[Analysis of the causes of long-standing pelvic anterior sacral space infection and discussion of management techniques]

Objective: To investigate the causes and management of long-term persistent pelvic presacral space infection. Methods: Clinical data of 10 patients with persistent presacral infection admitted to the Cancer Hospital of Zhengzhou University from October 2015 to October 2020 were collected. Different surgical approaches were used to treat the presacral infection according to the patients' initial surgical procedures. Results: Among the 10 patients, there were 2 cases of presacral recurrent infection due to rectal leak after radiotherapy for cervical cancer, 3 cases of presacral recurrent infection due to rectal leak after radiotherapy for rectal cancer Dixons, and 5 cases of presacral recurrent infection of sinus tract after adjuvant radiotherapy for rectal cancer Miles. Of the 5 patients with leaky bowel, 4 had complete resection of the ruptured nonfunctional bowel and complete debridement of the presacral infection using an anterior transverse sacral incision with a large tipped omentum filling the presacral space; 1 had continuous drainage of the anal canal and complete debridement of the presacral infection using an anterior transverse sacral incision. 5 post-Miles patients all had debridement of the presacral infection using an anterior transverse sacral incision combined with an abdominal incision. The nine patients with healed presacral infection recovered from surgery in 26 to 210 days, with a median time of 55 days. Conclusions: Anterior sacral infections in patients with leaky gut are caused by residual bowel secretion of intestinal fluid into the anterior sacral space, and in post-Miles patients by residual anterior sacral foreign bodies. An anterior sacral caudal transverse arc incision combined with an abdominal incision is an effective surgical approach for complete debridement of anterior sacral recalcitrant infections.

Prognostic value of preoperative immune-nutritional scoring systems in remnant gastric cancer patients undergoing surgery

BACKGROUND

Remnant gastric cancer (GC) is defined as GC that occurs five years or more after gastrectomy. Systematically evaluating the preoperative immune and nutritional status of patients and analyzing its prognostic impact on postoperative remnant gastric cancer (RGC) patients are crucial. A simple scoring system that combines multiple immune or nutritional indicators to identify nutritional or immune status before surgery is necessary.

AIM

To evaluate the value of preoperative immune-nutritional scoring systems in predicting the prognosis of patients with RGC.

METHODS

The clinical data of 54 patients with RGC were collected and analyzed retrospectively. Prognostic nutritional index (PNI), controlled nutritional status (CONUT), and Naples prognostic score (NPS) were calculated by preoperative blood indicators, including absolute lymphocyte count, lymphocyte to monocyte ratio, neutrophil to lymphocyte ratio, serum albumin, and serum total cholesterol. Patients with RGC were divided into groups according to the immune-nutritional risk. The relationship between the three preoperative immune-nutritional scores and clinical characteristics was analyzed. Cox regression and Kaplan–Meier analysis was performed to analyze the difference in overall survival (OS) rate between various immune-nutritional score groups.

RESULTS

The median age of this cohort was 70.5 years (ranging from 39 to 87 years). No significant correlation was found between most pathological features and immune-nutritional status (P > 0.05). Patients with a PNI score < 45, CONUT score or NPS score ≥ 3 were considered to be at high immune-nutritional risk. The areas under the receiver operating characteristic curves of PNI, CONUT, and NPS systems for predicting postoperative survival were 0.611 [95% confidence interval (CI): 0.460–0.763; P = 0.161], 0.635 (95%CI: 0.485–0.784; P = 0.090), and 0.707 (95%CI: 0.566–0.848; P = 0.009), respectively. Cox regression analysis showed that the three immune-nutritional scoring systems were significantly correlated with OS (PNI: P = 0.002; CONUT: P = 0.039; NPS: P < 0.001). Survival analysis revealed a significant difference in OS between different immune-nutritional groups (PNI: 75 mo vs 42 mo, P = 0.001; CONUT: 69 mo vs 48 mo, P = 0.033; NPS: 77 mo vs 40 mo, P < 0.001).

CONCLUSION

These preoperative immune-nutritional scores are reliable multidimensional prognostic scoring systems for predicting the prognosis of patients with RGC, in which the NPS system has relatively effective predictive performance.

[Reoperation and perioperative management of residual cyst wall with perineal intractable sinus after resection of presacral cyst tumors]

Objective: To investigate the reoperation and perioperative management of residual cyst wall with perineal intractable sinus after resection of presacral cyst tumors. Methods: The clinical data of 29 patients with residual cyst wall and perineal intractable sinus after resection of presacral cyst tumors in Affiliated Cancer Hospital of Zhengzhou University from January 2014 to August 2019 were reviewed, including the characteristics of the residual cyst wall with perineal intractable sinus after resection of presacral cyst tumors, surgical method, and perioperative management. Results: Twenty-nine patients with residual cyst wall and perineal intractable sinus after resection of presacral cyst tumors, including 9 cases of epidermoid cysts, 7 cases of dermoid cysts, 10 cases of mature teratomas and 3 cases of malignant cysts (including malignant transformation of caudate cyst and teratoma); The 29 patients underwent posterior approaches for cyst resection in other hospital before, of whom 1 patient underwent posterior combined with transabdominal approach. All of thes patients underwent resection of residual presacral cyst wall and perineal intractable sinus in our hospital, of whom 25 patients underwent a transperineal approach through an arc-shaped incision anterior to the apex of the coccyx, and the other 4 patients underwent transperineal arc-shaped incision combined with transabdominal approach. All of the patients were cured without serious complications occurring, postoperative pathological and the magnetic resonance imaging diagnosis showed that the residual cyst wall and perineal intractable sinus were all completely removed. Conclusion: Appropriate surgical approache and perioperative treatment for the patients with residual cyst wall and perineal intractable sinus are very important to promote the resection of residual cyst wall and the healing of perineal intractable sinus.

[Progress in biomodification of dentin type Ⅰ collagen by different types of cross-linkers]

Establishing a stable resin-dentin hybrid layer is an effective method to improve the adhesion durability of the restoration. The biomodification of dentin by cross-linkers can enhance the mechanical properties of collagen and resistance to enzymatic hydrolysis while, inhibiting the process of demineralization and promoting the remineralization of dentin, which has the potential clinical applicability of preventing dental caries and improving adhesive property. This review summarizes the biomodification of dentin type Ⅰ collagen by different cross-linkers.

[Effect of adenosine triphosphate on type Ⅰ collagen mineralization in hard tissue]

Objective: To observe the effect of adenosine triphosphate (ATP) phosphorylation on type Ⅰ collagen mineralization and explore the role of small molecule compound ATP in biomimetic mineralization. Methods: Fourier transform infrared spectroscopy (FT-IR) was used to analyze the phosphorylation of collagen molecules by different concentrations (0, 25, 50, 100 mmol/L) of ATP. The concentration of 50 mmol/L ATP was chosen to construct the phosphorylated collagen mineralization model. Transmission electron microscopy (TEM) was used to observed the ultrastructure of mineralized collagen and the collagen mineralization rate was further calculated by ImageJ software. The surface morphology of the collagen gel ATP group and the control group was observed by scanning electron microscopy (SEM) and the elemental analysis was performed by using an X-ray energy spectrometer. The artificial demineralized dentin samples were mineralized for 2 days and 4 days to compare the effect of ATP on dentin remineralization by SEM. Results: FT-IR analysis showed that the formation of new peaks at wavenumbers of 642, 818, and 902 cm(-1) indicated that ATP can phosphorylate type Ⅰ collagen. Through TEM and SEM observation, the mineralization degree of type Ⅰ collagen and demineralized dentin pretreated with 50 mmol/L ATP were significantly higher than that of the control group. Compared with the control group [(31.65±1.62)%], the mineralization rate of collagen in the ATP group [(100±0)%] was significantly increased after 2 days of mineralization (P<0.05). Conclusions: ATP phosphorylation can effectively promote the mineralization process of type Ⅰ collagen.

Effects of precementation on minimizing residual cement around the marginal area of dental implants

STATEMENT OF PROBLEM

Residual cement is detrimental to the long-term success of dental implants with a cement-retained restoration. The complete elimination of excess cement remains a challenge.

PURPOSE

The purpose of this in vitro study was to evaluate the effects of precementation technique on minimizing the residual cement and retention of restorations.

MATERIAL AND METHODS

Four custom cobalt-chromium alloy (Co-Cr) abutments were manufactured by computer-aided design and computer-aided manufacturing (CAD-CAM) as precementation abutments with height and radius reductions of 25 μm (A25), 50 μm (A50), 75 μm (A75), and 100 μm (A100). Fifty CAD-CAM-fabricated standard Co-Cr abutments and corresponding crowns were randomly matched and treated as follows: 10 specimens were cemented with the conventional cementation procedure with glass ionomer cement (G0), and 40 were precemented with precementation abutments (n=10) before the definitive cementation with standard abutments (G25, G50, G75, G100). The weight of the cement in the cement space was calculated, and the marginal sealing was evaluated by using a stereoscopic microscope. The effects of precementation with resin cement on minimizing residual cement around the marginal area of dental implants were further evaluated extraorally. The influence of precementation with glass ionomer and resin cement on the retention force was analyzed by using a universal testing machine at a crosshead speed of 0.5 mm/min. One-way ANOVA was used to analyze cement mass and marginal sealing values. Two-way ANOVA was used to compare the retention forces (α=.05).

RESULTS

The cement weight of G50 (7.2 ±0.6 mg) was significantly higher than that of G25 (6.0 ±1.1 mg, P<.05), while no significant differences in cement weights were found among G50, G75, and G100. Consistently, the G50, G75, and G100 had higher marginal sealing values than that of the G25 (P<.01). Extraoral experiments showed that the precementation with A50 reduced subgingival residual cement without affecting retention.

CONCLUSIONS

These in vitro results suggest that precementation with a precisely manufactured precementation abutment minimized the residual cement around implant abutments, and 50 μm could be a preferable precementation space.

[Research progress in the application of implantoplasty in the treatment of peri-implantitis]

Peri-implantitis is a kind of serious complication after tooth implantation. The absorption of alveolar bone lead to the exposure of rough implant surface, which would result in poor long-term therapeutic effect. Implantoplasty promises a better long-term therapeutic effect than bone augmentation technique. This article will introduce implantoplasty from two aspects: therapeutic effect and its influencing factor, safety and effectiveness.

[Regulation of dentin remineralization progress by non-collagenous protein analogues]

The use of various biomimetic methods to achieve remineralization of demineralized dentin and the formation of an organic matrix-inorganic mineral complex with a certain mechanical strength has been a research hotspot in recent years in the field of stomatology, and it also provides a new idea for the restoration of dentin defect. Dentin biomineralization is a process that simulates the mineralization of biological tissue in nature in which the remineralization of dentin collagen is induced and regulated by organic macromolecules. This review summarizes the process of remineralization of decalcified dentin regulated by non-collagenous protein analogues in vitro.

[Association between serum lipid level and depression in patients with chronic heart failure]

Objective: To investigate the association between serum lipid level and depression in patients with chronic heart failure (CHF). Methods: A total of 348 patients with CHF from the First department of Cardiology of the people's hospital of Shaanxi province from September 2016 to June 2017 were included.The Hamilton Depression Scale (HAMD) was used to evaluate the degree of depression and some related clinical data were tested.The serum lipid level and depression scores in the patients were analyzed using Pearson correlation analysis, and Logistic regression analysis was used to analyze the confounding factors of depression. Results: There was significant difference in the proportion of depression between normal serum lipid group and dyslipidemia group (P=0.044). Pearson correlation analysis showed that depression score was linearly related to total cholesterol (r=0.326, P<0.001) and low density lipoprotein cholesterol (r=0.354, P<0.001), and Logistic regression analysis showed that after adjusting for age, BMI, triglyceride, low density lipoprotein cholesterol, creatinine, total bilirubin, albumin, B type natriuretic peptide, total cholesterol (OR=3.523, P=0.007) and high density lipoprotein cholesterol (OR=0.205, P=0.041) were associated with depression in CHF patients. Conclusion: Total cholesterol can increase the risk of depression, and high density lipoprotein cholesterol can reduce the risk of depression in CHF patients.

Lanthanoid tagging via an unnatural amino acid for protein structure characterization

Lanthanoid pseudo-contact shift (PCS) provides long-range structural information between a paramagnetic tag and protein nuclei. However, for proteins with native cysteines, site-specific attachment may only utilize functional groups orthogonal to sulfhydryl chemistry. Here we report two lanthanoid probes, DTTA-C3-yne and DTTA-C4-yne, which can be conjugated to an unnatural amino acid pAzF in the target protein via azide-alkyne cycloaddition. Demonstrated with ubiquitin and cysteine-containing enzyme EIIB, we show that large PCSs of distinct profiles can be generated for each tag/lanthanoid combination. The DTTA-based lanthanoid tags are associated with large magnetic susceptibility tensors owing to the rigidity of the tags. In particular, introduction of the DTTA-C3 tag affords intermolecular PCSs and enables structural characterization of a transient protein complex between ubiquitin and a UBA domain. Together, we have expanded the repertoire of paramagnetic tags and the applicability of paramagnetic NMR.

Design and evaluation of multifunctional antibacterial ion-doped β-dicalcium silicate cements favorable for root canal sealing

Cu or Zn-doping dicalcium silicate-based cements exhibit multifunctional physiochemical and biological performances and meet some challenging criteria in root canal treatment.

[Effect of occlusal reconstruction on cerebral blood flow and cerebral oxygen saturation in patients with malocclusion]

OBJECTIVE

To investigate the effect of occlusal reconstruction on blood flow velocity and cerebral oxygen saturation in patients with malocclusion.

METHODS

Thirty-three patients with malocclusion treated with occlusal reconstruction in Department of Stomatology, Medical School of Huzhou Normal College from Feb 2011 to Oct 2013 were enrolled in the study. The systolic peak flow velocity (vs), end-diastolic peak flow (vd) , mean peak flow velocity (vm) of middle cerebral artery and the oxygen saturation (rScO2) in the brain were detected at rest or chewing status by using transcranial Doppler color ultrasonography and near-infrared spectroscopy, respectively.

RESULTS

In rest state, vm was significantly increased on 3 months after treatment, while vs and vd were significantly increased on 6 months after treatment and rScO2 were increased on 12 months after treatment (P<0.05). In chewing state, vs, vm, and rScO2 were increased on 3 months after treatment, and vd was increased on 6 months after treatment (P<0.05).

CONCLUSION

Occlusal reconstruction can increase blood flow velocity of middle cerebral artery and cerebral oxygen saturation and improve oxygen supply of the brain in patients with malocclusion.

A decadentate Gd(III)-coordinating paramagnetic cosolvent for protein relaxation enhancement measurement

Solvent paramagnetic relaxation enhancement (sPRE) arises from random collisions between paramagnetic cosolvent and protein of interest. The sPRE can be readily measured, affording protein structure information. However, lack of an inert cosolvent probe may yield sPRE values that are not consistent with protein structure. Here we synthesized a new sPRE probe, triethylenetetraamine hexaacetate trimethylamide gadolinium, or Gd(III)-TTHA-TMA. With a total of 10 coordination sites, this paramagnetic cosovlent eliminates an inner-sphere water molecule that can otherwise transfer relaxation to protein through exchange. With the metal ion centered, the new probe is largely spherical with a radius of 4.0 Å, permitting accurate back calculation of sPRE. The effectiveness Gd(III)-TTHA-TMA as a sPRE probe was demonstrated on three well-studied protein systems.

Overexpression of heat shock protein 70 and its relationship to intestine under acute heat stress in broilers: 1. Intestinal structure and digestive function

The objective of this study was to investigate the relationship between heat shock protein 70 (HSP70) overexpression and intestinal structure and digestive function in heat-stressed broilers. In total, 240 male broilers were injected intraperitoneally with l-(1)-glutamine (0.75 mg/kg of BW) or quercetin (5 mg/kg of BW). Twenty-four hours later, they were heat-stressed for 0, 2, 3, 5, and 10 h, respectively, under 36 ± 1°C. The HSP70 protein and mRNA expression were obviously elevated at 3 h of heat stress, and glutamine induced the overexpression of HSP70 in the jejunal mucosa at different heat-stress times (P < 0.01). No significant change of jejunal villus height, crypt, and villus height:crypt ratio were observed after heat stress, and there were no effects of HSP70 overexpression on intestinal morphology under heat stress. The overexpression of HSP70 significantly increased alkaline phosphatase activity at 3 h of heat stress (P < 0.01). There was a strong correlation between HSP70 expression and the digestive enzyme activity (P ≤ 0.001). The overexpression of HSP70 significantly increased the amylase, lipase, and trypsin activity under heat stress (P < 0.001). These results demonstrated that glutamine was a good HSP70 enhancer to establish an HSP70 overexpression model. Although the overexpression of HSP70 did not change intestinal morphology conditions, it significantly increased broiler digestive enzyme activity under heat stress.

[Effect of different irrigants on radicular dentin cleansing and resin tag formation after post space preparation]

OBJECTIVE

To evaluate the effect of different root canal irrigants on smear layer removal and dentinal tubule opening of root canal surfaces after post space preparation.

METHODS

Thirty maxillary anteriors were endodontically treated. After post space preparation, the teeth were assigned to three groups with ten teeth each: group A, B, C. 3% H2O2, 15% ethylenediamine tetraacetic acid(EDTA), 15% EDTA and 3% NaClO were used as irrigant of group A, B, C. After post space irrigation, eight teeth of each group were examined under scanning electron microscope (SEM) for smear layer removal and dentinal tubule opening. The left two specimens were restored with fiber posts and prepared for evaluation of resin tag formation.

RESULTS

The cleansing effectiveness of group A, B and C was respectively 3.89 +/- 0.36, 1.77 +/- 0.30, 1.25 +/- 0.21. The dentinal tubule opening of group A, B and C was respectively (2.53 +/- 0.19), (3 11 +/- 023) (3.83 +/- 0.52) microm. The cleansing effectiveness and dentinal tubule opening of root canal surfaces were significantly affected by different root canal irrigants (P < 0.05). Excessive erosion of the dentin was observed in group C. Resin tag formation differed between the three irrigant groups, and group B showed excellent resin tag formation.

CONCLUSION

Irrigation with 15% EDTA after post space preparation can excellently remove the smear layer and improve dentinal tubule opening, permitting well penetration of resin adhesive into the dentinal tubules and collagen fibrillar structure.

The proteasome inhibitor bortezomib inhibits intimal hyperplasia of autologous vein grafting in rat model

OBJECTIVE

Increasing evidence indicates that inflammation plays an important role in intimal hyperplasia (IH) induced by autologous vein grafts. The proteasome inhibitor bortezomib shows anti-inflammatory effects, so we used an autologous vein transplantation model to test whether bortezomib inhibits neointimal formation in transplant-induced vasculopathy.

MATERIALS AND METHODS

We subjected 88 rats to autologous external jugular vein grafting surgery randomly assigned to be treated with bortezomib or vehicle. After 24 or 72 hours, rats were humanely killed and vein grafts processed for real-time RT-PCR (24 and 72 hours), ELISA (24 hours), or neutrophil chemotaxis assay (24 hours). Subsequently, rats were humanely killed at 1 and 2 weeks after grafting with samples processed for morphometric analysis.

RESULTS

Bortezomib significantly inhibited IH at 2 weeks compared with untreated controls (P < .05). Expression of mRNA for vascular cell adhesion molecule-1, intercellular adhesion molecule-1, cytokine-induced neutrophil chemoattractant 2beta, monocyte chemoattractant-1, interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha markedly increased in injured vessels during the first day after surgery declining over the following 3 days. Bortezomib significantly attenuated gene expression and protein levels of most inflammatory mediators (P < .05), simultaneously inhibiting neutrophil chemotactic activity of vessel homogenates.

CONCLUSIONS

Bortezomib inhibited neointimal formation at least partially by attenuating the inflammatory response in transplant-induced vasculopathy. It may become a novel vasoprotective agent in the clinical field.

Thermoregulation responses of broiler chickens to humidity at different ambient temperatures. I. One week of age

Three trials were conducted to investigate the effect of RH (35, 60, and 85%) on thermoregulation of 1-wk-old broiler chickens at different temperatures (35, 30, and 25 degrees C). The response to humidity in rectal temperature and plumage temperature at the back and breast within 24 h after exposure were recorded at 5 time points (1,4,8,16, and 24 h). Humidity affected the thermoregulation of 1-wk-old broiler chickens by redistributing heat within the body at high, low, and thermoneutral temperatures. The redistribution of heat resulted in decreased rectal temperature and increased peripheral temperature, which were, respectively, beneficial and unfavorable at high and low temperatures. These results suggested that feedback effects of surface temperature on core temperature also exist in poultry, as already observed in mammals, and could be induced not only by changed ambient temperature but also by the changes in humidity at high temperature. The disturbance of thermal equilibrium could not be established solely by changes in RT, but rather core and surface temperatures had to be considered. The daily rhythms in rectal and surface temperatures were affected by humidity.

Thermoregulation responses of broiler chickens to humidity at different ambient temperatures. II. Four weeks of age

Two experiments were conducted to investigate the effect of RH (35, 60, and 85%) on thermoregulation of broiler chickens at high (35 degrees C) and mild (30 degrees C) temperatures at the age of 4 wk. The effects of humidity on rectal temperature (RT) and plumage temperature at back (PBAT) and skin temperature at breast (SBRT) were determined at 1, 4, 8, 16, and 24 h after exposure. The RT, PBAT, and SBRT were all significantly increased by high temperature (35 degrees C). Humidity had a significant influence on RT at 35 degrees C but not at 30 degrees C. The peripheral temperatures (PBAT and SBRT) were significantly affected by humidity but responded differently at high (35 degrees C) compared with mild temperature (30 degrees C). In conclusion, high humidity above 60% impaired the heat transmission from body core to the periphery at 35 degrees C but facilitated it at 30 degrees C in 4-wk-old broiler chickens. The effect of humidity on nonevaporative heat loss was depended on air temperature, as nonevaporative heat loss was suppressed by high humidity (>60% RH) at high temperature but enhanced at the mild temperature. The effect of humidity on the relationship between peripheral and core temperature depends on ambient temperature as well as on the age of the broiler chicken. The disturbance of thermal balance could not be determined only by changes in RT or peripheral temperature at a single time point but could be determined by mean body temperature within a certain time frame.

Marginal discrepancies and leakage of all-ceramic crowns: influence of luting agents and aging conditions

PURPOSE

This study evaluated the marginal discrepancies and leakage of all-ceramic crowns cemented with different luting agents after fatigue tests.

MATERIALS AND METHODS

Forty-eight all-ceramic crowns were cemented onto natural molars. Zinc-phosphate cement, compomer cement, and an adhesive composite resin luting system were used in 16 specimens each. Sixteen metal-ceramic crowns were cemented with zinc-phosphate cement as a control. Half of the specimens in each group were fatigued in a chewing simulator for 600,000 loading cycles with 3,500 thermocycles. The others received the 3,500 thermocycles only. An impression-replica technique and SEM were used for evaluation of the marginal discrepancies. Leakage of the specimens was microscopically assessed.

RESULTS

There were no significant differences between marginal discrepancies of the groups, with the exception of porcelain shoulder margins in the metal-ceramic group, which had significantly larger discrepancies (P < .01). There was no significant effect of the fatigue tests on marginal discrepancies. However, significant differences of leakage were found between the groups cemented with the different luting agents after both fatigue tests. The adhesive composite resin luting system demonstrated the least leakage. The compomer cement showed an intermediate level of leakage, and the zinc-phosphate cement showed severe leakage that extended through the dentinal tubules to the pulp chambers. No significantly different effect of the two fatigue tests on the leakage was found.

CONCLUSION

The adhesive composite resin luting system showed clinically acceptable marginal discrepancies and an excellent ability to minimize leakage of all-ceramic crowns.

[A comparative study of marginal microleakage using three different cements in ceramic crowns]

OBJECTIVE: To evaluate the marginal microleakage of IPS-Empress 2 all-ceramic crowns using three different cements. METHODS: Twenty-four IPS-Empress 2 all-ceramic crowns were built and luted onto standardly prepared human upper third molars using three different cements. All samples were thermocycled then submerged in 2% fuchsin for 24 hours. The marginal microleakage at tooth-cement and ceramic crown-cement interfaces was observed using light stereomicroscopy. RESULTS: The Panavia F adhesive luting system demonstrated the least microleakage(0.90+/-0.75, 0.46+/-0.37). Dyract compomer cement showed an intermediate level of microleakage (4.71+/-1.68, 5.28+/-1.48). Harvard zinc phosphate cement was associated with severe microleakage in all specimens( 6.99+/-0.04, 6.99+/-0.04). THe differences in microleakage among the three cements was highly significant(P<0.01). CONCLUSION: Panavia F adhesive luting system was the most effective dental cement to prevent microleakage. It can be used for IPS-Empress 2 posterior all-ceramic crowns.

Synthesis and biological evaluation of a series of novel N- or O-fluoroalkyl derivatives of tropane: potential positron emission tomography (PET) imaging agents for the dopamine transporter

A series of novel fluoroalkyl-containing tropane derivatives was synthesized, and their binding affinities for the dopamine transporter (DAT), serotonin transporter (SERT), and norepinephrine transporter (NET) were determined via competitive binding assays. Among these derivatives, the fluoropropyl ester of beta-CIT (19), the fluoroethyl ester of beta-CIT (20), the N-fluoropropyl derivative of beta-CBT (12), and the fluoropropyl ester of beta-CMT (18) displayed higher affinity and greater selectivity for the DAT versus SERT and NET than FP-CIT, which indicates that they are attractive candidates for the development of (18)F-labeled PET imaging agents for the DAT.

Mixed kappa agonists and mu agonists/antagonists as potential pharmacotherapeutics for cocaine abuse: synthesis and opioid receptor binding affinity of N-substituted derivatives of morphinan

A series of new N-substituted derivatives of morphinan was synthesized and their binding affinity for the three opioid receptors (mu, delta, and kappa) was determined. A paradoxical effect of N-propargyl (MCL-117) and N-(3-iodoprop-(2E)-enyl) (MCL-118) substituents on the binding affinities for the mu and kappa opioid receptors was observed. All of these novel derivatives showed a preference for the mu and kappa versus delta binding.

Design, synthesis, and monoamine transporter binding site affinities of methoxy derivatives of indatraline

A series of methoxy-containing derivatives of indatraline 13a-f and 17 were synthesized, and their binding affinities for the dopamine, serotonin, and norepinephrine transporter binding sites were determined. Introduction of a methoxy group to indatraline affected its affinity and selectivity greatly. Except for the 4-methoxy derivative 13a,which had the same high affinity at the dopamine transporter binding site as indatraline, the other methoxy-containing analogues (13b-f and 17) exhibited lower affinity than indatraline for the three transporter binding sites. However, some of the analogues were more selective than indatraline, and the 6-methoxy derivative 13c displayed the highest affinity for both the serotonin and norepinephrine transporters. This compound retained reasonable affinity for the dopamine transporter and is a promising template for the development of a long-acting inhibitor of monoamine transporters. Such inhibitors have potential as medications for treatment, as a substitution medication, or for prevention of the abuse of methamphetamine-like stimulants.

Syntheses and cytotoxicity evaluation of bis(indolyl)thiazole, bis(indolyl)pyrazinone and bis(indolyl)pyrazine: analogues of cytotoxic marine bis(indole) alkaloid

2,4-Bis(3'-indolyl)thiazoles, 3,5-bis(3'-indolyl)-2(1H)pyrazinone and 3,6-bis(3'-indolyl)pyrazine were synthesized and evaluated for cytotoxic activity against diverse human cancer cell lines by the National Cancer Institute. These compounds demonstrated significant inhibitory effects in the growth of a range of cancer cell lines. 2,4-Bis(3'-indolyl)thiazole displayed selective cytotoxicity against certain leukemia cell lines with GI50 values in the low micromolar range while the substituted derivatives showed a broad spectrum of cytotoxic activity. 3,5-Bis(3'-indolyl)-2(1H)pyrazinone and 3,6-bis[3'-(N-methyl-indolyl)]pyrazine possessed strong inhibitory activity against a wide range of human tumor cell lines. The mechanism of action remained unknown. The results suggested that 2,4-bis(3'-indolyl)thiazoles, 3,5-bis(3'-indolyl)-2(1H)pyrazinone and 3,6-bis[3'-(N-methyl-indolyl)] pyrazine offer potential as lead compounds for the discovery of anticancer agents.

Desensitization of cardiac beta-adrenoceptor signaling with heart failure produced by myocardial infarction in the rat. Evidence for the role of Gi but not Gs or phosphorylating proteins

This study examined mechanisms of beta-adrenergic (AR) desensitization in a myocardial infarction (MI) model of heart failure in the rat. Inotropic responses to isoproterenol (non-selective beta-AR agonist) and RO 363 (selective beta1-AR agonist), in left atria and left papillary muscle, were reduced by up to 65%, while chronotropic responses in right atria were unaffected. beta1- and beta2-AR density did not change after MI, suggesting that changes in beta-AR responsiveness are due to changes occurring downstream of the receptor. Inotropic and chronotropic responses to forskolin were not altered in right and left atria and left papillary muscle after MI, suggesting changes at the level of the G-proteins. Pertussis toxin treatment of animals restored inotropic responses to isoproterenol in left atria and left papillary muscle to levels seen in the sham group, indicating that inactivation of Gi-proteins improves inotropic function in MI rats, and that beta-ARs couple to Gi in cardiac failure. Expression of G-protein receptor kinase 2 (GRK2), beta-arrestin1 and the regulatory subunits of cAMPdPK (RI alpha and RII alpha), showed no change after MI. However the expression of Gi alpha2 was significantly increased in left ventricle (sham 0.888+/-0.140, MI 1. 759+/-0.352 P=0.026), right ventricle (sham 0.031+/-0.004, MI 0. 037+/-0.002 P=0.006) and atria (sham 0.107+/-0.006, MI 0.138+/-0.006 P=0.004), with no changes observed in the expression of Gs alpha. These results suggest that increases in Gi play an important role in the decreased beta-AR responsiveness in the rat model of MI.

Cathepsin G in degenerating and healthy discal tissue

OBJECTIVES

To assess the eventual presence, tissue localization, molecular forms, amount and activity of cathepsin G in the annulus fibrosus.

METHODS

Normal non-autolytic disc tissue was collected from cadavers within six hours after death. Degenerate disc samples were collected from low back pain patients undergoing anterior interbody fusion due to severe, discographically verified and painful disc degeneration, and from the posterior parts of intervertebral discs from 10 patients undergoing microscopic discoidectomy because of intervertebral herniation. Avidin-biotinperxidase complex staining of cathepsin G was quantitated by morphometry. Cellular localization was analyzed using double immunofluorescence staining of cathepsin G and CD68, proline 4-hydroxylase or von Willebrand factor. Neutral salt extracts were analyzed by using synthetic cathepsin G substrate in spectrophotometry, dot-immunoblotting and Western blotting.

RESULTS

Histological and morphometric image analysis showed increased cellularity, increased numbers of cathepsin G positive cells and neovascularization in degenerated discs compared to control discs. Neutral salt extract of disc tissue, degenerated or normal, in contrast to control material from synovial capsular tissue, did not contain measurable cathepsin G activity, although immunoreactive enzyme was detected in dot-immunoblotting. Western blotting demonstrated that the discal cathepsin G had an apparent molecular weight of 27 kDa.

CONCLUSION

Due to its properties and localization in normal and pathologically altered tissue, cathepsin G probably plays both a direct and an indirect role in extracellular matrix degradation in the annulus fibrosus. Extracted cationic cathepsin G was immunoreactive, but was functionally inhibited by serpins or, more likely, by polyanionic proteoglycans and saccharins derived from the connective tissue matrix of the annulus fibrosus.

Syntheses and biological activities of bis(3-indolyl)thiazoles, analogues of marine bis(indole)alkaloid nortopsentins

The thiazole analogues of the marine bis(indole)alkaloid nortopsentins, 2,4-bis(3-indolyl)thiazoles, were synthesized using Hantzsch reaction between indole-3-thioamides and 3-(alpha-bromoacetyl)indoles as the key step, and these analogues showed potent cytotoxic activities against a variety of human cancer cell lines in vitro.

Regulation of beta-adrenoceptors in a rat model of cardiac failure: effect of perindopril

This study investigated the effects of myocardial infarction (MI)-induced cardiac failure and treatment with an angiotensin-converting enzyme (ACE) inhibitor perindopril (2 mg/kg/day) on rat beta-adrenoceptor (beta-ar) subtypes in anatomically defined regions of infarcted left ventricular (LV) free wall and noninfarcted tissue from right ventricle (RV) by using autoradiography. After 5 weeks of MI, rats with large MI size (>42%) had developed cardiac failure and beta1-ars were significantly decreased (-59%; p < 0.01) in the border region of the infarcted LV and almost abolished in the infarcted area (-90%; p < 0.005) compared with normal LV from sham-operated controls. The beta-ar changes were not found in the noninfarcted area of the same LV or in RV. MI did not significantly alter the number of beta2-ar subtypes in any region of the ventricles. Perindopril treatment for 4 weeks reduced mean cardiac region weights but did not affect beta-ar density in any cardiac region in either sham-operated or MI rats. These results indicate that cardiac failure due to MI causes significant downregulation of beta1-ars only in border and infarcted regions of rat LV and no change in beta2-ar in any area. It also suggests that the improved response of the infarcted rat heart to isoprenaline stimulation after ACE inhibitors does not result from changes in the numbers of cardiac beta-ars.

Nerve and blood vessel growth in response to grafted dermis and cultured keratinocytes

The aim of this study was to study innervation and angiogenesis in response to grafts of dermis and cultured keratinocytes using immunohistochemical techniques. In a porcine model, fresh autologous de-epidermalized dermis and cultured autologous keratinocytes were combined using a two-stage technique, to produce keratodermal grafts. Wounds were encased within skin graft chambers that prevented the influence of the surrounding skin. As grafts contracted, a peripheral rim of granulation tissue became exposed, allowing us to compare the wound bed beneath grafts with that beneath the raw granulating surface. Grafts were studied for 6 weeks. Angiogenesis was studied using antisera to von Willebrand factor to detect endothelial cells. Nerve growth was studied using antisera to S-100, a Schwann cell marker, and to four axonal markers: protein gene product 9.5, C-flanking peptide of neuropeptide Y, calcitonin gene-related peptide, and vasoactive intestinal peptide. In kerato-dermal grafts (n = 28), organization of blood vessels and nerve growth occurred only beneath areas with epidermal cover as compared with the surrounding granulation tissue. Initially, the immunoreactivity to von Willebrand factor was high, but in areas with epidermal cover it assumed a more orderly pattern with fewer blood vessels. Innervation was first detected by S-100 immunoreactivity seen at 1 to 2 weeks, closely followed by that to protein gene product 9.5 and much later to calcitonin gene-related peptide. C-flanking peptide of neuropeptide Y and vasoactive intestinal peptide immunoreactivity were detected in the wound depth surrounding large blood vessels at 4 to 6 weeks. In control wounds that had been either grafted with de-epidermalized dermis alone (n = 10) or allowed to granulate (n = 10), persistently there was high immunoreactivity to von Willebrand factor but minimal immunoreactivity to the neural markers. In conclusion, kerato-dermal grafts become innervated, and beneath their surface there is also vascular organization to resemble normal skin. Keratinocytes themselves may influence angiogenesis and innervation, as both processes failed to occur beneath granulating areas.

Transforming growth factor beta 2 in labial salivary glands in Sjögren's syndrome

OBJECTIVE

To compare the distribution and the amount of transforming growth factor beta (TGF beta) in labial salivary glands (LSG) in patients with Sjögren's syndrome (SS) and healthy controls.

METHODS

LSG from SS patients (n = 10) and healthy controls (n = 6) were labelled with peroxidase-antiperoxidase staining for TGF beta 2, which was quantitated in image analysis using Video Interactive Display System software.

RESULTS

In all LSGs in SS and healthy controls, TGF beta 2 was found in endothelial cells of the capillaries and in the capsular and stromal fibroblasts. In LSGs in SS, TGF beta 2 was also found in some lymphocytes in the inflammatory cell foci and in fibroblasts in fibrotic areas. The TGF beta 2 staining index (microns 2/mm2 tissue) was greater in SS than in control LSGs (3670 (SEM 430) v 2061 (176); p < 0.01), with no difference between the primary and secondary forms of SS (p > 0.05).

CONCLUSION

The localisation and the level of expression of TGF beta 2 indicate its involvement in local tissue fibrosis, and may reflect attempts at immunosuppression.

Regeneration pattern of blood vessels and nerves in cultured keratinocyte grafts assessed by confocal laser scanning microscopy

The aim of this study was to investigate the pattern of both neovascularization and reinnervation, and the relationship between the two processes, in keratodermal grafts, using confocal laser scanning microscopy, at different time points during the healing process. Keratodermal grafts were prepared in pigs by combining autologous dermis with cultured autologous keratinocytes. Immunohistochemistry was carried out on thick cryostat sections (100-150 microns), using antisera to the endothelial marker von Willebrand factor (vWf) and the pan-neuronal marker protein gene product 9.5 (PGP9.5). The results suggest that the neovascularization and reinnervation in the cultured keratodermal graft is almost complete at 6 weeks. Neovascularization precedes innervation, reaching the surface covered by the keratinocytes at 2 weeks, initially with a linear vascular pattern. From 3 weeks, there is a gradual arborization of the vessels to form a typical vascular plexus. The process of reinnervation is similar in pattern to that of neovascularization, although slower in developing a full network of fibres. In conclusion, the use of confocal microscopy allows the precise definition of complex patterns of neovascularization and nerve growth, which are not fully apparent when using conventional microscopy. Because angiogenesis occurs first, it probably plays a leading role in the survival of keratodermal grafts during wound healing. Indeed, new blood vessels form a pathway for the subsequent innervation process, and quickly reach the epidermal layer which, in turn, may play a key role in the tropism of both blood vessels and nerves.

Early increase precedes a depletion of endothelin-1 but not of von Willebrand factor in cutaneous microvessels of diabetic patients. A quantitative immunohistochemical study

Endothelin-1 (ET-1) is a vasoconstrictor peptide which is produced by endothelial cells. The subcellular distribution of ET-1 in human skin and the variation of immunostaining for ET-1 by light microscopy in skin biopsies of diabetic patients have been analysed using immunohistochemistry and image analysis quantification. Skin biopsies were collected from 17 patients with type 1 diabetes of different durations and with presence or absence of microangiopathy in the retina; skin biopsies of healthy subjects were utilized as controls. The distribution of ET-1 immunoreactivity (IR) at both light and electron microscopy was compared to that of von Willebrand factor (vWf), a general marker of total cutaneous microvessels. Immunohistochemistry revealed that in controls the distribution of immunostaining was similar for ET-1 and vWf, being localized to microvessels in all areas of the skin. However, at the electron microscopical level ET-1-IR was localized in the endothelial cytoplasm rather than in specific organelles, while vWf immunostaining was associated with Weibel-Palade bodies. ET-1-IR was observed in 4/8 (50 per cent) biopsies from healthy subjects; this increased to 81.8 per cent in biopsies of patients affected by diabetes for less than 10 years and decreased to 16.6 per cent in patients with diabetes for more than 10 years. Quantification of ET-1 staining showed a significant decrease of ET-1-IR in patients affected by diabetes for more than 10 years compared with those affected by diabetes for less than 10 years (P < 0.05). Also, the percentage of biopsies showing positive ET-1 staining was lower in patients with retinopathy than in patients without retinopathy. On the contrary, vWf-IR was observed in all skin specimens and its quantification showed no differences between diabetic patients and controls. These changes are not related to variations in the number of blood vessels, and it is suggested that they reflect a possible functional alteration of the endothelial cells during diabetes.

Long-term immunogenicity and efficacy of recombinant yeast derived hepatitis B vaccine for interruption of mother-infant transmission of hepatitis B virus

Recombinant DNA Yeast-Derived Hepatitis B Vaccine (RYHB vaccine) is comparable to and can replace Plasma-Derived Hepatitis B Vaccine (PHB vaccine) for the prevention of mother-infant transmission of hepatitis B virus (HBV), but the duration of immune efficacy of RYHB vaccine is not clear. This study indicates the long-term efficacy for the prevention of mother-infant transmission of HBV. One hundred and six neonates born to HBsAg-carrier mothers with HBeAg positive were randomly divided into two groups, one receiving 20 micrograms per dose of RYHB vaccine and the another receiving 20 micrograms per dose of PHB vaccine on the day of birth, at 1 month and at 6 months (three times). Physical examination and blood tests were performed for all infants at 6, 12, 24, 36, 48 and 60 months of age. The results showed that the protective efficacies at 6, 12, 24, 36, 48 and 60 months were 67%, 75%, 63%, 62%, 57% and 56%, respectively for the RYHB vaccine group and 58%, 76%, 51%, 41%, 24% and 18%, respectively for the PHB vaccine group. The protective efficacy was notably significant in the last two years. The study indicates that the duration of protective efficacy is over 5 years with RYHB vaccine, being longer than that of PHB vaccine. These recipients of RYHB vaccine showed no side effects, and the vaccine is regarded as safe and effective.

Morphological changes of neural and vascular peptides in human skin suction blister injury

Suction blister injury is an experimental model for the investigation of the possible derangement of dermal/epidermal interaction in injury. An extensive fibre network can be stained in skin using antisera to the pan-neuronal marker protein gene product 9.5 (PGP) and the sensory neuropeptide calcitonin gene-related peptide (CGRP), while microvessels are identifiable with antisera to the endothelial marker von Willebrand's factor (vWf) and the peptide endothelin (ET). To investigate the possible involvement of superficial cutaneous innervation and microcirculation during the repair process in injury, human skin biopsies taken at different times after suction blister injury were investigated by quantitative immunohistochemistry. Neural and endothelial changes were seen in both edge and blister areas. PGP- and CGRP-immunoreactive nerves showed an increase in both areas compared with control skin up to 6 h after injury, followed by a decrease which lasted until 72 h. This was followed by a gradual increase of both nerve types starting from the blister edge and lasting up to 8 days after injury when the values were similar to controls. Similarly, in the blister area of the skin, vWF-immunoreactive capillaries showed statistically significant increases between 0 and 6 h after injury, followed by a decrease at 12 and 18 h which was maintained up to 72 h. ET-1 immunoreactivity showed a similar, although more variable, pattern of changes. At the blister edge from 23 h onwards, both vWf and ET-1 immunoreactivities showed a second increase from the edge of the blister spreading towards the centre of the blister ahead of the nerve increase. This lasted up to 8 days, when vWf immunoreactivity showed a statistically significant increase compared with control skin. Generally the numerical increase observed at early time points was accompanied by a strong staining intensity, which reverted to a normal staining intensity at later time points. These results suggest that there is a reactive process for all immunoreactive elements in the early stages of injury, followed by changes indicative of neuronal and endothelial damage (depletion phase) and the subsequent repair process. The repair started with re-epidermalization from the blister edge, followed by revascularization and, lastly, by reinnervation of the tissue. These results indicate a close relationship between epidermis, blood vessels, and nerve fibres during the healing process which follows suction blister injury.

Rapid proliferation of calcitonin gene-related peptide-immunoreactive nerves during healing of rat tibial fracture suggests neural involvement in bone growth and remodelling

The nervous system may be actively involved in bone repair and in remodelling of callous tissue in bone fractures, as well as in the regulation of nociceptive impulses from the site of the trauma. The aim of this study was to assess the distribution and nature of the periosteal innervation of normal control bone and during bone healing subsequent to fracture of rat tibiae at seven, 14 and 21 days after experimental fracture using immunocytochemistry and image analysis quantification of the neuronal marker protein gene product 9.5 and sensory neuropeptide calcitonin gene-related peptide. At seven days, periosteal protein gene product 9.5- and calcitonin gene-related peptide-immunoreactive fibres showed dense ramifications and terminal sprouting. In addition to periosteum, the nerve fibres were found in the middle of the callus interspersed with inflammatory cells and penetrating into secondary minor fractures. At days 14 and 21 many tortuous nerves were found in the periosteum but not in mid callus. Image analysis quantification revealed a uniform increased proliferation of nerves after seven days. At 21 days, the intercept countings showed in excess of a three-fold increase of calcitonin gene-related peptide-immunoreactive nerve fibres compared with the normal control group (P > or = 0.0001) and were almost as numerous as protein gene product 9.5-immunoreactive fibres (P < 0.005). It is postulated that calcitonin gene-related peptide-containing sensory innervation may have a potential importance in the fracture vascular control, angiogenesis and osteogenesis in addition to a protective role against excessive fracture movement. The results are consistent with the neural involvement in bone growth and remodelling.

Early increase precedes a depletion of VIP and PGP-9.5 in the skin of insulin-dependent diabetics--correlation between quantitative immunohistochemistry and clinical assessment of peripheral neuropathy

Diabetic neuropathy affects both sensory and autonomic peripheral nerve fibres. Vasoactive intestinal polypeptide (VIP) is present in autonomic fibres which modulate sweat secretion, while calcitonin gene-related peptide (CGRP) is localized to cutaneous sensory fibres. In this study, immunohistochemistry and image analysis were used to assess changes of VIP and CGRP, and of the pan-neuronal marker protein gene-product (PGP)-9.5, in skin biopsies of 18 patients affected by type 1 diabetes (age range 18-46 years) and from seven aged-matched controls. Patients were divided into three groups: group 1 (n = 6), with diabetes for 6 months to 3 years; group 2 (n = 5), with the disease for 5-10 years; and group 3 (n = 7), with diabetes for more than 10 years. VIP immunoreactivity (IR) and PGP-9.5-IR were significantly reduced around sweat glands (P < 0.005) in groups 2 and 3. Epidermal CGRP-IR and PGP-9.5-IR were significantly reduced in group 3 (P < 0.05). Twenty-eight per cent (5/18) of all patients showed high VIP-IR around sweat glands (> 95 per cent confidence limits of controls) and all of these patients had diabetes for less than 3 years. Conversely, 55 per cent (10/18) of patients had low VIP-IR (< 5 per cent confidence limit of controls). The latter, compared with the former, showed a significantly longer duration of diabetes (Fisher exact test P = 0.002), presence of clinical autonomic neuropathy (Fisher exact test P = 0.04), and a reduced sural nerve conduction velocity (Fisher exact test P = 0.04). These results suggest that quantitative immunohistochemical analysis of peptide-containing cutaneous nerves allows an objective evaluation of nerve fibre alterations at early stages of diabetes than is currently possible with neurophysiological functional tests.

Suppressive effect of GABA on insulin secretion from the pancreatic beta-cells in the rat

In order to investigate a possible role of GABA in the regulation of insulin secretion, we have studied the effect of GABA on insulin secretion from the isolated perfused rat pancreas in vitro and on the changes in the cytoplasmic Ca2+ of Beta-cells from the isolated rat islets. When glucose is present, GABA caused a dose dependent inhibition of the first phase of arginine-induced insulin secretion during the range of 10-1000 microM, but GABA did not affect arginine-induced insulin secretion in the absence of glucose. GABA inhibited not only the first phase but also the second phase of glucose-induced insulin secretion. A GABAB-receptor agonist, baclofen, also inhibited both phases of insulin secretion induced by 16.7 mM glucose. Furthermore, GABA inhibited the rise in cytoplasmic Ca2+ of Beta-cells in response to 16.7 mM glucose. These studies indicate that GABA decreases Beta cell secretory activity mainly in response to glucose. These inhibitory effects of GABA on insulin secretion may be mediated through GABAB-receptor and the inhibition of the rise in cytoplasmic Ca2+.

The effects of Ca(2+)-free perfusion and the calcium paradox on [125I] endothelin-1 binding to rat cardiac membranes

The binding characteristics of [125I]endothelin-1 (ET-1) to cardiac membranes isolated from rat hearts subjected to Ca(2+)-free perfusion or the Ca2+ paradox were examined. The effect of treatment with 2, 3 butanedione monoxime (BDM), which inhibits the tissue damage associated with the calcium paradox, was also investigated. Membranes from rat hearts perfused under control conditions bound [125I]ET-1 to a single population of sites with a Bmax of 107.7 +/- 3.7 fmol/mg protein and an affinity (KD) of 153 +/- 12 pM. Ten minutes of Ca(2+)-free perfusion resulted in a significant (P < 0.01) increase in Bmax to 167.5 +/- 8.3 fmol/mg protein without change in KD. Ca2+ repletion following Ca(2+)-free perfusion tended to increase further the Bmax (180.6 +/- 10.4 fmol/mg protein) without change in KD. Treatment with BDM attenuated but did not prevent the rise in Bmax following Ca(2+)-free perfusion. Following Ca2+ repletion, however, Bmax returned to control levels in the BDM treated group. These changes were not associated with changes in the ability of ET-1 and ET-3 to inhibit [125I]ET-1 binding. The results demonstrate that Ca(2+)-free perfusion is associated with an increase in the binding site density of [125I]ET-1 which is maintained or further increased upon Ca2+ repletion. If, however, the tissue damage associated with the Ca2+ paradox is prevented with BDM, Ca2+ repletion is associated with a reversal of the increase due to Ca(2+)-free perfusion.

Effect of amlodipine pretreatment on ischaemia-reperfusion-induced increase in cardiac endothelin-1 binding site density

Endothelin-1 (ET-1) may be implicated in the pathophysiology of myocardial ischaemia. To determine whether the long-acting calcium antagonist amlodipine attenuates the ischaemia- and reperfusion-induced increase in cardiac ET-1 binding sites, hearts from rats pretreated with amlodipine (0.25 or 0.5 mg/kg) 2 or 5 h before they were killed were made ischaemic for 20 or 40 min, reperfused, and subfractionated. Twenty- and 40-min ischaemia caused a time-dependent increase in ET-1 binding site density (Bmax) identified with [125I]ET-1. Amlodipine pretreatment attenuated this increase in a time- and dose-dependent manner. 0.25 and 0.5 mg/kg amlodipine also suppressed the reperfusion-induced increase in [125I]ET-1 binding site density, even when the 0.5-mg/kg pretreatment series reperfusion was administered after 40-min ischaemia.

Immunohistochemical measurements of nerves and neuropeptides in diabetic skin: relationship to tests of neurological function

Image-analysis was used to measure nerves immunoreactive to the general neuronal marker protein gene product 9.5 (PGP 9.5-IR) and the neuropeptides calcitonin gene-related peptide and vasoactive intestinal polypeptide in standardised leg skin biopsies of three age-matched groups of young subjects: non-diabetic (n = 14), diabetic patients with normal small fibre function ("non-neuropathic", (n = 11) and diabetic patients with abnormal small fibre function ("neuropathic", n = 11). Depletion of nerves and neuropeptides was most marked in the epidermis, where calcitonin gene-related peptide-immunoreactivity was more frequently absent than PGP 9.5-IR in diabetic patients. Epidermal PGP 9.5-IR nerve area and counts were reduced in neuropathic compared with normal subjects (p less than 0.001), as were epidermal calcitonin gene-related peptide nerve counts (p = 0.003). Sweat gland PGP 9.5 and vasoactive intestinal polypeptide, which may be involved in sweat production, showed no diminution in diabetic patients (area: p = 0.160, p = 0.372 by ANOVA). Two diabetic patients showed elevated sweat gland PGP 9.5-IR and three had increased sweat gland vasoactive intestinal polypeptide; this may represent nerve proliferation. In local sweat tests, acetylcholine-stimulated sweat output was associated with increased immunoreactivity, while the sympathetic skin response showed inverse correlations with immunoreactivity. There were no consistent changes with other commonly-used neurophysiological tests. HbA1 correlated negatively with immunohistochemical measurements. Neuropeptide changes were seen in the absence of macro- and microvascular disease, and epidermal nerve depletion occurred in patients with normal thermal thresholds and cardiac autonomic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Developmental pattern and distribution of nerve growth factor low-affinity receptor immunoreactivity in human spinal cord and dorsal root ganglia: comparison with synaptophysin, neurofilament and neuropeptide immunoreactivities

Immunocytochemical expression of the low-affinity nerve growth factor receptor was studied in human fetal and adult tissues using the monoclonal antibody ME20.4. In dorsal root ganglia, a few immunoreactive neurons were first detected in nine-week-old fetuses and many more were found in the following weeks of gestation. However, none was present in adult ganglia. The ME20.4-positive cells were larger than neurons immunostained by substance P, calcitonin gene-related peptide or galanin antibodies. In the spinal cord, fibres immunostained by ME20.4 appeared in a characteristic pattern that differed from the spatial and temporal distributions of synaptophysin- and neurofilament-immunoreactive fibres. Those expressing the low-affinity nerve growth factor receptor were only detected in regions containing collaterals of primary sensory axons: (i) in the dorsal funiculus between seven and 18 weeks of gestation; (ii) in a ventrodorsal bundle reaching the ventral horn from weeks 12-14; (iii) in the medial region of the dorsal horn between weeks 12 and 20; (iv) in the superficial layers and lateral portion of the dorsal horn after the 14th week of gestation and also in adult spinal cord. During the fetal period, ME20.4 immunoreactivity was also found in motoneurons and peripheral nerve fibres in the skin, myotomes and gut. Sheaths of peripheral nerves and the adventitia of blood vessels were stained both in fetal and adult tissues. Thus, the low-affinity nerve growth factor receptor is: (i) strongly expressed in the developing human nervous system; (ii) transiently associated with a subset of large primary sensory neurons and with motoneurons; (iii) transiently and sequentially expressed by various groups of sensory afferents to the spinal cord; (iv) permanently expressed by fibres in the superficial layers of the dorsal horn, Clarke's column, nerve sheaths and the adventitia of blood vessels.

Effect of age on endothelin-1 binding sites in rat cardiac ventricular membranes

To establish whether the density, affinity, or selectivity of endothelin-1 (ET-1) binding sites in cardiac ventricular membranes varies with age, membranes were harvested from 5- to 7-day-, 20-day-, and 8- to 9-week-old Sprague Dawley rats and labeled with [125I]ET-1. Selectivity was established by using cold ET-1, ET-2, ET-3, big ET-1, and (+)PN200-110 to inhibit specific binding of [125I]ET-1. Over the age span studied, selectivity and affinity of the [125I]ET-1 binding sites was unchanged, but density (Bmax) decreased from 209.7 +/- 18.4 at 5-7 days to 154.0 +/- 8.9 (p less than 0.02) at 20 days, and to 89.7 +/- 5.2 (p less than 0.01) fmol/mg protein at 8-9 weeks. These age-dependent differences in Bmax were not accompanied by a change in membrane yield and occurred at a time when the specific binding of (+)[3H]PN200-110 increased.

The inhibitory effect of [D-Arg1,D-Phe,D-Try7,9,Leu11] substance P on endothelin-1 binding sites in rat cardiac membranes

The specific binding of [125I]ET-1 to rat cardiac membrane fragments was inhibited by [D-Arg1,D-Phe, D-Try7,9,Leu11] substance P [substance P(D)], a potent bombesin antagonist. This inhibitory effect required high concentrations (greater than 3X10(-6)M) of substance P(D) and was accompanied by a steep increase in non-specific binding, and not a decrease in total binding. Such results indicate that substance P(D) does not competitively inhibit the specific binding of [125I]ET-1 to rat cardiac membrane fragments.

The unique binding properties of amlodipine: a long-acting calcium antagonist

Amlodipine is a 'second generation', long-acting calcium antagonist. To characterise the binding properties of this drug saturation binding studies were undertaken using (-)[3H]amlodipine and rat cardiac membrane fragments. (-)[3H]Amlodipine bound to a single population of high affinity binding sites with a KD of 1.64 +/- 0.17 nM, a Bmax of 0.45 +/- 0.08 pmol/mg protein and a Hill coefficient approaching unity. Binding was slow and required up to 5 hours to reach asymptote during incubation at 25 degrees C. The specific binding was totally inhibited by (-)amlodipine and (-)D600 and partially inhibited by (+)PN200-110, Bay K8644, (+)D600 and d-cis diltiazem. These results indicate that (-)[3H]amlodipine interacts strongly with the phenylalkylamine as well as the dihydropyridine binding sites. It also interacts with the benzothiazepine binding sites. The inhibition of (-)[3H]amlodipine binding by D600 is stereospecific, (-) greater than (+)D600. Bound (-)[3H]amlodipine dissociated slowly from its binding sites, less than 40% dissociation occurring during 5 hours of incubation (k-1 = 1.53 x 10(-3) min-1). These results indicate that the binding profile of amlodipine differs from that of other dihydropyridine-based Ca2+ antagonists. In addition they explain its slow onset of action, and slowed recovery on withdrawal.

(-)[3H]amlodipine binding to rat cardiac membranes

Amlodipine is a newly developed long-acting dihydropyridine-based calcium antagonist. To characterize the binding properties of this compound, saturation binding studies were undertaken, using (-)[3H]amlodipine and rat cardiac membrane fragments. (-)[3H]Amlodipine bound to a single population of high-affinity binding sites with a KD of 1.68 +/- 0.12 nM, a Bmax of 0.34 +/- 0.08 pmol/mg protein, and a Hill coefficient approaching unity. Binding required up to 5 h to reach asymptote, and was pH- and temperature-sensitive. The specific binding was totally inhibited by (-) amlodipine and (-) D600 (IC50 values of 9.20 +/- 5.56 and 6.58 +/- 6.57 nM, respectively) and only partially inhibited by (+) PN 200-110, (-) Bay K 8644, (+) D600, and d-cis diltiazem (IC50 values of 60 +/- 10, 160 +/- 20, 250 +/- 40, and 200 +/- 30 nM, respectively). These results indicate that in addition to its ability to bind to the dihydropyridine and benzothiazepine recognition sites in rat cardiac membrane fragments, (-)[3H]amlodipine also binds strongly to the recognition sites for the phenylalkylamine-based calcium antagonists. The results also show that the inhibition of (-)[3H]amlodipine binding by D600 is stereospecific with (-) greater than (+)D600. Dissociation of bound (-)[3H]amlodipine was slowed under acidotic (pH 6.0) and accelerated under alkalotic (pH 10.0) conditions.