Descending necrotising mediastinitis: two case reports and review of the literature

Descending necrotising mediastinitis is a rare and serious infection with a high mortality rate, which complicates pharyngeal or odontogenic infection. Early recognition and treatment are essential in order to minimise morbidity. Evaluation with computed tomography is necessary to confirm the diagnosis and facilitate surgical planning. In addition to prompt empirical antibiotic therapy, surgical intervention is necessary in nearly all cases. Surgical drainage and debridement may be performed through cervicotomy alone, or through combined cervicotomy and thoracotomy, depending upon the extent of disease. Hyperbaric oxygen therapy may play an auxiliary role. We present two recent cases with characteristic imaging findings, and review the relevant literature.

Lack of transmission of porcine circovirus type 2 to weanling pigs by feeding them spray-dried porcine plasma

An experiment was conducted to determine whether spray-dried porcine plasma containing 2.47 x 10(5) dna copies of porcine circovirus type 2 (pcv-2) could infect weanling pigs when fed to them. Five specific pathogen-free (spf) weanling pigs were fed ad libitum for 45 days a control diet and six pigs were fed a test diet containing 8 kg sdpp per 100 kg feed. The two groups were housed in separate biosecurity level-3 rooms. None of the pigs in either group developed any clinical signs or became pcv-2 viraemic or seroconverted.

Effects of Visual and Auditory Short-Term Memory Tasks on the Spatiotemporal Dynamics and Variability of Postural Sway

The authors measured postural sway while participants (N = 20 in each experiment) stood on a rigid or a compliant surface, with their eyes open or closed, and while they did or did not perform a short-term memory (STM) task. In Experiment 1, the STM stimuli were presented visually; in Experiment 2, the stimuli were presented auditorily. In both experiments, fine-scaled, mediolateral postural-sway variability decreased as the cognitive load imposed by the STM task increased. That effect was independent of support surface and vision manipulations. The spatiotemporal profile of postural sway was affected by both visual and auditory STM tasks, but to a greater degree by the auditory task. The authors discuss implications of the results for theories and models of postural control.

Utilization of spray-dried blood cells and crystalline isoleucine in nursery pig diets1

Three experiments were conducted to evaluate spray-dried blood cells (SDBC) and crystalline isoleucine in nursery pigs. In Exp. 1, 120 pigs were used to evaluate 0, 2, 4, and 6% SDBC (as-fed basis) in a sorghum-based diet. There were six replicates of each treatment and five pigs per pen, with treatments imposed at an initial BW of 9.3 kg and continued for 16 d. Increasing SDBC from 0 to 4% had no effect on ADG, ADFI, and G:F. Pigs fed the 6% SDBC diet had decreased ADG (P < 0.01) and G:F (P = 0.06) compared with pigs fed diets containing 0, 2, or 4% SDBC. In Exp. 2, 936 pigs were used to test diets containing 2.5 or 5% SDBC (as-fed basis) vs. two control diets. There were six replicates of each treatment at industry (20 pigs per pen) and university (six pigs per pen) locations. Treatments were imposed at an initial BW of 5.9 and 8.1 kg at the industry and the university locations, respectively, and continued for 16 d. Little effect on pig performance was noted by supplementing 2.5% SDBC, with or without crystalline Ile, in nursery diets. Pigs fed the 5% SDBC diet without crystalline Ile had decreased ADG (P < 0.01), ADFI (P < or = 0.10), and G:F (P < 0.05) compared with pigs fed the control diets. Supplementation of Ile restored ADG, ADFI, and G:F to levels that were not different from that of pigs fed the control diets. In Exp. 3, 1,050 pigs were used to test diets containing 5, 7.5, or 9% SDBC (as-fed basis) vs. a control diet. There were six replicates of each treatment at the industry (20 pigs per pen) location and five replicates at the university (six pigs per pen) locations. Treatments were imposed at an initial BW of 6.3 and 7.0 kg at the industry and university locations, respectively, and continued for 16 d. Supplementation of 5% SDBC without crystalline Ile decreased ADG and G:F (P < 0.01) compared with pigs fed the control diet, but addition of Ile increased ADG (P < 0.01) to a level not different from that of pigs fed the control diet. The decreased ADG, ADFI, and G:F noted in pigs fed the 7.5% SDBC diet was improved by addition of Ile (P < 0.01), such that ADG and ADFI did not differ from those of pigs fed the control diet. Pigs fed diets containing 9.5% SDBC exhibited decreased ADG, ADFI, and G:F (P < 0.01), all of which were improved by Ile addition (P < 0.01); however, ADG (P < 0.05) and G:F (P = 0.09) remained lower than for pigs fed the control diet. These data indicate that SDBC can be supplemented at relatively high levels to nursery diets, provided that Ile requirements are met.

Sinusoidal spread of liver metastases from renal cell carcinoma: simulation of diffuse liver disease on MR imaging

Rarely, hepatic metastases can simulate hepatic infiltrative diseases. We present a case of a patient with advanced metastatic renal cell carcinoma who developed hepatomegaly and clinical signs of hepatocellular injury. On magnetic resonance imaging, the injury simulated a diffuse process, e.g., acute fulminant viral or chemical hepatitis or drug toxicity. Despite its high resolution, magnetic resonance imaging might not depict focal lesions in patients with extensive metastases. In correlation with clinical history, malignant disease should be considered when diffusely abnormal hepatic signal intensity is noted.

Diffuse desmoplastic breast carcinoma metastases to the liver simulating cirrhosis at MR imaging: report of two cases

Two patients with breast carcinoma, without a prior diagnosis of liver lesions, had proved desmoplastic hepatic metastases that resembled cirrhosis at magnetic resonance (MR) imaging. The cirrhotic appearance of the livers may have resulted from the hepatotoxic effects of chemotherapy and/or hepatic infiltration by the metastatic tumor itself. Despite its high soft-tissue contrast, MR imaging may fail to depict extensive metastases from breast carcinoma, especially when they simulate other diseases (eg, cirrhosis). Correlation of MR imaging findings with clinical history is mandatory.

Anxiety as a predictor of response to interpersonal psychotherapy for recurrent major depression: an exploratory investigation

Major depression and anxiety frequently co-occur, but the implications for psychological treatments have rarely been studied. We examined predictors of acute response to interpersonal psychotherapy in 134 consecutively treated female outpatients with recurrent unipolar depression. Women who failed to remit with interpersonal psychotherapy alone experienced higher levels of somatic anxiety, were more likely to meet criteria for lifetime panic disorder, were more likely to meet criteria for nonendogenous or nonmelancholic depression, and reported greater vocational impairment, higher levels of global severity, a longer duration of the index episode, and, somewhat surprisingly, lower levels of social impairment at pretreatment evaluation. A series of backwards stepping logistic regression analyses showed higher levels of baseline somatic anxiety and social functioning to be the most consistent predictors of nonresponse. Our findings strengthen existing evidence that concomitant anxiety can adversely affect the outcome of interpersonal therapy for depression.

Dietary plasma protein is used more efficiently than extruded soy protein for lean tissue growth in early-weaned pigs

We compared the effects of supplementing either animal plasma or extruded soy protein in the diet based on the efficiency of dietary protein utilization for lean tissue growth in early-weaned pigs. Twenty-four 14-d-old pigs (4 kg body weight) were pair-fed (per kg body weight) either a control diet containing extruded soy protein (C; n = 12) or a diet with 10% animal plasma (P; n = 12) for 24 d. During the 24 days, protein intake was not different, yet mean daily body weight gains (+23%) and food conversion efficiencies (expressed as the ratio of body weight gain to protein intake) (+19%) were greater (P < 0.05) in the P group than in the C group. Lean body mass measured after 24 d, using both dual-energy X-ray absorptiometry and total body potassium analysis, was significantly (P < 0.05) greater (approximately 16%) in P than in C pigs. The circulating urea concentrations were 40% lower (P < 0.05) in P than in C pigs. Our results demonstrate that supplementing early-weaned pig diets with animal plasma rather than extruded soy protein increased the efficiency of dietary protein use for lean tissue growth and that this response is mediated in part by decreased amino acid catabolism.

Septin-dependent assembly of a cell cycle-regulatory module in Saccharomyces cerevisiae

Saccharomyces cerevisiae septin mutants have pleiotropic defects, which include the formation of abnormally elongated buds. This bud morphology results at least in part from a cell cycle delay imposed by the Cdc28p-inhibitory kinase Swe1p. Mutations in three other genes (GIN4, encoding a kinase related to the Schizosaccharomyces pombe mitotic inducer Nim1p; CLA4, encoding a p21-activated kinase; and NAP1, encoding a Clb2p-interacting protein) also produce perturbations of septin organization associated with an Swe1p-dependent cell cycle delay. The effects of gin4, cla4, and nap1 mutations are additive, indicating that these proteins promote normal septin organization through pathways that are at least partially independent. In contrast, mutations affecting the other two Nim1p-related kinases in S. cerevisiae, Hsl1p and Kcc4p, produce no detectable effect on septin organization. However, deletion of HSL1, but not of KCC4, did produce a cell cycle delay under some conditions; this delay appears to reflect a direct role of Hsl1p in the regulation of Swe1p. As shown previously, Swe1p plays a central role in the morphogenesis checkpoint that delays the cell cycle in response to defects in bud formation. Swe1p is localized to the nucleus and to the daughter side of the mother bud neck prior to its degradation in G(2)/M phase. Both the neck localization of Swe1p and its degradation require Hsl1p and its binding partner Hsl7p, both of which colocalize with Swe1p at the daughter side of the neck. This localization is lost in mutants with perturbed septin organization, suggesting that the release of Hsl1p and Hsl7p from the neck may reduce their ability to inactivate Swe1p and thus contribute to the G(2) delay observed in such mutants. In contrast, treatments that perturb actin organization have little effect on Hsl1p and Hsl7p localization, suggesting that such treatments must stabilize Swe1p by another mechanism. The apparent dependence of Swe1p degradation on localization of the Hsl1p-Hsl7p-Swe1p module to a site that exists only in budded cells may constitute a mechanism for deactivating the morphogenesis checkpoint when it is no longer needed (i.e., after a bud has formed).

Dietary plasma protein reduces small intestinal growth and lamina propria cell density in early weaned pigs

ABSTRACT We quantified the effects of a diet containing animal plasma protein on small intestinal growth and mucosal morphology in early weaned pigs. Ninety-six pigs [14 d old, 4 kg body weight (BW)] were assigned in groups of 32 to three dietary treatments as follows: 1) free access to control diet (C), 2) free access to plasma protein diet (P), and 3) plasma protein, pair-fed to C (PPF). Eight pigs from each group were killed at 2, 4, 8 or 16 d. Over a 16-d period, weight gain in the P group was 43% greater (P < 0.05) than that in C pigs; weight gain was similar in C and PPF groups. Protein intake in the P group was 33% higher (P < 0.05) than that in the PPF group; no significant difference was observed between the C and P groups. Dietary protein conversion efficiencies in both the P and PPF groups were approximately 18% greater (P < 0.05) than those in the C group. Intestinal masses in the three groups did not differ at 2, 4 and 8 d. By 16 d, the jejunal and ileal protein and DNA masses (mg/kg BW) in both the P and PPF groups were lower than those in the C group (P < 0.05). Dietary plasma protein did not affect crypt cell proliferation, crypt depth or villous height in either the jejunum or ileum. However, the intravillous lamina propria cell density in the jejunum was significantly lower (P < 0.05) in P and PPF pigs than in C pigs. Plasma urea concentrations were also 40 and 42% lower (P < 0.05) in the P and PPF groups, respectively, than in the C group. Our results indicate that dietary plasma protein reduces the cellularity of the lamina propria, but not epithelial cell surface of the small intestine. Feeding plasma protein also increased the efficiency of dietary protein utilization, in part, by decreasing amino acid catabolism.

Effect of supplemental sodium chloride and hydrochloric acid added to initial starter diets containing spray-dried blood plasma and lactose on resulting performance and nitrogen digestibility of 3-week-old weaned pigs

Four experiments evaluated the efficacy of Na or Cl or their combination added to weanling pig diets that contained plasma protein and lactose on pig performance and N digestibility. The four experiments used a total of 563 crossbred pigs weaned at 22+/-1 d of age averaging 6.4 kg body weight. The basal diet in each experiment contained 5.8% plasma protein and 20% lactose and analyzed .20% Na and .23% Cl. In Exp. 1, NaCl was added to treatment diets at 0, .20, .40, or .60%. The trial was conducted for a 21 d period in a randomized complete block (RCB) design in seven replicates. Improved growth rates (P < .01) and gain:feed ratios (P < .01) occurred up to a dietary salt level of .40%. In Exp. 2, we evaluated the interaction of Na and Cl on pig performance. The experiment was a 2 x 2 factorial arrangement in a RCB design conducted in seven replicates. Total dietary Na was .20 or .36%, and Cl was included at .25 or .45%. Although there was a numerical increase in pig gains with added Na, the response was not significant (P > .15), but both gains (P < .01) and gain:feed ratios (P < .01) increased at the higher dietary Cl level. In Exp. 3, we evaluated the effect of five dietary levels of Cl added at .06% increments to a basal diet that analyzed .34% Na and .20% Cl on postweaning pig performance. The experiment was a RCB design conducted in eight replicates. A growth response (P < .01) to the .38% Cl level occurred during the initial 14-d postweaning period and to the .32% Cl level from 14 to 21 d. Gain:feed ratio increased each week with added Cl, but it was significant only for the period from d 0 to 7 d (P < .01). A N digestibility trial, using the diets of Exp. 3, constituted Exp. 4, and groups of three pigs per stainless steel metabolism crate were pair-fed to pigs fed the basal diet. The experiment was a RCB design conducted in three replicates over a 3-wk period. The results demonstrated a weekly decrease in fecal N (P < .01), no effect on urinary N (P < .15), improved N retention (P < .01), and an improved apparent N digestibility (P < .01) to the .38% dietary Cl concentration during the initial 2 wk postweaning. These experiments suggest that although plasma protein contributed Na and Cl to the initial diets of weaned pigs, additional Na and Cl, but particularly Cl, improved pig growth, N retention, and N digestibility. The results suggest a dietary minimum of .38% total Cl level during the initial 2 wk postweaning.

Cervical prevertebral soft-tissue measurements and chest radiographic findings in acute traumatic aortic injury

Acute traumatic aortic injury (ATAI) results in several characteristic chest radiographic findings, most notably mediastinal widening. This study was based on the hypothesis that blood or fluid in the widened mediastinum might track up into the neck and be detected on lateral cervical radiographs. In a blinded, retrospective, case-control review of radiology files, 13 consecutive adult cases of ATAI were identified and compared with 19 cases of negative aortography (NAO) and 18 multiple trauma victims (MT) without aortography. Cases with inadequate cervical films or cervical injury were excluded. Measurements included the cervical soft-tissue (ST) width at the third (C3) and sixth (C6) cervical vertebrae, mediastinal width, mediastinal-chest width ratio, and the presence of several characteristic chest radiograph findings of ATAI. The C3 ST measurements averaged 9.1 +/- 2.8 mm, 8.5 +/- 2.7 mm, and 6.9 +/- 2.2 mm for the ATAI, NAO, and MT groups, respectively. The C6 ST measurements averaged 19.2 +/- 4.5 mm, 18.6 +/- 3.9, and 16.5 +/- 3.8 mm for the ATAI, NAO, and MT groups, respectively. These cervical ST values were not significantly different between groups at either C3 (P = .188) or C6 (P = .148). The incidence of abnormal ST swelling of >7 mm at C3 was 38%, 53%, and 33% for the ATAI, NAO, and MT groups, respectively. The incidence of abnormal ST swelling of >20 mm at C6 was 54%, 42%, and 11% for the ATAI, NAO, and MT groups, respectively. Cervical ST measurements at C3 or at C6 did not correlate with mediastinal-chest width ratios. Mediastinal widening, aortopulmonic window opacification, and blurring of the aortic knob were the most sensitive chest radiography findings in ATAI, although each of these lacked useful specificity and accuracy. Cervical ST swelling is not a useful marker for ATAI.

Screening tests for pathogenic corynebacteria

AIM

To provide simple tests that would help in the identification of corynebacteria that produce diphtheria toxin.

METHODS

A collection of 99 freshly isolated corynebacteria was assembled and the cultures identified by conventional tests confirmed by an identification kit. Modifications were made to procedures for preparation of the culture medium for the Elek test and to the test for detection of pyrazinamidase (pyrazine carboxylamidase) activity. These two together with an indicator medium for cystinase activity were applied to the collection of organisms.

RESULTS

Cystinase was detected in all 61 members of the toxigenic species and none produced pyrazinamidase. In contrast, all but two of the 38 representatives of non-toxigenic species yielded pyrazinamidase and none formed cystinase. Of the 61 cystinase producing cultures (which were also pyrazinamidase negative), 21 gave a positive Elek test with the modified culture medium. A total of 30 of these 61 were tested for toxigenicity in guinea pigs and the results of the animal and plate tests concorded. At least seven cultures could have been reported as non-toxigenic if Elek tests based on media prepared in the conventional way had been the only test available.

CONCLUSION

The three procedures described go some way towards meeting the needs of diagnostic laboratories for efficient procedures for distinguishing pathogenic corynebacteria.

Vitamin D metabolism, mineral homeostasis, and bone mineralization in term infants fed human milk, cow milk-based formula, or soy-based formula

The purpose of this study was to evaluate mechanisms of mineral homeostasis and mineralization in term infants with recommended vitamin D intakes. Infants fed human milk (nine), cow milk-based formula (11), or soy-based formula (11) were studied at 2 weeks and at 2, 4, 6, 9, and 12 months of age. While receiving 400 IU of vitamin D, all infants maintained serum vitamin D concentrations higher or equal to normal adult concentrations, and serum 25-hydroxyvitamin D levels were maintained at or above normal adult levels. Serum 1,25-dihydroxyvitamin D concentrations were higher than those of adults in the formula-fed but not in the human milk-fed infants. Serum calcium and phosphorus values were similar in all groups; however, urine phosphorus excretion and urine calcium excretion were adjusted to intakes. Serum parathyroid hormone values were normal in all groups. Bone mineral content significantly increased with age similarly in all groups; however, an apparent plateau occurred at 6 months of age in all groups. Bone width steadily increased with age. Taken as a whole, these data suggest that the vitamin D-sufficient term infant fed human milk, cow milk-based formula, or the soy-based formula studied can regulate mineral metabolism within acceptable physiologic limits to attain similar levels of serum minerals and bone mineral content.

Pregnancy outcome in women with reflux nephropathy--a review of experience at the Royal Women's Hospital Brisbane, 1977-1986

The outcome of pregnancy was examined, retrospectively, in women with a diagnosis of reflux nephropathy attending The Royal Women's Hospital from January, 1977 to August, 1986. Of 15 women, 10 were known to have had the disease antepartum and 5 were diagnosed postpartum. On the basis of plasma creatine concentration prior to pregnancy, 10 patients had 22 pregnancies with normal renal function and 5 patients had 7 pregnancies with plasma creatinine concentrations ranging from 0.12 to 0.17 mmol/l. The pregnancies of the women with normal renal function were complicated by urinary tract infections, while those with impaired renal function were associated with preeclampsia. The perinatal mortality for both groups were zero. A relatively low incidence of vesicoureteric reflux was found in 12 of the offspring who were subjected to micturating cystourethrography (mild reflux in 1 of 24 ureters).