Clinicopathological study of 13 cases of squamous cell carcinoma complicating hidradenitis suppurativa

BACKGROUND

To the best of our knowledge, only 52 cases of squamous cell carcinoma (SCC) complicating hidradenitis suppurativa (HS) have been reported since 1958. We describe 13 new cases.

METHODS

We propose a clinical and histological analysis of our cases. We include these results in a review of previously reported cases to analyze a total of 65 patients. In our series of 13 cases, we also investigate the presence of human papillomavirus (HPV) in tumor samples, by polymerase chain reaction (PCR) on paraffin-embedded material.

RESULTS

Malignant transformation affects mainly men with a long-term history of genitoanal HS. Although our cases were 7 well-differentiated carcinomas and 6 verrucous carcinomas, lymphatic and visceral metastasis occurred in 2 and 3 cases, respectively. With PCR, we demonstrated presence of HPV in genitoanal tumoral lesions, principally HPV-16.

CONCLUSION

SCC complicating HS evolves poorly, despite a good histological prognosis. Our results sustain the implication of HPV in the malignant transformation of HS.

Barriers to follow-up of abnormal Papanicolaou smears among women in Leon, Nicaragua

Cervical cancer screening programmes only succeed when the coverage, screening, treatment and follow-up of any abnormal results are of high quality. This study investigates the screening coverage and the quality of the follow-up of cervical cancer screening of women in León, Nicaragua, as well as the factors affecting coverage and barriers to follow-up. Two hundred and thirty-four sexually active women attending a public health centre (54), a public health post (63), or the gynaecology department of the public HEODRA hospital (117), were invited to answer an orally administered questionnaire. The screening coverage of cervical cancer was calculated and the follow-up after finding an abnormal screening result was assessed. The coverage was 60.6% (95% confidence interval 54.4–66.8%). One hundred and sixty-eight women (87%) were informed about the results. Eighteen (10, 7%) of the women who were informed about the results, were advised to have follow-up and 12 (66, 7%) of them did. Barriers to follow-up were financial constraints, pregnancy, postponement and absence of instruments/electricity. This study shows that the screening coverage and cytology services are adequate, but that there is insufficient follow-up and/or treatment after an abnormal screening result. In order to achieve a lower incidence and mortality of cervical cancer, follow-up and treatment after an abnormal screening result need to be improved. A visual inspection with acetic acid may be an attractive alternative.

Role of fine needle aspiration cytology in the diagnosis and management of Warthin's tumour of the salivary glands

OBJECTIVE

Local excision surgical procedures and non-surgical conservative management are considered alternatives to superficial parotidectomy in the treatment and management of Warthin's tumour (WT). Such therapeutic alternatives demand accurate diagnosis. In order to determine whether fine needle aspiration cytology (FNAC) is capable of rendering such a minimally invasive diagnosis, we evaluated its accuracy and diagnostic parameters in a large series of histologically proven cases of WT.

METHODS

A cytohistological study of 116 salivary tumours from 110 patients (four WT were bilateral) with a histological or cytological diagnosis of WT.

RESULTS

Histology confirmed the cytological diagnosis in 103 of 114 tumours (90.4%). Two tumours were incorrectly diagnosed on cytology as WT. In 11 cases of WT there was an erroneous or non-representative cytological diagnosis. The sensitivity was 90.4%, and positive predictive value 98.1%. Regarding malignancy, there were three misdiagnoses. One tumour diagnosed as WT was a low-grade mucoepidermoid carcinoma. Two cases considered 'suspicious of squamous cell carcinoma' corresponded to WT. After review, 81.3% of the cases of WT were considered typical and 18.7% non-typical; all misdiagnoses were in the latter group. Cytological difficulties could be divided into three areas: (i) absence of one or more diagnostic components; (ii) 'squamoid' pattern; and (iii) mucinous metaplasia. Degenerated oncocytes were present in 65% of cases.

CONCLUSIONS

FNAC offers the possibility of a reliable diagnosis of WT. Pathologists must pay attention to the squamous appearance of degenerated oncocytes. Cytology, when coupled with clinical and image findings, may permit conservative tumour management.

Family history of breast cancer (BC) and biological and clinicopathologic features in Uruguayan BC patients

e11622

Background: Hereditary BC can have a distinct phenotype and behavior in comparison to sporadic BC. The aim of the present study was to investigate if there is any difference in the age at diagnosis, disease extension and biological profile in BC patients (pts) with or without a significant family history of BC. Methods: We retrospectively reviewed clinical charts of BC pts, stage 0- III who had surgery between March 2006 and March 2008. We included pts with known estrogen receptor (ER), progesterone receptor (PR) and HER2 status. The family history was obtained from the clinical charts and confirmed by a telephone interview with a standardized questionnaire. A significant family history of BC was defined by the presence of one of the following criteria: (1) 3 or more BC cases among close relatives, at least one diagnosed before 50 years (2) 2 BC cases among close relatives, at least one diagnosed before 50 years and one of the following: bilateral BC, ovarian cancer diagnosed in the family, male BC, father´s inheritance, Ashkenazi Jewish ancestry Results: 435 pts were identified, with available data on ER/PR and HER2 status in 197 pts. Family history was evaluated in 136 pts (69%) and was classified as significant in 18 (13.2%). Between pts with and without a significant family history of BC cancer there were no difference in the proportion of pts < 50 years old at diagnosis (0.36 vs. 0.39), T3/T4 tumours (0.08 vs. 0.11), axillary node positivity (0.55 vs 0.66), ER/PR+ (0.77 vs. 0.72), HER2 + (0.11 vs. 0.11) and triple negative tumors (0.19 vs 0.17). Conclusions: our data does not show any difference in the main prognostic and predictive factors between operable BC pts with and without a significant family history of BC. These findings are concordant with previous published data about a greater prevalence of BRCA2 mutations in Uruguayan families.

No significant financial relationships to disclose.

The European contribution to "Sugarbaker's protocol" for the treatment of colorectal peritoneal carcinomatosis

INTRODUCTION

In 1981, Dr. PH Sugarbaker, challenging oncological orthodoxy, considered carcinomatosis to be a locoregional stage of the disease that was still susceptible to treatment with curative intent. To this end he developed a new therapeutic alternative based on the combined treatment. The macroscopic disease treated by maximum radical oncological cytoreductive surgery (through the peritonectomies described by him), followed by treatment of the residual microscopic disease with the direct intra-abdominal application of intraoperative chemotherapy with locoregional intensification, modulated by hyperthermia and early normothermic postoperative intra-abdominal chemotherapy. Using this new therapeutic regimen, known as "Sugarbaker s Protocol", his group has reported 45% survival rates in carcinomatosis of colorectal origin at 5 years, and, in selected groups of patients, 50% survival rates at 5 years. The scientific community, however, has criticized these results considering that: it is a personal experience, with a not homogenous treatment protocol with developmental modifications over time, that it is a retrospective non-randomized study, and finally that the cytostatics used in his protocol are obsolete. Various European groups have replied to these main criticisms confirming the good results that this new therapeutic alternative offers for patients with carcinomatosis of colorectal origin. The purpose of this article is to present these contributions.

MATERIAL AND METHODS

All the articles published in the English language by European groups in the world s medical literature have been reviewed using the Pubmed-MEDLINE database to identify the relevant articles related to the treatment of carcinomatosis of colorectal origin using cytoreduction and intraperitoneal chemotherapy from January 1980 to January 2008.

RESULTS

The European contribution during these 25 years in favour of the "Sugarbaker s Protocol" has consisted fundamentally in: a) one multicenter retrospective study; b) two randomized prospective phase III studies; and c) the use of oxaliplatin and irinotecan as new cytostatic agents in the protocols for intraperitoneal chemotherapy. At the same time, two new transcendental European contributions have been made in which the possibility has been considered of combined simultaneous treatment for patients with hepatic metastases and carcinomatosis, and the introduction, as a selection factor, of patients responsive to intravenous induction chemotherapy within the regimen of sandwich treatment (with systemic neoadjuvant and adjuvant chemotherapy) complementary to intraperitoneal chemotherapy.

CONCLUSIONS

The results obtained by European groups using "Sugarbaker s protocol" and "Elias protocol" with oxaliplatin compel us to request that these treatments be considered by all professionals involved in the treatment of patients with colorectal carcinomatosis as the best treatment currently available for this condition. Furthermore a randomized, prospective, multicenter study should be carried out to clarify its value and the degree of scientific evidence. A validation of this treatment will change, in the future, the dogmatic consideration of carcinomatosis as an incurable disease stage.

Supplementation with plant extracts (carvacrol, cinnamaldehyde and capsaicin): its effects on acid-base status and productive performance in growing/finishing bull calves

This study investigated the in vivo effects of a commercial blend of plant extracts (carvacrol, cinnamaldehyde and capsaicin) on blood acid-base balance and serum lactate levels in a 148-day feedlot experimentwith 24 double-muscled Belgian Blue bull calves. Animals were allotted randomly to one of two experimental groups: 1) a control group (C, no supplementation; n = 10), and 2) a group receiving dietary supplementation with a combination of plant extracts (PE, 100 mg per kg DM of concentrate; n = 14). All animals received a high-grain ration, typical of diets fed commercially to feedlot cattle in Spain, consisting mainly of barley plus other components in proportions depending on the production phase. Production data (weight, DMI, ADG and feed-to-gain ratio) were recorded, and venous blood pH, pCO2, HCO3(-), Base Excess -BE- and serum L-lactate were determined. Apparently, beneficial effects of supplementation on production parameters were observed in both growing and finishing periods, though statistically significant effects were only observed in the finishing period. As regards blood parameters, no significant effects of supplementation (or the supplementation x time interaction) were observed, except for an effect on blood pH in the growing period, when supplemented animals showed significantly higher values than controls. A beneficial supplementation x time interactive effect was observed on serum L-lactate levels: from the first week of the study until the end, supplemented animals showed significantly lower levels than controls. These in vivo results support the utility of this dietary supplement in feedlot cattle receiving a barley-based high-grain diet.

Sciatic nerve conditioned medium depleted of pro-NGF modulates sodium currents and neurite outgrowth in PC12 cells

Excitability and axon/dendrite specification are the most distinctive features in the establishment of neuronal polarization. Conditioned medium from rat sciatic nerve (CM) induced a neuronal-like morphology in PC12 cells. Here we show that CM neuritogenic activity is limited to the induction of dendrites in PC12 cells. However, treatment of these cells with CM in combination with a generic inhibitor for tyrosine kinase receptors (k252a) promoted the enhancement of neurite length, development of axons and induction of sodium currents. On the other hand, specific inhibition of TrkA and p75(NTR) receptors in CM-treated cells reduced the neurite length in comparison with cells treated only with CM, although the effect over the induction of sodium currents was continuously observed. These results suggested that CM had some components that, even though are able to start the morphological cell differentiation and produce short neurites (likely acting through TrkA and p75(NTR)), can restrain further neurite extension. Depletion of pro-NGF isoforms from CM produced a similar effect as the exerted by k252a, TrkA and p75(NTR) receptor inhibitors in CM-treated cells, inducing the elicitation of sodium currents. These results suggested that the effect of CM might be mediated through pro-NGF. The difference between the results obtained with the generic inhibitor for Trk receptors and the specific inhibitors for TrkA and p75(NTR) receptors in CM-treated cells, suggested that alternative pathways could be used to regulate neurite elongation, axon specification and sodium currents in PC12 cells. These findings represent important clues to improve the understanding of the initiation of neuronal polarity.

Learning and reliability of colour Doppler ultrasound in giant cell arteritis

OBJECTIVE

To evaluate a standardized training program and a reliability exercise in colour Doppler ultrasound (CDUS) for giant cell arteritis (GCA).

METHODS

Two workshops were conducted in 2007 and 2008 to train rheumatologists in CDUS for GCA ultrasound diagnosis. Twenty-nine and forty-three participants without previous experience in GCA ultrasound were admitted in 2007 and 2008, respectively. First, some theoretical knowledge about GCA ultrasound signs was provided; second, a reader evaluation session of temporal artery video recording examinations of 27 and 30 patients were projected in the 2007 meeting and the 2008 workshop, respectively (50% were cases and 50% were controls). Twenty-four cases were common to both reader sessions. A mean of six videos were shown of each patient. Each video had to be assessed as normal or pathologic. Finally, hands-on scanning training was performed. To assess the efficacy of the workshop: 1) a structured satisfaction questionnaire was graded (1-5 Likert scale), and 2) the reliability, specificity, and percentage of correctly classified cases by each participant were calculated.

RESULTS

The kappa coefficient of inter-reader agreement for the 29 and 43 participants was excellent (Kappa: 0.846) in 2007 and (Kappa: 0.848) in 2008. The intra-reader kappa result was also excellent (Kappa: 0.950). The satisfaction, sensitivity, specificity, and percentage of correctly classified patients and controls were very high.

CONCLUSION

The proposed learning method seemed to be effective and well accepted by the target audience. The inter-reader reliability of GCA ultrasound was excellent. These encouraging results support the need for planned standardized training programs.

Effects of malate supplementation on acid-base balance and productive performance in growing/finishing bull calves fed a high-grain diet

This study investigated the effects of malate supplementation on blood acid-base balance and serum lactate levels in a 137-day feedlot experiment with bull calves. Animals were allotted to one of two experimental groups: (1) A control group (no supplementation), and (2) a group receiving a salt of DL-malic acid. Blood pH, pCO2, HCO3-, base excess, serum L-lactate and productivity parameters were evaluated. Our data reveal that under the conditions of the present experiment malate supplementation did not have any significant effect on productivity parameters by comparison with non-supplemented animals. As regards acid-base balance, no significant effects attributable only to malate were observed. In conclusion, the time-course and the overall means of serum L-lactate for both groups in both growing and finishing periods (0.44 +/- 0.04 mmol/l and 0.39 +/- 0.02 mmol/l, respectively, for control animal; and 0.54 +/- 0.03 mmol/l and 0.49 +/- 0.01 mmol/l, respectively, for supplemented animals) suggests that malate does not have any beneficial effects in animals fed a diet of similar characteristics to that given in this study.

Toxic and essential metals in liver, kidney and muscle of pigs at slaughter in Galicia, north-west Spain

The aims of the study were to evaluate toxic and essential metal concentrations in meat and offal from pigs in north-west Spain to compare these with reported metal concentrations in pigs in other countries and in cattle in this region, and to relate the observed concentrations to maximum acceptable concentrations. Samples from 63 pigs aged 6 months were randomly collected at slaughter. After acid digestion, levels of metals were determined by ICP-OES and ICP-MS. As regards the toxic metals, mean concentrations in liver, kidney and muscle were 0.073, 0.308 and 0.009 mg kg(-1) fresh weight for cadmium, 0.004, 0.008 and 0.003 mg kg(-1) for lead, 0.013, 0.011 and 0.003 mg kg(-1) for arsenic, and 0.001, 0.002 and 0.001 mg kg(-1) for mercury. These concentrations can be considered low, and in general similar to those reported in similar studies in recent years. In addition, maximum admissible concentrations established by the European Union were not exceeded in any sample. As regards the essential metals, concentrations in liver, kidney and muscle were 14.9, 5.63 and 6.85 mg kg(-1) for copper, 81.3, 28.9 and 42.5 mg kg(-1) for zinc, 195, 51.6 and 26.5 mg kg(-1) for iron; 1.17, 2.51 and 0.656 mg kg(-1) for selenium, 3.32, 1.56 and 1.01 mg kg(-1) for manganese, 0.023, 0.027 and 0.003 mg kg(-1) for cobalt, 0.120, 0.077 and 0.131 mg kg(-1) for chromium, 0.009, 0.027 and 0.026 mg kg(-1) for nickel, and 1.62, 0.683 and 0.140 mg kg(-1) for molybdenum. These concentrations are all within the accepted adequate-safe ranges for this animal species, and in general are in line with those previously reported in the literature.

Toxic and trace metal concentrations in liver and kidney of dogs: influence of diet, sex, age, and pathological lesions

The aim of this study was to provide data on the main toxic and trace metals in the liver and kidney of domestic dogs in Galicia, NW Spain and to evaluate the influence of diet, sex, age, and pathological lesions on metal accumulation. Samples of the liver and kidney from 77 male and female dogs, aged between 6 mo and 18 yr, were collected during ordinary necropsy. Samples were acid-digested and metal concentrations determined by inductively coupled plasma (ICP)-mass spectrometry and ICP-atomic emission spectrometry. Mean toxic metal concentrations (geometric means for liver and kidney respectively) were 11.5 and 15.8 microg/kg wet weight for As, 56.3 and 166 microg/kg for Cd, 32.7 and 51.9 microg/kg for Hg, and 60.1 and 23.6 microg/kg for Pb. For the trace metals, these concentrations were respectively 16.3 and 21.0 microg/kg for Co, 57.6 and 43.9 microg/kg for Cr, 42.1 and 5.95 mg/kg for Cu, 394 mg/kg and 95.7 mg/kg for Fe, 2.39 and 0.956 mg/kg for Mn, 0.522 and 0.357 mg/kg for Mo, 23.8 and 26.8 microg/kg for Ni, 0.686 and 1.39 mg/kg for Se, and 46.7 and 26.0 mg/kg for Zn. Cd concentrations in the kidney significantly increased with age, and Co concentrations in the liver and kidney significantly decreased with age. Hepatic Pb concentrations were significantly higher in growing (<1 yr) and old (>10 yr) dogs. Animals with pathological lesions showed significantly higher Co and lower Mn and Zn concentrations in liver than animals without macroscopic abnormalities. Dogs that received commercial diets in general showed low variability in hepatic mineral status compared to animals that receive homemade feeds or a mixture of commercial and homemade feeds.

Assessment of some blood parameters as potential markers of hepatic copper accumulation in cattle

The increasing frequency of copper (Cu) toxicosis episodes in cattle in recent years, mainly associated with excess Cu supplementation, underscores the need to identify animals in the clinically silent phase of hepatic Cu accumulation. The aim of the study reported here was to evaluate the suitability of various blood parameters as potential early markers of hepatic Cu accumulation in cattle. Paired liver and blood samples from 70 calves aged 6 to 10 months were obtained at slaughter in a region in northwestern Spain where animals usually have hepatic Cu concentration higher than safe values. Neither serum Cu concentration nor ceruloplasmin (CP) concentration, the 2 parameters most commonly used for diagnosis of Cu deficiency, were significantly associated with hepatic Cu concentration. However, whole-blood Cu concentration had a slight but significant correlation with hepatic Cu concentration (r = 0.269, P = 0.026). The use of calculated blood parameters, such as the serum or whole-blood non-CP Cu fraction, or the CP-to-serum Cu ratio, increased the correlation with the hepatic Cu concentration (r = 0.393, P = 0.001, in the case of whole-blood, non-CP Cu concentration), but the strength of the association remained insufficient for accurate prediction of hepatic Cu values. Likewise, hepatic enzyme (aspartate transaminase and gamma-glutamyltransferase) activities were significantly or nearly correlated significantly with hepatic Cu concentration, but the strength of the association remained too low for accurate prediction. It is concluded that direct analysis of Cu concentration in liver biopsy specimens--preferably postmortem liver samples obtained at slaughter--is the best technique currently available for detecting chronic subclinical Cu accumulation in cattle at risk for supraoptimal Cu exposure.

Effects of monensin and yeast supplementation on blood acid-base balance in finishing feedlot steers fed a high-grain, high-protein diet

The aim of this study was to evaluate the effects of two dietary supplements (monensin and a live yeast culture) on acid-base balance in steers maintained in a commercial feedlot system, considering effects over the finishing productive cycle. Steers (no. =42) were allotted randomly to one of the three study groups: (1) control group (no supplementation, C), (2) monensin supplementation (MON), and (3) live Saccharomyces cerevisiae strain 47 supplementation (SACC). Venous blood samples were collected for the measurement of acid-base parameters and l-lactate. Production parameters were also used as a complementary tool for understanding the internal changes associated with supplementation. During the finishing period, MON steers tended to gain more efficiently than C and SACC steers. In the C group, the finishing-period diet caused a progressive decline in blood bases, in line with the high-grain diet consumption. In contrast, supplemented animals did not show this trend, although lower HCO3− and base excess values were registered in SACC steers than in MON, indicating that ionophore supplementation is less effective for reducing blood base consumption than yeast supplementation. In our study, the lack of the expected response to yeast supplementation may be attributable to the high crude protein content of the ration, a common feature of commercial feedlot industries.

Memory consolidation and amnesia modify 5-HT6 receptors expression in rat brain: An autoradiographic study

Traditionally, the search for memory circuits has been centered on examinations of amnesic and AD patients, cerebral lesions and, neuroimaging. A complementary alternative might be the use of autoradiography with radioligands. Indeed, ex vivo autoradiographic studies offer the advantage to detect functionally active receptors altered by pharmacological tools and memory formation. Hence, herein the 5-HT(6) receptor antagonist SB-399885 and the amnesic drugs scopolamine or dizocilpine were used to manipulate memory consolidation and 5-HT(6) receptors expression was determined by using [(3)H]-SB-258585. Thus, memory consolidation was impaired in scopolamine and dizocilpine treated groups relative to control vehicle but improved it in SB-399885-treated animals. SB-399885 improved memory consolidation seems to be associated with decreased 5-HT(6) receptors expression in 15 out 17 brain areas. Scopolamine or dizocilpine decreased 5-HT(6) receptors expression in nine different brain areas and increased it in CA3 hippocampus or other eight areas, respectively. In brain areas thought to be in charge of procedural memory such basal ganglia (i.e., nucleus accumbens, caudate putamen, and fundus striate) data showed that relative to control animals amnesic groups showed diminished (scopolamine) or augmented (dizocilpine) 5-HT(6) receptor expression. SB-399885 showing improved memory displayed an intermediate expression in these same brain regions. A similar intermediate expression occurs with regard to amygdala, septum, and some cortical areas in charge of explicit memory storage. However, relative to control group amnesic and SB-399885 rats in the hippocampus, region where explicit memory is formed, showed a complex 5-HT(6) receptors expression. In conclusion, these results indicate neural circuits underlying the effects of 5-HT(6) receptor antagonists in autoshaping task and offer some general clues about cognitive processes in general.

Effect of exogenous administration of melatonin and growth hormone on pro-antioxidant functions of the liver in aging male rats

Aging is accompanied by changes in the morphology and physiology of organs and tissues, such as the liver. This process might be due to the accumulation of oxidative damage induced by reactive oxygen (ROS) and reactive nitrogen species (RNS). Hepatocytes are very rich in mitochondria and have a high respiratory rate, so they are exposed to large amounts of ROS and permanent oxidative stress. Twenty-four male Wistar rats of 22 months of age were divided into three groups. One group remained untreated and acted as the control group. The second was treated with growth hormone (GH) (2 mg/kg/d sc) and the third was submitted to treatment wit 1 mg/kg/d of melatonin in the drinking water. A group of 2-months-old male rats was used as young controls. After 10 wk of treatment the rats were killed by decapitation, and the liver was dissected and homogenized. Mitochondrial, cytosolic and microsomal fractions were obtained and cytochrome C, glutathione peroxidase, s-transferase and nitric oxide (NO) were measured. Aging induced a significant increase in mitochondrial nitric oxide. An increase in cytochrome C in the cytosolic fraction and a reduction in the mitochondrial fraction with age was also observed. Both GH and melatonin treatments significantly reduced the enhanced measures and increased the reduced values. A reduction in glutathione peroxidase and glutathione S-transferase was found in old control rats when compared with the group of young animals. Treatment for 2.5 months of old rats with GH and melatonin were able to increase the enzymes reaching values similar to those found in young animals. In conclusion, GH and melatonin treatment seems to have beneficial effects against age-induced damage in the liver.

Effects of long-term dietary supplementation of monensin or saccharomyces cerevisiae on blood acid-base and productive performance in growing feedlot steers

The aim of this study was to evaluate the effects of two dietary supplements (monensin and a live yeast culture) on acid-base balance in steers maintained in a commercial feedlot system, considering effects over the growing period (14 to 23 weeks of age). A 63-day feedlot study was performed using 42 double-muscled Belgian Blue steers. Steers were allotted randomly to one of the three study groups: (1) control group [no supplementation, C], (2) monensin supplementation [MON] at a concentration of 30 mg/kg (DM basis), and (3) live Saccharomyces cerevisiae strain supplementation [SACC] at a dose of 500 mg/kg (DM basis). Venous blood samples were collected for the measurement of acid-base parameters and L-lactate. Production parameters were also used as a complementary tool for understanding the internal changes associated with supplementation. Our results show that during the study period no statistical differences were observed between supplemented and control steers, although non-supplemented animals tended to gain more efficiently than those fed monensin or yeast. Nevertheless, taking into account blood parameters, these control animals showed a greater risk of acid overload due to a more marked decline in blood buffer levels over time in comparison with supplemented steers although no differences were observed between monensin or yeast supplemented animals. Additionally, significant effect of supplementation was observed in packed cell volume (PCV) values.

Influence of Grain Processing on Acid–Base Balance in Feedlot Steers

Grain processing (e.g. grinding, steaming, pelleting, flaking) has been reported to modify the incidence of ruminal disturbances in feedlot cattle. This study investigated the effects of two grain processing methods widely used in Spanish feedlots (grinding and pelleting) on animal performance, blood acid-base balance, blood electrolyte levels and serum lactate in a 140-day feedlot experiment with double-muscled Belgian Blue steers. The main aim of the study was to evaluate the way in which these two feeds modify blood acid-base balance, which is closely associated with ruminal pH. In light of our results we conclude that the animals that received the pelleted feed showed a more stable acid-base balance over time than those fed a ground feed. Nevertheless, higher levels of L-lactate and lower base excess (BE) and HCO(3)(-) values for cattle fed pelleted grain reflect a greater risk of grain-acid overload.