Dust exposure and pulmonary inflammation in Standardbred racehorses fed dry hay or haylage: A pilot study.

Respirable dust exposure is linked to airway inflammation in racehorses. Feeding haylage may reduce dust exposure by 60-70%. The objective of this study was to compare dust exposure, airway cytology, and inflammatory cytokine concentrations between horses fed haylage or hay over 6 weeks while in training. Seven healthy Standardbred horses were randomly assigned to be fed alfalfa hay (n = 3) or grass-alfalfa mix haylage (n = 4) for six weeks while training on a treadmill. Dust exposure was measured gravimetrically at the breathing zone. Endotoxin and ß-glucan concentrations in respirable dust were measured. Bronchoalveolar lavage fluid (BALF) cytology was determined at baseline and after 2, 4, and 6 weeks. Cytokine concentrations (interferon-γ, tumor necrosis factor-α, and interleukin-4) were measured in BALF at baseline and week 6. The effect of forage on exposure, airway cytology and cytokines were evaluated using generalized linear mixed models. Respirable dust and ß-glucan exposures were lower in horses fed haylage than hay (0.02 ± 0.001 mg/m3 vs. 0.06 ± 0.01 mg/m3; P = 0.03, and 69 ± 18 pg/m3 vs. 160 ± 21 pg/m3; P = 0.02, respectively). In horses eating haylage, BALF neutrophil proportion decreased between baseline (2.2 ± 0.5%), week 2 (0.8 ± 0.3%; P = 0.01) and week 6 (0.7 ± 0.2%; P = 0.03). By week 6, horses fed haylage had lower BALF neutrophilia than horses fed hay (4.0 ± 0.7 %; P = 0.0004). Interleukin-4 concentration in BALF was higher at week 6 (14.4 ± 4.6 pg/mL) in horses fed hay compared to baseline (2.9 ± 4.6 pg/mL; P = 0.007). In conclusion, feeding haylage instead of hay to horses in training can reduce exposure to respirable irritants and mitigate airway neutrophilia.

Efficacy of oral potassium chloride administration in treating lactating dairy cows with experimentally induced hypokalemia, hypochloremia, and alkalemia.

Hypokalemia occurs commonly in lactating dairy cows. The objectives of this study were to determine (1) whether a 24-h oral KCl dose of 0.4 g/kg of body weight (BW) was effective and safe in hypokalemic cattle; (2) whether potassium was best administered as 2 large doses or multiple smaller doses over a 24-h period; and (3) the effect of oral KCl administration on plasma Mg concentration and urine Mg excretion in fasted lactating dairy cattle. Plasma K and Cl concentrations were decreased, and blood pH increased, in 15 lactating Holstein-Friesian cows by administering 2 intramuscular (i.m.) 10-mg injections of isoflupredone acetate 24h apart followed by 2 i.m. injections of furosemide (1mg/kg of BW) 8h apart and by decreasing feed intake. Cows were randomly assigned to 1 of 3 treatment groups with 5 cows/group: untreated control (group C); oral administration of KCl at 0.05 g/kg of BW 8 times at 3-h intervals (group K3); and oral administration of KCl at 0.2g/kg of BW twice at 12-h intervals (group K12). A 24-h KCl dose rate of 0.4 g/kg of BW increased plasma and milk K concentration and plasma Cl concentration, and corrected the metabolic alkalosis and alkalemia, with no clinically significant difference between 2 large doses (group K12) or multiple small doses (group K3) of KCl over 24 h. Oral KCl administration decreased peripheral fat mobilization in cattle with experimentally induced hypokalemia, as measured by changes in plasma nonesterified fatty acid concentration, and slightly augmented the fasting-induced decrease in plasma Mg concentration. Our findings support recommendations for a 24-h oral KCl dose of 0.4 g/kg of BW for treating moderately hypokalemic cattle. Additional Mg may need to be administered to inappetant lactating dairy cattle being treated with oral KCl to minimize K-induced decreases in magnesium absorption.

Effect of sample handling and storage time on the stability of total CO2 in equine plasma.

REASONS FOR PERFORMING STUDY: The stability of total CO2 concentration (ctCO2) in plasma is influenced by storage temperature and handling during sample processing. Conflicting information exists regarding the stability of ctCO2 in equine plasma over time, and the effect of centrifugation on the measured value for plasma ctCO2 is unclear. OBJECTIVES: To determine plasma ctCO2 stability over 5 days when equine blood is collected into Vacutainer tubes, centrifuged within 30 min of collection, and stored at 4 degrees C; and to determine whether a delay in centrifugation increases the rate at which plasma ctCO2 decreases over time. METHODS: Blood was collected from 6 adult horses into 3 ml plastic Vacutainer tubes and randomly assigned to be centrifuged immediately, or after, storage. Plasma ctCO2 was measured in triplicate at 0, 24, 48, 72 and 96 h after collection using a NOVA-4 analyser Data were analysed using multivariable linear regression, with P < 0.05 being defined as significant. RESULTS: Plasma ctCO2 decreased linearly over time during storage at 4 degrees C. The measured value for ctCO2 decreased at a faster rate (-0.28 mmol/l/day; P < 0.0001) when centrifugation was delayed, compared with immediate centrifugation (-0.10 mmol/l/day). There was a significant effect of sequence of sample analysis on the ctCO2 value when measured in triplicate: the second and third measurements were 0.31 and 0.41 mmol/l lower than the first measurement, respectively. CONCLUSIONS: Blood samples collected from horses into Vacutainer tubes should be centrifuged immediately after collection and analysed as soon as possible to ensure accurate values for plasma ctCO2. POTENTIAL RELEVANCE: Failure to centrifuge, or excessive delay in measuring ctCO2 after centrifugation, produces values significantly lower than the true value.

MRI appearances of the axilla in treated breast cancer.

Differentiation between recurrent axillary disease and changes due to radiotherapy or surgery has major implications for management in patients following breast cancer treatment, but clinical examination of the axilla may be difficult. This study was undertaken to correlate the MRI appearances of the axilla following breast cancer treatment with clinical outcome. 74 women with treated breast cancer were evaluated by MRI (0.5 T) and the appearances defined by consensus. Outcome was assessed by long-term clinical follow-up. 62 women had symptoms related to the axilla while 12 were scanned to stage the axilla. None of the axillary staging group had abnormal MRI appearances and none of these subsequently developed recurrence. The 62 symptomatic women were subdivided according to MRI appearances. 22 had normal axillary appearances, 18 had an axillary mass and 22 women had abnormal axillary appearances (rated mild, moderate and severe) in the absence of a mass. Normal axillary appearances on MRI excluded recurrent disease as the cause of symptoms with a specificity of 94.7% and a positive predictive value (PPV) of 95.5%. The presence of an axillary mass was commonly but not exclusively due to recurrent disease (sensitivity 68.4%, specificity 88.4%, PPV 72.2%). Sensitivity for diagnosis of axillary recurrence was increased to 89.5% with a specificity of 76.7% if the criteria for recurrent disease were taken as either the presence of an axillary mass or severe axillary changes in the absence of a mass lesion.

Primary choriocarcinoma of the urinary bladder: a case report.

We present a 37-year-old patient with primary choriocarcinoma arising in the urinary bladder, who received 5 months of intensive chemotherapy with a very good response. He died of a pulmonary embolus before his treatment could be completed. A post-mortem examination revealed extensive necrotic nodules in the lungs and brain. There was only one small focus of viable tumour in the brain. There was no residual tumour in the bladder, and no testicular tumours or scars fulfilling the criteria for a true extragonadal teratoma. It is likely that the origin of the bladder choriocarcinomas is from metaplasia/de-differentiation of a transitional cell carcinoma to the level of trophoblast. Lesser degrees of differentiation producing functional changes in the carcinoma cells with secretion of beta hCG without structural changes are much more common.

Are moving junctions in craniospinal irradiation for medulloblastoma really necessary?

The case notes of 35 patients treated for medulloblastoma using a standard technique of craniospinal irradiation (CSI) from 1978 to 1992 were reviewed. Two large opposed lateral fields to the whole brain and an orthogonal posterior spinal field were used. The position of the junction between the fields was constant throughout treatment with no feathering and no gap. We present our results, review the literature and discuss the need for feathering. The junction between the cranial and spinal fields produces an area of dose inhomogeneity but the clinical significance of this and the effect of feathering is uncertain.

Uterine sarcomas: a review of the Edinburgh experience from 1974 to 1992.

A retrospective review of patients treated for a uterine sarcoma in Edinburgh from 1974 to 1992 has been performed. Clinical details at presentation, tumour pathology, treatment and the outcome of treatment were all recorded. 82 patients' case notes were reviewed. 54 patients had died and 28 were alive (mean follow-up period 80.3 months). 39 patients had a malignant mixed mesodermal tumour, 12 patients had an endometrial stromal sarcoma, and 27 had a leiomyosarcoma. Using a modified FIGO staging retrospectively, 41 patients had Stage 1 disease, two patients had Stage 2, 16 patients had Stage 3, and 13 patients had Stage 4 disease. Definitive treatment of total abdominal hysterectomy and bilateral salpingo-oophorectomy was used in 69 patients, with 35 of these patients also receiving post-operative radiotherapy to the pelvis. 13 patients did not undergo surgery. Five of these patients received radical radiotherapy, three patients received palliative radiotherapy, and five patients were not treated. The overall median survival is 15 months and the 5-year actuarial survival is 31%. 25 of the 26 surviving patients had Stage 1 disease at presentation. Post-operative pelvic radiotherapy did not influence either survival or local tumour control. 51 of the 54 patients who relapsed had evidence of distant metastases. We conclude that total abdominal hysterectomy and bilateral salpingo-oophorectomy remains the treatment of choice for uterine sarcomas.

Sexual morbidity following radiotherapy for germ cell tumours of the testis.

An anonymous questionnaire study was designed to assess sexual function after orchidectomy and radiotherapy for testicular cancer. Questionnaires were sent to: (1) 237 patients treated with orchidectomy and abdominal radiotherapy in Edinburgh from 1974 to 1988; (2) 32 patients under "surveillance" following orchidectomy alone; (3) 402 "normal" age-matched controls. All were asked questions concerning sexual function over the preceding 6 months. All the patients were also asked the same questions with reference to the first 6 months after completion of treatment. Completed questionnaires were returned from 137 (62%) radiotherapy patients, 18 (56%) surveillance patients and 121 (35%) controls. There was a significant difference between the radiotherapy patients and the controls in almost all the parameters looked at including erection, ejaculation and libido with the treated group performing less well. In addition, almost 24% of the radiotherapy patients felt disabled or disfigured by the treatment, most commonly because of the presence of only one testicle. A deterioration in sexual function was observed with increasing age. In the radiotherapy group of patients there was no difference in response between the two time periods or in any of the treatment variables. The clinical significance of these observations are unclear but together with the increasing information on other toxicities emerging following this therapy the role of radiation for early stage seminoma is being brought into question. This study also confirms the morbidity of orchidectomy. We suggest that testicular implants should be offered more widely.

Cementum and bone: a histomorphometric study.

In the present study, a series of cementum and bone specimens were examined both qualitatively and quantitatively with a view to establishing histological criteria which may help in differentiating cementum from bone. This is for the first time that differences in cellularity and width of fibre bundles between the lamellar bone and the cementum has been reported.

Histological investigation of the tissue response to hydroxyapatite used as an implant material in periodontal treatment.

Patients with severe periodontitis and who had one or more teeth with infrabony pockets were treated by periodontal surgery with implantation of hydroxyapatite particles into the bone defects at the time of surgery. Subsequently, in three patients it was found necessary to extract a tooth for reasons not related to the previous periodontal treatment. Specimens that included the local soft tissues and crestal bone attached to the teeth were obtained at 22, 40 and 80 weeks after placement of the implant. They were decalcified and stained with haematoxylin and eosin and examined under light microscopy. The healing response was found to vary between specimens, and between sites within the same specimen. The early stage of healing showed the implant particles surrounded by collagen. Subsequently, varying degrees of resorption of the periphery of the particles was seen, and at some sites bone deposition was observed. These different healing responses were found to be progressing concurrently at sites in close proximity. Further work is needed to confirm the histological findings described in the paper.

The multinucleate cells in giant cell granulomas of the jaw are osteoclasts.

The giant cell granuloma of jaw is a well-vascularised lesion comprising a mononuclear cell infiltrate with a large number of giant cells. It has been suggested that the lesion is reparative in nature, rather than neoplastic, and that the giant cells are phagocytes accumulating in chronic reparative granulation tissue. However, the nature of the multinucleate giant cells never has been established. One possibility is that the constituent giant cells are osteoclasts. The authors assessed expression by the giant cells of several osteoclast-specific characteristics: excavation of bone; motility inhibition by calcitonin (CT); and binding of osteoclast specific monoclonal antibodies. Two tumors were disaggregated and incubated on slices of cortical bone in the presence and absence of CT. Both tumors were found to excavate bone, a function unique to osteoclasts. The giant cells also were responsive to CT, resulting in cytoplasmic quiescence and inhibition of bone resorption. Two osteoclast-specific monoclonal antibodies bound all the giant cells in one central and six peripheral tumors examined immunohistochemically. These results provide strong evidence for the osteoclastic nature of the giant cells. The presence of alkaline phosphatase-positive cells forming woven bone in giant cell granulomas suggests that osteoblasts are present in the lesion. As cells of osteoblastic lineage are known to regulate osteoclastic function, it may be that osteoblasts account for the characteristic infiltration of osteoclasts into giant cell granulomas of jaws, either as part of a reparative response by reactive osteoblasts or as an infiltrate induced by osteoblasts of aberrant function, as suggested for giant cell tumors of bone.

Central odontogenic fibroma.

An example of a central odontogenic fibroma is presented. This is a rare, benign neoplasm which affected the molar region of the left side of the mandible of a 63-year-old female Caucasian. Histologically, it consisted of fibroblast-like cells lying in a rather myxomatous delicate collagenous stroma. Few islands of odontogenic epithelium were also found. At the ultrastructural level, the tumour cells contained large numbers of fine filaments with focal densities similar to those described in smooth muscle cells. They also showed a moderately developed r ER. These features are consistent with cells referred to as myofibroblasts.

Kinetics of osteoclast formation: the significance of blood monocytes as osteoclast precursors during 1 alpha-hydroxycholecalciferol-stimulated bone resorption in the mouse.

The significance of blood monocytes as a source of osteoclast precursors was investigated during 1 alpha-hydroxycholecalciferol-stimulated bone resorption in mice. Animals were given three injections of tritiated thymidine at 8 hourly intervals in order to label blood monocytes. The proportion of labelled monocytes was then compared with the proportion of labelled nuclei in osteoclasts, the formation of which was provoked by daily injections of 1 alpha-hydroxycholecalciferol, beginning 48 hours after the first injection of isotope. Although more than 60% of blood monocytes were labelled during the period of peak osteoclast formation, labelling of osteoclast nuclei in the metaphyseal endosteum of the femur never exceeded 8%. These results suggest strongly that the majority of osteoclast nuclei were derived from a source of unlabelled precursors, and that very few osteoclasts were derived directly from blood monocytes. Although few labelled osteoclasts were found, the proportion of labelled spindle shaped cells in the metaphyseal endosteum rose gradually to 16%. It is likely, therefore, that labelled mononuclear cells, possibly blood monocytes, were attracted to the endosteum where they formed a population of tissue macrophages. At this site they may participate in bone resorption, either individually or by providing a local pool of osteoclast precursors.

Formation of osteoclasts from blood monocytes during 1 alpha-OH Vit D-stimulated bone resorption in mice.

In order to investigate a monocyte origin for osteoclasts, tritiated thymidine labelled blood monocytes, harvested from the blood of donor mice, were injected intravenously into syngeneic recipient animals in which osteoclast formation was being stimulated by concomitant intraperitoneal injections of 1 alpha-hydroxycholecalciferol. Labelled osteoclasts were found in autoradiographs prepared from the femurs of recipient mice, demonstrating for the first time that, during hormonally stimulated osteoclast formation, blood monocytes form one source of osteoclasts.

Osteoclast formation in response to intraperitoneal injection of 1 alpha-hydroxycholecalciferol in mice.

In order to assess osteoclast formation in response to 1 alpha-hydroxycholecalciferol, osteoclast counts per cm of bone surface were performed on paraffin sections of femurs of male CBA mice killed at daily intervals up to 5 days. All animals received daily intraperitoneal injections of 1 alpha-hydroxycholecalciferol up to the time of death. Peak osteoclast formation occurred during the third day, by the end of which maximum numbers of osteoclasts were achieved (11.9 +/- 0.9 osteoclast cm-1) compared to controls (3.5 +/- 0.6 osteoclast cm-1), this increase being highly significant (p less than 0.01). Although the osteoclast population was most dense at the metaphyseal plate in both experimental and control groups, osteoclast counts in this region only doubled whereas overall osteoclast counts more than tripled. The number of nuclei per osteoclast did not significantly alter following four daily injections of 1 alpha-hydroxycholecalciferol.