A comparison of melanin bleaching and azure blue counterstaining in the immunohistochemical diagnosis of malignant melanoma

Distinguishing heavily pigmented melanocytes from melanophages on routine hematoxylin and eosin slides can be difficult. Melanin bleaching with potassium permanganate solution is a traditional means of removing melanin from tissues and can be used before immunohistochemical staining to remove any pigment that might be confused with the brown chromogen diaminobenzidine. Azure B stains melanin granules green-blue, easily contrasts with diaminobenzidine, and may be used as a counterstain on unbleached sections after immunohistochemical staining. To our knowledge, studies comparing melanin bleaching with azure B counterstaining in the immunohistochemical evaluation of malignant melanomas have not been performed. Paraffin sections from 33 heavily pigmented malignant melanomas were bleached with a 3.0-g/L potassium permanganate solution, immunohistochemically stained for S-100 and HMB-45, and counterstained with hematoxylin. Unbleached sections were similarly stained for S-100 and HMB-45 and counterstained with azure B. To establish optimal permanganate concentrations, a variable number of sections were bleached with lower permanganate concentrations ranging from 0.125 to 2.5 g/L. S-100 antigenicity was preserved at all permanganate concentrations, whereas HMB-45 antigenicity was abolished at concentrations of 0.5 g/L and greater. At permanganate concentrations from 0.125 to 0.5 g/L, both antigenicities were preserved; however, melanin was incompletely removed. Complications of bleaching included tissue damage and loss of cytologic detail. Positive immunohistochemical staining was observed in azure B counterstained sections. Azure B stained melanin greenblue and was easily distinguished from the brown diaminobenzidine chromogen, regardless of the antibody tested. Neither tissue damage nor loss of cytologic detail was observed. We conclude that the use of azure B counterstaining is superior to permanganate bleaching in the histologic evaluation of heavily pigmented cutaneous malignant melanomas.

Sudden onset of disseminated porokeratosis of Mibelli in a renal transplant patient

Porokeratosis is a disorder of epidermal keratinization of uncertain cause. Five clinical variants of porokeratosis have been described. These include porokeratosis of Mibelli, punctate porokeratosis, linear porokeratosis, porokeratosis palmaris plantaris et disseminata, and disseminated superficial porokeratosis. Disseminated superficial porokeratosis and single plaque porokeratosis of Mibelli have each been documented to occur in association with immunosuppression. To our knowledge, only 5 cases of disseminated porokeratosis of Mibelli in transplant recipients have been reported. We present a patient who developed explosive onset of disseminated porokeratosis of Mibelli shortly after renal transplantation. It is important to differentiate this unusual variety of porokeratosis from other cutaneous manifestations in transplant patients so that appropriate therapy can be instituted.

Rapid oral hydration results in hydronephrosis as demonstrated by bedside ultrasound

STUDY OBJECTIVE

To determine whether vigorous oral hydration (20 mL/kg) causes hydronephrosis as determined by bedside ultrasound.

METHODS

We conducted a prospective laboratory trial in 35 healthy volunteers weighing less than 90 kg and between the ages of 18 and 50 years. The right kidney of the volunteers was scanned by emergency physicians at time 0 both before and after voiding, and the volunteers then drank 20 mL/kg of bottled water. The kidney was scanned in the transverse and sagittal planes both before and after voiding at 60 and 90 minutes after completion of the water load. The scans were interpreted by a physician trained and credentialed in emergency ultrasound, blinded to the volunteers' identity, the time of the scan, and the volume of urine voided by the subject. Images were rated as to the degree of hydronephrosis according to literature-established criteria, as follows: grade 0=no hydronephrosis, grade 1=mild, grade 2=moderate, and grade 3=severe hydronephrosis.

RESULTS

Hydronephrosis was present in 3 (8.6%) of the 35 subjects at time 0 (prehydration), 24 (68.6%) at 60 minutes, and 20 (57.1%) at 90 minutes. Overall, hydronephrosis occurred at least once in 28 (80%) of the 35 subjects after oral hydration compared with 3 (8.6%) of the 35 subjects before hydration. Hydronephrosis was found to be significantly related to forced hydration for all posthydration times (60 minutes, 90 minutes, and 60+90 minutes combined) versus prehydration time 0 (P <.001).

CONCLUSION

Without prior fluid intake, even mild degrees of hydronephrosis were relatively uncommon, and seen in only 8.6% of study patients. In the presence of vigorous oral hydration, however, mild or moderate hydronephrosis is a frequent occurrence seen at least once in 80% of our study of healthy volunteers after hydration. Caution is warranted in this setting when interpreting mild or moderate hydronephrosis found on bedside ultrasound by emergency physicians.

Extraparotid Warthin's tumor

Warthin's tumor (papillary cystadenoma lymphomatosum) is a well-known benign tumor of the parotid gland. Extraparotid tumors occasionally arise in the cervical region, where they may well be seen by the dermatologist. The following is a case report of an extraparotid Warthin's tumor encountered in a dermatology practice, with a review of the important clinical and histopathologic features of this tumor.

Cutaneous phaeohyphomycosis due to Cladophialophora bantiana

We present a case of cutaneous infection due to Cladophialophora bantiana, an agent of phaeohyphomycosis. The patient developed a nodule with pustule formation on the dorsum of the left hand; no trauma was reported. The lesion was successfully treated with itraconazole and surgical excision. Histopathologically, there was a blastomycosis-like tissue reaction pattern. Pigmented organisms were readily identified in tissue sections, and the cultural characteristics were those of Cladophialophora bantiana. This organism, known primarily for intracerebral involvement, can rarely produce cutaneous and subcutaneous infection. Immunosuppression should be suspected but is not always clinically apparent, as was demonstrated by our case.

Pilomatricoma: an alarming presentation

Pilomatricoma is an uncommon, benign growth with origination from the hair matrix that may have several clinical presentations and is frequently misdiagnosed. This case of a rapidly growing pilomatricoma in a 26-year-old was particularly deceptive, generating a differential diagnosis, principally of malignant tumors. The typical features, variants, histogenesis, differential diagnosis, and therapy are reviewed.

Familial multiple blue nevi

The blue nevus most commonly presents as a solitary blue nodule. Four histologic variants of blue nevus have been described. Rarely, multiple blue nevi blue nevi may occur in a single person. Only 1 case of familial multiple blue nevi has been described.

Does wearing a necktie influence patient perceptions of emergency department care?

We conducted a prospective study of discharged emergency department (ED) patients to determine the effect of wearing a necktie by emergency physicians (EPs) had on patients' impression of their medical care. All male EPs were assigned randomly by dates to wear a necktie or no necktie, and the attire worn was otherwise similar in all respects. The study was conducted at a community teaching hospital with an Emergency Medicine residency and an annual census of 40,000. A total of 316 patients were surveyed. There were no statistically significant differences between patient groups in any of the five areas surveyed, including patient perception of physicians' appearance. Nearly 30% of patients incorrectly identified their doctor as wearing a necktie when no necktie was worn, and the perception of tie wearing was correlated with a positive impression of physician appearance. Wearing or not wearing a necktie did not significantly affect patients' impression of their physician or the care they received. However, patients seemingly preferred the appearance of physicians who were perceived to wear neckties.

Nonpigmented dysplastic melanocytic nevi

BACKGROUND

Dysplastic melanocytic nevi (DMN) are thought to represent a clinical and histologic bridge between common pigmented nevi and superficial spreading malignant melanoma. The following clinical criteria for DMN were established to aid in the proper identification of these lesions: irregular perimeter, size exceeding 5 mm in diameter, background erythema, and variegated color (shades of browns, tans, blacks, and reds). Histologic features include basilar melanocytic proliferation with nuclear atypia, a patchy lymphocytic infiltrate with concentric eosinophilic fibroplasia, and lamellar fibroplasia. To our knowledge, there have been no previously reported cases of uniformly nonpigmented DMN.

OBSERVATIONS

A 31-year-old brown-haired, browneyed white woman with no personal or family history of either DMN or melanoma presented for evaluation of numerous, discrete, nonindurated, 2- to 5-mm-diameter, nonpigmented macules and slightly elevated papules that had appeared in a truncal distribution over the course of several years. Microscopic examination of these lesions showed lentiginous epidermal hyperplasia and disordered proliferation with variable cellular atypia of intraepidermal melanocytes.

CONCLUSIONS

Nonpigmented, nonindurated, macular or slightly elevated papular lesions may represent nevi with features of dysplasia. In light of the significant risk of malignant melanoma that is associated with pigmented varieties of dysplastic nevi, it is essential that clinicians consider nonpigmented DMN in the differential diagnosis of entities that present as hypopigmented macules.

Structure-activity relationships for inhibition of inosine monophosphate dehydrogenase by nuclear variants of mycophenolic acid

Structure-activity relationships in the region of the phthalide ring of the inosine monophosphate dehydrogenase inhibitor mycophenolic acid have been explored. Replacement of the lactone ring with other cyclic moieties resulted in loss of potency, especially for larger groups. Replacement of the ring by acyclic substituents also indicated a strong sensitivity to steric bulk. A phenolic hydroxyl group, with an adjacent hydrogen bond acceptor, was found to be essential for high potency. The aromatic methyl group was essential for activity; the methoxyl group could be replaced by ethyl to give a compound with 2-4 times the potency of mycophenolic acid in vitro and in vivo.

Ultrastructural changes in skeletal muscle mitochondria in gram-negative sepsis

Energy metabolism during sepsis is incompletely understood, but alterations in mitochondrial structure and function appear important. We measured time-dependent changes in mitochondrial structure during sepsis using serial skeletal muscle biopsies in anesthetized baboons injected with 10(10) CFU/kg of live Escherichia coli (LD(100)). Skeletal muscle biopsies were taken before bacterial challenge (0 h controls) and at 12 h, 24 h, and death. By qualitative electron microscopy, the organelles became enlarged with distorted cristae and developed electron lucent areas within the matrix. With advanced injury the inner membrane became fragmented. Quantitative morphometric analysis showed a 50% increase in mean cristal membrane surface density by 24 h (p < .05) accompanied by a 100% increase in intermembrane space (p < .01). Matrix volume density decreased progressively (p < .01). These changes in mitochondrial ultrastructure occur within 12 h after the onset of the bacterial insult. This damage, including destruction or reorganization of both membrane and matrix proteins, is severe enough to compromise oxidative metabolism in muscle in Gram-negative sepsis.

Effectiveness of different crystalloid i.v. solutions in establishing urine flow

There are several situations in Emergency Medicine when it is desirable to promote a prompt diuresis to fill the bladder or obtain urine for diagnostic tests. We attempted to determine which of 3 commonly used intravenous solutions is most effective in establishing urine flow. In a prospective, randomized double-blind crossover study of 12 healthy male volunteers, we rapidly infused 20 cc/kg of D5W, D51/2NS, or 1/2NS immediately after voiding. Voided urine volumes were then recorded at 30, 60, 90, and 120 min postinfusion and the degree of glycosuria, if any, was noted. Total mean urine volume after D5W was 1181 ml, significantly greater than after 1/2NS (825 ml) and 1/2NS (630 ml), which did not differ between each other. Mean urine volume was greater at every time interval for the D5W group, and glycosuria was common in both D5-containing groups. We conclude that in healthy subjects, D5W is more effective in promoting rapid diuresis than are sodium-containing solutions.

Effect of CBC results on ED management of women with lower abdominal pain

Recent studies have suggested that the results of complete blood counts (CBCs) are neither sensitive nor specific in diagnosing abdominal pain, but no study has attempted to determine whether CBC results actually influence the management of ED patients. This study attempted to determine whether CBC results in women with lower abdominal pain affect ED disposition or diagnosis. One hundred women between the ages of 15 and 45 with lower abdominal pain presenting to a community hospital ED with an annual census of 45,000 were enrolled in this prospective study. Before review of the CBC results but after review of all other studies, the ED physician recorded a presumptive diagnosis and indicated whether consultation and/or admission were warranted. After the results of the CBC were reviewed, these factors were reassessed. Patient management or ED diagnosis was affected in two cases (2%; 95% confidence interval 0% to 7%), one resulting in appropriate discharge and one resulting in unnecessary admission. It was concluded that in young women with abdominal pain CBC results rarely affect clinical decision-making.

Comparison of transthecal digital block and traditional digital block for anesthesia of the finger

STUDY OBJECTIVE

To compare the newly described transthecal (TT) and traditional (TD) methods of digital block anesthesia with regard to length of time to achieve anesthesia and pain during infiltration.

DESIGN

Prospective, randomized, controlled, blinded study.

PARTICIPANTS

Healthy adult paid volunteers.

INTERVENTIONS

Each subject received a TT block on one hand and a TD block on the opposite hand. All blocks were performed by the same investigator and were rated by an evaluator who was blinded to the technique that was used. Time to loss of pin-prick sensation was measured, and the pain of the procedure was recorded by the subject on a 10-cm visual-analog scale.

RESULTS

A total of 162 blocks (81 TT and 81 TD) were performed in 31 different subjects. All blocks were successful. Mean time to anesthesia for TT block was 188 seconds compared with 152 seconds for the TD block (P < .01). Mean analog pain score was slightly higher for TT block than for TD block (1.7 versus 1.4, P = .02).

CONCLUSION

TT block is clinically equal to the TD method in terms of time to anesthesia and visual-analog pain score.

Cutaneous malacoplakia

Indurated, erythematous plaques of the left arm and left flank developed in a 69-year-old white man with multiorgan failure from Escherichia coli sepsis. Cutaneous malacoplakia was diagnosed. Intravenous antibiotic therapy resulted in resolution of the malacoplakia and the E. coli sepsis.

Effects of hydrogen peroxide oxidation and calcium channel blockers on the equatorial potassium current of the frog lens

Hydrogen peroxide, in concentrations of 10-1000 microM, produces two major changes in the current-voltage relationships associated with the equatorial potassium current of the lens. First, the resting and reversal potentials become more negative than they were prior to treatment with hydrogen peroxide and second, the membrane resistance related to the equatorial current is decreased. The shift in the resting and reversal potentials is in the opposite direction from that produced by ouabain. Based on the Nernst equation, the shift in the reversal potential suggests that there is an increase in the concentration of potassium in the lens. The 86Rb uptake and efflux are increased. These observations suggest that hydrogen peroxide stimulates the Na,K-pump. The decrease in membrane resistance is inhibited by 100 microM of quinine, a calcium-dependent potassium channel blocker, and does not decrease in a calcium-free medium. This suggests that the decrease in resistance may be secondary to an increase in lenticular calcium. These effects of hydrogen peroxide are similar to those of p-chloromercuriphenylsulfonate (pCMPS), a nearly impermeant sulfhydryl binding agent, and suggest that permeant hydrogen peroxide may increase calcium influx by acting on sulfhydryl groups on the outer surface of lens membranes. Verapamil, a calcium channel blocker, is reported to prevent cataract formation. D600, the methoxy analogue of verapamil, is a calcium channel blocker that increases the resistance associated with the equatorial current in the presence and absence of hydrogen peroxide. The gadolinium ion has a similar effect. Thus, D600 and Gd3+ partially counteract the reduction in membrane resistance produced by 50 microM hydrogen peroxide.

Topical norepinephrine, isoproterenol, terbutaline, forskolin and 8-bromo cyclic AMP increase lens equatorial current

The equatorial current of the frog lens was studied with microelectrodes and a vibrating probe. Norepinephrine, isoproterenol and terbutaline applied topically at the surface of the cornea as a 1% solution increased the equatorial current of the lens about 80%. This increase was blocked by timolol. Topical forskolin increased the equatorial current by over 80%. This effect of forskolin was not blocked by timolol. These substances did not affect the equatorial current of the lens when the lens was suspended in a frog Ringers solution. 8-Bromo cyclic AMP increased the equatorial current when it was applied topically but not when it was added directly to the medium bathing an isolated lens. The results suggest that beta-adrenergic agonists, applied topically to the cornea, increase the equatorial current of the lens by a mechanism that is mediated by cyclic AMP. The finding that 8-bromo cyclic AMP did not act directly on the lens suggests that a currently unknown substance or process is active at the level of the lens.

D600 increases the resistance associated with the equatorial potassium current of the lens

The effects of D600, the methoxy analog of verapamil, on a pCMPS system were studied. A major effect of D600 is to increase the resistance associated with the equatorial potassium current of the lens. The increase in resistance is statistically significant at concentrations above 200 microM. At concentrations of 25-50 microM, D600 counteracts the decrease in resistance produced by binding sulfhydryl groups with 1 microM pCMPS. This effect is similar to that produced by quinine and by a calcium-free medium, and is attributed to the prevention of an increase in the calcium-dependent conductance produced by pCMPS.

Ultrastructural changes in acquired perforating dermatosis

We performed ultrastructural studies of skin lesions in seven adults with acquired perforating dermatosis. Three of the patients had diabetes mellitus and two were undergoing hemodialysis. Lesions in an early stage showed exocytosis of inflammatory cells and alteration of elastic fibers. Lesions in an intermediate stage featured discontinuities of the basement membrane and aggregates of electron-dense material lateral to the perforated focus, together with dermal edema, scattered macrophages, and densely aggregated collagen fibers that focally filled the papillary dermis. Later-stage lesions showed fibroblasts in the dermis and degenerated elastic fibers within transepidermal channels. In most cases there was a single large epidermal channel lined by flattened epithelial cells, and containing a variety of cellular and extracellular materials. Small "secondary" channels without abnormal keratinization were also observed within the epidermis. The findings suggest that altered keratinization is limited to the immediate vicinity of well-formed transepidermal channels, and that exocytosis of inflammatory cells and alterations of elastica are early and possibly key changes in lesion development. The unexpected discovery of hair fragments in one case suggests that curled hairs may play a role in the pathogenesis of some cases of acquired perforating dermatosis.

3-Carboxy-5-methyl-N-[4-(trifluoromethyl)phenyl]-4-isoxazolecarboxamide, a new prodrug for the antiarthritic agent 2-cyano-3-hydroxy-N-[4-(trifluoromethyl)phenyl]-2-butenamide

The title compound 3-carboxyisoxazole 3 was synthesized by cycloaddition of carbethoxyformonitrile oxide to N-[4-(trifluoromethyl)phenyl]-3-pyrrolidino-2-butenamide (6) with spontaneous elimination of pyrrolidine followed by hydrolysis of the ethyl ester. Compound 3 was shown to be absorbed intact after oral administration to rats. Over 24 h, the compound was metabolized to yield plasma concentrations of the antiinflammatory agent 2-cyano-3-hydroxy-N-[4-(trifluoromethyl)phenyl]-2-butenamide (2), similar to those obtained following an equivalent dose of the established prodrug of 5-methyl-N-[4-(trifluoromethyl)phenyl]isoxazole-4-carboxamide (1).