51
|
Dutta P, Chattopadhyay A, Bhansali A. Pseudohypoparathyroidism with Albright's hereditary osteodystrophy (AHO) phenotype. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2004; 52:46. [PMID: 15633718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
|
52
|
Abstract
Necrotizing fasciitis can be observed in a wide variety of clinical settings in the pediatric age group. But necrotizing fasciitis as a complication of chickenpox is rare. Five cases of necrotizing fasciitis following chickenpox were treated in the authors' institutions. Clinical signs like fever, tachycardia, pallor, erythema, marked edema of the affected area and patchy areas of discoloration or gangrene of the skin were present and were the important clues to the seriousness of infection. Patients were treated with aggressive surgical debridement, frequent dressings, broad-spectrum antibiotics, nutritional support, and split skin grafting. Early diagnosis and aggressive surgical therapy are critical. Literature search showed necrotizing fasciitis following chickenpox has not been reported in India. We feel early suspicion and aggressive management can decrease the morbidity and mortality in this rare complication.
Collapse
|
53
|
Dutta P, Chattopadhyay A, Bhansali A, Dash RJ. Lentiform nuclear degeneration following methanol ingestion. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2003; 51:692. [PMID: 14621039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
|
54
|
Biswas NM, Chattopadhyay A, Sarkar M. Protection of adrenocortical activity by dietary casein in ether anaesthetized rats. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2003; 41:367-9. [PMID: 15255650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Adrenal delta5-3beta-hydroxysteroid dehydrogenase (delta5-3beta-HSD) activity and serum corticosterone level were significantly higher in rats fed with 5% casein or 4% albumin diets after 1 hr of ether anaesthetic stress as compared to the controls, 5% casein and 20% casein (equivalent to 4% albumin) respectively. Ether anaesthesia to 20% casein fed rats caused no change in adrenal delta5-3beta-HSD activity and serum corticosterone level when compared with controls fed 20% casein diet. The results suggest that high milk protein diet may prevent acute stress effects by protecting adrenocortical activity. The present investigation opens up a new area of management of stress.
Collapse
|
55
|
Bhansali A, Kotwal N, Suresh V, Murlidharan R, Chattopadhyay A, Mathur K. Polyglandular autoimmune syndrome type 1 without chronic mucocutaneous candidiasis in a 16 year-old male. J Pediatr Endocrinol Metab 2003; 16:103-5. [PMID: 12585347 DOI: 10.1515/jpem.2003.16.1.103] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A 16 year-old boy presented with adrenal crisis and was incidentally found to have features of latent tetany. Also detected were Hashimoto's thyroiditis, alopecia and subnormal T cell function, and he was diagnosed as having polyglandular autoimmune syndrome type 1 (PGA-1), although chronic mucocutaneous candidiasis, a hallmark of PGA-1, was absent. The presentation of several components of this disorder at one time and at this age is uncommon, and the features of overt hypoparathyroidism were probably masked by associated adrenal insufficiency.
Collapse
|
56
|
Haliloglu G, Chattopadhyay A, Skorodis L, Manzur A, Mercuri E, Talim B, Akçören Z, Renda Y, Muntoni F, Topaloğlu H. Spinal muscular atrophy with progressive myoclonic epilepsy: report of new cases and review of the literature. Neuropediatrics 2002; 33:314-9. [PMID: 12571787 DOI: 10.1055/s-2002-37087] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Spinal muscular atrophy (SMA) is a clinically and genetically heterogeneous disease characterised by loss of motor function and muscle atrophy due to anterior horn cell degeneration. The most common variant is chromosome 5-linked proximal SMA, ranging in severity from congenital onset and infantile death to onset in adult life. Genetically separate variants with different distribution of weakness and/or additional features such as central nervous system involvement have been described. A rare variant with associated myoclonic epilepsy and lower motor neuron disease had been previously described in three families before the SMN gene, responsible for the common form of SMA, was isolated. We report four patients from two additional families affected by a syndrome characterised by severe and progressive myoclonic epilepsy and proximal weakness, tremor and lower motor neuron disease proven by electrophysiologic and muscle biopsy findings. Extensive metabolic investigations were normal and genetic analysis excluded the SMN gene. This study confirms that the association of myoclonic epilepsy and motor neuron disease represents a separate clinical and genetic entity from chromosome 5-linked SMA, the primary defect of which remains unknown.
Collapse
|
57
|
Abstract
Pyriform sinus fistulae/sinuses are rare causes of recurrent cervical abscess, especially on the left side. They can also present as acute thyroiditis. Treatment in the form of simple incision and drainage is invariably unsuccessful, and the entity may be confused with the residual tract of a second branchial arch anomaly. We report a case of pyriform sinus fistula, and believe that this is only the second case report in India. We feel that greater awareness can lead to proper and appropriate diagnosis of this anomaly.
Collapse
|
58
|
Chattopadhyay A, Kumar V, Maruliah M, Rao PLNG. Duodenojejunal obstruction by a hemangioma. Pediatr Surg Int 2002; 18:501-2. [PMID: 12415392 DOI: 10.1007/s00383-002-0838-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/28/2001] [Indexed: 11/29/2022]
Abstract
Gastrointestinal obstruction by hemangiomas is exceedingly rare. We report a case of a duodenojejunal obstruction caused by a large hemangioma. The patient underwent a gastrojejunostomy for relief of the obstruction and has been symptom-free, although the hemangioma persists.
Collapse
|
59
|
Kumar V, Marulaiah M, Chattopadhyay A, Rao PLNG. Unilateral inguinal ectopic scrotum with covered exstrophy. Pediatr Surg Int 2002; 18:511-3. [PMID: 12415396 DOI: 10.1007/s00383-002-0731-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/20/2001] [Indexed: 11/29/2022]
Abstract
A case of ectopic scrotum located in the right inguinal area and associated with covered exstrophy and ipsilateral renal agenesis is described. Initially, repair of the exstrophy was performed. Scrotal reconstruction was carried out after 1 year, during which time the patient developed an inguinal hernia in the ectopic scrotum. The literature is reviewed and the scrotal reconstruction procedure is discussed.
Collapse
|
60
|
Jungbluth H, Müller CR, Halliger-Keller B, Brockington M, Brown SC, Feng L, Chattopadhyay A, Mercuri E, Manzur AY, Ferreiro A, Laing NG, Davis MR, Roper HP, Dubowitz V, Bydder G, Sewry CA, Muntoni F. Autosomal recessive inheritance of RYR1 mutations in a congenital myopathy with cores. Neurology 2002; 59:284-7. [PMID: 12136074 DOI: 10.1212/wnl.59.2.284] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Central core disease (CCD) is a congenital myopathy due to dominant mutations in the skeletal muscle ryanodine receptor gene (RYR1). The authors report three patients from two consanguineous families with symptoms of a congenital myopathy, cores on muscle biopsy, and confirmed linkage to the RYR1 locus. Molecular genetic studies in one family identified a V4849I homozygous missense mutation in the RYR1 gene. This report suggests a congenital myopathy associated with recessive RYR1 mutations.
Collapse
|
61
|
Abstract
OBJECTIVE Traditionally the surgical treatment of Hirschsprung's disease (H.D.) includes preliminary colostomy in normally innervated bowel followed by one of several pull through procedures. The transanal single stage Soave procedure eliminated the need for preliminary colostomy and intraabdominal dissection. It is a recent concept in the management of this disease, and this is the first experience to be reported from India. METHODS Four children aged 3 weeks to one year underwent transanal pull through procedure over a two month period. A rectal mucosectomy was performed starting 0.5 cm. proximal to the dentate line and extending proximally to the level of intraperitoneal rectum. The muscular sleeve was divided circumferentially to allow the full thickness mobilization of the proximal colon. Ganglion cells were confirmed by frozen section and bowel was transected. The rectal muscular cuff was divided longitudinally and the anastomosis was completed. RESULTS Operative time including the frozen section averaged 160 minutes and average length of the bowel resected was 22 cm. There were no postoperative complications and all patients were discharged on seventh postoperative day. Median follow-up was 5 months (4-6 months) and stool output ranged from 2-4 per day. CONCLUSION The authors conclude that a single stage transanal Soave's pull through for Hirschsprung's Disease can be performed successfully in infants. When compared to conventional pull through procedure, it has the potential advantage of lower cost, less risk of damage to pelvic structures, absence of any abdominal incision, a lower incidence of intraperitoneal bleeding and adhesion formation. The preliminary functional results suggest that the patients gain early bowel function post operatively without soiling or constipation.
Collapse
|
62
|
Pawar AS, Chattopadhyay S, Chattopadhyay A, Mamdapur VR. Novel synthesis of a 1,4-dienic macrolide pheromone of Cucujid grain beetles. J Org Chem 2002. [DOI: 10.1021/jo00078a036] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
63
|
Chattopadhyay A, Mamdapur VR. (R)-2,3-O-Cyclohexylideneglyceraldehyde, a Versatile Intermediate for Asymmetric Synthesis of Chiral Alcohol. J Org Chem 2002. [DOI: 10.1021/jo00108a020] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
64
|
Kulkarni BA, Chattopadhyay S, Chattopadhyay A, Mamdapur VR. Synthesis of some bioactive acetylenic alcohols, components of the marine sponge Cribrochalina vasculum. J Org Chem 2002. [DOI: 10.1021/jo00074a022] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
65
|
Naqvi AA, Mandal S, Chattopadhyay A, Prasad A. Salt effect on the quality and recovery of essential oil of citronella (Cymbopogon winterianus Jowitt). FLAVOUR FRAG J 2002. [DOI: 10.1002/ffj.1059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
66
|
Chattopadhyay A, Kumar V, Bhat N, Rao P. Chromobacterium violaceum infection: A rare but frequently fatal disease. J Pediatr Surg 2002; 37:108-10. [PMID: 11781998 DOI: 10.1053/jpsu.2002.29439] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The authors report a rare case of Chromobacterium violaceum infection in a 2-month-old child. She presented with an apparently localized abscess, which appeared to respond well to therapy. However, the infection recurred later with a fulminant course. The organism frequently is dismissed as a contaminant or not identified properly, and the fatality rates are high. A high degree of awareness about this infection needs to be created, especially among pediatricians and pediatric surgeons, because children appear to be infected more commonly than adults, and aggressive therapy is needed to save these patients.
Collapse
|
67
|
Biswas NM, Chaudhuri GR, Chattopadhyay A, Sarkar M. Effect of casein diet on gonadotropin releasing hormone antagonist induced changes in adrenal gonadal functions in male rats. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2001; 39:1249-53. [PMID: 12018519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Adult male rats received daily injections (sc) of gonadotropin releasing hormone antagonist (0.2 mg/kg(-1) x day(-1)) for 21 days when they were sacrificed on day 22, adrenal weight, adrenal A5-3beta (delta 5-3beta) hydroxysteroid dehydrogenase (Delta5-3beta-HSD) activity and serum level of corticosterone were increased significantly while testicular 17beta (17beta) hydroxysteroid dehydrogenase (17beta-HSD) activity and serum level of testosterone and spermatogenesis were decreased in the rats fed on 5% casein diet. GnRH antagonist treated rats fed on 20% casein diet, resulted significant decrease in adrenal weight, serum corticosterone and adrenal A5-3beta-HSD activity while testicular 17beta-HSD activity serum testosterone levels and the weights of sex organs were increased with respect to anti GnRH treated rats fed on 5% casein diet. But the GnRH antagonist treated rats fed on 20% casein diet showed decreased spermatogenesis quantitatively and sperm count appeared similar to anti GnRH treated rats fed on 5% casein diet. These results indicate that high casein diet protects adrenocortical activity and stimulates testosterone synthesis without effecting spermatogenic arrest in GnRH antagonist treated rats. It may be concluded that GnRH antagonist in presence of high milk protein diet may be considered to be a suitable antihormone in the development of an ideal male contraceptive.
Collapse
|
68
|
Chattopadhyay A, Das Sarma S, Millis AJ. Transition temperature of ferromagnetic semiconductors: a dynamical mean field study. PHYSICAL REVIEW LETTERS 2001; 87:227202. [PMID: 11736422 DOI: 10.1103/physrevlett.87.227202] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2001] [Indexed: 05/23/2023]
Abstract
We formulate a theory of doped magnetic semiconductors such as Ga(1-x)Mn(x)As which have attracted recent attention for their possible use in spintronic applications. We solve the theory in the dynamical mean field approximation to find the magnetic transition temperature T(c) as a function of magnetic coupling strength J, carrier density n, and Mn density x. We find that T(c) is determined by a subtle interplay between carrier density and magnetic coupling.
Collapse
|
69
|
Biswas NM, Sen Gupta R, Chattopadhyay A, Choudhury GR, Sarkar M. Effect of atenolol on cadmium-induced testicular toxicity in male rats. Reprod Toxicol 2001; 15:699-704. [PMID: 11738523 DOI: 10.1016/s0890-6238(01)00184-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Cadmium-induced stress adversely affects testicular activity and causes sympathetic stimulation. To investigate the effect of atenolol, a beta-adrenergic receptor blocker, on testicular androgen synthesis after cadmium treatment, adult Sprague-Dawley strain male rats were given a single sc dose of cadmium chloride 0.45 mg/kg BW. Animals were killed on day 3 after treatment. Adrenal weight, adrenal delta 5-3 beta-hydroxysteroid dehydrogenase (delta 5-3 beta-HSD) activity, serum corticosterone, and brain noradrenaline were increased significantly while testicular delta 5-3 beta-HSD and 17 beta-HSD activities, serum testosterone, and accessory sex organs weight were decreased. Oral coadministration of atenolol at a dose of 2.0 mg/kg body weight for 3 days resulted in complete protection of adrenal delta 5-3 beta-HSD, testicular delta 5-3 beta-HSD, and 17 beta-HSD activities, adrenal weight, serum corticosterone, and serum testosterone when compared with cadmium-only group and there were no significant differences in these parameters from the vehicle control values. Simultaneous administration of cadmium and atenolol also protected brain noradrenaline content and reduced the rise of testicular cadmium concentration. All the parameters were similar to control levels in rats treated with atenolol alone. We conclude that atenolol may protect testicular androgen synthesis by inhibiting the action of noradrenaline on testicular Leydig cells and adrenocortical hyperactivity in cadmium-treated rats.
Collapse
|
70
|
Chattopadhyay A. Jahangir's interest in public health and medicine. BULLETIN OF THE INDIAN INSTITUTE OF HISTORY OF MEDICINE (HYDERABAD) 2001; 25:170-82. [PMID: 11618835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Jahangir, after his accession on the 24th October, 1605 A.D. passed twelve orders, as we learn from his Memoirs (Tuzuk-e-Jahangiri). According to fifth order manufacturing and sale of Rice-Spirit and any kind of intoxicating drug were forbidded. The tenth order was for the foundation of free hospitals and appointment of physicians in all the great cities of the empire. We learn from Edward Terry who was in India from 1615-18 A.D. that the common diseases of the time included the venereal disease, which was possibly syphilis. In the twelfth year of his reign Jahangir passed orders prohibiting smoking tobacco. In Tuzuk we find that in the third year of his reign a doe was brought to Jahangir, it was milked. Here Jahangir says that the milk of a she-antelope was believed to be a remedy for asthma. In the eighth year of his reign he tried to test the milk of a tigress which was brought to his court. He, however, failed to get the milk of the tigress. Here he says that, it was heard from philosophers that the milk of a tigress was highly useful for brightening eyes. Jahangir's belief in spiritual help in curing diseases is reflected in the fact that in the ninth year of his reign when he fell ill, he took a vow that after recovery he would make holes in his ears to declare that he owed his very existence to Khawaja Muinu-ddin and so he was Khawaja's ear-bored slave. After recovery he did accordingly and wore a pearl in each of his ears. Shaykh Hasan or Hassu whose father and grand father were surgeions of Akbar's times was a surgeon and a childhood friend of Jahangir. Jahangir after his accession made him governor of Gujarat and gave him the title of Mukarrab Khan. Another physician Hakim Ali whome Akbar had once sent as ambassador to Bijapur and was made a commander of 700 on his return, was made commander of 2,000 by Jahangir.
Collapse
|
71
|
Harikumar KG, Chattopadhyay A. Modulation of antagonist binding to serotonin1A receptors from bovine hippocampus by metal ions. Cell Mol Neurobiol 2001; 21:453-64. [PMID: 11860184 DOI: 10.1023/a:1013811221577] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
1. The serotonin1A (5-HT1A) receptors are members of a superfamily of seven transmembrane domain receptors that couple to G-proteins. They appear to be involved in various behavioral and cognitive functions. Although specific 5-HT1A agonists have been discovered more than a decade back, the development of selective 5-HT1A antagonists has been achieved only recently. 2. We have examined the modulation of the specific antagonist [3H]p-MPPF binding to 5-HT1A receptors from bovine hippocampal membranes by monovalent and divalent metal ions. Our results show that the antagonist binding to 5-HT1A receptors is inhibited by both monovalent and divalent cations in a concentration-dependent manner. This is accompanied by a concomitant reduction in binding affinity. 3. Our results also show that the specific antagonist p-MPPF binds to all available receptors in the bovine hippocampal membrane irrespective of their state of G-protein coupling and other serotonergic ligands such as 5-HT and OH-DPAT effectively compete with the specific antagonist [3H]p-MPPF. 4. These results are relevant to ongoing analyses of the overall modulation of ligand binding in G-protein-coupled seven transmembrane domain receptors.
Collapse
|
72
|
Chattopadhyay A, Singh S, Sood A, Wanchu A, Bambery P. Cervical osteophyte induced dysphagia. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2001; 49:1043-4. [PMID: 11848321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
|
73
|
Rukmini R, Rawat SS, Biswas SC, Chattopadhyay A. Cholesterol organization in membranes at low concentrations: effects of curvature stress and membrane thickness. Biophys J 2001; 81:2122-34. [PMID: 11566783 PMCID: PMC1301684 DOI: 10.1016/s0006-3495(01)75860-2] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cholesterol is often found distributed nonrandomly in domains in biological and model membranes and has been reported to be distributed heterogeneously among various intracellular membranes. Although a large body of literature exists on the organization of cholesterol in plasma membranes or membranes with high cholesterol content, very little is known about organization of cholesterol in membranes containing low amounts of cholesterol. Using a fluorescent cholesterol analog (25-[N-[(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-methyl]amino]-27-norcholesterol, or NBD-cholesterol), we have previously shown that cholesterol may exhibit local organization even at very low concentrations in membranes, which could possibly be attributable to transbilayer tail-to-tail dimers. This is supported by similar observations reported by other groups using cholesterol or dehydroergosterol, a naturally occurring fluorescent cholesterol analog which closely mimics cholesterol. In this paper, we have tested the basic features of cholesterol organization in membranes at low concentrations using spectral features of dehydroergosterol. More importantly, we have investigated the role of membrane surface curvature and thickness on transbilayer dimer arrangement of cholesterol using NBD-cholesterol. We find that dimerization is not favored in membranes with high curvature. However, cholesterol dimers are observed again if the curvature stress is relieved. Further, we have monitored the effect of membrane thickness on the dimerization process. Our results show that the dimerization process is stringently controlled by a narrow window of membrane thickness. Interestingly, this type of local organization of NBD-cholesterol at low concentrations is also observed in sphingomyelin-containing membranes. These results could be significant in membranes that have very low cholesterol content, such as the endoplasmic reticulum and the inner mitochondrial membrane, and in trafficking and sorting of cellular cholesterol.
Collapse
|
74
|
Mehlmann LM, Chattopadhyay A, Carpenter G, Jaffe LA. Evidence that phospholipase C from the sperm is not responsible for initiating Ca(2+) release at fertilization in mouse eggs. Dev Biol 2001; 236:492-501. [PMID: 11476587 DOI: 10.1006/dbio.2001.0329] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Release of Ca(2+) from intracellular stores at fertilization of mammalian eggs is mediated by inositol 1,4,5-trisphosphate (IP3), but the mechanism by which the sperm initiates IP3 production is not yet understood. We tested the hypothesis that phospholipase C (PLC) activity introduced into the mouse egg as a consequence of sperm-egg fusion is responsible for causing Ca(2+) release. We demonstrated that microinjecting purified, recombinant PLCgamma1 protein into mouse eggs caused Ca(2+) oscillations like those seen at fertilization. However, the PLC activity in the minimum amount of purified PLCgamma1 protein needed to elicit Ca(2+) release when injected into eggs was approximately 500-900 times the PLC activity contained in a single sperm. This indicates that a single mouse sperm does not contain enough PLC activity to be responsible for causing Ca(2+) release at fertilization. We also examined whether phosphatidylinositol 3-kinase (PI3K) could have a role in this process, and found that several inhibitors of PI3K-mediated signaling had no effect on Ca(2+) release at fertilization.
Collapse
|
75
|
Chattopadhyay A, Chiang CW, Yang E. BAD/BCL-[X(L)] heterodimerization leads to bypass of G0/G1 arrest. Oncogene 2001; 20:4507-18. [PMID: 11494146 DOI: 10.1038/sj.onc.1204584] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2000] [Revised: 04/19/2001] [Accepted: 04/27/2001] [Indexed: 11/08/2022]
Abstract
The pro-apoptotic molecule BAD binds BCL-[X(L)] or BCL2 and inactivates their survival function. In addition to their anti-apoptotic function, BCL2 and BCL-[X(L)] also delay cell cycle entry from quiescence. We found that the BH3-only molecule BAD also exerted a cell cycle effect. BAD expression resulted in failure to cell cycle block in growth arrest conditions. In low serum and in confluence, fibroblasts constitutively or inducibly expressing BAD persisted in S phase, continued to incorporate BrdU, and exhibited sustained cyclin E/cdk2 activity. Mutation analysis indicated that the cell cycle effect of BAD was not dependent on its phosphorylation status or subcellular localization, but strictly co-segregated with BCL-[X(L)] binding. bclx(-/-) MEFs expressing BAD and bad(-/-) MEFs both arrested in G0/G1 in low serum similar to wild-type controls, suggesting that the ability to overcome the G0/G1 checkpoint resulted from the presence of BAD/BCL-x(L) heterodimers, rather than the absence of BCL-[X(L)] or BAD. These data provide evidence that in addition to regulating apoptosis, the BAD/BCL-[X(L)] heterodimer has a novel cell cycle function.
Collapse
|