Characterization of Kluyveromyces marxianus as a potential feed additive for ruminants

AIM

The aim of this study was to find suitable yeast isolates as potential microbial feed additives for ruminants.

METHODS AND RESULTS

Yeast isolates from traditional fermented food (tapai) and home-made wine were selected based on their tolerance to volatile fatty acids (VFA) mixture of acetic, propionic and butyric acids and to pH and temperature according to the rumen condition. The ability to grow in and produce ethanol was determined in yeast extract peptone glucose broth supplemented with a VFA mixture (VFA-YEPG medium). Fifty-five isolates showed OD(660 nm) values between 0.35-0.6, and 27 isolates showed ethanol production in the range of 0.17-0.30% (v/v). All selected isolates were identified as Kluyveromyces marxianus base on biochemical tests (BioLog kit; Biolog Inc., Hayward, CA) and molecular techniques. The best isolate in terms of ethanol production (K. marxianus WJ1) significantly (P < 0.01) improved in vitro apparent dry matter (DM) digestibility of alfalfa (Medicago sativa), guinea grass (Panicum maximum) and timothy (Phleum pretense) hay by rumen microbes.

CONCLUSION

Yeast isolates from tapai and wine were able to grow in VFA-YEPG medium, and K. marxianus WJ1 improved in vitro DM digestibility of plant substrates.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study indicated the possibility of using K. marxianus as a microbial feed additive.

Mammographically non-calcified ductal carcinoma in situ: sonographic features with pathological correlation in 35 patients

AIM

To present the sonographic findings of mammographically non-calcified ductal carcinoma in situ (DCIS) with histopathologic correlation.

MATERIALS AND METHODS

The mammographic and ultrasonographic presentations of 47 radiographically non-calcified DCIS lesions in 35 patients were retrospectively analysed. Histological characteristics (architectural appearance, nuclear grade, percent of involved lobules, and presence of necrosis) were reviewed.

RESULTS

Seventeen lesions were not mammographically visible (17/47, 36%). Ultrasonographically, these lesions showed an irregular shape (28/47, 60%), microlobulated margins (34/47, 72%) and abrupt interfaces (42/47, 90%). Only 11% (5/47) displayed posterior shadowing. The echotexture of these lesions was most frequently complex (29/47, 62%); therefore, they were divided into two types: type I (24 cases), which were predominantly solid with cystic components, and type II (five cases), which were predominantly cystic with a solid intra-cystic component. A trend to have greater than 50% DCIS cells in cancerous lobules was observed in masses displaying type I echotexture (difference=36%, 95% confidence interval 10.6-62.5) and microlobulated margins (difference=32%, 95% confidence interval 5.1-58.7).

CONCLUSION

Ultrasonographically detected radiographically non-calcified DCIS commonly displays an irregular shape, microlobulated margins, and complex echotexture, giving a "pseudomicrocystic" appearance. Microlobulated margins and "pseudomicrocystic" echotexture seem to be associated with a cancerization of the lobules.

Short stature: increased in children with severe learning disability

INTRODUCTION

'Health for all children' recommends that children should be screened for growth disorders at school entry with a 0.4th centile 'cut-off'. Following the diagnosis of growth hormone deficiency in four children attending local special schools, our aim was to compare the height distribution of children attending special schools with mainstream schools.

METHODS

Children at two local special schools were measured using a Leicester height measurer and values converted to standard deviation scores (SDS). Children were categorized according to whether there were known factors that could affect height. The data were compared with those collected from local mainstream schools.

RESULTS

In total, 242 children were registered at the two special schools and 192 children were measured. The mean height SDS of children in mainstream school (n = 2301) was similar to national standards at -0.09 (SD 1.02). The mean height SDS distribution of the 192 children in special schools (age range 3.2-18.4 years; median age 11.3 years) was -0.73; 95%CI -0.9 to -0.5. In those with no established diagnosis to explain altered growth (n = 120) this was -0.613; 95%CI -0.8 to -0.4. Both pre-pubertal (n = 37) and pubertal (n = 83) children were short and eight (6.7%) had a height less than the 0.4th centile.

CONCLUSIONS

Children attending special school with severe or profound learning disability were shorter than those attending mainstream school. This is still the case following the exclusion of children with a known cause for abnormal growth. This underlines the importance of each child being assessed by professionals with a refined knowledge of normal and abnormal growth.

Digestion of rice straw and oil palm fronds by microflora from rumen and termite bacteria, in vitro

The digestion and Volatile Fatty Acid (VFA) production from rice straw and oil palm fronds by cellulolytic bacteria isolated from the termite Coptotermes curvignathus were investigated. The bacteria were Acinetobacter strain Raminalimon, Enterobacter aerogenes strain Razmin C, Enterobacter cloacae strain Razmin B, Bacillus cereus strain Razmin A and Chryseobacterium kwangyangense strain Cb. Acinetobacter strain Raminalimon is an aerobic bacterium, while the other species are facultative anaerobes. There were significant differences (p<0.05) among the bacteria for Dry Matter (DM) lost and acetic acid production from rice straw and Acinetobacter strain Raminalimon showed the highest activity. The facultative bacteria C. kwangyangense strain Cb (cfu mL(-1) 231 x 10(-6), OD: 0.5), E. cloacae (cfu mL(-1) 68 x 10(-7), OD: 0.5) and E. aerogenes (cfu mL(-1) 33 x 10(-7), OD: 0.5) were used for digestion study with the rumen fluid microflora. The in vitro gas production technique was applied for the comparative study and the parameters measured were pH, gas (volume), dry matter lost, acetic acid, propionic acid and butyric acid concentrations. pH was not significantly (p<0.05) different among the five treatments. The bacterium C. kwangyangense strain Cb showed the highest activity (p<0.05) for DM lost, acetic acid, propionic acid and butyric acid production from rice straw when compared to the other bacterial activities. There was no significance (p<0.05) difference between the three bacteria for the dry matter lost of oil palm fronds but the production of Volatile Fatty Acids (VFA) was significantly (p<0.05) high in the treatment which was inoculated with C. kwangyangense strain Cb. The Gen Bank NCBI/EMBL accession numbers for the bacterial strains are EU332791, EU305608, EU305609, EU294508 and EU169201.

Aspiration of Breast Abscess Under Ultrasound Guidance: Outcome Obtained and Factors Affecting Success

OBJECTIVE

To assess ultrasonographically (US) guided needle aspiration of breast abscesses as an alternative to surgical incision and drainage.

METHODS

In our prospective study, 30 patients with 31 breast abscesses (one patient had bilateral breast abscess) underwent percutaneous breast abscess drainage under US guidance with local anaesthesia and oral antibiotics between 1 January 2004 and 31 March 2005. These patients consisted of 16 (53.3%) non-lactating and 14 (46.7%) lactating women, with ages ranging from 18 to 68 years (median, 28 years). The racial distribution comprised 26 (86.7%) Malays, three (10%) Chinese and one (3.3%) Indian. All patients had the chief complaint of breast swelling and 25 (83.3%) had breast pain. Clinically, 28 (93.3%) were found to have a palpable mass. Nine (30%) lesions were in the upper outer quadrant of the left breast. US diameters ranged from 1 to 15 cm (median, 4 cm). The pus volumes varied from 1 to 200 mL (median, 14 mL).

RESULTS

Fifteen (50%) patients required only a single aspiration, 10 required multiple aspirations and five required incision and drainage. Those patients in whom needle aspiration failed had multiloculated lesions irrespective of abscess volume and size.

CONCLUSION

Needle aspiration with ultrasound guidance is an effective treatment for breast abscess irrespective of abscess volume and size.

Influence of β-glucanase-producing Lactobacillus strains on intestinal characteristics and feed passage rate of broiler chickens

Two experiments were conducted to study the effects of beta-glucanase produced by transformed Lactobacillus strains on the intestinal characteristics and feed passage rate of broiler chickens fed barley-based diets. Supplementation of transformed Lactobacillus strains to the diet of chickens significantly (P < 0.05) reduced the intestinal fluid viscosity by 21 to 46% compared with chickens fed an unsupplemented diet or a diet supplemented with parental Lactobacillus strains. The relative weights of pancreas, liver, duodenum, jejunum, ileum, ceca, and colon were reduced (P < 0.05) by 6 to 27%, and the relative length of duodenum, jejunum, ileum, and ceca was reduced (P < 0.05) by 8 to 15%. Histological examination of the intestinal tissues showed that the jejunal villus height of chickens fed a diet supplemented with transformed Lactobacillus strains was significantly (P < 0.05) higher than that of chickens fed other dietary treatments. The transformed Lactobacillus strains were found to reduce (P < 0.05) the time of feed passage rate by 2.2 h. Supplementation of transformed Lactobacillus strains to the diet improved the intestinal characteristics and feed, passage rate of the chickens.

Primary hyperaldosteronism with normokalaemia secondary to an adrenal adenoma (Conn's syndrome) in a 12 year-old boy

A 12-1/2 year-old boy presented to the Accident Department following an episode of dizziness and was found to be hypertensive. Investigations revealed primary hyperaldosteronism secondary to an adrenal adenoma (Conn's syndrome). He had normal electrolytes during the period of investigation and potassium concentrations were > or = 4.2 mmol/l on all but one occasion. The hypertension resolved following excision of the adrenal tumour. Normokalaemia with potassium >4.0 mmol/l is very unusual in patients with Conn's syndrome and has not been described in childhood before. Primary hyperaldosteronism needs to be considered in hypertensive children even when potassium concentrations are well within the laboratory reference range.

Removal of poly-histidine fusion tags from recombinant proteins purified by expanded bed adsorption

Enzymatic methods have been used to cleave the C- or N-terminus polyhistidine tags from histidine tagged proteins following expanded bed purification using immobilized metal affinity chromatography (IMAC). This study assesses the use of Factor Xa and a genetically engineered exopeptidase dipeptidyl aminopeptidase-1 (DAPase-1) for the removal of C-terminus and N-terminus polyhistidine tags, respectively. Model proteins consisting of maltose binding protein (MBP) having a C- or N-terminal polyhistidine tag were used. Digestion of the hexahistidine tag of MBP-His(6) by Factor Xa and HT15-MBP by DAPase-1 was successful. The time taken to complete the conversion of MBP-His(6) to MBP was 16 h, as judged by SDS-PAGE and Western blots against anti-His antibody. When the detagged protein was purified using subtractive IMAC, the yield was moderate at 71% although the overall recovery was high at 95%. Likewise, a yield of 79% and a recovery of 97% was obtained when digestion was performed with using "on-column" tag digestion. On-column tag digestion involves cleavage of histidine tag from polyhistidine tagged proteins that are still bound to the IMAC column. Digestion of an N-terminal polyhistidine tag from HT15-MBP (1 mg/mL) by the DAPase-I system was superior to the results obtained with Factor Xa with a higher yield and recovery of 99% and 95%, respectively. The digestion by DAPase-I system was faster and was complete at 5 h as opposed to 16 h for Factor Xa. The detagged MBP proteins were isolated from the digestion mixtures using a simple subtractive IMAC column procedure with the detagged protein appearing in the flowthrough and washing fractions while residual dipeptides and DAPase-I (which was engineered to exhibit a poly-His tail) were adsorbed to the column. FPLC analysis using a MonoS cation exchanger was performed to understand and monitor the progress and time course of DAPase-I digestion of HT15-MBP to MBP. Optimization of process variables such as temperature, protein concentration, and enzyme activity was developed for the DAPase-I digesting system on HT15-MBP to MBP. In short, this study proved that the use of either Factor Xa or DAPase-I for the digestion of polyhistidine tags is simple and efficient and can be carried out under mild reaction conditions.

Surface properties and microporosity of polyhydroxybutyrate under scanning electron microscopy

This study was designed to investigate the surface properties especially surface porosity of polyhydroxybutyrate (PHB) using scanning electron microscopy. PHB granules were sprinkled on the double-sided sticky tape attached on a SEM aluminium stub and sputtered with gold(10nm thickness) in a Polaron SC515 Coater, following which the samples were placed into the SEM specimen chamber for viewing and recording. Scanning electron micrographs with different magnification of PHB surface revealed multiple pores with different sizes.

The inframammary fold: contents, clinical significance and implications for immediate breast reconstruction

The amount of breast tissue within the inframammary fold (IMF) is controversial. Preservation of the IMF during mastectomy facilitates breast reconstruction and led some surgeons to practice conservation of the IMF, contrary to traditional descriptions of total mastectomy. The aim of this study was to analyse the clinical significance of IMF tissue content. A total of 50 IMF specimens were studied from 42 patients who underwent mastectomy between January 2001 and December 2002. The amount of breast tissue within each IMF was evaluated. The median patient age was 46 (range 33-86) years. The median body mass index was 23.4 (18.1-38.3)kg/m(2). The median IMF volume resected was 2 (0.2-9.7)cm(3) which was 0.6 (0.1-2.0)% of the breast volume. Ten specimens (20%) contained breast tissue and one (2%) contained breast tissue and an inframammary lymph node. Three specimens (6%) containing fibrofatty tissue without breast parenchyma had intramammary lymph nodes within the IMF. One patient (2%) who had a mastectomy for invasive ductal carcinoma had IMF tissue containing a lymph node within the IMF with breast cancer metastasis. The presence of breast tissue or lymph nodes within the IMF was unrelated to patient age, body mass index, the amount of IMF tissue in relation to breast volume and absolute breast size. Our finding that breast tissue and intramammary lymph nodes are present in 28% of IMF specimens requires re-consideration of the safety of preserving the IMF at mastectomy. If IMF tissue is resected and the immediate breast reconstruction is performed, the superficial fascial system should be reconstructed after excision of the IMF tissue in order to recreate the inframammary crease.

Measurement of tumour size in case selection for breast cancer therapy by clinical assessment and ultrasound

AIMS

Clinical assessment of tumour size is often used to choose between mastectomy and primary medical therapy. Clinical and imaging modalities may have varying levels of accuracy across the range of tumour sizes. The aim of this study was to compare the accuracy of clinical measurement and ultrasound in discriminating palpable tumours up to 3 cm vs those greater than 3 cm.

METHODS

A prospective analysis of 111 consecutive patients with palpable breast cancer was performed. All women had clinical measurement by caliper and ultrasound assessment prior to any needle biopsy. Clinical measurement and ultrasound assessment of size were compared to pathological tumour size of the surgical specimen.

RESULTS

Both clinical and ultrasound measurement underestimate the size of larger tumours. The overall accuracy of clinical assessment and ultrasound examination in correctly identifying a 30 mm cut off was 70.3 and 77.5%, respectively. Ultrasound was significantly more accurate at determining the size of tumours <30 mm (p=0.007) but there was no significant difference between both modalities in assessing tumours greater than 30 mm.

CONCLUSIONS

Ultrasound assessment of breast cancer size is more accurate than clinical assessment for tumours less than 30 mm. As clinical examination is as accurate on ultrasound for tumours greater than 30 mm, clinical assessment of tumour size alone is adequate to select patients for primary medical therapy or mastectomy.

Squamous cell carcinoma of the breast: clinico-pathologic implications and outcome

AIMS

Pure squamous cell carcinoma (SCC) of the breast is a rare tumour and little is known about long-term outcome. We report our experience of a consecutive series of patients.

METHODS

All patients with SCC treated at our institution between 1970 and 2001 were included. The pathological features, outcome and prognosis were studied.

RESULTS

Eleven patients were identified. The median age was 55 (38-90) years and median follow-up was 62 (3-332) months. Four tumours were T1, three were T2 and three were T3 (one tumour size was unknown). There were seven poorly differentiated and three moderately differentiated SCC. Tumour grade could not be assessed in one patient. Primary treatment was mastectomy in six patients, wide local excision in four patients and radiotherapy in one patient. There was lymph node (LN) involvement in two patients. Oestrogen receptor status was assessed in seven patients and only one tumour was positive. Adjuvant chemotherapy was given to three patients and five patients received adjuvant radiotherapy. Two patients developed local recurrence at 5 and 12 months and three patients developed distant metastasis at 2, 36 and 306 months. Three patients were treated with chemotherapy at recurrence. Three patients have died of the disease, two are alive with disease and six remain well. The 2- and 5-year overall survival was 80% (SE=13%) and 67% (SE=16%) respectively. Large tumour size and positive LN status were prognostic indicators of poor outcome.

CONCLUSION

SCC of the breast adopts an aggressive course with outcome comparable to poorly differentiated breast adenocarcinoma.

Effects of Lactobacillus cultures on growth performance, abdominal fat deposition, serum lipids and weight of organs of broiler chickens

1. The effects of a mixture of 12 Lactobacillus strains (LC) on the growth performance, abdominal fat deposition, serum lipids and weight of organs of broiler chickens were studied from 1 to 42 d of age. 2. One hundred and thirty-six 1-d-old male broiler chicks were assigned at random to two dietary treatments: a basal diet (control), and a basal diet with 0.1% LC. 3. The supplementation of LC in broiler diets improved the body weight gain and feed conversion rate from 1 to 42 d of age and was effective in reducing abdominal fat deposition but only after 28 d of age. 4. The LC diets reduced serum total cholesterol, low density lipoprotein (LDL) cholesterol and triglycerides in broilers from 21 to 42 d of age. However, there was no significant difference in serum high density lipoprotein (HDL) cholesterol between control and LC-fed broilers. There was also no significant difference in the weights of organs of control and LC-fed broilers. 5. The results indicated that the mixture of 12 Lactobacillus strains have a hypolipidaemic effect on broilers.

Optimization of carbon and nitrogen sources for phytase production by Mitsuokella jalaludinii, a new rumen bacterial species

AIMS

The effects of different carbon and nitrogen sources on phytase production by Mitsuokella jalaludinii were evaluated and the optimization of rice bran (RB) and soybean milk (SM) concentrations in the medium for phytase production was also determined.

METHODS AND RESULTS

Replacement of glucose, cellobiose and starch in MF1 medium by RB or palm kernel cake and replacement of trypticase peptone and yeast extract in the medium by SM or enzymatic digested soybean milk significantly increased the phytase production by M. jalaludinii. The optimal concentrations of RB and SM in the medium for phytase production were 15% RB and 20% SM or 20% RB and 10% SM or 20% RB and 20% SM and the phytase activities in the media were 12.53, 12.93 and 12.75 U g-1 culture broth, respectively.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

The high production of phytase by M. jalaludinii warrants further research to increase its yield by genetic manipulation for commercial application.