In vitro and in vivo efficacies of the new triazole albaconazole against Cryptococcus neoformans.

The activity of albaconazole (UR-9825; J. Uriach & Cía. S.A., Barcelona, Spain) was compared to that of fluconazole against 12 isolates of Cryptococcus neoformans in vitro and against 1 isolate in vivo in a rabbit model of cryptococcal meningitis. Albaconazole was 100-fold more potent in vitro than fluconazole on a per-weight basis and was fungicidal at potentially relevant concentrations for two isolates. MICs ranged from

Effect of LFA-1beta antibody on leukocyte adherence in response to hemorrhagic shock in rats.

The activation and adherence of leukocytes to the venular endothelium are critical steps in the pathogenesis of generalized microvascular injury following hemorrhagic shock. Previous studies have shown that the integrins CD11/CD18 play a significant role in this interaction. The purpose of this study is to examine the efficacy of anti-LFA-1beta, an antibody to CD11a/CD18, in attenuating leukocyte adherence before, during, and after hemorrhagic shock. Following a control period, blood was withdrawn to reduce the mean arterial pressure to 40 mm Hg for 30 min in urethane-anesthetized rats. Mesenteric venules in a transilluminated segment of the small intestines were examined to quantitate leukocyte adherence using intravital microscopy. In sham-operated rats (control), there was minimal to no leukocyte adherence throughout the experiment. Hemorrhagic shock resulted in significant leukocyte adherence during resuscitation (10.8 +/- 1.7 cells/100 microm, P < 0.01) when compared to control. Anti-LFA-1beta, when given before hemorrhagic shock, significantly attenuated leukocyte adherence during resuscitation (1.1 +/- 0.8, P < 0.01) when compared with hemorrhagic shock alone. This protective effect of anti-LFA-1beta on leukocyte adherence was even demonstrated when it was given during (1.6 +/- 0.3, P < 0.01) and 10 min after hemorrhagic shock (5.8 +/- 0.4, P < 0.05). These results suggest that anti-LFA-1beta may be of potential therapeutic benefit against microvascular injury caused by hemorrhagic shock.

Combination photoimmunotherapy and cisplatin: effects on human ovarian cancer ex vivo.

BACKGROUND: Patients with ovarian cancer that is clinically resistant to cisplatin-based chemotherapy have little hope of a cure of their disease. Photoimmunotherapy, which involves the antibody-targeted delivery of a nontoxic photosensitizer that is activated to a cytotoxic state with visible light, may offer a new treatment option. Photoimmunotherapy may be applied intraperitoneally to target disseminated tumor. We tested the hypothesis that this treatment in combination with cisplatin potentiates cytotoxicity in ovarian cancer cell lines and primary cultures of human tumors. METHODS: Five human cancer cell lines (ovarian and breast) and 19 primary cultures were studied. The primary cultures were from solid and ascites tumor samples obtained from 14 patients with ovarian cancer who were undergoing primary surgery. The photosensitizer chlorin e(6) was conjugated to the F(ab')(2) fragment of the murine monoclonal antibody OC-125, which is directed against the antigen CA 125. Cytotoxicity was measured by the microculture tetrazolium assay. Treatments consisted of cisplatin alone, photoimmunotherapy alone, and photoimmunotherapy followed by cisplatin. The fractional product method was used to assess synergy in treatment effects. Ex vivo cultured human cells exhibiting 80% or greater survival at cisplatin concentrations of 10 microM for 24 hours were defined as cisplatin resistant for this study. RESULTS: When all cell types (cisplatin sensitive and cisplatin resistant) were considered together, combination treatment yielded cytotoxicity that was, on average, 6.9 times (95% confidence interval = 1.86-11.94) greater than that of cisplatin alone (two-sided P =.023). Cisplatin-resistant cells showed a synergistic effect of the two treatments (two-sided P =.044), while cisplatin-sensitive cells showed an additive effect. CONCLUSION: These ex vivo data suggest that platinum resistance in human ovarian cancer cells may be reversible by pretreatment with OC-125-targeted photoimmunotherapy. Further studies are required to confirm the efficacy of this approach in vivo.

Monoclonal antibodies against synthetic peptides corresponding to the extracellular domain of the human Ca2+ receptor: characterization and use in studying concanavalin A inhibition.

We generated monoclonal antibodies against two synthetic peptides corresponding to residues 214-235 (ADD) and 374-391 (LRG) of the human Ca2+ receptor (hCaR) extracellular domain (ECD). Although both antibodies reacted well with their respective immunizing peptides on peptide-based enzyme linked immunosorbent assay, ADD was much more strongly reactive with the hCaR than LRG in assays such as immunoblots done under denaturing conditions. The opposite pattern was seen in flow cytometry analysis of the native receptor stably expressed in transfected 293 cells. We speculate that the ADD epitope is unexposed in the native receptor while the reverse is true for the LRG epitope. The ability to measure cell surface expression of the hCaR under native conditions using flow cytometry with the LRG monoclonal allowed us to study the basis for Concanavalin A (Con A) inhibition of CaR activation by Ca2+. Our studies show that Con A inhibition is partially accounted for by receptor internalization but, additionally, Con A may prevent Ca2+ stimulation directly by binding to carbohydrate residues in the receptor ECD.

The influence of sentential speaking rate on the internal structure of phonetic categories.

In the experiments reported in this paper we compared the effects of syllable-level and sentence-level speaking rate on phonetic perception. In an earlier set of experiments, we found that syllable-level rate influences the internal perceptual structure of phonetic categories [Miller and Volaitis, Percept. Psychophys. 46, 505-512 (1989); Volaitis and Miller, J. Acoust. Soc. Am. 92, 723-735 (1992)]. Specifically, a change in target-syllable rate altered the location of the stimuli judged to be the best category exemplars, as well as the width of this best-exemplar range. In the present investigation, it was asked whether sentence-level rate has the same influence. It was found that slowing sentence rate shifted the location of the best-exemplar range, but did not alter its width. These findings are discussed in terms of timing mechanisms that may operate during speech perception.

MIS priorities for MSO's (management services organization) & clinics without walls.

Organized and efficient systems that are responsive to the needs of the medical group, hospital and management services organization are at the heart of successful integrated healthcare systems. Unfortunately, selecting the right systems solution can be a time-consuming and difficult process, at best. The problems are many. First, not all management services organizations look alike. Some are limited in scope and function. Others offer an expansive menu of services to the participating groups and physicians. Second, the level of sophistication of clinic or MSO personnel evaluating systems varies. Often, hospital systems personnel with little experience in the practice management arena are assigned the job of evaluating practice systems. Third, the budget for a data processing system may be limited. The process of forming an MSO and organizing a group without walls may be very expensive. Unless adequate budgeting is done in advance, only limited funds may be left for investment in systems. Lastly, identifying viable systems which are available can be an arduous undertaking. Literally, hundreds of possible systems are available. Unfortunately, few sources offer comprehensive information on each system suitable for proper evaluation. This has led many organizations to strategically design and develop their own physician network solutions and options using such applications as 4th generation data base language. According to Mick Bassell of Partners in HealthCare, a systems consulting group in San Rafael, CA., "a request for proposal process is usually the best way to identify systems that meet the group's needs, weaknesses and strengths. This should be done before vendors are asked to supply information about various computer systems. Developing a good RFP is a building process for both the MSO and group which will help them to jointly identify, organize and prioritize system requirements."

Conformational energy analysis of the substitution of Val for Gly 233 in a functional region of platelet GPIb alpha in platelet-type von Willebrand disease.

Platelet-type von Willebrand disease (PT-vWD) is an autosomal dominant bleeding disorder in which patient platelets exhibit an abnormally increased binding of circulating von Willebrand factor (vWF). We have recently shown that this abnormality is associated with a point mutation resulting in substitution of Val for Gly 233 in platelet membrane glycoprotein Ib alpha (GPIb alpha), a major component of the platelet GPIb/IX receptor for vWF. To investigate the effect of this substitution on the three-dimensional structure of this region of the protein, we have generated the allowed (low energy) conformations of the region of the GPI alpha protein containing residues 228-238 (with 5 residues on either side of the critical residue 233) with Gly 233 (wild type) and Val 233 (PT-vWD) using the computer program ECEPP (Empirical Conformational Energies of Peptides Program). The wild-type sequence is Tyr-Val-Trp-Lys-Gln-Gly-Val-Asp-Val-Lys-Ala. We find that the Gly 233-containing peptide can exist in two low energy conformers. The lowest energy conformer is a structure containing a beta-turn at Gln 232-Gly 233 while the alternative conformation is an amphipathic helical structure. Only the amphipathic helical structure is allowed for the Val 233-containing peptide which contains a hydrophobic 'face' consisting of Val 229, Val 233 and Val 236 and another hydrophilic surface composed of such residues as Lys 231 and Asp 235. No such surfaces exist for the lowest energy bend conformer for the Gly 233-containing peptide, but do exist in the higher energy helical structure. The amphipathic surfaces in the 228-238 region of the Val 233-containing GPIb alpha protein may associate strongly with complementary surfaces during vWF binding to the GPIb/IX receptor complex and may help explain heightened association of vWF with this receptor in PT-vWD.

Selenium-75-cholesterol imaging and computed tomography of the adrenal glands in differentiating the cause of Cushing's syndrome.

Measurement of 75Se-cholesterol (Scintadren) uptake and computed tomography (CT) of the adrenal glands were compared as a means of differentiating the cause of Cushing's syndrome in 11 patients over a 2-year period. Quantitative Scintadren imaging differentiated adrenocorticotrophic hormone (ACTH)-dependent disease from local adrenocortical lesions as the cause of Cushing's syndrome in all the patients studied. CT of the adrenal glands rapidly and accurately detected the adrenal mass lesions in 2 cases and was effective in documenting bilateral hyperplasia due to ectopic ACTH-dependent disease. However, in entopic ACTH (pituitary)-dependent disease the adrenal glands were of normal thickness in all but 2 patients, who had bilateral hyperplasia. Scintadren imaging and CT are useful non-invasive procedures for differentiating local adrenal disease from ACTH-dependent disease as the cause of Cushing's syndrome and should be the initial investigations once a firm clinical and biochemical diagnosis of Cushing's syndrome has been made.

Quantitative selenium-75-cholesterol imaging and computed tomography of the adrenal glands in Conn's syndrome.

Six consecutive patients with biochemically proven primary aldosteronism (4 with unilateral aldosteronomas and 2 with bilateral hyperplasia) underwent imaging with 75Se-selenomethyl-nor-cholesterol (Scintadren; Radiochemical Centre, Amersham, UK) and computed tomography (CT) of the adrenal glands to aid in lateralizing unilateral aldosterone-producing adenomas (APA) and to differentiate APA from idiopathic adrenal hyperplasia (IAH). Scintadren quantitative imaging alone was successful in lateralizing the lesion in all 4 cases of unilateral APA; mean uptake by the affected adrenal gland was 0.47% of the administered dose as against 0.23% in the normal gland (P less than 0.01). The mean uptake ratio for the adenomatous as against the normal gland was 2.03 (range 1.75-2.21), which was significantly greater than the uptake ratio of 0.82 in 4 normal individuals (P less than 0.01). CT lateralized all the APAs. In the 2 cases of IAH, Scintadren uptake was bilaterally increased in one case in which CT was normal, whereas in the other case Scintadren uptakes were normal while CT showed two abnormal glands. The overall diagnostic yield for Scintadren was 83%; the figure for CT was also 83%. When the results of Scintadren imaging and CT are pooled, the accuracy in lateralizing APAs and differentiating APA from IAH as a cause of Conn's syndrome is 100%.