Intersection of Immunity, Metabolism, and Muscle Regeneration in an Autoimmune-Prone MRL Mouse Model

Due to the limited capacity of mammals to regenerate complex tissues, researchers have worked to understand the mechanisms of tissue regeneration in organisms that maintain that capacity. One example is the MRL/MpJ mouse strain with unique regenerative capacity in ear pinnae that is absent from other strains, such as the common C57BL/6 strain. The MRL/MpJ mouse has also been associated with an autoimmune phenotype even in the absence of the mutant Fas gene described in its parent strain MRL/lpr. Due to these findings, the differences between the responses of MRL/MpJ versus C57BL/6 strain are evaluated in volumetric muscle injury and subsequent material implantation. One salient feature of the MRL/MpJ response to injury is robust adipogenesis within the muscle. This is associated with a decrease in M2-like polarization in response to biologically derived extracellular matrix scaffolds. In pro-fibrotic materials, such as polyethylene, there are fewer foreign body giant cells in the MRL/MpJ mice. As there are reports of both positive and negative influences of adipose tissue and adipogenesis on wound healing, this model can provide an important lens to investigate the interplay between stem cells, adipose tissue, and immune responses in trauma and material implantation.

Pro-regenerative biomaterials recruit immunoregulatory dendritic cells after traumatic injury

During wound healing and surgical implantation, the body establishes a delicate balance between immune activation to fight off infection and clear debris and immune tolerance to control reactivity against self-tissue. Nonetheless, how such a balance is achieved is not well understood. Here we describe that pro-regenerative biomaterials for muscle injury treatment promote the proliferation of a BATF3-dependent CD103+XCR1+CD206+CD301b+ dendritic cell population associated with cross-presentation and self-tolerance. Upregulation of E-cadherin, the ligand for CD103, and XCL-1 in injured tissue suggests a mechanism for cell recruitment to trauma. Muscle injury recruited natural killer cells that produced Xcl1 when stimulated with fragmented extracellular matrix. Without cross-presenting cells, T-cell activation increases, pro-regenerative macrophage polarization decreases and there are alterations in myogenesis, adipogenesis, fibrosis and increased muscle calcification. These results, previously observed in cancer progression, suggest a fundamental mechanism of immune regulation in trauma and material implantation with implications for both short- and long-term injury recovery.

Dynamics of SARS-CoV-2 Seroprevalence in a Large US population Over a Period of 12 Months

Due to a combination of asymptomatic or undiagnosed infections, the proportion of the United States population infected with SARS-CoV-2 was unclear from the beginning of the pandemic. We previously established a platform to screen for SARS-CoV-2 positivity across a representative proportion of the US population, from which we reported that almost 17 million Americans were estimated to have had undocumented infections in the Spring of 2020. Since then, vaccine rollout and prevalence of different SARS-CoV-2 variants have further altered seropositivity trends within the United States population. To explore the longitudinal impacts of the pandemic and vaccine responses on seropositivity, we re-enrolled participants from our baseline study in a 6- and 12- month follow-up study to develop a longitudinal antibody profile capable of representing seropositivity within the United States during a critical period just prior to and during the initiation of vaccine rollout. Initial measurements showed that, since July 2020, seropositivity elevated within this population from 4.8% at baseline to 36.2% and 89.3% at 6 and 12 months, respectively. We also evaluated nucleocapsid seropositivity and compared to spike seropositivity to identify trends in infection versus vaccination relative to baseline. These data serve as a window into a critical timeframe within the COVID-19 pandemic response and serve as a resource that could be used in subsequent respiratory illness outbreaks.

Characterization of the antispike IgG immune response to COVID-19 vaccines in people with a wide variety of immunodeficiencies

Research on coronavirus disease 2019 vaccination in immune-deficient/disordered people (IDP) has focused on cancer and organ transplantation populations. In a prospective cohort of 195 IDP and 35 healthy volunteers (HV), antispike immunoglobulin G (IgG) was detected in 88% of IDP after dose 2, increasing to 93% by 6 months after dose 3. Despite high seroconversion, median IgG levels for IDP never surpassed one-third that of HV. IgG binding to Omicron BA.1 was lowest among variants. Angiotensin-converting enzyme 2 pseudo-neutralization only modestly correlated with antispike IgG concentration. IgG levels were not significantly altered by receipt of different messenger RNA-based vaccines, immunomodulating treatments, and prior severe acute respiratory syndrome coronavirus 2 infections. While our data show that three doses of coronavirus disease 2019 vaccinations induce antispike IgG in most IDP, additional doses are needed to increase protection. Because of the notably reduced IgG response to Omicron BA.1, the efficacy of additional vaccinations, including bivalent vaccines, should be studied in this population.

Ectopic adipogenesis in response to injury and material implantation in an autoimmune mouse model

Due to the limited capacity of mammals to regenerate complex tissues, researchers have worked to understand the mechanisms of tissue regeneration in organisms that maintain that capacity. One example is the MRL/MpJ mouse strain with unique regenerative capacity in ear pinnae that is absent from other strains, such as the common C57BL/6 strain. The MRL/MpJ mouse has also been associated with an autoimmune phenotype even in the absence of the mutant Fas gene described in its parent strain MRL/lpr. Due to these findings, we evaluated the differences between the responses of MRL/MpJ versus C57BL/6 strain in traumatic muscle injury and subsequent material implantation. One salient feature of the MRL/MpJ response to injury was a robust adipogenesis within the muscle. This was associated with a decrease in M2-like polarization in response to biologically derived extracellular matrix scaffolds. In pro-fibrotic materials, such as polyethylene, there were fewer foreign body giant cells in the MRL/MpJ mice. As there are reports of both positive and negative influences of adipose tissue and adipogenesis on wound healing, this model could provide an important lens to investigate the interplay between stem cells, adipose tissue, and immune responses in trauma and materials implantation.

Conserved and tissue-specific immune responses to biologic scaffold implantation

Upon implantation into a patient, any biomaterial induces a cascade of immune responses that influences the outcome of that device. This cascade depends upon several factors, including the composition of the material itself and the location in which the material is implanted. There is still significant uncertainty around the role of different tissue microenvironments in the immune response to biomaterials and how that may alter downstream scaffold remodeling and integration. In this study, we present a study evaluating the immune response to decellularized extracellular matrix materials within the intraperitoneal cavity, the subcutaneous space, and in a traumatic skeletal muscle injury microenvironment. All different locations induced robust cellular recruitment, specifically of macrophages and eosinophils. The latter was most prominent in the subcutaneous space. Intraperitoneal implants uniquely recruited B cells that may alter downstream reactivity as adaptive immunity has been strongly implicated in the outcome of scaffold remodeling. These data suggest that the location of tissue implants should be taken together with the composition of the material itself when designing devices for downline therapeutics.

Salvage surgery for cervical radioiodine refractory 18F-FDG-PET positive recurrence of papillary thyroid cancer

PURPOSE

Five percent of patients with differentiated thyroid cancer are diagnosed with radioiodine refractory relapse in the course of the disease. For isolated or oligometastatic cervical recurrence, resection or another local treatment is recommended. In this study, the impact of surgical treatment of cervical radioiodine refractory 18F-FDG-PET positive relapse of papillary thyroid cancer (PTC) was evaluated.

METHODS

Patients receiving radioiodine therapy between 2005 and 2015 at the University Hospital of Cologne, Germany, for PTC were screened. The subgroup of patients undergoing surgery during the course of disease after recommendation by a multidisciplinary endocrine team for cervical radioiodine refractory 18F-FDG-PET positive recurrence was identified. Demographics, clinic-pathologic characteristics, oncologic treatment, and outcome were analyzed.

RESULTS

Thirty (3%) of 969 patients with PTC treated with radioiodine therapy at our institution underwent surgery for radioiodine refractory 18F-FDG-PET positive cervical recurrence during the course of the disease. In eight (26.6%) patients, more than one operation was performed. Sixteen (53%) patients received external beam radiation therapy (EBRT) after surgery. Follow-up was on average, 79.2 ± 61.6 months after the last surgical treatment. Biochemical and radiological cure was seen in 12 (40%) patients. Remission was significantly more frequent in younger patients (P = 0.0001) with lymph node rather than soft tissue tumor recurrence (P = 0.004).

CONCLUSIONS

Surgical treatment of radioiodine refractory 18F-FDG-PET positive cervical recurrence led to biochemical and radiological cure in about 40% of patients in this study. Further data are needed concerning risk stratification of potential subgroups benefitting of surgical approach and the possible role of EBRT after repetitive surgery.

99mTc-MIBI SPECT in primary hyperparathyroidism

Aim of the study was to analyse the influence of a concomitant vitamin D deficiency on the results of 99mTc-MIBI studies in patients (pts) with primary hyperparathyroidism (pHPT). Patients, methods: Between January 1998 and May 2004, 71 pts with pHPT had undergone operation after a 99mTc-MIBI study of whom 54 pts (76%) had normal values of 25-OH-vitamin D3 and 17 pts (24%) had vitamin D deficiency. Results of a dual-phase 99mTc-MIBI protocol with SPECT were compared with histopathology. Results: In 54 pts with normal vitamin D values late SPECT images identified more lesions (n = 51, sensitivity 91%) than early planar (n = 45, sensitivity 82%) or late planar images (n = 50, sensitivity 88%). In 17 pts with vitamin D deficiency late SPECT images identified more lesions (n = 13, sensitivity 72%) than early planar (n = 10, sensitivity 56%) or late planar images (n = 10, sensitivity 56%) too. In pts with vitamin D deficiency the sensitivity of a 99mTc-MIBI SPECT study was lower than in those with normal vitamin D status (72% vs. 91%) and dependent on the value for PTH. However, the results did not reach statistical significance: early planar: p = 0.1625; late planar: p = 0.0039; 99mTc-MIBI SPECT: p = 0.1180. Conclusion: The likelihood of a pathological 99mTc-MIBI study being obtained in pts with pHPT is dependent on the parathyroid hormone level. However, a negative influence of a low vitamin D level on the scintigraphic detection rate of a parathyroid adenoma could not be proven which may be due to the low number of pts with vitamin D deficiency.

White paper on the promotion of an integrated risk assessment concept in European regulatory frameworks for chemicals

The vision of a sustainable and safe use of chemicals to protect human health, preserve the environment and maintain the ecosystem requires innovative and more holistic approaches to risk assessment (RA) in order to better inform decision making. Integrated risk assessment (IRA) has been proposed as a solution to current scientific, societal and policy needs. It is defined as the mutual exploitation of environmental risk assessment (ERA) for human health risk assessment (HHRA) and vice versa in order to coherently and more efficiently characterize an overall risk to humans and the environment for better informing the risk analysis process. Extrapolating between species which are relevant for HHRA and ERA requires a detailed understanding of pathways of toxicity/modes of action (MoA) for the various toxicological endpoints. Significant scientific advances, changes in chemical legislation, and increasing environmental consciousness have created a favourable scientific and regulatory environment to develop and promote the concept and vision of IRA. An initial proof of concept is needed to foster the incorporation of IRA approaches into different chemical sectorial regulations and demonstrate their reliability for regulatory purposes. More familiarity and confidence with IRA will ultimately contribute to an overall reduction in in vivo toxicity testing requirements. However, significant progress will only be made if long-term support for MoA-related research is secured. In the short term, further exchange and harmonization of RA terminology, models and methodologies across chemical categories and regulatory agencies will support these efforts. Since societal values, public perceptions and cultural factors are of increasing importance for the acceptance of risk analysis and successful implementation of risk mitigation measures, the integration of socio-economic analysis and socio-behavioural considerations into the risk analysis process may help to produce a more effective risk evaluation and consideration of the risks and benefits associated with the use of chemicals.

[Incidental finding: elevated TSH level]

The use of thyroid-stimulating hormone (TSH) testing in routine laboratory screening and testing of TSH before administration of contrast medium, resulted in an increased number of incidentally detected elevated TSH levels. In the case of slightly increased values in asymptomatic patients, repeated measurement of TSH is recommended for confirmation. Confirmed elevated TSH levels should lead to additional measurements of the peripheral thyroid hormones, determination of thyroid autoantibodies and performance of thyroid gland ultrasound examination. The most common reasons for acquired subclinical and overt hypothyroidism are autoimmune diseases of the thyroid gland and in many cases substitution therapy with levothyroxine is then necessary. In subclinical hypothyroidism it remains unclear at which TSH levels the initiation of substitution therapy makes sense. In the case of simultaneously elevated peripheral thyroid hormones rare diseases, such as secondary hyperthyroidism and thyroid hormone resistance should be considered.

Caloric restriction increases serum testosterone concentrations in obese male subjects by two distinct mechanisms

The concentration of serum testosterone is mainly regulated by the testicular function, which is under control of the central hypothalamic-pituitary-gonadal axis. A certain amount of testosterone is converted into β-estradiol by adipose tissue. Obesity in men is often associated with decreased androgen levels. The aim of the present study was to examine the effect of caloric restriction on serum testosterone levels in obese men. Dietary intervention study was performed with a very low calorie diet (800 kcal/d) for 12 weeks. Thirteen obese human male subjects (median body mass index: 42.7 kg/m2) were included. Body composition was assessed by impedance analysis. Insulin sensitivity was estimated by leptin-to-adiponectin ratio (LAR). Testosterone (T), β-estradiol, albumin, sex hormone-binding globulin (SHBG), LH, and FSH serum concentrations were measured by enzyme immunoassays. Statistical analysis was performed on baseline and values after 3 months. Caloric restriction significantly increased total testosterone (6.97 nmol/l to 13.21 nmol/l; p=0.001) and SHBG (22.11 nmol/l to 42.12 nmol/l; p=0.001) concentrations in serum. This is caused by a significant improvement of the testicular function (LH/T: 0.36-0.20; p=0.005) and a significant reduction of the T/β-estradiol conversion rate (73.59-104.29; p=0.003). There was a significant negative correlation of improvement of testicular function and LAR (rs=-0.683 (p=0.042)). In obese men caloric restriction significantly increases the serum testosterone concentration. This is achieved by 2 distinct mechanisms, that is, improvement of testicular function and reduced conversion of testosterone to β-estradiol by aromatase activity of the adipose tissue.

Perspectives for integrating human and environmental risk assessment and synergies with socio-economic analysis

For more than a decade, the integration of human and environmental risk assessment (RA) has become an attractive vision. At the same time, existing European regulations of chemical substances such as REACH (EC Regulation No. 1907/2006), the Plant Protection Products Regulation (EC regulation 1107/2009) and Biocide Regulation (EC Regulation 528/2012) continue to ask for sector-specific RAs, each of which have their individual information requirements regarding exposure and hazard data, and also use different methodologies for the ultimate risk quantification. In response to this difference between the vision for integration and the current scientific and regulatory practice, the present paper outlines five medium-term opportunities for integrating human and environmental RA, followed by detailed discussions of the associated major components and their state of the art. Current hazard assessment approaches are analyzed in terms of data availability and quality, and covering non-test tools, the integrated testing strategy (ITS) approach, the adverse outcome pathway (AOP) concept, methods for assessing uncertainty, and the issue of explicitly treating mixture toxicity. With respect to exposure, opportunities for integrating exposure assessment are discussed, taking into account the uncertainty, standardization and validation of exposure modeling as well as the availability of exposure data. A further focus is on ways to complement RA by a socio-economic assessment (SEA) in order to better inform about risk management options. In this way, the present analysis, developed as part of the EU FP7 project HEROIC, may contribute to paving the way for integrating, where useful and possible, human and environmental RA in a manner suitable for its coupling with SEA.

Calcitonin screening in patients with thyroid nodules. Diagnostic value

AIM

The positive predictive value (PPV) of a slightly elevated basal calcitonin (CT) for the diagnosis of medullary thyroid cancer (MTC) is still under debate.

PATIENTS, METHODS

A total of 11270 patients with thyroid nodules underwent calcitonin screening. Patients with known elevation of CT, renal insufficiency, bacterial infection, alcohol abuse, proton-pump inhibitor therapy or autoimmune thyroid disease were excluded from further analysis. Serum CT was determined by the solid-phase, enzyme-labeled, two-site chemiluminescent immunoassay Immulite 2000. If possible, a pentagastrin test was done to differentiate cases of hypercalcitoninaemia.

RESULTS

Hypercalcitoninsemia was found in 32 patients. 20 patients underwent surgery. In 10 patients a MTC was found. The PPV of hypercalcitoninaemia for MTC was 31%. The PPV increased to 50% for those patients who underwent surgery (10/20). A subgroup of 26 patients presented with basal CT between 13 and 50 pg/ml, 14 of them underwent surgery, in 4 cases evidence of MTC was revealed. This resulted in a PPV of 15% (4/26), although the value increased to 28% when only surgically treated patients were considered (4/14).

CONCLUSION

Taking all clinical data into account, calcitonin screening has an acceptable PPV for medullary thyroid cancer in patients with thyroid nodules. Therefore, we recommend calcitonin screening in centers for thyroid disorders.

Weight loss due to a very low calorie diet differentially affects insulin sensitivity and interleukin-6 serum levels in nondiabetic obese human subjects

Inflammatory mechanisms are involved in the pathogenesis of type 2 diabetes with interleukin (IL)-6 being particularly important. While long term exercise has been shown to be associated with reduction in IL-6 serum levels in several reports, the discussion on the effect of dietary intervention on IL-6 serum levels is controversial. In the present study, we aimed to investigate the effect of weight loss due to a very low calorie diet (VLCD) on insulin sensitivity and IL-6 serum levels in nondiabetic obese human individuals. 10 patients with obesity were examined during 12 weeks of a VLCD (800 kcal/d). Body composition was measured by impedance analysis. Blood samples were taken before, during, and after the dietary intervention. Leptin, adiponectin, and IL-6 serum levels were measured by ELISA. The body weight decreased significantly from 123.9±6.2-103.5±5.6 kg with a significant reduction in body fat content (43.2±2.3-36.1±3.1%). Leptin levels exhibited a significant decrease from 56.8±5.6-27.9±5.6 ng/ml while adiponectin levels increased significantly from 7.5±0.9-10.6±1.1 μg/ml. Thereby the leptin-to-adiponectin ratio, a novel marker for insulin sensitivity, significantly improved. Mean IL-6 serum concentrations were within the normal range (3.2±0.8 pg/ml) before the study and were not significantly altered by the nutritional therapy. Despite improvement of insulin sensitivity, IL-6 serum levels did not change throughout the study period, suggesting that in nondiabetic obese human subjects IL-6 might have only a minor role in the impairment of insulin sensitivity.

[Effect of various compositions of riboflavin eye drops on the intraoperative corneal thickness during UVA-cross-linking in keratoconus eyes]

BACKGROUND

During the UVA-cross-linking treatment in keratoconus patients, the UVA rays are partially absorbed in the stroma of the riboflavin-loaded cornea. This effect protects the corneal endothelium from UVA irradiation damage. The intensity of UVA light reaching the endothelium is inversely correlated with corneal thickness. The common composition of riboflavin eye drops may lead to a marked reduction in corneal thickness increasing the risk of endothelial damage.

PATIENTS AND METHODS

In a retrospective analysis of 23 UVA-cross-linking procedures on 23 patients we collected data about the pre-, intra- and postoperative corneal thickness (measured with ultrasound). Among these patients and depending on the preoperative state, 8 eyes received Medio Cross (TM) eye drops (group 1), 8 eyes received Medio Cross (TM) eye drops combined with riboflavin 0.1 %/methylhydroxypropylcellulose 1,5 %/NaCl 1.1 % (group 2) and 7 eyes received riboflavin 0.2 %/methylhydroxypropylcellulose 0.5 %/NaCl 0.7 % eye drops (group 3) before and during UVA irradiation. Data are presented as means ± standard deviation. A comparison of the data was performed using (one-way) ANOVA.

RESULTS

The mean corneal thickness at the end of the UVA cross-linking procedure was 67 ± 9 % (means ± standard deviation) of preoperative thickness in group 1, 118 ± 14 % in group 2 and 140 ± 23 % in group 3. The values in groups 2 and 3 were significantly different from those in the reference group 1.

CONCLUSIONS

Our results show a strong variability of the postoperative corneal thickness using different standard compositions of riboflavin eye drops. Further studies are needed to find a composition of riboflavin eye drops ensuring a moderate increase in intraoperative corneal thickness to protect the corneal endothelium.

Growth hormone deficient patients after traumatic brain injury--baseline characteristics and benefits after growth hormone replacement--an analysis of the German KIMS database

OBJECTIVE

In recent years, traumatic brain injury (TBI) has been identified as a significant cause of growth hormone deficiency (GHD). The aim of the present study was to characterize adult TBI patients with GHD to elucidate the effect of human growth hormone (hGH) replacement in TBI patients as documented in the German Pfizer International Metabolic (KIMS) database.

DESIGN

As of October 2006, 84 TBI patients had been included in the German KIMS database (n=28 childhood-onset and 54 adult-onset GHD). All 84 TBI patients were matched with 84 patients with GHD due to non-functioning pituitary adenoma (NFPA) also included in this database. Analysis of clinical and outcome variables was performed, with comparisons of childhood vs. adult TBI, and TBI vs. NFPA patients, at baseline and one-year follow-up.

RESULTS

TBI patients with GHD were significantly younger at the onset of pituitary disease and exhibited a significantly longer time span between GHD diagnosis and KIMS entry than NFPA patients. Those KIMS patients who had sustained their TBI in childhood were of significantly shorter stature than adult-onset TBI patients. At 1-year follow-up, insulin-like growth factor I (IGF-I) standard deviation score levels had returned to the normal range and quality of life (QoL), as measured by QoL- Assessment of Growth Hormone Deficiency in Adults (AGHDA) questionnaire, improved significantly in TBI as in NFPA patients.

CONCLUSION

This analysis provides preliminary data that TBI patients with GHD benefit from hGH replacement in terms of improved QoL in a similar fashion as do NFPA patients. Moreover, it suggests that belated diagnosis and treatment in childhood-onset GHD due to TBI might be related to a shorter final height in these children.

Right hemisphere sensitivity to novel metaphoric relations: application of the signal detection theory

The present study used the signal detection theory to test the hypothesis that the right hemisphere (RH) is more sensitive than the left hemisphere (LH) to the distant semantic relations in novel metaphoric expressions. In two divided visual field experiments, sensitivity (d') and criterion (beta) were calculated for responses to different types of word pairs. In the first experiment, subjects were presented with unfamiliar two-word novel metaphoric expressions ("signal") and unrelated word-pairs ("noise"). In the second experiment, literal expressions ("signal") and unrelated word pairs ("noise") were presented. In line with the Coarse Semantic Coding Theory [Beeman, M. (1998). Coarse semantic coding and discourse comprehension. In: M. Beeman & C. Chiarello (Eds.). Right hemisphere language comprehension: Perspectives from cognitive neuroscience. Mahwah, NJ: Erlbaum, pp. 255-284.] as well as with the Graded Salience Hypothesis [Giora, R. (2003). On our mind: Salience, context and figurative language. New York: Oxford University Press.], the findings suggest that the RH is more sensitive than the LH to unfamiliar metaphoric relations. Furthermore, this RH advantage in processing distant semantic relations did not extend to familiar semantic relations.

99mTc-MIBI SPECT in primary hyperparathyroidism. Influence of concomitant vitamin D deficiency for visualization of parathyroid adenomas

AIM of the study was to analyse the influence of a concomitant vitamin D deficiency on the results of (99m)Tc-MIBI studies in patients (pts) with primary hyperparathyroidism (pHPT).

PATIENTS, METHODS

Between January 1998 and May 2004, 71 pts with pHPT had undergone operation after a (99m)Tc-MIBI study of whom 54 pts (76%) had normal values of 25-OH-vitamin D3 and 17 pts (24%) had vitamin D deficiency. Results of a dual-phase (99m)Tc-MIBI protocol with SPECT were compared with histopathology.

RESULTS

In 54 pts with normal vitamin D values late SPECT images identified more lesions (n=51, sensitivity 91%) than early planar (n=45, sensitivity 82%) or late planar images (n=50, sensitivity 88%). In 17 pts with vitamin D deficiency late SPECT images identified more lesions (n=13, sensitivity 72%) than early planar (n=10, sensitivity 56%) or late planar images (n=10, sensitivity 56%) too. In pts with vitamin D deficiency the sensitivity of a (99m)Tc-MIBI SPECT study was lower than in those with normal vitamin D status (72% vs. 91%) and dependent on the value for PTH. However, the results did not reach statistical significance: early planar: p=0.1625; late planar: p=0.0039; (99m)Tc-MIBI SPECT: p=0.1180.

CONCLUSION

The likelihood of a pathological (99m)Tc-MIBI study being obtained in pts with pHPT is dependent on the parathyroid hormone level. However, a negative influence of a low vitamin D level on the scintigraphic detection rate of a parathyroid adenoma could not be proven which may be due to the low number of pts with vitamin D deficiency.

CT of jejunal diverticulitis: imaging findings, differential diagnosis, and clinical management

AIM

To describe the imaging findings of jejunal diverticulitis as depicted at contrast-enhanced computed tomography (CT) and review the differential diagnosis and clinical management.

MATERIALS AND METHODS

CT and pathology databases were searched for the diagnosis of jejunal diverticulitis. Three cases were identified and the imaging and clinical findings correlated.

RESULTS

Jejunal diverticulitis presents as a focal inflammatory mass involving the proximal small bowel. A trial of medical management with antibiotics may be attempted. Surgical resection may be required if medical management is unsuccessful.

CONCLUSION

The imaging findings at MDCT may allow a specific diagnosis of jejunal diverticulitis to be considered and may affect the clinical management of the patient.

An fMRI investigation of the neural correlates underlying the processing of novel metaphoric expressions

The neural networks associated with processing related pairs of words forming literal, novel, and conventional metaphorical expressions and unrelated pairs of words were studied in a group of 15 normal adults using fMRI. Subjects read the four types of linguistic expressions and decided which relation exists between the two words (metaphoric, literal, or unrelated). According to the Graded Salience Hypothesis (GSH, ), which predicts a selective RH involvement in the processing of novel, nonsalient meanings, it is primarily the degree of meaning salience of a linguistic expression rather than literality or nonliterality, which modulates the degree of left hemisphere (LH) and right hemisphere (RH) processing of metaphors. In the present study, novel metaphorical expressions represented the nonsalient interpretations, whereas conventional metaphors and literal expressions represented the salient interpretations. A direct comparison of the novel metaphors vs. the conventional metaphors revealed significantly stronger activity in right posterior superior temporal sulcus, right inferior frontal gyrus, and left middle frontal gyrus. These results support the GSH and suggest a special role for the RH in processing novel metaphors. Furthermore, the right PSTS may be selectively involved in verbal creativity.

Sequential processing deficits of reading disabled persons is independent of inter-stimulus interval

Developmental dyslexia is a language-based learning disability with frequently associated non-linguistic sensory deficits that have been the basis of various perception-based theories. It remains an open question whether the underlying deficit in dyslexia is a low level impairment that causes speech and orthographic perception deficits that in turn impedes higher phonological and reading processes, or a high level impairment that affects both perceptual and reading related skills. We investigated by means of contrast detection thresholds two low-level theories of developmental dyslexia, the magnocellular and the fast temporal processing hypotheses, as well as a more recent suggestion that dyslexics have difficulties in sequential comparison tasks that can be attributed to a higher-order deficit. It was found that dyslexics had significantly higher thresholds only on a sequential, but not a spatial, detection task, and that this impairment was found to be independent of the inter-stimulus interval. We also found that the poor performance of dyslexics on the temporal task was dependent on the size of the required memory trace of the image rather than on the number of images. Our findings do not support the magnocellular theory and challenge the fast temporal deficit hypothesis. We suggest that dyslexics may have a higher order, dual mechanism impairment. We also discuss the clinical implications of our findings.

The role of the right cerebral hemisphere in processing novel metaphoric expressions taken from poetry: a divided visual field study

Previous research suggests that the right hemisphere (RH) may contribute uniquely to the processing of metaphoric language. However, most studies have focused on familiar metaphoric expressions. The present study used the divided visual field paradigm to examine the role of the right cerebral hemisphere in processing novel metaphoric expressions taken from poetry. In two experiments, participants were presented with four types of word pairs, literal, conventional metaphoric and novel metaphoric expressions and unrelated word pairs, and asked to perform a semantic judgment task. Two different SOAs: 400 and 1100 ms were used. The results of both experiments showed that responses to LVF/RH presented target words were more accurate and faster than responses to RVF/LH target words for novel metaphoric expressions, but not for other types of word pairs. These results support previous research indicating that during word recognition, the RH activates a broader range of related meanings than the LH, including novel, nonsalient meanings. The findings thus suggest that the RH may be critically involved in at least one important component of novel metaphor comprehension, i.e., the integration of the individual meanings of two seemingly unrelated concepts into a meaningful metaphoric expression.

The K121Q polymorphism of the plasma cell glycoprotein-1 gene is not associated with diabetes mellitus type 2 in German Caucasians

The K121Q polymorphism of the human plasma cell membrane glycoprotein 1 (PC-1) gene is known to be associated with diabetes mellitus type 2 in some populations studied, with contradictory results. The purpose of the present study was to examine a possible association between the presence of diabetes and the PC-1 K121Q polymorphism in a German Caucasian population. Associations between the polymorphism and various metabolic and anthropometric parameters were also examined. The presence of the K121Q variant was investigated using polymerase chain reaction restriction fragment-length polymorphism in 402 subjects with diabetes (231 men, 171 women, age 63+/-11 yrs, body mass index 28.7+/-5.1 kg/m2) and in 432 age- and sex-matched controls (247 men, 185 women, age 64+/-7 yrs, BMI 26.5+/-3.7 kg/m2). Ninety-seven subjects were carriers of the K121Q polymorphism in the control and 110 in the diabetic group (allelic frequency 11.9% and 14.7%, respectively, P=0.25). The polymorphism had no significant influence on the presence of atherosclerotic disease, body mass index, and blood pressure, both, in diabetics and in non-diabetic controls. Our data suggest that the K121Q polymorphism of the PC-1 gene is not associated with diabetes, obesity, hypertension or atherosclerosis in a German Caucasian population.

Association of the promoter polymorphism -232C/G of the phosphoenolpyruvate carboxykinase gene (PCK1) with Type 2 diabetes mellitus

AIMS

The phosphoenolpyruvate carboxykinase gene (PCK1) is a potential candidate gene in the pathogenesis of Type 2 diabetes mellitus. A -232C/G promoter polymorphism of PCK1 has been associated with an increased risk of Type 2 diabetes in a Canadian population. The purpose of the present study was to examine this association in a German Caucasian population.

METHODS

We investigated 397 subjects with Type 2 diabetes [227 men, 170 women, age 63 +/- 11 years, body mass index (BMI) 28.7 +/- 5.1 kg/m2] and 431 control subjects without diabetes (247 men, 184 women, age 64 +/- 7 years, BMI 26.5 +/- 3.7 kg/m2) matched for sex and age.

RESULTS

In the diabetic and control groups, the CC genotype frequencies were 18.1 and 18.3%, the CG 48.6 and 48.7% and the GG 33.2 and 32.9%, respectively (P = 0.995). The allelic frequencies were 0.51 and 0.57 for the G allele and 0.49 and 0.43 for the C allele, respectively. In a logistic regression model only BMI and family history, but not the polymorphism, were predictors of Type 2 diabetes. In both the control and diabetic subjects, there were no significant differences in BMI or blood pressure between the groups with or without the polymorphism. The variant also had no significant influence on the presence of atherosclerotic disease, while the influence of other known cardiovascular risk factors was confirmed.

CONCLUSIONS

The present data suggest that, in a German Caucasian population, the -232C/G polymorphism of the PEPCK gene is not associated with Type 2 diabetes.