Immunogenicity and safety of the BNT162b2 mRNA COVID-19 vaccine in healthcare workers

Összefoglaló. Bevezetés: A SARS-CoV-2 koronavírus okozta COVID-19 általános egészségügyi és gazdasági krízist idézett elő. Célkitűzés: A megfigyeléses vizsgálat célja a BNT162b2 mRNS-Pfizer-BioNTech-vakcina hatásosságának, biztonságosságának és immunogenitásának igazolása a Budai Irgalmasrendi Kórház dolgozóin. Módszer: A vakcina adása után elemeztük a COVID-19-fertőzés előfordulását, az oltások utáni reakciókat, valamint a "spike" (S-) protein és a nukleokapszid (N)-protein elleni ellenanyag szintjének változását. Eredmények: A felmérésben részt vevő 295 dolgozó közül az oltást megelőzően 36 dolgozó esett át COVID-19-fertőzésen (COVID-19-pozitív csoport). A második oltás után a megfigyelési időszak három hónapjában COVID-19-fertőzés nem alakult ki a felmérésben részt vevő oltott dolgozók körében. Az oltási reakciók enyhék voltak. A COVID-19-pozitív csoportban az N-antitestek medián küszöbértékindexe az első vakcina után 4 héttel mérve szignifikánsan magasabb volt (28,37), mint a COVID-19-negatív (0,085) csoportban (p<0,0001). Az első vakcina után 4 héttel az S-antitestek medián értéke (8015 U/ml) a COVID-19-pozitív csoportban szignifikánsan magasabb volt (p<0,0001), mint a COVID-19-negatív csoportban (23,18 U/ml). A COVID-19-negatív csoport S-antitest-középértéke a második vakcina után szignifikáns (p<0,0001), mintegy 500×-os emelkedést mutatott (23,18 U/ml ről 1173 U/ml-re). Egy vakcina hatásosságát a fertőzések terjedésének megakadályozása igazolja. Következtetések: A második vakcina utáni megfigyelési időszakban új COVID-19-fertőzés nem volt az oltott dolgozók körében. A fertőzésen át nem esett COVID-19-negatív egyének esetén az S-antitest emelkedése mérsékelt az első oltás után, míg a második oltás után lényegesen emelkedik. A COVID-19-fertőzésen átesett egyének csoportjában már az első vakcina is jelentős S-antitest-termelődést vált ki. Orv Hetil. 2021; 162(39): 1551-1557.

SUMMARY

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic caused global public health and economic crises.

OBJECTIVE

The aim of this observation study was to estimate the effectiveness, safety and elicited immune response of the BNT162b2 mRNA Pfizer-BioNTech vaccine in healthcare workers of the Buda Hospital of the Hospitaller Order of St. John of God.

METHOD

After vaccination, the infection rate, adverse events and the kinetics of anti-SARS-CoV-2 spike (S) protein and anti-SARS-CoV-2 nucleocapsid (N) protein antibodies were evaluated.

RESULTS

Before vaccination, from the 295 healthcare workers 36 recovered from prior COVID-19 infection (COVID-19-positive group). After the second vaccination, there was no COVID-19 infection during the three-month follow-up period. The adverse events were mild. In the COVID-19-positive group, the median cut-off index of anti-N antibodies measured at 4 weeks after the first vaccination were significantly (p<0.0001) higher (28.37) than in the COVID-19-negative group (0.085). After the first vaccine, the median titer of anti-S antibodies was significantly higher (p<0.0001) in the COVID-19-positive group (8015 U/ml) compared to the COVID-19-negative group (23.18 U/ml). In the COVID-19-negative group, the median titer of anti-S antibodies increased significantly (p<0.0001) after the second vaccine (from 23.18 U/ml to 1173 U/ml), showing an increase of 500×.

CONCLUSIONS

After the second vaccination, there was no COVID-19 infection during the follow-up. In the COVID-19-negative group, the anti-S antibody titer is moderate after the first vaccination and increases significantly after the second vaccine. In the COVID-19-positive group, the first vaccine induces significant anti-S antibody production. Orv Hetil. 2021; 162(39): 1551-1557.

Beyond the physico-chemical barrier: Glycerol and xylitol markedly yet differentially alter gene expression profiles and modify signalling pathways in human epidermal keratinocytes

Polyols (e.g. glycerol, xylitol) are implicated as moisturizers of the skin and other epithelial tissues. However, we lack information about their exact cellular mechanisms and their effects on the gene expression profiles. Therefore, in this study, we aimed at investigating the effects of glycerol and xylitol on human epidermal keratinocytes. The polyols (identical osmolarities; xylitol: 0.0045%-0.45%; glycerol: 0.0027%-0.27%) did not alter cellular viability or intracellular calcium concentration. However, they exerted differential effects on the expression of certain genes and signalling pathways. Indeed, both polyols up-regulated the expression of filaggrin, loricrin, involucrin and occludin; yet, xylitol exerted somewhat more profound effects. Moreover, while both polyols stimulated the MAPK pathway, only xylitol induced the activation-dependent translocation of protein kinase Cδ, a key promoter of epidermal differentiation. Finally, in various keratinocyte inflammation models, both polyols (albeit with different efficacies) exerted anti-inflammatory effects. Taken together, these data strongly suggest that glycerol and xylitol differentially modulate expressions of multiple genes and activities of signalling pathways in epidermal keratinocytes. Thus, our findings invite clinical trials to explore the applicability and the impact of a combined glycerol-xylitol therapy in the management of various skin conditions.

Metastatic Spread from Abdominal Tumor Cells to Parathymic Lymph Nodes

Metastatic studies on rats showed that after subrenal implantation of tumor cells under the capsule of the kidney or subhepatic implantation under Glisson's capsule of the liver generated primary tumors in these organs. It was assumed that tumor cells that escaped through the disrupted peripheral blood vessels of primary tumors entered the peritoneal cavity, crossed the diaphragm, and appeared in the thoracal, primarily in the parathymic lymph nodes. This explanation did not answer the question whether distant lymph nodes were reached via the blood stream from the primary tumor or through the thoracal lymphatic vessels. In this work, we investigated the metastatic pathway in C3H/HeJ mice, after direct intraperitoneal administration of murine SCC VII cells bypassing the hematogenic spread of tumor cells. The direct pathway was also mimicked by intraperitoneal injection of Pelican Ink colloidal particles, which appeared in the parathymic lymph nodes, similarly to the tumor cells that caused metastasis in the parathymic lymph nodes and in the thymic tissue. The murine peritoneal-parathymic lymph node route indicates a general mechanism of tumor progression from the abdominal effusion. This pathway starts with the growth of abdominal tumors, continues as thoracal metastasis in parathymic lymph nodes and may proceed as mammary lymph node metastasis.

Sebaceous Gland-Rich Skin Is Characterized by TSLP Expression and Distinct Immune Surveillance Which Is Disturbed in Rosacea

The microbial community exhibits remarkable diversity on topographically distinct skin regions, which may be accompanied by differences in skin immune characteristics. Our aim was to compare the immune milieu of healthy sebaceous gland-rich (SGR) and sebaceous gland-poor skin areas, and to analyze its changes in an inflammatory disease of SGR skin. For this purpose, immunohistochemical, immunocytochemical, and quantitative real-time PCR analyses of thymic stromal lymphopoietin (TSLP) and other cytokines, phenotypic immune cell markers and transcription factors were carried out in samples from sebaceous gland-poor, SGR skin and from papulopustular rosacea. TSLP mRNA and protein production was also studied in cultured keratinocytes. In SGR skin, higher TSLP expression, dendritic cell appearance without prominent activation, and T cell presence with IL-17/IL-10 cytokine milieu were detected compared with sebaceous gland-poor skin. Linoleic acid, a major sebum component, was found to induce TSLP expression dose-dependently in keratinocytes. In papulopustular rosacea, significantly decreased TSLP level and influx of inflammatory dendritic cells and T cells with IL-17/interferon-γ cytokine milieu were observed. According to our results, SGR skin is characterized by a distinct, noninflammatory immune surveillance, which may explain the preferred localization of inflammatory skin diseases, and can influence future barrier repair therapeutic concepts.

Excessive pediatric fasciitis necrotisans due to Pseudomonas aeruginosa infection successfully treated with negative pressure wound therapy

The case of a 10-year old female child is described with a history of myeloproliferative disorder having skin, bone and visceral involvement. Bone marrow biopsy revealed histiocytosis X. During chemotherapy necrotizing fasciitis of the lower abdominal wall was diagnosed. Multiple microbiological cultures taken from the wound base revealed Pseudomonas aeruginosa infection. Surgical necrectomy and application of negative pressure wound therapy (NPWT) was started together with intensive care treatment for sepsis. As both wound and general condition of the patient improved, autologous split thickness skin grafting was carried out in two sitting under continuing NPWT application. The applied skin grafts showed excellent take, the perilesional subcutaneous recesses resolved and complete healing was achieved after 28 days of NPWT treatment. Proper dermatological diagnosis and immediate escharectomy complemented with application of NPWT can be life-saving in the treatment of necrotizing fasciitis.

Diagnostic accuracy of (18)F-FDG-PET/CT in early and late stages of high-risk cutaneous malignant melanoma

BACKGROUND

The precise role of total body (18) F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) in the clinical management of patients with cutaneous malignant melanoma (CMM) is not well established.

OBJECTIVE

The purpose of this study was to investigate the diagnostic accuracy of PET/CT in early- and late-stage patients with high-risk CMM.

METHODS

We retrospectively analysed various imaging, histopathological and clinical data from 97 patients also examined by PET/CT during a 5-year period (2007-2011). Three groups were assessed: stage I/II, resected stage III and unresectable stage III/stage IV.

RESULTS

The median follow-up time of living patients was 43.48 ± 19.67 (15-142) months. We observed a high diagnostic accuracy in all stages (91.3%, 92.5% and 96.2% respectively). PET/CT appeared to be reliable diagnostic tool even for the detection of small lymph node metastases. PET/CT was informative in 14 of 19 cases wherein another imaging examination provided inconclusive results regarding lesion dignity. However, PET/CT was less suitable for properly evaluating the dignity of a lung lesion. A true positive scan was twice as likely in clinically negative patients with resected stage III disease than in patients with stage I/II disease (35.9% and 14.5%, P = 0.007).

CONCLUSIONS

These results confirm that PET/CT is an important diagnostic tool in the management of patients with high-risk CMM, but it cannot replace the standard of care examinations. More accurate clinicopathological and timing criteria must be defined to best utilize the advantages of this imaging method.

European S1 guideline for the treatment of hidradenitis suppurativa/acne inversa

Hidradenitis suppurativa/acne inversa (HS) is a chronic, inflammatory, recurrent, debilitating skin disease of the hair follicle that usually presents after puberty with painful, deep-seated, inflamed lesions in the apocrine gland-bearing areas of the body, most commonly the axillae, inguinal and anogenital regions. A mean disease incidence of 6.0 per 100,000 person-years and an average prevalence of 1% has been reported in Europe. HS has the highest impact on patients' quality of life among all assessed dermatological diseases. HS is associated with a variety of concomitant and secondary diseases, such as obesity, metabolic syndrome, inflammatory bowel disease, e.g. Crohn's disease, spondyloarthropathy, follicular occlusion syndrome and other hyperergic diseases. The central pathogenic event in HS is believed to be the occlusion of the upper part of the hair follicle leading to a perifollicular lympho-histiocytic inflammation. A highly significant association between the prevalence of HS and current smoking (Odds ratio 12.55) and overweight (Odds ratio 1.1 for each body mass index unit) has been documented. The European S1 HS guideline suggests that the disease should be treated based on its individual subjective impact and objective severity. Locally recurring lesions can be treated by classical surgery or LASER techniques, whereas medical treatment either as monotherapy or in combination with radical surgery is more appropriate for widely spread lesions. Medical therapy may include antibiotics (clindamycin plus rifampicine, tetracyclines), acitretin and biologics (adalimumab, infliximab). A Hurley severity grade-relevant treatment of HS is recommended by the expert group following a treatment algorithm. Adjuvant measurements, such as pain management, treatment of superinfections, weight loss and tobacco abstinence have to be considered.

Protein kinase Cδ promotes proliferation and induces malignant transformation in skeletal muscle

In this paper, we investigated the isoform-specific roles of certain protein kinase C (PKC) isoforms in the regulation of skeletal muscle growth. Here, we provide the first intriguing functional evidence that nPKCδ (originally described as an inhibitor of proliferation in various cells types) is a key player in promoting both in vitro and in vivo skeletal muscle growth. Recombinant overexpression of a constitutively active nPKCδ in C2C12 myoblast increased proliferation and inhibited differentiation. Conversely, overexpression of kinase-negative mutant of nPKCδ (DN-nPKCδ) markedly inhibited cell growth. Moreover, overexpression of nPKCδ also stimulated in vivo tumour growth and induced malignant transformation in immunodeficient (SCID) mice whereas that of DN-nPKCδ suppressed tumour formation. The role of nPKCδ in the formation of rhabdomyosarcoma was also investigated where recombinant overexpression of nPKCδ in human rhabdomyosarcoma RD cells also increased cell proliferation and enhanced tumour formation in mouse xenografts. The other isoforms investigated (PKCα, β, ε) exerted only minor (mostly growth-inhibitory) effects in skeletal muscle cells. Collectively, our data introduce nPKCδ as a novel growth-promoting molecule in skeletal muscles and invite further trials to exploit its therapeutic potential in the treatment of skeletal muscle malignancies.

Function of RasGRP3 in the formation and progression of human breast cancer

Introduction

Ras guanine nucleotide exchange factors (RasGEFs) mediate the activation of the Ras signaling pathway that is over activated in many human cancers. The RasGRP3, an activator of H-Ras and R-Ras protein exerts oncogenic effects and the overexpression of the protein is observed in numerous malignant cancer types. Here, we investigated the putative alteration of expression and potential function of RasGRP3 in the formation and progression of human breast cancer.

Methods

The RasGRP3 and phosphoRasGRP3 expressions were examined in human invasive ductal adenocarcinoma derived samples and cell lines (BT-474, JIMT-1, MCF7, SK-BR-3, MDA-MB-453, T-47D) both in mRNA (Q-PCR) and protein (Western blot; immunohistochemistry) levels. To explore the biological function of the protein, RasGRP3 knockdown cultures were established. To assess the role of RasGRP3 in the viability of cells, annexin-V/PI staining and MitoProbe™ DilC1 (5) assay were performed. To clarify the function of the protein in cell proliferation and in the development of chemotherapeutic resistance, CyQuant assay was performed. To observe the RasGRP3 function in tumor formation, the Severe combined immunodeficiency (SCID) mouse model was used. To investigate the role of the protein in Ras-related signaling Q-PCR and Western blot experiments were performed.

Results

RasGRP3 expression was elevated in human breast tumor tissue samples as well as in multiple human breast cancer cell lines. Down-regulation of RasGRP3 expression in breast cancer cells decreased cell proliferation, induced apoptosis in MCF7 cells, and sensitized T-47D cells to the action of drugs Tamoxifen and trastuzumab (Herceptin). Gene silencing of RasGRP3 reduced tumor formation in mouse xenografts as well. Inhibition of RasGRP3 expression also reduced Akt, ERK1/2 and estrogen receptor alpha phosphorylation downstream from IGF-I insulin like growth factor-I (IGF-I) or epidermal growth factor (EGF) stimulation confirming the functional role of RasGRP3 in the altered behavior of these cells.

Conclusions

Taken together, our results suggest that the Ras activator RasGRP3 may have a role in the pathological behavior of breast cancer cells and may constitute a therapeutic target for human breast cancer.

Transfection of pseudouridine-modified mRNA encoding CPD-photolyase leads to repair of DNA damage in human keratinocytes: a new approach with future therapeutic potential

UVB irradiation induces harmful photochemical reactions, including formation of Cyclobutane Pyrimidine Dimers (CPDs) in DNA. Accumulation of unrepaired CPD lesions causes inflammation, premature ageing and skin cancer. Photolyases are DNA repair enzymes that can rapidly restore DNA integrity in a light-dependent process called photoreactivation, but these enzymes are absent in humans. Here, we present a novel mRNA-based gene therapy method that directs synthesis of a marsupial, Potorous tridactylus, CPD-photolyase in cultured human keratinocytes. Pseudouridine was incorporated during in vitro transcription to make the mRNA non-immunogenic and highly translatable. Keratinocytes transfected with lipofectamine-complexed mRNA expressed photolyase in the nuclei for at least 2days. Exposing photolyase mRNA-transfected cells to UVB irradiation resulted in significantly less CPD in those cells that were also treated with photoreactivating light, which is required for photolyase activity. The functional photolyase also diminished other UVB-mediated effects, including induction of IL-6 and inhibition of cell proliferation. These results demonstrate that pseudouridine-containing photolyase mRNA is a powerful tool to repair UVB-induced DNA lesions. The pseudouridine-modified mRNA approach has a strong potential to discern cellular effects of CPD in UV-related cell biological studies. The mRNA-based transient expression of proteins offers a number of opportunities for future application in medicine.

Treatment of partial thickness burns with Zn-hyaluronan: lessons of a clinical pilot study

A clinical investigation to determine the effectiveness of Zn-hyaluronan gel for the treatment of partial thickness burns was carried out. 60 patients were enrolled in the study with an average of 3% TBSA burn. Exudation lasted 3 days, no infectious complications were observed. By day 14 the wounds of 52 patients have healed, average complete healing time was 10,5 days. An overall 93,3% healing rate was achieved within the planned observation period. Reduction of spontaneous and movementrelated pain was reduced to less than half of the initial values by day 5,5 and 6,3 respectively. Development of a thin, elastic, well tolerable and protective membrane-like layer was noted. This kept the wounds moist while clean during wound-healing, and was spontaneously shed as epithelisation proceeded. Zn-hyaluronan gel is a novel topical wound care product that has proven to be suitable for the treatment of partial thickness burns.

In vitro and in vivo activity of 4-thio-uridylate against JY cells, a model for human acute lymphoid leukemia

We have previously reported the in vitro anti-proliferative effect of 4-thio-uridylate (s(4)UMP) on OCM-1 uveal melanoma cells. Here, we assessed the efficacy of s(4)UMP on JY cells. Treatment of JY cells with s(4)UMP suppressed their colony forming activity and induced apoptosis; healthy human bone marrow granulocyte-macrophage progenitor cells were 14-fold less sensitive to the nucleotide. In vivo effectiveness of s(4)UMP was determined using xenograft SCID mouse model. s(4)UMP decreased the cell number and colony forming activity of the total cell content of the femur of SCID mice transplanted with JY cells without affecting the bone marrow of healthy mice. These results suggest that s(4)UMP alone or in combination with other clinically approved anti-leukemic remedies should be further explored as a potential novel therapeutic agent.

Endocannabinoids modulate human epidermal keratinocyte proliferation and survival via the sequential engagement of cannabinoid receptor-1 and transient receptor potential vanilloid-1

We have recently shown that lipid mediators of the emerging endocannabinoid system (ECS) are key players of growth control of the human pilosebaceous unit. In this study, we asked whether the prototypic endocannabinoid anandamide (N-arachidonoylethanolamine, AEA) has a role in growth and survival of epidermal keratinocytes (KCs). Using human cultured KCs and skin organ-culture models, and by employing combined pharmacological and molecular approaches, we provide early evidence that AEA markedly suppresses KC proliferation and induces cell death, both in vitro and in situ. Moreover, we present that these cellular actions are mediated by a most probably constitutively active signaling mechanism that involves the activation of the metabotropic cannabinoid receptor CB(1) and a sequential engagement of the "ionotropic cannabinoid receptor" transient receptor potential vanilloid-1 (TRPV1). Finally, we demonstrate that the cellular effects of AEA are most probably due to a Ca(2+) influx via the non-selective, highly Ca(2+)-permeable ion channel TRPV1, and the concomitant elevation of intracellular Ca(2+) concentration. The data reported here may encourage one to explore whether the targeted manipulation of the above signaling pathway of the cutaneous ECS could become a useful adjunct treatment strategy for hyperproliferative human dermatoses such as psoriasis or KC-derived skin tumors.

Evaluation of mortality following severe burns injury in Hungary: external validation of a prediction model developed on Belgian burn data

PURPOSE

To evaluate mortality in a group of Hungarian burn patients and, as such, to perform an external validation of a prediction model developed on Belgian burn data by which the mortality appraisal was executed.

BASIC PROCEDURES

In a historical cohort we analysed all burn patients admitted between 1998 and 2006 to the Debrecen University Hospital (n=2326). The prediction model, based on three criteria (age, burned surface area (BSA) and inhalation injury) was also used to evaluate several subpopulations based on gender and age.

MAIN FINDINGS

Mean age was 35.3 years, mean BSA was 10.7%, 54% of the population was male, inhalation injury was rare (n=7; 0.3%) and overall mortality was 1.4% (1.6% male, 1.1% female). The men were younger and more severely burned, which was significant in every age group above 2 years. The model gave an accurate prediction of mortality, with a small overestimation in the lower risk categories. The receiver operating characteristic analysis demonstrated an area under the curve of 0.94 (95% confidence interval: 0.89-0.98).

CONCLUSION

Overall burn mortality in Hungary was low. The mortality prediction model demonstrated a high discriminative value. As such, this model is a helpful tool for outcome prediction and risk stratification for research purposes in burn patients.

Trastuzumab causes antibody-dependent cellular cytotoxicity-mediated growth inhibition of submacroscopic JIMT-1 breast cancer xenografts despite intrinsic drug resistance

Trastuzumab is a recombinant antibody drug that is widely used for the treatment of breast cancer. Despite encouraging clinical results, some cancers are primarily resistant to trastuzumab, and a majority of those initially responding become resistant during prolonged treatment. The mechanisms of trastuzumab resistance have not been fully understood. We examined the role of antibody-dependent cellular cytotoxicity (ADCC) using JIMT-1 cells that are ErbB2 positive but intrinsically resistant to trastuzumab in vitro. Unexpectedly, in experiments mimicking adjuvant therapy of submacroscopic disease in vivo (JIMT-1 cells inoculated s.c. in severe combined immunodeficiency mice), trastuzumab was able to inhibit the outgrowth of macroscopically detectable xenograft tumors for up to 5-7 weeks. The effect is likely to be mediated via ADCC because trastuzumab-F(ab')(2) was ineffective in this model. Moreover, in vitro ADCC reaction of human leukocytes was equally strong against breast cancer cells intrinsically sensitive (SKBR-3) or resistant (JIMT-1) to trastuzumab or even against a subline of JIMT-1 that was established from xenograft tumors growing despite trastuzumab treatment. These results suggest that ADCC may be the predominant mechanism of trastuzumab action on submacroscopic tumor spread. Thus, measuring the ADCC activity of patient's leukocytes against the tumor cells may be a relevant predictor of clinical trastuzumab responsiveness in vivo.

[Physiology of wound healing. Modern approach to wound care]

The wound healing cascade is based on the programmed, reproducible cooperation of the cells involved in reparation, their products, further humoral factors and the intercellular stroma. The author describes the physiological events during the phases of cutaneous acute wound healing by second intention, such as coagulation, inflammation, proliferation, remodelling, takes into account the local pathophysiological processes found in chronic wounds. The author reviews the recent scientific literature on wound healing as well. Information is rapidly growing about the communication between cells and factors involved in cutaneous wound repair. Parallel control of the same step is common among physiological processes, with redundant safety mechanisms. The failure of therapeutic approaches based on single factor substitution is predictable for the clinician, because it is yet impossible to properly orchestrate the introduction of these factors to the system. In case of chronic wounds sofar the most effective intervention into the course of wound healing can be achieved by adding complex live structures, such as in case of biotechnologically derived materials or skin transplantation.

Complete Inhibition of P-glycoprotein by Simultaneous Treatment with a Distinct Class of Modulators and the UIC2 Monoclonal Antibody

P-glycoprotein (Pgp) is one of the active efflux pumps that are able to extrude a large variety of chemotherapeutic drugs from the cells, causing multidrug resistance. The conformation-sensitive UIC2 monoclonal antibody potentially inhibits Pgp-mediated substrate transport. However, this inhibition is usually partial, and its extent is variable because UIC2 binds only to 10 to 40% Pgp present in the cell membrane. The rest of the Pgp molecules become recognized by this antibody only in the presence of certain substrates or modulators, including vinblastine, cyclosporine A (CsA), and SDZ PSC 833 (valspodar). Simultaneous application of any of these modulators and UIC2, followed by the removal of the modulator, results in a completely restored steady-state accumulation of various Pgp substrates (calcein-AM, daunorubicin, and 99mTc-hexakis-2-methoxybutylisonitrile), indicating near 100% inhibition of pump activity. Remarkably, the inhibitory binding of the antibody is brought about by coincubation with concentrations of CsA or SDZ PSC 833 approximately 20 times lower than what is necessary for Pgp inhibition when the modulators are applied alone. The feasibility of such a combinative treatment for in vivo multidrug resistance reversal was substantiated by the dramatic increase of daunorubicin accumulation in xenotransplanted Pgp+ tumors in response to a combined treatment with UIC2 and CsA, both administered at doses ineffective when applied alone. These observations establish the combined application of a class of modulators used at low concentrations and of the UIC2 antibody as a novel, specific, and effective way of blocking Pgp function in vivo.

Insulin-like growth factor-I-coupled mitogenic signaling in primary cultured human skeletal muscle cells and in C2C12 myoblasts. A central role of protein kinase Cδ

In this study, we have investigated the effects of insulin-like growth factor-I (IGF-I) on cellular responses of primary human skeletal muscle cells and mouse C2C12 myoblasts. In human muscle, IGF-I stimulated proliferation and fusion of the cells and the expression of the differentiation marker desmin. These effects were completely inhibited by Rottlerin, the inhibitor of the protein kinase C (PKC)delta, but were not affected by the inhibition of the mitogen-activated protein kinase (MAPK) or the phosphatidylinositide 3-kinase (PI-3K) pathways. Furthermore, IGF-I initiated the selective translocation of PKCdelta to the nucleus. In C2C12 myoblasts, the growth-promoting effects of IGF-I were abrogated by inhibition of PKCdelta, but not by the inhibition of the PI-3K system. However, in contrast to the human data, the MAPK inhibitor PD098059 partially (yet significantly) also inhibited the action of IGF-I and, furthermore, IGF-I induced phosphorylation of the MAPK Erk-1/2. In addition, overexpression of constitutively active form of PKCdelta in C2C12 cells fully mimicked, whereas overexpression of kinase inactive mutant of the isoform prevented the action of IGF-I. Finally, the inhibition of PKCdelta suspended the IGF-I-induced phosphorylation of Erk-1/2 and, moreover, the inhibition of the MAPK pathway partially (yet significantly) inhibited the accelerated growth of C2C12 cells overexpressing PKCdelta. Taken together, these results demonstrate a novel, central and exclusive involvement of PKCdelta in mediating the action of IGF-I on human skeletal muscle cells, with an additional yet PKCdelta-dependent contribution of the MAPK pathway on C2C12 myoblasts.

Role of acellular dermal matrix allograft in minimal invasive coverage of deep burn wound with bone exposed--case report and histological evaluation

A sandwich graft was applied to the debrided cortical bone layer of the tibia in the case of a 72-year-old male patient with full-thickness necrotic burn injury. The combined graft consisted of a dermal template material and autologous split thickness skin graft. After application, the graft was found totally accepted and provided good functionality with acceptable appearance. Histopathologic evaluation revealed a complete take with revascularisation of the implant. Supporting lamellar bony trabecules were also seen in the deep dermal dermis representing a connection to the underlying bone. The use of the dermal matrix in deep burn exposing the bone provides a satisfactory functional result and good cosmetic appearance.

Opposite roles of protein kinase C isoforms in proliferation, differentiation, apoptosis, and tumorigenicity of human HaCaT keratinocytes

We have previously shown that the protein kinase C (PKC) system plays a pivotal role in regulation of proliferation and differentiation of the human keratinocyte line HaCaT which is often used to assess processes of immortalization, transformation, and tumorigenesis in human skin. In this paper, using pharmacological and molecular biology approaches, we investigated the isoform-specific roles of certain PKC isoenzymes (conventional cPKCalpha and beta; novel nPKCdelta and epsilon) in the regulation of various keratinocyte functions. cPKCalpha and nPKCdelta stimulated cellular differentiation and increased susceptibility of cells to actions of inducers of apoptosis, and they markedly inhibited cellular proliferation and tumor growth in immunodeficient mice. In marked contrast, cPKCbeta and nPKCepsilon increased both in vitro and in vivo growth of cells and inhibited differentiation and apoptosis. Our data present clear evidence for the specific, antagonistic roles of certain cPKC and nPKC isoforms in regulating the above processes in human HaCaT keratinocytes.

In vivo and in vitro multitracer analyses of P-glycoprotein expression-related multidrug resistance

P-glycoprotein (Pgp) is an ABC (ATP binding cassette) transporter that is often overexpressed in tumours, contributing significantly to their multidrug resistance. In this study, we explored whether the radiotracers used in tumour diagnostics can be used for in vivo visualisation of Pgp-related multidrug resistance. We also examined the effects of different Pgp modulators on the accumulation of these radioligands in tumours with or without Pgp expression. In a SCID BC-17 mouse model, cells of the drug-sensitive KB-3-1 (MDR(-)) and the KB-V1 Pgp-expressing (MDR(+)) human epidermoid carcinoma cell lines were inoculated to yield tumours in opposite flanks. For in vivo scintigraphic (biodistribution) and positron emission tomography (PET) examinations, the mice were injected with technetium-99m hexakis-2-methoxybutylisonitrile ((99m)Tc-MIBI), carbon-11 labelled methionine and fluorine-18 fluoro-2-deoxy- d-glucose ((18)FDG). For validation, in vitro cell studies with (99m)Tc-MIBI,( 99m)Tc-tetrofosmin, [(11)C]methionine and (18)FDG were carried out using a gamma counter. The expression and function of the MDR product were proved by immunohistochemistry and spectrofluorimetry. (99m)Tc-MIBI uptake was significantly lower in KB-V1 cells as compared with KB-3-1-derived tumours in vivo (Pgp(+)/Pgp(-) =0.61+/-0.13; P<0.01) and cells in vitro (Pgp(+)/Pgp(-) =0.08+/-0.01; P<0.001).()Cyclosporin A reversed (99m)Tc-MIBI uptake in the Pgp+ cells, while verapamil failed to modify it. (18)FDG uptake was significantly higher in KB-V1 tumours (Pgp(+)/Pgp(-) =1.36+/-0.05; P<0.01) and cells (Pgp(+)/Pgp(- )=1.52+/-0.12; P<0.001). Whereas cyclosporin A eliminated the difference between FDG uptake in MDR(+) and MDR(-) cell lines, verapamil significantly increased it. When the animals were treated with verapamil, the ratio of (99m)Tc-MIBI uptake in the MDR(+) tumours to that in the MDR(-) tumours decreased to 0.38+/-0.05 ( P<0.01), while the ratio of (18)FDG uptake increased to 2.1+/-0.3 ( P<0.001). There were no significant differences in the [(11)C]methionine uptake in the MDR(+) and MDR(-) tumours and cell lines, nor was [(11)C]methionine accumulation modified by cyclosporin A. Parallel administration of (18)FDG and (99m)Tc-MIBI combined with verapamil treatment seems to be a good candidate as a non-invasive marker for the diagnosis of MDR-related Pgp expression in tumours.

Tumor cells expressing membrane-bound tumor necrosis factor activate macrophages and have a compromised growth in immunosuppressed and immunodeficient mice

Tumor necrosis factor (TNF)-alpha producing tumors as vaccines were demonstrated to induce a therapeutic anti-tumor immune response, but their clinical use is limited by the toxicity of soluble TNF. We investigated the growth characteristics and immunomodulatory properties of HeLa cells producing an uncleavable transmembrane form of TNF (preTNF). The growth of the transformed tumors was compromised in both immunosuppressed and severe combined immunodeficient mice; no signs of TNF toxicity were detected. Macrophages co-cultured with the transformed cells showed increased phagocytosis and cytokine production, indicating that activated macrophages may be the mediators of the anti-tumor effect. preTNF producing tumor cells are promising safe anti-tumor vaccine candidates.

Experiences with the use of povidone-iodine-containing local therapeutics in dermatological surgery and in the treatment of burns: testing for allergic sensitization in postsurgery patients

In dermatological surgery where the lesions to be removed are very often contaminated with bacteria, local use of antiseptics that are effective against a wide range of germs is often indicated. Polyvinylpyrrolidone (povidone = PVP)-bound iodine (in Hungary marketed as Betadine is used successfully in our department. After excision and suture in per primam healing wounds as well as after tissue destruction in per secundam healing wounds, a thin layer of Betadine ointment on the dressing right after surgery and at dressing changes may reduce the risk of wound infection. When the defect requires split-thickness skin grafting, a combination of tulle gras and a layer of gauze soaked with 1:10 dilution of Betadine solution is suggested. In the treatment of leg ulcers, Betadine is used for cleansing and for impregnating the gauze on top of the tulle gras layer both in the debridement and in the epithelization phases. PVP-I is beneficial on burn wounds due to its effect reducing bacterial colony counts. Its use is advised for superficial (grades 1 and 2a) burns as well as surgical debridement of deep burns or temporary xenograft or definitive autograft coverage of these wounds. After treating a large number of patients with Betadine, a statement can be made: despite its theoretical risk, no cytostatic effect is seen in the clinical setting. No allergy towards Betadine was observed among the author's patients over several years of its use. Fifty patients previously treated with PVP-I were challenged with epicutaneous patch testing, and no sensitization was found. An account is made on the adverse effects attributed to Betadine found in the scientific literature, and its use with regard to the proper indications is suggested.

Cimetidine and a tamoxifen derivate reduce tumour formation in SCID mice xenotransplanted with a human melanoma cell line

Histamine is produced by many cells expressing histidine decarboxylase (HDC), the enzyme responsible for the synthesis of histamine. Since melanoma cells and tissue contain relatively large amounts of histamine, the functional significance of histamine was examined using specific antihistamines in vitro and in vivo in the human melanoma cell line HT168 and severe combined immunodeficiency (SCID) mice. It was shown that the H2 receptor antagonist cimetidine when combined with N, N-diethyl-2-[4-(phenylmethyl)phenoxy]-ethanamine-HCl (DPPE), a tamoxifen derivate, inhibits the proliferation of HT168 cells. Furthermore, it is suggested that there is a factor(s) that interferes with the exponential growth of HT168 cells xenografted to immunodeficient mice, and cimetidine and DPPE together significantly influence this factor(s). This combination of antihistamines also increases the survival of human melanoma-grafted mice. These changes are accompanied by enhanced infiltration of interferon-gamma- producing mouse macrophages into the tumour tissue. These findings suggest that two different mechanisms are probably acting concordantly: direct inhibition of tumour cell proliferation by the H2 receptor antagonists, and activation of the local immune response characterized by interferon-gamma production. These findings may help to elucidate the possibility of a rationally designed antihistamine strategy in melanoma therapy.

Glomerular prostanoid production is modified by plasma samples of hypertensive and diabetic patients

The autocrin-paracrin prostanoid system plays a major role in the enhancement or inhibition of renal tissue damage. Our hypothesis was that there might be circulating factors in the plasma with a capability to modify renal (glomerular) prostanoid synthesis. We measured the synthesis of prostacyclin 1-2 (PGI2) and thromboxan A-2 (TxA2) of isolated glomeruli, incubated in plasma samples obtained from hypertensive and diabetic (NIDDM) patients. It was found that these plasma samples decreased the renal PGI2/TxA2 ratio, mostly by decreasing glomerular PGI2 synthesis and, to a lesser extent, increasing the synthesis of TxA2. Our results demonstrate that circulating factors in hypertension and diabetes might play a role in renal damage seen in these conditions.

Studies on the tissue-related phenotypic heterogeneity of murine B cells

The development of B cells is accompanied by their ability to specifically enter the peripheral lymphoid tissues. Recently, we described a novel rat monoclonal antibody (IBL-2; IgG2b/kappa) reacting with a 26/29-kD heterodimeric structure of the cell surface. This mAb has been found to recognize differentially the peripheral B cells of mice depending on their tissue origin. The majority of splenic B cells as well as the mature B cells in the bone marrow were stained with this mAb, whereas the B lymphocytes isolated from LN or Peyer's patches displayed only negligible reactivity. We extended these observations by analyzing the relationship between the expression of IBL-2 antigen and L-selection on the surface of B-cell precursors in the bone marrow by multiparameter flow cytometry. Within the B220 positive compartment, a significant difference of L-selectin expression could be observed between the various IBL-2-reactive subsets. Furthermore, we investigated whether evidences for the establishment of tissue-associated phenotypic heterogeneity similar to that found in normal mice could be found upon the adoptive transfer of normal unselected splenic lymphocytes into SCID recipients (Spl-SCID). It has been found that a large part of the splenic B cells preserved their IBL-2 reactivity, whereas the LN B cells had lost the IBL-2 antigen in Spl-SCID. These data indicate that the phenotypic difference within the SCID mice may be the result of the migration of B lymphocytes from the spleen toward the lymph nodes, and the altered expression of the IBL-2 antigen correlates with this process.

Repopulation of Langerhans cells during wound healing in an experimental human skin/SCID mouse model

The epidermal repopulation of Langerhans cells (LCs) during wound healing was examined using a human skin severe combined immunodeficient (SCID) mouse model. The experiments, were carried out after proving the human origin of keratinocytes repopulating the wound beds using the W6/32 monoclonal antibody. It was shown that CD1a- and HLA-DR-positive dendritic cells (mostly LCs) are already detectable 2 days after injury within the newly formed epithelium. In the excisional wounds investigated, neither HLA-DR nor ICAM-1 expression of human keratinocytes was observed. Our present data suggest that LC repopulation is an early event in the process of re-epithelization.

Thrombospondin receptor (CD36) expression of human keratinocytes during wound healing in a SCID mouse/human skin repair model

Using a human skin/severe combined immunodeficient (SCID) chimeric mouse model, we examined the keratinocyte expression of the thrombospondin receptor (CD36) and its ligand thrombospondin-1 (TSP1) in acute uninflamed wounds. Positive suprabasal keratinocyte expression of CD36 was observed as early as 30 minutes after wounding in the adjacent, intact epidermis; it disappeared 4 days later. Keratinocytes of the freshly re-epithelised wounds and those of the surrounding epidermis remained TSP1-negative throughout the whole observation period of 7 days. Our results indicate that CD36-positive keratinocytes, probably in connection with activated, TSP1-positive thrombocytes, may play an important role in the early phase of wound healing.

Relation of renal thromboxane A2 production to urine flow, electrolyte excretion and plasma renin activity in control state and drug induced hypotension

The functional importance of renal TxB2 generation in the maintenance of elevated arterial blood pressure in essential hypertension was followed in 22 patients, using the method of sustained blood pressure decrease by i.v. sodium nitroprusside infusion. Linear correlation between urinary excretion of TxB2, urine flow, and sodium excretion could be established in both control and hypotensive periods. Presumably, changes in urinary excretion of TxB2 reflect a secondary intrarenal counterregulatory response.

Surface markers of blood lymphocytes in bronchial carcinoma

The proportion of autologous rosette-forming, i.e. autoerythrocyte-binding, T-lymphocytes, was studied in 34 patients with untreated, operable bronchial carcinoma. The number of autorosettes in patients with bronchial carcinoma was considerably below the mean value for the normal control group. In patients with metastatic involvement of the regional lymph nodes at the time of surgery the reduction in the number of autorosettes was still more marked. On the 10th postoperative day after resection of the tumour and in case of remission five months after surgery, the number of autorosettes showed a significant rise approximating the normal value. The distribution of sheep-E-rosette-forming and of the "active-early" T-lymphocytes was also studied. On the evidence of the results, the number of autorosette-forming lymphocytes lends itself to a follow-up of bronchial carcinoma by early demonstration of remissions or recurrences.

Diurnal rhythm of beta endorphin in normotensive and hypertensive patients: the effect of clonidine

Diurnal rhythm of plasma beta endorphin was established with the highest level in the morning and the lowest one at midnight in normotensive subjects and also in patients with essential hypertension. Clonidine (300 micrograms daily) significantly increased plasma beta endorphin concentrations only in the hypertensive patients. The significant linear correlation between the increase in plasma beta endorphin concentration and the decrease in blood pressure (both systolic and diastolic) in these patients may point to the role of this endogenous opioid in the antihypertensive action of clonidine.

Effect of prazosin and oxprenolol on plasma renin activity and blood pressure in patients with essential hypertension

48 patients with normal-renin essential hypertension were treated with prazosin alone or in combination with oxprenolol. 1 h after a single dose of 2 mg prazosin tachycardia and a decrease in blood pressure developed. Renin activity in the peripheral plasma (PRA) increased from 1.04 +/- 0.15 to 2.64 +/- 0.20 ng AgT/ml/h. A 3-day treatment with 2 mg t.i.d. prazosin of 11 patients caused no further decrease in blood pressure, while PRA returned to the baseline level. Treatment for 3 days with 2 mg prazosin t.i.d. and 40 mg oxprenolol t.i.d. of 37 patients further decreased blood pressure as well as PRA. The increase in PRA after a single dose of prazosin could be related to the enhanced sympathetic activity. The decreased PRA after prazosin + oxprenolol therapy may be one of the factors responsible for the greater antihypertensive response to the combined therapy.

Amikacin: in vitro bacteriological studies, levels in human serum, lung and heart tissue, and clinical results

The amikacin sensitivity of bacteria cultured from 3282 clinical cases of mixed type was determined. Gentamicin and amikacin were equally effective against E. coli strains. Amikacin inhibited the growth of more Pseudomonas aeruginosa strains than did gentamicin. Against Gram-positive bacteria gentamicin proved to be more effective. Many of the gentamicin-resistant strains were sensitive to amikacin. Amikacin levels were measured during 21 pulmonary and 14 heart operations, subsequent to a intramuscular administration of 500 mg amikacin. The serum contained 17-20 microgram/ml amikacin, in the intact, inflamed and tumourous parts of removed lung tissue 9, 6 and 6 microgram/g concentrations were detected, respectively, whereas the cardiac auricle and the pericardial fluid contained 3-4 and 2-4 microgram/ml, respectively. These amikacin levels reach or in most cases even exceed the minimal inhibiting concentrations against the bacteria. Therefore, amikacin is excellent for the treatment of respiratory infections, pericarditis and endocarditis caused by Gram-negative, gentamicin-resistant bacteria. Amikacin treatment of 8 patients with grave diseases as well as the successful local administration of amikacin based on the therapy of 55 cases of surgical suppurations is reported.