Circadian gating of cell division in cyanobacteria growing with average doubling times of less than 24 hours

To ascertain whether the circadian oscillator in the prokaryotic cyanobacterium Synechococcus PCC 7942 regulates the timing of cell division in rapidly growing cultures, we measured the rate of cell division, DNA content, cell size, and gene expression (monitored by luminescence of the PpsbAI::luxAB reporter) in cultures that were continuously diluted to maintain an approximately equal cell density. We found that populations dividing at rates as rapid as once per 10 h manifest circadian gating of cell division, since phases in which cell division slows or stops recur with a circadian periodicity. The data clearly show that Synechococcus cells growing with doubling times that are considerably faster than once per 24 h nonetheless express robust circadian rhythms of cell division and gene expression. Apparently Synechococcus cells are able to simultaneously sustain two timing circuits that express significantly different periods.

Mobile teledermatology: a feasibility study of 58 subjects using mobile phones

We investigated the diagnostic agreement between teledermatology based on images from a mobile phone camera and face-to-face (FTF) dermatology. Diagnostic agreement was assessed for two teledermatologists (TD) in comparison with FTF consultations in 58 subjects. In almost three-quarters of the cases (TD1: 71%; TD2: 76%), the telediagnosis was fully concordant with the FTF diagnosis. Furthermore, the diagnosed diseases were almost all in the same diagnostic category (TD1: 97%; TD2: 90%). If mobile teledermatology had been used for remote triage, TD1 could have treated 53% subjects remotely and 47% subjects would have had to consult a dermatologist FTF. TD2 could have treated 59% subjects remotely, whereas 41% subjects would have had to consult a dermatologist FTF. Forty-eight subjects responded to a questionnaire, of whom only 10 had any concerns regarding teledermatology. Thirty-one subjects stated that they would be willing to pay to use a similar service in future and suggested an amount ranging from euro5 to euro50 per consultation (mean euro22) (euro = pound0.7, US $1.4). These results are encouraging as patient acceptance and reimbursement represent potential obstacles to the implementation of telemedicine services.

Differential expression of cytokine mRNA in skin specimens from patients with erythema migrans or acrodermatitis chronica atrophicans

Erythema migrans, the characteristic skin manifestation of acute Lyme borreliosis, is a self-limited lesion. In contrast, acrodermatitis chronica atrophicans, the typical cutaneous manifestation of late Lyme borreliosis, is a chronic skin condition. In an effort to understand pathogenic factors that lead to different outcomes in dermatoborrelioses, skin biopsy samples from 42 patients with erythema migrans and 27 patients with acrodermatitis chronica atrophicans were analyzed for mRNA expression of five pro-inflammatory cytokines (tumor necrosis factor alpha, interleukin-1 beta, interleukin-6, interferon-gamma, and interleukin-2) and two anti-inflammatory cytokines (interleukin-4 and interleukin-10) by in situ hybridization with cytokine-specific riboprobes. Among the 27 patients who had erythema migrans alone with no associated signs or symptoms, the major cytokines expressed in perivascular infiltrates of T cells and macrophages were the pro-inflammatory cytokine interferon-gamma and the anti-inflammatory cytokine interleukin-10. In the 15 erythema migrans patients who had associated signs and symptoms, including headache, elevated temperature, arthralgias, myalgias, or fatigue, a larger number of macrophages and greater expression of macrophage-derived pro-inflammatory cytokines, tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6, were also found. In comparison, infiltrates of T cells and macrophages in the skin lesions of acrodermatitis chronica atrophicans patients had very little or no interferon-gamma expression. Instead, they usually expressed only the pro-inflammatory cytokine tumor necrosis factor alpha and the anti-inflammatory cytokine interleukin-4. Thus, the activation of pro-inflammatory cytokines in erythema migrans lesions, particularly interferon-gamma, seems to be important in the control of the spirochetal infection. In contrast, the restricted pattern of cytokine expression in acrodermatitis chronica atrophicans, including the lack of interferon-gamma, may be less effective in spirochetal killing, resulting in the chronicity of this skin lesion. J Invest Dermatol 115:1115-1123 2000

Feasibility and acceptance of telemedicine for wound care in patients with chronic leg ulcers

We examined the feasibility and acceptance of teledermatology for wound management of patients with chronic leg ulcers by home-care nurses. Forty-one chronic leg ulcers of different origin in 14 patients were included. After an initial in-person visit in which leg ulcers were assessed and classified, and underlying diseases noted, follow-up visits were done by home-care nurses. Once a week 1-4 digital images of the wound and surrounding skin and relevant clinical information were transmitted via a secure Website to an expert at the wound care centre. The experts provided an assessment of wound status and therapeutic recommendations. In 89% of the 492 teleconsultations, the quality of images was sufficient or excellent and the experts were confident giving therapeutic recommendations. Treatment modalities were changed or adapted in one-third of the consultations. There was a significant decrease in visits to a general physician or the wound care centre. The acceptance of teledermatology was high in patients, home-care nurses and wound experts. Teledermatology offers great potential for chronic wound care and seems to be accepted both by patients and health-care persons.

Analysis of myeloperoxidase activity in wound fluids as a marker of infection

Background

Neutrophilic polymorphonuclear leukocytes play a crucial role in the host defence against bacterial and fungal infections. They participate in the inflammatory response through the liberation of peptides and enzymes like myeloperoxidase (MPO). Therefore, MPO has a potential as a marker enzyme for the diagnosis of wound infection.

Methods

Substrate specificities and reaction pathways of MPO were investigated for new MPO substrates: crystal violet, leuco crystal violet, fast blue RR (4-benzoylamino-2,5-dimethoxybenzenediazonium chloride hemi(zinc chloride) salt) and various systematically substituted model substrates based on 2,7-dihydroxy-1-(4-hydroxyphenylazo)naphtalene-3,6-disulphonic acid. In addition, fast blue RR was covalently bound to siloxanes allowing immobilization of the substrate, while cellobiosedehydrogenase was integrated for generation of hydrogen peroxide required by MPO.

Results

Elevated concentrations of MPO were found in infected wounds compared with non-infected wounds (92.2 ± 45.0 versus 1.9 ± 1.8 U/mL). Various soluble and immobilized substrates were oxidized by MPO in wound samples and the influence of substrate structure and reaction pathways were elucidated for selected compounds.

Conclusions

Incubation of different MPO substrates with infected wound fluid samples resulted in a clear colour change in the case of elevated MPO concentrations, thus allowing early diagnosis of wound infection.

The additive value of second opinion teleconsulting in the management of patients with challenging inflammatory, neoplastic skin diseases: a best practice model in dermatology?

BACKGROUND

Telemedicine is the practice of healthcare using interactive processes of communication to facilitate healthcare delivery, including diagnosis, consultation and treatment, as well as education and transfer of medical data. The aim of teledermatology, just as telemedicine, is to promote best practice procedures and to improve the consistency and competence of health care.

AIM

To investigate the diagnostic additive value of second opinion teleconsulting in patients with challenging dermatoses, among dermatologists working in two different dermatology departments.

SETTING

Thirty-three cases of patients with challenging inflammatory and neoplastic skin diseases at the University of L'Aquila Department of Dermatology were sent for teleconsultation to the Department of Dermatology, Medical University of Graz, Austria.

METHODS

All cases were selected in the outpatient service in L'Aquila. After face-to-face consultation with a local colleague had been completed, images were sent using a store-and-forward (SAF)-based system (http://www.telederm.org) to Graz. Histopathological examination together with follow-up of the patient represents the diagnostic gold standard for this study.

RESULTS

Telediagnosis was correct in 26 of 33 (78.8%) cases. Sixteen of 33 cases (48.5%) had already been diagnosed face-to-face by at least one of the two dermatologists in L'Aquila. In 10 of 33 cases (30.3%), the correct diagnosis was made in teleconsultation only.

CONCLUSIONS

Second opinion teleconsulting may represent an additive value in the diagnosis of numerous challenging inflammatory and neoplastic skin diseases. It may be particularly useful as a best practice model for smaller departments in order to discuss and/or to confirm diagnoses and also for the management of patients with unusual difficult dermatoses.

Teledermatological monitoring of leg ulcers in cooperation with home care nurses

OBJECTIVES

To examine the feasibility and acceptance of teledermatology for wound management for patients with leg ulcers by home care nurses and evaluate the reduction of costs and the acceptance of teledermatology by patients and home care nurses.

DESIGN

Case series of telemonitored patients with leg ulcers including cost-effectiveness analysis.

SETTING

Home monitoring by home care nurses.

PATIENTS

Sixteen patients with 45 leg ulcers of different origin were included.

MAIN OUTCOME MEASURES

After an initial outpatient visit when the leg ulcers were assessed and classified, teledermatological follow-up was done by home care nurses. Relevant clinical information and 1 to 4 digital images of the wound and surrounding skin were transmitted weekly via a secure Web site to an expert at the wound care center, who assessed the wound and made therapeutic recommendations.

RESULTS

Of the 707 images transmitted for teleconsultation, in 644 (89%) the quality of the images was excellent or sufficient and the experts were confident in giving therapeutic recommendations. Of the 45 ulcers, 32 (71%) decreased in size and 14 (31%) healed completely, whereas 10 of the 45 ulcers (22%) increased slightly in size despite the teledermatological monitoring. In 3 ulcers (7%), no measurement was possible owing to the overly large size of the ulcers. The acceptance of telemedicine was very good by most patients. Of 15 home care nurses working in the district, 7 were very satisfied with teledermatological monitoring of wound care. There was a reduction of 46% in transportation costs for the insurance companies as well as for the patients owing to a significant decrease in the number of visits to general physicians or the wound care center.

CONCLUSIONS

The acceptance of teledermatological monitoring of wound care was very high by patients, home care nurses, and wound experts. Decreased health care costs by reducing the number of visits to wound care centers or specialist physicians and improvement in quality of life for patients with leg ulcers using telemedicine seems possible. Teledermatology offers great potential for long-term wound care.

A hospital as victim and responder: the Sepulveda VA Medical Center and the Northridge earthquake

Many hospital emergency plans focus on the hospital as a disaster responder, with a fully operational medical facility, able to receive and treat mass casualties from a clearly defined accident scene. However, hospitals need to prepare a response for extreme casualty events such as earthquakes, tornadoes, or hurricanes. This article describes the planning, mitigation, response, and recovery of a major medical--surgical center thrust into a victim responder role following the devastating Northridge earthquake. The subsequent evacuation and care of patients, treatment of casualties, incident command, prior education and training, and recovery issues are addressed.

Wound teleconsultation in patients with chronic leg ulcers

BACKGROUND

The treatment of chronic leg ulcers requires frequent assessments of local wound status and adjustment of therapy. The availability of reasonably priced photographic equipment and quick electronic transfer of high-quality digital images should make it possible that the assessment of wound status can be made by remote experts.

OBJECTIVE

This study examines the feasibility of using teledermatology for wound assessment and therapeutic suggestions for patients with chronic leg ulcers.

METHODS

One hundred ten chronic leg ulcers of different origins were examined in face-to-face consultations. The examining doctor assessed the wound, made therapeutic recommendations and took 1-4 photographs of the wound using a digital camera. The digital images and relevant clinical information were then transmitted via a web application to an expert in wound care, who provided an independent teledermatological assessment of wound status and therapeutic recommendations.

RESULTS

In our study, a high accordance between direct consultations and electronic consultations was found in the assessment of chronic leg ulcers, especially for important features like slough (concordance: 84.6%), necrosis (concordance: 98.2%) and granulation tissue formation (concordance: 76.4%). Furthermore, the teledermatologist generally felt confident in recommending further treatment strategies and in planning further wound assessments via the internet.

CONCLUSIONS

Our results suggest that teledermatology offers great potential for the future in chronic wound care. By reducing the need to travel long distances to the hospital or to consult a physician with expertise in wound care, wound teleconsultation might lower health care costs and improve the quality of life for patients with chronic wounds, while still maintaining a high quality of wound care.

Increased prevalence of human papillomavirus in hairs plucked from patients with psoriasis treated with psoralen-UV-A

BACKGROUND

Patients with psoriasis treated with psoralen-UV-A (PUVA) are at increased risk of skin cancer; however, the exact causes of this increased incidence are not well understood. It has been suggested that PUVA may increase expression of the tumorigenic agent human papillomavirus (HPV) in skin by directly stimulating virus replication, immune suppression, or both, thereby leading to skin cancer formation.

OBJECTIVE

To determine whether HPV DNA prevalence in the skin is increased after long-term PUVA treatment.

DESIGN

Screening for the presence of HPV sequences in DNA isolated from plucked body hairs of patients with psoriasis with a history of PUVA exposure and a history of skin cancer (group A), PUVA exposure and no history of skin cancer (group B), and no PUVA exposure and no history of skin cancer (group C).

SETTING

University hospital.

PATIENTS AND METHODS

Hair samples were obtained from 81 patients with psoriasis (56 men and 25 women; mean age, 52 years), including 16 in group A (mean number of PUVA exposures, 702), 35 in group B (mean number of PUVA exposures, 282), and 30 in group C. DNA was isolated from the hair samples and analyzed by polymerase chain reaction with the use of 2 nested primer systems specific for epidermodysplasia verruciformis-associated or related and genital or mucosal virus types, respectively.

RESULTS

The rate of HPV DNA positivity was significantly higher in groups A (73% [11/15]) and B (69% [24/35]) than in group C (36% [10/28]) (A + B vs C, P =.009; chi(2) test; age adjusted). Conclusion The prevalence of HPV in the skin (hair follicles) is increased in patients with psoriasis who have a history of PUVA exposure.

The validity of telepathological frozen section diagnosis with ISDN-mediated remote microscopy

We investigated 109 randomly selected frozen section specimens from lung surgery patients in a retrospective blind mode using telepathology equipment. The telepathology system applied (HISTKOM) used one ISDN B-channel and telemicroscopy with a remotely operated robotic microscope. The performance of telepathological frozen section diagnosis was compared with that of conventional frozen section diagnosis. The false-positive rate achieved was identical for both methods. The sensitivity (P=0.03), but not the specificity, was significantly lower for the telepathological method. The time needed to establish a diagnosis with the remote microscope was too high; therefore, upgrading to multichannel technology is recommended. The quality of the images transmitted was judged to be sufficient by the pathologists involved in the study. In conclusion, with further technical improvements in telemicroscopy and additional experience in telepathology, remote diagnosis seems to be feasible.

Reliability of telepathology for frozen section service

One of the most promising applications of telepathology (pathology at a distance by electronic transmission of images in pathology) is frozen section diagnosis, especially because by means of this tool operations requiring an intraoperative histopathological diagnosis are feasible at hospitals without a pathologist on-site. For the introduction of this diagnostic tool into pathologist's daily practice the evidence of its diagnostic accuracy comparable to that of the conventional frozen section diagnosis is crucial. For this purpose the literature on the diagnostic accuracy of telepathological frozen section diagnosis was reviewed. In a metaanalysis these studies and reports, in which a total of more than 1290 cases had been examined, showed a slightly lower overall diagnostic accuracy (of the telepathological frozen section diagnosis) of about 0.91 than the conventional frozen section diagnosis with an average accuracy of about 0.98 found in an analysis of several studies (on frozen section diagnosis of different organs). This difference is at least predominantly caused by a higher rate of deferred and false negative frozen section diagnoses in the telepathological method, while the specificity of both methods, each more than 0.99 was not significantly different. In conclusion, the introduction of a telepathological frozen section diagnosis for hospitals without an acceptable access to a pathologist is justifiable already at the current state of the technological development especially when considering the advantages (time saving, reduction in costs) compared to the alternative of surgical interventions without access to an intraoperative diagnosis.

Novel protease-based diagnostic devices for detection of wound infection

A gelatinase-based device for fast detection of wound infection was developed. Collective gelatinolytic activity in infected wounds was 23 times higher (p ≤ 0.001) than in noninfected wounds and blisters according to the clinical and microbiological description of the wounds. Enzyme activities of critical wounds showed 12-fold elevated enzyme activities compared with noninfected wounds and blisters. Upon incubation of gelatin-based devices with infected wound fluids, an incubation time of 30 minutes led to a clearly visible dye release. A 32-fold color increase was measured after 60 minutes. Both matrix metalloproteinases and elastases contributed to collective gelatinolytic enzyme activity as shown by zymography and inhibition experiments. The metalloproteinase inhibitor 1,10-phenanthroline (targeting matrix metalloproteinases) and the serine protease inhibitor phenylmethlysulfonyl fluoride (targeting human neutrophil elastase) inhibited gelatinolytic activity in infected wound fluid samples by 11-37% and 60-95%, respectively. Staphylococcus aureus and Pseudomonas aeruginosa, both known for gelatinase production, were isolated in infected wound samples.

More than keratitis, ichthyosis, and deafness: Multisystem effects of lethal GJB2 mutations

BACKGROUND

Infant death in keratitis-ichthyosis-deafness (KID) syndrome is recognized; its association with specific genotypes and pathophysiology is inadequately understood.

OBJECTIVE

We sought to discover characteristics that account for poor outcomes in lethal KID syndrome.

METHODS

We collected 4 new cases and 9 previously reported, genotyped cases of lethal KID syndrome. We performed new molecular modeling of the lethal mutants GJB2 p.A88V and GJB2 p.G45E.

RESULTS

Infant death occurred in all patients with GJB2 p.G45E and p.A88V; it is unusual with other GJB2 mutations. Early death with those 2 "lethal" mutations is likely multifactorial: during life all had ≥1 serious infection; most had poor weight gain and severe respiratory difficulties; many had additional anatomic abnormalities. Structural modeling of GJB2 p.G45E identified no impact on the salt bridge previously predicted to account for abnormal central carbon dioxide sensing of GJB2 p.A88V.

LIMITATIONS

This clinical review was retrospective.

CONCLUSION

GJB2 p.G45E and p.A88V are the only KID syndrome mutations associated with uniform early lethality. Those electrophysiologically severe mutations in GJB2 reveal abnormalities in many organs in lethal KID syndrome. All patients with KID syndrome may have subtle abnormalities beyond the eyes, ears, and skin. Early genotyping of KID syndrome births will inform prognostic discussion.

The Development of Indicator Cotton Swabs for the Detection of pH in Wounds

Indicator cotton swabs have been developed in order to enable faster, less expensive, and simpler information gathering of a wound status. Swabs are normally used for cleaning the wound, but here, they were covalently functionalized with indicator chemistry. Thus, they in principle enable simultaneous wound cleaning and wound pH detection. Using an indicator dye with a color change from yellow to red, combined with an inert dye of blue color, a traffic light color change from green to red is induced when pH increases. The indicator cotton swabs (ICSs) show a color change from green (appropriate wound pH) to red (elevated wound pH). This color change can be interpreted by the naked eye as well as by an optical color measurement device in order to obtain quantitative data based on the CIE L*a*b* color space. Two types of swabs have been developed—indicator cotton swabs ICS1 with a sensitive range from pH 5 to 7 and swabs ICS2 with a sensitive range from 6.5 to 8.5. The swabs are gamma-sterilized and the effect of sterilization on performance was found to be negligible. Furthermore, cytotoxicity testing shows cell viability and endotoxin levels to be within the allowable range.

Tinea capitis in early infancy treated with itraconazole: a pilot study

BACKGROUND

Tinea capitis is the most common fungal infection of the scalp in childhood, but a very rare disorder in the first year of life.

OBJECTIVE

To evaluate the efficacy, tolerability and safety of itraconazole in 7 children aged between 3 and 46 weeks (median: 36 weeks) suffering from tinea capitis caused by Microsporum canis.

METHODS

Prospective case note study. In all patients KOH testing and fungal cultivation on Sabouraud dextrose agar were performed.

RESULTS

7 patients (5 girls and 2 boys) were included in the period between 2001 and 2008. The causative etiologic agent was Microsporum canis in all children. The patients received itraconazole 5mg/kg bodyweight daily for 3 to 6 weeks with no clinically side effects being noted. In all patients clinical and mycological cure could be achieved.

CONCLUSION

Itraconazole proved to be a safe and effective treatment option for Microsporum canis induced tinea capitis in children in their first year of life.

Sulfide-dependent photosynthetic electron flow coupled to proton translocation in thylakoids of the cyanobacterium Oscillatoria limnetica

Light-induced proton translocation coupled to sulfide-dependent electron transport has been studied in isolated thylakoids of the cyanobacterium Oscillatoria limnetica. The thylakoids are obtained by osmotic shock of washed spheroplasts, prepared with glycine-betaine as the osmotic stabilizer. 13C NMR studies suggests that betaine is the major osmoregulator in O. limnetica. Thylakoid preparations obtained from both sulfide-induced anoxygenic cells and noninduced oxygenic cells are capable of proton pumping coupled to phenazinemethosulfate-mediated cyclic electron flow. However, only in the induced thylakoids can sulfide-dependent proton gradient (delta pH) formation be measured, using either NADP or methyl viologen as the terminal acceptor. Sulfide-dependent delta pH formation correlates with a high-affinity electron donation site (apparent Km 44 microM at pH 7.9). This site is not lost upon washing of the thylakoids. In addition, both sulfide-dependent electron transport and delta pH formation are sensitive to inhibitors of the cytochrome b6f complex such as 2-n-nonyl-4-hydroxyquinoline-N-oxide, 2,4-dinitrophenyl ether of 2-iodo-4-nitrothymol, or stigmatellin. Sulfide-dependent NADP photoreduction of low affinity (which does not saturate by as much as 7 mM sulfide) is detected in both induced and noninduced thylakoids, but this activity is insensitive to the inhibitors and is not coupled to proton transport. It is suggested that the adaptation of O. limnetica to anoxygenic photosynthesis involves the induction of a thylakoid factor(s) which creates a high-affinity site for sulfide, and the transfer of its electrons via the cytochrome b6f complex, coupled to proton translocation.

ISG12 is a critical modulator of innate immune responses in murine models of sepsis

Sepsis is still a major burden for our society with high incidence of morbidity and mortality each year. Molecular mechanisms underlying the systemic inflammatory response syndrome (SIRS) associated with sepsis are still ill defined and most therapies developed to target the acute inflammatory component of the disease are insufficient. Recently the role of nuclear receptors (NRs) became a major topic of interest in transcriptional regulation of inflammatory processes. Nuclear receptors, such as the peroxisome proliferators-activated receptors (PPARs), have been demonstrated to exert anti-inflammatory properties by interfering with the NFκB pathway. We identified the nuclear envelope protein, interferon stimulated gene 12 (ISG12), which directly interacts with NRs. ISG12 is a co-factor stimulating nuclear export of NRs, thereby reducing the anti-inflammatory potential of NRs such as NR4A1. To examine the role of ISG12 in acute inflammatory processes we used recently generated ISG12 deficient mice. We can clearly demonstrate that lack of ISG12 prolongs survival in experimental sepsis and endotoxemia. Furthermore we can show that several acute inflammatory parameters, such as systemic IL6 cytokine levels, are downregulated in septic ISG12-/- animals. Consistently, similar results were obtained in in vitro experiments in peritoneal macrophages derived from ISG12 deficient mice. In contrast, mice deficient for the nuclear receptor NR4A1 exhibited an exacerbated innate immune response, and showed a significantly higher mortality after lethal endotoxemic challenge. This dramatic phenotype could be restored in ISG12/NR4A1 double deficient mice. We conclude from our data in vitro and in vivo that ISG12 is a novel modulator of innate immune responses regulating anti-inflammatory nuclear receptors such as NR4A1.