Hox genes and the evolution of vertebrate axial morphology

A common form of evolutionary variation between vertebrate taxa is the different numbers of segments that contribute to various regions of the anterior-posterior axis; cervical vertebrae, thoracic vertebrae, etc. The term ‘transposition’ is used to describe this phenomenon. Genetic experiments with homeotic genes in mice have demonstrated that Hox genes are in part responsible for the specification of segmental identity along the anterior-posterior axis, and it has been proposed that an axial Hox code determines the morphology of individual vertebrae (Kessel, M. and Gruss, P. (1990) Science 249, 347–379). This paper presents a comparative study of the developmental patterns of homeobox gene expression and developmental morphology between animals that have homologous regulatory genes but different morphologies. The axial expression boundaries of 23 Hox genes were examined in the paraxial mesoderm of chick, and 16 in mouse embryos by in situ hybridization and immunolocalization techniques. Hox gene anterior expression boundaries were found to be transposed in concert with morphological boundaries. This data contributes a mechanistic level to the assumed homology of these regions in vertebrates. The recognition of mechanistic homology supports the historical homology of basic patterning mechanisms between all organisms that share these genes.

Sonic hedgehog and Fgf-4 act through a signaling cascade and feedback loop to integrate growth and patterning of the developing limb bud

Proper limb growth and patterning requires signals from the zone of polarizing activity in the posterior mesoderm and from the overlying apical ectodermal ridge (AER). Sonic hedgehog and Fgf-4, respectively, have recently been identified as candidates for these signals. We have dissected the roles of these secreted proteins in early limb development by ectopically regulating their activities in a number of surgical contexts. Our results indicate that Sonic hedgehog initiates expression of secondary signaling molecules, including Bmp-2 in the mesoderm and Fgf-4 in the ectoderm. The mesoderm requires ectodermally derived competence factors, which include Fgf-4, to activate target gene expression in response to Sonic hedgehog. The expression of Sonic hedgehog and Fgf-4 is coordinately regulated by a positive feedback loop operating between the posterior mesoderm and the overlying AER. Taken together, these data provide a basis for understanding the integration of growth and patterning in the developing limb.

Research note: the effect of organic acids on Salmonella contamination originating from mouse fecal pellets

Laboratory mice were inoculated with a nalidixic acid and novobiocin-resistant strain of Salmonella typhimurium. Contaminated fecal pellets were harvested 2 days postinoculation. Each half of a fecal pellet was found to contain equal numbers of Salmonella on a per weight basis. When separate halves were placed into a poultry feed, either treated or untreated, with an organic acid mixture (SAL CURB), the treatment was able to significantly (P < .001) reduce Salmonella contamination of the feed by almost two log orders per gram when compared with the untreated control.

Temperature-dependent sex determination in the leopard gecko, Eublepharis macularius

The leopard gecko, Eublepharis macularius, has temperature-dependent sex determination (TSD). Previous reports have shown that females are produced predominantly at cool incubation temperatures and males are produced predominantly at warm incubation temperatures (Pattern Ib). We report here that incubation at even higher temperatures (34 and 35 degrees C) produces mostly females (Pattern II). The lethal maximum constant incubation temperature for this species appears to be just above 35 degrees C. Although a previous study indicated that females from a warm incubation temperature (32 degrees C) failed to lay eggs, we found that 12 of 14 mature females incubated at 32.5 degrees C, and 5 of 6 mature females incubated at 34 degrees C produced fertile eggs and viable hatchlings.

Strategies of mold control in dairy feeds

Mold growth can occur in dairy feeds only when nutrients are available, correct temperatures exist, oxygen is present, and unbound water is available. Because elimination of any one of these four factors prevents mold growth, management of feed that accounts for these elements is essential. Use of multiple ingredient mold inhibitors recently has become another tool for affecting successful microbiological control of feed.

A system for involving patients in program planning

Although standards exist that require occupational therapists and other health care professionals to include patients in the treatment planning process, our observations lead us to believe that patient involvement is not being maximized. The Patient Participation System allows therapists to actively involve patients in a systematic goal-setting process. The initial results of the use of this system indicate that patients can be effectively involved in establishing personalized, specific goals; identifying outcomes; and evaluating treatment effectiveness.

Use of a most probable number method modified with a deoxyribonucleic probe to monitor control by food preservatives of natural Salmonella contamination in animal meat meals

A most probable number (MPN) technique using a DNA probe was developed for determination of Salmonella in naturally contaminated meat meals. The method eliminated the need for 180 selective plates and 75 selective tubes and saved 27 h when compared with a traditional technique; yet it still yielded identical MPN of Salmonella per 100 g in five naturally contaminated samples. The method was used to monitor the effect of a commercial food preservative (Sal Curb) at 0, .25, .50, 1.0, and 2.0% in meat meals with initial contaminations of 1,100, 93, or 7 MPN organisms/100 g. The preservative greatly reduced MPN in the 1,100 and 93 MPN samples in a time and dose-dependent manner, but in the sample with 7 MPN organisms/100 g of material, it resulted in 0 MPN organisms per 100 g after 24 h at all levels tested.

Incidence of molds and mycotoxins in commercial animal feed mills in seven midwestern states, 1988-1989

A total of 82 feed manufacturers located within seven midwestern states (Iowa, Nebraska, Minnesota, Illinois, Indiana, Ohio, Michigan) participated in a survey of mold and mycotoxin contamination of corn. Samples were submitted from a composite of the grading samples taken from each incoming load of corn. The survey was initiated in July 1988. During the 12-mo period, moisture content of the corn samples upon receipt at the laboratory ranged from 10.5 to 13.3%. The greatest variation occurred in the springtime. Iowa's corn samples were driest (11.2%), and samples submitted from Ohio were wettest (12.8%). Mold counts averaged 2.63 x 10(4) per gram during the year. The predominant mold found was Fusarium sp. Samples were checked by black light and averaged 25.4% positive during the period. When assayed for mycotoxins, 19.5% of the samples were positive for at least one of the following: aflatoxin, zearalenone, T2 toxin and deoxynivalenol (vomitoxin). Aflatoxin and T2 toxin made up the majority of these samples containing toxin. The highest incidence of mycotoxin-contaminated corn (48%) occurred in samples submitted in July of 1988. Over the 12-mo period, the highest mycotoxin contamination occurred in Iowa, Illinois and Michigan. When samples were subjected to 90% relative humidity and 32 degrees C, an average of 3.9 d was required for mold growth to appear. After incubation, 24.7% of the samples contained one of the four toxins. The data indicate that mold and mycotoxin contamination of mixed samples of corn is widespread, even in the midwestern corn belt of the U.S.

Adult physical dysfunction content in professional curricula

This study examined the content of occupational therapy professional curricula as it pertains to adult physical dysfunction and the opinions and perceptions of faculty responsible for this content area. Survey results from 28 of 66 academic institutions offering professional-level education were received and analyzed. A great diversity in content and emphasis was reflected in the areas of medical conditions, general approaches to evaluation and treatment, specific evaluations, and specific treatment techniques and modalities. Most of the respondents were pleased with students' performances in physical dysfunction Level II fieldwork, believed that course work was applicable to local clinical settings, and agreed that courses were constantly changing to reflect evolving occupational therapy theory. Approximately 30% of the respondents believed that they had inadequate time to prepare students for entry-level practice, and about half agreed that their department had the necessary equipment to teach evaluation and treatment content.

Germ line p53 mutations in a familial syndrome of breast cancer, sarcomas, and other neoplasms

Familial cancer syndromes have helped to define the role of tumor suppressor genes in the development of cancer. The dominantly inherited Li-Fraumeni syndrome (LFS) is of particular interest because of the diversity of childhood and adult tumors that occur in affected individuals. The rarity and high mortality of LFS precluded formal linkage analysis. The alternative approach was to select the most plausible candidate gene. The tumor suppressor gene, p53, was studied because of previous indications that this gene is inactivated in the sporadic (nonfamilial) forms of most cancers that are associated with LFS. Germ line p53 mutations have been detected in all five LFS families analyzed. These mutations do not produce amounts of mutant p53 protein expected to exert a trans-dominant loss of function effect on wild-type p53 protein. The frequency of germ line p53 mutations can now be examined in additional families with LFS, and in other cancer patients and families with clinical features that might be attributed to the mutation.

p53 functions as a cell cycle control protein in osteosarcomas

Mutations in the p53 gene have been associated with a wide range of human tumors, including osteosarcomas. Although it has been shown that wild-type p53 can block the ability of E1a and ras to cotransform primary rodent cells, it is poorly understood why inactivation of the p53 gene is important for tumor formation. We show that overexpression of the gene encoding wild-type p53 blocks the growth of osteosarcoma cells. The growth arrest was determined to be due to an inability of the transfected cells to progress into S phase. This suggests that the role of the p53 gene as an antioncogene may be in controlling the cell cycle in a fashion analogous to the check-point control genes in Saccharomyces cerevisiae.

The dosimetric properties of an intraoperative radiation therapy applicator system for a Mevatron-80

An applicator system for intraoperative radiation therapy has been fabricated which does not require physical docking with the accelerator. A dosimetric study has been completed which documents the properties of this system for a variety of electron beam energies, applicator sizes, collimator settings, both primary and secondary, and source-surface distance (SSD) settings. Sensitivity of the system to common misalignment errors was also determined. Results indicate (a) applicator leakage of less than 5%, (b) beam flatness to within plus or minus 5% at the dMAX with a single primary collimator setting, (c) smooth changes in output with cone size, beam energy and SSD, and (d) negligible changes in dose distributions within alignment errors permitted by the system.

Effect of chemical treatment of poultry feed on survival of Salmonella

After treatment with a chemical preservative [Myco Curb (Kemin Industries, Des Moines, IA) at .25, .5, .75, or 1.0%], sterilized commercial poultry feed was contaminated with either Salmonella typhimurium ATCC 6994 or with a strain isolated from commercial broiler carcasses. All treatments resulted in the elimination of detectable Salmonella from heavily contaminated feed within 72 h and from lightly contaminated feed within 24 h. Nonsterilized feed showed similar results. Commercial feed fed to broilers for 56 days and inoculated with Salmonella daily for Days 35 to 56 was treated with the chemical preservative at .5 and 1.0% for the last 7 days. Treatment resulted in a reduction of the number of fecal and intestinal samples positive for Salmonella, demonstrating elimination of Salmonella in the feed by use of the feed preservative.

Rectal v. intravenous administration of indomethacin in the treatment of renal colic

Rectal administration of 100 mg indomethacin in solution had as good, and almost as rapid, an effect on renal colic as 50 mg given intravenously. Side effects were significantly fewer with the rectal than with the intravenous route.

Priapism in a patient with endometrioid prostatic carcinoma. A case report

A case of endometrioid carcinoma of the prostate is reported in which the initial symptom was hematuria. The patient slowly developed a painless priapism, and the tumor ultimately became generalized despite orchiectomy.

Ornithine decarboxylase activity and polyamine content in normal renal tissue and in renal carcinoma

Ornithine decarboxylase (ODC) activity and contents of putrescine, spermidine and spermine were determined in cortical and medullary tissue and clear cell tumours in human kidneys. Medullary ODC activity was 75 +/- 9% (n = 6; p less than 0.05) of the respective cortical value. The ODC activity in renal tumours varied considerably but did not differ significantly from the respective cortical values. Similar concentrations of putrescine were found in cortex and medulla, but a 5-fold increase was found in the tumours (p less than 0.02). Significantly lower values (p less than 0.01) of spermidine and spermine were found in medulla when compared to cortex. No significant change was found for these amines in the carcinomas when compared with corresponding cortical tissue.

Automatic prediction of platelet utilization by time series analysis in a large tertiary care hospital

The authors investigated the potential of various time series models to aid in the prediction of platelet utilization patterns at the authors' institution. During a seven-week feasibility study, prediction accuracy of time series models was slightly inferior to that of an experienced platelet transfusion coordinator. The models that adjusted for day-of-the-week variability were superior to simpler models in a prospective evaluation over a three-month period. Conversion to a time series model for platelet utilization prediction has resulted in significant savings in personnel costs for management of platelet concentrate inventory in the blood bank. Outdate rates have been lower than those achieved by the platelet transfusion coordinator, with no sacrifice in availability occurring during the evaluation period.

Analytic calculation of electron beam isodose distributions

Analytical techniques have been developed to generate electron beam isodose distributions from a modest set of experimental data. These techniques include (1) development of a compact yet powerful linear least-squares optimization program with a graphic display of the results, (2) coordinate transformations to allow straightforward fitting of the isodose distributions with simple polynomial functions, and (3) accurate interpolation methods to allow production of treatment planning dose matrices. The program, written in FORTRAN, has been implemented on a minicomputer and uses the standard peripherals of a commercially available treatment planning system (AECL TP-11). The computer-generated isodose and central-axis distributions correspond very closely with the data for electron energies from 5 to 20 MeV and for all field sizes.

Regulation of Proteinase Inhibitor Synthesis in Tomato Leaves : IN VITRO SYNTHESIS OF INHIBITORS I AND II WITH mRNA FROM EXCISED LEAVES INDUCED WITH PIIF (PROTEINASE INHIBITOR INDUCING FACTOR)

Messenger RNA was isolated from young excised tomato leaves, induced to accumulate proteinase Inhibitors I and II with the proteinase inhibitor inducing factor (PIIF), and translated in vitro in a rabbit reticulocyte lysate system. Translatable messenger RNAs specific for Inhibitors I and II were present in PIIF-induced leaves but were not present without PIIF induction. The nascent in vitro-synthesized inhibitors migrated with an apparent molecular weight 2,000 to 3,000 daltons larger than that of the two inhibitors isolated from leaves. The molecular weights of the preinhibitors were identical whether translated from mRNA from PIIF-induced leaves or translated from mRNA isolated from wounded leaves. Incubation of excised PIIF-induced plants in CO(2)-free air doubled the rate of in vivo synthesis of Inhibitor I over that in normal air (Ryan CA 1977 Biochem Biophys Res Commun 77: 1004-1008) but did not affect the rate of in vivo Inhibitor II accumulation. The rate of incorporation of (35)SO(4) (2-) into soluble proteins was 70% less when leaves were incubated in CO(2)-free air rather than normal air. Messenger RNA isolated from PIIF-induced plants incubated in the presence or absence of CO(2) was translated in vitro. The amount of in vitro-translatable mRNA present for each inhibitor (per microgram total mRNA) was the same in leaves incubated in either atmosphere. Therefore, the increased rate of synthesis and accumulation of Inhibitor I in a CO(2)-free atmosphere does not appear to result from an increased level of mRNA but appears to be controlled at a posttranscriptional level.

N-acetyltransferase phenotype and risk in urinary bladder cancer: approaches in molecular epidemiology. Preliminary results in Sweden and Denmark

A variable but often significant proportion of urinary bladder cancer in urban areas can be attributed to occupational and cultural (cigarette smoking) situations associated with exposures to various arylamines. The variable N-acetylation of carcinogenic arylamines by human hepatic enzyme systems, the known genetic regulation and polymorphic distribution of this enzyme activity in humans, and the known enhanced susceptibility of individuals with the genetically-distinct "slow acetylator" phenotype to various arylamine toxicities, has prompted examination of possible correlations between N-acetyltransferase phenotype and urinary bladder cancer risk in rural and urban populations. In this context, N-acetylation is viewed as a component of detoxication pathways with respect to arylamine bladder carcinogenesis. In preliminary utilizations of this approach, a population of urban urinary bladder cancer patients from Copenhagen, Denmark displayed a 13% excess (p = 0.065) of individuals with the slow acetylator phenotype (46/71 = 64.8%) when compared to a Danish control population (38/74 = 51.4%). These data are consistent with the possibility that arylamines may play an etiological role in bladder cancer in this locale and that slow acetylator individuals may be at higher relative risk (1.74) than rapid acetylator individuals. As 95% of patients reported histories of smoking, it was not possible to isolate and examine smoking factors. In contrast, a population of rural urinary bladder cancer patients from Lund, Sweden, where bladder cancer incidence (20/100,000) (1971) is lower than in Copenhagen (43.8/100,000) (1968-72), no difference in slow acetylator distribution was observed between bladder cancer (80/115 = 69.6%) and Swedish control (79/118 = 66.9%) populations, indicating a relative lack of involvement of arylamines in the etiology of rural bladder cancer. Populations of "spontaneous" bladder cancer patients would be expected to contain variable portions of disease related to arylamine exposure and would be less likely to display a detectable correlation than would an industrial population with documentable arylamine exposure. Consequently, confirmation of this hypothesis is being pursued by examination of industrial populations in an effort to obtain an empirical estimate of relative risk for slow and rapid acetylator phenotypes. These studies involve exposure-matched workmen both with and without bladder cancer.

Collection and evaluation of normal exfoliated urinary bladder cells in man using scanning electron microscopy

Normal exfoliated urinary bladder cells were collected from midstream urine samples from 21 male patients. Procedures for urine filtration using Millipore filters of Nucleopore filters, cell fixation and preparation for scanning electron microscopy investigation were developed. Correlations were made between the surface morphology of exfoliated cells and that of biopsies from different anatomical regions of the urinary bladder. Scanning electron microsocopy (SEM) of exfoliated normal urinary bladder cells proved to be a more sensitive method for discovering cellular surface details than light microscopy. This information forms the basis for further SEM studies of cell surface alterations due to urothelial diseases.