Mitochondrial permeability transition pore induction is linked to formation of the complex of ATPase C-subunit, polyhydroxybutyrate and inorganic polyphosphate.

Mitochondrial permeability transition pore (mPTP) opening allows free movement of ions and small molecules leading to mitochondrial membrane depolarization and ATP depletion that triggers cell death. A multi-protein complex of the mitochondrial ATP synthase has an essential role in mPTP. However, the molecular identity of the central 'pore' part of mPTP complex is not known. A highly purified fraction of mammalian mitochondria containing C-subunit of ATPase (C-subunit), calcium, inorganic polyphosphate (polyP) and polyhydroxybutyrate (PHB) forms ion channels with properties that resemble the native mPTP. We demonstrate here that amount of this channel-forming complex dramatically increases in intact mitochondria during mPTP activation. This increase is inhibited by both Cyclosporine A, an inhibitor of mPTP and Ruthenium Red, an inhibitor of the Mitochondrial Calcium Uniporter. Similar increases in the amount of complex formation occurs in areas of mouse brain damaged by ischemia-reperfusion injury. These findings suggest that calcium-induced mPTP is associated with de novo assembly of a channel comprising C-subunit, polyP and PHB.

Synergistic neuroprotection by epicatechin and quercetin: Activation of convergent mitochondrial signaling pathways.

In view of evidence that increased consumption of epicatechin (E) and quercetin (Q) may reduce the risk of stroke, we have measured the effects of combining E and Q on mitochondrial function and neuronal survival following oxygen-glucose deprivation (OGD). Relative to mouse cortical neuron cultures pretreated (24h) with either E or Q (0.1-10µM), E+Q synergistically attenuated OGD-induced neuronal cell death. E, Q and E+Q (0.3µM) increased spare respiratory capacity but only E+Q (0.3µM) preserved this crucial parameter of neuronal mitochondrial function after OGD. These improvements were accompanied by corresponding increases in cyclic AMP response element binding protein (CREB) phosphorylation and the expression of CREB-target genes that promote neuronal survival (Bcl-2) and mitochondrial biogenesis (PGC-1α). Consistent with these findings, E+Q (0.1 and 1.0µM) elevated mitochondrial gene expression (MT-ND2 and MT-ATP6) to a greater extent than E or Q after OGD. Q (0.3-3.0µM), but not E (3.0µM), elevated cytosolic calcium (Ca(2+)) spikes and the mitochondrial membrane potential. Conversely, E and E+Q (0.1 and 0.3µM), but not Q (0.1 and 0.3µM), activated protein kinase B (Akt). Nitric oxide synthase (NOS) inhibition with L-N(G)-nitroarginine methyl ester (1.0µM) blocked neuroprotection by E (0.3µM) or Q (1.0µM). Oral administration of E+Q (75mg/kg; once daily for 5days) reduced hypoxic-ischemic brain injury. These findings suggest E and Q activate Akt- and Ca(2+)-mediated signaling pathways that converge on NOS and CREB resulting in synergistic improvements in neuronal mitochondrial performance which confer profound protection against ischemic injury.

Cochlear protection against cisplatin by viral transfection of X-linked inhibitor of apoptosis protein across round window membrane.

We have previously demonstrated that both age-related and noise-induced hearing loss are reduced in transgenic mice that ubiquitously overexpress X-linked inhibitor of apoptosis protein (XIAP). In view of the therapeutic implications of these findings, we have developed a minimally invasive surgical method to deliver adenoid-associated virus (AAV) across the round window membrane (RWM) of the cochlea, enabling efficient gene transfer to hair cells and sensory neurons in this enclosed structure. This RWM approach was used in the present study to evaluate the effectiveness of AAV-mediated XIAP overexpression in protecting against cisplatin-induced ototoxicity. Two weeks following surgery, AAV-derived XIAP was detected in the majority of inner and outer hair cells, resulting in a threefold elevation of this antiapoptotic protein in the cochlea. The protection of AAV-mediated XIAP overexpression was evaluated in animals treated with cisplatin at a dose of 4 mg kg(-1) per day for 4-7 consecutive days. The XIAP overexpression was found to attenuate cisplatin-induced hearing loss by ~22 dB. This was accompanied by a reduction of the loss of vulnerable hair cells and sensory neurons in the cochlea by 13%.

Inter- and intra-year variation in foraging areas of breeding kittiwakes (Rissa tridactyla).

While seabird conservation efforts have largely focused on protection from threats at the colony (e.g. reducing disturbance and predation), attention is increasingly being given to implementing protection measures for foraging areas at sea. For this to be effective, important foraging areas must be identified. Although numerous studies have examined seabird foraging behaviour, information is still lacking on the variability in area utilisation within and among breeding seasons. GPS devices were attached to adult black-legged kittiwakes breeding at an expanding North Sea colony (55°20'N, 1°32'W) during both incubation and chick-rearing in 2012 and during chick-rearing in 2011, to determine whether foraging areas remained consistent and to identify the oceanographic characteristics of areas used for foraging. The type and size of prey items consumed at different stages of the breeding cycle was also examined. During incubation (April-May 2012), kittiwakes foraged substantially further from the colony and fed on larger sandeels than when feeding chicks, and there was significant inter-annual variation in foraging areas used during the chick-rearing period (June-July 2011 and 2012). Foraging areas were characterised by cooler sea surface temperatures and areas of high chlorophyll a concentration, although association with specific oceanographic features changed within the breeding season and between years. These results emphasise the importance of considering how foraging areas and reliance on specific oceanographic conditions change over time when seeking to identify important marine areas for seabirds.

Efficient cochlear gene transfection in guinea-pigs with adeno-associated viral vectors by partial digestion of round window membrane.

The auditory portion of the inner ear, the cochlea, is an ideal organ for local gene transfection owing to its relative isolation. Various carriers have been tested for cochlear gene transfection. To date, viral vectors appear to have much higher transfection efficacy than non-viral mechanisms. Among these vectors, recombinant adeno-associated virus (rAAV) vectors have several advantages such as being non-pathogenic and the ability to produce prolonged gene expression in various cell types. However, rAAV vectors cannot pass through the intact round window membrane (RWM), otherwise a very attractive approach to access the human inner ear. In this study, performed in guinea-pigs, we describe a method to increase the permeability of RWM to rAAV vectors by partial digestion with collagenase solution. Elevated delivery of rAAV across the partially digested RWM increased transfection efficacy to a satisfactory level, even though it was still lower than that achieved by direct cochleostomy injection. Functional tests (auditory brainstem responses) showed that this enzymatic manipulation did not cause permanent hearing loss if applied appropriately. Morphological observations suggested that the damage to RWM caused by partial digestion healed within four weeks. Taken together, these findings suggest that partial digestion of the RWM is a safe and effective method for increasing the transfection of cochlear sensory cells with rAAV.

Overexpression of X-linked inhibitor of apoptosis protein protects against noise-induced hearing loss in mice.

Apoptosis is responsible for cochlear cell death induced by noise. Here, we show that transgenic (TG) mice that overexpress X-linked inhibitor of apoptosis protein (XIAP) under control of the ubiquitin promoter display reduced hearing loss and cochlear damage induced by acoustic overstimulation (125 dB sound pressure level, 6 h) compared with wild-type (WT) littermates. Hearing status was evaluated using the auditory brainstem response (ABR), whereas cochlear damage was assessed by counts of surviving hair cells (HCs) and spiral ganglion neurons (SGNs) as well as their fibers to HCs. Significantly smaller threshold shifts were found for TG mice than WT littermates. Correspondingly, the TG mice also showed a reduced loss of HCs, SGNs and their fibers to HCs. HC loss was limited to the basal end of the cochlea that detects high frequency sound. In contrast, the ABRs demonstrated a loss of hearing sensitivity across the entire frequency range tested (2-32 kHz) indicating that the hearing loss could not be fully attributed to HC loss alone. The TG mice displayed superior hearing sensitivity over this whole range, suggesting that XIAP overexpression reduces noise-induced hearing loss not only by protecting HCs but also other components of the cochlea.

Microwave ablation for unresectable hepatic tumours: clinical results using a novel microwave probe and generator.

BACKGROUND: Microwave ablation is an in situ method of tumour destruction used to treat patients with unresectable liver tumours. A new microwave generator and probe, designed to deliver high energy into solid tumours quickly has been developed at our institution. We report the results of its use in patients with unresectable liver tumours treated by a single surgeon in a single institution. METHODS: Thirty-one patients with 89 unresectable liver tumours were recruited into the study and underwent microwave ablation in a single procedure. RESULTS: There were no post-operative complications. At a median of 24 months post ablation, 15 patients were alive with 7 patients disease free. At a median of 26 months, 8 patients were alive with tumour recurrence but only 1 with local recurrence. The remaining 7 patients with recurrence were found to have new disease at locations remote from the ablation site. Fourteen patients died of disease progression at a median survival of 15 months, with only 1 patient with local and remote tumour recurrence. Of the total numbers of tumours treated (n=89), a local tumour recurrence rate of 2% was observed. Overall median survival was 29 months with 3 year survival of 40%. DISCUSSION: Microwave tissue ablation using this novel generator and probe has a low local recurrence and complication rate. Overall survival is comparable to alternative ablation modalities and its ability to treat, even large tumours, with a single insertion of the probe makes it an extremely attractive treatment option.

Surgical treatment of combined hepatic and pulmonary colorectal cancer metastases.

AIMS: Surgical resection of combined hepatic and pulmonary metastases remains controversial in light of limited supportive evidence. This study aimed to audit our initial experience with this aggressive surgical strategy. METHODS: Between 1997 and 2006 we assessed 19 patients with colorectal cancer metastases for combined liver and lung metastasectomy, of whom 16 patients underwent surgery. We retrospectively reviewed perioperative and survival data. RESULTS: Synchronous liver metastases were present in three out of 16 patients at time of diagnosis of the primary tumour, and one out of 16 patients had synchronous lung and liver metastases with the primary tumour. Of those 12 patients who developed metachronous metastases five patients developed liver metastases first, one patient developed pulmonary metastases first, and six patients developed synchronous liver and lung metastases. Thirty nine operations were performed on 16 patients. The median hospital stay was 5.5 (2-10) days for the pulmonary and 7 (1-23) days for the hepatic resections. There were no in-hospital deaths. Chemotherapy was given to five patients prior to metastasectomy and nine received adjuvant chemotherapy following metastasectomy. Median survival from diagnosis of metastatic disease was 44 months (8-87 months). Estimated 1-year survival from diagnosis of metastatic disease was 94%, estimated 5-year survival was 20%. CONCLUSION: We believe an aggressive but selective surgical approach to combined hepatic and pulmonary colorectal metastases is justified by limited resource requirements and encouraging survival.

Delayed administration of a potent cyclin dependent kinase and glycogen synthase kinase 3 beta inhibitor produces long-term neuroprotection in a hypoxia-ischemia model of brain injury.

We compared the neuroprotective efficacy of a potent and CNS-penetrant cyclin dependent kinase (CDK) and glycogen synthase kinase 3 beta (GSK3beta) inhibitor (Compound 1) in juvenile (postnatal day 21; P21) and adult C57Bl/6 mice (postnatal day 60; P60) using a model of hypoxic-ischemic brain injury (HI). Neuronal cell counts and density measures from brain sections stained with Cresyl Violet revealed that exposure of P21 mice to 60 min of HI resulted in extensive damage to the ipsilateral cornu ammonis 1 (CA1) region of the hippocampus (40% cell loss) and striatum (30% cell loss) 7 days later. Exposure of P60 mice to 40 min of HI produced a similar pattern of cell loss. Intraperitoneal administration of Compound 1 (3 mg/kg) 1, 5 and 9 h after 60 min of HI did not reduce brain injury in P21 mice relative to vehicle controls. By contrast, in P60 mice, this treatment significantly decreased cell loss in the ipsilateral hippocampus (10% cell loss) and striatum (15% loss) relative to vehicle controls. Terminal uridine deoxynucleotidyl transferase (TUNNEL) positive cell counts and infarct volume were also substantially reduced in P60 mice treated with Compound 1. A motor coordination test performed twice weekly until 5 weeks post-HI confirmed that Compound 1 produced long lasting functional recovery. Our results indicate that Compound 1 produced long lasting neuroprotective effects in adult but not juvenile mice suggesting that inhibition of the CDKs and GSK3beta plays a distinct neuroprotective role in the juvenile and adult brain.

Expression of the inhibitor of apoptosis protein family in multiple sclerosis reveals a potential immunomodulatory role during autoimmune mediated demyelination.

A failure of autoreactive T cells to undergo apoptosis may contribute to the pathogenesis of multiple sclerosis (MS). The role of the inhibitor of apoptosis (IAP) family of anti-apoptotic proteins such as X-linked IAP (XIAP), human inhibitor of apoptosis-1 (HIAP-1), human inhibitor of apoptosis-2 (HIAP-2), neuronal apoptosis inhibitory protein (NAIP) and Survivin in relapsing-remitting, secondary-progressive, primary-progressive or benign forms of MS is unclear. We report here that expression of the IAP family of genes in peripheral blood samples and brain tissues from MS cases support a role for differential regulation of these potent anti-apoptotic proteins in the pathology of MS. XIAP mRNA and protein levels were elevated in peripheral blood mononuclear cells from patients with active disease relative to normal subjects. In patients with active MS, HIAP-1 and HIAP-2 mRNA levels were elevated in resting T cells while NAIP mRNA was increased in whole blood. In post-mortem MS brain tissue, XIAP and HIAP-1 in myelin lesions were co-localized with microglia and T cells, respectively. Only in primary-progressive patients was Survivin expression elevated suggestive of a distinct pathological basis for this subtype of MS. Taken together, these results suggest that patterns of inhibitor of apoptosis expression in immune cells may have value in distinguishing between MS subtypes and offer insight into the mechanisms responsible for their distinct clinical courses.

Laparoscopic repair of direct inguinal hernia: a new technique that reduces the development of postoperative seroma.

BACKGROUND: Seroma are common early postoperative complications encountered in laparoscopic inguinal hernia repair. Previous anecdotal evidence from our surgical practice suggested a lower incidence of postoperative seroma formation with direct hernia repairs when the lax transversalis fascia (TF) is inverted by tacking to the pubic ramus. We undertook a study to investigate whether TF inversion in this way reduces the incidence of postoperative seroma. METHOD: A total of 216 patients undergoing transabdominal preperitoneal (TAPP) laparoscopic inguinal hernia repairs from August 2003 to December 2005 were included in this prospective non-randomised controlled study. Surgeon 1 would routinely invert the TF whereas surgeon 2 would not. At follow-up the presence of postoperative seroma and pain was recorded. RESULTS: Mann-Whitney U test demonstrated no significant difference in terms of age, sex and time to follow-up between the surgeons' patient groups (P > 0.05), and Chi-square test demonstrated significantly that inversion of the TF is associated with a lower incidence of postoperative seroma (P < 0.05). There was no significant difference in terms of postoperative pain at follow-up. CONCLUSION: Inversion of the TF is associated with a statistically lower incidence of postoperative seroma, without increasing postoperative pain despite the use of one or two additional tacks.

An algorithm for the management of bile leak following laparoscopic cholecystectomy.

INTRODUCTION: The management of bile leaks following laparoscopic cholecystectomy has evolved with increased experience of ERCP and laparoscopy. The purpose of this study was to determine the impact of a minimally invasive management protocol. PATIENTS AND METHODS: Twenty-four patients with a bile leak following laparoscopic cholecystectomy were recorded consecutively between 1993 and 2003. Between 1993-1998, 10 patients were managed on a case-by-case basis. Between 1998-2003, 14 patients were managed according to a minimally invasive protocol utilising ERC/biliary stenting and re-laparoscopy if indicated. RESULTS: Bile leaks presented as bile in a drain left in situ post laparoscopic cholecystectomy (8/10 versus 10/14) or biliary peritonitis (2/10 versus 4/14). Prior to 1998, neither ERC nor laparoscopy were utilised routinely. During this period, 4/10 patients recovered with conservative management and 6/10 (60%) underwent laparotomy. There was one postoperative death and median hospital stay post laparoscopic cholecystectomy was 10 days (range, 5-30 days). In the protocol era, ERC +/- stenting was performed in 11/14 (P = 0.01 versus pre-protocol) with the main indication being a persistent bile leak. Re-laparoscopy was necessary in 5/14 (P = 0.05 versus preprotocol). No laparotomies were performed (P < 0.01 versus pre-protocol) and there were no postoperative deaths. Median hospital stay was 11 days (range, 5-55 days). CONCLUSIONS: The introduction of a minimally invasive protocol utilising ERC and re-laparoscopy offers an effective modern algorithm for the management of bile leaks after laparoscopic cholecystectomy.

Darbepoetin alfa (Aranesp) improves recognition memory in adult rats that have sustained bilateral ventral hippocampal lesions as neonates or young adults.

Recognition memory was assessed in adult rats that received bilateral injections of saline (sham lesions) or ibotenic acid (lesioned) in the ventral hippocampus as neonates (postnatal day 7, PD7) or young adult (42 days of age, PD42) using the Novel Object Recognition Test (NORT). Normal or sham-lesioned rats were able to distinguish novel from familiar objects over a 0.5 and 2 h delay between the sample and choice phases. Adult rats (PD70) lesioned as neonates performed progressively worse than sham-lesioned animals at delays of 0.5 and 2 h. A single injection of darbepoetin alfa (500 or 5000 U/kg, i.p.), given 1 h before the sample phase restored performance 0.5 or 2 h later in the choice phase to same levels as sham-lesioned rats. Adults lesioned on PD42 displayed deficits in NORT performance with a 2 h delay between the choice and sample phases that were completely reversed by administration of darbepoetin alfa (5000 U/kg, i.p.) 1 h before the sample phase. These results suggest that darbepoetin alfa may have utility in treating memory deficits associated with brain dysfunction related to developmental disorders such as schizophrenia.

Neuroanatomical and pharmacological assessment of Fos expression induced in the rat brain by the phosphodiesterase-4 inhibitor 6-(4-pyridylmethyl)-8-(3-nitrophenyl) quinoline.

A major obstacle in the therapeutic development of phosphodiesterase-4 (PDE4) inhibitors is the production of adverse side effects such as nausea and vomiting. Immunohistochemical detection of Fos-like immunoreactivity (FLI) was used to address the neuroanatomical basis for the pharmacological actions of PDE4 inhibitors. The potent and selective PDE4 inhibitors 6-(4-pyridylmethyl)-8-(3-nitrophenyl) quinoline (PMNPQ) and rolipram elevated FLI in brain regions potentially relevant to the anti-depressant and emetic effects of PDE4 inhibition. PMNPQ and rolipram elevated FLI in the locus coeruleus, habenula, paraventricular nucleus of the thalamus, amygdala and nucleus accumbens, all structures with strong limbic connectivity implicated in arousal, memory and affective aspects of behaviour. Consistent with the emetic effects of PDE4 inhibitors such as PMNPQ and rolipram, these compounds elevated FLI in caudal brainstem nuclei such as the area postrema and nucleus of the solitary tract. Administration of the NK(1) antagonist RP 67580 prior to PMNPQ reversed increases in FLI produced by PMNPQ in these regions. RP 67580 did not, however, reduce PMNPQ-induced FLI in limbic structures. These findings suggest that PDE4 inhibitors produce emesis by increasing NK(1) receptor activation in the AP/NTS and implicate brain regions associated with reward and mood such as the amygdala, paraventricular nucleus of the thalamus, habenula and nucleus accumbens in the anti-depressant activity of such compounds.

Peripheral phosphodiesterase 4 inhibition produced by 4-[2-(3,4-Bis-difluoromethoxyphenyl)-2-[4-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-phenyl]-ethyl]-3-methylpyridine-1-oxide (L-826,141) prevents experimental autoimmune encephalomyelitis.

Administration of phosphodiesterase 4 (PDE4) inhibitors suppresses the pathogenesis associated with experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). In the present study, we compared the effects of rolipram and 4-[2-(3,4-bis-difluoromethoxyphenyl)-2-[4-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-phenyl]-ethyl]-3-methylpyridine-1-oxide (L-826,141), a novel nonbrain penetrant PDE4 inhibitor, on the onset and severity of clinical signs in a chronic, nonrelapsing/remitting model of EAE. Both rolipram (10 mg/kg p.o.) and L-826,141 (3 mg/kg p.o.) reduced the severity of EAE relative to controls, whereas L-826,141 (3 mg/kg p.o.) also delayed disease onset. To assess whether L-826,141 prevented EAE progression after the first signs of clinical onset, rolipram (10 mg/kg p.o.) or L-826,141 (3 or 30 mg/kg p.o.) were administered 24 h after the first signs of EAE were observed. Only L-826,141 at a dose of 30 mg/kg p.o. significantly decreased the clinical severity of EAE compared with vehicle controls. Immunohistochemical detection of the neuronal activity marker Fos confirmed that L-826,141 did not reach concentrations in the central nervous system sufficient to activate central neurons. Lipopolysaccharide-induced tumor necrosis factor-alpha in whole blood and plasma concentrations of L-826,141 revealed that only the 30-mg/kg dose resulted in levels sufficient to produce a near complete inhibition of PDE4 activity in immune cells. Taken together, these results demonstrate that peripheral PDE4 inhibition, produced by L-826,141, prevents the progression of EAE after the first onset of clinical signs, and suggest that similar compounds may have clinical efficacy in the treatment of MS.

Caspase-3 cleaved spectrin colocalizes with neurofilament-immunoreactive neurons in Alzheimer's disease.

Corticocortical disconnection in Alzheimer's disease occurs by the progressive impairment and eventual loss of a small subset of pyramidal neurons in layers III and V of association areas of the neocortex. These neurons exhibit large somatic size, extensive dendritic arborization and high levels of nonphosphorylated neurofilaments of medium and high molecular weight that can be identified using a monoclonal SMI-32 antibody. It is thought that the accumulation of amyloid Abeta and neurofibrillary tangles may provoke metabolic disturbances that result in the loss of these SMI-32 immunoreactive neurons. The recent detection of increased levels of caspase-3 cleaved fodrin in frontal, temporal and parietal association areas in Alzheimer's disease brains suggests that programmed cell death may contribute to the destruction of SMI-32 positive neurons. In the present study, we utilized an antibody that selectively recognizes the 120 kDa breakdown product of alphaIIspectrin (fodrin) generated by caspase-3 to determine whether this protease is activated in vulnerable pyramidal neurons located in layers III and V of Alzheimer's disease brains. Neurons immunoreactive for caspase-3 cleaved alphaIIspectrin were located predominantly in layers III and V of the inferior frontal and superior temporal cortices of patients with Alzheimer's disease but not age-matched controls. Pyramidal neurons immunoreactive for caspase-3 cleaved alphaIIspectrin invariably displayed SMI-32 immunoreactivity suggesting that caspase-3 activation is a pathological event that may be responsible for the loss of a subset of pyramidal neurons that comprise corticocortical projections.

Effects of minocycline and tetracycline on retinal ganglion cell survival after axotomy.

In the present study, we compared the in vivo neuroprotective efficacy of intraperitoneally administered tetracycline and minocycline to enhance the survival of retinal ganglion cells (RGCs) following unilateral axotomy of the adult rat optic nerve. We also examined the effects of the tetracycline drugs on the activation of retinal microglia. RGCs in retinal whole-mounts were visualized by retrograde labeling with fluorogold. The presence of activated microglia was confirmed immunohistochemically using OX-42 monoclonal antibodies. Optic nerve axotomy produced RGC death and increased activation of microglia. No significant RGC loss was seen prior to 5 days and approximately 50% and 80-90% cell loss occurred at 7 and 14 days, respectively. Examination of the effects of tetracycline and minocycline on RGC survival at 7 days post-axotomy, revealed increased numbers of RGCs in minocycline-treated animals (75% of non-axotomized control) compared with vehicle-only (52% of control) and tetracycline-treated (58% of control) animals. The densities of RGCs (RGCs/mm2+/-S.D.) for control, vehicle-, tetracycline- and minocycline-treated axotomized animals were 1996+/-81, 1029+/-186, 1158+/-190 and 1497+/-312, respectively. The neuroprotective effect of minocycline seen at 7 days was transient, since RGCs present in minocycline-treated animals at 14 days post-axotomy (281+/-43, 14% of control) were not significantly different to vehicle-treated animals (225+/-47, 11% of control). OX-42 staining of activated retinal microglia was reduced in tetracycline- and minocycline-treated axotomized animals compared with axotomized animals receiving vehicle-only. These results demonstrate that systemic administration of the second-generation tetracycline derivative, minocycline, delays the death of axotomized RGCs by a mechanism that may be associated with inhibition of microglia activation. The neuroprotective efficacy of minocycline following optic nerve axotomy was superior to that of tetracycline.

Effects of fimbria-fornix transection on calpain and choline acetyl transferase activities in the septohippocampal pathway.

The ability of fimbria-fornix bilateral axotomy to elicit calpain and caspase-3 activation in the rat septohippocampal pathway was determined using antibodies that selectively recognize either calpain- or caspase-cleaved products of the cytoskeletal protein alphaII-spectrin. Radioenzymatically determined choline acetyl transferase (ChAT) activity was elevated in the septum at day 5, but reduced in the dorsal hippocampus at days 3, 5 and 7, after axotomy. Prominent accumulation of calpain-, but not caspase-3-, cleaved spectrin proteolytic fragments was observed in both the septum and dorsal hippocampus 1-7 days after axotomy. ChAT-positive neuronal cell bodies in the septum also displayed calpain-cleaved spectrin indicating that calpain activation occurred in cholinergic septal neurons as a consequence of transection of the septohippocampal pathway. Calpain-cleaved alphaII-spectrin immunoreactivity was observed in cholinergic fibers coursing through the fimbria-fornix, but not in pyramidal neurons of the dorsal hippocampus, suggesting that degenerating cholinergic nerve terminals were the source of calpain activity in the dorsal hippocampus following axotomy. Accumulation of calpain-cleaved spectrin proteolytic fragments in the dorsal hippocampus and septum at day 5 after axotomy was reduced by i.c.v. administration of two calpain inhibitors. Calpain inhibition partially reduced the elevation of ChAT activity in the septum produced by transection but failed to decrease the loss of ChAT activity in the dorsal hippocampus following axotomy. These findings suggest that calpain activation contributes to the cholinergic cell body response and hippocampal axonal cytoskeletal degradation produced by transection of the septohippocampal pathway.

How valuable is ascitic cytology in the detection and management of malignancy?

INTRODUCTION: Ascitic cytology is often requested in the early stages of ascitic assessment. A review of this practice in a major English teaching hospital is presented. METHOD: Patients were retrospectively identified using the histopathology and patient administration system between January 1999 and May 2001. RESULTS: Of 276 samples sent for assessment 35 cases were found to be negative when on further review an intra-abdominal malignancy was present. The malignancy was diagnosed using a radiological modality. The sensitivity of ascitic cytology was found to be 60% with 100% specificity. A delay of up to five days could be incurred awaiting the cytology results before further radiological examinations were undertaken. CONCLUSION: Too much hope is placed on ascitic cytology to provide the diagnosis at the expense of other investigations. It is recommended that the initial assessment should concentrate on history, examination, and basic tests on ascitic fluid to assess the serum-ascites albumin gradient. Ovarian malignancy is the only tumour type yielding a significant rate of detection from cytology with some prognostic impact. Results should not be awaited before abdominal ultrasound is undertaken. This more directed practice would help reduce unnecessary workload for the pathologist and has resource implications.