Physical activity and the triggering of myocardial infarction: the case for regular exercise

The authors present signs and symptoms in Gr?nblad-Strandberg syndrome and current opinions on therapeutic procedures in choroidal neovascularization where central vision is threatened. The publication includes a case report.     

Biomechanical evaluation of the medial collateral ligament of the elbow

Anatomical dissection and biomechanical testing were used to study twenty-eight cadaveric elbows in order to determine the role of the medial collateral ligament under valgus loading. The medial collateral ligament was composed of anterior, posterior, and occasionally transverse bundles. The anterior bundle was, in turn, composed of anterior and posterior bands that tightened in reciprocal fashion as the elbow was flexed and extended. Sequential cutting of the ligament was performed while rotation caused by valgus torque was measured. The anterior band of the anterior bundle was the primary restraint to valgus rotation at 30, 60, and 90 degrees of flexion and was a co-primary restraint at 120 degrees of flexion. The posterior band of the anterior bundle was a co-primary restraint at 120 degrees of flexion and a secondary restraint at 30 and 90 degrees of flexion. The posterior bundle was a secondary restraint at 30 degrees only. The reciprocal anterior and posterior bands have distinct biomechanical roles and theoretically may be injured separately. The anterior band was more vulnerable to valgus overload when the elbow was extended, whereas the posterior band was more vulnerable when the elbow was flexed. The posterior bundle was not vulnerable to valgus overload unless the anterior bundle was completely disrupted. The intact elbows rotated a mean of 3.6 degrees between the neutral position and the two-newton-meter valgus torque position. Cutting of the entire anterior bundle caused an additional 3.2 degrees of rotation at 90 degrees of flexion, where the effect was greatest. CLINICAL RELEVANCE: Physical findings in a patient who has an injury of the anterior bundle may be subtle, and an examination should be performed with the elbow in 90 degrees of flexion for greatest sensitivity. As the anterior bundle is the major restraint to valgus rotation, reconstructive procedures should focus on anatomical reproduction of that structure. Parallel limbs of tendon graft placed from the inferior aspect of the medial epicondyle to the area of the sublimis tubercle will simulate the reciprocal bands of the anterior bundle. Temporary immobilization with the elbow in flexion may relax the critically important anterior band of the reconstruction during healing.     

Role of permanent stents

Brain dead patients are ideal donors for organ transplantation. The lack of organs has aroused new interest in other kinds of patients who are called non-heart-beating donors. In these donors the warm ischaemia time should be as short as possible. This problem has led to a discrepancy between a proper diagnosis of death and a fast organ procurement. In non-heart-beating donor protocols the death should be determined in an unambiguous manner that can also be accepted in other situations. The best solution would be to create one set of criteria of death that can be applied to all situations. Brain death as the criterion of death also in patients with asystole would serve this purpose.     

First year serologic response to treatment for syphilis: a model for prediction of seroreversion

There is no straightforward test available, within weeks of treatment for syphilis, to assess adequacy of serologic response. We propose a method to predict non-treponemal seroreversion based on short term response. To develop and illustrate this method, we used data from 370 individuals with infectious syphilis. Individual serologic response appears to be a linear function of (log) time, suggesting the possibility of using rapid plasma reagin titres recorded in the first few months after treatment to determine the slope of the linear treatment response line. The slope of the response line, during the first year after treatment, is an important predictor of seroreversion but must be considered in conjunction with pre-treatment titre. We recommend development of an action line be developed based on these variables. Such a line would indicate the necessity for retreatment if the line plotted from the patient's first year response failed to fall below the action line.     

Genetic diversity of feline immunodeficiency virus: dual infection, recombination, and distinct evolutionary rates among envelope sequence clades

For the rapid genetic analysis of feline immunodeficiency virus (FIV), we developed a heteroduplex mobility assay (HMA) that utilizes a PCR-amplified fragment of the FIV envelope gene spanning the third and fourth variable regions of the envelope surface protein coding sequence. Viral sequences were successfully amplified from blood specimens from 98 naturally infected cats from Australia, Canada, Germany, Italy, South Africa, and the United States. Eighty were clearly assignable to the A or B envelope sequence subtypes. Three belonged to subtype C, one was dually infected with viruses harboring the A and B env subtypes, and several were categorized as outliers to any of the established subtypes or as probable intersubtype recombinants. Some geographic clustering was evident, with subtypes A and B found in greater frequency in the western and eastern regions of the United States, respectively. Subtypes A, B, and C were found on more than one continent, and countries with more than two samples analyzed contained at least two subtypes. The broadest representation of subtypes was found in Munich, Germany, where three subtypes and one virus that was not classifiable by HMA were found. Thirteen samples were selected for DNA sequence determination over the same region of env used for HMA. Analysis of all available FIV env sequences from this and previous studies revealed the existence of recombinant viruses generated from subtype A/B, B/D, and A/C envelope gene sequences. Subtype A env sequences were less diverse than subtype B sequences, although both groups had well-supported clusters. Furthermore, the mutational pattern giving rise to diversification in the two subtypes differed, with the subtype A viruses showing half as many synonymous site mutations compared to subtype B yet showing similar levels of nonsynonymous site changes. These results are consistent with the hypothesis that FIV-B is an older virus group and is possibly more host adapted than FIV-A.     

Hypertension in thoracic transplant recipients

There are many mechanisms underlying the hypertension which occurs after thoracic transplantation. Previous disease, effects of cyclosporin, tacrolimus and steroid immunosuppression and cardiac denervation are major contributory factors. Abnormal sodium and water balance is an important common mediating factor. A new approach is clearly needed for classifying the severity of hypertension in these patients taking into account day-night variation and total blood pressure (BP) load. This would allow improved strategies for investigation and treatment. The evidence suggests that ambulatory BP measurements should be included in the assessment of initial severity of post-transplant hypertension as well as response to treatment. Further studies are needed to look at the effects of raised clinic and 24-h ambulatory BP and its treatment on longer term morbidity and mortality in thoracic transplant patients.     

Stimulation of prohormone convertase-1 mRNA expression by second messenger signaling systems

The purpose of this study was to investigate the effects of activation of various second messenger signaling systems on gene expression (i.e. mRNA levels) of a peptide hormone processing enzyme called prohormone convertase-1 (PC-1, also called PC-3) in a human pancreatic carcinoid cell line (BON) that expresses several endocrine peptides (chromogranin A, pancreastatin, neurotensin). Pharmacologic activation of adenylate cyclase-cAMP, protein kinase-C and Ca2+ mobilization pathways increased PC-1 mRNA levels and neurotensin secretion. Elevations in PC-1 mRNA levels were dose and time-related. Secretagogue-induced cellular depletion of neurotensin was followed by a replenishment of cellular neurotensin stores and an upregulation of PC-1 mRNA levels. Together, these data indicate that PC-1 mRNA expression is increased with peptide secretion and coordinated with maintenance of cellular stores of peptides.     

Fetal retinoblastoma

Fetal tumors are sporadic entities and in some cases can be diagnosed prenatally. A team approach, incorporating the skills of obstetricians, radiation therapists, pediatric medical oncologists and hematologists, neonatal surgeons, rehabilitation specialists, and social workers, is imperative to ensure that the patient receives the best treatment. Retinoblastoma is a relatively uncommon tumor of childhood that arises in the retina. The estimated annual incidence is between 1 in 15,000 and 1 in 34,000. Although it may occur at any age, it most often arises in younger children, with 80% of cases diagnosed before the age of 5 years. We report a case of prenatally diagnosed fetal retinoblastoma.