Fetal cardiac ventricle volumetry in the second half of gestation assessed by 4D ultrasound using STIC combined with inversion mode

OBJECTIVE

Quantification of fetal heart ventricle volume can aid in the evaluation of functional and anatomical aspects of congenital heart disease. The aim of this study was to establish nomograms for ventricular volume using three-dimensional (3D) inversion mode ultrasonography with the spatio-temporal image correlation (STIC) modality and to calculate ejection fraction and stroke volume.

METHODS

The fetal heart was scanned using the STIC modality, during fetal quiescence with abdomen uppermost, at an angle of 30-50 degrees , without color Doppler flow mapping. In post-processing, starting with the classic four-chamber view plane in the A-frame, the reference point was moved to the center of the ventricle. The operator used the edit volume followed by Virtual Organ Computer-aided AnaLysis (VOCAL) mode options; in manual trace the VOCAL settings were set to 15 degrees . The trace was drawn and included the myocardium; inversion mode thresholding provided the volume of the intraventricular (anechoic) voxels within the region of interest. The total volume and the intraventricular volume were displayed. The process was repeated for right (R) and left (L) ventricles at end diastole (EDV) and end systole (ESV). The stroke volume (SV = EDV - ESV) and ejection fraction (EF = SV/EDV) were calculated from these measurements. Intraclass correlation was used to evaluate intra- and interobserver agreement.

RESULTS

One hundred fetuses ranging from 20 + 5 to 40 + 0 gestational weeks were included in the study. In addition, six fetuses diagnosed during the study period with a cardiac anomaly were examined and their ventricular volumes compared with those of the main study group. LEDV ranged from a mean of 0.53 cm(3) at midgestation to a mean of 3.96 cm(3) at term. LESV ranged from a mean of 0.17 cm(3) at midgestation to 1.56 cm(3) at term. REDV ranged from a mean of 0.68 cm(3) at midgestation to a mean of 5.44 cm(3) at term. RESV ranged from a mean of 0.26 cm(3) at midgestation to 2.29 cm(3) at term. Total stroke volume ranged from a mean of 0.78 cm(3) at midgestation to a mean of 5.5 cm(3) at term. The mean right : left ventricle ratio was 1.4, and left ejection fraction ranged from 42.5 to 86% in these fetuses. Nomograms were created for RESV, LESV, REDV, LEDV and total stroke volumes vs. estimated fetal weight and gestational age. Intra- and interobserver agreement reached 96%.

CONCLUSIONS

3D inversion mode sonography combined with STIC represents a simple and reproducible method for estimating fetal cardiac ventricle volume. This innovative methodology may add to overall evaluation of cardiac volume and function, and improve our understanding of normal and abnormal cardiac structure, as well as the severity and prognosis of cardiac lesions.

First and early second trimester fetal heart screening

PURPOSE OF REVIEW

This review describes the recent advances in timing and effectiveness of first and early second trimester fetal echocardiography screening.

RECENT FINDINGS

Fetal echocardiography can now be reliably performed from 11 weeks' gestation owing to improvements in ultrasound transducers and processors. Three-dimensional and four-dimensional ultrasound modalities in image acquisition and postprocessing analysis, including spatio-temporal image correlation, rendering three-dimensional power Doppler and high definition power flow Doppler, and B-flow have further improved our capabilities in this area. Fetal nuchal translucency measurement screening programs create a new population of at-risk pregnancies that will be referred for early fetal echocardiography. The majority of congenital heart defects, however, still occur in low-risk patients. Improved technology has lowered the gestational age at which fetal cardiac anatomy scanning can be reliably performed by properly trained and experienced examiners.

SUMMARY

Early fetal echocardiography can be offered as a screening examination to at-risk and low-risk patients, with the proviso that it be repeated following screen-negative scans at mid-gestation to exclude later developing lesions.

The FEMA GRAS assessment of aromatic substituted secondary alcohols, ketones, and related esters used as flavor ingredients

This publication is the 11th in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. The list of GRAS substances has now grown to more than 2100 substances. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. In this monograph, a detailed interpretation is presented on the renal carcinogenic potential of the aromatic secondary alcohol alpha-methylbenzyl alcohol, aromatic ketone benzophenone, and corresponding alcohol benzhydrol. The relevance of these effects to the flavor use of these substances is also discussed. The group of aromatic substituted secondary alcohols, ketones, and related esters was reaffirmed as GRAS (GRASr) based, in part, on their rapid absorption, metabolic detoxication, and excretion in humans and other animals; their low level of flavor use; the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential.

3D and 4D ultrasound in fetal cardiac scanning: a new look at the fetal heart

Over the last decade we have been witness to a burgeoning literature on three-dimensional (3D) and four-dimensional (4D) ultrasound-based studies of the fetal cardiovascular system. Recent advances in the technology of 3D/4D ultrasound systems allow almost real-time 3D/4D fetal heart scans. It appears that 3D/4D ultrasound in fetal echocardiography may make a significant contribution to interdisciplinary management team consultation, health delivery systems, parental counseling, and professional training. Our aim is to review the state of the art in 3D/4D fetal echocardiography through the literature and index cases of normal and anomalous fetal hearts.

Point mutation in codons 12 and 61 of the Ha-ras gene in rat urinary bladder carcinomas induced by N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide

Male F344 rats were fed N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) for up to 4 wk, then were given the basal diets (Prolab 3200 or AIN-76A) with or without 5% sodium saccharin for up to 100 wk. Eleven transitional cell carcinomas (TCCs), one undifferentiated carcinoma, and two sarcomas of the urinary bladder were examined for the expression of ras gene product, p21, by immunohistochemical staining and western blot analysis. Point mutation in codons 12 or 61 of the Ha-ras genes amplified by polymerase chain reaction was examined by a slot-blot screening procedure using allele-specific oligonucleotide probes. Immunohistochemical staining showed enhanced immunoreactivity with the antibody to ras p21 in seven TCCs and one undifferentiated carcinoma. Western blot analysis showed faster migration of the p21 band in 6 of 11 TCCs. Oligonucleotide hybridization revealed the point mutation in codon 12 of Ha-ras gene (GGA----GTA in 1 TCC) and in codon 61 (CAA----CGA in 5 TCCs and CAA----CTA in 1 TCC). Two mutations in codons 12 and 61 coexisted in one tumor, which were found to be present in different Ha-ras alleles. The incidence of Ha-ras gene mutations were similar in groups treated with (3 of 6) or without (3 of 8) sodium saccharin. These results suggest the involvement of activated Ha-ras gene in rat urinary bladder carcinogenesis induced by FANFT.

Rendering in fetal cardiac scanning: the intracardiac septa and the coronal atrioventricular valve planes

OBJECTIVE

In this study we aimed to apply spatio-temporal image correlation (STIC) rendering to visualize the virtual planes of the interventricular and interatrial septa (IVS, IAS) as well as the atrioventricular (AV) annuli plane just distal to the semilunar valves (coronal atrioventricular (CAV) plane) in normal and pathological fetal hearts, to ascertain whether these planes add to fetal cardiac examination.

METHODS

Unselected gravidae presenting for anatomy scan or patients referred for fetal echocardiography in the second and third trimesters of pregnancy with suspected or diagnosed cardiac malformation were scanned using the five planes technique with the STIC modality to obtain cardiac volume sets for each patient. Rendering capabilities were employed to obtain the 'virtual planes' to evaluate the IVS, IAS, AV annuli, and size and alignment of the great vessels.

RESULTS

A total of 136 normal scans were performed to establish a learning curve for STIC acquisition and post-processing rendering and analysis. An additional 35 cases with cardiac anomalies were accrued. In 131/136 (96.3%) normal scans the IAS and IVS were visualized successfully, while in 127/136 (93.4%) normal fetuses the CAV plane was successfully visualized. In 13 anomalous cases the IVS plane improved ventricular septal defect (VSD) evaluation, and in four the IAS plane contributed to foramen ovale evaluation. The modality improved visualization of the septa and the assessment of the defects, as well as the foramen ovale flap and pattern of movement of the foramen ovale. In five cases the CAV plane improved evaluation of the alignment of the major vessels in relation to the AV annuli, and in three the evaluation of the semilunar valves, with or without malalignment of the great vessels.

CONCLUSIONS

Rendering STIC technology allows the visualization of virtual planes (IAS, IVS, AV annuli-CAV plane), which can clarify our understanding of anatomical defects and may improve communication with the management team and family.

The shadow of the intrauterine device

OBJECTIVE

An intrauterine device (IUD) is a highly effective and prevalent form of birth control with a low failure rate. It is not without complications, including irregular bleeding and pelvic pain, perforation, expulsion, and pregnancy. Investigation of the symptomatic patient and routine follow-up of asymptomatic women with IUDs include transvaginal ultrasonography to rule out IUD malposition and other complications. Three-dimensional ultrasonography (3DUS) has been shown to have added value in imaging the pelvic organs, including the uterus. However, even with 3DUS, the operator may encounter difficulty in imaging the IUD in its entirety, because of variability in both echogenicity and exact location.

METHODS

More than 30 women undergoing IUD placement evaluation, including routine examinations and cases of suspected pregnancy, irregular bleeding, infection, and pelvic pain, were evaluated with 3DUS and volume contrast imaging in the C plane (VCI-C), which visualized acoustic shadows of the IUDs, facilitating identification of the intrauterine position and type of the device.

RESULTS

Four examples are presented from women undergoing evaluation of IUD placement in whom 2-dimensional ultrasonography failed to visualize the device satisfactorily. Volume contrast imaging in the C plane allowed visualization of the acoustic shadows of the IUDs, thereby providing more exact imaging of the type of device as well as aiding in locating the IUD. In a woman with irregular bleeding, a bicornuate uterus with pregnancy in 1 horn and a bowed T-type IUD in the contralateral horn were diagnosed with VCI-C.

CONCLUSIONS

We conclude from these shadow images that VCI-C is a useful modality in cases of difficult visualization of the IUD; VCI-C visualization of the acoustic shadow of the IUD may provide an adjunctive approach.

Three-dimensional power Doppler (3DPD) ultrasound in the diagnosis and follow-up of fetal vascular anomalies

OBJECTIVE

This study was undertaken to examine the value of 3-dimensional power Doppler (3DPD) ultrasound imaging in diagnosis and follow-up of fetal vascular anomalies.

STUDY DESIGN

In 174 women undergoing early second-trimester targeted organ scanning, followed by a midtrimester second scan in a university hospital setting, 3DPD was applied to the fetal intra-abdominal and intrathoracic vessels.

RESULTS

In 137 of 174 fetuses (75%) in the earlier scan, and in 164 of 174 fetuses (95%) in the later scan, 3DPD ultrasound successfully visualized the fetal vessels. In an additional 9 cases, anomalous vascularity was identified: fetal intra-abdominal umbilical vein varix (2), persistent right umbilical vein (1), agenesis of ductus venosus (2), eventration of diaphragm (1), parenchymal and vascular lung anomaly (1), sacrococcygeal teratoma (1), and chorioangioma (1). 3DPD improved diagnostic precision, aided our understanding of anomalous structure, and added information on the vascular volume of lesions in some cases.

CONCLUSION

3DPD improved ultrasound visualization of the fetal vessels of the abdomen and thorax in normal and anomalous cases.

The FEMA GRAS assessment of benzyl derivatives used as flavor ingredients

This publication is the eighth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of benzyl derivatives as flavoring ingredients is evaluated. The group of benzyl derivatives was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food; their rapid absorption, metabolic detoxication, and excretion in humans and other animals, their low level of flavor use, the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential. This evidence of safety is supported by the fact that the intake of benzyl derivatives as natural components of traditional foods is greater than their intake as intentionally added flavoring substances.

The FEMA GRAS assessment of phenethyl alcohol, aldehyde, acid, and related acetals and esters used as flavor ingredients

This publication is the ninth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of phenethyl alcohol, aldehyde, acid, and related acetals and esters as flavoring ingredients is evaluated. The group of phenethylalcohol, aldehyde, acid, and related acetals and esters was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food, their rapid absorption, metabolic detoxication, and excretion in humans and other animals, their low level of flavor use, the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential. This evidence of safety is supported by the fact that the intake of phenethyl alcohol, aldehyde, acid, and related acetals and esters as natural components of traditional foods is greater than their intake as intentionally added flavoring substances.

The FEMA GRAS assessment of hydroxy- and alkoxy-substituted benzyl derivatives used as flavor ingredients

This publication is the ninth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of hydroxy- and alkoxy-substituted benzyl derivatives as flavoring ingredients is evaluated. The group of hydroxy- and alkoxy-benzyl derivatives was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food; their rapid absorption, metabolic detoxication, and excretion in humans and other animals; their low level of flavor use; the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential. This evidence of safety is supported by the fact that the intake of hydroxy- and alkoxy-substituted benzyl derivatives as natural components of traditional foods is greater than their intake as intentionally added flavoring substances.

A procedure for the safety evaluation of natural flavor complexes used as ingredients in food: essential oils

A scientifically based guide has been developed to evaluate the safety of naturally occurring mixtures, particularly essential oils, for their intended use as flavor ingredients. The approach relies on the complete chemical characterization of the essential oil and the variability of the composition of the oil in the product intended for commerce. Being products of common plant biochemical pathways, the chemically identified constituents are organized according to a limited number of well-established chemical groups called congeneric groups. The safety of the intake of the each congeneric group from consumption of the essential oil is evaluated in the context of data on absorption, metabolism, and toxicology of members of the congeneric group. The intake of the group of unidentified constituents is evaluated in the context of the consumption of the essential oil as a food, a highly conservative toxicologic threshold, and toxicity data on the essential oil or an essential oil of similar chemotaxonomy. The flexibility of the guide is reflected in the fact that high intake of major congeneric groups of low toxicologic concern will be evaluated along with low intake of minor congeneric groups of significant toxicological concern (i.e., higher structural class). The guide also provides a comprehensive evaluation of all congeneric groups and constituents that account for the majority of the composition of the essential oil. The overall objective of the guide is to organize and prioritize the chemical constituents of an essential oil in order that no reasonably possible significant risk associated with the intake of essential oil goes unevaluated. The guide is, however, not intended to be a rigid checklist. The Flavor and Extract Manufacturers Association (FEMA) Expert Panel will continue to evaluate each essential oil on a case by case basis applying their scientific judgment to insure that each natural flavor complex is exhaustively evaluated.

Safety evaluation of natural flavour complexes

Natural flavour complexes (NFCs) are chemical mixtures obtained by applying physical separation methods to botanical sources. Many NFCs are derived from foods. In the present paper, a 12-step procedure for the safety evaluation of NFCs, 'the naturals paradigm', is discussed. This procedure, which is not intended to be viewed as a rigid check list, begins with a description of the chemical composition of the commercial product, followed by a review of the data on the history of dietary use. Next, each constituent of an NFC is assigned to one of 33 congeneric groups of structurally related substances and to one of three classes of toxic potential, each with its own exposure threshold of toxicological concern. The group of substances of unknown structure is placed in the class of greatest toxic potential. In subsequent steps, for each congeneric group the procedure determines the per capita intake, considers metabolic pathways and explores the need and availability of toxicological data. Additional toxicological and analytical data may be required for a comprehensive safety evaluation. The procedure concludes with an evaluation of the NFC in its entirety, also considering combined exposure to congeneric groups. The first experiences with the use of this procedure are very promising. Future safety evaluations of larger numbers of NFCs will indicate the usefulness of the system, either in its present form or in a form modified on the basis of experience.

Urinary tract calculi and thresholds in carcinogenesis

Numerous chemicals administered to rodents at relatively high doses produce urinary tract calculi, resulting in erosions or ulcerations of the urothelium, consequent regenerative hyperplasia, and ultimately tumors. This is a high-dose (threshold) phenomenon, which appears to occur more readily in rodents than in primates, including humans. Several anatomic and urinary physiologic differences between rodents and humans affect the quantitative extrapolation from results in rodent bioassays to human risk assessment. For most chemicals producing tumors by this mode of action, human exposures are significantly lower than would be expected to be required for production of calculi, and therefore pose no carcinogenic hazard to humans.

Alternative models for carcinogenicity testing: weight of evidence evaluations across models

Twenty-one chemicals were evaluated by standardized protocols in 6 mouse models that have been sugggested as alternatives to the 2-year mouse bioassay. Included were genotoxic and nongenotoxic chemicals, carcinogens and noncarcinogens, immunosuppressive and estrogenic agents, peroxisome proliferators, and chemicals producing cancer in rodents by other mechanisms. Mice were sacrificed at the end of 6 to 12 months, depending on the model. Standardized histopathology, biostatistical analyses, and criteria for overall evaluation of the results were employed. The TgAC transgenic (dermal and oral administration), the Tg-rasH2 transgenic, the heterozygous p53 gene knockout, the homozygous XPA and homozygous XPA-heterozygous p53 gene knockout, and the neonatal mouse models were evaluated. The chemicals were also evaluated in the in vitro SHE assay. Comparison of the results between the various in vivo models suggest that they might have usefulness as screening bioassays for hazard identification for potential human carcinogens. They have the benefits of being quicker, less expensive, and involve fewer animals than the traditional 2-year mouse bioassay. They do not appear to be overly sensitive. However, they do not definitively distinguish between genotoxic and nongenotoxic carcinogens, and they do not have 100% specificity for identifying human carcinogens. Like the 2-year bioassay, the results from these models need to be evaluated in conjunction with other information on a chemical in an overall weight-of-evidence, integrated analytical approach to assess risk for human exposures.

Limb development: getting down to the ground state

In 1935, Snodgrass proposed that the evolutionary ground state of arthropod limbs consisted of two segments. Recent genetic studies on the Antennapedia and Homothorax genes of Drosophila raise questions about the nature of this ground state appendage.

Regulation of Apterous activity inDrosophilawing development

Apterous is a LIM-homeodomain protein that confers dorsal compartment identity in Drosophila wing development. Apterous activity requires formation of a complex with a co-factor, Chip/dLDB. Apterous activity is regulated during wing development by dLMO, which competes with Apterous for complex formation. Here, we present evidence that complex formation between Apterous, Chip and DNA stabilizes Apterous protein in vivo. We also report that a difference in the ability of Chip to bind the LIM domains of Apterous and dLMO contributes to regulation of activity levels in vivo.

Alternative models for carcinogenicity testing

The International Conference on Harmonisation Expert Working Group on Safety suggested that under certain circumstances, data from alternative assays could be used in safety evaluation in place of a second bioassay. Several alternatives were discussed. Six of these models were evaluated in a collaborative effort under the auspices of the Health and Environmental Sciences Institute (HESI) branch of the International Life Sciences Institute (ILSI). Standard protocols, pathology review, and statistical evaluations were developed. Twenty-one chemicals were evaluated, including genotoxic, nongenotoxic, carcinogenic, and noncarcinogenic chemicals. The models that were evaluated included the p53(+/-) heterozygous knockout mouse, the rasH2 transgenic mouse, the TgAC transgenic mouse (dermal and oral administration), the homozygous XPA knockout and the XPA/p53 knockout mouse models. Also evaluated were the neonatal mouse models and the Syrian Hamster Embryo (SHE) transformation assay. The results of this comprehensive study suggest that some of these models might be useful in hazard identification if used in conjunction with information from other sources in a weight of evidence, integrated analysis approach to risk assessment.

Evaluation of diet and dimethylarsinic acid on the urothelium of Syrian golden hamsters

Few studies have examined the carcinogenicity of chemicals toward the urinary bladder in hamsters, and the effect of diet on hamster urine and urothelium has not been reported. Our laboratory recently began investigating the effects of dimethylarsinic acid (DMA) on the hamster bladder, and we noticed subtle urothelial changes even in controls. The possible effect of various diets on hamster urothelium was evaluated by feeding different diets to 4-week-old Syrian Golden hamsters for 5 weeks. The diets examined were Tekland 8656, Purina 5002, Purina 5L79, and NIH-07. Light microscopic examination showed a slight increase in urothelial hyperplasia in hamsters fed Purina 5L79. An increase in the incidence of urinary bladder necrosis, exfoliation, and mild hyperplasia were noted by scanning electron microscopy (SEM) with all dietary preparations except NIH-07. The constituents in the diets producing the urothelial alterations are not known at present, but NIH-07 diet was chosen for experiments to investigate the effects of DMA on the hamster bladder epithelium. Male and female 5-week-old Syrian Golden hamsters were fed 100 ppm DMA for 10 weeks. Examination of urinary parameters showed no treatment-related changes. Light microscopic examination and SEM revealed no changes of the urothelium of DMA-treated male or female hamsters.

Effects of spectator ligands on the specific recognition of intrastrand platinum-DNA cross-links by high mobility group box and TATA-binding proteins

The results presented describe the effects of various spectator ligands, attached to a platinum 1,2-intrastand d(GpG) cross-link in duplex DNA, on the binding of high mobility group box (HMGB) domains and the TATA-binding protein (TBP). In addition to cisplatin-modified DNA, 15-base pair DNA probes modified by [Pt(1R,2R-diaminocyclohexane)](2+), cis-[Pt(NH(3))(cyclohexylamine)](2+), [Pt(ethylenediamine)](2+), cis-[Pt(NH(3))(cyclobutylamine)](2+), and cis-[Pt(NH(3))(2-picoline)](2+) were examined. Electrophoretic mobility shift assays show that both the A and B domains of HMGB1 as well as TBP discriminate between different platinum-DNA adducts. HMGB1 domain A is the most sensitive to the nature of the spectator ligands on platinum. The effect of the spectator ligands on protein binding also depends highly on the base pairs flanking the platinated d(GpG) site. Double-stranded oligonucleotides containing the AG*G*C sequence, where the asterisks denote the sites of platination, with different spectator ligands are only moderately discriminated by the HMGB proteins and TBP, but the recognition of dsTG*G*A is highly dependent on the ligands. The effects of HMGB1 overexpression in a BG-1 ovarian cancer cell line, induced by steroid hormones, on the sensitivity of cells treated with [Pt(1R,2R-diaminocyclohexane)Cl(2)] and cis-[Pt(NH(3))(cyclohexylamine)Cl(2)] were also examined. The results suggest that HMGB1 protein levels influence the cellular processing of cis-[Pt(NH(3))- (cyclohexylamine)](2+), but not [Pt((1R,2R)-diaminocyclohexane)](2+), DNA lesions. This result is consistent with the observed binding of HMGB1a to platinum-modified dsTG*G*A probes but not with the binding affinity of HMGB1a and HMGB1 to platinum-damaged dsAG*G*C oligonucleotides. These experiments reinforce the importance of sequence context in platinum-DNA lesion recognition by cellular proteins.

The LRR proteins capricious and Tartan mediate cell interactions during DV boundary formation in the Drosophila wing

Mechanisms to segregate cell populations play important roles in tissue patterning during animal development. Rhombomeres and compartments in the ectoderm and imaginal discs of Drosophila are examples in which initially homogenous populations of cells come to be separated by boundaries of lineage restriction. Boundary formation depends in part on signaling between the distinctly specified cell populations that comprise compartments and in part on formation of affinity boundaries that prevent intermingling of these cell populations. Here, we present evidence that two transmembrane proteins with leucine-rich repeats, known as Capricious and Tartan, contribute to formation of the affinity boundary between dorsal and ventral compartments during Drosophila wing development.

Cisplatin: from DNA damage to cancer chemotherapy

Cisplatin [cis-DDP, cis-diamminedichloroplatinum(II)] is a potent anticancer drug that has been used successfully to treat tumors of the head, neck, lungs, and genitourinary tract. The biological activity of cisplatin was discovered serendipitously more than 30 years ago, and since that time research efforts have focused on elucidating its mechanism of action. The present review provides a historical perspective of our attempts to understand this complex phenomenon and the results of recent work that guides our current activities in this field. Continued efforts to understand the mechanism of genotoxicity of cisplatin are expected to lead to the discovery of new drugs and combinations for the improvement of cancer chemotherapy.