Biomedical subjects

Jonathan Green

Publications and source records attributed to Jonathan Green.

27 records · Page 2Linked to original sources

PubMed2003

Zoledronic acid treatment of 5T2MM-bearing mice inhibits the development of myeloma bone disease: evidence for decreased osteolysis, tumor burden and angiogenesis, and increased survival.

Multiple myeloma is characterized by the growth of plasma cells in the bone marrow and the development of osteolytic bone disease. Myeloma cells are found closely associated with bone, and targeting this environment may therefore affect both the bone disease and the growth of myeloma cells. We have investigated the effect of the potent bisphosphonate, zoledronic acid, on the development of bone disease, tumor burden, and disease-free survival in the 5T2MM model of myeloma. 5T2MM murine myeloma cells were injected intravenously into C57BL/KaLwRij mice. After 8 weeks, all animals had a paraprotein. Animals were treated with zoledronic acid (120 microg/kg, subcutaneously, twice weekly) or vehicle, from the time of tumor cell injection or from paraprotein detection for 12 or 4 weeks, respectively. All animals injected with tumor cells developed osteolytic lesions, a decrease in cancellous bone volume, an increase in osteoclast perimeter, and a decrease in bone mineral density. Zoledronic acid prevented the formation of lesions, prevented cancellous bone loss and loss of bone mineral density, and reduced osteoclast perimeter. Zoledronic acid also decreased paraprotein concentration, decreased tumor burden, and reduced angiogenesis. In separate experiments, Kaplan-Meier analysis demonstrated a significant increase in survival after treatment with zoledronic acid when compared with control (47 vs. 35 days). A single dose of zoledronic acid was also shown to be effective in preventing the development of osteolytic bone disease. These data show that zoledronic acid is able to prevent the development of osteolytic bone disease, decrease tumor burden in bone, and increase survival in a model of established myeloma.

Animals↗

PubMed2002

Arylaminoethyl amides as novel non-covalent cathepsin K inhibitors.

A series of N(alpha)-benzyloxycarbonyl- and N(alpha)-acyl-L-leucine(2-phenylaminoethyl)amide derivatives were prepared and evaluated for their inhibitory activity against rabbit and human cysteine proteases cathepsins K, L, and S. These data indicate that N(alpha)-acyl-alpha-amino acid-(arylaminoethyl)amides represent a new class of selective non-covalent inhibitors of cathepsin K. Compounds 4b, 4e, and 4g exhibit high potency toward rabbit and human cathepsin K (IC(50) < 0.006 microM) and are characterized by an excellent selectivity profile vs human cathepsins L and S.

Amides↗

PubMed2002

Molecular epidemiology of rotaviral infection in South Indian children with acute diarrhea from 1995-1996 to 1998-1999.

The distribution of VP7 (G-) and VP4 (P-) genotypes among 126 rotavirus strains from South Indian children, < 5 years of age and with acute diarrhoea, presenting to a single hospital during the months to November and December, from 1995 to 1998, was studied. Multiplex hemi-nested G- and P-typing polymerase chain reactions determined 101 (80%) G types and 78 (61%) P types, respectively. In order of frequency, the commonest G types were G1, G4, G2, G9, G3, and G8, and P types were P1B[4], P1A[8], and P2A[6] and the most common G:P combinations were G1:P1A[8], G1:P1B[4], G2P1B[4] and G4:P1A[8]. G1, G2, and G4 types were seen in all years. The single G3 isolate was seen in 1998. The single G8 isolate and the 5 G9 isolates were seen in 1997, after a period of heavy rain. Sequence analysis showed that the G8 isolate was related most closely to the bovine strain A5, and the G9 strains were distinct from the nonpathogenic Indian isolate 116E and similar to G9s isolated in Mysore and the United Kingdom described previously.

Acute Disease↗

PubMed2002

Disease modifying and anti-nociceptive effects of the bisphosphonate, zoledronic acid in a model of bone cancer pain.

Inoculation of syngeneic MRMT-1 mammary tumour cells into one tibia of female rats produced tumour growth within the bone associated with a reduction in bone mineral density (BMD) and bone mineral content (BMC), severe radiological signs of bone destruction, together with the development of behavioural mechanical allodynia and hyperalgesia. Histological and radiological examination showed that chronic treatment with the bisphosphonate, zoledronic acid (30 microg/kg, s.c.), for 19 days significantly inhibited tumour proliferation and preserved the cortical and trabecular bone structure. In addition, BMD and BMC were preserved and a dramatic reduction of tartrate resistant acid phosphatase-positive polykaryocytes (osteoclasts) was observed. In behavioural tests, chronic treatment with zoledronic acid but not the significantly less effective bisphosphonate, pamidronate, or the selective COX-2 inhibitor, celebrex, attenuated mechanical allodynia and hyperalgesia in the affected hind paw. Zoledronic acid also attenuated mechanical hyperalgesia associated with chronic peripheral neuropathy and inflammation in the rat. In contrast, pamidronate or clodronate did not have any anti-hyperalgesic effect on mechanical hyperalgesia in the neuropathic and inflammatory pain models. We conclude that zoledronic acid, in addition to, or independent from, its anti-metastatic and bone preserving therapeutic effects, is an anti-nociceptive agent in a rat model of metastatic cancer pain. This unique property of zoledronic acid amongst the bisphosphonate class of compounds could make this drug a preferred choice for the treatment of painful bone metastases in the clinic.

Animals↗

PubMed2002

Evaluation of a one-tube RT-PCR system for detection of enteroviruses.

BACKGROUND: A highly sensitive PCR assay for early and rapid detection of enteroviral (EV) RNA in CSF is necessary to investigate the role of EV in acute neurological illnesses. OBJECTIVES: To evaluate and compare two PCR protocols (Titan one-tube RT-PCR and random primed RT-PCR) for detection of enteroviral RNA in CSF. STUDY DESIGN: The PCR protocols were evaluated for lower limit of input detection using log dilutions of five stock EV strains and an isolate of enterovirus-71 in minimum essential medium and three EV stock strains in CSF. The tests were also applied on 77 CSF samples, 46 from patients with suspected acute EV neurological illness and 31 from 'disease controls'. RESULTS: Even though in the initial virus titration assays there was no statistically significant difference in the limit of input detection by Titan system and the random primed two-step PCR, the latter had a higher positivity rate when used on CSF samples from patients (20/46 vs. 10/46, P<0.01). CONCLUSIONS: Random primed RT-PCR assay is superior to Titan one-tube RT-PCR for detection of EV RNA in CSF.

Enterovirus↗

PubMed2002

Conversational behaviour of children with Asperger syndrome and conduct disorder.

BACKGROUND: Social communication problems in individuals who have Asperger syndrome constitute one of the most significant problems in the syndrome. This study makes a systematic analysis of the difficulties demonstrated with the use of language (pragmatics) in adolescents who have Asperger syndrome. METHOD: Recent advances in discourse analysis were applied to conversational samples from a group of children with Asperger syndrome and a matched control group of children with severe conduct disorder. Two types of conversation were sampled from each group, differing in emotional content. RESULTS: The results showed that in these contexts children with Asperger syndrome were no more verbose as a group than controls, though they showed a tendency to talk more in more emotion-based conversations. Children with Asperger syndrome, as a group, performed similarly to control subjects in ability to respond to questions and comments. However, they were more likely to show responses which were problematic in both types of conversation. In addition, individuals with Asperger syndrome showed more problems in general conversation than during more emotionally and socially loaded topics. The group with Asperger syndrome was found to contain a small number of individuals with extreme verbosity but this was not a reliable characteristic of the group as a whole.

Adolescent↗

PubMed2002

Annotation: attachment disorganisation and psychopathology: new findings in attachment research and their potential implications for developmental psychopathology in childhood.

BACKGROUND: The past 10 years have seen a fruitful line of enquiry building on identification of previously unclassifiable patterns of infant-mother interaction. A critical review of these new findings in attachment theory, highlighting their potential relevance to child psychopathology, is presented. METHOD: Selective literature review relating to disorganised attachment in childhood. RESULTS: Disorganised patterns of attachment have only relatively recently been described. They show characteristic patterns of evolution in development. There is evidence that disorganised attachments are associated with specific forms of distorted parenting, which are distinct from general parental insensitivity and are associated with unresolved loss or trauma in the caregiver. There are also links with aspects of neurodevelopment vulnerability in the child. Attachment disorganisation is a powerful predictor of a range of later social and cognitive difficulties and psychopathology. CONCLUSIONS: The identification of disorganised attachment has greatly increased the potential relevance of attachment theory to general clinical work. However, the concept raises many methodological and theoretical issues. Among issues needing further exploration is the way in which attachment disorganisation relates to children's general mental states and may be affected by cognitive functioning and developmental impairment.

Adolescent↗

PubMed2002

Cost effectiveness of proton pump inhibitors in gastro-oesophageal reflux disease without oesophagitis: comparison of on-demand esomeprazole with conventional omeprazole strategies.

OBJECTIVES: To evaluate the cost effectiveness of on-demand treatment with esomeprazole 20mg compared with two alternative omeprazole treatment strategies for the long-term management of patients with gastro-oesophageal reflux disease (GORD) without oesophagitis. DESIGN: A simple Markov model was designed to compare the cost effectiveness of on-demand esomeprazole 20mg therapy for 6 months with a strategy consisting of intermittent 4-week acute treatment courses of omeprazole 20mg once daily or a strategy consisting of continuous omeprazole treatment (20mg once daily) following acute treatment of first relapse while on no drug treatment (a commonly used conventional care strategy). Relapse probabilities were based on pooled results from two 6-month placebo-controlled clinical studies of on-demand esomeprazole 20mg treatment in patients with GORD without oesophagitis and on results from a GORD study with a 6-month untreated follow-up. The expected number of relapses per patient was used as the effectiveness measure. SETTING AND PERSPECTIVE: Patient management assumptions were based on a UK physician survey. The cost-effectiveness analysis considered UK direct medical costs from the perspective of the National Health Service. RESULTS: The pooled analysis showed that after 6 months treatment, 90% of patients could control symptoms effectively with on-demand esomeprazole 20mg. The expected number of relapses per patient was estimated at 0.10 for on-demand esomeprazole, 0.57 to 1.12 for intermittent omeprazole and 0.47 to 0.75 for conventional omeprazole treatment. The esomeprazole strategy incurred considerably lower direct medical costs (16 to 61%) than either omeprazole strategy. CONCLUSION: On-demand treatment with esomeprazole 20mg is cost effective compared with two alternative omeprazole treatment strategies in patients with GORD without oesophagitis.

Adult↗

PubMed2002

Cost effectiveness of esomeprazole compared with omeprazole in the acute treatment of patients with reflux oesophagitis in the UK.

BACKGROUND: Clinical studies have demonstrated that esomeprazole is superior to omeprazole for the acute treatment of reflux oesophagitis. OBJECTIVE: To compare the cost effectiveness of esomeprazole 40mg once daily with omeprazole 20mg once daily in patients with reflux oesophagitis. METHODS: Pooled data were used from three 8-week clinical trials comparing the efficacy and safety of esomeprazole 40mg once daily and omeprazole 20mg once daily for the acute treatment of reflux oesophagitis. A simple decision analysis model, using UK direct medical costs, compared the cost effectiveness of the two treatments. Healing probabilities derived from the clinical studies using the Life Table method were used to estimate the effectiveness and cost of treating 100 patients with reflux oesophagitis. Patient management assumptions were based on a clinical management survey involving 25 UK physicians. PERSPECTIVE: UK National Health Service. RESULTS: After 4 weeks' therapy, the Life Table estimated the oesophageal healing rate to be 77.7% in esomeprazole 40mg once-daily recipients (n = 2446), compared with 67.6% in omeprazole 20mg once-daily recipients (n = 2431; p < 0.001). The corresponding values after 8 weeks' treatment were 93.4% and 86.2%, respectively (p < 0.001). The model predicted that when considering healing probabilities over 8 weeks, esomeprazole 40mg once daily produced total direct cost savings of pound1290 (14%) when compared with omeprazole 20mg once daily. When considering the cost of treating patients who had failed treatment (defined as patient not healed as assessed by endoscopy) after 8 weeks, the cost advantage for esomeprazole was even greater. CONCLUSION: Esomeprazole 40mg once daily is cost effective compared with omeprazole 20mg once daily in the acute treatment of patients with reflux oesophagitis; esomeprazole provides greater effectiveness at a lower cost.

Anti-Ulcer Agents↗