Israel Medical Association Journal

Fasting, a practice with deep historical roots, has gained scientific attention for its potential benefits on human health, particularly in autoimmune diseases. In this review, we explored the impact of fasting on immune function and autoimmunity. Autoimmune diseases, characterized by the immune system's attack on the body’s own tissues, are influenced by genetic, environmental, and dietary factors. Various forms of fasting (intermittent, water fasting, calorie restriction, ketogenic diets, and time-restricted feeding) affect metabolism, immune modulation, and inflammation reduction. These changes can promote autophagy, stem cell renewal, and immune system rebalancing by offering potential therapeutic effects for autoimmune conditions. Although more research is needed, fasting may serve as an adjunctive therapy for immune-mediated diseases by reducing symptoms and promoting remission. However, fasting must be approached with caution, particularly for individuals with specific autoimmune disorders. We reviewed the physiological changes during fasting, types of fasting regimens, and the clinical relevance in autoimmunity. Further studies are needed to validate these observations in patient populations.

The concept of starvation osteopathy is an old and an investigated one, which is well established in many ways. Studies were conducted on famine survivors during World War I, in the Ukraine in the early 1930s, throughout Europe during World War II, and in Asia and Africa soon after. However, the main topic of this article is the effect of starvation inflicted during the Holocaust.

Background: Klotho is a transmembrane protein that can be shed and can act as a circulating hormone in three forms: soluble klotho (KL1 + KL2), KL1, and KL2. Klotho was discovered as a gene implicated in aging through inhibition of the IGF-I pathway. Our laboratory discovered the role of klotho as a tumor suppressor in breast cancer and other malignancies. Furthermore, we showed that the KL1 domain mediates this activity. Altered cancer cell metabolism is a hallmark of cancer and our lab demonstrated various effects of klotho on breast cancer cell metabolism. Thus, klotho inhibited glycolysis and activated adenosine monophosphate activating kinase (AMPK), an energy sensor pathway. Moreover, inhibition of AMPK reduced the tumor suppressor activity of klotho.

Objectives: To assess the effect of KL1 on breast tumor cells metabolism, as KL1 possesses the tumor suppressor activity of klotho.

Methods: We used MCF-7 breast cancer cells treated with soluble or over-expressed KL1 and klotho. Glycolysis was assessed by measuring mRNA levels of key glycolytic enzymes using reverse transcription polymerase chain reaction and by measuring lactate and glucose levels in media. The AMPK pathway was studied by monitoring AMPK phosphorylation as well as its down-stream target, acetyl-CoA carboxylase, using western blotting. Wound healing assay was used to assess cell migration.

Results: KL1 treatment reduced glycolytic enzymes mRNA levels and the activity of hexokinase, similar to klotho treatment. Furthermore, KL1 reduced glucose uptake and decreased lactate production. KL1 elevated phosphorylated acetyl-CoA carboxylase and phosphorylatedAMPK levels. Inhibition AMPK (using a mutant AMPK activator) stopped KL1 from inhibiting cell migration, suggesting AMPK underlies klotho’s tumor suppressor activity.

Conclusions: Our data indicate KL1 as a regulator of metabolic activity in breast cancer and suggest that metabolic alterations underlie KL1 tumor suppressor activities. Furthermore, as KL1 and klotho share a similar effect on cell metabolism, our results further support the central role KL1 domain plays in klotho’s tumor suppressor activity.

Background: Diffuse large B-cell lymphoma (DLBCL) accounts for 30% of all non-Hodgkin lymphomas (NHL) and 80% of agressive lymphomas. Besides the traditional International Prognostic Index (IPI), some other factors may also influence the prognosis of DLBCL patients.

Objectives: To study how the genetic polymorphisms in the metabolic pathway influence the event-free and overall survivals and therapeutic responses in DLBCL.

Methods: The study was comprised of 51 patients (32 men, 19 women). The average age was 53.1 years. DLBCL was diagnosed between 2011 and 2016 and the average follow-up time was 3.78 years. These patients received 1–8 cycles (an average of 6.2 cycles) of rituximab, cyclophosphamide, doxorubicin, vincristin, prednisolon (R-CHOP) immunochemotherapy. Real-time polymerase chain reaction was used to determine the genetic polymorphisms of CYP2E1, GSTP1, NAT1, and NAT2 genes.

Results: Our results showed that the polymorphisms of CYP2E1, GSTP1, and NAT1 genes did not influence the prognosis of DLBCL patients significantly. In terms of the NAT2 gene, GG homozygous patients showed slightly better therapeutic response and survival results compared to those bearing an A allele; however, the differences were not statistically significant.

Conclusions: Our results could not confirm that genetic polymorphism in metabolic pathways has any predictive role in DLBCL. 

 

Background: Ulcerative colitis (UC) is a common and difficult-to-treat disease. In non-smokers the relative risk of developing UC[1] is 2.9 compared with smokers, who tend to have a later onset and a milder disease. Nicotine is the component of cigarette smoke responsible for the favorable effects in UC. Nicotine is metabolized by the enzyme CYP2A6. Subjects who are homozygotes for CYP2A6*4 gene polymorphism are poor nicotine metabolizers, while homozygotes for CYP2A6*1A polymorphism are extensive metabolizers.

Objectives: To compare the frequency of CYP2A6 and CHRNA3 polymorphisms among smokers and non-smokers with UC, and their effect on disease severity.

Methods: Data on the age at onset of disease, disease activity, and treatment were obtained from questionnaires completed by the 69 subjects in our study group. CYP2A6

*1A,*4A and CHRNA3 polymorphisms were determined by polymerase chain reaction and restriction enzyme analysis.

Results: Nine percent of the patients were current smokers, 30% were former smokers and 61% non-smokers. Among smokers and former smokers 63% were homozygotes for CYP2A6*1A and 4% were homozygotes for CYP2A6*4A, whereas among non-smokers 66% were homozygotes for CYP2A6*4A (P < 0.0001). There was no significant effect of CYP2A6 or CHRNA3 genotype on UC activity.

Conclusions: We found a very high proportion of poor nicotine metabolizers among non-smoking patients with UC and a very low proportion among current and former smokers, making it difficult to determine the effect of poor metabolizer genotype on disease activity in smokers with UC. However, it may be possible to identify UC patients who are poor metabolizers of nicotine and who may benefit from nicotine or nicotine-like pharmacological treatment.

Background: Traditionally, medication dosage was based on clinical and demographic parameters, but drug metabolism was recently recognized as an important factor for proper dosing and prediction of side effects. Metabolic considerations are crucial when administering drugs with a narrow therapeutic index, such as those of the thioguanides family (azathioprine and 6-MP). These can cause life-threatening myelosuppression due to low activity of a critical metabolic enzyme, thiopurine S-methyl transferase. A number of single nucleotide substitutions encoding variant enzymes account for most enzyme deficiencies.

Objectives: To determine the frequency of individuals from different Israeli ethnic groups who may be at risk for drug toxicity from drugs of the thioguanide family due to enzymatic variants.

Methods: DNA analysis was performed using polymerase chain reaction methods. We tested TPMT[1] allelic variants TPMT*3A (G460A, A719G), TPMT*3B (G460A) and TPMT*3C (A719G) in five subpopulations in Israel: mixed-origin Israeli Jews, Arabs, Druze, Jews of Kurdish extraction, and Ethiopian Jews.

Results: The Druze (P = 0.0002) and Ethiopian Jewish (P = 0.015) subpopulations had a significantly unique distribution of allelic variants compared to the rest of the Israeli population. The Druze subpopulation showed a high number of TPMT variants with decreased activity, and a homozygote for TPMT*3A/ *3A was detected.  Ethiopian Jews were found to carry mainly the TPMT*3C variant, also observed in other studies of African populations.

Conclusions: It is advisable that Druze patients be tested for the TPMT enzyme before starting treatment with 6-MP or azathioprine. Such testing may also be considered for other Israeli ethnic subgroups.

Background: In contrast to the relative scarcity of donor kidneys and hearts, the potential supply of deceased donor pancreata is exceeding the demand. However, this potential organ surplus is not being fully realized because in current transplantation practice the duration of pancreas storage before transplantation is limited and many organs with established or anticipated cold ischemia time exceeding 8–10 hours are discarded owing to the extreme vulnerability of pancreatic tissue to anaerobic damage caused by preservation.

Objectives: To reduce cold ischemic injury in order to increase the utilization of donor pancreases in Israel for whole-organ and cell transplantation.

Methods: We evaluated a novel two-layer preservation oxygenated cold storage method that uses perfluorocarbon to continuously supply oxygen to the pancreas during preservation in conventional University of Wisconsin solution.

Results: Pancreatic tissue morphology, viability and adenosine-triphosphate content were serially examined during preservation of the pig pancreas for 24 hours either by a two-layer or by conventional simple cold storage. Already after 12 hours of storage, the superiority of the two-layer method over the University of Wisconsin method was apparent. Starting at this time point and continuing throughout the 24 hours of preservation, the tissue architecture, mitochondrial integrity, cellular viability and ATP[1] tissue concentration were improved in samples preserved in oxygenated UW[2]/PFC[3] as compared to controls stored in conventional UW solution alone.

Conclusions: The UW/PFC two-layer preservation method allowed tissue ATP synthesis and amelioration of cold ischemic tissue damage during extended 24 hour pancreas preservation. This method could be implemented in clinical practice to maximize utilization of pancreata for whole-organ and islet transplantation as well as for pancreas sharing with remote centers.

Background: Iron deficiency and lead poisoning are common and are often associated. This association has been suggested previously, mainly by retrospective cross-sectional studies.

Objective: To assess the impact of short-term lead exposure at indoor firing ranges, and its relationship to iron, ferritin, lead, zinc protoporphyrin, and hemoglobin concentrations in young adults.

Methods: We conducted a clinical study in 30 young healthy soldiers serving in the Israel Defense Forces. Blood samples were drawn for lead, zinc protoporphyrin, iron, hemoglobin and ferritin prior to and after a 6 week period of intensive target practice in indoor firing ranges.

Results: After a 6 week period of exposure to lead dust, a mean blood lead level increase (P < 0.0001) and a mean iron (P < 0.0005) and mean ferritin (P < 0.0625) decrease occurred simultaneously. We found a trend for inverse correlation between pre-exposure low ferritin levels and post-exposure high blood lead levels.

Conclusions: The decrease in iron and ferritin levels after short-term lead exposure can be attributed to competition between iron and lead absorption via divalent metal transport 1, suggesting that lead poisoning can cause iron depletion and that iron depletion can aggravate lead poisoning. This synergistic effect should come readily to every physician's mind when treating patients with a potential risk for each problem separately.
 

Systemic infection or inflammation causes a decrease in intestinal iron absorption and impairs the release of recycled iron from macrophages. Decreased availability of iron may deny this essential element to invading pathogens and may inhibit their multiplication and other metabolic processes but also results in anemia of chronic disease. This article reviews recent discoveries that shed light on the regulation of iron metabolism during infection and iron overload, and point to the central role of a newly discovered peptide, hepcidin. Evidence to date indicates that hepcidin is a negative regulator of intestinal iron absorption, placental iron transport, and the release of iron from macrophages that recycle iron from senescent red cells. It may also be the central mediator of iron sequestration during infections and inflammatory states and the mediator of anemia of chronic disease. Rapid progress in this area is a good example of the beneficial effects of improvements in peptide analysis and chemistry, advances in genomics, and the increasing use of transgenic mice to determine the function of newly discovered genes and proteins.

Background: Most corneal damage induced by contact lenses is due to interference with corneal oxygenation.

Objective: To investigate the effect on the rabbit cornea of a rigid gas-permeable contact lens with a newly designed periphery.

Method: We fitted New Zealand white rabbits (n=12) with RGP[1] contact lenses that were identical in all respects except for the design of the periphery. In each animal, one contact lens had an innovative periphery consisting of a microscopic diffractive relief lathed on the back surface; the other contact lens was of a conventional design. The lenses were worn continuously for 7 days. During this experimental period and for 1 additional week we assessed the corneal damage by daily testing lactic dehydrogenase activity in the tears.

Results: On the last day of the experimental week and the first 3 days of the healing period, mean tear LDH[2] activity was significantly lower in the eyes with the new contact lens design than in eyes with the conventional lenses.

Conclusions: The novel periphery design reduces corneal damage resulting from contact lens wear, as reflected by LDH levels in the tears. The new design probably facilitates the flow and exchange of tears under the contact lens, resulting in improved metabolism of the cornea. These findings may also prove applicable to soft contact lenses.