Lisch nodules of the iris in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disease. The Lisch nodule represents one of the most common NF1 ocular manifestations. Several studies have reported that the Lisch nodule is a melanocytic hamartoma but its pathogenesis is still debated. We have studied the histopathological and ultrastructural features of a Lisch nodule of a 50-year-old woman biopsied during an intracapsular cataract extraction. Our researches revealed that it was composed of three main cytotypes: pigmented cells, fibroblast-like cells and mast cells, showing a pattern similar to a neurofibroma. Furthermore, we hypothesize that Lisch nodules are compatible with neurofibromas.     

A two-step intervention of increase mammography among women aged 65 and older.

OBJECTIVES: This study evaluated a two-step intervention for mammography screening among older women. METHODS: Four hundred and sixty women, identified from physician practices, were randomized to a control or a two-step intervention (physician letter and peer counseling call) group. Women in the intervention group who obtained a mammogram received a grocery coupon. RESULTS: Over the 12 months of the study, more women in the intervention group than in the control group obtained mammograms (38% vs 16%). The most dramatic difference was in the higher odds that women in the intervention group would obtain a mammogram within 2 months (odds ratio = 10.5). CONCLUSIONS: The intervention significantly increased screening mammography. Future efforts must be multifaceted and incorporate the unique concerns of older women.     

Production and reversibility of right ventricular hypertrophy and right heart failure in dogs.

Combined heart-lung transplantation has been used for end-stage primary pulmonary hypertension. Experience with single-lung transplantation for other conditions suggested that associated severe right ventricular dysfunction resulting from increased afterload would recover after placement of a satisfactory lung allograft. Early experience with the application of single-lung transplantation for pulmonary hypertension supports this contention. We devised a reversible canine model of chronic progressive pressure-overloaded right heart failure by pulmonary artery banding to study the echocardiographic, hemodynamic, and pathological reversibility of the failing right heart. Clinical right heart failure was defined as the development of ascites and pleural effusions. Right heart failure developed in 23 dogs 67 to 348 days after banding, and they were divided into two groups to determine its early and long-term effects. Group 1 dogs (n = 11) were either sacrificed immediately after the onset of right heart failure (n = 5) or unbanded (n = 6); group 2 dogs (n = 12) were maintained in right heart failure for 3 months and then either sacrificed (n = 6) or unbanded. Unbanded dogs in both groups were observed for 4 additional months before sacrifice. A control group of 6 normal dogs was sacrificed for pathological comparisons. After unbanding, the right ventricular systolic pressure fell from 97 +/- 17 mm Hg (group 1) and 88 +/- 31 mm Hg (group 2) to 44 +/- 11 mm Hg and 47 +/- 13 mm Hg, respectively. Despite this persistent gradient across the pulmonary artery, echocardiographic and hemodynamic measures of right ventricular function returned to normal, albeit more slowly in the group 2 dogs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Laser speckle flowmetry for the study of cerebrovascular physiology in normal and ischemic mouse cortex.

Laser speckle flowmetry (LSF) is useful to assess noninvasively two-dimensional cerebral blood flow (CBF) with high temporal and spatial resolution. The authors show that LSF can image the spatiotemporal dynamics of CBF changes in mice through an intact skull. When measured by LSF, peak CBF increases during whisker stimulation closely correlated with simultaneous laser-Doppler flowmetry (LDF) measurements, and were greater within the branches of the middle cerebral artery supplying barrel cortex than within barrel cortex capillary bed itself. When LSF was used to study the response to inhaled CO2 (5%), the flow increase was similar to the response reported using LDF. For the upper and lower limits of autoregulation, mean arterial pressure values were 110 and 40 mm Hg, respectively. They also show a linear relationship between absolute resting CBF, as determined by [C]iodoamphetamine technique, and 1/tau(c) values obtained using LSF, and used 1/tau(c) values to compare resting CBF between different animals. Finally, the authors studied CBF changes after distal middle cerebral artery ligation, and developed a model to investigate the spatial distribution and hemodynamics of moderate to severely ischemic cortex. In summary, LSF has distinct advantages over LDF for CBF monitoring because of high spatial resolution.     

The role of personality disorder in 'difficult to reach' patients with depression: findings from the ODIN study.

Individuals with personality disorders (especially paranoid personality disorder) tend to be reluctant to engage in treatment. This paper aimed to elucidate the role of personality disorder in predicting engagement with psychological treatment for depression. The Outcomes of Depression International Network (ODIN) involves six urban and three rural study sites throughout Europe at which cases of depression were identified through a two-stage community survey. One patient in seven who was offered psychological treatment for depression had a comorbid diagnosis of personality disorder (most commonly paranoid personality disorder). Forty-five percent of patients who were offered psychological treatment for depression did not complete treatment. The odds of completion were higher for patients with a comorbid diagnosis of personality disorder, especially paranoid, anxious or dependent personality disorder. The relatively low number of cases with some specific personality disorders (e.g. schizoid personality disorder) limited the study's power to reach conclusions about these specific disorders. This study focused on a community-based sample which may lead to apparently lower rates of engagement when compared to studies based on treatment-seeking populations. Episodes of depression in the context of personality disorder may represent a valuable opportunity to engage with patients who might otherwise resist engagement.     

In vivo imaging of insulin receptors in monkeys using 18F-labeled insulin and positron emission tomography.

We previously described a prosthetic group methodology for incorporating 18F into peptides and showed that 18F-labeled insulin (18F-insulin) binds to insulin receptors on human cells (IM-9 lymphoblastoid cells) with affinity equal to that of native insulin (1). We now report studies using 18F-insulin with positron emission tomography to study binding to insulin receptors in vivo. Positron emission tomography scans were performed in six rhesus monkeys injected with 0.3-1.4 mCi of 18F-insulin (approximately 0.1 nmol, SA 4-11 Ci/mumol). Integrity of the tracer in blood, determined by immunoprecipitation, was 94% of control for the first 5 min and decreased to 31% by 30 min. Specific, saturable uptake of 18F was observed in the liver and kidney. Coinjection of unlabeled insulin (200 U, approximately 1 nmol) with the 18F-insulin reduced liver and increased kidney uptake of the labeled insulin. Liver radioactivity was decreased by administration of unlabeled insulin at 3 min, but not 5 min, after administration of the tracer, while some kidney radioactivity could be displaced 5 min after injection. Clearance of 18F was predominantly in bile and urine. 18F-insulin is a suitable analogue for studying insulin receptor-ligand interactions in vivo, especially in the liver and kidney.