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Biomedical subjects

A J Watson

Publications and source records attributed to A J Watson.

At least 19 recordsLinked to original sources
PubMed2006

Acute renal disease, as defined by the RIFLE criteria, post-liver transplantation.

Acute renal failure (ARF) can complicate up to 60% of orthotopic liver transplants (OLT). The RIFLE criteria were developed to provide a consensus definition for acute renal disease in critically ill patients. Using the RIFLE criteria, we aimed to determine the incidence and risk factors for ARF and acute renal injury (ARI), and to evaluate the link with the outcomes, patient survival and length of hospital stay. Three hundred patients, who received 359 OLTs, were retrospectively analyzed. ARI and ARF occurred post 11.1 and 25.7% of OLTs, respectively. By multivariate analysis, ARI was associated with pre-OLT hypertension and alcoholic liver disease and ARF with higher pre-OLT creatinine, inotrope and aminoglycoside use. ARF, but not ARI, had an impact on 30-day and 1-year patient survival and longer length of hospital stay. ARI and ARF, as defined by the RIFLE criteria, are common complications of OLT, with distinct risk factors and ARF has serious clinical consequences. The development of a consensus definition is a welcome advance, however these criteria do need to be validated in large studies in a wide variety of patient populations.

Acute Disease↗
PubMed2006

Strategies for detecting colon cancer and/or dysplasia in patients with inflammatory bowel disease.

BACKGROUND: Patients with longstanding ulcerative colitis and colonic Crohn's disease have an increased risk of colorectal cancer compared with the general population. This review assesses the evidence that endoscopic surveillance may prolong life by allowing earlier detection of colon cancer or its pre-cursor lesion, dysplasia, in patients with inflammatory bowel disease. OBJECTIVES: To assess the effectiveness of cancer surveillance programs in reducing the death rate from colorectal cancer in patients with ulcerative colitis and colonic Crohn's disease. SEARCH STRATEGY: The following strategies were used to identify relevant studies:1. MEDLINE and the Cochrane Central Register of Controlled Trials were searched from 1966 to August 2005. The medical subject headings "Ulcerative Colitis", "Crohn Disease" or "Inflammatory Bowel Disease" and "Surveillance" or "Cancer" were used to perform key-word searches of the databases.2. Hand searching of reference lists from papers. SELECTION CRITERIA: Potentially relevant articles were reviewed independently and unblinded by three authors to determine if they fulfilled the selection criteria. Each article was rated as being eligible, ineligible, or without sufficient information to determine eligibility. Any disagreement between reviewers was resolved by consensus. Any trials published in abstract form were only considered if it was possible to obtain full details of the protocol and results from the authors. DATA COLLECTION AND ANALYSIS: Eligible articles were reviewed in duplicate and the results of the primary research trials were abstracted onto specially designed data extraction forms. The proportion of patients dying from bowel cancer or other causes in the control and surveillance groups of each study was derived from life tables, survival curves or where possible, by calculating life tables from the data provided. Data from the original research articles were converted into 2x2 tables (survival versus death x surveillance versus control) for each of the individual studies for comparable follow-up intervals. The presence of significant heterogeneity among studies was tested by the chi-square test. Because this is a relatively insensitive test, a P value of less than 0.1 was considered statistically significant. Provided statistical heterogeneity was not present, the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled relative risk (RR) and 95% confidence intervals as described by Cochrane and Mantel and Haenszel. MAIN RESULTS: Karlen 1998a in a nested case-control study comprising 142 patients from a study population of 4664 UC patients, found that 2/40 patients dying of colorectal cancer had undergone surveillance colonoscopy on at least one occasion compared with 18/102 controls (RR 0.28, 95% CI 0.07 to 1.17). One of 40 patients who died from colorectal cancer had undergone surveillance colonoscopies on two or more occasions compared with 12/102 controls (RR 0.22, 95% CI 0.03 to 1.74) in contrast to a more modest effect observed for patients who had only one colonoscopy (RR 0.43, 95% CI 0.05 to 3.76). Choi 1993 found that carcinoma was detected at a significantly earlier stage in the surveilled patients; 15/19 had Duke's A or B carcinoma in the surveilled group compared to 9/22 in the non-surveilled group (P = 0.039). The 5-year survival rate was 77.2% for cancers occurring in the surveillance group and 36.3% for the no-surveillance group (P = 0.026). Four of 19 patients in the surveillance group died from colorectal cancer compared to 11 of 22 patients in the non-surveillance group (RR 0.42, 95% CI 0.16 to 1.11). Lashner 1990 found that four of 91 patients in a surveillance group died from colorectal cancer compared to 2 of 95 patients in a non-surveilled group (RR 2.09, 95% CI 0.39 to 11.12). Colectomy was less common in the surveillance group, 33 compared to 51 (P < 0.05) and was performed four years later (after 10 years of disease) in the surveillance group. For the pooled data analysis 8/110 patients in the surveillance group died from colorectal cancer compared to 13/117 patients in the non-surveillance group (RR 0.81, 95% CI 0.17 to 3.83). AUTHORS' CONCLUSIONS: There is no clear evidence that surveillance colonoscopy prolongs survival in patients with extensive colitis. There is evidence that cancers tend to be detected at an earlier stage in patients who are undergoing surveillance, and these patients have a correspondingly better prognosis, but lead-time bias could contribute substantially to this apparent benefit. There is indirect evidence that surveillance is likely to be effective at reducing the risk of death from IBD-associated colorectal cancer and indirect evidence that it may be acceptably cost-effective.

Biopsy↗
PubMed2005

O6-(4-bromothenyl)guanine reverses temozolomide resistance in human breast tumour MCF-7 cells and xenografts.

Tumour resistance to chemotherapy involving methylating agents such as DTIC (dacarbazine) and temozolomide is linked to expression of the DNA repair protein O(6)-alkylguanine-DNA alkyltransferase (MGMT). There is considerable interest in improving the efficacy of such O(6)-alkylating chemotherapy by the prior inactivation of MGMT. We have examined the effect of the modified guanine base, O(6)-(4-bromothenyl)guanine (PaTrin-2, Patrin, Lomeguatrib) on MGMT activity and cell or xenograft tumour growth inhibition by temozolomide in the human breast carcinosarcoma cell line, MCF-7. PaTrin-2 effectively inactivated MGMT in MCF-7 cells (IC(50) approximately 6 nM) and in xenografts there was complete inactivation of MGMT within 2 h of dosing (20 mg kg(-1) i.p.) and only slight recovery by 24 h. MGMT inactivation in a range of murine host tissues varied between complete and approximately 60%, with extensive recovery by 24 h. PaTrin-2 (10 microM) substantially increased the growth inhibitory effects of temozolomide in MCF-7 cells (D(60)=10 microM with PaTrin-2 vs 400 microM without). In MCF-7 xenografts, neither temozolomide (100 mg kg(-1) day(-1) for 5 days) nor PaTrin-2 (20 mg kg(-1) day(-1) for 5 days) had any significant effect on tumour growth. In contrast, the PaTrin-2-temozolomide combination produced a substantial tumour growth delay: median tumour quintupling time was increase by 22 days (P<0.005) without any significant increase in toxicity as assessed from animal weight. A PaTrin-2-temozolomide combination may therefore be beneficial in the treatment of human breast cancers.

Animals↗
PubMed2005

UPR-independent dithiothreitol stress-induced genes in Aspergillus niger.

A subtraction library was prepared from cultures of Aspergillus niger that had or had not been exposed to dithiothreitol (DTT), in order to identify genes involved in the unfolded protein response (UPR) or in the response to reductive stress. A large fraction of the clones in the library (40%) encoded two putative methyltransferases (MTs) whose function has yet to be determined. Other stress-responsive genes included a homologue of the Mn2+-containing superoxide dismutase gene (sodB) and a number of genes predicted to code for products that function in protein turnover and in intra- and extracellular transport of molecules. Transcriptional microarray analysis was carried out with a group of 15 genes, comprising 11 from the cDNA library, two genes linked to the putative MT genes but not represented in the library, and two UPR control genes (bipA and pdiA). Eleven of the 15 genes were inducible with DTT. This was either reflected by the presence of transcripts in cells subjected to DTT stress compared to absence under control conditions, or by an induction ratio of between 1.4 and 8.0 in cases where transcripts were already detectable under control conditions. The MT genes were among the four most highly induced. None of the genes, apart from bipA and pdiA, showed significant induction in response to other stresses that are known to induce the UPR in fungi. We conclude that DTT alone does not provide for specific induction of UPR genes and that other stress conditions must also be examined.

Amino Acid Sequence↗
PubMed2005

Dose finding and O6-alkylguanine-DNA alkyltransferase study of cisplatin combined with temozolomide in paediatric solid malignancies.

Cisplatin may have additive activity with temozolomide due to ablation of the DNA repair protein O6-alkylguanine-DNA alkyltransferase (MGMT). This phase I/II study determined recommended combination doses using the Continual Reassessment Method, toxicities and antitumour activity in paediatric patients, and evaluated MGMT in peripheral blood mononuclear cells (PBMCs) in order to correlate with haematological toxicity. In total, 39 patients with refractory or recurrent solid tumours (median age approximately 13 years; 14 pretreated with high-dose chemotherapy, craniospinal irradiation, or having bone marrow involvement) were treated with cisplatin, followed the next day by oral temozolomide for 5 days every 4 weeks at dose levels 80 mg m(-2)/150 mg m(-2) day(-1), 80/200, and 100/200, respectively. A total of 38 patients receiving 113 cycles (median 2, range 1-7) were evaluable for toxicity. Dose-limiting toxicity was haematological in all but one case. Treatment-related toxicities were thrombocytopenia, neutropenia, nausea-vomiting, asthenia. Hearing loss was experienced in five patients with prior irradiation to the brain stem or posterior fossa. Partial responses were observed in two malignant glioma, one brain stem glioma, and two neuroblastoma. Median MGMT activity in PBMCs decreased after 5 days of temozolomide treatment: low MGMT activity correlated with increased severity of thrombocytopenia. Cisplatin-temozolomide combinations are well tolerated without additional toxicity to single-agent treatments; the recommended phase II dosage is 80 mg m(-2) cisplatin and 150 mg m(-2) x 5 temozolomide in heavily treated, and 200 mg m(-2) x 5 temozolomide in less-heavily pretreated children.

Adolescent↗
PubMed2004

Strategies for detecting colon cancer and/or dysplasia in patients with inflammatory bowel disease.

BACKGROUND: Patients with longstanding ulcerative colitis and colonic Crohn's disease have an increased risk of colorectal cancer compared with the general population. This review assesses the evidence that endoscopic surveillance may prolong life by allowing earlier detection of colon cancer or its pre-cursor lesion, dysplasia in patients with inflammatory bowel disease. OBJECTIVES: To assess the effectiveness of cancer surveillance programs in reducing the death rate from colorectal cancer in patients with ulcerative colitis and colonic Crohn's disease. SEARCH STRATEGY: The following strategies were used to identify relevant studies: 1. MEDLINE and the Cochrane Central Register of Controlled Trials were searched from 1966 to December 2002. The medical subject headings "Ulcerative Colitis", "Crohn Disease" or "Inflammatory Bowel Disease" and "Surveillance" or "Cancer" were used to perform key-word searches of the databases. 2. Hand searching of reference lists from papers. SELECTION CRITERIA: Potentially relevant articles were reviewed independently and unblinded by three authors to determine if they fulfilled the selection criteria. Each article was rated as being eligible, ineligible, or without sufficient information to determine eligibility. Any disagreement between reviewers was resolved by consensus. Any trials published in abstract form were only considered if it was possible to obtain full details of the protocol and results from the authors. DATA COLLECTION AND ANALYSIS: Eligible articles were reviewed in duplicate and the results of the primary research trials were abstracted onto specially designed data extraction forms. The proportion of patients dying from bowel cancer or other causes in the control and surveillance groups of each study was derived from life tables, survival curves or where possible, by calculating life tables from the data provided. Data from the original research articles were converted into 2x2 tables (survival versus death x surveillance versus control) for each of the individual studies for comparable follow-up intervals. The presence of significant heterogeneity among studies was tested by the chi-square test. Because this is a relatively insensitive test, a p value of less than 0.1 was considered statistically significant. Provided statistical heterogeneity was not present (p>0.10), the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled relative risk (RR) and 95% confidence intervals as described by Cochrane and Mantel and Haenszel. MAIN RESULTS: Karlen 1998a found that 2/40 of the patients dying of colorectal cancer had undergone surveillance colonoscopy on at least one occasion compared with 18/102 of the controls (RR 0.28, 95% confidence interval 0.07 to 1.17). One of 40 patients who died from colorectal cancer had undergone surveillance colonoscopies on two or more occasions compared with 12/102 controls (RR 0.22, 95% confidence interval 0.03 to 1.74) in contrast to a more modest effect observed for patients who had only one colonoscopy (RR 0.43, 95% confidence intervals 0.05 to 3.76). Choi 1993 found that carcinoma was detected at a significantly earlier stage in the surveillance group; 15/19 had Duke's A or B carcinoma in the surveilled group compared to 9/22 in the non-surveilled group (P= 0.039). The 5-year survival rate was 77.2% for cancers occurring in the surveillance group and 36.3% for the no-surveillance group (P= 0.026). Four of 19 patients in the surveillance group died from colorectal cancer compared to 11 of 22 patients in the non-surveillance group (RR 0.42, 95% CI 0.16 to 1.11). Lashner 1990 found that four of 91 patients in the surveillance group died from colorectal cancer compared to 2 of 95 patients in the non-surveilled group (RR 2.09, 95% CI 0.39 to 11.12). Colectomy was less common in the surveillance group, 33 compared to 51 (p < 0.05) and was performed four years later (after 10 years of disease) in the surveillance group. For the pooled data analysis 8/110 patients in the surveillance group died from colorectal cancer compared to 13/117 patients in the non-surveillance group (RR 0.81, 95% CI 0.17 to 3.83). REVIEWERS' CONCLUSIONS: There is no clear evidence that surveillance colonoscopy prolongs survival in patients with extensive colitis. There is evidence that cancers tend to be detected at an earlier stage in patients who are undergoing surveillance and these patients have a correspondingly better prognosis but lead-time bias could contribute substantially to this apparent benefit. There is indirect evidence that surveillance is likely to be effective at reducing the risk of death from IBD-associated colorectal cancer and indirect evidence that it is acceptably cost-effective.

Biopsy↗
PubMed2004

Molecular regulation of blastocyst formation.

Preimplantation development encompasses the interval from insemination until embryo implantation and thus includes the 'freeliving' period of oviduct and uterine development. Formation of the blastocyst is required for implantation and establishment of pregnancy, and is a principal determinant of embryo quality prior to embryo transfer. Development through this period is regulated by the expression of specific gene families that encode for cell polarity, cell junctional, cytoskeletal, ion transporter, and water channel gene products that direct the acquisition of cell polarity and differentiation of the outer cells of the early embryo. This results in the formation of the trophectoderm, which is the first epithelium of development. This review considers the roles of each of these gene families in trophectoderm differentiation and blastocyst formation. The principal hypothesis under investigation is that blastocyst formation is regulated by a Na/K-ATPase-generated trans-trophectoderm ion gradient that promotes the accumulation of water across the epithelium. This, combined with the formation of the tight junction seal controlling paracellular movement of water between adjacent trophectoderm cells, results in the formation of a fluid-filled blastocyst cavity and the expansion of the blastocyst. Results from recent experiments, however, have cast some doubt on the role of Na/K-ATPase in mediating these events and have defined water channels or Aquaporins (AQPs) as physiological mediators of fluid movement across the trophectoderm. In addition, studies have now implicated mitogen-activated protein kinase (MAPK) signaling as an important mediator of development to the blastocyst stage. Such studies define the physiology of blastocyst formation and serve to support the application of assisted reproductive technologies (ART) to both human and animal species.

Animals↗
PubMed2004

Deletion of the Na/K-ATPase alpha1-subunit gene (Atp1a1) does not prevent cavitation of the preimplantation mouse embryo.

Increases in Na/K-ATPase activity occur concurrently with the onset of cavitation and are associated with increases in Na(+)-pump subunit mRNA and protein expression. We have hypothesized that the alpha1-isozyme of the Na/K-ATPase is required to mediate blastocyst formation. We have tested this hypothesis by characterizing preimplantation development in mice with a targeted disruption of the Na/K-ATPase alpha1-subunit (Atp1a1) using embryos acquired from matings between Atp1a1 heterozygous mice. Mouse embryos homozygous for a null mutation in the Na/K-ATPase alpha1-subunit gene are able to undergo compaction and cavitation. These findings demonstrate that trophectoderm transport mechanisms are maintained in the absence of the predominant isozyme of the Na(+)-pump that has previously been localized to the basolateral membranes of mammalian trophectoderm cells. The presence of multiple isoforms of Na/K-ATPase alpha- and beta-subunits at the time of cavitation suggests that there may be a degree of genetic redundancy amongst isoforms of the catalytic alpha-subunit that allows blastocyst formation to progress in the absence of the alpha1-subunit.

Animals↗
PubMed2003

Assessment of the acoustic properties of common tissue-mimicking test phantoms.

Ultrasound (US) test phantoms incorporating tissue-mimicking materials (TMMs) play an important role in the quality control (QC) and performance testing of US equipment. Three commercially available TMMs (Zerdine from CIRS Inc.; condensed-milk-based gel from Gammex RMI; urethane-rubber-based from ATS Labs) and a noncommercial agar-based TMM, were investigated. Acoustic properties were measured over the frequency range 2.25 to 15 MHz at a range of ambient temperatures (10 to 35 degrees C). The acoustic velocity of the TMMs remained relatively constant with increasing frequency. Only the agar-based TMM had a linear increase of attenuation with frequency, with the other materials exhibiting nonlinear responses to varying degrees (f(1.08) to f(1.83)). The acoustic velocity and attenuation coefficient of all the TMMs varied with temperature, with the urethane-rubber TMM showing the greatest variation of +/- 1.2% for acoustic velocity and +/- 12% for attenuation coefficient. The data obtained in this study highlight the importance of greater knowledge of the acoustic behavior of TMMs to variations in both frequency and temperature, to ensure that accurate and precise measurements are obtained during QC and performance testing.

Gels↗
PubMed2002

The presentation and management of juvenile-onset chronic inflammatory bowel disease in Northeastern Scotland.

PURPOSE: This study reviews the presentation and management of juvenile onset chronic inflammatory bowel disease and identifies changes in incidence of the disease over a 20-year period. METHODS: This was a retrospective study of all patients aged 16 and under with chronic inflammatory bowel disease diagnosed in 1 health region between 1980 and 1999. The patients were identified from computer records and the following variables studied: age, sex, mode of presentation, medical and surgical management, and length of follow-up. RESULTS: One hundred seven patients were identified: 77 with Crohn's disease and 30 with ulcerative colitis. The incidence of ulcerative colitis and Crohn's disease has risen from 0.7 in 100,000 and 2.2 in 100,000, respectively, in the years 1980 through 1989 to 1.5 in 100,000 and 4.4 in 100,000 in the period 1990 through 1999. The median age at presentation was 10.1 years for ulcerative colitis and 10.8 years for Crohn's disease. The majority of disease was diagnosed within 1 year of the onset of symptoms, which were principally abdominal pain, diarrhea, and rectal bleeding. The average length of follow-up was 6.9 years. Analysis of the surgical management of Crohn's patients has shown a low rate of surgical intervention. CONCLUSIONS: This study has shown an increasing incidence of chronic inflammatory bowel disease in the Grampian region of Scotland coupled with a low rate of surgical intervention in Crohn's disease. These findings could be the result of early referral and diagnosis, with the disease being documented earlier in its course or more aggressive preemptive medical therapy.

Abdominal Pain↗
PubMed2002

The gamma-subunit of the Na-K-ATPase as a potential regulator of apical and basolateral Na+-pump isozymes during development of bovine pre-attachment embryos.

Expression and activity of the Na-K-ATPase within the basolateral membrane domains of the trophectoderm epithelium provide the driving force for accumulation of Na(+) and Cl(-) across the nascent epithelium, mediating fluid movement into the forming blastocoel. Within the trophectoderm of the bovine blastocyst, multiple isozymes of the Na-K-ATPase are expressed. Immunolocalization has demonstrated that the alpha1-isozyme localizes within the basolateral membrane, whereas the alpha 3-isozyme localizes to the apical cell margins. Gene-specific RT-PCR and wholemount indirect immunofluorescence confocal laser scanning microscopy were used to examine expression of the Na-K-ATPase gamma-subunit (a regulatory subunit of the Na-K-ATPase) throughout development of bovine preattachment embryos in vitro. Expression of mRNA transcripts for the gamma-subunit was detected throughout bovine pre-attachment development from the fertilized one-cell embryo to the blastocyst stage. A similar pattern of expression was also observed for gamma-subunit protein, and immunofluorescence was detected within the membranes of embryonic blastomeres at all stages of development. In contrast to the expression patterns observed for the alpha-subunits, gamma-subunit proteins were detected in both the basolateral and apical cell margins of the trophectoderm, and surrounding all cells of the inner cell mass. Co-localization studies demonstrated that gamma-subunit peptides are co-expressed with the alpha1-subunit in the basolateral domains of the trophectoderm. These results indicate a role for the gamma-subunit of the Na-K-ATPase in modulating Na(+)-pump activity in both apical and basolateral margins of the trophectoderm during formation and expansion of the bovine blastocyst, and adds a further level of complexity to Na(+)-pump regulation of cavitation.

Animals↗
PubMed2001

Amino acid concentrations in fluids from the bovine oviduct and uterus and in KSOM-based culture media.

Amino acids in bovine oviductal and uterine fluids were measured and compared with those in modified simplex optimized medium (KSOM) supplemented with either fetal calf serum or Minimum Essential Medium amino acids in addition to bovine serum albumin, fetal calf serum or polyvinyl alcohol. Concentrations of cysteine, threonine, tryptophan, alanine, aspartate, glycine, glutamate, proline, beta-alanine, and citrulline were higher in oviductal fluids than in KSOM-based culture media. Nonessential and essential amino acids were present in ratios of 5:1 and 2:1 in oviductal and uterine fluids, respectively. Concentrations of alanine (3.7 mM), glycine (14.1 mM) and glutamate (5.5 mM) were high in oviductal fluids, comprising 73% of the free amino acid pool. Of the amino acids measured in uterine fluids, alanine (3.1 mM), glycine (12.0 mM), glutamate (4.2 mM), and serine (2.7 mM) were highest in concentration, and the first three comprised 43% of the free amino acid pool. In conclusion, amino acid concentrations in the bovine reproductive tract were substantially higher than those in embryo culture media. Certain amino acids, particularly alanine, glutamate, glycine and taurine, are present in strikingly high concentrations in both oviductal and uterine fluids, suggesting that they might play important roles in early embryo development. The particular pattern of amino acid concentrations may be an important factor to be considered for the improvement of embryo culture media.

Amino Acids↗
PubMed2001

Regulation of blastocyst formation.

Preimplantation or pre-attachment development encompasses the "free"-living period of mammalian embryogenesis, which directs development of the zygote through to the blastocyst stage. Blastocyst formation is essential for implantation, establishment of pregnancy and is a principal determinant of embryo quality prior to embryo transfer. Cavitation (blastocyst formation) is driven by the expression of specific sets of gene products that direct the acquisition of cell polarity within the trophectoderm, which is both the first epithelium of development and the outer cell layer encircling the inner cell mass of the blastocyst. Critical gene families controlling these events include: the E-cadherin-catenin cell adhesion family, the tight junction gene family, the Na/K-ATPase gene family and perhaps the aquaporin gene family. This review will update the roles of each of these gene families in trophectoderm differentiation and blastocyst formation. The current principal hypothesis under investigation is that blastocyst formation is mediated by a trans-trophectoderm ion gradient(s) established, in part, by Na/K-ATPase, which drives the movement of water through aquaporins (AQPs) across the epithelium into the extracellular space of the blastocyst to form the fluid-filled blastocoel. The trophectoderm tight junctional permeability seal regulates the leakage of blastocoel fluid, and also assists in the maintenance of a polarized Na/K-ATPase distribution to the basolateral plasma membrane domain of the mural trophectoderm. The cell-to-cell adhesion provided by the E-cadherin-catenin gene families is required for the establishment of the tight junction seal and the maintenance of the polarized Na/K-ATPase distribution. Blastocyst formation is therefore directly linked with trophectoderm cell differentiation, which arises through fundamental cell biological processes that are associated with the establishment of cell polarity.

Animals↗
PubMed2001

Orthotopic reimplantation of cryopreserved ovarian cortical strips after high-dose chemotherapy for Hodgkin's lymphoma.

BACKGROUND: Infertility is a common late effect of chemotherapy and radiotherapy, and has a substantial effect on the quality of life for young survivors of cancer. For men, semen cryopreservation is a simple way of preserving reproductive potential but for women, storage of mature eggs rarely proves successful, and the alternative-immediate in vitro fertilisation with cryopreservation of embryos-is not always appropriate. Reimplantation of cryopreserved ovarian tissue has been shown to restore natural fertility in animals. We applied this technique in a woman who had received sterilising chemotherapy for lymphoma. METHODS: A 36-year-old woman underwent a right oophorectomy with cryopreservation of ovarian cortical strips before receiving high-dose CBV chemotherapy for a third recurrence of Hodgkin's lymphoma. 19 months later, when serum sex steroid analysis confimed a postmenopausal state, two ovarian cortical strips were thawed and reimplanted-one onto the left ovary and another at the site of the right ovary. FINDINGS: 7 months after reimplantation of ovarian cortical strips, the patient reported resolution of hot flashes and, for the first time, oestradiol was detected in the serum. This finding was associated with a decrease in the concentrations of follicle-stimulating hormone and luteinising hormone, and ultrasonography revealed a 10 mm thick endometrium, a poorly visualised left ovary, and a 2 cm diameter follicular structure to the right of the midline. The patient had one menstrual period, but by 9 months after the implantation, her sex steroid concentrations had returned to those seen with ovarian failure. INTERPRETATION: Orthotopic reimplantation of frozen/thawed ovarian cortical strips is a well tolerated technique for restoring ovarian function in women treated with sterilising chemotherapy for cancer.

Adult↗
PubMed2001

Caspase activation during spontaneous and radiation-induced apoptosis in the murine intestine.

The aim of this study was to characterize the activation of caspase-3 along the crypt/villus axis in the normal and irradiated intestine and to compare active caspase-3 expression with existing apoptosis detection techniques. Small and large intestine were removed from mice at various time points after exposure to 8 Gy gamma-radiation. Positive apoptotic cells stained with an antibody against active caspase-3, haematoxylin and eosin (H&E) or TUNEL were scored in histological sections of small and large intestinal crypts and villi. In the control intestine, active caspase-3 expression was rarely observed; however, expression was markedly increased following exposure to radiation and was predominantly confined to apoptotic bodies. Measurement of apoptosis in intestinal crypts using active caspase-3 expression gave similar results to apoptosis detected from H&E-stained sections. In the normal villus, active caspase-3 expression was observed infrequently and did not significantly increase following radiation, consistent with a lack of apoptotic body formation from H&E sections. This study indicates that caspase-3 is activated in intestinal crypts but not in villi following gamma-radiation. Active caspase-3 detection compared favourably with existing immunological techniques, suggesting that it is a suitable alternative method for apoptosis quantification.

Animals↗
PubMed2001

Expression of PTHrP and PTHR (PTH/PTHrP-r) mRNAs and polypeptides in bovine ovary and stimulation of bovine blastocyst development in vitro following PTHrP treatment during oocyte maturation.

Parathyroid hormone related protein (PTHrP) and its receptor have well-established roles in the development and regulation of many tissues, including bone and mammary gland. The objectives of this study were: (1) to characterize the distribution of mRNAs encoding parathyroid hormone (PTH)-related protein (PTHrP) and receptor (PTHR) in bovine ovary; (2) to characterize the distribution of PTHrP and PTHR polypeptides in bovine ovary; (3) to examine the influences of PTHrP (1-141) treatment during bovine oocyte maturation in vitro on blastocyst development. mRNAs encoding PTHrP and PTHR were detected by in situ hybridization methods in oocytes, and granulosa cells in all follicles from primordial to large antral. PTHrP and PTHR polypeptides displayed distinct distribution patterns with PTHrP polypeptides primarily confined to oocytes from primordial to large antral follicles. PTHrP polypeptides were detectable but at a reduced level in ovarian stroma and in granulosa and thecal layers. PTHR polypeptides were detected in oocytes of all follicular stages but were predominantly found in ovarian stroma, granulosa and theca follicular layers. Supplementation of serum-free cSOFMaa oocyte maturation medium with PTHrP (1-141) resulted in a concentration-dependent increase in development to the blastocyst stage in vitro. The results suggest that granulosa cells may be a primary site of PTHrP production and release. Oocytes from all follicular stages stained strongly for PTHrP polypeptides and PTHrP enhanced development to the blastocyst stage in vitro.

Animals↗