Spoken words are processed during dexmedetomidine-induced unresponsiveness.

BACKGROUND: Studying the effects of anaesthetic drugs on the processing of semantic stimuli could yield insights into how brain functions change in the transition from wakefulness to unresponsiveness. Here, we explored the N400 event-related potential during dexmedetomidine- and propofol-induced unresponsiveness. METHODS: Forty-seven healthy subjects were randomised to receive either dexmedetomidine (n=23) or propofol (n=24) in this open-label parallel-group study. Loss of responsiveness was achieved by stepwise increments of pseudo-steady-state plasma concentrations, and presumed loss of consciousness was induced using 1.5 times the concentration required for loss of responsiveness. Pre-recorded spoken sentences ending either with an expected (congruous) or an unexpected (incongruous) word were presented during unresponsiveness. The resulting electroencephalogram data were analysed for the presence of the N400 component, and for the N400 effect defined as the difference between the N400 components elicited by congruous and incongruous stimuli, in the time window 300-600 ms post-stimulus. Recognition of the presented stimuli was tested after recovery of responsiveness. RESULTS: The N400 effect was not observed during dexmedetomidine- or propofol-induced unresponsiveness. The N400 component, however, persisted during dexmedetomidine administration. The N400 component elicited by congruous stimuli during unresponsiveness in the dexmedetomidine group resembled the large component evoked by incongruous stimuli at the awake baseline. After recovery, no recognition of the stimuli heard during unresponsiveness occurred. CONCLUSIONS: Dexmedetomidine and propofol disrupt the discrimination of congruous and incongruous spoken sentences, and recognition memory at loss of responsiveness. However, the processing of words is partially preserved during dexmedetomidine-induced unresponsiveness. CLINICAL TRIAL REGISTRATION: NCT01889004.

Comparative effects of dexmedetomidine, propofol, sevoflurane, and S-ketamine on regional cerebral glucose metabolism in humans: a positron emission tomography study.

INTRODUCTION: The highly selective α2-agonist dexmedetomidine has become a popular sedative for neurointensive care patients. However, earlier studies have raised concern that dexmedetomidine might reduce cerebral blood flow without a concomitant decrease in metabolism. Here, we compared the effects of dexmedetomidine on the regional cerebral metabolic rate of glucose (CMRglu) with three commonly used anaesthetic drugs at equi-sedative doses. METHODS: One hundred and sixty healthy male subjects were randomised to EC50 for verbal command of dexmedetomidine (1.5 ng ml-1; n=40), propofol (1.7 µg ml-1; n=40), sevoflurane (0.9% end-tidal; n=40) or S-ketamine (0.75 µg ml-1; n=20) or placebo (n=20). Anaesthetics were administered using target-controlled infusion or vapouriser with end-tidal monitoring. 18F-labelled fluorodeoxyglucose was administered 20 min after commencement of anaesthetic administration, and high-resolution positron emission tomography with arterial blood activity samples was used to quantify absolute CMRglu for whole brain and 15 brain regions. RESULTS: At the time of [F18]fluorodeoxyglucose injection, 55% of dexmedetomidine, 45% of propofol, 85% of sevoflurane, 45% of S-ketamine, and 0% of placebo subjects were unresponsive. Whole brain CMRglu was 63%, 71%, 71%, and 96% of placebo in the dexmedetomidine, propofol, sevoflurane, and S-ketamine groups, respectively (P<0.001 between the groups). The lowest CMRglu was observed in nearly all brain regions with dexmedetomidine (P<0.05 compared with all other groups). With S-ketamine, CMRglu did not differ from placebo. CONCLUSIONS: At equi-sedative doses in humans, potency in reducing CMRglu was dexmedetomidine>propofol>ketamine=placebo. These findings alleviate concerns for dexmedetomidine-induced vasoconstriction and cerebral ischaemia. CLINICAL TRIAL REGISTRATION: NCT02624401.

Dermal expression of laminin-332 and type IV collagen in humans with severe sepsis.

BACKGROUND: An intact basement membrane at the dermal-epidermal junction is essential to the viability of the skin. The effect of sepsis on the basement membrane is unknown. METHODS: Skin biopsies were used to study basement membrane structure in severe sepsis (Day 1). Subsequent biopsies were taken on Day 8 and at 3 months in the survivors. Immunohistochemical staining was undertaken using laminin-223 and type IV collagen. Twenty patients with severe sepsis and four control subjects were included in the analysis. RESULTS: Intensive care unit mortality was 4/20, and total 30-day mortality was 5/20. Exactly, 7/17 of patients with severe sepsis exhibited weak or absent laminin-332 expression and 11/15 exhibited weak or absent type IV collagen expression compared with 0/4 of control subjects on Day 1 in intact skin. The proportion of sepsis patients with weak or absent laminin-332 expression was 5/11 on Day 8 and fell to 1/7 at 3 months. The proportion of sepsis patients with weak or absent type IV collagen expression was 10/11 on Day 8 and 4/7 at 3 months. CONCLUSION: These findings suggest that basement membrane formation may be compromised in patients with severe sepsis.

Industrial membrane processes in the treatment of process waters and liquors.

A review on pulp and paper industrial membrane processes using a variety of modules and processes is presented. Membranes are mostly used today to purify process waters and to recover coating colours. Ultrafiltration using tubular membrane modules or cross-rotational (CR) filtration has been widely applied for the purification of process waters. The reuse of UF membrane permeate has decreased the fresh water consumption to lower than 6 m³/t of paper in some paper machines. Some industrial membrane processes also recover valuable products from different streams (e.g lignosulphonates). Membranes are also combined with biological degradation processes in some paper mills. Nanofiltration has been used to purify the effluents discharged from the activated sludge process. At least two reverse osmosis plants purify river water to be used as raw water in the mill. Furthermore, advantages of different membrane modules and the current ways to treat membrane concentrate are discussed.

Survival markers related to bone metastases in prostate cancer.

Prognostic value of a bone resorption marker, tartrate-resistant acid phosphatase isoform 5b (TRACP 5b), and two matrix metalloproteinases (MMP-2 and MMP-9) was compared with the standard clinical analyses of total alkaline phosphatase (tALP) and prostate-specific antigen (PSA), in prostate cancer (PC) patients with (BM+) or without (BM-) bone metastases. Diagnostic accuracy evaluation showed the highest area under the curve for tALP (AUC=0.98), followed by PSA (AUC=0.87), TRACP 5b (AUC=0.82), MMP-9 (AUC=0.62) and MMP-2 (AUC=0.53). Significantly shorter survival was observed for patients with tALP (p<0.001), TRACP 5b (p=0.002) and PSA (p<0.001) levels, above the determined cut-off values compared with lower marker levels. In multivariate Cox regression analysis, only tALP and PSA, in addition to Gleason score were independent prognostic factors for survival. Of the three novel markers tested, only TRACP 5b proved to be predictive of survival in PC with bone metastases. MMP-2 and -9 are thus not recommended for further studies in this context.

Dupuytren's contracture; increased cellularity--proliferation, is there equality?

BACKGROUND: Dupuytren's disease is a chronic inflammatory process which causes contractures of the fingers by shortening and thickening the palmar fascia. During the proliferative phase, fibroblasts transform into myofibroblasts apparently under the influence of several different factors. The disease usually develops slowly, but in some patients it tends to develop aggressively. The pathogenesis of Dupuytren's disease remains unsolved. In this study, we analyzed some histological characteristics that seem to predict rapid recurrence. MATERIAL AND METHODS: 21 patients were divided into two groups. In 11 patients the disease was classified as aggressive because it had recurred within two years after an operation. In 10 cases it was non-aggressive, as no recurrence had been seen. Five control samples were taken from healthy palmar aponeurosis. The differences in cellularity, collagen, Ki-67, MSA, alpha-SMA and tenascin between the specimens were analyzed using immunohistochemistry. RESULTS: Alpha-SMA and Ki-67 were present more often in the aggressive specimens. Immunohistochemical stainings for macrophages and lymphocytes were negative. CONCLUSION: There may be differences in the histology and/or immunohistochemical appearance of pathological palmar connective tissue cords in aggressive and normal Dupuytren's disease. Further studies are needed to elucidate the pathogenesis of this disease.

Basement membranes in experimentally induced skin tumors.

Basement membrane changes in the epidermis and hair follicle apparatus resulting from topical 9,10-dimethylbenzanthracene applications were studied in mice, rats, and hamsters by light and electron microscopy and using antibodies to human collagen type IV and laminin. The basement membrane was distinct in epidermal hyperplasia, dysplasia, and papillomas, as well as around most of the keratoacanthomas and squamous cell carcinomas, which showed basement membrane irregularities, thickening, and reduplication in some areas. The invading edges of the squamous cell carcinomas with inflammatory infiltrates were devoid of laminin and collagen. Collagen IV and laminin-positive structures were observed around preserved follicular structures in rat: hair nevi and hair-follicle nevi, but partly absent around trichoepitheliomas and trichofolliculomas. Basal cell tumors were usually surrounded by a distinct basement membrane, which was lacking around some tumor cells.

Collagen synthesis in granuloma annulare.

Previous research has demonstrated active collagen synthesis in granuloma annulare (GA), a mainly degenerative disease of the skin. The present investigation is aimed to characterize details of the collagen synthesis and its regulation. Northern and in situ hybridization techniques and immunohistochemical methods are used to identify type I and type III collagen synthesis, regulation-associated polypeptides TGF-beta, Il-1 alpha, and Il-1 beta and an extracellular matrix protein tenascin, as well as lymphohistiocytic cells present in GA lesions. High mRNA levels of both pro-alpha 1 (I) and pro-alpha 1 (III) collagens were detected in GA lesions. In situ hybridization with cDNA probes revealed active fibroblasts with signals for both type I and III collagen mRNA around GA lesions. Some TGF-beta expression was found within the areas of inflammatory cells. Immunohistochemically, most of the mononuclear/lymphatic cells were CD3+ T cells. The helper/inducer phenotype (CD4+) was common among them, but there were no T-suppressor (CD8) cells. CD1+ cells were few in number, as were cells with activation or proliferation markers (CD26, CD30, and Ki67 antigens). Il-1 alpha- and Il-1 beta-positive lymphocytes/monocytes as well as interleukin-2 receptor containing cells were detected around the lesions, i.e., in the same areas as collagen-synthesizing fibroblasts. Another possible association with the regulation of collagen synthesis was the finding of an accumulation of tenascin, a growth-promoting extracellular matrix protein, in the surroundings of the GA lesions. We suggest that the firmly established and seemingly well-regulated type I and type III collagen synthesis presents a reparative phenomenon in the cutaneous lesions of GA.

A homozygous nonsense mutation and a combination of two mutations of the Wilson disease gene in patients with different lysyl oxidase activities in cultured fibroblasts.

Wilson disease is a rare autosomal recessive disease of copper metabolism. The gene for Wilson disease was characterized recently and has been predicted to encode a copper-transporting ATPase highly homologous to the protein encoded by the gene of Menkes disease. In this study, the genetic mutations of two Finnish patients with Wilson disease were investigated. One patient was homozygous for a novel nonsense mutation in exon 4, while the other was a compound heterozygote. Lysyl oxidase (EC 1.4.3.13) is an extracellular copper enzyme with deficient activity in Menkes disease. The levels of lysyl oxidase activity in cultured skin fibroblasts from these Wilson disease patients were also measured.

Necrobiosis lipoidica: ultrastructural and biochemical demonstration of a collagen defect.

Ten patients with necrobiosis lipoidica lesions were studied. Five patients had diabetes mellitus. The age of the patients varied from 15 to 73 years and the duration of the skin lesions was from 2 to 20 years. Histologically, the lesions were characterized by degeneration of collagen and elastin. In some lesions elastin fibers could be seen in areas devoid of normal-looking collagen. Electron microscopy revealed loss of cross-striation of collagen fibrils and a marked variation in the diameter of individual collagen fibrils. The concentration of collagen, measured by assay of hydroxy-proline, a collagen-specific amino acid, was markedly decreased in the lesional skin, but the ratio of type I/III collagen was unchanged in the affected skin. Fibroblasts established from affected skin synthesized less collagen than cells derived from healthy-looking skin. The decreased collagen synthesis was due to a decreased amount of messenger RNA for type I procollagen, measured by hybridization with a specific human cDNA clone. The production of collagenase by these fibroblasts was not increased. Our results thus indicate that in necrobiosis lipoidica lesions, collagen fibrils are defective and the amount of collagen is reduced, probably due to decreased synthesis of collagen by affected fibroblasts.

Basement membrane laminin and type IV collagen in various benign and malignant adnexal tumors of the skin: an immunohistochemical study.

Thirty benign and seven malignant adnexal tumors of the skin and one lymph node metastasis were stained for laminin and type IV collagen with rabbit antibodies against the human basement membrane (BM) proteins using the immunoperoxidase technique. Fifteen of the benign sweat gland, sebaceous gland, and hair follicle tumors showed a continuous and distinct BM around the tumor aggregates. The cylindromas and eccrine spiradenomas seemed to produce excessive amounts of BM material, part of which was seen as amorphic patches within the tumor cell clusters, whereas the trichofolliculomas, trichoepitheliomas, and pilomatrixomas showed an absence of BM from many areas. In syringomas, in addition to the tubular structures surrounded by a continuous BM, undifferentiated cell nests containing granular BM material were present. They probably represent primitive structures obtaining during early development into tubules. The seven malignant tumors and the only metastasis studied here all contained small, narrow strips of BM material extracellularly between the infiltrating tumor clusters. Only in two cases was faint staining for laminin found within the cells. The pepsin pretreatment of the formalin-fixed, paraffin-embedded samples had most probably degraded the intracytoplasmic BM material in most cases. The BM defects were found to be associated with malignancy and low differentiation of the adnexal skin tumors, as reported previously for other tumor types, but a partial loss of BM was also associated with high differentiation in some benign adnexal tumors.

Discontinuity of the basement membrane in fibrosing basocellular carcinomas and basosquamous carcinomas of the skin: an immunohistochemical study with human laminin and type IV collagen antibodies.

Thirteen basocellular carcinomas (BCC) of different histologic types and 5 basosquamous carcinomas (BSC) of the skin were stained for laminin and type IV collagen with rabbit antibodies against the human basement membrane (BM) proteins, using an immunoperoxidase technique. The BM around the tumor aggregates contained both laminin and type IV collagen, and was continuous and distinct in all the nonfibrosing BCCs but indistinct or interrupted in the fibrosing BCCs and BSCs. The BM was not influenced by the focal adnexal differentiation of the BCC cells. The disintegrity of the BM in the fibrosing BCCs and BSCs may reflect some kind of disturbance in the interaction between the neoplastic epithelium and the connective tissue stroma, and be connected with the more aggressive nature of these tumors compared with ordinary BCCs. Thus local aggressive behavior seems to be accompanied by defects in the BM.

Destruction of the epithelial anchoring system in lichen planus.

To find out whether the epithelial anchoring system shows any alterations in lichen planus, we examined the distribution of type VII collagen, alpha 6 beta 4 integrin, and kalinin in lesions of lichen planus. These molecules were chosen because they are structural components of anchoring fibrils, hemidesmosome-associated complexes, and anchoring filaments. The localization of type VII collagen in lichen planus was strikingly different from that in nonaffected mucosa or dermis or in other mucocutaneous lesions. In the normal mucosa, type VII collagen was localized only at the basement membrane zone. In lichen planus, type VII collagen was present not only in the basement membrane area but also in streaked patterns deep in the connective tissue. The hemidesmosome-associated complex, alpha 6 beta 4 integrin, was localized at the basal aspect of basal epithelial cells of nonaffected sites, but was diffuse and discontinuous in lichen planus lesions. Most of the basal keratinocytes, however, stained for this integrin. Kalinin staining was discontinuous in lichen planus lesions. Often, finger-like projections of kalinin staining were found protruding into the connective tissue stroma. Kalinin was localized at the basement membrane zone of the nonaffected tissue and other mucocutaneous lesions. These results indicate that in cutaneous and mucosal lichen planus, the epithelial anchoring system is disturbed.

Abnormal ornithine decarboxylase activity in transgenic mice increases tumor formation and infertility.

A transgenic mouse line carrying ornithine decarboxylase cDNA as the transgene under the control of a mouse mammary tumor virus long terminal repeat (MMTV LTR) promoter was generated in order to study whether ornithine decarboxylase transgene expression will have any physiological or pathological effect during the entire life of a transgenic mouse. The high frequency of infertile animals and the loss of pups made the breeding of homozygous mice unsuccessful. However, a colony of heterozygous transgenic mice was followed for 2 years. In adult heterozygous transgenic mice, ornithine decarboxylase activity was significantly increased in the testis, seminal vesicle and preputial gland when compared to non-transgenic controls. In contrast, ornithine decarboxylase activity was decreased in the kidney and prostate of transgenic mice. No significant changes in ornithine decarboxylase activity were found in the ovary and mammary gland and only moderate changes in ornithine decarboxylase activity were detected in the heart, brain, pancreas and lung. The most common abnormalities found in adult animals (12 males and 20 females) of the transgenic line were inflammatory processes, including pancreatitis, hepatitis, sialoadenitis and pyelonephritis. Spontaneous tumors were observed in eight animals, including two benign tumors (one dermatofibroma, one liver hemangioma) and six malignant tumors (one lymphoma, one intestinal and three mammary adenocarcinomas and one adenocarcinoma in the lung). No significant pathological changes were found in 17 nontransgenic controls.

Laminin-5 expression is independent of the injury and the microenvironment during reepithelialization of wounds.

We examined the expression of laminin-5 and its integrin receptors during reepithelialization of human wounds. We used suction blisters of skin as a model of keratinocyte migration on a basement membrane matrix and mucosal full-thickness wounds as a model in which keratinocytes migrate in a provisional matrix. An animal model, in which human epidermal keratinocytes were injected into the back of athymic mice, was used to follow the deposition of the basement membrane components. In 4-day-old blisters, about 20-50 cells at the leading edge of the migrating tongue showed cytoplasmic laminin-5 immunostaining. Laminin-5 mRNA was detected in 15-30 cells at the leading edge of the migrating epidermis. alpha3beta1 and alpha6beta4 integrins were found in membrane projections of the migrating basal cells and also in suprabasal cell layers, suggesting their combined role in binding laminin-5. In mucosal wounds, laminin-5 was the only basement membrane zone component that was deposited between the clot and the migrating keratinocytes. In the animal model, linear deposition of laminin-5 and alpha6beta4 integrin was already seen on Day 2, whereas the other basement membrane zone components were not yet organized. The results suggest that, regardless of the injury and the microenvironment, laminin-5 plays an essential role in the interaction between wound keratinocytes and the surrounding matrix.

Bone modeling and cell-material interface responses induced by nickel-titanium shape memory alloy after periosteal implantation.

The purpose of this study was to evaluate the new bone formation, modeling and cell-material interface responses induced by nickel-titanium shape memory alloy after periosteal implantation. We used a regional acceleratory phenomenon (RAP) model, in which a periosteal contact stimulus provokes an adaptive modelling response. NiTi has thermal shape memory and superelasticity properties uncommon in other implant alloys. So far, there are insufficient data concerning the biocompatibility of NiTi as a bone implant. NiTi was compared to stainless steel (stst) and Ti-6Al-4V. The test implant was placed in contact with the intact femur periosteum, but it was not fixed inside the bone. Histomorphometry with digital image analysis was used to determine the bone formation and resorption parameters. The ultrastructural features of cell-material adhesion were analysed with scanning electron microscopy (FESEM). A typical peri-implant bone wall modelation was seen due to the normal RAP. The maximum new woven bone formation started earlier (2 weeks) in the Ti-6Al-4V group than in the NiTi (P < 0.01) group, but also decreased earlier, and at 8 weeks the NiTi (P < 0.05) and stst (P < 0.005) groups had greater cortical bone width. At 12 and 26 weeks no statistical differences were seen in the histomorphometric values. The histological response of the soft tissues around the NiTi implant was also clearly non-toxic and non-irritating. Cell adhesion and focal contacts were similar between the materials studied by FESEM. We conclude that NiTi had no negative effect on total new bone formation or normal RAP after periosteal implantation during a 26-week follow-up.

Occult neurofibroma and increased S100 protein in the skin of patients with neurofibromatosis type 1: new insight to the etiopathomechanism of neurofibromas.

BACKGROUND: Neurofibromas represent proliferation of the connective tissue cells of peripheral nerves and deposition of collagenous extracellular matrix. There is evidence that the appearance and growth of neurofibromas may be associated with prior or ongoing mechanical trauma in patients with neurofibromatosis type 1 (NF1). OBJECTIVE: To study the histologic characteristics of apparently healthy skin of patients with NF1. DESIGN: The histologic features of healthy-looking skin of patients with NF1 were analyzed. SETTING: University hospital. PATIENTS: Ten patients who fulfilled the criteria for NF1. INTERVENTIONS: Punch biopsy specimens of healthy-looking skin of the forearm from 9 volunteer patients and of the upper eyelid during cosmetic operation from 1 volunteer patient were obtained. MAIN OUTCOME MEASURES: The main outcomes were not predicted, and the hypothesis was formulated during data collection. RESULTS: Apparently unaffected skin of 5 patients with NF1 was studied by routine histologic testing with respect to expression of S100 protein. Unexpectedly, analysis of the samples revealed the presence of a small neurofibroma tumor in one of the samples. The tumor was located in deep dermis around a hair follicle. In addition, neurofibromatous tissue not large enough to be called a tumor was found on the same anatomical location in another patient. In further studies, 10 punch biopsy specimens of apparently healthy skin from patients with NF1 were similarly sectioned and analyzed. No tumors were found in these additional samples. In 4 patients, however, abundant S100 protein-positive cells were located within collagenous extracellular matrix surrounding hair follicles. CONCLUSIONS: The skin of patients with NF1 might be more widely affected than previously thought and occult neurofibromas are not rare.

Systemic therapy with estrogen or estrogen with progestin has no effect on skin collagen in postmenopausal women.

OBJECTIVES: To investigate the effect of estrogen alone or combined with progestin on the amount and synthesis of skin collagen in postmenopausal women. METHODS: Forty-three early postmenopausal women were enrolled into this open, non-randomized parallel-groups study. Fifteen women received a continuous oral dose of 2 mg of 17 beta-estradiol and 1 mg of norethisterone acetate daily and 14 women an oral dose of 2 mg estradiol valerate daily. Fourteen subjects served as controls. The histology and type I and III procollagen immunohistochemistry of the skin, skin thickness, the amount of total collagen determined by a colorimetric method and the synthesis of type I and III collagens determined by analysing procollagen propeptides in the suction blister fluid were studied before the treatment and at 6 and 12 months. The proportional area of elastic fibers and the thickness of the epidermis were assessed from the sections obtained before the treatment and at 12 months, with computerized image analysis. RESULTS: Skin thickness, the amount and rate of collagen synthesis, the proportional area of elastic fibers and the thickness of the epidermis were not affected by either 17 beta-estradiol and 1 mg of norethisterone acetate or 2 mg of estradiol valerate. No histological or immunohistological changes were detected in the skin specimens during the 12-month treatment period compared to the baseline or to the skin specimens of the control group. CONCLUSIONS: A 1-year treatment with systemic estrogen alone or combined with progestin does not change the amount of collagen or the rate of collagen synthesis in postmenopausal women.