Diamond preservation in the lithospheric mantle recorded by olivine in kimberlites

The diamond potential of kimberlites is difficult to assess due to several mantle and magmatic processes affecting diamond content. Traditionally, initial evaluations are based on the compositions of mantle-derived minerals (garnet, chromite, clinopyroxene), which allow an assessment of pressure-temperature conditions and lithologies suitable for diamond formation. Here we explore a complementary approach that considers the conditions of diamonds destruction by interaction with melts/fluids (metasomatism). We test the hypothesis that carbonate-rich metasomatism related to kimberlite melt infiltration into the deep lithosphere is detrimental to diamond preservation. Our results show that high diamond grades in kimberlites worldwide are exclusively associated with high-Mg/Fe olivine, which corresponds to mantle lithosphere minimally affected by kimberlite-related metasomatism. Diamond dissolution in strongly metasomatised lithosphere containing low-Mg/Fe olivine provides a causal link to the empirical associations between low diamond grades, abundant Ti-Zr-rich garnets and kimberlites with high Ti and low Mg contents. This finding show-cases olivine geochemistry as a viable tool in diamond exploration.

Heatmaps to Assess Tumor Motion Probability with MRcine in Head and Neck Cancer

PURPOSE/OBJECTIVE(S)

Intrafraction motion affects tumor position during radiation for head and neck cancers (HNC) and can be assessed using magnetic resonance cine (MR-cine). Heatmaps - visual representation of patient specific temporal tumor location akin to internal target volume (ITV) - were analyzed to demonstrate the variation of population-based motion margins in primary oropharyngeal (OP) and laryngeal/hypopharyngeal (LH) sites with the goal to provide insights towards personalized margins.

MATERIALS/METHODS

MR-cine were performed for LH and OP HNC patients as part of simulation protocol. Images (900-1500 slices) were acquired across 3-5 minutes per patient. Gross target volumes were propagated on T1 contrast sagittal sequence using deformable image registration then adjusted manually. Tumor locations were integrated across all frames and displayed as heatmaps representing location probability. To determine individualized motion, a baseline contour representing average tumor rest position was expanded both isotropically and directionally in 1 mm increments in a novel analysis to define the contribution of each increment on target coverage. To assess directional dependence, displacements from rest position were evaluated in 4 planes from centroid: (A) 12 o'clock (OC) to 6OC (capturing volumetric shift in a portion of superior, posterior and inferior directions), B) 3OC-9OC, C) 6OC-12OC, D) 9OC-3OC. Histograms demonstrating the proportion of scan time the tumor was within expansions were generated, with expansion margins for 25%-95% coverage analyzed by patient. Wilcoxon-rank-sum test was performed to compare motion by site.

RESULTS

Motion was evaluated in 66 patients (LH n = 27, OP n = 39). In LH, a median (med) isometric expansion of 8.5mm to achieve 95% target was required, with large variations observed for minimum (min): 2.8mm and maximum (max):23.5mm. Smaller differences were observed for OP with med of 5.3mm, (min:1.9mm, max:14.6mm). At 75%, 50% and 25% coverage, expansions for LH (med: 4.8 min: 1.9 max: 17.3; med: 3.8 min: 1.2 max: 12.9; med: 3.3, min: 0.6, max: 9.3) were not significantly different than OP (med: 3.8, min: 1.7, max: 10.9; med: 3.1 min: 1.3, max: 9.4; med: 2.1, min: 0.7, max: 8.4), suggesting larger but infrequent shifts in LH. Directional tumor displacement varied widely (Table 1), and by site and points describing the need for personalized margins.

CONCLUSION

Current literature as well as the analysis in this study indicate a wide range of motion - both in magnitude and duty cycle - between and within HN sub-sites not captured on CT simulation. Moving forward, motion based heatmaps based on MR-cine may serve as visualization tool for ITV contouring or to generate personalized motion margins.

Long-distance trade in the Middle Chalcolithic of the southern Levant: The case of the olivine beads from Tel Tsaf, Jordan Valley, Israel

Eight olivine beads found at the Middle Chalcolithic site of Tel Tsaf (ca. 5,200–4,700 cal. BC), Jordan Valley, Israel, underscore a new facet of interregional exchange for this period. The current paper presents the olivine beads assemblage, its morphometric and technological characteristics, and chemical composition. The results of the chemical analysis suggest that all eight beads derive from the same source. By means of comparison with the chemical characteristics of known olivine sources, we argue for a northeastern African–western Arabian provenience and cautiously suggest Ethiopia as a probable origin. Finally, we discuss the significance of the assemblage, its possible origin, and the mechanisms that may have brought the beads to the site.

Helium in diamonds unravels over a billion years of craton metasomatism

Chemical events involving deep carbon- and water-rich fluids impact the continental lithosphere over its history. Diamonds are a by-product of such episodic fluid infiltrations, and entrapment of these fluids as microinclusions in lithospheric diamonds provide unique opportunities to investigate their nature. However, until now, direct constraints on the timing of such events have not been available. Here we report three alteration events in the southwest Kaapvaal lithosphere using U-Th-He geochronology of fluid-bearing diamonds, and constrain the upper limit of He diffusivity (to D ≈ 1.8 × 10⁻¹⁹ cm² s⁻¹), thus providing a means to directly place both upper and lower age limits on these alteration episodes. The youngest, during the Cretaceous, involved highly saline fluids, indicating a relationship with late-Mesozoic kimberlite eruptions. Remnants of two preceding events, by a Paleozoic silicic fluid and a Proterozoic carbonatitic fluid, are also encapsulated in Kaapvaal diamonds and are likely coeval with major surface tectonic events (e.g. the Damara and Namaqua–Natal orogenies).

Diamonds encapsulate the deep Earth fluids that form them, providing windows to deep mantle processes. This study constrains their ages, based on uranium-thorium-to-helium radioactive decay in the fluids and helium diffusivity in diamond, and relates diamond formation to geological events in Southern Africa.

Interaction of Multiple Surface Cues in Motion Grouping

A rotating ellipse and a translating ogive may appear rigid or nonrigid depending on their shapes. By placing moving dots (‘satellites’) in the space surrounding the contour one can cause the percept to switch between rigid and nonrigid, depending on how the dots move. We have studied how multiple surface cues can influence this grouping effect.

One set of displays consisted of the ambiguous contour and a group of consistently moving satellites. We found that under this condition the grouping was extremely robust. The influence of the satellites on the perceived rigidity of the contour remained powerful when they were moved far away from the contour and even when they were placed at a different stereoscopic depth plane. A second set of displays consisted of the ambiguous contour and two groups of satellites: one group moving rigidly and the other nonrigidly. In these displays we found a strong effect of stereo and distance. One could cause the percept to switch from rigid to nonrigid by manipulating the relative distances of the display elements or the relative disparities. We discuss how these results can be accounted for in a computational model that combines form and motion information in a robust estimation framework.

In situ hybridisation detects pro-apoptotic gene expression of a Bcl-2 family member in white syndrome-affected coral

White syndrome has been described as one of the most prolific diseases on the Great Barrier Reef. Previously, apoptotic cell death has been described as the mechanism driving the characteristic rapid tissue loss associated with this disease, but the molecular mechanisms controlling apoptotic cell death in coral disease have yet to be investigated. In situ methods were used to study the expression patterns of 2 distinct regulators of apoptosis in Acropora hyacinthus tissues undergoing white syndrome and apoptotic cell death. Apoptotic genes within the Bcl-2 family were not localized in apparently healthy coral tissues. However, a Bcl-2 family member (bax-like) was found to localize to cells and tissues affected by white syndrome and those with morphological evidence for apoptosis. A potential up-regulation of pro-apoptotic or bax-like gene expression in tissues with apoptotic cell death adjacent to disease lesions is consistent with apoptosis being the primary cause of rapid tissue loss in coral affected by white syndrome. Pro-apoptotic (bax-like) expression in desmocytes and the basal tissue layer, the calicodermis, distant from the disease lesion suggests that apoptosis may also underlie the sloughing of healthy tissues associated with the characteristic, rapid spread of tissue loss, evident of this disease. This study also shows that in situ hybridisation is an effective tool for studying gene expression in adult corals, and wider application of these methods should allow a better understanding of many aspects of coral biology and disease pathology.

Highly saline fluids from a subducting slab as the source for fluid-rich diamonds

The infiltration of fluids into continental lithospheric mantle is a key mechanism for controlling abrupt changes in the chemical and physical properties of the lithospheric root, as well as diamond formation, yet the origin and composition of the fluids involved are still poorly constrained. Such fluids are trapped within diamonds when they form and so diamonds provide a unique means of directly characterizing the fluids that percolate through the deep continental lithospheric mantle. Here we show a clear chemical evolutionary trend, identifying saline fluids as parental to silicic and carbonatitic deep mantle melts, in diamonds from the Northwest Territories, Canada. Fluid-rock interaction along with in situ melting cause compositional transitions, as the saline fluids traverse mixed peridotite-eclogite lithosphere. Moreover, the chemistry of the parental saline fluids--especially their strontium isotopic compositions--and the timing of host diamond formation suggest that a subducting Mesozoic plate under western North America is the source of the fluids. Our results imply a strong association between subduction, mantle metasomatism and fluid-rich diamond formation, emphasizing the importance of subduction-derived fluids in affecting the composition of the deep lithospheric mantle.

Reporter gene recombination in juxtaglomerular granular and collecting duct cells by human renin promoter-Cre recombinase transgene

To assess the feasibility of using the renin promoter for expressing Cre recombinase in juxtaglomerular (JG) cells only, we generated five independent transgenic mouse lines (designated hRen-Cre) expressing Cre recombinase under control of a 12.2-kb human renin promoter. In the kidneys of adult mice Cre mRNA (RT-PCR) was found in the renal cortex, with Cre protein (immunohistochemistry) being localized in afferent arterioles and to a lower degree in interlobular arteries. Cre mRNA levels were regulated in a renin-typical fashion by changes in oral salt intake, water restriction, or isoproterenol infusion, indicating the presence of key regulatory elements within 12.2 kb of the 5′-flanking region of the human renin gene. hRen-Cre mice were interbred with both the ROSA26-EGFP and ROSA26-lacZ reporter strains to assess renin promoter activity from Cre-mediated excision of a floxed stop cassette and subsequent enhanced green fluorescent protein (EGFP) and β-galactosidase (β-gal) detection. In adult mice, β-gal staining and EGFP were observed in afferent arterioles and interlobular arteries, overlapping with Cre protein expression. In addition, intense β-gal staining was found in cortical and medullary collecting ducts where Cre expression was minimal. In embryonic kidneys, β-gal staining was detected in the developing collecting duct system beginning at embryonic day 12, showing substantial activity of the human renin promoter in the branching ureteric bud. Our data indicate that besides its well-known activity in JG cells and renal vessels the human renin promoter is transiently active in the collecting duct system during kidney development, complicating the use of this approach for JG cell-specific excision of floxed targets.

Management of varicocele in military obligatory service: Israel Defense Forces Medical Corps policy

Varicocele is a well-known and highly prevalent medical problem in young obligatory service recruits. Still, there are many questions regarding its management. Is there a clear relation between varicocele and infertility? Can early varicocelectomy in young soldiers prevent future infertility? Is there a role for varicocelectomy in pain relief in physically active soldiers? And finally, what are the pros and cons of the open surgical, laparoscopic, or radiographic techniques in this specific population? Answering these questions should help military physicians in varicocele patients' care. It should also help decision makers to build cost-effective and evidence-based health policy. In this article, we review the literature regarding the controversies in the management of varicocele in young adults and delineate the current policy of the Israel Defense Forces Medical Corps.

Beyond junctions: nonlocal form constraints on motion interpretation

Because of the aperture problem, local motion measurements must be combined across space. However, not all motions should be combined. Some arise from distinct objects and should be segregated, and some are due to occlusion and should be discounted because they are spurious. Humans have little difficulty ignoring spurious motions at occlusions and correctly integrating object motion, and are evidently making use of form information to do so. There is a large body of theoretical and empirical evidence supporting the importance of form processes involving junctions in the way motion is integrated. To assess the role of more complex form analysis, we manipulated nonlocal form cues that could be varied independently of local junctions. Using variants on diamond and plaid stimuli used in previous studies, we found that manipulations distant from the junctions themselves could cause large changes in motion interpretation. Nonlocal information often overrides the integration decisions that would be expected from local cues. The mechanisms implicated appear to involve surface segmentation, amodal completion, and depth ordering.

Correctness of belief propagation in Gaussian graphical models of arbitrary topology

Graphical models, such as Bayesian networks and Markov random fields, represent statistical dependencies of variables by a graph. Local "belief propagation" rules of the sort proposed by Pearl (1988) are guaranteed to converge to the correct posterior probabilities in singly connected graphs. Recently, good performance has been obtained by using these same rules on graphs with loops, a method we refer to as loopy belief propagation. Perhaps the most dramatic instance is the near Shannon-limit performance of "Turbo codes," whose decoding algorithm is equivalent to loopy propagation. Except for the case of graphs with a single loop, there has been little theoretical understanding of loopy propagation. Here we analyze belief propagation in networks with arbitrary topologies when the nodes in the graph describe jointly gaussian random variables. We give an analytical formula relating the true posterior probabilities with those calculated using loopy propagation. We give sufficient conditions for convergence and show that when belief propagation converges, it gives the correct posterior means for all graph topologies, not just networks with a single loop. These results motivate using the powerful belief propagation algorithm in a broader class of networks and help clarify the empirical performance results.

Diagnosis of abdominal tuberculosis by transabdominal ultrasound-guided needle biopsy

Laparotomy and laparoscopy have been used for biopsy of pelvic masses in the differential diagnosis between abdominal tuberculosis and ovarian cancer. We suggest the use of transabdominal needle biopsy under ultrasound guidance in such cases. Two women developed abdominal distention, one of whom had been receiving medical treatment for known tuberculosis. In both cases, ultrasonography showed a pelvic mass and ascites associated with high levels of CA 125. A transabdominal ultrasonographically-guided biopsy of the masses with a trucut needle established their tuberculous origin. The transabdominal sonographic needle biopsy is a reliable diagnostic procedure in the differential diagnosis between abdominal tuberculosis and ovarian malignancy. This minimally invasive procedure saves the patient with tuberculosis from unnecessary laparotomy.

Adventures with gelatinous ellipses--constraints on models of human motion analysis

An ellipse rotating rigidly about its center may appear to rotate rigidly or to deform nonrigidly so that it appears gelatinous. We use this ambiguous stimulus to study how motion information is propagated across space. We find that features that are quite far from the contour of the ellipse may have a strong influence on the percept of the ellipse, provided they move in a way consistent with the motion of the ellipse. We show that the percept cannot be accounted for by computational models that pool constraints over a local area only, or by models that propagate information along contours, or by models that indiscriminately propagate information across space. However, the percept can be accounted for by a class of models that assume smoothness in a layered representation.

Correctness of local probability in graphical models with loops

Graphical models, such as Bayesian networks and Markov networks, represent joint distributions over a set of variables by means of a graph. When the graph is singly connected, local propagation rules of the sort proposed by Pearl (1988) are guaranteed to converge to the correct posterior probabilities. Recently a number of researchers have empirically demonstrated good performance of these same local propagation schemes on graphs with loops, but a theoretical understanding of this performance has yet to be achieved. For graphical models with a single loop, we derive an analytical relationship between the probabilities computed using local propagation and the correct marginals. Using this relationship we show a category of graphical models with loops for which local propagation gives rise to provably optimal maximum a posteriori assignments (although the computed marginals will be incorrect). We also show how nodes can use local information in the messages they receive in order to correct their computed marginals. We discuss how these results can be extended to graphical models with multiple loops and show simulation results suggesting that some properties of propagation on single-loop graphs may hold for a larger class of graphs. Specifically we discuss the implication of our results for understanding a class of recently proposed error-correcting codes known as turbo codes.

High levels of maternal serum human chorionic gonadotropin in Down syndrome pregnancies: the possible role of a transcription factor on chromosome 21

Increased levels of human chorionic gonadotropin (hCG) are used as markers for Down syndrome (DS) screening of low-risk populations. The pathophysiology for increased hCG levels remains unknown. In general, hCG synthesis is limited by the rate of beta-chain formation. In the placenta, 2 of a total of 6 hCG beta-genes are expressed. We hypothesized that in DS, a transcriptional factor may upregulate beta-chain transcription by interacting with the beta5-promoter. Primary cell cultures of skin fibroblasts from both normal and DS midtrimester fetuses were established and transfected with the beta5-promoter linked to the chloramphenicol-acetyl-transferase reporter gene. The chloramphenicol-acetyl-transferase activity was measured. Three of six DS-derived cell cultures showed a three-fold increase in acetylation. The increase in hCG promoter activity in DS-derived fibroblasts suggests a possible role for a transcriptional factor located on the human chromosome 21 by either directly or indirectly interacting with the beta5-promoter.

Alveolar macrophages fat stain in early diagnosis of fat embolism syndrome

The aim of this study was to assess the contribution of bronchoalveolar lavage (BAL) in the diagnosis of fat embolism syndrome (FES). The presence of fat droplets in alveolar macrophages was addressed in 13 trauma patients with bone fractures and 10 non-trauma patients with acute respiratory distress syndrome (ARDS). The control group was composed of 5 anesthesized patients with ischemic heart disease, immediately prior to cardiac surgery. Two patients with suggestive clinical and laboratory signs of FES had 40% and 24% fat-containing alveolar cells, respectively. The trauma patients without signs of FES displayed a wide variation in the percentage of fat-containing macrophages (from 3% to 95%). Most of the patients with ARDS who were receiving lipid emulsion as part of their parenteral nutrition, had a high percentage (> 85%) of fat-containing macrophages. Patients with normal lungs had no fat-containing macrophages. Our findings suggest that BAL Oil Red O-positive macrophages are frequently observed in trauma patients irrespective of the presence of FES. Therefore, estimation of the percentage of fat-containing macrophages from BAL is an unreliable marker of FES.

Impaired glucose-induced insulin response in transgenic mice overexpressing the L-phosphofructokinase gene

The selective impairment of glucose-induced insulin secretion in NIDDM can be attributed to defects in the glucose-signaling system. An alteration in the activity of phosphofructokinase (PFK), a key enzyme in the glycolytic pathway, may play a role in the abnormal glucose-induced insulin secretion. In this study, we evaluated insulin secretion in transgenic (Tg) mice overexpressing the liver-type subunit of phosphofructokinase (PFKL). Three independently derived Tg-PFKL lines showed random and postprandial hyperglycemia with diminished acute insulin response following intravenous glucose tolerance load. Isolated islets of Tg-PFKL mice exhibited a shift to the right of the glucose insulin dose curve. However, the maximal insulin secretory capacity, as well as the potentiation effect by arginine, were retained. PFK activity in Tg-PFKL islets was increased by 30-70%, because of the overexpression of PFKL. Conceivably, a selective overexpression of the PFKL isoform in Tg-PFKL mice altered the enzymatic properties of the tetrameric PFK and thereby affected glucose metabolism. A similar phenomenon was previously observed in transfected PC12-PFKL cells. The data show that overexpression of PFKL in transgenic mice was associated with diminished glucose-induced insulin response and suggest a mechanism to explain the role of beta-cell PFK activity in glucose-induced insulin secretion.

Match quality, new information, and marital dissolution

"This article investigates the role of surprises in marital dissolution [in the United States]. Surprises consists of changes in the predicted earning capacity of either spouse. Data from the National Longitudinal Study of the High School Class of 1972 is used. We find that an unexpected increase in the husband's earning capacity reduces the divorce hazard, while an unexpected increase in the wife's earning capacity raises the divorce hazard. Couples sort into marriage according to characteristics that are likely to enhance the stability of the marriage. The divorce hazard is initially increasing with the duration of marriage, and the presence of children and high levels of property stabilizes the marriage."

Positive end-expiratory pressure-induced hemodynamic changes are reflected in the arterial pressure waveform

OBJECTIVE

To examine whether the hemodynamic changes due to mechanical ventilation with positive end-expiratory pressure (PEEP) can be assessed by the respiratory-induced variations in the arterial pressure waveform during normovolemia and experimental acute ventricular failure.

DESIGN

Prospective, controlled experimental study.

SETTING

Institutional experimental laboratory.

SUBJECTS

Adult mongrel dogs.

INTERVENTIONS

Experimental acute ventricular failure was induced by the infusion of pentobarbital (a cardiodepressant) and methoxamine (a vasoconstrictor), combined with volume loading. Both the control and acute ventricular failure groups were subjected to ventilation with incremental levels of PEEP up to 20 cm H2O.

MEASUREMENTS AND MAIN RESULTS

Cardiac function was evaluated by cardiac output and left and right ventricular change in pressure over time (dP/dt) measurements. Arterial pressure waveform analysis was performed by measuring the systolic pressure variation, which is the difference between the maximal and minimal systolic blood pressure values during one mechanical breath. The components of the systolic pressure variation, namely, dUp and dDown, which are the increase and decrease in the systolic pressure during the mechanical breath relative to the systolic pressure during apnea, were also measured at each PEEP level. PEEP caused significant reduction of cardiac output in normovolemic dogs, and was associated with significant increases in systolic pressure variation and dDown. Acute ventricular failure decreased the variations in the systolic pressure and caused the dDown component to disappear. The application of PEEP did not affect cardiac output in dogs with acute ventricular failure, nor did it change systolic pressure variation and the dDown.

CONCLUSIONS

Analysis of arterial pressure waveforms during mechanical ventilation reflected the decrease in cardiac output in dogs with normal cardiac function subjected to incremental PEEP. In dogs with acute ventricular failure in which PEEP did not affect cardiac output, the systolic pressure variation was similarly unaffected by PEEP. In the absence of cardiac output measurement during mechanical ventilation with PEEP, the analysis of the respiratory variations in the arterial pressure waveform may be useful in assessing changes in cardiac output.

[Epidural analgesia for postoperative pain in infants and children]

Until recently it was thought that children do not suffer as much from postoperative pain as adults. Coupled with the fear of administering systemic opiates to young children, this meant that babies were often left "to cry it out." Lately it has been acknowledged that children and even babies not only feel pain, but similar to adults, suffer from the physiologic consequences of the untreated stress response. It has also been shown that preventing this response improves the postoperative period in babies after undergoing cardiac surgery. Regional analgesia is commonly used to provide postoperative pain control in adults and children. Following minor lower abdominal surgery, pain relief is often provided by caudal analgesia or specific nerve blocks. Epidural and spinal anesthesia are also gaining popularity for young children and even babies. We describe 3 cases of continuous epidural analgesia in babies, and review other methods for postoperative pain relief. These cases are representative of the many which we have treated over the past 2 years. We use epidural analgesia in children who undergo major thoracic, abdominal, pelvic and major lower limb surgery, and are expected to suffer significant postoperative pain for more than 24 hours. We have not encountered any major complications or inadvertent dural punctures. We judiciously monitor these children, especially their respiratory function, as long as they receive epidural narcotics.

Prevention of diabetes-associated embryopathy by overexpression of the free radical scavenger copper zinc superoxide dismutase in transgenic mouse embryos

OBJECTIVES

It has recently been suggested that oxygen free radicals are involved in the high incidence of fetal dysmorphogenesis that is associated with diabetic pregnancies. The purpose of the current investigation was to study the effect of copper zinc superoxide dismutase, a free radical scavenging enzyme, on the prevention of diabetes-associated embryopathy in mice.

STUDY DESIGN

Mice used in this study were either transgenic, bearing the human copper zinc superoxide dismutase gene, or nontransgenic controls. Diabetes was generated by streptozotocin administration on days 6 and 7 of gestation. Hyperglycemia developed on day 8 and was maintained through day 10 (critical period of organogenesis). On day 10 fetuses were examined for external anomalies, and their crown-rump lengths and deoxyribonucleic acid content were determined.

RESULTS

Induction of maternal diabetes produced a significant reduction in mean crown-rump length of control embryos (4.48 +/- 0.7 mm vs 3.65 +/- 0.6 mm, p = 0.0001), whereas transgenic embryos were not affected (4.72 +/- 0.6 mm vs 4.45 +/- 0.8 mm, p > 0.05). After induction of diabetes fetal loss and malformation rates were significantly higher in control embryos (6.0% vs 23.8% and 8.4% vs 16.5%, respectively). Transgenic embryos were practically unaffected by diabetes and showed fetal loss and malformation rates of 5.9% and 4.4%, respectively, after induction of diabetes.

CONCLUSIONS

Elevated levels of copper zinc superoxide dismutase, a key enzyme in the metabolism of free oxygen radicals, elicit a protective effect against diabetes-associated embryopathy.

Aortic distensibility in normotensive, untreated and treated hypertensive patients

BACKGROUND

Compared with normotensive subjects, untreated hypertensive patients show a decrease of their aortic distensibility. Whether antihypertensive treatment, by reducing blood pressure and changing functional and/or structural abnormalities of the arterial wall, may prevent or reverse the arterial damage due to the accelerated ageing process remains unclear. The objective of the present study was to determine, using a cross-sectional approach, whether aortic distensibility as measured by pulse wave velocity, in treated hypertensive patients whose diastolic blood pressure had been normalised for several months, was significantly improved over that of untreated hypertensive patients.

METHODS

Carotid femoral pulse wave velocity was measured in 124 normotensive subjects and 388 hypertensive patients. The latter group included 164 treated patients with well controlled diastolic blood pressure and 224 untreated hypertensive subjects. The three groups did not differ in other cardiovascular risk factors.

RESULTS

In each group there was a significant relationship between age and pulse wave velocity. When compared with untreated hypertensives, treated hypertensives with well controlled diastolic blood pressure had significantly lower blood pressure and pulse wave velocity according to age. However, although diastolic blood pressure of well controlled hypertensives was not significantly different from that of normotensive subjects, the aortic distensibility of the controlled hypertensives remained reduced showing two characteristics: a faster increase in pulse wave velocity with age and a negative relationship with HDL-cholesterol.

CONCLUSION

These results suggest that long-term antihypertensive treatment and control of blood pressure using only diastolic blood pressure criteria may not fully reverse arterial alteration associated with hypertensive vascular disease.

Overexpression of liver-type phosphofructokinase (PFKL) in transgenic-PFKL mice: implication for gene dosage in trisomy 21

The human liver-type subunit of the key glycolytic enzyme, phosphofructokinase (PFKL), is encoded by a gene residing on chromosome 21. This chromosome, when triplicated, causes the phenotypic expression of Down's syndrome (trisomy 21). Increased phosphofructokinase activity, a result of gene dosage, is commonly found in erythrocytes and fibroblasts from Down's syndrome patients. We describe the construction of transgenic mice overexpressing PFKL for use as a well-defined model system, in which the effects of PFKL overexpression in various tissues, and throughout development, can be studied. Mice transgenic for a murine PFKL 'gene cDNA' hybrid construct were found to overexpress PFKL in a tissue-specific manner resembling that of the endogenous enzyme. Although unchanged in adult brain, PFK specific activity was found to have been almost doubled in brains of embryonic transgenic-PFKL mice, suggesting that the extra copies of the PFKL gene are expressed during the developmental period. This pattern of overexpression of PFKL in brains of transgenic-PFKL mice suggests that gene-dosage effects may be temporally separated from some of their consequences, adding an additional layer of complexity to the analysis of gene dosage in trisomy 21.

Isolation, chromosomal localization, and sequence analysis of human chromosome 21 zinc finger domains

The zinc finger element is a conserved motif among a group of proteins involved in binding to nucleic acid. This motif has been detected in many regulatory factors and is highly represented in the human genome. To investigate the presence of zinc-finger-encoding genes on human chromosome 21, chromosome-specific libraries were screened with an oligodeoxynucleotide probe representing the conserved H-C link region between adjacent fingers. Three distinct genomic clones, designated ZF21-1, ZF21-2, and ZF21-3, were isolated and mapped to the long arm of chromosome 21 as well as to the heterochromatic short arm of several other chromosomes. DNA sequence analysis has shown that these genomic clones contain multiple zinc finger elements of the Kruppel type with only partial similarity to other known zinc finger genes. However, in each clone, few fingers were degenerated; they contain inframe stop codons and frameshifts that would preclude their translation. It seems therefore, that these chromosome 21 zinc finger sequences are not parts of functional genes. Nevertheless, the possibility that these domains are transcribed, and thus might have a regulatory role, is considered.

Prevalence of left ventricular systolic dysfunction in Duchenne muscular dystrophy: an echocardiographic study

The prevalence and hemodynamic consequences of regional wall motion abnormalities (RWMA) were evaluated in 84 advanced-stage Duchenne muscular dystrophy (DMD) patients who underwent echocardiographic and systolic time interval (STI) examination. A satisfactory echocardiogram was obtained in 72 patients who were divided into two groups: group I (33 patients) had normal wall motion or minor changes, and group II (39 patients) had akinetic and/or dyskinetic areas. In group II, 15 patients had ventricular dilation; 8 of the 15 had a history of cardiac failure and 4 died during the study. Wall motion index (WMI), end-diastolic volume (EDV), and STI values increased significantly from group I to group II. In the whole group, a strong correlation was found between WMI and STI ratios. This study demonstrates a high prevalence of RWMA and supports the viewpoint that RWMA, consequences of the myopathic process, result in progressive left ventricular dilation, heart failure, and cardiac death.

Prevalence of hepatitis B virus markers among hospital personnel in Israel: correlation with some risk factors

During 1986-1987, 480 employees of the Tel-Aviv Medical Center were screened for hepatitis B virus (HBV) markers as a preliminary step in a vaccination campaign. One hundred and seventeen (24.4%) had evidence of previous infection, including nine (1.9%) carriers. The effect of potential risk factors on seropositivity was evaluated by multiple logistic regression analysis, which enabled assessment of the individual contribution of each risk factor under the specific environmental conditions. The following risk factors were found to influence seropositivity: origin from Third World countries as opposed to the Western World, employment as sanitary workers, age over 40 years, and history of accidental needle punctures. In the heterogeneous Israeli population, hospital workers had a relatively high prevalence of HBV markers, probably resulting from occupational exposure.

Protein kinase C (PKC) level is increased in PC12 cells overexpressing transfected liver-type phosphofructokinase

PC12 cells which overexpress transfected liver-type phosphofructokinase (PFKL) have previously been described as a model system for PFKL overexpression in Down's syndrome and have been shown to perform glycolysis at enhanced rates. Here we report that levels of protein kinase C (PKC) in PC12-PFKL cells were almost doubled, as estimated from in vitro activity and phorbol ester binding experiments and from an increase found in PKC-alpha mRNA levels. Most of the added PKC was found to be associated with the cellular membrane while the cytoplasmic levels of PKC were barely increased. The steady-state levels of 1,2-sn-diacylglycerol in PC12-PFKL cells were found to be unaltered, suggesting that enhanced glycolysis in these cells did not influence PKC by altering the amounts of this compound. PFKL is one of several genes known to be overexpressed in Down's syndrome. Upregulation of PKC due to PFKL overexpression could result in widespread disturbances of gene expression and play a part in causing some of the many symptoms of the disease.

Transfers among divorced couples: evidence and interpretation

An analysis of the economic impact of divorce settlements in the United States is presented using data for a white cohort taken from the National Longitudinal Study of the High School Class of 1972. "The effects of spouses' incomes on the divorce transfer are estimated and used to simulate the welfare effects of divorce on husbands, wives, and children under alternative assumptions about marriage contracts and the ability of a couple to continue coordinating resources in the aftermath of divorce. We find a positive (negative) relationship between divorce transfers and the growth of husband's (wife's) earnings during marriage. The estimated expenditure on children in the divorce state is only half the accustomed level during marriage."

A first instance of human philophthalmosis in Israel

Conjunctivitis due to the trematode Philophthalmus in a 13-year-old Israeli girl is described. A single worm, probably a mature Philophthalmus palpebrarum, was detected on the palpebral conjunctiva of the upper eyelid of the right eye. Removal of the worm resulted in rapid abatement of the ocular symptoms. This is the first documentation of human philophthalmosis in Israel.

Teaching bedside interviewing skills in a social work training program

Teaching interviewing skills has become a permanent feature of the training of social workers, although no standardization exits for interview training. At a learning center established through a collaborative effort between Haifa University and the Kupat Holim, an effective program for teaching bedside interviewing skills was established.

Maintenance of blood pressure control in elderly hypertensives on ketoprofen

In elderly patients, nonsteroidal anti-inflammatory drugs (NSAIDs) are often used concomitantly with antihypertensive agents. It is therefore important to assess the potential for interactions between NSAIDs and these agents. In a double-blind, placebo-controlled study, 40 elderly hypertensive patients treated with acebutolol or atenolol, together with frusemide, were randomized to receive either ketoprofen, 200 mg/day (50 mg q.i.d.), or matching placebo for 7 days. Arterial blood pressure and heart rate were monitored for a 24-hour period at baseline and at the end of treatment. Standard sphygmomanometric measurements of blood pressure and heart rate were conducted twice a day during the study. No clinically significant side effects or blood pressure or heart rate alterations were observed during the trial. The results indicate that ketoprofen does not interfere with blood pressure control in elderly hypertensive patients being treated with a combination of beta-blockers and diuretics.

Unknown syndrome: radial ray defects, omphalocele, diaphragmatic hernia, and hepatic cyst

We present a male infant with a giant omphalocele, diaphragmatic hernia, hepatic cyst, bilateral radioulnar synostosis, absent left thumb, and triphalangeal right thumb.

Traumatic central retinal artery occlusion

A healthy 6-year-old boy with a clinical picture of central retinal artery occlusion (CRAO) of his left eye is presented here. The underlying cause was a trauma to the boy's left cheek some 6 months earlier. Possible pathophysiological mechanisms are discussed. To the best of our knowledge, the late onset of traumatic CRAO has not yet been reported in the literature.

Paracecal hernia: a cause of intestinal obstruction

During a two-year period, five patients were treated by us for acute intestinal obstruction caused by an incarcerated paracecal hernia. All patients underwent surgery early, so none required bowel resection. The possibility of an internal hernia as a cause of intestinal obstruction and a profound knowledge of the pericecal anatomy, however, are necessary for successful diagnosis and treatment of paracecal hernias.

Distribution and possible abnormality in antigenic composition of sodium channels in peripheral axons of dystrophic mice

In some dystrophic mice (Bar-Harbour 129 dy/dy), axons of the sciatic nerve are a-myelinated but are capable of carrying action potentials. In this study, we showed by immunofluorescence that such excitability is supported by the presence of voltage-gated sodium channels along the a-myelinated axon. In addition, the number of sodium channels measured by radioimmunoassay in sciatic nerves of these dystrophic mice is significantly higher. Furthermore, the composition of sodium channel epitopes is abnormal. This suggested a link between the disease and the biogenesis of the sodium channels.

[Incidence of antinuclear antibodies during treatment with acebutolol. A 1-year prospective study in 45 hypertensive patients treated by monotherapy]

Determinations of antinuclear antibodies (ANA) were performed before treatment, then every 3 months for one year, in 45 hypertensive patients treated with acebutolol alone in daily doses equal or superior to 800 mg. Non significant ANA titers (1/10 to 1/40) were detected before treatment in 8.8% of the patients. After one year of treatment, 15.5% of the patients were found to have antinuclear antibodies. In 4 (8.8%) female patients (3 of whom were ANA-negative before treatment) the ANA titers were above 1/40. Treatment was discontinued in one of these due to the occurrence of bronchospasm. No lupus-like syndrome was observed during the course of the study. Prolonged prospective studies with acebutolol alone would be required to determine whether in the long term the incidence of significant ANA titers remains at the 8.8% level or increases.