Health and environmental effects to wildlife from radio telemetry and tracking devices-state of the science and best management practices

This paper discusses the potential health risks and benefits to tagged wildlife from the use of radio tracking, radio telemetry, and related microchip and data-logger technologies used to study, monitor and track mostly wildlife in their native habitats. Domestic pets, especially canids, are briefly discussed as radio-tagging devices are also used on/in them. Radio tracking uses very high frequency (VHF), ultra-high frequency (UHF), and global positioning system (GPS) technologies, including via satellites where platform terminal transmitters (PTTs) are used, as well as geo-locating capabilities using satellites, radio-frequency identification (RFID) chips, and passive integrated responder (PIT) tags, among others. Such tracking technologies have resulted in cutting-edge findings worldwide that have served to protect and better understand the behaviors of myriad wildlife species. As a result, scientists, field researchers, technicians, fish and wildlife biologists and managers, plus wildlife and other veterinarian specialists, frequently opt for its use without fully understanding the ramifications to target species and their behaviors. These include negative physiological effects from electromagnetic fields (EMF) to which many nonhuman species are exquisitely sensitive, as well as direct placement/use-attachment impacts from radio collars, transmitters, and implants themselves. This paper provides pertinent studies, suggests best management practices, and compares technologies currently available to those considering and/or using such technologies. The primary focus is on the health and environmental risk/benefit decisions that should come into play, including ethical considerations, along with recommendations for more caution in the wildlife and veterinarian communities before such technologies are used in the first place.

[Interpretation of the Implant Dentistry Core Outcome Set and Measurement international consensus report]

Selection and measurement of clinical outcome are key components of clinical research in implant dentistry. Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine took the lead and collaborated with multiple internationally renowned colleges of stomatology to develop an international consensus on the core outcome set and measurement in implant dentistry, which took two years and was published in May, 2023 in Journal of Clinical Periodontology and Clinical Oral Implants Research simultaneously. The consensus, aiming at identifying the full spectrum of benefits and harms of interventions, provides a comprehensive, agreed, and standardized set of outcomes that should be measured and reported as a minimum in clinical trials relating with implant dentistry, bone augmentation, and soft tissue augmentation. The present review describes the methodology and key elements of the consensus to help Chinese clinical researchers fully understand and appropriately apply the core outcome set and improve the overall quality of Chinese clinical research in implant dentistry.

Performance of neuroretinal rim thickness measurement by Cirrus high-definition optical coherence tomography in myopic eyes

Neuroretinal rim (NRR) measurement can aid the diagnosis of glaucoma. A few studies reported that Cirrus optical coherence tomography (OCT) had NRR segmentation errors. The current study investigated segmentation success of NRR in myopic eyes using the Cirrus built-in software and to determine the number of acquisitions required to identify NRR thinning. Right eye of 87 healthy adult myopes had an optic disc scanned using Cirrus HD-OCT for five successive acquisitions. A masked examiner evaluated 36 radial line images of each scan to screen for segmentation errors using the built-in software at the Bruch's membrane opening (BMO) and/or internal limiting membrane (ILM). Participants with three accurate NRR acquisitions had their average NRR thickness determined. This result was compared with average of the two acquisitions and the first acquisition. Among 435 OCT scans of the optic disc (87 eyes × 5 acquisitions), 129 (29.7%) scans had segmentation errors that occurred mainly at the ILM. The inferior-temporal and superior meridians had slightly more segmentation errors than other meridians, independent of axial length, amount of myopia, or presence of peripapillary atrophy. Sixty-five eyes (74.7%) had at least three accurate NRR measurements. The three acquisitions had high reliability in NRR thickness in the four quadrants (intraclass correlation coefficient > 0.990, coefficient of variation < 3.9%). NRR difference between the first acquisition and the average of three acquisitions was small (mean difference 2 ± 13 μm, 95% limits of agreement within ± 30 μm) among the four quadrants. Segmentation errors in NRR measurements appeared regardless of axial length, amount of myopia, or presence of peripapillary atrophy. Cirrus segmentation lines should be manually inspected when measuring NRR thickness.

Effects of non-ionizing electromagnetic fields on flora and fauna, Part 3. Exposure standards, public policy, laws, and future directions

Due to the continuous rising ambient levels of nonionizing electromagnetic fields (EMFs) used in modern societies-primarily from wireless technologies-that have now become a ubiquitous biologically active environmental pollutant, a new vision on how to regulate such exposures for non-human species at the ecosystem level is needed. Government standards adopted for human exposures are examined for applicability to wildlife. Existing environmental laws, such as the National Environmental Policy Act and the Migratory Bird Treaty Act in the U.S. and others used in Canada and throughout Europe, should be strengthened and enforced. New laws should be written to accommodate the ever-increasing EMF exposures. Radiofrequency radiation exposure standards that have been adopted by worldwide agencies and governments warrant more stringent controls given the new and unusual signaling characteristics used in 5G technology. No such standards take wildlife into consideration. Many species of flora and fauna, because of distinctive physiologies, have been found sensitive to exogenous EMF in ways that surpass human reactivity. Such exposures may now be capable of affecting endogenous bioelectric states in some species. Numerous studies across all frequencies and taxa indicate that low-level EMF exposures have numerous adverse effects, including on orientation, migration, food finding, reproduction, mating, nest and den building, territorial maintenance, defense, vitality, longevity, and survivorship. Cyto- and geno-toxic effects have long been observed. It is time to recognize ambient EMF as a novel form of pollution and develop rules at regulatory agencies that designate air as 'habitat' so EMF can be regulated like other pollutants. Wildlife loss is often unseen and undocumented until tipping points are reached. A robust dialog regarding technology's high-impact role in the nascent field of electroecology needs to commence. Long-term chronic low-level EMF exposure standards should be set accordingly for wildlife, including, but not limited to, the redesign of wireless devices, as well as infrastructure, in order to reduce the rising ambient levels (explored in Part 1). Possible environmental approaches are discussed. This is Part 3 of a three-part series.

Low-level EMF effects on wildlife and plants: What research tells us about an ecosystem approach

There is enough evidence to indicate we may be damaging non-human species at ecosystem and biosphere levels across all taxa from rising background levels of anthropogenic non-ionizing electromagnetic fields (EMF) from 0 Hz to 300 GHz. The focus of this Perspective paper is on the unique physiology of non-human species, their extraordinary sensitivity to both natural and anthropogenic EMF, and the likelihood that artificial EMF in the static, extremely low frequency (ELF) and radiofrequency (RF) ranges of the non-ionizing electromagnetic spectrum are capable at very low intensities of adversely affecting both fauna and flora in all species studied. Any existing exposure standards are for humans only; wildlife is unprotected, including within the safety margins of existing guidelines, which are inappropriate for trans-species sensitivities and different non-human physiology. Mechanistic, genotoxic, and potential ecosystem effects are discussed.

Effects of non-ionizing electromagnetic fields on flora and fauna, Part 2 impacts: how species interact with natural and man-made EMF

Ambient levels of nonionizing electromagnetic fields (EMF) have risen sharply in the last five decades to become a ubiquitous, continuous, biologically active environmental pollutant, even in rural and remote areas. Many species of flora and fauna, because of unique physiologies and habitats, are sensitive to exogenous EMF in ways that surpass human reactivity. This can lead to complex endogenous reactions that are highly variable, largely unseen, and a possible contributing factor in species extinctions, sometimes localized. Non-human magnetoreception mechanisms are explored. Numerous studies across all frequencies and taxa indicate that current low-level anthropogenic EMF can have myriad adverse and synergistic effects, including on orientation and migration, food finding, reproduction, mating, nest and den building, territorial maintenance and defense, and on vitality, longevity and survivorship itself. Effects have been observed in mammals such as bats, cervids, cetaceans, and pinnipeds among others, and on birds, insects, amphibians, reptiles, microbes and many species of flora. Cyto- and geno-toxic effects have long been observed in laboratory research on animal models that can be extrapolated to wildlife. Unusual multi-system mechanisms can come into play with non-human species - including in aquatic environments - that rely on the Earth's natural geomagnetic fields for critical life-sustaining information. Part 2 of this 3-part series includes four online supplement tables of effects seen in animals from both ELF and RFR at vanishingly low intensities. Taken as a whole, this indicates enough information to raise concerns about ambient exposures to nonionizing radiation at ecosystem levels. Wildlife loss is often unseen and undocumented until tipping points are reached. It is time to recognize ambient EMF as a novel form of pollution and develop rules at regulatory agencies that designate air as 'habitat' so EMF can be regulated like other pollutants. Long-term chronic low-level EMF exposure standards, which do not now exist, should be set accordingly for wildlife, and environmental laws should be strictly enforced - a subject explored in Part 3.

Effects of non-ionizing electromagnetic fields on flora and fauna, part 1. Rising ambient EMF levels in the environment

Ambient levels of electromagnetic fields (EMF) have risen sharply in the last 80 years, creating a novel energetic exposure that previously did not exist. Most recent decades have seen exponential increases in nearly all environments, including rural/remote areas and lower atmospheric regions. Because of unique physiologies, some species of flora and fauna are sensitive to exogenous EMF in ways that may surpass human reactivity. There is limited, but comprehensive, baseline data in the U.S. from the 1980s against which to compare significant new surveys from different countries. This now provides broader and more precise data on potential transient and chronic exposures to wildlife and habitats. Biological effects have been seen broadly across all taxa and frequencies at vanishingly low intensities comparable to today's ambient exposures. Broad wildlife effects have been seen on orientation and migration, food finding, reproduction, mating, nest and den building, territorial maintenance and defense, and longevity and survivorship. Cyto- and geno-toxic effects have been observed. The above issues are explored in three consecutive parts: Part 1 questions today's ambient EMF capabilities to adversely affect wildlife, with more urgency regarding 5G technologies. Part 2 explores natural and man-made fields, animal magnetoreception mechanisms, and pertinent studies to all wildlife kingdoms. Part 3 examines current exposure standards, applicable laws, and future directions. It is time to recognize ambient EMF as a novel form of pollution and develop rules at regulatory agencies that designate air as 'habitat' so EMF can be regulated like other pollutants. Wildlife loss is often unseen and undocumented until tipping points are reached. Long-term chronic low-level EMF exposure standards, which do not now exist, should be set accordingly for wildlife, and environmental laws should be strictly enforced.

Host Genetic Associations with Salivary Microbiome in Oral Cancer

Despite the growing recognition of a host genetic effect on shaping gut microbiota composition, the genetic determinants of oral microbiota remain largely unexplored, especially in the context of oral diseases. Here, we performed a microbiome genome-wide association study in 2 independent cohorts of patients with oral squamous cell carcinoma (OSCC, n = 144 and 67) and an additional group of noncancer individuals (n = 104). Besides oral bacterial dysbiosis and signatures observed in OSCC, associations of 3 loci with the abundance of genus-level taxa and 4 loci with β diversity measures were detected (q < 0.05) at the discovery stage. The most significant hit (rs10906082 with the genus Lachnoanaerobaculum, P = 3.55 × 10^-9 at discovery stage) was replicated in a second OSCC cohort. Moreover, the other 2 taxonomical associations, rs10973953 with the genus Kingella (P = 1.38 × 10^-9) and rs4721629 with the genus Parvimonas (P = 3.53 × 10^-8), were suggestive in the meta-analysis combining 2 OSCC cohorts. Further pathway analysis revealed that these loci were enriched for genes in regulation of oncogenic and angiogenic responses, implicating a genetic anchor to the oral microbiome in estimation of casual relationships with OSCC. Our findings delineate the role of host genotypes in influencing the structure of oral microbial communities.

P–522 Cervical secretion methylation profile is associated with the success of frozen-thawed embryo transfer - a proof-of-concept study

Study question

Is cervical secretion gene methylation profile different between receptive and non-receptive endometrium and associated with implantation outcome in frozen-embryo transfer (FET) cycle?

Summary answer

The combination of candidate genes methylation profiles obtained from cervical secretion showed significant associations with pregnancy outcomes.

What is known already

Implantation failure remains a black box in reproductive medicine, and the exact mechanism of how endometrial receptivity is regulated is still unknown. Epigenetic modifications play a role in the gene expression pattern and may alter the endometrial receptivity in the human endometrium. Cervical secretion containing various implantation-related cytokines, and the gene methylation change can be used as a non-invasive molecular source that reflects the endometrium condition.

Study design, size, duration

In this retrospective case-control study, sixty-two women who entered the FET cycle (30 pregnant and 32 non-pregnant women) were enrolled.

Participants/materials, setting, methods

Cervical secretion was collected before embryo transfer from women enrolled in multicenter university-affiliated reproductive units. The DNA methylation status of six candidate genes was measured using quantitative methylation-specific PCR (qMSP). The correlation between methylation change and the pregnancy outcome was analyzed.

Main results and the role of chance

The candidate genes were selected from that associated with implantation with literature review and the original genome-wide DNA methylation data from NCBI GEO DataSets (GSE90060) which processed using bioinformatics analysis. Six candidate genes whose CpG-level methylation analysis with β-value statistically higher in receptive endometrium than in a pre-receptive endometrium were selected. All six candidate genes showed different degrees of correlation with the pregnancy outcomes. Among them, PRKAG2 methylation changes showed the highest correlation with the pregnancy outcome. A logistic regression model was used to evaluate the performance of a single gene or a combination of genes for implantation prediction. The results showed a statistically significant association between the methylation status of a combination of genes (PRKAG2, KRS1, HAND2) and the pregnancy outcome (p = 0.008), resulting in an optimal AUC of 0.7 (95% CI: 0.57 - 0.81) for implantation prediction.

Limitations, reasons for caution

The results obtained from a relatively small cohort size. A larger study and further comprehensive methylome investigations are warranted.

Wider implications of the findings: This study is the first proof-of-concept study that cervical secretion methylation profile is associated with implantation outcome in a FET cycle, and showed potential as a non-invasive method for implantation prediction.

Trial registration number

non applicable

[Prevention and management of hardware and biological complications in implant dentistry]

Due to the highly predictable long-term clinical outcomes, modern implant dentistry has become one of the most preferred treatment modalities for restoring missing teeth. However, the complications of implant therapy compromise the long-term implant success and remain a great challenge to clinicians. Hardware complications include the mechanical complications which are related to the manufacturer-fabricated components of the prosthesis, such as abutment/screw loosening, fracture and implant fracture; and the technical complication which are related to laboratory-fabricated components of the prosthesis, such as veneer chipping. The biological complications mainly include peri-implant mucositis and peri-implantitis. It is crucial to figure out how to effectively avoid and manage the complications of implant therapy. This article reported the definitions, incidences, risk factors, prevention and treatment of both mechanical and biological complications of implant therapy.

Effects of radiation from a radiofrequency identification (RFID) microchip on human cancer cells

PURPOSE

Radiofrequency identification (RFID) microchips are used to remotely identify objects, e.g. an animal in which a chip is implanted. A passive RFID microchip absorbs energy from an external source and emits a radiofrequency identification signal which is then decoded by a detector. In the present study, we investigated the effect of the radiofrequency energy emitted by a RFID microchip on human cancer cells.

MATERIALS AND METHODS

Molt-4 leukemia, BT474 breast cancer, and HepG2 hepatic cancer cells were exposed in vitro to RFID microchip-emitted radiofrequency field for 1 h. Cells were counted before and after exposure. Effects of pretreatment with the spin-trap compound N-tert-butyl-alpha-phenylnitrone or the iron-chelator deferoxamine were also investigated. Results We found that the energy effectively killed/retarded the growth of the three different types of cancer cells, and the effect was blocked by the spin-trap compound or the iron-chelator, whereas an inactive microchip and energy from the external source had no significant effect on the cells. Conclusions Data of the present study suggest that radiofrequency field from the microchip affects cancer cells via the Fenton Reaction. Implantation of RFID microchips in tumors may provide a new method for cancer treatment.

DNA damage in dihydroartemisinin-resistant Molt-4 cells

Artemisinin generates carbon-based free radicals when it reacts with iron, and induces molecular damage and apoptosis. Its toxicity is more selective toward cancer cells because cancer cells contain a higher level of intracellular free iron. Dihydroartemisinin (DHA), an analog of artemisinin, has selective cytotoxicity toward Molt-4 human lymphoblastoid cells. A major concern is whether cancer cells could develop resistance to DHA, thus limiting its therapeutic efficacy. We have developed a DHA-resistant Molt-4 cell line (RTN) and found out that these cells exhibited resistance to DHA but no significant cross- resistance to artemisinin-tagged holotransferrin (ART-TF), a synthetic artemisinin compound. In the present study, we investigated DNA damage induced by DHA and ART-TF in both Molt-4 and RTN cells using the comet assay. RTN cells exhibited a significantly lower level of basal and X-ray-induced DNA damage compared to Molt-4 cells. Both DHA and ART-TF induced DNA damage in Molt-4 cells, whereas DNA damage was induced in RTN cells by ART-TF, and not DHA. The result of this study shows that by the cell selection method, it is possible to generate a Molt-4 cell line which is not sensitive to DHA, but sensitive to ART-TF, as measured by DNA damage.

Development of a dihydroartemisinin-resistant Molt-4 leukemia cell line

Artemisinin generates cytotoxic free radicals when it reacts with iron. Its toxicity is more selective toward cancer cells because cancer cells contain a higher level of intracellular-free iron. We previously reported that dihydroartemisinin (DHA), an active metabolite of artemisinin, has selective cytotoxicity toward Molt-4 human lymphoblastoid cells. A concern is whether cancer cells could develop resistance to DHA after repeated administration, thus limiting its therapeutic efficacy. In the present study, we developed a DHA-resistant Molt-4 cell line (RTN) by exposing Molt-4 cells to gradually increasing concentrations of DHA in vitro. The half-maximal inhibitory concentration (IC50) of DHA for RTN cells is 7.1-times higher than that of Molt-4 cells. RTN cells have a higher growth rate than Molt-4 cells. In addition, we investigated the toxicities of two more potent synthetic artemisinin compounds, artemisinin dimer-alcohol and artemisinin-tagged holotransferrin toward RTN cells; RTN cells showed no significant cross-resistance to these compounds.

Cytotoxicity of dihydroartemisinin toward Molt-4 cells attenuated by N-tert-butyl-alpha-phenylnitrone and deferoxamine

Derivatives of artemisinin, a compound extracted from the wormwood Artemisia annua L, have potent anticancer properties. The anticancer mechanisms of artemisinin derivatives have not been fully-elucidated. We hypothesize that the cytotoxicity of these compounds is due to the free radicals formed by interaction of their endoperoxide moiety with intracellular iron in cancer cells. The effects of N-tert-butyl-alpha-phenylnitrone (PBN), a spin-trap free radical scavenger, and deferoxamine (DX), an iron chelating agent, on the in vitro cytotoxicity of dihyroartemisinin (DHA) toward Molt-4 human T-lymphoblastoid leukemia cells were investigated in the present study. Dihydroartemisinin effectively killed Molt-4 cells in vitro. Its cytotoxicity was significantly attenuated by PBN and DX. Based on the data of our present and previous studies, we conclude that one anticancer mechanism of dihydroartemisinin is the formation of toxic-free radicals via an iron-mediated process.

Effects of artemisinin dimers on rat breast cancer cells in vitro and in vivo

Artemisinin has been shown to be an effective antimalarial and anticancer compound. Dimers of artemisinin have been synthesized and shown to be potent antimalarials compared with monomers. In the present study, we investigated the effect of two artemisinin dimers (dimer-alcohol and dimer-hydrazone) on rat mammary adenocarcinoma cells (MTLn3) in vitro and in vivo compared with that of the artemisinin monomer dihydroartemisinin (DHA). We found that the dimers are considerably more potent than DHA in killing MTLn3 cells in vitro and suppressing the growth of MTLn3 breast tumors in vivo.

Cytotoxicity of ethanolic extracts of Artemisia annua to Molt-4 human leukemia cells

Although dihydroartemisinin (DHA) and other artemisinin derivatives have selective toxicity towards cancer cells, Artemisia annua (A. annua) extracts containing artemisinin have not been evaluated for their anticancer potential. Our main goal was to assess the anticancer effect of ethanolic leaf extracts of A. annua from Brazilian and Chinese origins (with DHA as a comparison) on normal and cancer cells. Leukocytes and leukemia (Molt-4) cells were counted at 0, 24, 48, and 72 hr after treatment with extracts having artemisinin concentrations of 0, 3.48, 6.96, and 13.92 µg/mL. Also, we assessed the antioxidant capacity of these extracts using the oxygen radical absorbance capacity (ORAC) test. Both extracts had high antioxidant capacity and toxicity towards Molt-4 cells. DHA was significantly more potent (p < 0.05) in killing Molt-4 cells than Brazilian extract at 48 and 72 hr and Chinese extract at 72 hr. In Molt-4 cells, LD₅₀ values for Brazilian and Chinese extracts were comparable at all time points and not significantly different from DHA at 24 hr. In leukocytes, DHA, Chinese extract, and Brazilian extract had LD₅₀ values of 760.42, 13.79, and 28.23 µg/mL of artemisinin, respectively, indicating a better safety index for the Brazilian extract compared to that of the Chinese extract at 24 hr. However, at 48 and 72 hr, the toxicity in leukocytes for any of the treatment groups was not significantly different. These experiments suggest that these extracts may have potential application in cancer treatment.

Effect of hyperbaric oxygen on the anticancer effect of artemisinin on molt-4 human leukemia cells

BACKGROUND

Artemisinin selectively kills cancer cells which have more intracellular free iron than do normal cells. Hyperbaric oxygen (HBO(2)) may be beneficial in the treatment of cancer. The hypothesis of this study was that HBO(2) enhances anticancer activity of artemisinin.

MATERIALS AND METHODS

After pretreatment with 12 μM holotransferrin, Molt-4 human leukemia cells were cultured in 10 μM artemisinin and exposed for 90 min to one of three different conditions: control, room air control, and HBO(2). Cell growth was determined for 48 h after exposure.

RESULTS

Differences in growth were noted after 6 h of incubation. After 48 h of incubation, growth of cells treated with artemisinin alone or HBO(2) alone was 85% of that of cells grown under artemisinin-free control conditions. Combined artemisinin and HBO(2) treatment resulted in an additional 22% decrease in growth.

CONCLUSION

Combined HBO(2) and artemisinin exposure may be an effective anticancer chemotherapeutic strategy.

Chemotherapy with low-dose bevacizumab and carboplatin in the treatment of a patient with recurrent cervical cancer

Management of patients with recurrent or advanced cervical cancer is a challenge. Concurrent chemotherapy has become the mainstay of treatment and platinum remains the most effective single agent. Combinations of other agents have not demonstrated significant advantages. The application of angiogenesis inhibitors such as bevacizumab, an antibody inhibiting vascular endothelial growth factor, in metastatic or advanced cervical cancer remains to be evaluated. We present the case of a patient with platinum-resistant recurrent cervical cancer treated with low-dose bevacizumab and carboplatin, with resultant improved disease progression and tolerable toxicity profiles.

Passively Q-switched Yb3+:YCa4O(BO3)3 laser with InGaAs quantum wells as saturable absorbers

A diode-pumped Yb:YCOB laser at 1086 nm is passively Q switched by using InGaAs quantum wells as saturable absorbers and utilizing the Bragg mirror structure as an output coupler. With an absorbed pump power of 9.2 W the laser produces pulses of 100 ms duration with average pulse energy of as much as 165 microJ at a pulse repetition rate of 7 kHz.

InGaAs quantum-well saturable absorbers for a diode-pumped passively Q-switched Nd:YAG laser at 1123 nm

A low-loss semiconductor saturable absorber based on InGaAs quantum wells was developed for highly efficient Q switching of a diode-pumped Nd:YAG laser operating at 1123 nm. With an incident pump power of 16 W, an average output power of 3.1 W with a Q-switched pulse width of 77 ns at a pulse repetition rate of 100 kHz was obtained.

Synergistic cytotoxicity of artemisinin and sodium butyrate on human cancer cells

BACKGROUND

Butyric acid is a short chain fatty acid produced by large bowel bacterial flora. It serves as an antiinflammatory agent and nutrient for normal colon cells. Butyric acid has also been shown to induce apoptosis in colon and many other cancer cells. Artemisinin is a compound extracted from the wormwood Artemisia annua L. It has been shown to selectively kill cancer cells in vitro and to be effective in treating animal and human cancer. We and others have found that the artemisinin analog, dihydroartemisinin (DHA), kills cancer cells by apoptosis. In the present study, the efficacy of a combined treatment of DHA and butyric acid at low doses in killing cancer cells was investigated.

MATERIALS AND METHODS

Molt-4 cells (a human lymphoblastoid leukemia cell line) and freshly isolated human lymphocytes, cultured in complete RPMI-1640 medium, were first incubated with 12 microM of human holotransferrin at 37 degrees C in a humid atmosphere of 5% CO2 for one hour to enhance the iron concentration in the cells. Cells from each cell type were then divided into 20 flasks. These flasks were grouped into four sets of five cultures each. Zero, 5, 10 or 20 microM of DHA was added, respectively, to these sets and the cells were incubated at 37 degrees C for one hour. Zero, 1, 5, 10, or 20 mM of sodium butyrate was then added to the five cultures of each set, respectively. Thus, the treatments involved a combination of 4 doses of DHA and 5 doses of sodium butyrate. The cells were counted immediately before the addition of DHA, and at 24 and 48 hours after the addition of sodium butyrate.

RESULTS

DHA alone at the 24-hour time-point and 20 microM concentration significantly reduced the number of Molt-4 cells in the culture by approximately 40% (p < 0.001, compared to non-treated control), whereas it did not significantly affect the number of normal human lymphocytes. Similarly, 1 mM sodium butyrate alone at 24 hours reduced the number of Molt-4 cells by approximately 32% (p < 0.001, compared to non-treated control), without significantly affecting normal human lymphocytes. The combination of 20 microM DHA and 1 mM sodium butyrate killed all Molt-4 cells at the 24-hour time-point and did not significantly affect lymphocytes.

CONCLUSION

DHA in combination with butyric acid acts synergistically at low doses. The combination may provide a less toxic, inexpensive and effective cancer chemotherapy.

Accuracy of various iron parameters in the prediction of iron deficiency in an acute care hospital

INTRODUCTION

Iron parameters like serum ferritin and iron saturation are routinely used in diagnosing iron deficiency. However, these tests are influenced by many factors. We aimed to review the accuracy of iron parameters among inpatients in an acute care hospital.

MATERIALS AND METHODS

From October 1997 to April 2002, bone marrow aspirate samples from patients on whom concurrent iron studies had been done were analysed. Accuracy of the various iron parameters was analysed using receiver operating characteristic curves.

RESULTS

Among 92 bone marrow aspirate samples, 58, 86 and 83 had a concurrent serum ferritin, serum iron and percentage iron saturation done respectively. Serum ferritin is the best marker for predicting the presence of iron deficiency. This is followed by percentage iron saturation and lastly by serum iron. At the most optimal, a serum ferritin of <60 ng/mL has a positive likelihood ratio of 24.35, sensitivity of 69.6%, specificity of 97.1% and positive predictive value of 94.1%. An iron saturation of <7% has a positive likelihood ratio of 21.62, sensitivity of 44.1%, specificity of 98.0% and positive predictive value of 93.8%. Seven out of 50 samples, which had concurrent measurements of iron saturation and serum ferritin, were discordant in indicating the presence of iron deficiency. In 6 cases, the iron saturation was the spurious result.

CONCLUSION

A serum ferritin of <60 ng/mL or a percentage iron saturation of <7% is highly predictive of iron deficiency among inpatients in an acute care hospital.

Haematological parameters in severe acute respiratory syndrome

Clinical presentation of severe acute respiratory syndrome (SARS) is non‐specific and isolation of all suspected patients is difficult because of the limited availability of isolation facilities. We studied changes in haematological parameters in SARS patients using median values analysed according to the day of symptom onset. White cell (WCC), absolute neutrophil, absolute lymphocyte (ALC) and platelet counts followed a v‐shaped trend with the nadir at day 6 or 7 after symptom onset except for ALC in the ICU group that had not reached the nadir by day 12. None of our patients had a platelet count < 80 × 10⁹/l and WCC < 2 × 10⁹/l in the first 5 days of symptoms and these parameters may allow early stratification of febrile patients into likely and unlikely SARS cases to allow effective utilization of isolation facilities. On multivariate analysis, age is the only independent predictor for ICU admission.

InAs/GaAs quantum-dot saturable absorber for a diode-pumped passively mode-locked Nd:YVO4 laser at 1342 nm

We report that InAs/GaAs quantum dots were developed to be saturable absorbers as well as output couplers in diode-pumped passively mode-locked Nd:YVO4 lasers at 1342 nm. With an incident pump power of 12.6 W, an average output power of 0.85 W with a mode-locked pulse width of 26 ps at a repetition rate of 152 MHz was obtained.

InAs/GaAs quantum-dot saturable absorbers for diode-pumped passively Q-switched Nd-doped 1.3-microm lasers

A low-loss semiconductor saturable absorber based on InAs/GaAs quantum dots was developed for Q switching of a diode-pumped Nd-doped laser operating at 1.3 microm. With an InAs/GaAs quantum-dot saturable absorber, a diode-pumped Nd:YVO4 laser at 1342 nm was achieved. With an incident pump power of 2.2 W, an average output power of 360 mW with a Q-switched pulse width of 90 ns at a pulse repetition rate of 770 kHz was obtained.

Artemisinin induces apoptosis in human cancer cells

BACKGROUND

Artemisinin is a chemical compound extracted from the wormwood plant, Artemisia annua L. It has been shown to selectively kill cancer cells in vitro and retard the growth of implanted fibrosarcoma tumors in rats. In the present research, we investigated its mechanism of cytotoxicity to cancer cells.

MATERIALS AND METHODS

Molt-4 cells, in complete RPMI-1640 medium, were first incubated with 12 microM of human holotransferrin at 37 degrees C in a humid atmosphere of 5% CO2 for one hour. This enhanced the iron supply to the cells. The cells were then pelleted and transferred to a complete RPMI-1640 containing 200 microM of an analog dihydroartemisinin (DHA) and incubation was started (0 h). In addition, some culture samples were treated with holotransferrin alone and some (controls) were assayed without neither holotransferrin nor DHA treatment. Cells were counted and DNA diffusion assay was used to evaluate apoptosis and necrosis in each sample at 0 h and at 1, 2, 4 and 8 h of incubation.

RESULTS

DHA treatment significantly decreased cell counts and increased the proportion of apoptosis in cancer cells compared to controls (chi2=4.5, df=1, p<0.035). Addition of holotransferrin significantly further decreased cell counts (chi2=4.5, df=1, p<0.035) and increased apoptosis (chi2=4.5, df=1, p<0.035). No necrotic cells were observed.

CONCLUSION

This rapid induction of apoptosis in cancer cells after treatment with DHA indicates that artemisinin and its analogs may be inexpensive and effective cancer agents.

Identifying the combination of genetic factors that determine susceptibility to cervical cancer

Cervical cancer is common among women all over the world. Although infection with high-risk types of human papillomavirus (HPV) has been identified as the primary cause of cervical cancer, only some of those infected go on to develop cervical cancer. Obviously, the progression from HPV infection to cancer involves other environmental and host factors. Recent population-based twin and family studies have demonstrated the importance of the hereditary component of cervical cancer, associated with genetic susceptibility. Consequently, single-nucleotide polymorphism (SNP) markers and microsatellites should be considered genetic factors for determining what combinations of genetic factors are involved in precancerous changes to cervical cancer. This study employs a Bayesian network and four different decision tree algorithms, and compares the performance of these learning algorithms. The results of this study raise the possibility of investigations that could identify combinations of genetic factors, such as SNPs and microsatellites, that influence the risk associated with common complex multifactorial diseases, such as cervical cancer.

Rules of selection for spontaneous coherent states in mesoscopic systems: using the microcavity laser as an analog study

The selection rules for spontaneous coherent waves in mesoscopic systems are experimentally studied using the transverse patterns of a microcavity laser and theoretically analyzed using the theory of SU(2) coherent states. Comparison of the experimental results with the theoretical analyses reveals that an amplitude factor A should be included in the representation of the partially coherent states. The determination of the amplitude factor A is found to be associated with the constraint of minimum energy uncertainty.

Observation of vector vortex lattices in polarization states of an isotropic microcavity laser

We experimentally investigate the formation of a vector polarization pattern from an isotropic microcavity laser. It is found that the orthogonal components of the observed pattern are localized on the geometrical rays. The connection between eigenfunctions and geometrical rays is analytically constructed by using the SU(2) coherent states. With the analytical function form, the observed vector pattern is completely reconstructed and the vector vortex lattice is apparent.

Observation of the wave function of a quantum billiard from the transverse patterns of vertical cavity surface emitting lasers

We demonstrate experimentally that the near-field and far-field transverse patterns of a large aperture vertical cavity surface emitting laser (VCSEL) can be successfully interpreted as a two-dimensional (2D) billiard system. It is found that the near-field and far-field transverse patterns of a large aperture VCSEL evidently represent the coordinate-space and momentum-space wave functions of a 2D quantum billiard, respectively. The result of this paper suggests that large aperture VCSELs are potentially appropriate physical systems for the wave-function study in quantum problems.

Efficient identification of amino acid types for fast protein backbone assignments

We describe a procedure that allows for very efficient identification of amino acid types in proteins by selective 15N-labeling. The usefulness of selective incorporation of 15N-labeled amino acids into proteins for the backbone assignment has been recognized for several years. However, widespread use of this method has been hindered by the need to purify each selectively labeled sample and by the relatively high cost of labeling with 15N-labeled amino acids. Here we demonstrate that purification of the selectively 15N-labeled samples is not necessary and that background-free HSQC spectra containing only the peaks of the overexpressed heterologous protein can be obtained in crude lysates from as little as 100 ml cultures, thus saving time and money. This method can be used for fast and automated backbone assignment of proteins.

The significance of human papillomavirus viral load in prediction of histologic severity and size of squamous intraepithelial lesions of uterine cervix

OBJECTIVES

Persistence of high-risk types of human papillomavirus (HPV) in cervical scrapes is responsible for the development, maintenance, and progression of squamous intraepithelial lesions (SILs). Previous studies of viral load and histologic severity have ended with controversial results. This study evaluated the relationships of HPV viral load with size and histologic severity of cervical lesions, which has not been reported previously.

METHODS

By using Hybrid Capture II, DNA level of high-risk HPVs was determined in cervical scrapes and correlated with lesion size and histologic confirmation for 73 women referred for colposcopy. The lesion size was classified as nonvisible (n = 12), small (< or =2/5 of the 12x colposcopic visual filed, n = 36), and large (>2/5 of the 12x field, n = 25) lesions. The final disease status was categorized as high-grade SIL (HSIL)/squamous cell carcinoma (SCC) (designated HSIL+) (n = 32), low-grade SIL (LSIL) (n = 19), and no detectable SIL (n = 22).

RESULTS

A distinct upward trend of high-risk HPV DNA levels paralleled increasing size and histologic severity of cervical lesions (P = 0.003 and 0.001, respectively). With respect to relative risk, women who had high viral load of HPV were at significantly greater risk for large lesion size (odds ratio [OR] = 5.3, 95% confidence interval [CI] = 1.1-24.9) and HSIL+ (OR = 35.0, 95% CI = 4.2-294.5). Of particular note, the risk of developing large lesion size and HSIL+ significantly increased with increasing viral load of HPV (P values for trend test were 0.008 and 0.0004, respectively). In contrast, there were no significant associations of trend in viral load with risk in small lesion size and LSIL.

CONCLUSIONS

The present study revealed that the effect of HPV infection on SIL development is highly influenced by high viral load and highlighted a potential application of viral load testing in predicting the size and severity of lesions of the uterine cervix.

A reevaluation and discussion on the threshold limit for hemolysis in a turbulent shear flow

One major factor of red blood cell damage induced by artificial heart valves is the magnitude of turbulent shear stresses in the flow field. An often-cited threshold for hemolysis is 400 N/m(2) (Sallam and Hwang, Biorheology 21 (1984) 783). This value, however, was measured with a one-component laser Doppler anemometer and was not calculated from the major principal Reynolds shear stress, therefore underestimating the threshold. This study performed flow field measurements under similar conditions, using a two-component laser Doppler anemometer and determining major principal Reynolds shear stress, to reevaluate the hemolytic threshold as 800 N/m(2) with an exposure time of 1 ms. The Kolmogorov length scales, approximately 9 microm, are capable of inflicting direct damage to the red blood cells. These results will serve as a more accurate reference in future heart valve design and testing.

Association study of apolipoprotein E epsilon4 with clinical phenotype and clozapine response in schizophrenia

Schizophrenic patients with the apolipoprotein E (APOE = gene; apoE = protein) epsilon4 allele exhibited lower psychosis scores than patients without the epsilon4 allele in previous reports. The present study tested the hypothesis that the APOE epsilon4 allele confers association with the clinical manifestations of schizophrenia or clozapine response. A total of 95 schizophrenic patients who were treatment resistant were included in the study. The results demonstrated that the presence of the APOE epsilon4 allele did not influence the response to clozapine in schizophrenic patients, neither was the baseline psychopathology related to the APOE epsilon4 allele. Given the multiple functions of the apoE protein in the brain, further study of the influence of APOE on CNS medication response is needed.

The role of RsmA in the regulation of swarming motility in Serratia marcescens

Swarming motility is a multicellular phenomenon comprising population migration across surfaces by specially differentiated cells. In Serratia marcescens, a network exists in which the flhDC flagellar regulatory master operon, temperature, nutrient status, and quorum sensing all contribute to the regulation of swarming motility. In this study, the rsmA (repressor of secondary metabolites) gene (hereafter rsmA(Sm)) was cloned from S. marcescens. The presence of multicopy, plasmid-encoded rsmA(Sm) expressed from its native promoter in S. marcescens inhibits swarming. Synthesis of N-acylhomoserine lactones, presumably by the product of smaI (a luxI homolog isolated from S. marcescens), was also inhibited. Knockout of rsmA(Sm) on the S. marcescens chromosome shortens the time before swarming motility begins after inoculation to an agar surface. A single copy of the chromosomal PrsmA(Sm)::luxAB reporter of rsmA(Sm) transcription was constructed. Using this reporter, the roles of the flhDC flagellar regulatory master operon, temperature and autoregulation in the control of rsmA(Sm) expression were determined. Our findings indicate that RsmA(Sm) is a component of the complex regulatory network that controls swarming.

Early diagnosis of cystic fibrosis through neonatal screening prevents severe malnutrition and improves long-term growth. Wisconsin Cystic Fibrosis Neonatal Screening Study Group

OBJECTIVE

Despite its relative frequency among autosomal recessive diseases and the availability of the sweat test, cystic fibrosis (CF) has been difficult to diagnose in early childhood, and delays can lead to severe malnutrition, lung disease, or even death. The Wisconsin CF Neonatal Screening Project was designed as a randomized clinical trial to assess the benefits and risks of early diagnosis through screening. In addition, the incidence of CF was determined, and the validity of our randomization method assessed by comparing 16 demographic variables.

METHODOLOGY

Immunoreactive trypsinogen analysis was applied to dried newborn blood specimens for recognition of CF risk from 1985 to 1991 and was coupled to DNA-based detection of the DeltaF508 mutation from 1991 to 1994. Randomization of 650 341 newborns occurred when their blood specimens reached the Wisconsin screening laboratory. This created 2 groups-an early diagnosis, screened cohort and a standard diagnosis or control group. To avoid selection bias, we devised a unique unblinding method with a surveillance program to completely identify the control subjects. Because sequential analysis of nutritional outcome measures revealed significantly better growth in screened patients during 1996, we accelerated the unblinding and completely identified the control group by April 1998. Having each member of this cohort enrolled and evaluated for at least 1 year and having completed a comprehensive surveillance program, we performed another statistical analysis of anthropometric evaluated indices that includes all CF patients without meconium ileus.

RESULTS

The incidence of classical CF, ie, patients diagnosed in this trial with a sweat chloride of 60 mEq/L greater, was 1:4189. By incorporating other CF patients born during the randomization period, including 2 autopsy diagnosed patients and 8 probable patients, we calculate a maximum incidence of 1:3938 (95% confidence interval: 3402-4611). Although there were group differences in the proportion of patients with DeltaF508 genotypes and with pancreatic insufficiency, validity of the randomization plan was demonstrated by analyzing 16 demographic variables and finding no significant difference after adjustment for multiple comparisons. Focusing on patients without meconium ileus, we found a marked difference in the mean +/- standard deviation age of diagnosis for screened patients (13 +/- 37 weeks), compared with the standard diagnosis group (100 +/- 117). Anthropometric indices of nutritional status were significantly higher at diagnosis in the screened group, including length/height, weight, and head circumference. During 13 years of study, despite similar nutritional therapy and the inherently better pancreatic status of the control group, analysis of nutritional outcomes revealed significantly greater growth associated with early diagnosis. Most impressively, the screened group had a much lower proportion of patients with weight and height data below the 10th percentile throughout childhood.

CONCLUSIONS

Although the screened group had a higher proportion of patients with pancreatic insufficiency, their growth indices were significantly better than those of the control group during the 13-year follow-up evaluation and, therefore, this randomized clinical trial of early CF diagnosis must be interpreted as unequivocally positive. Our conclusions did not change when the height and weight data before 4 years of age for the controls detected by unblinding were included in the analysis. Also, comparison of growth outcomes after 4 years of age in all subjects showed persistence of the significant differences. Therefore, selection bias has been eliminated as a potential explanation. In addition, the results show that severe malnutrition persists after delayed diagnosis of CF and that catch-up may not be possible. We conclude that early diagnosis of CF through neonatal screening combined with aggressive nutritional therapy can result

Role of flhDC in the expression of the nuclease gene nucA, cell division and flagellar synthesis in Serratia marcescens

We investigated in Serratia marcescens the functions of the flhDC operon, which controls motility and cell division in enteric bacteria. Included in our evaluations were investigation of cell division, flagellar synthesis and regulation of the expression of nuclease (encoded by the nucA(Sm) gene, one of the virulence factors). Interruption of the chromosomal flhDC operon in S. marcescens CH-1 resulted in aberrant cell division and loss of nuclease and flagella. Expression of nucA(Sm) and other mutated phenotypes was restored in the flhDC mutant by the induction of overexpression of flhDC in a multicopy plasmid. Multicopied flhDC also induced the formation of differentiated cells (polyploid aseptate cells with oversynthesis of peritrichous flagella) in broth culture using minimal growth medium. Expression of the flhDC operon showed positive autoregulation, and was growth phase dependent (upregulated in early log phase). In addition, flhDC expression was inhibited when the temperature increased from 30 to 37 degrees C, and when osmolarity was increased, but was not influenced by glucose catabolite repression. These results show that FlhD/FlhC is a multifunctional transcriptional activator involved in the process of cell differentiation, swarming and virulence factor expression.

Association study of a functional serotonin transporter gene polymorphism with schizophrenia, psychopathology and clozapine response

Serotonin is implicated in the pathogenesis of schizophrenia. Following serotonin release, the serotonin transporter (5-HTT) is the major determinant of serotonin inactivation. The present study tested the hypothesis that a biallelic polymorphism in the 5' regulatory region of the 5-HTT gene (5-HTTLPR) confers susceptibility to schizophrenia, association with the clinical manifestations of schizophrenia or clozapine response. 90 treatment-resistant schizophrenic patients were assessed using the Brief Psychiatric Rating Scale before and after clozapine treatment. The results demonstrated that the 5-HTTLPR variants did not play a major role in the susceptibility, clinical manifestations or clozapine response in schizophrenia.

Apolipoprotein E genotype and schizophrenia

Schizophrenic disorders are complex genetic disorders and may involve multiple genes of small effect. The presence of apolipoprotein E (apoE) is associated with several neuropsychiatric disorders. Previous studies on apoE genotype distribution in schizophrenia have reported conflicting findings. We studied the genotype frequencies in a large group of schizophrenic patients. The genotype distribution was significantly different between the schizophrenic patients and the control subjects. Persons who were sigma3 carriers have an increased risk of schizophrenia. This result suggests that apoE isoforms may play a functional role in the pathogenesis of schizophrenic disorders. Some possible mechanisms regarding the effect of apoE on the development of schizophrenia are discussed.

Risk of persistent growth impairment after alternate-day prednisone treatment in children with cystic fibrosis

BACKGROUND

It is uncertain whether the growth impairment that occurs in children during long-term treatment with glucocorticoids persists after the medication is discontinued and ultimately affects adult height.

METHODS

We evaluated growth six to seven years after alternate-day treatment with prednisone had been discontinued in 224 children 6 to 14 years of age with cystic fibrosis who had participated in a multicenter trial of this therapy from 1986 through 1991. Of the children, 151 had been randomly assigned to receive prednisone (either 1 or 2 mg per kilogram of body weight) and 73 to receive placebo. We obtained data on growth up to 1997 from the Cystic Fibrosis Foundation Patient Registry and standardized the data to sex- and age-specific norms from the National Center for Health Statistics. We used z scores to compare growth patterns among treatment groups.

RESULTS

In 1997, 68 percent of the patients were 18 years of age or older. The z scores for height declined during prednisone therapy; catch-up growth began two years after treatment with prednisone was discontinued. Among the boys, the z scores for height in those treated with prednisone remained lower than the scores for those who received placebo (P=0.02). The mean heights for boys 18 years of age or older were 4 cm less in the prednisone groups than in the placebo group, an equivalent of 13 percentile points (P=0.03). Among the girls, differences in height between those who were treated with prednisone and those who received placebo were no longer present two to three years after prednisone therapy was discontinued.

CONCLUSIONS

Among children with cystic fibrosis who have received alternate-day treatment with prednisone, boys, but not girls, have persistent growth impairment after treatment is discontinued.

Nutritional status of patients with cystic fibrosis with meconium ileus: a comparison with patients without meconium ileus and diagnosed early through neonatal screening

OBJECTIVE

This study was pursued as an extension of a randomized clinical investigation of neonatal screening for cystic fibrosis (CF). The objective was to determine if CF patients with meconium ileus (MI) were more likely to be malnourished compared with those without MI who were diagnosed during early infancy through neonatal screening.

METHODOLOGY

Nutritional status was evaluated from early infancy to 13 years of age based on anthropometric, biochemical, and dietary assessments.

RESULTS

MI patients (n = 32) were smaller at birth (3117 g compared with 3413 g) and were shorter (22nd percentile compared with 48th percentile) and thinner (24th percentile compared with 49th percentile) compared with non-MI early diagnosed patients (n = 50) up to 13 years of age. Poor growth was particularly evident in 26 MI patients who required surgery for MI (height and weight at the 20th percentile), whereas those treated without surgery (n = 6) showed better height (45th percentile) and weight (37th percentile). Abnormal essential fatty acid profiles were significantly more prevalent in MI compared with non-MI early-diagnosed patients before 3 years of age. Daily intakes of calorie (130% compared with 111% recommended dietary allowances) and protein (339% compared with 279% recommended dietary allowances) were higher but the percentage of fat (37% compared with 38%) and linoleic acid (4.5% compared with 4.7%) in the diet were similar between the two groups.

CONCLUSIONS

These results demonstrated a clear association of MI with malnutrition in CF. The observed poor growth among our MI patients was not because of poor dietary intakes, but was related to surgical treatment for MI and poor essential fatty acid status. These findings present new challenges regarding the optimal medical treatment and nutritional intervention for CF patients with MI.