Israel Medical Association Journal

Background: Patients with mechanical prosthetic heart valves must be treated with vitamin K antagonists (VKA) due to an increased risk of valve thrombosis and systemic embolism.

Objectives: To assess the effects of the COVID-19 pandemic on VKA treatment control in patients with mechanical prosthetic heart valves.

Methods: We conducted a retrospective nationwide cohort study using the Clalit Health Services database. The cohort included patients who underwent either aortic or mitral valve replacement using a prosthetic mechanical valve. The primary outcomes included the overall time in therapeutic range (TTR) and the percent of patients with a TTR < 50% during the first year of the COVID-19 pandemic compared to preceding year.

Results: The cohort included 2381 patients. The percentage of patients who had at least two international normalized ratio (INR) tests during the first year of the COVID-19 pandemic was significantly lower compared to the year preceding the pandemic (81% and 87%, respectively, P < 0.001). In both years, the percentage of patients without any documented INR test was high (31.5% in the first COVID-19 pandemic year and 28.9% in the preceding year, P < 0.001). TTR was significantly lower during the 1st year of the COVID-19 pandemic compared to the preceding year (68.1% ± 26 and 69.4% ± 24, P = 0.03). A TTR > 50% was demonstrated in 78% and 81% during the pandemic and the preceding year, P = 0.009.

Conclusions: We noted overall poor VKA control in patients with mechanical heart valves. During the COVID-19 pandemic, VKA control became even worse as reflected by significantly lower TTR and INR tests rates.

Background: Current guidelines for the treatment of heart failure with reduced ejection fraction (HFrEF) are based on studies that have excluded or underrepresented older patients.

Objectives: To assess the value of guideline directed medical therapy (GDMT) in HFrEF patients 80 years of age and older.

Methods: A single-center retrospective study included patients hospitalized with a first and primary diagnosis of acute decompensated heart failure (ADHF) and ejection fraction (EF) of ≤ 40%. Patients 80 years of age and older were stratified into two groups: GDMT, defined as treatment at hospital discharge with at least two drugs of the following groups: beta-blockers, angiotensin converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB), or mineralocorticoid antagonists; and a personalized medicine group, which included patients who were treated with up to one of these drug groups. The primary outcomes were 90-day all-cause mortality, 90-day rehospitalization, and 3-years mortality.

Results: The study included 1152 patients with HFrEF. 254 (22%) patients who were at least 80 years old. Of the group, 123 were GDMT at discharge. When GDMT group was compared to the personalized medicine group, there were no statistically significant differences in terms 90-day mortality (17% vs. 13%, P = 0.169), 90-day readmission (51 % vs. 45.6%, P = 0.27), or 3-year mortality (64.5% vs. 63.3%, P = 0.915).

Conclusions: Adherence to guidelines in the older adult population may not have the same effect as in younger patients who were studied in the randomized clinical trials. Larger prospective studies are needed to further address this issue.

Background: Circulating endothelial progenitor cells have an important role in the process of vascular repair. Impaired recruitment and function of endothelial progenitor cells is related to the pathophysiology of congestive heart failure. Endothelial progenitor cells have been shown to express the mineralocorticoid receptor. 

Objectives: To investigate the effect of mineralocorticoid receptor antagonists on endothelial progenitor cells in patients with heart failure. 

Methods: Twenty-four patients with compensated heart failure, who were not under mineralocorticoid receptor antagonist therapy, were recruited. Either eplerenone (n=8) or spironolactone (n=16) therapy was initiated. Circulating endothelial progenitor cell level, identified as the proportion of mononuclear cells expressing vascular endothelial growth factor receptor 2 (VEGFR-2), CD133, and CD34, was evaluated by flow cytometry at baseline and after 8 weeks. Following 7 days of culture, colonies were counted by microscopy and MTT assay was performed on randomly selected patients (n=12) to estimate viability.

Results: Both median CD34+/VEGFR2+ and median CD133+/VEGFR2+ increased significantly (P = 0.04 and 0.02, respectively). However, the number of colonies and viability of the cells after therapy (as assessed by the MTT assay) was not significantly different compared with the baseline. 

Conclusions: These preliminary results suggest that mineralocorticoid receptor blockade may enhance endothelial progenitor cells recruitment in patients with compensated heart failure.

The Ink4a-Arf locus, which encodes two distinct tumor suppressor proteins, is inactivated in many cancers. Whereas p16^Ink4a is an inhibitor of cyclin D-dependent kinases, p19^Arf (p14^ARF in humans) antagonizes the E3 ubiquitin protein ligase activity of Mdm2 to activate p53. We now recognize that Arf functions in both p53-dependent and -independent modes to counteract hyper-proliferative signals originating from proto-oncogene activation, but its p53-independent activities remain poorly understood. Arf proteins are highly basic (> 20% arginine content, pI > 12) and predominantly localize within nucleoli in physical association with an abundant acidic protein, nucleophosmin (NPM/B23). When bound to NPM[1], Arf proteins are relatively stable with half-lives of 6–8 hours. Although mouse p19^Arf contains only a single lysine residue and human p14^ARF has none, both proteins are N-terminally ubiquitinated and degraded in proteasomes. Through as yet uncharacterized mechanisms, p19^Arf induces p53-independent sumoylation of a variety of cellular target proteins with which it interacts, including both Mdm2 and NPM. A naturally occurring NPM mutant (NPMc) expressed in myeloid leukemia cells redirects both wild-type NPM and p19^Arf to the cytoplasm, inhibits Arf-induced sumoylation, and attenuates p53 activity. Thus, ubiquitination and sumoylation can each influence Arf tumor suppressor activity.

Background: Repaglinide, a new insulin secretagogue, is purported to be as effective as sulphonylurea but is less hypoglycemic-prone.

Objectives: To assess the efficacy of repaglinide and its proclivity for hypoglycemia in a post-marketing study.

Methods: The study group comprised 688 patients, aged 26–95 years, clinically diagnosed with non-insulin-dependent type 2 diabetes. The patients were divided into three groups based on previous therapy: a) sulphonylurea-treated (group 1, n=132); b) metformin with or without sulphonylurea where sulphonylurea was replaced with repaglinide. (group 2, n=302); and c) lifestyle modification alone (drug-naïve) (group 3, n=254). At initiation of the study, all patients were transferred from their current treatment to repaglinide. Only patients in group 2, with combined sulphonylurea plus metformin, continued with metformin plus repaglinide. Fasting blood sugar, hemoglobin A1c and weight were measured at study entry and 4–8 weeks following repaglinide therapy. A questionnaire documented the number of meals daily and the presence of eating from fear of hypoglycemia.

Results: The fasting blood sugar level of the entire cohort dropped from 191 ± 2.4 to 155 ± 2.0 mg/dl (P < 0.0001); HbA1c from 8.8 ± 0.1 to 7.7 ± 0.1% (P < 0.0001). The drop of HbA1c in groups 1, 2 and 3 respectively were: 1.04 ± 0.22% (P < 0.0001), 1.14 ± 0.24% (P < 0.0001), and 1.51 ± 0.31% (P = 0.0137). Weight dropped from 81 ± 0.7 to 80.2 ± 0.7 kg (P < 0.0001), and eating from fear of hypoglycemia from 157 to 97 (P < 0.001). The daily number of meals decreased from 2.9 ± 0.4 to 2.4 ± 0.4 (P < 0.001). No serious adverse reactions occurred during the study.

Conclusions: Repaglinide is an effective oral hypoglycemic agent taken either as monotherapy or combination therapy. There is less eating to avoid hypoglycemia, fewer meals consumed, and weight loss.
 

Background: Repaglinide, a new insulin secretagogue, is purported to be as effective as sulphonylurea but is less hypoglycemic-prone.

Objectives: To assess the efficacy of repaglinide and its proclivity for hypoglycemia in a post-marketing study.

Methods: The study group comprised 688 patients, aged 26–95 years, clinically diagnosed with non-insulin-dependent type 2 diabetes. The patients were divided into three groups based on previous therapy: a) sulphonylurea-treated (group 1, n=132); b) metformin with or without sulphonylurea where sulphonylurea was replaced with repaglinide. (group 2, n=302); and c) lifestyle modification alone (drug-naïve) (group 3, n=254). At initiation of the study, all patients were transferred from their current treatment to repaglinide. Only patients in group 2, with combined sulphonylurea plus metformin, continued with metformin plus repaglinide. Fasting blood sugar, hemoglobin A1c and weight were measured at study entry and 4–8 weeks following repaglinide therapy. A questionnaire documented the number of meals daily and the presence of eating from fear of hypoglycemia.

Results: The fasting blood sugar level of the entire cohort dropped from 191 ± 2.4 to 155 ± 2.0 mg/dl (P < 0.0001); HbA1c from 8.8 ± 0.1 to 7.7 ± 0.1% (P < 0.0001). The drop of HbA1c in groups 1, 2 and 3 respectively were: 1.04 ± 0.22% (P < 0.0001), 1.14 ± 0.24% (P < 0.0001), and 1.51 ± 0.31% (P = 0.0137). Weight dropped from 81 ± 0.7 to 80.2 ± 0.7 kg (P < 0.0001), and eating from fear of hypoglycemia from 157 to 97 (P < 0.001). The daily number of meals decreased from 2.9 ± 0.4 to 2.4 ± 0.4 (P < 0.001). No serious adverse reactions occurred during the study.

Conclusions: Repaglinide is an effective oral hypoglycemic agent taken either as monotherapy or combination therapy. There is less eating to avoid hypoglycemia, fewer meals consumed, and weight loss.

Background: Leukotriene antagonist therapy in asthmatic patients alleviates symptoms and improves exercise tolerance, however the effect of these drugs on bronchial provocation tests and exhaled nitric oxide levels are less clearly established.

Objective: To determine the effect of montelukast treatment on airway hyperresponsiveness to exercise, methacholine and adenosine-5’-monophosphate and on exhaled nitric oxide levels in steroid-naive asthmatics.

Methods: Following a 2 week run-in period, 20 mild to moderate asthmatics were enrolled in an open label 6 week trial of oral montelukast-sodium therapy. Bronchial hyperreactivity (exercise, methacholine and adenosine-5’-monophosphate challenges) and exhaled nitric oxide levels were measured before and after the 6 week period.

Results: Montelukast treatment resulted in a significant improvement in exercise tolerance: median DFEV₁ 20.0% (range 0–50) prior to treatment vs. 15.0% (range 0–50) post-treatment (P = 0.029). A significant difference was also observed for exhaled NO[1] following therapy: median NO 16.0 ppb (range 7–41) vs. 13.0 (range 4.8–26) (P = 0.016). No change was seen in baseline lung function tests (FEV₁, MEF₅₀) or in the bronchial responsiveness (PC₂₀) for methacholine and adenosine-5’-monophosphate.

Conclusions: This study demonstrates that the leukotriene antagonist, montelukast-sodium, reduces bronchial hyperreactivity in response to exercise and reduces exhaled nitric oxide levels but has little effect on bronchial responsiveness to methacholine and adenosine challenges.

Ghrelin, a 28 amino acid acylated peptide predominantly produced by the stomach, displays strong growth hormone-releasing activity mediated by the hypothalamus-pituitary GH[1] secretagogue receptors that were found to be specific for a family of synthetic, orally active GH secretagogues. The discovery of ghrelin brings us to a new understanding of the regulation of GH secretion. However, ghrelin is much more than simply a natural GH secretagogue. It also acts on other central and peripheral receptors and exhibits other actions, including stimulation of lactotroph and corticotroph secretion, orexigenia, influences gastroenteropancreatic functions, and has metabolic, cardiovascular and anti-proliferative effects. Knowledge of the whole spectrum of biologic activities of this new hormone will provide new understanding of some critical aspects of neuroscience, metabolism and internal medicine. In fact, GHS[2] were born more than 20 years ago as synthetic molecules, eliciting the hope that orally active GHS could be used to treat GH deficiency as an alternative to recombinant human GH. However, the dream did not become reality and the usefulness of GHS as an anabolic anti-aging intervention restoring the GH/IGF-I[3] axis in somatopause is still unclear. Instead, we now face the theoretic possibility that GHS analogues acting as agonists or antagonists could become candidate drugs for the treatment of pathophysiologic conditions in internal medicine totally unrelated to disorders of GH secretion. 

Background: Superantigens produced by Staphylococcus aureus and Streptococcus pyogenes are among the most lethal of toxins. Toxins in this family trigger an excessive cellular immune response leading to toxic shock.

Objectives: To design an antagonist that is effective in vivo against a broad spectrum of superantigen toxins.

Methods: Short peptide antagonists were selected for their ability to inhibit superantigen-induced expression of human genes for cytokines that mediate shock. The ability of these peptides to protect mice against lethal toxin challenge was examined.

Results: Antagonist peptide protected mice against lethal challenge with staphylococcal enterotoxin B and toxic shock syndrome toxin-1, superantigens that share only 6% overall amino acid homology. Moreover, it rescued mice undergoing toxic shock. Antagonist peptides show homology to a β-strand/hinge/a-helix domain that is structurally conserved among superantigens, yet remote from known binding sites for the major histocompatibility class II molecule and T cell receptor that function in toxic T cell hyperactivation.

Conclusions: The lethal effect of superantigens can be blocked with a peptide antagonist that inhibits their action at the top of the toxicity cascade, before activation of T cells occurs. Superantigenic toxin antagonists may serve not only as countermeasures to biologic warfare but may be useful in the treatment of staphylococcal and streptococcal toxic shock, as well as in some cases of septic shock.