Medical Journal of The Islamic Republic of Iran (MJIRI)

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  Abstract

  Background: The interest in using bacteria as anti- cancer therapeutic agents dates back to the end of the19th century. Some bacteria like Salmonella and Listeria replicate effectively inside malignant cell lines and suppress their growth. The bacterium Streptococcus pyogenes has become medically famous as a flesh-eating pathogen since mid-1980s. It is the causative agent of a life threatening clinical condition called necrotizing fasciitis. S. pyogenes usually produces a range of lytic enzymes that promote bacterial pathogenesis. With these characters, could this bacteria. be employed as a curing agent for certain cancers? The aim of this study was to determine the influence of S. pyogenes on malignant cellular death (apoptosis or necrosis)- in an ex-vivo "experimental- interventional" study.

  Methods: The cytotoxicity of fifteen internalized streptococcal strains( including 12

  clinical isolates, 2 known M types [M1, M3] and standard strain), on four types of malignant cell lines- A549, BT-20, PC-3, L-929- were tested by Trypan blue exclusion, DNAfragmentation and WST-1 methods. The streptococcal protease, lipase, DNase and serum opacity factor (SOF) were tested concurrently. The standard strain of Streptococcus (Enterococcus) faecalis was employed as negative control. The results were analyzed by statistical Minitab software.

  Results: The overall cytotoxicity rate of -internalized- S. pyogenes was 57% by trypan

  blue method and 50 % by DNA electrophoresis. False positive results occurred for the negative control in WST-1 therefore this test did not present reasonable results. The correlation between production of SOF, lipase, DNase and cytotoxicity of S. pyogenes was not significant (p > 0.05). However, 67% of the protease positive strains induced cellular death in at least one type of - malignant cell line (p<0.05).

  Conclusion: Our findings indicated that, some non-invasive S. pyogenes that cause benign infection like pharyngitis can induce cell death in various cancerous cell lines. It

  seemed that among bacterial products, the proteolytic enzymes- linked to the streptococcal pyrogenic exotoxin B (spe-B)- were more related to bacterial invasion.

 

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    Background: The preterm labor has increased in multiple pregnancies over the past 2 decades. Preterm labor has led to increase in neonatal mortality rates, long-term morbidity, respiratory distress, and neonatal infections. Thus, this study aimed at investigating the effect of cerclage versus pessary on the prevention of preterm birth in twin pregnancies.
   Methods: This prospective randomized clinical trial was performed on 50 women pregnant with twins who visited Taleghani hospital in 2016-2018. Their cervical length, which was measured by transvaginal ultrasonography (TVS), was less than 30 millimeters at week 14 of pregnancy. The participants were randomly divided into 2 groups (n=25). They separately underwent cervical pessary and cerclage. McDonald's procedure was performed in cerclage group from 14 to 27 weeks. The suture material was Mersilene Ethicon 5-0 double-armed s14 needle. Ring hodge pessary was also inserted in the vagina of the participants in the pessary group. All the patients were injected 250 mg intramuscular 17 alpha-hydroxyprogesterone caproate weekly from week 16 to week 36. All statistical analyses were performed using SPSS 18 software.
   Results: The results of this study showed that the mean ± standard deviation (SD) for pregnancy length of the cerclage and pessary groups were 238.6±32.4 and 223.6±16.6, respectively. Also, significant differences were found between the 2 groups (p=0.048). No significant difference was found in pregnancy (p=0.565), length of pessary/cerclage use (p=0.491), and BMI before and after delivery between the cerclage and pessary groups (p>0.05).
   Conclusion: The use of cerclage in twin pregnancies is recommended to increase the length of pregnancy.