Biocatalytic Synthesis of Nitrile-Bearing All-Carbon Quaternary Stereocenters.

The synthesis of all-carbon quaternary stereocenters containing nitriles is a very important and challenging subject in organic chemistry. We used a biocatalytic approach under mild conditions to obtain new derivatives of these scaffolds by oxidation of catechols by Myceliophthora thermophila laccase (Novozym 51003) to afford o-quinones and 1,4-addition of a series of carbon nucleophiles containing tertiary alkyle nitriles to these intermediates. Using this approach, α-cyano carbonyls bearing a quaternary stereocenter were also prepared. Finally, the yields for the prepared compounds were 72-94%.

Implementation of an adapted perioperative ventriculoperitoneal shunting protocol in a tertiary center located in a low-to-middle-income country.

OBJECTIVE: Preventative protocols have efficaciously reduced shunt infection in developed countries. However, the generalizability of these protocols in low-to-middle-income countries (LMICs) remains unclear. Previously, shunt insertion in the authors' center was routinely performed under institutional preventative precautions, which was updated via merging with the Hydrocephalus Clinical Research Network (HCRN) protocol. This study aimed to investigate the ventriculoperitoneal shunt (VPS) infection rates in pediatric patients following the implementation of the adapted protocol. METHODS: The adapted protocol was implemented in all first-time VPS implantations between 2011 and 2021. The primary outcome was a 6-month shunt infection. The Pearson chi-square test was used for categorical variables and the Mann-Whitney U-test for numeric variables to evaluate the correlation with shunt infection. RESULTS: A total of 352 first-time VPS procedures were performed adhering to the adapted protocol. The median age was 5 months, and 189 (53.7%) were male. Overall, 37 patients (10.5%) experienced shunt infection, with 30 (8.5%) occurring within the first 6 months, which was lower than 13.3% infection rate of the previous series of the same center. The infection rate was slightly higher than the 5.7% and 6.0% rates reported by HCRN studies. Patients with shunt infection were significantly younger (7.5 versus 17.5 months, P < 0.001). CONCLUSIONS: This study validates the efficacy of an adapted perioperative protocol in mitigating shunt infection in a high-volume center in a LMIC. Adhering to a step-by-step protocol, modified to suit the healthcare resources and financial constraints of LMICs, could maintain low shunt infection rates that are roughly comparable to those of centers in high-income countries.

Biocatalytic stereoselective synthesis of pyrrolidine-2,3-diones containing all-carbon quaternary stereocenters.

Highly functionalized pyrrolidine-2,3-diones can be synthesized efficiently and stereoselectively under mild conditions using a biocatalytic approach. The reaction led to the formation of new all-carbon quaternary stereocenters from Myceliophthora thermophila laccase (Novozym 51003) catalyzed oxidation of catechols to ortho-quinones and subsequent 1,4-addition with 3-hydroxy-1,5-dihydro-2H-pyrrol-2-ones. The reaction was conducted with various substituents on both reactants, resulting in 13 products in moderate to good yields (42-91%). The same 15 reactions were also tested with K3Fe(CN)6 as a catalyst, but here only one reaction resulted in a product (60% yield).

Biocatalytic synthesis of oxadiazole thioethers and evaluation of their antitumor activity.

A multicomponent enzyme-catalyzed process is suggested for the synthesis of a novel series of 1,3,4-oxadiazole thioether derivatives with yields ranging from 65 to 94%. Novozym 435, the immobilized form of Candida antarctica lipase B (CALB), was found to efficiently catalyze the reaction. The products were evaluated for antitumor activities against two cancer cell lines, HT-29 (human colorectal cancer cell) and HepG2 (human liver cancer cell), by MTT assays. Among them, two compounds exhibited higher antitumor activities, for both cell lines, compared to doxorubicin. In silico molecular docking and computational ADME analysis were performed to propose a mode of action for the anti-cancer activities and to predict drug-likeness, respectively.

CNS tumor with BCOR internal tandem duplication.

CNS tumor with BCOR internal tandem duplication is a recently proposed malignant tumor. The patient was an 18-month-old boy with torticollis and vomiting due to cerebellar hemispheric mass with extension to cerebellopontine angle and foramen magnum. Histopathologic examination of the tumor showed a moderately cellular tumor with microcystic formation, myxoid change, and atypical rosettes resembling Homer Wright rosettes. Illumina TruSight RNA Pan-Cancer NGS of the tumor genome revealed BCOR gene exon 15 internal tandem duplications.

A clinical clue toward recognition of split cord malformation type-I resembling meningocele in neonates.

This is a letter to share the clinical experience we had with neonates born with a specific feature of spina bifida. The lesion is like a meningocele containing skim amount of fluid, with a tiny dimple around the center of the cutaneous lesion which causes inward retraction of the dysplastic coverage. This feature is in favor of accompanied split cord malformation (SCM) type I, and the central nidus is in continuous with the dural sleeve around the bony septum of SCM. By recognition of this clinical clue, surgical repair can be planned to perform with appropriate provision, particularly foreseeing the amount of intraoperative bleeding and duration of anesthesia in the newborn patients.

External-internal cranial expansion to treat patients with craniocerebral disproportion due to post-shunt craniosynostosis: a case series.

INTRODUCTION: Secondary craniosynostosis subsequent to shunting is one of the late complications of ventricular shunt placement in the early childhood. Several interventions have been used to treat high intracranial pressure associated with this condition. This study aimed to evaluate the patients' clinical symptoms and head circumference before and after a method of decompressive craniotomy, coined as external-internal cranial expansion (EICE). METHODS: A retrospective study was conducted, and the patients who had undergone EICE for the treatment of post-shunt craniosynostosis between 2010 and 2020 were enrolled. This approach was a combination of a hinge multiple-strut decompressive craniectomy and internal cranial flap thinning by drill. Data, extracted from medical records, were used to evaluate the patients' symptoms and head circumferences before and 12 months after surgery. RESULTS: A total of 16 patients were enrolled in the study, of which eight were females. Before the surgery, 9 patients (56.2%) suffered from visual impairment, and all had intractable headache. Papilledema was recorded in all, with 3 cases having optic disc paleness. After cranial expansion, only two patients had headaches, diagnosed as migraine-type and psychosomatic headaches, respectively. In two patients, progressive visual impairments got worsening after surgery, which would be due to severe preoperative optic nerve atrophy. Patients' head circumferences significantly increased after the surgery (mean of 48.97 ± 4.28 cm vs. 45.78 ± 4.31 cm; P value < 0.0001). CONCLUSION: In lower resource countries, where newer technologies like distraction osteogenesis is not easily available, external-internal cranial expansion can be considered an effective alternative for patients with post-shunt craniosynostosis.

Odd presentation of shunt malfunction: a case series and review of literature.

OBJECTIVE: Children with previous ventriculoperitoneal shunt (VPS) insertion due to hydrocephalus may refer to the hospital with various clinical complaints. Shunt malfunction is frequently diagnosed in these children necessitating shunt revision. Although increased head circumference, setting sun eye in younger children, and headache, nausea/vomiting, loss of consciousness, visual disturbance, and other signs of intracranial hypertension are common clinical manifestations of shunt malfunction, some patients may present with odd or unusual symptoms. Here, we present a series of patients with shunted hydrocephalus who presented with odd and unexpected clinical manifestations of shunt malfunction. METHODS: Eight children with shunt malfunction were enrolled in this series. The age, sex, age of shunting, etiology of hydrocephalus and management, post-shunt insertion symptoms/sign, revision surgery, outcome, and follow-up were evaluated. RESULTS: Patients were aged from 1 to 13 years (mean, 6.38 years). There were 5 males and 3 females. The odd presentation associated with shunt malfunction included facial palsy in three children, ptosis in 3 children, and torticollis and dystonia each in one child. All patients underwent shunt revision except for one patient in whom a new shunt was inserted. Follow-up showed improvement of the symptoms in all patients. CONCLUSION: In this series, we reported eight patients with unusual signs and symptoms following shunt malfunction that were successfully diagnosed and managed.

The Predictors of Seizures in Patients with Encephalocele: An 11-Year Experience from a Tertiary Hospital.

INTRODUCTION: The aim of the study was to investigate and identify the predictors associated with the incidence of seizures in patients with encephalocele (EC). METHODS: A retrospective analysis was undertaken of patients treated for EC at a tertiary medical center in Tehran between 2010 and 2021. Data including age at presentation, gender, location, size, and content of EC, ventriculomegaly, hydrocephalus, associated anomalies, and neurodevelopmental delay (NDD) were evaluated for their prognostic value. In addition, univariate and multivariate analyses were performed to identify the correlation between independent predictors and seizure incidence. RESULTS: One hundred and two cases of EC were identified. Seventy-one ECs (69.6%) were posterior ECs, while 31 (30.4%) were anterior. Neural tissue was found in 43 (42.2%) of the ECs. Thirty-three patients (32.4%) had ventriculomegaly, of which 90.9% underwent shunt placement for progressive or symptomatic hydrocephalus. Seizure was found in 26 (25.5%) patients. On univariate analysis, presence of other anomalies, postoperative infections, and NDD were associated with seizures (p < 0.05). When the anomalies were categorized into intracranial and extracranial groups in univariate analysis, none was associated with statistically significant increase in seizure (p values of 0.09 and 0.61, respectively). Although according to multivariate analysis, only the association between other associated anomalies and seizure was near significant (OR: 2.0, 95% CI: 0.95-4.2, p = 0.049). Children with NDD and postoperative infection were, respectively, 3.04 and 1.3 times more at risk to experience seizures compared to other patients. CONCLUSION: We found a rate of 25.5% risk of seizure in patients with EC. This study could not find any significant predictors of seizure in children with EC. However, pediatric patients with postoperative infections including sepsis, wound infection, and NDD require more consideration to reduce the risk of seizure.

Gorham-Stout disease of skull base leading to cranial settling and rhinorrhea: a case-based review.

PURPOSE: Gorham-Stout disease (GSD) is a rare progressive osteolytic disorder, theoretically caused by lymphovascular endothelial proliferation. Spinal involvement carries a dismal prognosis because of neurological consequences. Lesions of the skull base are extremely rare and entail even more devastating prognosis due to cervical instability and cerebrospinal fluid (CSF) leakage. Due to scarcity of this condition, the aim of this study was to give an overview of skull base GSD and review the cases with such condition reported in the literature. METHODS: In this case-based review, different aspects of skull base GSD are discussed, and a sample clinical case of GSD leading to cranial settling and rhinorrhea is presented. The characteristics, symptoms, and managements of all English-language PubMed-reported cases were reviewed, and different features of presentation and methods of treatments were analyzed. RESULTS: Based on the literature review, most of the cases encountered serious problems in the course of the disease. Meningitis/CSF leakage was detected in 12 of 26 collected cases, followed by hearing loss/tinnitus/otitis media in 10 cases, headache in 8, and neck pain/stiffness in 8 patients. Despite a variety of treatments, improvement was only observed in 8 of 26 collected cases. The reminders showed either stable condition or worsening and death. CONCLUSION: All cases of GSD of the skull base should be evaluated for rhinorrhea/otorrhea and cranial settling, both of them being among the most life-threatening conditions. Since definite treatment, in order to stop disease progression, is sometimes impossible, symptomatic and supportive treatment should be started as possible.

A multi-component approach for co-immobilization of lipases on silica-coated magnetic nanoparticles: improving biodiesel production from waste cooking oil.

The capability of multi-component reactions in rapid immobilization of enzymes was considered for co-immobilization of Thermomyces lanuginous lipase (TLL) and Candida antarctica lipase B (CALB) [TLL: CALB]; Rhizomucor miehei lipase (RML) and CALB [RML: CALB] on amine-functionalized silica-coated magnetic nanoparticles (Fe3O4@SiO2-NH2). Immobilization of different ratios of lipases was performed within 3 h under mild conditions; producing specific activity ranging from 29 to 35 U/mg for TLL:CALB and 21-34 U/mg for RML:CALB. The co-immobilized derivatives showed improved co-solvent and thermal stability compared to the corresponding free enzymes. All the derivatives were also used to catalyze the transesterification of waste cooking oil with methanol to produce biodiesel (fatty acid methyl esters). Response surface method (RSM) and a central composite rotatable design (CCRD) were used to study the effects of different factors on the FAME yield. Fe3O4@SiO2-NH2-RML-CALB and Fe3O4@SiO2-NH2-TLL-CALB had maximum FAME yields of 99-80%, respectively.

Spontaneous regression of congenital brain tumors: a report of two cases.

BACKGROUND: Vanishing brain tumor is defined as spontaneously disappearing or decreasing of the initial brain mass volume to ≤ 70% before establishing the definitive diagnosis. The condition is rare and can be attributed to different factors. The exact mechanism is under debate, but the increasing rate and accuracy of neuroimaging studies and occurrence of similar scenario in other pathologies rather than brain tumors can be of particular importance in finding vanishing brain lesions. CASE REPORT: We present two unusual cases of congenital brain masses which underwent spontaneous shrinkage within the first months of life. CONCLUSION: The condition is scarcely observed in congenital brain masses. As congenital brain lesions are distinct entities with peculiar characteristics, this rare phenomenon may reflect different aspects in this age group.

The effects of COVID-19 pandemic on pediatric neurosurgery practice and training in a developing country.

PURPOSE: COVID-19 pandemic has influenced all aspects of societies, with the healthcare being the most affected field. All specialties including neurosurgery are involved, and due to resource limitations, the number of elective surgeries in subspecialized filed has substantially decreased. Herein, we report our practice experience in pediatric neurosurgery in a tertiary hospital during pandemic, and the effects of pandemic on educational issues. METHODS: All the patients on whom any kind of neurosurgical operation was performed from March to June 2020 were retrospectively collected, and also from the same period in the previous year. RESULTS: A total of 111 patients underwent surgery in this period. This figure was 159 patients during the same period in 2019. The total number of surgical cases reduced by 31% compared to the last year. While ventriculoperitoneal shunts and supratentorial tumor were more frequent, there was a considerable reduction in subspecialized educational surgeries like neural tube defects and craniosynostoses. CONCLUSION: CVID-19 pandemic changed all scopes of medical practice and training. Considering the limitation in the available resources, the number of educational cases may decrease in subspecialized disciplines like pediatric neurosurgery. If pandemic continues, alternative measures should be taken to compensate for the shortcoming in technical and practical training.

Isolated primary spinal epidural hydatid cyst in a child with progressive paraparesis.

BACKGROUND: Primary spinal hydatid cyst is a rare but serious condition which occurs in about 1% of patients with hydatid disease. This disease may result in severe spinal cord compression presenting with various neurological deficits. CASE REPORT: A 3-year-old boy was referred to our center with progressive weakness of lower limbs, frequency, and urinary incontinence. His parents did not report back pain during child's illness. Lumbar magnetic resonance imaging (MRI) revealed an extradural well-defined thin-walled cystic lesion at L4 to S3 vertebral levels without enhancement. The cyst had compressed the thecal sac associated with bone scalloping of vertebral bodies and posterior elements. Osteoplastic laminectomy of L4-L5 and laminectomy of S1-S3 was done. Intraoperative and histopathological findings indicated an epidural hydatid cyst. CONCLUSION: Although spinal hydatid cysts are rare but might be considered in the differential diagnosis of any patient with signs and symptoms of spinal cord compression. The pathophysiology, clinical manifestations, epidemiology, diagnosis, and surgical treatment of extradural hydatid cyst are discussed.

Cytomegalovirus DNA in non-glioblastoma multiforme brain tumors of infants.

PURPOSE: CMV antigens have been detected in some brain tumors specially glioblastoma multiforme (GBM). As brain tumors in the first years of life are among the most aggressive neoplasms with poor prognosis, novel therapeutic options like targeted therapy against virus antigens are demanded. Infantile central nervous system tumors, other than GBM, have not been so far studied for CMV. To our best knowledge, this is the first study in which the presence of CMV-DNA, as a potential viral target for therapy, in non-GBM infantile brain tumors has been investigated. METHODS: The paraffin blocks of non-GBM brain neoplasms of 36 infants (age < 24 months) who were operated on between 2006 and 2016 were examined for CMV-DNA, using real-time polymerase chain reaction (PCR). Paraffin blocks of CMV infected lung tissue were used as positive control. Extraction and amplification of ß2 microglobulin gene from each tumor tissue were carried as positive internal control. We also assayed 25 paraffin blocks of meningomyelocele for CMV DNA as negative tissue controls. RESULTS: Histopathological diagnoses consisted of 13 glial/neuroglial tumors (36.1%), 8 ependymomas (22.2%), 7 medulloblastomas (19.4%), 3 choroid plexus tumors (8.3%), 2 atypical teratoid rhabdoid tumors (5.6%), 2 embryonal CNS tumors (5.6%), and 1 germ cell tumor (2.8%). We could not detect CMV DNA in all samples examined. CONCLUSION: Although CMV may be associated with GBM, no role could be proposed for this virus in development of non-GBM infantile brain tumors. Further investigations on larger series of brain tumors should be conducted to confirm or rule out our conclusion.

Porcine pancreas lipase as a green catalyst for synthesis of bis-4-hydroxy coumarins.

4-Hydroxycoumarins represents an important structural motif in life sciences molecules with remarkable biological properties. 4-Hydroxycoumarins are important precursors in the synthesis of organic compounds and critical pharmacophores in medicinal chemistry. One of the derivatives of this compound is biscoumarin, which has anticoagulant medicinal properties. Porcine pancreas lipase (PPL) has been used as an efficient green biocatalyst for the synthesis of bis-4-hydroxycoumarin compounds and expands the biocatalytic promiscuity of lipase in organic synthesis. Some aromatic aldehydes have been used in this investigation for screening and examining the ability of enzyme in knoevenagel condensation. Various parameters including temperature, solvent, and the amount of biocatalyst were investigated, ethanol, 45 °C and 10 mg of PPL gave rise to best yields. Bis-4-hydroxy coumarin compounds were synthesized under mild reaction conditions with high conversion yields (81-88%).

Biotransformation of androst-4-ene-3,17-dione and nandrolone decanoate by genera of Aspergillus and Fusarium.

The ability of five fungal species belonging to two genera of Aspergillus and Fusarium has been examined in the microbial transformation of androst-4-ene-3, 17-dione (AD). Furthermore, the biotransformation of nandrolone decanoate (2) by F. fujikuroi has been studied. AD (1) was converted by cultures of Aspergillus sp. PTCC 5266 to form 11α-hydroxy-AD (3) as the only product, with a yield of 86% in 3 days. Moreover, two hydroxylated metabolites 11α-hydroxy-AD (3, 65%) and 7ß-hydroxy-AD (4; 18%) were isolated in biotransformation of AD by A. nidulans. On the other hand, it was metabolized by F. oxysporum to produce 14α-hydroxy-AD (5; 38%) and testosterone (6; 12%). Microbial transformation of AD by F. solani led to the production of 11α-hydroxy-AD (3; 54%) and testosterone (6; 14%). AD was reduced at the 17-position by F. fujikuroi to produce testosterone in the yield of 42%. Finally, nandrolone decanoate was transformed by F. fujikuroi via hydrolysis and oxidation at the 17-position to produce two metabolites namely 17ß-hydroxyestr-4-en-3-one (7, 25.4%) and estr-4-en-3,17-dione (8, 33%), respectively. The all metabolites were purified and subsequently identified based on their spectra data analysis and comparing them to the literature data.

Peripheral facial nerve palsy following ventriculoperitoneal shunting in an infant.

Peripheral facial palsy due to injury to the extracranial segment of facial nerve following ventriculoperitoneal (VP) shunting has been reported in a few adults or adolescents. Herein, we present a case of iatrogenic facial nerve palsy secondary to VP shunt insertion in a 20-month infant. To the best of our knowledge, this is the first infantile case to be ever reported in the literature. Regarding the postnatal development of the mastoid and styloid process, the underdeveloped bony structures may render extracranial part of the facial nerve more vulnerable to blunt trauma. The lesson can be learned from this case is that tunneling procedure should be done with caution in pediatric age group especially around the mastoid area.

Contralateral facial nerve paresis subsequent to posterior fossa meningioma surgery in a child: case report.

INTRODUCTION: Meningiomas are relatively uncommon neoplasms in the pediatric population and posterior fossa is a very rare location for these tumors. Only a few cases of contralateral cranial nerve deficits have been reported but no cases of pediatric meningioma with contralateral facial nerve paresis have been documented in literature. CEREBELLOPONTINE ANGLE MENINGIOMA WHO CASE REPORT: We present a 4 year old girl with found postoperative contralateral facial nerve paresis. DISCUSSION: The possible pathogenesis and literature review concerning this complication are discussed. The mechanisms leading to this complication could be distortion of brainstem, traction during resection and subsequent compression of brainstem against the contralateral petrous or tentorium.

Extensive aplasia cutis congenita associated with cephalocranial disproportion and brain extrusion.

Aplasia cutis congenita (ACC) is a rare congenital disorder which can be linked with a variety of other abnormalities. However, the association of this anomaly with cephalocranial disproportion and brain extrusion is rarely reported. In this report, we present a neonate with an extensive ACC with exposed dura mater and sagittal sinus, who later presented with brain extrusion from the defect and an acrocephalic-like feature required decompressive surgery during the first month of life. Theories regarding etiology and progression of acrocephalic feature and brain protrusion in this case have been discussed.