D-2-hydroxyglutarate supports a tolerogenic phenotype with lowered major histocompatibility class II expression in non-malignant dendritic cells and acute myeloid leukemia cells

D-2-hydroxyglutarate (D-2-HG) accumulates in primary acute myeloid leukemia (AML) patients with mutated isocitrate dehydrogenase (IDH) and other malignancies. D-2-HG suppresses antitumor T cell immunity but little is known about potential effects on non-malignant myeloid cells. Here we show that D-2-HG impairs human but not murine dendritic cell (DC) differentiation, resulting in a tolerogenic phenotype with low major histocompatibility (MHC) class II expression. In line, IDH-mutated AML blasts exhibited lower expression of HLA-DP and were less susceptible to lysis by HLA-DP-specific T cells. Interestingly, D-2-HG reprogrammed metabolism towards increased lactate production in DCs and AML besides its expected impact on DNA demethylation. Vitamin C accelerated DNA demethylation, but only the combination of vitamin C and glycolytic inhibition lowered lactate levels and supported MHC class II expression. Our results indicate an unexpected link between the immunosuppressive metabolites 2-HG and lactic acid and suggest a potentially novel therapeutic strategy with combinations of anti-glycolytic drugs and epigenetic modulators (hypomethylating agents) or other therapeutics for the treatment of AML.

Empagliflozin Reduces Renal Hyperfiltration in Response to Uninephrectomy, but Is Not Nephroprotective in UNx/DOCA/Salt Mouse Models

Large-scale clinical outcome studies demonstrated the efficacy of SGLT2 inhibitors in patients with type II diabetes. Besides their therapeutic efficacy in diabetes, significant renoprotection was observed in non-diabetic patients with chronic kidney disease (CKD), suggesting the existence of glucose-independent beneficial effects of SGLT2 inhibitors. However, the relevant mechanisms by which SGLT2 inhibition delays the progression of renal injury are still largely unknown and speculative. Previous studies showed that SGLT2 inhibitors reduce diabetic hyperfiltration, which is likely a key element in renoprotection. In line with this hypothesis, this study aimed to investigate the nephroprotective effects of the SGLT2 inhibitor empagliflozin (EMPA) in different mouse models with non-diabetic hyperfiltration and progressing CKD to identify the underlying diabetes-independent cellular mechanisms. Non-diabetic hyperfiltration was induced by unilateral nephrectomy (UNx). Since UNx alone does not result in renal damage, renal disease models with varying degrees of glomerular damage and albuminuria were generated by combining UNx with high NaCl diets ± deoxycorticosterone acetate (DOCA) in different mouse strains with and without genetic predisposition for glomerular injury. Renal parameters (GFR, albuminuria, urine volume) were monitored for 4–6 weeks. Application of EMPA via the drinking water resulted in sufficient EMPA plasma concentration and caused glucosuria, diuresis and in some models renal hypertrophy. EMPA had no effect on GFR in untreated wildtype animals, but significantly reduced hyperfiltration after UNx by 36%. In contrast, EMPA did not reduce UNx induced hyperfiltration in any of our kidney disease models, regardless of their degree of glomerular damage caused by DOCA/salt treatment. Consistent with the lack of reduction in glomerular hyperfiltration, EMPA-treated animals developed albuminuria and renal fibrosis to a similar extent as H₂O control animals. Taken together, the data clearly indicate that blockade of SGLT2 has the potential to reduce non-diabetic hyperfiltration in otherwise untreated mice. However, no effects on hyperfiltration or progression of renal injury were observed in hypervolemic kidney disease models, suggesting that high salt intake and extracellular volume might attenuate the protective effects of SGLT2 blockers.

Lactonization of the Oncometabolite D-2-Hydroxyglutarate Produces a Novel Endogenous Metabolite

Simple Summary

Somatic mutations in isocitrate dehydrogenase give rise to the excessive production and accumulation of D-2-hydroxyglutarate in certain malignancies. In addition to this well-described oncometabolite, we discovered a chemically related metabolite, namely 2-hydroxyglutarate-γ-lactone, which is derived directly from 2-hydroxyglutarate. This novel metabolite may impact the anti-tumor immune response.

Abstract

In recent years, onco-metabolites like D-2-hydroxyglutarate, which is produced in isocitrate dehydrogenase-mutated tumors, have gained increasing interest. Here, we report a metabolite in human specimens that is closely related to 2-hydroxyglutarate: the intramolecular ester of 2-hydroxyglutarate, 2-hydroxyglutarate-γ-lactone. Using ¹³C₅-L-glutamine tracer analysis, we showed that 2-hydroxyglutarate is the endogenous precursor of 2-hydroxyglutarate-lactone and that there is a high exchange between these two metabolites. Lactone formation does not depend on mutated isocitrate dehydrogenase, but its formation is most probably linked to transport processes across the cell membrane and favored at low environmental pH. Furthermore, human macrophages showed not only striking differences in uptake of 2-hydroxyglutarate and its lactone but also in the enantiospecific hydrolysis of the latter. Consequently, 2-hydroxyglutarate-lactone may play a critical role in the modulation of the tumor microenvironment.

Optimized Protocol for the In Situ Derivatization of Glutathione with N-Ethylmaleimide in Cultured Cells and the Simultaneous Determination of Glutathione/Glutathione Disulfide Ratio by HPLC-UV-QTOF-MS

Glutathione (GSH) and glutathione disulfide (GSSG) are commonly used to assess the oxidative status of a biological system. Various protocols are available for the analysis of GSH and GSSG in biomedical specimens. In this study, we present an optimized protocol for the in situ derivatization of GSH with N-ethylmaleimide (NEM) to prevent GSH autooxidation, and thus to preserve the GSH/GSSG ratio during sample preparation. The protocol comprises the incubation of cells in NEM containing phosphate buffered saline (PBS), followed by metabolite extraction with 80% methanol. Further, to preserve the use of QTOF-MS, which may lack the linear dynamic range required for the simultaneous quantification of GSH and GSSG in non-targeted metabolomics, we combined liquid chromatographic separation with the online monitoring of UV absorbance of GS-NEM at 210 nm and the detection of GSSG and its corresponding stable isotope-labeled internal standard by QTOF-MS operated with a 10 Da Q1 window. The limit of detection (LOD) for GS-NEM was 7.81 µM and the linear range extended from 15.63 µM to 1000 µM with a squared correlation coefficient R² of 0.9997. The LOD for GSSG was 0.001 µM, and the lower limit of quantification (LLOQ) was 0.01 µM, with the linear (R² = 0.9994) range extending up to 10 µM. The method showed high repeatability with intra-run and inter-run coefficients of variation of 3.48% and 2.51% for GS-NEM, and 3.11% and 3.66% for GSSG, respectively. Mean recoveries of three different spike-in levels (low, medium, high) of GSSG and GS-NEM were above 92%. Finally, the method was applied to the determination of changes in the GSH/GSSG ratio either in response to oxidative stress in cells lacking one or both monocarboxylate transporters MCT1 and MCT4, or in adaptation to the NADPH (nicotinamide adenine dinucleotide phosphate) consuming production of D-2-hydroxyglutarate in cells carrying mutations in the isocitrate dehydrogenase genes IDH1 and IDH2.

A comparative trial of two retinoids commonly used in the treatment of acne vulgaris

BACKGROUND

Topical retinoids are highly effective treatments for acne vulgaris. The various formulations and concentrations available allow physicians to tailor therapies to individual patient's needs and minimize the cutaneous irritation that is often observed with the use of these drugs.

OBJECTIVE

To compare the efficacy and safety of tretinoin gel microsphere 0.1% with adapalene gel 0.1% in the treatment of acne vulgaris.

METHODS

A 12-week double-blind study was conducted, and patients were evaluated at baseline and at weeks 2, 3, 4, 6, 8, 10, and 12.

RESULTS

Although the two drugs displayed similar efficacy in the resolution of acne lesions at 12 weeks, a significantly greater reduction in the number of comedones was seen at week 4 among patients treated with tretinoin gel microsphere (p = 0.047). Patients receiving tretinoin gel microsphere had an increased incidence of dryness (weeks 8 and 10) and peeling (weeks 3, 6, 8, and 10) compared with those patients treated with adapalene gel, but the two groups were comparable with respect to erythema, burning/stinging, and itching.

CONCLUSION

Both drugs have similar efficacy in the resolution of acne lesions but tretinoin gel microsphere may result in a faster onset of action in the reduction of comedones compared to adapalene.

Lack of burning and stinging from a novel first-aid formulation applied to experimental wounds

Antiseptic-anesthetic first aid formulations typically produce a burning or stinging sensation when used on wounds. The aim of this study was to assess the lack of sting/burn potential of a prototype first-aid wipe when applied to superficial wounds. This was a one-day, double-blind, randomized study, evaluating the stinging/burning sensation from a prototype first-aid wipe with a cellulose base containing 1.0% pramoxine HCL and 0.13% benzalkonium chloride. The study followed a direct comparison test design of four test formulations. The remaining three articles were: (a) sterile 0.9% sodium chloride (no-sting/no-burn control), (b) 3% hydrogen peroxide (first-aid sting/burn control), and (c) 70% isopropyl alcohol (second sting/burn control). The test was performed on 24 subjects. The tape stripping method was used to create four standardized wounds on the volar forearms, reaching the glistening layer. Each test article was applied to the wound for 15 seconds. The subjects were asked to report the intensity of the stinging/burning sensation during the application. The prototype pramoxine-benzalkonium chloride wipe produced significantly less stinging/burning than both 70% isopropyl alcohol and 3% hydrogen peroxide. Also, the prototype wipe did not produce more stinging and burning in superficial wounds compared to the saline control.

The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial

BACKGROUND

Recent studies of antidandruff shampoos or tonics containing antifungal or antibacterial agents produced effects suggestive of a potential hair growth benefit.

OBJECTIVES

The purpose of this 6-month, 200-patient, randomized, investigator-blinded, parallel-group clinical study was to assess the hair growth benefits of a 1% pyrithione zinc shampoo. The efficacy of a 1% pyrithione zinc shampoo (used daily), was compared with that of a 5% minoxidil topical solution (applied twice daily), a placebo shampoo and a combination of the 1% pyrithione zinc shampoo and the 5% minoxidil topical solution.

METHODS

Two hundred healthy men between the ages of 18 and 49 years (inclusive) exhibiting Hamilton-Norwood type III vertex or type IV baldness were enrolled. Total hair counts, the primary efficacy measure, were obtained using fibre-optic microscopy and a computer-assisted, manual hair count method. Secondary measures of efficacy included assessments of hair diameter, as well as patient and investigator global assessments of improvement in hair growth. These were based on photographs of the scalp using both midline and vertex views.

RESULTS

Hair count results showed a significant (P < 0.05) net increase in total visible hair counts for the 1% pyrithione zinc shampoo, the 5% minoxidil topical solution, and the combination treatment groups relative to the placebo shampoo after 9 weeks of treatment. The relative increase in hair count for the 1% pyrithione zinc shampoo was slightly less than half that for the minoxidil topical solution and was essentially maintained throughout the 26-week treatment period. No advantage was seen in using both the 5% minoxidil topical solution and the 1% pyrithione zinc shampoo. A small increase in hair diameter was observed for the minoxidil-containing treatment groups at week 17. Assessments of global improvements by the patients and investigator generally showed the benefit of 5% minoxidil. The benefit of the 1% pyrithione zinc shampoo used alone tended (P < 0.1) to be apparent only to the investigator.

CONCLUSIONS

Hair count results show a modest and sustained improvement in hair growth with daily use of a 1% pyrithione zinc shampoo over a 26-week treatment period.

Comparison of the efficacy and safety of a combination topical gel formulation of benzoyl peroxide and clindamycin with benzoyl peroxide, clindamycin and vehicle gel in the treatments of acne vulgaris

BACKGROUND

Topical clindamycin and benzoyl peroxide have each demonstrated clinical efficacy in the treatment of acne vulgaris. When used in combination, they promise greater efficacy than either individual agent used alone and the combined use of benzoyl peroxide with topical antibacterial has been shown to decrease the emergence of antibacterial resistant species.

OBJECTIVE

The objective was to determine the efficacy and safety of a combination benzoyl peroxide plus clindamycin in a gel formulation compared with each of its 2 active constituents in gel vehicle, and gel vehicle given alone in the treatment of acne vulgaris.

METHODS

In this 10-week, multicenter, double-blind trial, 480 patients with moderate to moderately severe acne were randomized to receive twice-daily treatment with 5% benzoyl peroxide plus 1% clindamycin, 5% benzoyl peroxide, 1% clindamycin, or vehicle.

RESULTS

Significantly greater reductions in the number of inflammatory and total lesions were demonstrated in patients using combination therapy compared with those using any of its 3 individual components. Likewise, both physicians' and patients' global evaluations showed significantly greater improvements with the combination therapy than with its individual components. The most frequent adverse effect, dry skin, occurred to a similar extent in the combination and benzoyl peroxide treatment groups.

CONCLUSION

The improved efficacy obtained with the combination therapy was accompanied by a tolerability profile similar to that of benzoyl peroxide alone, making this new combination product an alternative antimicrobial therapy for acne vulgaris.

A newly formulated topical triple-antibiotic ointment minimizes scarring

A randomized study of polymyxin B sulfate-bacitracin zinc-neomycin sulfate versus simple gauze-type dressings in dermabrasion wounds assessed the effects that each treatment had on scarring. Each of three uniform dermabrasion wounds created on the upper backs of 70 subjects was treated concurrently with a triple-antibiotic ointment (polymyxin B-bacitracin-neomycin), a double antibiotic (polymyxin B-bacitracin), or a simple, non-occlusive, gauze-type dressing, twice daily for up to 14 days. Pigmentary changes and textural changes (scarring) appearing after healing at the skin surface test sites were compared to adjacent normal skin at 45 and 90 days post-dermabrasion. These changes were graded visually utilizing fluorescent light, long-wave ultraviolet light, and by clinical color photography. The triple-antibiotic ointment was superior to simple gauze-type dressing alone in minimizing the scarring observed in dermabrasion wounds. The benefit of this new ointment was more pronounced in its effect on pigmentary changes.

Comparison of adapalene 0.1% solution and tretinoin 0.025% gel in the topical treatment of acne vulgaris

A multicentre study was conducted to compare clinical safety and efficacy of adapalene 0.1% solution and tretinoin 0.025% gel, both topical treatments for acne, in a once-daily dosage regimen for 12 weeks. A total of 297 patients were enrolled by eight investigators in this randomized, investigator-masked study in a parallel group design. An open label period using adapalene followed this study to assess the long-term safety of adapalene solution. Adapalene and tretinoin proved to be clinically and statistically effective in treating acne by reducing inflammatory (47% and 50%, respectively) and non-inflammatory lesions (57% and 54%) as compared to baseline. When comparing patients who had 75% or greater improvement in open comedones, adapalene was shown to be significantly more effective than tretinoin. No serious adverse event was reported during this study, including during the long-term period. The reactions that occurred were similar between treatments, i.e. burning, pruritus, scaling, dryness and erythema.

Irritation potential of a new topical tretinoin formulation and a commercially-available tretinoin formulation as measured by patch testing in human subjects

BACKGROUND

A novel tretinoin preparation uses polyolprepolymer-2, a compound designed to reduce skin irritation by helping retain drugs on and in the surface layers of the skin.

OBJECTIVE

We used patch testing to measure the effect of polyolprepolymer-2 on tretinoin-associated irritation.

METHODS

Two patch test studies were conducted. The first assessed the effect of polyolprepolymer-2 by comparing commercially-available tretinoin formulations with respective polyolprepolymer-containing formulations of 0.025% tretinoin gel and 0.025%, 0.05%, and 0.1% tretinoin creams. The second assessed the effect of the polyolprepolymer-2 concentration on the potential decrease in irritation by comparing: (1) a commercially-available tretinoin cream with prototype tretinoin creams containing 20% polyolprepolymer-2 at three different concentrations of tretinoin (0.025%, 0.05%, and 0.1%); and (2) the effect of three different polyolprepolymer-2 concentrations (10%, 15%, and 20%) in prototype tretinoin creams on cumulative irritation. Patch agents were assigned to subjects according to a randomization schedule, and during a period of 5 days each subject received three 24-hour exposures to the test materials. Twenty-four hours elapsed between old patch removal and new patch application.

RESULTS

In the first study, the tretinoin gel and cream containing polyolprepolymer-2 caused significantly less irritation than all equivalent formulations of the commercially-available tretinoin gel and creams except the 0.025% cream formulation. Irritation scores were not significantly different in terms of irritation in the 0.025% creams although scores did indicate a trend towards lower irritation with 0.025% tretinoin cream containing polyolprepolymer-2. In the second study, the tretinoin gel containing polyolprepolymer-2 and the three tretinoin prototype creams also containing polyolprepolymer-2 caused significantly less irritation than comparable concentrations of the commercially-available tretinoin. In addition, the 0.025% tretinoin gel formulation containing polyolprepolymer-2 was no more irritating than the commercially-available 0.025% tretinoin cream.

CONCLUSION

Tretinoin formulations containing polyolprepolymer-2 are, in general, less irritating than the currently marketed tretinoin formulations.

Effects of stress inoculation training on athletes' postsurgical pain and rehabilitation after orthopedic injury

The efficacy of a cognitive-behavioral intervention (stress inoculation training; SIT) for postsurgical anxiety, pain, and physical rehabilitation in injured athletes was tested. Sixty male athletes who underwent arthroscopic surgery for miniscus injury in 1 knee were randomly assigned to either treatment (SIT and physical therapy) or control (physical therapy only) conditions. Results showed that participants in the treatment group demonstrated significantly less postsurgical pain and anxiety during the rehabilitation process, compared with controls. Additionally, treated participants required fewer days to return to criterion physical functioning, compared with nontreated participants.

Effects of stress inoculation training on athletes' postsurgical pain and rehabilitation after orthopedic injury

The efficacy of a cognitive-behavioral intervention (stress inoculation training; SIT) for postsurgical anxiety, pain, and physical rehabilitation in injured athletes was tested. Sixty male athletes who underwent arthroscopic surgery for miniscus injury in 1 knee were randomly assigned to either treatment (SIT and physical therapy) or control (physical therapy only) conditions. Results showed that participants in the treatment group demonstrated significantly less postsurgical pain and anxiety during the rehabilitation process, compared with controls. Additionally, treated participants required fewer days to return to criterion physical functioning, compared with nontreated participants.

Noninvasive assessment of anesthetic activity of topical lidocaine formulations

The effectiveness of a series of lidocaine formulations in producing anesthesia after topical application was evaluated in human volunteers. The formulations, five suspensions in 20% propylene glycol and one cream, were applied to the forearms for 3 h with occlusion with Hilltop chambers. Testing for anesthesia was performed electrometrically. All lidocaine-containing formulations produced significantly greater anesthesia than the blanks. The formulation containing tetradecyltrimethylammonium bromide produced greater anesthesia than that containing octadecyltrimethylammonium chloride. Changing the pH of the formulation from 7.9 to 10.0 had no significant effect. Other formulations (sodium lauryl sulfate and the cream) were no more effective than the plain formulation without surfactants. The rank order for the suspension formulations was the same as for steady-state permeation in in vitro experiments. However, application of the cream formulation produced greater effect in vivo than was anticipated from in vitro flux values.

Defining the susceptibility of acne-prone and sensitive skin populations to extrinsic factors

Acne-Prone Skin. Acne-prone skin appears to be more susceptible to certain extrinsic factors that can either exacerbate existing disease or generate new lesions. Awareness of the factors that could worsen or interfere with therapy is important. In addition, identification of patients with minimal acne who are prone to outbreaks from extrinsic factors and provision of relevant advice could prove beneficial to significant numbers of patients. Sensitive Skin. From the perspective of our research, the definition of sensitive skin is still evolving. Certain individuals may view sensitive skin as fashionable; however, clinicians and the people who work in the personal-care industry know that when certain materials are applied to the skin, some individuals report symptoms (burning, stinging, itching, a tight feeling) and sometimes show traditional signs of irritation. The reasons for sensitive skin in these individuals may be obvious, but many times the complaints and signs of irritation occur in individuals who appear to be normal. Using our ongoing work we would like to suggest that the label "sensitive skin" apply to the following four categories: 1. Those individuals with obvious skin disease. 2. Those individuals with subclinical (mild) or atypical clinical signs of disease. 3. Those individuals who have experienced past insults to the skin. 4. Those individuals who do not fit into one of the above three categories and appear to be "normal". To define sensitive skin fully we may need to perform full profiles of the skin of these patients. In addition to history and examination, a battery of noninvasive tests may be helpful.(ABSTRACT TRUNCATED AT 250 WORDS)

Locus of control and perceived alcohol ingestion in performance of a fine motor skill

To investigate the influence of locus of control on a fine motor corrdination task where subjects had ingested or believed that they had ingested alcohol, 60 men who were enrolled in introductory psychology and scored in the upper or lower thirds of the population on Rotter's I-E Scale (30 external and 30 internal scorers) were randomly assigned to one of three treatment conditions: a control group (no alcohol expected/no alcohol received), an alcohol group (alcohol expected/alcohol received), and a placebo group (alcohol expected/no alcohol received). Pretest and posttest measures of performance on the Purdue Pegboard Test were obtained from all subjects. Subjects in the control groups were given three 6-oz. (177.4-ml) glasses of fruit punch over a 35-min. waiting period between pretest and posttest on the Purdue Pegboard. The alcohol groups drank a sufficient number of similar glasses (usually three) to produce a 0.1% measure on a breathalyzer before completing the posttest on the Purdue. Pegboard. The placebo groups were told that they were drinking an alcohol-based drink but were served three glasses of a nonalcoholic, rum-flavored fruit drink. These groups were also told that they measured 0.1% on a breathalyzer. Control groups, both internal and external scorers, showed essentially no change from pre- to posttest on the Purdue Pegboard. The alcohol groups, on the other hand, both internal and external scorers, showed a significant decrement in performance. The internal-placebo group did not differ from the two control groups and showed no decrement in performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Whirlpool folliculitis: a review of its cause, treatment, and prevention

Folliculitis caused by Pseudomonas aeruginosa has been increasing due to the popularity of hot tubs, swimming pools, and whirlpools. The follicular pustules and inflammatory papules usually occur after an incubation period of two to four days and improve spontaneously in seven to ten days. Despite the discomforts of the condition, treatment is usually not necessary and may even prolong the infection. Since it is difficult to control the growth of Pseudomonas in hot tubs and whirlpools, attention to water conditions is the best way to prevent this irritating skin condition.

Erythema dyschromicum perstans and lichen planus: are they related?

A 53-year-old woman initially had lichen planus primarily on her extremities. Approximately 1 year later, lesions consistent with erythema dyschromicum perstans were observed. Both diseases cleared with griseofulvin therapy but returned after discontinuation of the drug. Retreatment with griseofulvin again resulted in clearing.

Fulminant transfusion-associated graft-versus-host disease in a premature infant

A fatal case of transfusion-associated graft-versus-host disease developed in a premature infant after receiving several blood products, including nonirradiated white blood cells. Transfusion-associated graft-versus-host disease can be prevented. Irradiation of blood products is the least controversial and most effective method. Treatment was unsuccessful in most reported cases of transfusion-associated graft-versus-host disease. Therefore irradiation of blood products before transfusing to patients susceptible to transfusion-associated graft-versus-host disease is strongly recommended.

Sun protection and skin cancer

Sun exposure causes the majority of skin cancers. Ultraviolet radiation is important in the initiation and promotion of these cancers. Basal cell carcinomas, squamous cell carcinomas, and many melanomas can be prevented by the proper use of sun protection. Sun defense methods can reduce morbidity and death from skin cancer.

Cutaneous manifestations of early human immunodeficiency virus exposure

After demonstrating antibodies to the human immunodeficiency virus (HIV), two hundred patients were interviewed and given a complete cutaneous and mucous membrane examination. By means of the Walter Reed Staging Classification System for HIV infection, 155 patients were classified as having Walter Reed stage 1A-2A (WR1A-WR2A) infection. The prevalence of seborrheic dermatitis in this group was 36%. There were no other significant cutaneous findings in the WR1A-WR2A patient population.

A double-blind, multiple-dose, placebo-controlled, cross-over study to compare the incidence of gastrointestinal complaints in healthy subjects given Doryx R and Vibramycin R

Ninety-eight healthy subjects completed a double-blind, placebo-controlled, multiple-dose cross-over study to compare the incidence of gastrointestinal side effects of Doryx (Parke-Davis, Morris Plains, NJ) capsules (enteric-coated doxycycline hyclate pellets) and Vibramycin (Pfizer, New York, NY) capsules (doxycycline hyclate powder). Doryx produced statistically significantly fewer episodes of nausea, vomiting, stomach of abdominal discomfort, and decreased appetite than did Vibramycin. For every symptom, Vibramycin produced statistically significantly more symptom reports than did placebo. Although Doryx produced significantly more reports of nausea than did placebo, there was no significant difference for the other symptoms. Based on these results, Doryx is superior to Vibramycin when considering the incidence of gastrointestinal side effects.

Calcium enhances the sensitivity of immunofluorescence for pemphigus antibodies

Indirect immunofluorescence (IF) to detect pemphigus and pemphigoid autoantibodies is commonly performed with monkey esophagus (ME) as substrate and phosphate-buffered saline (PBS) as a diluent. The purpose of this study was to evaluate comparative IF titers using human skin (HS) as substrate with variations in the buffers employed. Substrates (ME or HS) were incubated in PBS, Tris-acetate-buffered saline (TAS), TAS with 5 mM CaCl+2 (TAS-Ca+2), and PBS or TAS with 1 mM EDTA, prior to incubation with pemphigus or pemphigoid sera for indirect IF. We examined sera from 11 patients with pemphigus vulgaris (PV), 10 patients with Brazilian pemphigus foliaceus (BPF), and 4 patients with bullous pemphigoid. In 20 of 21 pemphigus sera, endpoint indirect IF titers were highest on normal skin with TAS-Ca+2. Six sera (2 PV and 4 BPF) had endpoints that were 5 double dilutions higher than the endpoints obtained with ME and PBS. Six sera (3 PV and 3 BPF) were 4 double dilutions higher, 7 sera (3 PV and 4 BPF) were 2-3 double dilutions higher, and 2 PV sera were equivalent with both substrate/buffers. Preincubation of either tissue with EDTA prior to indirect IF abolished PV and BPF antibody binding completely. Exposure to EDTA after the tissue was incubated with PV or BPF sera did not affect indirect IF titers. In the presence of Ca+2, the antigen was resistant to trypsin in concentrations of 0.001%; however, in the absence of added Ca+2 it was destroyed by 0.0001% trypsin. These differences were not observed with bullous pemphigoid sera; all 4 sera had similar endpoint indirect IF titers. This study shows a significant increase in the sensitivity of indirect IF assays for pemphigus autoantibodies by the use of Ca+2-supplemented buffers on human skin. This finding may also have implications for procedures designed to purify and/or detect pemphigus antigens.

Leishmaniasis: the touch preparation as a rapid means of diagnosis

A 31-year-old man from Yemen presented with a 6-month history of a nonhealing ulcerated plaque on his right elbow. Initial evaluation included hematoxylin-and-eosin and Giemsa stains of a skin biopsy specimen. These preparations were interpreted as consistent with leishmaniasis, but no organisms were seen. A second biopsy specimen was obtained for culture on special media. A touch preparation demonstrated amastigotes, and cultures demonstrated leishmanial organisms at 2 weeks. The touch preparation as a rapid means of diagnosing leishmaniasis is discussed in detail, and a review of leishmanial disease and treatment is presented.

Venereal herpes-like molluscum contagiosum: treatment with tretinoin

Molluscum contagiosum spread by sexual contact may be mistaken for other venereal diseases. The occurrence of a penile lesion resembling herpes progenitalis, and successful therapy of genital mollusca with topical tretinoin (vitamin A acid) is described.

Processing interaction between two dimensions of nonphonetic auditory signals

In 1974 Wood proposed a hybrid serial-parallel model to account for the within-stimulus interactions between the acoustic cue of "pitch" and the phonetic cure of "place." Three of the five experiments in this paper replicate the Wood findings with analogous, clearly nonphonetic stimuli and thus refute Wood's implicit assumption of the involvement of any uniquely phonetic processes as factors in his results. The experiments in this paper demonstrate that the patterns of interaction found by Wood are independent of the experience of the subjects, the order of cue presentation, and whether the cues are presented simultaneously or sequentially. We conclude that the given patterns of interaction are general characteristics of the auditory system. These characteristics probably are not related to backward or forward "recognition" masking but may be a function of several other general factors.

Processing interaction between two dimensions of nonphonetic auditory signals

In 1974 Wood proposed a hybrid serial-parallel model to account for the within-stimulus interactions between the acoustic cue of "pitch" and the phonetic cure of "place." Three of the five experiments in this paper replicate the Wood findings with analogous, clearly nonphonetic stimuli and thus refute Wood's implicit assumption of the involvement of any uniquely phonetic processes as factors in his results. The experiments in this paper demonstrate that the patterns of interaction found by Wood are independent of the experience of the subjects, the order of cue presentation, and whether the cues are presented simultaneously or sequentially. We conclude that the given patterns of interaction are general characteristics of the auditory system. These characteristics probably are not related to backward or forward "recognition" masking but may be a function of several other general factors.

2,6-dichlorophenol, sex pheromone of the lone star tick

The compound 2,6-dichlorophenol was identified from female lone star ticks, Amblyomma americanum, and is believed to be a sex pheromone of this arthropod. The natural occurrence of a chlorinated organic compound in a land animal is new. The presence of similar compounds of exogenous origin is common in animals, but efforts to implicate an outside source for the halogenated phenol have failed.

Sex Attractant of Cabbage Looper, Trichoplusia ni (Hübner)

When virgin male cabbage loopers were exposed to filter-paper strips containing an extract from female abdomens, they exhibited a response lasting from 2 to 5 minutes. Gases of a component (or components) of these extracts emanating from a chromatography column attracted the males and then evoked the same response. The attractant is fairly volatile and has relatively low molecular weight.