The Role of Growth Hormone Receptor Isoforms and Their Effects in Bone Metabolism and Skeletal Fragility

Acromegaly and Growth Hormone Deficiency (GHD) are associated with skeletal fragility and with an increased prevalence of Vertebral Fractures (VFs). In the most recent years, several authors tried to investigate surrogate markers that may predict the risk of bone fragility in these endocrine disorders. The aim of this review is to evaluate the role of GH receptor polymorphisms in skeletal fragility in patients affected by GHD and acromegaly. In fact, until now, two different isoforms of the GH Receptor (GHR) were described, that differ for the presence or the absence of transcription of the exon 3 of the GHR gene. Both the isoforms produce a functioning receptor, but the exon 3-deleted isoforms (d3-GHR) has a higher sensitivity to endogenous and recombinant GH as compared to the full-length isoform (fl-GHR).

Is the number of microembolic signals related to neurologic outcome in coronary bypass surgery?

Coronary artery bypass surgery (CABG) without cardiopulmonary bypass (CPB) may potentially reduce the number of microembolic signals (MES) associated with aortic manipulation or generated by the pump circuit, resulting in a better neurologic outcome after surgery. Our aim was to compare the frequency of MES and neurologic complications in CABG with and without CPB. Twenty patients eligible to routine CABG without CPB were randomized to surgery with CPB and without CPB and continuously monitored by transcranial Doppler. Neurologic examination was performed in all patients before and after surgery. The two groups were similar with respect to demographics, risk factors, grade of aortic atheromatous disease and number of grafts. The frequency of MES in the nonCPB group was considerably lower than in CPB patients, however, we did not observe any change in the neurologic examination during the early postoperative period. Neurologic complications after CABG may be related to the size and composition of MES rather than to their absolute numbers. A large prospective multicentric randomized trial may help to elucidate this complex issue.

Impact of the Pathfinder in a cytology laboratory

OBJECTIVE

To assess the value of Pathfinder (CompuCyte, Cambridge, Massachusetts, U.S.A.) in improving adequacy and accuracy of screening and supporting quality control programs.

STUDY DESIGN

The investigations were carried out on cervical cytologic smears only. Screening adequacy was assessed through the evaluation of percentage of slide coverage, percentage of overlapping and amount of elapsed time on smears screened with or without the Pathfinder by junior (426 cases) and senior (1,552 cases) screeners. Screening accuracy was investigated by comparing the performances of the same observer when reexamining, with the Pathfinder, a series of 1,051 cases already evaluated without the Pathfinder at least three months earlier. The review process was analyzed by both monitoring the elapsed time for relocation of manually or electronically marked cells (824 fields in 80 smears) and by comparing diagnostic discrepancies after the review of two series (74 + 74 cases) of randomly selected negative cases screened with or without Pathfinder.

RESULTS

Pathfinder-assisted screening increased the number of cases with optimal slide coverage (> or = 90% of screenable area) and optimal overlapping (between 15% and 20%) by both junior (P < .00001 and P < .00001) and senior (P < .00001 and P < .0003) screeners. It also improved screening accuracy by decreasing the number of cases "unsatisfactory for evaluation" (P < .00001) (as a consequence of better coverage and overlapping) and the number of diagnostic discrepancies detected after review (P = .05). During the latter process, the time elapsed for relocation of electronically marked fields, as compared to manually marked ones, was greatly reduced (1 hour, 25 minutes saved for revision of 40 smears).

CONCLUSION

In these preliminary studies, the Pathfinder was a useful tool for both education and diagnosis (screening and review) in a cytology laboratory.

Thoracic human vertebrae. Quantitative three-dimensional anatomy

This study details the quantitative three-dimensional surface anatomy of thoracic vertebrae based on a study of 144 vertebrae. The thoracic spine was found to have three distinct regions: upper, middle, and lower segments. The two end segments appear to be transitional zones toward cervical and lumbar regions. The middle zone (T3 to T9) is of utmost importance due to the presence of the combination of narrow spinal canal and critical vascular supply. Means and standard errors of the means for linear, angular, and area dimensions of vertebral bodies, spinal canal, pedicle, pars articularis, spinous and transverse processes, and rib articulations are provided for all thoracic vertebrae. This information is necessary for constructing accurate mathematical models of the human spine. It will also provide a better understanding of the spine, and allow for a more precise clinical and surgical management of spinal problems.