Development of a novel low-background noise blood loop model for testing blood-contacting biomaterials and medical devices in fresh human blood

A novel low volume blood loop model (Ension Triad System [ETS]) incorporating pulsatile flow and a proprietary low-activation blood-contacting surface (Ension bioactive surface [EBS]) enabling high signal-to-noise performance is described. The ETS system incorporates a test chamber that allows direct comparison of material samples or finished medical devices such as catheters with varying compositions and/or surface treatments. ETS performance is presented from two independent organizations (Medtronic and MLM Labs) and includes results for hemolysis (pfHgb), platelet count, platelet activation (βTG), coagulation (TAT), inflammation (PMN Elastase, PMN CD112b, and monocyte CD112b) and immune response (SC5b-9) were made on: (1) the EBS-treated system itself without a test material (No Material, NM); (2) the EBS-treated system with an idealized untreated catheter (UC); and (3) the EBS-treated system with the prototype catheter treated with the EBS surface treatment (CC). The untreated catheter (UC) was associated with significant elevation of all activation marker levels (pfHgb excluded). The EBS-treated catheter, in direct comparison to the UC and NM catheters, appeared invisible with respect to the activation markers (all markers statistically different than the UC and equivalent to the NM control). Based on these data, we conclude that using a relatively small surface area test sample and a small volume of fresh human blood, the high signal-to-noise performance of the ETS system demonstrates comprehensive and statistically significant material differences in the major ISO 10993-4 categories of blood interaction. These data underscore the important benefit of minimal confounding of test/device responses with non-test-material/model-related responses. ETS offers a practical alternative to the common one-test-category-at-a-time approach when assessing blood/medical device interactions.

Bentracimab demonstrates reversal of antiplatelet effects of ticagrelor: impact of hematocrit and generic versions of ticagrelor in vitro

 

Recent clinical studies demonstrated bentracimab provides immediate and sustained reversal of ticagrelor's antiplatelet effects in patients undergoing surgical procedures or with bleeding. Ticagrelor reversal was assessed by VerifyNow PRUTest (VN) and other platelet function testing assays in Phase I-III studies. As decreases in hematocrit (hct) may impact the VN result, it remains to be demonstrated whether this assay can detect platelet function restoration by bentracimab in bleeding patients with low hct. Additionally, bentracimab utility against generic ticagrelors is unknown. The purpose of this study was to determine the impact of decreased hct and generic forms of ticagrelor on platelet function and subsequent reversal by bentracimab, as measured by light transmission aggregometry (LTA) and VN. The hct level in blood samples collected from healthy volunteers (n=10) was sequentially lowered to 32, 30, 25, 22.5, 20 or 15% by addition of autologous platelet-rich plasma to whole blood with matching platelet counts. Prepared samples were treated with nothing, vehicle, or ticagrelor (3.0 μg/mL) followed by treatment with bentracimab (1.2 mg/mL). In a separate study, blood collected from healthy volunteers (n=10) was treated with nothing, vehicle, ticagrelor or generic ticagrelors (3.0 and 5.6 μg/mL; mean and peak plasma levels in the Phase 1 trial) prior to addition of bentracimab (0, 0.6, 1.2, 1.8 and 2.4 mg/mL; below the reported minimum to peak plasma level) to demonstrate a dose response. Reversal was assessed by either ADP-mediated LTA or VN or both assays. Results show a decrease in hct to <30% significantly increased the PRU in untreated samples (p<0.05). Ticagrelor treatment significantly decreased the PRU in all hct groups (p<0.0001). When normalized to each donor's baseline PRU values, bentracimab reversed the ticagrelor effects within 10-min, restoring the PRU value to 54–73% for all hct groups. PRU values were further restored to 85–93% of baseline PRU after 1-hr treatment. The PRU inhibition for both 10-min and 1-hr treatments were not significantly different across the hct groups, except for the 10-min treatment in the 15% hct group vs. unadjusted hct group (p<0.05), suggesting equivalent reversal by bentracimab across the hct range. In the second study, treatment with generic ticagrelor demonstrated significant platelet inhibition and was comparable to standard ticagrelor. Bentracimab (>0.6 mg/mL) immediately restored platelet function after ticagrelor treatment to 80–100% of baseline using the VN test. LTA data demonstrated similar results to VN, but as expected, reversal was less robust with 5.6 μg/mL ticagrelor + 0.6 mg/mL bentracimab combination (mean 55% of baseline values). Collectively, these data suggest the VN test can effectively measure the antiplatelet effects of ticagrelor and subsequent reversal, even at low hct, and bentracimab is also capable of reversing the antiplatelet effects of generic forms of ticagrelor.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): PhaseBio Pharmaceuticals, Inc

Oxytocin Release Increases With Age and Is Associated With Life Satisfaction and Prosocial Behaviors

Helping behaviors and life satisfaction generally increase after middle-age. Identifying the neural substrates of prosocial behaviors in older adults may offer additional insights into these changes over the lifespan. The present study examines the endogenous release of the neuromodulator oxytocin (OT) in participants aged 18-99 and its relationship to prosocial behaviors. OT has been shown to influence trust, altruism, charity, and generosity, yet the effect of age on OT release has not been well-established. Blood samples before and after a video stimulus were obtained from 103 participants in order to examine the impact of OT on prosocial behaviors. We found that OT release following a social prime increased with age (r = 0.49, p = 0.001) and that OT moderated the relationship between age and donations to charity. We tested for robustness by examining three additional prosocial behaviors, money and goods donated to charity during the past year and social-sector volunteering. OT moderated the impact of age on all three prosocial behaviors (ps < 0.05). The analysis also showed that participants' change in OT was positively associated with satisfaction with life (p = 0.04), empathic concern (p = 0.015), dispositional gratitude (p = 0.019), and religious commitment (p = 0.001). Our findings indicate that the neural chemistry that helps sustain social relationships and live a fulfilled life appear to strengthen with age.

Pancreatic cancer prognosis is predicted by an ATAC-array technology for assessing chromatin accessibility

Unlike other malignancies, therapeutic options in pancreatic ductal adenocarcinoma (PDAC) are largely limited to cytotoxic chemotherapy without the benefit of molecular markers predicting response. Here we report tumor-cell-intrinsic chromatin accessibility patterns of treatment-naïve surgically resected PDAC tumors that were subsequently treated with (Gem)/Abraxane adjuvant chemotherapy. By ATAC-seq analyses of EpCAM+ PDAC malignant epithelial cells sorted from 54 freshly resected human tumors, we show here the discovery of a signature of 1092 chromatin loci displaying differential accessibility between patients with disease free survival (DFS) < 1 year and patients with DFS > 1 year. Analyzing transcription factor (TF) binding motifs within these loci, we identify two TFs (ZKSCAN1 and HNF1b) displaying differential nuclear localization between patients with short vs. long DFS. We further develop a chromatin accessibility microarray methodology termed "ATAC-array", an easy-to-use platform obviating the time and cost of next generation sequencing. Applying this methodology to the original ATAC-seq libraries as well as independent libraries generated from patient-derived organoids, we validate ATAC-array technology in both the original ATAC-seq cohort as well as in an independent validation cohort. We conclude that PDAC prognosis can be predicted by ATAC-array, which represents a low-cost, clinically feasible technology for assessing chromatin accessibility profiles.

Ex vivo synergistic effects of apixaban with dual anti-platelet therapy (DAPT) in lowering platelet reactivity and thrombin generation (SEARCH)

 

Direct oral anticoagulants such as apixaban are increasingly being evaluated clinically for the secondary prevention of cardiovascular events; however, their effects on platelet function in combination with dual anti-platelet therapy (DAPT) have not been fully investigated. The purpose of this translational, in vitro study was to determine if apixaban via inhibition of thrombin generation exhibits synergistic activity with DAPT to reduce platelet reactivity. Consented subjects with a prior history (&lt;12 mo) of ACS on DAPT regime with aspirin and clopidogrel (n=15; DAPT-C) or aspirin and ticagrelor (n=15; DAPT-T) were recruited, along with the age-matched healthy subjects as controls. Enrolled DAPT subjects had taken their prescribed regimen &gt;7 days prior to blood collection. Platelet-rich plasma from TSC anticoagulated blood was prepared and treated in vitro with nothing, a carrier control or apixaban (40, 90 and 220 ng/mL). The range of 40 to 220 ng/mL brackets the expected apixaban exposure at steady state with all three approved regimens with the 40 ng/mL treatment corresponding to &lt;5th percentile for the 2.5 mg bid dose, the 90 ng/mL corresponding to Cmax after the 2.5 mg bid or to Cmin after the 5 mg bid dose, and the 220 ng/mL corresponding to the Cmax after 10 mg bid dose. Platelet aggregation was measured by light transmission aggregometry (LTA) with tissue factor (TF) as agonist. Platelet p-selectin expression was measured by flow cytometry and thrombin generation was quantified. TF agonist was chosen to evaluate endogenous thrombin effects via Factor Xa activation (fXa). The CaCl2 concentration in the TF was titrated in the presence of peptide GPRP which minimized fibrin generation. The baseline maximal aggregation (MA) response was similar for both DAPT-T and DAPT-C (64%). Compared to DAPT alone, 90 and 220 ng/mL apixaban treatments decreased MA from 64% to 36% and 17% in the DAPT-T group and from 64% to 28% and 9% in the DAPT-C group (p&lt;0.009), respectively. Platelet P-selectin expression decreased by 53% in the DAPT-T group with 220 ng/mL apixaban treatment (p&lt;0.02) and in the DAPT-C group by 70% and 76% with 90 and 220 ng/mL apixaban treatment (p&lt;0.004), respectively, compared to DAPT alone. Apixaban treatment (90 and 220 ng/mL) significantly increased thrombin generation lag time and time-to-peak results and significantly decreased peak thrombin in both DAPT groups (p&lt;0.05). ACS patients on a DAPT regimen were susceptible to thrombin-mediated platelet activation via fXa. Apixaban treatment in vitro caused a larger reduction in thrombin-mediated platelet activation in the clopidogrel group compared to the ticagrelor group, consistent with ticagrelor having a more potent anti-platelet effect compared to clopidogrel. The in vitro addition of apixaban that corresponded to currently approved dosing regimens and at plasma drug levels routinely achieved demonstrated synergy with DAPT to reduce platelet reactivity and thrombin generation.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Bristol-Myers Squibb

A novel pathway for the induction of DNA damage in human spermatozoa involving extracellular cell-free DNA

DNA damage is a common feature of human spermatozoa associated with an impaired capacity to fertilize the oocyte and an increased mutational load in the offspring. However, the etiology of this damage remains poorly defined. In this study we demonstrate that a major pathway for the induction of DNA damage in mammalian spermatozoa is triggered by exposure to exogenous cell free DNA (cfDNA). Exposure of human and mouse spermatozoa to cfDNA (calf thymus, mouse liver and salmon testes) in vitro induced a dose-dependent increase in sperm DNA damage that could be effectively suppressed by the concomitant presence of DNase. The induction of such damage was not accompanied by any concomitant change in sperm motility or vitality and was not directly associated with the induction of oxidative stress. In vivo the injection of exogenous DNA again precipitated an increase in sperm DNA fragmentation that could be reversed by the prior administration of DNase. Similarly, the induction of a transient unilateral testicular ischemia induced an increase in DNA fragmentation that was evident within 24 h and sustained for at least 14 days via mechanisms that could be completely suppressed by the prior administration of DNase. We conclude that exogenous cfDNA activates a defensive response in human spermatozoa associated with the nuclease-mediated induction of DNA fragmentation, possibly involving the participation of TLR9 and CD4. These novel insights have significant implications for our understanding of DNA fragmentation in the male germ line and open up new pathways for the remediation of this condition.

Human spermatozoa possess an IL4I1 l-amino acid oxidase with a potential role in sperm function

Reactive oxygen species (ROS) are known to play an important role in the regulation of human sperm function. In this study, we demonstrate for the first time that human spermatozoa possess interleukin-induced gene 1 (IL4I1), anl-amino acid oxidase (LAAO) which is capable of generating ROS on exposure to aromatic amino acids in the presence of oxygen. The preferred substrates were found to be phenylalanine and tryptophan while the enzyme was located in the acrosomal region and midpiece of these cells. In contrast to equine and bovine spermatozoa, enzyme activity was lost as soon as the spermatozoa became non-viable. On a cell-to-cell basis human spermatozoa were also shown to generate lower levels of hydrogen peroxide than their equine counterparts on exposure to phenylalanine. Stimulation of LAAO activity resulted in the induction of several hallmarks of capacitation including tyrosine phosphorylation of the sperm flagellum and concomitant activation of phospho-SRC expression. In addition, stimulation of LAAO resulted in an increase in the levels of acrosomal exocytosis in both the presence and absence of progesterone stimulation, via mechanisms that could be significantly reversed by the presence of catalase. As is often the case with free radical-mediated phenomena, prolonged exposure of human spermatozoa to phenylalanine resulted in the stimulation of apoptosis as indicated by significant increases in mitochondrial superoxide generation and the activation of intracellular caspases. These results confirm the existence of an LAAO in human spermatozoa with a potential role in driving the redox regulation of sperm capacitation and acrosomal exocytosis.

Effects of surface-bound and intravenously administered heparin on cell-surface interactions: inflammation and coagulation

Intravenous administration of heparin and heparin-bonded extracorporeal circuits are frequently used to mitigate the deleterious effects of blood contact with synthetic materials. The work described here utilized human blood in a micro-perfusion circuit to experimentally examine the effects of intravenous and surface-bound heparin on cellular activation. Activation markers of coagulation and of the inflammatory response were examined using flow cytometry; specifically, markers of platelet, monocyte, polymorphonuclear leukocyte (PMN), and lymphocyte activation were quantified. The results indicate that surface-bound heparin reduces the inflammatory response whereas systemically administered heparin does not. This finding has important implications for blood-contacting devices, particularly within the context of recently elucidated connections between inflammation pathways and coagulation disorders. Data presented indicate that surface-bound heparin and intravenously administered heparin play distinct, but vital roles in rendering biomaterial surfaces compatible with blood.

Functional constraints on nest characteristics of pebble mounds of breeding male hornyhead chub Nocomis biguttatus

Breeding male hornyhead chub Nocomis biguttatus constructed nests in areas with relatively high but less than maximum flow rate and greater than average water depth. Nests comprised c. 3000 pebbles for a total mass of 11 kg. Males selected pebbles of smaller diameter but higher density than pebbles in the immediate vicinity. Thus, nests balanced the risk of mound erosion and energetic cost of nest construction with the benefits of protection from egg predators and a stable internal flow rate for oxygenation. These data help establish environmental management goals for the conservation of N. biguttatus and the lotic ecosystems dependent upon them.

The clinical anatomy of the cephalic vein in the deltopectoral triangle

Identification and recognition of the cephalic vein in the deltopectoral triangle is of critical importance when considering emergency catheterization procedures. The aim of our study was to conduct a cadaveric study to access data regarding the topography and the distribution patterns of the cephalic vein as it relates to the deltopectoral triangle. One hundred formalin fixed cadavers were examined. The cephalic vein was found in 95% (190 right and left) specimens, while in the remaining 5% (10) the cephalic vein was absent. In 80% (152) of cases the cephalic vein was found emerging superficially in the lateral portion of the deltopectoral triangle. In 30% (52) of these 152 cases the cephalic vein received one tributary within the deltopectoral triangle, while in 70% (100) of the specimens it received two. In the remaining 20% (38) of cases the cephalic vein was located deep to the deltopectoral fascia and fat and did not emerge through the deltopectoral triangle but was identified medially to the coracobrachialis and inferior to the medial border of the deltoid. In addition, in 4 (0.2%) of the specimens the cephalic vein, after crossing the deltopectoral triangle, ascended anterior and superior to the clavicle to drain into the subclavian vein. In these specimens a collateral branch was observed to communicate between the cephalic and external jugular veins. In 65.2% (124) of the cases the cephalic vein traveled with the deltoid branch of the thoracoacromial trunk. The length of the cephalic vein within the deltopectoral triangle ranged from 3.5 cm to 8.2 cm with a mean of 4.8+/-0.7 cm. The morphometric analysis revealed a mean cephalic vein diameter of 0.8+/-0.1 cm with a range of 0.1 cm to 1.2 cm. The cephalic vein is relatively large and constant, usually allowing for easy cannulation.

The clinical anatomy of the internal thoracic veins

The branching pattern and adequacy of the internal thoracic veins (ITV) are important factors, providing useful information on the availability of vessels and their appropriateness as an option for anastomoses in plastic and reconstructive surgery. During 100 cadaveric examinations of the anterior thoracic wall it was observed that ITVs were formed by the venae commitantes of ITAs, which united to form a single vein (one for the right side and one for the left) draining into the right and left brachiocephalic veins. The tributaries of ITVs corresponded to the branches of ITA. The right internal thoracic vein bifurcated at the 2(nd) rib in 36% of the specimens, at the 3(rd) rib in 30% of the specimens, at the 4(th) rib in 10% of the specimens and in 24% of the specimens it remained a single vein. The left internal thoracic vein bifurcated at the 3(rd) rib in 52% of specimens, at the 4(th) rib in 20% of specimens and in 28% of the specimens it remained as a single vein. In addition, it was observed that in 78% of specimens ITVs were connected to each other by a venous arch. This arch displayed four distinct morphologies: transverse (n = 7), oblique (n = 16), U-shaped (n = 51) and double-arched (n = 4). All 78 arches were posterior to the xiphisternal joint and no artery accompanied them. In the remaining specimens, RITV and LITV exhibited a venous plexus formation. The distance from the sternum to ITV gradually decreased as the vessel passed caudally; the diameter of the vessel similarly decreased along the vein's caudal course. The frequent appearance of two concomitant veins on both sides of the thorax may offer the opportunity to reduce venous congestion by two vein anastomoses. More detailed knowledge of the anatomy of ITV may prove useful in planning surgical procedures in the anterior thorax in order to avoid unexpected bleeding.

Identification of greater occipital nerve landmarks for the treatment of occipital neuralgia

Important structures involved in the pathogenesis of occipital headache include the aponeurotic attachments of the trapezius and semispinalis capitis muscles to the occipital bone. The greater occipital nerve (GON) can become entrapped as it passes through these aponeuroses, causing symptoms of occipital neuralgia. The aim of this study was to identify topographic landmarks for accurate identification of GON, which might facilitate its anaesthetic blockade. The course and distribution of GON and its relation to the aponeuroses of the trapezius and semispinalis capitis were examined in 100 formalin-fixed adult cadavers. In addition, the relative position of the nerve on a horizontal line between the external occipital protuberance and the mastoid process, as well as between the mastoid processes was measured. The greater occipital nerve was found bilaterally in all specimens. It was located at a mean distance of 3.8 cm (range 1.5-7.5 cm) lateral to a vertical line through the external occipital protuberance and the spinous processes of the cervical vertebrae 2-7. It was also located approximately 41% of the distance along the intermastoid line (medial to a mastoid process) and 22% of the distance between the external occipital protuberance and the mastoid process. The location of GON for anaesthesia or any other neurosurgical procedure has been established as one thumb's breadth lateral to the external occipital protuberance (2 cm laterally) and approximately at the base of the thumb nail (2 cm inferior). This is the first study proposing the use of landmarks in relation to anthropometric measurements. On the basis of these observations we propose a target zone for local anaesthetic injection that is based on easily identifiable landmarks and suggest that injection at this target point could be of benefit in the relief of occipital neuralgia.

Anaesthetic management of thoracopagus twins with complex cyanotic heart disease for cardiac assessment: special considerations related to ventilation and cross-circulation

We describe the anaesthetic management of a pair of thoracopagus twins of 14 months of age undergoing complex cardiac evaluation. Synchronous ventilation of the twins, needed for the ECG-gated magnetic resonance imaging-angiography, was achieved through a Carlens (Y) adaptor during procedures and transport. The complex logistical implications are obvious. We also describe the first use of bispectral index monitor for detection of cross-circulation in conjoint twins.

Design, characterization, and structure of a biologically active single-chain mutant of human IFN-gamma

A mutant form of human interferon-gamma (IFN-gamma SC1) that binds one IFN-gamma receptor alpha chain (IFN-gamma R alpha) has been designed and characterized. IFN-gamma SC1 was derived by linking the two peptide chains of the IFN-gamma dimer by a seven-residue linker and changing His111 in the first chain to an aspartic acid residue. Isothermal titration calorimetry shows that IFN-gamma SC1 forms a 1:1 complex with its high-affinity receptor (IFN-gamma R alpha) with an affinity of 27(+/- 9) nM. The crystal structure of IFN-gamma SC1 has been determined at 2.9 A resolution from crystals grown in 1.4 M citrate solutions at pH 7.6. Comparison of the wild-type receptor-binding domain and the Asp111-containing domain of IFN-gamma SC1 show that they are structurally equivalent but have very different electrostatic surface potentials. As a result, surface charge rather than structural changes is likely responsible for the inability of the His111-->Asp domain of to bind IFN-gamma R alpha. The AB loops of IFN-gamma SC1 adopt conformations similar to the ordered loops of IFN-gamma observed in the crystal structure of the IFN-gamma/IFN-gamma R alpha complex. Thus, IFN-gamma R alpha binding does not result in a large conformational change in the AB loop as previously suggested. The structure also reveals the final six C-terminal amino acid residues of IFN-gamma SC1 (residues 253-258) that have not been observed in any other reported IFN-gamma structures. Despite binding to only one IFN-gamma R alpha, IFN-gamma SC1 is biologically active in cell proliferation, MHC class I induction, and anti-viral assays. This suggests that one domain of IFN-gamma is sufficient to recruit IFN-gamma R alpha and IFN-gamma R beta into a complex competent for eliciting biological activity. The current data are consistent with the main role of the IFN-gamma dimer being to decrease the dissociation constant of IFN-gamma for its cellular receptors.

A new variation of abductor digiti minimi accessorius

An anomalous hypothenar muscle, similar to previous descriptions of an abductor digiti minimi accessorius, was discovered during routine cadaveric dissection. This muscle is unique in that it differs in its insertion from those described previously. In addition, the abductor digiti minimi presented with 2 heads that received innervation from the same ulnar nerve branch as the anomalous muscle rather than from the deep branch of the ulnar nerve. This knowledge is useful to the hand surgeon in diagnosing and surgically treating problems associated with Guyon's canal.

ZD4190: an orally active inhibitor of vascular endothelial growth factor signaling with broad-spectrum antitumor efficacy

There is evidence that vascular endothelial growth factor (VEGF) contributes to solid tumor growth through the promotion of both angiogenesis and tumor vascular permeability. To abrogate VEGF signaling, we developed a small molecular weight inhibitor of VEGF receptor tyrosine kinase (RTK) activity that was compatible with chronic oral administration. ZD4190, a substituted 4-anilinoquinazoline, is a potent inhibitor of KDR and Flt-1 RTK activity, and VEGF stimulated HUVEC proliferation in vitro. Chronic once-daily oral dosing of ZD4190 to young rats produced a dose-dependent increase in the femoral epiphyseal growth plate area, which may be attributed to the inhibition of VEGF signaling in vivo because vascular invasion of cartilage is a prerequisite to the process of ossification. Once-daily oral dosing of ZD4190 to mice bearing established (approximately 0.5 cm3) human tumor xenografts (breast, lung, prostate, and ovarian) elicited significant antitumor activity and at doses that would not be expected to have any direct antiproliferative effect on tumor cells. Prolonged tumor cytostasis was further demonstrated in a PC-3 xenograft model with 10 weeks of ZD4190 dosing, and upon withdrawal of therapy, tumor growth resumed after a short delay. These observations are entirely consistent with the proposed mode of action. ZD4190 is one of a series of VEGF RTK inhibitors that may have utility in the treatment of a range of histologically diverse solid tumor types.

Creutzfeldt-Jakob disease (CJD) after blood product transfusion from a donor with CJD

We report a second case of an association between an albumin transfusion and Creutzfeldt-Jakob disease. On balance, we believe our case represents a chance and not a causal relation.

Radiation-associated gliosarcoma

The authors report a case of radiation-associated intracerebral gliosarcoma with fibrosarcomatous predominance, arising at the site of a low-grade glioma treated 10 years previously. The features of this case conform to the accepted criteria for radiation-induced tumour, in that the tumour developed within the radiation field, differed dramatically in histologic features from the original tumour and did not develop until 10 years after treatment. Although such tumours are most uncommon, this case suggests that radiation-induced gliosarcoma should be considered in the differential diagnosis of recurrent mass at the site of a treated intracranial neoplasm.

Paired helical filament tau (PHFtau) in Niemann-Pick type C disease is similar to PHFtau in Alzheimer's disease

Niemann-Pick Type C disease (NPC) is a cholesterol storage disease with defects in the intracellular trafficking of exogenous cholesterol derived from low density lipoproteins. In NPC cases with a chronic progressive course, neurofibrillary tangles (NFTs) that consist of paired helical filaments (PHFs) have been reported. To determine if NPC tangles contain abnormal tau proteins (known as PHFtau) similar to those found in Alzheimer's disease (AD) tangles, we examined the brains of five NPC cases by immunohistochemical and Western blot methods using a library of antibodies to defined epitopes of PHFtau. We show here that PHFtau in tangle-rich NPC brains is indistinguishable from PHFtau in AD brains. We speculate, that the generation of PHFtau in NPC may induce a cascade of pathological events that contribute to the widespread degeneration of neurons, and that these events may be similar in NPC and AD.

Isolated cerebellar lymphomatoid granulomatosis progressing to malignant lymphoma. Case report

A 60-year-old man presented with progressive and unique neurological symptoms. Investigations identified an isolated cerebellar lesion. This lesion fulfilled the histological criteria for lymphomatoid granulomatosis, and in situ hybridization and deoxyribonucleic acid (DNA) dot blot techniques revealed significant amounts of Epstein-Barr virus DNA within the tumor cells. The patient underwent cranial radiation therapy, and 16 months after the initial presentation the lesion evolved into a malignant lymphoma. He subsequently died secondary to subdural empyema, bacterial meningitis, and bronchopneumonia. The unique clinical and etiological aspects of this case are addressed.

Increasing radiation dose intensity using hyperfractionation in patients with malignant glioma. Final report of a prospective phase I-II dose response study

We attempted to show a dose effect relationship for radiation therapy by treating patients harbouring malignant glioma with increasing doses of radiation in a step-wise fashion. We postulated that no increase in delayed toxicity would be seen because we used hyperfractionation technique. Between January 1981 and December 1988 we treated 280 patients three times daily at 4 hour intervals. 100 patients received a total dose of 6141 cGy, 73 patients received 7120 cGy, and 107 patients received 8000 cGy. CCNU was given at the time of tumor progression following radiotherapy. Median time to tumor progression was 28 weeks for patients who received 6141 cGy, 27 weeks for patients who received 7120 cGy and 36 weeks for patients who received 8000 cGy. Median survival was 46 weeks for patients who received 6141 cGy, 38 weeks for patients who received 7120 cGy and 45 weeks for patients who received 8000 cGy. There was no statistically significant difference in either time to tumor progression or survival among the three treatment arms and no dose response effect was seen. There was no increase in delayed radiation toxicity when the total radiation dose was increased up to 8000 cGy.

Epstein-Barr virus-associated primary B-cell lymphoproliferative disorder of the cerebellum in an immune competent man

BACKGROUND

The role of the Epstein-Barr virus (EBV) in lymphoproliferative lesions has been widely accepted. Most of these lesions occur in patients who have deficiencies in their immune status. Lymphomatoid granulomatosis (LG) is a lymphoproliferative disorder originally characterized as an angiocentric, necrotizing, pleomorphic infiltrate of mononuclear cells. The etiology of LG is unknown. It was originally hypothesized that LG may represent an unusual lymphoid response to an infective organism, possibly EBV.

METHODS

Tissues from a previously healthy 60-year-old, healthy white man with primary cerebellar lymphomatoid granulomatosis were examined for the presence of EBV by nucleic acid hybridization.

RESULTS

The original LG lesion was a polyclonal B-cell proliferation that contained detectable amounts of EBV. Peripheral blood leukocytes were negative for EBV by the same assay. After an 18-month remission, a tumor reappeared near the site of the primary lesion, which had the histologic appearance of a lymphoma. The cells showed restricted clonality and contained a similar amount of EBV-related DNA as the original lesion. Peripheral blood leukocytes at the time of recurrence were negative for EBV. The patient died approximately 2 months after the recurrent tumor was detected.

CONCLUSIONS

This case demonstrated the development of a primary cerebellar B-cell lymphoproliferative disorder, histologically identical to lymphomatoid granulomatosis, that transformed into a lymphoma. The original tumor and the subsequent lymphoma contained, on average, several copies of EBV-related DNA per cell. Despite an extensive survey of the patient, no immune deficit was detected. Interpretation of the literature with the results of this case suggest that this instance of primary cerebellar LG arose as a consequence of an unusual EBV-associated B-cell lymphoproliferation. It is suggested that EBV may be a significant factor in the initiation of the abnormal proliferations of T-cells or B-cells reported in this disorder.

Hygromycin B therapy of a murine coronaviral hepatitis

Hepatitis caused by mouse hepatitis virus (MHV-A59), a murine coronavirus, is accompanied by direct infection and replication of virus within the liver. We demonstrate here that the aminoglycoside hygromycin B is able to eliminate MHV-A59 infection from mouse peritoneal macrophages and cultured liver cells in vitro and is also able to reduce levels of virus replication and necrotic liver foci in vivo.

Bronchial blood flow reduction with positive end-expiratory pressure after acute lung injury in sheep

Smoke inhalation increases bronchial blood flow (Qbr) and produces edema of the airway system. This study investigates whether the increased Qbr seen 24 h after inhalation injury can be affected by mechanical ventilation with PEEP (5, 10, 15 cm H2O). Sheep (n = 8) previously prepared with cardiopulmonary catheters and ultrasonic transit time flow probes mounted around their bronchial arteries were insufflated with four sets of 12 breaths each of cotton smoke. Different levels of PEEP were added to the mechanical ventilation 24 h after injury; each PEEP level was applied for 45 min. There were significant increases in Qbr and lung lymph flow (QL) associated with a marked decrease in bronchial vascular resistance (BVR) 24 h after injury. However, no change was observed in mean arterial pressure (MAP) or cardiac index (CI). There was a substantial reduction in PaO2/FIO2 (P/F), which indicated a deterioration in arterial oxygenation. The application of varying levels of PEEP decreased Qbr (p less than .05) while BVR increased (p less than .05), but QL and P/F did not. CI and MAP were recorded. After removal of PEEP, none of the cardiopulmonary variables were significantly different from their postsmoke control values. These findings suggest that mechanical ventilation with PEEP markedly decreases the smoke-induced hyperemia edema frequently seen after inhalation injury without any significant alterations in MAP or CI.

Prolonged suppression of rat testis function by a depot formulation of Zoladex, a GnRH agonist

A sustained-release formulation of a potent gonadotropin-releasing hormone (GnRH) agonist, Zoladex (D-Ser(But),6 Aza Gly10-GnRH; ICI 118,630; goserelin), was administered subcutaneously (3.6 mg/depot) to male rats once every 28 days for 2-24 wk to determine the extent to which pituitary-testis function could be suppressed and whether suppression was maintained throughout the period of treatment. Administration of Zoladex resulted in sustained decreases in weight of the testis, epididymis, seminal vesicles and prostate gland. The decreases were apparent within 2 wk of initiating treatment. Patchy degeneration of the seminiferous tubules and atrophy of the Leydig cells were observed, but did not progress beyond the degree observed after 1 month of treatment. Serum and testis testosterone were markedly depressed after 2 wk of treatment, as was testis [125I]hCG binding. Serum gonadotropins were also reduced by treatment. Serum androgen binding protein (ABP) was elevated, testis ABP content remained unchanged, and epididymal ABP content was reduced. The changes are consistent with the hypothesis that this compound affects both the anterior pituitary gland and the testis. These findings indicate that depot delivery systems are a convenient way to administer GnRH analogs for sustained treatment schedules.

Neuropathologic findings in three cases of profound hypoglycemia

Three clinical cases of profound hypoglycemia are described with survival periods ranging from 2 1/2 months to 6 years. Although prolonged clinical coma was present in all cases, only subtle evidence of neuronal loss was found. The value of immunohistochemical examination of the grey and white matter of the telencephalon in detecting evidence of neuronal loss in such cases is demonstrated. Infarcts were uniformly absent, as would be expected from the lack of cerebral acidosis in hypoglycemia. In addition to the usual absence of infarction, the pathologic findings in hypoglycemia distinguish themselves from hypoxic/ischemic encephalopathy in that the cerebellum is regularly spared, and that there is sometimes a characteristic involvement of the dentate gyrus, a structure relatively resistant to hypoxic/ischemic damage.

Fluorescence histochemistry of RNA in human pituitary adenomas

Acridine orange (AO)-RNA fluorescence was studied histochemically in 9 normal human pituitary glands, in 26 secretory and nonsecretory pituitary adenomas, and in a dysgerminoma. Six adenomas showing immunoreactivity for prolactin showed intense orange-red cytoplasmic fluorescence; 6 other tumours exhibiting immunoperoxidase activity of growth hormone showed less intense AO-RNA fluorescence, and 5 adrenocorticotropic hormone-containing adenomas showed still weaker orange fluorescence. Among the chromophobe adenomas without immunoreactivity for secretory products, 5 had uniformly very weak AO-RNA fluorescence, while in 4 other a few scattered cells with strong AO-RNA fluorescence were detected among the majority of weakly fluorescent cells. The pituitary dysgerminoma contained many cells with strong AO-RNA fluorescence. Electron microscopy of these cases showed good correlation of cytoplasmic concentration of ribosomes with AO-RNA fluorescence of the adenomas. AO is useful as an inexpensive, simple supplementary stain for frozen or paraffin sections of pituitary tumours to infer secretory activity as a correlate of RNA concentration and to demonstrate a secretory potential in some cells of hormonally inactive tumours.

Traumatic basal subarachnoid hemorrhage. Report of six cases and review of the literature

Basal subarachnoid hemorrhage due to rupture of normal extra- and intracranial arteries, in association with minor trauma to the face and neck and alcohol intoxication, has been well described but often goes unrecognized at autopsy. This results in the incorrect classification of the manner of death as natural. Six cases of subarachnoid hemorrhage due to mild-to-moderate blows to the head or neck are presented. All were men in the age range 28-61 years (mean, 38.8 years). Four had blood alcohol levels of 0.09-0.28 g % at autopsy, and five of six were comatose or dead within 30 min of the initiating trauma. Traumatic ruptures of otherwise normal extra- and intracranial arteries were identified in four cases. The site of rupture was not found in one case, and the final case had rupture of a fibrotic intracranial vertebral artery. Multiple sites of incomplete and complete rupture were found in four cases. Postmortem angiography was used in one case to demonstrate the site of rupture prior to removal of the brain. Postmortem angiography and careful gross and histologic examination of extra- and intracranial cerebral arteries is recommended in all cases of basal subarachnoid hemorrhage where minor trauma to the head or neck has occurred prior to collapse or death, especially if the decedent was intoxicated at the time of the trauma.

ICI 176,334: a novel non-steroidal, peripherally selective antiandrogen

Pure antiandrogens, like flutamide, antagonize androgen action both peripherally and centrally at the hypothalamic-pituitary axis, which leads to an increase in LH and testosterone secretion. A new non-steroidal antiandrogen ICI 176,334 [2RS)-4'-cyano-3-(4-fluorophenylsulphonyl)-2-hydroxy-2-methyl-3'- trifluoromethyl)propion-anilide) has now been discovered which causes regression of the accessory sex organs but does not increase serum concentrations of LH and androgens. ICI 176,334 binds to rat prostate androgen receptors with an affinity around fourfold that of hydroxyflutamide. When administered s.c. concurrently with testosterone propionate (200 micrograms/kg) for 7 days to immature castrated rats, ICI 176,334 (10 mg/kg) significantly (P less than 0.001) inhibited growth of the seminal vesicles and ventral prostate gland. Oral administration of ICI 176,334 at doses of 1, 5 and 25 mg/kg for 14 days to adult rats caused a dose-related reduction in accessory sex organ weights but had no effect on the testes. None of these doses caused a significant increase in serum LH and testosterone. Flutamide was around fourfold less potent and significantly increased serum LH and testosterone at the higher doses. ICI 176,334 was well tolerated. ICI 176,334 should, therefore, prove useful for the treatment of androgen-responsive benign and malignant diseases.

Gliosis and glioma distinguished by acridine orange

Acridine orange fluorochrome of nucleic acids was applied to sections of cerebral tissue from 20 patients showing acute or chronic reactive gliosis. The results were compared with the findings in 39 well differentiated and malignant astrocytomas. The orange cytoplasmic fluorescence of ribonucleic acid is lacking in reactive astrocytes of all ages including gemistocytes, but is uniformly present in astrocytoma cells. Acridine orange is a useful supplementary stain for distinguishing between astrocytosis and astrocytoma, particularly for small cerebral biopsies showing scattered or diffusely infiltrating pleomorphic glial cells.

Primary degenerative dementia without Alzheimer pathology

To define the pathology in cases of non-Alzheimer primary degenerative dementia (non-AD PDD), we have studied autopsies from four medical centres accessioned in consecutive years since 1976. Neurochemical studies of the basal forebrain-cortical (BF-C) cholinergic system have been conducted in cases from which frozen tissue was available. Twenty-two cases (mean age 70 years, range 47-86) in which the history was consistent with PDD, but which did not meet anatomic criteria for AD, were selected. Approximately 70 cases of PDD, which were accessioned in the same years and met the anatomic criteria for AD, were excluded. The pathologic findings permitted a classification into six groups: Lewy body disease (LBD), 4 cases; Pick's disease, 6 cases: cortical degeneration with motor neuron disease (CDmnd), 2 cases; hippocampal and temporal lobe sclerosis, 3 cases; few or nonspecific abnormalities, 5 cases; other disorders, 2 cases. Our findings suggest that LBD and Pick's disease account for a large proportion of cases of non-AD PDD in the presenile age group, but that a large number of other disorders occasionally present as PDD. Careful examination of the motor systems, as well as cerebral structures relate to cognitive function, is important in the neuropathologic evaluation. Lesions of the BF-C cholinergic system have been most consistent and severe in LBD, and have not been identified in CDmnd.

Multiple daily fractionated radiation therapy and misonidazole in the management of malignant astrocytoma. A preliminary report

Various attempts have been made to improve the effectiveness of radiation in the treatment of cerebral malignant astrocytomas. A trend favoring multiple daily fractionated (MDF) radiation therapy over conventional single daily fractionated (CF) radiation therapy was identified in our previous study. In order to assess the effect of MDF with and without misonidazole, a province-wide prospective randomized trial was initiated in January 1981. By March 1984, 124 patients with histologically verified grade III and IV astrocytomas were randomized to CF (5800 cGy/6 weeks/30 fractions), MDF (6141 cGy/4.5 weeks/69 fractions at 89 cGy every 3-4 hours, three times a day) and MDF in combination with misonidazole (1.25 g/m2 three times weekly for the first 3 weeks). Thirty-eight patients were randomized to CF, 43 patients to MDF, and 43 patients to MDF and misonidazole. At the preliminary assessment in July 1984, the median survival time was 27 weeks for the CF group, 39 weeks for the MDF group and 49 weeks for MDF and misonidazole group. The 1-year actuarial survival rate from surgery was 20% for CF group, 41% for MDF group, and 45% for MDF and misonidazole group. There is a statistically significant difference (P less than 0.001) between the CF and MDF group. However, the addition of misonidazole does not significantly alter survival.

Fatal nemaline myopathy in infancy

The clinical and neuropathological findings in two infants with congenital nemaline myopathy are described. One patient presented at birth with severe hypotonia, respiratory failure and contractures and died shortly after the neonatal period. The other presented at age two months with hypotonia and, following a period of clinical stability, died at age seven months from respiratory failure. Pathological findings in the fatal neonatal case revealed numerous rod bodies in lingual, pharyngeal, diaphragm and limb muscles, correlating with clinical findings. Significant, but less rod body involvement was found in the diaphragm and limb muscles of the second patient. Although a neural basis has been suggested for this disorder, no abnormalities were found in the central nervous system or in the peripheral nerves of these two severely affected patients.

Clinicopathological conference. Carcinoma of the pituitary gland with metastases to bone

The diagnosis of extracranial metastases from a pituitary tumor was confirmed by the use of the immunoperoxidase technique. This is believed to be the first case of carcinoma of the pituitary gland with bony metastases where the diagnosis has been confirmed in that manner.

Infantile Huntington's disease

A unique case of Huntington's disease is reported because of the extremely early onset and death, and the atypical mode of presentation including severe behavioural problems and a negative family history. Although rare, Huntington's disease must be considered along with the established degenerative disorders of white and gray matter peculiar to the pediatric population when one examines an infant or child with progressive motor deterioration, rigidity, mental retardation and behavioural abnormalities. Computed tomography is a reliable and non-invasive method of establishing the diagnosis during life.

Neuroaxonal dystrophy in young adults: a clinicopathological study of two unrelated cases

The clinical and pathological features of two unrelated sporadic cases of neuroaxonal dystrophy occurring in young adults are described. Initial clinical manifestations in both patients were those of primary psychiatric disorders. They subsequently developed extrapyramidal symptoms, dementia, cerebellar ataxia, and corticospinal dysfunction, but neither demonstrated myoclonic seizures. In one patient the diagnosis was made before death by brain biopsy. On pathological examination both patients showed a generalized distribution of spheroids within the central nervous system and, in one, in the peripheral nerves. In both patients, Lewy bodies were demonstrated in the pigmented brainstem nuclei. In addition, one patient showed ultrastructurally verified Lewy bodies in the cerebral cortex. Although these two cases could be considered examples of juvenile neuroaxonal dystrophy, we prefer to regard them as transitional forms in a disease spectrum with classic infantile neuroaxonal dystrophy and Hallervorden-Spatz disease at the two extremes.

Salivary gland heterotopia: a unique cerebellopontine angle tumor

An unusual maldevelopmental lesion, a salivary gland heterotopia of the right cerebellopontine angle, was studied. There was an associated primary adenoid cystic carcinoma. Possible modes of development and the relationship to salivary heterotopia of the middle ear are discussed.

Dysplastic vertebral artery with paradoxical infarction

A rare abnormality of the vertebral artery is described in a 63-year-old male. The right vertebral artery consisted of several minute endothelial lined channels which failed to perfuse at autopsy. The anterior spinal artery showed areas of muscular media dysplasia. These anomalies were associated with large posterior communicating arteries. The terminal event was precipitated by thrombotic occlusion of the left vertebral artery. The embryological aspect of these anomalies are discussed.

Effect of lipid A-associated protein and lipid A on the expression of lipopolysaccharide activity. I. Immunological activity

A detailed investigation has been made of the contribution of the various chemical moieties of bacterial endotoxins, namely lipid A-associated protein (LAP), lipid A and O-antigen polysaccharide to a number of the immunological activities of these active bacterial products. Advantage was taken of the availability of antigenically identical endotoxin preparations from Escherichia coli 0111:B4 which differed greatly in their content of LAP and/or lipid A. The capacity to initiate in vitro proliferative responses in murine splenocytes was in a large part related to the presence of LAP with a less potent, although still critical, dependence upon lipid A. On the other hand, the in vivo polyclonal antibody response was dependent only upon lipid A. In this respect, the presence of LAP had no apparent effect on the stimulation of nonspecific low affinity antibody. All preparations, regardless of LAP and lipid A content, stimulated similar in vivo enhancement of antibody responses to a protein antigen (adjuvanticity) and specific immune responses to the endotoxin polysaccharide antigen. The results emphasize the lack of correlation between in vitro B lymphocyte proliferative responses and in vivo immunostimulatory responses of bacterial endotoxin preparations. These data also suggest a minimal contribution of LAP to in vivo responses and an extremely limited contribution of lipid A to the adjuvant activity and the primary immune response to O-antigen polysaccharide.

Interpretation of the resonance Raman spectrum of bathorhodopsin based on visual pigment analogues

Resonance Raman spectra of visual pigment analogues have been used to evaluate various models for the structure of the retinal chromophore in bathorhodopsin. Deuteration or removal of the 18-methyl on the beta-ionyl ring or of the 19-methyl on the polyene chain demonstrates that the three intense low wavenumber bands of bathorhodopsin at 853, 875, and 920 cm-1 are not due to exomethylene or ring modes. Rather, assignment of these lines to out-of-plane vinyl hydrogen motions on the chain best accounts for the experimental data. Our calculations show that the intensity of these vibrations can be explained by twists of 10-30 degrees about chain single bonds. The 1100-1400-cm-1 Raman fingerprint indicates that the configuration of the double bonds is trans. This suggests that the structure of the bathorhodopsin chromophore is twisted all-trans.

Cytomegalovirus infection of the female genital tract. Histologic findings in three cases and review of the literature

Three cases of cytomegalovirus infection of the female genital tract, diagnosed on curettage, revealed a characteristic, although nonspecific histologic picture. This consisted of dense lymphocytic and plasma cell infiltrates with lymphoid follicles and signs of rapid cell turnover in the cervix when the latter was affected. The characteristic inclusions were very scant or even absent. The symptoms were not of diagnostic value.

Visceral neurofibromatosis. An unusual cause of obstructive jaundice

A case of visceral neurofibromatosis presenting as obstructive jaundice is described. Laparotomy revealed an ampullary tumour which was presumed to be malignant. A palliative cholecystojejunostomy was performed but death occurred 10 days postoperatively as a result of obstructive jaundice. At necropsy the ampullary tumour was found to be a benign neurofibroma.