Risk factors for reoperation,readmission, and early complications after below knee amputation

Background

Many patients undergoing below knee amputations (BKA) return for subsequent unplanned operations, hospital readmission, or postoperative complications. This unplanned medical management negatively impacts both patient outcomes and our healthcare system. This study primarily investigates the risk factors for unplanned reoperation following BKA.

Melatonin alleviates brain injury in mice subjected to cecal ligation and puncture via attenuating inflammation,apoptosis, and oxidative stress: the role of SIRT1 signaling

Sepsis is a systemic inflammatory response to infection that causes severe neurological complications. Previous studies have suggested that melatonin is protective during sepsis. Additionally, silent information regulator 1 (SIRT1) was reported to be beneficial in sepsis. However, the role of SIRT1 signaling in the protective effect of melatonin against septic encephalopathy remains unclear. This study aimed to investigate the role of SIRT1 in the protective effect of melatonin. EX527, a SIRT1 inhibitor, was used to reveal the role of SIRT1 in melatonin's action. Cecal ligation and puncture or sham operation was performed in male C57BL/6J mice. Melatonin was administrated intraperitoneally (30 mg/kg). The survival rate of mice was recorded for the 7‐day period following the sham or CLP operation. The blood–brain barrier (BBB) integrity, brain water content, levels of inflammatory cytokines (TNF‐α, IL‐1β, and HMGB1), and the level of oxidative stress (superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA)) and apoptosis were assessed. The expression of SIRT1, Ac‐FoxO1, Ac‐p53, Ac‐NF‐κB, Bcl‐2, and Bax was detected by Western blot. The results suggested that melatonin improved survival rate, attenuated brain edema and neuronal apoptosis, and preserved BBB integrity. Melatonin decreased the production of TNF‐α, IL‐1β, and HMGB1. Melatonin increased the activity of SOD and CAT and decreased the MDA production. Additionally, melatonin upregulated the expression of SIRT1 and Bcl‐2 and downregulated the expression of Ac‐FoxO1, Ac‐p53, Ac‐NF‐κB, and Bax. However, the protective effects of melatonin were abolished by EX527. In conclusion, our results demonstrate that melatonin attenuates sepsis‐induced brain injury via SIRT1 signaling activation.     

Melatonin prevents cell death and mitochondrial dysfunction via a SIRT1‐dependent mechanism during ischemic‐stroke in mice

Silent information regulator 1 (SIRT1), a type of histone deacetylase, is a highly effective therapeutic target for protection against ischemia reperfusion (IR) injury (IRI). Previous studies showed that melatonin preserves SIRT1 expression in neuronal cells of newborn rats after hypoxia–ischemia. However, the definite role of SIRT1 in the protective effect of melatonin against cerebral IRI in adult has not been explored. In this study, the brain of adult mice was subjected to IRI. Prior to this procedure, the mice were given intraperitoneal with or without the SIRT1 inhibitor, EX527. Melatonin conferred a cerebral‐protective effect, as shown by reduced infarct volume, lowered brain edema, and increased neurological scores. The melatonin‐induced upregulation of SIRT1 was also associated with an increase in the anti‐apoptotic factor, Bcl2, and a reduction in the pro‐apoptotic factor Bax. Moreover, melatonin resulted in a well‐preserved mitochondrial membrane potential, mitochondrial Complex I activity, and mitochondrial cytochrome c level while it reduced cytosolic cytochrome c level. However, the melatonin‐elevated mitochondrial function was reversed by EX527 treatment. In summary, our results demonstrate that melatonin treatment attenuates cerebral IRI by reducing IR‐induced mitochondrial dysfunction through the activation of SIRT1 signaling.     

Is it safe to breastfeed while taking methylphenidate?

Question My patient has narcolepsy and is currently breastfeeding her 3-month-old infant. Lately she has had difficulties adjusting to caring for her baby, especially staying alert with the demands of breastfeeding. If she starts taking methylphenidate again, should I advise her to switch to formula?Answer Methylphenidate is excreted in breast milk only in small amounts, and to date there have been no reports of breastfed infants demonstrating any adverse effects. Based on the available data, methylphenidate appears to be compatible with breastfeeding; however, the long-term neurodevelopmental effects have not been adequately studied.     

A Novel Approach for the Synthesis of Thermo‐Responsive Co‐Polyesters Incorporating Reversible Diels–Alder Adducts

The proof of concept for a new copolymerization approach taking advantage of the thermally reversible aptitude of the furan/maleimide Diels–Alder (DA) adducts is reported here. A new monomer bearing two carboxylic acids as end‐groups and a Diels–Alder adduct within its structure is synthesized using benign and mild reaction conditions. Two polyesters are then fabricated from the DA‐diacid and 1,6‐hexanediol and 1,4‐benzenedimethanol, respectively, and characterized by ¹H‐NMR, GPC, DSC, and TGA. Kinetic studies of these polyesters, performed by ¹H‐NMR spectroscopy at variable temperatures, establish the appropriate conditions for their controlled depolymerization, through the retro Diels–Alder reaction (rDA), and their re‐construction through the DA reaction, showing moreover the reproducibility of this rDA/DA cycle. Finally, by exploiting this peculiar feature, a copolyester is successfully synthesized from the concomitant treatment of the two homopolymers, demonstrating the effectiveness of the method. The present approach provides a new method for the fabrication of multicomponent copolymers based on the DA/rDA strategy that is extendable to a variety of other polycondensation materials, such as polyesters, polyamides, polyurethanes, and epoxies, allowing the establishment of a library of novel architectures through this one‐pot approach.     

In vitro activity of ertapenem against selected respiratory pathogens

OBJECTIVES: The in vitro activity of ertapenem was evaluated in comparison to 21 selected agents against a large collection of recently isolated respiratory tract pathogens including: 180 Streptococcus pneumoniae, 100 Streptococcus pyogenes, 70 Haemophilus influenzae, 70 Moraxella catarrhalis, 100 methicillin-susceptible Staphylococcus aureus and 30 Klebsiella pneumoniae. Additional in vitro tests (time-kill curves with ertapenem alone and in combination with four other agents) for S. pneumoniae were carried out. METHODS: MIC determinations and time-kill curves were carried out following the procedures suggested by the NCCLS. RESULTS: According to NCCLS susceptibility breakpoints, ertapenem was comparable to the most potent compounds tested for all pathogens studied. Ertapenem was 100% active against penicillin-susceptible and -intermediate S. pneumoniae and against 60% of penicillin-resistant strains. Time-kill tests at 4x MIC confirmed a pronounced bactericidal potency of ertapenem against these organisms. Interactions of ertapenem with several other agents against pneumococci resulted in clear synergic interactions (98.4%). Indifference was extremely rare and antagonism was not observed. All S. pyogenes strains tested were inhibited by ertapenem, irrespective of their macrolide resistance phenotypes. Ertapenem was also fully active against H. influenzae (100% susceptible) and M. catarrhalis (MIC90 0.015-0.03 mg/L) even when capable of synthesizing beta-lactamases. Methicillin-susceptible S. aureus and K. pneumoniae, including extended-spectrum beta-lactamase-producing strains, were 100% susceptible to ertapenem. CONCLUSIONS: Our results indicate that ertapenem has a suitable spectrum of activity against organisms encountered in community-acquired bacterial respiratory tract infections.     

Solitary sacral osteochondroma without neurological symptoms: a case report and review of the literature

Purpose

To report a case of solitary sacral osteochondroma without neurological symptoms and describe the en bloc excision of the tumour, as well as review the literature on osteochondroma involving the sacrum.

Methods

Summary of the background data: although osteochondromas are among the most common benign tumours of the bone, they uncommonly involve the spine. Its occurence in the sacrum is rare, accounting for only 0.5 % of the osteochondromas involving spine. All previous cases of sacral osteochondroma have reported neurological symptoms on presentation.

Case report

A 21-year-old male presented with a palpable, painless mass in the left side of the sacral region of 1 year duration, without neurological symptoms. Radiological studies showed a well-circumscribed lesion with bony osteoid within arising from the sacrum at S3–S4 level left to midline, with features suggestive of osteochondroma. The tumour was excised en bloc through posterior approach. A literature review of sacral osteochondroma was conducted using MEDLINE search of English Literature and bibliographies.

Results

Histopathological studies showed the lesion to consist mature bone trabeculae with active enchondral ossification with cap of normal hyaline cartilage. Literature review yielded only 8 cases of sacral osteochondroma reported earlier.

Conclusion

This is the 9th case of solitary osteochondroma of the sacrum to be reported, the first to be reported without any neurological symptoms, and third case reported for which en bloc excision was performed.