Trace metals in fish and invertebrates of three California coastal Wetlands

Metal concentrations were measured in selected fish and invertebrate species from Mugu Lagoon, Malibu Lagoon and Ballona Wetlands in southern California in order to assess the extent of metal contamination in these three wetlands. Ranges of element concentrations (in microgram/g) found in biota were: Zn 12-650; Cu 1.9-440; Ni < 1-37; Cr < 1-55; Pb < 0.5-6.8; As < 1-8.5; Se < 1-3.8; Cd < 0.2-0.90; and Ag < 0.3-5.9. Relative to previous studies of California biota, the highest metal concentrations found were for chromium and nickel. The highest levels were in one of the two bottom-dwelling fish (juvenile Leptocottus armatus) (55 micrograms/g) and the two water-column fish sampled (Fundulus parvipinnis and Atherinops affinis) (30 and 24 micrograms/g). At Ballona Lagoon, elevated levels of copper and silver were found in the bivalve Tagelus californianus (440 and 5.9 micrograms/g). Chromium and nickel appeared to be most persistent in fish from Mugu (4.6-55 and 2.6-37 micrograms/g), the most northern site and an active military base, and Ballona (< 1-30 and < 1-16 micrograms/g), believed to be the most metal-contaminated site. Compared to previously measured metal concentrations in species of California coastal waters, these regions revealed higher levels of chromium, nickel, silver, arsenic, zinc, copper and, to a lesser extent, cadmium and selenium. Chromium and silver were present at high enough levels at all three sites to be considered environmental health hazards.

Relationship of psychosis to aggression, apathy and function in dementia

BACKGROUND

Psychosis has been associated with aggression in dementia, but the nature of this relationship has been unclear. There has been very little research into the relations between apathy and functional status to psychosis in dementia. The purpose of this study is to investigate the relationship between psychosis and aggression, apathy, and functional status in outpatients with dementia.

METHODS

The presence of psychosis was assessed by clinical interview and two scales: the Neuropsychiatric Inventory and the Columbia University Scale for Psychopathology in Alzheimer's Disease. The maximum likelihood estimation technique was used to determine the best estimate of the presence of psychosis. Aggression, apathy, and functional status (activities of daily living: ADLs) were measured using structured instruments.

RESULTS

Sixty-one subjects were included. The CUSPAD and NPI provided low false positive and negative rates. ANCOVA analyses showed that psychosis was significantly associated with aggression, even when controlling for apathy, depression, and ADLs. Psychosis was related to apathy only when depression was controlled for. Hallucinations were related to impaired basic ADLs, even when depression and apathy were controlled for.

CONCLUSIONS

Relationships were found between psychotic symptoms in dementia and aggression as well as apathy and impaired functional status. These relationships suggest pathophysiologic mechanisms and have possible treatment implications.

Effect of dexmedetomidine on propofol requirements in healthy subjects

Dexmedetomidine-propofol pharmacodynamic interaction was evaluated in nine healthy subjects in a crossover design. Dexmedetomidine/placebo was infused using a computer-controlled infusion pump (CCIP) to maintain a pseudo-steady-state plasma concentration of 0.66 +/- 0.080 or 0 ng/mL, respectively. Forty-five minutes after the dexmedetomidine/placebo infusion was started, propofol was infused using a second CCIP to achieve a stepwise logarithmically ascending propofol concentration (1.00 to 13.8 microg/mL) profile. Each propofol step lasted 10 min. Blood was sampled for plasma concentration determination, and pharmacodynamic endpoint assessments were made during the study. Propofol and dexmedetomidine/placebo infusions were terminated when three endpoints (subjects were too sedated to hold a syringe, followed by loss of eyelash reflex, followed by loss of motor response to electrical stimulation) were achieved sequentially. The concentration of propofol associated with 50% probability of achieving a pharmacodynamic endpoint in the absence of dexmedetomidine (EC50; placebo treatment) was 6.63 microg/mL for motor response to electrical stimulation and ranged from 1.14 to 1.98 microg/mL for the ability to hold a syringe, eyelash reflex, and sedation scores. The apparent EC50 values of propofol (EC50APP; concentration of propofol at which the probability of achieving a pharmacodynamic endpoint is 50% in the presence of dexmedetomidine concentrations observed in the current study; dexmedetomidine treatment) were 0.273, 0.544-0.643, and 3.89 microg/mL for the ability to hold a syringe, sedation scores, and motor response, respectively. Dexmedetomidine reduced propofol concentrations required for sedation and suppression of motor response. Therefore, the propofol dose required for sedation and induction of anesthesia may have to be reduced in the presence of dexmedetomidine.

The magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group and its application to a highly stereoselective synthesis of (+/-)-matatabiether. Allylmagnesium compounds by reductive magnesiation of allyl phenyl sulfides

The first example of a magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group is demonstrated by a highly stereoselective synthesis of the bicyclic terpene matatabiether 10. The synthetic method is particularly valuable, not only because of the stereochemical control and the utility of the versatile hydroxyl group introduced into the product, but also because the precursor of the allylmagnesium is an allyl phenyl sulfide, which is more stable and more easily prepared in a connective fashion than the usual allyl halide precursor. Since the presence of lithium ions encourages undesirable proton transfer to the cyclized organometallic and is detrimental to the stereochemical control, the conversion of the allylic thioether to the allylmagnesium utilizes a lithium-free method involving direct reductive magnesiation in the presence of the magnesium-anthracene complex.

Interaction between interferon consensus sequence-binding protein and COP9/signalosome subunit CSN2 (Trip15). A possible link between interferon regulatory factor signaling and the COP9/signalosome

Interferon consensus sequence-binding protein (ICSBP) is a member of the interferon regulatory factors (IRF) that has a pivotal role in mediating resistance to pathogenic infections in mice and in promoting the differentiation of myeloid cells. ICSBP exerts some of its transcriptional activities via association with other factors that enable its binding to a variety of promoters containing DNA composite elements. These interactions are mediated through a specific COOH-terminal domain termed IAD (IRF association domain). To gain a broader insight of the capacity of ICSBP to interact with other factors, yeast two-hybrid screens were performed using ICSBP-IAD as a bait against a B-cell cDNA library. Trip15 was identified as a specific interacting factor with ICSBP in yeast cells, which was also confirmed by in vitro glutathione S-transferase pull-down assays and by coimmunoprecipitation studies in COS7 cells. Trip15 was recently identified as a component of the COP9/signalosome (CSN) complex composed of eight evolutionary conserved subunits and thus termed CSN2. This complex has a role in cell-signaling processes, which is manifested by its associated novel kinase activity and by the involvement of its subunits in regulating multiple cell-signaling pathways and cell-cycle progression. We show that in vitro association of ICSBP with the CSN leads to phosphorylation of ICSBP at a unique serine residue within its IAD. The phosphorylated residue is essential for efficient association with IRF-1 and thus for the repressor activity of ICSBP exerted on IRF-1. This suggests that the CSN has a role in integrating incoming signals that affect the transcriptional activity of ICSBP.

Can traumatic brain injury cause psychiatric disorders?

Traumatic brain injury (TBI) may cause psychiatric illness. This article reviews the evidence on the basis of an established set of causation criteria. The evidence is convincing for a strong association between TBI and mood and anxiety disorders. Substance abuse and schizophrenia are not strongly associated with TBI, and there is little research into the rates of personality disorders after TBI. Evidence for a biologic gradient is lacking, but such a gradient may not be relevant to TBI. Evidence for the correct temporal sequence is present. Preliminary evidence suggests a biologic rationale for TBI causing psychiatric illness. Further and methodologically improved research is supported and required.

Neuropilin-2 is a receptor for the vascular endothelial growth factor (VEGF) forms VEGF-145 and VEGF-165 [corrected]

Neuropilin-1 (np-1) and neuropilin-2 (np-2) are receptors for axon guidance factors belonging to the class 3 semaphorins. np-1 also binds to the 165-amino acid heparin-binding form of VEGF (VEGF(165)) but not to the shorter VEGF(121) form, which lacks a heparin binding ability. We report that human umbilical vein-derived endothelial cells express the a17 and a22 splice forms of the np-2 receptor. Both np-2 forms bind VEGF(165) with high affinity in the presence of heparin (K(D) 1.3 x 10(-10) m) but not VEGF(121). np-2 also binds the heparin-binding form of placenta growth factor. These binding characteristics resemble those of np-1. VEGF(145) is a secreted heparin binding VEGF form that contains the peptide encoded by exon 6 of VEGF but not the peptide encoded by exon 7, which is present in VEGF(165). VEGF(145) binds to np-2 with high affinity (K(D) 7 x 10(-10) m). Surprisingly, VEGF(145) did not bind to np-1. Indeed, VEGF(145) does not bind to MDA-MB-231 breast cancer cells, which predominantly express np-1. By contrast, VEGF(145) binds to human umbilical vein-derived endothelial cells, which express both np-1 and np-2. The binding of VEGF(165) to porcine aortic endothelial cells expressing recombinant np-2 did not affect the proliferation or migration of the cells. Nevertheless, it is possible that VEGF-induced np-2-mediated signaling will take place only in the presence of other VEGF receptors such as VEGF receptor-1 or VEGF receptor-2.

The role of depression severity in the cognitive functioning of elderly subjects with central nervous system disease

OBJECTIVE

To examine the hypothesis that there is a causal relation between depression and cognitive dysfunction in patients with central nervous system (CNS) disease.

DESIGN

Retrospective analysis of a clinical database.

SETTING

Tertiary geriatric day hospital.

PATIENTS

Sixty-five patients with depression and CNS disease, and 201 patients with depression but without CNS disease.

OUTCOME MEASURES

Scores on the Hamilton Depression Rating Scale (Ham-D) and the Mattis Dementia Rating Scale (MDRS).

RESULTS

A logistic regression analysis using MDRS status as the dependent variable, and a number of clinical variables as the predictor variables, showed that, in patients with CNS disease, only the Ham-D score predicted MDRS status (R = -0.19, p = 0.02). Ham-D score even more strongly predicted scores on a frontal system subtest of the MDRS (R = -0.262, p = 0.005). Ham-D score did not predict MDRS status in patients without CNS disease. Mean Mini Mental State Examination scores for the group with CNS disease were 25.1 at admission and 26.1 at discharge (p < 0.001).

CONCLUSIONS

These findings suggest that depression contributes to frontal cognitive dysfunction in patients with CNS disease.

Influence of cardiac output on dexmedetomidine pharmacokinetics

Dexmedetomidine, a highly selective alpha(2)-adrenoceptor agonist, reduces the requirements for anesthetic, analgesic, sedative, and hypnotic drugs. Dexmedetomidine pharmacokinetics were characterized in healthy subjects after intravenous administration by means of a computer-controlled infusion pump. A series of seven stepwise increasing pseudo-steady-state plasma concentrations were targeted. The influence of cardiac output on the pharmacokinetics was investigated by use of a compartmental modeling approach in which the elimination clearance was characterized as being either cardiac output independent or dependent. At dexmedetomidine concentrations of 0, 0.6, and 1.2 ng/mL, mean (SD) estimated cardiac outputs were 5. 6 (0.85), 5.1 (0.67), and 4.5 (0.83) L/min, and mean (SD) clearances were 40 (10), 38 (9.0), and 35 (8.5) L/h, respectively. Dexmedetomidine V(SS) and elimination half-life were 72 (19) L and 1. 9 (0.62) h, respectively. The approximately 3 to 19% decrease in cardiac output observed within the anticipated therapeutic range of 0.3 to 1.2 ng/mL was similar to that observed for clonidine. The decrease in cardiac output with increasing plasma concentrations of dexmedetomidine resulted in a corresponding decrease in drug elimination clearance of < or =12% within the therapeutic range; however, this decrease in dexmedetomidine clearance is likely not clinically relevant.

The VEGF splice variants: properties, receptors, and usage for the treatment of ischemic diseases

Vascular endothelial growth factor (VEGF) was discovered 10 years ago as a growth factor that can regulate angiogenesis and in addition the permeability of blood vessels. Numerous studies have revealed that it is essential for normal embryonic development and that it plays a major role in physiological and pathological events of angiogenesis in adults. It is unique in that its expression is regulated directly by hypoxia. These properties are now being exploited in attempts aimed at the induction of new blood vessels in pathological situations such as ischemic heart disease. Five VEGF forms of 121 to 206 aminoacids are produced from a single gene by alternative splicing. Cells expressing VEGF usually express several forms simultaneously. VEGF121 does not contain exons 6 and 7 of the gene and consequently lacks a heparin binding ability. However, this form is fully active as an inducer of angiogenesis, and as a blood vessel permeabilizing agent. Exon 6 and 7 contain 2 independent heparin binding domains. The VEGF form containing exon 7 (VEGF165) and the vascular endothelial growth factor form containing exon 6 (VEGF145) display similar biological potencies raising the question of why so many VEGF forms are required. It was found that VEGF121 diffuses better because it does not bind to heparan-sulfate proteoglycans. In contrast, VEGF145 binds to extracellular matrix and is released from it slowly. When the receptor binding properties of VEGF121 and VEGF165 were compared it was found that VEGF165 binds to a class of VEGF receptors that is not recognized by VEGF121. These receptors are encoded by the neuropilin-1 gene, and we have recently found that the related neuropilin-2 gene also encodes a VEGF165 receptor. We have recently found evidence indicating the neuropilins form complexes with another VEGF receptor, VEGFR-1. However, the biological function of this complex remains to be elucidated.

The prediction and prevention of Alzheimer's disease--towards a research agenda

This paper sets a research agenda for the prediction and prevention of future onset of Alzheimer's disease (AD). From a MEDLINE review of the literature, the authors found age to be a predictor of AD. The literature also indicates that memory and attentional impairments predict AD, although the relative risk is relatively low. Late-onset depression may also predict AD, but these data are limited by a lack of cohort studies. Studying cognitively impaired subjects with late-onset depression may identify a high-risk group, facilitating prevention trials. Characteristics of an "ideal" preventive agent are suggested. There is a biologic rationale, and preliminary evidence, that non-steroidal anti-inflammatory drugs (including ASA), estrogen and vitamin E may play a preventive role in AD. Other compounds (such as acetylcholinesterase inhibitors) are also promising, but costs, side effects, and lack of other health benefits may preclude their use in all but very high-risk groups.

Effect of vascular endothelial growth factor on hepatic regenerative activity following partial hepatectomy in rats

BACKGROUND/AIMS

Vascular endothelial growth factor (VEGF) is an angiogenic factor with a growth-promoting effect that is thought to be restricted to vascular endothelial cells. Its essential role during liver regeneration has yet to be determined. The aim of this study was to document the effect of exogenous VEGF administration on liver regeneration in rats undergoing submaximal hepatic resections.

METHODS

Adult male Sprague-Dawley rats (n = 4/group) undergoing 30% partial hepatectomy were administered 200 ng VEGF165 intravenously and were sacrificed at 24, 36, and 48 h postoperatively. Liver regeneration was monitored by measuring the restituted liver mass, proliferating cell nuclear antigen (PCNA) immunostaining, and hepatic PCNA protein by Western blot.

RESULTS

Changes in restituted liver mass 48 h postsurgery were more prominent, but did not differ statistically between VEGF-treated and control rats (47% vs. 29%; p<0.06). Nevertheless, PCNA immunostaining showed increased labeling index of hepatocytes, apparent at 36 and 48 h after partial hepatectomy (38% vs. 18% [p<0.041 and 42% vs. 11% [p<0.021], respectively). Hepatic PCNA proteins measured by Western blot showed a 3-fold increase in VEGF-treated rats 48 h postsurgery compared with controls (p<0.01).

CONCLUSION

Exogenous VEGF administration early after partial hepatectomy stimulates liver regeneration in rats. Whether or not VEGF165 is a direct mitogen for hepatocytes remains to be determined.

Vascular endothelial growth factor (VEGF) and its receptors

Vascular endothelial growth factor (VEGF) is a highly specific mitogen for vascular endothelial cells. Five VEGF isoforms are generated as a result of alternative splicing from a single VEGF gene. These isoforms differ in their molecular mass and in biological properties such as their ability to bind to cell-surface heparan-sulfate proteoglycans. The expression of VEGF is potentiated in response to hypoxia, by activated oncogenes, and by a variety of cytokines. VEGF induces endothelial cell proliferation, promotes cell migration, and inhibits apoptosis. In vivo VEGF induces angiogenesis as well as permeabilization of blood vessels, and plays a central role in the regulation of vasculogenesis. Deregulated VEGF expression contributes to the development of solid tumors by promoting tumor angiogenesis and to the etiology of several additional diseases that are characterized by abnormal angiogenesis. Consequently, inhibition of VEGF signaling abrogates the development of a wide variety of tumors. The various VEGF forms bind to two tyrosine-kinase receptors, VEGFR-1 (flt-1) and VEGFR-2 (KDR/flk-1), which are expressed almost exclusively in endothelial cells. Endothelial cells express in addition the neuropilin-1 and neuropilin-2 coreceptors, which bind selectively to the 165 amino acid form of VEGF (VEGF165). This review focuses on recent developments that have widened considerably our understanding of the mechanisms that control VEGF production and VEGF signal transduction and on recent studies that have shed light on the mechanisms by which VEGF regulates angiogenesis.

A practical guide to Papanicolaou smear rescreens: how many slides must be reevaluated to make a statistically valid assessment of screening performance?

BACKGROUND

The question of the minimum number of Papanicolaou (Pap) smear slides that must be rescreened to draw statistically valid conclusions regarding the accuracy of screening often is raised. No method for generating answers in varying laboratory circumstances has achieved widespread application; standard statistical sample size calculations may represent such a resource.

METHODS

A series of tables was constructed to display minimum required numbers of rescreens, with each table representing differing hypothetical laboratory circumstances. To use each table, assumptions must be specified in advance as to prevalence of abnormality, definition of error, baseline false-negative proportions (FNPs) of performance, and a degree of increase in FNPs that is considered a departure from baseline warranting concern, among others.

RESULTS

The authors constructed four sample tables displaying minimum numbers of slides that must be rescreened in differing specified laboratory scenarios. Depending on assumed conditions and predetermined levels of satisfactory and unsatisfactory accuracy, the range of numbers is very broad (38-10,000). One example representing likely conditions indicates that 1040 slides must be reexamined; in another scenario, a sample size of 300 is sufficient.

CONCLUSIONS

The minimum number of rescreened slides needed to draw statistically valid conclusions regarding Pap smear screening accuracy can be calculated using standard statistical methods. However, a number of assumptions must be detailed in advance. The authors offer this as a practical guide and a continuation of a general inquiry regarding Pap smear error rate measurement and display. The use of these tables raises at least as many questions as it answers, but still may represent a significant advance. Future efforts at further numeric characterization of aspects of Pap smear screening performance are warranted to enable rational decision making when performance is examined in the course of quality assurance, and during quality control and regulatory activities. [See editorial on pages 127-9, this issue.]

A syndrome including thumb malformations, microcephaly, short stature, and hypogonadism

We report on eight patients from seven different families affected with a syndrome which includes thumb defects, short stature, microcephaly, and mental retardation. Most of the patients had additional malformations, in particular amenorrhoea and azoospermia in the adults. There were no haematological manifestations and the chromosomes were normal without evidence of breakage even after stimulation. In five of the cases the probands' mother received hormonal treatment before or at the beginning of her pregnancy or both. The syndrome may be inherited as an autosomal recessive trait since the patients included both males and females and their parents were related in most cases. In addition, supporting this possibility, they all originated from a small village which may be considered as an isolate. However, in all cases but one, only one person was affected in each family and there was a significant apparent excess of healthy sibs of the probands. These observations may be the result of the variability of the syndrome or a more complex type of inheritance.

VEGF145, a secreted vascular endothelial growth factor isoform that binds to extracellular matrix

A vascular endothelial growth factor (VEGF) mRNA species containing exons 1-6 and 8 of the VEGF gene was found to be expressed as a major VEGF mRNA form in several cell lines derived from carcinomas of the female reproductive system. This mRNA is predicted to encode a VEGF form of 145 amino acids (VEGF145). Recombinant VEGF145 induced the proliferation of vascular endothelial cells and promoted angiogenesis in vivo. VEGF145 was compared with previously characterized VEGF species with respect to interaction with heparin-like molecules, cellular distribution, VEGF receptor recognition, and extracellular matrix (ECM) binding ability. VEGF145 shares with VEGF165 the ability to bind to the KDR/flk-1 receptor of endothelial cells. It also binds to heparin with an affinity similar to that of VEGF165. However, VEGF145 does not bind to two additional endothelial cell surface receptors that are recognized by VEGF165 but not by VEGF121. VEGF145 is secreted from producing cells as are VEGF121 and VEGF165. However, VEGF121 and VEGF165 do not bind to the ECM produced by corneal endothelial cells, whereas VEGF145 binds efficiently to this ECM. Basic fibroblast growth factor (bFGF)-depleted ECM containing bound VEGF145 induces proliferation of endothelial cells, indicating that the bound VEGF145 is active. The mechanism by which VEGF145 binds to the ECM differs from that of bFGF. Digestion of the ECM by heparinase inhibited the binding of bFGF to the ECM and released prebound bFGF, whereas the binding of VEGF145 was not affected by heparinase digestion. It therefore seems that VEGF145 possesses a unique combination of biological properties distinct from those of previously characterized VEGF species.

Four sibs with arterial tortuosity: description and review of the literature

We described four offspring of a consanguineous couple with arterial tortuosity "syndrome" (ATS). The affected children had extensive arterial involvement although the clinical presentations were quite variable. Clinical manifestations included cutis laxa or soft/thin skin, joint laxity or contractures, and arachnodactyly. Aortic tortuosity and pulmonary artery aneurysms with or without peripheral stenoses were demonstrated in all four sibs. All three males had inguinal hernias. Inconsistent facial anomalies were downslanting palpebral tissues, beaked nose, micrognathia, and high-arched palate. Results of collagen type I and type III biosynthesis studies were normal on skin fibroblasts. Histologic findings on autopsy of one affected child showed arterial changes with disruption of elastic fibers of the media and fragmentation of the internal elastic membrane as well as mucosal and transmural necrosis of the stomach, small bowel, colon, and extensive necrosis of the liver. Coronary artery involvement was also seen in this child as well as biventricular hypertrophy. We conclude that ATS is an autosomal recessive connective tissue condition associated with diffuse arterial changes and involvement of the skin, joints, and other organs.

Segregation analysis of microcephaly

Microcephaly is a heterogeneous disorder with genetic and environmental causes. However, there is little information on what proportion of cases are caused by inherited susceptibility, or the mode of inheritance in familial cases. To address these questions, we have performed classical and complex segregation analyses for microcephaly on 2 sets of family data collected from genetic counseling clinics in Vancouver and Jerusalem. These samples consisted of 143 affected individuals in 127 families ascertained from Vancouver, and 101 affected individuals in 59 families ascertained from Jerusalem. The results of the segregation analyses for the Vancouver sample indicated that approximately half of all microcephaly cases were due to highly penetrant recessive mutant alleles, with the remainder being sporadic. Although a recessive model allowing for the occurrence of sporadic cases fit the data from Vancouver best, a dominant model could not be statistically rejected. The classical segregation analysis on the Jerusalem sample suggested that both a dominant model with 29% of the cases being sporadic and a purely recessive model provided adequate fit to the data. Although the complex segregation analysis of this sample indicated that a dominant model provided a more parsimonious explanation for the observed familial variation, a recessive model was only marginally rejected. It should be noted that in the Jerusalem sample, families tended to be ascertained in the genetic counseling clinic only after the birth of a second affected child. This could be a potential bias which could inflate the segregation ratio, thus giving the impression of dominant inheritance. Our analyses, while confirming the complex nature of the cause of microcephaly, indicate that it may be necessary to await the results of genetic linkage analysis before a definitive mode of inheritance can be determined.