Pulp reactions to restoration of experimentally induced crown fractures

OBJECTIVES: Reattachment of the avulsed enamel-dentine coronal fragment to the remaining tooth structure has become an accepted clinical alternative to a resin composite build-up for the restoration of crown fractured teeth. Since little knowledge exists as to the pulpal response to this procedure, this study was designed to observe the condition of the pulp following experimentally induced crown fracture and restoration in monkeys. METHODS: Experiments were conducted in eight young green Vervet monkeys (Cercopithecus aethiops). In all, 64 fractured incisors were investigated. Light microscopic examination of pulp tissue specimens was carried out after 3 months of observation. RESULTS: The evaluation was restricted to specimens having a fracture plane within 2 mm of the pulp and no pulpal exposure. In general, pulp tissue was well preserved irrespective of the restorative procedure. Even if the restoration or the bonded tooth fragment had been lost during the follow-up period, the pulp generally remained in good condition. Inflammatory infiltrates where seen in only a few specimens and then as clusters of mononuclear leukocytes. Hard tissue repair was frequently observed and displayed various configurations from isolated hard tissue deposits to areas of extensive hard tissue repair in the coronal portion of the pulp. Pronounced hard tissue repair and occurrence of inflammatory cell infiltrates correlated with the presence of stainable bacteria on the fractured dentine surface. CONCLUSIONS: In the absence of direct exposure, reparative dentine is a frequent feature of the pulp's response to crown fracture and restoration with composite or reattachment of the crown fragment with dentine bonding. These restorative procedures appear to ensure continued function of the underlying pulp.     

Different design scenarios related to an open loop groundwater heat pump in a large building: Impact on subsurface and primary energy consumption

A multidisciplinary methodology is proposed for analyzing opportunities to use existing boreholes and an open-loop groundwater heat pump to provide summer cooling needs for large university buildings in Turin (NW Italy). The approach starts from a model of the buildings to determine the time profile of the cooling load. This curve is then coupled with a model of the off-design behaviour of the heat pump, which allows calculation of its energy performance (coefficient of performance, electricity consumption, etc.) as well as profiles of water discharge to the aquifer in terms of mass flow rate and temperature.Covering the peak energy needs of the buildings requires a variable amount of groundwater during the day. This could be provided varying the withdrawals from the aquifer but, as possible alternatives, two storage system solutions are examined: (1) chilled water storage and (2) groundwater storage. Simulations show that in both cases the use of storage systems produces environmental advantages, as the extent of the thermal plume reduces significantly. Moreover, chilled water storage presents a benefit in terms of reduced total primary energy consumption. The additional costs incurred by storage systems could necessitate public funding as well as system optimization.     

Altered intracellular processing and enhanced secretion of procathepsin D in a highly deviated rat hepatoma

Using immunomagnetic cell separation and fluorescent in situ hybridization (FISH), we studied nine patients who had chronic granulocytic leukemia (CGL) for the proportion of interphase nuclei with Mbcr/abl fusion in a direct preparation of the bone marrow and also in the mononuclear cell (MNC), neutrophil, and B- and T-cell fractions of the peripheral blood. In five untreated patients, conventional cytogenetics revealed 97% to 100% Philadelphia chromosome (Ph)+ metaphases. In three of these five patients, FISH studies on bone marrow direct preparations and peripheral blood MNCs indicated that an Mbcr/abl fusion occurred in 62% to 69% of the cells. We observed 69% to 88% of nuclei with Mbcr/abl fusion within the neutrophil fractions. In contrast, the values were 12% to 39% within the T-cell fractions in the four patients we studied. B-cell fractions were studied in three patients, and only one had an abnormal value (58%). In the four patients receiving alpha-interferon therapy, the degree of conventional cytogenetic remission correlated best with the degree of FISH remission observed in the peripheral blood neutrophil fraction. Our results are in agreement with earlier studies in that both B and T lymphocytes may be involved with the clonal process in CGL. The FISH-based detection of Mbcr/abl fusion in the peripheral blood neutrophil compartment provided the best estimate for the proportion of Ph metaphases determined by conventional cytogenetics.     

M-plasty in the treatment of carcinomas located on the interglabellar region

One of the main tasks of current cutaneous surgery is to completely eliminate the tumor while avoiding unnecessary normal tissue extirpation. This is especially important when removing facial tumors close to the external canthus, mouth angles and perialar regions. In all these areas we advise fusiform excision but with distal M-plasty in the nearest angle so as to avoid angle retraction. The same is true for mediofrontal tumors, as this often causes a drawing together of the eyebrows. We have reviewed all mediofrontal excisions carried out during the last six years. M-plasty following fusiform excision was always performed in the interglabellar area. The good results achieved allow us to recommend this technique in this location.     

Mechanisms underlying spinal motor neuron excitability during the cutaneous silent period in humans

The transient suppression of muscle contraction during the cutaneous silent period (CSP) could be produced either through postsynaptic inhibition of motoneurons or through presynaptic inhibition of the excitatory inputs to motoneurons that sustain voluntary contraction. We sought to delineate the mechanisms underlying the CSP in hand muscles by measuring changes in H-reflexes and motor-evoked potentials (MEPs) produced by transcranial magnetic stimulation (TMS) during the CSP in 10 healthy volunteers. H-reflexes and MEPs both measure the excitability of the motoneuron pool and activate similar subpopulations of motoneurons through different pathways. Inhibition of H-reflexes and MEPs of similar size was maximal at the midpoint of the CSP and gradually returned to baseline. The similar time course of recovery suggests that the H-reflex and MEP are affected by inhibition at a common site, most likely postsynaptic inhibition of the motoneurons.     

Evaluation of pregnancy rates after intrauterine insemination according to indication, age, and sperm parameters

The intention of this review is to compare studies on the morphology and histology (light and electron microscopic) of ultimobranchial glands of various groups of reptiles. Moreover, experiments (including our investigations) on suppression or stimulation of the ultimobranchial gland are included. Adult reptiles possess one (on the left side) or two ultimobranchial glands (UBG). The UBG lie just anterior to the heart. Light as well as electron microscopically, the gland has been shown to contain follicles and cell cords (cell aggregates). The follicular epithelium is lined by simple cuboidal or pseudostratified columnar cells. Ciliated and goblet cells may be present in the follicular epithelia in some groups. The lumen may contain a colloid-like substance with desquamated cells or debris. The UBG of reptiles seem to be an active secretory organ with influence on calcium regulation. Other functions of calcitonin have also been suggested in reptiles for example in neurotransmission, in volume regulation, phosphate balance and promotion of bone calcification (at least in juveniles).     

Teaching smoking-cessation counseling to medical students using simulated patients

The controversy continues over the appropriate use of vaginal hysterectomy for many indications that were previously treated only with abdominal or laparoscopic methods. Current outcomes data have pointed up the need for established guidelines to ensure that patients receive appropriate surgical treatment that is most cost-effective and that meets the standard of quality care. Dr Kovac reviews recent data regarding the various surgical options for hysterectomy and offers guidelines based on objective pathologic criteria.     

Antimicrobial susceptibility of Mycoplasma hyorhinis in a liquid medium compared to a disc assay

Sulfates and glucuronides of 2,4-dinitrobenzyl alcohol 1a and 2,6-dinitrobenzyl alcohol 1b, which are major or putative metabolites of 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT), were synthesized from 1a and 1b by reaction with pyridinium sulfonate and methyl (2,3,4-tri-O-acetyl-alpha-D-glucopyranosyl)uronate bromide 3, respectively, as their pyridinium salts (2a, 2b) and potassium salts (6a, 6b). These conjugates are important for the study of the carcinogenicity of 2,4-DNT and 2,6-DNT.