A frameless stereotaxic localisation system using MRI, CT and DSA

The authors present a method of stereotaxic localisation using magnetic resonance imaging (MRI) computerized tomography (CT) and digital subtracted angiography (DSA) which does not require localisation frams fixed to the patient's skull, but uses only four cranial landmarks corresponding to the holders of the neurosurgical stereotaxic frame. The method presents no major constraints in routine examinations. The geometrical distortions of the imaging devices are corrected. Three-dimensional localisation is performed using sagittal and axial slices in MRI, axial slices in CT and only two associated frontaly and lateral views in DSA. The images data are transferred to a PC-based system. By locating the landmarks on the images, the transformation matrixes can be computed to obtain the 3D coordinates of a target in the stereotaxic space and in any imaging modality. The results obtained show the precision of the corrections and the millimetre accuracy of pin-point target localisation.

RF-transmitted CsI radio-isotopic ambulatory recorder for left ventricular ejection fraction monitoring

We have developed a CsI multidetector probe in order to produce a nuclear ambulatory recorder to study simultaneously cardiac electric activity and the left ventricular ejection fraction. To make the device lighter, the electronics were designed with surface-mounted technology, and a serial data RF transmission system was used. The data are processed on a real-time basis using a portable microcomputer. Unlike other commercially available devices, this monitor avoids the problems of volume, weight, recording time capacity and slow off-line data processing. Our device permits global and regional analysis of the ejection fraction for a moderate manufacturing cost. It is intended primarily for ambulatory use and can easily be adapted to perform a monitoring function. The first tests on patients conducted using the prototype demonstrate the technical reliability and satisfactory operation of the device.

Evaluation of a 99mTc-antimyosin kit for myocardial infarct imaging

The Fab fragment of a mouse monoclonal antibody AM(3-48) that recognizes alpha and beta-heavy chains of human atrial and ventricular myosin and beta-heavy chain of human slow skeletal muscle myosin [CardioVisionTM] was labeled with 99mTc using stannous reductant in a simple, instant kit method. The infarcted heart uptake in dogs of 99mTc-AM(3-48)Fab' was compared with that of established radiopharmaceuticals routinely used for cardiac imaging in humans. The dog infarct was induced by bringing a catheter from the femoral artery to the coronary artery where an artificial blood clot was generated. The 99mTc-AM(3-48)Fab' preparation was selectively taken up by infarcted myocardium, resulting in diagnostic quality images of the infarcted area as early as 6 hour post-injection, rendering CardioVisionTM particularly useful for SPECT imaging. Good agreement was found between the images obtained with 99mTc-Pyrophosphate and those obtained with 99mTc-AM(3-48)Fab', while the infarcted area was clearly delineated as a cold spot with 99mTc-MIBI or 201 Tl-thallous chloride. The biodistribution of 99mTc-AM(3-48)Fab' was also studied in healthy and isoproterenol-infarcted rats, from which dosimetry values in man were extrapolated. The data indicate that the kidneys will receive the highest radiation dose and that they will be the main contributors to the total radiation burden, which was estimated at 0.005 rad/mCi.

High-resolution PET imaging and quantitation of pharmaceutical biodistributions in a small animal using avalanche photodiode detectors

The feasibility of high-resolution PET using BGO-avalanche photodiode detectors for in vivo imaging and quantitation of the biodistribution of radiopharmaceuticals in small animals is demonstrated. A prototype PET camera consisting of two scanning arrays of eight EG&G C30994 solid-state scintillation detectors was used to simulate a 310-mm diameter dual-ring animal tomograph having a 130-mm port and three imaging slices, each about 3.5 mm thick. The spatial resolution (FWHM) is 3 mm or less, isotropic and uniform throughout the 120-mm diameter field of view.

METHODS

Female Fischer 344/CRBL rats implanted with subcutaneous mammary adenocarcinoma tumors were injected with copper-tetrasulfophthalocyanine (CuPcS4), a potential sensitizer for the photodynamic therapy of cancer, labeled with 64Cu (T1/2 = 12.7 hr, beta +:19%).

RESULTS

In spite of the low specific radioactivity of 64Cu and other inherent limitations, organs such as the liver, kidneys and the tumor could be resolved with sufficient detail for their separation and quantitation. Apart from the tumor, agreement was obtained between the biodistributions measured by PET and by scintillation counting. The discrepancy for the tumor measurement results from averaging the radioactivity over the entire tumor volume when, in fact, CuPcS4 does not completely penetrate the tumor. This incomplete penetration is noted on the PET images.

CONCLUSIONS

PET based on avalanche photodiode detectors provides an accurate measurement of target organ and tumor tissue concentrations. These preliminary results demonstrate the potential of very high resolution PET for biodistribution studies in small animals.

Technical note: magnetic resonance imaging of agarose gel phantom for assessment of three-dimensional dose distribution in linac radiosurgery

An agarose gel phantom is used to evaluate the spatial distribution of the dose delivered by a linac radiosurgery device. Dependence of the absorbed dose on the T1 relaxation time is checked. T1 magnetic resonance images show the close correspondence between the actual absorbed dose distribution and the dose distribution expected by the treatment planning.

A miniature cesium iodide-photodiode detector for ambulatory monitoring of left ventricular function

The physical characteristics of a portable nonimaging scintillation probe system for continuous ambulatory monitoring of the left ventricular function are described. The detector of the equilibrium radionuclide labeled blood pool is a single cesium iodide (CsI) crystal coupled to a silicium photodiode and interfaced to a microcomputer. The spatial properties of this small CsI crystal (1 x 1 x 1 cm3) were evaluated with various single-hole collimators. Linearity was studied in nonattenuating medium. Saturation began at 3000 cps, count loss was 10% at 4000 cps, maximal count rate was 24,000 cps. In attenuating medium, isocount curve of 5% of the maximal count rate was 100 mm deep and 160 mm wide. The most appropriate tested lead collimator to record the global ejection fraction of the left ventricle was a disc-shaped (thickness 5 mm, diameter 41 mm) single-hole (proximal aperture 8 mm, distal aperture 18 mm) collimator. Sensitivity was similar to the sensitivity of a sodium iodide nuclear probe. The detection performance appeared comparable to other available detector systems. Our results indicate that such a CsI-photodiode probe is a promising candidate for left ventricular function monitoring. The application to an ambulatory multicrystal detector system is presented and discussed.

2- and 4-fluorinated 16 alpha(-)[125I]iodoestradiol derivatives: synthesis and effect on estrogen receptor binding and receptor-mediated target tissue uptake

The effect of 2- and 4-fluoro substitution on the estrogen receptor-mediated tissue localization of radioiodinated 16 alpha-iodoestradiol (16 alpha-IE2) and its 11 beta-methoxy analogue (11 beta-OMe-16 alpha-IE2) was evaluated. Electrophilic substitution of estrone or 11 beta-methoxyestrone with N-fluoropyridinium salt gave the 2- and 4-fluoro derivatives which were subsequently converted to the 3,17 beta-enol diacetate and brominated to yield exclusively the 16 alpha-bromo analogues. Epimerization gave the corresponding 16 beta-bromoestrones which were reduced to the 17 beta-hydroxy derivatives. Halogen exchange with NaI or Na[125I]I provided the A-ring fluorinated 16 alpha-iodoestradiols. The 4-F analogue exhibited higher affinity for estrogen receptors than the corresponding 2-F analogue, and these differences were more pronounced at higher incubation temperatures. Biodistribution studies in immature female rats showed that 4-fluoro substitution had only a moderate effect on receptor-mediated tissue uptake of the parent molecules whereas 2-fluoro substitution resulted in strongly diminished tissue specificity. The lower target selectivity of the 2-F, compared to the 4-F, analogue correlates to some extent with their different receptor binding properties; however, the rate of catabolism may also be involved. Differences in blood clearance further accentuated the localization properties to yield particularly high uterus to blood ratios in the case of the 4-F-11 beta-OMe-16 alpha-IE2, suggesting the potential of the analog labeled with 123I as a radiopharmaceutical for receptor imaging in nuclear medicine. The isopotential maps of the fluorinated steroids, obtained via semiempirical computer modeling on the molecular structures, show striking differences between the 4-F and 2-F derivatives reflecting their varying biological properties.

Frameless method of stereotaxic localization with DSA

PURPOSE

To improve a method of stereotaxic localization with digital subtraction angiography that does not require use of a localization frame fixed to the patient's skull during examination.

MATERIALS AND METHODS

An independent, low-cost, stereotaxic computing system was devised. Software programs used magnetic resonance images, computed tomographic scans, and digitized radiographs of plastic bone implants with head landmarks to establish reference trihedrons in each imaging system, transpose target coordinates from one system to another, adjust surgical instruments, help plan radiation surgery, and compute and display isodose curves.

RESULTS

The geometric distortions of the image intensifier were corrected. Distortion problems of the conic projection were solved, and three-dimensional localization was achieved with only two associated front and lateral views. Accuracy to within 1 mm was achieved for the three coordinates.

CONCLUSION

This frameless stereotaxic localization technique is highly accurate and reliable. The system allows maximum automation of examination procedures.

Synthesis, receptor binding and biodistribution of the gem-21-chloro-21-iodovinylestradiol derivatives

Radioiodinated 11 beta-methoxy-(17 alpha,20E)iodovinylestradiol (11 beta-OMe-IVE2) shows high estrogen receptor (ER)-mediated uterus uptake and good potential as an ER-imaging agent. In order to examine the tolerance of the ER for modification about the iodovinyl substituent, we prepared the (17 alpha,20Z-chloro)21-chloro-21-iodovinylestradiol (4a) and several derivatives featuring 11 beta-methoxy (4b), 11 beta-ethoxy (4c) or 7 alpha-methyl (4d) substituents. All gem-dihalogen derivatives 4a-d were prepared from the 17 alpha-chloroethynyl precursors. The intermediate chlorostannylvinyl derivatives were obtained using tri-n-butyltin hydride and palladium acetate catalyst. Compounds 4a and 4b were labeled with 125I via their corresponding tin intermediates and their tissue distribution was studied in immature female rats. Addition of a 21-Cl to the 17 alpha-ethynylestradiols reduced ER binding affinity, except for the 11 beta-substituted analogs which showed a pronounced increase. Surprisingly, addition of a 21-Cl to the (17 alpha,20E)IVE2 resulted in increased ER binding affinities and augmented ER-mediated uterus uptake, which may result from the pronounced increase in the dipole moment of the molecule. Thus, further modifications at the C-21 position of IVE2 are well tolerated by the ER. However, addition of the 21-Cl also resulted in increased radioiodine uptake by the thyroid, much slower blood clearance and lower uterus to blood/nontarget ratios, suggesting increased in vivo instability of the C--I bond of the gem-chlorine-iodine atoms which may reflect the increase in steric and electronic interference.

Synthesis of A-ring fluorinated derivatives of (17 alpha,20E/Z)-[125I]iodovinylestradiols: effect on receptor binding and receptor-mediated target tissue uptake

We have prepared a series of 2- and 4-fluoro derivatives of the isomeric (17 alpha,20E)- and (17 alpha, 20Z)iodovinylestradiols (IVE2) and also the analogs substituted with either a 7 alpha-methyl (7 alpha-Me-IVE2) or 11 beta-methoxy group (11 beta-OMe-IVE2) and evaluated their in vitro and in vivo properties. Electrophilic substitution of the estrone derivatives with N-fluoropyridinium salt gave the 2- and 4-fluoro analogs which were subsequently converted to the 17 alpha-ethynyl derivatives. The tributylstannyl intermediates were obtained from the corresponding 17 alpha-ethynyl analogs using azobisisobutyronitrile or triethylborane as catalyst. All 12 products were also prepared as their no-carrier-added [125I]iodovinyl analogs via destannylation of the tributylstannyl precursors. Binding affinity for the estrogen receptor (ER) was in general higher for the 4-F derivatives as compared to the 2-F derivatives, while the 20Z isomers of the same compounds showed somewhat higher ER binding affinity as compared to the 20E isomers. The combination of an A-ring fluoro and 7 alpha- or 11 beta-substituent decreased ER binding affinity. Substitution of a fluoro atom at C-4 on either the 17 alpha-ethynylestradiol or isomeric 17 alpha-IVE2 enhanced the affinity of the parent molecule for the ER. A-ring fluorination of all other analogues tested had no effect or depressed ER binding affinity. Varying incubation conditions showed substantial differences in ER binding kinetics between the 20E and 20Z isomers. Tissue distribution in immature female rats showed that the highest uterus uptake and uterus to blood/nontarget ratios in the IVE2 series were obtained with the 4-F-(17 alpha,20Z)IVE2 isomer. The combination of A-ring fluoro and 7 alpha- or 11 beta-substitution decreased uterus uptake but had little or no effect on uterus to blood/nontarget ratios. The highest uterus to blood ratios were observed for the 4-F-(17 alpha,20E)11 beta-OMe-IVE2 (75 at 6 h and 125 at 12 h pi) reflecting rapid blood clearance and in vivo stability, as confirmed by the low levels of thyroid radioactivity. The lack of correlation between ER binding affinities and uterus uptake, and/or uptake ratios, suggests that other factors, including nonspecific binding and metabolic processes, also are involved in the tissue localization process. Our data suggest that 4-F substitution onto (17 alpha,20Z)IVE2 and (17 alpha,20E)11 beta-OMe-IVE2 enhances the potential of these compounds to function as SPECT imaging agents of ER-rich tissues.

The value of variable number of tandem-repeat polymorphisms in cases of disputed paternity not resolved by conventional markers: two case reports

Disputed paternity cases are routinely tested in the authors' laboratory for red cell antigen, plasma protein, red cell enzyme, and HLA polymorphisms. This report concerns two cases in which the above test results made exclusion of paternity doubtful. In one case, exclusion of paternity was based on one discrepancy in the Duffy blood group system only, a unique situation in the investigators' experience of more than 2500 cases; the investigators were, therefore, reluctant to use this as the only evidence of exclusion. In the other case, it was necessary to postulate the presence of a rare haplotype, MSu, in the MNS blood group system to explain paternity. It was therefore decided to investigate allelic variable number of tandem-repeat (VNTR) DNA polymorphisms in these disputed paternity trios. VNTR DNA typing convincingly excluded these accused men from paternity.

Bone mineral and fat measurement with a novel dual photon absorptiometer

The authors have produced an original dual-photon absorptiometer, with specific algorithms, permitting real-time automatic bone recognition, to reduce examination time (to 5 min). It permits the simultaneous measurement of the mineral density of an area of bone (BMD), the fat percentage of the soft tissues (PFST) that surround it, and the variation in this percentage. It visually represents, on one and the same picture, freely defined in terms of dimension and definition, bone mineral distribution and fat mass distribution. The performances are analysed, using phantoms and taking ten control subjects, in the region of the femoral neck. The variations in PFST in the control subjects are compared with the measurements carried out in MRI in the same region. In all these control subjects, there is a regular decrease in PFST in this region along an upper external/lower internal axis. This decrease has been likened to a regression line, the slope of which, representing between -0.16 per cent of fat per cm and -1.7 per cent per cm, has a mean value of -0.81 per cent per cm. The BMD is thus reduced by 0-2.5 per cent, depending on the subjects.

7 alpha-Methyl- and 11 beta-ethoxy-substitution of [125I]-16 alpha-iodoestradiol: effect on estrogen receptor-mediated target tissue uptake

The 7 alpha-methyl and 11 beta-ethoxy derivatives of 16 alpha-[125I]iodoestradiol were prepared via halogen exchange with 125I of the corresponding 16 beta-bromoestradiol precursors. The 16 alpha-bromo derivatives were obtained via halogenation of the analogous 17-enol acetate, epimerization to the 16 beta-isomer, and hydride reduction. Stereochemical assignments were based on high resolution 1H NMR. To evaluate the effect of the nature and stereochemistry of the 16-halo substituent on the relative binding affinity for the estrogen receptor, the analogous 16-chloro derivatives were also prepared. The highest binding affinities were observed with the 7 alpha-methyl-16 alpha-haloestradiols, particularly the bromo and chloro derivatives while the 16 alpha-iodo derivatives gave somewhat lower values. Both the 11 beta-ethoxy and 7 alpha-methyl-16 alpha-[125I]iodoestradiols localize in the uteri of immature female rats via a receptor-mediated process. Rapid blood clearance of the 125I-labeled 7 alpha-methyl derivative results in lower 125I uptake by the uterus as well as nontarget organs as compared to the 11 beta-substituted estradiol analogs. However, uterus to blood and nontarget ratios are more favorable for the 7 alpha-methyl-16 alpha-[125I]iodoestradiol as compared to the analogous 11 beta-ethoxy derivatives suggesting that this compound substituted with 123I may be useful for the in vivo imaging of estrogen receptor-rich breast tumors by single photon emission computerized tomography.

Approach, avoidance, and contact behavior of individually recognized animals automatically quantified with an imaging technique

A low-cost system was developed that allows the assessment of the location and the direction of movements of two individually recognized animals in a social interaction. The program was validated by (i) assessing deliberately induced approach and avoidance movements of artificial objects, (ii) the effects of known differences in social behavior between differently treated rats, and (iii) repeatedly testing social behavior under similar circumstances to assess enhanced social contact due to being familiar with the arena. Movements toward and away from each other of individually housed versus group-housed animals, and of young versus aged animals, were analyzed by the system. The results obtained, demonstrated that in the case of randomly moving artificial objects specific approachers or avoiders could not be identified, whereas isolated and young rats showed more approach behavior than their respective controls. In addition, the algorithm applied for calculating relative approach and avoidance movements elucidated differences between groups that were not noticed by human observers. Social contact behavior of rats was assessed automatically. Habituation to the testing situation in repeated testing increased social contact behavior.

Synthesis, receptor binding and target-tissue uptake of carbon-11-labeled carbamate derivatives of estradiol and hexestrol

Carbon-11-labeled estradiol and hexestrol derivatives were prepared via the reaction of [11C]ethylchloroformate with the 2- and 4-amino derivatives of estradiol, the 3'-amino derivatives of hexestrol, and the 1-aminophenoxy derivatives of hexestrol and 1-norhexestrol. The corresponding nonradioactive carbamates were prepared for chemical characterization and in vitro receptor binding assays. The positions of the substituents on the parent molecules were selected with a view to minimize interference with the receptor binding process. In spite of this, affinity for the estrogen receptor was strongly impaired for all carbamate derivatives. Likewise, in vivo, the [11C]carbamate analogs failed to localize in receptor rich tissue via an estrogen receptor mediated process.

[Role of echoencephalography in myelomeningocele]

Infants with myelomeningocele very often present cranio-cerebral anomalies such as Arnold Chiari malformation. Cranial ultrasonography allows early evaluation of these malformations and helps to detect complications in surgically treated children.

HLA class II induction by interferon-gamma in K562 variant cell line: inhibition by serum lipid

The induction of class II antigen (Ag) by interferon-gamma (IFN-gamma) in variants of the K562 cell line has been examined in this study. Following incubation of K562A cells with IFN-gamma, surface expression of HLA-DR molecules was demonstrated by indirect immunofluorescence, confirmed by immunoblotting, and HLA-DR3 Ag specificity identified. HLA-DP and HLA-DRW52 Ag were co-expressed, but no HLA-DQ expression occurred. A variant of this line, designated K1A, spontaneously developed resistance to IFN-gamma induction of class II Ag, but continued to express class I Ag. In a third K562 variant, designated K562B, no class II gene products could be induced. Northern blot analysis indicated that mRNA levels correlated with surface class I and II Ag expression in all of the K562 cell lines. Resistance to IFN-gamma inducible class II Ag expression in K1A cells did not involve changes in IFN-gamma receptor affinity or number but was shown to be due to an inhibitory effect of serum lipid. These results indicate that cells derived from a common parental line may differ in susceptibility to a regulatory mechanism affecting IFN-gamma inducible class II Ag expression.

HLA DQ beta restriction fragment length polymorphism and rheumatoid arthritis. Association between DQw7 and rheumatoid arthritis in DR4-positive subjects

Two variants of the HLA-DR4-linked DQw3 allele, namely DQw7 and DQw8, were analysed in patients of mixed ancestry (Cape Coloureds) with rheumatoid arthritis and in healthy individuals from the same population group using a DQ beta-specific cDNA probe. The DQw7 allele, identified by 3,4 kb Hind III or 3,7 kb and 6,9 kb Bam HI DQ beta-specific restriction fragments, was expressed in 93% of DR4-positive patients (N = 15), compared with 12.5% DR4-positive normal individuals (N = 8). This DQ variant showed a highly significant association (relative risk = 98; P less than 0.0001) with rheumatoid arthritis in this population group and may play a role in their susceptibility to this disease.

Synthesis, receptor binding, and tissue distribution of 7 alpha- and 11 beta-substituted (17 alpha,20E)- and (17 alpha,20Z)-21-[125I]iodo-19-norpregna-1,3,5(10),20-tetraene-3,17-diols

The 11 beta-methoxy, 11 beta-ethoxy, and 7 alpha-methyl derivatives of the isomeric (17 alpha,20E)- and (17 alpha,20Z)-(iodovinyl)estradiols 3 and 6, and their no-carrier-added [125I]iodovinyl analogues, were evaluated for their relative target-tissue retention and binding affinity for the estrogen receptor. The isomeric iodovinyl and [125I]iodovinyl derivatives were prepared via destannylation of the corresponding tributylstannyl precursors in the presence of H2O2 or chloramine-T, with retention of configuration. The 20Z isomers 6 exhibited slightly higher receptor binding affinities than the 20E isomers 3, with all eight isomeric products giving relative binding affinity values in the 20-50 range. The 11 beta- and 7 alpha-substituted (iodovinyl)estradiols gave substantially higher estrogen receptor-mediated uterus uptake as compared to the nonsubstituted parent molecule. Synergism between the effect of 11 beta- or 7 alpha-substituents and the configuration of the iodovinyl group was evident from the in vivo distribution pattern of [125I]-3 and -6. The best uterus uptake was observed, at 2 h postinjection, with the 20E isomer of 11 beta-methoxy derivative 3b. However, at 5 h postinjection the 20Z isomer 6b reached higher uterus concentrations than the 20E isomer 3b, and furthermore, these values are now comparable to those observed with the 20Z isomer of the 11 beta-ethoxy derivative 6c. In the case of the 7 alpha-methyl derivatives the differences in in vivo stability between the 20E and 20Z isomers was less pronounced, whereas the 20Z isomer 6d reached somewhat higher uterus to blood as well as nontarget ratios.

[Cerebral magnetic resonance imaging in the neonatal period. Initial results]

The place of neonatal cerebral MRI and its specific contribution compared with conventional imaging techniques were evaluated in 36 patients. The difficulties specific to the patient population studied met during this preliminary period are described, with their local solutions. A preliminary evaluation of the diagnostic and prognostic value of MRI according to the disease state and gestational age is presented. The specific contribution of MRI compared with transfontanellar ultrasonography and CT scan is discussed.

Biodistribution and tumor uptake of [67Ga]chlorogallium-tetraoctadecyloxy phthalocyanine and its sulfonation products in tumor bearing C3H mice

To evaluate the biodistribution and tumor uptake of chlorogallium tetraoctadecycloxy phthalocyanine, a potential new drug for the photodynamic therapy of cancer, we prepared the radioactive 67Ga-labeled complex and its water soluble sulfonated derivative. The non-sulfonated dye was obtained by condensation of octadecyloxyphthalonitrile in the presence of a mixture of 67Ga and 69Ga chloride. The sulfonated derivative was obtained by treatment of the condensation product with oleum. As singlet molecular oxygen has been implicated in the photodynamic action of phthalocyanines (Pcs), the quantum yield of singlet oxygen (phi delta) was evaluated for chlorogallium tetraoctadecyloxy Pc, and also its zinc, aluminum and metal free analogues. After intraperitoneal administration of the non-sulfonated dye into RIF tumor bearing C3H mice, a very high 67Ga-uptake was observed in the spleen, while tumor radioactivity remained low during the 3 day study. The in vivo stability of the 67Ga-phthalocyanine complex was confirmed by comparing the distribution pattern with that of 67Ga-citrate, which proved to be significantly different. Intravenous injection of the sulfonated dye resulted in an overall lowering of 67Ga-uptake by most tissues, particularly in the spleen, while tumor radioactivities were slightly higher. These data suggest that amphiphilic photosensitizers, containing both polar sulfonate groups and long aliphatic substituents, exhibit the best distribution pattern for both imaging and photodynamic therapy of tumors.

A computer-assisted system for 3-D frameless localization in stereotaxic MRI

A low-cost PC-based system for 3-D localization of brain targets in stereotaxic imaging is presented. It relies on a method, using MR images, in which four markers are inserted in the fastenings of a Talairach stereotaxic frame during MRI examination. By locating these markers on the images with this system, the transformation matrixes can be computed to obtain the 3-D coordinates of the center of a tumour in the stereotaxic space or in the MRI space. The system calculates the frame and arc setting parameters of a probe trajectory to the target, either for an orthogonal or a double oblique approach if needed. Simulated probe trajectory intersections with consecutive slices can be viewed in order to validate the trajectory before and during the surgical procedure. The method presents no major constraints in routine examinations. Mathematical details on the calculation of the transformation matrices are given.

Biological activities of phthalocyanines. XII: Synthesis tumor uptake and biodistribution of 14C-labeled disulfonated and trisulfonated gallium phthalocyanine in C3H mice

The biodistribution and metabolism of 14C-labeled disulfonated and trisulfonated gallium phthalocyanine (Ga-PcS) was studied in radiation-induced fibrosarcoma tumor-bearing C3H mice. The [14C]Ga-PcS compounds were prepared via the condensation of [14C]phthalic acid and sulfophthalic acid in the presence of gallium chloride and characterized by their spectroscopic and chromatographic properties. The tissue concentrations of the dyes was measured by scintillation counting of the 14C and by extraction and fluorescence measurements. Elevated dye levels were found in the liver, lungs, kidneys and spleen as well as in the tumor. Lower sulfonation of Ga-PcS favored liver and spleen uptake whereas higher dye sulfonation resulted in greater kidney uptake. Both dyes showed high tumor uptake with peak concentrations exceeding those of most tissues except for the liver in the case of Ga-PcS2. The highest tumor uptake was observed with Ga-PcS3. Both dyes were slowly excreted from the body. The liver-feces pathway was favored in the case of Ga-PcS2 with high activities persisting in the liver, even after 21 days. The Ga-PcS3 was preferentially excreted via the kidney-urine pathway. High performance liquid chromatography analysis of the liver and tumor extracts of [14C]Ga-PcS3-treated animals did not reveal desulfonation of the dye. However, urine analysis showed the presence of radioactive metabolites lacking the characteristic phthalocyanine absorption.

[Normal values in children of bone mineral content measured by dual photon absorptiometry]

We analyzed the results of dual photon absorptiometry measurements in 43 normal children. Results were correlated with age, body weight, and stature. Reference stature-specific values for bone mineral content in children are proposed. Furthermore, our results show that mineralization continues beyond the end of statural growth.

A new, fully versatile surface coil for MRI

To enable surface coils to be adapted to a wide variety of examinations and anatomical features, the authors present a flexible detector coupled with an auto tuning device. The conductive loop, which is a flexible mercury filled tube, can be used to obtain various shapes, such as a single flat 22-cm diameter loop or an 11-cm diameter two-turn coil. Tuning is carried out at 21 MHz (0.5 T field) by a microprocessor controlled varactor. Studies conducted on a phantom are used to evaluate the signal/noise ratio and the spatial sensitivity of the coil according to different geometrical arrangements (saddle-shaped and two-turn). The results are compared with those obtained with the constructor's spine coil. The studies of patients described show good image resolution, even in the case of short sequences with thin slices and restricted fields of view. The clinical results and those obtained on the phantom demonstrate the feasibility and value of the device, particularly in examining anatomical regions of different forms.

Infarcted heart uptake and biodistribution of radiolabelled anti-myosin monoclonal antibody in rat and dog myocardial infarct models

A new mouse monoclonal antibody that recognizes alpha- and beta-heavy chains of human atrial and ventricular myosin and beta-heavy chain of human slow skeletal muscle myosin was obtained. The 125I- and 111In-labelled antibody, and its F(ab')2 and Fab fragments localize in isoproterenol induced infarcted rat heart, with the F(ab')2 fragment showing the highest uptake. Comparison with 99Tc-pyrophosphate uptake in infarcted dog heart, induced by selective obstruction of a coronary artery, suggest that the 111In-labelled F(ab')2 localizes specifically in infarcted myocardium only.

[Giant diverticulum of the colon. Apropos of 2 cases]

Two cases of giant colonic diverticulum are reported. Clinical and radiological features are described. Surgery is absolutely necessary.

Ifenprodil and SL 82.0715 as cerebral anti-ischemic agents. I. Evidence for efficacy in models of focal cerebral ischemia

Recent studies have strongly implicated the excitatory neurotransmitter glutamate in the cascade of pathological mechanisms that cause neuronal loss after certain types of brain ischemia. The neurotoxic effects of glutamate are mediated, at least in global ischemia, via NMDA receptors. In the present study we have examined the effects of compounds that possess NMDA receptor antagonist properties (ifenprodil, SL 82.0715 [(+/-)-alpha-(4-chlorophenyl)-4-[(4-fluorophenyl)methyl]- 1-piperidineethanol] and 1-[1-(2-thienyl)cyclohexyl]piperidine) on the histological consequences of focal, as opposed to global, cerebral ischemia in both the rat and the cat. Ifenprodil (0.3-3 mg/kg i.v.) administered as a perfusion over 3 hr after occlusion of the feline middle cerebral artery reduced the volume of infarcted tissue (measured 4 days after occlusion) in a dose-related manner. At the highest dose a 42% reduction of infarcted volume was noted, essentially in cortical tissue. In an identical protocol, a derivative of ifenprodil, SL 82.0715, reduced the volume of infarction in a manner comparable to that described for ifenprodil. As SL 82.0715 possesses better p.o. bioavailability, this compound was also evaluated in the rat, again after middle cerebral artery occlusion. First administered 30 min after the induction of ischemia, SL 82.0715 (1 and 10 mg/kg p.o.) reduced infarction volume by 34 and 48%, respectively. The quantitative histology was performed 2 days after middle cerebral artery occlusion. The noncompetitive receptor antagonist, 1-[1-(2-thienyl)cyclohexyl]piperidine, administered (1 mg/kg i.p.) before the induction of focal ischemia, similarly and significantly decreased the final volume of infarction. As both ifenprodil and SL 82.0715 are noncompetitive antagonists of the NMDA receptor, two conclusions may be drawn from the present investigation. First, NMDA antagonism by ifenprodil and its derivative is an effective approach for tissue sparing in animal models of stroke and brain infarction. Second, these pharmacological observations provide evidence for the involvement of excitatory amino-acid induced-neurotoxicity in the evolution and consequences of focal cerebral ischemia.

Synthesis, receptor binding, and tissue distribution of (17 alpha,20E)- and (17 alpha,20Z)-21-[125I]iodo-19-norpregna-1,3,5(10), 20-tetraene-3,17-diol

The isomeric (17 alpha,20E)- and (17 alpha,20Z)-(iodovinyl)estradiol derivatives 3 and 6, and their no-carrier-added (nca) [125I]iodovinyl analogues, were tested for their relative target tissue retention and binding affinity for the estrogen receptor. The (iodovinyl)estradiols 3 and 6 were prepared via destannylation of the (17 alpha,20E)- and (17 alpha,20Z)-tributylstannyl precursors 2 and 4 with retention of configuration. Selective formation of the E or Z isomers 2 and 4 during the reaction of 17 alpha-ethynylestradiol 1a with tri-n-butyltin hydride was controlled by the presence or absence of the catalyst, the polarity of the solvent, and the reaction temperature. The nca [125I]iodovinyl analogues [125I]-3a and [125I]-6a were obtained in good radiochemical yield and high purity by treatment of 2a and 4a with [125I]NaI in the presence of H2O2 and chloroamine-T, respectively. Of the two isomeric iodovinyl derivatives 3 and 6, the 20Z isomer 6a exhibited the highest receptor binding affinity and the [125I]-6a gave the highest in vivo receptor-mediated target tissue uptake.

Scrambling of bands in gel electrophoresis of DNA

Under certain conditions of agarose gel electrophoresis, larger DNA molecules migrate faster than smaller ones. This anomalous mobility of DNA, which can lead to serious errors in the measurement of DNA fragment lengths, is related to near-zero velocity conformations which can trap DNA chains during electrophoresis. Intermittent electric fields can be used to alter the chain conformations so as to restore the monotonic mobility-size relationship which is necessary for a correct interpretation of the gel. These data are in agreement with the results of a computer simulation based on a theoretical model of electrophoresis.

Pulsed-field electrophoresis: application of a computer model to the separation of large DNA molecules

The biased reptation theory has been applied to the pulsed-field electrophoresis of DNA in agarose gels. A computer simulation of the theoretical model that calculates the mobility of large DNA molecules as a function of agarose pore size, DNA chain properties, and electric field conditions has been used to generate mobility curves for DNA molecules in the size range of the larger yeast chromosomes. Pulsed-field electrophoresis experiments resulting in the establishment of an electrophoretic karyotype for yeast, where the mobility of the DNA fragments is a monotonic function of molecular size for the entire size range that is resolved (200-2200 kilobase pairs), has been compared to the theoretical mobility curves generated by the computer model. The various physical mechanisms and experimental conditions responsible for band inversion and improved electrophoretic separation are identified and discussed in the framework of the model.

Synthesis of a series of compounds related to betaxolol, a new beta 1-adrenoceptor antagonist with a pharmacological and pharmacokinetic profile optimized for the treatment of chronic cardiovascular diseases

A series of para-substituted phenoxypropanolamines has been synthesized and tested for beta-adrenoceptor blocking activity. Some derivatives (8, 11, 12, 20, 21) exhibited greater in vitro potency than the reference drugs metoprolol and propranolol. This series, in contrast to propranolol but similar to metoprolol, possesses cardioselectivity. The 3-[p-[(cycloalkylmethoxy)ethyl]phenoxy]-1-substituted-amino-2-prop anol derivatives 8 (cyclopropylmethoxyethyl: betaxolol) and 11 (cyclobutylmethoxyethyl) produced antihypertensive effects in spontaneously hypertensive rats. Betaxolol (Kerlon, 8) was found to exhibit an appropriate preclinical pharmacological and human pharmacokinetic profile (elevated oral bioavailability and prolonged plasma half-life) for the treatment of chronic cardiovascular diseases such as hypertension and angina.

[Cancer of the anal canal. Results of the treatment of a series of 195 cases]

Between 1968 and 1982, 195 patients with invasive anal canal carcinoma were treated at Institut Curie (Paris, France). There were 168 females and 27 males --sex-ratio: 5.7/1, mean age: 67 +/- 11 yrs. (range: 38-85 yrs.). The initial size of the tumors was analyzed according to the circumferential invasion of the anal canal. The tumor involved 1/4 of the circumference in 49 cases, 1/2 of the circumference in 108 cases, 3/4 of the circumference in 22 cases and the whole circumference in 16 cases. Pathological examination revealed 20 cloacogenic carcinomas and 175 squamous carcinomas. All patients received radiotherapy as initial treatment and none received chemotherapy as a curative procedure. Eight patients received only palliative treatment. Twenty-seven patients were operated on because the response of the tumor to irradiation was partial or incomplete. One hundred and sixty patients received the full course of irradiation with a complete response. Among the latter, 100 patients were alive NED with a normal anal function with at least a 2-year follow-up. Local recurrences (n = 42) underwent salvage surgery in 50 p. 100 of the cases with a 3-year survival over 50 p. 100. Actuarial survival of the 195 patients was 68.5 p. 100 at 3 years and 58 p. 100 at 5 years. Survival was highly related to the initial size of the tumor and to the presence of positive inguinal nodes (p less than 0.0002). The histologic type was not related to the response to radiotherapy, nor to local recurrence or to survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis, tissue distribution and tumor uptake of 99mTc- and 67Ga-tetrasulfophthalocyanine

Complexes of tetrasulfophthalocyanine with 99mTc, 69Ga and 67Ga were prepared by the condensation of sulfophthalic acid with the appropriate metal-species. The Ga-complex was also obtained by exchange of the central hydrogens of the empty tetrasulfophthalocyanine. The labeled complexes were purified by thin layer chromatography and characterized by their chromatographic properties. Their biodistribution in rabbits and tumor-bearing rats revealed that most of the radioactivity accumulated in the kidneys, liver, ovaries, adrenals and spleen. Comparison of these distribution pattern with those of [99mTc]pertechnetate and 67Ga-citrate confirmed the in vivo stability of the labeled complexes. The 67Ga-complex reached better tumor-to-blood and tumor-to-muscle ratios than 67Ga-citrate.

Incidence of Hb Barts and alpha-thalassaemia genotypes in a South African population

The cord blood of 1,207 randomly selected neonates from the Cape Coloured population of South Africa was analysed for the presence of Hb Barts. 40 individuals (3.3%) had detectable Hb Barts levels with values ranging from 1.1 to 7.3%. Restriction enzyme analysis of DNA from subjects with Hb Barts showed that 85% of the cases studied had the genotypes -alpha 3.7/alpha alpha or -alpha 3.7/-alpha 3.7. The observed frequency of the -alpha/alpha alpha genotype was much lower than the expected frequency which suggests that this genotype is often not associated with detectable levels of Hb Barts. Mapping of the sigma-globin locus in three subjects with HbH disease revealed the presence of the--SEA/alpha-thalassaemia determinant in this population.

[Congenital factor XII deficiency: a rare cause of increased activated cephalin time]

The fortuitous detection of an increased activated cephalin clotting time is often dependent on defects of the blood-clotting factors synthesized by the liver, haemophilia or von Willebrand's disease, circulating anticoagulants or specific deficiencies of various factors necessary for blood-clotting mechanisms. Much more rarely, it may be due to an isolated Hageman factor defect. This deficiency does not lead to an increased bleeding tendency and surgery has proved surprisingly uneventful. On the other hand, thromboembolic events may appear. Being and inherited disease with autosomal recessive transmission, the discovery of Hageman factor deficiency must lead to a complete family investigation.

Synthesis, receptor binding, and target-tissue uptake of carbon-11 labeled carbamate derivatives of estradiol and hexestrol

The reaction of ethyl chloroformate with amino compounds has been evaluated as a simple route to carbon-11 labeling of steroid hormone-receptor-based imaging agents. Both a 17 beta-amino analogue of estradiol and an aminoethyl derivative of the nonsteroidal estrogen hexestrol with potential affinity for the estrogen receptor were studied. The unlabeled carbamate derivatives of the amino estrogens were prepared by standard methods, and the 11C-labeled analogues were synthesized from [11C]ethyl chloroformate, generated by purging ethanol with [11C]phosgene. Both carbamates showed weak in vitro binding affinity for the estrogen receptor, and only the 11C-labeled hexestrol exhibited a small but significant estrogen-responsive uterus uptake in immature rats.

Treatment of epidermoid anal canal cancer

Between 1968 and 1979, 183 patients with invasive epidermoid cancer of the anal canal were treated at Institut Curie. There was 156 women, 27 men with a mean age of 67 +/- 11 years (range 40 to 85 years). The initial height of the tumor was less than 4 cm (65 patients), 4 to 6 cm (98 patients), and more than 6 cm (20 patients). All the patients received radiotherapy, either preoperatively or as curative procedure. Twenty-five patients received preoperative radiotherapy, and there was no residual tumor in 9 biopsies obtained at operation. Four local recurrences were observed. One hundred fifty-eight patients received curative radiotherapy, 115 of whom did not undergo operation. Eighty were alive with no evidence of disease and good anal function with a minimum of 3 years follow-up. We observed 15 local recurrences, 4 inguinal recurrences, and 8 visceral metastases. In addition, eight patients initially had such a big tumor that radiotherapy was only a palliative procedure. Forty-three patients required a surgical procedure after this curative radiotherapy. Colostomy (12 patients) or abdominoperineal amputation (25 patients) was required for local recurrence and colostomy was required for necrosis related to radiotherapy. Five year survival was 59 percent. The survival was related to the size of the tumor (p less than 0.0001). The likelihood of retaining normal anal function with local control of the tumor was also closely related to the initial size of the tumor.