The clinical antitumor efficacy of nitrogen mustards such as chlorambucil may relate to their abi... more The clinical antitumor efficacy of nitrogen mustards such as chlorambucil may relate to their ability to cause programmed cell death (apoptosis), probably through their DNA cross-linking properties. In contrast, bisbenzimidazoles such as Hoechst 33342 interact noncovalently with the minor groove of DNA, and appear to cause apoptosis in a fundamentally different way, which may involve the inhibition of topoisomerase (topo) I enzymes. A series of DNA minor groove binding nitrogen mustards with selective DNA affinity and in vivo antitumor activity in animal models was studied. Although two examples of such compounds proved to inhibit topo I enzymes in vitro, they were equally toxic towards topo I-proficient and- deficient strains of yeast, suggesting that topo I inhibition was not involved in cell killing. Flow cytometric analysis of Chinese hamster cells highlighted the differences in the propensity to cause apoptosis by chlorambucil compared with Hoechst 33342, revealing two distinct...
This review gives a brief overview of the expression patterns, molecular pharmacology and physiol... more This review gives a brief overview of the expression patterns, molecular pharmacology and physiological role of the cannabinoid 2 receptor (CB2) in pain. Particular emphasis is given to the therapeutic utility of CB2 receptor agonists. Through studies utilizing selective CB2 receptor agonists, non-selective cannabinoid agonists in conjunction with selective CB1 and CB2 receptor antagonists, or CB2 receptor knockout mice, it is now clear that this receptor plays a critical role in nociception. To this end, CB2 receptors have been shown to modulate acute pain, chronic inflammatory pain, post-surgical pain, cancer pain and pain associated with nerve injury. Here we review these studies and the compounds that were utilized. We hypothesize the mechanism of action by which the CB2 receptor could be involved in these processes. Finally we summarize the most recent novel chemical scaffolds that are being investigated towards advancing selective CB2 receptor agonists into the clinic. Many new pharmacological agents have been identified by high throughput screening and small molecule lead discovery and optimization in the past 10 years. It is anticipated that at least some of these agents may ultimately constitute effective new pain therapeutics that lack the side effects associated with traditional cannabinoid ligands.
We describe an updated protocol which allows the combination of the previously described TUNEL an... more We describe an updated protocol which allows the combination of the previously described TUNEL and Hoechst 33342 double-labelling (G. Whiteside, N. Cougnon, S.P. Hunt, R. Munglani, An improved method for the detection of apoptosis in tissue sections and cell culture, using the TUNEL technique combined with Hoechst stain, Brain Res. Protocols, 2, 1998, 160-164 [3]), with immunohistochemistry. The inclusion of the immunohistochemistry step allows identification of apoptosis in distinct cell types by using cell specific markers. It also permits investigation into the proteins expressed in cells undergoing apoptotic cell death. We have evaluated the triple staining in sections of post-axotomy neonatal dorsal root ganglia.
Proceedings of the European Dialysis and Transplant Association. European Dialysis and Transplant Association, 1979
Our experience of CAPD in 21 patients over a total period of 118 patients months has been evaluat... more Our experience of CAPD in 21 patients over a total period of 118 patients months has been evaluated and compared with intermittent peritoneal dialysis (IPD). CAPD was associated with greater clearance of urea creatinine and phosphate, higher concentrations of haemoglobin, improved control of hypertension and saline overload, and better patient acceptance than IPD. It is concluded that CAPD is an effective form of dialysis with many advantages over IPD, although the incidence of peritonitis is still twice that IPD.
Primary enuresis is essentially of two main types - the common diurnal-nocturnal type with associ... more Primary enuresis is essentially of two main types - the common diurnal-nocturnal type with associated bladder instability and the less common nocturnal type which shows normal cystometry. The importance of depth of sleep in both types is stressed, particularly the former. A rationale of treatment, self-monitored, voluntary, escalating cystometry, is described.
Endocannabinoids (eCBs) function as retrograde signaling molecules at synapses throughout the bra... more Endocannabinoids (eCBs) function as retrograde signaling molecules at synapses throughout the brain, regulate axonal growth and guidance during development, and drive adult neurogenesis. There remains a lack of genetic evidence as to the identity of the enzyme(s) responsible for the synthesis of eCBs in the brain. Diacylglycerol lipase-alpha (DAGLalpha) and -beta (DAGLbeta) synthesize 2-arachidonoyl-glycerol (2-AG), the most abundant eCB in the brain. However, their respective contribution to this and to eCB signaling has not been tested. In the present study, we show approximately 80% reductions in 2-AG levels in the brain and spinal cord in DAGLalpha(-/-) mice and a 50% reduction in the brain in DAGLbeta(-/-) mice. In contrast, DAGLbeta plays a more important role than DAGLalpha in regulating 2-AG levels in the liver, with a 90% reduction seen in DAGLbeta(-/-) mice. Levels of arachidonic acid decrease in parallel with 2-AG, suggesting that DAGL activity controls the steady-state levels of both lipids. In the hippocampus, the postsynaptic release of an eCB results in the transient suppression of GABA-mediated transmission at inhibitory synapses; we now show that this form of synaptic plasticity is completely lost in DAGLalpha(-/-) animals and relatively unaffected in DAGLbeta(-/-) animals. Finally, we show that the control of adult neurogenesis in the hippocampus and subventricular zone is compromised in the DAGLalpha(-/-) and/or DAGLbeta(-/-) mice. These findings provide the first evidence that DAGLalpha is the major biosynthetic enzyme for 2-AG in the nervous system and reveal an essential role for this enzyme in regulating retrograde synaptic plasticity and adult neurogenesis.
The clinical antitumor efficacy of nitrogen mustards such as chlorambucil may relate to their abi... more The clinical antitumor efficacy of nitrogen mustards such as chlorambucil may relate to their ability to cause programmed cell death (apoptosis), probably through their DNA cross-linking properties. In contrast, bisbenzimidazoles such as Hoechst 33342 interact noncovalently with the minor groove of DNA, and appear to cause apoptosis in a fundamentally different way, which may involve the inhibition of topoisomerase (topo) I enzymes. A series of DNA minor groove binding nitrogen mustards with selective DNA affinity and in vivo antitumor activity in animal models was studied. Although two examples of such compounds proved to inhibit topo I enzymes in vitro, they were equally toxic towards topo I-proficient and- deficient strains of yeast, suggesting that topo I inhibition was not involved in cell killing. Flow cytometric analysis of Chinese hamster cells highlighted the differences in the propensity to cause apoptosis by chlorambucil compared with Hoechst 33342, revealing two distinct...
This review gives a brief overview of the expression patterns, molecular pharmacology and physiol... more This review gives a brief overview of the expression patterns, molecular pharmacology and physiological role of the cannabinoid 2 receptor (CB2) in pain. Particular emphasis is given to the therapeutic utility of CB2 receptor agonists. Through studies utilizing selective CB2 receptor agonists, non-selective cannabinoid agonists in conjunction with selective CB1 and CB2 receptor antagonists, or CB2 receptor knockout mice, it is now clear that this receptor plays a critical role in nociception. To this end, CB2 receptors have been shown to modulate acute pain, chronic inflammatory pain, post-surgical pain, cancer pain and pain associated with nerve injury. Here we review these studies and the compounds that were utilized. We hypothesize the mechanism of action by which the CB2 receptor could be involved in these processes. Finally we summarize the most recent novel chemical scaffolds that are being investigated towards advancing selective CB2 receptor agonists into the clinic. Many new pharmacological agents have been identified by high throughput screening and small molecule lead discovery and optimization in the past 10 years. It is anticipated that at least some of these agents may ultimately constitute effective new pain therapeutics that lack the side effects associated with traditional cannabinoid ligands.
We describe an updated protocol which allows the combination of the previously described TUNEL an... more We describe an updated protocol which allows the combination of the previously described TUNEL and Hoechst 33342 double-labelling (G. Whiteside, N. Cougnon, S.P. Hunt, R. Munglani, An improved method for the detection of apoptosis in tissue sections and cell culture, using the TUNEL technique combined with Hoechst stain, Brain Res. Protocols, 2, 1998, 160-164 [3]), with immunohistochemistry. The inclusion of the immunohistochemistry step allows identification of apoptosis in distinct cell types by using cell specific markers. It also permits investigation into the proteins expressed in cells undergoing apoptotic cell death. We have evaluated the triple staining in sections of post-axotomy neonatal dorsal root ganglia.
Proceedings of the European Dialysis and Transplant Association. European Dialysis and Transplant Association, 1979
Our experience of CAPD in 21 patients over a total period of 118 patients months has been evaluat... more Our experience of CAPD in 21 patients over a total period of 118 patients months has been evaluated and compared with intermittent peritoneal dialysis (IPD). CAPD was associated with greater clearance of urea creatinine and phosphate, higher concentrations of haemoglobin, improved control of hypertension and saline overload, and better patient acceptance than IPD. It is concluded that CAPD is an effective form of dialysis with many advantages over IPD, although the incidence of peritonitis is still twice that IPD.
Primary enuresis is essentially of two main types - the common diurnal-nocturnal type with associ... more Primary enuresis is essentially of two main types - the common diurnal-nocturnal type with associated bladder instability and the less common nocturnal type which shows normal cystometry. The importance of depth of sleep in both types is stressed, particularly the former. A rationale of treatment, self-monitored, voluntary, escalating cystometry, is described.
Endocannabinoids (eCBs) function as retrograde signaling molecules at synapses throughout the bra... more Endocannabinoids (eCBs) function as retrograde signaling molecules at synapses throughout the brain, regulate axonal growth and guidance during development, and drive adult neurogenesis. There remains a lack of genetic evidence as to the identity of the enzyme(s) responsible for the synthesis of eCBs in the brain. Diacylglycerol lipase-alpha (DAGLalpha) and -beta (DAGLbeta) synthesize 2-arachidonoyl-glycerol (2-AG), the most abundant eCB in the brain. However, their respective contribution to this and to eCB signaling has not been tested. In the present study, we show approximately 80% reductions in 2-AG levels in the brain and spinal cord in DAGLalpha(-/-) mice and a 50% reduction in the brain in DAGLbeta(-/-) mice. In contrast, DAGLbeta plays a more important role than DAGLalpha in regulating 2-AG levels in the liver, with a 90% reduction seen in DAGLbeta(-/-) mice. Levels of arachidonic acid decrease in parallel with 2-AG, suggesting that DAGL activity controls the steady-state levels of both lipids. In the hippocampus, the postsynaptic release of an eCB results in the transient suppression of GABA-mediated transmission at inhibitory synapses; we now show that this form of synaptic plasticity is completely lost in DAGLalpha(-/-) animals and relatively unaffected in DAGLbeta(-/-) animals. Finally, we show that the control of adult neurogenesis in the hippocampus and subventricular zone is compromised in the DAGLalpha(-/-) and/or DAGLbeta(-/-) mice. These findings provide the first evidence that DAGLalpha is the major biosynthetic enzyme for 2-AG in the nervous system and reveal an essential role for this enzyme in regulating retrograde synaptic plasticity and adult neurogenesis.
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Papers by G. Whiteside