). Sequence analysis revealed an open reading frame of 1152 bases. The deduced amino-acid sequence had 383 amino acids. The mature protein consisted of 362 amino acids and had a calculated MW of 39,210 Da. Multiple-sequence alignment of Omp-EA with other porins from the Enterobacteriaceae family revealed 51% to 63% identity. The first 16 amino acids from the N-terminal exhibited the highest identity (100%) to the porins OmpC, OmpF, and PhoE of Escherichia coli. Two methods were used to predict the secondary structure: APSSP2 and Hidden and Markov's model. The monomers of Omp-EA porin presented a topology of 16 transmembranal beta-strands. The area of the loops between the beta -strands was proposed. It is suggested that further research on the porin and its loops may be important for understanding the mechanism of E. amylovor to invade plant tissues.

Die-off of Cryptosporidium parvum in soil and wastewater effluents

AIMS

To determine the effect of biotic and abiotic components of soil on the viability and infectivity of Cryptosporidium parvum, and evaluate the suitability of viability tests as a surrogate for oocyst infectivity under various environmental settings.

METHODS AND RESULTS

The die-off of C. parvum in saturated and dry loamy soil was monitored over time by immunofluorescence assay (IFA) and PCR to estimate oocysts viability and by cell culture to estimate oocysts infectivity. Pseudomonas aeruginosa activity resulted in digestion of the outer layer of the oocysts, as demonstrated by loss of the ability to react in IFA. Whereas, P. aeruginosa activity did not affect the DNA amplification by PCR. A 1-log reduction in the oocysts infectivity was observed at 30 degrees C in distilled water and in saturated soil while oocysts viability was unchanged. Incubation for 10 days in dry loamy soil at 32 degrees C resulted in a 3-log(10) reduction in their infectivity while no change of oocysts viability was recorded.

CONCLUSIONS

Under low temperature, C. parvum oocysts may retain their infectivity for a long time. Soil desiccation and high temperatures enhance the die-off rate of C. parvum.

SIGNIFICANCE AND IMPACT OF THE STUDY

Previous die-off studies of C. parvum used viability tests that do not necessarily reflect the oocyst infectivity. Under low temperatures, there was an agreement observed between viability and infectivity tests and oocysts retained their infectivity for a long time. Desiccation and high temperatures enhance the loss of infectivity of C. parvum. The presented die-off data have significant implications on the management of wastewater reuse in warm environments.

An Easy Sonochemical Route for the Encapsulation of Tetracycline In Bovine Serum Albumin Microspheres

A one-step sonochemical process starting with the native BSA and tetracycline was employed to encapsulate the antibiotic drug in microspheres of BSA. The tetracycline loading studies showed that the maximum tetracycline loading capacity was found to be 65%. The antimicrobial activity of the tetracycline loaded in BSA microspheres was demonstrated on two bacterial strains that are sensitive to tetracycline.

Contribution of microbial activity to virus reduction in saturated soil

Application of wastewater to soil may result in the contamination of groundwater and soil with pathogenic microorganisms and other biological and chemical agents. This study was performed to determine the antiviral microbial activity of soil saturated with secondary effluent. Low concentrations (0.05mg/ml) of protease pronase resulted in the inactivation of more than 90% of seeded Cox-A9 virus, whereas Poliovirus type 1, Hepatitis A virus (HAV) and MS2 bacteriophages were found to be insensitive to the enzyme activity. Exposure of Cox A9 virus to P. aeruginosa extracellular enzymes resulted in 99% inactivation of the seeded virus. Hepatitis A virus was found to be as sensitive as the Cox A9 virus, whereas Poliovirus 1 and MS2 were found to be insensitive to P. aeruginosa extracellular enzymatic activity. Furthermore, the time required for 99% reduction (T99) of Cox A9 and MS-2 Bacteriophage, at 15 degrees C, in soil saturated with secondary effluent was found to be 7 and 21 days, respectively. Faster inactivation was observed for MS2 and Cox A9 in soil saturated with secondary effluent incubated at 30 degrees C, T99 of 2 and 0.3 days, respectively. Although the concentration of the total bacterial count in the soil samples increased from 10(3) cfu/g to 10(5) cfu/g after 20 days of incubation at 30 degrees C, the proteolytic activity was below the detection level. The results of this study indicate that the virucidal effect of microbial activity is virus type dependent. Furthermore microbial activity in the soil material can be enhanced by the application of secondary effluent at higher temperature. The results also showed that MS2 bacteriophage can be used to predict viral contamination of soil and groundwater.

Photoinactivation of Acinetobacter baumannii and Escherichia coli B by a cationic hydrophilic porphyrin at various light wavelengths

Photodynamic treatment by the cationic TMPyP photosensitizer was undertaken on the multiple antibiotic-resistant bacteria Acinetobacter baumannii and Escherichia coli. Total eradication of the bacterial cultures was determined immediately after initiation of illumination when these bacteria were treated with 5, 10, 15, 20-tetra (4-N methylpyridyl)porphine (TMPyP) at a concentration of 29.4 micromol/L and illuminated by blue, green, or red light. Total eradication of both bacteria was obtained also after treatment of bacterial cultures with 3.7 micromol/L TMPyP and illumination with blue light (400-450 nm). On the other hand, an 8- or 16- to 20-fold higher light intensity, respectively, was required for total eradication upon illumination with green (480-550 nm) or red light (600-700 nm). A 407-nm blue light only 7 and 9 joules/cm2, respectively, was needed for total eradication of both bacteria even at a concentration of 3.7 micromol/L TMPyP. X-ray-linked microanalysis demonstrated loss of potassium and a flood of sodium and chloride into the cells, indicating serious damage to the cytoplasmic membrane. Transmission electron microscopy (TEM) revealed structural changes and damage to the membrane of treated E. coli. In A. baumannii-treated cells, mesosomes and black dots that resemble aggregation of polyphosphate polymers could be seen. DNA breakage appeared only after a long period of illumination, when the bacterial cell was no longer viable. It can be concluded that cytoplasmic membrane damage and not DNA breakage is the major cause for bacterial death upon photosensitization.

Isolation of Vibrio vulnificus from sea water and sand along the Dan region coast of the Mediterranean

The occurrence of Vibrio vulnificus incoastal sea water and sand was investigated. Samples (286 in toto) were taken during the period between November 1993 and July 1994. Ten V. vulnificus isolates (6.9%) were recovered from sea water and two isolates were recovered from sand (1.4%). The total isolation rate for this period was 4.2%. In a longer period of investigation, from June 1996 until June 1998 (24 months), 1,248 samples were taken and 205 V. vulnificus isolates were recorded (32.8%) in sea water while only 18 isolates in sand (2.9%). The total isolation rate was 17.9%. The monthly occurrence of this bacterial species in the various beaches surveyed demonstrated that V. vulnificus is more frequent during the months of July, August and September. The increase in the number of isolates during the past 2 years started as early as March and finished as late as October. Antibiotic sensitivity testing revealed that this species is sensitive to most antibiotics, except polymyxin B and colistin. The relatively high isolation rate of this bacterium from sea water may be dangerous to bathers, fishermen and divers with predisposed wounds.

Characterization of porins isolated from the outer membrane of Serratia liquefaciens

A major outer membrane protein with an apparent molecular weight of 42 kDa was purified from Serratia liquefaciens grown on Brain Heart Infusion medium. The same protein was obtained when the cells were grown on a synthetic medium supplemented with 2% glucose. The amino acid composition of this protein revealed it to be hydrophilic. The pore-forming ability of the 42-kDa protein was determined by the liposome swelling assay. This assay demonstrated that the protein forms nonspecific channels with a diameter between 1.16 and 1.6 nm. An additional protein with a molecular weight of 47 kDa was obtained on synthetic medium supplemented with maltose. This protein exhibited specific pore-forming ability to maltose and maltodextrins, but was also permeable to other compounds, according to their size. When bacteria were grown on Nutrient Broth medium, two outer membrane proteins with molecular weights of 41 kDa and 42 kDa were produced by the bacteria. All three types of proteins represent monomers of respective oligomers. The monomers did not exhibit pore-forming ability when incorporated into liposomes. We, therefore, propose that the oligomer is the functional unit of a porin capable of forming permeability channels in the outer membrane of Serratia liquefaciens. These results indicate that S. liquefaciens contains several porins exhibiting specific osmoregulation or that are induced by a specific nutrient, where the 42-kDa outer membrane protein of this bacterium is certainly a major porin.

Isolation and Characterization of Heat-Modifiable Proteins From the Outer Membrane of Porphyromonas Asaccharolytica and Acinetobacter Baumannii

Active porins were isolated and purified from the outer membranes of the gram-negative anaerobic rod Porphyromonas asaccharolytica and the aerobic coccobacillus Acinetobacter baumannii. The porins from both bacteria appear to be monomers when isolated and purified. Both porins exhibited decreased mobility on SDS-PAGE after boiling for 10 min in the sample buffer. After heating, their molecular weight is estimated at 43 kDa while without heating they run as proteins with a molecular weight of approximately 37 kDa. Due to their characteristic heat-modifiability, these proteins were named HMP (heat-modifiable protein)-P. asaccharolytica and HMP-A. baumannii. Amino acid analysis revealed both porins to be hydrophilic proteins. These proteins have been shown to be active in transporting sugars when incorporated into liposomes. The permeability of both porins for L-arabinose was less than that produced by the porin of Escherichia coli B. Permeability to high molecular weight disaccharides was lower than for small monosaccharides. Western blot analysis did not reveal any antigenic cross reaction between HMP-A. baumannii and the HMP-P. asaccharolytica. The results obtained in this study confirm that although these heat-modifiable proteins are pore forming proteins and have similar activity they differ in their antigenicity.

Characterization of porins isolated from the outer membrane of Vibrio damsela

A protein oligomer with an approximate molecular weight of its 37-kDa monomer form was purified from the cell envelope fraction of Vibrio damsela cells. This oligomer exhibited strong porin activity when reconstituted into proteoliposomes with phosphatidyl choline. The functional properties for the 37-kDa protein suggest that it is a nonspecific or general porin, with an apparent pore size of 1.6 nm. This porin allows penetration of a variety of hydrophilic solutes according to their molecular mass. After electroelution, the oligomer was partially dissociated into monomers, whereas treatment with EDTA did not affect its dissociation. The monomers of the 37-kDa protein were not active in the reconstitution assay. The effect of culture media on the composition of the outer membrane protein of V. damsela was examined. Only one outer membrane protein with an apparent molecular weight of 37 kDa (37-kDa protein) was formed in cells grown in 3% NaCl-BHI broth and in 3% NaCl-nutrient broth with the addition of 2% glucose. Three outer membrane proteins, with apparent molecular weights of 37 kDa, 40 kDa, and 46 kDa, were produced in cells grown in 3% NaCl-nutrient broth. An additional outer membrane protein with an apparent molecular weight of 44 kDa (44-kDa protein) was found in cells grown in 3% NaCl-nutrient broth with the addition of 2% maltose. This protein was found to exhibit specificity to maltose derivatives. The results obtained in this study confirm the porin-like character of discussed proteins and give a basis for advanced study of those proteins.

Eradication of Acinetobacter baumannii by photosensitized agents in vitro

The photodynamic effects of photosensitizers on Acinetobacter baumannii were studied. These Gram negative bacteria have recently been implicated in various infections, mainly acquired in hospitals. They have outstanding characteristics of multidrug high resistance to antimicrobial agents. The best photodynamic effect was obtained when A. baumannii cultures were treated with light activated deuteroporphyrin (Dp) at a concentration of 34 mumoles l-off and polymyxin nonapeptide (PMNP) at a concentration of 200 mumoles l-1. At these concentrations the culture in brain heart infusion (BHI) broth was found to be sterile after l h of treatment. Some inhibition was also obtained under the same conditions with Cd-texaphyrin (Cd-Tx) in the presence of PMNP. Treatment with various other photosensitizers in the presence of PMNP exhibited only marginal antibacterial activity. The cationic photosensitizer tetra-methylpyridyl porphine (TMPyP) did not exhibit any photodynamic effect on A. baumannii when illuminated during its growth in BHI broth. Bacteria grown in nutrient broth or suspended in saline and treated by TMPyP resulted in a significant photoinactivation by the sensitizer alone even in the absence of PMNP. It was found that a high concentration of the proteins present in BHI or in serum prevent TMPyP from acting as a photosensitizer against A. baumannii. Bovine serum albumin at the same high protein concentration prevents Dp (in the presence of PMNP) to act as a photosensitizer. The anionic photosensitizer tetra-sulfonatophenyl porphine (TPPS4) did not show any photodynamic effect in high or low protein media. In this study it was found that despite the high resistance of the Acinetobacter baumannii to antibiotics, these bacteria can be significantly photoinactivated by treatment with either Dp + PMNP or TMPyP in low protein content environments. When the protein concentration is high photoinactivation efficiency depends on the type of protein present in the medium.

The use of porphyrins for eradication of Staphylococcus aureus in burn wound infections

The assessment of deuteroporphyrin-hemin complex as an agent for the treatment of burn wounds infected with a multiple-drug resistant strain of Staphylococcus aureus was performed. The effect of the porphyrin on the survival of the infectious bacteria was first assayed in culture, and later tested as well in a burned infected animal model. The addition of deuteroporphyrin and hemin, separately or together (as a complex) to a growing culture of S. aureus was monitored during 8 hours. It was found that deuteroporphyrin alone was strongly bactericidal only after photosensitization. On the other hand, hemin alone was moderately bactericidal but light independent. A combination of both deuteroporphyrin and hemin was extremely potent even in the dark and did not require illumination to eradicate the bacteria. The in vivo experiments by application of the above porphyrins in combination to infected burn wounds in guinea pigs was an effective way to reduce dramatically the contaminating S. aureus. Reduction of more than 99% of the viable bacteria was noted after the porphyrin mixture was dropped on the eschar or injected into the eschar, an effect that lasted for up to 24 hours. The deuteroporphyrin-hemin complex may be suggested as a new bactericidal treatment of S. aureus infected burns since it was found to be a potent and promising anti-Staphylococcal agent.

The dynamics of inflammation of the anterior eye in a novel experimental model for hypersensitivity

A novel immunologically provoked inflammatory process was studied in guinea pigs. The animals were immunized by i.p. injections of ovalbumin (OA) suspended in Freund's complete adjuvant and challenged by the application of OA into the conjunctival sac of one eye. An inflammatory reaction was seen a few minutes after provocation and lasted normally for 4-7 days. The process was characterized by early damage to the epithelial layer which was partly detached in small flakes; an intense tearing with the tear fluid soon turning mucous and then purulent; vasodilation in the bulbar conjunctiva, in particular towards the limbal region; margination and emigration of polymorphonuclear, and to a lesser extent, eosinophil, leucocytes which migrated towards and infiltrated the surface epithelial layer. Subsequently, the dominant cell type infiltrating the submucosa was lymphocytes. Later, opacity of the cornea occurred, probably due to oedema and neovascularization of the stroma progressing centrally from the periphery. When the antigenic challenge was repeated, thickening of the conjunctival mucosa, and neoformation of collagen bundles in the submucosa led to the swelling of the upper lids. The facets of this inflammatory trauma may not fit easily into any of the classical types of hypersensitivity. Rather, it may combine features of several of them, at least type 1 and type 4. This syndrome shows several features similar to those of human vernal keratoconjunctivitis.

Structure-activity relationship of porphines for photoinactivation of bacteria

The antibacterial photodynamic effects of uncharged (o-tetrahydroxyphenyl porphine [THPP], m-THPP and p-THPP), cationic (5,10,15,20-tetra[4-N-methylpyridyl]porphine [TMPyP]) and anionic (5,10,15,20-tetra[4-sulfonatophenyl porphine] [TPPS4]) porphines on Staphylococcus aureus and Escherichia coli bacteria inactivation were examined. The results show that uncharged porphines provoked antibacterial photodynamic activity on S. aureus, and also on E. coli in the presence of the membrane-disorganizing peptide polymixin B nonapeptide (PMNP). The TMPyP compound was highly photoactive toward gram-positive bacteria but only marginally effective on gram-negative cells, whereas TPPS4 showed no activity on either gram-positive or gram-negative bacteria. The photoactivity of TMPyP is due to the electrostatic attraction between the positively charged sensitizer molecule and the negatively charged membrane of the gram-positive target cells. For TPPS4, the inactivity toward gram-positive bacteria is due to electrostatic repulsion between the charged sensitizer molecule and the cell membrane. For gram-negative bacteria, the inactivity is conceivably due to preferential (electrostatic) binding to the positively charged PMNP, which is an adjuvant for membrane disorganization, but has no effect on cell viability. For hydrophobic sensitizers, the photoactivity depends on the state of aggregation. The extent of deaggregation of the different THPP isomers was determined by fluorescence measurements of bound sensitizers and could be positively correlated with their photoinactivation capacity. We conclude that the structure-activity relationships of these porphines are affected by their net charge and by aggregation.

A 28,000 mol. wt toxin from Bacillus thuringiensis israelensis induces cation transport in rat muscle cultures

The mechanism by which the Bacillus thuringiensis israelensis (Bti) 28,000 mol. wt toxin exerts its effect on mature muscle cultures was examined. The toxin inhibited Na+/K(+)-ATPase activity as revealed by 86Rb influx. A 50% inhibition of Na+/K(+)-ATPase activity was obtained with 0.2 microgram/ml of the toxin. The inhibition was time and dose dependent, and it was reversible with low doses of the toxin (up to 0.2 microgram/ml. A considerable release of 86Rb was obtained by doses greater than 0.2 microgram/ml. The 86Rb release was also time and dose dependent. This effect is probably non-specific, since 45Ca influx is also accelerated by toxin-treated cultures. Pre-incubation of the toxin with phosphotidylserine (PS) antagonized the toxin. It is concluded that the toxin is a hydrophobic protein which interacts with the membrane. In low doses this interaction reduces the activity of the sodium pump and in high doses it causes non-specific permeability of the sarcolemma.

Spectroscopy and photosensitization of sapphyrins in solutions and biological membranes

A spectroscopic and photophysical study of three new sapphyrin molecules is presented. The sapphyrin backbone that was derivatized to make them water soluble possesses an absorption band around 700 nm, a desired property for biological photosensitization. We studied the absorption and fluorescence spectra, from which evidence for aggregation in solvents of different polarities was obtained. The extent of aggregation is correlated with the nature of the attached moiety. The absolute quantum yields of singlet oxygen production were measured, with 1,3-diphenyl isobenzofuran as a model target, and were 0.13-0.18 in ethanol. The binding constants to liposomes and to cells were determined spectroscopically and were found to correspond to the hydrophobicities of the compounds, with an additional effect, ascribed to the sugar moiety, which was found in the case of one of the sapphyrins. The efficiency of photodamage to Staphylococcus aureus by sapphyrins and hematoporphyrin was equivalent, on the basis of cells killed per microgram of sensitizer in the incubation mixture.

Biochemical and morphological changes in rat muscle cultures caused by 28,000 mol. wt toxin of Bacillus thuringiensis israelensis

The 28,000 mol. wt protein of Bacillus thuringiensis israelensis showed a high degree of toxicity to rat muscle in culture. Application of 1 microgram/ml to the culture medium completely inhibited cell fusion. Reversibility of this effect was demonstrated by replacement of the culture medium with fresh medium, and the consequence was that cell fusion was resumed. When differentiated myotubes were treated with 1 microgram/ml of the toxin, the spontaneous contractile activity was abolished within 20 min. Cytotoxic effects were observed 1 hr after treatment was initiated, as manifested by creatine kinase (CK) release to the medium. Two hours after toxin was applied to the muscle culture, the myotubes were deteriorated whereas the mononucleated cells were not affected. Six or 7-day-old cultures which were treated by 1 microgram/ml of 28,00 mol. wt toxin revealed a change in the levels of Na+ and K+ within the fibres as analysed by X-ray microanalysis (XRMA). Preincubation of the toxin for 20 min with phospholipids before application to the cells reduced the cytotoxic effect. Phosphatidylinositol and phosphatidylserine were the most efficient inhibitors, whereas phosphatidylcholine, sphingomyelin and phosphatidylethanolamine were less effective in protecting cultures from the cytotoxic effects of the 28,000 mol. wt protein.

Inactivation of anaerobic bacteria by various photosensitized porphyrins or by hemin

The photodynamic effects of deuteroporphyrin (DP), hematoporphyrin derivative (HPD), hematoporphyrin (HP), or protoporphyrin (PP) on a variety of anaerobic microorganisms were examined in this study. The majority of the species, among the 350 strains tested, were inhibited by concentrations of < or = 2.5 micrograms/ml of light-activated DP. Species found to be resistant to this treatment included Bilophila wadsworthia, Fusobacterium mortiferum, Fusobacterium varium, and Bacteroides gracilis. These species were inhibited by concentrations of > 60 micrograms/ml of DP. The porphyrin-producing species, Porphyromonas and Prevotella spp, were all inhibited by < or = 2.5 micrograms/ml DP and light. Comparing the photodynamic activity of the porphyrins used on Porphyromonas strains resulted in the following pattern: DP > HPD > HP > PP. Porphyromonas spp., Gram-positive cocci, and many Gram-positive rods (excluding clostridia) were inactivated by hemin (a metal-containing porphyrin) at 10-20 micrograms/ml. Hemin inhibitory action was not affected by light. Binding and insertion of DP into bacteria (both inactivated and non-inactivated strains by DP and light) were monitored by the characteristic fluorescence band of bound DP at 622 nm. Porphyromonas spp. bound DP tightly, whereas only low binding was seen with B. wadsworthia and other DP-resistant species. High binding of DP to B. wadsworthia can be achieved by pretreatment of the bacteria with imipenem or cefoxitin, beta-lactam agents known to interfere with the integrity of the cell wall. If cell wall integrity is disturbed (e.g., by these agents), inactivation of B. wadsworthia by DP can occur.

Chlamydia trachomatis direct isolation, antibody prevalence and clinical symptoms in women attending outpatient clinics

Two hundred and ninety-seven women with complaints of vaginal or urethral discharge and 100 women attending outpatient clinics for contraceptive or other advice (enrolled as controls) were studied and compared. A meticulous sampling for Chlamydia trachomatis was taken from one hundred and seventy-seven women enrolled in the study group (A1). Technical difficulties were encountered with the remaining 120 cases--study group (A2). It was found that ninety-three out of the 177 women (of group A1) were infected with either Chlamydia trachomatis or Neisseria gonorrhoeae (52.5%) compared to four out of 120 (3.4%) in the A2 subgroup. The overall prevalence of C. trachomatis antibodies was found to be 171/397 (43.1%) when all three groups studied were tested by immunoperoxidase (IPA). In comparison, by direct culture alone 92/397 (23.2%) were positive. The most significant clinical symptoms for chlamydial infection were purulent or mucoid discharge, bleeding and vaginitis (p = 0.005). This study demonstrates that immunoperoxidase (IPA) and ELISA techniques for C. trachomatis serology are helpful for the identification of infection by this agent. The possibility of using these serological methods in screening tests for vaginal infections in addition to C. trachomatis direct culture and clinical symptoms in outpatient clinics should be considered.

Gram negative bacteria isolated from blood cultures in a general hospital

This study reviews 2205 significant positive blood cultures from 534 patients treated at the Meir General Hospital during the period 1988-1990. In addition, a comparison was made with a previous survey performed twelve years ago (1976-1978). Gram negative rods accounted for 68% of the septicemia cases indicating a small increase since the former survey (61.2%). The order of Gram negative frequencies was E. coli, Urea positive Gram negative bacteria (UPGNB) Klebsiella, Enterobacter, Pseudomonas (in a decreasing order). E. coli was most predominant in both surveys in the internal wards while UPGNB were predominant in the geriatric-rehabilitation wards. A significant rise in frequency of cephalothin and sulfamethoxazole-trimethoprim resistant E. coli isolates was noticed. In UPGNB, Klebsiella and Pseudomonas a significant increase in resistant isolates to cephalothin, gentamicin, sulfamethoxazole-trimethoprim and chloramphenicol was found. As for tobramycin, amikacin and mezlocillin, it is clear that the Gram negative bacteria have gained resistance to these drugs over recent years. Resistance frequencies of above 20% were found in Enterobacter and Pseudomonas for the newer antimicrobial agents such as: ceftriaxone, cefotaxime or ceftazidime. Low resistance is still seen in all above bacteria against ciprofloxacin and ofloxacin. The minimal inhibitory concentrations (M.I.C.) of gentamicin, cephalothin, cefotaxime, ceftazidime ceftriaxone and sulfamethoxazole-trimethoprim do not exceed the range of 30 micrograms/ml. The M.I.C. range of the quinolone ciprofloxacin does not exceed 6 micrograms/ml.

Collapse of K+ and ionic balance during photodynamic inactivation of leukemic cells, erythrocytes and Staphylococcus aureus

1. The immediate and fast ionic fluxes in Friend erythroleukemic cells (FELC), erythrocytes and Staphylococcus aureus during short intervals of porphyrin mediated photosensitization were determined uniquely by X-ray microanalysis (XRMA) combined with electron microscopy. 2. Photodynamic inactivation of FELC was mediated by either endogenous protoporphyrin induced by 5-amino levulinic acid (5-ALA), or Photofrin-II. We describe the predominant phenomena of > 85% K-loss within 2-10 min of photoactivation. However the accompanied Na inflow and the collapse of the cellular balance of elemental-composition were inconsistent and acted as a function of cell damage. 3. Erythrocytes treated with hematoporphyrin (HP) lost most of their intracellular K yet instantly gained Na. Nevertheless the K/Na molar ratio of the control erythrocytes was nearly 12/1 while after photosensitization and K loss it changed to 1/1. 4. The S. aureus bacteria photosensitized with HP showed entire K-loss as well as marked Na efflux which increased with irradiation time; this was accompanied by the decline of other cell elements. 5. The prevailing K loss in FELC, erythrocytes and bacteria during the first minutes of photosensitization is deduced to be an immediate primary consequence of the photodynamic effect, while other ionic changes are joined in order with the development of cellular damage.

Electric depolarization of photosensitized cells: lipid vs. protein alterations

We have monitored several photosensitized reactions in proteins, liposomes and cells under similar conditions. We found that the depolarization of K(+)-diffusion potential of liposomes or the leakage of an entrapped molecule, calcein, progress at a much slower rate than the photosensitized damage to proteins and the photosensitized killing of bacterial and leukemic cells. X-ray microanalysis revealed that upon light exposure of HP-treated leukemic cells and bacteria, they totally lost their cellular potassium. We deduce that the direct photosensitized oxidation of lipid components cannot cause the depolarization of cells, which in turn could be responsible for their death. A photosensitized damage to protein sites in the cell, probably in the membrane, is a more likely reason for the depolarization, the loss of potassium ions and cell death that is caused in light-activated photodynamic processes.

The antibacterial activity of haemin compared with cobalt, zinc and magnesium protoporphyrin and its effect on potassium loss and ultrastructure of Staphylococcus aureus

The unique antibacterial properties of Fe-protoporphyrin (haemin) on Staphylococcus aureus, compared to Co-protoporphyrin (Co-PP), Mg-protoporphyrin (Mg-PP) and Zn-protoporphyrin (Zn-PP) are described. Only haemin (20 microM) exhibits a strong light-independent antibacterial effect on S. aureus; the other metalloporphyrins, Co-PP, Mg-PP or Zn-PP, have no antibacterial effect in the dark. Only light photosensitization of Mg-PP-treated cells resulted in the inhibition of the bacterial growth, while Co-PP or Zn-PP were photodynamically inactive. A notable effect of haemin on inactivation of S. aureus was the induction of immediate ion fluxes as determined by X-ray microanalysis (XRMA) of fast-frozen cells. A marked efflux of K (96%) and Cl (94%) was expressed immediately as determined by X-ray microanalysis of S. aureus cells treated with haemin for 5 min. Only 48% loss of Na was detected in the cells under these treatment conditions, while P content was increased by 150%. Electron microscopy analysis revealed the appearance of a mesosome-like structure connected to the new septa, filamentous chromosome and arrays of aggregated ribosomes in the cytoplasm. We propose that haemin has multiple cellular targets for its oxidative effect in S. aureus.

Is syphilis an incurable disease?

Structures which morphologically resemble treponemes have been found in material from patients suffering from latent or late latent syphilis, many of whom have received treatment in the past. These structures were also found in the blood or spinal fluid (SF) of asymptomatic patients with both positive and negative serological tests for syphilis. They have been found in the eye in the presence of active disease as well as in cases without inflammation ('quiet eye'). In latent syphilis, the presence of treponemes after penicillin treatment raises the question of whether the patient is completely cured of syphilis after treatment. Experimental evidence indicates that continued specific antibody production following penicillin treatment depends on the persistence of the specific antigen in the body. This raised three questions: a) Are these stimuli living treponemes? b) Are they still virulent? c) Is syphilis completely curable following penicillin treatment? Our hypothesis is that slowly dividing treponemes are not killed by penicillin. The persistence of living treponemes somewhere in the body may be the proof of this hypothesis. Cases of relapsing neurosyphilis after penicillin treatment have recently been described. We return to the old dilemma: is it a scar-tissue injury or a reactivation of the disease? Since neurosyphilis is asymptomatic, the patient is usually examined because of seroconversion. Only repeated serological analyses and clinical observations of treated cases with immediate penicillin administration can prevent relapse and damage to the central nervous system (CNS) or to other parts of the body.

Possible relationship between Chlamydia trachomatis and acquired immunodeficiency syndrome

This study suggests the possibility that the intracellular parasite Chlamydia trachomatis (Ct) may facilitate the transmission of the human immunodeficiency virus (HIV) during vaginal or rectal intercourse. This is based on the following findings: a) elevated titers of anti-Ct IgG are present in symptomatic acquired immunodeficiency syndrome (AIDS) patients; b) elevated titers of anti-Ct IgA are found in asymptomatic AIDS patients; c) low anti-Ct IgA titers were observed during the progression of the disease; d) high titers of anti-Ct IgA were found in patients suffering from autoimmune diseases; e) high levels of C3 fraction of the complement are found in many of the Ct patients. The presence of anti-Ct IgA and high C3 may be crucial since IgA inactivates Ct and C3 which may increase the invasion of HIV into the cells. This activity of IgA and C3 in Ct patients may increase the susceptibility of male homosexuals and other risk groups in the population to AIDS.

Inactivation of gram-negative bacteria by photosensitized porphyrins

Photosensitization of Escherichia coli and Pseudomonas aeruginosa cells by deuteroporphyrin (DP) is shown to be possible in the presence of the polycationic agent polymyxin nonapeptide (PMNP). Previous studies established complete resistance of Gram-negative bacteria to the photodynamic effects of porphyrins. The present results show that combined treatment of E. coli or P. aeruginosa cultures with DP and PMNP inhibit cell growth and viability. No antibacterial activity of PMNP alone could be demonstrated and cell viability remained unchanged. Spectroscopically, PMNP was found to bind DP, a mechanism which probably assists its penetration into the cell's membranes. Insertion of DP into the cells was monitored by the characteristic fluorescence band of bound DP at 622 nm. Binding times were 5-40 min and the extent of binding increased with decreasing the pH from 8.5 to 6.5. DP binding constants, as well as the concentrations of PMNP which were required for maximal effect on the various Gram-negative bacteria, were determined fluorometrically. By the treatment of DP, PMNP and light the growth of E. coli and P. aeruginosa cultures was stopped and the viability of the culture was dramatically reduced. Within 60 min of treatment the survival fraction of E. coli culture was 9 x 10(-6) and that of P. aeruginosa was 5.2 x 10(-4). Electron microscopy depicted ultrastructural alterations in the Gram-negative cells treated by DP and PMNP. The completion of cell division was inhibited and the chromosomal domain was altered markedly.

In vivo effects of porphyrins on bacterial DNA

The DNA damage in intact Staphylococcus aureus and E. coli cells induced by photosensitized deuteroporphyrin or hemin is described. Treatment of S. aureus cultures with hemin or photosensitized deuteroporphyrin (Dp) caused time-dependent changes in the plasmidial DNA profiles. The major observation was the disappearance of the plasmid supercoiled fraction. The chromosomal DNA was also affected by hemin and by photosensitized Dp, since its degradation products were detected after exposing the bacterial cells to the porphyrin drugs. Photosensitization of E. coli cells, pretreated with Dp and polymyxin B nonapeptide (PMBNP), also resulted in plasmidial damage. No such damage occurred when E. coli cultures were treated with hemin and PMBNP. The above results can be tightly correlated with the antimicrobial action of porphyrins. Their damage to the bacterial DNA seems to reflect one of the in vivo effects of these porphyrins.

Virulence characteristics of male genital tract Escherichia coli isolated from semen of suspected infertile men

The role of Escherichia coli isolates from the semen in the etiology of male infertility, was investigated in this study. Several possible virulence factors of E. coli, such as possession of O antigens or certain K antigens (K1, K5), the type of fimbriae, resistance to antimicrobial drugs and adherence studies to various mammalian sperm cells were examined. It was found that out of 181 E. coli isolates 76.4% belonged to four different urinary serotypes: O1, O2, O4 and O6 (5.7%, 7.5%, 17.0% and 46.2%, respectively). The predominant fimbrial phenotype (81.2%) was T1F+/P-, while 15.8% showed also the possession of P fimbriae (T1F+/P+). No isolate was found with the T1F-/P+ phenotype. The possession of antigens K1, K5 was found to be low (12% only). A relatively high level of adherence to different mammalian sperm cells was found among E. coli isolates. 43% of the E. coli isolates were resistant to doxycycline (the drug of choice) and additionally, most of these were resistant also to ampicillin. We suggest that there is a close subpopulation of E. coli which possess certain virulence properties and have the potential to adhere to sperm cells and to colonize on other target tissues in the male genital tract. Such virulent may cause asymptomatic male infertility and may be termed male genital tract (MGT)-E. coli.

The bactericidal activity of a deuteroporphyrin-hemin mixture on gram-positive bacteria. A microbiological and spectroscopic study

The combined antibacterial activity of various porphyrins with hemin on Gram-positive bacteria was studied. Protoporphyrin, hematoporphyrin derivative and deuteroporphyrin show only a marginal inhibitory effect in the dark. However, hemin has a strong cytotoxic effect which is independent of illumination and is equally strong in the dark. The disadvantage of hemin treatment is that it is temporary. In this study, we have demonstrated that a combination of deuteroporphyrin and hemin has a unique cytotoxic activity on Staphylococcus aureus, Streptococcus faecalis and Bacillus cereus. The effect of the combined compound is stronger than that of the separate constituents, and is as strong in the dark as in the light. Only 0.005% of the initial S. aureus population survive after a 2 h treatment. Absorption and fluorescence spectra of hemin-deuteroporphyrin mixtures in water and liposomes suggest the formation of a species with spectroscopic properties which are different from those of the two constituents.

Bactericidal effects of photoactivated porphyrins--an alternative approach to antimicrobial drugs

Photoactivated porphyrins display a potent cytotoxic activity towards a variety of Gram positive bacteria, mycoplasma and yeasts, but not Gram negative cells. The prerequisite for photosensitization of a microbial cell is the binding of porphyrin to the cytoplasmic membrane in a pH-dependent manner. On illumination, the membrane bound, and possibly, cytoplasmic porphyrin molecules generate singlet oxygen and radicals which sensitize biomolecules and lead to cell death. The immediate inhibition of cell growth on photodynamic treatment is accompanied by alterations in cell wall and membrane synthesis, leading to the formation of large mesosomes adjacent to the unaccomplished septa. Hemin bound to microbial cells exerts cytotoxic activity by peroxidative and oxidative reactions independent of light. Future research in the field may enhance the possibility of using porphyrin photosensitization for treatment of microbial infections. Such clinical use will be unrelated to the antibiotic resistance of the pathogen. Resistance of Gram negative bacteria to porphyrin photosensitization is the main impediment to its use as a broad spectrum antibacterial method.

Chlamydia trachomatis as a possible agent of human autoimmune diseases

A high percentage of patients (61.2%), suspected of having rheumatoid factor and autoimmune diseases, were infected with Chlamydia trachomatis (Ct). Patients with significantly high titres (greater than 256) against Ct (53.8%), also had a significant high level of antinuclear factor and anti DNA. Complement fractions, C3, C4 and the immunoglobulins, IgG, IgA and IgM, were also found in high levels. No cases of rheumatoid factor or autoimmune disease were diagnosed in a control group of patients. The results indicate that patients infected with Ct may develop rheumatic or connective-tissue diseases.

Combined treatment with Pseudomonas aeruginosa toxin and interferon on mouse and human cells

The combined biological effect of Pseudomonas toxin and beta-interferon on mammalian cells was studied on two cell lines. The first was a virus-producing clone derived from NIH/3T3 mouse fibroblasts transformed by Moloney murine sarcoma virus. The second was a clone derived from human amnion cells. The parameters examined were either retrovirus release from the mouse cells or the rate of protein synthesis in both cell lines. When applied together with Pseudomonas toxin, interferon inhibits virus release even at a Pseudomonas toxin concentration that by itself does not exhibit any biological effect on NIH/3T3 cells. This enhancement phenomenon is both Pseudomonas toxin and interferon dose-dependent. Likewise, the combined treatment of either mouse or human cells with Pseudomonas toxin and the appropriate species-specific interferon, inhibits protein synthesis to a much greater extent than either of these agents alone. The kinetics of the inhibition of virus release is different from that seen with protein synthesis indicating that the enhancement phenomenon observed on virus release is not a result of the inhibition of total cellular protein synthesis. Interferon potentiates the effect of Pseudomonas toxin in a species-specific manner, thus suggesting that this process does not occur at the level of cell receptors but is a consequence of a subsequent intracellular event. It is concluded that the enhancement phenomenon does not reflect a direct interaction between interferon and Pseudomonas toxin, since Pseudomonas incubated together with interferon retained its normal biological activity as indicated by the ability of the toxin molecule to transfer the adenine diphosphoribose (ADP-ribose) moiety of nicotinamide-adenine dinucleotide (NAD) onto elongation factor 2 (EF-2).

Pseudomonas aeruginosa isolates from different medical institutions

Patients screened for antibiotic resistance at three different medical institutions yielded 1,597 isolates of Pseudomonas aeruginosa. Most of the isolates were sensitive to amikacin (92.8%), tobramycin (70.6%), gentamicin (59.1%) neomycin (89.4%), azlocillin (84.6%), mezlocillin (83.9%), piperacillin (85.7%), cefsulodin (83.8%) and colistin (98.5%); only 43.8% were sensitive to carbenicillin. In a rehabilitation hospital the frequency of isolates resistant to most of these antibiotics was twice as high than in the two other institutions. The frequency of phenotypes resistant to the combination of carbenicillin and gentamicin was twice as high in the rehabilitation hospital isolates (47.3%) than in the general hospital isolates (28.5%). The frequency of isolates resistant to the combination of aminoglycosides and the new beta-lactam antibiotics is relatively lower than in the former combinations. Serogroup 11 is predominant in the isolates from all three institutions (44%). In carbenicillin- and gentamicin-resistant isolates, 61% were of serogroup 11. On the other hand, in the carbenicillin- and gentamicin-sensitive isolates, serogroup 11 accounted for only 27.2%.

Urinary tract infection and drug-resistant bacteria in different patient populations

A 1-year survey of the pathogens causing urinary tract infections was conducted in three institutions: a rehabilitation hospital, a general hospital and outpatient clinics. Gram-negative rods accounted for 96% of the infections. In the general hospital and the outpatient clinics, Escherichia coli was the most prevalent pathogen, while Proteus sp. were most prevalent in the rehabilitation hospital. The frequency of drug-resistant isolates was significantly higher in the rehabilitation hospital than in the general hospital and the outpatient clinics. This was most conspicuous in the use of the beta-lactam antibiotics, aminoglycosides and sulfonamides against such organisms as E. coli, Klebsiella sp., Enterobacter sp. and Proteus sp. Urinary E. coli were more sensitive to antimicrobial drugs than were other urinary pathogens. Pseudomonas aeruginosa isolates were highly resistant to most antibiotics. About half of the isolates were resistant to gentamicin and another half to carbenicillin. In some instances the frequency of drug-resistant isolates was higher in the general hospital than in the outpatient clinics, reflecting the greater usage of antimicrobials in the general hospital.

Streptococcus group B isolates in a regional hospital area

A survey of the frequency of group B streptococcal infections in the Sharon area (Israel) was done in this laboratory. In the female genital tract streptococcus group B was found in 11.8%. This microorganism was recovered in lower frequencies (1.6%-7.4%) in other infection sites (CSF, wounds, throat, blood, and urine). The streptococci were identified as belonging to group B by biochemical properties such as resistance to bacitracin and capability to hydrolyze hippurate. Later the isolates were classified serologically. Serotypes Ib, Ic, and II were predominant in the vaginal smears (25%-28% each serotype). In the other infection sites serotype Ib was the most frequent (36%). The isolates were sensitive to penicillin, cloxacillin, cephalothin, and erythromycin - M.I.C. 0.1-0.2 microgram/ml. Most of the isolates were resistant to tetracycline (69%) and some to chloramphenicol (17.5%). Synergism has been obtained in vitro using a combination of gentamicin and penicillin simultaneously. Group B streptococci or Streptococcus agalactiae first became known because of association with bovine mastitis. This microorganism is now widely appreciated as a potent human pathogen. In several geographic regions it is the leading cause of meningitis during the first two months of life (Eickhoff et al. 1965; Franciosi et al. 1973; Baker et al. 1973; Patterson and Hafeez 1976; Anthony and Okada 1977; Baker 1977). Two clinical syndromes have been defined among infants. The first syndrome, called early onset, is observed in neonates aged five days or less (Baker et al. 1973). In older infants (between 10 days and three months of age) the second syndrome or the late-onset may appear (Franciosi et al. 1973; Baker et al. 1973). In the last few years infections in adults have also been reviewed (Bayer et al. 1976; Lerner et al. 1977). Group B streptococci are divided into five serological types: Ia, Ib, Ic, II, and III (Wilkinson and Eagon 1971); some strains to be devoid of type-specific antigens and are called nontypable (NT). The serotypes of group B streptococci isolated from infants with early onset disease are identical with those isolated from the genital tracts of their mothers. Infants probably acquire the microorganism during passage through the birth canal (Baker and Barrett 1973). Furthermore, the genitourinary tract is known to be a major reservoir of infection and a source for subsequent dissemination in both men and women (Wilkinson 1978). The appearance of sepsis and meningitis in neonates caused by group B streptococci and which was reported previously by this laboratory (Maayan et al. 1978; Nitzan et al. 1978) has prompted us to study the current situation of the infections caused by this microorganism. This study presents a survey on the frequency of infections, serotype distribution, and susceptibility to antimicrobial agents of group B streptococcal isolates in the Sharon district (Israel). It seems that the transformation of the group B streptococci to human pathogens has also affected this area.