Effect of the cap layer growth temperature on the Sb distribution in InAs/InSb/InAs sub-monolayer heterostructures for mid-infrared devices.

Sub-monolayer (SML) deposition of InSb within InAs matrix by migration enhanced epitaxy tends to form type II SML nanostructures offering efficient light emission within the mid-infrared (MIR) range between 3 and 5 µm. In this work, we report on the Sb distribution in InSb/InAs SML nanostructures with InAs cap layers grown at temperatures lower than that associated with the under-grown InSb active layer. Analysis by transmission electron microscopy (TEM) in 002 dark field conditions shows that the reduction in the growth temperature of the InAs cap layer increases the amount of Sb deposited in the layers, in good agreement with the x-ray diffraction results. TEM micrographs also show that the layers are formed by random InSbAs agglomerates, where the lower cap temperature leads to a more continuous InSb layer. Quantitative atomic column resolved high angle annular dark field-scanning (S)TEM analyses also reveal atomic columns with larger composition of Sb for the structure with the lowest InAs cap layer temperature. The dependence of the Sb distribution on InAs cap growth temperature allows tuning the corresponding emission wavelength in the MIR range, as shown by the photoluminescence emission spectra.

Human placental amnion is a novel substrate for detecting autoantibodies in autoimmune bullous diseases by immunoblotting.

BACKGROUND: Identification of antigens by immunoblotting techniques, using epidermal and dermal extracts, is regarded as essential for making a definitive diagnosis in autoimmune bullous diseases (AIBDs). These procedures involve epidermal-dermal separation for subsequent protein extraction, which may result in partial loss of some antigenic polypeptides and changes in the conformational epitopes targeted by autoantibodies in AIBDs. It may therefore be necessary to use different substrates for consistent results. Objectives To evaluate the usefulness of human placental amnion extract as a substrate for immunoblotting in the diagnosis of AIBDs. METHODS: We checked the structural components of the desmosomes and basement membrane zone (BMZ) of amnion by electron microscopy. Using immunofluorescence and immunoblotting techniques, we tested the amnion immunoreactivity with antibodies to desmosomal and BMZ proteins, and with sera from 76 patients with AIBDs including pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid (BP), pemphigoid gestationis, linear IgA bullous dermatosis, epidermolysis bullosa acquisita, paraneoplastic pemphigus and mucous membrane pemphigoid. RESULTS: The desmosomes and BMZ of the amnion tissue were ultrastructurally similar to those in skin. Antigen mapping confirmed that amnion contains all the proteins that were recognized by a panel of monoclonal and polyclonal antibodies. Immunoblotting showed that the antibodies clearly detected bands corresponding to desmogleins 1 and 3, desmocollins 1 and 2, desmoplakins 1 and 2, three subunits (alpha3, beta3 and gamma2) of laminin 5, BP antigens 1 and 2, the 97-kDa LAD antigen and type VII collagen. In addition, most of the patient sera (82%) reacted exclusively with their respective antigens. CONCLUSIONS: Harvesting proteins from amnion does not require epidermal-dermal separation, and a sufficient yield of desmosomal and hemidesmosomal proteins can be obtained. Therefore, amnion may be a more reliable source of substrate than skin samples for immunoblot analysis of AIBDs.

Severe nutritional deficiencies in toddlers resulting from health food milk alternatives.

It is widely appreciated that health food beverages are not appropriate for infants. Because of continued growth, children beyond infancy remain susceptible to nutritional disorders. We report on 2 cases of severe nutritional deficiency caused by consumption of health food beverages. In both cases, the parents were well-educated, appeared conscientious, and their children received regular medical care. Diagnoses were delayed by a low index of suspicion. In addition, nutritional deficiencies are uncommon in the United States and as a result, US physicians may be unfamiliar with their clinical features. Case 1, a 22-month-old male child, was admitted with severe kwashiorkor. He was breastfed until 13 months of age. Because of a history of chronic eczema and perceived milk intolerance, he was started on a rice beverage after weaning. On average, he consumed 1.5 L of this drink daily. Intake of solid foods was very poor. As this rice beverage, which was fallaciously referred to as rice milk, is extremely low in protein content, the resulting daily protein intake of 0.3 g/kg/day was only 25% of the recommended dietary allowance. In contrast, caloric intake was 72% of the recommended energy intake, so the dietary protein to energy ratio was very low. A photograph of the patient after admission illustrates the typical features of kwashiorkor: generalized edema, hyperpigmented and hypopigmented skin lesions, abdominal distention, irritability, and thin, sparse hair. Because of fluid retention, the weight was on the 10th percentile and he had a rotund sugar baby appearance. Laboratory evaluation was remarkable for a serum albumin of 1.0 g/dL (10 g/L), urea nitrogen <0.5 mg/dL (<0.2 mmol/L), and a normocytic anemia with marked anisocytosis. Evaluation for other causes of hypoalbuminemia was negative. Therapy for kwashiorkor was instituted, including gradual refeeding, initially via a nasogastric tube because of severe anorexia. Supplements of potassium, phosphorus, multivitamins, zinc, and folic acid were provided. The patient responded dramatically to refeeding with a rising serum albumin and total resolution of the edema within 3 weeks. At follow-up 1 year later he continued to do well on a regular diet supplemented with a milk-based pediatric nutritional supplement. The mortality of kwashiorkor remains high, because of complications such as infection (kwashiorkor impairs cellular immune defenses) and electrolyte imbalances with ongoing diarrhea. Children in industrialized countries have developed kwashiorkor resulting from the use of a nondairy creamer as a milk alternative, but we were unable to find previous reports of kwashiorkor caused by a health food milk alternative. We suspect that cases have been overlooked. Case 2, a 17-month-old black male, was diagnosed with rickets. He was full-term at birth and was breastfed until 10 months of age, when he was weaned to a soy health food beverage, which was not fortified with vitamin D or calcium. Intake of solid foods was good, but included no animal products. Total daily caloric intake was 114% of the recommended dietary allowance. Dietary vitamin D intake was essentially absent because of the lack of vitamin D-fortified milk. The patient lived in a sunny, warm climate, but because of parental career demands, he had limited sun exposure. His dark complexion further reduced ultraviolet light-induced endogenous skin synthesis of vitamin D. The patient grew and developed normally until after his 9-month check-up, when he had an almost complete growth arrest of both height and weight. The parents reported regression in gross motor milestones. On admission the patient was unable to crawl or roll over. He could maintain a sitting position precariously when so placed. Conversely, his language, fine motor-adaptive, and personal-social skills were well-preserved. Generalized hypotonia, weakness, and decreased muscle bulk were present. Clinical features of rickets present on examination included: frontal bossing, an obvious rachitic rosary (photographed), genu varus, flaring of the wrists, and lumbar kyphoscoliosis. The serum alkaline phosphatase was markedly elevated (1879 U/L), phosphorus was low (1.7 mg/dL), and calcium was low normal (8.9 mg/dL). The 25-hydroxy-vitamin D level was low (7.7 pg/mL) and the parathyroid hormone level was markedly elevated (114 pg/mL). The published radiographs are diagnostic of advanced rickets, showing diffuse osteopenia, frayed metaphyses, widened epiphyseal plates, and a pathologic fracture of the ulna. The patient was treated with ergocalciferol and calcium supplements. The published growth chart demonstrates the dramatic response to therapy. Gross motor milestones were fully regained within 6 months. The prominent neuromuscular manifestations shown by this patient serve as a reminder that rickets should be considered in the differential diagnosis of motor delay. (ABSTRACT TRUNCATED)

Tacky but refined: a "slick" technique for dressings that hold better.

For decades benzoin has been used to enhance the "stickiness" of the skin for improved adherence complementing the protective and functional aspects of well-constructed surgical bandages/dressings. The fully adherent and longer-lasting pressure dressing is both aesthetically pleasing to the patient (and surgeon) and, at the same time, functions to decrease seroma or hematoma formation, enhances antisepsis by blocking transient bacterial contamination, and inhibits traumatic sabotage of surgical wounds due to patient overactivity or inadvertent collision with a door jam, car door, table leg, or grandchild, etc. Also, when the bandage looks good, the patient realizes the operation was a success (at least aesthetically). Although simple, our additional steps of deoiling the skin with acetone, followed by multiple compress/release cycles of gauze to the Mastisol area reaps benefits to the patient and surgeon both in function (adherence) and in the production of a truly "dressy" beautiful and long-lasting dressing. In this way, the dressing "bed" is not only more receptive to one's aesthetically pleasing bandage, but is more tacky, yet refined. This same technique can be utilized prior to application of adhesive strips to healing wounds after sutures have been removed, allowing them to "stay on" longer with potentially better cosmesis and less spreading of the scar.

The effects of finasteride on scalp skin and serum androgen levels in men with androgenetic alopecia.

BACKGROUND: Data suggest that androgenetic alopecia is a process dependent on dihydrotestosterone (DHT) and type 2 5alpha-reductase. Finasteride is a type 2 5alpha-reductase inhibitor that has been shown to slow further hair loss and improve hair growth in men with androgenetic alopecia. OBJECTIVE: We attempted to determine the effect of finasteride on scalp skin and serum androgens. METHODS: Men with androgenetic alopecia (N = 249) underwent scalp biopsies before and after receiving 0.01, 0.05, 0.2, 1, or 5 mg daily of finasteride or placebo for 42 days. RESULTS: Scalp skin DHT levels declined significantly by 13.0% with placebo and by 14.9%, 61.6%, 56. 5%, 64.1%, and 69.4% with 0.01, 0.05, 0.2, 1, and 5 mg doses of finasteride, respectively. Serum DHT levels declined significantly (P <.001) by 49.5%, 68.6%, 71.4%, and 72.2% in the 0.05, 0.2, 1, and 5 mg finasteride treatment groups, respectively. CONCLUSION: In this study, doses of finasteride as low as 0.2 mg per day maximally decreased both scalp skin and serum DHT levels. These data support the rationale used to conduct clinical trials in men with male pattern hair loss at doses of finasteride between 0.2 and 5 mg.

Basal cell carcinoma: a comparison of shave biopsy versus punch biopsy techniques in subtype diagnosis.

BACKGROUND: There are two standard ways to obtain tissue for histologic classification of a clinically suspected basal cell carcinoma: shave and punch biopsy. However, information on the value of each method is limited. OBJECTIVE: The purpose of this study was to identify accuracy rates of two standard biopsy techniques in diagnosing subtypes of basal cell carcinoma. METHODS: A total of 86 cases were identified that had received either a punch or a shave biopsy with subsequent total excision of tumor. The biopsy specimens and excisions were compared for histologic correlation. RESULTS: Analysis of specimens from punch and shave biopsies produced equivalent diagnostic accuracy rates: 80.7% and 75.9%, respectively. There was no statistically significant tendency to overcall or undercall any particular tumor subtype on the basis of the type of biopsy procedure used. CONCLUSION: For histologic classification of basal cell carcinoma, there is an approximately 80% accuracy rate with both the shave and the punch biopsy. Therefore either biopsy technique is appropriate.

Spiders and Borrelia burgdorferi: no evidence of reservoir occurrence in central Arkansas.

BACKGROUND: Although Ixodes ticks are considered the chief vector for Borrelia burgdorferi in the USA, B. burgdorferi has also been identified in mosquitoes, horse flies, and deer flies. We examined the possibility of these organisms being harbored in two species of spider in central Arkansas. METHODS: Ten wolf spiders (Lycosa gulosa) and two brown recluse spiders (Loxosceles reclusa) were collected in central Arkansas during early summer and fixed in formalin. Paraffin-embedded sections of the spiders were examined for spirochetes using the modified Steiner spirochete staining method and examined for B. burgdorferi using immunohistochemistry. RESULTS: All 12 spiders from both species were found to be negative for all spirochetes including B. burgdorferi. CONCLUSIONS: Spiders in our sample appeared not to harbor B. burgdorferi. Further studies utilizing larger sample sizes, more sensitive testing measures, or spiders from an area more endemic with B. burgdorferi may further prove or disprove that spiders are capable of harboring this organism.

Telepathology between Richmond and Beckley Veterans Affairs Hospitals: report on the first 1000 cases.

OBJECTIVE: A telepathology connection between Richmond VAMC and Beckley VAMC using dynamic robotic telepathology to provide pathology services remotely was established. MATERIALS AND METHODS: This study reports a 14-month experience using telepathology to diagnose surgical specimens obtained from patients at the Beckley VA Medical Center and viewed in Richmond 250 miles away. Over 14 months, 2325 slides representing 1000 cases were viewed. RESULTS: Discrepancies were observed in 20 of 2325 slides, or 0.86% of the total. None of the patients, where a discrepancy was found, were adversely affected by the preliminary report given. CONCLUSIONS: This study demonstrates that telepathology is a reliable and cost-effective alternative to on-site pathology services and reviews advantages and disadvantages of the system.

Grover's disease (transient acantholytic dermatosis): relationship of acantholysis to acrosyringia.

Transient acantholytic dermatosis is often associated with excessive sweating, fever, and bed confinement. The pathogenesis of this disease has been postulated to be poral occlusion of damaged eccrine intraepidermal ducts. Histological and immunohistochemical and ultrastructural studies were performed on 10 biopsies from 10 patients with transient acantholytic dermatosis. Immunoreactions for carcinoembryonic antigen and cytokeratin-7 to identify eccrine duct epithelium were performed on all 11 biopsies. In addition, 5 of the biopsies were immunoreacted for cytokeratin 8. All immunoreactions were reviewed independently by two observers to determine extent of reactivity and whether it correlated with areas of epidermal acantholysis. Among the 11 biopsies, 8 showed acantholysis not associated with eccrine duct outflow tracts. In 2 biopsies the acantholysis was consistently associated with acrosyringea; in one case acantholysis was inconsistently associated with eccrine outflow tracts. Epidermal acantholysis in patients with Grover's disease is associated with the outflow tracts of eccrine ducts in a subgroup of patients. Although leakage of sweat from occluded sweat ducts in acrosyringia may be the mechanism operating in a subgroup of patients with Grover's disease, this does not appear to be the subgroup of patients in whom Grover's disease develops in the setting of being bedridden and/or sweating.

Plaque-like erythema with milia: a noninfectious dermal mucinosis mimicking cryptococcal cellulitis in a renal transplant recipient.

Cellulitis of the skin is most commonly a bacterial infection caused by either staphylococcal or streptococcal species. However, in immunocompromised patients, cellulitis may be a harbinger of more ominous disease. In these patients, rapid clinical diagnosis and treatment is necessary. We describe an immunosuppressed renal transplant recipient with the clinical diagnosis of cryptococcal cellulitis who was found to have a heretofore unreported dermal mucinosis of the upper chest associated with milia. We believe that cyclosporine was a significant pathogenic factor. This entity, which should be included in the clinical differential diagnosis of cryptococcal cellulitis, has a benign nature and does not require treatment.

IgD myeloma with multiple cutaneous plasmacytomas.

Extramedullary cutaneous plasmacytoma is an uncommon observation in clinical practice. In most of the cases it is usually an extension of underlying medullary plasmacytoma. This case report describes a patient with IgD myeloma who went into plateau phase following standard intravenous chemotherapy. After more than a year in plateau phase, he developed multiple fleshy nodular lesions in the skin. Biopsy of one of the lesions revealed relapse of myeloma in the skin. His IgD paraprotein remained in plateau phase and the bone marrow showed only 1% plasma cells. The patient has been treated with systemic intravenous chemotherapy followed by local radiotherapy.

Cytokeratins in primary cutaneous amyloidosis.

The expression of keratins was investigated immunohistochemically on formalin-fixed and snap-frozen primary cutaneous amyloidosis tissue with a panel of monospecific and polyspecific antikeratin antibodies, with recognized keratins K1, K5, K6, K7, K8, K10, K14, K16, K17, K18 and K19. Amyloid deposits in frozen sections of seven cases of macular amyloidosis and lichen amyloidosus always reacted with antibodies LP34 (labelling K5, K6 and K18), MNF 116 (labelling K5, K6, K8, K10, K17 and K18), and RCK 102 (labelling K5 and K8); frozen sections in one case each of the seven cases also reacted with antibodies LL001 (labelling K14), LP1K (labelling K7 and K17), and LP2K (labelling K19). In formalin-fixed sections of 13 cases of macular amyloidosis and lichen amyloidosus, amyloid deposits were labelled with LP34 in three sections, MNF 116 in four sections, LL020 (labelling keratins K5 and K6) in one section, and LP2K in two sections. In nodular primary cutaneous amyloidosis, amyloid deposits were not labelled with any antikeratin antibodies. These data confirm that amyloid in macular amyloidosis and lichen amyloidosus contains keratin epitopes, and suggests derivation of the fibrillar component from keratin intermediate filaments. Several different keratins appear to undergo conversion to amyloid. LP34, MNF 116 and RCK 102 antibodies, which have in common the labelling of keratin K5, may be useful in the diagnosis of macular and papular amyloidosis with frozen tissue sections.

Deep penetrating dermatofibroma.

BACKGROUND: Deep penetrating dermatofibroma is an unusual and histologically distinctive form of dermatofibroma that usually occurs on the lower extremities of adults. OBJECTIVE: The dermatologic surgeon and pathologist should be aware of this entity to prevent excessive treatment of a benign condition. METHODS: We are reporting a case of deep penetrating dermatofibroma with the results of histologic examination and immunohistochemical studies. RESULTS: The neoplasm consisted of a fibrohistiocytic tumor penetrating into the subcutis accompanied by scalloped extensions along the septae. Immunohistochemical stains were positive for Factor XIIIa and negative for CD34. CONCLUSION: Recognition of the histologic pattern is important in distinguishing deep penetrating dermatofibroma from dermatofibrosarcoma protuberans.

Atrophoderma elastolytica discreta.

Atrophoderma elastolytica discreta is the clinicopathologic name for a unique entity herein first described in a patient with cutaneous lesions simulating atrophoderma of Pasini and Pierini but coupled with histopathologic changes of anetoderma. The clinical and histological findings seen here have not been previously seen in the many variants of anetoderma, and, as such, they are sui generis evidence of a new entity in clinical dermatology.

Hypopigmented macules in acantholytic disorders.

BACKGROUND: Widespread hypopigmented macules are rarely seen in heavily pigmented patients with Darier's disease. Previous hypotheses concerning the cause of decreased pigmentation suggest it is a postinflammatory phenomenon or that the hypomelanosis is evidence of subclinical acantholysis. PATIENTS: This report presents 2 patients: a new case of disseminated guttate leukoderma in a black patient with Darier's disease and the first such case in a patient with transient acantholytic dermatosis (Grover's disease). Direct immunofluorescence and electron-microscopic studies were carried out on lesional biopsies. OBSERVATIONS: Numerous small hypopigmented macules were observed in two black patients followed for acantholytic disorders. Three biopsies of the hypopigmented macules revealed acantholysis, while one showed only decreased melanin. Direct immunofluorescence studies were negative. Electron-microscopic studies of the leukodermic macules showed sparse melanocytes and melanosomes that were mostly pigmented stage IV melanosomes. CONCLUSIONS: Disseminated guttate leukoderma can occur in transient acantholytic dermatosis, as well as in Darier's disease. It is readily apparent on darkly pigmented skin because of contrast. The etiology of this phenomenon is still unknown.