Integrated transcriptomic and proteomic analysis identifies protein kinase CK2 as a key signaling node in an inflammatory cytokine network in ovarian cancer cells

We previously showed how key pathways in cancer-related inflammation and Notch signaling are part of an autocrine malignant cell network in ovarian cancer. This network, which we named the "TNF network", has paracrine actions within the tumor microenvironment, influencing angiogenesis and the immune cell infiltrate.The aim of this study was to identify critical regulators in the signaling pathways of the TNF network in ovarian cancer cells that might be therapeutic targets. To achieve our aim, we used a systems biology approach, combining data from phospho-proteomic mass spectrometry and gene expression array analysis. Among the potential therapeutic kinase targets identified was the protein kinase Casein kinase II (CK2).Knockdown of CK2 expression in malignant cells by siRNA or treatment with the specific CK2 inhibitor CX-4945 significantly decreased Notch signaling and reduced constitutive cytokine release in ovarian cancer cell lines that expressed the TNF network as well as malignant cells isolated from high grade serous ovarian cancer ascites. The expression of the same cytokines was also inhibited after treatment with CX-4945 in a 3D organotypic model. CK2 inhibition was associated with concomitant inhibition of proliferative activity, reduced angiogenesis and experimental peritoneal ovarian tumor growth.In conclusion, we have identified kinases, particularly CK2, associated with the TNF network that may play a central role in sustaining the cytokine network and/or mediating its effects in ovarian cancer.

Adaptive Upregulation of EGFR Limits Attenuation of Tumor Growth by Neutralizing IL6 Antibodies, with Implications for Combined Therapy in Ovarian Cancer

Excess production of the proinflammatory IL6 has both local and systemic tumor-promoting activity in many cancers, including ovarian cancer. However, treatment of advanced ovarian cancer patients with a neutralizing IL6 antibody yielded little efficacy in a previous phase II clinical trial. Here, we report results that may explain this outcome, based on the finding that neutralizing antibodies to IL6 and STAT3 inhibition are sufficient to upregulate the EGFR pathway in high-grade serous and other ovarian cancer cells. Cell treatment with the EGFR inhibitor gefitinib abolished upregulation of the EGFR pathway. Combining neutralizing IL6 antibodies and gefitinib inhibited malignant cell growth in 2D and 3D culture. We found that ErbB-1 was localized predominantly in the nucleus of ovarian cancer cells examined, contrasting with plasma membrane localization in lung cancer cells. Treatment with anti-IL6, gefitinib, or their combination all led to partial restoration of ErbB-1 on the plasma membrane. In vivo experiments confirmed the effects of IL6 inhibition on the EGFR pathway and the enhanced activity of a combination of anti-IL6 antibodies and gefitinib on malignant cell growth. Taken together, our results offer a preclinical rationale to combine anti-IL6 and gefitinib to treat patients with advanced stage ovarian cancer.

Murine CD27(-) Vγ6(+) γδ T cells producing IL-17A promote ovarian cancer growth via mobilization of protumor small peritoneal macrophages

Cancer-associated inflammation mobilizes a variety of leukocyte populations that can inhibit or enhance tumor cell growth in situ. These subsets include γδ T cells, which can infiltrate tumors and typically provide large amounts of antitumor cytokines, such as IFN-γ. By contrast, we report here that in a well-established transplantable (ID8 cell line) model of peritoneal/ovarian cancer, γδ T cells promote tumor cell growth. γδ T cells accumulated in the peritoneal cavity in response to tumor challenge and could be visualized within solid tumor foci. Functional characterization of tumor-associated γδ T cells revealed preferential production of interleukin-17A (IL-17), rather than IFN-γ. Consistent with this finding, both T cell receptor (TCR)δ-deficient and IL-17-deficient mice displayed reduced ID8 tumor growth compared with wild-type animals. IL-17 production by γδ T cells in the tumor environment was essentially restricted to a highly proliferative CD27((-)) subset that expressed Vγ6 instead of the more common Vγ1 and Vγ4 TCR chains. The preferential expansion of IL-17-secreting CD27((-)) Vγ6((+)) γδ T cells associated with the selective mobilization of unconventional small peritoneal macrophages (SPMs) that, in comparison with large peritoneal macrophages, were enriched for IL-17 receptor A, and for protumor and proangiogenic molecular mediators, which were up-regulated by IL-17. Importantly, SPMs were uniquely and directly capable of promoting ovarian cancer cell proliferation. Collectively, this work identifies an IL-17-dependent lymphoid/myeloid cross-talk involving γδ T cells and SPMs that promotes tumor cell growth and thus counteracts cancer immunosurveillance.

A dynamic inflammatory cytokine network in the human ovarian cancer microenvironment

Constitutive production of inflammatory cytokines is a characteristic of many human malignant cell lines; however, the in vitro and in vivo interdependence of these cytokines, and their significance to the human cancer microenvironment, are both poorly understood. Here, we describe for the first time how three key cytokine/chemokine mediators of cancer-related inflammation, TNF, CXCL12, and interleukin 6, are involved in an autocrine cytokine network, the "TNF network," in human ovarian cancer. We show that this network has paracrine actions on angiogenesis, infiltration of myeloid cells, and NOTCH signaling in both murine xenografts and human ovarian tumor biopsies. Neutralizing antibodies or siRNA to individual members of this TNF network reduced angiogenesis, myeloid cell infiltration, and experimental peritoneal ovarian tumor growth. The dependency of network genes on TNF was shown by their downregulation in tumor cells from patients with advanced ovarian cancer following the infusion of anti-TNF antibodies. Together, the findings define a network of inflammatory cytokine interactions that are crucial to tumor growth and validate this network as a key therapeutic target in ovarian cancer.

The tumor-promoting actions of TNF-alpha involve TNFR1 and IL-17 in ovarian cancer in mice and humans

Cytokines orchestrate the tumor-promoting interplay between malignant cells and the immune system. In many experimental and human cancers, the cytokine TNF-alpha is an important component of this interplay, but its effects are pleiotropic and therefore remain to be completely defined. Using a mouse model of ovarian cancer in which either TNF receptor 1 (TNFR1) signaling was manipulated in different leukocyte populations or TNF-alpha was neutralized by antibody treatment, we found that this inflammatory cytokine maintained TNFR1-dependent IL-17 production by CD4+ cells and that this led to myeloid cell recruitment into the tumor microenvironment and enhanced tumor growth. Consistent with this, in patients with advanced cancer, treatment with the TNF-alpha-specific antibody infliximab substantially reduced plasma IL-17 levels. Furthermore, expression of IL-1R and IL-23R was downregulated in CD4+CD25- cells isolated from ascites of ovarian cancer patients treated with infliximab. We have also shown that genes ascribed to the Th17 pathway map closely with the TNF-alpha signaling pathway in ovarian cancer biopsy samples, showing particularly high levels of expression of genes encoding IL-23, components of the NF-kappaB system, TGF-beta1, and proteins involved in neutrophil activation. We conclude that chronic production of TNF-alpha in the tumor microenvironment increases myeloid cell recruitment in an IL-17-dependent manner that contributes to the tumor-promoting action of this proinflammatory cytokine.

"Re-educating" tumor-associated macrophages by targeting NF-kappaB

The nuclear factor κB (NF-κB) signaling pathway is important in cancer-related inflammation and malignant progression. Here, we describe a new role for NF-κB in cancer in maintaining the immunosuppressive phenotype of tumor-associated macrophages (TAMs). We show that macrophages are polarized via interleukin (IL)-1R and MyD88 to an immunosuppressive “alternative” phenotype that requires IκB kinase β–mediated NF-κB activation. When NF-κB signaling is inhibited specifically in TAMs, they become cytotoxic to tumor cells and switch to a “classically” activated phenotype; IL-12^high, major histocompatibility complex II^high, but IL-10^low and arginase-1^low. Targeting NF-κB signaling in TAMs also promotes regression of advanced tumors in vivo by induction of macrophage tumoricidal activity and activation of antitumor activity through IL-12–dependent NK cell recruitment. We provide a rationale for manipulating the phenotype of the abundant macrophage population already located within the tumor microenvironment; the potential to “re-educate” the tumor-promoting macrophage population may prove an effective and novel therapeutic approach for cancer that complements existing therapies.

Role of IgE receptors in IgE antibody-dependent cytotoxicity and phagocytosis of ovarian tumor cells by human monocytic cells

Antibodies directed against tumor-associated antigens are emerging as effective treatments for a number of cancers, although the mechanism(s) of action for some are unclear and still under investigation. We have previously examined a chimeric IgE antibody (MOv18 IgE), against the ovarian tumor-specific antigen, folate binding protein (FBP), and showed that it can direct human PBMC to kill ovarian cancer cells. We have developed a three-color flow cytometric assay to investigate the mechanism by which IgE receptors on U937 monocytes target and kill ovarian tumor cells. U937 monocytes express three IgE receptors, the high-affinity receptor, FcepsilonRI, the low-affinity receptor, CD23, and galectin-3, and mediate tumor cell killing in vitro by two mechanisms, cytotoxicity, and phagocytosis. Our results suggest that CD23 mediates phagocytosis, which is enhanced by upregulation of CD23 on U937 cells with IL-4, whereas FcepsilonRI mediates cytotoxicity. We show that effector : tumor cell bridging is associated with both activities. Galectin-3 does not appear to be involved in tumor cell killing. U937 cells and IgE exerted ovarian tumor cell killing in vivo in our xenograft model in nude mice. Harnessing IgE receptors to target tumor cells suggests the potential of tumor-specific IgE antibodies to activate effector cells in immunotherapy of ovarian cancer.

IgE-antibody-dependent immunotherapy of solid tumors: cytotoxic and phagocytic mechanisms of eradication of ovarian cancer cells

Abs have a paramount place in the treatment of certain, mainly lymphoid, malignancies, although tumors of nonhemopoietic origin have proved more refractory ones. We have previously shown that the efficacy of immunotherapy of solid tumors, in particular ovarian carcinoma, may be improved by the use of IgE Abs in place of the conventional IgG. An IgE Ab (MOv18 IgE) against an ovarian-tumor-specific Ag (folate binding protein), in combination with human PBMC, introduced into ovarian cancer xenograft-bearing mice, greatly exceeded the analogous IgG1 in promoting survival. In this study, we analyzed the mechanisms by which MOv18 IgE may exert its antitumor activities. Monocytes were essential IgE receptor-expressing effector cells that mediated the enhanced survival of tumor-bearing mice by MOv18 IgE and human PBMC. Monocytes mediated MOv18 IgE-dependent ovarian tumor cell killing in vitro by two distinct pathways, cytotoxicity and phagocytosis, acting respectively through the IgE receptors FcepsilonRI and CD23. We also show that human eosinophils were potent effector cells in MOv18 IgE Ab-dependent ovarian tumor cell cytotoxicity in vitro. These results demonstrate that IgE Abs can engage cell surface IgE receptors and activate effector cells against ovarian tumor cells. Our findings offer a framework for an improved immunotherapeutic strategy for combating solid tumors.

Ovarian cancer cell-derived migration inhibitory factor enhances tumor growth, progression, and angiogenesis

In view of our previous findings that tumor cell-derived macrophage migration inhibitory factor (MIF) increased macrophage-mediated ovarian cancer cell invasiveness in vitro, we investigated the wider significance of ovarian cancer cell-derived MIF for tumor growth, metastasis, and angiogenesis. We found that MIF is expressed in borderline and malignant ovarian tumors, and active MIF is found in malignant ascitic fluid. We next investigated the expression and function of MIF in a syngeneic ovarian cancer model. Stable knockdown of MIF in the murine ovarian cancer cell line ID8 decreased in vivo tumor burden and overall survival. Tumors arising from MIF knockdown cells had decreased proliferation and significantly increased apoptosis. This was associated with an increased phosphorylation of p53 and reduced Akt phosphorylation. MIF knockdown led to a changed cytokine profile in the ascitic microenvironment; tumor necrosis factor-alpha, interleukin-6 (IL-6), and IL-10 expression were all significantly decreased. Accompanying this decrease in cytokine expression was a significant decrease in macrophage infiltration into ascites. Additionally, MIF knockdown reduced the expression of proangiogenic cytokines vascular endothelial growth factor and keratinocyte chemoattractant (KC) and reduced the amount of endothelial cells in the malignant ascites. We conclude that autocrine production of MIF by ovarian cancer cells stimulates other cytokines, chemokines, and angiogenic factors that may promote colonization of the peritoneum and neovascularization of tumor deposits.

Music Enhances Category Fluency In Healthy Older Adults And Alzheimer's Disease Patients

Exposure to some music, in particular classical music, has been reported to produce transient increases in cognitive performance. The authors investigated the effect of listening to an excerpt of Vivaldi's Four Seasons on category fluency in healthy older adult controls and Alzheimer's disease patients. In a counterbalanced repeated-measure design, participants completed two, 1-min category fluency tasks whilst listening to an excerpt of Vivaldi and two, 1-min category fluency tasks without music. The authors report a positive effect of music on category fluency, with performance in the music condition exceeding performance without music in both the healthy older adult control participants and the Alzheimer's disease patients. In keeping with previous reports, the authors conclude that music enhances attentional processes, and that this can be demonstrated in Alzheimer's disease.

TNF-alpha regulates epithelial expression of MMP-9 and integrin alphavbeta6 during tumour promotion. A role for TNF-alpha in keratinocyte migration?

Mice deficient in TNF-alpha (TNF-alpha(-/-) mice) are resistant to skin carcinogenesis and expression of MMP-9 is inhibited in TNF-alpha(-/-) mice during skin tumour development. In the early stages of tumour promotion, MMP-9 protein initially localized to the follicular epidermis but subsequently began to accumulate in the interfollicular epidermis of wild-type but not TNF-alpha(-/-) mice. Inhibition of TNF-alpha or MMP-9 function reduced keratinocyte migration in vitro. In addition, a deficiency of TNF-alpha delayed re-epithelialization in vivo and this correlated with reduced MMP-9 expression. Collectively, these data suggest that MMP-9 regulates keratinocyte migration in a TNF-alpha-dependent manner. Expression profiling of genes that control cell adhesion and migration revealed markedly lower levels of the integrin subunits alphav and beta6 in TNF-alpha(-/-) compared with wild-type keratinocytes in vitro. alphavbeta6 expression was upregulated by keratinocytes in vitro and during tumour promotion in vivo in a TNF-alpha-dependent manner. Furthermore, alphavbeta6 blockade significantly inhibited keratinocyte migration and TNF-alpha-stimulated MMP-9 expression in vitro. These data illustrate a novel TNF-alpha-dependent mechanism for the control of alphavbeta6 expression and suggest one pathway for TNF-alpha regulation of MMP-9. Increased MMP-9 and alphavbeta6 expression may stimulate epithelial cell migration during tumour formation and may be one mechanism whereby TNF-alpha acts as an endogenous tumour promoter.

Expression of both TNF-alpha receptor subtypes is essential for optimal skin tumour development

Keratinocyte-derived TNF-alpha acts as an endogenous tumour promoter and can also regulate AP-1 activity in mouse epidermis. To gain further insight into TNF-alpha signalling during skin tumour formation, mice deficient in TNFR1 (TNFR1-/- mice) or TNFR2 (TNFR2-/- mice) were subjected to chemical carcinogenesis. Tumour multiplicity was significantly reduced in TNFR1-/- and TNFR2-/- mice compared to wild-type (wt) mice, suggesting that both receptors have protumour activity. However, TNFR1-/- mice were markedly more resistant to tumour development than TNFR2-/- mice indicating that TNFR1 is the major mediator of TNF-alpha-induced tumour formation. TNFR1 and TNFR2 were both expressed in wt epidermis during tumour promotion and by primary keratinocytes in vitro. TPA-induced c-Jun expression was transient in TNFR1-/- and TNFR2-/- compared to wt epidermis and this was reflected by reduced induction of the AP-1-responsive genes granulocyte/macrophage-colony stimulating factor, matrix metalloproteinase-9 and matrix metalloproteinase-3. These genes were differentially regulated in TNFR1-/- compared to TNFR2-/- epidermis, suggesting that the TNF-alpha receptors act independently via different AP-1 complexes to transduce TNF-alpha signals during tumour promotion. In addition, TNFR2 cooperated with TNFR1 to optimise TNFR1-mediated TNF-alpha bioactivity on keratinocytes in vitro. Our data provide further insight into TNF-alpha signalling in malignancy and provide some rationale for the use of TNF-alpha antagonists in the treatment of cancer.

A chemokine receptor antagonist inhibits experimental breast tumor growth

The leukocyte infiltrate of human and murine epithelial cancers is regulated by chemokine production in the tumor microenvironment. In this article, we tested the hypothesis that chemokine receptor antagonists may have anticancer activity by inhibiting this infiltrate. We first characterized CC chemokines, chemokine receptors, and the leukocyte infiltrate in the 410.4 murine model of breast cancer. We found that CCL5 (RANTES) was produced by the tumor cells, and its receptors, CCR1 and CCR5, were expressed by the leukocyte infiltrate. As Met-CCL5 is an antagonist of CCR1 and CCR5 with activity in models of inflammatory disease, we tested its activity against 410.4 tumors. After 5 weeks of daily treatment with Met-CCL5, the volume and weight of 410.4 tumors was significantly decreased compared with control-treated tumors. Met-CCL5 was also active against established tumors. The total cell number obtained after collagenase digestion was decreased in Met-CCL5-treated tumors as was the proportion of infiltrating macrophages. Furthermore, chemokine antagonist treatment increased stromal development and necrosis. Our results provide direct evidence that macrophages contribute to tumor development and are the first indication that chemokine receptor antagonists may provide novel strategies in cancer prevention and treatment.

An anti-tumor necrosis factor-alpha antibody inhibits the development of experimental skin tumors

The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) was originally considered to have activity against malignant disease. However, recent studies suggest TNF-alpha may also act as an endogenous tumor promoter. In the present work, mice deficient in TNF-alpha either genetically (TNF-alpha(-/-)) or after blockade with a neutralizing antibody (cV1q) were used to investigate the role of TNF-alpha in skin tumor development. Papillomas were induced in wild-type (wt) mice after treatment of skin with the initiating agent 9,10-dimethyl-1,2-benzanthracene followed by promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA) for 15 weeks. TNF-alpha(-/-) mice were resistant to papilloma development when compared with wt mice on C57Bl/6J, 129/SvEv, and BALB/c genetic backgrounds. Primary murine keratinocytes (newborn keratinocytes) and skin homogenates were used to characterize TPA-stimulated TNF-alpha expression. TPA induced TNF-alpha protein in newborn keratinocytes in vitro and epidermis in vivo. Neutralization of TNF-alpha protein with cV1q in vivo for 0-15 weeks of promotion significantly decreased skin tumor development after 9,10-dimethyl-1,2-benzanthracene/TPA treatment. cV1q treatment during the early stages of tumor promotion (0-6 weeks) was equally effective. These data suggest that early induction of TNF-alpha is critical for skin tumor promotion. cV1q also reduced TPA-stimulated expression of matrix metalloproteinase 9 and granulocyte macrophage colony-stimulating factor, proteins that are differentially regulated in wt and TNF-alpha(-/-) epidermis. Treatment of the 410.4 transplantable breast carcinoma with cV1q reduced tumor growth in vivo, illustrating that inhibition of tumor growth through neutralization of TNF-alpha is not limited to skin carcinogenesis. These results provide further evidence for procancer actions of TNF-alpha and give some rationale for use of TNF-alpha antagonists in cancer prevention and treatment.

Activity of human monocytes in IgE antibody-dependent surveillance and killing of ovarian tumor cells

We have previously shown that a chimeric IgE antibody against the folic acid receptor (MOv18 IgE) inhibits tumor growth in a SCID mouse model of ovarian carcinoma. MOv18 IgE gave greater protection than the corresponding chimeric MOv18 IgG1. We have now confirmed these effects in a nude-mouse model of ovarian carcinoma and have demonstrated for the first time that human monocytes are active in IgE antibody-dependent cell-mediated cytotoxicity. Injection of tumor-bearing mice with PBMC and MOv18 IgE led to infiltration of monocytes into the tumors and prolonged survival of the mice. Incubation of PBMC or purified monocytes and MOv18 IgE with ovarian tumor cells in vitro resulted in tumor cell killing proportional to the expression of unoccupied FcepsilonRI on monocytes.We observed phagocytosis of tumor cells by the monocytes in vitro. Our results suggest that tumor-specific IgE antibodies may be exploited for immunotherapy of cancer.

Custom cranioplasty using stereolithography and acrylic

Numerous methods of cranioplasty have been described. Customization and prefabrication have been reported to reduce operating time and improve cosmesis. An original technique for the manufacture of customized cranioplastic implants has been developed and tested in 30 patients.Thirty patients requiring cranioplasties were selected. Data acquired from computed tomography (CT) were used to manufacture exact plastic replicas (biomodels) of craniotomy defects and master cranioplastic implants using the rapid prototyping technology of stereolithography (SL). The three-dimensional (3D) imaging techniques of mirroring and interpolation were used to extrapolate on existing anatomy to design the master implants. The master implants were hand finished to fit the defect in the corresponding cranial biomodel exactly and were then used to create a cavity mould. The mould was used to cast thermally polymerised custom acrylic implants. The surgeons reported that the customized implants reduced operating time, afforded excellent cosmesis and were cost effective. The patients reported that the opportunity to see the biomodel and implant preoperatively improved their understanding of the procedure. Two complications were noted, one infection and one implant required significant trimming. The simultaneous manufacture of the master implant (male) and biomodel (female) components from SL allowed custom accurate implants to be manufactured. Disadvantages identified were the time required for computer manipulations of the CT data (up to 2 h), difficulty in assessing the accuracy of the computer generated master as a 3D rendering, the potential for SL parts to warp, manufacturing time (minimum 2 days) and the cost of approximately $1300 US per case ($1000 for the SL biomodel and $300 for the acrylic casting).

Cerebrovascular biomodelling: a technical note

BACKGROUND

Recently computed tomographic angiography (CTA) and MR angiography (MRA) have been used to image cerebrovascular structures. Although CTA and MRA are accurate and sensitive imaging modalities, limitations have been identified in relation to image interpretation. Stereolithographic (SL) biomodelling is a new technology that allows three-dimensional (3D) CT and MR data to be used to accurately manufacture solid plastic replicas of anatomical structures. A prospective trial of SL biomodelling in cerebrovascular surgery has been performed to investigate the feasibility and clinical utility of this new display medium.

METHODS

Fifteen patients with cerebral aneurysms and 1 patient with a cerebral arteriovenous malformation (AVM) were selected. 3D CT and/or MR angiograms were acquired and 19 solid anatomical biomodels manufactured using the rapid prototyping technology of stereolithography. The biomodels were used for patient education, diagnosis, operative planning and surgical navigation.

RESULTS

The biomodels replicated the CTA and MRA source data. The accuracy of one biomodel was verified by comparison with a post mortem specimen, which corresponded exactly in the x and y planes but differed by 2 mm in the z plane. The ability to closely study an overview of complex cerebrovascular anatomy from any perspective on a solid biomodel was reported to enhance the surgeon's understanding, particularly when conventional images were equivocal. Cerebrovascular biomodels were found to be useful when positioning the patient's head for surgery, for selecting the best aneurysm clip and for the simulation of clipping. Patient informed consent was anecdotally improved. Disadvantages of the technology were the cost and manufacturing time.

CONCLUSIONS

Cerebrovascular biomodelling may have utility in complex cases or when the standard imaging is felt to be equivocal.

Spinal biomodeling

STUDY DESIGN

A prospective trial of stereolithographic biomodeling in complex spinal surgery.

OBJECTIVES

To investigate the use of stereolithographic biomodeling as an aid to complex spinal surgery.

SUMMARY OF BACKGROUND DATA

Of the array of imaging methods available to assist the spinal surgeon, no single method provides a complete overview of the anatomy, although three-dimensional imaging has been shown to have advantages.

METHODS

Stereolithographic biomodeling is a new technology that allows data from three-dimensional computed tomographic scans to be used to generate exact plastic replicas of anatomic structures. Five patients with complex deformities were selected: two children with congenital deformities, a patient with an osteoblastoma, a patient with basilar invagination caused by osteogenesis imperfecta, and a patient with a failed lumbar fusion. Computed tomographic scanning was performed and stereolithographic biomodels generated. The stereolithographic biomodels were used for patient education, operative planning, and surgical navigation.

RESULTS

The surgeons reported that biomodeling was useful in complex spinal surgery and was an effective technology. Stereolithographic biomodels were found to be particularly useful in morphologic assessment, in the planning and rehearsal of surgery, for intraoperative navigation, and for informing patients about surgical procedures.

CONCLUSIONS

Stereolithographic biomodeling allows imaging data to be displayed in a physical form. This intuitive medium may improve data display and allows surgical simulation on a proxy of the surgical site. Draw-backs of the technology were a minimum 24 hours' manufacturing time and the cost.

Voluntary intoxication and criminal responsibility

This paper reviews the law related to voluntary intoxication and criminal responsibility in the 50 United States, the District of Columbia, the US Virgin islands, and Puerto Rico. Statutory and case law citations are provided which govern the use of intoxication evidence in each jurisdiction to negate mens rea (i.e., to establish diminished capacity), to support an insanity defense, and to mitigate criminal sentencing. Factors that courts typically focus on when deciding whether to admit this evidence in a particular case are discussed, and these factors are related to clinically relevant criteria.

Stereolithographic (SL) biomodelling in craniofacial surgery

BACKGROUND

Stereolithographic (SL) biomodelling allows 3D CT to be used to generate solid plastic replicas of anatomical structures (biomodels). Case reports in the literature suggest that such biomodels may have a use in craniofacial surgery but no large series or assessment of utility has been reported. A prospective trial to assess the utility of biomodelling in craniofacial surgery has been performed.

METHODS

Forty patients with complex craniofacial abnormalities were selected and 3D CT scanning performed. The data of interest was used to guide a laser to selectively polymerise photosensitive resin to manufacture SL biomodels. The biomodels were used for patient education, diagnosis and operative planning. An assessment protocol was designed to test the hypothesis that biomodels in addition to standard imaging had greater utility in the surgery performed than the standard imaging alone.

RESULTS

Anecdotally surgeons found biomodelling useful in 40 complex craniofacial operations. The formal assessment of the first 10 cases suggested biomodels improved operative planning (image 76%, image with biomodel 97%, P < 0.01) and diagnosis (image 82.5%, image with biomodel 99.25%, P < 0.01). Surgeons estimated that the use of biomodels had reduced operating time by a mean of 16% and were cost effective at a mean price of $1100 AUS.

CONCLUSION

Biomodelling was reported as an intuitive, user-friendly technology that facilitated diagnosis, operative planning and communication between colleagues and patients. Limitations of the technology were manufacturing time and cost.

Pramlintide, a synthetic analog of human amylin, improves the metabolic profile of patients with type 2 diabetes using insulin. The Pramlintide in Type 2 Diabetes Group

OBJECTIVE

To examine the effects of 4 weeks of subcutaneous administration of pramlintide, a synthetic analog of human amylin, on metabolic control in patients with type 2 diabetes using insulin.

RESEARCH DESIGN AND METHODS

Serum fructosamine, HbA1c, and fasting plasma lipids were measured in 203 patients in a randomized double-blind placebo-controlled parallel-group multicenter trial using doses of 30 micrograms q.i.d., 60 micrograms t.i.d., and 60 micrograms q.i.d.

RESULTS

Statistically significant reductions in serum fructosamine concentrations were observed in the pramlintide 30 micrograms q.i.d. group (17.5 +/- 4.9 mumol/l, P = 0.029), the pramlintide 60 micrograms t.i.d. group (24.1 +/- 4.9 mumol/l, P = 0.003), and the 60 micrograms q.i.d. group (22.6 +/- 4.1 mumol/l, P = 0.001) compared with the placebo group (3.5 +/- 3.8 mumol/l). There were also statistically significant shifts in the proportion of patients with an abnormal serum fructosamine concentration at baseline that normalized at week 4 within the pramlintide 60 micrograms t.i.d. group and the 60 micrograms q.i.d. group. Consistent with the fructosamine results, there were statistically significant reductions in HbA1c in the pramlintide 30 micrograms q.i.d. group (0.53 +/- 0.07%, P = 0.0447), the pramlintide 60 micrograms t.i.d. group (0.58 +/- 0.07%, P < 0.0217), and the pramlintide 60 micrograms q.i.d. group (0.51 +/- 0.08%, P = 0.0242) compared with the placebo group (0.27 +/- 0.08%). Total cholesterol concentrations were also statistically significantly reduced in both the pramlintide 60 micrograms t.i.d. group (8.4 mg/dl, P < 0.01) and 60 micrograms q.i.d. group (10.5 mg/dl, P < 0.01) compared with placebo (1.2 mg/dl). Body weight decreased in both of the pramlintide 60 micrograms groups, but the trend did not achieve statistical significance. The incidence of hypoglycemia was similar in all treatment groups.

CONCLUSIONS

Reductions in serum fructosamine, plasma total and LDL cholesterol concentrations, and HbA1c support the hypothesis that pramlintide may improve metabolic control in patients with type 2 diabetes using insulin.

Fetal biomodelling

A study has been performed to determine if a stereolithographic (SL) biomodel of a fetal face could be created from 3 dimensional (3D) ultrasound (US). 3D ultrasound images were acquired by Diasonics Gateway 2D Array ultrasound systems (Diasonics Ultrasound, San Jose, CA, USA) using an electromagnetic localizer (Tomtec Free Hand Scanning Device, Tomtec Imaging Systems, Middle Cove, Australia). 3D volumetric reconstruction of the fetal face was performed and the data was prepared to guide the construction of an exact solid biomodel by stereolithography (SLA 250 3D Systems, Valencia, CA, USA). A faithful solid representation of the fetal face was produced within 12 hours of the US scan. The fetal biomodel seemed to improve the display of the 3D data. The user-friendly nature of biomodelling may have clinical utility for fetal morphological assessment and as an aid when counselling parents.

Effects of 4 weeks' administration of pramlintide, a human amylin analogue, on glycaemia control in patients with IDDM: effects on plasma glucose profiles and serum fructosamine concentrations

The effects of 4 weeks' administration of pramlintide, an analogue of the human hormone amylin, on blood glucose control in 215 patients with insulin-dependent diabetes mellitus were examined in a 4-week, randomized, double-blind, placebo-controlled, parallel-group trial. Pramlintide was administered subcutaneously prior to meals in four dosing regimens: 30 microg four times per day (breakfast, lunch, dinner, and evening snack), 30 microg three times per day (breakfast, lunch and dinner [BLD]), 30 microg three times per day (breakfast, dinner and evening snack [BDS]), and 60 microg twice per day (breakfast and dinner). After 4 weeks of pramlintide 30 microg four times per day administration, there was a statistically significant reduction in the mean 24 h plasma glucose concentration when compared to placebo (-1.4 +/- 0.5 vs 0.3 +/- 0.5 micromol/l, p = 0.009). Serum fructosamine concentrations were reduced 62 +/- 10 micromol/l in the pramlintide 30 mg four times per day group, 43 +/- 7 micromol/l in the pramlintide 30 microg three times per day (BLD) group, 47 +/- 6 micromol/l in the pramlintide 30 microg three times per day (BDS) group, 46 +/- 7 micromol/l in the pramlintide 60 microg twice per day group, and 29 +/- 8 micromol/l by placebo. The incidence of hypoglycaemia was not different in any pramlintide group compared to the placebo group. Nausea, the most frequent adverse event, subsided after the first week of treatment in the majority of patients. In conclusion, pramlintide improved blood glucose control over a 4-week period without increased hypoglycaemia and was well tolerated. Future studies using a longer period of pramlintide administration with assessment of HbA1c as the measurement of glycaemic control are warranted.

Pramlintide: a human amylin analogue reduced postprandial plasma glucose, insulin, and C-peptide concentrations in patients with type 2 diabetes

In order to determine the influence of a 5 h infusion of pramlintide compared to placebo on postprandial glucose, lactate, insulin, and C-peptide concentrations in patients with Type 2 diabetes, a single-blind, randomized, cross-over study was conducted in 24 patients; 12 treated with exogenous insulin and 12 managed with diet and/or oral hypoglycaemic agents. One hour after initiation of infusion, patients consumed a Sustacal test meal. The protocol was repeated on the following day with each patient receiving the alternate study medication. Pramlintide infusion in the insulin-treated patients resulted in statistically significant reductions in mean glucose, insulin, C-peptide, and lactate concentrations during the 4-h period after the Sustacal test meal. Pramlintide infusion also resulted in significant reductions of mean insulin, C-peptide, and lactate concentrations, but not glucose concentrations, in the patients treated with diet and/or oral hypoglycaemic agents. Within this latter group, reduction in postprandial glucose concentrations in individual patients correlated with glycated haemoglobin values. These results suggest that administration of pramlintide may improve glycaemic control in patients with Type 2 diabetes treated with insulin or poorly controlled on diet and/or oral hypoglycaemic agents.

Effects of pramlintide, an analog of human amylin, on plasma glucose profiles in patients with IDDM: results of a multicenter trial

The effects of subcutaneous administration of 10, 30, or 100 microg q.i.d. pramlintide, an analog of human amylin, on plasma glucose regulation in patients with IDDM were evaluated in a multicenter trial. The plasma glucose response to a Sustacal test meal was significantly reduced compared with placebo both after 1 week and after 2 weeks of administration of 30 or 100 microg pramlintide. In addition, 24-h mean plasma glucose concentrations were significantly lowered in patients receiving 30 microg of pramlintide for 2 weeks compared with placebo, while the 100-microg pramlintide dose did not reach statistical significance for the 24-h glucose profiles. At 10 microg, pramlintide had no effect on the 24-h glucose profile or on the plasma glucose response to a Sustacal test meal. The reduction in 24-h glucose concentrations and glucose concentrations after the Sustacal test meal observed at the 30-microg pramlintide dose was not accompanied by an increased incidence of hypoglycemic events. The most frequent adverse events were dose-related and involved transient upper gastrointestinal symptoms. A majority (>80%) of the patients who reported these adverse events during week 1 did not report them in week 2. These data indicate that pramlintide effectively reduces plasma glucose concentrations as reflected in both a 24-h glucose profile and a Sustacal test meal while maintaining an acceptable safety profile.

An AIDS training program for rural mental health providers

A total of 194 mental health care providers in Arkansas, primarily from rural areas and small communities, participated in a four-hour training program designed to improve their knowledge about the psychosocial and neuropsychiatric aspects of HIV and AIDS. Participants' responses to questionnaires completed before and after training indicated that the program was successful in achieving its goal. However, only a minimal number of providers reported completing drug, alcohol, and sexual histories and AIDS risk assessments for any of their patients before the training occurred. The authors emphasize the importance of AIDS training for rural providers.

Somatic embryogenesis and plant regeneration from immature embryos of western larch

Somatic embryogenesis was initiated from immature embryos of western larch (Larix occidentalis Nutt.) on media containing 2,4-dichlorophenoxyacetic acid and N6- benzyladenine. The effects of explant type and ammonium nitrate and glutamine concentrations on initiation were tested. Although 21-93% of explants rendered cultures in various experiments, only 3% yielded sustainable embryogenic lines. Excised embryos at the early cotyledonary stage were optimal for initiation. Maturation of somatic embryos was promoted by abscisic acid. Response to abscisic acid concentrations and duration of exposure to abscisic acid varied with genotype. Maximal results were obtained with 0.025 μ M abscisic acid for 1 to 2 weeks followed by individual culture on medium without growth regulators. Mature somatic embryos developed into shoots with roots. Plantlets have been established in peat.

Detection of nicotinic receptor ligands with a light addressable potentiometric sensor

The nicotinic acetylcholine receptor, purified from Torpedo electric organ, was coupled to a light addressable potentiometric sensor (LAPS) to form a LAPS-receptor biosensor. Receptor-ligand complexes containing biotin and urease were captured on a biotinylated nitrocellulose membrane via a streptavidin bridge and detected with a silicon-based sensor. Competition between biotinylated alpha-bungarotoxin and nonbiotinylated ligands formed the basis of this assay. This biosensor detected both agonists (acetylcholine, carbamylcholine, succinylcholine, suberyldicholine, and nicotine) and competitive antagonists (d-tubocurarine, alpha-bungarotoxin, and alpha-Naja toxin) of the receptor with affinities comparable to those obtained using radioactive ligand binding assays. Consistent with agonist-induced desensitization of the receptor, the LAPS-receptor biosensor reported a time-dependent increase in affinity for the agonist carbamylcholine as expected, but not for the antagonists.

Pharmacological specificity of a nicotinic acetylcholine receptor optical sensor

The pharmacological specificity of a nicotinic acetylcholine receptor (nAChR) optical biosensor was investigated using three fluorescein isothiocyanate (FITC)-tagged neurotoxic peptides that vary in the reversibility of their receptor inhibition: alpha-bungarotoxin (alpha-BGT), alpha-Naja toxin (alpha-NT), and alpha-conotoxin (GI) (alpha-CNTX). Kinetic analysis of the time course of binding of FITC-neurotoxins to the nAChR-coated fiber gave association rate constants (k+1) of 8.4 x 10(6) M-1 min-1 for FITC-alpha-BGT, 6.0 x 10(6) M-1 min-1 for FITC-alpha-NT and 1.4 x 10(6) M-1 min-1 for FITC-alpha-CNTX. The dissociation rate constants (k-1) for the three neurotoxins were 7.9 x 10(-3) min-1. 4.8 x 10(-2) min-1 and 8.0 x 10(-1) min-1 for FITC-alpha-BGT. FITC-alpha-NT and FITC-alpha-CNTX, respectively. The equilibrium dissociation constant (Kd) values for the three toxins. calculated from these rare constants, were similar to published values obtained from tissue responses or ligand binding assays. The optical signal generated by FITC-alpha-NT binding to the nAChR-coated fiber was effectively quenched by agonists and antagonists of the nAChR but not by most of the tested agonists and antagonists of muscarinic cholinergic, adrenergic, glutamatergic, serotonergic, dopaminergic or GABAergic receptors. Interestingly, 5-hydroxy-tryptamine, haloperidol and (+)cis-methyldioxolane gave significant inhibition of FITC-alpha-NT binding to the immobilized receptor. Equilibrium constants of inhibition (Ki) for d-tubocurarine (d-TC) and carbamylcholine (carb) were determined from competition studies using FITC-alpha-CNTX. FITC-alpha-NT or FITC-alpha-BGT as probes for receptor occupancy. When the more reversible probe FITC-alpha-CNTX was used, the Ki value for d-TC was an order of magnitude lower than those determined using the less reversible probes. Ki values for carb however, were independent of the FITC-toxin probe used.

Opal phytoliths found on the teeth of the extinct ape Gigantopithecus blacki: implications for paleodietary studies

Identification of opal phytoliths bonded to the enamel surface of the teeth of Gigantopithecus blacki indicates that this extinct ape had a varied diet of grasses and fruits. By using the scanning electron microscope at magnifications of 2000-6000x specific opal phytoliths were observed and photographed on the fossilized teeth of an extinct species. Since opal phytoliths represent the inorganic remains of once-living plant cells, their documentation on the teeth of Gigantopithecus introduces a promising technique for the determination of diet in extinct mammalian species which should find numerous applications in the field of paleoanthropology as well as vertebrate paleontology.

Biosynthetic human growth hormone in the treatment of growth hormone deficiency

A total of 309 previously untreated children with growth hormone deficiency (GHD) (219 boys, 90 girls; mean age 8.4 +/- 3.9 years, range 1.5-19 years) were treated for up to 3 years in an ongoing trial designed to examine the long-term efficacy and safety of biosynthetic somatropin (rhGH). The children were treated with rhGH, 0.06 mg/kg (0.16 IU/kg) three times weekly. In the prepubertal children, the mean height velocity increased during the first year from 3.8 +/- 1.8 cm/year to 8.9 +/- 2.2 cm/year (n = 188). During the second and third years, their height velocities were 7.1 +/- 1.1 (n = 147) and 6.3 +/- 1.2 cm/year (n = 64), respectively. The height velocity SDS increased from -2.5 +/- 1.9 before treatment to 3.1 +/- 2.6 during the first year of treatment in the prepubertal children. The mean pretreatment height velocity in those with idiopathic GHD (3.8 +/- 1.6 cm/year) did not differ from that in children with organic GHD (3.8 +/- 2.3 cm/year). In addition, the height velocities during the first year of therapy did not differ significantly with respect to the aetiology of GHD. For the children who entered puberty during the study, the mean height velocity increased from 3.0 +/- 1.7 cm/year before treatment to 8.4 +/- 2.3 cm/year during the first year of rhGH therapy. In the first year, the height velocity of children with a bone age of less than 5 years (9.4 +/- 2.3 cm/year) was significantly greater than that in children with a bone age of 5-10 years (8.4 +/- 1.8 cm/year) or greater than 10 years (7.8 +/- 2.2 cm/year: p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of lindane, bicyclophosphate and picrotoxin binding to the putative chloride channel sites in rat brain and Torpedo electric organ

The relative potencies of lindane, picrotoxin and several bicyclophosphate derivatives were compared in their ability to compete with 35S-t-butylbicyclophosphorothionate (35S-TBPS) binding sites in membranes derived from Torpedo electric organ and rat brain. Lindane proved to be ten times more potent in competing with 35S-TBPS binding in electric organ than rat brain, while the bicyclophosphate analogs displayed up to three orders of magnitude greater affinity for rat brain over electric organ. GABA inhibited 35S-TBPS binding in rat brain with moderate potency (IC50 = 30 microM), while unlabelled TBPS inhibited the binding of 3H-muscimol to the GABA receptor with an IC50 greater than 100 microM. The GABA receptor antagonist bicuculline increased 35S-TBPS binding in rat brain both in the presence and absence of 30 microM GABA. The results of the study are discussed in the context of a pharmacological discrimination between voltage-sensitive and receptor-gated Cl- channels in nervous tissue, with lindane and the i-propylbicyclophosphate derivative being the most selective compounds for discriminating between them.

Chlamydia trachomatis infection in late pregnancy: a prospective study

During a 1-year period, 3309 women were screened in pregnancy for Chlamydia trachomatis infection. A cervical swab was taken and chlamydial antigen was detected, using a monoclonal antibody ELISA technique, in 198 women (6%). The prevalence of chlamydial infection was high in women under 20 years (14.5%), single women (14.2%) and black women (16.8%). Binomial regression of these data estimates a relative risk of 2.9 for women under 20 years compared with women aged 25 and over. There was an interaction between race and marital status with a high risk in single white and single asian women (2.3, 4.5 respectively) but a similar risk in black single and black married women (3.0, 4.0 respectively). Parity and social class did not effect the prevalence of antigen carriage. There was no demonstrable effect of maternal antigen carriage on outcome of pregnancy, gestation or admission to neonatal unit. Infants of 174 antigen-positive mothers were followed-up. Tissue culture for Chlamydia trachomatis was positive in 43 (24%) infants. Complications occurred in 23 (53%): 17 had conjunctivitis, three had lower respiratory tract infection and three both complications. Amongst 131 chlamydia-negative infants, complications occurred in 21 (16%). Since this infection, in infants, responds promptly to erythromycin therapy, screening and treatment in pregnancy will convey little benefit in prevention of perinatal morbidity or perinatal mortality.

Resonance Raman studies of Escherichia coli sulfite reductase hemoprotein. 1. Siroheme vibrational modes

Resonance Raman (RR) spectra are reported for the hemoprotein subunit (SiR-HP) of Escherichia coli NADPH-sulfite reductase (EC 1.8.1.2) in various ligation and redox states. Comparison of the RR spectra of extracted siroheme and the mu-oxo FeIII dimer of octaethylisobacteriochlorin with those of mu-oxo FeIII octaethylchlorin dimer and mu-oxo FeIII octaethylporphyrin dimer demonstrates that many siroheme bands can be correlated with established porphyrin skeletal modes. Depolarization measurements are a powerful tool in this correlation, since the 45 degrees rotation of the C2 symmetry axis of the isobacteriochlorin ring relative to the chlorin system results in reversal of the polarization properties (polarized vs anomalously polarized) of bands correlating with B1g and B2g modes of porphyrin. Various SiR-HP adducts (CO, NO, CN-, SO3(2-] show upshifted high-frequency bands, characteristic of the low-spin state and consistent with the expected core size sensitivity of the skeletal modes. Fully reduced unliganded SiR-HP (both siroheme and Fe4S4 cluster reduced) in liquid solution displays RR features comparable to those of high-spin ferrous porphyrins; on freezing, the RR spectrum changes, reflecting an apparent mixture of siroheme spin states. At intermediate reduction levels in solution a RR species is observed whose high-frequency bands are upshifted relative to oxidized and fully reduced SiR-HP. This spectrum, thought to arise from the "one-electron" state of SiR-HP (siroheme reduced, cluster oxidized), may be due to S = 1 FeII siroheme.

Chlamydia trachomatis infection in infants: a prospective study

In a prospective study of Chlamydia trachomatis infection in pregnancy, 198 mothers positive for chlamydial antigen were identified; the infants of 174 were followed for up to six months and C trachomatis was recovered in cell culture from 43 infants (25%). Conjunctivitis occurred in significantly more infants who were positive for C trachomatis (20 of 43, 47%) than in those who were negative (18 of 131, 14%). There were also significantly more lower respiratory tract infections among infants with positive cultures (six of 43, 14%, compared with three of 131, 2%). The chlamydial antigen enzyme linked immunosorbent assay (ELISA) was positive in 61 of 131 infants from whom C trachomatis was not recovered in cell culture. False positive results were usually associated with the isolation of Staphylococcus aureus from samples of pharyngeal aspirate. Our results confirm that C trachomatis infection is a common cause of neonatal conjunctivitis, and respiratory infection in the first few months of life, with an incidence of 8.2/1000 live births. Because the infection is easily treated by oral erythromycin, however, screening during pregnancy is not warranted.

Inhibition of calcium channel dihydropyridine receptor binding by purified Mojave toxin

Mojave toxin, the principal toxic component of the venom of the Mojave rattlesnake Crotalus scutulatus scutulatus, is a protein complex of about 22,000 mol. wt. The mechanism of action of this potent (LD50 = 0.039 micrograms/g, mouse, IV) neurotoxin is a matter of conjecture, but physiologic data suggest a presynaptic site of action with disruption of stimulus-secretion coupling and neurotransmitter release. The selectivity of Mojave toxin's effect on several ion channels involved in neurotransmission was assessed in the present study using competitive radioisotopic binding procedures. Synaptic membranes from rat brain were used to assess the toxin's interaction with Ca++ and Cl- channels while membrane fragments from the Torpedo fish electric organ were used to determine toxin interaction with the nicotinic acetylcholine receptor-coupled Na+ channel. Mojave toxin was found to irreversibly inhibit 3H-nitrendipine binding to dihydropyridine receptors associated with Ca++ channels in rat brain, but had no effect on radioligand binding in the Na+ and Cl- channel assays. Saturation analysis of the binding further showed that the effects of MoTX on dihydropyridine binding were noncompetitive, with MoTX producing a decrease in both the affinity and density of 3H-nitrendipine sites. These results are consistent with the hypothesis that MoTX acts selectively on Ca++ channel function and that this interaction occurs via an allosteric mechanism in which MoTX binds to a membrane site that is topologically distinct from the dihydropyridine receptor.

Biosynthetic human growth hormone: current status and future questions

Human growth hormone derived from human pituitaries resulted in excellent growth in children with growth hormone deficiency but limited supplies in many countries prevented treatment of all children, delayed the onset of therapy, and/or forced the use of doses that may have been less than optimal. Recent advances in technology allow the production of byosynthetic human growth hormone (hGH) by recombinant methods resulting in increased supplies of hormone. More than 200 previously untreated children with growth hormone deficiency have been evaluated for two years or longer while receiving biosynthetic natural sequence hGH (somatropin). The mean growth velocity of 3.6 cm/yr prior to therapy increased to 8.8 cm/yr after one year and 7.25 cm/yr in the second year. Growth response was inversely related to age when calculated as cm/yr. This response paralleled the normal decrease in growth velocity as children approach puberty. Children with hGH deficiency who had previously received replacement hGH were enrolled in a double-blind study using either 0.06 or 0.10 mg/kg thrice weekly for 12 months. Growth rate was significantly greater with the higher dose during the first six months but not during the second six month period. The use of a higher dose of hGH must be individualized as not all patients have accelerated growth with the increased dose and the mean group response is not permanent. Multiple questions remain unanswered after three decades of treating growth hormone deficiency. Are the current criteria for diagnosis of growth hormone deficiency appropriate? What dose of hGH is correct? Do children need increases in replacement therapy as their height approaches normal?(ABSTRACT TRUNCATED AT 250 WORDS)

Rates of pi-electron oxidation and reduction of free base and Zn(II) porphyrins, chlorins, and isobacteriochlorins

The rates of pi-electron oxidation and reduction of two homologous series of free base and Zn(II) porphyrins, chlorins, and isobacteriochlorins were studied by chronocoulometry at a platinum disk electrode. The macrocycles were octaethylporphyrin, tetraphenylporphyrin, and the chlorins and isobacteriochlorins derived therefrom. The rates were found to vary to within a factor of 3, and some consistent trends are noted. However, the most important conclusion of this work is that pi-electron redox processes for these macrocycles occur at essentially the same rate, despite the previously noted large differences in pi-electron redox potentials.

Simple versus complex performance impairments at three blood glucose levels

By using a visual reaction time paradigm, we sought to determine if disruption of relatively simple responding (finger tapping or letter recognition) or more complex responding (choice reaction time) would occur in response to blood glucose deviations. Glucose levels were maintained in 24 male diabetics to within 4% of the following targeted concentrations: 55 mg/dl (hypoglycemia), 110 mg/dl (euglycemia/control), and 300 mg/dl (hyperglycemia). The results indicate that simple motor and perceptual skills were not affected by blood glucose alterations, while more complex cognitive processing required significantly longer response latencies during hypoglycemia. Performance impairments occurred independently of disease duration and control, and without documented neuropathy, underscoring the sensitivity of some cognitive skills to acute glucose fluctuations.

Social and school competencies in children with short stature: longitudinal patterns

Longitudinal evaluation of 47 children with short stature secondary to growth hormone deficiency (GHD), constitutional delay (CD), and Turner's syndrome (TS) was undertaken approximately 3 years after initial assessment. Parent ratings of social and school competence indicated a developmental trend of poorer adjustment during early adolescence (ages 12 and 14), which was preceded (age 9) and followed (age 17) by age-appropriate functioning. Evaluation of social competence scores suggested that large organized group activities were avoided, although children had close friends with whom they interacted regularly. Children with short stature obtained age-expected scores for their involvement in solitary activities (i.e., hobbies and household chores) and tended to participate in individual sports (i.e., fishing, swimming), consistent with a pattern of withdrawal from large groups. Younger children with CD evidenced academic functioning at least 1 SD higher than children from all other groups, and this age-related effect may explain performance inconsistencies reported previously with other groups of CD children. Of the children studied, girls with TS experienced the greatest academic difficulty.

Management of infection of major amputation stumps after failed femorodistal grafts

A retrospective review was performed of 174 patients who underwent 199 lower-extremity amputations for unreconstructable vascular insufficiency from 1976 to 1983 at the Northwestern University Medical Center. This study was initiated to identify the cause of amputation wound healing complications and secondary ascending prosthetic graft infection, as well as to propose a plan of management for the failed prosthetic grafts at the time of major limb amputation. Ninety-eight amputations were performed primarily, 12 were performed secondary to graft infection, and 89 were performed in patients who had previously undergone infrainguinal arterial bypass procedures. At the time of amputation, graft management consisted of high transection and suture ligation, allowing the graft to retract into the substance of the stump and away from the skin suture line and weight-bearing area of the limb. Delayed stump healing was noted to occur more commonly in the group who had undergone previous bypasses as opposed to those who had undergone primary amputation (34.8% versus 14.3%). Fourteen graft infections developed in 89 patients after amputation (15.7%), which is significantly higher than the overall 1.4% incidence of lower-extremity bypass infections that occurred during the same interval in patients with intact extremities. In addition, it was found that when infected grafts in amputated limbs were completely removed, stump healing without recurrent wound and graft sepsis was better than when treated locally or with partial graft removal. We therefore recommend removal of a thrombosed graft with an infected wound or an infected graft at the time of major limb amputation to decrease the incidence of wound complications and graft infection.

Computer analysis of double-labeled two-dimensional electrophoresis gels

A computerized process for the automatic analysis of double-label autoradiography after two-dimensional polyacrylamide gel electrophoresis has been developed. Matching fluorographs and autoradiographs produced from gels containing 3H- and 14C-labeled proteins are digitized by a rotating drum densitometer and analyzed by the Man-computer Interactive Data Analysis System III. This system locates corresponding protein spots in the films with edge-detection algorithms, converts spot density readings to isotopic disintegrations by reference to standard curves, and computes a 3H:14C ratio for each spot in the gels. On the average, calculated ratios are accurate to approximately 9% for test strips of polyacrylamide gel containing uniform mixtures of 3H and 14C. Values obtained for two-dimensional gels containing n protein spots with a known 3H:14C ratio of 8.6 +/- 0.1 are as follows: 8.1 +/- 1.4 (n = 268), 8.8 +/- 2.1 (n = 278), 9.1 +/- 1.7 (n = 245), and 8.8 +/- 2.2 (n = 223). The computer process greatly reduces the time required to precisely compare two complex protein mixtures and has sufficient precision to detect a doubling in the biosynthesis of any individual protein.

Regulation of NO(3) Influx in Barley : Studies Using NO(3)

Short-term (10 minutes) measurements of plasmalemma NO(3) (-) influx (phi(oc)) into roots of intact barley plants were obtained using (13)NO(3) (-). In plants grown for 4 days at various NO(3) (-) levels (0.1, 0.2, 0.5 millimolar), phi(oc) was found to be independent of the level of NO(3) (-) pretreatment. Similarly, pretreatment with Cl(-) had no effect upon plasmalemma (13)NO(3) (-) influx. Plants grown in the complete absence of (13)NO(3) (-) (in CaSO(4) solutions) subsequently revealed influx values which were more than 50% lower than for plants grown in NO(3) (-). Based upon the documented effects of NO(3) (-) or Cl(-) pretreatments on net uptake of NO(3) (-), these observations suggest that negative feedback from vacuolar NO(3) (-) and/or Cl(-) acts at the tonoplast but not at the plasmalemma. When included in the influx medium, 0.5 millimolar Cl(-) was without effect upon (13)NO(3) (-) influx, but NH(4) (+) caused approximately 50% reduction of influx at this concentration.

The detection of Escherichia coli heat-labile enterotoxin by enzyme-linked immunosorbent assay

An enzyme linked immunosorbent assay (ELISA) technique was modified and used to detect heat-labile (LT) enterotoxigenic Escherichia coli (ETEC) from specimens of faeces sent to a routine diagnostic laboratory. Strains of LT ETEC were detected in eight of 250 (3.2%) diarrhoeal stools but were not found in 110 non-diarrhoeal stools. All eight patients found to have LT ETEC were travellers returning with diarrhoea. LT ETEC was the most common bacterial pathogen found (15.4%) in this group of patients, exceeding Campylobacter sp. (5.8%) and Salmonella sp. (7.7%). The ELISA technique was simple to perform and visual readings were found to be reliable.

Verbal fluency and naming performance in type I diabetes at different blood glucose concentrations

The effect of serum glucose alterations on selected verbal skills was examined in a group of diabetic men between 18 and 35 yr of age. An artificial insulin infusion system was used to set and maintain glucose concentrations during testing at each of three levels: hypoglycemia (55 mg/dl), euglycemia (110 mg/dl), and hyperglycemia (300 mg/dl). Subjects were used as their own controls, with performance at euglycemia serving as the comparison standard. A double-blind crossover design was employed as described in Holmes et al. (see ref. 14). Results showed significantly disrupted naming or labeling skills at hypoglycemia, with a trend toward poorer performance at hyperglycemia. During hypoglycemia, rate of responding was slowed from 6% to 18%, compared with euglycemic performance, but accuracy was not impaired. In contrast, word recognition skills were not affected by deviations in glucose. These performance effects were not correlated with duration of disease except for one of the five tests administered. This one exception, on the most difficult task, was less notable than the general finding of no relation between disease duration (from 6 mo to 17.5 yr) and test performance. Thus, in addition to considering long-term consequences of blood glucose alterations, clinicians and diabetic patients may wish to consider acute neuropsychological consequences of disrupted euglycemia.