No abstract

Numerous studies suggest an essential role for the intermediate (IRt) and parvocellular (PCRt) reticular formation (RF) in consummatory ingestive responses. Although the IRt and PCRt contain a large proportion of neurons with projections to the oromotor nuclei, these areas of the RF are heterogeneous with respect to neurotransmitter phenotypes. Glutamatergic, GABAergic, cholinergic, and nitrergic neurons are all found in the PCRt and IRt, but the projections of neurons with these phenotypes to the motor trigeminal (mV) and hypoglossal nucleus (mXII) has not been fully evaluated. In the present study, after small injections of Fluorogold (FG) into mV and mXII, sections were processed immunohistochemically to detect retrogradely labeled FG neurons in combination with the synthetic enzymes for nitric oxide (nitric oxide synthase) or acetylcholine (choline acetyltransferase) or in situ hybridization for the synthetic enzyme for GABA (GAD65/67) or the brainstem vesicular transporter for glutamate (VGLUT2). In three additional cases, FG injections were made into one motor nucleus and cholera toxin (subunit b) injected in the other to determine the presence of dual projection neurons. Premotor neurons to mXII (pre-mXII) were highly concentrated in the IRt. In contrast, there were nearly equal proportions of premotor-trigeminal neurons (pre-mV) in the IRt and PCRt. A high proportion of pre-oromotor neurons were positive for VGLUT2 (pre-mXII: 68%; pre-mV: 53%) but GABAergic projections were differentially distributed with a greater projection to mV (25%) compared to mXII (8%). Significant populations of cholinergic and nitrergic neurons overlapped pre-oromotor neurons, but there was sparse double-labeling (<10%). The IRt also contained a high proportion of neurons that projected to both mV and MXII. These different classes of premotor neurons in the IRt and PCRt provide a substrate for the rhythmic activation of lingual and masticatory muscles.

Microvascular free tissue transfer has been one of the greatest milestones in reconstruction of the mandible and maxilla after tumor ablative surgery. Although fibula free flap reconstruction allows for immediate bony reconstruction, dental rehabilitation usually requires 6 to 12 months before it is completed. This can have a serious psychological impact on patients because they go without teeth during this timeframe. The "jaw-in-a-day" procedure was previously described by a group at New York University Medical Center. It allowed for tumor removal and full jaw reconstruction and dental rehabilitation in 1 surgery. This report describes 3 patients treated with this novel technique and adds to the 4 cases previously reported in the literature. To their knowledge, the authors are the second group to report on this technique. A series of photographs and videos are referenced in this article to illustrate the different steps used in this procedure.

No abstract

Inflammation of the muscle invariably leads to muscle cell damage and impaired regeneration. Biomechanical signals play a vital role in the regulation of myogenesis in healthy and inflamed muscle. We hypothesized that biomechanical signals counteract the actions of proinflammatory mediators and upregulate the basic helix-loop-helix and MADS box transcription enhancer factor 2 (MEF2) families of transcription factors, leading to increased myogenesis in inflamed muscle cells. For this purpose, C2C12 cells plated on collagenized silastic membranes were subjected to equibiaxial cyclic tensile strain (CTS) in the presence or absence of TNF-alpha, and the myogenic gene induction was examined over a period of 72 h. Exposure of cells to CTS resulted in a significant upregulation of mRNA expressions and synthesis of myogenic regulatory factors, MYOD1, myogenin (MYOG), MEF2A, and cyclin-dependent kinase inhibitor 1A (CDKN1A; p21) as well as muscle structural proteins like myosin heavy chain (MYHC) isoforms (MYH1, MYH2, and MYH4) and alpha-tropomyosin (TPM1), eventually leading to an increase in myotube formation. Contrarily, TNF-alpha suppressed the expression of all of the above differentiation-inducing factors in C2C12 cells. Further results revealed that simultaneous exposure of C2C12 cells to CTS and TNF-alpha abrogated the TNF-alpha-mediated downregulation of myogenic differentiation. In fact, the mRNA expression and protein synthesis of all myogenic factors (Myod1, Myog, Mef2a, Cdkn1a, Myh1, Myh2, Myh4, and Tpm1) were increased in stretched C2C12 cells despite the sustained presence of TNF-alpha. These results demonstrate that mechanotransduction regulates multiple signaling molecules involved in C2C12 cell differentiation. On one hand, these signals are potent transducers of myotube phenotype in myoblasts; on the other, these signals counteract catabolic actions of proinflammatory cytokines like TNF-alpha and allow the expression of myogenic genes to upregulate muscle cell differentiation.

ObjectiveDesign Prospective, observational study.Setting John Radcliffe Maternity Hospital, Oxford, UK. Participants and MethodsMiddle cerebral artery velocities were measured by transcranial Doppler ultrasound in 25 nonpregnant women, 22 women longitudinally followed throughout pregnancy and 2 1 women serially studied from delivery until the late puerperium.To study changes throughout gestation and the puerperium of middle cerebral artery flow velocity waveforms obtained by transcranial Doppler ultrasound.Main outcome measures Transcranial Doppler changes in pregnancy and the puerperium. ResultsThe transcranial Doppler ultrasound measurements showed good reproducibility. Signals from one middle cerebral artery could not be obtained in 4.6% of the examinations, but otherwise readings were similar on both sides. Women in the second half of pregnancy had lower middle cerebral artery mean velocities than nonpregnant women. Velocities decreased with advancing gestation but increased in the immediate puerperium to levels comparable to those found in nonpregnant women.Conclusions Transcranial Doppler ultrasound is a noninvasive technique suitable for studying maternal cerebral haemodynamics in pregnancy and postpartum. Middle cerebral artery mean velocity decreased with advancing gestation and increased to nonpregnant values in the immediate puerperium. These physiological changes need to be considered when comparing data with measurements taken in abnormal pregnancy states.

Additional alveolar bone loss has a negative influence on the stress concentration in the surrounding bone of quad zygomatic implant-supported prostheses. More care should be taken if these additional bone defects are at the sites of anterior zygomatic implants.

Objective To establish reference ranges for the human fetal middle cerebral artery pulsatility index (MCA PI) for the local obstetric population, and to compare computerised antenatal fetal heart rate (FHR) analysis with the MCA PI as indicators of fetal compromise. Design Prospective data collection for selected patients. Setting High risk pregnancy unit of a teaching hospital. Subjects Group 1 consisted of 18 healthy women with uncomplicated singleton pregnancies. Group 2 consisted of 27 women admitted to the high risk pregnancy unit over a 9 month period with intrauterine growth retardation and other related problems; all these women were delivered by prelabour caesarean section. Intervention Serial Duplex sonography to determine fetal MCA PI in Groups 1 and 2. Serial FHR analysis using computerised numerical techniques in Group 2 only. Main outcome measures Serial MCA PI values from 24 to 39 completed weeks of gestation in Group 1. Comparison of serial MCA PI values with FHR analysis in relation to fetal outcome in Group 2. Results In Group 1 the MCA PI diminished significantly as gestation advanced from 1.73 (SD 0.25) at 24 weeks to 1.38 (SD 0.26) at 39 weeks (P<0.01). In Group 2 eleven babies were hypoxaemic at delivery: all had low MCA PI values while only nine had an abnormal FHR prior to delivery. Conclusion In normal pregnancy, there is a fall in the fetal MCA PI with advancing gestation which probably reflects a decreasing vascular resistance to fetal cerebral blood flow. Hypoxaemia at delivery appeared to be better recognised by the fetal MCA flow velocity waveform than the FHR analysis. This increased sensitivity, however, was achieved at the expense of a reduced specificity. Larger studies are needed to confirm the findings of this preliminary investigation.