Early clinical experience with the new generation Pipeline Vantage flow diverter in the treatment of unruptured saccular aneurysms using short-term dual antiplatelet therapy

PURPOSE

The Pipeline Vantage flow diverter with Shield technology (PV) used in this study is a 4th-generation flow diverter (FD) designed to reduce thrombogenicity, promote endothelialization of the implant and increase efficiency in achieving aneurysm closure. In this study, we report the aneurysm occlusion rate, complication rate and clinical outcome with short-term dual antiplatelet therapy (DAPT) in the treatment of unruptured intracranial saccular aneurysms using the PV.

METHODS

We retrospectively identified patients treated between September 2021 and January 2023 with the PV and subsequently underwent short-term DAPT for 3 months. Patient and aneurysm characteristics, peri- and post-procedural complications, clinical outcomes and the grade of aneurysm occlusion were documented.

RESULTS

Thirty patients with 32 aneurysms were treated. Successful FD implantation was achieved in all cases (100%). No periprocedural complications were documented. The overall symptomatic complication rate was 10% and the neurologic, treatment-related symptomatic complication rate was 6.6%. Only one symptomatic complication (3.3%) was device-related. Permanent clinical deterioration occurred in 2/30 patients (6.6%), leading to deterioration of the mRS within the first 3 months after treatment. No mortality was documented. The rate of complete aneurysm occlusion after 3 months and after a mean imaging follow-up of 9.9 months was 65.6% and 75%, respectively.

CONCLUSION

Implantation of the PV for the treatment of saccular intracranial aneurysms achieves a good aneurysm occlusion rate with a low rate of complications. In addition, the use of short-term DAPT after PV implantation appears to be safe.

Subsea permafrost organic carbon stocks are large and of dominantly low reactivity

Subsea permafrost carbon pools below the Arctic shelf seas are a major unknown in the global carbon cycle. We combine a numerical model of sedimentation and permafrost evolution with simplified carbon turnover to estimate accumulation and microbial decomposition of organic matter on the pan-Arctic shelf over the past four glacial cycles. We find that Arctic shelf permafrost is a globally important long-term carbon sink storing 2822 (1518-4982) Pg OC, double the amount stored in lowland permafrost. Although currently thawing, prior microbial decomposition and organic matter aging limit decomposition rates to less than 48 Tg OC/yr (25-85) constraining emissions due to thaw and suggesting that the large permafrost shelf carbon pool is largely insensitive to thaw. We identify an urgent need to reduce uncertainty in rates of microbial decomposition of organic matter in cold and saline subaquatic environments. Large emissions of methane more likely derive from older and deeper sources than from organic matter in thawing permafrost.

Thawing Yedoma permafrost is a neglected nitrous oxide source

In contrast to the well-recognized permafrost carbon (C) feedback to climate change, the fate of permafrost nitrogen (N) after thaw is poorly understood. According to mounting evidence, part of the N liberated from permafrost may be released to the atmosphere as the strong greenhouse gas (GHG) nitrous oxide (N₂O). Here, we report post-thaw N₂O release from late Pleistocene permafrost deposits called Yedoma, which store a substantial part of permafrost C and N and are highly vulnerable to thaw. While freshly thawed, unvegetated Yedoma in disturbed areas emit little N₂O, emissions increase within few years after stabilization, drying and revegetation with grasses to high rates (548 (133–6286) μg N m⁻² day⁻¹; median with (range)), exceeding by 1–2 orders of magnitude the typical rates from permafrost-affected soils. Using targeted metagenomics of key N cycling genes, we link the increase in in situ N₂O emissions with structural changes of the microbial community responsible for N cycling. Our results highlight the importance of extra N availability from thawing Yedoma permafrost, causing a positive climate feedback from the Arctic in the form of N₂O emissions.

During permafrost thaw, nitrogen can be released as the greenhouse gas nitrous oxide, but the magnitude of this flux is unknown. Nitrous oxide emissions from ice-rich permafrost deposits are reported here, showing that emissions increase after thawing and stabilization and could represent an unappreciated positive climate feedback in the Arctic.

Century-scale time since permafrost thaw affects temperature sensitivity of net methane production in thermokarst-lake and talik sediments

Permafrost thaw subjects previously frozen soil organic carbon (SOC) to microbial degradation to the greenhouse gases carbon dioxide (CO₂) and methane (CH₄). Emission of these gases constitutes a positive feedback to climate warming. Among numerous uncertainties in estimating the strength of this permafrost carbon feedback (PCF), two are: (i) how mineralization of permafrost SOC thawed in saturated anaerobic conditions responds to changes in temperature and (ii) how microbial communities and temperature sensitivities change over time since thaw. To address these uncertainties, we utilized a thermokarst-lake sediment core as a natural chronosequence where SOC thawed and incubated in situ under saturated anaerobic conditions for up to 400 years following permafrost thaw. Initial microbial communities were characterized, and sediments were anaerobically incubated in the lab at four temperatures (0 °C, 3 °C, 10 °C, and 25 °C) bracketing those observed in the lake's talik. Net CH₄ production in freshly-thawed sediments near the downward-expanding thaw boundary at the base of the talik were most sensitive to warming at the lower incubation temperatures (0 °C to 3 °C), while the overlying sediments which had been thawed for centuries had initial low abundant methanogenic communities (< 0.02%) and did not experience statistically significant increases in net CH₄ production potentials until higher incubation temperatures (10 °C to 25 °C). We propose these observed differences in temperature sensitivities are due to differences in SOM quality and functional microbial community composition that evolve over time; however further research is necessary to better constrain the roles of these factors in determining temperature controls on anaerobic C mineralization.

ADAMTS-13 Activity Predicts Outcome in Acute Ischaemic Stroke Patients Undergoing Endovascular Treatment

Background Endovascular treatment improves outcome in patients with acute ischaemic stroke due to large vessel occlusion in general. But outcome in some of these patients is jeopardized by recanalization failure or bleeding.

Objectives This study aimed to determine a possible association of mediators of inflammation and haemostasis (C-reactive protein, interleukin-6, matrix metalloproteinase-9, monocyte chemoattractant protein-1, asymmetric dimethylarginine [ADMA], symmetric dimethylarginine, von Willebrand factor and a disintegrin and metalloproteinase with a thrombospondin type 1 motif 13 [ADAMTS-13]) with the post-intervention grade of reperfusion, complications and clinical outcome in patients who underwent endovascular treatment of ischaemic stroke.

Patients/Methods Forty-one patients with acute ischaemic stroke due to large vessel occlusion were prospectively enrolled into the study. Peripheral venous blood was taken prior to treatment and 24 hours and 3, 7 and 90 days after symptom onset. The post-intervention grade of reperfusion was determined using the modified Treatment in Cerebral Infarction (mTICI) score. Clinical outcome on day 90 was assessed using the modified Rankin's scale (mRS).

Results Low ADAMTS-13 activity (p = 0.009) and missing of statin therapy (p = 0.038) on admission were independently associated with unfavourable outcome (mRS: 5–6). Patients with unsuccessful reperfusion (mTICI: 0–1) showed higher ADMA levels on admission (p = 0.018). However, this association could not be confirmed in the binary logistic regression analysis.

Conclusion Low ADAMTS-13 activity is a predictor of unfavourable outcome in patients with ischaemic stroke undergoing endovascular therapy. Further studies are warranted to elucidate the clinical and potential therapeutic role of ADAMTS-13 in acute ischaemic stroke.

67Ga-Szintigraphie bei retroperitonealer Fibrose (RPF): Indikation, Durchführung und klinische Bedeutung

Ziel: Ziel der Arbeit ist die Überprüfung der Indikationsstellung und der klinischen Bedeutung der Galliumszintigraphie bei retroperitonealer Fibrose (RPF). Hat angesichts der ausgezeichneten Bilddarstellung durch Computertomographie (CT) und Kernspintomographie (NMR) die Nuklearmedizin hier noch einen aktuellen Wert? Methode: Als Methode dienten planare abdominale Szintigramme 48 bzw. 72 h nach i.v.-lnjek-tion von 370 MBq 67Ga-Zitrat. Ergebnis: Als Ergebnis fanden sich bei fünf seit 1992 beobachteten Patienten mit RPF eine ausgezeichnete Übereinstimmung von klinischer Symptomatik, histologischem Nachweis von zellreichem Bindegewebe und nuklearmedizinischer Dokumentation der 67Ga-Aktivität im erkrankten Bereich. Schlußfolgerung: Als Schlußfolgerung läßt sich ableiten, daß zwar der morphologische Befund der RPF durch CT und NMR gut zu erfassen ist, daß zur Beurteilung der Floridität des Prozesses die Galliumszintigraphie der Computertomographie und Kernspintomographie jedoch eindeutig überlegen ist.

Circumpolar distribution and carbon storage of thermokarst landscapes

Thermokarst is the process whereby the thawing of ice-rich permafrost ground causes land subsidence, resulting in development of distinctive landforms. Accelerated thermokarst due to climate change will damage infrastructure, but also impact hydrology, ecology and biogeochemistry. Here, we present a circumpolar assessment of the distribution of thermokarst landscapes, defined as landscapes comprised of current thermokarst landforms and areas susceptible to future thermokarst development. At 3.6 × 106 km2, thermokarst landscapes are estimated to cover ∼20% of the northern permafrost region, with approximately equal contributions from three landscape types where characteristic wetland, lake and hillslope thermokarst landforms occur. We estimate that approximately half of the below-ground organic carbon within the study region is stored in thermokarst landscapes. Our results highlight the importance of explicitly considering thermokarst when assessing impacts of climate change, including future landscape greenhouse gas emissions, and provide a means for assessing such impacts at the circumpolar scale.

A simplified, data-constrained approach to estimate the permafrost carbon-climate feedback

We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. We call the approach the Permafrost Carbon Network Incubation-Panarctic Thermal scaling approach (PInc-PanTher). The approach assumes that C stocks do not decompose at all when frozen, but once thawed follow set decomposition trajectories as a function of soil temperature. The trajectories are determined according to a three-pool decomposition model fitted to incubation data using parameters specific to soil horizon types. We calculate litterfall C inputs required to maintain steady-state C balance for the current climate, and hold those inputs constant. Soil temperatures are taken from the soil thermal modules of ecosystem model simulations forced by a common set of future climate change anomalies under two warming scenarios over the period 2010 to 2100. Under a medium warming scenario (RCP4.5), the approach projects permafrost soil C losses of 12.2-33.4 Pg C; under a high warming scenario (RCP8.5), the approach projects C losses of 27.9-112.6 Pg C. Projected C losses are roughly linearly proportional to global temperature changes across the two scenarios. These results indicate a global sensitivity of frozen soil C to climate change (γ sensitivity) of -14 to -19 Pg C °C(-1) on a 100 year time scale. For CH4 emissions, our approach assumes a fixed saturated area and that increases in CH4 emissions are related to increased heterotrophic respiration in anoxic soil, yielding CH4 emission increases of 7% and 35% for the RCP4.5 and RCP8.5 scenarios, respectively, which add an additional greenhouse gas forcing of approximately 10-18%. The simplified approach presented here neglects many important processes that may amplify or mitigate C release from permafrost soils, but serves as a data-constrained estimate on the forced, large-scale permafrost C response to warming.

A shift of thermokarst lakes from carbon sources to sinks during the Holocene epoch

Thermokarst lakes formed across vast regions of Siberia and Alaska during the last deglaciation and are thought to be a net source of atmospheric methane and carbon dioxide during the Holocene epoch. However, the same thermokarst lakes can also sequester carbon, and it remains uncertain whether carbon uptake by thermokarst lakes can offset their greenhouse gas emissions. Here we use field observations of Siberian permafrost exposures, radiocarbon dating and spatial analyses to quantify Holocene carbon stocks and fluxes in lake sediments overlying thawed Pleistocene-aged permafrost. We find that carbon accumulation in deep thermokarst-lake sediments since the last deglaciation is about 1.6 times larger than the mass of Pleistocene-aged permafrost carbon released as greenhouse gases when the lakes first formed. Although methane and carbon dioxide emissions following thaw lead to immediate radiative warming, carbon uptake in peat-rich sediments occurs over millennial timescales. We assess thermokarst-lake carbon feedbacks to climate with an atmospheric perturbation model and find that thermokarst basins switched from a net radiative warming to a net cooling climate effect about 5,000 years ago. High rates of Holocene carbon accumulation in 20 lake sediments (47 ± 10 grams of carbon per square metre per year; mean ± standard error) were driven by thermokarst erosion and deposition of terrestrial organic matter, by nutrient release from thawing permafrost that stimulated lake productivity and by slow decomposition in cold, anoxic lake bottoms. When lakes eventually drained, permafrost formation rapidly sequestered sediment carbon. Our estimate of about 160 petagrams of Holocene organic carbon in deep lake basins of Siberia and Alaska increases the circumpolar peat carbon pool estimate for permafrost regions by over 50 per cent (ref. 6). The carbon in perennially frozen drained lake sediments may become vulnerable to mineralization as permafrost disappears, potentially negating the climate stabilization provided by thermokarst lakes during the late Holocene.

Embryonic and postnatal development of the serotonergic raphe system and its target regions in 5-HT1A receptor deletion or overexpressing mouse mutants

The neurotransmitter 5-HT regulates early developmental processes in the CNS. In the present study we followed the embryonic and postnatal development of serotonergic raphe neurons and catecholaminergic target systems in the brain of 5-HT1A receptor knockout (KO) and overexpressing (OE) in comparison with wild-type (WT) mice from embryonic day (E) 12.5 to postnatal day (P) 15.5. Up to P15.5 no differences were apparent in the differentiation and distribution of serotonergic neurons in the raphe area as revealed by the equal number of serotonergic neurons in the dorsal raphe in all three genotypes. However, the establishment of serotonergic projections to the mesencephalic tegmentum and hypothalamus was delayed at E12.5 in KO and OE animals and projections to the cerebral cortex between E16.5 and E18.5 were delayed in OE mice. This delay was only transient and did not occur in other brain areas including septum, hippocampus and striatum. Moreover, OE mice caught up with WT and KO animals postnatally such that at P1.5 serotonergic innervation of the cortex was more extensive in the OE than in KO and WT mice. Tissue levels of 5-HT and of its main metabolite 5-hydroxyindoleacetic acid as well as 5-HT turnover were considerably higher in brains of OE mice and slightly elevated in KO mice in comparison with the WT, starting at E16.5 through P15.5. The initial differentiation of dopaminergic neurons and fibers in the substantia nigra at E12.5 was transiently delayed in KO and OE mice as compared with WT mice, but no abnormalities in noradrenergic development were apparent in later stages. The present data indicate that 5-HT1A receptor deficiency or overexpression is associated with increased 5-HT synthesis and turnover in the early postnatal period. However, they also show that effects of 5-HT1A KO or OE on the structural development of the serotonergic system are at best subtle and transient. They may nonetheless contribute to the establishment of increased or reduced anxiety-like behavior, respectively, in adult mice.

Differential distribution of voltage-gated potassium channels Kv 1.1-Kv1.6 in the rat retina during development

The discharge behavior of neurons depends on a variable expression and sorting pattern of voltage-dependent potassium (Kv) channels that changes during development. The rodent retina represents a neuronal network whose main functions develop after birth. To obtain information about neuronal maturation we analyzed the expression of subunits of the Kv1 subfamily in the rat retina during postnatal development using immunocytochemistry and immunoelectron microscopy. At postnatal day 5 (P5) all the alpha-subunits of Kv1.1-Kv1.6 channels were found to be expressed in the ganglion cell layer (GCL), most of them already at P1 or P3. Their expression upregulates postnatally and the pattern and distribution change in an isoform-specific manner. Additionally Kv1 channels are found in the outer and inner plexiform layer (OPL, IPL) and in the inner nuclear layer (INL) at different postnatal stages. In adult retina the Kv 1.3 channel localizes to the inner and outer segments of cones. In contrast, Kv1.4 is highly expressed in the outer retina at P8. In adult retina Kv1.4 occurs in rod inner segments (RIS) near the connecting cilium where it colocalizes with synapse associated protein SAP 97. By using confocal laser scanning microscopy we showed a differential localization of Kv1.1-1.6 to cholinergic amacrine and rod bipolar cells of the INL of the adult retina.

Effects of brain-derived neurotrophic factor (BDNF) on glial cells and serotonergic neurones during development

Serotonergic neurones are among the first to develop in the central nervous system. Their survival and maturation is promoted by a variety of factors, including serotonin itself, brain-derived neurotrophic factor (BDNF) and S100beta, an astrocyte-specific Ca(2+) binding protein. Here, we used BDNF-deficient mice and cell cultures of embryonic raphe neurones to determine whether or not BDNF effects on developing serotonergic raphe neurones are influenced by its action on glial cells. In BDNF-/- mice, the number of serotonin-immunoreactive neuronal somata, the amount of the serotonin transporter, the serotonin content in the striatum and the hippocampus, and the content of 5-hydroxyindoleacetic acid in all brain regions analysed were increased. By contrast, reduced immunoreactivity was found for myelin basic protein (MBP) in all brain areas including the raphe and its target region, the hippocampus. Exogenously applied BDNF increased the number of MBP-immunopositive cells in the respective culture systems. The raphe area displayed selectively reduced immunoreactivity for S100beta. Accordingly, S100beta was increased in primary cultures of pure astrocytes by exogenous BDNF. In glia-free neuronal cultures prepared from the embryonic mouse raphe, addition of BDNF supported the survival of serotonergic neurones and increased the number of axon collaterals and primary dendrites. The latter effect was inhibited by the simultaneous addition of S100beta. These results suggest that the presence of BDNF is not a requirement for the survival and maturation of serotonergic neurones in vivo. BDNF is, however, required for the local expression of S100beta and production of MBP. Therefore BDNF might indirectly influence the development of the serotonergic system by stimulating the expression of S100beta in astrocytes and the production MBP in oligodendrocytes.

Differential effects of Rho GTPases on axonal and dendritic development in hippocampal neurones

Formation of neurites and their differentiation into axons and dendrites requires precisely controlled changes in the cytoskeleton. While small GTPases of the Rho family appear to be involved in this regulation, it is still unclear how Rho function affects axonal and dendritic growth during development. Using hippocampal neurones at defined states of differentiation, we have dissected the function of RhoA in axonal and dendritic growth. Expression of a dominant negative RhoA variant inhibited axonal growth, whereas dendritic growth was promoted. The opposite phenotype was observed when a constitutively active RhoA variant was expressed. Inactivation of Rho by C3-catalysed ADP-ribosylation using C3 isoforms (Clostridium limosum, C3(lim) or Staphylococcus aureus, C3(stau2)), diminished axonal branching. By contrast, extracellularly applied nanomolar concentrations of C3 from C. botulinum (C3(bot)) or enzymatically dead C3(bot) significantly increased axon growth and axon branching. Taken together, axonal development requires activation of RhoA, whereas dendritic development benefits from its inactivation. However, extracellular application of enzymatically active or dead C3(bot) exclusively promotes axonal growth and branching suggesting a novel neurotrophic function of C3 that is independent from its enzymatic activity.

Deltamethrin differentially affects neuronal subtypes in hippocampal primary culture

The effects of deltamethrin on neuronal development and survival were studied using primary mouse hippocampal neurons in culture. Repeated applications of deltamethrin (between 2 nM and 2000 nM) decreased the number of neurons by 16-40%, respectively. Neuronal death was accompanied by an overall decrease of synaptic proteins. Deltamethrin treatment increased the K(+)-stimulated release of amino acid transmitters, GABA and glutamate. The release of the latter might also contribute to neuronal damage. A considerable number of neurons survived treatment with high concentrations of deltamethrin (200-2000 nM) and still displayed characteristics of mature neurons such as synaptic contacts or the expression of members of the Kv1 channel family. When analyzing subtypes of neurons calbindin- as well as somatostatin-positive neurons decreased by 50% after repeated treatment with 2 nM deltamethrin. Under the same conditions neuropeptide Y-positive neurons were up-regulated by 250%.Taken together these data show that deltamethrin at concentrations relevant in human toxicology differentially affects survival of neuronal subtypes by exerting either deleterious or supportive effects. We conclude that deltamethrin disturbs fine-tuning of neuronal efficiency in neuronal networks and might also interfere with the correct wiring during development.

Filiform polyposis of the colon in chronic inflammatory bowel disease (so-called giant inflammatory polyps)

On the basis of 3 of our own cases, we describe unusually intense forms of filiform polyposis and local giant polyposis as a consequence of chronic inflammatory bowel disease. The patients are: A 52-year-old woman who for 7 years has been known to have Crohn's disease (CD); a 55-year-old man who for 14 years has been known to have chronic inflammatory bowel disease, which was first thought to have been ulcerative colitis, but, as a result of the findings on the subtotal colectomy specimen, had to be classified as Crohn's disease or colitis indeterminate; and a 53-year-old woman known to have had ulcerative colitis for 37 years. From the literature on the subject, we drew up a chronological list of a total of 43 cases with similar or completely identical findings. The clinical significance of the findings in their particularly massive intensity results from their necessary differentiation--in the context of differential diagnosis--from a malignant tumor, in particular from a carcinoma in association with chronic inflammatory bowel disease, or from a villous adenoma. The indication of a need to operate results from the impossibility of being able definitely to rule out a malignant degeneration by means of clinical methods. Also, experience shows that with massive findings of the kind described a spontaneous disappearance cannot be expected. Finally, too, the clinical symptoms and the patients subjective complaints necessitate balanced surgical treatment, taking into consideration the site and the extent of the lesion.

Expression of Kv1 potassium channels in mouse hippocampal primary cultures: development and activity-dependent regulation

Excitability and discharge behavior of neurons depends on the highly variable expression pattern of voltage-dependent potassium (Kv) channels throughout the nervous system. To learn more about distribution, development, and activity-dependent regulation of Kv channel subunit expression in the rodent hippocampus, we studied the protein expression of members of the Kv1 subfamily in mouse hippocampus in situ and in primary cultures. In adult hippocampus, Kv1 (1-6) channel alpha-subunits were present, whereas at postnatal day 2, none of these proteins could be detected in CA1-CA3 and dentate gyrus. Kv1.1 was the first channel to be observed at postnatal day 6. The delayed postnatal expression and most of the subcellular distribution observed in hippocampal sections were mimicked by cultured hippocampal neurons in which Kv channels appeared only after 10 days in vitro. This developmental upregulation was paralleled by a dramatic increase in total K(+) current, as well as an elevated GABA release in the presence of 4-aminopyridine. Thus, the developmental profile, subcellular localization, and functionality of Kv1 channels in primary culture of hippocampus closely resembles the in situ situation. Impairing secretion by clostridial neurotoxins or blocking activity by tetrodotoxin inhibited the expression of Kv1.1, Kv1.2, and Kv1.4, whereas the other Kv1 channels still appeared. This activity-dependent depression was only observed before the initial appearance of the respective channels and lost after they had been expressed. Our data show that hippocampal neurons in culture are a convenient model to study the developmental expression and regulation of Kv1 channels. The ontogenetic regulation and the activity-dependent expression of Kv1.1, Kv1.2, and Kv1.4 indicate that neuronal activity plays a crucial role for the development of the mature Kv channel pattern in hippocampal neurons.

[Clinical behavior of serous and mucinous borderline tumors of the ovary with diploid DNA stem line. Follow-up studies after organ preserving and non-organ preserving therapy]

Even today, the situation is still unclear with regard to the radicality of the operation and any adjuvant therapy required in treatment of borderline tumors of the ovary. In the last two decades, treatment of these tumors in the Department of Gynecology and Obstetrics at our hospital has depended on the stage of the disease and the age of the patient. It ranged from laparoscopic cyst extirpation to hysterectomy with bilateral adnectomy and omental resection and regional lymphnodectomy. From the end of 1985 to the end of 1992, 35 patients with borderline tumors of the ovaries were operated on. Histologically, 14 borderline tumors were mucinous, 21 were serous. A follow-up investigation was carried out five to 11 years after primary operation. In this period, no patient died of borderline tumor. Twenty-eight patients who were followed up were clinically free of recurrence, five patients are alive, but could not be followed up. Two patients have died of other diseases after five years. Only one patient received adjuvant chemotherapy. She could not be followed up. In the meantime, peritoneal implants were demonstrated at second-look laparoscopies in four out of 18 patients. Later, these could no longer be demonstrated (one patient) or did not affect the survival time (three patients) and thus ultimately was not pathologically relevant. Primarily, two of these four patient had stage Ia-Ic. The paraffin blocks of the preparations are still available from 26 patients, and additional investigations could be carried out. Nineteen percent of the borderline tumors showed micropapillary structures of an MPCS (= micropapillary serous carcinoma), which evidently did not have a negative effect on the prognosis. All borderline tumors showed diploid distributions in DNA cytometry. It is not possible to make a definitive treatment recommendation on the basis of this investigation because the number of patients followed up was too small.

SNAP-25 requirement for dendritic growth of hippocampal neurons

Structure and dimension of the dendritic arbor are important determinants of information processing by the nerve cell, but mechanisms and molecules involved in dendritic growth are essentially unknown. We investigated early mechanisms of dendritic growth using mouse fetal hippocampal neurons in primary culture, which form processes during the first week in vitro. We detected a key component of regulated exocytosis, SNAP-25 (synaptosomal associated protein of 25 kDa), in axons and axonal terminals as well as in dendrites identified by the occurrence of the dendritic markers transferrin receptor and MAP2. Selective inactivation of SNAP-25 by botulinum neurotoxin A (BoNTA) resulted in inhibition of axonal growth and of vesicle recycling in axonal terminals. In addition, dendritic growth of hippocampal pyramidal and granule neurons was significantly inhibited by BoNTA. In contrast, cleavage of synaptobrevin by tetanus toxin had an effect on neither axonal nor dendritic growth. Our observations indicate that SNAP-25, but not synaptobrevin, is involved in constitutive axonal growth and dendrite formation by hippocampal neurons.

Co-infection by Cryptococcus neoformans and Mycobacterium avium intracellulare in AIDS. Clinical and epidemiological aspects

In the observation of various opportunistic pathogens in HIV-positive persons, co-infection by Cryptococcus neoformans together with Mycobacterium avium intracellulare was found if there was a CD4 lymphocyte count as low as 3-20/microliters. In 1540 HIV-positive patients under treatment at a Berlin hospital (Auguste-Viktoria-Krankenhaus) during 1985-1994, all AIDS-relevant diseases were examined in a multivariate analysis as variables of influence on the manifestation of a systemic Mycobacterium avium complex (MAC) infection. The analysis involved data on 36 cases of cryptococcosis and 202 cases with a typical clinical course in whom MAC had been detected at sterile body sites. As significant and independent factors of influence, the following were identified: C. neoformans infection, wasting syndrome, lower age, low CD4 lymphocyte count and preceding Pneumocystis carinii pneumonia (PcP) prophylaxis. Cryptococcosis ranged first with an ods ratio of 2.75. The concomitant manifestation of cryptococcosis and systemic MAC infection in six patients is shown. Because both opportunists, C. neoformans and avian mycobacteria, may have their common habitat in droppings of defined species of pet birds, a common source of infection deserves further clinical and epidemiological attention.

[Nevus cell aggregates in axillary lymph nodes in simultaneous mucinous breast carcinoma]

Nevus cell aggregates in lymph nodes are uncommon. This benign phenomenon may be difficult to differentiate from metastatic neoplasia. We report the case of a 56-year-old patient who underwent breast biopsy, followed by radical mastectomy including lymphadenectomy. Histological examination revealed solid cell aggregates as foreign tissue in the capsule of 1 of 11 identified lymph nodes devoid of any keratin immunoreaction. Strong immunohistological staining for the S-100 protein confirmed the diagnosis of nevus cell aggregates.

Prenatal hippocampal granule cells in primary cell culture form mossy fiber boutons at pyramidal cell dendrites

Mossy fiber boutons are the sites of synaptic signalling between hippocampal granule and pyramidal neurons. We studied the formation and localization of these terminals during development of prenatal hippocampal neurons in primary culture. Using the synaptic vesicle membrane proteins synaptophysin and synaptoporin as markers we observed that both proteins were mainly localized in perikarya and processes of fetal hippocampal neurons during the first days in vitro (DIV). Following DIV 6 synaptophysin was present in small terminals. After DIV 20 in addition large terminals immunoreactive for synaptophysin and synaptoporin were found, which were identified by electron microscopy as mossy fiber boutons impinging on pyramidal neuron dendrites. Synaptic vesicles and endosomes in the mossy fiber boutons were labeled when incubated with exogenous horseradish peroxidase, indicating that they were competent for exo-endocytosis. Taken together, our data show that hippocampal granule neurons grown in dissociated primary cultures form mossy fiber boutons containing synaptophysin and synaptoporin at pyramidal cell dendrites. Since the composition and the characteristic morphology of mossy fiber boutons formed in vitro is the same as observed in vivo we conclude that their development follows an intrinsic program.

[Disseminated cryptococcosis with extensive cutaneous involvement in AIDS]

BACKGROUND

Diagnosis of an ulceratively decaying indolent papule in the skin of an AIDS patient.

CASE REPORT

In a 36-year-old HIV-positive man with a CD4 lymphocyte count of 60/microliters, a diagnosis of disseminated cryptococcosis was established based on a biopsy of an ulceratively decaying indolent papule in the skin of the left side gluteal region. In additional papulopustular skin lesions of neck, upper arm, upper thigh, and rima ani, Cryptococcus neoformans var. neoformans was detected by specific culture. The Cryptococcus neoformans antigen titre in serum was 1:160. The extensive cryptococcal skin involvement was accompanied by symptoms of meningeal cryptococcosis like hearing at an abnormal sound volume, a sensation of high pressure in the head and a change of behaviour, but absence of cephalgia and stiff neck. Attention is drawn to the importance of biopsy for the differential diagnosis of the skin lesions and to the significance of a specific cultural detection of Cryptococcus neoformans in view of the therapy and epidemiology of this mycosis. Under a combination therapy, consisting of amphotericin B, flucytosine and fluconazole, a healing of the skin lesions and disappearance of the neurological symptoms followed by negative cultural and serological tests were seen. Specific comments on the epidemiology of cryptococcosis in AIDS are made.

CONCLUSION

In case of doubt, papulopustular skin lesions of HIV-positive patients should be biopsied. Cryptococcosis should also be considered.

Fulminant primary manifestation of Crohn's colitis "Hot Crohn's disease"

Following the very short course of a disease with watery diarrhea, fever, nausea, meteorism and a severe feeling of general illness, a 22-year-old patient was diagnosed as having a toxic megacolon, and a subtotal colectomy was carried out. The postoperative progression was uncomplicated and the patient recovered quickly. The examination of the operation specimen revealed a serious ulcerous colitis with relative omission of the rectum and the distal sigmoid colon. After critical evaluation of the histological findings, it was judged to be a fulminant Crohn's colitis and, for the purposes of differential diagnosis, differentiated from ulcerative colitis and colitis indeterminate. The formal pathogenesis of the inflammatory-ulcerous processes is discussed, in particular with regard to the activation of the macrophages and the very short anamnesis in a clinically established primary manifestation of the disease.

Pathological and epidemiological aspects of skin lesions in histoplasmosis. Observations in an AIDS patient and badgers outside endemic areas of histoplasmosis

As a consequence of HIV infection, histoplasmosis is increasingly occurring as an opportunistic infection with a systemic course outside histoplasmosis-endemic areas, e.g. in Europe. Accordingly, questions concerning the epidemiology of this mycosis arise. Two incidents involving histoplasmosis in man and badgers with prevailing involvement of the skin encouraged us to review the pathogenesis and epidemiology of this mycosis in Germany, where so far Histoplasma capsulatum has not been endemic. With a view to prevention, attention is drawn to the avoidance of microfoci of H. capsulatum in the newly introduced concept of biowaste and its composting plants in countries with modern waste management.

Malignant gastrointestinal lymphomas in patients with AIDS

HIV-associated malignant lymphomas are a common complication in late HIV infection, and there is a high percentage of gastrointestinal tract involvement. Non-Hodgkin's lymphoma was found in 108 of 2,750 HIV-positive patients (3.9%) in our institution, whereas gastrointestinal manifestation was diagnosed in 48 of 108 patients (44.4%). 44 of these cases were found during endoscopy of the upper and lower gastrointestinal tract (or by laparotomy or laparoscopy in 4 cases). Endoscopy is a reliable procedure for the diagnosis of lymphoma. Unusual manifestations such as oral, esophageal or perianal lesions and multifocal disease were common findings. Life-threatening complications such as gastrointestinal bleeding, perforation, and obstruction occurred in 37.5%. High-grade B-cell lymphomas were found in all cases including mainly lymphoblastic, immunoblastic, centroblastic and Burkitt subtypes. 52% of the patients had disseminated lymphoma with Ann Arbor stage III or IV. Standard chemotherapy with cyclophosphamide, adriamycin, vincristine and prednisone was started in 25 patients and resulted in a mean survival time of 4.8 months. The prognosis of AIDS patients presenting with malignant gastrointestinal lymphoma depends mainly on the presence or absence of previous AIDS-defining diseases, not CD4 cells, lymphoma-associated gastrointestinal complications or the histopathologic lymphoma type at the time of diagnosis.

Cryptococcosis in HIV infection of man: an epidemiological and immunological indicator?

Cryptococcosis is an epidemiological and immunological indicator due to the absence of Cryptococcus neoformans as a saprophyte in immunocompetent humans and the advantage of specific C. neoformans culture. On this basis, a report is presented on the CD4 lymphocyte count of 36 AIDS patients suffering from cryptococcosis and other concomitant or missing opportunistic AIDS-defining infections. In 26 out of 36 patients, i.e. 72%, a CD4 lymphocyte count of < or = 50/microL (mean value 39.5%) was found. Cryptococcosis as the sole opportunistic infection was diagnosed in 5 cases (13.9%). In 31 cases, various combinations of AIDS-associated diseases were found: Pneumocystis carinii pneumonia (PCP) (n = 19), cytomegalovirus infection (CMV) (n = 10), Kaposi's sarcoma (n = 6), Mycobacterium avium intracellulare infection (MAI) (n = 5), pneumonia (n = 2), toxoplasmosis (n = 2), Candida esophagitis (n = 1), tuberculosis (n = 1), lambliasis (n = 1), salmonellosis (n = 1) and wasting syndrome (n = 5). The conspicuous simultaneous occurrence or succession of pneumocystosis and cryptococcosis and the contrasting absence of aspergillosis and mucormycosis (zygomycosis) are commented. Based on the present observations in HIV-infected persons in Berlin, a CD4 lymphocyte count of < 150/microL may be used as a parameter indicating a predisposition for cryptococcosis as an airborne AIDS-defining infection. Attention is drawn to bird droppings as the sole habitat of C. neoformans and accidental niche of various other microorganisms.

Brown-red pigment formation by the mycelial phase of a clinical isolate of Histoplasma capsulatum on Staib agar. A preliminary report

In an HIV-positive patient, the suspected diagnosis of histoplasmosis capsulatum (being the first opportunistic infection indicating AIDS) on the basis of histopathological findings in biopsy material could be proved by culture on Staib agar (syn. Guizotia abyssinica creatinine agar, bird seed agar, etc.). On Staib agar, after 4 weeks at 26 degrees C, there was a cockade-like colony growth, consisting of a white centre, followed by a brown-red pigmented zone surrounded by a border of submerged mycelial growth of tan to brownish colour. Morphologically, there was a moderate formation of tuberculate macroconidia and a heavy formation of microconidia. On neutral Sabouraud's dextrose agar, there was a colony formation without pigment (albino type) free of tuberculate macroconidia and microconidia. Proposals for further investigation of these preliminary observations are made.

[67Ga scintigraphy in retroperitoneal fibrosis (RPF): indications, application and clinical relevance--report of five patients]

AIM

The aim of the study was to evaluate the indication for 67Ga-citrate imaging and its clinical impact on patients with retroperitoneal fibrosis (RPF).

METHOD

The scanning with ventral and dorsal projections was done 48 an 72 h after i.v.-injection of 370 Mbq 67Ga-citrate.

RESULTS

In the 5 patients with idiopathic RPF included in the study, there was a remarkably high correlation between the clinical symptoms, the surgical and histologic findings, the activity of the disease and the results of 67Ga-scintigraphy.

CONCLUSION

While CT and--maybe even better--MRI might perfectly show the extension, shape and contour of the fibrotic tissue, Gallium-67 scan appears to be superior in assessing the intensity and activity of the disease process.

CD4 lymphocyte count in HIV-positive persons exposed to Cryptococcus neoformans

A report is presented on four HIV-positive homosexual men examined after several months of exposure during cleaning of a flat from masses of pigeon droppings heavily colonized by Cryptococcus neoformans. Only one out of the four persons, with a CD4 lymphocyte count of 50/microL, fell sick from systemic cryptococcosis, but not the others, with CD4 lymphocyte counts of 180, 250, and 630/microL, respectively; they remained clinically and mycologically inconspicuous and free from C. neoformans. Open questions in view of the epidemiology of opportunistic pathogens in AIDS are discussed with regard to the CD4 cell count as a parameter indicating a predisposition for cryptococcosis as an airborne AIDS-defining opportunistic infection. This has been confirmed by specific cultural diagnosis of the agent in both the environment and the patient. Already in 1987/88, the probable source of infection had been the subject of epidemiological studies on C. neoformans in Berlin.

Simultaneous Position-Resolved Determination of Phase and Stress Distributions by means of an X-ray Diffractometer with a Two-Dimensional Position-Sensitive Detector

With an X-ray area detector and a suitable Soller-plate collimator in the scattered radiation field, it is possible to realize a versatile X-ray diffractometer. The local diffraction information of a sample can be registered simultaneously and visualized with a spatial resolution better than 0.5 mm, maintaining reasonable measuring times of a few minutes. Results of measurements applied to local phase analysis (distribution of retained austenite and carbon on a cross section of case-hardened steel), to the determination of lateral stress distributions (laser-hardened track on C45 steel) and to the analysis of crystallite orientation (coarse-grained YBa2Cu3O δ ) are presented.

Disseminated toxoplasmosis in AIDS patients--report of 16 cases

Between June 1986 and October 1992, disseminated toxoplasmosis was diagnosed in 16 AIDS patients. 13 cases were diagnosed at autopsy where multiple organ involvement was documented in all 13. Three patients were diagnosed intra vitam. All 3 survived with appropriate treatment. Clinical features indicative of disseminated toxoplasmosis were: fever of unknown origin between 39 degrees and 40 degrees C in 16 cases, clinical signs suggestive of sepsis or septic shock in 15, with progression to multiorgan failure in 10, disseminated intravascular coagulopathy in 6, confusion, disorientation or apathy in 13 and lack of a systemic pneumocystis carinii prophylaxis in all 16. Typical laboratory markers were: CD4 cell counts below 100 x 10(6)/l in 16 cases, elevation of serum lactic dehydrogenase in 16 and creatine phosphokinase (in 4/6), normal or only slightly elevated C-reactive protein (in 9/11), positive Toxoplasma gondii IgG antibodies in 15/16 and negative IgM antibodies in all 16. Lesions indicative of cerebral toxoplasmosis were visualized on cranial computerized tomography in only 3/10 evaluated patients. In patients with advanced HIV infection presenting with a systemic illness, including the clinical and laboratory features described above, systemic Toxoplasma gondii infection must be included in the differential diagnosis. In these patients, specific and if warranted, invasive diagnostic procedures followed by early vigorous therapeutic intervention should be considered.

Severe toxoplasmic ventriculomeningoencephalomyelitis in two AIDS patients following treatment of cerebral toxoplasmic granuloma

Two patients with acquired immunodeficiency syndrome (AIDS) who were successfully treated for cerebral toxoplasmosis presented a few weeks later with neurologic abnormalities. Brain CT scan showed ventricular dilatation, ependymitis, and meningoencephalitis. Both patients died despite extensive treatment. Neuropathological examination showed enlargement of the cerebral ventricles, severe ventriculoencephalitis with large ependymal and subependymal necrosis, and numerous pseudomembranes within the ventricle lumen. Microscopic examination revealed severe necrotizing ventriculoencephalitis, meningoencephalitis and myelitis. Immunohistochemical studies revealed the presence of miriads of tachyzoites within and around the necrotic areas. Such form of toxoplasmosis as a diffuse meningo-encephalo-ventriculo-myelitis appear unique to AIDS and, to our knowledge, have not been previously documented.

[Histoplasmosis of the skin as an initial opportunistic infection in AIDS]

A 55-year-old homosexual Indonesian (last stay in Indonesia 2 years previously), known to be HIV positive since 1986, developed desquamating, in part ulcerating, skin eruption over the face and shoulder region. On admission his temperature was 38.2 degrees C, erythrocyte sedimentation rate 72/95 mm, white cell count 3.100/microliters, and the CD4 cell count 30/microliters. Examination of lung, oesophagus, stomach, duodenum and colon for possible opportunistic infections was negative. Fundoscopy revealed an infiltrate in the right eye with destruction of the vitreous. Skin biopsy suggested histoplasmosis, confirmed by culturing H. capsulatum varietas capsulatum. It is likely that this was the reactivation of a latent, previously symptom-free infection, in this case the first opportunistic infection in the presence of AIDS. For 30 days he received infusions of amphotericin B (initially 0.1 mg/kg daily, after the 5th day 0.5 mg/kg), resulting in rapid healing of the skin lesions. Subsequently he has received (for 6 months so far) itraconazole, 400 mg daily, without further complications.

Anergic disseminated toxoplasmosis in a patient with the acquired immunodeficiency syndrome

Cerebral toxoplasmosis is the most common cause of focal brain disease in patients with the acquired immunodeficiency syndrome. A 24-year-old human immunodeficiency virus-infected woman with two previous episodes of Pneumocystis carinii pneumonia presented with diarrhea and fever. Despite antibiotic treatment, septic shock developed, and she died 3 weeks after the symptoms began. Histologic and histochemical studies revealed an anergic toxoplasmosis with dissemination in all examined organs. There were multiple foci of toxoplasmic cysts and free tachyzoites, sometimes with minute areas of necrosis, but no inflammatory reaction at all. Since effective treatment of toxoplasmosis is available, the occurrence of this rare form of toxoplasmosis should be kept in mind.

[Carcinosarcoma of the urinary bladder]

A female patient is presented who had a large carcinosarcoma of the urinary bladder that became clinically manifest only 2 months before treatment. The initial treatment by transurethral resection was followed by radical cystectomy; 7 months postoperatively the patient died of local tumour recurrence with widespread metastases. Carcinosarcoma of the urinary bladder is a rare tumour with a poor prognosis. The majority of such tumours are not diagnosed until tumour growth is already far advanced. Owing to the small number of cases there is no clinically proven form of management. In contrast with superficial transitional cell carcinoma of the bladder, superficial carcinosarcoma of the bladder has always invaded the lamina propria, since in addition to the carcinomatous degeneration of the mucosa, sarcomatous degeneration of the underlying submucosal stroma is also present. Any local surgical treatment, such as TUR or partial cystectomy, involves the risk of incomplete tumor removal, because the sarcomatous elements typically invade the submucosa while the overlying mucosa remains intact. Therefore, radical cystectomy appears to be the treatment of choice for both superficial and invasive carcinosarcoma of the urinary bladder.

Hyaline globules reacting positively with zidovudine antibody in brain and spinal cord of AIDS patients

Histology of the central nervous system in nine AIDS showed extracellular hyaline globules in the white matter of the brain and the spinal cord. In immunohistochemical studies with a battery of antibodies, the only positive reaction of these globules was with an antibody to zidovudine. High-performance liquid chromatography showed the presence of a zidovudine isomer in eluates of brain tissue from these patients.

[Intestinal spirochetosis in HIV infection: prevalence, isolation and morphology of spirochetes]

The prevalence of intestinal spirochaetosis was investigated in 39 HIV-positive homosexual males (mean age 39 [24-65] years) in different stages of HIV infection (3 with the lymphadenopathy syndrome, 8 with AIDS-related complex and 28 with AIDS). Biopsies for cultural and histological demonstration of spirochaetes were obtained during routine ileoscopies. At the time of examination 35 of the 39 patients had intestinal symptoms. 27 patients had had no previous antimicrobial treatment. In 12 of the 27 previously untreated patients with intestinal symptoms spirochaetes were demonstrated, to different extent, from the terminal ileum to the rectum, while the treated group of eight and the control group of four were negative. There were no significant inflammatory changes histologically. Treatment with metronidazole in most cases improved symptoms. In their ultrastructure the microorganisms showed several complete convolutions, cone-shaped cell endings, cell length of 4-18 microns, cell diameter of 0.21-0.35 microns and five subterminal flagella. Morphological considerations favour the inclusion of these microorganisms in the genus Treponema rather than Brachyspira.

Vacuolar myelopathy in AIDS. A morphological analysis

Between 1986 and 1988 we studied the spinal cord of 40 patients dying of AIDS. Transverse and longitudinal sections from a minimum of four levels of the spinal cord were examined by means of conventional histology, immunohistochemistry and electron microscopy. Out of 22 cases there were 6 showing a mild, 11 a moderate and 5 a severe myelopathy. Among these cases with severe myelopathy, vacuolar degeneration of the posterior, lateral, and anterior columns of the white matter, which are typical findings of vacuolar myelopathy (VM), were present. Cervical and thoracic cords were affected in all cases, the lumbal cord, however, in only two. Fusiform vacuoles, 30 to 180 microns in diameter and 200 to 500 microns in length, could be seen rising between the axolemma and the myelin sheath. Most of them were still containing an axon cylinder. Foamy phagocytic cells, phagocytosing axons of apparently preserved structure were found within the vacuoles. These foamy macrophages contained rests of axons in their cytoplasm. However, only one case with severe tissue disruption exhibited myelin debris as well. Our morphological findings suggest that in VM of AIDS a process of phagocytosis directed against the axon cylinders occurs simultaneously with vacuolar degeneration of the white matter of the spinal cord. The results suggest furthermore that VM, especially its moderate form, appears to be a more frequent condition than previously assumed.