COVID-19 vaccination - Does it affect sick leave in military personnel?

OBJECTIVE: Sick leave is a major negative economic effect of the COVID-19 pandemic. In April 2021, the Integrated Benefits Institute reported that employers spent a total of US $50.5 billion for workers absent due to the COVID-19 pandemic. While vaccination programs lowered the number of severe illness and hospitalizations worldwide, the number of side effects following vaccination against COVID-19 were high. The present study aimed to evaluate the effect of vaccination on the probability of taking sick leave in the week following vaccination. SUBJECTS AND METHODS: The study population was comprised of all personnel serving in the Israel Defense Forces (IDF) between October 7, 2020, and October 3, 2021, (a total of 52 weeks) who were vaccinated with at least one dose of the BNT162b2 vaccine. Data on Israel Defense Forces (IDF) personnel sick leaves were retrieved and the probability of a "post-vaccination week sick leave" and a "regular (not post-vaccination week) sick leave" were analyzed. An additional analysis was performed to determine whether winter-related diseases or the sex of the personnel affected the probability of taking sick leave. RESULTS: The probability of taking sick leave in a post-vaccination week was significantly higher than the probability of taking sick leave in a regular week (8.45% vs. 4.3%, respectively, p < 0.01). The increased probability remained unchanged after analysis of sex-related and winter disease-related variables. CONCLUSIONS: Given the major effect of vaccination against COVID-19 by BNT162b2 vaccine on the probability of taking sick leave, when medically feasible, the timing of the vaccination should be considered by medical, military, and industrial authorities with the intent to minimize the effect on overall national economy and safety.

Reprint of: Comparative Studies of Rabbit Cardiac and Skeletal Myosins.

Rabbit cardiac myosin contains fewer cysteine residues than the skeletal myosin (7 and 8.8 moles/105 gm. of myosin, respectively). A similar difference is found between the cysteine content of rabbit cardiac and skeletal heavy meromyosins; the cardiac heavy meromyosin contains 8.9 moles/105 gm. of protein as compared to 11 moles in the skeletal heavy meromyosin. In skeletal myosin, actomyosin, and myofibrils the Ca++-ATPase, Ca++-ITPase, and EDTA-ATPase activities are about three times higher than those of cardiac myosin, actomyosin, and myofibrils; whereas the skeletal to cardiac actomyosin-ATPase activity ratio is higher. The ATPase activities of both cardiac and skeletal myosins, actomyosins, and myofibrils, however, are close to each other when determined in the presence of Mg++ at high ionic strength. The abilities of cardiac and skeletal myosins to combine with actin at either high or low ionic strength are also essentially the same. The Ca++-ATPase, Ca++-ITPase, EDTA-ATPase, and actomyosin-ATPase activities of cardiac myosin, heavy meromyosin, and myofibrils, unlike those of skeletal myosin, heavy meromyosin, and myofibrils, do not increase over pH 8.0. The ATPase activities of cardiac and skeletal myosins in the presence of Mg++ at high ionic strength, on the other hand, are affected similarly by changes of pH. In cardiac myosin, heavy meromyosin, and myofibrils, the Ca++activated ATPase is less sensitive to high KC1 concentrations than is that of skeletal myosin, heavy meromyosin, and myofibrils.

Molecular structure of the bony tissue after experimental trauma to the mandibular region followed by laser therapy.

OBJECTIVE: We investigated the therapeutic efficiency of laser irradiation and Bio-Oss, both and separately, on the post-traumatic regeneration of bone tissue in rats using infrared spectroscopy as an informative and accurate measuring method. BACKGROUND DATA: The therapeutic effect of low-power laser irradiation on bone tissue regeneration processes in animal models has been studied using morphogenic, biochemical, roentgenographic and electron microscopic measurements. Natural bone minerals, such as Bio-Oss collagen, were recommended for the reconstruction of bone defects in the alveolar process. MATERIALS AND METHODS: 29 male Wistar rats, divided into four random groups in a blinded manner were operated on the right alveolar process. A bone defect was made by penetrating the right alveolar process of the mandible bone using a 3-mm drill. The rats were divided into four groups as follows: Group I, left side served as intact bone and right injured side as the control; Group II, right injured side was treated by organic bovine bone (Bio-Oss); Group III, right side bone defect was treated by HeNe laser (632.8 nm, 35 mW) applied transcutaneously for 20 min to the injured area daily for the following 14 consecutive days; and Group IV, Bio-Oss was placed loosely in the right side defect followed by laser treatment. After 2 weeks, the intact bone and bone replicas of the trauma area were removed and analyzed by infra-red spectroscopy technique. The composition and the structure of the bone tissue mineral substances were determined and compared among the four groups. For quantitative analysis of the regenerative bone process, the Mineralization index was used. An increase in this index indicates regenerative bone processes. RESULTS: The normal state analysis of the IR spectra of the normal alveolar bone tissue within the intervals of 400 to 4000 cm(-1) revealed characteristic absorption bands for the inorganic bone component in spectrum regions 450-1480 cm(-1), and the organic component at 1540-3340 cm(-1). In the case of trauma, the intensity of absorption of the inorganic component was decreased by 54%, and the absorption band became narrow, which can be interpreted as quantitative changes of the bone tissue mineral content. The wavelength characteristics of the inorganic component remained unchanged; that is, the induced trauma under these experimental conditions did not provoke alterations in the structure of the phosphate framework. The organic component showed decreased absorption by 10-15%, compared to the normal bone, and slight displacement of the wavelength, which can be interpreted as changes occurring in the quality of the organic content of the bone tissue. In the Bio-Oss-treated group, the intensity of absorption of the inorganic component increased by 43%, compared to the control injured area; however, there was a decrease of 22.6% in the normal bone. The wavelength characteristics of the inorganic component remained unchanged. The organic component showed similar absorption results in the injured non-treated group and absorption was 10-15% less than in the normal bone. Mineralization Index in the Bio-Oss-treated group was 0.93, compared to 0.63 in the control group and 2.04 in the normal bone. In the laser-treated group, the intensity of absorption of the inorganic component increased by 62, compared to the control injured area, and decreased only 11.4% in the normal bone. The wavelength characteristics of the organic component remained unchanged; that is, the organic component was similar to that of normal bone. Mineralization Index in the laser-treated group increased significantly to 1.86, compared to 0.63 in the control group and 2.04 in the normal bone. In the combined laser and Bio-Oss-treated groups, the intensity of absorption of the inorganic component and organic component was similar to that of normal bone. Mineralization Index in this group increased significantly to 1.98, compared to 0.63 in the control group and 2.04 in the normal bone. CONCLUSION: The results suggest that low-power laser irradiatults suggest that low-power laser irradiation alone and in combination with Bio-Oss enhances bone healing and increases bone repair.

Cathepsin S activity regulates antigen presentation and immunity.

MHC class II molecules display antigenic peptides on cell surfaces for recognition by CD4(+) T cells. Proteolysis is required in this process both for degradation of invariant chain (Ii) from class II-Ii complexes to allow subsequent binding of peptides, and for generation of the antigenic peptides. The cysteine endoprotease, cathepsin S, mediates Ii degradation in human and mouse antigen-presenting cells. Studies described here examine the functional significance of cathepsin S inhibition on antigen presentation and immunity. Specific inhibition of cathepsin S in A20 cells markedly impaired presentation of an ovalbumin epitope by interfering with class II-peptide binding, not by obstructing generation of the antigen. Administration of a cathepsin S inhibitor to mice in vivo selectively inhibited activity of cathepsin S in splenocytes, resulting in accumulation of a class II-associated Ii breakdown product, attenuation of class II-peptide complex formation, and inhibition of antigen presentation. Mice treated with inhibitor had an attenuated antibody response when immunized with ovalbumin but not the T cell-independent antigen TNP-Ficoll. In a mouse model of pulmonary hypersensitivity, treatment with the inhibitor also abrogated a rise in IgE titers and profoundly blocked eosinophilic infiltration in the lung. Thus, inhibition of cathepsin S in vivo alters Ii processing, antigen presentation, and immunity. These data identify selective inhibition of cysteine proteases as a potential therapeutic strategy for asthma and autoimmune disease processes.

Neuroactive steroids protect against pilocarpine- and kainic acid-induced limbic seizures and status epilepticus in mice.

Several structurally related metabolites of progesterone (3 alpha-hydroxy pregnane-20-ones) and deoxycorticosterone (3 alpha-hydroxy pregnane-21-diol-20-ones) and their 3 beta-epimers were evaluated for protective activity against pilocarpine-, kainic acid- and N-methyl-D-aspartate (NMDA)-induced seizures in mice. Steroids with the 3-hydroxy group in the alpha-position and 5-H in the alpha- or beta-configurations were highly effective in protecting against pilocarpine (416 mg/kg, s.c.)-induced limbic motor seizures and status epilepticus (ED50 values, 7.0-18.7 mg/kg, i.p.). The corresponding epimers with the 3-hydroxy group in the beta-position were also effective but less potent (ED50 values, 33.8-63.5, i.p.). Although the neuroactive steroids were considerably less potent than the benzodiazepine clonazepam in protecting against pilocarpine seizures, steroids with the 5 alpha,3 alpha-configuration had comparable or higher protective index values (TD50 for motor impairment divided by ED50 for seizure protection) than clonazepam, indicating that some neuroactive steroids may have lower relative toxicity. Steroids with the 5 alpha,3 alpha- or 5 beta,3 alpha-configurations also produced a dose-dependent delay in the onset of limbic seizures induced by kainic acid (32 mg/kg, s.c.), but did not completely protect against the seizures. However, when a second dose of the steroid was administered 1 hr after the first dose, complete protection from the kainic acid-induced limbic seizures and status epilepticus was obtained. The steroids also caused a dose-dependent delay in NMDA (257 mg/kg, s.c.)-induced lethality, but did not completely protect against NMDA seizures or lethality. We conclude that neuroactive steroids are highly effective in protecting against pilocarpine- and kainic acid-induced seizures and status epilepticus in mice, and may be of utility in the treatment of some forms of status epilepticus in humans.

Color associations of male and female fourth-grade school children.

Four groups (two male and two female) were asked to respond to a number of concepts with the first color that came to mind. Results led to the following conclusions: (a) We replicated Byrnes' (1983) findings that indicated that there is a definite color association among children to stimuli; (b) there was no significant difference between the responses of the male children and those of the female children; (c) two opposing findings concerning the perceived valence of colors were both supported by the data; and (d) we found that emotionally loaded stimuli evoked similar responses from males and females, whereas neutral stimuli elicited different responses.

Norepinephrine stimulation of pentose cycle in rat brain prisms.

Using the C1/C6 14CO2 ratio as a relative measure of pentose shunt metabolism, rat brain prisms were incubated with (1-14C) or (6-14C) glucose and respired 14CO2 collected. Shunt metabolism was stimulated with 10-4M but not 10-5M norepinephrine. MAO inhibitors and reserpine blocked norepinephrine stimulation but uptake inhibition did not. These data demonstrate that, under the tested conditions, MAO mediated norepinephrine metabolism does stimulate shunt activity but not at physiological concentrations.

Hemispheric differences in simple reaction time to auditory stimuli of different frequencies.

To determine whether reaction time varies as a function of tone frequency and/or ear stimulated 27 adult subjects were presented with two two-tone series (1,000 Hz vs 2,500 Hz and 1,500 Hz vs 4,000 Hz) in a simple reaction-time paradigm. The analyses clearly indicated that the higher tone in each series and stimulation to the right ear resulted in significantly shorter reaction times. These results were interpreted as indicating that cerebral asymmetries are apparent in tasks and with stimuli that do not seem to require higher-order inferences regrading the functional organization of the cerebral hemispheres.