Evidence of a Generalized Defect of Acinar Cell Function in Shwachman-Diamond Syndrome

: Because the acinar cells of the exocrine pancreas in patients with Shwachman-Diamond syndrome (SDS) are severely depleted, we hypothesized that a similar deficiency may be present in acinar cells of the parotid gland.

Generalized expansion of nociceptive reflex receptive fields in chronic pain patients

Widespread central hypersensitivity is present in chronic pain and contributes to pain and disability. According to animal studies, expansion of receptive fields of spinal cord neurons is involved in central hypersensitivity. We recently developed a method to quantify nociceptive receptive fields in humans using spinal withdrawal reflexes. Here we hypothesized that patients with chronic pelvic pain display enlarged reflex receptive fields. Secondary endpoints were subjective pain thresholds and nociceptive withdrawal reflex thresholds after single and repeated (temporal summation) electrical stimulation. 20 patients and 25 pain-free subjects were tested. Electrical stimuli were applied to 10 sites on the foot sole for evoking reflexes in the tibialis anterior muscle. The reflex receptive field was defined as the area of the foot (fraction of the foot sole) from which a muscle contraction was evoked. For the secondary endpoints, the stimuli were applied to the cutaneous innervation area of the sural nerve. Medians (25-75 percentiles) of fraction of the foot sole in patients and controls were 0.48 (0.38-0.54) and 0.33 (0.27-0.39), respectively (P=0.008). Pain and reflex thresholds after sural nerve stimulation were significantly lower in patients than in controls (P<0.001 for all measurements). This study provides for the first time evidence for widespread expansion of reflex receptive fields in chronic pain patients. It thereby identifies a mechanism involved in central hypersensitivity in human chronic pain. Reverting the expansion of nociceptive receptive fields and exploring the prognostic meaning of this phenomenon may become future targets of clinical research.

The effect of different implant neck configurations on soft and hard tissue healing: a randomized-controlled clinical trial

Objective: To compare the soft and hard tissue healing and remodeling around tissue-level implants with different neck configurations after at least 1 year of functional loading. Material and methods: Eighteen patients with multiple missing teeth in the posterior area received two implants inserted in the same sextant. One test (T) implant with a 1.8 mm turned neck and one control (C) implant with a 2.8 mm turned neck were randomly assigned. All implants were placed transmucosally to the same sink depth of approximately 1.8 mm. Peri-apical radiographs were obtained using the paralleling technique and digitized. Two investigators blinded to the implant type-evaluated soft and hard tissue conditions at baseline, 6 months and 1 year after loading. Results: The mean crestal bone levels and soft tissue parameters were not significantly different between T and C implants at all time points. However, T implants displayed significantly less crestal bone loss than C implants after 1 year. Moreover, a frequency analysis revealed a higher percentage (50%) of T implants with crestal bone levels 1–2 mm below the implant shoulder compared with C implants (5.6%) 1 year after loading. Conclusion: Implants with a reduced height turned neck of 1.8 mm may, indeed, lower the crestal bone resorption and hence, may maintain higher crestal bone levels than do implants with a 2.8 mm turned neck, when sunk to the same depth. Moreover, several factors other than the vertical positioning of the moderately rough SLA surface may influence crestal bone levels after 1 year of function.