1.Translating blood-borne stimuli: chemotransduction in the carotid body.
Acta Physiologica Sinica 2007;59(2):128-132
The carotid body can transduce hypoxia and other blood-borne stimuli, perhaps including hypoglycaemia, into afferent neural discharge that is graded for intensity and which forms the afferent limb of a cardiorespiratory and neuroendocrine reflex loop. Hypoxia inhibits a variety of K(+) channels in the type I cells of the carotid body, in a seemingly species-dependent manner, and the resultant membrane depolarisation is sufficient to activate voltage-gated Ca(2+) entry leading to neurosecretion and afferent discharge. The ion channels that respond to hypoxia appear to do so indirectly and recent work has therefore focussed upon identification of other proteins in the type I cells of the carotid body that may play key roles in the oxygen sensing process. Whilst a role for mitochondrial and/or NADPH-derived reactive oxygen species (ROS) has been proposed, the evidence for their signalling hypoxia in the carotid body is presently less than compelling and two alternate hypotheses are currently being tested further. The first implicates haemoxygenase 2 (HO-2), which may control specific K(+) channel activation through O(2)-dependent production of the signalling molecule, carbon monoxide. The second hypothesis suggests a role for the cellular energy sensor, AMP-activated protein kinase (AMPK), which can inhibit type I cell K(+) channels and increase afferent discharge when activated by hypoxia-induced elevations in the AMP: ATP ratio. The apparent richness of O(2)-sensitive K(+) channels and sensor mechanisms within this organ may indicate a redundancy system for this vital cellular process or it may be that each protein contributes differently to the overall response, for example, with different O(2) affinities. The mechanism by which low glucose is sensed is not yet known, but recent evidence suggests that it is not via closure of K(+) channels, unlike the hypoxia transduction process.
AMP-Activated Protein Kinases
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metabolism
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Animals
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Carotid Body
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physiology
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Chemoreceptor Cells
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physiology
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Heme Oxygenase (Decyclizing)
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metabolism
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Humans
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Hypoxia
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physiopathology
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Potassium Channels
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metabolism
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Reactive Oxygen Species
;
metabolism
2.Open Partial Nephrectomy With Zero IschemiaTechnique Using Thulium Laser: Our Experience of4 Cases
Kumar PREM ; Pankaj KUMAR ; Zia Ur REHMAN ; Somesh JANORIA
Korean Journal of Urological Oncology 2020;18(2):155-160
With the advent of newer technologies, the management of small renal masses has shown a paradigm shift.This has resulted in preferring partial nephrectomy over radical nephrectomy, emphasizing the concept of nephronsparing surgery. Various lasers have been used in few cases. We prospectively evaluated the use of thuliumlaser in open partial nephrectomy over last 1 year. The aim is to study thulium laser as an energy source forpartial nephrectomy for peripheral tumor. The role of partial nephrectomy and zero ischemia time in renalpreservation is already proven. Outcomes of total of 4 patients who underwent open partial nephrectomy wereanalyzed prospectively. We used Quanta Cyber TM laser at setting of 30 W both for cutting and coagulation.Preoperative characteristics and outcomes were analyzed. Four patients underwent open partial nephrectomy withzero ischemia. The mean tumor size was 5.26 cm, mean RENAL nephrometry score was 4.5, mean operativetime was 67.5 minutes, active laser time was 2 minutes, mean blood loss related to partial nephrectomy perse was 65 mL. Mean preoperative hemoglobin was 11.12 g% and mean postoperative hemoglobin was 10.05g%. Mean duration of stay was 6 days. Histologically all lesions were renal cell carcinoma pT1/T2, with marginsnegative for tumor and no deterioration in renal function during follow-up. The thulium laser at 2013 nm wavelengthdemonstrates excellent hemostasis and precise cutting capabilities of the renal cortex during open partialnephrectomy for peripheral tumors without requiring renal artery clamping.
3.Acute kidney injury (AKI) with the use of antibiotic-impregnated bone cement in primary total knee arthroplasty.
Bernard P H LAU ; V Prem KUMAR
Annals of the Academy of Medicine, Singapore 2013;42(12):692-695
Acute Kidney Injury
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chemically induced
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Aged
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Anti-Bacterial Agents
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administration & dosage
;
adverse effects
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Arthroplasty, Replacement, Knee
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Bone Cements
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adverse effects
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Drug-Related Side Effects and Adverse Reactions
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complications
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Female
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Humans
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Surgical Wound Infection
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prevention & control
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Treatment Outcome
4.Ombitasvir/paritaprevir/ritonavir+dasabuvir and ribavirin associated drug-induced liver injury and syndrome of inappropriate secretion of anti-diuretic hormone: A case report
Rahul KUMAR ; John Chen HSIANG ; Jessica TAN ; Prem Harichander THURAIRAJAH
Clinical and Molecular Hepatology 2019;25(3):326-330
No abstract available.
Drug-Induced Liver Injury
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Ribavirin
5.EBV reactivation mimicking a lymphoproliferative disorder associated with ruxolitinib therapy for myelofibrosis
Shruti PREM ; David LOACH ; Jeffrey LIPTON ; Rajat KUMAR ; Vikas GUPTA
Blood Research 2019;54(4):282-284
No abstract available.
Herpesvirus 4, Human
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Lymphoproliferative Disorders
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Primary Myelofibrosis
6.Rare case of impalement of two occupants of a vehicle by the same object: insights into the management of complex thoracic impalements.
Maneesh SINGHAL ; Madduri-Vijay KUMAR ; Prem PRAKASH ; Amit GUPTA ; Subodh KUMAR ; Sushma SAGAR
Chinese Journal of Traumatology 2012;15(1):50-53
Thoracic impalement injuries are very rare and the majority of patients do not survive to reach a medical care facility. In this case report, we describe the successful outcome of a case of double thoracic impalement by two steel tors, of which one steel tor had impaled two patients simultaneously. The case report highlights all aspects of managing such rare and complex cases right from prehospital care; extrication process which happened under controlled environment at the trauma centre itself, till the definitive management of the impaled thoracic objects. Thoracic impalement injuries are dramatic and appear very challenging. However presence of mind of the managing team, coordinated team effort and availability of adequate facilities can lead to a successful outcome.
Humans
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Thoracic Injuries
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Wounds, Penetrating
8.Morphometric analysis of sacral corridor in the upper three sacral segments to prevent neurovascular injury
Binita CHAUDHARY ; Prem KUMAR ; Ruchika NARAYAN ; Adil ASGHAR ; Padamjeet PANCHAL ; Neelam KUMARI
Anatomy & Cell Biology 2024;57(2):221-228
Although studies of the sacral corridor dimension have been reported in the European population, little attention has been paid to this issue in the Asian population. The purpose of the study is to estimate the safe dimension of the corridor to avoid neurovascular damage during the fixation of the sacral fracture. The study aimed to examine the cephalocaudal (vertical) and the anteroposterior diameter of the bony passage in the upper three sacral segments. The study further examines the effect of age and sex on corridor dimensions at different sacral levels. Three-dimensionally reconstructed sacra from computed tomography of normal subjects were included in the study. Cephalocaudal and anteroposterior diameters were measured in coronal and axial sections using Geomagic Freeform Plus software. Anteroposterior diameter of the sacral corridor at the first, second, and third sacral segments are significantly higher in males (P=0.013, 0.0011, and <0.0001, respectively). The length of the sacrum also revealed sexual dimorphism (P<0.00016). The anteroposterior diameter of the second sacral segment (ap-S2c) correlated moderately with the first sacral anteroposterior diameter (ap-S1c) (R=0.519, P<0.001). The ap-S2c exhibited a moderate correlation to the third sacral segment (ap-S3c) (R=0.677, P<0.001). The sacral corridor at the level of S1 has the largest cephalocaudal (18.25 mm) and anteroposterior diameter (17.11 mm). Placement of the screw in the first sacral corridor may avoid damage to the neurovascular bundle during the fixation of the sacral fracture.
9.Morphometric analysis of sacral corridor in the upper three sacral segments to prevent neurovascular injury
Binita CHAUDHARY ; Prem KUMAR ; Ruchika NARAYAN ; Adil ASGHAR ; Padamjeet PANCHAL ; Neelam KUMARI
Anatomy & Cell Biology 2024;57(2):221-228
Although studies of the sacral corridor dimension have been reported in the European population, little attention has been paid to this issue in the Asian population. The purpose of the study is to estimate the safe dimension of the corridor to avoid neurovascular damage during the fixation of the sacral fracture. The study aimed to examine the cephalocaudal (vertical) and the anteroposterior diameter of the bony passage in the upper three sacral segments. The study further examines the effect of age and sex on corridor dimensions at different sacral levels. Three-dimensionally reconstructed sacra from computed tomography of normal subjects were included in the study. Cephalocaudal and anteroposterior diameters were measured in coronal and axial sections using Geomagic Freeform Plus software. Anteroposterior diameter of the sacral corridor at the first, second, and third sacral segments are significantly higher in males (P=0.013, 0.0011, and <0.0001, respectively). The length of the sacrum also revealed sexual dimorphism (P<0.00016). The anteroposterior diameter of the second sacral segment (ap-S2c) correlated moderately with the first sacral anteroposterior diameter (ap-S1c) (R=0.519, P<0.001). The ap-S2c exhibited a moderate correlation to the third sacral segment (ap-S3c) (R=0.677, P<0.001). The sacral corridor at the level of S1 has the largest cephalocaudal (18.25 mm) and anteroposterior diameter (17.11 mm). Placement of the screw in the first sacral corridor may avoid damage to the neurovascular bundle during the fixation of the sacral fracture.
10.Morphometric analysis of sacral corridor in the upper three sacral segments to prevent neurovascular injury
Binita CHAUDHARY ; Prem KUMAR ; Ruchika NARAYAN ; Adil ASGHAR ; Padamjeet PANCHAL ; Neelam KUMARI
Anatomy & Cell Biology 2024;57(2):221-228
Although studies of the sacral corridor dimension have been reported in the European population, little attention has been paid to this issue in the Asian population. The purpose of the study is to estimate the safe dimension of the corridor to avoid neurovascular damage during the fixation of the sacral fracture. The study aimed to examine the cephalocaudal (vertical) and the anteroposterior diameter of the bony passage in the upper three sacral segments. The study further examines the effect of age and sex on corridor dimensions at different sacral levels. Three-dimensionally reconstructed sacra from computed tomography of normal subjects were included in the study. Cephalocaudal and anteroposterior diameters were measured in coronal and axial sections using Geomagic Freeform Plus software. Anteroposterior diameter of the sacral corridor at the first, second, and third sacral segments are significantly higher in males (P=0.013, 0.0011, and <0.0001, respectively). The length of the sacrum also revealed sexual dimorphism (P<0.00016). The anteroposterior diameter of the second sacral segment (ap-S2c) correlated moderately with the first sacral anteroposterior diameter (ap-S1c) (R=0.519, P<0.001). The ap-S2c exhibited a moderate correlation to the third sacral segment (ap-S3c) (R=0.677, P<0.001). The sacral corridor at the level of S1 has the largest cephalocaudal (18.25 mm) and anteroposterior diameter (17.11 mm). Placement of the screw in the first sacral corridor may avoid damage to the neurovascular bundle during the fixation of the sacral fracture.