Effect of monensin on milk production efficiency and milk composition in lactating dairy cows fed modern diets.

Since the US Food and Drug Administration's approval of monensin in 2004, significant nutritional advances have been made to increase feed efficiency and milk fat production. Recent evidence suggests monensin's adverse effect on milk fat percentage may be absent when diets are formulated to address known diet-induced milk fat depression risk factors. Thus, study objectives were to evaluate effects of monensin level on dry matter intake (DMI), milk production and composition, and efficiency of high-producing cows fed diets formulated to optimize milk fat. Ninety-six lactating Holstein cows (36 primiparous, 60 multiparous; 106 ± 17 d in milk [DIM]) were balanced by parity, DIM, and milk production and were randomly assigned to 1 of 12 pens with 8 cows per pen. All cows received 11 g/t monensin for 5 wk after which pens received 1 of 4 dietary treatments (n = 3) formulated to provide 0 (CON), 11 (R11), 14.5 (R14.5), or 18 (R18) g/t monensin for 9 wk. The basal diet was 54% forage, 27% NDF, 29% starch, and 2.3% rumen unsaturated fatty acid load. Pen was the experimental unit and data were analyzed using the Fit Model Procedure of JMP. Effects of treatment, time, and treatment × time interaction were included as fixed effects and pen as a random effect. Least squares means were determined and linear and quadratic contrasts were tested. Dry matter intake tended to decrease linearly with increasing monensin dose. Milk yield, fat percentage, and protein percentage and yield were unaffected by treatment while fat yield was quadratically increased. Milk de novo and mixed fatty acid (FA) yields (g/d) increased quadratically with monensin whereas preformed FA linearly decreased during the experimental period. Energy-corrected milk (ECM) was quadratically increased by monensin. Milk urea nitrogen concentrations increased linearly with increasing monensin dose. Monensin linearly increased feed efficiency (ECM/DMI, 3.5% fat-corrected milk/DMI, and solids-corrected milk/DMI). Body weight gain did not differ between treatments. Estimated dietary energy tended to increase linearly with increasing monensin level. These data suggest monensin improves component-corrected milk production efficiency, estimated dietary energy, and does not negatively affect milk fat percentage or FA profile.

Effect of prepartum anionic supplementation on periparturient feed intake, health, and milk production.

Our objectives were to determine if dietary cation-anion difference (DCAD) and source of anions influence periparturient feed intake and milk production of dairy cattle during the transition period. Diets differed in DCAD (cationic or anionic) and anionic supplement. The 4 diets used prepartum were (1) control [DCAD +20 mEq/100g of dry matter (DM)], (2) Bio-Chlor (DCAD -12 mEq/100g of DM; Church & Dwight Co. Inc., Princeton, NJ), (3) Fermenten (DCAD -10 mEq/100g of DM; Church & Dwight Co. Inc.), and (4) salts (DCAD -10 mEq/100g of DM). Urine pH was lower for cows that consumed an anionic diet prepartum compared with control. Prepartum diet had no effect on prepartum dry matter intake (DMI) of multiparous or primiparous cows. Postpartum DMI and milk yield for multiparous cows fed anionic diets prepartum were greater compared with those fed the control diet. Postpartum DMI and milk yield of primiparous cows were similar for prepartum diets. Feeding prepartum anionic diets did not affect plasma Ca at or near calving. However, cows fed anionic diets began their decline in plasma Ca later than control cows. Postpartum ß-hydroxybutyrate and nonesterified fatty acids were lower for primiparous cows fed prepartum anionic diets compared with those fed the control diet. Prepartum and postpartum plasma glucose concentrations were not affected by prepartum diet for all cows. Liver triglyceride differed for parity by day. Parities were similar at 21 d prepartum, but at 0 d and 21 d postpartum, levels were greater for multiparous cows. Results indicate that decreasing the DCAD of the diet during the prepartum period can increase postpartum DMI and milk production of multiparous cows without negatively affecting performance of primiparous cows.

Dry matter intake and blood parameters of nonlactating Holstein and Jersey cows in late gestation.

An experiment was conducted using 14 multiparous Holstein and 14 multiparous Jersey cows to determine if dry matter intake (DMI), specifically the decline in prepartum DMI and plasma parameters differed between breeds. Cows were blocked by expected calving date and received a dry cow total mixed ration (15% crude protein and 39% neutral detergent fiber) beginning 30 d before expected calving date. At calving, cows were switched to a lactation total mixed ration (17% crude protein and 33% neutral detergent fiber). Data were collected from d 23 prepartum to d 1 postpartum. Body weight was greater for Holsteins compared with Jerseys, but body condition score did not differ between breeds. Dry matter intake decreased for both Holsteins and Jerseys as parturition approached. The interaction of breed x day prepartum was significant for DMI with the magnitude of depression being greater for Holsteins compared with Jerseys. Plasma glucose and beta-hydroxy-butyrate was similar between breeds. Plasma nonesterified fatty acids (NEFA) were similar for the two breeds up to d 5 prepartum, but greater for Holsteins compared with Jerseys thereafter. The decline in prepartum DMI was positively correlated to plasma NEFA for Holsteins, but not for Jerseys. These results indicate that breed differences exist for the decline in prepartum DMI and plasma NEFA. In addition, these data show an association between prepartum DMI depression and plasma NEFA but do not suggest a causal relationship.

Recalcitrant Trichomonas vaginalis infection--a case series.

The objective of this study was (1) to estimate the prevalence of recalcitrant Trichomonas vaginalis (TV) infection in a UK genitourinary medicine clinic; (2) to use a case series and literature review to suggest an algorithm for management of recalcitrant TV (rTV). A retrospective review of laboratory records, case-notes and literature review was conducted. Fifteen patients were studied, representing 1.16% of the cases presenting during the study period. A wide variety of therapeutic agents was used, the treatment regimen differed for each patient. No treatment was universally effective in achieving cure, but the use of acetarsol pessaries vaginally appeared to be the most frequently successful strategy. Based on these results, an algorithm for treatment of rTV is presented, although clinical trials will be needed to elucidate the best clinical approaches to this problem.

The use of therapeutic drug monitoring in the management of protease inhibitor-related toxicity.

The aim of this project was to determine whether therapeutic drug monitoring (TDM) and subsequent dose modification is effective in the management of protease inhibitor (PI)-associated toxicity. A retrospective case-notes review of patients who had had TDM for suspected antiretroviral drug toxicity from November 2000 to March 2002 was carried out. This identified six symptomatic patients in whom high plasma drug levels of a PI had been found and subsequent dose modification was associated with improvement/resolution of symptoms. In 5/6 patients viral loads were below the level of detection prior to TDM and remained so after dose reduction of PI. TDM-directed dose modification of PI enables patients to continue effective regimens of highly active antiretroviral therapy, thus avoiding the need to switch the regimen.

A cognitive behavioural intervention to reduce sexually transmitted infections among gay men: randomised trial.

OBJECTIVE: To determine the effectiveness of a brief cognitive behavioural intervention in reducing the incidence of sexually transmitted infections among gay men. DESIGN: Randomised controlled trial with 12 months' follow up. SETTING: Sexual health clinic in London. PARTICIPANTS: 343 gay men with an acute sexually transmitted infection or who reported having had unprotected anal intercourse in the past year. MAIN OUTCOME MEASURES: Number of new sexually transmitted infections diagnosed during follow up and self reported incidence of unprotected anal intercourse. RESULTS: 72% (361/499) of men invited to enter the study did so. 90% (308/343) of participants returned at least one follow up questionnaire or re-attended the clinic and requested a check up for sexually transmitted infections during follow up. At baseline, 37% (63/172) of the intervention group and 30% (50/166) of the control group reported having had unprotected anal intercourse in the past month. At 12 months, the proportions were 27% (31/114) and 32% ( 39/124) respectively (P=0.56). However, 31% (38/123) of the intervention group and 21% (35/168) of controls had had at least one new infection diagnosed at the clinic (adjusted odds ratio 1.66, 95% confidence interval 1.00 to 2.74). Considering only men who requested a check up for sexually transmitted infections, the proportion diagnosed with a new infection was 58% (53/91) for men in the intervention group and 43% (35/81) for men in the control group (adjusted odds ratio 1.84, 0.99 to 3.40). Using a regional database that includes information from 23 sexual health clinics in London, we determined that few participants had attended other sexual health clinics. CONCLUSIONS: This behavioural intervention was acceptable and feasible to deliver, but it did not reduce the risk of acquiring a new sexually transmitted infection among these gay men at high risk. Even carefully designed interventions should not be assumed to bring benefit. It is important to evaluate their effects in randomised trials with objective clinical end points.

Africans in London continue to present with advanced HIV disease in the era of highly active antiretroviral therapy.

Our findings show that despite the numerous advances in the management of HIV disease, this has not resulted in earlier presentation in Africans or non-Africans. African patients are still presenting with significantly more advanced disease than non-Africans, and are more likely to have AIDS at presentation in 1998-1999 than in 1982-1995. An urgent need exists to identify the factors associated with delayed presentation, both to optimize clinical outcomes and reduce the possibility of onward transmission.

Oral mucosal leishmaniasis as a presenting feature of HIV infection and its management.

Leishmaniasis is a chronic parasitic protozoal disease transmitted by sandfly vectors and is endemic in some regions of South America, Asia, Africa and Mediterranean countries. This case report describes a British patient who presented with oral mucosal leishmaniasis and in whom it was also the first sign of HIV disease. We believe it is the first reported case of isolated oral mucosal leishmaniasis as a presenting feature of otherwise unknown HIV infection.

Empirically treated Pneumocystis carinii pneumonia in London, 1983-1989.

For 227 episodes of Pneumocystis carinii pneumonia (PCP) treated at St Mary's between 1983 and 1989, factors predictive of fatal outcome were age, haemoglobin levels, peripheral lymphocyte count and alveolar-arterial oxygen gradient. Case fatality for the 47 empirically-treated episodes was significantly higher compared with the 180 cytologically proven episodes (55% vs 18%, chi 2 = 25.7, P less than 0.0001). Case fatality for episodes which could not be bronchoscoped was significantly higher compared with bronchoscopy negative cases (66% vs 25%, chi 2 = 4.5, P less than 0.05). Predictive factors for fatal outcome differed significantly for cases which could not be bronchoscoped and cytologically proven cases: haemoglobin level (10.7 g/dl vs 12.0 g/dl, P less than 0.001), lymphocyte count (0.64 x 10(9)/l vs 0.87 x 10(9)/l, P = 0.05) and oxygen gradient (77.7 mmHg vs 58.9 mmHg, P less than 0.02). Such differences were not observed between bronchoscopy negative and cytologically proven cases. Case fatality decreased significantly over time (b = -0.39, SE = 0.14, P less than 0.05). Total and non-fatal first time episodes displayed an inverse relationship between oxygen gradient and time (r = -0.22, P less than 0.006 and r = -0.24, P less than 0.01, respectively). Mean oxygen gradient of fatal episodes for sequential years increased significantly from 73 mmHg in 1983 to 102 mmHg in 1989 (r = 0.92, P less than 0.01). This suggests that medical intervention as well as presentation with less severe disease both contributed to improved case fatality over time.

Improved outcome of Pneumocystis carinii pneumonia in AIDS patients: a multifactorial treatment effect.

Factors determining the outcome of an episode of Pneumocystis carinii pneumonia (PCP) in 149 AIDS patients treated at St Mary's Hospital were identified and their importance on improved survival evaluated between 1984 and 1989. The proportion of fatal episodes of PCP decreased over time. Fatal compared with nonfatal episodes had lower mean alveolar-arterial oxygen gradient (82.5 mmHg vs 53.8 mmHg, P less than 0.001), mean haemoglobin level (11.2 g/dl vs 12.1 g/dl, P = 0.01), mean lymphocyte count (0.68 x 10(9)/l vs 0.92 x 10(9)/l, P = 0.05) and more coinfections (31% vs 5%, P less than 0.001). Over time, the most significant change which occurred was a reduction in alveolar-arterial oxygen gradient at time of first presentation with PCP (r = -0.37, P less than 0.001). Mean alveolar-arterial oxygen gradient declined from 79.9 mmHg in 1984 to 45.3 mmHg in 1989 (r = -0.88, P = 0.02), independently of zidovudine therapy or PCP prophylaxis. Patients were being treated at an earlier stage in their disease course as indicated by their reduced alveolar arterial oxygen gradient. This is due either to earlier patient presentation, earlier medical diagnosis or both. The widespread introduction of zidovudine and PCP prophylaxis may further contribute to improve morbidity and mortality patterns in the future.

Auditory function in patients infected with the human immunodeficiency virus.

A prospective study of auditory function in 18 HIV positive male patients at different CDC (Centres for Disease Control) stages was undertaken. One-third had abnormalities on either auditory evoked response testing or pure tone audiometry. No correlation was found between interwave latencies I-V, I-III, III-V and stage of disease determined either clinically or by T-cell subset. There was a weak correlation between pure tone averages at 1,2,4 kHz and 2,4,8 kHz and T-cell subset ratio in CDC Group IV disease (Rs = 0.56 and 0.57 respectively; P less than 0.05). Abnormalities of BSER were similar to those previously reported in HIV infection, and suggest isolated changes within the brain-stem.

Cytomegalovirus ulceration of the oropharynx.

Cytomegalovirus (CMV) is a common opportunistic infection in both iatrogenic and HIV-induced immunosuppression. The usual sites of involvement are the gastro-intestinal tract, retina and lung. We present three cases of CMV ulceration of the oropharynx. All three patients presented with symptoms localized to the oropharynx and in each case the diagnosis was only made on histological examination of ulcer biopsy specimens. The patients all responded well to ganciclovir treatment and at writing none have required maintenance therapy (7-11 months post diagnosis).

Sexual assault of men: a series.

The case records of five male victims of sexual assault presenting to two genito-urinary clinics are presented. The cases were chosen to illustrate the variety of presentations and possible sequelae of sexual assault of adult males.