The effect of a unilateral costochondral graft on the growth of the marmoset mandible.

PURPOSE: The purpose of the investigation was to examine growth of the mandible after costochondral grafting with special reference to the amount of cartilage included in the grafts. MATERIALS AND METHODS: The material consisted of 5 growing and 3 adult marmoset monkeys, Callithrix jacchus, in which the condylar process was removed unilaterally and replaced with a costochondral graft (CCG) containing either a short or long cartilage end. Growing animals were followed for 15 months until they attained maturity; and adult animals were followed for 13 months. Measurements made on frontal radiographs performed bimonthly, and direct measurements made on dry mandibles and crania at the end of the experiment, were used to evaluate the growth of the mandible and glenoid fossa. RESULTS: Longitudinal cephalometric evaluation revealed a gradual deviation of the lower dental midline to the unoperated side in growing monkeys with a long cartilage transplant. In all other animals, virtually no midline deviation occurred. Measurements on dry mandibles showed that the length and ramus height were longer in growing animals with long cartilage transplants compared with those with short cartilage transplants. In adult animals, the amount of cartilage did not make any difference with regard to the mandibular measurements. Enlargement of the articulating head on the grafted side was recorded in all animals. A morphologic change in the glenoid fossa of growing monkeys with a long cartilage transplant was also noted. CONCLUSIONS: The findings of this investigation indicate that depending on the amount of cartilage in a unilateral CCG, a tissue-separating force is generated in growing monkeys, capable of propelling the mandible to the unoperated side. This gradual overgrowth occurs during the entire growth period, indicating a strong hormonal and growth factor influence on the growth process. Jaw function may have an effect on the articulating surface of the CCG, seen as enlarged articulating head on the grafted side in all animals.     

Primary structure of mouse and rat nephrin cDNA and structure and expression of the mouse gene

Nephrin is a central component of the glomerular podocyte slit diaphragm and is essential for the normal renal filtration process. This study describes the complete structure of the mouse nephrin gene, which was shown to be homologous to the human gene, the major difference being 30 exons in the mouse gene as opposed to 29 in human. The complete primary structure of mouse and rat nephrins was also determined. The sequence identity between the mouse and rat proteins was shown to be 93%, while both rodent proteins have only about 83% sequence identity with human nephrin. The availability of the three mammalian sequences is significant for the interpretation of sequence variants and mutations in the nephrin gene in patients with congenital nephrotic syndrome. In situ hybridization analyses of whole mouse embryos and tissues revealed high expression of nephrin in kidney glomeruli and, surprisingly, an intense and highly restricted expression in a set of cells in hindbrain and spinal cord. No expression was observed elsewhere. This expression pattern may explain occasionally occurring neural symptoms caused by inactivating mutations in the nephrin gene in patients with congenital nephrotic syndrome.     

Comparison of effects of nicotinic acid or tryptophan on tryptophan 2,3-dioxygenase in acute and chronic studies

Tryptophan is one of the strongest activators of tryptophan 2,3-dioxygenase, the rate-limiting enzyme in the pathway which degrades tryptophan. One of the metabolites thus formed is nicotinic acid, widely administered as a drug--often at high doses--and a vitamin. This study determined whether nicotinic acid also has a potency to activate tryptophan 2,3-dioxygenase and, if so, by what mechanism, whether changes in plasma tryptophan result, and if such activation is permanent. The results showed that nicotinic acid activated the enzyme almost as strongly as tryptophan. The results confirmed the activation to be of the "substrate" type, i.e., at least partly due to increased tryptophan concentrations in the liver. In repeated nicotinic acid administration plasma tryptophan levels did not diminish, despite the high activation of tryptophan 2,3-dioxygenase (high flux of tryptophan through the kynurenine pathway). However, the activation disappeared after 11 days of treatment. The powerful and sustained activation of tryptophan 2,3-dioxygenase by nicotinic acid may at least partly explain some of its side effects, such as glucose intolerance. However, mental disturbance as a side effect of diminished brain levels of tryptophan is not supported by these findings.     

Weak smoking cessation awareness in primary health care before surgery: a real-world,retrospective cohort study

Abstract

Objective: Tobacco smoking is a well-established risk factor for postoperative complications. Research on preoperative smoking cessation in primary health care is scarce.

Design: This was a retrospective cohort study.

Setting: The Stop Smoking before Surgery Project (SSSP) started in Porvoo, Finland, in May of 2016, involving both primary health care and specialized health care. The goals of the project were smoking awareness and preoperative smoking cessation.

Subjects: Our study involved 1482 surgical patients operated at Porvoo Hospital between May and December of 2016.

Main outcome measures: We studied the recording of smoking status in all patients, and ICD-10 diagnosis of nicotine dependency and the initiation of preoperative smoking cessation in current smokers. Variables were studied from electronic patient records, comparing primary health care referrals and surgical outpatient clinic records.

Results: Smoking status was visible in 14.2% of primary health care referrals, and in 18.4% of outpatient clinic records. Corresponding rates for current smokers (n?=?275) were 0.0 and 8.7% for ICD-10 diagnosis of nicotine dependence, and 2.2 and 15.3% for initiation of preoperative smoking cessation. The differences between primary health care referrals and outpatient clinic records were statistically significant for all three variables (p?≤?.001).

Conclusion: In primary health care, very little attention was paid to preoperative smoking cessation. Rates were significantly better at the surgical outpatient clinic, but still low. We could not demonstrate any certain effect of the intervention. Our results call for future research on ways to improve smoking cessation rates.

• Key points

• Tobacco smoking is a well-established risk factor for postoperative complications. Research on preoperative smoking cessation in primary health care is scarce.

• We found weak smoking awareness and weak smoking cessation intervention numbers among both primary and specialized health care doctors. Our results indicate an urgent need for an efficient preoperative smoking cessation model involving both primary and specialized health care.

     

The dorsal raphe nucleus—From silver stainings to a role in depression

Over a hundred years ago, Santiago Ramón y Cajal used a new staining method developed by Camillo Golgi to visualize, among many other structures, what we today call the dorsal raphe nucleus (DRN) of the midbrain. Over the years, the DRN has emerged as a multifunctional and multitransmitter nucleus, which modulates or influences many CNS processes. It is a phylogenetically old brain area, whose projections reach out to a large number of regions and nuclei of the CNS, particularly in the forebrain. Several DRN-related discoveries are tightly connected with important events in the history of neuroscience, for example the invention of new histological methods, the discovery of new neurotransmitter systems and the link between neurotransmitter function and mood disorders. One of the main reasons for the wide current interest in the DRN is the nucleus' involvement in depression. This involvement is particularly attributable to the main transmitter of the DRN, serotonin. Starting with a historical perspective, this essay describes the morphology, ascending projections and multitransmitter nature of the DRN, and stresses its role as a key target for depression research.     

Proton transfer ratio,lactate, and intracellular pH in acute cerebral ischemia

The amide proton transfer ratio (APTR) from the asymmetry of the Z‐spectrum was determined in rat brain tissue during and after unilateral middle cerebral artery occlusion (MCAo). Cerebral lactate (Lac) as determined by ¹H NMR spectroscopy, water diffusion, and T_1ρ were quantified as well. Lac concentrations were used to estimate intracellular pH (pH_i) in the brain during the MCA occlusion. A decrease in APTR during occlusion indicated acidification from 7.1 to 6.79 ± 0.19 (a drop by 0.3 ± 0.2 pH units), whereas pH_i computed from Lac concentration was 6.3 ± 0.2 (a drop by 0.8 ± 0.2 pH units). Despite the disagreement between the two methods in terms of the size of the change in the absolute pH_i during ischemia, ΔAPTR and pH_i (and Lac concentration) displayed a strong correlation during the MCAo. Diffusion and T_1ρ indicated cytotoxic edema following MCA occlusion; however, APTR returned slowly toward the values determined in the contralateral hemisphere post‐ischemia. These data argue that the APTR during ischemia is affected not only by pH_i but by other physicochemical factors as well, and indicates different aspects of pathology in the post‐ischemic brain compared to those that influence water diffusion and T_1ρ. Magn Reson Med 57:647–653, 2007. © 2007 Wiley‐Liss, Inc.