Comparative Survival Rates of Lactic Acid Bacteria Isolated from Blood, Following Spray-drying and Freeze-drying

The effect of two dehydration technologies, spray-drying and freeze-drying, on the viability of 12 lactic acid bacteria (LAB) were compared. All LAB cultures had been previously isolated from porcine blood and were candidates to be used as biopreservatives in order to maintain the quality of porcine blood until further processing to obtain added-value blood derivatives is carried out. The residual viability and the reductions in microbial counts in dried LAB samples at 20 °C and 5 °C during 60-day storage were determined. Cellular damage due to freeze-drying was observed immediately after drying whereas cellular damage due to spray-drying did not become evident until the subsequent phase of storage. For most of the strains, the faster decrease in viability of spray-dried as compared to freeze-dried cultures was compensated by the higher percentage of viable cells obtained after dehydration, leading to comparable survival rates at the end of the storage period. Dehydration resulted in a good alternative to freezing at 80 °C for preservation purposes. Spray-drying has been shown to be as suitable as freeze-drying for preserving LAB strains during a 2-month storage period. Results suggest the possibility of achieving a good formulation system for the LAB strains with a high number of viable cells to be used for the industrial development of bioprotective cultures.

High Hydrostatic Pressure as a Method to Reduce Microbial Contamination of Porcine Blood Plasma

The suitability of high hydrostatic pressure as an alternative method to produce porcine blood plasma with a sufficient microbial stability without affecting its functional properties was evaluated. The effects of high pressure on plasma microorganisms were highly dependent on processing temperature. Treatments of 15 min at 450 MPa carried out at 5 'C led to reductions of about 90% in microbial counts and to 20-50% decreases in the growth ability of the survivors. At 25 'C and 40 'C, the efficiency was increased to reduction values of 99.82 and 99.97%, respectively. The lowering of the growth capacity was about 50% at 25 'C and up to 80% at 40 'C. The most efficient treatment (450 MPa, for 15 min at 40 'C) did not lead to appreciable negative effects on the functional properties of heat-induced gels from porcine blood plasma.

Colour Stabilization of Spray-Dried Porcine Red Blood Cells Using Nicotinic Acid and Nicotinamide

The effect of nicotinic acid (NA) and nicotinamide (NAm) on colour parameters (CIE L*, a*, b*) of spray dried red blood cells and colour stability during a 7-weeks storage period at room temperature were investigated. The influence of pH on the colour of powder stabilized with NA or NAm was also determined by using starch gels as a model matrix. The results showed that nicotinic acid at 2% (w/v) considerably prevented colour deterioration of haemoglobin concentrate during spray-drying as well as during the storage period. The powder obtained was clearer, redder and more yellow than the control. A positive effect was also detected with 2.5% (w/v) nicotinamide, but the improvement achieved was never as high as it was when nicotinic acid was used. However, powder containing nicotinamide at 2.5% (w/v) showed higher capacity as a red colourant than nicotinic acid at 2% (w/v) when added to starch gels either at pH 7.5 or 4.5.

Foaming and Emulsifying Properties of Porcine Red Cell Protein Concentrate

This work focuses on studying the effects of pH (7.0 and 4.5) and protein concentration on the foaming and emulsifying properties of fresh (F) and spray-dried (SD) porcine red cell protein (RCP) concentrates in order to evaluate the proper use of this blood protein as a functional food ingredient. Also, protein solubility is measured through the pH range from 3.0 to 8.0. In each case, all concentrates show a high solubility, although this is significantly affected by pH. Spray drying slightly reduces the solubility at mild acid and neutral conditions. The foaming capacity is found to be dependent on pH as well as on the drying treatment. SD-RCP concentrates show better foaming capacity than F-RCP. The minimum protein concentration required to attain the highest foaming capacity is found under acid pH for the spray-dried concentrates. Although F-RCP shows low foam stability at acid and neutral pH, spray drying and protein content enhance the stability of foams. Emulsifying properties show dependence on pH as well as on protein content. Furthermore, spray drying affects the emulsifying properties but in different ways, depending on pH and protein concentration.

[Study of colorectal metachronous neoplastic lesions]

BACKGROUND

To analyse the frequency and characteristics of metachronous neoplastic lesions, carcinomas and adenomas, following resection of colorectal cancer.

PATIENTS AND METHODS

We reviewed 382 patients subjected to RCC operations and followed up through complete colonoscopies in two hospitals in our province. We analysed the metachronous lesions registered, evaluating their localisation, time of diagnosis, histology, number and size. We studied the frequency of early adenomas (12 months), comparing their size with the rest of the lesions.

RESULTS

The average follow-up was 48 months (12-112), with 2.74+/-1.47 colonoscopies/case. We diagnosed 7 metachronous cancers (1.8%), 4 of them in stage I. The average time until their diagnosis was 24 months (13-54). We registered metachronous adenomas in 162 cases (42.4%), without differences between the two hospitals: 42.1% vs. 43.8% (p=0.88). Six point three percent of the patients presented advanced adenomas. In 164 cases where the control was carried out after 12 months, the incidence of adenomas was 24%. In the majority of cases, the adenomas were sole (60.8%) and smaller than 5 mm (68.5%). In 55.5% of the cases with polyps, some had a proximal localisation. Diagnosis was made on the 1st exploration (56.2%), the 2nd (27.8%) or the 3rd (9%). Average time until diagnosis was 21 months (12-112) for simple adenoma and 35 (12-112) for advanced adenoma.

CONCLUSIONS

Our follow up made it possible to apply a theoretically curative treatment in the majority of the metachronous carcinomas diagnosed. The high incidence of adenomas and the frequent proximal localisation make a follow up with complete colonoscopies necessary, which must be started one year after the operation and can become less strict following three consecutive explorations without polyps.

[Capsule endoscopy interpretation: the role of physician extenders]

BACKGROUND AND AIMS

capsule endoscopy (CE) allows for a new era in small-bowel examination. Nevertheless, physicians time for CE-interpretation remains longer than desirable. Alternative strategies to physicians have not been widely investigated. The aim of this study was to evaluate the accuracy of physician extenders in CE-interpretation.

MATERIAL AND METHODS

one CE-experienced gastroenterologist and two physician extenders reviewed independently 20 CE-procedures. Each reader was blinded to the findings of their colleagues. A consensus formed by the readers and a second CE-experienced gastroenterologist was used as gold standard. Number, type and location of images selected, character of CE-exams and their relationship with indications were recorded. Gastric emptying time (GEt), small-bowel transit time (SBTt) and time spent by readers were also noted.

RESULTS

sensitivity and specificity for "overall" lesions was 79 and 99% for the gastroenterologist; 86 and 43% for the nurse; and 80 and 57% for the resident. All 34 "major" lesions considered by consensus were found by the readers. Agreement between consensus and readers for images classification and procedures interpretation was good to excellent (? from 0.55 to 1). No significant differences were found in the GEt and SBTt obtained by consensus and readers. The gastroenterologist was faster than physician extenders (mean time spent was 51.9 +/- 13.5 minutes versus 62.2 +/- 19 and 60.9 +/- 17.1 for nurse and resident, respectively; p < 0.05).

CONCLUSIONS

physician extenders could be the perfect complement to gastroenterologists for CE-interpretation but gastroenterologists should supervise their findings. Future cost-efficacy analyses are required to assess the benefits of this alternative.

[Study of frequency, distribution and diagnostic performance in synchronic neoplastic lesions of colorectal carcinoma]

AIM

To analyse the frequency, characteristics and diagnosis of synchronic neoplastic lesions in colorectal cancer.

METHODS

A review was carried out of 384 colorectal cancers, diagnosed through complete colonoscopy and resected. The synchronic cancers and the characteristics of the adenomas were determined: number, size, histological type, dysplasia, as well as their localisation in the colon and with respect to the carcinoma.

RESULTS

Twenty-eight synchronic cancers were found (7.3% of the total); 8 developed tumours and 20 malignant polyps. In 54.4% of the cases there was a synchronic adenoma. In patients with synchronic lesions, 43% showed an advanced adenoma. Twenty percent of the synchronic polyps found were proximal to the splenic flexure; 41% were distal and 38% had both localisations. Fifty-nine point one percent of the patients had some adenoma proximal to the cancer, with criteria of advanced adenoma in 13.9%. The distribution of the adenomas was more uniformly spread in the cancers with a proximal localisation (p = 0.038). Seventeen percent of the distal cancers presented synchronic lesions with a proximal colon localisation exclusively. Partial endoscopies would diagnose the distal cancers, but would omit a synchronic adenoma in 42.3% of the sigmoidoscopies and 40% of the short colonoscopies.

CONCLUSIONS

High rates of carcinoma and synchronic adenomas were registered. We underline the high index of advanced adenomas and the frequency of synchronic lesions proximal to the cancer, which is why incomplete colonoscopies, although allowing the diagnosis of the distal cancer, omit a high percentage of synchronic adenomas, including advanced lesions. All of this confirms the need to perform a complete pre-, intra- and post operational colonoscopy in resectable colorectal cancer.

[New applications of capsule endoscopy: PILLCAMTM ESO]

Capsule endoscopy has opened a new era in small bowel examination. Its indications are now well-defined and currently, wireless capsule endoscopy is considered as the first-line imaging tool for the diagnosis of small bowel diseases. ECE has been shown to be feasible, safe and a good alternative technique in patients refusing conventional endoscopy. Although results reported in both GERD and cirrhotic patients are encouraging, great differences in terms of accuracy (particularly in GERD patients) have been found in published studies. These differences have been attributed to study designs, the lack of adequate experience and inconvenience of ingestion protocols. In summary, more large-scale studies evaluating the new 14-fps capsule, adequate ECE-experience and new modified ingestion protocols are still needed.

[Utility of endoscopy in digestive hemorrhage due to vasculitis]

Vasculitides constitute a heterogeneous group of diseases characterized by inflammation of blood vessels. The skin is mainly affected, although the gastrointestinal tract mucosa can also be involved. The contribution of endoscopy in these cases has not been clearly determined. We report three cases of systemic vasculitis (polyarteritis nodosa, Schonlein-Henoch purpura and Behcet's disease) presenting with acute digestive bleeding. Endoscopy was an effective technique for completing the diagnosis and in establishing an effective nonsurgical therapeutic approach in these potentially lethal cases of gastrointestinal hemorrhage.

[Chronic hepatitis B virus infection]

Many factors are involved in the pathogenesis of chronic hepatitis B virus infection (HBV), such as, for example, characteristics of the virus, ethanol intake, coinfection with other viruses (HCV, HIV, HDV), and therapeutic interventions such as the use of cytotoxic drugs or immunosuppressors, or specific antiviral agents. The clinical, pathological and serological characteristics of chronic hepatitis B virus infection are besides very heterogeneous. Chronic HBV infection can be recognised facing persistence of the Australia antigen (HBsAg) for more than six months. The presence of HBeAg is usually associated with active viral replication and can be measured by the quantity of DNA-HBV present in the serum or by the hepatic expression of HBcAg. The hepatic damage that is produced in chronic hepatitis due to HBV is not so much due to the effect of the virus on the hepatocytes as to the immune reaction that it provokes in the host. For this reason a certain inversely proportionate correlation can be observed between the intensity of viral replication and the degree of hepatic inflammation. The presence of active chronic hepatitis in the initial biopsy has not been associated with the development of cirrhosis, nor does the histological diagnosis of persistent chronic hepatitis guarantee that cirrhosis will be developed in the future.

Hydrolysis of caprine beta-casein by plasmin

The proteolytic activity of plasmin on soluble caprine beta-casein (CN) was studied in 50 mM Tris.HCI buffer, pH 8.0, at 37 degrees C. Electrophoretic studies showed that hydrolysis of this protein results in an electrophoretic pattern that is similar to the pattern obtained from plasmin hydrolysis of bovine beta-CN (gamma-CN and complementary N-terminal fragments), suggesting that plasmin probably attacks the same regions that are susceptible to cleavage in bovine beta-CN. As determined by SDS-PAGE, the gamma-like components of caprine milk consisted of two fragments with relative molecular mass of 9200 and two with relative molecular mass of 21,400 that could differ in the level of phosphorylation. Apparently, the high molecular mass components are homologous to bovine beta-CN (f 29-209) (gamma 1-CN), and the low molecular mass components are homologous to bovine beta-CN (f 106-209) and beta-CN (f 108-209) (gamma 2- and gamma 3-CN). Complementary N-terminal fragments had values for molecular masses in the range 13,600 to 8500 and urea-PAGE patterns that were more complex than those obtained in bovine casein because of the different phosphorylation levels in caprine beta-CN. These fragments were also present in the hydrolysate of whole caprine casein that had been treated with plasmin.