In vitro evaluation of Saccharomyces cerevisiae cell wall fermentability using a dog model.

Six Saccharomyces cerevisiae cell wall samples were tested by the in vitro gas production technique using dog faeces as inoculum. In particular, the substrates resulted from three different production processes (alcoholic_A, bakers_BA and brewers_BR) and were characterized by two different carbohydrates (mannans + glucans) concentrations nitrogen-free extract (NFE high and low). Gas production of fermenting cultures was recorded for 72 hr to estimate the fermentation profiles. The organic matter degradability (OMD), fermentation liquor pH, short-chain fatty acids (SCFA) and ammonia (NH3 ) productions were also measured. All substrates presented a high percentage of OMD (>92%) and moderate fermentability in terms of cumulative volume of gas related to incubated OM (OMCV >50 ml/g) and short-chain fatty acids production (>25 mmol/g), proving their functional properties. Comparing the substrates, it seems evident that the production process affects the chemical composition of the yeast cell wall in terms of crude protein, ether extract and ash content. Consequently, the in vitro fermentation process was significantly different among substrates for volume of gas, SCFA and ammonia production. Regarding the fermentation rate profiles, the production process influenced mainly the curve shape, whereas the NFE concentration affected the quantity of gas produced per hour. In particular, both S. cerevisiae_BR showed very high percentage of OM degradability, gas and SCFA productions and a fast fermentation process due to their high content of fermentable carbohydrates. On the contrary, both S. cerevisiae_BA yeast cell walls appeared to be less degradable and fermentable, probably due to their high content of ether extract. Regarding both S. cerevisiae_A, the high protein content of these substrates could explain the contrasting in vitro results (high degradability with low gas and SCFA production).

Impact of macronutrient composition and palatability in wet diets on food selection in cats.

Cats are obligate carnivores adapted to high-protein diets, but are commonly fed diets rich in carbohydrate. The aim of this study was to examine the food intake choices of cats when diets with different protein and carbohydrate contents were offered. Thirty-nine cats participated in voluntary dietary intake studies. Four foods were formulated to provide between 24% and 53% of metabolizable energy as protein, between 43% and 11% as carbohydrate and holding dietary fat constant with a contribution of approximately 36%. Foods were offered either singly to evaluate voluntary food intake or in pairs to compare food intake between pairs of diets. Cats regulated their macronutrient intake to attain an overall diet composition that provided 53% of metabolizable energy as protein, 11% as carbohydrate and 36% as fat. The protein contribution corresponded to approximately 6 g of protein/kg body weight/day. High-protein/low-carbohydrate diets were always eaten preferentially over low-protein/high-carbohydrate foods. When low-protein/high-carbohydrate diets were offered, cats limited their food intake to limit daily carbohydrate intake to less than 3 g of carbohydrate/kg body weight. This carbohydrate ceiling may limit protein and even energy intake when only low-protein/high-carbohydrate diets were offered. The inclusion of palatability enhancer in the diets increased food intake but did not change protein or carbohydrate intake patterns, indicating that macronutrient intake can be regulated regardless of the use of palatability enhancers in cats. We conclude that cats can discriminate between diets based on macronutrient composition and regulate their intake to maintain maximal protein intake but limit carbohydrate intake.

Endoscopic transnasal resection of an Os odontoideum with preservation of the atlas: a short anatomic report.

We present a short anatomic report on the feasibility of an endoscopic resection of an Os odontoideum, with preservation of the anterior arch of the atlas.

"Shave" biopsy of the optic nerve in isolated neurosarcoidosis.

We report a case of isolated central nervous system sarcoidosis, limited to the optic nerve, characterized by negative systemic work up and neuroradiological features consistent with both optic sheath meningioma and optic nerve glioma. A magnetic resonance imaging examination revealed a dural tail sign associated with a diffuse enhancement and enlargement of the optic nerve. Both positive laboratory findings and systemic manifestation of sarcoidosis or autoimmune diseases were absent. Because of progressive visual loss, tissue confirmation was sought and the optic nerve itself biopsied after non-diagnostic dural samplings. The approach to this was to perform a "shave" biopsy of the optic nerve within its intracranial compartment. This procedure spared the central macular fibers and was not associated with loss of vision. The use of the fiber-sparing "shave" biopsy provided diagnostic samples containing non-caseating granulomas, without compromising the patient's preoperative central visual field. The authors advocate the use of this simple and safe technique when a definitive diagnosis among optic nerve meningioma, optic nerve glioma and isolated neurosarcoidosis cannot be reached by means of less invasive procedures.

Fiberscopic fenestration and prophylactic stenting of periaqueductal cysts: technical report on three cases.

The authors report on three consecutive cases of periaqueductal cysts, causing non-communicating hydrocephalus, successfully treated with endoscopic fenestration and aqueductal stenting. Navigation and cyst fenestration were accomplished using a slim (1.1 mm outside diameter) optic fiberscope inserted via a pre-coronal-paramedian burr hole. Third ventriculostomy was also performed after cyst fenestration in two cases. Because of the lack of data regarding such lesions and the possible recurrence with simple fenestration, an aqueductal stent connected to a subcutaneous reservoir was placed, in all 3 cases, under direct visualization. Average duration of the procedure was less than sixty minutes and there were no intra- or perioperative complications. All patients recovered clinically and their postoperative neuroimaging assessment confirmed a decrease in size of both the ventricular system and cyst (mean follow-up: 6.8 months). The authors conclude than this minimally invasive procedure is a promising, safe and effective method to treat cerebral symptomatic periaqueductal cysts and associated non-communicating hydrocephalus.

Posterior fossa meningiomas: surgical experience in 161 cases.

BACKGROUND: We report the clinical, radiological, and surgical findings of patients with posterior fossa meningiomas surgically treated at our institution over the last 6 years. METHODS: We reviewed 161 consecutive cases of posterior fossa meningiomas operated on between April 1993 and April 1999 at The George Washington University Medical Center. RESULTS: There were 128 female and 33 male patients (mean age 47 years, range of 10-81 years). Meningiomas were classified as petroclival (110 cases), foramen magnum (21 cases), cerebellar hemispheric, lateral tentorial (14 cases), cerebellopontine angle (9 cases), and jugular foramen (7 cases). Mean tumor equivalent diameter (TED) = (D1xD2xDE)(1/3) was 3.1 cm (range of 0.53-8.95). Head pain (50% of cases) and disturbance of gait (44%) were the most common presenting symptoms, and cranial neuropathies the most common neurological signs on admission. Mean preoperative performance status (Karnofsky scale) was 80.2 (range 40-100). Surgical approaches to these tumors included partial labyrinthectomy petrous apicectomy, fronto-temporal/fronto-temporal orbitozygomatic osteotomy, retrosigmoidal, extreme lateral, transpetrosal, and combined. In 38 cases a staged procedure was performed. Gross-total resection was achieved in 57% of patients, and subtotal/partial in 43%. Surgical mortality was 2.5% and complications were encountered in 41% of patients. Postoperative CSF leak occurred in 22 cases (13.6%). The mean follow-up was 19 months, ranging from 0.2 to 63.6, and the mean performance status of patients with a follow-up of at least 12 months was 77 (range of 40-100). Recurrence or progression of disease was found in 13.7% of cases (follow-up 2 years or more). CONCLUSION: Our experience suggests that although posterior fossa meningiomas represent a continuing challenge for contemporary neurosurgeons, such tumors may be completely or subtotally removed with low rate of mortality and acceptable morbidity, allowing most of these patients to achieve a good outcome in a long-term follow-up.

Estimation of dietary intake of pesticide residues by the Italian population during 1997.

In 1997 the Italian monitoring programme for pesticide residues in food comprised 7951 samples of 152 different foods for which a total of 275 pesticides were analysed. For 90 pesticides, the National Estimated Daily Intakes (NEDIs) were calculated by using the 90th percentile value and the food consumption data for the general Italian population. The calculated NEDIs were found to represent only a small portion of the respective Acceptable Daily Intake (ADI).