Cellular and biochemical effects induced by antiretroviral drugs.

Ph. D. University of KwaZulu-Natal, Durban 2013.In the treatment of HIV/AIDS, protease inhibitors (PIs) and nucleoside/nucleotide analogue reverse transcriptase inhibitors (NRTIs) are the major components of highly active antiretroviral therapy (HAART). The side effects of these drugs include various metabolic disorders including insulin resistance, dyslipidaemia and lipodystrophy. The precise mechanistic basis of these remains largely unknown. In this study we aimed to understand the molecular basis of these metabolic effects by analysing the effects on lipoprotein lipase (LPL) activity, insulin signaling and the cellular metabolic profile. It was previously shown by this group that indinavir inhibits insulin signaling at a proximal level. The study was extended to a wider range of ARVs and in particular, the effects of sodium salicylate (NaSal) and berberine chloride (BBR) were analysed to determine if they could reverse the effects of the drugs on insulin signalling. In addition, Chinese hamster ovary cells transfected with the human insulin receptor (CHO-IR) were used for the first time to study the effects of NRTIs on the insulin signaling pathways. The high level of expression of insulin receptor facilitated sensitive detection of any alteration in the phosphorylation of signaling proteins as compared to 3T3-L1 adipocytes. Three PIs, indinavir, nelfinavir and ritonavir were used in this study. Indinavir and nelfinavir treatment significantly reduced the insulin-stimulated phosphorylation of the IRβ, IRS-1, Akt and MAPK in CHO-IR cells. However phosphorylation of GSK-3α\β was not affected by the PIs. Ritonavir also decreased (not statistically significant) the phosphorylation of IR-β and IRS-1 but its inhibitory effect on MAPK was the same as by the other PIs. NRTI’s did not inhibit insulin-stimulated tyrosine phosphorylation of IRβ and IRS-1 but reduced phosphorylation at MAPK and Akt. In order to understand the role of NFκ-B pathway in blocking insulin-stimulated tyrosine phosphorylation, IKK-16, a selective inhibitor of IkB kinase (IKK) was used but no significant involvement of this pathway was found in blocking tyrosine phosphorylation at IRS-1. Similarly, NaSal and BBR were also used to reverse the effects induced by PIs and NRTIs in CHO-IR cells but no significant change was observed on Akt and MAPK. NaSal and BBR reduced (but not significantly) the effects of PIs (indinavir and nelfinavir) on IR-β and IRS-1. These findings suggest that PIs induce insulin resistance by affecting multiple steps in the signaling pathway. At the proximal end of the insulin signalling pathway, protease inhibitors affect IR-β and IRS-1 while at the distal end they affect phosphorylation of Akt and MAPK. CHO-IR cells were also used to measure LPL activity using a colorimetric method employing pNPB as substrate. The most commonly used ARVs were tested. These included four PIs and six NRTIs .The results showed that NRTIs stavudine and emtricitabine significantly inhibited the LPL activity from the CHO-IR cells. PIs indinavir and nelfinavir were also found to decrease LPL activity extracellularly when added to the assay reaction in vitro. Similarly nelfinavir and atazanavir sulfate inhibited the activity of the LPL from the CHO-IR cells after 16 hour treatment. This suggested that these drugs may interfere with the enzyme activity intracellularly either at the level of its synthesis or its transportation from cytoplasm to the cell surface. These finding suggests that protease inhibitors may play a role in inhibiting lipoprotein lipase activity in vivo, and may thereby induce metabolic disorders in HIV-positive patients being treated with protease inhibitors. Metabolomic analysis was performed on the supernatant of cells treated with PIs and NRTIs, with and without insulin stimulation. Many significant alterations and trends in amino acids and organic acids levels in CHO-IR cells supernatants (treated with PIs) were recorded using 1H-NMR. For example, PIs decreased the synthesis of threonine, phenylalanine, lysine, arginine, isoleucine butyrate, glutamate, histidine and 2-oxo-isovalerate. Furthermore overproduction of lactate and ketones were observed in the nelfinavir treated cells. This may be a consequence of the secondary effects of insulin resistance induced by the PIs. Similarly NRTIs (stavudine and tenofovir) treatment also induced changes in the levels of many amino acids and organic acids .NRTIs decreased the synthesis of acetate, acetoacetate, histidine, methionine, phenylalanine and tryptophan while significant increase in the acetone was observed in stavudine-treated cells. Taken together, the results of this study suggest that PIs and NRTIs, inhibits LPL activity and synthesis, affects insulin signalling pathways at different levels and alters the synthesis of different cellular metabolites which may affect the signalling pathways of insulin

1-(2,6-Dichloro­benzo­yl)-3-(2,3,5,6-tetra­chloro­phen­yl)thio­urea trichloro­methane hemisolvate

The title compound, C14H6Cl6N2OS·0.5CHCl3, crystallizes with four 1-(2,6-dichloro­benzo­yl)-3-(2,3,5,6-tetra­chloro­phen­yl)thio­urea mol­ecules and two trichloro­methane mol­ecules in the asymmetric unit. The thiourea molecules exist in the solid state in their thione forms with typical thio­urea C—S and C—O bonds lengths, as well as shortened C—N bonds. The —NH—C(=S)—NH—C(=O)— plane is almost perpen­dicular to the benzene ring in each thiourea molecule. Intra­molecular N—H⋯O hydrogen bonds stabilize the mol­ecular conformation and inter­molecular N—H⋯S hydrogen bonds stabilize the packing arrangement

Comparative Study of Early Neonatal Versus Late Circumcision in Terms of Post Operative Complications

Objective: The objective of this study was to compare early neonatal versus late circumcision by plastibell in terms of postoperative complications. Methodology: It was a comparative study conducted at Department of Pediatric Surgery at Shifa International Hospital Islamabad from January 2018 to November 2019. The present study is a prospective analytical review of 482 uncircumcised patients who presented to the Shifa International Hospital, Islamabad. The variables that were observed in this study were age, mode of presentation, and complications. Patients divided into 2 groups. In Group A circumcision was done within the first 3 days of life and in Group B circumcision was done from in conventional manner after one week of life till 3 months of age. Results: Total 482 patients were presented during this study period, out of which 70 belong to Group A and 412 belong to Group B. In Group A, bell retraction was seen in 4 patients (5.71%), infection of glans in the form of flakes of pus was seen in 1 patient (1.42%), delayed fall was seen in 2 patients (2.85%) and meatal ulcer was seen in 1 patient (1.42%). In Group B, bell retraction was seen in 8 patients (1.94%), infection in 4 patients (0.97%) and delayed fall in 4 patients (0.97%). Complications like bleeding, over/under circumcision, smegmal cyst, meatal stenosis and urethrocutaneous fistula were not seen in any group. Conclusion: We conclude that neonatal circumcision done within first 3 days of life or even soon after birth is safe and has no significant difference of complications as compared to patients in whom circumcision is done at a later stage

2-Benzoyl-1-(2,4-dichloro­phen­yl)-3-phenyl­guanidine

In the title compound, C20H15Cl2N3O, a typical polysubstituted guanidine with normal geometric parameters, the torsion angles [C—N—C—O = 3.8 (2), N—C—N—C = −6.1 (2)°] indicate that the guanidine and carbonyl groups are almost coplanar, due to the pseudo-hexa­gonal ring formed by intra­molecular N—H⋯O hydrogen bonds. The crystal packing is stabilized by inter­molecular N—H⋯O hydrogen bonds, which link the mol­ecules into centrosymmetric dimers

Flow-Based Rules Generation for Intrusion Detection System using Machine Learning Approach

Rapid increase in internet users also brought new ways of privacy and security exploitation. Intrusion is one of such attacks in which an authorized user can access system resources and is major concern for cyber security community. Although AV and firewall companies work hard to cope with this kind of attacks and generate signatures for such exploits but still, they are lagging behind badly in this race. This research proposes an approach to ease the task of rules generationby making use of machine learning for this purpose. We used 17 network features to train a random forest classifier and this trained classifier is then translated into rules which can easily be integrated with most commonly used firewalls like snort and suricata etc. This work targets five kind of attacks: brute force, denial of service, HTTP DoS, infiltrate from inside and SSH brute force. Separate rules are generated for each kind of attack. As not every generated rule contributes toward detection that's why an evaluation mechanism is also used which selects the best rule on the basis of precision and f-measure values. Generated rules for some attacks have 100% precision with detection rate of more than 99% which represents effectiveness of this approach on traditional firewalls. As our proposed system translates trained classifier model into set of rules for firewalls so it is not only effective for rules generation but also give machine learning characteristics to traditional firewall to some extent.&nbsp

Anterior Cervical Discectomy and Fusion Surgery: Results with Zero-Profile Spacer/Cage

Objective:  Study provides proof to support the promised benefits of employing stand-alone zero-profile cages in multilevel ACDF procedures, as the stand-alone zero-profile device has proven safety and a reduction of the risk of dysphagia in single-level ACDF surgeries. Materials and Methods:  This is a retrospective descriptive study, conducted at the Punjab Institute of Neurosciences, Lahore, Pakistan. Data of 36 patients evaluated for post-operative dysphagia and fusion, who had multi-level ACDF surgery employing stand-alone zero-profile cages. Results:  Total of 36 patients underwent ACDF surgeries. 86.1% (31/36) patients operated for 2 levels and 13.9% (5/36) patients operated for 3 levels. Dysphagia developed postoperatively in 2 (5.6%) patients in which zero-profile stand-alone cages were used. Fusion was achieved in 94.4% (34/36) patients. Conclusion:  Stand-alone zero-profile cages in multi-level ACDF surgeries have a good outcome in terms of post-operative less dysphagia and higher fusion rates. Keywords:  Anterior Cervical Discectomy (Decompression) And Fusion (ACDF), Zero-Profile Cages, Cervical Spondylotic Myelopathy

Clinical Presentation and Surgical Outcomes of Chronic Subdural Hematoma

Objective: The aim of this study was to access clinical presentation of chronic subdural hematoma and to evaluate the surgical outcome of evacuation of chronic subdural hematoma after single burrhole craniotomy with a close drainage system under local anesthesia. Material & Methods:  A descriptive study conducted in the Neurosurgery Department of Khairpur Medical College Sindh. 30 patients of chronic subdural hematoma were included. Patients prepared for evacuation of chronic subdural hematoma through single burr hole followed by closed drainage system for two days. Results:  The most common feature was gait disturbance followed by Hemiparesis and headache. Coexisting diseases were hypertension, Diabetes mellitus and Chronic Liver Disease, etc. and causes of CSDH were head injury (trivial trauma) and anticoagulant. Surgical decisions were taken on the bases of clinical presentation and radiological findings of patients. Surgical procedure single burrhole craniotomy followed by irrigation with normal saline and close drainage system for two days. On post-operative follow-up, a recurrence of CSDH occurred in two patients. Conclusion:  Single burrhole craniotomy with close drainage system is a simple and safe procedure under local anesthesia for treatment of chronic subdural hematoma. Keywords:  CSDH (chronic subdural hematoma), GCS (Glasgow coma score), Burrhole craniotomy, Neurosurgery & Subdural drain

Incidence and Surgical Outcome of the Intracranial Epidermoid Cyst at Punjab Institute of Neurosciences Lahore, Pakistan

Objectives:  The incidence and microsurgical outcomes of intracranial epidermoid cysts in the Department of Neurosurgery III, Punjab Institute of Neurosciences (PINS), Lahore, Pakistan, are described in this case series. Materials and Methods:  This study was a data analysis of a case series of 15 patients (mean age, 40 years) of both gender with intracranial epidermoid cysts who had microsurgical surgical excision over five years. Results:  This study comprised 11 (73.3%) male and 4 (26.7%) female patients, 11 (73.3%) cases were infratentorial and 4 (26.7%) cases were in supratentorial region. The epidermoid was located in the CP angle in 11 (73.3%) patients, 3 (20%) in the midline supra sellar region, and 1 (6.66%) in the frontotemporal region. The presenting complaints were mainly headache in 11 (73.33%), cranial nerve palsy and cerebellar signs in 8 (53.3%) patients, Trigeminal neuralgia in 3 (20%) patients, Fits and hydrocephalus in 2 (13.3%) patients. There were 14 (93.3%) patients with GTR (gross total resection), 1 (6.6%) patients STR (subtotal resection). According to Karnofsky's performance scoring (KPS), 3 (20%) patients improved, 11 (73.3%) patients had the same KPS, and 1 (6.6%) patient had a lower KPS. Conclusion:  The epidermoid cysts in the brain are usually found in the infratentorial region rather than the supratentorial region. Infratentorial lesions typically cause cranial nerve deficits, whereas the supratentorial area symptom is a headache

Evaluation of Electrolyte Imbalance in Acute Stroke

Objective:  Electrolyte imbalance is common in acute stroke; it may cause severe morbidity and mortality, so timely management of electrolyte imbalance may improve morbidity and mortality in cerebro-vascular accident. The purpose of this study was to evaluate electrolyte imbalance in acute stroke and its effect on the outcome of patients. Material and Methods:  This study was prospective descriptive in nature and it is comprised of 106 patients of acute stroke after clinically diagnosis confirmed by CT scan brain plain admitted in Khairpur Medical College Hospital. Serum electrolyte along with the other baseline investigation was performed. Results:  Hyponatremia was comparatively more common in brain infraction than spontaneous ICH. Hypokalemia is also more common in brain infarction as compared to the hemorrhagic stroke patients of this study. Conclusion:  Incidence of Hyponatremia was more common than hypokalemia in patients with acute stroke. Keywords:  Hemorrhage, Infraction, Hyponatremia, Hypokalemia

Intracranial Hydatid Cyst: A Case Report of Three Cases

A cerebral hydatid cyst is a less common condition as compared to hydatid diseases of liver and lungs. Surgical removal of the cyst without rupturing it should be the primary goal of surgery. We reported three cases of supratentorial cerebral hydatid cysts in this case-series. All of the cases belonged to three different age groups. One, 10 year old patient was previously operated at another hospital and presented with the recurrent disease. This patient was operated three times with a gap of six and nine months in-between surgeries. Currently, he is symptoms free for the last one year. Another, 40 year old patient was operated, 22 months back and is now disease free. Third case was of a 72 year old patient, who had a hepatic hydatid cyst as well. The relevant literature on the cerebral hydatid disease was reviewed and compared with our cases. The cerebral hydatid cyst should be included in the differential diagnosis of patients presenting with altered neurological status, especially in those who belongs to those regions where the disease is endemic. Total cyst removal without rupturing it should be the goal of surgery whenever possible. Postoperative treatment with Tablet Albendazole should be given in every case