How well are graduates prepared for practice when measured against the latest GMC recommendations?

This article investigates the perspectives of University of Liverpool graduate foundation doctors and their consultants on their preparedness for professional practice.

Transmission of syphilis by solid organ transplantation

Two organ recipients developed serologic evidence of syphilis infection after renal transplantation from a common deceased donor with a history of treated syphilis. Testing of donor serum for syphilis, which occurred after transplantation, gave results interpreted as consistent with past infection. However, subsequent serologic results in the recipients suggested transmission of infection at transplantation due to active infection of the donor. This may be explained by recent donor re-infection in view of the current syphilis epidemic in the United Kingdom. An initial error in the treatment of recipients further served to highlight unfamiliarity in managing this resurgent infection in the context of organ transplantation.

Characterization of the flanking regions of Zea mays microsatellites reveals a large number of useful sequence polymorphisms

Sequence characterization of the flanking regions of 52 sequence-tagged microsatellite loci and two gene fragments from 11 Zea mays inbred lines identified a total of 324 sequence polymorphisms. The sequence polymorphisms consisted of both single-nucleotide polymorphisms and insertions/deletions in a ratio of approximately two to one. The level of sequence variation within the flanking regions of microsatellites linked to expressed sequence tags was lower than microsatellites that were unlinked to expressed sequence tags. However, both types of microsatellites generated a similar number of sequence-based alleles across the 11 genotypes surveyed. In two out of 20 microsatellites examined in detail, evidence was found for size-based allele homoplasy. Conversion of the observed sequence polymorphisms into allele-specific oligonucleotides followed by covalent binding to glass slides allowed the sequence polymorphisms to be used in a simple hybridization-based genotyping procedure. This procedure enabled us to discriminate between different inbred lines and allowed variations within a single inbred to be identified. The sequence information presented in this report could be used as a starting point for other programmes in the further development of a non-gel based, multi-locus, multi-allele screen for large-scale maize genotyping.

Prevalence and genotyping of HPV in cervical cancer among Australian women

OBJECTIVE

To investigate the association between HPV DNA detection and histological examination of tumor biopsies from women with cervical cancer.

METHOD

A total of 186 women with cervical cancer were screened for HPV infection using MY09/MY11 primer based PCR. The status of HPV infection was correlated with histological and demographic characteristics by Fisher's exact test or Chi square test.

RESULT

The prevalence of HPV infection in this Australian population was 91.9% (171). Among these 53.8% (100) were HPV type 16, 17.2% (32) HPV type 18, and 21.0% (39) other HPV types. Three significant associations were identified: (1) HPV genotype 18 and adenocarcinomas/adenosquamous carcinomas (P < 0.001); (2) HPV DNA negativity and postmenopausal status (P = 0.02); and (3) HPV DNA positivity and lymphocyte infiltration of tumor tissues (P = 0.03).

CONCLUSION

HPV infection is present in the vast majority of cervical cancer patients. However, its presence or genotyping does not seem to have a major influence on the pathogenesis of cervical cancer, such as tumor grade, FIGO staging and metastasis (P > 0.1).

Lack of association between HLA DQB1 alleles with HPV infection and histology findings in cervical cancer in Australian women

The association of human leukocyte antigen (HLA) types with cervical cancer and human papillomavirus (HPV) infection is controversial. In this study we examined 186 Australian women who had biopsy-confirmed cervical cancer and detected HLA DQB1 alleles and HPV DNA, using the polymerase chain reaction (PCR) amplification and sequence specific oligonucleotides probe (SSOP) hybridization methods. We analyzed the frequencies of 11 DQB1 alleles according to HPV DNA status (HPV positivity and HPV genotyping) and histology (tumor type, staging, grades, lymphocyte infiltration and nodal status). No significant differences among these 11 HLA DQB1 alleles were found with respect to HPV status and histology.

GnRH perikarya in medial basal hypothalamus of pubertal female rhesus macaque are ensheathed with glia

A previous study in our laboratory revealed that the cell bodies of gonadotropin releasing hormone (GnRH) neurons in the preoptic area (POA) of early to midpubertal female rhesus monkeys were extensively invested with thick glial processes. Because the medial basal hypothalamus (MBH) plays a critical role in the control of pulsatile and cyclic gonadotropin release in the primate, we have now focused on the ultrastructural milieu of GnRH neurons of this region in the same sample of monkeys. The ensheathment of the perikarya of GnRH neurons in the MBH with such glial processes was more pronounced than in the POA. Whereas the mean proportion of the cell membrane covered by these glia was 57% in the POA, it was 72% in the MBH. In addition, the cell bodies of GnRH neurons in the MBH of the pubertal monkey (unlike those in the POA) were less well innervated than were those in the adult cycling monkey, further highlighting differences between these brain regions. Differences in the anatomical milieu of the MBH between immature monkeys, in which GnRH release is still relatively quiescent, and adult cycling monkeys are consistent with the hypothesis that GnRH neurons within the MBH are under particular constraint in the immature animals. The functional significance of these observations must, however, await further studies.

The use of povidone iodine in exit site care for patients undergoing continuous peritoneal dialysis (CAPD)

Exit site infection is a major risk factor for the development of peritonitis in continuous ambulatory peritoneal dialysis. The frequency of infection can be reduced by scrupulous exit site care with or without topical antiseptics. A randomized trial was performed of 149 catheters in 130 patients to assess any additional benefits conferred by the use of povidine iodine dry powder spray at dressing changes over an existing strict protocol of exit care. Exit infections occurred in 14 (18%) of 77 patients using spray and in 15 (21%) of 72 patients not using spray. The risk of peritonitis was also similar in each group. The proportion of infections caused by Staphylococcus aureus was reduced in the spray group, but those caused by Pseudomonas aeruginosa were increased. Rash occurred in 6% of those using the spray. The use of the spray did not therefore seem justified.

Quantitative detection of hepatitis C virus RNA in patients undergoing hemodialysis

The purpose of the current study was to detect quantitatively hepatitis C virus (HCV)-RNA among patients undergoing maintenance hemodialysis. Study subjects were 88 patients on hemodialysis at the Miami Veterans Administration Medical Center and the REN Dialysis Unit at the University of Miami School of Medicine. There were 66 men and 22 women, mean age 52 years (range, 22-87 years), and mean duration of dialysis was 2.8 years (range 0.2-12.5 years). Seventy-three percent had a history of blood transfusion. Anti-HCV was determined by enzyme linked immunosorbent assay (ELISA), confirmed by four antigen strip immunoblot assay (RIBA 2.0 SIA). HCV-RNA was quantitated directly in human sera using a branched DNA (bDNA) signal amplification assay. Twenty-seven of 88 (31%) patient samples were found to be anti-HCV reactive by ELISA. Twenty-two of 27 were confirmed reactive, 2 were indeterminate, and 3 were nonreactive by RIBA HCV. Eighteen of 22 (82%) reactive by RIBA 2.0 HVC were found to have detectable (> 3.5 X 10(5) Eq/ml) HCV-RNA levels (mean [&/- SD], 43.3 +/- 35.4 X 10(5) Eq/ml; range 4.9-123.3). No additional cases were identified with reverse transcription polymerase chain reaction (RT-PCR) using 5' untranslated region "nested" primers. HCV-RNA was not detected in four RIBA HCV 2.0 reactive, the two intermediate, or the 64 patient samples nonreactive for anti-HCV. The two epitopes most commonly associated with HCV-RNA were c22-3 and c33c. Sixteen of 18 (89%) patients with detectable levels of HCV-RNA had normal alanine aminotransferase (ALT). Three patients with the highest levels of HCV-RNA were infected with the human immunodeficiency virus. The authors conclude that HCV-RNA by bDNA assay is a sensitive, specific, and simple test that can be used in association with antibody assays and a PCR-based assay to study the prevalence and management of HCV infection in the dialysis setting.

Novel associations among gonadotropin-releasing hormone neurons

GnRH is secreted in bursts into the hypophyseal portal vasculature by a small dispersed population of neurons. The means by which the activity of these intrinsically pulsatile cells is coordinated are unknown. This study was initiated as a continuation of our examination of the synaptic input to these cells and their anatomical relationships. Brain tissue from female rhesus monkeys and male and female rats was prepared for the immunocytochemical demonstration of GnRH. At the light microscopic level, GnRH neurons were occasionally found to be in close apposition. Such pairs (or small groups) were randomly distributed throughout the population of GnRH neurons from the diagonal band of Broca through the anterior hypothalamic area in rats and monkeys and in the medial basal hypothalamus in monkeys. The percentage of neurons found in such associations was small (2-7% in rats and 3-15% in monkeys) and was independent of the hormonal condition of the animal. GnRH neurons, either singly or in pairs, were serially sectioned for electron microscopic examination. The sparsity of synaptic input to the cell body that we had reported earlier on the basis of random sampling was confirmed. No soma had more than a dozen synapses, but none totally lacked innervation. The most significant result of serial reconstruction was the discovery of intercellular bridges or passageways between contiguous pairs of GnRH neurons. These were formed by the fusion of processes extending from the two cells or by fusion and opening of passageways in the membranes along regions of contiguity between the two cells. They were found in four of seven pairs of neurons examined in the rat and in four of eight pairs in the monkey. This syncytial arrangement along with GnRH-GnRH synaptic interactions could contribute to the coordination of dispersed influences on these neurons and the propagation of coordinated pulsatile release of GnRH.

Organelle-cytoskeletal interactions: actin mutations inhibit meiosis-dependent mitochondrial rearrangement in the budding yeast Saccharomyces cerevisiae

During early stages of meiosis I, yeast mitochondria fuse to form a single continuous thread. Thereafter, portions of the mitochondrial thread are equally distributed to daughter cells. Using time-lapse fluorescence microscopy and a membrane potential sensing dye, mitochondria are resolved as small particles at the cell periphery in pre-meiotic, living yeast. These organelles display low levels of movement. During meiosis I, we observed a threefold increase in mitochondrial motility. Mitochondrial movements were linear, occurred at a maximum velocity of 25 +/- 6.7 nm/s, and resulted in organelle collision and fusion to form elongated tubular structures. Mitochondria do not co-localize with microtubules. Destabilization of microtubules by nocodazole treatment has no significant effect on the rate and extent of thread formation. In contrast, yeast bearing temperature-sensitive mutations in the actin-encoding ACT1 gene (act1-3 and act1-133) exhibit abnormal mitochondrial aggregation, fragmentation, and enlargement as well as loss of mitochondrial motility. In act1-3 cells, mitochondrial defects and actin delocalization occur only at restrictive temperatures. The act1-133 mutation, which perturbs the myosin-binding site of actin without significantly affecting actin cytoskeletal structure in meiotic yeast, results in mitochondrial morphology and motility defects at restrictive and permissive temperatures. These studies support a role for the actin cytoskeleton in the control of mitochondrial position and movements in meiotic yeast.

Glial ensheathment of GnRH neurons in pubertal female rhesus macaques

During the period of development, prior to full sexual maturity, gonadotropin hormone-releasing hormone (GnRH) neurons are fully capable of synthesizing and processing the GnRH decapeptide. Nonetheless, the secretion of the hormone is not adequate to stimulate adult patterns of gonadotropin release. The present study was undertaken to examine ultrastructural characteristics of the GnRH neuron and its relationship to its environment in early-midpubertal female rhesus monkey. The neurons bore all the ultrastructural immunocytochemical characteristics of those in mature animals, but quantitative morphometrics revealed that they were extensively apposed by glial processes. Such ensheathment was described earlier in ovariectomized adult animals and was found to be reversible by administration of gonadal steroids. The density of synaptic input to GnRH neurons in the pubertal animals did not differ significantly from that of adult intact or ovariectomized animals from a previous study. Chemical identification will be required to determine whether there are age or hormonal differences in the innervation of these neurons. These results provide anatomical evidence in support of indications from other studies that the ovarian steroidal milieu affects GnRH-glial relationships. Further testing will be required to determine whether the attainment of sexual maturity in the female rhesus macaque is dependent upon a reduction in glial ensheathment of GnRH neurons.

Human bone marrow biochemical function and megaloblastic hematopoiesis after nitrous oxide anesthesia

Prolonged exposure to nitrous oxide (N2O) inhibits bone marrow function. The duration of exposure to nitrous oxide necessary to induce these changes and their permanence is unknown. The possible prophylactic effect of prior treatment with folinic acid has not been examined previously. Bone marrow function in patients receiving nitrous oxide was assessed by the deoxyuridine (dU) suppression test. Morphologic changes in the bone marrow were also studied. One group was exposed for under 6 h, the next for between 12 and 24 h and a control group who received nonitrous oxide. The control group and the short exposure group showed no abnormality of bone marrow function. The long exposure group had abnormal dU supression tests and a megaloblastic hematopoiesis. The changes observed in this group resolved 12 h after discontinuance of the anesthetic. The changes observed could be prevented by the preoperative administration of folinic acid. The absence of either morphologic or dU suppression test abnormalities following N2O anesthesia for periods of less than 6 h confirms the safety of this anesthetic for the majority of operations for which it is used. It has been confirmed that prolonged exposure to the gas causes impaired marrow function which is of a temporary nature and may be prevented by the prior administration of folinic acid.