BackgroundThe American Heartworm Society currently recommends the use of a monthly macrocyclic lactone, a 28-day course of 10 mg/kg doxycycline BID, and the 3-dose protocol of melarsomine dihydrochloride for the treatment of canine heartworm disease. Doxycycline is necessary for the reduction of the bacterium Wolbachia, found in all heartworm life-stages. Previous price increases and decreasing availability prompted us to evaluate alternative tetracycline antibiotics, i.e. minocycline, for the reduction of Wolbachia during canine heartworm treatment.MethodsThirty-two heartworm-positive dogs were randomized to receive 10 mg/kg or 5 mg/kg of either doxycycline or minocycline for 28 days BID, for a total of 8 dogs per experimental group. All dogs received 6 months of Heartgard Plus® (ivermectin/pyrantel) and the 3-dose protocol of 2.5 mg/kg melarsomine dihydrochloride. Blood samples were collected prior to the initiation of treatment, every 7 days throughout tetracycline treatment, and then monthly thereafter until the dog tested negative for the presence of heartworm antigen. DNA was isolated from circulating microfilarial samples and qPCR was performed on each sample.ResultsA greater number of dogs in the 10 mg/kg doxycycline and minocycline treated groups experienced gastrointestinal side effects as compared to the 5 mg/kg doxycycline and minocycline treated groups. All eight dogs in the 10 mg/kg doxycycline-treated group tested negative for the presence of Wolbachia DNA by 28 days post-tetracycline treatment. A total of two dogs in both the 5 mg/kg doxycycline- and 10 mg/kg minocycline-treated groups and three dogs in the 5 mg/kg minocycline-treated group remained positive for the presence of Wolbachia DNA by the end of tetracycline treatment.ConclusionsNo lung pathology was assessed in this clinical trial, therefore the clinical effect of the remaining Wolbachia DNA in the 10 mg/kg minocycline-, 5 mg/kg doxycycline- and 5 mg/kg minocycline-treated groups cannot be determined. Owner compliance in the proper administration of these tetracyclines may be impacted by the increased severe gastrointestinal side effects reported for the 10 mg/kg doxycycline- and minocycline-treated groups. We recommend that veterinarians prescribe the recommended 10 mg/kg doxycycline for canine heartworm treatment and reduce the dosage to 5 mg/kg in cases of severe gastrointestinal side effects in order to improve owner compliance in administration of medications.

The processes by which the storage proteins of seeds, especially legume seeds, are converted to the proteins of the growing organs of the seedling have been an object of study since the early days of plant biochemistry (4). It has usually been believed that the reserve proteins are hydrolyzed to their constituent amino acids, which are interconverted before or after their transport to the site of new protein synthesis. The interconversions lead to the proper array of amino acids to make up the new proteins. However, recent MATERIALSPea seeds (Pisum sativurn L. var. Unica) (11) were obtained from Holland. The peas were surface sterilized by immersing them in 0.5 % sodium hypochlorite for 30 minutes, followed by 2 washings with sterile water. They were planted 2 inches deep in uniformly washed vermiculite (plaster aggregate) supplied with distilled water with no added nutrients. Growth was in an incubator at 180 C, and samples were taken at 1, 3 and 5 days, by which time the seedlings had not emerged through the surface. At 1 day, all seeds, except the few discolored ones, were used for the samples. Older seedlings were selected for uniformity by using, at 3 days, those between 35 and 70 mm long from root tip to shoot hook, and at 5 days, those between 115 and 180 mm long (usually about 80 % for both).After washing the seedlings free from vermiculite, the seed coat was removed. For the 1 day samples, the embryonic root-shoot axis (including the cotyledon petioles) was dissected from the cotyledons. The 3 and 5 day samples were dissected into five parts: the cotyledons; the shoot tip, to the middle of the hook; the shoot shaft, including the cotyledon petioles; the root tip, about 2.5 mm long; and the root shaft. All parts were immediately frozen on dry ice, and kept frozen until lyophilized; then they were ground in a mortar (or in a micro-Wiley mill for cotyledons) and stored at -18°C until analyzed. Where necessary, lyophilization was continued for longer than overnight in order to bring the samples to less than 5 I% moisture. No correction for this residual moisture has been made in the calculations, but mechanical losses during grinding were allowed for.The initial seed samples were dissected without any preliminary softening by moistening. In fact it was found best to reduce the normal moisture content by drying the seeds in a vacuum desiccator for about a week. Each seed then cracked readily when struck lightly with a pestle, the seed coat fell away, and the embryonic root-shoot axis was cut away from the cotyledons mainly on the basis of its different color.

No abstract

No abstract

No abstract