Evaluating longitudinal relationships between parental monitoring and substance use in a multi-year, intensive longitudinal study of 670 adolescent twins

Introduction

Parental monitoring is a key intervention target for adolescent substance use, however this practice is largely supported by causally uninformative cross-sectional or sparse-longitudinal observational research designs.

Methods

We therefore evaluated relationships between adolescent substance use (assessed weekly) and parental monitoring (assessed every two months) in 670 adolescent twins for two years. This allowed us to assess how individual-level parental monitoring and substance use trajectories were related and, via the twin design, to quantify genetic and environmental contributions to these relationships. Furthermore, we attempted to devise additional measures of parental monitoring by collecting quasi-continuous GPS locations and calculating a) time spent at home between midnight and 5am and b) time spent at school between 8am-3pm.

Results

ACE-decomposed latent growth models found alcohol and cannabis use increased with age while parental monitoring, time at home, and time at school decreased. Baseline alcohol and cannabis use were correlated (r = .65) and associated with baseline parental monitoring (r = -.24 to -.29) but not with baseline GPS measures (r = -.06 to -.16). Longitudinally, changes in substance use and parental monitoring were not significantly correlated. Geospatial measures were largely unrelated to parental monitoring, though changes in cannabis use and time at home were highly correlated (r = -.53 to -.90), with genetic correlations suggesting their relationship was substantially genetically mediated. Due to power constraints, ACE estimates and biometric correlations were imprecisely estimated. Most of the substance use and parental monitoring phenotypes were substantially heritable, but genetic correlations between them were not significantly different from 0.

Discussion

Overall, we found developmental changes in each phenotype, baseline correlations between substance use and parental monitoring, co-occurring changes and mutual genetic influences for time at home and cannabis use, and substantial genetic influences on many substance use and parental monitoring phenotypes. However, our geospatial variables were mostly unrelated to parental monitoring, suggesting they poorly measured this construct. Furthermore, though we did not detect evidence of genetic confounding, changes in parental monitoring and substance use were not significantly correlated, suggesting that, at least in community samples of mid-to-late adolescents, the two may not be causally related.

Genes for Good: Engaging the Public in Genetics Research via Social Media

The Genes for Good study uses social media to engage a large, diverse participant pool in genetics research and education. Health history and daily tracking surveys are administered through a Facebook application, and participants who complete a minimum number of surveys are mailed a saliva sample kit ("spit kit") to collect DNA for genotyping. As of March 2019, we engaged >80,000 individuals, sent spit kits to >32,000 individuals who met minimum participation requirements, and collected >27,000 spit kits. Participants come from all 50 states and include a diversity of ancestral backgrounds. Rates of important chronic health indicators are consistent with those estimated for the general U.S. population using more traditional study designs. However, our sample is younger and contains a greater percentage of females than the general population. As one means of verifying data quality, we have replicated genome-wide association studies (GWASs) for exemplar traits, such as asthma, diabetes, body mass index (BMI), and pigmentation. The flexible framework of the web application makes it relatively simple to add new questionnaires and for other researchers to collaborate. We anticipate that the study sample will continue to grow and that future analyses may further capitalize on the strengths of the longitudinal data in combination with genetic information.

Postinterventional pain and complications of sonographically guided interventions in the liver and pancreas

PURPOSE

Sonographically guided interventions in abdominal organs are routine procedures with rare severe complications. However, potential patient discomfort or pain is frequently not addressed in the literature.

MATERIALS AND METHODS

In a prospective 1-year study, the peri- and postinterventional pain of patients undergoing sonographically guided punctures of the liver and pancreas was analyzed. Data acquisition was done with a standardized questionnaire. This included three numeric rating scales (NRS) ranging from "0" to "10" to be answered at puncture and 1 hour and 4 hours later. Data concerning complications and administered analgesic medication was acquired from the patients' charts.

RESULTS

223/274 patients could be analyzed (83 %). 91 women (40.8 %) and 132 men (59.2 %) were included. The mean age was 56.0 yrs. Overall the average level of pain was 2.98  at puncture, 1.21 after 1 hour and 0.71 after 4 hours. In patients with diagnostic biopsies, the pain levels were 3.37(0  h)/1.33(1  h)/0.71(4  h) for liver parenchyma, 2.64(0  h)/0.95(1  h)/0.65(4  h) for focal liver lesions and 3.1(0  h)/1.9(1  h)/1.1(4  h) for pancreatic punctures. The pain levels at therapeutic interventions were 3.00(0  h)/2.00(1  h)/0.50(4  h). Female and younger (< 50 yrs) patients had statistically significantly more pain at puncture and 1 hour postintervention. Only minor complications occurred (0.9 %).

CONCLUSION

Severe pain after sonographically guided interventions is rare. Most patients suffer only from mild pain postinterventionally.

Efficacy of contrast-enhanced US versus CT or MRI for the therapeutic control of percutaneous radiofrequency ablation in the case of hepatic malignancies

PURPOSE

The goal of this study was to assess the informative value of contrast-enhanced ultrasound after radiofrequency ablation (RFA). Patients who had undergone RFA of malignant liver tumors were followed up with contrast-enhanced sonography (CEUS), computed tomography (CT) and/or magnetic resonance tomography (MRI), and the outcomes were compared.

MATERIALS AND METHODS

76 patients undergoing 194 RFAs for 118 hepatic neoplasms (n = 55 HCC, n = 63 metastases) in the course of a 7-year period were examined post-interventionally using CEUS and CT or MRI. During follow-up (gold standard of evaluation), contrast agent rim accumulations with a diameter greater than 5 mm and a growth rate of at least 25 % were counted as a recurrence.

RESULTS

CEUS-CT comparison group: A total of 65 scan pairs were compared. In 54 cases (83.1 %) the findings were the same with either method. In 7 cases (10.8 %) CEUS confirmed the correct diagnosis, and in 2 cases (3.1 %) only CT was correct. In 2 cases (3.1 %) both methods yielded incorrect results. Diagnostic accuracy (DA): CEUS 93.8 %, CT 86.2 %. CEUS-MRI comparison group: In 23 cases (88.5 %) of a total of 26 scan pairs, the findings were the same for both CEUS and MRI. In 3 discordant cases only CEUS confirmed the correct diagnosis (3 cases, 11.5 %). Diagnostic accuracy DA (n = 26): CEUS 100 %, MRI 88.4 %.

CONCLUSION

CEUS performs equally to CT and MRI in the follow-up of patients treated for liver tumors by RFA.

[A comparative study of the hepatic transit time (HTT) of different ultrasound contrast agents in patients with liver metastases and healthy controls]

PURPOSE

Liver metastases lead to a shortening of the HTT of an echo enhancer. Studies using SonoVue™ also showed a shortening of the HTT in healthy controls. Hence the HTT depends on the applied contrast agent. We examined whether the HTT of SonoVue™, Luminity™ und Levovist™ is useful to discriminate between patients with and without liver metastases.

MATERIALS AND METHODS

We compared the arteriovenous HTT of Levovist™, Sonovue™ und Luminity™ in 20 patients with liver metastases and in 15 controls. An Acuson Sequoia™ ultrasound system was used. The HTT results from the difference of the arrival time of the microbubbles in the hepatic artery and a hepatic vein.

RESULTS

Using Levovist™ six patients and three controls had to be excluded from further analysis. The arrival time was undetectable. The mean HTT values in healthy controls were: Levovsit™ 14.75 sec (SD ± 2.53 sec), SonoVue™ 9.27 sec (SD ± 2.41 sec) and Luminity™ 9.2 sec (SD ± 2.34 sec). In patients the mean HTT values were: Levovist™ 9.89 sec (SD ± 1.04 sec), SonoVue™ 6.28 sec (SD ± 2.41 sec) and Luminity™ 6.33 sec (SD ± 1.37 sec). Using a cut off of 8 sec for SonoVue™ and Luminity™, the sensitivity to exclude liver metastases was 75% and 80%.

CONCLUSION

The mean HTT values of all contrast agents were shorter in patients. Levovist™ showed a longer HTT in patients and controls than Luminity™ and SonoVue™. Levovist™ showed the best separation between patients and controls but some patients and controls had to be excluded. The HTT could still be a useful tool to exclude liver metastases but the HTT depends on the contrast agent and the applied contrast technique.

Coagulation activation and fluid retention associated with the use of black cohosh: a case study

Black cohosh is one of the most popular herbal therapies for premenstrual discomfort, hot flushes and other climacteric and menopausal symptoms. Most often, it is tolerated well. However, there are some recent reports on serious adverse events, probably associated with this complementary and alternative herbal medicine. We report a case of coagulation activation, fluid retention and transient autoimmune hepatitis most likely triggered by the use of black cohosh. Diagnostic procedures aimed to explain lower leg edema are not uncommon in the age group of women suffering from climacteric and menopausal symptoms. Therefore, black cohosh-induced fluid retention and coagulation activation should be considered in differential diagnosis, especially if thrombosis has been excluded.

[Spectrum and bleeding complications of sonographically guided interventions of the liver and pancreas]

PURPOSE

Sonographically guided fine-needle punctures (p.) are considered to be a low risk procedure. Interventions with needles with a larger diameter seem to cause more complications. In search of potential complications, we examined 1923 sonographically guided interventions of the liver and pancreas in a retrospective analysis.

MATERIALS AND METHODS

We examined the coherence of the kind of intervention and complications. We considered bleeding with a need for transfusion and/or a need for surgical treatment as complications. Diseases and medication increasing the probability of post-interventional bleeding were also detected.

RESULTS

1923 sonographically guided interventions in the abdomen (1800 in the liver, 123 in the pancreas) were analyzed (n = 1696 diagnostic interventions, n = 227 therapeutic interventions). Needles with diameters > 1 mm were primarily used. Drainage and radiofrequency ablation (RFA) (12 % of all interventions) were performed with devices with diameters between 2 - 3.96 mm. A need for transfusion was found in 8 / 1923 patients (0.4 %), predominantly in the first 24 h. There was no significant correlation between coagulation preventing drugs (heparin, NSAIDs, antiaggregants) and bleeding events. Patients who suffered from liver cirrhosis with a thromboplastin time of < 50 % had a higher risk of post-interventional bleeding than patients with liver cirrhosis and a thromboplastin time > 50 %. Furthermore, therapeutic interventions showed higher complication rates than diagnostic procedures.

CONCLUSION

Severe bleeding complications with a need for transfusion in sonographically guided procedures are rare (0.4 %). Our results showed that liver cirrhosis with a low thromboplastin time (< 50 %) seems to be the most important risk factor for patients. Overall, sonographically guided interventions are safe and have low complication rates considering careful performance and contraindications.

[Renal cell cancer does not show a typical perfusion pattern in contrast-enhanced ultrasound]

PURPOSE

Grayscale ultrasound has improved the outcome of renal cell cancer (RCC), since most significant RCCs are discovered coincidently during routine abdominal ultrasound examinations. The CT scan is currently the method of choice for further evaluation. The therapeutic approach depends on the results of the CT scan. The purpose of this study was to evaluate whether RCCs would show typical vascularization patterns in contrast-enhanced ultrasonography (CEUS).

METHODS AND MATERIALS

We examined 30 patients with solid renal tumors before surgery with CEUS using the microbubble contrast agent SonoVue (Bracco, Italy). All patients had suspected malignant lesions on a CT scan. The examination was performed with an Acuson Sequoia (Siemens, Erlangen, Germany) with a low mechanical index (low MI) using the contrast agent imaging method "contrast pulsed sequencing" (CPS). We looked at the vascularization in the early phase (< 30 s) and the late phase (60 - 120 s). These findings were compared to the histopathological results.

RESULTS

25 (83 %) had an RCC, and two (7 %) patients showed an urothelial carcinoma. Benign tumors were diagnosed in three (10 %) patients. All of them were oncocytomas. In grayscale ultrasound 52 % of the RCCs were hypoechoic, 36 % isoechoic, and 12 % hyperechoic. After the application of the contrast agent, all RCCs showed a chaotic vascularization pattern. In the early phase (< 30 s), 12 tumors showed hyperperfusion, three showed isoperfusion, and nine showed hypoperfusion. During the late phase (60 - 120 s), five tumors showed hyperperfusion, nine showed isoperfusion, and ten showed hypoperfusion. One small cystic tumor did not indicate contrast enhancement at any time.

CONCLUSION

In our study RCC showed chaotic vascularization in CEUS without typical vascularization patterns.

Hepatic transit time in benign liver lesions

PURPOSE

Shortening of the hepatic transit time (HTT) of an echo enhancer indicates a potential metastatic spread to the liver. Previous studies showed a significant difference in the HTT between patients with metastases (6.5 sec) and patients without liver lesions (15 sec). The influence of benign liver lesions on the HTT is unclear, although benign liver tumors are a frequent finding. We therefore compared the HTT of benign liver lesions to the HTT of liver metastases.

MATERIALS AND METHODS

Patients with focal liver lesions were enrolled in this study. We measured the HTT of an echo enhancer (Sonovue) in pulse inversion mode on the basis of time intensity curves (TIC). For this the hepatic artery and a branch of the hepatic vein were visualized simultaneously in an intercostal section. The difference between the arrival time of the echo enhancer in the hepatic artery and the hepatic vein offered the real HTT.

RESULTS

42 patients were enrolled in this study. 19 patients had metastatic growth in the liver, benign lesions were found in 23 patients. The mean HTT in patients with liver metastasis (6.4 sec +/- 1.6) was significantly less than in patients with benign lesions (10.4 sec +/- 3.4) (p < 0.001). None of the patients with liver metastasis had an HTT of greater than 10 sec.

CONCLUSION

An HTT of greater than 10 sec seems to rule out liver metastasis. If the HTT is less than 10 sec, further evaluation of the liver is needed. There are indications that benign liver lesions also lead to a shortening of the HTT, but this is less pronounced than in patients with liver metastasis.

Percutaneous ultrasound-guided radiofrequency ablation (RFA) using saline-perfused (wet) needle electrodes for the treatment of hepatocellular carcinoma--long term experience

PURPOSE

For many reasons, resection of hepatocellular cancer (HCC) is not feasible in most cases. Radiofrequency (RFA) ablation has proven to be an effective minimally invasive alternative. It has been shown in ex vivo and animal trials that needle applicators perfused with isotonic saline solution could be an effective approach to enlarging the coagulation zone. However, long term survival data for the treatment of HCC are not yet available.

MATERIALS AND METHODS

37 patients with a total of 64 histologically proven HCC with a maximum of 3 tumors of up to 6 cm and a contraindication to partial liver resection or orthotopic liver transplantation were treated with the Integra HiTT106 using wet monopolar single, wet bipolar double or wet triple needle electrodes. The mean HCC size was 37.7 mm (range 15 to 60 mm). Follow-up examinations were performed 2 days and 1, 3, 6, 9 months after RFA and every 6 months thereafter. The survival rate was calculated from the time of the first RFA session.

RESULTS

1, 2 and 5-year survival was 24/32 (75%), 14/31 (45%) and 3/21 (14%) overall; 18/19 (95%), 12/18 (67%) and 3/10 (30%) for HCC Child A; and 6/13 (46%), 2/13 (15%) and 0/11 (0%), for HCC Child B. Complete remission was achieved in 86.5 % of the patients (total: 32 out of 37, multi-needle 18 / 21, single needle 14 / 16). Distant recurrence occurred overall in 20 out of 37 patients (54%), including 9 of 21 treated with multiple needles (43% of patients) and 11 of the 16 patients treated with a single electrode (69%). The overall complication rate was 10.8%. Local recurrence was found for tumors measuring 3 cm-5 cm (n=28) in 7 out of 13 cases after single electrode RFA and in 1 out of 15 after multiple electrode treatment (significant, p=0.009). No significant difference between the single and multi-needle group was found for tumors >5 cm and <3 cm.

CONCLUSION

RFA using multiple wet electrodes shows promise as an effective method for treating inoperable HCC especially in cases with well-preserved liver function. Multiple electrodes seem to be superior to single electrodes with respect to the local recurrence rate for tumors between 3 and 5 cm.

[Prolonged survival through combined treatment with radiofrequency ablation/ethanol instillation compared with radiofrequency ablation alone in the VX2 rabbit liver tumour model]

Combination of radiofrequency ablation (RFA)/ethanol instillation (EI) leads to higher survival rates compared to single RFA for the treatment of VX2 liver tumours in a rabbit tumour model.

INTRODUCTION

To improve the outcome and survival rates of RFA in treatment of liver tumours, a comparative study of RFA with or without EI was performed.

MATERIAL AND METHODS

We implanted a single tumour in the liver of 46 rabbits. After 20 days, animals were treated with RFA/EI or RFA alone. The animals were observed for a maximum of 110 days, after which an autopsy was conducted.

RESULTS

30 animals of the RFA group and 16 of combination therapy were analysed. After interim analysis with the Kaplan-Meier method, a significantly higher survival rate for the combination therapy was observed (P = 0.004). Following the study design, the experiment was therefore terminated ahead of schedule. Rate of metastasis (M) and local recurrence (LR) did not differ between the combination or RFA alone.

CONCLUSION

RFA/EI is superior to treatment with RFA alone with regard to survival rates.

Radiofrequency ablation using perfused needle electrodes - study of intermittent and continuous triple needle application ex vivo

To increase necrotic zones, bovine livers were treated by means of three parallel-oriented radiofrequency ablation (RFA) needles spaced at 3 cm using a puncture guide. The triple application was varied as a continuous and intermittent energy application compared to a single needle applicator. In all three study arms the applied energy (60 W) and the perfusion rate (240 ml/h) were kept constant. After treatment the smallest necrosis diameter was determined. In addition, temperature and the device's power output were monitored. Our study shows that synchronous use of three RFA application needles achieves significantly larger necrosis zones ex vivo than does single needle application. Intermittent energy application heats up the necrosis faster and more evenly with highest average temperature than continuous energy application.

Contrast-enhanced sonography for the characterisation of hepatocellular carcinomas--correlation with histological differentiation

AIM

We aimed to characterise the vascularisation patterns of hepatocellular carcinomas in contrast-enhanced sonography in correlation to the histological differentiation of hepatocellular carcinomas (HCC), and we also compared the diagnostic value of contrast-enhanced sonography in addition to B-scan sonography and power Doppler sonography.

METHODS

51 hepatocellular carcinomas (21 well differentiated, 27 moderately differentiated, 3 poorly differentiated) were examined: by B-scan sonography, power Doppler sonography and contrast-enhanced sonography using phase or pulse inversion harmonic imaging with a low mechanical index (< 0.3) and second generation microbubble contrast medium (Optison, Sonovue) as echo-enhancing agent. Lesion vascularity and the kinetics of contrast enhancement within the lesions in the early arterial phase, arterial phase, portal phase and late phase were analysed. The final diagnosis of a HCC was assessed after B-scan sonography, power Doppler sonography and contrast-enhanced sonography.

RESULTS

Hypervascularisation and/or irregular tumour vascularisation could be detected in 18/48 HCCs (37.5%) by power Doppler sonography. After contrast application, 46/51 HCCs (90.2%) were identified as hyperechoic lesions during the early arterial or arterial phase with no correlation to histological differentiation. In the portal phase and late phase, the echogenicity of HCCs after contrast application was variable. A hypoechoic appearance was noted in 17/51 HCCs (33.3%) in the portal phase and in 21/51 HCCs (41.2%) in the late phase. Moderately differentiated HCCs were more often hypoechoic than well differentiated HCCs (p = 0.04).

CONCLUSION

Contrast-enhanced sonography is highly efficient for the detection of tumour vascularity in HCCs. The majority of HCCs--regardless of histological differentiation--can be characterised as hypervascular lesions in the early arterial and arterial phase with irregular tumour vessels using contrast-enhanced sonography. In addition to B-scan sonomorphology, contrast-enhanced sonography may offer helpful information in patients with liver cirrhosis and focal liver lesions.

Radiofrequency Ablation of Liver Tumors: How to Enlarge the Necrotic Zones?

In an attempt to increase necrotic zones in liver tissue by radiofrequency ablation fresh bovine liver was coagulated by means of a needle electrode continuously perfused with NaCl solution. Power output (60 W) and application time (15 min) were kept constant while the perfusion was varied in terms of saline concentration (0.9, 5.85 and 10%) and perfusion rate (40 or 80 ml/h). Our results showed that the use of higher osmolar saline solutions in radiofrequency ablation with perfused needle electrodes did not lead to significantly larger coagulation volumes. By contrast, increasing the perfusion rate produced significantly larger necrotic zones. Doubling the perfusion rate made it possible to reach higher temperatures (>60 degrees C) within significantly shorter time.

[Detection of liver metastases--comparison of contrast--enhanced ultrasound using first versus second generation contrast agents]

AIM

To compare detection rates for liver metastases for conventional ultrasound, US using tissue harmonic imaging (THI), echo-enhanced pulse inversion harmonic imaging using Optison and Levovist.

METHOD

In 73 patients with histologically proven gastrointestinal tumors spiral CT (S-CT), conventional US, US in the THI-mode, echo-enhanced ultrasound in the portal venous phase (ECI Optison ) and in the liver specific late phase (ECI Levovist) were performed and reviewed by blinded readers.

RESULTS

73 patients (25 female, 48 male, age 63 +/- 11) were included. S-CT detected 158 liver metastases. Conventional US detected 117, THI 119, ECI Optison 169 and ECI Levovist 166 liver metastases. Especially for small (< 2 cm) liver metastases and metastases near the diaphragm echo-enhanced ultrasound exceeded conventional US (p < 0.001). Between both echo enhancers there was no significant difference.

CONCLUSION

Using echo enhancers increases the ultrasound detection rate significantly. Examination in the portalvenous phase using a second generation enhancer (Optison) is equal to a late-phase examination using Levovist.

Radiofrequency ablation of hepatocellular carcinoma with a saline solution perfusion device: a pilot study

PURPOSE

The majority of patients with hepatocellular carcinoma (HCC) cannot be treated with surgery. This study evaluated the treatment of patients with radiofrequency ablation (RFA) with use of needle applicators perfused with isotonic saline solution.

MATERIALS AND METHODS

Twenty patients with a maximum of three HCCs as large as 60 mm and a contraindication to partial liver resection or orthotopic liver transplantation were enrolled in the study. They were treated with ultrasound-guided RFA with use of perfused needle applicators and followed with sonography and computed tomography.

RESULTS

Twenty patients (14 men, six women) with a total of 29 HCCs were treated with RFA. In total, 56 RFA treatments were performed. Mean HCC size was 31 mm (range, 10-60 mm). Two cases of self-limiting bleeding requiring transfusion of blood products took place. Complete response (CR) was achieved in 85% of patients (17 of 20). Partial response occurred in three tumors 45 mm in diameter or larger. There was a total of six local recurrences in five patients (25% of patients, 21% of tumors). Six patients (30%) exhibited distant recurrence, two of whom also showed local recurrence. In three patients, repeat treatment led to renewed CR. After a median follow-up of 445 days (range, 114-1,071 days), 12 patients (71% of the 17 patients with initial CR) still showed CR. Twelve patients (60% of all patients, 71% of those with initial CR) survived. Three of the eight patients who died were free of viable tumor at the time of death.

CONCLUSIONS

RFA with use of perfused needle applicators shows promise as an effective method for treating inoperable HCC. The most frequent complication was bleeding.

Synthetic 2-aroylindole derivatives as a new class of potent tubulin-inhibitory, antimitotic agents

A new class of simple synthetic antimitotic compounds based on 2-aroylindoles was discovered. (5-Methoxy-1H-2-indolyl)-phenylmethanone (1) as well as analogous 3-fluorophenyl- (36) and 3-methoxyphenyl (3) derivatives displayed high cytotoxicity of IC(50) = 20 to 75 nM against the human HeLa/KB cervical, SK-OV-3 ovarian, and U373 astrocytoma carcinoma cell lines. The inhibition of proliferation correlated with the arrest in the G2/M phase of the cell cycle. In in vitro assays with tubulin isolated from bovine brain, in general antiproliferative activity correlated with inhibition of tubulin polymerization. Thus, the antimitotic activity of 2-aroylindoles is explained by interference with the mitotic spindle apparatus and destabilization of microtubules. In contrast to colchicine, vincristine, nocodazole, or taxol, 1 did not significantly affect the GTPase activity of beta-tubulin. Interestingly, selected compounds inhibited angiogenesis in the chorioallantoic membrane (CAM) assay. In xenograft experiments, 1 was highly active after oral administration at 200 mg/kg against the human amelanocytic melanoma MEXF 989 in athymic nude mice. We conclude, that 2-aroylindoles constitute an interesting new class of antitubulin agents with the potential to be clinically developed for cancer treatment.

Dendritic hypertrophy of Stach type VI neurons within experimentally altered ileum of pigs

Myenteric neurons were investigated morphometrically to answer the question if type-specific somal hypertrophy of type VI neurons in mechanically stressed ileum of pigs, which was known from an earlier study, is correlated with an increased dendritic arborization, that is, with dendritic hypertrophy. Muscular hypertrophy was induced in the ileum of two juvenile pigs by narrowing the gut circumference (mechanical stenosis) and by reversing a loop of ileum which results in an antiperistaltic segment (functional stenosis), respectively. After a survival time of 6 weeks, wholemounts from the pre- and poststenotic ileal regions, from the antiperistaltic segment as well as from an age matched control animal, were silver impregnated. Dendritic parameters of Stach types IV and VI neurons were recorded using a computer-aided morphometric program and analysed statistically. Type IV neurons showed no change of dendritic parameters, neither within control nor within stenosed ileal segments. In contrast, the type VI neurons displayed increased dendritic parameters within zones of muscular hypertrophy such as total dendritic length, numbers of dendrites, of dendritic branching points and of dendritic endings. We suggest that type VI neurons may participate as descending nitrergic interneurons or motorneurons in the control of muscular function, thus, undergoing plastic changes in case of experimental muscular hypertrophy. Type IV neurons which are involved in the regulation of mucosal processes were not affected by muscular hypertrophy.

Experimental hypertrophy of myenteric neurones in the pig: a morphometric study

Muscular hypertrophy in the ileum of two pigs aged 6 weeks was induced using two different surgical techniques, narrowing of the gut circumference (mechanical stenosis) and segmental reversal of an ileal loop which results in a persistent antiperistalsis of that segment (functional stenosis). These pigs were sacrificed 5-6 weeks postoperatively. Cross sections through the gut wall at various distances from the operation sites revealed marked muscular hypertrophy in the pre-stenotic regions and in the reversed segment. Whole mounts from pre- and post-stenotic, as well as reversed ileal regions, were silver- impregnated. The corresponding ileal region of a third, nonoperated pig served as control. Using a computer-aided morphometric device, somal areas of five morphological neurone types were measured at various distances orally and anally from the operation sites and along the control ileum. Values between hypertrophic and nonhypertrophic zones as well as between two corresponding zones of nonoperated ileum were compared statistically. Along the control ileum, values revealed no differences in soma sizes. Within the experimentally altered material, somal areas of type VI neurones showed marked hypertrophy related to the sites of muscular hypertrophy whereas the other types remained constant throughout (II, IV in segmental reversal) or showed slightly larger somal areas within the post-stenotic, nonhypertrophied zones (I, V, IV in stenosis). Additionally, within the reversed segment, neuronal perikarya of type I, II, IV and V neurones were larger as compared to the neighbouring regions. However, this enlargement of perikarya within the reversed segment may not be correlated with muscular hypertrophy but rather with the transections of intramural axons before reversing this segment. The results suggest that morphologically distinct neurone types may play different roles within the mechanically stressed small intestine and possibly also in the coordination of normal muscular function.

Developmental regulation of the laminin alpha5 chain suggests a role in epithelial and endothelial cell maturation

We have previously shown that mouse and bovine endothelial cells express a novel 400-kDa laminin alpha chain complexed to beta1 and gamma1 laminin chains. We describe here purification of this laminin isoform from the conditioned medium of a mouse peripheral lymph node endothelial cell line, SVEC. The laminin alpha chain was isolated from the laminin complex, subjected to Edman digestion, and the amino acid sequences of the resulting peptides were determined. Amino acid sequence revealed 100% identity to the predicted amino acid sequence of the recently reported laminin alpha5 gene. A monoclonal antibody to the laminin alpha5 chain was raised (4G6), allowing investigation of its distribution in embryonic, newborn, and mature mouse tissues. The laminin alpha5 chain was expressed mainly by epithelial, endothelial, and myogenic cells: In both embryonic and mature tissues the laminin alpha5 chain was strongly expressed by epithelial cells, the bronchi of the lungs and the developing kidney tubules being the sites of strongest expression. However, laminin alpha5 was not associated with early stages of epithelial cell development, but rather with epithelial cell maturation. Widespread expression of laminin alpha5 in endothelial cells was apparent only in tissues of mature mice, its appearance correlating approximately with sexual maturity. During embryogenesis and in newborn tissues, laminin alpha5 occurred in basement membranes of larger blood vessels only, excluding a role in angiogenic processes. Smooth muscle and skeletal muscle cells were the only other cell types which showed considerable laminin alpha5 expression, with skeletal muscle exhibiting a developmentally regulated pattern of expression: The laminin alpha5 chain occurred in skeletal muscle fiber basement membranes early in embryogenesis (E13-E15) but decreased with development, remaining strongly expressed only at the neuromuscular junction. The data show that laminin alpha5 expression is associated with epithelial and endothelial cell maturation, implicating a role for this laminin chain in the maintenance of differentiated epithelial and endothelial cell phenotype.

Cloning of the mouse laminin alpha 4 cDNA. Expression in a subset of endothelium

Endothelial cells express a 400-kDa or 240-kDa laminin alpha chain, depending on their tissue of origin or physiological state [1, 2]. Using differential display and subsequent screening of a mouse endothelial cell cDNA library we here identify the gene coding for the 240-kDa laminin chain as the laminin alpha 4 gene. The complete mouse laminin alpha 4 cDNA sequence is reported and compared with other laminin alpha chains. In situ hybridization of embryonic and new born mouse tissues revealed expression of laminin alpha 4 mRNA in a subset of endothelium, in particular aortic endothelium, endocardium and endothelium of blood vessels in the skin and in the brain. Strong laminin alpha 4 expression by aortic endothelia was confirmed by data obtained from cultured bovine aortic endothelial cells (BAEC). Isolation of laminin from BAEC conditioned medium revealed a Y-shaped molecule in rotary shadowing. Subsequent sequencing of BAEC laminin resulted in laminin alpha 4, beta 1 and gamma 1 amino acid sequences, confirming that laminin alpha 4 is one of the major laminin alpha chains expressed by aortic endothelium not only in the mouse. In addition, strong laminin alpha 4 mRNA expression occurred in peripheral nerves, cardiac muscle, fat, the dermis of the skin and lung stroma of mouse tissues. The data demonstrate a cytokine and progesterone-regulated differential expression of laminin alpha 4 mRNA in mouse endothelium, suggesting a distinct functional role for this laminin chain in endothelium.

Integrin-mediated intracellular Ca2+ signaling in Jurkat T lymphocytes

T lymphocytes interact with components of the extracellular matrix after transendothelial migration on their way to sites of inflammation. To characterize the molecular basis of the interaction between T lymphocytes with different extracellular matrix proteins, we investigated the role of intracellular Ca2+ as a signal mediating such interactions and identified the cell surface integrins involved in this process. When Jurkat T lymphocytes loaded with the calcium-sensitive fluorescent dye fura-2 were placed on coverslips coated with human fibronectin, human collagen types I, IV, and VI, human tenascin, human laminin I, or mouse laminin I, an elevation in intracellular Ca2+ concentration was observed. In contrast, contact of the Jurkat T lymphocytes with vitronectin and thrombospondin did not induce Ca2+ signals in more cells as compared with control measurements in which cells were in contact with only BSA or polylysine. Furthermore, the percentage of Jurkat T lymphocytes responding with Ca2+ signals to collagen types I and IV, fibronectin, and laminin I was completely reduced to levels observed on BSA or polylysine when the cells were pretreated with specific anti-integrin Abs, suggesting a role for cell surface integrins as mediators of cell matrix-induced intracellular Ca2+ signaling. Similar results were obtained with peripheral human T lymphocytes activated by phytohemagglutinin.

Integrin-mediated intracellular Ca2+ signaling in Jurkat T lymphocytes

T lymphocytes interact with components of the extracellular matrix after transendothelial migration on their way to sites of inflammation. To characterize the molecular basis of the interaction between T lymphocytes with different extracellular matrix proteins, we investigated the role of intracellular Ca2+ as a signal mediating such interactions and identified the cell surface integrins involved in this process. When Jurkat T lymphocytes loaded with the calcium-sensitive fluorescent dye fura-2 were placed on coverslips coated with human fibronectin, human collagen types I, IV, and VI, human tenascin, human laminin I, or mouse laminin I, an elevation in intracellular Ca2+ concentration was observed. In contrast, contact of the Jurkat T lymphocytes with vitronectin and thrombospondin did not induce Ca2+ signals in more cells as compared with control measurements in which cells were in contact with only BSA or polylysine. Furthermore, the percentage of Jurkat T lymphocytes responding with Ca2+ signals to collagen types I and IV, fibronectin, and laminin I was completely reduced to levels observed on BSA or polylysine when the cells were pretreated with specific anti-integrin Abs, suggesting a role for cell surface integrins as mediators of cell matrix-induced intracellular Ca2+ signaling. Similar results were obtained with peripheral human T lymphocytes activated by phytohemagglutinin.

Mouse polymorphonuclear granulocyte binding to extracellular matrix molecules involves beta 1 integrins

The mechanism of adhesion of purified mouse polymorphonuclear granulocytes (PMN) to extracellular matrix proteins characteristic of basement membranes and the interstitium has been investigated and compared with the adhesion of a mouse progranulocytic cell line, 32DC13, and a mouse monocytic cell line, WEHI 78/24. All three cell types bound specifically to fibronectin and vitronectin to different degrees under different cellular activation states. 32DC13 bound to fibronectin and vitronectin strongly, and this binding increased upon cellular activation with phorbol 12-myristate-13-acetate (PMA) but not with formyl-Met-Leu-Phe. Only 32DC13 showed significant binding to laminin-1. By contrast, WEHI 78/24 and PMN bound only fibronectin and vitronectin; this binding was weak and was altered only marginally upon activation with PMA. In the case of WEHI 78/24, a slight increase in adhesion both to fibronectin and to vitronectin was observed after cellular activation with PMA, while PMN adhesion to both substrates was slightly reduced. The mechanism of binding to fibronectin and vitronectin was similar in the three cell types. The integrin alpha5 beta1 mediated fibronectin adhesion, demonstrating for the first time the existence of a functionally active beta1 integrin on mouse PMN. Vitronectin binding was mediated by alpha(v) beta3, as demonstrated by the ability of alpha(v)-specific cyclic L-Arg-L-Gly-L-Asp-D-Phe-L-Val (RGDfV) peptide (EMD66203), and anti-beta3 antibody to inhibit cell adhesion. 32DC13 adhesion to laminin-1 was via the alpha6 beta1 integrin. None of the three cell types tested bound to the basement membrane proteins collagen type IV and perlecan, or to the interstitial stromal constituents tenascin, collagen types I, V and VI. Interestingly, perlecan and collagen type IV were found to repel all three cell types. The relative inability of PMN, WEHI 78/24, and 32DC13 to bind to extracellular matrix proteins characteristic of basement membranes and their ability to bind inflammatory markers of the interstitium is discussed with respect to leukocyte extravasation processes.