Bacterial adhesins as a drug carrier: covalent attachment of K99 fimbriae to 6-methylprednisolone.

A bioadhesive drug delivery system based on the covalent attachment of a therapeutic agent to bacterial fimbriae is described. This approach involves the isolation of the fimbrium K99 as well as the covalent coupling of 6-methylprednisolone to this adhesin via a linker, especially designed to be cleaved by unspecific luminal esterases. Analysis of the conjugate showed a direct correlation between solubility and coupling extent. Under physiological conditions, a conjugate exhibiting a coupling extent higher than 0.8 (mol therapeutic agent/mol fimbrial subunit) demonstrated a dramatically decrease of solubility. Release of the drug could be verified by enzymatic cleavage of the conjugate in vitro. The adhesive properties of a drug delivery system containing 6-methylprednisolone and K99 fimbriae were assayed by a haemagglutination test.

Drug-protein conjugates: preparation of triamcinolone-acetonide containing bovine serum albumin/keyhole limpet hemocyanin-conjugates and polyclonal antibodies.

A radioimmunoassay has been developed for the quantitation of triamcinolone-acetonide (TAAc) at the picogram level. For use of TAAc as an antigenic epitope first the drug was hemisuccinoylated at C-21 as confirmed by 13C-NMR- and mass spectroscopy after derivatization. This hapten was conjugated to the carrier-protein bovine serum albumin (BSA) or keyhole limpet hemocyanin (KLH) by different amide-bond generating methods (imidazolide-, carbodiimide-, carbodiimide/sulfo-N-hydroxysuccinimide-, mixed anhydride-method) yielding antigens of quite different conjugation number, solubility and usefulness. The mixed anhydride-method yielded most useful soluble conjugates bearing 0.3-31.5 mol TAAc per mol carrier-protein. Coupling by the carbodiimide-method yielded insoluble conjugates, inappropriate for antigen synthesis in hapten immunoassays because of formation of coupling agent modified residues and crosslinking of the carrier-protein. Specificity of the antisera obtained by immunization with TAAc-BSA and TAAc-KLH was assessed by isolation of the soluble hapten-antibody complex and a RIA protocol was developed providing a detection limit of 200 pg (0.46 pmol) TAAc/ml sample.

Mycobacterium phlei infection of the foot: a case report.

A case of Mycobacterium phlei infection in the flexor digitorum longus and posterior tibialis tendon of an otherwise healthy adult male is reported. To our knowledge, this is the second reported case in the English literature of human infection by M. phlei. Diagnosis and treatment of nontuberculous mycobacterial infection are discussed. The clinician is encouraged to include this infection in the differential diagnosis of pain and swelling in the extremity.

Preparation and central action of propofol/hydroxypropyl-beta-cyclodextrin complexes in rabbits.

Inclusion complexes of propofol (CAS 2078-54-8) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) were examined in aqueous solution and in the solid state by phase solubility technique, IR-spectroscopy and differential scanning calorimetry. Solid complexes obtained by kneading method were dissolved in artificial plasma leading to a colloidal solution which was suitable for intravenous administration. In the in vivo studies propofol (15 mg/kg) was given intravenously to rabbits in equimolar doses as cyclodextrin complexes and as Diprivan. The central action of the drug was verified by recording the bioelectrical activity of the precentral cortex. The statistical evaluation of the results do not indicate differences in onset, duration and maximum of action between the two dosage forms.

Longitudinal epiphyseal growth after replantation and transplantation in children.

Previous investigators have shown that epiphyses are unlikely to grow after free grafting although there have been rare reports of good and even normal growth. However, growth has usually continued whenever the epiphyseal vascular supply has been maintained by microanastomosis. Of 25 growing epiphyses in our series that were transferred, 17 by replantation and eight by free tissue transfer supported by microvascular anastomosis, over an interval varying from 27 to 81 months, average length attained was 89% of normal in elective transfer, 93% of normal in replanted digits, and 92% overall. Maximum growth attained in any digit in our series was 102% of the length of the normal contralateral digit; the minimum attained was 70%.

Neurilemoma of the lower extremity.

A series of 76 patients with 85 neurilemomas of the lower extremity was reviewed. The tumors were located throughout the lower extremity and had varied clinical presentations, which often posed problems in diagnosis. Pain, however, was a consistent symptom, and 63 (83%) of the patients presented with local or radiating (or both) pain. Electromyography was done in seven cases, but the results were abnormal in only two. When evaluating a painful mass or an atypical pain in the lower extremity, the clinician should have a high index of suspicion for neurilemoma.

Differential calcium leucovorin protection of human lymphoid cell lines from methotrexate.

Human lymphoid cell lines were studied for leucovorin requirements to protect from methotrexate (MTX)-induced growth suppression. Over a 72h continuous exposure leucovorin provided better protection to the cell lines LAZ-007 and RAJI than to the cell lines CCRF-CEM and MOLT-4. The lower leucovorin requirement for LAZ-007 protection versus CCRF-CEM was also seen over a 3h exposure period in which leucovorin protection was assessed by measuring its effect on MTX-induced suppression of 3H-deoxyuridine incorporation into acid-precipitable material. Growth experiments with addition of hypoxanthine or thymidine did not abolish differential protection, suggesting that the phenomenon is not related to selective differences in the tolerance of these cells to an MTX-induced purineless or thymineless state. Preloading of cells with calcium leucovorin caused an identical shift of the CCRF-CEM and LAZ-007 MTX dose - response curves, suggesting that differential catabolism of leucovorin does not contribute to differential protection. The same degree of differential protection was observed for 5-methyltetrahydrofolate as for leucovorin, suggesting that differences in the metabolism of leucovorin do not contribute to differential protection. To elucidate the mechanism of differential protection the influence of leucovorin on [3H]MTX transport and polyglutamylation were studied. Although the Km(MTX) influx and the Ki(leucovorin) for MTX uptake were lower in CCRF-CEM compared with LAZ-007 cells, the size of the difference does not seem adequate to explain differential protection. The extent of MTX polyglutamylation in CCRF-CEM and LAZ-007 cells was identical and the influence of leucovorin on MTX polyglutamylation was the same in both cell lines.

Comparison of leucovorin protection from variety of antifolates in human lymphoid cell lines.

Leucovorin requirements for protection of the T cell line CCRF-CEM and the B cell line LAZ-007 against the cytotoxic effects of a variety of antifolates were studied. Differential leucovorin protection for DDMP-induced growth suppression occurred in the opposite direction to that for MTX, with CCRF-CEM requiring less leucovorin than LAZ-007 for equivalent protection. A pattern of differential protection from DDMP different from that of protection from MTX was also seen for the cell lines RAJI and MOLT-4. Differential leucovorin protection was observed for the chain-extended MTX analogue PT441. The degree of differential protection was similar to that seen for MTX, and transport studies showed that PT441 was a weak inhibitor of tritiated MTX uptake into CCRF-CEM cells. Differential leucovorin protection was observed for the lipophilic antifolate trimetrexate glucoronate (TMQ) but the degree of differential protection was smaller than that seen for PT441 or for MTX. Since TMQ is not transported into cells by the reduced folate system, while PT441 is a weak competitive inhibitor of [3H]MTX transport, and since neither is polyglutamylated, these results support the conclusion reached in previous experiments that differential leucovorin protection of MTX is unlikely to be a transport-related phenomenon and is not due to an effect on polyglutamylation. In addition, the different patterns of relative leucovorin requirements for DDMP and MTX protection suggest that differential metabolism or catabolism of leucovorin does not account for differential protection.

Extensor hallucis longus transfer for hallux varus deformity.

The hallux varus deformity results from a dynamic imbalance of the tendons that cross the first metatarsophalangeal joint. This condition most frequently occurs after McBride-type operative treatment for hallux valgus. A new procedure, developed to correct this imbalance, involves transferring the extensor hallucis longus beneath the first intermetatarsal ligament into the base of the proximal phalanx, along with an arthrodesis of the first interphalangeal joint. This procedure in fifteen affected great toes gave over-all satisfactory correction of the hallux varus deformity.