Osteopontin regulates proliferation, apoptosis, and migration of murine claudin-low mammary tumor cells.

BACKGROUND: Osteopontin is a secreted phosphoglycoprotein that is expressed by a number of normal cells as well as a variety of tumor cells. With respect to breast cancer, osteopontin has been implicated in regulating tumor cell proliferation and migration/metastasis and may serve as a prognostic indicator. However it remains unclear whether osteopontin has the same impact in all breast cancer subtypes and in particular, osteopontin's effects in claudin-low breast cancer are poorly understood. METHODS: cDNA microarrays and qRT-PCR were used to evaluate osteopontin expression in mammary tumors from MTB-IGFIR transgenic mice and cell lines derived from these tumors. siRNA was then used to determine the impact of osteopontin knockdown on proliferation, apoptosis and migration in vitro in two murine claudin-low cell lines as well as identify the receptor mediating osteopontin's physiologic effects. RESULTS: Osteopontin was expressed at high levels in mammary tumors derived from MTB-IGFIR transgenic mice compared to normal mammary tissue. Evaluation of cell lines derived from different mammary tumors revealed that mammary tumor cells with claudin-low characteristic expressed high levels of osteopontin whereas mammary tumor cells with mixed luminal and basal-like features expressed lower levels of osteopontin. Reduction of osteopontin levels using siRNA significantly reduced proliferation and migration while increasing apoptosis in the claudin-low cell lines. Osteopontin's effect appear to be mediated through a receptor containing ITGAV and not through CD44. CONCLUSIONS: Our data suggests that mammary tumors with a mixed luminal/basal-like phenotype express high levels of osteopontin however this osteopontin appears to be largely produced by non-tumor cells in the tumor microenvironment. In contrast tumor cells with claudin-low characteristics express high levels of osteopontin and a reduction of osteopontin in these cells impaired proliferation, survival and migration.

Survey of pathogens in hatchery Chinook salmon with different out-migration histories through the Snake and Columbia rivers.

The operation of the Federal Columbia River Power System (FCRPS) has negatively affected threatened and endangered salmonid populations in the Pacific Northwest. Barging Snake River spring Chinook salmon Oncorhynchus tshawytscha through the FCRPS is one effort to mitigate the effect of the hydrosystem on juvenile salmon out-migration. However, little is known about the occurrence and transmission of infectious agents in barged juvenile salmon relative to juvenile salmon that remain in-river to navigate to the ocean. We conducted a survey of hatchery-reared spring Chinook salmon at various points along their out-migration path as they left their natal hatcheries and either migrated in-river or were barged through the FCRPS. Salmon kidneys were screened by polymerase chain reaction for nine pathogens and one family of water molds. Eight pathogens were detected; the most prevalent were Renibacterium salmoninarum and infectious hematopoietic necrosis virus. Species in the family Saprolegniaceae were also commonly detected. Pathogen prevalence was significantly greater in fish that were barged through the FCRPS than in fish left to out-migrate in-river. These results suggest that the transmission of infectious agents to susceptible juvenile salmon occurs during the barging process. Therefore, management activities that reduce pathogen exposure during barging may increase the survival of juvenile Chinook salmon after they are released.

Molecular quantitative analysis of human viruses in California stormwater.

Many human pathogenic viruses are transmitted via the oral-fecal route and water is one possible vector, representing a risk for public health. Sixty-one large-volume water samples from storm drains in California were processed by a two-step hollow fiber ultrafiltration procedure followed by molecular analysis for human enterovirus and adenovirus types. Each sample was spiked with a surrogate, the benign bacteriophage PP7. Both surrogate and human viruses were quantified by newly designed TaqMan PCR assays. Equations were developed that account for the main variables in the procedure: recovery of the ultrafiltration, efficiency of nucleic acid extraction, and effect of inhibitors on the amplification of viral targets. Adenovirus 40/41 was detected in one sample at 230 genomes per liter, and no other adenovirus or enterovirus types were found. Samples that resulted in nondetects are reported together with the corresponding sample-specific limit of detection (S(LOD)), a useful tool when estimating the public health risk associated with the contact or ingestion of water. Virus concentrations did not correlate with traditional viable indicator concentrations or any of the physicochemical parameters measured. In contrast, coliform concentrations were correlated with total suspended solids. To our knowledge, this is the first study where all factors known to influence limits of detection have been investigated and integrated into equations that are widely applicable to the quantification of viruses or other microbial targets by PCR.

Vertebral fracture prevalence among women screened for the Fracture Intervention Trial and a simple clinical tool to screen for undiagnosed vertebral fractures. Fracture Intervention Trial Research Group.

OBJECTIVE: To evaluate the ability of self-reported risk factors to identify postmenopausal women likely to have extant vertebral fractures because approximately two thirds of women with radiographic evidence of vertebral fracture are unaware of the fracture. PATIENTS AND METHODS: Questionnaire and spinal radiographic data were collected from postmenopausal women with a femoral neck bone mineral density T score of -1.6 or lower during screening for the Fracture Intervention Trial. Logistic regression was used to identify risk factors for extant vertebral fractures and to derive a final multivariable model. RESULTS: Almost two thirds of 25,816 women 55 years and older met the bone density criterion, and 21% of those had an extant vertebral fracture. The final model consisted of 5 self-reported items: history of vertebral fracture, history of nonvertebral fracture, age, height loss, and diagnosis of osteoporosis. These were combined to yield a Prevalent Vertebral Fracture Index (PVFI). The prevalence of women with vertebral fracture varied from 3.8% to 62.3% over the range PVFI of 0 to greater than 5. Among the 13,051 women screened with spinal radiographs, a PVFI of 4 or greater identified 65.5% of women with vertebral fractures (sensitivity), with a specificity of 68.6%. Excluding 881 women who reported prior vertebral fractures reduced the sensitivity to 53.6 % and increased the specificity to 70.7% but did not alter the fracture prevalence at PVFI values less than 6. CONCLUSION: In this population, 5 simple questions identified women who were likely to have undiagnosed vertebral fractures. Further research is needed to determine the validity of this index in other populations, including women without low bone mineral density.

Prevalent vertebral deformities predict mortality and hospitalization in older women with low bone mass. Fracture Intervention Trial Research Group.

OBJECTIVES: To determine the relationship between prevalent vertebral deformities and the risk of mortality and hospitalization in older women with low bone mass. DESIGN: A prospective cohort study. SETTING: Eleven clinical centers in the United States. PARTICIPANTS: A total of 6459 community-dwelling women with low bone mass aged 55 to 81 participated in the Fracture Intervention Trial (FIT), a multicenter clinical trial of alendronate that enrolled women into one of two study arms based solely on the presence or absence of existing radiographic vertebral deformities. There were 2027 women with at least one vertebral deformity enrolled in the vertebral fracture arm of FIT and followed prospectively for an average of 2.9 years, whereas 4432 women with no vertebral deformity were enrolled in the clinical fracture arm of FIT and followed prospectively for an average of 4.2 years. MEASUREMENTS: Determination of prevalent vertebral deformities on baseline lateral thoracic and lumbar spine radiographs was made at the coordinating center using a combination of radiographic morphometry by digitization and semiquantitative radiologic interpretation. Deaths were confirmed by obtaining copies of original death certificates of all participants who died. Episodes of hospitalization were captured through adverse event reporting; hospitalizations resulting solely from adverse events containing the words "fracture" or "trauma" were excluded from the analyses. RESULTS: During the follow-up period, 122 women died, and 1676 women were hospitalized on at least one occasion for reasons not related solely to fracture. Compared with women without prevalent vertebral deformities, those women with prevalent deformities had higher risks of mortality (age- and treatment assignment-adjusted relative risk 1.60, 95% confidence interval (CI), 1.10-2.32) and hospitalization (age- and treatment assignment-adjusted relative risk 1.18, 95% CI, 1.06-1.31). In addition, further adjustment for other factors, including smoking status, physical activity, hypertension, coronary heart disease, obstructive lung disease, any fracture since the age of 50, health status, total hip BMD, and body mass index did not alter the association between prevalent vertebral deformities and risk of mortality substantially (multivariate relative risk 1.49, 95% CI, 1.05-2.21). Adjustment for all these factors and diabetes also did not change the relationship between prevalent vertebral deformities and hospitalization (multivariate relative risk 1.14, 95% CI, 1.02-1.27). Rates of mortality and hospitalization increased with increasing number of prevalent vertebral deformities (tests for trend P < .01). CONCLUSIONS: Prevalent vertebral deformities in older women with low bone mass are associated with increased risks of mortality and hospitalization. Only a portion of this increased risk was explained by other known predictors of these outcomes.

Effect of alendronate on limited-activity days and bed-disability days caused by back pain in postmenopausal women with existing vertebral fractures. Fracture Intervention Trial Research Group.

BACKGROUND: Women with new vertebral fractures have an increased risk of back pain and functional limitation because of back pain. Alendronate sodium treatment reduces the risk of new vertebral fracture by 50% in postmenopausal women with osteoporosis. OBJECTIVE: To determine the effect of alendronate therapy on days affected by back pain in postmenopausal women with existing vertebral fractures. DESIGN: Three-year, placebo-controlled, randomized, double-blind study. SETTING: Fifteen university-based research clinics in the United States. PARTICIPANTS: A total of 2027 postmenopausal women aged 55 to 81 years with low femoral neck bone density and a preexisting vertebral fracture. INTERVENTION: Alendronate sodium (5 mg/d for 2 years and 10 mg/d for the third year) or placebo. MAIN OUTCOME MEASURES: Occurrence and severity of back pain, number of days with back pain, and number of days of bed rest or limited activity because of back pain during 3 years of follow-up. RESULTS: Irrespective of treatment assignment, women with new, clinically recognized vertebral fractures during follow-up had an increased risk of days of bed disability and days of limited activity because of back pain after the fracture. Women receiving alendronate reported an average of 3.2 fewer days of bed rest (P = .001) and 11.4 fewer days of limited activity (not including days of bed rest) because of back pain (P = .04) during follow-up than those receiving placebo. In the alendronate group, relative to the placebo group, there was a reduced risk of 1 or more bed-rest days (relative risk, 0.68; 95% confidence interval, 0.53-0.87), of 7 or more bed-rest days (0.44; 0.30-0.64), and of 7 or more limited-activity days (0.87; 0.76-0.99). There were no statistically significant differences between treatment groups in the frequency of days of back pain or increases in back-related disability between baseline and study end. CONCLUSION: In postmenopausal women with preexisting vertebral fracture, alendronate therapy for 3 years reduced the number of days of bed disability and days of limited activity caused by back pain.

Skeletal benefits of two years of alendronate treatment are similar for early postmenopausal Asian and Caucasian women.

Alendronate has been shown to increase bone density among early postmenopausal women. Osteoporosis is common among both Asian and Caucasian women, but most clinical trials have consisted primarily of Caucasian women, and it does not appear that the effectiveness of antiresorptive agents such as alendronate has been compared between the two races. In this study we compared the response of bone density and biochemical markers to alendronate among 136 Asian and 126 Caucasian women who participated in the Early Postmenopausal Interventional Cohort (EPIC) at the Hawaii center. Approximately 40 women of each race were randomly assigned to placebo or to 2.5 mg/day or 5 mg/day alendronate. Bone mineral density (BMD) was measured at the spine, total hip and total body at baseline, 12 months and 24 months; biochemical markers of bone turnover were measured at 6-month intervals. Responses were greater for the 5 mg dose than 2.5 mg, and were similar in the two races. For example, mean (SE) changes in spine BMD at 24 months for Caucasians and Asians, respectively, were -1.9% (0.5%) and -1.9% (0.4%) for the placebo group, 2.0% (0.5%) and 3.4% (0.5%) at 2.5 mg/day and 4.2% (0. 5%) for both races at 5 mg/day. Corresponding changes in urinary N-telopeptide collagen crosslinks were -33.6% (5.6%) and -27.8% (5. 8%) for placebo, -51.4% (4.0%) and -62.1 (4.3%) at 2.5 mg/day and -70.8% (2.4%) and -73.5% (3.1%) at 5 mg/day. We conclude that (1) the rate of bone loss in untreated Asian and Caucasian postmenopausal women is similar, with the possible exception of the hip; (2) 5 mg alendronate daily provides greater skeletal benefits than 2.5 mg/day in both Asian and Caucasian early postmenopausal women; and (3) the response at 5 mg/day is similar in the two races.

Osteochondrodysplasia in Scottish Fold cats.

OBJECTIVE: To better characterise the bone and joint problems which can develop in Scottish Fold cats. DESIGN: Retrospective study of cases seen in five veterinary clinics and radiographic survey of cats in a cattery. RESULTS: Six Scottish Fold cats (four castrated males, two spayed females) aged between 5 months and 6 years were presented for signs of skeletal disease including lameness, reluctance to jump, a stiff stilted gait, short misshapen distal limbs, swelling of plantar tarsometatarsal regions and short thick inflexible tails. A further four cases (one male, three females, 15 months to 11 years) were identified by radiographic screening of a cattery. A diagnosis of osteochondrodysplasia was based on characteristic radiological findings including irregularity in the size and shape of tarsal, carpal, metatarsal and metacarpal bones, phalanges and caudal vertebrae, narrowed joint spaces, and progressive new bone formation around joints of distal limbs with diffuse osteopenia of adjacent bone. A plantar exostosis caudal to the calcaneus was present in advanced cases. In all nine cases where pedigree information was available, affected cats allegedly originated from the mating of a Scottish Fold to a cat with normal ears. The severity and time of onset of physical signs, and rate of progression and extent of radiographic abnormalities, varied from case to case. Limited histological observations suggested the underlying problem may be an osteochondrodysplasia, related to inadequate cartilage maturation. Clinical signs were ameliorated by administration of pentosan subcutaneously in two of three cats in which it was trailed, and one of these also benefited from an oral glycosaminoglycan preparation. CONCLUSIONS: Clinical and radiological findings were ascribed to defective maturation and function of cartilage, particularly in the distal limbs, ears and tail. As all Scottish Fold cats suffered from osteochondrodysplasia of some degree, the best solution would be to avoid using fold-eared cats for breeding and instead use Scottish shorthairs.

Biochemical and radiologic improvement in Paget's disease of bone treated with alendronate: a randomized, placebo-controlled trial.

PURPOSE: The potent bisphosphonates offer great promise in the management of Paget's disease of bone, but are currently available only as parenteral preparations in most countries. There is a need for a well-tolerated, oral therapy. Furthermore, none of the currently available therapies have been rigorously demonstrated to heal the lytic bone lesions characteristic of this condition. Alendronate is a potent new oral aminobisphosphonate that has shown promising effects on Paget's disease in preliminary studies. METHODS: We report a double-blind, randomized comparison of oral alendronate 40 mg/day and placebo over 6 months in 55 patients with Paget's disease. Efficacy was determined from measurements of biochemical indices of bone turnover (serum alkaline phosphatase and urine N-telopeptide) and blinded radiologic assessment of lytic bone lesions. RESULTS: N-telopeptide excretion declined by 86% and serum alkaline phosphatase by 73% in patients receiving alendronate, but remained stable in patients receiving placebo (P < 0.001 between groups for both indices). Responses were similar whether or not patients had previously received bisphosphonate treatment. Alendronate treatment normalized alkaline phosphatase in 48% of patients. Forty-eight percent of alendronate-treated patients showed radiologic improvement in osteolysis whereas in the placebo group only 4% improved (P = 0.02 for between-groups comparison). No patient in either group showed worsening of osteolysis. Bone histomorphometry indicated that alendronate tended to normalize turnover indices. There was no evidence of abnormal mineralization in bone biopsies taken from 12 alendronate-treated subjects. The treatment was well tolerated. CONCLUSION: Oral alendronate appears to be a safe and effective therapy for Paget's disease and results in healing of lytic bone lesions.

Cancer incidence in atomic bomb survivors. Part I: Use of the tumor registries in Hiroshima and Nagasaki for incidence studies.

More than 30 years ago, population-based tumor registries were established in Hiroshima and Nagasaki. This report, the first of a series of papers on cancer incidence, describes methodological aspects of the tumor registries and discusses issues of data quality in the context of the Life Span Study (LSS) cohort, the major atomic bomb survivor population. The tumor registries in Hiroshima and Nagasaki are characterized by active case ascertainment based on abstraction of medical records at area hospitals, augmented by tissue registries operational in the area and a number of clinical and pathological programs undertaken over the years among the atomic bomb survivors. Using conventional measures of quality, the Hiroshima and Nagasaki tumor registries have a death certificate-only (DCO) rate of less than 9%, a mortality/incidence (M/I) ratio of about 50%, and a histological verification (HV) rate in excess of 70%, which place these registries among the best in Japan and comparable to many established registries worldwide. All tumor registry data pertaining to the LSS population were assembled, reviewed and handled with special attention given to the quality and uniformity of data based on standardized procedures. Special studies and monitoring programs were also introduced to evaluate the quality of the tumor incidence data in the LSS. Analyses were performed to examine the quality of incidence data overall and across various substrata used for risk assessment such as age, time and radiation dose groups. No significant associations were found between radiation dose and data quality as measured by various indices. These findings warrant the use of the present tumor registry-based data for studies of cancer incidence in the atomic bomb survivors.

Cancer incidence in atomic bomb survivors. Part II: Solid tumors, 1958-1987.

This report presents, for the first time, comprehensive data on the incidence of solid cancer and risk estimates for A-bomb survivors in the extended Life Span Study (LSS-E85) cohort. Among 79,972 individuals, 8613 first primary solid cancers were diagnosed between 1958 and 1987. As part of the standard registration process of the Hiroshima and Nagasaki tumor registries, cancer cases occurring among members of the LSS-E85 cohort were identified using a computer linkage system supplemented by manual searches. Special efforts were made to ensure complete case ascertainment, data quality and data consistency in the two cities. For all sites combined, 75% of the cancers were verified histologically, 6% were diagnosed by direct observation, 8% were based on a clinical diagnosis, and 12.6% were ascertained by death certificate only. A standard set of analyses was carried out for each of the organs and organ systems considered. Depending on the cancer site, Dosimetry System 1986 (DS86) organ or kerma doses were used for computing risk estimates. Analyses were based on a general excess relative risk model (the background rate times one plus the excess relative risk). Analyses carried out for each site involved fitting the background model with no dose effect, a linear dose-response model with no effect modifiers, a linear-quadratic dose-response model with no effect modifiers, and a series of linear dose-response models that included each of the covariates (sex, age at exposure, time since exposure, attained age and city) individually as effect modifiers. Because the tumor registries ascertain cancers in the registry catchment areas only, an adjustment was made for the effects of migration. In agreement with prior LSS findings, a statistically significant excess risk for all solid cancers was demonstrated [excess relative risk at 1 Sv (ERR1Sv) = 0.63; excess absolute risk (EAR) per 10(4) person-year sievert (PY Sv) = 29.7]. For cancers of the stomach (ERR1SV = 0.32), colon (ERR1SV = 0.72), lung (ERR1SV = 0.95), breast (ERR1SV = 1.59), ovary (ERR1SV = 0.99), urinary bladder (ERR1SV = 1.02) and thyroid (ERR1SV = 1.15), significant radiation associations were observed. There was some indication of an increase in tumors of the neural tissue (excluding the brain) among persons exposed to the bombs before age 20. For the first time, radiation has been associated with liver (ERR1SV = 0.49) and nonmelanoma skin (ERR1SV = 1.0) cancer incidence in the LSS cohort. The present analysis also strengthened earlier findings, based on a smaller number of cases, of an effect of A-bomb radiation on salivary gland cancer.(ABSTRACT TRUNCATED AT 400 WORDS)

Cancer incidence in atomic bomb survivors. Part IV: Comparison of cancer incidence and mortality.

This report compares cancer incidence and mortality among atomic bomb survivors in the Radiation Effects Research Foundation Life Span Study (LSS) cohort. Because the incidence data are derived from the Hiroshima and Nagasaki tumor registries, case ascertainment is limited to the time (1958-1987) and geographic restrictions (Hiroshima and Nagasaki) of the registries, whereas mortality data are available from 1950-1987 anywhere in Japan. With these conditions, there were 9,014 first primary incident cancer cases identified among LSS cohort members compared with 7,308 deaths for which cancer was listed as the underlying cause of death on death certificates. When deaths were limited to those occurring between 1958-1987 in Hiroshima or Nagasaki, there were 3,155 more incident cancer cases overall, and 1,262 more cancers of the digestive system. For cancers of the oral cavity and pharynx, skin, breast, female and male genital organs, urinary system and thyroid, the incidence series was at least twice as large as the comparable mortality series. Although the incidence and mortality data are dissimilar in many ways, the overall conclusions regarding which solid cancers provide evidence of a significant dose response generally confirm the mortality findings. When either incidence or mortality data are evaluated, significant excess risks are observed for all solid cancers, stomach, colon, liver (when it is defined as primary liver cancer or liver cancer not otherwise specified on the death certificate), lung, breast, ovary and urinary bladder. No significant radiation effect is seen for cancers of the pharynx, rectum, gallbladder, pancreas, nose, larynx, uterus, prostate or kidney in either series. There is evidence of a significant excess of nonmelanoma skin cancer in the incidence data, but not in the mortality series. Cancers of the salivary gland and thyroid are also in excess in the incidence series, but they were not evaluated in the earlier mortality analyses. For all solid tumors the estimated excess relative risk at 1 Sv (ERR1Sv) for incidence (ERR1Sv = 0.63) is 40% larger than the excess relative risk (ERR) based on mortality data from 1950-1987 in all Japan (ERR1Sv = 0.45). The corresponding excess absolute risk (EAR) point estimate is 2.7 times greater for incidence than mortality. For some cancer sites, the difference in the magnitude of risk between incidence and mortality is greater. These differences reflect the greater diagnostic accuracy of the incidence data and the lack of full representation of radiosensitive but relatively nonfatal cancers, such as breast and thyroid, in the mortality data. Analyses of both incidence and mortality data are needed since the two end points provide complementary information for risk assessment.

Cytotoxic effects of residual chemicals from polymeric biomaterials for artificial soft intraocular lenses.

Development of improved hydrogels for soft intraocular lenses, based on 2-hydroxyethyl methacrylate monomer, requires the use of various other monomers and polymerization additives which have potential ocular toxicity. Three monomers, 2-hydroxyethyl methacrylate, methyl methacrylate, and 2-ethoxyethyl methacrylate, as well as two common inhibitors, hydroquinone and 4-methoxyphenol, were subjected to in vitro cytotoxicity assays as aqueous solutions at different concentrations. A new polymerization initiator, 2,2'-azo-bis-(2,4-dimethyl valeronitrile), was thermally decomposed in water at different concentrations and the products were also assayed for cytotoxicity. Assays were based on incubation with human choroidal fibroblasts. Cell death was evaluated by trypan blue dye exclusion, DNA synthesis inhibition, and lactate dehydrogenase tests. While methyl methacrylate and 2-ethoxyethyl methacrylate were found nontoxic, the other chemicals displayed high cytotoxicity. However, when extracts of synthesized poly(2-hydroxyethyl methacrylate) specimens, differentially treated after polymerization, were subjected to the same assays it was found that toxicity from residual 2-hydroxyethyl methacrylate monomer was lost during steam sterilization and storage in water because of the removal of the monomer through aqueous washing. The lack of toxicity in these specimens suggests that residual contents of inhibitor and initiator are too low to cause toxic effects on choroidal fibroblasts. It is concluded that hydrogels have low cytotoxic effects in vitro.

Planning tendon paths using an interactive graphic workstation.

This study provides a technique to be used for planning tendon paths in thumb reconstruction surgery. All mathematical modeling computations are performed on a VAX 11/750 host computer and the graphic manipulation is carried out by the Evans & Sutherland PS390 color display system. The results of the simulation are stored in a log file, including the rotation angles of the joints and the location of the pulley and the insertion points as a record of the tendon transfer design for a specific hand. The methods are based on the modeling of two separate types of tendon paths that consist of straight line segments and curved segments that follow bone contours. The method further assumes that the path of the tendon will always evolve to a planar curve. By integrating this technique with an existing kinematic model of the hand derived from CT-scans, a clinically relevant method has been developed.

The complete amino acid sequence of the Clostridium botulinum type A neurotoxin, deduced by nucleotide sequence analysis of the encoding gene.

A 26-mer oligonucleotide probe was synthesized (based on the determined amino acid sequence of the N-terminus of the Clostridium botulinum type A neurotoxin, BoNT/A) and used in Southern blot analysis to construct a restriction map of the region of the clostridial genome encompassing BoNT/A. The detailed information obtained enabled the cloning of the structural gene as three distinct fragments, none of which were capable of directing the expression of a toxic molecule. The central portion was cloned as a 2-kb PvuII-TaqI fragment and the remaining regions of the light chain and heavy chain as a 2.4-kb ScaI-TaqI fragment and a 3.4-kb HpaI-PvuII fragment, respectively. The nucleotide sequence of all three fragments was determined and an open reading frame identified, composed of 1296 codons corresponding to a polypeptide of 149 502 Da. The deduced amino acid sequence exhibited 33% similarity to tetanus toxin, with the most highly conserved regions occurring between the N-termini of the respective heavy chains. Conservation of Cys residues flanking the position at which the toxins are cleaved to yield the heavy chain and light chain allowed the tentative identification of those residues which probably form the disulphide bridges linking the two toxin subfragments.

Physical characterisation of the replication region of the Streptococcus faecalis plasmid pAM beta 1.

The complete nucleotide (nt) sequence of a 5.1-kb EcoRI DNA restriction fragment carrying the replication region of the Streptococcus faecalis plasmid pAM beta 1 has been determined. Of the seven major open reading frames (ORF A-G) identified within this fragment, two (C and E) were shown to be encoding by in vitro transcription/translation assays. Evidence was obtained that synthesis of the polypeptide (Mr 57,380) encoded by the largest ORF (E) was essential for replication. Deletion analysis indicated that the minimum unit of DNA required for replication resided on a 2.59-kb AccI-HpaI subfragment. ORF C resided outside of this fragment and encompassed an extensive region of directly repeated nt sequence. The encoded polypeptide (Mr 30,471) was therefore composed of large tracts of reiterated amino acid sequence (11 x VDP and 35 x TEP tripeptides) which probably caused the observed anomalous electrophoretic mobility of the synthesised protein (equivalent to 61 kDa). Deletion of a 416-bp segment of DNA between unique KpnI and StyI sites caused an increase in copy number, which correlated with the in vitro production of higher levels of ORF E polypeptide. Although homology was detected between the sequenced DNA, and the replicon of a closely related streptococcal plasmid (pSM19035), none was evident to any other characterised Gram+ plasmid.

A community-based study of gastrointestinal helminth and protozoan infection in Western Jamaica

A study of gastrointestinal parasitic infection was conducted in four communities in the Parish of Westmoreland, Jamica. All blood smears (n=1,025) werw negative and 63,7% of stool specimens (n=696) contained ova/cysts of one or more of 7 helminth and 9 protozoan spcecies. Trichuris and Giardia were the most prevalent species. Prevalence was markedly age-dependent, with infection occuring most commonly in children. It is concluded that gastreointestinal parasitic infections persist at intensity and prevalence levels likely to have a significant impact on community health

Taxol for the treatment of proliferative vitreoretinopathy.

Proliferative vitreoretinopathy (PVR) results in retinal detachment and visual impairment due to fibroblastic proliferation in the vitreous and subsequent cellular contraction. The authors have used an in vitro model for PVR to evaluate the action of the antineoplastic drug, taxol, on chorioretinal fibroblast proliferation and contractility. Dose response curves obtained show taxol to be a potent inhibitor of both cellular events. Fifty percent inhibition of contraction and proliferation occurred at 2 X 10(-8)M and 3 X 10(-9)M, respectively. On the basis of this pharmacodynamic data, three dosage regimes were chosen to evaluate possible prevention of PVR in an animal model based on the intravitreal injection of cultured fibroblasts. These animals trials show that a single intravitreal dose of either 35 micrograms or 0.5 microgram taxol significantly reduces incidence and extent of PVR. The average grade of vitreoretinal traction at 28 days for 35 micrograms taxol and 250,000 cells was 0.4 (control 1.8); for 35 micrograms taxol and 700,000 cells, 1.0 (control 2.2); and for 0.5 microgram taxol and 250,000 cells, 1.0 (control 2.3). Delayed optic nerve damage was noted with the highest dose used, but a good therapeutic margin may exist. Long-term clinical histopathologic and electrophysiologic studies will be required. The authors conclude from these preliminary studies that taxol holds definite promise for the relief of traction retinal detachment and PVR.

X-linked spondyloepiphyseal dysplasia tarda: mucopolysaccharide excretion studies.

Sex linked spondyloepiphyseal dysplasia tarda is described in a family with four affected members. The characteristic features of short trunk, hip disease, and flattening of the vertebrae with a posterior "hump" were present. Urinary mucopolysaccharides were characterized both quantitatively and qualitatively and were within normal values.