Gallbladder cancer mimicking perihilar cholangiocarcinoma-considerable rate of postoperative reclassification with implications for prognosis

BACKGROUND

For some patients undergoing resection under the suspicion of a perihilar cholangiocarcinoma (pCCA), postoperative diagnosis may differ from the preoperative diagnosis. While a postoperative finding of benign bile duct stricture is known to affect 3-15% of patients, less has been described about the consequences of finding other biliary tract cancers postoperatively. This study compared pre- and postoperative diagnoses, risk characteristics, and outcomes after surgery for suspected pCCA.

METHODS

Retrospective single-center study, Karolinska University Hospital, Stockholm, Sweden (January 2009-May 2017). The primary postoperative outcome was overall survival. Secondary outcomes were disease-free survival and postoperative complications. Survival analysis was performed by the Kaplan-Meier method.

RESULTS

Seventy-one patients underwent resection for suspected pCCA. pCCA was confirmed in 48 patients (68%). Ten patients had benign lesions (14%), 2 (3%) were diagnosed with other types of cholangiocarcinoma (CCA, distal n = 1, intrahepatic n = 1), while 11 (15%) were diagnosed with gallbladder cancer (GBC). GBC patients were older than patients with pCCA (median age 71 versus 58 years, p = 0.015), with a large proportion of patients with a high tumor extension stage (≥ T3, 91%). Median overall survival was 20 months (95% CI 15-25 months) for patients with pCCA and 17 months (95% CI 11-23 months) for patients with GBC (p = 0.135). Patients with GBC had significantly shorter median disease-free survival (DFS), 10 months (95% CI 3-17 months) compared 17 months (95% CI 15-19 months) for patients with pCCA (p = 0.010).

CONCLUSIONS

At a large tertiary referral center, 15% of patients resected for suspected pCCA were postoperatively diagnosed with GBC. Compared to patients with pCCA, GBC patients were older, with advanced tumors and shorter DFS. The considerable rate of re-classification stresses the need for improved preoperative staging, as these prognostic differences could have implications for treatment strategies.

Preoperative immunological plasma markers TRAIL, CSF1 and TIE2 predict survival after resection for biliary tract cancer

Introduction

Systemic inflammatory markers have been validated as prognostic factors for patients with biliary tract cancer (BTC). The aim of this study was to evaluate specific immunologic prognostic markers and immune responses by analyzing preoperative plasma samples from a large prospectively collected biobank.

Methods

Expression of 92 proteins representing adaptive and innate immune responses was investigated in plasma from 102 patients undergoing resection for BTC 2009-2017 (perihilar cholangiocarcinoma n=46, intrahepatic cholangiocarcinoma n=27, gallbladder cancer n=29), by means of a high-throughput multiplexed immunoassay. Association with overall survival was analyzed by Cox regression, with internal validation and calibration. Tumor tissue bulk and single-cell gene expression of identified markers and receptors/ligands was analyzed in external cohorts.

Results

Three preoperative plasma markers were independently associated with survival: TRAIL, TIE2 and CSF1, with hazard ratios (95% confidence intervals) 0.30 (0.16-0.56), 2.78 (1.20-6.48) and 4.02 (1.40-11.59) respectively. The discrimination of a preoperative prognostic model with the three plasma markers was assessed with concordance-index 0.70, while the concordance-index of a postoperative model with histopathological staging was 0.66. Accounting for subgroup differences, prognostic factors were assessed for each type of BTC. TRAIL and CSF1 were prognostic factors in intrahepatic cholangiocarcinoma. In independent cohorts, TRAIL-receptor expression was higher in tumor tissue and seen in malignant cells, with TRAIL and CSF1 expressed by intra- and peritumoral immune cells. Intratumoral TRAIL-activity was decreased compared to peritumoral immune cells, while CSF1-activity was increased. The highest CSF1 activity was seen in intratumoral macrophages, while the highest TRAIL-activity was seen in peritumoral T-cells.

Discussion

In conclusion, three preoperative immunological plasma markers were prognostic for survival after surgery for BTC, providing good discrimination, even compared to postoperative pathology. TRAIL and CSF1, prognostic factors in intrahepatic cholangiocarcinoma, showed marked differences in expression and activity between intra- and peritumoral immune cells.

Increased Prevalence of Alpha-1-Antitrypsin Deficiency in Patients with Biliary Tract Cancer and Its Associated Clinicopathological Features

Alpha-1 antitrypsin deficiency (A1ATD) is underdiagnosed and associated with liver diseases. Here, we genotyped 130 patients with biliary tract cancer (BTC) scheduled for liver resection and found A1ATD in 10.8% of the patients. A1ATD was found in all BTC subtypes, and patients had similar clinical features as non-A1ATD BTC, not permitting their identification using clinical routine liver tests. In intrahepatic cholangiocarcinoma (iCCA), the abundance of A1AT protein was increased in the tumor and appeared to be influenced by the genomic alterations. On the one hand, BTC with A1ATD had lower perineural invasion at histopathology and displayed a longer survival, suggesting that a deficiency in this protein is associated with a less aggressive phenotype. On the other hand, iCCA with high A1AT expression had more advanced tumor staging and enriched pathways for complement system and extracellular matrix interactions, indicating that A1AT protein might contribute to a more aggressive phenotype. With increased awareness, screening, and basic studies, A1ATD could represent one more layer of stratification for future targeted therapies in BTC.

Prognostic influence of multiple hepatic lesions in resectable intrahepatic cholangiocarcinoma: A systematic review and meta-analysis

BACKGROUND

Presence of multiple hepatic lesions in intrahepatic cholangiocarcinoma (iCCA) is included in staging as a negative prognostic factor, but both prognostic value and therapeutic implications remain debated. The aim of this study was to systematically review the prognostic influence of multiple lesions on survival after resection for iCCA, with stratification for distribution and number of lesions.

METHODS

Medline and Embase were systematically searched to identify records (2010-2021) reporting survival for patients undergoing primary resection for iCCA. Included were original articles reporting overall survival, with data on multiple lesions including tumour distribution (satellites/other multiple lesions) and/or number. For meta-analysis, the random effects model and inverse variance method were used. PRISMA 2020 guidelines were followed.

RESULTS

Thirty-one studies were included for review. For meta-analysis, nine studies reporting data on the prognostic influence of satellite lesions (2737 patients) and six studies reporting data on multiple lesions other than satellites (1589 patients) were included. Satellite lesions (hazard ratio 1.89, 95% confidence interval 1.67-2.13) and multiple lesions other than satellites (hazard ratio 2.41, 95% confidence interval 1.72-3.37) were significant negative prognostic factors. Data stratified for tumour number, while limited, indicated increased risk per additional lesion.

CONCLUSION

Satellite lesions, as well as multiple lesions other than satellites, was a negative prognostic factor in resectable iCCA. Considering the prognostic impact, both tumour distribution and number of lesions should be evaluated together with other risk factors to allow risk stratification for iCCA patients with multiple lesions, rather than precluding resection for the entire patient group.

Mucosal-associated invariant T-cell tumor infiltration predicts long-term survival in cholangiocarcinoma

BACKGROUND AND AIMS

Cholangiocarcinoma (CCA) is a malignancy arising from biliary epithelial cells of intra- and extrahepatic bile ducts with dismal prognosis and few nonsurgical treatments available. Despite recent success in the immunotherapy-based treatment of many tumor types, this has not been successfully translated to CCA. Mucosal-associated invariant T (MAIT) cells are cytotoxic innate-like T cells highly enriched in the human liver, where they are located in close proximity to the biliary epithelium. Here, we aimed to comprehensively characterize MAIT cells in intrahepatic (iCCA) and perihilar CCA (pCCA).

APPROACH AND RESULTS

Liver tissue from patients with CCA was used to study immune cells, including MAIT cells, in tumor-affected and surrounding tissue by immunohistochemistry, RNA-sequencing, and multicolor flow cytometry. The iCCA and pCCA tumor microenvironment was characterized by the presence of both cytotoxic T cells and high numbers of regulatory T cells. In contrast, MAIT cells were heterogenously lost from tumors compared to the surrounding liver tissue. This loss possibly occurred in response to increased bacterial burden within tumors. The residual intratumoral MAIT cell population exhibited phenotypic and transcriptomic alterations, but a preserved receptor repertoire for interaction with tumor cells. Finally, the high presence of MAIT cells in livers of iCCA patients predicted long-term survival in two independent cohorts and was associated with a favorable antitumor immune signature.

CONCLUSIONS

MAIT cell tumor infiltration associates with favorable immunological fitness and predicts survival in CCA.

Outcome after resection for perihilar cholangiocarcinoma in patients with primary sclerosing cholangitis: an international multicentre study

BACKGROUND

Resection for perihilar cholangiocarcinoma (pCCA) in primary sclerosing cholangitis (PSC) has been reported to lead to worse outcomes than resection for non-PSC pCCA. The aim of this study was to compare prognostic factors and outcomes after resection in patients with PSC-associated pCCA and non-PSC pCCA.

METHODS

The international retrospective cohort comprised patients resected for pCCA from 21 centres (2000-2020). Patients operated with hepatobiliary resection, with pCCA verified by histology and with data on PSC status, were included. The primary outcome was overall survival. Secondary outcomes were disease-free survival and postoperative complications.

RESULTS

Of 1128 pCCA patients, 34 (3.0%) had underlying PSC. Median overall survival after resection was 33 months for PSC patients and 29 months for non-PSC patients (p = .630). Complications (Clavien-Dindo grade ≥ 3) were more frequent in PSC pCCA (71% versus 44%, p = .003). The rate of posthepatectomy liver failure (21% versus 17%, p = .530) and 90-day mortality (12% versus 13%, p = 1.000) was similar for PSC and non-PSC patients.

CONCLUSION

Median overall survival after resection for pCCA was similar in patients with underlying PSC and non-PSC patients. Complications were more frequent after resection for PSC-associated pCCA, with no difference in postoperative mortality.

Prognostic value of preoperative inflammatory markers in resectable biliary tract cancer - Validation and comparison of the Glasgow Prognostic Score and Modified Glasgow Prognostic Score in a Western cohort

INTRODUCTION

Established preoperative prognostic factors for risk stratification of patients with biliary tract cancer (BTC) are lacking. A prognostic value of the inflammation-based Glasgow Prognostic Score (GPS) and Modified Glasgow Prognostic Score (mGPS) in BTC has been indicated in several Eastern cohorts. We sought to validate and compare the prognostic value of the GPS and the mGPS for overall survival (OS), in a large Western cohort of patients with BTC.

MATERIAL AND METHODS

We performed a retrospective single-center study for the period 2009 until 2017. 216 consecutive patients that underwent surgical exploration with a diagnosis of perihilar cholangiocarcinoma (PHCC), intrahepatic cholangiocarcinoma (IHCC), or gallbladder cancer (GBC) were assessed. GPS and mGPS were calculated where both CRP and albumin were measured pre-operatively (n = 168/216). Survival was analyzed by Kaplan-Meier estimate and uni-/multivariate Cox regression.

RESULTS

GPS and mGPS were negatively associated with survival (p < 0.001/p < 0.001), and the association was significant in all three subgroups. GPS, but not the mGPS, identified an intermediate risk group: with GPS = 1 having better OS than GPS = 2 (p = 0.003), but worse OS than GPS = 0 (p = 0.008). In multivariate analyses of resected patients, GPS (p = 0.001) and mGPS (p = 0.03) remained significant predictors of survival, independent of postoperatively available risk factors.

CONCLUSIONS

Preoperative GPS and mGPS are independent prognostic factors in BTC. The association to OS was shown in all patients undergoing exploration, in resected patients only, and in both cholangiocarcinoma and gallbladder cancer. Furthermore, GPS - which weights hypoalbuminemia higher - could identify an intermediate risk group.

Imbalance of Genes Encoding Natural Killer Immunoglobulin-Like Receptors and Human Leukocyte Antigen in Patients With Biliary Cancer

BACKGROUND & AIMS

Bile duct tumors are rare and have poor prognoses. Natural killer (NK) cells are frequent in human liver and infiltrate these tumors but do not control their progression. Responses of NK cells are regulated by NK immunoglobulin-like receptors (KIRs), which interact with HLA class I ligands. We aimed to characterize the features of the KIR gene loci and their ligands in patients with bile duct cancer (BDC).

METHODS

We performed combined multidimensional characterization of genes that encode KIRs and their ligands in blood samples from patients with BDC from Sweden, followed for up to 8 years after diagnosis (n = 148), in 2 geographically matched cohorts of healthy individuals from Northern Europe (n = 204 and n = 900), and in healthy individuals from 6 geographically unrelated populations (n = 2917). We used real-time polymerase chain reaction, RNA sequencing, immunohistochemistry, and flow cytometry to evaluate NK-cell presence, as well as KIR and KIR-ligand expression in bile duct tumors and control tissues.

RESULTS

Patients with bile duct tumors had multiple alterations at the KIR gene loci. KIR loci are grouped into genotypes that encode more inhibitory (group A) and more activating (group B) receptors, which can be subdivided into centromeric and telomeric fragments. Patients with BDC had a lower prevalence of KIR2DL3, which was linked to disequilibrium in centromeric A/B and B/B genotypes, compared with control individuals. The associations between KIRs and KIR ligands differed between patients with BDC and control individuals; patients had an altered balance between activating and inhibitory KIRs. KIR-positive NK cells infiltrated biliary tumors that expressed matched KIR ligands.

CONCLUSIONS

In a multidimensional analysis of DNA from blood samples of patients with BDC in Europe, we found patients to have multiple alterations at the KIR and HLA gene loci compared with control individuals. These alterations might affect NK-cell tumor surveillance. NK cells from bile duct tumors expressed KIRs and were found in tumors that expressed cognate ligands. This should be considered in development of immune-based therapies for BDC.

A novel non-surgical method for mild peri-implantitis- a multicenter consecutive case series

AIM

The aim of the present study was to evaluate the effect on peri-implant mucosal inflammation from the use of a novel instrument made of chitosan in the non-surgical treatment of mild peri-implantitis across several clinical centers.

MATERIALS AND METHODS

In this 6-month multicenter prospective consecutive case series performed in six different periodontal specialist clinics, 63 implants in 63 patients were finally included. The subjects had mild peri-implantitis defined as radiographic bone loss of 1-2 mm, pocket probing depth (PPD) ≥4 mm and a positive bleeding on probing (mBoP) score. The patients were clinically examined at baseline and after 2, 4, 12 and 24 weeks, and radiographs were taken at baseline and at 3 and 6 months. Treatment of the implants with the chitosan brush seated in an oscillating dental drill piece was performed at baseline and at 3 months. Reductions in the clinical parameters (PPD and mBoP) were compared between baseline and the later examination time points.

RESULTS

Significant reductions in both PPD and mBoP were observed at all time points compared with the baseline clinical measurements (p < 0.001). The mean PPD and mBoP at baseline were 5.15 mm (4.97; 5.32) and 1.86 (1.78; 1.93), respectively, whereas the mean PPD and mBoP at 6 months were 4.0 mm (3.91; 4.19) and 0.64 (0.54; 0.75), respectively. Stable reductions in PPD and mBoP were evident up to 6 months after the initial treatment and 3 months after the second treatment. All 63 implants were reported to have stable radiographic levels of osseous support.

CONCLUSIONS

This case series demonstrated that an oscillating chitosan brush is safe to use and seems to have merits in the non-surgical treatment of dental implants with mild peri-implantitis. To measure the effectiveness of the method, a multicenter randomized clinical trial needs to be undertaken.

A Nordic survey of management practices and owners' attitudes towards keeping horses in groups

Keeping horses in groups is widely recommended but limited information is available about how this is implemented in practice. The aim of this survey was to describe how horses are kept in the Nordic countries in relation to sex, age, breed, and equestrian discipline and to assess owners' attitudes toward keeping horses in groups. Horse owners in Denmark, Finland, Norway, and Sweden were approached using a web-based questionnaire, which was translated into 4 languages and distributed online via equestrian forums, organizations, and social media. The number of respondents was 3,229, taking care of 17,248 horses. Only 8% of horses were never kept in groups, 47% were permanently grouped for 24 h/d, and 45% were stabled singly but grouped during turnout. Yearlings were most often permanently kept in groups (75%), mares and geldings more commonly during parts of the day (50 and 51%, respectively), and stallions were often kept alone (38%). Icelandic horses were more likely to be permanently kept in groups (36%) than warmbloods (16%) and ponies (15%). Twice as many competition horses (51%) were never grouped compared with horses used for breeding (20%) or leisure purposes (15%). The majority of respondents (86%) strongly agreed that group housing benefits horse welfare and that it is important for horses to have the company of conspecifics (92%). Nevertheless, not all horses were kept in groups, showing that attitudes toward group housing may not necessarily reflect current management. The risk of injury was a concern of many respondents (45%), as was introducing unfamiliar horses into already established groups (40%) and challenges in relation to feeding in groups (44%). Safety of people (23%) and difficulties handling group-kept horses (19%) were regarded as less problematic. Results suggest that the majority of horses have the possibility to freely interact with other horses, either as fulltime members of a group during 24 h/d or during turnout. Future research should address the extent to which being a part-time member of a group affects horse welfare. For permanent group housing to become more widespread, such as it is the case for most farm animals, future research could focus on solving some of the reoccurring problems perceived with keeping horses in groups. The dissemination of evidence-based information on all aspects around keeping horses in groups can ultimately stimulate further positive changes in the management of group-kept horses.

Type 2 diabetes and risk for periodontal disease: a role for dental health awareness

BACKGROUND

Several studies have found correlations between diabetes and an increased prevalence of periodontitis.

OBJECTIVE

To analyse, in a group of subjects with type 2 diabetes (T2D), (i) the association between medical characteristics and severe periodontal disease and (ii) dental care habits and knowledge of oral health.

METHODS

One hundred and ninety-one subjects with T2D were examined. Based on assessment of marginal bone height in panoramic radiographs, two periodontal subgroups were identified: one periodontally diseased (PD+) and one periodontally healthy (PD-) group. All subjects completed a questionnaire about their medical and oral health.

RESULTS

Twenty per cent of the subjects were classified as PD+. This was verified by clinical parameters. PD+ individuals had higher haemoglobin A1c (HbA1c) levels (p=0.033) and higher prevalences of cardiovascular complications (p=0.012). They were also less likely to be of Scandinavian origin (p=0.028) and more likely to smoke (p<0.001) than the PD- group. The PD+ group rated their oral health as poor (p<0.0001) and believed that T2D had an influence on their oral status (p<0.0001).

CONCLUSION

The best predictor for severe periodontal disease in subjects with T2D is smoking followed by HbA1c levels. T2D subjects should be informed about the increased risk for periodontal disease when suffering from T2D.

Dynamics of Fresh and Freeze-Dried Strawberry and Red Onion by Quasielastic Neutron Scattering

The microscopic behavior of fresh and freeze-dried strawberry and red onion at different water contents (45 and 20 wt % water) has been investigated by quasielastic neutron scattering (QENS). To distinguish between the dynamics of the water and the biological material isotopic (H/D) substitution was used. The results show that all samples exhibit an onset of anharmonic motions on the experimental time scale (3-100 ps) at about 230-240 K. Above 250 K the dynamics is mainly of translational character and strongly dependent on the hydration level. The diffusion constant increases rapidly with increasing water content and at 280 K it is approximately 20% higher for the hydration water in freeze-dried strawberry than in freeze-dried red onion and around 2 orders of magnitude faster for the hydration water than for the biological material. Moreover, the diffusion constant of the biological part is about 50% faster in freeze-dried strawberry than in freeze-dried red onion. It was also found that the average relaxation time is slightly faster in fresh strawberry than in freeze-dried strawberry. From the results we can conclude that the water dynamics is not only promoting motions in the biological material, it is also affected by the structure (and possibly also the dynamics) of the biological material. Thus, the microscopic properties of the biological materials are interrelated with the properties of their hydration water.

Dynamics of water in a molecular sieve by quasielastic neutron scattering

We have investigated the dynamics of water confined in a molecular sieve, with a cylindrical pore diameter of 10 A, by means of quasielastic neutron scattering (QENS). Both the incoherent and coherent intermediate scattering functions I(Q,t) were determined by time-of-flight QENS and the neutron spin-echo technique, respectively. The results show that I(Q,t) is considerably more stretched in time with a slightly larger average relaxation time in the case of coherent scattering. From the Q dependence of I(Q,t) it is clear that the observed dynamics is almost of an ordinary translational nature. A comparison with previous dielectric measurements suggests a possible merging of the alpha and beta relaxations of the confined water at T=185 K, although the alpha relaxation cannot be directly observed at lower temperatures due to the severe confinement. The present results are discussed in relation to previous results for water confined in a Na-vermiculite clay, where the average relaxation time from spin-echo measurements was found to be slower than in the present system (particularly at low temperatures).

Dynamics of water in strawberry and red onion as studied by dielectric spectroscopy

We have investigated the microscopic dynamics of strawberry and red onion by means of broadband dielectric spectroscopy. In contrast to most of the previous experiments on carbohydrate-rich biological materials, which have mainly considered the more global dynamics of the "biological matrix," we are here focusing on the microscopic dynamics of mainly the associated water. The results for both strawberry and red onion show that the imaginary part of the permittivity contains one conductivity term and a clear dielectric loss peak, which was found to be similar to the strongest relaxation process of water in carbohydrate solutions. The temperature dependence of the relaxation process was analyzed for different water content. The relaxation process slows down, and its temperature dependence becomes more non-Arrhenius, with decreasing water content. The reason for this is most likely that, on average, the water molecules interact more strongly with carbohydrates and other biological materials at low water content, and the dynamical properties of this biological matrix changes substantially with increasing temperature (from an almost rigid matrix where the water is basically unable to perform long-range diffusion due to confinement effects, to a dynamic matrix with no static confinement effects), which also changes (i.e., reduces) the activation energy of the relaxation process with increasing temperature (i.e., causes a non-Arrhenius temperature dependence). This further changes the conductivity from mainly polarization effects at low temperatures, due to hindered ionic motions, to long-range diffusivity at T>250 K . Thus, around this temperature ions in the carbohydrate solution no longer get stuck in confined cavities, since the motion of the biological matrix "opens up" the cavities and the ions are then able to perform long-range migration.

Dynamics of water in molecular sieves by dielectric spectroscopy

We present recent dielectric data on the dynamics of water confined in molecular sieves with pore sizes 5 and 10 A. The dielectric measurements in the frequency and temperature ranges 10(-2)-10(6) Hz and 120-300 K show three relaxation processes for both samples. In the case of the 10 A pore the slowest process shows an Arrhenius temperature dependence at low temperatures (<220 K), while at high temperatures the relaxation appears to follow a more Vogel-Fulcher-Tammann (VFT) like behaviour. The relaxation time for this process is 100 s at about 170 K. The second slowest process is at low temperatures very similar to the main process of (bulk-like) water in a fully hydrated clay, but also this process seems to exhibit some kind of dynamical transition, in this case at T approximately 185 K. All the three processes in the 5 A pore exhibit Arrhenius temperature dependence, and two of them are considerably slower than the main relaxation in the hydrated clay. Thus, dynamics of bulk-like water is only observed in the 10 A molecular sieves, and most of the water molecules in both 5 and 10 A pores have considerably slower dielectric relaxation than has been observed for water confined in clay, most likely due to strong interactions with the considerably more hydrophilic inner surfaces of molecular sieves.

Clinical outcome observed in subjects with recurrent periodontal disease following local treatment with 25% metronidazole gel

BACKGROUND

The aim of this study was to evaluate the clinical outcome in patients with recurrent periodontal disease following treatment with 25% metronidazole gel.

METHODS

Twenty subjects in a maintenance care program but with recurrent periodontal disease participated. Three months after scaling and root planing, a total of 40 sites, 2 in each patient, with probing depth > or = 5 mm were selected. One site randomly selected was treated with metronidazole gel (test) and the other site with a placebo gel (control). Baseline and follow-up measurements included plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL).

RESULTS

There were no statistically significant differences in PI, GI, BOP, PD, or CAL between test and control sites.

CONCLUSION

This study showed that local treatment with 25% metronidazole gel did not seem to influence the clinical healing in this group of subjects with recurrent periodontal disease.

Matrilinear phylogeography of Atlantic salmon (Salmo salar L.) in Europe and postglacial colonization of the Baltic Sea area

Sixty-four samples from 46 salmon populations totalling 2369 specimens were used for polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial ND1 region. The final analyses included 3095 specimens from 60 populations in Northern Europe. A subsample was analysed by RFLP of ND3/4/5/6. Representative RFLP haplotypes from different parts of the distribution area were sequenced and the phylogeny of European haplotypes and their relations to the North American lineage was described. The four common European haplotypes derive from the ancestral ND1-BBBA (rooting the European clade to the North American) by one-step substitutions: AAAA < AABA < BBBA > BBBB. The Swedish west-coast populations differ from the geographically close southern Baltic, indicating absence of inward and limited outward gene flow through the Danish straits during the last 8000 years. Within the Baltic Sea, only three ND1 haplotypes were detected and there was no variation for ND3/4/5/6. In the whole southern Baltic and in lakes Vänern, Ladoga and Onega the haplotype AABA dominated. Proposed postglacial colonization routes to the Baltic Sea are discussed in relation to the haplotype distribution pattern.

Growth of Arthrobotrys superba from a birch wood resource base into soil determined by radioactive tracing

The ability of a nematode-trapping fungus to establish in field soil is an important characteristic when considering its use as a biological control agent. The outgrowth of the nematode-trapping fungus Arthrobotrys superba from wood was recorded by labelling the fungus with [(14)C]3-O-methylglucose and [(32)P]orthophosphoric acid and by using the soil sprinkling method. The fungus reached a distance of 7-8 cm during 25 days in heat-treated (60 degrees C) soil, detected by either radioactive tracing or the soil sprinkling technique. The two labelled compounds were co-distributed at all sampling times (r(2)=0.946) which indicates that the glucose pool (as methylglucose) and phosphorus content were correlated throughout the mycelium. In natural, non-heat-treated soil the fungus reached a distance of 1.5 cm from one disc of birch wood after 30 days, while it reached 3.2 cm during the same period when the food base was a pile of five inoculated discs. The experiments showed, for the first time, that a nematophagous fungus, A. superba, can grow out into soil from a piece of wood and supported by nutrients translocated from the resource base to the edge of the mycelium.

Proteolysis in isolated autophagic vacuoles from the rat pancreas. Effects of chloroquine administration

Administration of the antimalaria drug chloroquine increased the number of autophagic vacuoles (AVs) in the rat pancreas. Ultrastructural analysis showed that AVs contained segregated organelles such as mitochondria, zymogen granules, peroxisomes and small portions of cytoplasm. The maximum number of AVs was observed after 3 h of chloroquine treatment. The effect lasted for 12 h and almost disappeared after 16 h. The increase in AVs caused by chloroquine made it possible to isolate them in a discontinuous Metrizamide gradient with high purity. The proteolytic capacity of the AVs isolated after different chloroquine exposure times was measured after prelabeling pancreatic proteins with an injection of L-(1-14C)leucine 16 h before sacrifice. Protein degradation in isolated AVs increased during the first 6 h of chloroquine exposure and then returned to control values 16 h after the administration. In addition, the activities of two lysosomal enzymes, acid phosphatase and cathepsin B, increased in the AV-fractions following chloroquine treatment. It is concluded that the augmented proteolysis in the isolated AVs is due to a combination of increased substrate content and increased proteolytic lysosomal enzyme activities.

Intracellular distribution and effect of the antimalarial drug mefloquine on lysosomes of rat liver

Mefloquine was administered in a single dose (1-30 mg/100 g) to rats in order to study its subcellular distribution and effects on rat liver lysosomal structure and function. Subcellular fractionation showed a significant enrichment of mefloquine in lysosomes. Even repeated administration of mefloquine did not affect the levels of cytochrome-P-450 or its reductase, indicating, although not proving, that it is not metabolized by this mono-oxygenase system. Mefloquine caused an expansion of the lysosomal apparatus, earliest seen by 24 h and lasting for some 7 days. Initially, cytoplasmic constituents were seen inside the lysosomes. Later, the lysosomes harboured myelin-like figures (multilamellar bodies) disappearing after 7-10 days. The proteolytic and lipolytic capacity was assessed in isolated lysosomes. Mefloquine caused increased protein degradation but decreased breakdown of lipids. Concomitantly, all five major phospholipids (phosphatidyl-choline, -ethanolamine, -inositol, -serine and sphingomyelin) increased in the lysosomes. It is concluded that: (1) mefloquine is a lysosomotropic drug that accumulates in lysosomes; (2) mefloquine impairs lipid degradation with ensuing accumulation of lipids in lysosomes; and (3) lysosomal trapping explains the high volume distribution of mefloquine.

Isolation and characterization of crinosomes--a subclass of secondary lysosomes

A technique is presented for isolating a subclass of lysosomes, designated crinosomes, by one-step floating-up centrifugation in a cesium-containing sucrose gradient. Rats were treated with vinblastine in order to induce the formation of crinosomes. Vinblastine blocked exocytosis of secretory granules at the cell border. Later on, lipoprotein-containing granules were seen throughout the cytoplasm. Immunolabeling with polyclonal antibodies against albumin demonstrated a severalfold greater presence of gold particles over crinosomes and Golgi cisternae than over the surrounding organelles. The induction of crinosomes by vinblastine made it possible to isolate thenm on a sucrose gradient. These organelles contained marker enzymes for the Golgi complex (galactosyl transferase) and lysosomes (cathepsins). The purity of the fraction was high. The crinosomes were proteolytically and lipolytically very active. The crinosomes were positive to cytochemical acid phosphatase staining. It is concluded that crinosomes develop from fusion between lysosomes and secretory granules and that they are active in degrading retained secretory material.

Isolation of liver lysosomes by iron loading. Ultrastructural characterization

In summary, the data demonstrate that, by the use of repeated injections of an iron sorbitol complex, it is possible to isolate a fraction highly enriched in hydrolytic enzymes (60 times over the homogenate) and in well preserved lysosomes emanating almost entirely from liver parenchymal cells. The advantage of adding fixative to the bottom of the gradient and of using en bloc staining with uranyl acetate is also demonstrated.

Use of a Digital Computer For Studying Velocity Judgements of Radar Targets

Ten subjects estimated the velocity of simulated radar targets according to the method of constant stimuli. The experimental procedure was rendered automatic through a PDP 12 digital computer, and the data were processed on line. Less than 50 man-hours were required to complete the experiment, a fact which demonstrates the suitability of a small computer when solving specific problems for system designers.