The use of extrapolation based on modeling and simulation to support high-dose regimens of ceftaroline fosamil in pediatric patients with complicated skin and soft-tissue infections

A model-informed drug development approach was used to select ceftaroline fosamil high-dose regimens for pediatric patients with complicated skin and soft-tissue infections caused by Staphylococcus aureus with a ceftaroline minimum inhibitory concentration (MIC) of 2 or 4 mg/L. Steady-state ceftaroline concentrations were simulated using a population pharmacokinetics (PK) model for ceftaroline fosamil and ceftaroline including data from 304 pediatric subjects and 944 adults. Probability of target attainment (PTA) for various simulated pediatric high-dose regimens and renal function categories were calculated based on patients achieving 35% fT>MIC (S. aureus PK/pharmacodynamic target for 2-log10 bacterial killing). For extrapolation of efficacy, simulated exposures and PTA were compared to adults with normal renal function receiving high-dose ceftaroline fosamil (600 mg 2-h infusions every 8 h). For safety, predicted ceftaroline exposures were compared with observed pediatric and adult data. Predicted ceftaroline exposures for the approved pediatric high-dose regimens (12, 10, or 8 mg/kg by 2-h infusions every 8 h for patients aged >2 to <18 years with normal/mild, moderate, or severe renal impairment, respectively; 10 mg/kg by 2-h infusions every 8 h for patients aged ≥2 months to <2 years with normal renal function/mild impairment) were well matched to adults with normal renal function. Median predicted maximum concentration at steady state (Cmax,ss ) and area under the plasma concentration-time curve over 24 h at steady state pediatric to adult ratios were 0.907-1.33 and 0.940-1.41, respectively. PTAs (>99% and ≥81% for MICs of 2 and 4 mg/L, respectively) matched or exceeded the adult predictions. Simulated Cmax,ss values were below the maximum observed data in other indications, including a high-dose pediatric pneumonia trial, which reported no adverse events related to high exposure.

Pharmacological Evaluation of Selected Medicinal Plants Used in the Management of Oral and Skin Infections in Ebem-Ohafia District, Abia State, Nigeria

Oral and skin infections contribute significantly to the global health challenges responsible for the current trend of increased morbidity and premature death. The purpose of this study was to document medicinal plants used in the management of oral and skin infections in Ebem-Ohafia Local Government Area (LGA), Abia State, and to characterize the in vitro antioxidant and antibacterial activity. The thin layer chromatography (TLC) profiling of ten of the selected folklore medicine was carried out using a various solvent system of different polarity index. The antioxidant capacity of the plant extracts was evaluated using chemical-based methods, and its antibacterial effect was investigated using disc diffusion and microdilution methods. Sixty-one plant species belonging to 26 families were discovered, and the most frequently cited species are Euphorbiaceae (18.03%), Fabaceae (11.47%), and Asteraceae (11.47%). All the plant extracts showed a promising free radical scavenging activity and efficient ferric reducing antioxidant power in a concentration-dependent manner possibly due to their richness in polyphenol with TLC profiling showing maximum three bands of phytochemicals. Also, the plant extracts exhibited a mild to weak antibacterial activity against our panel of bacterial strains having MIC values ranging from 256 to > 512 μg/ mL reflected in their zone of inhibition at 10 μg/disc. The data obtained for Breynia nivosa (BN), Eleusine indica (EI), Cassia alata (CA), Chromolaena odorata (CO), and Acalypha hispida (AH) extracts substantiate the traditional use of these herbal remedies in the region and open the possibility for the development of cheaper and affordable drugs in the treatment of oral and skin infections. Further studies are needed to identify active ingredient with strong antibacterial and antioxidant capacities along with their molecular mechanisms.

A critical review on the clinical pharmacokinetics, pharmacodynamics, and clinical trials of ceftaroline

Only a parenteral formulation of ceftaroline is commercially available, and the prodrug, ceftaroline fosamil, is hydrolyzed quickly and completely upon intravenous administration. Ceftaroline is relatively minimally bound to plasma proteins (15-28 %), with a volume of distribution of 30-40 L. Ceftaroline undergoes minimal metabolism and does not appear to be a cytochrome P450 substrate. Its renal clearance (e.g. 4-7 L/h after multiple dosing) approximates glomerular filtration rate, with a terminal half-life of ~2.6 h in healthy subjects. The pharmacokinetics of ceftaroline have been described thoroughly in clinical investigations primarily conducted by the manufacturer. Despite its indications for treating skin and skin structure infections (SSSI) or community-acquired pneumonia (CAP), some studies that contributed data to the final drug labelling were conducted only in healthy volunteers. A significant amount of data have been contributed by the drug maker, and the overall quality of the pharmacodynamics and clinical data, based on our critical analysis provided in this review, is strong. Ceftaroline can be considered as a therapeutic alternative for complicated SSSI and CAP (Pneumonia Outcome Research Team Class III-IV). The current dosing regimen of ceftaroline 600 mg intravenously every 12 h appears sufficient to establish pharmacokinetic-pharmacodynamic relationships and achieve optimal clinical efficacy. More clinical studies are needed to define the place of ceftaroline in therapy for SSSI, CAP, and other indications such as osteomyelitis, endocarditis, and other types of pneumonia. Moreover, continued development in population modelling incorporating more patient-specific data would allow further analysis to identify intrinsic and extrinsic factors that influence the pharmacokinetics of ceftaroline in humans.

[Dynamics of local expression of connexin-43 and basic fibroblast growth factor receptors in patients with skin and soft-tissue infections against the background of diabetes mellitus type II]

Clinical results of wound healing dynamics were studied in 60 patients with soft-tissue infection against the background of diabetes mellitus type II. At the same time the study considered indices of intercellular contacts protein tissue expression such as connexin 43 (Cx43) and basic fibroblast growth factor receptors (bFGFR). The basic therapy of biopsy material of wound borders was applied. The reduction of bFGFR expression and the minor growth of Cx43 expression were observed. The pain syndrome proceeded for a long time and there were signs of perifocal inflammation, retard wound healing with granulation tissue. The application of combined method of ozone therapy which included autohemotherapy with ozone and an external management of wound by ozone-oxygen mixture facilitated to considerable shortening of inflammatory phase and regeneration. It was associated with increased Cx43 expression (in 1.9 times) in comparison with initial level and bFGFR was enlarged in 1.7 times to eighth day of postoperative period.

Essential functions of the unique N-terminal region of the varicella-zoster virus glycoprotein E ectodomain in viral replication and in the pathogenesis of skin infection

Varicella-zoster virus (VZV) glycoprotein E (gE) is a multifunctional protein important for cell-cell spread, envelopment, and possibly entry. In contrast to other alphaherpesviruses, gE is essential for VZV replication. Interestingly, the N-terminal region of gE, comprised of amino acids 1 to 188, was shown not to be conserved in the other alphaherpesviruses by bioinformatics analysis. Mutational analysis was performed to investigate the functions associated with this unique gE N-terminal region. Linker insertions, serine-to-alanine mutations, and deletions were introduced in the gE N-terminal region in the VZV genome, and the effects of these mutations on virus replication and cell-cell spread, gE trafficking and localization, virion formation, and replication in vivo in the skin were analyzed. In summary, mutagenesis of the gE N-terminal region identified a new functional region in the VZV gE ectodomain essential for cell-cell spread and the pathogenesis of VZV skin tropism and demonstrated that different subdomains of the unique N-terminal region had specific roles in viral replication, cell-cell spread, and secondary envelopment.

Population pharmacokinetics of tigecycline in patients with complicated intra-abdominal or skin and skin structure infections

Tigecycline, a first-in-class expanded glycylcycline antimicrobial agent, has demonstrated efficacy in the treatment of complicated skin and skin structure infections (cSSSI) and complicated intra-abdominal (cIAI) infections. A population pharmacokinetic (PK) model for tigecycline was developed for patients with cSSSI or cIAI enrolled in two phase 2 clinical trials, and the influence of selected demographic factors and clinical laboratory measures was investigated. Tigecycline was administered as an intravenous loading dose followed by a 0.5- or 1-h infusion every 12 h for up to 14 days. Blood samples were collected the day before or the day of hospital discharge for the determination of serum tigecycline concentrations. Patient covariates were evaluated using stepwise forward (alpha = 0.05) and backward (alpha = 0.001) procedures. The predictive performance of the model was assessed separately using pooled data from either two phase 3 studies for patients with cSSSI or two phase 3 studies for patients with cIAI. A two-compartment model with zero-order input and first-order elimination adequately described the steady-state tigecycline concentration-time data. Tigecycline clearance was shown to increase with increasing weight, increasing creatinine clearance, and male gender (P < 0.001). The final model provided a relatively unbiased fit to each data set. Individual predicted values of the area under the concentration-time curve from 0 to 12 h (AUC(0-12)) were generally unbiased (median prediction error, -1.60% to -3.78%) and were similarly precise (median absolute prediction error, <4%) when compared across data sets. The population PK model provided the basis to obtain individual estimates of steady-state AUC(0-12) in later exposure-response analyses of tigecycline safety and efficacy in patients with cSSSI or cIAI.

Deficiency of dermcidin-derived antimicrobial peptides in sweat of patients with atopic dermatitis correlates with an impaired innate defense of human skin in vivo

Antimicrobial peptides are an integral part of the epithelial innate defense system. Dermcidin (DCD) is a recently discovered antimicrobial peptide with a broad spectrum of activity. It is constitutively expressed in human eccrine sweat glands and secreted into sweat. Patients with atopic dermatitis (AD) have recurrent bacterial or viral skin infections and pronounced colonization with Staphylococcus aureus. We hypothesized that patients with AD have a reduced amount of DCD peptides in sweat contributing to the compromised constitutive innate skin defense. Therefore, we performed semiquantitative and quantitative analyses of DCD peptides in sweat of AD patients and healthy subjects using surface-enhanced laser desorption ionization time-of-flight mass spectrometry and ELISA. The data indicate that the amount of several DCD-derived peptides in sweat of patients with AD is significantly reduced. Furthermore, compared with atopic patients without previous infectious complications, AD patients with a history of bacterial and viral skin infections were found to have significantly less DCD-1 and DCD-1L in their sweat. To analyze whether the reduced amount of DCD in sweat of AD patients correlates with a decreased innate defense, we determined the antimicrobial activity of sweat in vivo. We showed that in healthy subjects, sweating leads to a reduction of viable bacteria on the skin surface, but this does not occur in patients with AD. These data indicate that reduced expression of DCD in sweat of patients with AD may contribute to the high susceptibility of these patients to skin infections and altered skin colonization.

Immunohistopathological appearance of three different types of injury in human skin

OBJECTIVE AND DESIGN

To determine whether underlying mechanisms of inflammation, like cellular infiltrates, expression of adhesion molecule and cytokine patterns are similar under different conditions of injury. Skin biopsies were taken of three different groups of patients in which local inflammation of the skin might occur. MATERIAL, PATIENTS: Skin activation was studied as a result of incision during surgery under aseptic conditions, as a result of a local bacterial infection and as a result of blunt trauma, resulting in a femoral fracture, without disruption of the epithelial barrier.

METHODS

Skin biopsies were snap frozen for immunohistochemical analysis.

RESULTS

Incision of the skin resulted in a granulocyte infiltrate, paralleled by E-selectin expression. As a result of infection granulocytes were observed and monocyte/macrophage and T cell numbers were increased. Furthermore, E-selectin, VCAM-1 and ICAM-1 expression increased and cytokine expression markedly changed compared to normal skin. Skin taken at the site of the femoral fracture showed no signs of inflammation.

CONCLUSION

Different stimuli lead to different local inflammatory responses in human skin.

Nitric oxide--a newly discovered chemical transmitter in human skin

Nitric oxide (NO) is synthesized by many cells in the body. Low concentrations of NO have homeostatic roles in the circulation and nervous system, whereas high concentrations are biocidal, cytocidal and have immunomodulatory roles. The place of NO in the skin has recently become the focus of much attention, and this review highlights studies on the part played by NO in health and disease.

Cutaneously applied acyclovir acts systemically in the treatment of herpetic infection in the hairless mouse

Using the SKH-1 hairless mouse (HM) we have addressed the issue as to whether topically applied acyclovir (ACV) may mediate some of its antiviral actions by a systemic effect. When topically applied in a formulation consisting of polyvinyl alcohol (25% w/v):DMSO:cremophor EL:linoleic acid (63:16:16:5, v/v/v/v), ACV penetrated hairless mouse skin in a concentration-dependent manner and dose-dependently reduced cutaneous herpes simplex virus 1 (HSV-1) KOS infection. Topically applied ACV also effectively reduced the mortality associated with disseminated HSV-2 HG-52 infection. At 1 h following topical application of 1.7% w/v ACV the plasma and skin concentrations of ACV were 5.5 nmoles/ml and 120 nmoles/g. At 1 h following an oral dose of ACV with antiviral efficacy comparable to topically applied ACV (1.7% w/v) the plasma and skin concentrations of ACV were 21.3 nmoles/ml and 51 nmoles/g. These findings imply that when applied topically to the HM, ACV can mediate a portion of its antiviral activity through a systemic mode of action.

p53, WAF1/CIP1 and mdm2 expression in skin lesions associated with human papillomavirus and human immunodeficiency virus

Human papillomaviruses (HPVs) express various gene products, such as E6 protein which complexes with the p53 tumor suppressor protein and therefore diminishes p53-related regulatory mechanisms. This interaction is assumed to be HPV type-specific as "high risk" or oncogenic HPV types have more affinity for p53 binding than their "low risk" or non-oncogenic counterparts. Furthermore, HIV infection is believed to activate latent HPV infection and transcription via direct and indirect interaction with HPVs as well as cellular genes and functions. Accordingly, we carried out experiments on biopsies which originated from condylomas ("low risk" HPVs), HIV-positive condylomas (infection with multiple "low risk" and "high risk" HPVs) and anogenital squamous cell carcinomas (SCCs, "high risk" HPV infection). Using reverse transcription PCR (RT-PCR) and western immunoblotting, mRNA and protein levels of p53 and genes regulated by p53, such as mdm2 and WAF1/CIP1 were determined. We found that the presence of HPV can diminish p53 and increase WAF1/CIP1 and mdm2 protein levels. There were no significant differences in this regulation between "low risk" and "high risk" lesions. Our data suggest that these HPV-mediated cellular effects are not type-specific, and they might be part of a viral-cell interaction or represent a cellular defense mechanism against the virus. However, HIV-seropositivity renders HPV lesions containing both "low risk" and "high risk" significantly different. This may be due to the alteration of HPV-controlling cellular pathways by HIV tat and/or activation of cellular pathways different from HIV-negative counterparts. Either possibility is of great interest and needs further verification.

Prospective validation of an optimal sparse plasma-sampling strategy for estimating ciprofloxacin pharmacokinetics

Data obtained from 23 critically ill patients treated with intravenous ciprofloxacin in two clinical trials were used to validate prospectively a previously developed maximum a posteriori (MAP)-Bayesian estimator and optimal plasma-sampling strategy (OSS). Dosages ranged from 200 mg every 12 hours to 400 mg every 8 hours. Each patient had 8-16 samples taken, either as large gold standard sampling sets or as a mix of gold standard sets and OSSs. The MAP-Bayesian estimator used a two-compartment model and identified apparent volumes of distribution of the central and peripheral compartments, distributional clearance, and the slope and intercept of the relationship between creatinine clearance and total body clearance. Fit parameters were used to derive the apparent volume of distribution at steady state and the 24-hour area under the curve. All parameters derived from the OSS using the MAP-Bayesian estimates matched up almost identically to those obtained from modeling the gold standard sets. There was no systematic bias, and good precision was seen among all the parameters. These data demonstrate the usefulness and validity of the current OSS and MAP-Bayesian estimator, and provide further evidence of the utility of optimal sampling theory.

[Levofloxacin in the field of dermatology]

1. Minimum inhibitory concentrations (MICs) of levofloxacin (LVFX, DR-3355), ofloxacin (OFLX), tosufloxacin (TFLX), norfloxacin (NFLX) were determined, with an inoculum size of 10(6) cfu/ml, against 122 strains of Staphylococcus aureus isolated from lesions of skin infections. LVFX showed most frequent MIC values of 0.20 micrograms/ml. OFLX, TFLX, and NFLX showed most frequent MIC values of 0.39 micrograms/ml, less than or equal to 0.05 micrograms/ml and 0.78 micrograms/ml, respectively. 2. Serum and skin levels of LVFX after oral administration (10 mg/kg, fasting) were determined in rats. Serum levels were 1.79, 1.29, 0.60, 0.43 and 0.18 micrograms/ml, and corresponding skin levels were 1.63, 1.77, 1.04, 0.87 and 0.64 micrograms/g (wet weight) at 0.5, 1, 2, 4 and 8 hours after administration (n = 5), respectively. 3. LVFX was used clinically in 43 cases at doses of 200-300 mg divided into 2 or 3 doses, and evaluated for final overall clinical efficacy in 41 cases. Cure was observed in 21 cases, remarkable improvement in 13 cases, improvement in 4 cases, unchanged in 1 case, aggravation in 1 case, and remarkable aggravation in 1 case. Diarrhea was observed in 2 cases, diffuse erythema with feverishness in 1 case and slight dyspnea in 1 case. Transient slight eosinophilia, elevation of Al-P, anemia and leukopenia were observed.

[Clinical study of panipenem/betamipron for burn infections in the domain of plastic and reconstructive surgery]

The effectiveness and the safety of panipenem/betamipron, new antibiotics of the carbapenems for burn infections, were studied and the following results were obtained: 1. The preparation, 0.5 g/0.5 g, was administered by intravenous drip infusion twice a day to 11 cases of patients with burn infections. In 10 cases for which clinical effects were evaluable, results were rated as "excellent" in 2 cases, "good" in 2 cases and "fair" in 6 cases, with an efficacy rate of 40%. 2. Penetration to the affected tissue was studied in 2 cases. The tissue level of panipenem was 0.20 micrograms/g immediately after the end of drip infusion and 6.86 micrograms/g 60 minutes thereafter. 3. As for the safety, a slight increase in GOT, GPT and Al-P was noted in 1 case; a slight increase in GPT, NAG and beta 2MG was found in 1 case; and a slight increase in GOT, GPT, Al-P and LAP was noted in 1 case, as abnormal variations in laboratory test results.

[A multicenter study on panipenem/betamipron in dermatology]

Panipenem/betamipron (PAPM/BP), a new carbapenem, was studied in dermatology. PAPM/BP was used clinically in the treatment of skin and skin structure infections in a multicenter trial. Fifty three patients were enrolled in the trial. Clinical evaluations were made in 50 patients. Most patients received intravenous infusion of PAPM/BP in a dose of 500 mg twice daily. Other dosages were used in some patients. The overall clinical efficacy rate was 78%. When 15 cases of secondary infections were excluded, the rate was 85.7%. Adverse responses were nausea and/or vomiting in 3 patients, redness with itching in 1 patient, headache or head heaviness in 2 patients and diarrhea in 1 patient. The patient with redness and itching had also nausea and vomiting. This occurred 1 hour after the start of the first infusion of this drug. After the discontinuation of the treatment the symptoms went away on the next day. Abnormalities in laboratory test results were observed in 7 out of 53 patients. One patient with liver cirrhosis and hepatocellular carcinoma developed anemia (RBC 372 x 10(4)/mm3----275 x 10(4)/mm3, Hb 11.9 g/dl----8.8 g/dl, 35.1%----26.0%). Other abnormalities were all mild. Penetration of the drug into skin tissues after intravenous infusion of 500 mg of this drug in skin surgery patients was studied. Skin/serum concentration ratios ranged from 0.20 to 0.97. Skin concentrations were higher than the concentration of PAPM inhibiting 80% of clinical isolates over a period of 6 hours. In rats, skin concentrations were much lower than serum concentrations probably due to the difference in in vivo metabolism of PAPM. A few resistant strains of Staphylococcus aureus against PAPM and imipenem (IPM) were isolated. However, PAPM and IPM showed good antibacterial activities compared to other drugs tested. In conclusion, PAPM/BP is considered to be a useful drug in the treatment of skin and skin structure infections.

[Clinical and pharmacokinetic evaluation of cefdinir in children]

Thirty children were treated with cefdinir (CFDN) for the evaluation of its clinical efficacy and side effects. Their ages ranged from 1 to 9 years. The dosage of CFDN ranged from 8.1 to 15.9 mg/kg/day with the treatment continued for 2 to 10 days. Twenty-eight of the 30 patients were evaluated for clinical efficacy; 10 patients with tonsillitis, 3 with scarlet fever, 4 with lower respiratory infections, 2 with otitis media, 2 with cervical lymphadenitis, 3 with urinary tract infections and 4 with skin and soft tissue infections. The remaining 2 patients who had viral diseases were included in the evaluation for side effects. Clinical responses were excellent in 14 patients, good in 12, fair in 1 and poor in 1 with an efficacy rate of 92.9%. Diarrhea was noted in one of the 30 patients. A pharmacokinetic study on CFDN was performed in 8 fasting patients whose ages ranged from 3 to 7 years. Serum concentrations of CFDN peaked at 0.59 to 1.76 micrograms/ml (mean 1.13 microgram/ml) at 2 hours after dosing of 3 mg/kg in 4 patients, and 0.89 to 2.49 micrograms/ml (mean 1.49 micrograms/ml) 2 or 3 hours after dosing of 6 mg/kg in the other 4 patients. The 8-hour urinary excretion rates were 16.0% to 21.3% (mean 17.4%) in 4 patients given a dose of 3 mg/kg and 10.9 to 21.1% (mean 15.5%) in 4 patients given a dose of 6 mg/kg.

Steady-state pharmacokinetics of fleroxacin in patients with skin and skin structure infections

Steady-state pharmacokinetics of oral fleroxacin were studied in six males who had skin or skin structure infections and who were receiving 400 mg of fleroxacin once a day. Blood samples (n = 10) and total urine output were collected during a 24-h dosing interval. Fleroxacin concentrations in serum and urine were determined by high-performance liquid chromatography. The maximum concentration in serum and the time to achieve that maximum were 6.2 +/- 2.2 micrograms/ml and 0.94 +/- 0.62 h, respectively. The absorption half-life, alpha half-life, beta half-life, apparent steady-state volume of distribution, apparent total body clearance, and renal clearance were 0.56 +/- 0.37 h, 0.78 +/- 0.51 h, 10.56 +/- 1.40 h, 0.85 +/- 0.31 liters/kg, 129.2 +/- 19.6 ml/min, and 53.3 +/- 16.7 ml/min, respectively. Fleroxacin disposition in this patient population was similar to that in noninfected volunteers with normal renal function.

Epithelium-specific response of cultured keratinocytes to infection with adenovirus type 2

Adenoviruses are pathogenic for certain stratified squamous epithelia. The sites most frequently involved are the upper respiratory tract and oropharynx. Adenovirus infections of the epidermis are quite rare. We examined the virus-cell interactions of adenovirus type 2 (Ad2) and cultured human keratinocytes grown from a variety of body sites. Our intent was to explore the nature of the apparent epithelium-specific susceptibility to Ad2. In brief, we found that in vitro viral susceptibility of the keratinocytes could be reliably predicted based on whether the cells originated from an epidermal or oropharyngeal surface. Ad2 proceeded through a complete vegetative cycle when used to infect cultured keratinocytes from oropharyngeal sites (e.g., gingiva and soft palate). In contrast, Ad2 infection was severely restricted in keratinocytes from epidermal sites (e.g., foreskin, abdomen, and buttock). These results demonstrate that the in vitro response to infection with Ad2 reflects in vivo tissue-specific susceptibility. In vivo, cervical epithelium is rarely infected with Ad2 and yet in culture, cervical keratinocytes were fully permissive for Ad2 replication. We propose that the permissive or nonpermissive response to Ad2 may be regulated by a particular aspect of cell phenotype. Because the permissive responses seen in this study were all generated in keratinocytes from mucosal sites, it is possible the in vitro response to Ad2 reflects inherent differences between mucosal and epidermal keratinocytes.

Pharmacokinetics of cefonicid in patients with skin and skin structure infections

The disposition of cefonicid (2 g intravenously every 24 h) was assessed in 15 patients with skin and skin structure infections. Trough and peak concentrations in serum were measured on two successive days to verify the attainment of steady state; and 1 trough and 12 postdose values of the concentration in serum were collected on the following day. Cefonicid concentrations in serum were determined by high-performance liquid chromatography. The cefonicid serum concentration versus time profile after intravenous infusion was clearly biexponential in all patients. The terminal elimination half-life determined by nonlinear regression analysis was 4.63 +/- 1.49 h (mean +/- standard deviation). The steady-state volume of distribution and total body clearance were 0.12 +/- 0.04 liter/kg and 0.369 +/- 0.110 ml/min per kg, respectively. These results are comparable to parameters derived from previous studies in noninfected normal volunteers. Thus, the disposition of cefonicid is not altered in patients with severe skin and skin structure infections.

Epidermal Langerhans cells, dermal dendritic cells, and keratinocytes in viral lesions of skin and mucous membranes: an immunohistochemical study

We wanted to evaluate the eventual expression of viral antigens and MHC class II products by keratinocytes as well as the alterations of epidermal Langerhans cells and dermal dendritic cells in viral lesions of skin and mucous membranes. Therefore we investigated 68 biopsy specimens of protracted viral lesions, such as warts, condylomas, and mollusca contagiosa, and of rapidly resolving viral lesions such as herpes simplex virus infection. For this we used immunohistochemical staining techniques and several monoclonal and polyclonal antisera. In most cases investigated viral antigens (human papilloma virus antigens or herpes simplex virus type 1 antigens) could be demonstrated in keratinocytic nuclei. Except for a few viral lesions in which epidermal Langerhans cells were rather numerous, epidermal Langerhans cells were reduced in number or absent in almost all viral lesions. Moreover, epidermal Langerhans cells and dermal dendritic cells showed changes in morphology, distribution, and immunophenotype. These alterations may be caused by a toxic effect of the virus on dendritic cells. HLA-DR+ keratinocytes could be identified in few viral lesions only; HLA-DQ+ keratinocytes were not seen. Possible explanations for this lack of MHC class II expression by keratinocytes are discussed.

Subcutaneous staphylococcal infections in mice: the influence of antibiotics on staphylococcal extracellular products

Using a mouse subcutaneous abscess model the effect of subinhibitory concentrations of antibiotics upon alpha-hemolysin, nuclease, lipase and esterase production was investigated. Infected mice treated with erythromycin (10 mg/kg), chloramphenicol (10 mg/kg) and fucidin (5 mg/kg) were compared with those given lincomycin (10 mg/kg) and clindamycin (5 mg/kg). In reference to the first three drugs, early blanching occurred at the inoculation site and necrosis appeared within 18 h, whereas wit the other two agents, lesion progressed more slowly with a slight induration only at the site of injection becoming apparent after 24 h. Neither alpha-hemolysin nor nuclease was elaborated in the lesion of mice treated with lincomycin and clindamycin. Histological examinations of skin of mice treated with the latter antibiotics revealed a localized abscess with little or no spreading of the bacteria as compared to untreated mice and to mice treated with the other antibiotics. Evidence is presented which suggests significant involvement of the extracellular products in the pathogenesis of staphylococcal infection.

[Spontaneous peripheral proteolysis as a disturbing factor (author's transl)]

With a modification of the Astrup - fibrin - plate method about 300 patients were investigated. In chronic infections of the skin and mucous membranes a spontaneous peripheral proteolysis was found. There is a connection between infections, proteolysis and chronic continuance.

Cutaneous carbohydrate studies. IV. The skin glucose content of fasting diabetics with and without infection

Enzymatic analyses of the skin and blood glucose content of fasting diabetic patients without signs of any infection show that: 1. The fasting skin glucose level reflects the blood glucose level which in turn depends upon diabetic control. 2. The ratio of skin to blood glucose is slightly higher in diabetics taking insulin (71%)than in diabetics controlled with tolbutamide or diet alone (69%) and both are statistically higher than in normal persons (55%) (P < 0.01). Comparison of diabetics with cutaneous infection and diabetics without cutaneous infection show that: 1. The presence of cutaneous infection in diabetics does not consistently correlate with higher ratios of skin to blood glucose as measured by the technics used in this study. 2. In certain instances the skin glucose may equal the blood glucose concentration (i.e. skin: mg/100 gm (w.w.)/blood: mg/100 cc (vol.).