Late recurrences of pancreatic cancer in patients with long-term survival after pancreaticoduodenectomy

BackgroundPancreatic cancer remains a relevant clinical problem due to poor prognosis. Even after curative pancreaticoduodenectomy tumor recurrences occur in up to 80%. Risk factors for postoperative tumor recurrences have been identified before, but data on risk factors for tumor recurrences in patients with long-term-survival is scarce.MethodsIn this retrospective study consecutive long-term survival-patients (defined as at least 60 months survival) undergoing pancreaticoduodenectomy for pancreatic cancer from 2007–2014 were identified in the 2nd largest pancreatic surgery center in Germany. Clinical, pathohistological and laboratory values were analyzed to identify risk factors for tumor recurrence.ResultsThirty-four of one-hundred-sixty-seven patients were identified as long-term-survival-patients in the study period. Of those, 10 patients (29.4%) suffered from tumor recurrence. Lymph vessel invasion was identified as an independent risk factor (P=0.031, hazard ratio 13.127, 95% confidence interval: 1.270–135.698). Median postoperative time to tumor recurrence in long-term-survival-patients was 49 months. Overall survival after diagnosis of tumor recurrence was 33 months. 80% (N=8) of the patients were asymptomatic. Half of the patients (N=5) suffered from local disease, with 40% undergoing curative tumor resection. CA 19-9 levels were significantly elevated at 57 U/mL (normal <27 U/mL).ConclusionsTumor recurrence in long-term-survival-patients is typically asymptomatic. Especially long-term-survival-patients with lymph vessel invasion are more likely to develop tumor recurrence. Therefore, a structured follow-up program including CT-scans and CA 19-9 surveillance must be continued in all patients undergoing pancreaticoduodenectomy even in cases of long-term-survival.     

Risk factors and etiology of childhood hearing loss: a cohort review of 296 subjects

Abstract

Background: The association between the Joint Committee on Infant Hearing (JCIH) risk factors and etiology of hearing loss (HL) is not studied well in children.

Objectives: To clarify the etiologic causes and evaluate the JCIH risk characteristics of children with HL.

Methods: A retrospective study of 296 children with HL born between 2009.01 and 2013.12 in Stokholm. Demographic data, family and medical histories, audiologic results, imaging findings, and genetic results were ascertained and analyzed.

Results: In 221 with bilateral hearing loss (BHL), family history and neonatal risk indicators were the most common risks (59 each), followed by syndrome related risks. In 75 with unilateral hearing loss (UHL), craniofacial anomaly was the most common risk, followed by family history. Etiology was established in 93 with BHL, in which syndromic HL accounted for 37.2%, chromosomal aberrations for 21.3%, and environmental causes for 19.1%. Etiology was established in 35 with UHL, in which ear malformation accounted for the most (74.3%), followed by environmental causes (14.3%).

Conclusions and significance: Childhood HL can be attributed to a variety of causes with an etiology identifiable in 42.5% of BHL and 46.7% of UHL. BHL and UHL have different patterns of JCIH risk exposure and etiology.     

Visual pathways in the brain of the jumping spider Marpissa muscosa

Some animals have evolved task differentiation among their eyes. A particular example is spiders, where most species have eight eyes, of which two (the principal eyes) are used for object discrimination, whereas the other three pairs (secondary eyes) detect movement. In the ctenid spider Cupiennius salei, these two eye types correspond to two visual pathways in the brain. Each eye is associated with its own first- and second-order visual neuropil. The second-order neuropils of the principal eyes are connected to the arcuate body, whereas the second-order neuropils of the secondary eyes are linked to the mushroom body. We explored the principal- and secondary eye visual pathways of the jumping spider Marpissa muscosa, in which size and visual fields of the two eye types are considerably different. We found that the connectivity of the principal eye pathway is the same as in C. salei, while there are differences in the secondary eye pathways. In M. muscosa, all secondary eyes are connected to their own first-order visual neuropils. The first-order visual neuropils of the anterior lateral and posterior lateral eyes are connected with a second-order visual neuropil each and an additional shared one (L2). In the posterior median eyes, the axons of their first-order visual neuropils project directly to the arcuate body, suggesting that the posterior median eyes do not detect movement. The L2 might function as an upstream integration center enabling faster movement decisions.     

Influence of heat from light curing units and dental composite polymerization on cells in vitro

OBJECTIVES: The aim of the present study was to test the hypothesis that the use of a light curing unit (LCU) with high light power would result in a higher temperature and therefore a statistically significant lower number of living human gingiva fibroblasts within a pulp chamber model than the use of a light emitting diode (LED) LCU. MATERIALS AND METHODS: The composites Admira, Grandio, Filtek Supreme and Filtek Z250 were polymerized with the LCUs Swiss Master Light, Optilux 501 and an LED LCU prototype in a mould on top of a pulp chamber model. The temperature was recorded within the pulp chamber with a thermocouple. The cytotoxicity of the polymerized samples was tested by using the MTT test. RESULTS: In general there was no considerable difference in the temperature increase within the pulp chamber model for the different LCUs and composites. There was no statistically significant difference in the cell number (p=0.3767) when the different LCUs were used. CONCLUSIONS: Using a high power halogen LCU for a short time or a standard halogen or LED LCU for a longer time did not result in a considerable difference in the temperature increase or the number of living cells within a pulp chamber model. This study indicates not only that the temperature may have an effect on the living cells, but also that cells may be negatively affected by the unpolymerized composite or light of the LCUs.     

Time dependence of composite shrinkage using halogen and LED light curing.

OBJECTIVES: The polymerization shrinkage of light cured dental composites presents the major drawback for these aesthetically adaptable restorative materials. LED based light curing technology has recently become commercially available. Therefore, the aim of the present study was to investigate if there was a statistically significant difference in linear and volumetric composite shrinkage strain if a LED LCU is used for the light curing process rather than a conventional halogen LCU. METHODS: The volumetric shrinkage strain was determined using the Archimedes buoyancy principle after 5, 10, 20, 40 s of light curing and after 120 s following the 40 s light curing time period. The linear shrinkage strain was determined with a dynamic mechanical analyzer for the composites Z100, Spectrum, Solitaire2 and Definite polymerized with the LCUs Trilight (halogen), Freelight I (LED) and LED63 (LED LCU prototype). The changes in irradiance and spectra of the LCUs were measured after 0, 312 and 360 min of duty time. RESULTS: In general there was no considerable difference in shrinkage of the composites Z100, Spectrum or Solitaire2 when the LED63 was used instead of the Trilight. There was, however, a statistically significant difference in shrinkage strain when the composite Definite was polymerized with the LED63 instead of the Trilight. The spectrum of the Trilight changed during the experiment considerably whereas the LED63 showed an almost constant light output. The Freelight I dropped considerably in irradiance and had to be withdrawn from the study because of technical problems. SIGNIFICANCE: The composites containing only the photoinitiator camphorquinone showed similar shrinkage strain behaviour when a LED or halogen LCU is used for the polymerization. The irradiance of some LED LCUs can also decrease over time and should therefore be checked on a regular basis.     

The influence of storage and indenter load on the Knoop hardness of dental composites polymerized with LED and halogen technologies.

OBJECTIVES: The mechanical properties of light cured dental composites are greatly influenced by the light curing unit (LCU) used for the polymerization. Previous studies have shown that for some composites lower mechanical properties were obtained if light emitting diode (LED) LCUs were used for the polymerization instead of halogen LCUs. Previous studies have also shown that light cured composites improve their mechanical properties through a post-curing process after the initial illumination with the LCUs. Therefore, this study investigated the post-curing process, to ascertain if it can compensate for the lower mechanical properties of composites polymerized with LED LCUs. METHODS: The Knoop hardness was measured for four dental composites (Z100, Spectrum, Definite, Solitaire2) polymerized with an LED LCU (LED63 prototype) or a halogen LCU (Trilight), directly after the curing process and after 5 days of storage. In addition, the load on the indenter was varied from 200 to 400 gf to investigate the influence of the load on the measured hardness on the top and bottom of the 2 mm thick samples. RESULTS: In general the Knoop hardness at the bottom of the stored samples, cured with the LED LCU, was the same or statistically significantly greater than for the samples cured with the halogen LCU. A statistically significantly lower (p<0.0001) Knoop hardness was obtained on the top of the samples if the composite Definite was polymerized with the LED LCU instead of the halogen LCU. The load of 200 or 400 gf on the indenter had a statistically significant influence (p<0.0001) on the measured Knoop hardness for the composite Z100. The Knoop hardness measured with an indenter load of 400 gf increased statistically significantly (p<0.0001) for all composites after the 5 days' storage, whether cured with the LED LCU or halogen LCU. SIGNIFICANCE: The post-curing effect cannot compensate for the lower hardness of composites containing co-initiators if polymerized with an LED LCU instead of a halogen LCU. The indenter load had a statistically significant influence on the measured Knoop hardness of composites and has the potential to falsify results if not selected carefully.     

Do infections provoke exacerbations and relapses of thrombotic thrombocytopenic purpura?

Several case reports have suggested an association between infections and thrombotic thrombocytopenic purpura (TTP). In Case 1, a 37-year-old female presented with TTP 6 times over 7 years, requiring 242 therapeutic plasma exchanges (TPE), for a per-course range of 4-57 TPE (median 48), and treatment durations of 4-241 days (median 71 days), largely on account of multiple exacerbations (range 0-3, median 3). Twelve of 17 (71%) of her presentations or exacerbations were associated with suspected infections, with confirmation in 9 episodes. These included pulmonary TB, CMV pneumonitis, mucocutaneous HSV, ventilator-associated or urinary tract-associated gram-negative sepsis, central line-associated staphylococcal bacteremia, and cellulitis. Except for TB, all infections occurred after splenectomy, which had been performed on day 33 of presentation 1. In Case 2, a 24-year-old female presented with TTP 3 times over 15 months. Her courses were managed with brief courses of TPE (5-11 treatments per course, median 5). Suppressed ADAMTS13 levels due to inhibitors were confirmed twice. Presentation 1 was antedated by atypical community acquired pneumonia. Presentation 3 (and possibly 2) followed prolonged, progressive, antibiotic-refractory periodontal infections ultimately requiring exodontic surgery. Our cases add to a literature that suggests that infection may be associated with exacerbations or relapses of TTP in some patients. Our patients demonstrated repeated TTP exacerbations in association with different infectious agents. A better understanding of the possible relationship between infection and clinical expression of TTP might lead to improved treatment decisions for patients with this complex illness.     

Analysis of signal processing in vestibular circuits with a novel light‐emitting diodes‐based fluorescence microscope

Optical visualization of neural network activity is limited by imaging system‐dependent technical tradeoffs. To overcome these constraints, we have developed a powerful low‐cost and flexible imaging system with high spectral variability and unique spatio‐temporal precision for simultaneous optical recording and manipulation of neural activity of large cell groups. The system comprises eight high‐power light‐emitting diodes, a camera with a large metal‐oxide‐semiconductor sensor and a high numerical aperture water‐dipping objective. It allows fast and precise control of excitation and simultaneous low noise imaging at high resolution. Adjustable apertures generated two independent areas of variable size and position for simultaneous optical activation and image capture. The experimental applicability of this system was explored in semi‐isolated preparations of larval axolotl (Ambystoma mexicanum) with intact inner ear organs and central nervous circuits. Cyclic galvanic stimulation of semicircular canals together with glutamate‐ and γ‐aminobutyric acid (GABA)‐uncaging caused a corresponding modulation of Ca²⁺ transients in central vestibular neurons. These experiments revealed specific cellular properties as well as synaptic interactions between excitatory and inhibitory inputs, responsible for spatio‐temporal‐specific sensory signal processing. Location‐specific GABA‐uncaging revealed a potent inhibitory shunt of vestibular nerve afferent input in the predominating population of tonic vestibular neurons, indicating a considerable impact of local and commissural inhibitory circuits on the processing of head/body motion‐related signals. The discovery of these previously unknown properties of vestibular computations demonstrates the merits of our novel microscope system for experimental applications in the field of neurobiology.