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Biomedical subjects

P D Hoeprich

Publications and source records attributed to P D Hoeprich.

At least 19 recordsLinked to original sources
PubMed1992

Acquisition of coccidioidomycosis at necropsy by inhalation of coccidioidal endospores.

Coccidioidomycosis is accepted as being noncontagious because the infectious arthroconidial form of Coccidioides immitis is not produced in humans and other mammalian hosts. However, disseminated coccidioidomycosis developed in a veterinarian who autopsied a horse with disseminated disease but without draining lesions or productive cough. We postulate transmission occurred by inhalation of tissue-phase endospores aerosolized in the course of dissection.

Adult↗
PubMed1992

Clinical use of amphotericin B and derivatives: lore, mystique, and fact.

Since 1955, when amphotericin B was introduced into clinical therapy, a lore has grown up surrounding its use that often lacks evidential basis. Matters such as rate of intravenous injection, periodicity of administration, dosage, and the monitoring of therapy should not be shrouded in a mystique that is passed on from one generation of house officers to another. Factual rationalization of the use of amphotericin B should be pursued and is attempted in this article.

Amphotericin B↗
PubMed1991

Antibodies that neutralize human beta interferon biologic activity recognize a linear epitope: analysis by synthetic peptide mapping.

The location of biologically relevant epitopes on recombinant human beta interferon in which Ser-17 replaces Cys-17 (rh[Ser17]IFN-beta) was evaluated by testing the immunoreactivity of antibodies against 159 sequential, overlapping octamer peptides. Three monoclonal antibodies (mAbs) that neutralize rh[Ser17]IFN-beta biologic activity, designated A1, A5, and A7, bound to peptides spanning only residues 39-48, whereas nonneutralizing mAb bound less specifically at multiple sites near the amino terminus. The immunoreactivity of peptides spanning residues 40-47 that contained a series of single amino acid substitutions suggested that residues 41-43 (Pro-Glu-Glu) and 46 (Gln) are important for the binding of neutralizing mAbs. The reactivity of mAbs to larger synthetic peptides containing rh[Ser17]IFN-beta sequences from residue 32 through residue 56 was evaluated. All mAbs except A7 reacted with synthetic peptides representing rh[Ser17]IFN-beta residues 32-47, 40-56, and 32-56, but only mAbs A1 and A5 bound to the core peptide composed of residues 40-47. Peptide 32-56 effectively blocked the binding of mAbs A1 and A5 to rh[Ser17]IFN-beta and markedly inhibited their neutralizing activity. Biologic activity of the peptides was undetectable. Rabbit antisera raised against peptides 32-47 and 40-56 recognized rh[Ser17]IFN-beta but did not neutralize its antiviral activity. Thus, structure-function analysis by peptide mapping has permitted the identification of a linear epitope recognized by neutralizing antibody on a biologically active cytokine. We conclude that the region spanning residues 32-56 is of major importance in the expression of the biologic activity of human IFN-beta.

Amino Acid Sequence↗
PubMed1990

Itraconazole treatment of phaeohyphomycosis.

Nineteen patients with phaeohyphomycosis were treated with itraconazole. Of these, 17 were assessable for clinical outcome. Of these, two had received no prior therapy, five had failed amphotericin B therapy, four had failed ketoconazole or miconazole therapy, and five had failed both amphotericin B and azole therapy. One patient had received only prior surgical intervention. Fungi of seven different genera caused disease of the skin in nine patients, soft tissue in nine, sinuses in eight, bone in five, joints in two, and lungs in two. Itraconazole was given in dosages ranging from 50 to 600 mg/day for 1 to 48 months. Clinical improvement or remission occurred in nine patients. Two patients have had stabilization of disease. Six patients failed treatment, one had a relapse after initially successful treatment. Itraconazole appears to be highly effective in some patients with phaeohyphomycosis, including patients refractory to other antifungal agents.

Adult↗
PubMed1989

Identification of immunodominant regions of transforming growth factor alpha. Implications of structure and function.

Human transforming growth factor alpha (TGF alpha) is a 50-residue mitogenic peptide with a compact structure restrained by three disulfide bonds. Sequential and overlapping synthetic peptides were made to identify epitopes of TGF alpha using a panel of murine monoclonal antibodies and rabbit polyclonal antibodies. Antibodies were raised against human TGF alpha from different preparations obtained from either chemical synthesis or recombinant DNA techniques. Two related methodologies were used in these experiments. In the first method, probes were synthesized as peptides immobilized on polyethylene pins by the method of Geysen et al. (Geysen, H. M., Meloen, R. H., and Barteling, S. J. (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 3998-4002). Three sets of sequentially overlapping tetrapeptides, hexapeptides, and octapeptides covering the entire length of the human TGF alpha sequence were synthesized. In the second method, a set of overlapping 8-residue synthetic peptides, freely soluble in solution, were used as probes. By both methods, the nonneutralizing monoclonal antibodies, i.e. those that did not inhibit TGF alpha in mitogenic assays, recognized two immunodominant regions represented by the NH2-terminal segment (residues 1-9) and the most prominent beta-sheet of the molecule (residues 22-31). The NH2 terminus and the beta-sheet-(22-31) are in the same face of the molecule as determined by the solution structure. These two immunodominant regions were also recognized by the polyclonal antibodies as well as regions in the COOH terminus as minor epitopes. However, none of the neutralizing monoclonal antibodies recognized any synthetic peptides. Thus, our results suggest that the receptor-binding surface of TGF alpha does not involve the face represented by the NH2-terminal fragment and the major beta-sheet of residues 22-31, but rather, that the opposite face represented by two loops formed by residues 12-20 and 34-43 may be involved in TGF alpha binding to its receptor.

Amino Acid Sequence↗
PubMed1988

Treatment of fungal infections with semisynthetic derivatives of amphotericin B alpha.

AME appeared to be as effective as AmB in the treatment of mycoses in humans. AME was much less nephrotoxic than AmB, and was better tolerated in terms of rapid onset and reversible adverse reactions. AME may be more ototoxic than AmB. AME, even as AmB and OAME, may cause neurotoxicity and leukoencephalopathy, particularly when high doses are given for long periods.

Adult↗
PubMed1988

Multifocal systemic sporotrichosis with lobar pulmonary involvement.

Multifocal systemic sporotrichosis (disseminated sporotrichosis) with lobar pulmonary involvement is uncommon. We describe successful treatment with amphotericin B in such a patient and review data from 1 other similar case previously reported and 7 with nonlobar pulmonary involvement.

Aged↗
PubMed1987

Ovine pulmonary transit of tetracycline and minocycline.

Following cannulation of the right external jugular vein and the efferent duct of the right caudal mediastinal lymph node (the caudal end of this node was ligated to cut off the inflow of systemic lymph, i.e., 90%-95% of the efferent lymph was of pulmonary origin), sheep were given either tetracycline or minocycline as single doses of 5 mg/kg body weight infused intravenously over 30 min. Venous blood plasma and pulmonary lymph collected contemporaneously before infusion and from 5 min to 24 hr postinfusion were assayed by a well-agar diffusion method using Bacillus cereus. Peak concentrations of both drugs were observed in both plasma and lymph at 5 min postinfusion. Tetracycline penetrated into the lymph better than minocycline (percent penetration 67.3% of cf. 38.2%). The concentration of tetracycline was significantly higher in lymph during and 5 min postinfusion (p less than 0.01), a factor that may be of importance when selecting a tetracycline for the treatment of a pulmonary infection.

Animals↗
PubMed1987

Comparative efficacy of forphenicinol, cyclosporine, and amphotericin B in experimental murine coccidioidomycosis.

Cohorts of ten mice, uninfected and infected (intratracheal injection of coccidioidal arthroconidia), were treated for 23 days by intravenous injections of either 5% glucose solution, an immunostimulant (forphenicinol), an immunodepressant (cyclosporine), or amphotericin B. All mice were autopsied (survivors at 26 days postinoculation) and suspensions of lungs, livers, and spleens were cultured. All uninfected animals survived and gained weight, whereas, only 20% of the infected controls survived, and all lost weight. Treatment with forphenicinol had no effect on survival or weight. Cyclosporine secured 90% survival at the lowest dose and 60% at the higher doses, with no net loss of weight; however, all cultures of organs yielded heavy growth of Coccidioides immitis. With amphotericin B, all mice survived and gained weight; four mice from each of the two treatment groups yielded modest growth of C. immitis from the lungs, and one mouse of each group yielded sparse growth from liver and spleen. The paradox of no effect from an immunostimulant and therapeutic effect from an immunodepressant correlated with susceptibility testing of C. immitis in vitro.

Amphotericin B↗
PubMed1987

Entry of five antifungal agents into the ovine lung.

The passage of antifungal agents into pulmonary parenchyma was studied in normal sheep prepared by cannulation of the right external jugular vein and the efferent duct of the right caudal mediastinal lymph node. Five sheep were given single, sequential, intravenous injections of flucytosine, ketoconazole, BAY n 7133, amphotericin B methyl ester, and amphotericin B. Venous blood plasma and pulmonary lymph were collected before infusion and from 5 min to 24 h postinfusion; the concentrations of the drugs were assayed by a well-agar diffusion method. All drugs appeared promptly in the pulmonary lymph and disappeared at approximately exponential rates from both liquids. The lymph/plasma ratios of the drug concentrations did not differ between flucytosine and the two azoles but were lower for both polyenes. Binding by plasma proteins did not appear to be a determinant of pulmonary entry.

Animals↗
PubMed1987

Effect of buffers on testing of Candida species susceptibility to flucytosine.

Synthetic amino acid medium for fungi (SAAMF) is a totally defined, nutritionally adequate, macromolecule-free culture medium for fungi that is buffered with an organic weak acid-weak base pair: 2-(N-morpholino)-propanesulfonic acid (MOPS) and 2-amino-2-(hydroxymethyl)-1,3-propanediol (Tris). In 1984, it was reported that MOPS-Tris in SAAMF antagonized the activity of flucytosine against Candida albicans (D. L. Calhoun and J. N. Galgiani, Antimicrob. Agents Chemother. 26:364-367, 1984). Accordingly, we evaluated the buffering capacity of seven synthetic organic buffers and monobasic potassium phosphate, both singly and in pairs, over the pH range 7.4 to 6.0. Of these buffers, MOPS, BES [N,N-bis(2-hydroxyethyl)-2-aminomethanesulfonic acid], a BES-MOPS combination, and KH2PO4 provided the best buffering. Growth of C. albicans, in unbuffered SAAMF was equivalent overall to that in SAAMF containing buffers, singly or in pairs. Twelve strains of C. albicans and five strains of Candida lusitaniae were tested for susceptibility to flucytosine in SAAMF, with and without buffers. In the presence of Tris, the geometric mean MICs were 6.5- and 3.6-fold higher, respectively, for C. albicans and C. lusitaniae. We recommend replacing Tris with the nonantagonistic MOPS.

Buffers↗
PubMed1986

The HTLV-III envelope protein contains a hexapeptide homologous to a region of interleukin-2 that binds to the interleukin-2 receptor.

A region of human interleukin-2 (IL-2) which was predicted to be a contact point with its receptor was used to locate a homologous region in the envelope protein of human T-lymphotropic retrovirus (HTLV-III). This homologous six amino acid peptide from the carboxy (C)-terminus of the HTLV-III envelope protein was found to inhibit the biological activity of human IL-2 in a murine spleen cell proliferation assay. When conjugated to a carrier protein, this peptide inhibited the binding of radiolabelled IL-2 to its receptor. The biological activity of the peptide was antagonized by a six amino acid peptide fragment of the IL-2 receptor which was predicted to be the contact point on the receptor that corresponded to the binding region of IL-2. The HTLV-III peptide also inhibited the binding of radiolabelled IL-2 to polyclonal anti-IL-2 antiserum. These data support the previous assignment of contact points between IL-2 and its receptor. They also suggest two possible mechanisms of immunosuppression during acquired immunodeficiency syndrome (AIDS). One involves direct competition of the envelope protein or its fragments with IL-2 for binding to the IL-2 receptor. The other involves antibodies to the envelope protein which crossreact with and neutralize IL-2.

Amino Acid Sequence↗
PubMed1986

Helical conformation at the carboxy-terminal portion of human C3a is required for full activity.

Human C3a, a 77-residue fragment released during complement activation, is a potent spasmogen that contracts smooth muscle, enhances vascular permeability, and suppresses humoral immune responses. Studies with synthetic peptides have shown that the active site of this anaphylatoxin resides in the COOH-terminal portion of C3a; the minimal peptide structure capable of expressing activity contains residues 73-77, Leu-Gly-Leu-Ala-Arg (C3a-73-77). Longer synthetic C3a analogue peptides, e.g., C3a-57-77 containing the 21 COOH-terminal amino acids, exhibit activity nearly equivalent to that of intact C3a. Circular dichroism spectra of peptide C3a-57-77 in aqueous buffer containing 25% (v/v) trifluoroethanol indicated helical structure (41% helix), and analysis of the sequence suggested an amphipathic surface. We have synthesized several 21-residue peptide analogues of the natural C3a sequence containing residues 57-77 that were designed to enhance helix and to accentuate amphipathy. Syntheses were designed to include strategic placement of the helix-promoting residues 2-aminobutyric acid (beta-methylalanine) and 2-aminoisobutyric acid (alpha-methylalanine). Two 21-residue C3a analogue peptides that were designed to enhance helical content were shown to exhibit greater biological activity than either the native factor C3a or C3a-57-77. Moreover, activity was abrogated by the appropriate placement of helix-breaking residues, e.g., proline, suggesting that a conformational requirement for activity is genuine. These observations suggest that a helical conformation is requisite for optimal C3a activity and that in intact C3a the NH2-terminal portion (residues 1-21) and the disulfide-linked core (residues 22-57) function primarily to stabilize ordered conformation at the COOH-terminal region of the molecule.

Amino Acids↗