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A new THz/IR/UV photon source at Jefferson Lab is the first of a new generation of light sources based on an Energy-Recovered, (superconducting) Linac (ERL). The machine has a 160 MeV electron beam and an average current of 10 mA in 75 MHz repetition rate hundred femtosecond bunches. These electron bunches pass through a magnetic chicane and therefore emit synchrotron radiation. For wavelengths longer than the electron bunch the electrons radiate coherently a broadband THz ∼ half cycle pulse whose average brightness is >5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20 W of average power extracted [Carr, et al., Nature 420 (2002) 153]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100 fs pulses with >200 W of average power. The FELs also provide record-breaking laser power [Neil, et al., Phys. Rev. Lett. 84 (2000) 662]: up to 10 kW of average power in the IR from 1 to 14 μm in 400 fs pulses at up to 74.85 MHz repetition rates and soon will produce similar pulses of 300–1000 nm light at up to 3 kW of average power from the UV FEL. These ultrashort pulses are ideal for maximizing the interaction with material surfaces. The optical beams are Gaussian with nearly perfect beam quality. See www.jlab.org/FEL for details of the operating characteristics; a wide variety of pulse train configurations are feasible from 10 ms long at high repetition rates to continuous operation. The THz and IR system has been commissioned. The UV system is to follow in 2005. The light is transported to user laboratories for basic and applied research. Additional lasers synchronized to the FEL are also available. Past activities have included production of carbon nanotubes, studies of vibrational relaxation of interstitial hydrogen in silicon, pulsed laser deposition and ablation, nitriding of metals, and energy flow in proteins. This paper will present the status of the system and discuss some of the discoveries we have made concerning the physics performance, design optimization, and operational limitations of such a first generation high power ERL light source.

The effect of patient positioning on thallium-201 images in the left lateral projection was evaluated in 28 patients. The left lateral image was performed with the patient on his right side (LLrs) and also supine (LLsup). False-positive inferoposterior defects were reported in five patients (18%) in the LLsup view, but not in the LLrs view. Image quality was better in the LLrs view. The false-positive results in the LLsup view may result from two factors: a) overlap of the left hemidiaphragm and myocardium; or b) changes in orientation of the heart in the two lateral positions. Therefore, thallium-201 images in the LL position should be performed with the patient lying on his right side.

A sample prepared by adsorption of [Ir4(CO)12] on MgO powder was treated in CO at 100°C and 1 atm, whereupon the surface species was converted to [Ir8(CO)22]2− in high yield. The surface-bound cluster anion was characterized by infrared spectroscopy, and it could be extracted into solution by cation metathesis. The chemistry of the iridium carbonyls on the basic MgO surface in the absence of solvents is similar to the chemistry of the iridium carbonyls in basic solutions. The surface chemistry is an alternative method for preparation of [Ir8(CO)22]2−.

Cobra venom (Naja naja naja) phospholipase A2 (PLA2) contains 14 cysteines in the form of 7 disulfide bonds amongst its 119 amino acids. A gene encoding the PLA2 was synthesized and inserted into a bacterial expression vector containing the phage lambda pL promoter. In order to obtain protein without the initiating methionine at the N-terminus, a Factor Xa site was engineered upstream from the PLA2 gene. Upon heat-induction of the cells transformed with the expression plasmid, the protein is produced as insoluble inclusion bodies. The enzyme was partially purified by washing the inclusion bodies with Triton X-100 and urea. The expressed protein was first denatured with 8 M guanidine-HCl and 10 mM DTT. After digestion with Factor Xa, formation of disulfide bonds and refolding into the fully active form was carried out in the presence of cysteine and Ca2+. The renatured recombinant protein was purified by Affi-gel blue column chromatography. The purified recombinant enzyme had the same specific activity as the native enzyme when assayed on a variety of substrates and cross-reacted with antisera prepared against the native enzyme. This is the first report of the expression of a recombinant PLA2 from any venom.

Catalysts for CO hydrogenation were prepared by treatment in CO+H 2 of samples prepared by introduction of [H 2 Os(CO) 4 ] from the vapor phase into the pores of zeolite Y that had been made basic by treatment with NaN 3 . The catalyst, before and after use in a flow reactor, was characterized with extended X-ray absorption fine structure (EXAFS) spectroscopy

[Ir4(C0)12o] n the surface of MgO reacts to give [HIr4(CO)ll]-,w hich upon treatment with co at 200 OC gives [Ir6(C0)15]2- on the surface in high yield. Treatment of the latter with a solution of [PPN][CI] leads to extraction of [Ir6(C0)15]2b-y cation metathesis. The surface-bound [Ir6(CO)15]2w- as characterized by extended X-ray absorption fine structure (EXAFS) sk :e icnt rcolsocsoep ayg,r weeimthe tnhte w diatht at hined piucabtliinshge adn c rayvsetraalgloeg Irra-plrh icc odoartad ifnoart itohnis naunmiobne rin o tfh 4e. 1so alindd s taant ea.v Terhaeg er eIarc-Itrio ndsi sotfa nthcee iorfi d2iu.7m7 carbonyls on the basic MgO surface closely parallel those of iridium carbonyl anions in basic solutions. Treatment of the MgO-supported [h6(CO)IS]2- in He followed by H2 at 300 OC gives decarbonylated surface species shown by EXAFS spectroscopy to have iridium cluster frames substantially unchanged from those of the carbonyl anion precursor. The decarbonylated iridium clusters are among the most nearly uniform supported metals.

The addition of cyclic AMP (cAMP) to Saccharomyces cerevisiae cyr1 mutant cells resulted in an increase in the rate of phosphatidylinositol synthesis at the expense of phosphatidylserine synthesis. The decrease in phosphatidylserine synthesis correlated with the down regulation of phosphatidylserine synthase activity by cAMP-dependent protein kinase phosphorylation. The increase in phosphatidylinositol synthesis was not due to the regulation of phosphatidylinositol synthase by cAMP-dependent protein kinase.

[Ir4(CO)12] was used as a precursor for the preparation of a MgO-supported catalyst with a uniquely simple metal structure, Ir4. The precursor was adsorbed on MgO from hexanes with the metal framework remaining intact, as determined by extended X-ray absorption fine structure (EXAFS) spectra. The surface-bound species was inferred to be predominantly [HIr4(CO)11]−, which could be extracted from the surface by cation metathesis and identified in solution by infrared spectroscopy. After treatment of the MgO-supported iridium carbonyl in He followed by H2 at 300 °C, the sample was characterized again by EXAFS spectroscopy; the results provide evidence that the predominant surface species are clusters of four Ir atoms with an average Ir-Ir distance of 2.69 A.

The seroprevalence of hepatitis C (HCV) infection was examined among a sample of incoming inmates in the Texas Department of Criminal Justice (TDCJ) prison system. Rates were compared across demographic factors and three types of prison facilities: substance abuse felony punishment units (SAFPs), state jails and prisons. The study sample consisted of 3712 incoming inmates incarcerated for any duration, dating from 1 November 1998 to 31 May 1999. Among males, inmates entering SAFPs and state jails had comparable HCV infection rates (29.7 and 27.0%, respectively) to those entering prisons (27.3%). Among females, inmates entering prisons had a higher rate of infection (48.6%) than those entering state jails (35.1%) or SAFPs (38.3%). For both genders, blacks exhibited a lower overall infection rate than whites and Hispanics, and HCV seroprevalence increased in a stepwise fashion with age. All subgroups of TDCJ inmates, including those held in alternative correctional facilities, exhibited HCV infection rates that were comparable with previous reports of inmate populations, but dramatically higher than general community samples. Given that most inmates held in alternative facilities will return to the general community in a short period of time, understanding the HCV infection rates in these subgroups holds particular public health relevance.

The homeostatic mechanisms responsible for intraocular pressure (IOP) regulation are not understood. Studies were conducted to evaluate the hypothesis that trabecular meshwork (TM) cells sense increases in IOP as stretching or distortion of their extracellular matrix (ECM) and respond by increasing ECM turnover enzymes.Flow rates were increased in perfused human anterior segment organ cultures and the matrix metalloproteinase (MMP) levels and IOP were evaluated. Human TMs in stationary anterior segment organ culture were mechanically stretched, and MMP levels were analyzed. TM cells were grown on membranes, which were then stretched, and MMP levels were evaluated. Western immunoblots, zymography, and confocal immunohistochemistry were used to evaluate changes in MMPs and their tissue inhibitors, the TIMPS:Doubling the flow rate in perfused human organ cultures increased gelatinase A levels in the perfusate by 30% to 50% without affecting gelatinase B or stromelysin levels. Immediately after doubling the flow rate, the measured IOP doubled. However, over the next few days the IOP gradually returned to the initial level, although the flow rate was maintained at double the initial value. Stretching stationary organ cultures or stretching TM cells grown on membranes resulted in similar increases in gelatinase A without changes in gelatinase B or stromelysin levels. The gelatinase A increases occurred between 24 and 72 hours and were approximately proportional to the degree of stretching. Although coating the membranes with different ECM molecule affected the gelatinase A response, the optimum response occurred when the cells had been grown long enough to produce their own ECM. By Western immunoblot and confocal immunohistochemistry, the stretch-induced increases in gelatinase A were accompanied by strong decreases in TIMP-2 levels and moderate increases in one membrane type MMP, MT1-MMP. After mechanical stretching of the membrane, gelatinase A, MT1-MMP and TIMP-2 all exhibited a similar punctate immunostaining pattern over the TM cell surface.These results are compatible with the hypothesis that elevations in IOP are sensed by TM cells as ECM stretch/distortion. TM cells respond by increasing gelatinase A and MT1-MMP, while decreasing TIMP-2 levels. This will increase ECM turnover rates, reduce the trabecular resistance to aqueous humor outflow, and restore normal IOP levels. This hypothesis provides a regulatory feedback mechanism for IOP homeostasis.

Several authors have demonstrated that prophylactically inserted inferior vena cava filters have decreased pulmonary thromboembolic complications in selected high-risk trauma patients. Guidewire-related mishaps are potential complications of inferior vena cava filters and are likely underreported. The authors present two cases and review strategies to prevent these complications.

Neuroendocrine tumors of the lung consist of a spectrum of neoplasms, including typical carcinoids, atypical carcinoids, large-cell neuroendocrine carcinomas (LCNEC), and small-cell lung carcinomas (SCLC). We previously reported frequent inactivation of the gene responsible for multiple endocrine neoplasia type 1 (MEN1) in both typical and atypical carcinoid tumors. In the present study, we extend the analysis of human NE lung tumors to include 9 primary SCLCs, 36 SCLC cell lines, and 13 primary LCNECs for MEN1 gene inactivation. In SCLC, loss of heterozygosity (LOH) at the MEN1 gene on chromosome band 11q13 was detected in one primary tumor and two cell lines. The coding sequence and splice junctions of the MEN1 gene were screened for mutations in all 44 tumors and cell lines, and no mutations were detected. Northern blot analysis of 13 SCLC cell lines showed the MEN1 transcript to be present and of normal size. In LCNECs, a somatic frameshift in the MEN1 gene (1226delC) was found in one of 13 tumors, representing the first mutation observed outside the spectrum of neoplasms associated with MEN1. Interestingly, neither a deletion nor a mutation was detected in the other allele, and wild-type mRNA sequence was expressed in the tumor, suggesting that the MEN1 gene was not inactivated by a conventional two-hit mechanism. The data support the hypothesis that SCLC and lung carcinoids develop via distinct molecular pathways; however, further investigation is necessary to determine the significance of the MEN1 gene mutation observed in a single case of LCNEC. Published 2000 Wiley-Liss, Inc.

Loss of p16 functional activity leading to disruption of the p16/cyclin-dependent kinase (CDK) 4:cyclin D/retinoblastoma pathway is the most common event in human tumorigenesis, suggesting that compounds with CDK4 kinase inhibitory activity may be useful to regulate cancer cell growth. To identify such inhibitors, the 60 cancer cell lines of the National Cancer Institute drug screen panel were examined for p16 alterations (biallelic deletion, intragenic mutations, or absent p16 protein), and the growth-inhibitory activity of more than 50,000 compounds against these 60 cell lines was compared with their p16 status. One compound, 3-amino thioacridone (3-ATA; NSC 680434), whose growth-inhibitory activity correlated with the p16 status of the cell lines had an IC50 of 3.1 microM in a CDK4 kinase assay. In addition, four compounds structurally related to 3-ATA inhibited CDK4 kinase with IC50s ranging from 0.2-2.0 microM. All five of these compounds were less potent inhibitors of cell division cycle 2 and CDK2 kinases, with IC50s 30- to 500-fold higher than that for CDK4. ATP competition experiments demonstrated a noncompetitive mode of inhibition for 3-ATA (K(i) = 5.5 microM) and a linear mixed mode for benzothiadiazine (NSC 645787; K(i) = 0.73 microM). We have successfully demonstrated a novel approach to identify specific CDK4 kinase inhibitors that may selectively induce growth inhibition of p16-altered tumors.

The antibacterial effectiveness of an ultraviolet-irradiated nylon 6, 6 film was investigated for potential use as a food-packaging material to reduce the surface microbial contamination of foods. The film-surface analyses showed that UV irradiation induced conversion of surface amide groups to amines. Irradiation also increased the dimensional scale of the film surface topography (depth of valleys) approximately 5-fold on the scale of nanometers. The irradiated nylon demonstrated antagonistic activity against Staphylococcus aureus 25923 and Escherichia coli TV1058 with 4.5 and 6 log reductions, respectively, of an initial population of 10(6) cfu mL(-1). The irradiated nylon was ineffective against Pseudomonas fluorescens 13525 and Enterococcus faecalis 19433 under similar conditions. The film demonstrated increased antimicrobial activity against S. aureus 25923 with increasing temperatures up to 45 degrees C, the highest temperature tested. Protein and salt inhibited the antibacterial nature of the irradiated film. Amines in solution (4.31 x 10(-8) M; the calculated equivalent of amines on the film) killed at least 1 x 10(4) cfu mL(-1) E. coli TV1058, and 4. 31 x 10(-7) M amines killed up to 1 x 10(7) cfu mL(-1) E. coli TV1058. The amines in solution required similar exposure time to the bacteria for population reduction as was observed with the irradiated film.

The murine anti-bombesin monoclonal antibody, 2A11, has been demonstrated to inhibit growth of some small-cell lung cancer (SCLC) cells in nude mice xenografts and in a clinical trial. To determine if the expression of bombesin-like peptides (BLP) and their receptors (GRP-R and NMB-R) correlate with an in vitro response to 2A11, we measured these parameters in seven SCLC cell lines. Gastrin releasing peptide (GRP) mRNA was detected in three of seven cell lines (NCI-H69, NCI-H345, NCI-H510) and neuromedin B (NMB) mRNA was detected in all seven lines using an RNase protection assay (RPA). Immunoreactive BLP was detected in the cell pellets of all lines (range 0.11-59.90 pmol/mg protein) by a solid phase GRP radioimmunoassay (RIA) using 125I-labeled 2A11. RPA detected GRP-receptor mRNA in two cell lines (NCI-H69 and NCI-H345) and NMB-receptor in three lines (NCI-H345, NCI-H510, and NCI-H660). Reverse transcriptase-PCR confirmed the presence of receptor mRNA in these lines and detected NMB-receptor in an additional three lines (NCI-H69, NCI-H82, and NCI-H187). Calcium mobilization in response to BLP stimulation was detected in the six cell lines expressing either GRP-R or NMB-R mRNA but not in NCI-N417, which had no detectable BLP-receptor. 2A11 (5 microg/ml) inhibited colony formation by 26-61% after 2 weeks in all cell lines except NCI-N417. Thus, growth inhibition by 2A11 requires the presence of at least one BLP-receptor. These findings may be useful in selecting patients with SCLC for treatment with 2A11.

The mammalian pulmonary toxin 4-ipomeanol (IPO) is activated by the cytochrome P450 system in bronchial Clara cells in animals. The resulting metabolites bind rapidly to macromolecules, producing localized cytotoxicity. IPO has in vitro and in vivo antitumor activity in non-small cell lung cancer (NSCLC) and thus was proposed as a lung cancer-specific antitumor agent. We have completed a directed Phase I trial in patients with NSCLC. Forty-four patients (34 men and 10 women) with NSCLC were treated with IPO. All but two patients had an Eastern Cooperative Oncology Group performance status of 0 or 1. They received 91 courses of therapy with i.v. IPO; 82 courses were administered daily for five days, and 9 were single bolus doses. The dose-limiting toxicity of elevated serum transaminases was observed in three of seven patients at 922 mg/m2/day. The maximum tolerated dose was 693 mg/m2/day on 5 consecutive days every 3 weeks. One patient developed grade 4 pulmonary toxicity at 167 mg/m2/day. There was no significant hematological or renal toxicity. No objective antitumor responses were observed. Pharmacokinetic analysis of 39 patients from day 1 of IPO administration showed biexponential elimination with mean half-lives of 8.6 (alpha half-life) and 76 min (beta half-life). There was a linear relationship between the area under the plasma drug concentration-time curve and the dose of IPO. There was no significant difference between the pharmacokinetic parameters measured on day 1 and day 5. Using a 4-day in vitro cytotoxicity assay, two tumor cell lines established from patients treated at 693 mg/m2/day had IC50s of approximately 6 mM, a concentration more than 75-fold higher than the plasma levels measured in these patients. Thus, although the total amount of drug administered per cycle on a daily times five dose schedule is more than 2.5-fold higher than the recommended single daily dose, IPO is unlikely to be a useful drug for patients with lung cancer.

Two different clinical trials using biological agents directed against an autocrine growth factor and a surface marker of neuroendocrine differentiation have been used for patients with relapsed small-cell lung cancer. In a phase II trial, an antibody (2A11) directed against the autocrine growth factor gastrin-releasing peptide has been used to treat patients with relapsed small-cell lung cancer. One of 12 evaluable patients treated with 2A11 250 mg/m2 three times weekly for 4 weeks achieved a complete response. An antibody directed against the neural cell adhesion molecule has been linked to a modified ricin molecule. This immunotoxin, N901-bR, has undergone phase I testing, and a recommended phase II dose of 30 micrograms/kg/day for 7 days by continuous infusion has been determined. In the phase I trial, one of 21 patients with relapsed or refractory small-cell lung cancer had a partial response to this treatment. Therefore, it appears that an antibody directed against an autocrine growth factor and an immunotoxin directed against a surface marker of neuroendocrine differentiation can inhibit the growth of small-cell lung cancer in vitro and in vivo; both produced some evidence of antitumor activity in patients. Further studies with agents directed against autocrine growth factors and surface markers of neuroendocrine differentiation appear warranted.

This article outlines a process for developing standardized patient cases. The initial step in the process is to define the educational goals of the exercise. Following this step the patient characteristics, setting for the interaction and clinical information are developed. Clinical information, in addition to history, may include elements of nonverbal communication, actual or simulated abnormal physical findings, and laboratory results. Guidelines for the standardized patient regarding disclosure of information to the student and providing feedback to the student enhance the value of the case. If the case is to be used as part of an examination, a grading system must be developed. Issues of cost, validity, and reliability are briefly addressed.

A model catalyst prepared from [Re2Pt(CO)12] supported on ç-Al2O3 was characterized by extended X-ray absorption fine structure (EXAFS) spectroscopy, and its stability in operation in a flow reactor was tested for the dehydrogenation of methylcyclohexane at 1 atm and 400 ¢XC. EXAFS data characterizing the unused catalyst measured at both the Re LIII and Pt LIII edges at liquid nitrogen temperature with the sample in the presence of H2 distinguish the Re-Pt from the Pt-Pt and Re-Re interactions. The EXAFS results form the basis of a simplified model of the supported bimetallic structures, consisting of Re4Pt2 entities, with oxophilic Re in a low positive oxidation state interacting strongly with the oxygen atoms of the ç-Al2O3 support and stabilizing the dispersion of the Pt atoms. The catalyst made from [Re2Pt(CO)12] was found to be more resistant to deactivation during catalytic dehydrogenation of methylcyclohexane than catalysts prepared conventionally from Re and Pt salt precursors. The catalyst prepared from [Re2Pt(CO)12] was more highly dispersed than the others, and its resistance to deactivation is attributed to the role of Re in stabilizing the dispersion of the Pt.

It has been known that the incidence of p53 mutation is very rare in HBX-positive primary human hepatocellular carcinoma (HCC) tissues. The frequency of p53 mutation, however, in established cell lines with integrated HBV DNA and/or HBX has not been well studied. To know p53 mutational frequency, and to investigate whether the presence of HBX DNA sequence correlates with the absence of p53 mutation in the established HCC cell lines, we studied the p53 mutation and the presence of HBX sequence in 12 recently characterized HCC cell lines. As a result, all 12 (100%) lines showed mutation in the p53 gene. Three (25%) cell lines had transversion of codon 215 while no mutation of codon 249 was found. In contrast with previous reports, although HBX DNA was present in 11 cell lines, p53 mutation had occurred, indicating that the presence of HBX viral DNA does not correlate with a lack of p53 mutation in established HCC cell lines. Our results suggest that the frequency of p53 mutation is extremely high even in HBX DNA positive HCC cell lines.

We performed genetic analysis on 12 second primary non-small cell lung cancers in patients surviving small cell lung cancer to assess the potential contribution of smoking to the development of these tumors. Mutations of TP53 were found in three (25%) tumors, KRAS2 in three (25%) tumors, and CDKN2 in two (18%) tumors. Four (50%) mutations (one each in TP53 and CDKN2 and two in KRAS2) were G:C to T:A transversions on the coding strand, a mutation accounting for approximately one-third of mutations in smoking-related tumors but uncommonly found in lung cancers not associated with smoking. The genetic changes in these second lung cancers are more representative of smoking-associated malignancies than lung cancers arising in patients occupationally exposed to irradiation and atomic bomb survivors.

The CDKN2 tumor suppressor gene encodes an inhibitor of type D cyclin dependent kinases. CDKN2 is homozygously deleted in approximately 25% of nonsmall cell lung cancer (NSCLC) cell lines and these deletions are associated with advanced stage cancer. Conflicting reports of the frequency of CDKN2 alterations in NSCLC tumors prompted us to examine the relationship of these alterations and those of the related gene, MTS2, with patient stage and site of cancer. One hundred twenty-five NSCLC samples (71 cell lines and 54 tumors) were examined by PCR-SSCP. Twenty of 71 (28%) tumor cell lines had homozygous deletions, and six (8%) had point mutations compared to 4 (7%) with point mutations among 54 tumor samples. All mutations were observed in tumors or cell lines from patients with stage III or IV disease. Two patients with no mutations in their primary tumor had a CDKN2 point mutation detected in a metastatic tumor. Point mutations were G:C to T:A transversion on the coding strand in five of 10 and resulted in nonsense mutations in seven of 10. Undetectable CDKN2 mRNA, in the absence of detectable genetic alteration, was noted in a similar fraction of cell lines derived from patients with stage I or II disease [two of seven (29%)] and stage III or IV disease [15 of 49 (31%)]. Homozygous deletion of MTS2 was found in 17 of 20 cell lines with CDKN2 deletions; no point mutations of MTS2 were identified by SSCP in the 125 samples. Thus, CDKN2 is a frequent target of genetic alterations at 9p21 in NSCLC. Both deletions and point mutations of CDKN2 are closely associated with tumor dissemination.

Manoalide, a natural product of sponge, irreversibly inhibits phospholipase A2 (PLA2) by reacting with lysine residues. Cobra venom PLA2 mutants were constructed in which four of the six lysine residues were independently replaced by arginine or methionine, which cannot react with manoalide. The mutants were overexpressed in Escherichia coli, renatured, and purified. The enzyme mutants lacking Lys-6 (K6R and K6M) or Lys-79 (K79R) were inhibited only 40% by manoalide while the native cobra venom PLA2 was inhibited 80% under the same conditions. This means that the manoalide modification of either Lys-6 or Lys-79 accounted for only half of the manoalide inhibition. The double mutant (K6R79R) was not inhibited by manoalide at all. Lys-56 (K56R) and Lys-65 (K65R) mutants were inhibited to the same extent as the native enzyme which indicates that these residues are not responsible for any of the inhibitory effects produced by manoalide. These results demonstrate that the reaction of manoalide with both Lys-6 and Lys-79 can account for all of its inhibition of cobra venom PLA2. The inhibition of PLA2 and its mutants with manoalide did not affect the activity of the enzyme toward monomeric substrate, which suggests that manoalide does not modify the catalytic site residues, that it does not block access to this site, and that its inhibition requires an interface. Furthermore, as with native PLA2, the activation of phosphatidylethanolamine hydrolysis by phosphorylcholine-containing compounds was exhibited by all of the mutants suggesting that none of the lysines examined are essential for this activation.

The study of the genetic alterations of tumor suppressor genes and protooncogenes in solid tumors has greatly increased our understanding of cancer biology. These findings have extended epidemiologic associations of carcinogens with certain tumors. Further analysis of patterns of genetic changes may implicate carcinogenic substances in cases where epidemiology has not been able to do so. Identification of germline mutations in p53, APC, and NF1 has provided improved diagnosis and presymptomatic screening in cancer kindreds. The identification of additional alterations in tumor suppressor genes may further improve the ability to predict inherent cancer risk. Screening strategies based on detection of genetic abnormalities of preinvasive cancerous lesions, such as mutant ras in colonic polyps, may improve early diagnosis. Finally, strategies to replace lost tumor suppressor function may provide a future therapeutic modality.

This study reports the first demonstration of a marked reduction in alpha-crystallin chaperone activity in an experimental model of cataract, and the study implicates activation of the cysteine protease calpain II (EC 3.4.22.17) as the in vivo protease responsible for decreased chaperone activity. Chaperone activity of normal alpha-crystallin from lenses of young rats was assayed by measuring attenuation of heat-induced aggregation and scattering of beta L-crystallin. alpha-Crystallin from the nucleus of lenses with selenite cataract showed specific selective proteolysis, and chaperone activity was diminished. Proteolysis of alpha-crystallin from selenite cataract lenses was mimicked by incubating normal alpha-crystallin with calpain II, and this also resulted in loss of chaperone activity. Two-dimensional gel electrophoresis and peptide mapping were used to identify four partially degraded alpha A- and alpha B-crystallin polypeptides following incubation of normal alpha-crystallin with calpain. Similar partially degraded alpha A and alpha B polypeptides were found in selenite cataract. Previous experiments indicated that alpha-crystallin chaperone activity decreases because of removal of the COOH terminus. Our experiments support this observation and suggest that calpain proteolysis of alpha-crystallin at the COOH terminus may result in a loss of chaperone activity in selenite cataract.

Through extensive reviews of literature, the semi-lunar cartilaginous discs (located within the tibiofemoral joint) will be examined with regard to their make-up, function, and response to trauma. Methods of diagnosing meniscal injury will be explored, as will past and present surgical procedures. An outlook into future methods of treating meniscal lesions will be touched upon.