Basic epidemiology of inflammatory bowel disease in Puerto Rico

BACKGROUND: Previous epidemiological studies have suggested that the incidence of inflammatory bowel disease (IBD) is lower in Latin American populations. The aim of this study was to estimate the incidence of IBD in Puerto Rico, a predominantly Hispanic population. METHODS: A nonconcurrent prospective study was conducted in collaboration with private gastroenterologists in southwest Puerto Rico. Basic medical history and demographics were extracted from the medical records of patients for which a new diagnosis of IBD (Crohn's disease, CD; ulcerative colitis, UC; or nonspecified IBD) was made during each of the years 1996-2000. RESULTS: A total of 202 eligible cases of IBD were identified (95 male, 107 female). Forty-eight patients were diagnosed with CD, 102 with UC, and 52 with nonspecified IBD. The total incidence of IBD increased significantly between 1996 and 2000 (3.07/100,000 to 7.74/100,000; p < 0.001), being significantly higher for CD (four-fold increase, p < 0.01) and nonspecified IBD (fourfold increase, p < 0.005), but not UC (1.7-fold increase). The prevalence of CD was higher in males with an earlier age of onset (p < 0.05). CONCLUSIONS: This study demonstrates that the incidence of IBD within the Puerto Rican population is increasing and may be higher than previously reported for other Latin American populations.     

Arthroscopic estimation of the extent of chondropathy

INTRODUCTION: Arthroscopy has been used to evaluate articular cartilage (AC) pathology in osteoarthritis (OA) for outcome measurement and validation of non-invasive imaging. However, many fundamental aspects of arthroscopic assessment remain un-validated. OBJECTIVES: This study evaluated arthroscopic estimates of extent of chondropathy. METHODS: Serial arthroscopic assessments were performed in a group of 15 sheep before and after bilateral stifle medial meniscectomy (MMx). Post-mortem assessments were performed in un-MMx sheep and 4 and 16 weeks post-MMx. Arthroscopic assessments of the extent of each grade of chondropathy were compared with a non-arthroscopic hybrid assessment that incorporated biomechanical, thickness and macroscopic assessments. RESULTS: Arthroscopy evaluated only 36% of AC and missed significant pathological changes, softening and chondro-osteophyte, occurring in peripheral regions. The patterns of change in arthroscopic assessments were similar to those of the non-arthroscopic assessment but there was a very strong tendency to over-estimate the extent of softened AC after MMx. In spite of these limitations arthroscopic assessments were responsive to change. Estimates of the extent of normal and softened AC were most responsive to change over time followed by estimates of superficial and deep fibrillation. Arthroscopy was as an excellent discriminator between normal and OA. Assessments of chondro-osteophyte and exposed bone were not responsive to change. CONCLUSIONS: Arthroscopic estimates of extent of chondropathy are prone to substantial error. While experience and training may reduce these errors other approaches may more effectively improve performance.     

Organization and properties of GABAergic neurons in solitary tract nucleus (NTS)

Cranial visceral afferents enter the brain at the solitary tract nucleus (NTS). GABAergic neurons are scattered throughout the NTS, but their relation to solitary tract (ST) afferent pathways is imprecisely known. We hypothesized that most GABAergic NTS neurons would be connected only indirectly to the ST. We identified GABAergic neurons in brain stem horizontal slices using transgenic mice in which enhanced green fluorescent protein (EGFP) expression was linked to glutamic acid decarboxylase expression (GAD(+)). Finely graded electrical shocks to ST recruit ST-synchronized synaptic events with all-or-none thresholds and individual waveforms did not change with greater suprathreshold intensities--evidence consistent with initiation by single afferent axons. Most (approximately 70%) GAD(+) neurons received ST-evoked excitatory postsynaptic currents (EPSCs) that had minimally variant latencies (jitter, SD of latency <200 micros) and waveforms consistent with single, direct ST connections (i.e., monosynaptic). Increasing stimulus intensity evoked additional ST-synchronized synaptic responses with jitters >200 micros including inhibitory postsynaptic currents (IPSCs), indicating indirect connections (polysynaptic). Shocks of suprathreshold intensity delivered adjacent (50-300 microm) to the ST failed to excite non-ST inputs to second-order neurons, suggesting a paucity of axons passing near to ST that connected to these neurons. Despite expectations, we found similar ST synaptic patterns in GAD(+) and unlabeled neurons. Generally, ST information that arrived indirectly had small amplitudes (EPSCs and IPSCs) and frequency-dependent failures that reached >50% for IPSCs to bursts of stimuli. This ST afferent pathway organization is strongly use-dependent--a property that may tune signal propagation within and beyond NTS.