Local anesthetic toxicity in interscalene block: clinical series

We experienced two cases of local anesthetic toxicity by interscalene block. A 62-year-old man received interscalene block with lidocaine 1% 30 mL and bupivacaine 0.25% 20 mL under light sedation followed by general anesthesia. He was not awake at one hour after surgery with his pupils dilated. Three hours after interscalene block, he became awake with no complication. A 73-year-old female received interscalene block with lidocaine 1% 15 mL and ropivacaine 0.75% 15 mL under light sedation. After the injection, a catheter was inserted 5 cm. About 7-8 min after catheter insertion, generalized tonic seizure occurred. Seizure stopped in two min after anesthesia induction. She had no complication after surgery. These two cases showed neurological toxicity by interscalene block with lidocaine and bupivacaine or with ropivacaine without hemodynamic complication.

Novel antagonists for proteinase-activated receptor 2: inhibition of cellular and vascular responses in vitro and in vivo

BACKGROUND AND PURPOSE

Proteinase-activated receptor 2 (PAR(2)) is a G-protein coupled receptor associated with many pathophysiological functions. To date, the development of PAR(2) antagonists has been limited. Here, we identify a number of novel peptide-mimetic PAR(2) antagonists and demonstrate inhibitory effects on PAR(2)-mediated intracellular signalling pathways and vascular responses.

EXPERIMENTAL APPROACH

The peptide-mimetic compound library based on the structures of PAR(2) agonist peptides were screened for inhibition of PAR(2)-induced calcium mobilisation in human keratinocytes. Representative compounds were further evaluated by radioligand binding and inhibition of NFkappaB transcriptional activity and IL-8 production. The vascular effects of the antagonists were assessed using in vitro and in vivo models.

KEY RESULTS

Two compounds, K-12940 and K-14585, significantly reduced SLIGKV-induced Ca(2+) mobilisation in primary human keratinocytes. Both K-12940 and K-14585 exhibited competitive inhibition for the binding of a high-affinity radiolabelled PAR(2)-ligand, [(3)H]-2-furoyl-LIGRL-NH(2), to human PAR(2) with K(i) values of 1.94 and 0.627 microM respectively. NFkappaB reporter activity and IL-8 production were also significantly reduced. Furthermore, relaxation of rat-isolated aorta induced by SLIGRL-NH(2) was inhibited competitively by K-14585. K-14585 also significantly lowered plasma extravasation in the dorsal skin of guinea pigs and reduced salivation in mice.

CONCLUSIONS AND IMPLICATIONS

K-12940 and K-14585 antagonized PAR(2) competitively, resulting in inhibition of PAR(2)-mediated signalling and physiological responses both in vitro and in vivo. These peptide-mimetic PAR(2) antagonists could be useful in evaluating PAR(2)-mediated biological events and might lead to a new generation of therapeutically useful antagonists.

The Jones Morbidity Index as an aid for community pharmacists to identify poor asthma control during the dispensing process

Objective

To determine if the Jones Morbidity Index can be used in community pharmacy when asthmatic patients collect their prescriptions to identify those who have poor control.

Method

Structured questionnaires were completed by asthmatics who presented prescriptions at community pharmacies to assess their morbidity and knowledge of asthma and their attitudes towards and usage of medication.

Setting

Community pharmacies throughout the UK.

Key findings

Complete data on 306 patients were returned by 41 community pharmacists. Seventy-one patients reported using an asthma diary, 161 attended an asthma clinic and 194 had visited their doctor during the past year because of an acute exacerbation (GPV). Problems with metered dose inhaler (MDI) technique were identified in 165 patients. Patients' mean (SD) asthma knowledge score (K) (maximum 5) was 3.48 (1.32). Over the past six months they had received 0.88 (1.78) courses of oral prednisolone (P), 1.12 (1.85) courses of antibiotics (A) and 1.20 (4.51) courses of cough medicine (CM). Using the Jones Morbidity Index (JMI), 74 patients (24.2%) had low morbidity, 90 (29.4%) had medium morbidity and 142 (46.4%) had high morbidity. Comparisons between the morbidity categories revealed significant differences for P, A, GPV, “happy with” preventer (P < 0.001) and “happy with” reliever (P < 0.01) together with CM, K and compliance (P < 0.05). More patients classed as having high morbidity overused their reliever (P < 0.01) and were less compliant with their preventer (P < 0.001). There was no association between JMI and medication.

Conclusion

The JMI is a valuable tool to identify poor asthma control when patients present prescriptions at community pharmacies. More than half the asthmatics presenting their prescriptions at pharmacies had symptoms and signs indicating poor control.

Interaction between midazolam and serotonin in spinally mediated antinociception in rats

PURPOSE

Intrathecal administration of serotonin (5-HT) is antinociceptive through the involvement of spinal cord gamma-aminobutyric acid (GABA) receptors. Therefore, 5-HT would interact with the GABA agonist, midazolam, which is well known to exert spinally mediated antinociception in the spinal cord. The present study investigated the antinociceptive interaction between spinally administered 5-HT and midazolam, using two different rat nociceptive models.

METHODS

Sprague-Dawley rats with lumbar intrathecal catheters were tested for their thermal tail withdrawal response and paw flinches induced by formalin injection after the intrathecal administration of midazolam or 5-HT, or the midazolam/ HT combination. The effects of the combination were tested by isobolographic analysis, using the combination of each 1, 1/2, 1/4, 1/8, and 1/16 of the 50% effective dose (ED50). The total fractional dose was calculated. Behavioral side effects were also examined.

RESULTS

5-HT alone and midazolam alone both showed dose-dependent antinociception in both the tail flick test and the formalin test. The ED50 of the combination was not different from the calculated additive value either in the tail flick test or in phase 2 of the formalin test, but it was significantly smaller than the calculated additive value in phase 1 of the formalin test. The total fractional dose value was 0.90 in the tail flick test, 0.093 in phase 1 of the formalin test, and 1.38 in phase 2 of the formalin test. The agitation, allodynia, or motor disturbance observed with either agent alone was not seen with the combination treatment.

CONCLUSION

The antinociceptive effects of intrathecal midazolam and 5-HT were additive on thermal acute and inflammatory facilitated stimuli, and synergistic on inflammatory acute stimulation.

High-gravity-assisted pulsed laser ablation system for the fabrication of functionally graded material thin film

This paper describes a novel method for the fabrication of a thin film deposited on an appropriate substrate having a continuous composition gradient. The composition gradient was achieved by a combination of pulsed laser ablation (PLA) of the target material with a very strong acceleration field generated on a moving disk rotating at a very high speed. The PLA process was used to produce a cloud of high-energy particles of the target material that will be deposited on a substrate placed on the rotating disk. After deposition, the particles will diffuse on the surface of the thin film under a strong acceleration field. The high energy of the particles and their diffusion on the substrate surface in a high-vacuum environment produces a macroscopic composition distribution in the thin film. We have constructed an experimental apparatus consisting of a vacuum chamber in which a circular disk made of titanium is driven by a high-frequency inductive motor. An acceleration field of up to 10,000 G can be generated by this apparatus. Functionally graded material thin films of FeSi(2) with a continuous concentration gradient were successfully fabricated by this method under a gravity field of 5400 G. A significant advantage of this method is that it allows us to fabricate graded thin films with a very smooth surface covered by few droplets.

Plasmin induces degradation and dysfunction of laminin 332 (laminin 5) and impaired assembly of basement membrane at the dermal-epidermal junction

BACKGROUND

The epidermal basement membrane (BM), located at the dermal-epidermal junction (DEJ), plays important roles not only in adhesion between epidermis and dermis, but also in controlling skin functions. In sun-exposed skin, the BM becomes disrupted and multilayered. In order to explore the impairment of BM assembly, we have used a skin-equivalent (SE) as a model of BM damage and previously clarified the involvement of matrix metalloproteinases (MMPs) in impairment of BM assembly.

OBJECTIVES

In this work, we examined the role of urokinase-type plasminogen activator (uPA) and plasmin in impairment of BM assembly at the DEJ by using the SE, as ultraviolet irradiation to the skin increases uPA as well as MMPs.

METHODS

SEs were used as a model of formation and damage of BM. Human uPA was detected by enzyme-linked immunosorbent assay and zymography, and gelatinases such as MMP-2 and MMP-9 were detected by zymography. Human plasminogen was added at 0.06 micromol L(-1) (about 3% of plasma level) to increase plasmin to a pathological level. N-terminal peptide sequence analysis of plasmin-treated laminin 332 was carried out to identify alpha3, beta3 and gamma2 chains of laminin 332 and their cleavage sites of each chain. Plasmin-treated laminin 332 was analysed in keratinocyte adhesion activity and binding to type VII collagen.

RESULTS

Human uPA was detected in addition to MMP-2 and MMP-9, in conditioned medium of SE. Although the BM was well organized in the presence of an MMP inhibitor alone, the activated plasmin disorganized the BM even in the presence of the inhibitor. The impairment of BM assembly made the epidermis thinner as compared with that of a control cultured in the presence of MMP inhibitor, indicating that the BM affects the polarity and differentiation of the epidermis. The addition of aprotinin, a serine proteinase inhibitor, and tranexamic acid, a uPA-plasmin inhibitor, inhibited the plasmin-induced impairment of BM assembly and facilitated BM reorganization, thereby improving the epidermal structure. N-terminal peptide sequence analysis of plasmin-treated laminin 332 revealed the removal of a 5- or 10-kDa fragment, including the cell adhesion region, from the G3 domain of the alpha3 chain, and the LN domain, which binds to the noncollagenous 1 domain in type VII collagen, from the beta3 chain. Plasmin-treated laminin 332 showed lower keratinocyte adhesion activity and reduced binding to type VII collagen.

CONCLUSIONS

These results suggest that uPA and plasmin are involved in the impairment of BM assembly and epidermal differentiation, and that these effects arise at least partly through direct degradation of laminin 332.

Interaction between a NMDA receptor antagonist, AP-5 and an AMPA receptor antagonist, YM 872 in antinociception in the spinal cord

BACKGROUND

The intrathecal N-methyl-D-aspartate (NMDA) receptor antagonist, AP-5 and the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor antagonist, YM 872 showed inhibition on both acute and facilitated nociception in our previous study. The present study was performed to investigate the interaction between intrathecal AP-5 and YM 872 in antinociception for acute and chronic nociception.

METHODS

Sprague-Dawley rats with lumbar intrathecal catheters were tested for their thermal tail withdrawal response and for their paw flinches by formalin injection after intrathecal administration of AP-5 or YM 872. The effects of the combination were tested by an isobolographic analysis using 50% effective dose (ED50). Total fractional dose was calculated as (ED50 dose of AP-5 in combination)/(ED50 dose of AP-5 alone)+(ED50 dose of YM 872 in combination)/(ED50 dose of YM 872 alone).

RESULTS

Intrathecally administered AP-5, YM 872, and their combination produced dose-dependent increases of the tail-flick latency and decreases in the number of flinches in both phase 1 and 2 of the formalin test. The ED50 values of the combination were significantly lower than the calculated additive values (P<0.01). Total fractional dose value was 0.22 in the tail flick test, 0.12 in the phase 1 and 0.14 in the phase 2 of the formalin test.

CONCLUSION

An NMDA receptor antagonist, AP-5 and an AMPA receptor antagonist, YM 872 had synergistic antinociceptive effects on both acute thermal and inflammatory induced acute and facilitated nociception.

Expression of androgen receptor through androgen-converting enzymes is associated with biological aggressiveness in prostate cancer

Aims:

The association between the expression of androgen receptor (AR) or androgen-converting enzymes and malignant potential in prostate cancer (PCa) was examined.

Methods:

PCa specimens from 44 cases of stage II, 10 cases of stage III, four cases of stage IV and two recurrent cases were semi-quantitatively studied with immunohistochemistry for AR and androgen-converting enzymes.

Results:

The expression scores for AR, 5α-reductase type 1 (SRD5A1), 5α-reductase type 2 (SRD5A2), and aldo-keto reductase family 1 member C3 (AKR1C3) in the metastatic lesion of stage IV or recurrent cancer (n = 6) were 284.2 (30.1), 300 (0.0), 279.2 (51) and 254.2 (74.9), respectively; these scores were significantly higher than the respective scores of 121.8 (82.1), 135.1 (59.7), 167.0 (66.4) and 150.5 (62.8) for stage II and III cancer (n = 54) (p<0.001, p<0.001, p = 0.002 and p = 0.018, respectively). The expression scores for AR and SRD5A1 in stage II and III cancer with Gleason score 7 (n = 19) were 128.7 (72.3) and 150.5 (52.9); these were significantly higher than the scores of 78.8 (67.2) and 100.0 (39.6), respectively, for cancers with a Gleason score of ⩽6 (n = 20) (p = 0.032 and p = 0.002, respectively). The expression scores for AR, SRD5A1 and AKR1C3 in stage II and III cancer with primary Gleason pattern ⩾4 (n = 21) were 158.1 (84.3), 158.3 (61.1) and 173.8 (64.8); these were significantly higher than the scores of 98.6 (72.8), 120.3 (54.7) and 135.6 (57.6), respectively, for cancers with primary Gleason pattern ⩽3 (n = 33) (p = 0.011, p = 0.026 and p = 0.034, respectively). Within Gleason score 9 cancer, the expression scores for AR and SRD5A1 in the primary lesion of stage IV (n = 3) were 276.7 (5.8) and 283.3 (28.9); these scores were significantly higher than the scores of 182.1 (86.0) and 140.0 (56.6), respectively, for stage II and III cancer (n = 7) (p = 0.027 and p = 0.001, respectively).

Conclusions:

Both AR and androgen-converting enzymes were upregulated in high-grade or advanced PCa.

Amelioration of lacrimal gland inflammation by oral administration of K-13182 in Sjögren's syndrome model mice

Regulation of the adhesion of mononuclear cells to endothelial cells is considered to be a critical step for the treatment of inflammatory diseases, including autoimmune diseases. K-13182 was identified as a novel inhibitor for these adhesions. K-13182 inhibited the expression of vascular cell adhesion molecule-1 (VCAM-1, CD106) on human umbilical vein endothelial cells (HUVECs) and on mouse vascular endothelial cell line (MAECs) induced by tumour necrosis factor (TNF)-alpha. K-13182 also inhibited the adhesion of mononuclear cells to these HUVECs and MAECs, indicating that K-13182 suppressed these adhesions mediated by cellular adhesion molecules including VCAM-1. To evaluate the therapeutic effect in autoimmune disease model mice, K-13182 was orally administered to non-obese diabetic (NOD) mice as Sjögren's syndrome (SS) model mice. Severe destructive inflammatory lesions were observed in the lacrimal glands of vehicle-treated control mice; however, 8-week administration of K-13182 inhibited the mononuclear cell infiltration into the inflammatory lesions of the lacrimal glands. In K-13182-treated mice, the decrease in tear secretion was also prevented compared to the control mice. In addition, the apoptosis and the expression of FasL (CD178), perforin, and granzyme A was suppressed in the lacrimal glands of K-13182-treated mice. Therefore, K-13182 demonstrated the possibility of therapeutic efficacy for the inflammatory region of autoimmune disease model mice. These data reveal that VCAM-1 is a promising target molecule for the treatment of autoimmune diseases as a therapeutic strategy and that K-13182 has the potential as a new anti-inflammatory drug for SS.

Importance of the intracrine metabolism of adrenal androgens in androgen-dependent prostate cancer

The metabolic pathways of androgens and processes by which androgens induce re-growth after androgen deprivation therapy in prostate cancer have not been fully elucidated. In this study, finasteride decreased PSA secretion in medium containing testosterone, androstenedione, androstenediol and dehydroepiandrosterone, whereas dihydrotestosterone (DHT)- and hydroxy-flutamide-induced PSA production was not inhibited by finasteride in LNCaP-FGC cells. The present data show that adrenal androgen precursors do not directly interact with androgen receptors (ARs) but are converted to DHT via the intraprostatic metabolic pathways, resulting in the induction of LNCaP activity. This is the first report confirming this mechanism experimentally and also suggest the use of combined therapies that target ARs and prevent the formation of DHT within prostate cancer cells to achieve optimal therapeutic efficacy.

Establishment of a mouse skin model of the lichenification in human chronic eczematous dermatitis

BACKGROUND

Repeated mechanical stresses, such as scratching and rubbing, on a lesional skin area induce a rough skin condition known as lichenification in patients with chronic eczematous dermatitis. For ethical reasons, the pathomechanisms involved are difficult to study, so an animal model is required.

OBJECTIVES

To study the pathomechanisms of the unique rough skin changes seen in chronic eczematous dermatitis, we established a mouse skin model by repeated tape stripping to inflict stratum corneum (SC) barrier disruption. The skin characteristics of the model were investigated biologically, histologically and pharmacologically.

METHODS

Tape stripping was done on mouse back skin three times a week for 4 weeks. The skin changes were studied by obtaining negative replicas, haematoxylin and eosin staining, immunostaining for CD31 and BrdU, and measuring epidermal and cutaneous thickness and skin capacitance. Activities of matrix metalloproteinase (MMP)-2, 9 and urokinase-type plasminogen activator (uPA) in the skin tissues were analysed by zymography. The effects of MMP inhibitor and glycine were assessed.

RESULTS

The repeated tape stripping produced crusting and desquamation at 48 h, followed 1 week later by the formation of shallow furrows, which became much deeper after 4 weeks, appearing as fine and regular wrinkles. The resultant wrinkled skin resembled lichenified skin seen in patients with chronic eczematous dermatitis. Histopathologically, we found acanthosis, hypergranulosis and hyperkeratosis even at 48 h, and the skin was 2.5 times thicker than untreated control skin at 4 weeks. We observed angiogenesis in the upper dermis at 1 and 4 weeks. Skin capacitance, a parameter of SC hydration, displayed consistently low levels throughout the experimental period. Although the dermis was also thickened, the activity of MMP-9 was sharply increased only at 24 and 48 h after tape stripping, declining thereafter to the control level. Topical applications of CGS-27023A (CGS), an MMP inhibitor, failed to suppress this tape-stripping-induced wrinkle formation. In contrast, topical applications of a barrier recovery accelerator, glycine, effectively inhibited the wrinkle formation induced by repeated tape stripping.

CONCLUSIONS

The induction of fine and regular wrinkles by inflicting chronic SC barrier disruption in this model involves mainly epidermal changes, which is in sharp contrast to the mainly dermal changes induced by chronic ultraviolet B irradiation.

Comparison of the transcutaneous oxygen and carbon dioxide tension in different electrode locations during general anaesthesia

BACKGROUND AND OBJECTIVE

The best place for the electrode of transcutaneous measurement of oxygen tension (tcPO2) and carbon dioxide tension (tcPCO2) during general anaesthesia was investigated in three different locations.

METHODS

Fifteen patients for major abdominal surgery in the supine position were studied. The electrode of the TCM4 (Radiometer, Copenhagen, Denmark) was put on the chest, upper arm or forearm. TcPO2, tcPCO2, end-tidal carbon dioxide tension (etCO2), percutaneous oxygen saturation (SaO2), arterial oxygen tension (PaO2 ) and arterial carbon dioxide tension (PaCO2) were simultaneously measured at four different etCO2 concentrations and inhaled oxygen percentages and the location of the electrode was changed to other places to repeat the same measurement. In total, 12 measurements for each patient and 60 measurements for each place were performed.

RESULTS

TcPO2 correlated better than SaO2 (R2 = 0.58) with PaO2 (R2 = 0.76), and tcPCO2 correlated well with PaCO2 (R2 = 0.76) and etCO2 (R2 = 0.74) when the electrode was put on the chest, while not on the upper arm or forearm (R2 < 0.5). However, limits of agreement were too big to use tcPO2 (bias, -67.9; limits of agreement, 16.5, -152.3) and tcPCO2 (bias, -0.47; limits of agreement, 8.7, -9.64) as surrogate measures of PaO2 and PaCO2, respectively even when the electrode was put on the chest.

CONCLUSIONS

When the electrode was put on the chest, tcPO2 and tcPCO2 might be available as non-invasive monitors of oxygenation and CO2 status during general anaesthesia, while the absolute values were not interchangeable with PaO2 and PaCO2, respectively.