Phenoxymethylpenicillin Research Articles

Pharmacodynamic Analysis and Clinical Trial of Amoxicillin Sprinkle Administered Once Daily for 7 Days Compared to Penicillin V Potassium Administered Four Times Daily for 10 Days in the Treatment of Tonsillopharyngitis Due to Streptococcus pyogenes in Children

An a priori pharmacokinetic/pharmacodynamic (PK/PD) target of 40% daily time above the MIC (T >MIC; based on the MIC(90) of 0.06 microg/ml for Streptococcus pyogenes reported in the literature) was shown to be achievable in a phase 1 study of 23 children with a once-daily (QD) modified-release, multiparticulate formulation of amoxicillin (amoxicillin sprinkle). The daily T >MIC achieved with the QD amoxicillin sprinkle formulation was comparable to that achieved with a four-times-daily (QID) penicillin VK suspension. An investigator-blinded, randomized, parallel-group, multicenter study involving 579 children 6 months to 12 years old with acute streptococcal tonsillopharyngitis was then undertaken. Children were randomly assigned 1:1 to receive either the amoxicillin sprinkle (475 mg for ages 6 months to 4 years, 775 mg for ages 5 to 12 years) QD for 7 days or 10 mg/kg of body weight of penicillin VK QID for 10 days (up to the maximum dose of 250 mg QID). Unexpectedly, the rates of bacteriological eradication at the test of cure were 65.3% (132/202) for the amoxicillin sprinkle and 68.0% (132/194) for penicillin VK (95% confidence interval, -12.0% to 6.6%). Thus, neither antibiotic regimen met the minimum criterion of > or =85% eradication ordinarily required by the U.S. FDA for first-line treatment of tonsillopharyngitis due to S. pyogenes. The results of subgroup analyses across demographic characteristics and current infection characteristics and by age/weight categories were consistent with the primary-efficacy result. The clinical cure rates for amoxicillin sprinkle and penicillin VK were 86.1% (216/251) and 91.9% (204/222), respectively (95% confidence interval, -11.6% to -0.4%). The results of a post hoc PD analysis suggested that a requirement for 60% daily T >MIC(90) more accurately predicted the observed high failure rates for bacteriologic eradication with the amoxicillin sprinkle and penicillin VK suspension studied. Based on the association between longer treatment courses and maximal bacterial eradication rates reported in the literature, an alternative composite PK/PD target taking into consideration the duration of therapy, or total T >MIC, was considered and provides an alternative explanation for the observed failure rate of amoxicillin sprinkle.

Improving calf survival and performance by supplementation in Bali cattle

An on-farm experiment was conducted in several villages in the district of Kupang, East Nusa Tenggara Province (NTT), Indonesia from June to October 2007. The experiment investigated the efficacy of a supplementation strategy to improve calf survival and performance during the dry season. A total of 258 Bali (Banteng, Bos javanicus) cow–calf pairs were used in the experiment. Calves from the 190 cow–calf pairs in the treatment groups were allocated grass hay + concentrate supplementation as follows: 1% (n = 98), 2% (n = 56) and 3% (n = 42) of calf bodyweight. There were 62 cow–calf pairs in the unsupplemented control group. The supplement consisted of grass hay and concentrate (rice bran, cornmeal, leucaena leaf and fish meal) containing 18% crude protein. The supplement was introduced to calves in the morning while confined to calf pens when the dams were grazing. Calves were reunited with the cows during the night. Parameters measured were calf mortality, calf and cow daily gain, and milk production. Supplementation tended to reduce calf mortality (P = 0.094) from 6.4% in control to 0% in calves receiving 2% and 3% supplement. Levels of supplementation significantly (P < 0.001) improved calf daily weight gain. Bodyweight changes and milk production of cows were unaffected by calf supplementation. It can be concluded that supplementation at 2% calf bodyweight reduces calf mortality and improves calf weight gain.

Development and validation of an HPLC method for the determination of penicillin antibiotics residues in bovine muscle according to the European Union Decision 2002/657/EC

A high-performance liquid chromatographic method was developed for the determination of five penicillins: penicillin G (PENG), penicillin V (PENV), oxacillin (OX), cloxacillin (CLO), and dicloxacillin (DICLO), in bovine muscle. Samples were macerated with a mixture of H(2)O/CH(3)CN (1:1) and purified using RP-8 Adsorbex SPE cartridges after centrifugation, with mean recovery from spiked samples higher than 89%. The separation of the examined penicillins was achieved on an analytical column, an Inertsil C8 5 microm, 250x4 mm(2), at ambient temperature. The mobile phase consisted of 0.1% TFA/ACN 50:50 v/v delivered isocratically at a flow rate of 1.1 mL/min. Analytes were monitored at 240 nm. The procedure was validated according to the European Union Decision 2002/657/EC by means of selectivity, stability, decision limit, detection capability, accuracy, and precision. Method's LOQ values achieved were 54 microg/kg for PENG and DICLO, 46 microg/kg for PENV, 16 microg/kg for OX, and 43 microg/kg for DICLO. The detection capabilities (CC(beta)) were 73.6 microg/kg for PENG, 29.1 microg/kg for PENV, 350.6 microg/kg for OX, 379.9 microg/kg for CLO, and 355.8 microg/kg for DICLO. The method was applied to various samples from the local market. Two penicillins were identified by photodiode array (PDA) detection and quantified.

Comparative bioavailability study of two phenoxymethylpenicillin potassium tablet formulations in healthy volunteers

The aim of this study was to evaluate the performance of 2 phenoxymethylpenicillin 500,000 UI tablet formulations in healthy human volunteers. The study was conducted using an open, randomized crossover design with a 7-day washout interval. A single dose of each formulation was administered to 26 healthy volunteers as assessed by clinical and laboratory test evaluations. The plasma samples were obtained over an 8-h interval and phenoxymethylpenicillin concentrations were quantified by a suitable and validated HPLC-UV method with detection at 220 nm. Systolic and diastolic blood pressure and pulse rate measurement were taken pre dose and at intervals up to 8 h. Tolerance of both products was adequate. The mean of Meracilina/Pen-Ve-Oral 500,000 UI% geometric mean was 99.89% for AUC0-t, 100.86% for AUC0-infinity and 101.11% for Cmax. The 90% confidence intervals were 94.62 - 105.46%, 95.22 - 106.83% and 98.61 - 103.87%, respectively. The mean recovery of phenoxymethylpenicillin was 94.8%, while the retention time observed for phenoxymethylpenicillin and phenytoin (internal standard) was 4 and 10 min, respectively. The limit of quantification was 0.10 mg/l. Since the 90% CI for AUC0-t, AUC0-infinity and Cmax ratios were all within the 80 - 125% interval proposed by the US FDA and accepted by ANVISA, it was concluded that the Meracilina formulation (manufactured by AchA(c) S.A.) is bioequivalent to Pen-Ve-Oral (manufactured by Eurofarma) for both the rate and the extent of bioavailability.

Salmonella Typhimurium persistence in a Hunter Valley dairy herd

An epidemiological study was undertaken at a Hunter Valley dairy with persistent Salmonella Typhimurium infection. The aim of the study was to identify cattle currently or previously infected with Salmonella, possible sources of the organism, patterns of spread, and husbandry practices that could be improved. Faecal samples, feed, water and environmental samples were cultured for Salmonella and blood samples were tested for antibodies against Salmonella (Dublin and Typhimurium). A questionnaire was designed to identify possible risk factors associated with Salmonella excretion. S Typhimurium was apparently introduced from an old to a new dairy through manure spread as fertiliser. Salmonella apparently persisted in the effluent pond, and the following year clinical cases occurred after pasture, irrigated with water from the pond, was grazed by dry cows, and adult cattle became clinically ill with salmonellosis. The disease spread to other cows and calves. Poor design of calf pens assisted spread of Salmonella from sick to healthy calves. In addition, there was suspected transmission to the dairy farmer's 9-month-old daughter. Salmonellosis on a farm is a potential zoonotic risk to farm workers and their families. There is also the risk that cull cows may carry Salmonella to the abattoir and subsequently into the human food chain. Methods of waste management, and the design of calf pens, were identified as major risk factors that could be improved to minimise the spread of salmonellosis on this property.

The labour input associated with calf care on Irish dairy farms

The objective of this study was to quantify the overall labour requirement for calf care and how it is influenced by enterprise scale and facilities, together with an evaluation of specific calf-feeding systems with respect to labour requirement and calf performance. One hundred and twenty nine spring-calving dairy herds participated in the investigation of overall labour input. Herds were categorized into three groups depending on herd size (small = < 50 cows, medium = 50 to 80 cows, large = > 80 cows). The total average time consumed by calf care per farm increased ( P < 0.01) with herd size and the average time consumed per calf was highest in the small herd group (2.1 min/day). The proportion of farms bucket feeding was lower ( P < 0.05) and the proportion feeding calves ad libitum and using cold milk was higher ( P < 0.05) with the large group compared to the small herd group. Fifty-seven of the 129 herds participated in the measurement of labour input associated with specific calf-feeding systems. The labour input time per calf required for the task of milk feeding tended ( P = 0.08) to be longer when calves were fed twice daily, using buckets or teats compared to automatic feeders, once daily feeding with teats and twice daily feeding with a trough. The labour input per calf for the cleaning of milk feeding equipment and for bedding and cleaning calf pens was greater ( P < 0.05) with automatic feeding systems compared to the other feeding systems. A further sub-set of ten herds (from the 57 herds) underwent calf performance measurements. The mean calf weight at day 77 for automatic feeding, once daily feeding, twice daily feeding with teats and twice daily feeding with troughs was 95, 95, 93, 91 kg, respectively. In conclusion, labour input associated with calf care was influenced by herd size (and indirectly calf number), and calf-feeding system. Milk feeding of calves on a once daily basis tended to reduce the total labour input per calf and did not adversely affect calf performance. Thus, it is possible to improve efficiency of calf care by selecting time efficient methods of calf-feeding without affecting calf performance.

Propionibacterium acnes: an under-appreciated cause of post-neurosurgical infection

Propionibacterium acnes is increasingly recognized as a cause of post-neurosurgical infection. This review of patients with P. acnes neurosurgical infection was carried out in order to determine clinical characteristics and outcomes in relation to duration of antimicrobial treatment. We retrospectively reviewed the charts of consecutive patients with P. acnes isolated from neurosurgical specimens from 1 January 1999 to 30 June 2005. We defined P. acnes neurosurgical infection as isolation of P. acnes alone from a sterile neurosurgical site in a patient who clinically improved following treatment with an appropriate antibiotic. We identified 28 patients with definite P. acnes neurosurgical infection; median age 49 years (range 23-77); 15 (54%) male. All patients had prior neurosurgical procedures: 27 (96%) post-craniotomy. The median time from surgery to presentation was 54 days (range 12-1,578). Eighteen out of 28 (64%) patients who met the definition of neurosurgical infection had Gram-positive bacilli seen in at least one surgical specimen compared with only 2/56 (4%) patients who did not meet the definition (P < 0.0001). Intravenous benzyl penicillin +/- oral penicillin VK was the most common treatment. The median duration of antibiotic treatment for intracranial infection was 29 days. Five of nine patients who had extracranial bone-flap-associated infection had <or=7 days of intravenous treatment and were cured. Two patients had relapse or reinfection. P. acnes neurosurgical infection often presents in an indolent fashion. Gram-positive bacilli on Gram stain should not be discounted as a contaminant in neurosurgical specimens. Associated bone flaps should be removed. Intravenous benzyl penicillin +/- oral penicillin VK remains effective treatment.

Effects of short-term exposure of feeder cattle to calves persistently infected with bovine viral diarrhea virus

Research using 2,954 auction-derived feeder steers and heifers was conducted at a single commercial feedlot in Kansas to determine the effects of testing for cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) at 10-14 days-on-feed (DOF), and removing them at 13-18 DOF. After removal of test-positive animals, the effect of the short-term exposure (STE) to PI cattle on health, performance and carcass characteristics was determined. The percentage of calves exhibiting signs of illness was increased (P&lt;0.01) in cattle with STE to PI-BVDV. Cattle with no exposure (NE) to PI-BVDV calves had a morbidity rate of 18.8%, while a 29.6% morbidity rate was observed in pens of calves with STE to a PI-BVDV calf. Characterization of the temporal pen morbidity rate of STE and NE calves revealed that 31.7% of all STE and 15.3% of NE illness occurred in the first seven DOF. Additionally, the incidence of cattle treated for bovine respiratory disease in STE calves was 2.17 (95% CI 1.73 to 2.72) initial treatments per 1,000 head-days at risk, whereas the incidence of treatment of calves in NE pens was 1.28 (95% CI 0.98 to 1.68) initial treatments per 1,000 head-days at risk. Short-term exposure to PI-BVDV calves had no effect on retreatment rate, death loss, or performance. There was no evidence of a BVD-PI exposure X sex interaction (P=0.62) for carcasses that graded USDA Choice or better, but there was a main effect of sex (P&lt;0.01). There was evidence of a BVD-PI exposure X sex interaction for Yield Grade 2 or greater carcasses (P=0.03). In this study, testing at 10-14 DOF was too late in the feeding period to eliminate the initial morbidity spike that occurred during 0-7 DOF, and the subsequent morbidity differences between calves with STE or NE to PI calves.

Aminopenicillin-induced exanthema allows treatment with certain cephalosporins or phenoxymethyl penicillin

Aminopenicillin-induced exanthema poses a problem in the management of infectious diseases. Due to theoretically possible immunological cross-reactivity, all beta-lactam drugs, i.e. penicillins, penicillin derivatives and cephalosporins, are usually avoided. The available alternative antibiotics (macrolides, quinolones and glycopeptides) may be less effective, have more side effects, and their use increases medical costs. Moreover, their use contributes to the increasing bacterial resistance to antibiotics. The aim of the study is to demonstrate that patients with aminopenicillin-induced exanthema may receive specific beta-lactams for future antibiotic therapy. Skin testing followed by oral challenges to identify beta-lactams that are tolerated by patients despite confirmed delayed-type non-immunoglobulin E (IgE)-mediated allergic hypersensitivity to aminopenicillins. Sixty-nine out of 71 patients (97.2%) with non-IgE-mediated allergic hypersensitivity to aminopenicillins tolerate cephalosporins without an aminobenzyl side chain such as cefpodoxime or cefixime and 51 patients (71.8%) also tolerate phenoxymethyl penicillin. The majority of patients with non-IgE-mediated allergic hypersensitivity to aminopenicillins do not cross-react to certain cephalosporins or phenoxymethyl penicillin. Skin and drug challenge tests can be helpful to determine individual cross-reactivity.

A Patient With Sickle Cell Disease and a Low Baseline Sleeping Oxygen Saturation

A Patient With Sickle Cell Disease and a Low Baseline Sleeping Oxygen Saturation

Amoxicillin Pulsatile – MiddleBrook

Amoxicillin Pulsatile – MiddleBrook

Liječenje akutnih infekcija gornjih respiratornih puteva u ordinaciji porodične medicine

Acute respiratory infections (ARI), represent the most frequent infections in general. ARI, particularly those located in the upper respiratory tract, are often the reason for seeing the family medicine doctor and the pediatrician. The aim of the study was to examine the incidence of the upper respiratory tract ARI in the family medicine practice, applied diagnostic procedures and the way of treatment, with particular emphasis to prescription of antibiotics. The data were taken from the patients' medical records, and were related to the age, sex, diagnostic procedures, indication, ways and successfulness of the treatment. Out of 294 examined patients with the signs and symptoms of ARI, acute infection of the upper respiratory channels has been diagnosed in 197 cases (67.0%). There were established acute pharyngitis and tonsillitis, as well as acute respiratory infections of multiple and nonspecific localizations. In the majority of patients, the diagnose was established solely on the basis of the clinical examination, performed by the family medicine doctor. Antibiotics were prescribed in 150 (76.1%) patients with the acute upper respiratory tract ARI. The most frequently prescribed were amoxicillin, phenoxymethyl penicillin, amoxicillin with clavulanic acid, cefaclor and azithromycin. Symptomatic therapy was recommended to all the patients. It was established an excessive use of antibiotics in treatment of acute upper respiratory tract infections and it was emphasized the necessity of a more rational approach in their treatment. Particularly irrational application of antibiotics was observed in treatment of acute noncomplicated sinusitis, acute pharyngitis and tonsillitis.

Incidence of Allergic Reactions Associated with Antibacterial Use in a Large, Managed Care Organisation

Data on the incidence of serious allergic reactions to fluoroquinolone antibacterials are mainly derived from spontaneous reports that cannot be used to accurately estimate incidence. This study estimated the drug-specific incidence of serious allergic reactions after fluoroquinolone, cephalosporin and phenoxymethylpenicillin potassium exposure, using claims for healthcare services with confirmation through medical record abstraction within a large health insurer database. Cohorts exposed to each antibacterial of interest (moxifloxacin, levofloxacin, ciprofloxacin, gatifloxacin, cephalosporins and penicillin) were identified, and followed for 14 days for anaphylaxis (9th revision of the International Classification of Diseases [ICD-9] code 995.0), other allergic drug reactions (ICD-9 995.2, 995.3) or cardiopulmonary resuscitation. The incidence per 10,000 first dispensings of any allergic diagnosis made in the hospital or emergency department was similar for moxifloxacin (4.3; 95% CI 3.5, 5.3), penicillin (4.7; 95% CI 3.8, 5.7) and ciprofloxacin (5.4; 95% CI 4.4, 6.5). The incidence for moxifloxacin was lower than that for levofloxacin (8.7; 95% CI 7.4, 10.0), gatifloxacin (6.7; 95% CI 5.6, 7.9) and the cephalosporins (7.5; 95% CI 6.3, 8.8). The incidence of anaphylaxis/anaphylactoid reactions after first dispensings was similar for the fluoroquinolones: 0.1 (95% CI 0.0, 0.3) for ciprofloxacin, 0.3 (95% CI 0.1, 0.5) for moxifloxacin, 0.3 (95% CI 0.1, 0.6) for gatifloxacin and 0.5 (95% CI 0.3, 0.9) for levofloxacin; and comparable with that of the cephalosporins (0.2; 95% CI 0.0, 0.4) and penicillin (0.1; 95% CI 0.0, 0.3). Anaphylactic reactions were rare and their incidence did not differ substantially among the drug groups studied. By determining the occurrence of reactions following defined exposures, these results provide a context for the interpretation of spontaneous reports of allergic reactions.

Calf Respiratory Disease and Pen Microenvironments in Naturally Ventilated Calf Barns in Winter

Relationships between air quality, a variety of environmental risk factors, and calf respiratory health were studied in 13 naturally ventilated calf barns during winter. A minimum of 12 preweaned calves were randomly selected and scored for the presence of respiratory disease in each barn. An air sampling device was used to determine airborne bacteria colony-forming units per cubic meter (cfu/m3) of air in calf pens and central alleys within the barns. Airborne bacteria samples were collected on sheep blood agar (BAP) and eosin methylene blue (EMB) agar plates. Temperature and relative humidity were recorded in each calf pen, the barn alley, and outside the barn. Samples of bedding were collected in each pen and DM was measured. Pen bedding type and a calf nesting score (degree to which the calves could nestle into the bedding) was assigned to each barn. Calf numbers, barn and pen dimensions, ridge, eave, and curtain openings, and exterior wind speed and direction were determined and used to estimate building ventilation rates. Factors that were significantly associated with a reduced prevalence of respiratory disease were reduced pen bacterial counts (log10 cfu/m3) on BAP, presence of a solid barrier between each calf pen, and increased ability to nest. Individual calf pen bacterial counts were significantly different from barn alley bacterial counts on both BAP and EMB. Significant factors associated with reduced calf pen bacterial counts on BAP were increasing pen area, increasing number of open planes of the calf pen, decreasing pen temperature, and wood-particle bedding. Significant factors associated with reduced alley bacterial counts on BAP were increased ventilation changes per hour, increased barn volume per kilogram of calf, reduced pen bacterial counts, and barn type.

Predictors of Stillbirth for Cows Moved to Calving Pens when Calving is Imminent

The objective of this study was to identify predictors for stillbirth in cows moved from freestalls to a calving pen when calving is imminent. The risk of stillbirth was modeled using multivariate logistic regression. The calving ease score (CES) was contracted to three levels of assistance (1: none, 2: light and 3+: required). The advance of parturition at moving time was scored as a) presence of only mucus, b) presence of a "water bag" or c) presence of feet. The other predictors tested were parity, total serum calcium, calf weight (CW) and BCS. A total of 495 single births were observed on a 2,500-cow dairy, with 15% stillbirths. The odds ratios adjusted for the other predictors are shown. Stillbirth was not associated with BCS. Compared to unassisted calvings (CESl), the odds of stillbirth were 2.9x higher for CES2 and 46x higher for CES3+. Stillbirth odds were reduced by 36% per 1 % unit increase of CW relative to the dam (OR = 0.64), and by 22% per 1 mg/dL increase in calcium (OR = 0.78). The odds of stillbirth were 5.2x higher for heifers vs. cows. Cows moved to a calving pen earlier in the parturition process (mucus only) were 2.5x more at risk of stillbirth than those moved later with a "water bag", but presence of feet was not different from the "water bag" stage. The fact that advance of parturition, parity and serum calcium remained in the model after adjustment for CES could be due to an association with duration of calving.

Prevalence of shiga toxin-encoding bacteria and shiga toxin-producing Escherichia coli isolates from dairy farms and county fairs

Shiga toxin-encoding bacteria (STB) and shiga toxin-producing Escherichia coli (STEC) were detected and isolated from dairy cattle and their farm environment and from manure piles at Minnesota (MN) county fairs from 2001 to 2002. A total of 2540 samples were collected from 28 dairy cattle farms (8 organic and 20 conventional), 17 calf pens (5 organic and 12 conventional), and 12 county fairs. STB were detected from 71 (3.2%) of 2208 fecal samples with 20 (71.4%) of 28 dairy farms having at least one positive animal sample. In samples collected from conventional farms, 41 (2.3%) of 1750 fecal samples were STB-positive and 13 (65%) of 20 farms had at least one positive animal. Thirty (6.6%) of 458 fecal samples from organic farms were STB-positive and 7 (87.5%) of 8 farms had at least one positive animal. STB was detected from 31 (17.4%) of 178 samples and 7 (58.3%) out of 12 manure piles at county fairs. A total of 43 STEC isolates were recovered and belonged to 26 different serotypes (19 O and 18 H types). Among STEC, 60.5% possessed only stx1, 30.2% stx2, and 9.3% both stx1 and stx2. The genes eae and hlyA were detected in more than 50% of the STEC isolates. STB can be found on most dairy cattle farms including organic and conventional herds and county fairs. The presence of these potentially pathogenic bacteria in county fairs may pose a risk to the public who have contact with cattle or their environment.

Cryptosporidium and Giardia in different age groups of Danish cattle and pigs—Occurrence and management associated risk factors

To obtain information both about the prevalence of Giardia and Cryptosporidium in Danish cattle and pigs as well as the possible influence of different management systems on the occurrence and intensity of infection, we conducted an epidemiological survey comprising 50 randomly selected dairy and sow herds, respectively. Each herd was visited once for the collection of faecal samples and registration of basic management parameters. Faecal samples were collected from three different age groups of animals, i.e. 5 sows/cows, 10 nursing piglets/calves less than 1 month, and 10 weaner pigs 8–45 kg/calves 1–12 months. The faecal samples were purified and the number of (oo)cysts quantified. The study revealed an age-specific herd prevalence of Cryptosporidium of 16, 31 and 100% for sows, piglets and weaners, respectively, and of 14, 96 and 84% for cows, young calves and older calves, respectively. For Giardia the age-specific herd prevalence was 18, 22 and 84% for the sows, piglets and weaners, while for cattle herds the prevalence was 60, 82 and 100% for cows, young calves and older calves, correspondingly. The (oo)cyst excretion levels varied considerably both within and between herds for all age groups. Risk factors were evaluated by using proportional odds models with (oo)cyst excretion levels divided into four categories as response. Among the numerous risk factors examined, only a few were demonstrated to have a statistically significant influence, e.g. the use of an empty period in the calf pen between introduction of calves for both parasites had a protective effect in young calves. For weaners, use of straw in the pen and high pressure cleaning between batches of weaners had a preventive effect against higher Cryptosporidium oocyst excretion levels.

Decrease of selective immunoglobulin E response to amoxicillin despite repeated administration of benzylpenicillin and penicillin V

Subjects with IgE responses to betalactams can develop selective or cross-reactive responses after the administration of penicillin derivatives. After the reaction, however, the hapten induces a boosting phenomenon, which may increase the titre and the affinity of the antibody, with the resulting risk of developing allergic reactions to other penicillins. To determine in subjects with selective responses to amoxicillin (AX) and good tolerance to benzylpenicillin (BP) and penicillin V (PV) whether the administration of these compounds induced any change in specificity, measured by either skin or in vitro testing, which could predict the appearance of cross-reactivity. Ten subjects with a selective response to AX were followed-up for 2 years with the periodic administration of penicillin G and V (Group A) and compared with another group composed of 10 persons with identical clinical characteristics but without repeated penicillin administration (Group B). Periodic in vitro and in vivo measurements of specific IgE antibodies were performed at 6-month intervals. Patients were randomized to Group A or B according to their order of inclusion. In both groups, skin test reactivity tended to decrease, and although greater in Group A, the difference was not significant compared with Group B. Median RAST values also decreased over time and showed no differences in the exposed group compared with the controls. One patient in Group A became positive to benzylpenicilloyl (BPO), despite becoming negative to AX. Subjects with selective IgE responses to side-chain-specific determinants seem to become negative, with no influence from subsequent administration of a closely related penicillin.

Clinical Update: A Nonhealing Fractured Mandible

Bisphosphonates have shown significant clinical benefit in reducing skeletal fractures in patients with multiple myeloma or bone: penicillin VK 500 mg or amoxicillin 500 mg; both 4 times daily (QID) initially and twice daily (BID) for maintenance, If penicillin allergic: 1. Clindamycin 150 to 300 mg QID. 2. Vibramycin 100 mg once daily (QD). 3. Erythromycin ethylsuccinate 400 mg 3 times daily (TID). 4. Antifungals when required: 5. Nystatin oral suspension 5 to 15 mL QID or 100,000 IU/mL. 6. Mycelex troches (clotrimazole 10 mg) x 5/day. 7. Fluconazole 200 mg initially, then 100 mg QD. 8. Other potential systemic antifungals include itraconazole or ketoconazole. 9. Antivirals, if required: 10. Acyclovir 400 mg BID. 11. Valacyclovir hydrochloride 500 mg to 2g BID.

The effect of group size on health and growth rate of Swedish dairy calves housed in pens with automatic milk-feeders

Group pens equipped with automatic milk-feeding systems are increasingly being used for young dairy calves in Sweden. The system is, however, associated with an increased risk of clinical respiratory-tract disease and a reduced growth rate. In an experimental study we compared the health and growth rate of two different group sizes of calves (6–9 versus 12–18) kept in pens with automatic milk-feeders. The experiment was performed from September 2002 to February 2004, in nine commercial dairy farms in south-west Sweden. Each farm was equipped with two pens with automatic milk-feeders and no possibility of direct contact between calves from different pens. The calves were housed individually until 3–35 (median, 12) days of age, and then were allocated to one of the two group pens by random-number lists. Altogether 892 calves were studied: 297 in the small- and 595 in the large-sized groups. The calves’ heart girths were measured at birth and at 56 days of age. Blood samples for analysis of serum haptoglobin concentration (S-Hp) were collected once for each calf, at four to eight weeks of age. Diseases were recorded by the farmers and by a veterinarian, who visited the farms every third week and physically examined all the calves. The effects of group size on the risks of diarrhoea, clinical respiratory-tract disease and increased respiratory sounds, and on the growth rate and S-Hp were evaluated using multiple logistic- and linear-regression models with herd as fixed effect. Age at transfer to group pen, breed, immunoglobulin concentration of colostrum received, parity of the dam and presence of diarrhoea before transfer to the group pen, season, sex, year, and, in the analysis of growth rate, birth heart girth were extra explanatory variables. Calves in pens for 12–18 calves had a higher incidence of respiratory illness (OR: 1.4) and grew 0.022 cm/day less than calves housed in groups of 6–9 animals (equivalent to approximately 40 g/day). We detected no differences between calves kept in the small-sized versus the large-sized groups in terms of risk of diarrhoea or mean S-Hp. We concluded that housing calves in groups of under 10 calves is preferable from a health and growth perspective.