Pharmacokinetic disposition of polyethylene glycol-modified salmon calcitonins in rats

This study first reports the pharmacokinetic disposition of polyethylene glycol (PEG)-modified salmon calcitonin (sCT) based on the number of attached PEG molecules. PEG-modified sCT was prepared by covalent linkage with succinimidyl carbonate monomethoxy polyethylene glycol. Mono- and di-PEG-sCTs were separated by size exclusion and reverse phase HPLC, and radioiodinated by the chloramine-T method with Na125I. 125I-mono-PEG sCT, 125I-di-PEG-sCT and unmodified 125I-sCT were administered to rats by i.v. injection. Serial blood samples, urine and various tissue samples were taken for the determination of radioactivity. Di-PEG-sCT exhibited significantly reduced systemic clearance (2.3 vs. 11.1 ml/min/kg) and steady-state volume of distribution (229.9 vs. 603.1 ml/kg), while mono-PEG-sCT showed a prolonged elimination half-life (189.1 min vs. 59.8 min) compared with unmodified sCT. The extent of urinary excretion of the PEG-modified sCTs was higher than for the unmodified sCT, but all these chemicals were excreted in urine in small quantities (< or = 0.6%). There was a tendency toward reduced accumulation of PEGylated sCTs in tissues, with its reduction being inversely proportional to the molecular size. Accumulation of the total radioactivity of the unmodified and PEG-modified sCTs was highest in the liver, followed by kidneys, lungs, spleen, heart and thyroid. When expressed per tissue gram weight, however, the highest radioactivity was found in the kidneys. PEGylated sCTs may have greater therapeutic potential via reduced systemic clearance and prolonged elimination half-life over unmodified sCT.

Effect of betulinic acid on intracellular-free Ca(2+) levels in Madin Darby canine kidney cells

The effect of betulinic acid, an anti-tumor and apoptosis-inducing natural product, on intracellular-free levels of Ca(2+) ([Ca(2+)](i)) in Madin Darby canine kidney (MDCK) cells was examined by using fura-2 as a Ca(2+) dye. Betulinic acid caused significant increases in [Ca(2+)](i) concentration dependently between 25 and 500 nM with an EC(50) of 100 nM. The [Ca(2+)](i) signal was composed of an initial gradual rise and a plateau. The response was decreased by removal of extracellular Ca(2+) by 45+/-10%. In Ca(2+)-free medium, pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) abolished 250 microM betulinic acid-induced [Ca(2+)](i) increases. Conversely, pretreatment with betulinic acid only partly inhibited thapsigargin-induced [Ca(2+)](i) increases. Addition of 3 mM Ca(2+) induced a [Ca(2+)](i) increase after pretreatment with 250 nM betulinic acid in Ca(2+)-free medium for 5 min. This [Ca(2+)](i) increase was not altered by the addition of 20 microM SKF96365 and 10 microM econazole. Inhibiting inositol 1,4,5-trisphosphate formation with the phospholipase C inhibitor U73122 (2 microM) abolished 250 nM betulinic acid-induced Ca(2+) release. Pretreatment with 10 microM La(3+) inhibited 250 nM betulinic acid-induced [Ca(2+)](i) increases by 85+/-3%; whereas 10 microM of verapamil, nifedipine and diltiazem had no effect. In Ca(2+) medium, pretreatment with 2.5 nM betulinic aid for 260 s potentiated 10 microM ATP and 1 microM thapsigargin-induced [Ca(2+)](i) increases by 33+/-3% and 45+/-3%, respectively. Trypan blue exclusion revealed that acute exposure of 250 nM betulinic acid for 2-30 min decreased cell viability by 6+/-2%, which could be prevented by pretreatment with 2 microM U731222. Together, the results suggest that betulinic acid induced significant [Ca(2+)](i) increases in MDCK cells in a concentration-dependent manner, and also induced mild cell death. The [Ca(2+)](i) signal was contributed by an inositol 1,4, 5-trisphosphate-dependent release of intracellular Ca(2+) from thapsigargin-sensitive stores, and by inducing Ca(2+) entry from extracellular medium in a La(3+)-sensitive manner.

NPC-14686, a novel anti-inflammatory agent, increased intracellular Ca(2+) concentrations in MDCK renal tubular cells

The effect of NPC-14686 (Fmoc-L-homophenylalanine), a novel anti-inflammatory agent on intracellular free Ca(2+) concentrations ([Ca(2+)](i)) in Madin Darby canine kidney (MDCK) renal tubular cells, was investigated, using fura-2 as a Ca(2+) dye. At concentrations between 10 and 200 microM NPC-14686 increased [Ca(2+)](i) concentration dependently. The [Ca(2+)](i) signal comprised an initial rise and a sustained phase. Ca(2+) removal inhibited the Ca(2+) signals by 90%. In Ca(2+)-free medium, pretreatment with 100 microM NPC-14686 nearly abolished the [Ca(2+)](i) increase induced by 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) and abolished the [Ca(2+)](i) increase induced by 2 microM carbonylcyanide m-chlorophenylhydrazone (CCCP) (a mitochondrial uncoupler). NPC-14686 (100 microM) induced a slight [Ca(2+)](i) increase after pretreatment with 2 microM CCCP and 1 microM thapsigargin. Addition of 3 mM Ca(2+) elicited a [Ca(2+)](i) increase in cells pretreated with 100 microM NPC-14686 in Ca(2+)-free medium. Inhibition of inositol-1,4,5-trisphosphate (IP(3)) production by suppressing phospholipase C with 2 microM U73122 did not alter NPC-14686-induced Ca(2+) release. Trypan blue exclusion revealed that incubation with 10 or 200 microM NPC-14686 for 1-30 min decreased cell viability by 10-20% concentration dependently. Collectively, the results demonstrate that, in MDCK tubular cells, NPC-14686 induced Ca(2+) release followed by Ca(2+) entry, with the latter playing a major role. NPC-14686 appears to release intracellular Ca(2+) in an IP(3)-uncoupled manner. NPC-14686 may be of mild cytotoxicity.

Exact zeros of the partition function for a continuum system with double gaussian peaks

We calculate the exact zeros of the partition function for a continuum system where the probability distribution for the order parameter is given by two asymmetric Gaussian peaks. When the positions of the two peaks coincide, the two separate loci of the zeros that used to give a first-order transition touch each other, with the density of zeros vanishing at the contact point on the positive real axis. Instead of the second-order transition of the Ehrenfest classification as one might naively expect, one finds a critical behavior in this limit.

Lindane (gamma-hexachlorocyclohexane) induces internal Ca2+ release and capacitative Ca2+ entry in Madin-Darby canine kidney cells

The effect of lindane (gamma-hexachlorocyclohexane), an organochlorine pesticide, on Ca2+ mobilization in Madin-Darby canine kidney cells was examined by fluorimetry using fura-2 as a Ca2+ indicator. Lindane (5-200 microM) increased [Ca2+]i concentration-dependently. The [Ca2+]i signal comprised an immediate initial rise followed by a persistent phase. Ca2+ removal inhibited the [Ca2+]i signal by reducing both the initial rise and the sustained phase. This implies lindane-triggered Ca2+ influx and Ca2+ release. In Ca2+ -free medium, 0.15 mM lindane increased [Ca2+]i after pretreatment with carbonylcyanide m-chlorophenylhydrazone (CCCP, 2 microM), a mitochondrial uncoupler, and two endoplasmic reticulum Ca2+ pump inhibitors, thapsigargin and cyclopiazonic acid. Conversely, pretreatment with lindane abolished CCCP- and thapsigargin-induced Ca2+ release. This suggests that 0.15 mM lindane released Ca2+ from the endoplasmic reticulum, mitochondria and other stores. La3+ (1 mM) partly inhibited 0.1 mM lindane-induced [Ca2+]i increase, confirming that lindane induced Ca2+ influx. Addition of 3 mM Ca2+ increased [Ca2+]i after pretreatment with 0.15 mM lindane for 750 sec. in Ca2+ -free medium, which indicates lindane-induced capacitative Ca2+ entry. Lindane (0.15 mM)-induced Ca2+ release was not reduced by inhibiting phospholipase C with 2 microM U73122, but was inhibited by 70% by the phospholipase A2 inhibitor aristolochic acid (40 microM).

Dual effect of tamoxifen, an anti-breast-cancer drug, on intracellular Ca(2+) and cytotoxicity in intact cells

The effect of tamoxifen on Ca(2+) signaling and viability in Madin Darby canine kidney (MDCK) cells was investigated by using fura-2 as a Ca(2+) probe. Tamoxifen evoked a rise in cytosolic free Ca(2+) levels ([Ca(2+)](i)) concentration-dependently between 1 and 50 microM with an EC50 of 10 microM. The response was decreased by extracellular Ca(2+) removal. In Ca(2+)-free medium, pretreatment with 5 microM tamoxifen abolished the [Ca(2+)](i) increase induced by the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (1 microM), but pretreatment with brefeldin A (50 microM; a Ca(2+) mobilizer of the Golgi complex), thapsigargin (an inhibitor of the endoplasmic reticulum Ca(2+) pump), and carbonylcyanide m-chlorophenylhydrazone (CCCP; a mitochondrial uncoupler), only partly inhibited tamoxifen-induced [Ca(2+)](i) increases. This suggests that tamoxifen released Ca(2+) from multiple pools. Addition of 3 mM Ca(2+) induced a [Ca(2+)](i) rise after pretreatment with 5 microM tamoxifen in Ca(2+)-free medium. Inhibiting inositol 1,4,5-trisphosphate formation with the phospholipase C inhibitor U73122 (2 microM) did not alter 5 microM tamoxifen-induced Ca(2+) release. The [Ca(2+)](i) increase induced by 5 microM tamoxifen was not altered by La(3+), nifedipine, verapamil, or diltiazem. Tamoxifen (1-10 microM) decreased cell viability in a concentration- and time-dependent manner. Tamoxifen (5 microM) also increased [Ca(2+)](i) in neutrophils, bladder cancer cells, and prostate cancer cells from humans and glioma cells from rats. Collectively, it was found that tamoxifen increased [Ca(2+)](i) in MDCK cells by releasing Ca(2+) from multiple Ca(2+) stores in a manner independent of the production of inositol 1,4, 5-trisphosphate and also by triggering Ca(2+) influx from extracellular space. The [Ca(2+)](i) increase was accompanied by cytotoxicity.

Dual action of palmitoyl trifluoromethyl ketone (PACOCF3) on Ca2+ signaling: activation of extracellular Ca2+ influx and alteration of ATP- and bradykinin-induced Ca2+ responses in Madin Darby canine kidney cells

The effect of the phospholipase A2 inhibitor palmitoyl trifluoromethyl ketone (PACOCF3) on Ca2+ signaling in Madin Darby canine kidney (MDCK) cells was examined using fura-2 as the fluorescent Ca2+ indicator. At a concentration of 20 microM, PACOCF3 did not change basal cytosolic free calcium concentrations ([Ca2+]i), but at concentrations of 50-250 microM PACOCF3 induced an increase in [Ca2+]i by activating extracellular Ca2+ entry which was partly suppressed by 50 microM La3+. The effect of PACOCF3 was abolished by removal of extracellular Ca2+. PACOCF3 (10 microM) enhanced both the peak value and the area under the curve of the [Ca2+]i increase induced by 10 microM ATP and 1 microM bradykinin by potentiating extracellular Ca2+ influx without affecting internal Ca2+ release. Several other phospholipase A2 inhibitors had no effect on basal [Ca2+]i or agonist-induced [Ca2+]i increases. Collectively, the results suggest that PACOCF3 alters Ca2+ signaling in renal tubular cells in a manner independent of phospholipase A2 inhibition.

Hepatitis B viral transactivator HBx alleviates p53-mediated repression of alpha-fetoprotein gene expression

Chronic infection with hepatitis B virus (HBV) is associated with development of hepatocellular carcinoma (HCC). The exact mechanism by which chronic infection with HBV contributes to onset of HCC is unknown. However, previous studies have implicated the HBV transactivator protein, HBx, in progression of HCC through its ability to bind the human tumor suppressor protein, p53. In this study, we have examined the ability of HBx to modify p53 regulation of the HCC tumor marker gene, alpha-fetoprotein (AFP). By utilizing in vitro chromatin assembly of DNA templates prior to transcription analysis, we have demonstrated that HBx functionally disrupts p53-mediated repression of AFP transcription through protein-protein interaction. HBx modification of p53 gene regulation is both tissue-specific and dependent upon the p53 binding element. Our data suggest that the mechanism by which HBx alleviates p53 repression of AFP transcription is through an association with DNA-bound p53, resulting in a loss of p53 interaction with liver-specific transcriptional co-repressors.

Janibacter terrae sp. nov., a bacterium isolated from soil around a wastewater treatment plant

A bacterial strain, CS12T, which was isolated from soil around a wastewater treatment plant, was subjected to a polyphasic taxonomic study using phenotypic characterizations and genetic methods. The cell wall of strain CS12T contains meso-diaminopimelic acid as the diamino acid but no arabinose and galactose. The predominant menaquinone is MK-8(H4). Mycolic acids are absent. Strain CS12T has a cellular fatty acid profile containing saturated, unsaturated, branched and 10-methyl fatty acids. The major fatty acids are iso-C16:0, C18:1 omega9c and anteiso-C17:0, The G+C content is 69 mol%. A phylogenetic tree based on 16S rDNA sequences showed that strain CS12T forms an evolutionary lineage within the radiation enclosing the members of the family Intrasporangiaceae and, in particular, a coherent cluster with Janibacter limosus DSM 11140T. The level of 16S rDNA similarity between strain CS12T and J. limosus DSM 11140T is 98.7%. The phenotypic characteristics and DNA-DNA relatedness data indicate that strain CS12T should be distinguished from J. limosus DSM 11140T. Therefore, on the basis of the data presented, a new species of the genus Janibacter, Janibacter terrae, is proposed. The type strain of the new species is strain CS12T (= KCCM 80001T = JCM 10705T).

Fractionated stereotactic radiation therapy for extracranial head and neck tumors

BACKGROUND

This study is to report the clinical experiences of fractionated stereotactic radiation therapy (FSRT) for extracranial head and neck tumors.

METHODS AND MATERIALS

Between the period of July 1995 and November 1998, 48 patients with extracranial head and neck tumors were given FSRT as a boost and sole modality. Individualized treatment planning was performed using XKnife-3 system with relocatable Gill-Thomas-Cosman frame. In 24 patients, FSRT was applied as a boost technique following the 2-dimensional conventional external radiation therapy (ERT); in 24 patients FSRT was the sole radiotherapy modality. The primary diseases in the boost group consisted of nasopharynx cancer (19), lacrimal gland adenoid cystic carcinoma (3), orbital lymphoma (1), and skull-base recurrence of maxillary sinus adenoid cystic carcinoma (1). The primary diseases in the sole modality group consisted of recurrent nasopharynx cancer (12), orbital pseudotumor (4), skull-base recurrence of maxillary sinus, submandibular gland, and hypopharynx cancers (3), orbital rhabdomyosarcoma (2), orbital lymphoma (1), orbital metastasis of neuroblastoma (1), and nasal cavity melanoma (1). The fractionation schedule was to give 5 treatments per one week and the fractional doses were 2.0-3 Gy depending on the treatment aim and the FSRT volume. The FSRT doses varied depending on the nature of the primary diseases.

RESULTS

The local tumor response in nasopharynx cancer patients was excellent compared to retrospective data without occurrence of unexpectedly severe complication. FSRT to other regions was well tolerated by the patients and resulted in good to excellent local tumor responses with no unacceptable side effects as expected by the authors.

CONCLUSION

Based on the current observations, FSRT is a very effective and safe modality in the treatment of extracranial head and neck tumors.

Syndrome myxoma presenting as a pulmonary embolism: a case report

Although the incidence of primary cardiac tumors is approximately 0.28%, they are encountered in every age group and their clinical presentation usually resembles that of other cardiac or systemic diseases. The clinical symptoms of primary cardiac tumors are usually few until they are at an advanced critical stage making early diagnosis and treatment problematic. However, there is a subgroup of patients who may present with extracardiac systemic, endocrinologic or cutaneous manifestations and familiar inheritance allowing for early detection. This article describes the diagnosis and treatment of a young female who presented with an acute thromboembolic complication of an intracardiac myxoma.

Selection of treatment modalities for cerebral arteriovenous malformations: a retrospective analysis of 348 consecutive cases

The objective was to establish the selection criteria for the optimal management modalities for cerebral arteriovenous malformations. We analysed the complications and late outcomes in 348 consecutive cases (132 microsurgical resections, 202 stereotactic radiosurgeries, 8 embolisations only, 6 combined treatments) managed at Yonsei University Hospital from 1988 to 1997. Files for all patients were analysed. The outcome was classified into good for the patients who returned to their previous job with or without neurological deficits, fair for the patients who were unable to return to work but performed daily activities independently with minor deficits, and poor for the patients who were performing dependent daily activities with major deficits. The outcome of microsurgery was considered good in 108 patients (81.8%), fair in 18 (13.6%), poor in 4 (3.1%), and 2 (1.5%) patients died. Initial insults and haemodynamic complications were the major cause of an unfavourable outcome. The cumulative occlusion rate of the nidus after radiosurgery was 10.2% within 12 months, 75.3% within 24 months, and 89.8% within 36 months. Perilesional imaging changes with neurological deficits (4 permanent and 6 transient, 4.8%) and haemorrhage (16 patients, 7.7%) during the latent interval were the major cause of an unfavourable outcome (1 poor, 4 dead after radiosurgery). Postradiosurgery bleeding occurred frequently within 6 months (6 patients), and between 13 and 24 months (8 patients). In conclusion, selection of treatment modality for cerebral AVMs depends on the preoperative evaluation of the risk/benefit ratio in each case. Microsurgical removal, which eliminates the risk of bleeding immediately, is preferred for lesions in non-eloquent areas. Radiosurgery is an effective treatment modality for small lesions in eloquent areas, but has a substantial risk of haemorrhage during the latency period. Results of this study suggest that microsurgical removal should be considered for lesions in eloquent areas with high haemorrhage risk, such as prior haemorrhage, medium to large size lesion, and single deep venous drainage.

SNARE protein trafficking in polarized MDCK cells

A key feature of polarized epithelial cells is the ability to maintain the specific biochemical composition of the apical and basolateral plasma membrane domains. This polarity is generated and maintained by the continuous sorting of apical and basolateral components in the secretory and endocytic pathways. Soluble N-ethyl maleimide-sensitive factor attachment protein receptors (SNARE) proteins of vesicle-associated membrane protein (VAMP) and syntaxin families have been suggested to play a role in the biosynthetic transport to the apical and basolateral plasma membranes of polarized cells, where they likely mediate membrane fusion. To investigate the involvement of SNARE proteins in membrane trafficking to the apical and basolateral plasma membrane in the endocytic pathway we have monitored the recycling of various VAMP and syntaxin molecules between intracellular compartments and the two plasma membrane domains in Madin-Darby canine kidney (MDCK) cells. Here we show that VAMP8/endobrevin cycles through the apical but not through the basolateral plasma membrane. Furthermore, we found that VAMP8 localizes to apical endosomal membranes in nephric tubule epithelium and in MDCK cells. This asymmetry in localization and cycling behavior suggests that VAMP8/endobrevin may play a role in apical endosomal trafficking in polarized epithelium cells.

c-kit immunocytochemical staining in the cytologic diagnosis of metastatic gastrointestinal stromal tumor. A report of two cases

BACKGROUND

Gastrointestinal stromal tumor (GIST) is a distinct group of mesenchymal neoplasms recently shown to exhibit differentiation toward interstitial cells of Cajal (ICC). C-kit (CD117), an immunocytochemical marker consistently expressed in normal ICC, is demonstrable in 81-100% of GISTs. We report two cases wherein immunocytochemical staining for c-kit aided in the diagnosis of metastatic GIST in the liver.

CASES

Two patients, a 37-year-old female (case 1) and a 76-year-old male (case 2), presented with multiple nodules in the liver. They had a history of small bowel GIST resected 11 and 1 year earlier, respectively. Fine needle aspiration of the liver nodules showed loose aggregates or fascicles of spindle cells with elongated to oval nuclei, rare paranuclear vacuoles and eosinophilic cytoplasm. The spindle cells showed minimal (case 1) to moderate nuclear pleomorphism (case 2), with occasional mitotic figures seen in case 2. Immunocytochemical staining revealed strong and diffuse staining for c-kit; it was negative for actin, desmin, CD34 and S-100 protein. Thus, a diagnosis of metastatic GIST was rendered. Histologic review of the primary small bowel GISTs of both cases and the subsequently resected liver nodules in case 1 confirmed the diagnosis.

CONCLUSION

Metastatic GIST may pose diagnostic problems due to its broad morphologic spectrum and variable cytologic atypia; in particular, distinction from leiomyosarcoma and other mesenchymal tumors is difficult. The diagnostic difficulty is compounded when the prior history of gastrointestinal tumor is not available or forgotten and when GIST is the initial presentation of the tumor. C-kit is a highly sensitive and reliable immunocytochemical marker that can aid in the diagnosis.

Prompt radiation oncology record access by patient centered digital image chart system

The authors have developed and evaluated a radiation oncology digital image chart system (RODICS). With this system we could achieve paperless and filmless practice, and thus improved operational efficiency within the department. In this paper, we describe characteristics and clinical usage of RODICS.

Differential modulatory roles of cholera toxin and pertussis toxin in the regulation of pain responses induced by excitatory amino acids administered intrathecally in mice

The present study was designed to characterize the possible roles of spinally located cholera toxin (CTX)- and pertussis toxin (PTX)-sensitive G-proteins in excitatory amino acids induced pain response. Intrathecal (i.t.) injection of glutamate (20 microg), N-methyl-D-aspartic acid (NMDA; 60 ng), alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA; 13 ng), and kainic acid (12 ng) showed pain response. Pretreatment with CTX (0.05 and 0.5 microg, i.t.) attenuated pain response induced by glutamate, NMDA, AMPA and kainic acid administered i.t. in a dose-dependent manner. On the other hand, i.t. pretreatment with PTX further increased the pain response induced by glutamate, NMDA, AMPA and kainic acid administered i.t., especially at the dose of 0.5 microg. Our results suggest that, at the spinal cord level, CTX- and PTX-sensitive G-proteins appear to play opposite roles in modulating the pain response induced by spinally administered. Furthermore, CTX- and PTX-sensitive G-proteins appear to modulate pain response induced by stimuli of both NMDA and non-NMDA glutamate receptors.

Absorption, first-pass metabolism, and disposition of itraconazole in rats

This study examined the pharmacokinetic disposition, oral absorption and hepatic extraction of itraconazole and its active metabolite, hydroxyitraconazole, in rats. After i.v. injection, serum itraconazole concentrations decreased biexponentially, with an average terminal elimination half-life, volume of distribution and systemic clearance of 4.9 h, 6.0 l/kg and 14.2 ml/min/kg, respectively. When given orally, its absorption was low, with a mean absolute bioavailability of 16.6%. The metabolite to parent drug area under the curve (AUC) ratio was higher after oral administration compared with i.v. injection (mean ratio, 2.7 vs. 0.9). The hepatic drug extraction ratio determined after femoral and portal vein administration averaged 18.5%. When hydroxyitraconazole was injected i.v., the elimination half-life, volume of distribution and systemic clearance of itraconazole averaged 10.0 h, 2.4 l/kg and 3.4 ml/min/kg, respectively. The fraction of the systemically available itraconazole that was metabolized to hydroxyitraconazole was 21.0% and 76.0% after i.v. and oral administration, respectively. In summary, this study is the first reporting the hepatic extraction of itraconazole and the i.v. disposition characteristics of hydroxyitraconazole in rats. Itraconazole is a drug with a low hepatic extraction ratio and its systemic clearance appears to be largely accounted for by hepatic metabolism.

Biodistribution and genetic stability of the novel antitumor agent VNP20009, a genetically modified strain of Salmonella typhimurium

VNP20009 is a genetically modified strain of Salmonella typhimurium possessing an excellent safety profile, including genetically stable attenuated virulence (a deletion in the purI gene), reduction of septic shock potential (a deletion in the msbB gene), and antibiotic susceptibility. VNP20009 is genetically stable after multiple generations in vitro and in vivo. In mice, VNP20009 is rapidly cleared from the blood from a peak level of 1x104 cfu/mL to undetectable levels in 24 h. In tumor-bearing mice, VNP20009 accumulates preferentially in tumors over livers at a ratio of 1000&rcolon;1. In nonhuman primates, VNP20009 was also rapidly cleared from the blood, from a peak level of 1.0x106 cfu/mL to undetectable levels in 24 h. VNP20009 was detected in the liver, spleen, and bone marrow of monkeys; the amount decreased over time, and VNP20009 was cleared from all organs by day 41; no VNP20009 could be detected in the urine or feces of the monkeys. VNP20009 is genetically stable after many generations of growth (>140) both in vitro and in vivo.

The C282Y mutation of the HFE gene is not found in Chinese haemochromatotic patients: multicentre retrospective study

OBJECTIVE

To detect two novel mutations (C282Y and H63D) of the HFE gene in Chinese patients with hepatic iron overload.

DESIGN

Multicentre retrospective study.

SETTING

Four public hospitals, Hong Kong.

PARTICIPANTS

Fifty Chinese patients who presented from January 1987 through December 1999 with hepatic iron overload from various causes.

MAIN OUTCOME MEASURES

The DNA from liver biopsy samples was tested for HFE mutations by restriction fragment length polymorphism analysis.

RESULTS

The sample DNA quality was unsatisfactory for analysis of the C282Y mutation in one case and the H63D mutation in nine cases. The C282Y mutation was not detected in any of the 49 satisfactory samples. Three of the 41 samples were heterozygous for the H63D mutation and only one was homozygous, giving an allele frequency of 6.1%. Of the three H63D-heterozygotes, one had beta-thalassaemia major, one had beta-thalassaemia minor, and one had hereditary spherocytosis. None of the 12 patients who were presumed to have primary haemochromatosis were positive for either mutation.

CONCLUSIONS

The classical form of human leukocyte antigen-linked hereditary haemochromatosis appears to be absent form this locality. The H63D mutation is found in a minority (9.8%) of the patients, in whom it may act synergistically with an erythropoietic factor.

Vitamin D receptor gene polymorphisms influence susceptibility to type 1 diabetes mellitus in the Taiwanese population

OBJECTIVE

Vitamin D and its receptor have been suggested to play a role in the pathogenesis of type 1 diabetes mellitus. We have therefore studied the influence of vitamin D receptor (VDR) gene polymorphisms on susceptibility to type 1 diabetes, and rates of glutamic acid decarboxylase (GAD65) autoantibody and islet cell autoantibody (ICA512) positivity.

SUBJECTS

AND MEASUREMENTS One hundred and fifty-seven type 1 diabetic patients and 248 unrelated normal controls were recruited for this study. Genomic DNA was extracted from peripheral blood leucocytes. All type 1 diabetic patients and controls were genotyped using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), for three restriction sites in the VDR gene, BsmI, ApaI and TaqI. The chi2 test was used to compare the frequency of the VDR gene polymorphisms in patients and normal controls. The association of VDR gene polymorphisms in type 1 diabetes with the presence of GAD65 and ICA512 autoantibodies were also examined using the chi2 test.

RESULTS

The allele frequency of the BsmI and ApaI polymorphisms, but not TaqI polymorphism, differed between patients and controls (BsmI P = 0.015; ApaI P = 0.018; TaqI P = 0.266). However, after correction for the three different polymorphisms tested, only the BsmI was significant (pc = 0.045).

CONCLUSIONS

Vitamin D receptor gene polymorphisms were associated with type 1 diabetes in a Taiwanese population. However, functional studies are needed to establish the role of the vitamin D receptor in the pathogenesis of type 1 diabetes mellitus.

Somatotropin and adipose tissue metabolism: substrate and temporal effects

The purpose of these studies was to determine the time course for changes in feed intake, blood metabolites, and lipogenic activity in adipose tissue in response to the initiation of porcine somatotropin (pST) treatment and following withdrawal from treatment in barrows. An initial study was conducted to determine the impact of chronic pST treatment (4 wk of daily injection; 0 vs 4 mg/d) on adipose tissue lipid metabolism in barrows (initial weight 67 kg). Feed efficiency was improved 27%, backfat thickness was decreased 43%, and glucose and lactate oxidation and incorporation into lipid in adipose tissue was reduced 70 to 86% in pST-treated pigs. Palmitate esterification was decreased 44%, whereas palmitate oxidation was unaffected. In vitro metabolism of lactate, glucose, and palmitate in liver slices was not affected by pST treatment. The time-course for changes in intake and adipose tissue metabolism in response to 7 d of pST (0 vs 4 mg/d) treatment and 7 d of withdrawal was examined in subsequent studies in barrows (initial weight 75 kg). Feed intake during pST treatment was significantly (P < .05) less than in control pigs within 24 h of the initiation of treatment and remained low through 3 d after withdrawal. Adipose tissue biopsies were obtained on d 0, 1, 2, 4, and 7 of the treatment phase and on d 2, 4, and 7 after withdrawal from 7 d of treatment. Maximal inhibition of lipogenesis by pST treatment in adipose tissue in vitro was observed on d 4 (-68%) and d 7 (-69%). Similarly, fatty acid synthase activity declined during the treatment period, with the greatest change noted on d 7 (-26%). After withdrawal from treatment, lipogenesis gradually increased, returning to control values 7 d after withdrawal. Levels of IGF-I began to increase from d 1 to d 7 of treatment, continually decreased during withdrawal, and were normalized by the end of the withdrawal period. Plasma urea nitrogen concentrations decreased during treatment, increased during the withdrawal phase, and were normalized 4 d after the last pST treatment. Overall results indicate that most of the metabolic changes in response to pST occur within 1 wk of treatment and return to pretreatment values after 7 d of withdrawal from treatment.

Emergency surgical recanalisation of A1 segment occluded by a Guglielmi detachable coil

We describe a case of A1 segment occlusion caused by a tangled Guglielmi detachable coil (GDC) during an endovascular treatment for a ruptured anterior communicating aneurysm. Immediate surgical recanalisation of the occluded artery and clipping of the aneurysm rescued the patient. This case demonstrates that an emergency surgical team, as well as an operating room, should be available during any complicated intra-aneurysmal procedure, so that timely surgical intervention could be carried out without delay.

Regulation of bcl-2 family in hydrogen peroxide-induced apoptosis in human leukemia HL-60 cells

Numerous types of cells have been shown to undergo apoptosis when exposed to oxidant agent such as hydrogen peroxide. In order to understand the functional relationship between the anti- and pro-apoptotic regulatory proteins in the cells under oxidant stress, we have studied the level of expression of apoptosis regulatory proteins, bcl-2 and bax, in human leukemia HL-60 cells. The exposure of HL-60 cells to different concentrations of H2O2 for 6 h resulted in a typical apoptosis of the cells as characterized by flow cytometry, cell cycle analysis, and DNA fragmantation. There was a block in G1 to S transition and apoptotic cells were mainly derived from S and G2 cells. Kinetic study demonstrated that the levels of both bcl-2-mRNA and -protein expression were decreased with the progression of cellular apoptosis whereas the level of bax-mRNA was unchanged but the expressed bax-protein was not detectable. Cycloheximide, a nonspecific translation inhibitor, did not prevent the hydrogen peroxide-mediated apoptosis in HL-60 cells. These results suggest that the regulation of bcl-2, but not of bax are important factor in the oxidative stress-induced apoptosis in HL-60 cells.

Differential potentiative effects of GABA receptor agonists in the production of antinociception induced by morphine and beta-endorphin administered intrathecally in the mouse

The effect of muscimol or baclofen injected intrathecally (i.t.) on the inhibition of the tail-flick response induced by morphine and beta-endorphin administered i.t. was studied in ICR mice. The i.t. injection of muscimol (100 ng) or baclofen (10 ng) alone did not affect the basal inhibition of the tail-flick response. Morphine (0.2 microg) and beta-endorphin (0.1 microg) caused only slight inhibition of the tail-flick response. Baclofen, but not muscimol, injected i.t. enhanced the inhibition of the tail-flick response induced by i.t. administered morphine. Both muscimol and baclofen injected i.t. significantly enhanced i.t. injected beta-endorphin-induced inhibition of the tail-flick response. Our results suggest that the GABA(B), but not GABA(A), receptors located in the spinal cord appear to be involved in enhancing the inhibition of the tail-flick response induced by morphine administered spinally. In addition, both GABA(A) and GABA(B) receptors are involved in enhancing the inhibition of the tail-flick response induced by beta-endorphin administered i.t.

A glass compensator filter to improve breast image quality in radiation therapy simulation

PURPOSE

To improve the image quality of simulation films in tangential radiotherapy for breast cancer, we have designed a new compensator filter for the variation of breast contour using high-density-glass material.

METHODS AND MATERIALS

The measurements and analyses of the body contour were done using CT scans, taken in the treatment position, of 20 breast cancer patients. The maximum tissue deficit that needed to be compensated for was 8 cm, and the authors fabricated the compensator system using high-density-glass material to maintain transparency. The glass compensator can be attached to the accessory mount of the simulator head and its position can be easily adjusted according to breast shape and position. The image qualities of simulation films taken with and without the glass compensator in tangential breast radiotherapy field were compared and the film densitometry was performed using the humanoid phantom.

RESULTS

Using this compensator system, the overall image quality improved, resulting in enhanced contrast and resolution of the breast simulation image. The delineator wires for the beam margins were also well depicted, and the surgical clips within the breast tissue can be easily demonstrated. The film densitometry resulted in much less saturation over the breast tissue when using the glass compensator.

CONCLUSION

Using the glass compensator system, the geographical miss may be reduced with the virtue of the improved image quality.

Subcutaneous nodules attributed to nocardiosis in a renal transplant recipient on tacrolimus therapy

We report a renal transplant patient who suffered from disseminated nocardiosis after empirical tacrolimus rescue therapy for chronic allograft rejection. The nocardiosis presented initially as only mildly tender subcutaneous calf nodules without any other signs of inflammation nor constitutional upset, which later spread to the lung and brain causing bronchopneumonia and brain abscesses. The risk factors for nocardial infection in our patient include the use of potent immunosuppressive agents such as tacrolimus, poorly controlled diabetes mellitus and kidney dysfunction. She responded well to combination antibiotic therapy comprising parenteral meropenem, cefotaxime and oral minocycline. We conclude that in transplant recipients, especially those receiving newer and more potent immunosuppressive agents like tacrolimus, nocardial infection can present as apparently 'cold' subcutaneous nodules without any systemic upset. An associated brain lesion should be excluded even in patients without neurological symptoms.

Nontraumatic nasal septal abscesses in the immunocompromised: etiology, recognition, treatment, and sequelae

Proper management of a nasal septal abscess requires prompt diagnosis, adequate surgical drainage, and antibiotics to prevent the potentially dangerous spread of infection and the development of severe functional and cosmetic sequelae. Most septal abscesses are the result of trauma to the nose with septal hematoma and subsequent infection. We present our experience with nasal septal abscesses in five immunocompromised patients without history of nasal trauma. All patients were treated with surgical drainage and antibiotics. The infections in four patients resolved, whereas in the fifth, the infection led to death. We report these cases to depict alternate etiologies of nasal septal abscess, particularly in the immunocompromised patient. Our review illustrates the wide spectrum of disease presentation, provides treatment strategies, and emphasizes the potentially catastrophic sequelae of this disease when unrecognized. With the growing number of immunocompromised individuals, it is important to recognize the potential for immunocompromise to influence the development of septal abscess.

Giant cisterna chyli: MRI depiction with gadolinium-DTPA enhancement

AIM

To demonstrate the use of MRI with Gadolinium-DTPA enhancement in the diagnosis of giant cisterna chyli.

MATERIALS AND METHODS

The study consisted of contrast enhanced MRI with ultrasound and CT correlation in three patients with a giant cisterna chyli. An analysis of the morphology, location and post-contrast MR signal characteristics in relation to time was performed.

RESULTS

Cisterna chyli has a characteristic lobulated morphology and location but the unenhanced MRI appearances are not specific. The post-Gadolinium-DTPA MRI appearances are critically dependent on the time elapsed after injection of contrast medium. Within the first 5 min, there is no enhancement at all, but by 10 min there is early layering of contrast medium evident, which by 30 min produces a clear fluid-fluid level. Delayed images at 4-5 h demonstrate a uniform enhancement of the cisternal contents producing a homogeneous intermediate signal. All of these features are best visualized on T1 fast saturation sequences.

CONCLUSION

MRI with Gadolinium-DTPA enhancement is valuable in confirming the nature of the lymphatic ducts in the retroperitoneal space and helps to differentiate these normal structures from alternative lesions such as lymphadenopathy and tumour recurrence.

Trucut needle biopsy through superior orbital fissure for the diagnosis of rabies

Necropsy diagnosis of rabies can be done by taking a brain biopsy specimen with a trucut needle inserted through the superior orbital fissure into the cranial cavity. This technique reduces the number of personnel who require post-exposure prophylaxis and avoids full necropsy if the deceased's relatives are opposed.

Comparison of incidence of gastroesophageal reflux and regurgitation associated with timing of removal of the laryngeal mask airway: on appearance of signs of rejection versus after recovery of consciousness

STUDY OBJECTIVES

To compare the incidence of gastroesophageal reflux and regurgitation associated with laryngeal mask airway (LMA) removal when signs of rejecting the LMA, such as swallowing, struggling, and restlessness, were observed and when the patient could open his or her mouth on command.

DESIGN

Randomized clinical trial.

SETTING

Operating room and recovery room of a tertiary care referral hospital.

PATIENTS

63 ASA physical status I and II adult patients scheduled for elective orthopedic surgery.

INTERVENTIONS

Using a standardized general anesthetic technique, patients were allocated randomly to Group A (n = 34; LMA removed when signs of rejection, such as swallowing, struggling, and restlessness, were observed) or Group B (n = 29; LMA removed when the patient could open his or her mouth on command).

MEASUREMENTS AND MAIN RESULTS

To detect gastroesophageal reflux throughout anesthesia, a pH monitoring probe was positioned in the lower esophagus on the day before surgery. To assess regurgitation during emergence, a gelatin capsule of methylene blue (50 mg) was swallowed prior to induction. At the end of anesthesia, episodes of reflux and regurgitation of gastric contents were analyzed/determined by pH below 4 and bluish staining of the pharynx and/or LMA, respectively. Physical events such as bucking, straining, and coughing during the arousal phase were recorded in both groups by an independent observer. The incidence of reflux (pH < 4) from the time of the appearance of rejection signs to LMA removal and the total incidence of reflux in Group B were significantly higher than in Group A (p < 0.05). Staining of the LMA and the pharynx by methylene blue was not observed in patients from either experimental group. The number of physical events in Group B during the arousal phase was significantly increased compared to Group A (p < 0.05). Considering all patients in Group A and Group B, physical events were associated with the occurrence of reflux (p < 0.05). Desaturation (SpO2 < 95%) and clinical evidence of aspiration of gastric contents did not occur in either group.

CONCLUSION

Maintenance of the LMA until the patient can open his or her mouth on command increases the incidence of gastroesophageal reflux.

Increased bioavailability of clomipramine after sublingual administration in rats

This study examined the absorption and disposition of clomipramine in rats after sublingual (5 and 50 mg/kg), oral (50 mg/kg), and iv (5 mg/kg) administration. The mean oral bioavailability of clomipramine was 24.8% and 29.7%, respectively, in conscious rats and in rats anesthetized with ketamine/xylazine (30/3 mg/kg). When given sublingually in isotonic saline at a dose of 50 mg/kg, clomipramine was rapidly absorbed, and the mean absolute bioavailability (36.2%) was increased over oral dosing. The mean AUC values of clomipramine were 2258 +/- 1762 ng.h/mL and 1891 +/- 867 ng.h/mL after oral administration to conscious and anesthetized rats, respectively, and 3303 +/- 1576 ng.h/mL after sublingual administration to anesthetized rats. Sublingual administration (5 mg/kg doses) of clomipramine formulated with a permeation enhancer, 2-hydroxypropyl beta-cyclodextrin, further increased the sublingual bioavailability to 57.1%. The sublingual route may be an alternative route of administration of clomipramine, providing enhanced bioavailability.

Variability of P1 protein of zucchini yellow mosaic virus for strain differentiation and phylogenetic analysis with other potyviruses

The complete nucleotide sequence of a Singapore isolate of zucchini yellow mosaic potyvirus (ZYMV-S) was determined from viral cDNA clones. The complete genome is 9603 nucleotides in length excluding the poly (A) tail. Computer analysis of the sequence revealed a single large open reading frame (ORF) that presumably encodes a polyprotein of 3082 amino acids with a calculated molecular weight of 350 kDa. Analysis of the helper component (HC) protein showed that the highly conserved motif K-I-T-C which is involved in aphid transmission appeared as K-L-S-C. There is also a change of D-A-G to G-A-G triplet near the N-terminal of the coat protein (CP). Amino acid sequence identity comparison of ZYMV-S gene products with the California and Reunion Island isolates of ZYMV revealed a minimum range of 65-75% to a maximum range of 95-98%. Comparison with other distinct potyviruses showed a low degree of identity from 19-74%. The 5' untranslated region (UTR) of ZYMV-S showed 67% and 72% identity when compared with the California and Reunion Island isolates, respectively. The sequence variability in the 5' UTR of ZYMV can be exploited for strain differentiation and phylogenetic analysis. ZYMV-S shared 94% and 82% identity in the 3' UTR as compared to the California and Reunion Island isolates, respectively. The P1 protein of ZYMV-S shared moderate sequence variability among ZYMV isolates but high sequence variability among all potyviruses. In addition, phylogenetic analysis using the P1 protein indicated that highly variable proteins in the viral genome could also be employed in the study of potyvirus taxonomy and used for strain differentiation.

Stability and cytotoxicity of Fab-ricin A immunotoxins prepared with water soluble long chain heterobifunctional crosslinking agents

The effects of the hindered and non-hindered water soluble long-chain disulfide bonds on the stability and cytotoxicity of the ricin A chain (RTA) immunotoxin were examined. The RTA immunotoxins were prepared with the Fab fragments of anti-common acute lymphoblastic leukemia antigen (CALLA) monoclonal antibody (Fab-RTA) using sulfosuccinimidyl-6-[(-methyl-(-(2-pyridyldithio)toluamido]hexanoate (S-LC-SMPT) and sulfosuccinimidyl-6-[3-(2-pyridyldithio)-propionamido]hexanoate (S-LC-SPDP). The prepared Fab-RTA immunotoxins were evaluated for their conjugation yield, immunoreactivity, thermal and disulfide bond stability and cytotoxicity. The conjugation yield of the Fab-RTA immunotoxin from the water soluble long chain crosslinking agents, S-LC-SMPT and S-LC-SPDP, were comparable. Both Fab-RTA immunotoxins exhibited a similar immunoreactivity and thermal stability in aqueous solution. However, S-LC-SMPT -mediated Fab-RTA, sterically hindered, showed an enhanced disulfide bond stability in vitro over S-LC-SPDP mediated one. In the cytotoxicity against antigenic cell Daudi, the S-LC-SMPT -mediated RTA immunotoxin maintained a comparable cytotoxicity, compared with S-LC-SPDP mediated Fab-RTA immunotoxin.

Presence of donor- and recipient-derived DNA in cell-free urine samples of renal transplantation recipients: urinary DNA chimerism

BACKGROUND

Previous studies have indicated that microchimerism is present in body tissues, peripheral blood, and plasma of recipients after organ transplantation. We hypothesize that donor-derived DNA may also be present in cell-free urine of renal transplant recipients and that the concentrations of urine DNA may be correlated with graft rejection.

METHODS

Thirty-one female patients who had renal transplantation were enrolled in the study. In women with male organ donors, the SRY gene on the Y chromosome was used as a marker for donor-derived DNA. Real-time quantitative PCR for the SRY and beta-globin genes was carried out on cell-free urinary DNA from these patients. Serial urine samples from a female renal transplant recipient undergoing an acute rejection episode were also collected and analyzed with the beta-globin quantitative PCR system.

RESULTS

SRY sequences were detected in the urine of 14 of 17 female patients with male organ donors. None of the 14 patients with female organ donors had detectable SRY sequences in urinary DNA. The median fractional concentration of donor-derived DNA was 8.7% (interquartile range, 1.9-26.4%). During the acute rejection episode, urinary concentrations of the beta-globin gene were markedly increased, with the concentrations returning rapidly to normal following antirejection treatment.

CONCLUSIONS

Our results demonstrate that urinary DNA chimerism is present following renal transplantation. The measurement of urinary DNA using quantitative PCR may be useful for the diagnosis and monitoring of graft rejection.

Primary non-Hodgkin's lymphoma of the breast: breast conservation therapy in two patients

We report two patients with primary non-Hodgkin's lymphoma of the breast who were treated with breast conservation therapy. These two patients were diagnosed with primary breast lymphoma by fine-needle aspiration cytology and underwent tumorectomy followed by adjuvant chemoradiation therapy. Follow-up studies showed that the two patients were free of disease for two and three years, respectively. To date, there exists no therapeutic standard for this disease and there is no survival advantage for patients who undergo radical mastectomy. Despite the rarity of lymphoma in the breast, a preoperative accurate diagnosis is essential so that unnecessary, extended breast ablation or delayed treatment is avoided. Cytologic diagnosis of breast lymphoma is an easy procedure and provides guidance for appropriate preoperative management. Early diagnosis combined with breast conservation therapy and systemic adjuvant therapy results in a favorable outcome for patients with breast lymphoma.

Hepatocyte nuclear factor 3 relieves chromatin-mediated repression of the alpha-fetoprotein gene

The alpha-fetoprotein gene (AFP) is tightly regulated at the tissue-specific level, with expression confined to endoderm-derived cells. We have reconstituted AFP transcription on chromatin-assembled DNA templates in vitro. Our studies show that chromatin assembly is essential for hepatic-specific expression of the AFP gene. While nucleosome-free AFP DNA is robustly transcribed in vitro by both cervical (HeLa) and hepatocellular (HepG2) carcinoma extracts, the general transcription factors and transactivators present in HeLa extract cannot relieve chromatin-mediated repression of AFP. In contrast, preincubation with either HepG2 extract or HeLa extract supplemented with recombinant hepatocyte nuclear factor 3 alpha (HNF3alpha), a hepatic-enriched factor expressed very early during liver development, is sufficient to confer transcriptional activation on a chromatin-repressed AFP template. Transient transfection studies illustrate that HNF3alpha can activate AFP expression in a non-liver cellular environment, confirming a pivotal role for HNF3alpha in establishing hepatic-specific gene expression. Restriction enzyme accessibility assays reveal that HNF3alpha promotes the assembly of an open chromatin structure at the AFP promoter. Combined, these functional and structural data suggest that chromatin assembly establishes a barrier to block inappropriate expression of AFP in non-hepatic tissues and that tissue-specific factors, such as HNF3alpha, are required to alleviate the chromatin-mediated repression.

VAMP-7 mediates vesicular transport from endosomes to lysosomes

A more complete picture of the molecules that are critical for the organization of membrane compartments is beginning to emerge through the characterization of proteins in the vesicle-associated membrane protein (also called synaptobrevin) family of membrane trafficking proteins. To better understand the mechanisms of membrane trafficking within the endocytic pathway, we generated a series of monoclonal and polyclonal antibodies against the cytoplasmic domain of vesicle-associated membrane protein 7 (VAMP-7). The antibodies recognize a 25-kD membrane-associated protein in multiple tissues and cell lines. Immunohistochemical analysis reveals colocalization with a marker of late endosomes and lysosomes, lysosome-associated membrane protein 1 (LAMP-1), but not with other membrane markers, including p115 and transferrin receptor. Treatment with nocodozole or brefeldin A does not disrupt the colocalization of VAMP-7 and LAMP-1. Immunoelectron microscopy analysis shows that VAMP-7 is most concentrated in the trans-Golgi network region of the cell as well as late endosomes and transport vesicles that do not contain the mannose-6 phosphate receptor. In streptolysin- O-permeabilized cells, antibodies against VAMP-7 inhibit the breakdown of epidermal growth factor but not the recycling of transferrin. These data are consistent with a role for VAMP-7 in the vesicular transport of proteins from the early endosome to the lysosome.

Spontaneous renal allograft rupture attributed to acute tubular necrosis

A renal allograft recipient receiving triple immunosuppressive therapy developed spontaneous allograft rupture 5 days after her second cadaveric renal transplantation. Renal biopsy showed interstitial edema with severe acute tubular necrosis (ATN). There was no evidence of acute rejection or renal vein thrombosis. The ruptured renal graft was salvaged by an aggressive fluid resuscitation therapy and surgical hemostasis. The renal function was satisfactory on discharge. We conclude that renal allograft rupture can be the result of interstitial edema solely attributed to ATN in the absence of graft rejection. The ruptured graft kidney is potentially salvageable for those patients whose hemodynamic status can be stabilized by appropriate supportive therapy.

Tentorial meningioma encroaching the transverse sinuses and sigmoid sinus junction area associated with dural arteriovenous fistulous malformation: a case report

A 62-year-old woman was evaluated for tinnitis and headache. Magnetic resonance imaging and angiography revealed the coexistence of a tentorial tumor encroaching the junction of the right transverse-sigmoid sinuses, and dural arteriovenous fistulous malformation (AVFM) of the right transverse sinus. AVFM was not manipulated at all during the surgery. The pathology was fibroblastic meningioma. Postoperatively, the dural AVFM completely disappeared on follow-up angiography. The fistulas were occluded also after surgery, even though there was no manipulation of the AVFM. It is suggested that the right dominant transverse-sigmoid sinuses are partially occluded by tentorial meningioma, developing the dural arteriovenous fistula of the right transverse sinus. An acquired origin of the dural AVFM was suggested in this case.

Analysis of correlation between rectal complications and rectal dose following high dose rate intracavitary radiotherapy in patients with uterine cervix cancer: in vivo dosimetric analysis

PURPOSE

To investigate the correlation between late rectal complications and rectal dose in uterine cervix cancer patients treated with high dose rate intracavitary radiotherapy (HDR ICR) and to analyze dose factors reducing complications.

METHODS

A retrospective analysis was done of 74 patients treated with external beam RT and HDR ICR between 1995 and 1997. Radiotherapy (RT) consisted of a median 50.4 Gy external beam plus six fractions of HDR ICR given two times per week, concurrent with the last three weeks of external beam therapy, to a total dose of median 24 Gy to point A or the reference point. Rectal doses were calculated at rectal reference points using barium contrast criteria. In vivo measurement of rectal dose was performed with thermoluminescent dosimeters (TLD) immediately prior to the first fraction of HDR ICR.

RESULTS

Eight patients developed rectal complications (11%). There was a significant difference between measured rectal doses for patients with rectal complications and those without (p < 0.05), and the doses were higher in complicated patients. A significant increase in the probability of development of complications was found for patients receiving measured rectal doses of ICR fractional dose 320 cGy or more, ICR total dose 2000 cGy or more, and ICR% to point A 80% or more.

CONCLUSIONS

This study showed that in vivo dosimetry using TLD during HDR ICR could have a useful role as a predictor of late rectal complications. Dose limitation to the rectum could possibly be achieved by thorough vaginal packing or use of an applicator with proper shielding while maintaining a high dose to the tumor.

Isolation, characterization, and stability of positional isomers of mono-PEGylated salmon calcitonins

PURPOSE

To separate and characterize the different positional isomers of mono-PEGylated salmon calcitonins (mono-PEG-sCTs) and to evaluate the effects of the PEGylation site on the stability of different mono-PEG-sCTs in rat kidney homogenate.

METHODS

Mono-PEG-sCTs were prepared using succinimidyl carbonate monomethoxy polyethylene glycol (5,000 Da) and separated by gel-filtration HPLC followed by reversed-phase HPLC. To characterize PEGylated sCTs, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) and reversed-phase HPLC of the trypsin digested samples were performed. Mono-PEG-sCTs and sCT in rat kidney homogenates were measured by column-switching reversed-phase HPLC with on-line detection of the radioiodinated samples using a flow-through radioisotope detector.

RESULTS

Three different mono-PEGylated sCTs were separated by reversed-phase gradient HPLC. From the MALDI-TOF MS analysis, the average molecular weight of mono-PEG-sCTs was confirmed as around 8650 Da. The presence of PEG moiety in the mono-PEG-sCTs was also manifested by the fact that the distance between two adjacent mass spectum lines was 44 Da which corresponds to PEG monomer unit. Tryptic digestion analysis demonstrated that these mono-PEG-sCTs are 3 positional isomers of N-terminus, Lys18- and Lys11-residue modified mono-PEGylated sCTs. The degradation half-life of these 3 positional isomers in rat kidney homogenates significantly increased in order of the N-terminus (125.5 min), Lys11- (157.3 min), and Lys18 residue modified mono-PEGylated sCT (281.5 min) over the native sCT (4.8 min).

CONCLUSION

Three positional isomers of mono-PEGylated sCTs were purified and characterized. Of these, the resistance to proteolytic degradation was highest for the Lys18-residue modified mono-PEG-sCT. These studies demonstrate that the in vivo stability of PEGylated sCTs is highly dependent on the site of PEG molecule attachment.

Cytomegalovirus colitis in individuals without apparent cause of immunodeficiency

Cytomegalovirus infection is usually reported in immunocompromised patients. In this study, apparently immunocompetent patients with cytomegaloviral colitis were reviewed. Records with a diagnosis of cytomegaloviral colitis from January 1989 to June 1996 were retrieved for analysis. Ten patients were included (median age 70 yr). The major presenting symptoms were diarrhea and hematochezia. Ulceration was the main macroscopic finding. Rectal bleeding was mostly self-limiting. Three patients developed local complications (rectovaginal fistula in two; rectal stricture in one). In the two patients with rectovaginal fistula, lymphocytes subsets and proliferative response were entirely normal. In the other patient, low B lymphocyte count and low response to mitogen were demonstrated. However, the immunoglobulins were not suppressed and rectal biopsies revealed noncaseating granulomas, suggesting activated cell-mediated immunity. In conclusion, a high index of suspicion is crucial for early diagnosis of cytomegaloviral colitis in patients with bloody diarrhea, even though obvious evidence of immunodeficiency is lacking.

Preparation and characterization of polyethylene-glycol-modified salmon calcitonins

The conjugation of salmon calcitonin (sCT) by covalent linkage of polyethylene glycol (PEG) was attempted to overcome several disadvantages of sCT as a therapeutic drug, namely its rapid clearance from blood circulation and enzymatic degradation. The polymer employed was succinimidyl carbonate monomethoxypolyethylene glycol (12 kDa). Superose HR size-exclusion chromatography was applied to separate the PEGylated sCTs (mono-PEG-sCT and di-PEG-sCT) from the unmodified sCT. The PEGylation of sCT was verified by an electrophoresis gel stained with iodine and by MALDI-TOF mass spectrometry. The molecular weights of mono-PEG-sCT and di-PEG-sCT were determined to be 16,094 and 29,077 Da, respectively. PEGylated sCTs showed a substantially improved stability in rat liver homogenates as compared to the intact sCT, indicating that PEG molecules protected sCT from various degrading enzymes. These PEGylated sCTs exhibited similar biological activity to the intact sCT by adenosine cyclic 3',5'-phosphate (cAMP) assay. In clearance studies in the rat, PEGylated sCTs had significantly longer circulating half-lives than the intact sCT (11.2 min for mono-PEG-sCT and 54.0 min for di-PEG-sCT versus 4.7 min for intact sCT).

Three Hong Kong Chinese cases of pretibial epidermolysis bullosa: a genodermatosis that can masquerade as an acquired inflammatory disease

Three patients in two families presented with many years' history of fragile skin, blisters, erosions and scars affecting almost exclusively the shin areas, accompanied by a variable degree of itching. Two of the patients also had toenail dystrophy. Skin biopsy revealed dermal-epidermal blister formation and milia but no immunohistochemical evidence of immunoglobulin or complement deposition. Electron microscopic study of the lesional and perilesional skin showed very sparse or absent anchoring fibrils. Immunolabelling for type VII collagen using LH 7.2 monoclonal antibody revealed a bright, linear staining pattern at the dermal-epidermal junction. The clinicopathological features were thus compatible with pretibial epidermolysis bullosa, a subtype of dystrophic epidermolysis bullosa. Of note, the inflammatory nature of the skin lesions, and their resemblance to nodular prurigo and hypertrophic lichen planus, had caused diagnostic difficulties in all cases in the past. A high degree of awareness of this rare subtype of epidermolysis bullosa is important to establish the correct diagnosis, to allow for genetic counselling and to plan clinical management.

Microbore high-performance liquid chromatographic determination of cisapride in rat serum samples using column switching

For the determination of cisapride from serum samples, an automated microbore high-performance liquid chromatographic method with column switching has been developed. After serum samples (100 microl) were directly injected onto a Capcell Pak MF Ph-1 pre-column (10 x 4 mm I.D.), the deproteinization and concentration were carried out by acetonitrile-phosphate buffer (20 mM, pH 7.0) (2:8, v/v) at valve position A. At 2.6 min, the valve was switched to position B and the concentrated analytes were transferred from MF Ph-1 pre-column to a C18 intermediate column (35x2 mm I.D.) using washing solvent. By valve switching to position A at 4.3 min, the analytes were separated on a Capcell Pak C18 UG 120 column (250 x 1.5 mm I.D.) with acetonitrile-phosphate buffer (20 mM, pH 7.0) (5:5, v/v) at a flow-rate of 0.1 ml/min. Total analysis time per sample was 18 min. The linearity of response was good (r=0.999) over the concentration range of 5-200 ng/ml. The within-day and day-to-day precision (CV) and inaccuracy were less than 3.7% and 3.8%, respectively. The mean recovery was 96.5+/-2.4% with the detection limit of 2 ng/ml.

Isolation and characterization of biologically active lectin from Korean mistletoe, Viscum album var. Coloratum

A mistletoe lectin was isolated from water extracts of Korean mistletoe, a subspecies of Viscum album, grown on Quercus mongolica using CM-Sepharose chromatography followed by an affinity chromatography on a concanavalin A-Sepharose column. The compound proved to be a mistletoe lectin II with D-galactose and N-acetyl-D-galactosamine specificity. Matrix-assisted laser desorption time-of-flight mass spectroscopy showed it to have an average molecular mass of 62.7 kDa and to consist of two subunits of 30.6 kDa and 32.5 kDa. It was a basic protein with isoelectric points of 9.4 and 9.6 by capillary isoelectric focusing and was cytotoxic to Molt4 cell.