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C A Llewelyn

Publications and source records attributed to C A Llewelyn.

12 recordsLinked to original sources
PubMed2006

Creutzfeldt-Jakob disease and blood transfusion: results of the UK Transfusion Medicine Epidemiological Review study.

BACKGROUND AND OBJECTIVES: This paper reports the results to 1 March 2006 of an ongoing UK study, the Transfusion Medicine Epidemiological Review (TMER), by the National CJD Surveillance Unit (NCJDSU) and the UK Blood Services (UKBS) to determine whether there is any evidence that Creutzfeldt-Jakob disease (CJD), including sporadic CJD (sCJD), familial CJD (fCJD), and variant CJD (vCJD) is transmissible via blood transfusion. MATERIALS AND METHODS: Sporadic CJD and fCJD cases with a history of blood donation or transfusion are notified to UKBS. All vCJD cases aged > 17 years are notified to UKBS on diagnosis. A search for donation records is instigated and the fate of all donations is identified by lookback. For cases with a history of blood transfusion, hospital and UKBS records are searched to identify blood donors. Details of identified recipients and donors are checked against the NCJDSU register to establish if there are any matches. RESULTS: CJD cases with donation history: 18/31 vCJD, 3/93 sCJD, and 3/5 fCJD cases reported as blood donors were confirmed to have donated labile components transfused to 66, 20, and 11 recipients respectively. Two vCJD recipients have appeared on the NCJDSU register as confirmed and probable vCJD cases. The latter developed symptoms of vCJD 6.5 years and 7.8 years respectively after receiving non-leucodepleted red blood cells (RBCs) from two different donors who developed clinical symptoms approximately 40 and 21 months after donating. A third recipient, given RBC donated by a further vCJD case approximately 18 months before onset of clinical symptoms, had abnormal prion protein in lymphoid tissue at post-mortem (5-years post-transfusion) but had no clinical symptoms of vCJD. CJD cases with history of transfusion: Hospital records for 7/11 vCJD and 7/52 sCJD cases included a history of transfusion of labile blood components donated by 125 and 24 donors respectively. Two recipients who developed vCJD were linked to donors who had already appeared on the NCJDSU register as vCJD cases (see above). No further links were established. CONCLUSION: This study has identified three instances of probable transfusion transmission of vCJD infection, including two confirmed clinical cases and one pre- or sub-clinical infection. This study has not provided evidence, to date, of transmission of sCJD or fCJD by blood transfusion, but data on these forms of diseases are limited.

Aged↗
PubMed2004

Possible transmission of variant Creutzfeldt-Jakob disease by blood transfusion.

BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD) is a novel human prion disease caused by infection with the agent of bovine spongiform encephalopathy (BSE). Epidemiological evidence does not suggest that sporadic CJD is transmitted from person to person via blood transfusion, but this evidence may not apply to vCJD. We aimed to identify whether vCJD is transmissible through blood transfusion. METHODS: The national CJD surveillance unit reported all cases of probable or definite vCJD to the UK blood services, which searched for donation records at blood centres and hospitals. Information on named recipients and donors was provided to the surveillance unit to establish if any matches existed between recipients or donors and the database of cases of vCJD. Recipients were also flagged at the UK Office of National Statistics to establish date and cause of death. FINDINGS: 48 individuals were identified as having received a labile blood component from a total of 15 donors who later became vCJD cases and appeared on the surveillance unit's register. One of these recipients was identified as developing symptoms of vCJD 6.5 years after receiving a transfusion of red cells donated by an individual 3.5 years before the donor developed symptoms of vCJD. INTERPRETATION: Our findings raise the possibility that this infection was transfusion transmitted. Infection in the recipient could have been due to past dietary exposure to the BSE agent. However, the age of the patient was well beyond that of most vCJD cases, and the chance of observing a case of vCJD in a recipient in the absence of transfusion transmitted infection is about 1 in 15000 to 1 in 30000.

Blood Donors↗
PubMed2004

Using patient-identifiable data for epidemiological research.

The use of patient-identifiable data in epidemiological research is subject to increasingly complex regulation. This article reports the experience of a research team in setting up the Epidemiology and Survival of Transfusion Recipients (EASTR) study in which patient-identifiable information was needed in order to link data from two sources for analysis and obtain long-term survival patterns of transfusion recipients. The process of establishing the study involved obtaining separate ethical, research and development and data protection approval, including application to the newly formed Patient Information Advisory Group, set up under Section 60 of the Health and Social Care Act, 2001. We describe the high cost in administrative procedures and time now necessary to gain statutory approval before such a study can begin, which has been the result of recent legislation. Issues arising from our experience are discussed.

Epidemiology↗
PubMed1995

Influence of season and housing on ovarian activity of indigenous goats in Zimbabwe.

Progesterone profiles were monitored in goats housed in single (n = 9) or group (n = 14) pens during winter (JJA) and spring (SON). Normal cycles (n = 97) were < or = 30 days. Extended cycles (n = 45) were > 30 days and, except for one cycle with a persistent corpus luteum, had periovulatory periods of 10 to 20 days (n = 29) or averaging 65.1 days in length (n = 15), mostly characterised by recurrent oestrus and/or occasional transient rises in progesterone. The proportion of normal cycles occurring in winter was 87.5% (28/32) and 77.7% (42/54) for goats in single and group pens respectively, falling to 62.5% (15/24) and 37.5% (12/32) respectively in spring. The distribution of normal vs extended cycles according to season was significant (P < 0.05, single; P < 0.001 group pens). Goats housed communally experienced a greater fall in the percentage of normal cycles in spring, possibly due to increased stress associated with group feeding. Within each season, however, housing per se did not influence the distribution of normal vs extended cycles. For normal cycles, Harvey's Analysis of Variance showed that season was significantly associated with length of the periovulatory period (3.99 days (JJA) vs 5.79 days (SON); P < 0.001), oestrus detection rate (87% (JJA) vs 55% (SON); P < 0.01) and oestrus duration (1.94 days (JJA) vs 1.13 days (SON); P < 0.05). In contrast, luteal phase length was not affected by season, but was significantly associated with housing (16.93 days (single pens) vs 18.32 days (group pens); P < 0.01). The reduction in ovarian activity observed in spring may reflect a seasonal reduction in fertility, possibly linked with increasing temperature and photoperiod.

Animals↗
PubMed1992

Plasma progesterone concentrations during pregnancy and pseudopregnancy and onset of ovarian activity post partum in indigenous goats in Zimbabwe.

Eight pregnant does were housed individually and fed a hay and concentrate diet throughout pregnancy and lactation. The mean gestation period was 146.7 +/- 3.0 days, with a twinning rate of 75 per cent. Mean body condition scores improved from 2.4 +/- 0.2 to 2.8 +/- 0.2 over the first 80 days of gestation and were maintained at 2.8 until 45 days before kidding. From then until kidding, mean scores fell to 2.2 +/- 0.2. Plasma progesterone concentrations during pregnancy rose significantly from 3.91 +/- 0.51 ng/ml on day 40 to 5.96 +/- 0.51 ng/ml on day 60 (P < 0.05) and remained high until 5 days before kidding. Three pseudopregnant does had similar progesterone profiles to pregnant does over the first 80 days, but the rise around day 35 to 40 was not significant and progesterone concentrations returned gradually to basal levels after day 100. The same 8 does, together with an additional 4 does which had been brought inside 60 to 70 days before kidding, were used to study onset of ovarian activity post partum. The twinning percentage was 83 per cent. Mean body condition score at parturition was 2.2 +/- 0.1. By day 35 post partum, mean condition scores had fallen to 1.9 +/- 0.1, and mean weights from 36.9 +/- 1.9 kg at kidding to 32.1 +/- 2.0 kg. Ovarian cyclicity was resumed just before mean scores and weights started to improve. The mean interval from kidding to onset of oestrous cycles was 97.3 +/- 9.5 days. This coincided with mean time to weaning which was 99.5 +/- 5.5 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1981

Conversion of [4-14C]progesterone to androstenedione in vitro by thecal tissue from the ovary of the domestic fowl (Gallus domesticus).

The conversion of [4-14C]progesterone to androstenedione by thecal tissue homogenates from the large yellow follicles of the hen ovary was measured at two periods of the ovulatory cycle after incubation for 1 h in the presence of cofactors. Production of androstenedione by the largest follicle, F1, was reduced significantly 1-2 h before ovulation compared with 15 h before ovulation, whereas production of an unidentified androgen increased. These differences were not observed in the next largest follicles, F2 and F3. Thecal tissue homogenates from all the follicles converted [4-14C]progesterone to 17 alpha-hydroxyprogesterone, androstenedione and testosterone.

Androgens↗
PubMedDate not supplied

Oestrus in the British white goat: timing of plasma luteinizing hormone surge and changes in behavioural and vaginal traits in relationship to onset of oestrus.

Length of oestrus and timing of the LH surge was measured in six British White does, housed with a vasectomized buck (experiment 1). The following breeding season, pulsatile LH release during the cycle was measured in eight does and the pattern of behavioural and vaginal traits in relation to onset of oestrus (time 0) determined (experiment 2). In experiment 1, the interval to first oestrus after introduction of the buck on 1st October was 10.3 +/- 3.0 days (n = 6) but in experiment 2, when the buck was put in on 1st September, first oestrus occurred after 39.3 +/- 3.4 days in 7/8 does and 7 days in 1/8 does indicating that adequate exposure to short days is needed before the buck can initiate ovarian activity. LH pulse frequency increased from 0-1 pulses/8 h to 3 pulses/8 h after luteolysis, with no change in pulse amplitude, suggesting that progesterone regulates LH pulse frequency. Mean LH values rose from basal to 102.1 +/- 7.8 ng/ml, 12 +/- 1.5 h after the onset of oestrus, which was 16.3 +/- 1.7 h in length. Does sought out the buck and displayed tail wagging, bleating and restlessness from -60 h to +36 h relative to the onset of oestrus (time 0). The incidence of these activities rose at -12 h and peaked at 0 h. Tail wagging, but not bleating or restlessness, also increased in intensity at 0 h, as did the intensity with which the doe actively sought out the buck. Vulval redness and swelling and onset of a clear thin vaginal discharge were first observed 1-2 days before oestrus, becoming maximal on day 0. It was concluded that onset of frequent tail wagging was the most useful trait for detecting onset of oestrus.

Animals↗
PubMedDate not supplied

A randomized trial of solvent/detergent-treated and standard fresh-frozen plasma in the coagulopathy of liver disease and liver transplantation.

BACKGROUND: Virus inactivation of pooled fresh-frozen plasma (FFP) by the solvent/detergent (SD) method results in a loss of approximately 20 percent of factor VIII. This study aimed to assess the efficacy of SD-treated plasma in correcting the coagulopathy associated with liver disease and liver transplantation. STUDY DESIGN AND METHODS: Forty-nine patients with coagulation deficits due to liver disease, who required FFP for invasive procedures or liver transplantation, were randomly assigned to receive either FFP or SD-treated plasma. Patients were assessed for side effects, correction of coagulopathy over 24 hours, and seroconversion for viral markers 6 to 18 months after treatment. RESULTS: In the liver disease group, equal correction of clotting factors and partial thromboplastin time was seen with FFP and SD-treated plasma, with a similar return to baseline values over 24 hours. There was greater correction of the International Normalised Ratio in patients receiving SD-treated plasma (p = 0.037), but this patient group had higher baseline values than recipients of FFP (p = 0.024). Liver transplant patients also showed equivalent correction of coagulopathy with the same dose of FFP and SD-treated plasma. The use of other blood components during transplantation was identical in the two treatment groups. No seroconversions were seen for HIV or hepatitis B or C virus. One patient who had received FFP seroconverted for human parvovirus B19. Apparent seroconversion for hepatitis A virus seen at 9 to 13 months in four other patients was probably due to detection of passively transferred antibodies, as later testing of these patients gave negative results. Minor side effects were rare in both groups. CONCLUSION: SD-treated plasma is an efficacious source of coagulation factors for patients with liver disease who are undergoing biopsy or transplantation. Assessment of seroconversion for viral markers in recipients of plasma-derived products and plasma components should include consideration of the possibility that passively transferred antibodies were detected.

Adult↗