A phase II study of capecitabine and oxaliplatin combination chemotherapy in patients with inoperable adenocarcinoma of the gall bladder or biliary tract

BACKGROUND

Advanced biliary tract carcinomas are associated with a poor prognosis, and palliative chemotherapy has only modest benefit. This multi-centre phase II study was conducted to determine the efficacy of capecitabine in combination with oxaliplatin in patients with inoperable gall bladder or biliary tract cancer.

METHODS

This was a Phase II, non-randomised, two-stage Simon design, multi-centre study. Ethics approval was sought and obtained by the North West MREC, and then locally by the West Glasgow Hospitals Research Ethics Committee. Eligible patients with inoperable locally advanced or metastatic adenocarcinoma of the gall bladder or biliary tract and with adequate performance status, haematologic, renal, and hepatic function were treated with capecitabine (1000 mg/m(2) po, twice daily, days 1-14) and oxaliplatin (130 mg/m(2) i.v., day 1) every 3 weeks for up to six cycles. The primary objective of the study was to determine the objective tumour response rates (complete and partial). The secondary objectives included assessment of toxicity, progression-free survival, and overall survival.

RESULTS

Forty-three patients were recruited between July 2003 and December 2005. The regimen was well tolerated with no grade 3/4 neutropenia or thrombocytopenia. Grade 3/4 sensory neuropathy was observed in six patients. Two-thirds of patients received their chemotherapy without any dose delays. Overall response rate was 23.8% (95% CI 12.05-39.5%). Stable disease was observed in a further 13 patients (31%) and progressive disease observed in 12 (28.6%) of patients. The median progression-free survival was 4.6 months (95% CI 2.8-6.4 months; Fig. 1) and the median overall survival 7.9 months (95% CI 5.3-10.4 months; Fig. 2). Fig. 1 Progression-free survival Fig. 2 Overall survival

CONCLUSION

Capecitabine combined with oxaliplatin has a lower disease control and shorter overall survival than the combination of cisplatin with gemcitabine which has subsequently become the standard of care in this disease. However, capecitabine in combination with oxaliplatin does have modest activity in this disease, and can be considered as an alternative treatment option for patients in whom cisplatin and/or gemcitabine are contra-indicated.

Pancreatic cancer genomics: where can the science take us?

The incidence of pancreatic ductal adenocarcinoma (PDAC) is steadily increasing and the annual death-to-incidence ratio approaches one. This is a figure that has not changed for several decades. Surgery remains the only chance of cure; however, only less than 20% of patients are amenable to operative resection. Despite successful surgical resection, the majority of the patients still succumb to recurrent metastatic disease. Therefore, there is an urgent need to develop novel therapeutic strategies and to better select patients for current therapies. In this review, we will discuss current management by highlighting the landmark clinical trials that have shaped current care. We will then discuss the challenges of therapeutic development using the current randomized-controlled trial paradigm when confronted with the molecular heterogeneity of PDAC. Finally, we will discuss strategies that may help to shape the management of PDAC in the near future.

Metabolic activation of sulfur mustard leads to oxygen free radical formation

We recently published electron paramagnetic resonance (EPR) spin trapping results that demonstrated the enzymatic reduction of sulfur mustard sulfonium ions to carbon-based free radicals using an in vitro system containing sulfur mustard, cytochrome P450 reductase, NADPH, and the spin trap α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) in buffer (A.A. Brimfield et al., 2009, Toxicol. Appl. Pharmacol. 234:128-134). Carbon-based radicals have been shown to reduce molecular oxygen to form superoxide and, subsequently, peroxyl and hydroxyl radicals. In some cases, such as with the herbicide paraquat, a cyclic redox system results, leading to magnified oxygen free radical concentration and sustained tissue damage. Low mustard carbon radical concentrations recorded by EPR in our in vitro system, despite a robust (4.0mM) sulfur mustard starting concentration, led us to believe a similar oxygen reduction and redox cycling process might be involved with sulfur mustard. A comparison of the rate of mustard radical-POBN adduct formation in our in vitro system by EPR at atmospheric and reduced oxygen levels indicated a sixfold increase in 4-POBN adduct formation (0.5 to 3.0 μM) at the reduced oxygen concentration. That result suggested competition between oxygen and POBN for the available carbon-based mustard radicals. In parallel experiments we found that the oxygen radical-specific spin trap 5-tert-butoxycarbonyl-5-methylpyrroline-N-oxide (BMPO) detected peroxyl and hydroxyl radicals directly when it was used in place of POBN in the in vitro system. Presumably these radicals originated from O(2) reduced by carbon-based mustard radicals. We also showed that reactive oxygen species (ROS)-BMPO EPR signals were reduced or eliminated when mustard carbon radical production was impeded by systematically removing system components, indicating that carbon radicals were a necessary precursor to ROS production. ROS EPR signals were completely eliminated when superoxide dismutase and catalase were included in the complete in vitro enzymatic system, providing additional proof of oxygen radical participation. The redox cycling hypothesis was supported by density functional theory calculations and frontier molecular orbital analysis.

A population based study of the incidence, clinical course and prognostification of GIST in Scotland in the pre-imatinib era (1995–1999)

10050

Background: GIST's are rare tumours characterised by C-KIT and or CD34 positivity. Population based studies have been performed in countries including Iceland, Spain, Sweden and Holland but this is the first in the United Kingdom. Methods: Pathology records from the entire country were screened for actual or potential GIST cases and the tissues stained with CD117 for C-KIT to confirm a genuine diagnosis of GIST. The primary endpoint was to calculate the incidence of GIST in Scotland from 1995–1999. Secondary endpoints included information re stage, site, survival, sex, age and geographical distribution, and to validate the NIH (National Institute for Health) prognostic index currently used. To date 132 patients have been confirmed with GIST who were previously diagnosed as having either GIST or another similar malignancy. We await final information from 1 region. Results: Primary Endpoint. The incidence of GIST in Scotland from 1995–1999 was 5.2/million/year. Secondary endpoints. Median age at time of diagnosis was 69 with a similar male to female ratio. Original tumour site was 55.8% gastric, 38 % small bowel, 2.3 % colorectal; other sites were < 1 % each. 50.4% were originally diagnosed as GIST's. Other diagnosis included leiomyoma (21.7%) and leiomyosarcoma (14%). All others were <5% each. According to the prognostic index 10.9% were very low risk, 26.4% low risk, 23.3% intermediate, 30.2% high risk Conclusions: Although C- KIT staining was not standard practice during the study period a high percentage of patients were correctly diagnosed originally. Despite a study designed to maximise case ascertainment we report an incidence of GIST in Scotland lower than that of other studies (11 to 14.5 million/ year). This discrepancy may be due to differing study designs and/or failures in the original pathology coding; fundamental in our methodology. Ongoing work to assess the importance of original tumour site, size, prognostic index, etc is underway and this data will be available prior to the 2007 Annual Meeting.

No significant financial relationships to disclose.

A cutaneous full-thickness liquid sulfur mustard burn model in weanling swine: clinical pathology and urinary excretion of thiodiglycol

Sulfur mustard (bis(2-chloroethyl)sulfide, HD) is a well-known blistering chemical warfare agent. We have developed a cutaneous full-thickness HD burn model in weanling pigs for efficacy testing of candidate treatment regimens. This report addresses clinical pathology findings and the urinary excretion profile of a major HD metabolite (thiodiglycol, TDG) in this model. Six female Yorkshire pigs were exposed to HD liquid on the ventral surface for 2 h, generating six 3-cm diameter full-thickness dermal lesions per pig. Blood samples were collected throughout a 7-day observation period for hematology and serum chemistry examinations. Urine was collected in metabolism cages. Routine urinalysis was performed and the urine analyzed for TDG using gas chromatography/mass spectrometry. Examination of clinical pathology parameters revealed subtle HD-related changes that are suggestive of a mild hemolytic episode. No other signs of clinically significant systemic toxicities were noted, including bone marrow suppression. Thiodiglycol was detected at the earliest time point tested (6-8 h post-exposure) at levels ranging from 0.66 to 4.98 microg ml(-1) with a mean of 2.14 microg ml(-1). Thiodiglycol concentrations were the highest for half of the animals at this earliest time point and at 24-48 h for the others. By the evening of day 3, the mean level had reached 50 ng ml(-1). Mean levels remained 10-40 ng ml(-1) for the remainder of the 7-day observation period, with the highest individual concentration noted during this period of 132 ng ml(-1). Our results are in general agreement with the TDG excretion profiles previously described for rodent models and humans. Urinary excretion of absorbed HD in our weanling pig wound healing model appears to follow the same pattern as is seen in other laboratory animals models. In general, urinary excretion of TDG appears to peak within the first 1-4 days following exposure, with detectable levels after 1 week. Relatively high urinary TDG levels may thus indicate agent exposure within the previous 96 h. Low levels significantly above natural background levels may indicate either exposure to low levels of agent or exposure that occurred more than 4 days prior to collection of the sample.

Detection and measurement of sulfur mustard offgassing from the weanling pig following exposure to saturated sulfur mustard vapor

Animal models are employed to investigate mechanisms of injury and to evaluate protective measures against sulfur mustard (HD) exposure. The ability to detect and quantify HD enables the researcher to follow safe procedures in handling skin samples. We designed an experimental procedure to measure HD offgassing from animal models. A Minicams--a portable gas chromatograph equipped with a flame photometric detector and on-line sorbent collection and desorption--was used to monitor the HD concentration. Confirming measurements were made using a two-step process that trapped HD on a Tenax sorbent off-line and then transferred the sample by means of an ACEM 900 to a gas chromatograph equipped with either a flame photometric detector or a mass spectrometer. Sulfur mustard offgassing data are presented from three experiments in which weanling pigs were exposed to saturated HD vapor via vapor caps containing 10 microl of HD. The HD concentration was measured in time-weighted-average (TWA) units at a specific HD application site. The current 8-h maximum exposure limit for HD is 3-ng l(-1), (1 TWA unit). The largest TWA value measured near a 3 h time point was a Minicams measurement of 0.48 TWA at 2 h and 53 min after removal of a vapor cap containing HD from a single exposure site on an animal that had 24 concurrent dorsal exposure sites. Gas chromatography/flame photometric detection and gas chromatography/mass spectrometry were used to confirm the Minicams data and to provide greater sensitivity and selectivity down to 0.1 TWA. The gas chromatography/mass spectrometry data confirmed that HD concentrations fell below 0.1 TWA in <5 h for a specific site. These measurements of HD concentrations provided information on the expeditious and safe handling of HD-exposed tissue.

Conformational stabilities of the rat alpha- and beta-parvalbumins

It is widely believed that beta-parvalbumin (PV) isoforms are intrinsically less stable than alpha-parvalbumins, due to greater electrostatic repulsion and an abbreviated C-terminal helix. However, when examined by differential scanning calorimetry, the apo-form of the rat beta-PV (i.e. oncomodulin) actually displays greater thermal stability than the alpha-PV. Whereas the melting temperature of the a isoform is 45.8 degrees C at physiological pH and ionic strength, the Tm for the beta isoform is more than 7 degrees higher (53.6 degrees C). This result suggests that factors besides net charge and C-terminal helix length strongly influence parvalbumin conformational stability. Extension of the F helix in the beta-PV, by insertion of Ser-109, has a modest stabilizing effect, raising the Tm, by 1.1 degrees. Truncation of the alpha-PV F helix, by removal of Glu-108, has a more profound impact, lowering the Tm by 4.0 degrees.

Sensitivity of cross-reacting antihuman antibodies in formalin-fixed porcine skin: including antibodies to proliferation antigens and cytokeratins with specificity in the skin

Although no animal is a perfect skin model for the study of toxicological and therapeutic agents, structurally the pig may be superior to even non-human primates. Because our work involves effects of toxicological and therapeutic agents on the skin, we wanted to identify stains which may prove useful as well as determine cross-reactivity of some newer antihuman antibodies. We performed a battery of formalin-fixed skin from weanling pigs and minipigs. The battery of antibodies included LCA, CD3, OPD-4, CD34, UCHL-1, L-26, KP-1, MAC-387, Factor XIIIa, Leu-7, S-100 protein, HMB-45, GFAP, synaptophysin, neurofilament protein, ubiquitin, vimentin, type IV collagen, laminin, fibronectin, Factor VIII related antigen, Desmin-M, smooth muscle actin, cytokeratin 7, cytokeratin 20, AEI/AE3, CAM 5.2, EMA, GCDFP, Ki-67, and PCNA. Immunohistochemical stains for CD3, Leu-7, S-100 protein, type IV collagen, laminin, Factor VIII related antigen, GFAP, synaptophysin, neurofilament protein, ubiquitin, smooth muscle actin, vimentin, Desmin-M, cytokeratin 7, cytokeratin 20, AE1/AE3, CAM 5.2, Ki-67 and PCNA showed consistent cross-reactivity. In formalin-fixed tissue, only antibodies to lymphoreticular cells showed poor cross-reactivity. A high percentage of the remaining antibodies did show good cross-reactivity but with some interesting similarities and differences in specificity.

Histopathologic and immunohistochemical features in human skin after exposure to nitrogen and sulfur mustard

N-methyl-2,2'-dichlorodiethylamine (HN2)is a topical chemotherapeutic agent used as therapy for cutaneous T-cell lymphomas (CTCL). Di(2-chloroethyl)sulfide (SM), and less often HN2, have been used as chemical weapons, with the skin being a principle target. The mechanisms by which these chemicals produce their therapeutic and toxic effects in skin, however, are not clearly defined. We exposed human skin explants to two doses of HN2 and SM. At 18 hours after exposure, histopathologic features were compared. In addition, immunohistochemical markers to basement membrane proteins were used to evaluate the effects of both chemicals on the basement membrane zone. Gross vesication was not seen. Pyknotic nuclei with or without dyskeratotic changes within epidermal keratinocytes were present at both doses. These changes varied more between skin specimens than they did between doses. Ballooning degeneration was more marked after SM exposures. Diffuse dermal-epidermal separation was present only at high-dose exposures and did not appear to correlate with the degree of changes locally in the overlying epidermis. Antibodies to laminin-5 showed decreased immunoreactivity after exposure to HN2 and SM. Immunoreactivity for laminin- was decreased to a lesser extent, and immunoreactivity for collagen IV and VII was unchanged. HN2 and SM produce similar histopathologic and immunohistochemical features after cutaneous exposure. These features suggest that part of mechanism of action of HN2 and SM is a direct effect on the basement membrane zone. Understanding the effects of HN2 and SM separate from their effect on DNA may be important in designing therapies and in advancing our understanding of the pathophysiologic changes induced by these chemicals when delivered topically.

Increased smooth muscle actin, factor XIIIa, and vimentin-positive cells in the papillary dermis of carbon dioxide laser-debrided porcine skin

BACKGROUND

Pulsed carbon dioxide (CO2) laser debridement is now being used as therapy for photodamaged skin. It has been proposed that the long duration of erythema and a tissue scaffold, which results from tightening of the collagen helix induced by the laser heat, may lead to tightening of sagging skin and skin creases of lesser magnitude.

METHODS

Weanling pigs exposed to mild and moderate erythema producing doses of sulfur mustard (bis-2-chloroethyl sulfide; HD) were treated with the CO2 laser (Tru-Pulse) at 6, 24, and 48 hours after exposure. In addition to histologic examination of laser-debrided and nondebrided biopsy specimens obtained at 14 days after exposure, immunohistochemical staining with antibodies to smooth muscle actin, Factor XIIIa, vimentin, and CD3 was performed.

RESULTS

CO2 laser debridement of the HD-exposed skin resulted in clearing of the cytologic atypia induced by this chemical carcinogen and reduced the inflammatory infiltrate. In addition laser debridement resulted in increased numbers of stromal cells within the papillary dermis, which showed immunohistochemical staining for smooth muscle actin, Factor XIIIa, and vimentin.

CONCLUSIONS

CO2 laser debridement is effective in clearing the epidermis of cytologically damage cells in HD as well as solar-damaged skin. In addition CO2 laser debridement may result in tightening of sagging skin and produce a decrease in skin creases initially, by inducing increased stromal cells within the papillary dermis, with prominent contractile actin filaments. The collagen produced by these stromal cells may subsequently maintain these improvements in the photoaged skin.

Immunohistochemical studies of basement membrane proteins and proliferation and apoptosis markers in sulfur mustard induced cutaneous lesions in weanling pigs

Sulfur mustard (2,2-dichlorodiethyl sulfide, HD) is a chemical warfare agent that is a threat to both troops and civilians. The focus of HD research has been on intracellular adduct formation leading to apoptosis and/or necrosis in cutaneous lesions. However, there is work which suggests that HD may have a more direct effect on the basement membrane zone. Immunohistochemical staining to desmosomal proteins, cellular fibronectin, laminin 1, laminin 5, collagen IV, collagen VII, p53, Bcl-2, and PCNA was performed on weanling pig skin exposed to vesicating doses of HD, GB3, an antibody to laminin 5, showed a progressive decrease with loss of expression during the time period of clinical vesiculation. The other basement membrane proteins showed no change or inconsistent changes. PCNA, and p53 staining increased in the overlying epidermis in areas of vesiculation without significant necrosis. Bcl-2 positive cells were decreased or absent after exposure. This study implicates laminin 5 as the main basement membrane protein affected acutely by HD exposure. The patterns of staining of PCNA, Bcl-2, and p53 within the epidermis suggest that apoptosis and cellular necrosis both may play a role in cell death secondary to HD.

Depth of morphologic skin damage and viability after one, two, and three passes of a high-energy, short-pulse CO2 laser (Tru-Pulse) in pig skin

BACKGROUND

CO2 laser energy is absorbed by water, which is present in all tissue. The depth of penetration of CO2 lasers is narrow with minimal reflection, scatter, or transmission. However, thermal damage has limited the usefulness of conventional, continuous-wave CO2 lasers for debridement as demonstrated by wound healing studies. The development of high-energy CO2 lasers, with pulse durations that are less than the thermal relaxation time of tissue, have made vaporization of skin for resurfacing and wound debridement possible because of the decreased risk of thermal damage.

OBJECTIVE

This study was performed to evaluate thermal damage produced by a CO2 laser.

METHODS

Routine histopathologic examination and nitroblue-tetrazolium chloride (NBTC) staining were used to evaluate the depth of tissue damage and viability in weanling pig skin after one, two, and three passes of the laser.

RESULTS

At a pulse energy of 300 mJ, with a pulse duration of 60 microseconds, one pass of the laser produced vaporization of the epidermis with minimal thermal damage. Two passes produced areas of denatured collagen with loss of viable cells in the superficial papillary dermis. Three passes extended the damage into the papillary dermis.

CONCLUSION

Hyalinization of collagen appears to correspond well with the level of thermal damage as measured by NBTC staining. Our findings suggest that the energy necessary to vaporize the dermis may be greater than that needed to vaporize epidermis.

Construction and characterization of the soybean leaf metalloproteinase cDNA

The cloning and analysis of a cDNA clone encoding the soybean metalloproteinase obtained by polymerase chain reaction (PCR) and the rapid amplification of cDNA ends (RACE) reaction are described. The cDNA was constructed from poly(A)+ RNA isolated from 15-17 day old leaves. The deduced amino acid sequence of the cDNA reveals that the plant metalloproteinase is synthesized as a preproenzyme and the proenzyme form shares a structural motif, responsible for maintenance of inactive zymogen, with the matrix metalloproteinase (e.g. collagenase) family of enzymes from vertebrate origin. Northern and Western blot analysis demonstrated that the metalloproteinase transcript and protein are under a strict developmental program in that both are expressed only in leaf tissue and in a temporal fashion. The physiological function of the metalloproteinase still remains unclear although the data suggest that the enzyme is extracellular and a portion of the mature form of the enzyme is tightly bound to the cell wall.

Evaluation of cross-reacting anti-human antibodies in the euthymic hairless guinea pig model (HGP) suggests that the HGP may be a model for the study of proliferative skin disease

Animal models have an important role in cutaneous research. The guinea pig has proven to be a useful model in a wide spectrum of these cutaneous studies; however, its usefulness is often compromised by the need for depilation. A euthymic hairless guinea pig (HGP) model avoids the problems associated with depilation. Morphologically, as in human skin, these animals have a multi-cell-layer epidermis. Proliferation kinetic studies, as well as documentation of the degree of immunologic cross-reactivity between available antibodies to human cutaneous antigens, could extend the usefulness of this animal model. We performed a battery of anti-human antibodies on formalin fixed tissue, to a variety of antigens present within the skin and on inflammatory cells. These included CD3, UCHL-1, OPD4, L-26, KP-1, Factor XIIIa, S-100 protein, cytokeratin (AE1, AE3 and CK1), CAM 5.2, vimentin, CD 34, Factor VIII, fibronectin, SM actin, collagen IV, laminin, Bcl-2, p53, Ki-67, and PCNA. Cross-reacting antibodies included: CD3, S-100 protein, cytokeratin (AE1, AE3 and CK1), vimentin, Factor VIII, SM actin, collagen IV, p53, Ki-67, and PCNA. Although this battery of antibodies is limited, the markedly increased staining of Ki-67 and PCNA within keratinocytes in the epidermis as compared to normal human skin reflects a high proliferative rate. In addition, positive staining for p53, Ki-67, and PCNA may be useful in studying effects on cell cycle kinetics and apoptosis.

Purification and molecular analysis of an extracellular gamma-glutamyl hydrolase present in young tissues of the soybean plant

A polypeptide present in intercellular wash fluids of young leaves of Glycine max has been purified to electrophoretic homogeneity. The protein has been identified as gamma-glutamyl hydrolase (GGH) based on the shared homology with a recently cloned cDNA from rat. The enzyme is present within the extracellular space of young leaves and a portion is bound to the cell wall. Northern and Western analysis confirm that this polypeptide is expressed only in young (1-15 d old) leaf, stem and root tissue and is therefore expressed under a strict developmental program. The primary sequence of gamma-glutamyl hydrolase shares amino acid identity with a cDNA clone from rat and two partially sequenced cDNAs from Arabidopsis. Although the complete in vivo function of gamma-glutamyl hydrolase in plants is unclear, it is known that the protein plays a critical role in folate metabolism and therefore likely in meeting the physiological demands of growing plant tissues.

Percutaneous versus open tracheostomy: a retrospective cohort outcome study

Percutaneous tracheostomy has been advocated as a faster, safer, and less invasive method of placing tracheostomy tubes in ventilated patients. To compare outcome differences, as measured by complication rates, between percutaneous and open tracheostomy, a retrospective cohort study was performed. All procedures were performed in the intensive care unit of a university-affiliated hospital. The minor complication rates did not differ significantly between percutaneous and open tracheostomy (12/31 vs. 12/29, respectively; p > 0.05), nor did there appear to be a difference in rates of major complications between the two groups (7/31 vs. 5/29; p > 0.05). This study identified a trend towards an increased risk of delayed airway loss in the percutaneous tracheostomy group.

A review of computed tomography in the diagnosis of intestinal and mesenteric injury in pediatric blunt abdominal trauma

OBJECTIVE

To determine the sensitivity, specificity, and positive and negative predictive values of the computed tomography (CT) scan in the diagnosis of clinically significant intestinal and mesenteric injury in pediatric blunt abdominal trauma.

PATIENTS

The records of 145 children who presented to a tertiary care pediatric hospital between 1987 and 1994 were reviewed retrospectively. All had experienced single or multiple injuries and underwent CT as part of the trauma assessment.

METHODS

The patients were divided into two cohorts, based on the results of the initial CT scan: either positive (n = 20) or negative (n = 152) for evidence of intestinal or mesenteric injury. The two cohorts were similar with respect to age, trauma score, and timing of CT scan. The outcome of surgical (n = 23) and conservative management (n = 122) was compared with the initial CT scan results. (Some of the laparotomies were for solid-organ injury only.)

RESULTS

The sensitivity of the CT scan in the diagnosis of clinically significant intestinal and mesenteric injury is 0.93. The specificity and positive and negative predictive values are 0.95, 0.65, and 0.99, respectively.

CONCLUSION

The CT scan is an excellent test to screen for clinically significant intestinal and mesenteric injury in pediatric patients with blunt abdominal trauma. Because of the lower positive value, other clinical and diagnostic imaging information may help to improve diagnostic accuracy. Most importantly, CT rarely misses a significant intestinal or mesenteric injury.

Microtubule-associated protein 2 (MAP-2): a sensitive marker of seizure-related brain damage

We have assessed the efficacy of MAP-2 immunohistochemistry as a marker of seizure-related brain damage and its suitability for quantitation of the damage using densitometric and morphometric image analysis. Seizures were produced in rats by administration of 1.5 LD50 soman, an irreversible AChE inhibitor. Our results demonstrate that neuronal damage, assessed using hematoxylin and eosin, and cresyl violet staining, was colocalized on adjacent serial sections with clearly demarcated reductions in MAP-2 staining. The most severely damaged brain regions were devoid of MAP-2 staining. Reductions in MAP-2 immunostaining were found to be exceptionally well suited for quantitation using densitometric and morphometric image analysis. This study represents the first demonstration of seizure-induced excitotoxic alterations in MAP-2.

Purification and Developmental Analysis of an Extracellular Proteinase from Young Leaves of Soybean

A proteinase present in intercellular wash fluids from leaves of Glycine max has been purified 600-fold to electrophoretic homogeneity. The native protein is monomeric with a molecular mass of 60 kD, as estimated by denaturing gel electrophoresis, and has an isoelectric point of 7.7. The enzyme has a pH optimum of 9.5 when assayed with Azocoll as a substrate. The proteolytic activity is inhibited by p-chloromercuribenzoic acid and mercuric chloride and requires the presence of reducing agents. The enzyme activity is refractory to other classical sulfhydryl proteinases. The soybean leaf endoproteinase is present within the extracellular space of young leaves, and a portion is bound to the cell wall. Western blot analysis and activity measurements show that the enzyme is present only during the first 15 d postemergence of the leaf and is therefore under strict developmental control. We suggest that the enzyme may play a critical role in the extracellular milieu during rapid cell growth and leaf expansion.

Histopathologic features seen in sulfur mustard induced cutaneous lesions in hairless guinea pigs

Sulfur mustard (SM), a chemical warfare agent first used early in the 20th century, has re-emerged in the past decade as a major threat around the world. At present, there are no effective therapeutic measures for SM exposure. Because the skin as well as other interface epithelial surfaces are the first tissues effected as this agent is absorbed, reactions within the skin are an area of active research into the mechanism of action of this alkylating agent. The euthymic hairless guinea pig has been used as the animal model for the study of SM induced injuries because of morphologic similarity of its skin to human skin, with a multiple layer epidermis, and because this animal has a normal immune system. We reviewed 102 biopsy specimens from 51 animals exposed to three different dose times of saturated SM vapor. Histopathologic evidence exists for increased programmed cell death as well as cellular necrosis, subepidermal blister formation, and delayed re-epithelialization secondary to problems with adhesion. Information obtained from this study adds to the body of information important in the investigation of the mechanisms of action of SM.

Staining mast cells for morphometric evaluation on an image analysis system

Multiple skin sections from three nonhuman primates (Macaca mulatta) and three hairless guinea pigs (Cavia porcellus) were stained with 12 different histologic stains to determine whether mast cells could be selectively stained for morphometric analysis using an image analysis system (IAS). Sections were first evaluated with routine light microscopy for mast cell granule staining and the intensity of background staining. Methylene blue-basic fuchsin and Unna's method for mast cells (polychrome methylene blue with differentiation in glycerin-ether) stained mast cell granules more intensely than background in both species. Toluidine blue-stained sections in the guinea pig yielded similar results. Staining of the nuclei of dermal connective tissue was enhanced with the methylene blue-basic fuchsin and toluidine blue stains. These two stains, along with the Unna's stain, were further evaluated on an IAS with and without various interference filters (400.5-700.5 nm wavelengths). In both the methylene blue-basic fuchsin and toluidine blue stained sections, mast cell granules and other cell nuclei were detected together by the IAS. The use of interference filters with these two stains did not distinguish mast cell granules from stained nuclei. Unna's stain was the best of the 12 stains evaluated because mast cell granule staining was strong and background staining was faint. This contrast was further enhanced by interference filters (500.5-539.5 nm) and allowed morphometric measurements of mast cells to be taken on the IAS without background interference.

Purification and partial amino acid sequence of a wound-inducible, developmentally regulated anionic peroxidase from soybean leaves

We have isolated a peroxidase activity to electrophoretic homogeneity from the leaves of the soybean plant, Glycine max. The highly anionic peroxidase isozyme has an isoelectric point of 3.7 and a molecular mass of 32 kilodaltons. Partial amino acid sequence information confirms the identity of the enzyme as a peroxidase but shows significant deviation from other plant peroxidases in the distal histidine box. The enzyme is developmentally regulated as it begins to accumulate in 8-10 day old leaves and its level remains fairly constant thereafter. The expression of this isozyme is also responsive to environmental cues in that it accumulates in young (less than 8 day old) leaves as a consequence of mechanical wounding. The appearance of the isozyme begins approximately 8 hr post-wounding and continues to accumulate for 48 hr.

Sequencing and characterization of the soybean leaf metalloproteinase : structural and functional similarity to the matrix metalloproteinase family

A novel zinc endoproteinase has been sequenced and characterized from soybean leaves (Glycine max var Williams 82) and has been designated as Protein Identification Resource accession No. A41820 SMEP1 (soybean metalloendoproteinase 1). Comparison of the primary amino acid sequence with other zinc proteinases revealed the enzyme to be a new member of the matrix metalloproteinase (MMP) family of enzymes. SMEP was found to have MMP cleavage specificity toward peptide substrates and the enzyme is specifically inhibited by naturally occurring tissue inhibitors of MMPs through a high-affinity interaction (inhibitor concentration resulting in an approximate 50% decrease in enzyme activity = 23 x 10(-9) molar). Together, these results suggest that the origin of the MMP family of enzymes and their cognate inhibitors predates the divergence of plants and animals.

Effect of ritanserin, a highly selective 5-HT2 receptor antagonist, on Parkinson's disease

There is both experimental and clinical evidence to suggest a role for 5-hydroxytryptamine (5-HT) in Parkinson's disease. The effect of ritanserin, a highly selective 5-HT2 receptor antagonist, on Parkinsonian symptomatology was investigated in 10 patients in a single-blind placebo-controlled study. Akinesia and gait improved significantly in a dose-dependent manner in 5 and 7 patients respectively. However there was no significant improvement in tremor. The effects of ritanserin on akinesia and gait are consistent with a role for 5-HT in Parkinson's disease.

Complete amino Acid sequence of soybean leaf p21 : similarity to the thaumatin-like polypeptides

A polypeptide structurally related to the thaumatin family of proteins has been purified from soybean (Glycine max) leaves and the complete amino acid sequence has been determined. The mature protein, which we have termed P21, has a calculated molecular weight of 21,461 and an isoelectric point of 4.6. The soybean protein shows 64% amino acid identity with thaumatin, a sweet-tasting protein found in the West African shrub Thaumatococcus danielli, and as much as 71% identity with thaumatin-like polypeptides present in tobacco and maize.

Purification and Developmental Analysis of a Metalloendoproteinase from the Leaves of Glycine max

A metalloendoproteinase from leaves of soybean (Glycine max) has been purified 1160-fold to electrophoretic homogeneity. The native protein is monomeric with a molecular mass of 15 kilodaltons as estimated by gel filtration and 19 kilodaltons as estimated by denaturing gel electrophoresis. The enzyme has a pH optima of 8.0 to 9.0 using Azocoll as substrate. The proteolytic activity is susceptible to metal chelating agents and the inactivated enzyme can be restored to 69% of original activity by the addition of ZnCl(2). Western analysis shows that a fraction of the soybean metalloendoproteinase is present within the extracellular space of older leaves. Soybean metalloendoproteinase 1 is the Azocollase A activity first described by Ragster and Chrispeels (Plant Physiol 64: 857-862; 1979).

Complete Amino Acid Sequence of a Polypeptide from Zea mays Similar to the Pathogenesis-Related-1 Family

A polypeptide serologically related to the tobacco pathogenesis-related-1 family of proteins has been purified from the root tissue of maize (Zea mays L.), and the complete amino acid sequence has been determined. The mature protein has a calculated molecular weight of 14,970 and isoelectric point of 4.2. The maize protein shows 66 to 68% amino acid identity with the tobacco pathogenesis-related-1 family and 55% identity with the tomato p14 protein.

Purification and Developmental Analysis of the Major Anionic Peroxidase from the Seed Coat of Glycine max

We show that the majority of peroxidase activity in soybean (Glycine max var Williams 82) seeds is localized to the seed coat. A single isozyme is responsible for this activity and has been purified to electrophoretic homogeneity by successive chromatography on DEAE Sepharose Fast Flow, concanavalin A-Sepharose, and Sephadex G-75. The peroxidase exhibits a pl of 4.1, an apparent molecular mass of 37 kilodaltons, and has properties characteristic of a glycoprotein. The enzyme begins to accumulate approximately 21 days after anthesis and continues to do so throughout the maturation of the seed coat where it can represent at least 5% of the soluble protein in dry seed coats. Due to its localization in the seed, we propose that this isozyme may play a role in the hardening of the seed coat.

A comparison of standard Madopar and controlled release Madopar in Parkinson's disease

In a randomised, double-blind cross-over study, objective measures were used to compare the effect of a single oral dose of a standard preparation of levodopa-benserazide (Madopar M) with a sustained-release preparation (Madopar HBS) in 9 Parkinsonian patients with 'end of dose deterioration'. The response of patients to an optimised regimen of each preparation was also assessed using a patient diary. In all patients the onset of effect of Madopar HBS following a single dose was delayed compared with Madopar M. The duration of effect of a single dose of Madopar HBS was substantially (38-120%) longer than Madopar M in five patients and the same or shorter in four patients. According to the patients' diaries, six patients noted an increase in 'on' hours while on Madopar HBS. The duration and severity of dyskinesia was similar for the two preparations. Madopar HBS is likely to be useful in some Parkinsonian patients with 'end of dose deterioration'. As the effect of each dose is delayed it is probably best given in combination with standard Madopar.

Phosphorylation status of nuclear and cytosolic androgen receptors in the rat ventral prostate

We demonstrate that endogenous phosphatases are active in cytosolic and nuclear androgen receptor fractions from the rat ventral prostate. Under our androgen binding assay conditions, the effect of acid phosphatase inhibitors (sodium fluoride, tartaric acid, sodium orthovanadate) on the endogenous phosphatases could be correlated with an increase in dihydrotestosterone (DHT) binding to fractions of partially purified cytosolic androgen receptor. In contrast, tetramisole, an alkaline phosphatase inhibitor, did not alter the binding of DHT to the same receptor fraction. Immunoprecipitation of androgen receptor fractions with polyclonal anti-phosphotyrosine antibody resulted in the recovery of [3H]-DHT binding activity from nuclear receptor fractions and partially purified cytosolic receptor fractions prepared from 20- to 24-hr castrated rats. In control fractions depleted of androgen receptor, negligible levels of binding activity were recovered following immunoprecipitation with the antibody. Therefore, acid phosphatases may be acting on phosphotyrosyl residues of the androgen receptor, thus playing a role in the dephosphorylation and inactivation of the androgen receptor.

Cardiomyopathy in Soman and Sarin intoxicated rats

Rats surviving various single dose of the organophosphorus anticholinesterase nerve agents Soman and Sarin were examined by light microscopy at intervals up to 35 days post-exposure. Brain lesions, identical to those that have been reported elsewhere were present, as well as a previously unreported finding associated with Soman or Sarin intoxication: half of all animals that had brain lesions also had areas of myocardial degeneration and necrosis. Depending upon the point in time at which cardiac tissues were examined, findings varied from areas of acute myolysis and necrosis to areas undergoing resolution of damage. The finding of brain lesions in those animals having cardiac lesions suggests a relationship between the convulsion induced neurologic and cardiac lesions. These studies suggest that convulsive doses of chemical warfare agents induce pathological changes in the cardiovascular system of laboratory animals.

Radiolabeling of a wound-inducible pyridoxal phosphate-utilizing enzyme: evidence for its identification as ACC synthase

1-Aminocyclopropane-1-carboxylic acid (ACC) synthase, a pyridoxal phosphate-utilizing enzyme, catalyzes the conversion of S-adenosylmethionine to ACC, the rate-limiting step in the biosynthesis of the plant hormone ethylene. We report the partial purification (400-fold) of ACC synthase from wounded pink tomato pericarp. Further purification results in a decrease in specific activity apparently due to the instability of the enzyme. Radiolabeling of a pyridoxal phosphate-utilizing protein in the ACC synthase-enriched fraction was achieved by reduction using tritiated sodium borohydride. Evidence that this radiolabeled protein is ACC synthase is presented.

Regulation of synthesis of proteinase inhibitors I and II mRNAs in leaves of wounded tomato plants

Levels of two wound-inducible serine proteinase inhibitors, called Inhibitor I and Inhibitor II, and their mRNAs were quantified in leaves of tomato (Lycopersicon escululentum (L.) Mill.) plants after wounding the leaves with a hemostat. A single wound on a lower leaf of 25-old tomato plants caused the accumulation of the two inhibitor proteins in wounded and non-wounded leaves beginning about 4-6 h following wounding. The rate of inhibitor accumulation was maximal in leaves for the next 4 h and then declined. By 20 h the accumulation had nearly ceased. Following a single wound, Inhibitor I mRNA [600 bases in length] and Inhibitor II mRNA (760 bases) began to accumulate in wounded leaves about 2 h before the inhibitor proteins could be detected. The levels of mRNA for both inhibitors reached a maximum at about 8 h following wounding and then decayed, both with apparent half lives of about 10 h. Four consecutive wounds, inflicted hourly, increased the levels of mRNA for both inhibitors to over twice the levels induced by a single wound. Within 4 h following multiple wounds, Inhibitor I mRNA represented about 0.5% of the total polyadenylated mRNA (poly(A(+))mRNA) and Inhibitor II mRNA about 0.15% of the total. The rates of accumulation of the two inhibitor proteins varied depending upon the age of the plants and their environment during growth, and ranged between 3 and 10 μg Inhibitor I·h(-1)·(g tissue)(-1) for Inhibitor I and about half of these rates for Inhibitor II. Nuclei were isolated from leaves of wounded and non-wounded plants, and in mRNA runoff experiments using specific inhibitor copy DNAs (cDNAs) as probes the synthesis of Inhibitor I and II mRNAs were shown to be regulated, at least in part, at the level of transcription.

Molecular characterization and phylogenetic studies of a wound-inducible proteinase inhibitor I gene in Lycopersicon species

A gene coding for proteinase inhibitor I, whose expression is induced in tomato leaves (Lycopersicon esculentum L. var. Bonny Best) in response to wounding or insect attacks, was isolated from a genomic library and characterized. The nucleotide sequence revealed that the gene is complete and encodes the sequence of an inhibitor I cDNA that was previously isolated from a cDNA library prepared from wound-induced mRNA from tomato leaves. This gene is located 13.1 kilobase pairs (kbp) upstream from an inhibitor II gene. The wound-inducible gene is interrupted by two intervening sequences of 445 and 404 bp, situated within the codons of amino acids 17 and 47, respectively, of the open reading frame. In addition to the presence of putative regulatory sequences, TATAAA and CCACT, two copies of an imperfect direct repeat approximately 100 bp long were identified in the 5'-flanking region. Phylogenetic comparisons of wound-inducible inhibitor I genes within the genomes of various Lycopersicon species revealed that the repeat is found in seven ancestral species of tomato.

Regulation of proteinase inhibitor genes in food plants

Proteinase inhibitor proteins in the families Solanaceae, Leguminosae and Graminae are stored in seeds and tubers and are also found to accumulate in leaves in response to pest attacks. The isolation of the proteinase Inhibitor I cDNA and its gene from tomato has provided information concerning proteinase inhibitor synthesis, processing and compartmentation in leaves under pest attacks. Strategies are now being developed using proteinase inhibitor genes, to genetically engineer the quantity and quality of these potentially defensive and highly nutritional proteins of important crop plants.

Wound-induced proteinase inhibitors from tomato leaves. II. The cDNA-deduced primary structure of pre-inhibitor II

A cDNA containing the complete amino acid-coding region of wound-induced tomato Inhibitor II was constructed in the plasmid pUC9. The open reading frame codes for 148 amino acids including a 25-amino acid signal sequence preceding the N-terminal lysine of the mature Inhibitor II. The Inhibitor II sequence exhibits two domains, one domain having a trypsin inhibitory site and the other a chymotrypsin inhibitory site, apparently evolved from a smaller gene by a process of gene duplication and elongation. The amino acid sequence of tomato leaf Inhibitor II exhibits homology with two small proteinase inhibitors isolated from potato tuber and an inhibitor from eggplant. The small potato tuber inhibitors are homologous with 33 amino acids of the N-terminal domain and 19 amino acids from the C-terminal domain. Two identical nucleotide sequences of Inhibitor II cDNA in the 3' noncoding region were present that were also found in an Inhibitor I cDNA. These include an atypical polyadenylation signal, AATAAG, and a 10-base palindromic sequence, CATTATAATG, for which no function is yet known.

Wound-induced proteinase inhibitors from tomato leaves. I. The cDNA-deduced primary structure of pre-inhibitor I and its post-translational processing

A cDNA containing the coding region for the complete amino acid sequence of wound-induced proteinase Inhibitor I from tomato leaves was constructed in the plasmid pUC9 and characterized. The open reading frame codes for a protein of 111 amino acids. This deduced amino acid sequence revealed the presence of a 42-amino acid N-terminal sequence that is not found in the native protein. This sequence appears to contain a 23-amino acid segment typical of a signal sequence followed by a 19-amino acid sequence containing 9 charged amino acids. The 42-amino acid sequence is apparently lost during maturation to the native Inhibitor I and represents 38% of the translated protein. The Inhibitor I amino acid sequence contains 71% identity with potato tuber Inhibitor I sequence and 35% identity with an inhibitor from the leech.

Multiple sclerosis: capping of surface immunoglobulin G on macrophages engaged in myelin breakdown

Macrophages were examined for immunoglobulin G (IgG) and albumin in actively demyelinating lesions in two patients with multiple sclerosis (MS) using the peroxidase-antiperoxidase immunocytochemical technique. In both cases, macrophages were present that stained for cytoplasmic or surface IgG or both. In one case, in which the tissue was rapidly fixed in chilled fixative, macrophages located among myelinated nerve fibers at plaque margins, but not elsewhere in the plaque, revealed surface IgG in the form of caps restricted to one or both poles of the cell. These caps were absent in sections stained for albumin. Because capping implies the presence of a multivalent ligand close to the cell surface and because cap formation was observed only in macrophages contacting myelin sheaths, we suggest that antimyelin antibody cytophilic for macrophages may be present in the central nervous system in MS, and that immune ligand-mediated phagocytosis may play a role in myelin breakdown in the disease. This study provides the first direct evidence that IgG participates locally in myelin breakdown in MS.

Locus of control and cardiac response to reaction time, mental arithmetic, and time-estimation tasks

In Exp. 1 subjects, classified on the basis of locus of control scores, performed both reaction time and mental arithmetic tasks. In Exp. 2, similarly classified subjects were required to estimate the duration of a signal with feedback following each trial. Between-groups comparisons in Exp. 1 showed no differences on heart rate or performance measures. This does not support an explanation of differential heart rates during cardiac conditioning based upon cognitive styles of "rejecting" or "accepting" stimuli. Similar comparisons in Exp. 2 indicated significant differences for heart rate and proficiency in time estimation. These differences suggest greater task involvement for internally controlled subjects on feedback tasks, with cardiac acceleration a function of that involvement.