How should low-contrast detail detectability be measured in fluoroscopy?

The relationship and precision of four methods for measuring the low-contrast detail detectability in fluoroscopic imaging were studied. These included the physical measurement of the accumulation rate of the square of the signal-to-noise ratio (SNR(rate)2), two-alternative forced-choice (2-AFC) experiments, sixteen-alternative forced-choice (16-AFC) experiments and subjective determination of the threshold contrast. The precision and sensitivity of the threshold contrast measurement were seen to be modest in the constancy testing of fluoroscopic equipment: only large changes in system performance could be reliably detected by that method. The measurement of the SNR(rate)2 is suggested instead. The relationship between the results of the various methods were studied, and it was found that human performance can be related to SNR(rate)2 by introducing the concept of the effective image information integration time (t(eff)). When measured for an unlimited observation time, it depicts the saturation of human performance in detecting a static low-contrast detail in dynamic image noise. Here, t(eff) was found to be about 0.6 s in 2-AFC tests and 0.3 s in 16-AFC tests.     

How should stainable iron in bone marrow films be assessed?

AIMS: To identify how many particles should be examined to enable a confident assessment of the presence or absence of iron stores and the quantity of iron in a bone marrow aspirate to be made. METHODS: One hundred and ninety consecutive bone marrow aspirate samples were stained with Perls' stain and the iron content of 10 consecutive particles was recorded. The first particle found to be positive and the particle that was most positive were also noted. RESULTS: A minimum of seven particles must be examined to establish the absence of stainable iron. A minimum of nine particles must be reviewed to see the maximum iron stores in 100% of samples and therefore make a valid judgment of whether iron stores are reduced, normal, or increased. By these criteria, 46% of the samples tested here could not be optimally assessed for absence of iron or maximum iron stores. CONCLUSIONS: The sensitivity of examination of bone marrow aspirates for iron stores can be optimised by increasing the number of particles reviewed to seven or more. This may require the staining of additional slides.     

How should be the genetic medicine in the near future?

Massive and systematic information on human genes and genome is accumulating with progress in the Human Genome Project. Information on the genome has the characteristics of a digital signal appropriate for high-throughput handing by computers. Therefore, the field of gene tests has a high affinity to the field of laboratory medicine. In addition, it is important for survival strategy by departments of laboratory medicine that stand on the edge. We have to establish an infrastructure to utilize genome information in clinical medicine while anticipating numerous issues. The following issues need to be addressed in addition to the previous report(Rinsho Byori 50: 156-160, 2002) 1. Integral system for genetic medicine. 2. Center for human germline gene tests. 3. Quality control of human gene tests. 4. Epidemiological data of germline gene tests.     

Do greater rates of body heat storage precede the accelerated reduction of self-paced exercise intensity in the heat?

Aim

To reevaluate the previous hypothesis that greater reductions in self-paced exercise intensity in the heat are mediated by early differences in the rate of body heat storage (S).

Methods

Eight trained volunteers cycled in 19 °C/1.8 kPa (COOL), 25 °C/1.2 kPa (NORM), and 34 °C/1.6 kPa (HOT), while maintaining an RPE of 16. Potential differences in S following the onset of exercise were assessed by comparing rates of esophageal temperature change (ΔT _es/Δt); and estimated S values using a traditional two-compartment thermometric model (S _therm) of changes in rectal (T _re) and skin (T _sk) temperature, and partitional calorimetry (S _cal).

Results

After 15 min of exercise, workload decreased more in HOT vs. COOL (P = 0.03), resulting in a shorter time (HOT: 40.7 ± 14.9 min; COOL: 53.5 ± 18.7 min; P = 0.04) to 70 % of initial workload. However, there were no preceding differences in ΔT _es/Δt between conditions (P = 0.18). S _therm values were different between HOT and COOL during the first 5 min of exercise (P < 0.05), primarily due to negative S _therm values (?32 ± 15 kJ min^?1) in COOL, which according to partitional calorimetric measurements, required improbably high (~56 kJ min^?1) rates of evaporation when no sweating on the back and thigh was observed until after 7.6 ± 1.5 min and 4.8 ± 1.7 min of exercise, respectively. S _cal values in the first 5 min of exercise confirmed S was actually positive in COOL (+21 ± 8 kJ min^?1) and not negative. Different S _therm values following the onset of exercise at different environmental temperatures are simply due to transient differences in the rate of change in T _sk.

Conclusion

Reductions in self-paced exercise intensity in the heat are not mediated by early differences in S following the onset of exercise.     

Serious genetic disorders: can or should they be defined?

The word "serious" appears in laws and policies regarding genetics services but is not defined. Genetics professionals would most likely be consulted if definitions are made. We surveyed all U.S. board-certified genetics services providers and all members of the European Society of Human Genetics (ESHG), Canadian College of Medical Geneticists (CCMG), and Ibero-American Society of Human Genetics (IASHG), using anonymous, mailed questionnaires. Respondents were asked to list three conditions they considered lethal, three that were serious but not lethal, and three that were not serious. Of 3,317 asked to respond, 1,481 (45%) returned questionnaires. Analysis was limited to responses of the 1,264 (85%) who saw patients. Respondents listed 537 conditions, with extensive overlap between categories; 46% of conditions listed as serious were also listed as not serious and 41% were listed as lethal. Respondents did not want professional societies, laws, or national ethics committees to define serious. They favored individual patients as decision makers, with the help of individual doctors. Their reasons were that genetic disorders vary in expression, individuals perceive disorders differently, professional or legal definitions could be unfair to minority groups, definitions tend to be inflexible when new treatments appear. In the United States, most would not use a definition of serious to limit reproductive services, carrier screening, or neonatal intensive care; outside the United States, more supported limitations. There is not sufficient consensus among experienced genetics professionals to define serious genetic conditions for purposes of law or policy. Responses point to social and economic influences on perceptions of what constitutes a serious genetic disorder.     

Hexameric immunoglobulin M in humans: desired or unwanted?

Immunoglobulin M (IgM) is the first antibody produced upon infection, and is often suggested as the first line of defense of human immune system. In addition to being present on the surface of naïve B cells as a monomeric molecule, IgM is always secreted as a polymer. The most abundant IgM polymer in humans is pentamer, composed of five monomeric units, joined together by so-called joining or J chain. On the other hand, it is well known that hexameric IgM can be also found in human sera. Its presence is often related to different dissorders (Waldenström’s macroglobulinemia, cold agglutinin, and recurrent urinary bacterial infections), although it is believed that small amounts of hexamer are present in normal human sera as well. Unlike pentamer, IgM hexamer contains six monomeric blocks and completely lacks J chain. Although it has been decades since its discovery, the precise function of IgM hexamer is still unknown. Since it was documented that hexamer is very potent in activating complement, it is suggested that its production in humans must be under strict control, and that it is produced in special conditions, when strong activation of complement is absolutely needed. However, the question is whether hexameric IgM is really a secret weapon or just an undesirable molecule in humans. According to structural and known functional characteristics of both pentamers and hexamers of IgM, it can be concluded that hexamers are, in addition to being maybe too reactive to be around, probably not that efficient in protecting us from bacterial and viral infections.     

How should the chest wall be opened at necropsy?

AIMS: To compare several different instruments used to open the chest wall during necropsy and to assess whether any one type reduced the production of sharp rib ends and thus the potential for receiving an injury. METHODS: During the necropsy the pathologist opened the chest wall using two randomly assigned instruments from a selection of hand saw, electric saw, rib shears, and bread knife. The age, weight, sex, and height of the deceased were recorded, in addition to the textures of the resultant exposed rib ends. During the procedure, the speed, length, production of spray, and site of incision were also noted. The thoracic cavity was inspected and any details of tumours, adhesions, fluid, or organ damage were noted. RESULTS: Twenty four necropsies were carried out on an equal number of men and women. The total number of ribs that were incised was 422, with 206 through the bony aspect (49%). Sixty seven per cent of the bony rib ends were rough, and this was found to be instrument dependent. The rib shears produced the highest number of rough bony and cartilage rib ends. The electric saw produced the smoothest contoured rib ends. Spray occurred in 29% of cases, exclusively with the use of the electric saw. Organ damage was most frequently associated with the use of the bread knife. CONCLUSION: Rib shears, the instrument most frequently used to open the chest wall, appear to cause the highest frequency of rough, potentially dangerous rib ends. The electric saw produced the smoothest rib ends, both in cartilage and bone, and thus seems to offer the most efficacious method of reducing the potential hazard associated with ragged, spiky bone ends during the opening of the thoracic cavity. Although each of the procedures detailed in this study was shown to have its own advantages and disadvantages, personal preference and operator experience are perhaps the most important factors in ultimately determining the method used.     

How optional should regional anatomy be in a medical course? An opinion piece

The use of optional (elective) courses within the medical curriculum is increasingly being seen as a way of allowing students to pursue their studies according to their personal interests. For anatomy, particularly where the subject is being taught in an integrative curriculum and by means of a systemic approach, the development of elective regional anatomy courses is being employed to reintroduce regional anatomy and/or dissection by students. However, there is presently little evidence that objectively evaluates optional/elective courses. In this paper we critique the concept and practice of using elective courses and assess whether their deployment is ultimately in the interests of medical education, the medical profession, society in general and the layperson (potential patient) in particular. Clin. Anat. 29:702–710, 2016. © 2016 Wiley Periodicals, Inc.     

How many bones? Every bone in my body

Textbooks frequently report that there are 206 human bones, or 200 bones and 6 auditory ossicles. The human bone counts in history and within adulthood were reviewed. Tallies of 197 to 307 bones have been reported over the past several centuries. The relatively low modern reckoning of 206 was due to exclusion of teeth and sesamoid ossicles, and to reassessments of the hyoid, sacrum, coccyx, and sternum as unitary bones. An audit of bone counts during adulthood failed to confirm a rational justification for the total of 206. The number is higher in young adults and lower in the elderly. Difficulties in establishing a definitive bone count include individual differences and the inconsistency of viewing the adult cranium as a collection of 21 bones. Clin. Anat. 33:187–191, 2020. © 2019 Wiley Periodicals, Inc.     

Hepatitis B: who should be treated?

Patients with moderate to severe chronic hepatitis and active HBV replication should be managed according to HBeAg status and presence of coinfecting virus(es) (HDV, HCV, HIV). Treatment is also recommended for immunocompromised patients and those older than 60 years with acute HBV infection. Current treatment of chronic hepatitis B has limited long-term efficacy. The patient's age, severity of liver disease, likelihood of response and possibility of adverse effects and complications should be considered before deciding on treatment.     

Hepatitis C: who should be treated?

The goals of treatment for hepatitis C are eradication of viral infection and prevention of progression to end-stage liver disease. To decide on whom to treat, it is necessary to consider the following parameters: stage of disease, comorbidity, patient age, probability of therapeutic success, contraindications, and therapy associated risks. Therapy is recommended in patients with elevated ALT levels, patients with normal ALT level and at least F2 METAVIR score, nonresponders to standard interferon monotherapy, patients with compensated liver cirrhosis, and patients with acute infection. It is possible to treat patients with HBV and HIV co-infection, patients with severe extrahepatic manifestations of HCV infection, and patients with transplanted liver. Drug users and alcoholics can be treated after 12-month abstinence. Therapy is not recommended in patients with fulminant hepatitis, patients with persistently normal ALT levels without fibrosis, kidney transplant recipients, and pregnant women.     

Self-efficacy and mood in cardiac rehabilitation: should gender be considered?

The authors proposed to (a) determine the influence of phase II cardiac rehabilitation (CR) on task and barrier efficacy and mood in men and women, (b) determine the influence of task and barrier efficacy on postphase II CR exercise adherence, and (c) examine the bidirectional relationship between self-efficacy and mood. Fifty-seven men and 24 women completed task and barrier efficacy scales and the anxiety, depression, and vigor subscales 3 to 5 weeks before phase II CR, immediately before and after phase II CR, and 6 to 10 weeks after phase II CR. They found that the women had significantly larger increases in task and barrier efficacy from pre- to postphase II CR than the men did, whereas both men and women had a significant decline at follow-up. Men and women had a similar decrease in anxiety and an increase in vigor during phase II CR. However, vigor significantly declined at follow-up. All changes in mood were significantly related to changes in task and barrier efficacy.