Effect of bone density on the drill-hole diameter made by a cannulated drill bit in cancellous bone.

BACKGROUND: When a pilot hole is made prior to a screw's insertion into bone, the same drill bit is used irrespective of the bone quality. However, osteoporotic bone is fragile and this may affect the hole diameter, which is of particular concern in cancellous bone. In this study, the relationship between bone density and drill-hole diameter was investigated assuming a pre-drilling process in screw-only osteosynthesis in the metaphysis and epiphysis. METHODS: Two types of drill bit (triple-flute [T] and quadruple-flute [Q]) with different shapes and diameters were prepared: type T bits with 3.5 mm and 4.4 mm diameters, and type Q bits with 3.5 mm and 4.2 mm diameters. Drilling was performed manually in simulated bones with four densities: 5, 10, 15, and 20 pounds per cubic foot. We measured the hole diameters with a coordinate measuring machine and analyzed the relationship between the drill-hole diameters and the densities of the simulated bones. We then compared the screw pull-out strength between the two 3.5-diameter drill bits. RESULTS: In all cases, the diameters of the drill holes were larger than those of the drill bits. The relationship between the drill-hole diameters and the bone densities was a negative linear correlation. Enlarging the hole diameter decreased the screw pull-out strength. CONCLUSIONS: For cannulated drill bits of 3.5, 4.2 and 4.4 mm diameter, the diameter of the drill hole in cancellous bone obtained by the manual drilling technique tends to be larger in low-density (e.g., osteoporotic) compared to high-density (e.g., healthy) bone.

Relationship between thread depth and fixation strength in cancellous bone screw.

BACKGROUND: Clarifying the effect of each parameter of screw design on its fixation strength is critical in the development of any type of screw. The purpose of this study was to clarify the relationship between the thread depth and fixation strength of metal screws for cancellous bone. METHODS: Nine types of custom-made screws with the only changed variable being the thread depth were manufactured. Other elements were fixed at a major diameter of 4.5 mm, a thread region length of 15 mm, a pitch of 1.6 mm, and a thread width of 0.20 mm. The pull-out strength and insertion torque of each screw were measured for each of two foam-block densities (10 or 20 pcf). The correlation between the thread depth of the screw and the mechanical findings were investigated with single regression analysis. RESULTS: Regardless of the foam-block density, the pull-out strength significantly increased as the thread depth increased from 0.1 mm to 0.4 mm; after that, the increase was more gradual (p < 0.01, respectively). The relationship between the thread depth and insertion torque was similar. In addition, the insertion torque tended to be more strongly affected by screw depth than the pull-out strength (2.6 times at 20 pcf and 1.4 times at 10 pcf). CONCLUSIONS: The pull-out strength of 4.5-mm-diameter metal screws in a cancellous bone model was found to be biphasic, although linearly correlated with the change in screw depth in both phases. The boundary of the correlation was 0.4 mm regardless of the density of the bone model, with the effect of screw depth on pull-out strength beyond that being small in comparison.

Incidence and risk factors for velamentous umbilical cord insertion in singleton pregnancies after assisted reproductive technology.

AIM: Assisted reproductive technology (ART) is gaining popularity worldwide. However, it is associated with increased incidence of velamentous umbilical cord insertion (VCI) in the placenta, resulting in adverse perinatal outcomes. This study aimed to identify the risk factors that might affect the incidence of VCI in pregnancies after ART treatment. METHODS: We retrospectively analyzed the records of 906 singleton pregnancies via ART; all women delivered in our facility. Three ART-related variables and infant sex were examined: (1) fertilization method (conventional in vitro fertilization or intracytoplasmic sperm injection), (2) type of embryo at the time of transfer (fresh or frozen-thawed), (3) developmental stage of embryo at the time of transfer (cleavage stage or blastocyst), and (4) infant sex (male or female). Logistic regression analysis was used to assess the impact of these variables on the incidence of VCI. RESULTS: Of 906 cases, 55 had VCI (incidence rate, 6.1%). After adjusting for potential confounders, blastocyst stage of development (adjusted odds ratio [aOR]: 4.3, 95% confidence interval [CI]: 1.9-12.7) and female sex (aOR: 2.2, 95% CI: 1.2-3.9) emerged as independent risk factors for the development of VCI. The fertilization method and type of embryo at the time of transfer did not affect the incidence of VCI. CONCLUSIONS: Blastocyst stage of development and female sex pose a higher risk for developing VCI. Thus, more attention should be paid to pregnancies achieved by blastocyst and with a female fetus to detect VCI proactively and safeguard the health of both mother and fetus/neonate.

Feeding Support Team for Frail, Disabled, or Elderly People during the Early Phase of a Disaster.

Japan was struck by two catastrophic disasters on March 11, 2011 and on April 16, 2016. The former was the Great East Japan Earthquake (M9.0) and the latter was the Kumamoto Earthquake (M7.0). Most inhabitants in the affected areas of both disasters were forced to live in evacuation centers right after the earthquake. Poor oral hygiene, inactivity, malnourishment, appetite loss, eating problems, and swallowing problems due to lack of support for frail, disabled, or elderly evacuees occur during the early phases after a disaster. Disaster-related sequelae, such as pneumonia and disuse syndrome, may also occur as a result of inappropriate nutritional and physical support. Adequate oral intake and physical activity are important to the quality of life for evacuees. We learned lessons from our experiences of evacuee support after the two disasters, focused on feeding support, which consisted of nutritional and physical care. Our experiences revealed that more rapid intervention is necessary, particularly for frail, disabled, or elderly people. In this study, based on our experiences from the two dreadful disasters in Japan, we propose a new concept of medical assistance after a disaster, the Disaster Feeding Support Team (D-FST). The D-FST is composed of multidisciplinary professionals and provides comprehensive nutritional, physical, and health support. The D-FST also performs interventions for swallowing exercises, activity, health condition, and cognition that are related to eating circumstances. We suggest that D-FSTs are organized nationwide and initiate support activities immediately after the onset of a disaster.

A case of organizing pneumonia in rearranged during transfection fusion-positive lung adenocarcinoma treated with selpercatinib.

Selpercatinib is the first targeted therapy for rearranged during transfection (RET) fusion-positive unresectable non-small-cell lung cancer (NSCLC). The main adverse effects of selpercatinib include hypertension, liver dysfunction, diarrhea, and QT prolongation on electrocardiograms. However, instances of drug-induced interstitial lung disease (DI-ILD) are infrequently reported. We describe the first case of a patient with RET fusion-positive NSCLC treated with selpercatinib who developed DI-ILD, confirmed pathologically. The patient, a 72-year-old woman, initiated selpercatinib treatment following the postoperative recurrence of lung adenocarcinoma. After 15 months of treatment, computed tomography scans revealed multiple infiltrates and ground-glass opacities in both lungs. A thoracoscopic lung biopsy identified organizing pneumonia, attributed to DI-ILD caused by selpercatinib. Although she was asymptomatic, the patient's selpercatinib treatment was discontinued, leading to a gradual improvement in the lung infiltrates. Despite the lack of detailed reports, DI-ILD with selpercatinib represents a potentially serious adverse event and should be approached with caution.

Navigating Complex Diagnostics During COVID-19: Repeated Testing Unveils Infective Endocarditis in a 61-Year-Old Woman.

BACKGROUND Infective endocarditis (IE), a systemic infection characterized by bacterial vegetative growths on heart valves and endothelium, often manifests variably and leads to severe complications, sometimes even death. Accurate and timely diagnosis is paramount, yet the variety of symptoms can lead to delays, especially amidst the complexities of the ongoing COVID-19 pandemic. CASE REPORT A 61-year-old woman with a history of mitral valve regurgitation was admitted after a month of low-grade fever, night sweats, and polyarthritis. Initial blood cultures and CT scans were inconclusive. Upon admission, clinical examination uncovered a heart murmur, leukocytosis, and elevated C-reactive protein levels. Further examination by another physician revealed conjunctival hemorrhage and Janeway lesions. Subsequent blood cultures tested positive for Streptococcus oralis, and transesophageal echocardiography revealed mitral valve prolapse with vegetation, leading to a diagnosis of IE. Following a 6-week course of ampicillin, the patient recovered successfully. CONCLUSIONS This case underlines the necessity of maintaining a high index of suspicion and flexible diagnostic approach, particularly in high-risk patients and complex care environments like the COVID-19 pandemic. A single inconclusive test should not preclude a diagnosis, underscoring the importance of repeated testing and comprehensive assessments in timely disease identification.

Aseptic Meningitis With an Isolated Positive Ocular Globe Compression Sign Diagnosed by Repeat Lumbar Puncture.

Aseptic meningitis is diagnosed using clinical and laboratory findings of meningeal inflammation in the absence of bacteria in cerebrospinal fluid smear and culture. It is commonly caused by a viral infection, and most cases are improved without specific treatment. We present a case of aseptic meningitis in a 33-year-old Japanese man that was diagnosed only after a repeat lumbar puncture. The patient had a positive ocular globe compression sign with no other positive meningeal signs. This case highlights the importance of repeated lumbar puncture in patients with suspected aseptic meningitis if the initial lumbar puncture results are negative, and there is a clinical value in assessing the ocular globe compression sign, particularly when other clinical signs of meningitis are absent.

Paragonimus westermani as a cause of Löeffler's syndrome.

In 1936, Löeffler first recognized the association between a distinctive form of severe heart failure and marked eosinophilia. Most cases are caused by either parasitic infections or drugs; however, no cause has been identified in one-third of the patients [1]. This report presents a rare case of Löeffler's syndrome caused by the parasite Paragonimus westermani.

A nationwide survey of hepatitis E virus (HEV) infection in wild boars in Japan: identification of boar HEV strains of genotypes 3 and 4 and unrecognized genotypes.

To investigate the nationwide prevalence of hepatitis E virus (HEV) infection and to characterize HEV genomes among Japanese wild boars (Sus scrofa leucomystax), 578 boars captured in 25 prefectures from 2003 to 2010 were studied. Anti-HEV IgG was detected in 8.1%, and HEV RNA in 3.3% of boars. Among the 19 boar HEV isolates obtained from infected boars, 14 isolates (74%) were classified as genotype 3, 4 isolates (21%) as genotype 4, and the remaining isolate (wbJOY_06) was distantly related to all known HEV isolates of genotypes 1-4, differing by 18.4-25.0% and 18.0-24.3% within the 412-nucleotide sequence of ORF1 and ORF2, respectively. A genotype 4 boar HEV isolate (wbJGF_08-1) obtained herein shared 98.6% identity over the entire genome with a human HEV isolate obtained from a patient who developed acute hepatitis after consuming undercooked wild boar meat, suggesting that wild boars are also reservoirs for genotype 4 HEV in humans.

Effect of implant surface roughness on bone fixation: the differences between bone and metal pegs.

BACKGROUND: Pegs made from cortical bone are used to fix osteochondral fractures and osteochondral dissecans. This technique has many advantages, but it requires long-term immobilization. This study examined the effect of surface roughness on fixation with bone and metal pegs. METHODS: Pegs with either rough or smooth surfaces were made of cortical bone from Japanese black cattle or from stainless steel (SUS316L). The mean roughness of the rough surface was 15.0 microm, whereas that of the smooth surface was less than 0.6 microm. Pegs were inserted into holes made in the distal femurs of 34 rabbits. At the time of surgery and 14 days later, mechanical tests and micro-computed tomography were performed. RESULTS: At the time of surgery, although the push-out forces were less than 0.3 N, the rough surface had a higher value than the smooth surface (P = 0.0002). No difference was observed according to the material (P = 0.54). Fourteen days after surgery, no significant difference was detected in the push-out forces between bone pegs with rough and smooth surfaces (489.0 +/- 149.6 vs 478.3 +/- 134.4 N (mean +/- SD), respectively), but a marked difference was seen with the metal pegs (235.7 +/- 115.7 vs 2.2 +/- 1.6 N). The bone pegs with rough surfaces made contact with the recipient bone at the high points on the abraded surfaces. After the mechanical tests, the fusion was broken within the new bone for bone pegs with rough or smooth surfaces, but no breakage occurred at the junction of bone peg and new bone. CONCLUSION: The surface roughness of bone pegs has little effect on bone-to-bone fusion 2 weeks postoperatively, unlike the effect with metal pegs.

Snail suppresses cellular senescence and promotes fibroblast-led cancer cell invasion.

Snail, a zinc finger transcription factor, induces an epithelial-mesenchymal transition (EMT) in various cancer and epithelial cells. We investigated the function of Snail (SNAI1) by downregulating its expression with short interfering RNA (siRNA). Suppression of Snail expression induced cellular senescence in several cancer cells and in normal fibroblast IMR90 cells. Cancer progression is facilitated by fibroblasts, so-called fibroblast-led cancer cell invasion. Snail-silenced cancer cells exhibited reduced motility, which was further decreased by cocultivation with Snail-silenced IMR90 cells. Our data suggest that cell motility and cellular senescence, which are regulated by Snail in cancer cells and fibroblasts, modulate fibroblast-led cancer cell invasion. Therefore, we propose that local suppression of Snail in cancer and the cancer microenvironment represents a potent therapeutic strategy.