“Click-to-Clear”: A Strategy to Minimize Radioactivity from the Blood Pool Utilizing Staudinger Ligation

The availability of several bioorthogonal reactions that can proceed selectively and efficiently under physiologically relevant conditions has garnered the interest of biochemists and organic chemists alike. Bioorthogonal cleavage reactions represent the latest innovation in click chemistry. Here, we employed the Staudinger ligation reaction to release radioactivity from immunoconjugates, improving target-to-background ratios. In this proof-of-concept study, model systems, including the anti-HER2 antibody trastuzumab, radioisotope I-131, and a newly synthesized bifunctional phosphine, were used. Staudinger ligation occurred when biocompatible N-glycosyl azides reacted with this radiolabeled immunoconjugate, leading to cleavage of the radioactive label from the molecule. We demonstrated this click cleavage in vitro and in vivo. Biodistribution studies in tumor models showed that radioactivity was eliminated from the bloodstream, thereby improving tumor-to-blood ratios. SPECT imaging revealed that tumors could be visualized with enhanced clarity. Our simple approach represents a novel application of bioorthogonal click chemistry in the development of antibody-based theranostics.

Preclinical Evaluation of hnRNPA2B1 Antibody in Human Triple-Negative Breast Cancer MDA-MB-231 Cells via PET Imaging

Triple-negative breast cancer (TNBC) does not express estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. Because TNBC lacks the expression of commonly targeted receptors, it is challenging to develop a new imaging agent for this cancer subtype. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are RNA–protein complexes that have been linked to tumor development and progression. Considering the high expression of hnRNPA2B1, an hnRNP subtype, in TNBC MDA-MB-231 cells, this study aimed to develop a novel hnRNPA2B1 antibody-based nuclear imaging agent. The hnRNPA2B1-specific antibody was radiolabeled with ⁶⁴Cu and evaluated in vitro and in vivo. The trans-cyclooctene (TCO) was functionalized on the antibody to obtain hnRNP-PEG₄-TCO and reactive tetrazine (Tz) on the ultrastable bifunctional chelator PCB-TE2A-alkyne to yield PCB-TE2A-Tz for the inverse electron demand Diels–Alder reaction. The ⁶⁴Cu-radiolabeled antibody was administered and imaged at 1–18 h time points for conventional imaging. Alternatively, the unlabeled antibody conjugate was administered, and 48 h later radiolabeled ⁶⁴Cu-PCB-TE2A-Tz was administered to the same mice for the pretargeting strategy and imaged at the same time intervals for direct comparison. The tumor was successfully visualized in both strategies, and comparatively, pretargeting showed superior results. The ⁶⁴Cu-PCB-TE2A-Tz was successfully clicked at the tumor site with hnRNP-PEG₄-TCO and the non-clicked were concurrently eliminated. This led to increase the tumor uptake with extremely high tumor-to-background ratio manifested by positron emission tomography (PET) imaging and biodistribution studies.

Imaging Strategy that Achieves Ultrahigh Contrast by Utilizing Differential Esterase Activity in Organs: Application in Early Detection of Pancreatic Cancer

Most nanoparticles show much higher uptake in mononuclear phagocyte system (MPS) organs than in tumors, which has been a long-lasting dilemma in nanomedicine. Here, we report an imaging strategy that selectively decreases MPS organ uptakes by utilizing the differential esterase activity in tumors and other organs. When an esterase-labile radiotracer loaded liposome was injected into the body, radioactivity was rapidly excreted from the liver and spleen after breakage of the ester bond by esterase. However, the lipophilic radiotracer delivered to the tumor remained in the tumor with minimal bond cleavage. The underlying mechanism was fully characterized in vitro and in vivo in colon tumor models. As a proof of concept, the liposomal radiotracer was further optimized for the early detection of pancreatic cancer. The folate-coated liposomal radiotracer showed highly selective tumor uptake. At 4 h postinjection, a pancreatic tumor a few millimeters in size was unambiguously visualized in orthotopic tumor models by PET imaging. At 24 h, an exceptionally high tumor-to-background ratio was achieved, enabling the visualization of tumors alone with minimal background noise. More than 9% of the total radioactivity was found in the tumor. Utilizing our imaging strategy, various tumor imaging agents can be developed for sensitive detection with ultrahigh contrast.

Successful Application of CuAAC Click Reaction in Constructing 64Cu-Labeled Antibody Conjugates for Immuno-PET Imaging

Immuno-positron emission tomography (immuno-PET) is a rapidly growing imaging technique in which antibodies are radiolabeled to monitor their in vivo behavior in real time. However, effecting the controlled conjugation of a chelate-bearing radioactive atom to a bulky antibody without affecting its immunoreactivity at a specific site is always challenging. The in vivo stability of the radiolabeled chelate is also a key issue for successful tumor imaging. To address these points, a facile ultra-stable radiolabeling platform is developed by using the propylene cross-bridged chelator (PCB-TE2A-alkyne), which can be instantly functionalized with various groups via the click reaction, thus enabling specific conjugation with antibodies as per choice. The PCB-TE2A-tetrazine derivative is selected to demonstrate the proposed strategy. The antibody trastuzumab is functionalized with the trans-cyclooctene (TCO) moiety in the presence or absence of the PEG linker. The complementary ⁶⁴Cu-PCB-TE2A-tetrazine is synthesized via the click reaction and radiolabeled with ⁶⁴Cu ions, which then reacts with the aforementioned TCO-modified antibody via a rapid biorthogonal ligation. The ⁶⁴Cu-PCB-TE2A-trastuzumab conjugate is shown to exhibit excellent in vivo stability and to maintain a higher binding affinity toward HER2-positive cells. The tumor targeting feasibility of the radiolabeled antibody is evaluated in tumor models. Both ⁶⁴Cu-PCB-TE2A-trastuzumab conjugates show high tumor uptakes in biodistribution studies and enable unambiguous tumor visualization with minimum background noise in PET imaging. Interestingly, the ⁶⁴Cu-PCB-TE2A-PEG₄-trastuzumab containing an additional PEG linker displays a much faster body clearance compared to its counterpart with less PEG linker, thus affording vivid tumor imaging with an unprecedentedly high tumor-to-background ratio.

Visualization and Quantification of Radiochemical Purity by Cerenkov Luminescence Imaging

Determination of radiochemical purity is essential for characterization of all radioactive compounds, including clinical radiopharmaceuticals. Radio-thin layer chromatography (radio-TLC) has been used as the gold standard for measurement of radiochemical purity; however, this method has several limitations in terms of sensitivity, spatial resolution, two-dimensional scanning, and quantification accuracy. Here, we report a new analytical technique for determination of radiochemical purity based on Cerenkov luminescence imaging (CLI), whereby entire TLC plates are visualized by detection of Cerenkov radiation. Sixteen routinely used TLC plates were tested in combination with three different radioisotopes (¹³¹I, ¹²⁴I, and ³²P). All TLC plates doped with a fluorescent indicator showed excellent detection sensitivity with scanning times of less than 1 min. The new CLI method was superior to the traditional radio-TLC scanning method in terms of sensitivity, scanning time, spatial resolution, and two-dimensional scanning. The CLI method also showed better quantification features across a wider range of radioactivity values compared with radio-TLC and classical zonal analysis, especially for β^--emitters such as ¹³¹I and ³²P.

Anti-inflammatory effects of ursolic acid-3-acetate on human synovial fibroblasts and a murine model of rheumatoid arthritis

Ursolic acid (UA), a pentacyclic triterpenoid, is a common natural substance known to be effective in the treatment of inflammation, oxidative stress, and ulcers in arthritis. This study examined the effects of ursolic acid-3-acetate (UAA), a derivative of UA, on rheumatoid arthritis (RA) and verified the underlying mechanism of action by using a type-II collagen-induced arthritis (CIA) mice model and tumor necrosis factor (TNF)-α-stimulated RA synovial fibroblasts. The oral administration of UAA showed a decrease in clinical arthritis symptoms, paw thickness, histologic and radiologic changes, and serum IgG1 and IgG2a levels. UAA administration reduced Th1/Th17 phenotype CD4+ T lymphocyte expansion and inflammatory cytokine production in draining lymph nodes. In addition, UAA effectively reduced the expression and production of inflammatory mediators, including cytokines and matrix metalloproteinase-1/3 in the knee joint tissue and RA synovial fibroblasts, through the downregulation of IKKα/β, ΙκBα, and nuclear factor-κB. Our findings showed that UAA modulated helper T cell immune responses and matrix-degrading enzymes. The effects of UAA were comparable with those of the positive control drug, dexamethasone. In summary, all the evidence presented in this paper suggest that UAA could be a therapeutic candidate for the treatment of RA.

Phosphonate Pendant Armed Propylene Cross-Bridged Cyclam: Synthesis and Evaluation as a Chelator for Cu-64

A propylene cross-bridged macrocyclic chelator with two phosphonate pendant arms (PCB-TE2P) was synthesized from cyclam. Various properties of the synthesized chelator, including Cu-complexation, Cu-complex stability, (64)Cu-radiolabeling, and in vivo behavior, were studied and compared with those of a previously reported propylene cross-bridged chelator (PCB-TE2A).

Oleanolic acid acetate inhibits rheumatoid arthritis by modulating T cell immune responses and matrix-degrading enzymes

Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with a combination of synovium joint inflammation, synovium hyperplasia, and destruction of cartilage and bone. Oleanolic acid acetate (OAA), a compound isolated from Vigna angularis, has been known to possess pharmacological activities, including anti-inflammation and anti-bone destruction. In this study, we investigated the effects of OAA on RA and the underlying mechanisms of action by using a type-II collagen-induced arthritis (CIA) mouse model and tumor necrosis factor (TNF)-α-stimulated RA synovial fibroblasts. Oral administration of OAA decreased the clinical arthritis symptoms, paw thickness, histologic and radiologic changes, and serum total and anti-type II collagen IgG, IgG1, and IgG2a levels. OAA administration reduced Th1/Th17 phenotype CD4(+) T lymphocyte expansions and inflammatory cytokine productions in T cell activated draining lymph nodes and spleen. OAA reduced the expression and production of inflammatory mediators, such as cytokines and matrix metalloproteinase (MMP)-1/3, in the ankle joint tissue and RA synovial fibroblasts by down-regulating Akt, mitogen-activated protein kinases, and nuclear factor-κB. Our results clearly support that OAA plays a therapeutic role in RA pathogenesis by modulating helper T cell immune responses and matrix-degrading enzymes. The immunosuppressive effects of OAA were comparable to dexamethasone and ketoprofen. We provide evidences that OAA could be a potential therapeutic candidate for RA.

Apoptosis imaging studies in various animal models using radio-iodinated peptide

Apoptosis has a role in many medical disorders and treatments; hence, its non-invasive evaluation is one of the most riveting research topics. Currently annexin V is used as gold standard for imaging apoptosis. However, several drawbacks, including high background, slow body clearance, make it a suboptimum marker for apoptosis imaging. In this study, we radiolabeled the recently identified histone H1 targeting peptide (ApoPep-1) and evaluated its potential as a new apoptosis imaging agent in various animal models. ApoPep-1 (CQRPPR) was synthesized, and an extra tyrosine residue was added to its N-terminal end for radiolabeling. This peptide was radiolabeled with (124)I and (131)I and was tested for its serum stability. Surgery- and drug-induced apoptotic rat models were prepared for apoptosis evaluation, and PET imaging was performed. Doxorubicin was used for xenograft tumor treatment in mice, and the induced apoptosis was studied. Tumor metabolism and proliferation were assessed by [(18)F]FDG and [(18)F]FLT PET imaging and compared with ApoPep-1 after doxorubicin treatment. The peptide was radiolabeled at high purity, and it showed reasonably good stability in serum. Cell death was easily imaged by radiolabeled ApoPep-1 in an ischemia surgery model. And, liver apoptosis was more clearly identified by ApoPep-1 rather than [(124)I]annexin V in cycloheximide-treated models. Three doxorubicin doses inhibited tumor growth, which was evaluated by 30-40% decreases of [(18)F]FDG and [(18)F]FLT PET uptake in the tumor area. However, ApoPep-1 demonstrated more than 200% increase in tumor uptake after chemotherapy, while annexin V did not show any meaningful uptake in the tumor compared with the background. Biodistribution data were also in good agreement with the microPET imaging results. All of the experimental data clearly demonstrated high potential of the radiolabeled ApoPep-1 for in vivo apoptosis imaging.

Pathologic findings in patients who underwent robot-assisted radical prostatectomy following active surveillance: a prospective study in a single center

AIM

Active surveillance is the recommended treatment of option for men with very low-risk prostate cancer. In this study, the clinicopathological results of patients who were initially treated with active surveillance and subsequently underwent robot-assisted radical prostatectomy during follow-up are described.

METHODS

A prospective cohort of 106 men enrolled in active surveillance was reviewed. Pathologic specimens for patients who ultimately underwent robot-assisted radical prostatectomy for progression or personal preference were analyzed.

RESULTS

After exclusion of 14 patients who were lost to follow-up or with incomplete data collection, 92 men were included in the present analyses. Median follow-up was 27.6 months (range 3.3 to 193.1). Twenty-nine patients underwent robot-assisted radical prostatectomy. Progression occurred in 32 patients (34.8%), of which 23 men elected to undergo surgery. Robot-assisted radical prostatectomy was performed in 6 additional patients who chose definitive intervention due to anxiety. Pathologic analyses revealed organ-confined disease in 24 patients (82.8%), and Gleason score was ≥ 7 in nine (31%). Fourteen (48.3%) specimens were identified as having an advanced disease (Gleason score ≥ 7 and/or T3). In comparison to the patients with low-risk disease post-operatively (Gleason score <7 and T2), patients with advanced disease had significantly higher PSA density level and lower prostate volume.

CONCLUSION

In this prospective active surveillance cohort, the progression rate was 34.8% over the follow-up period of 27.6 months. In specimens of patients who underwent robot-assisted radical prostatectomy, 48.3% displayed advanced pathologic features. Therefore we recommend that patients considering active surveillance should be counseled on risk of advanced disease as a possible hazard.

New bifunctional chelator for 64Cu-immuno-positron emission tomography

A new tetraazamacrocyclic bifunctional chelator, TE2A-Bn-NCS, was synthesized in high overall yield from cyclam. An extra functional group (NCS) was introduced to the N-atom of TE2A for specific conjugation with antibody. The Cu complex of TE2A-Bn-NCS showed high kinetic stability in acidic decomplexation and cyclic voltammetry studies. X-ray structure determination of the Cu-TE2A-Bn-NH2 complex confirmed octahedral geometry, in which copper atom is strongly coordinated by four macrocyclic nitrogens in equatorial positions and two carboxylate oxygen atoms occupy the elongated axial positions. Trastuzumab was conjugated with TE2A-Bn-NCS and then radiolabeled with 64Cu quantitatively at room temperature within 10 min. Biodistribution studies showed that the 64Cu-labeled TE2A-Bn-NCS-trastuzumab conjugates maintain high stability in physiological conditions, and NIH3T6.7 tumors were clearly visualized up to 3 days by 64Cu-immuno-positron emission tomography imaging in animal models.

Vivid tumor imaging utilizing liposome-carried bimodal radiotracer

By developing a new bimodal radioactive tracer that emits both luminescence and nuclear signals, a trimodal liposome for optical, nuclear, and magnetic resonance imaging is efficiently prepared. Fast clearance of the radiotracer from reticuloendothelial systems enables vivid tumor imaging with minimum background.

pH-responsive gold nanoparticles-in-liposome hybrid nanostructures for enhanced systemic tumor delivery

We report a pH-responsive gold nanoparticles-in-liposome hybrid nanostructure, which effectively combines the pH-responsive assembly and surface plasmon property changes of 'smart' gold nanoparticles and enhanced systemic circulation and tumor accumulation of the PEG-grafted liposomes.

Non-cross-bridged tetraazamacrocyclic chelator for stable (64)cu-based radiopharmaceuticals

N-mono/dimethylated TE2A tetraazamacrocycles (MM-TE2A and DM-TE2A) were synthesized in high yields. Both Cu-MM/DM-TE2A complexes showed increased kinetic stability compared to that of Cu-TE2A, whereas Cu-DM-TE2A showed even higher in vitro stability than that of Cu-ECB-TE2A. MM-TE2A and DM-TE2A were quantitatively radiolabeled with (64)Cu ions and showed rapid clearance from the body to emerge as a potential efficient bifunctional chelator.

pH-responsive assembly of gold nanoparticles and "spatiotemporally concerted" drug release for synergistic cancer therapy

A challenge in using plasmonic nanostructure-drug conjugates for thermo-chemo combination cancer therapy lies in the huge size discrepancy; the size difference can critically differentiate their biodistributions and hamper the synergistic effect. Properly tuning the plasmonic wavelength for photothermal therapy typically results in the nanostructure size reaching ∼100 nm. We report a new combination cancer therapy platform that consists of relatively small 10 nm pH-responsive spherical gold nanoparticles and conjugated doxorubicins. They are designed to form aggregates in mild acidic environment such as in a tumor. The aggregates serve as a photothermal agent that can selectively exploit external light by their collective plasmon modes. Simultaneously, the conjugated doxorubicins are released. The spatiotemporal concertion is confirmed at the subcellular, cellular, and organ levels. Both agents colocalize in the cell nuclei. The conjugates accumulate in cancer cells by the rapid phagocytic actions and effective blockage of exocytosis by the increased aggregate size. They also effectively accumulate in tumors up to 17 times over the control because of the enhanced permeation and retention. The conjugates exhibit a synergistic effect enhanced by nearly an order of magnitude in cellular level. The synergistic effect is demonstrated by the remarkable reductions in both the therapeutically effective drug dosage and the photothermal laser threshold. Using an animal model, effective tumor growth suppression is demonstrated. The conjugates induce apoptosis to tumors without any noticeable damage to other organs. The synergistic effect in vivo is confirmed by qRT-PCR analysis over the thermal stress and drug-induced growth arrest.

Development of the deep flexor tendons and lumbricalis muscle in the hand and foot: a histological study using human mid-term foetuses

To revisit foetal development of the deep flexor tendons of the hand and foot, we examined the paraffin-embedded histology of 20 mid-term foetuses at 8-15 weeks of estimated gestational age (35-118 mm crown-rump length or CRL). At 8-9 weeks, in front of the metacarpal bones, the flexor pollicis longus and flexor digitorum profundus (FDP) muscles provided a plate-like, common tendon from which the lumbricalis muscles originated. However, in the foot, we had no evidence of such a common tendon. The flexor pollicis tendon was separated from the common tendon at 9-10 weeks possibly due to mechanical stress from the laterally growing thumb. Notably, at the lumbricalis muscle origins at 10-12 weeks, the FDP and flexor digitorum longus tendons remained undifferentiated and the primitive tenocytes were dispersed from them. The dispersed cells seemed to develop into an interface tissue between the lumbricalis muscle fibre and the deep tendon. In 3 of 5 specimens at 15 weeks, we found an excess number of the FDP tendons (5-7) in the proximal side of the lumbricalis muscle origin. However, the excess tendons dispersed in the lumbricalis muscle origin. The development of the lumbricalis muscle origin might follow the tendon splitting for four fingers. However, conversely, we hypothesised that the developing lumbricalis muscles re-arranged the deep flexor tendons to provide a configuration of one deep tendon per one finger (or toe). The quadrates plantae muscle seemed not to contribute on the re-arrangement.

Synthesis and evaluation of a radioiodinated bladder cancer specific peptide

Bladder cancer is the second most common cancer of the urinary tract, however the invasive cystoscopy is still the standard technique for diagnosis and surveillance of bladder cancer. Herein, we radiolabel bladder cancer specific peptide with radioactive iodine ((131/124)I) and evaluate its potential as a new radiopharmaceutical for the non-invasive diagnosis of bladder cancer. A 9-mer bladder cancer specific peptide (BP) was conjugated with tyrosine and cyclized by disulfide bond formation to give Y-BP, which was further radioiodinated to give [(131/124)I]Y-BP in good radiochemical yield. The biodistribution data showed the high selectivity of [(124)I]Y-BP in HT1376 human bladder cancer xenograft models with a tumor-to-muscle ratio of 6.2. This tumor targeting was not observed in control B16F10 melanoma tumor models. In microPET studies, while the control scrambled peptide, [(124)I]Y-sBP, did not accumulate in either the bladder cancer or melanoma, [(124)I]Y-BP showed high tumor uptake only in animals with HT1376 bladder cancer cells. Furthermore, [(124)I]Y-BP showed superior bladder cancer uptake even compared to most commonly used cancer imaging tracer, [(18)F]FDG. The experimental results suggest the potential of [(124)I]Y-BP as a new radiopharmaceutical for the non-invasive diagnosis of bladder cancer with high binding affinity and selectivity.

New macrobicyclic chelator for the development of ultrastable 64Cu-radiolabeled bioconjugate

Ethylene cross-bridged cyclam with two acetate pendant arms, ECB-TE2A, is known to form the most kinetically stable (64)Cu complexes. However, its usefulness as a bifunctional chelator is limited because of its harsh radiolabeling conditions. Herein, we report new cross-bridged cyclam chelator for the development of ultrastable (64)Cu-radiolabeled bioconjugates. Propylene cross-bridged TE2A (PCB-TE2A) was successfully synthesized in an efficient way. The Cu(II) complex of PCB-TE2A exhibited much higher kinetic stability than ECB-TE2A in acid decomplexation studies, and also showed high resistance to reduction-mediated demetalation. Furthermore, the quantitative radiolabeling of PCB-TE2A with (64)Cu was achieved under milder conditions compared to ECB-TE2A. Biodistribution studies strongly indicate that the (64)Cu complexes of PCB-TE2A cleared out rapidly from the body with minimum decomplexation.

The hOGG1 mutant genotype is associated with prostate cancer susceptibility and aggressive clinicopathological characteristics in the Korean population

BACKGROUND

The gene encoding human 8-oxoguanine glycosylase 1 (hOGG1) is involved in DNA base excision repair from oxidatively damaged DNA. A case-control study was conducted to evaluate the correlation between the susceptibility and clinicopathological outcomes of prostate cancer (CaP) and hOGG1 genotype.

PATIENTS AND METHODS

Subjects were recruited from 266 CaP patients and 266 age-matched benign prostatic hyperplasia patients. The hOGG1 codon 326 genotype was determined by peptide nucleic acid-mediated PCR clamping and compared with Gleason score and tumor stage.

RESULTS

The Cys allele at codon 326 of hOGG1 was associated with an increased risk of CaP in comparison with the Ser allele (P = 0.005). Gleason scores of 8 or higher were observed more often in patients with the mutant genotypes Ser/Cys and Cys/Cys than in those with a wild-type genotype (P = 0.045), and the Cys/Cys homozygous genotype was associated with a significantly higher risk of metastatic disease in comparison with the Ser/Ser genotype (P = 0.017).

CONCLUSIONS

These results suggest that hOGG1 is associated with the susceptibility to CaP and its aggressive clinicopathological characteristics.

Evaluation of kidney repair capacity using 99mTc-DMSA in ischemia/reperfusion injury models

Quantitative (99m)Tc-DMSA renal uptake was studied in different renal ischemia/reperfusion (I/R) mice models for the assessment of renal repair capacity. Mice models of nephrectomy, uni- and bi-lateral I/R together with sham-operated mice were established. At 1h, 1d, 4d, 1, 2 and 3 wk after I/R, (99m)Tc-DMSA (27.7 ± 1.3 MBq) was injected via tail vein and after 3h post-injection, the mice were scanned for 30 min with pinhole equipped gamma camera. Higher uptake of (99m)Tc-DMSA was measured in normal kidneys of uni-lateral I/R model and nephrectomized kidney I/R model at 3 wk post-surgery. Comparing the restoration capacities of the affected kidneys of nephrectomy, uni- and bi-lateral I/R models, higher repair capacity was observed in the nephrectomized model followed by bi-lateral then uni-lateral models. The normal kidney may retard the restoration of damaged kidney in uni-lateral I/R model. Moreover, 3 wk after Uni-I/R, the size of injured kidney was significantly smaller than non-ischemic contralateral and sham operated kidneys, while nephrectomy I/R kidneys were significantly enlarged compared to all others at 3 wk post-surgery. Very strong correlation between (99m)Tc-DMSA uptake and weight of dissected kidneys in I/R models was observed. Consistent with (99m)Tc-DMSA uptake results, all histological results indicate that kidney recovery after injury is correlated with the amount of intact tubules and kidney sizes. In summary, our study showed good potentials of (99m)Tc-DMSA scan as a promising non-invasive method for evaluation of kidney restoration after I/R injuries. Interestingly, mice with Bi-I/R injury showed faster repair capacity than those with uni-I/R.

Unusual findings in cerebral abscess: report of two cases

Markedly restricted water diffusion is a characteristic of purulent fluid in brain abscesses. We report two cases of brain abscesses with unusual diffusion findings.

A protein kinase from Colletotrichum trifolii is induced by plant cutin and is required for appressorium formation

When certain phytopathogenic fungi contact plant surfaces, specialized infection structures (appressoria) are produced that facilitate penetration of the plant external barrier; the cuticle. Recognition of this hydrophobic host surface must be sensed by the fungus, initiating the appropriate signaling pathway or pathways for pathogenic development. Using polymerase chain reaction and primers designed from mammalian protein kinase C sequences (PKC), we have isolated, cloned, and characterized a protein kinase from Colletotrichum trifolii, causal agent of alfalfa anthracnose. Though sequence analysis indicated conserved sequences in mammalian PKC genes, we were unable to induce activity of the fungal protein using known activators of PKC. Instead, we show that the C. trifolii gene, designated LIPK (lipid-induced protein kinase) is induced specifically by purified plant cutin or long-chain fatty acids which are monomeric constituents of cutin. PKC inhibitors prevented appressorium formation and, to a lesser extent, spore germination. Overexpression of LIPK resulted in multiple, abnormally shaped appressoria. Gene replacement of lipk yielded strains which were unable to develop appressoria and were unable to infect intact host plant tissue. However, these mutants were able to colonize host tissue following artificial wounding, resulting in typical anthracnose lesions. Taken together, these data indicate a central role in triggering infection structure formation for this protein kinase, which is induced specifically by components of the plant cuticle. Thus, the fungus is able to sense and use host surface chemistry to induce a protein kinase-mediated pathway that is required for pathogenic development.

Synthesis of (R)- and (S)-10,16-dihydroxyhexadecanoic acid: cutin stereochemistry and fungal activation

The first asymmetric syntheses of the cutin monomers (R)- and (S)-10,16-dihydroxyhexadecanoic acid (10,16-DHPA) and confirmation of (S)(+)-absolute configuration for 10,16-DHPA derived from tomato are reported. The individual DHPA stereoisomers display differences in their ability to activate the fungal pathogen Colletotrichum trifolii.

Clinical analysis of 34 diffuse axonal injured (DAI) patients below GCS 8

A consecutive series of 34 severe head-injured patients (DAI) were studied prospectively. Patients were categorized according to a new, simple classification system comprised of four lesion types according to the compression or obliteration of the ventricles or cisterns. Five patients belonged to type II and 19 patients to type IV. Each type was further subdivided into two GCS score ranges (5 to 8 and below 5). The distribution of the posttraumatic infarction was mainly in the frontal and temporal lobes (60% of all cases). Our data demonstrated that the ICP was significantly lower at a 30 degrees head elevation than at 0 degree (18.6 +/- 7.21 mmHg vs 23.0 +/- 10.60 mmHg. t = 4.22 P < 0.001), but head position did not statistically affect CPP (69.4 +/- 19.86 mmHg vs 68.2 +/- 19.87 mmHg. t = -0.54, P < 0.59). The effect of intensive therapy on ICP, CPP and AVDO2 was studied in all cases, employing steroids and diuretics in a modified intensive care scale. In cases where barbiturates were employed, there were statistically significant changes in ICP and AVDO2 (P < 0.001), but CPP was not affected (P < 0.59). Surviving patients were analyzed by using the GOS and the neurological grading score (NGS, Nihon University) of the persistent vegetative state. Our data suggests that head elevation of 30 degrees and barbiturate therapy are more effective on ICP and AVDO2, and NGS more exact than GOS in vegetative patients.

Intraventricular or epidural injection of morphine for severe pain

Intraventricular or epidural injection of morphine through implantable infusion devices was used for severe pain in 50 patients with advanced cancer, arachnoiditis, or spinal injury. Intraventricular catheter was inserted for injection of morphine in 21 patients, 29 were treated through epidural infusion. For the evaluation of results the multimodal evoked potential (MEP) has been obtained before and after each treatment. 80% of the patients experienced good results. No significant side effects have been noted in patients with either epidural or intraventricular injection of morphine. These may be excellent methods for pain control in well selected patients.

Giant global intracranial aneurysm in an infant

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Intra-arterial ACNU therapy for malignant brain tumors. Experimental studies and preliminary clinical results

The authors examined the growth rate of mouse 203 glioma cells in vitro and found it to be markedly inhibited after exposure to ACNU for 5 minutes at a drug concentration of 100 micrograms/ml. Rats that had undergone intracranial implantation of T1 neurogenic tumor were treated by 5 mg/kg of ACNU administered either intravenously or intra-arterially. The median survival times for the control animals and the animals undergoing intravenous or intracarotid administration of ACNU were 23, 29, and 46 days, respectively. The difference in survival time between the intravenous and intracarotid administration groups was statistically significant (p less than 0.01) when examined by the Cox-Mantel test. In a clinical trial, 17 patients with glioblastoma were treated by ACNU, eight intravenously and nine by the intra-arterial route. The drug was given in doses of 2 to 3 mg/kg at least twice before and twice after a course of postoperative radiotherapy. Intra-arterial administration was performed over a period of 5 minutes under local anesthesia. The median postoperative survival time for the patients in the intra-arterial group was 12.5 months, compared with 9.0 months for those in the intravenous group. The survival rate for the intra-arterial group was slightly higher, although statistically not significant, probably because the number of cases was small. The degree of thrombocytopenia due to ACNU tended to be less marked in the intra-arterially treated patients. The theoretical advantages of the intra-arterial administration of ACNU are discussed.

[Clinical analysis of 22 spinal neurinomas--with special reference to ct metrizamide myelography and CO2 laser--]

Twenty-two spinal neurinomas, admitted to the Department of Neurosurgery, Kyoto University Medical School during the past 40 years, were retrospectively analysed under the circumstances that most of lower spinal and or spinal cord tumors had usually been handled by orthopedic surgeons in Japan. Of the total of 22 cases, there were 14 cervical, 6 thoracic and 2 lumbar neurinomas. Age distribution was from 16 to 70 years of age with the average 38. Von Recklinghausen's disease accompanied spinal neurinoma in 4 cases. Of 3 cases under the age of 20, two were associated with von Recklinghausen's disease. Motor deficits were the prominent clinical symptoms on admission in 63% of the cases, while pains were the initial symptoms in 77% of the cases. Twenty-nine percent of cervical neurinomas were of dumbbell type, extending both in the intraspinal and extraspinal spaces. In addition to the conventional neuroradiologic investigations, CT metrizamide myelography was extremely advantageous in detecting the localization and relation of spinal neurinomas to the spine and spinal cord as well as bony changes. Laser surgery was utilized in the recent two cases of spinal neurinomas of dumbbell type. It was found useful in that it enabled intraspinal decompression by a non-touch technique prior to laminectomy.