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Rolf Hoffmann

Publications and source records attributed to Rolf Hoffmann.

At least 19 recordsLinked to original sources

Restrictive dermopathy associated with transposition of the great arteries and microcolon: a rare neonatal entity with new symptoms.

BACKGROUND: Restrictive dermopathy is a very rare autosomal recessive skin disorder. The typical pathologic findings are striking: microstomia, micrognathia, thin but very tight translucent skin that tears spontaneously, and arthrogryposis multiplex. The mechanisms behind this disease are unknown. OBSERVATIONS: We describe for the first time a newborn girl with restrictive dermopathy, transposition of the great vessels, and microcolon. She had thin shiny skin with nearly no compliance indicating restrictive dermopathy. Additional dysmorphic findings included enlarged fontanelle, hypertelorism, absent eyelashes, small pinched nose, microstomia, micrognathia, dysplastic ears, pterygium colli, dyplastic fingers and toes with upper- and partial lower-limb flexion contractures, dysplastic genitalia, and muscular hypotonia. She also had left transposition of the great artery with small atrial septal defect, bilateral hypoplasia of the first rib, and congenital stenosis of the small bowel with microcolon. CONCLUSIONS: The pathogonomic diagnostic features remain reduced dermal thickness and nearly complete absence of elastic fibers in the dermis. In mice, a defective fatty acid transport protein 4 gene (Fatp4) leads to clear signs of restrictive dermopathy by influencing the arrangement of the lipids in the epidermis. Whether the left transposition of the great artery is associated with restrictive dermopathy or represents an additional malformation of multifactorial, polygenetic, or monogenetic cause remains open.

Abnormalities, Multiple↗

Transfer of CD8(+) cells induces localized hair loss whereas CD4(+)/CD25(-) cells promote systemic alopecia areata and CD4(+)/CD25(+) cells blockade disease onset in the C3H/HeJ mouse model.

Alopecia areata (AA) is a suspected hair follicle specific autoimmune disease. The potential for cell transfer of AA using the C3H/HeJ mouse model was examined. Cells isolated from lymph nodes and spleens of AA-affected mice using magnetic bead conjugated monoclonal antibodies were subcutaneously injected into normal C3H/HeJ recipients. Within 5 wk, all CD8(+) cell-injected mice exhibited localized hair loss exclusively at the site of injection that persisted until necropsy. In contrast, some CD4(+) and CD4(+)/CD25(-) cell-injected mice developed extensive, systemic AA, and a combination of CD8(+) and CD4(+)/CD25(-) cells injected yielded the highest frequency of systemic AA induction. CD4(+)/CD25(+) cells were less able to transfer the disease phenotype, partially blockaded systemic AA induction by CD4(+)/CD25(-) cells, and prevented CD8(+) cell-induced, injection site-localized hair loss. CD11c(+) and CD19(+) cells failed to promote significant phenotype changes. Increases in co-stimulatory ligands CD40 and CD80, plus increased leukocyte apoptosis resistance with reduced CD95, CD95L, and CD120b expression, were associated with successful alopecia induction. The results suggest that CD8(+) cells may be the primary instigators of the hair loss phenotype. However, systemic disease expression fate is, apparently determined by CD4(+)/CD25(-) cells, while CD4(+)/CD25(+) lymphocytes may play a predominantly regulatory role.

Adoptive Transfer↗

Reduced expression of interleukin-2 decreases the frequency of alopecia areata onset in C3H/HeJ mice.

Alopecia areata (AA) is an autoimmune hair loss disease, that can be transferred between C3H/HeJ mice by skin grafting. We explored whether AA susceptibility is influenced by the availability of interleukin (IL)-2, a cytokine with leukocyte activating and regulatory properties. Mice heterozygous for a targeted deletion of IL-2 from the histocompatible C3.129P2(B6)-Il2(tm1Hor) substrain, that produce reduced levels of IL-2, were examined for AA development after grafting skin from AA-affected C3H/HeJ mice. After grafting, nine of 19 (47%) heterozygous IL-2+/-versus 16 of 18 (88%) IL-2+/+ wild-type littermates developed AA. Although dense follicular leukocyte infiltrates were apparent in AA affected wild-type mice, AA-developing IL-2+/- littermates had a reduced leukocyte infiltration, and AA-resistant IL-2+/- mice had no inflammation. Lymph node cell analysis revealed a reduction in leukocyte activation markers in AA-developing IL-2+/- mice. IL-2+/- mice presented with low level expression of cytokines (IL-4, IL-10, interferon-gamma, transforming growth factor-beta), upregulation of tumor necrosis factor receptors, and increased leukocyte apoptosis susceptibility independent of AA expression. In the skin, CD4+ cells and monocytes were reduced; activation markers were not upregulated and very few CD44v3+ or CD44v10+ leukocytes were recovered. Taken together, our data suggest that AA resistance of IL-2+/- mice is because of the failure of activated leukocyte recruitment, thus pointing toward an involvement of IL-2 in AA pathogenesis.

Alopecia Areata↗

Recent findings with computerized methods for scalp hair growth measurements.

Sensitive tools have been developed in order to monitor hair loss and treatment responses. Recently the Tricho-Scan was presented (by RH) as such a method which combines epiluminescence microscopy (ELM) with automatic digital image analysis. Herewith new TrichoScan data obtained from 10 women and 21 men with androgenetic hair loss after 6 mo of treatment with 5%-minoxidil are presented. Even in this small cohort of patients, we noticed a significant increase of hair density, cumulative hair thickness and terminal hair counts. Alternative methods were developed during a human alopecia investigation and research technology (HAIR Technology) programme at Skinterface. This involves contrast-enhancement, image acquisition, and processing by qualified technicians followed by computer-assisted image analysis. The specific identification of exogen hair, further adds to this very refined non-invasive investigative method for hair follicle function investigation. Regional variations of hair growth dynamics do exist in the human scalp such as in female patients complaining of hair loss, scalp hair density and growth on top of the head differs significantly from the occipital site. Finally, from transversal studies and from detailed monitoring of subsequent hair cycles during longitudinal studies, data were obtained that support the fact that shortening of hair cycle, slowing down of growth rates and thinning of hair shafts are heralding hair miniaturisation. In the workshop the TrichoScan, the method of Canfield and Skinterface have been shown.

Adult↗

Trichoscan: what is new?

The treatment of androgenetic alopecia (AGA) is usually long lasting, and the effects of treatment attempts are difficult to measure. Consequently, there was a need for a sensitive tool to monitor hair loss and treatment response. Therefore, we developed the Trichoscan as a method which combines epiluminescence microscopy with automatic digital image analysis for the measurement of human hair. The Trichoscan is able to analyze all important parameters of hair growth (density, diameter, growth rate, vellus and terminal hair density) with an intraclass correlation of approximately 91% within the same Trichoscan operator and an intraclass correlation of approximately 97% for different Trichoscan operators. The application of the technique was demonstrated by comparison of the hair parameters in 9 men with frontal balding which were treated for 6 months with 5% minoxidil. Even in this small cohort of patients, we noticed after 3 months of treatment compared to baseline a significant increase in hair density (+21.3 hairs/cm2; p = 0.047) and cumulative hair thickness (+0.61 mm; p = 0.008) and after 6 months a significant increase in hair density (+34 hairs/cm2; p = 0.011) and cumulative hair thickness (+0.88 mm; p = 0.010). The study shows that the Trichoscan has many advantages. It can be used for clinical studies to compare placebo versus treatment or to compare the relative potencies of different hair-growth-promoting substances. It can be used for studying AGA or other forms of diffuse hair loss, and it can be adopted to study the effect of drugs or laser treatment on hypertrichosis or hirsutism. The drawbacks, however, are that the Trichoscan still needs a hair dye for contrast enhancement and the measurement area must be clipped before analysis. This mini-review summarizes recent attempts to optimize the technique and shows new options such as the calculation of follicular units or the 'anagen hair count'.

Alopecia↗

Apoptosis resistance in peripheral blood lymphocytes of alopecia areata patients.

Alopecia areata (AA) is a putative, cell-mediated autoimmune disease of anagen stage hair follicles. Inter- and intra-follicular lymphocytic infiltrates are associated with alopecia that may progress from an initially patchy presentation to extensive, even universal, hair loss. We previously noted in a mouse model of AA that regulatory T cells (Treg) are absent from draining lymph nodes and that expression of CD44v7 is transiently upregulated. Both features might explain autoreactive T cell persistence. Here we explored whether similar changes are seen in AA patients' peripheral blood mononuclear cells (PBMC). There was no clear evidence for a reduction in Treg as a possible means to support sustained T cell activation. However, progressive AA patients' PBMC displayed increased resistance towards apoptosis, which was accompanied by a decrease in CD95L+ and an increase in CD44v7+ cells. Notably, an expanded population of CD4+CD25+CD154+ T cells in progressive AA patients' PBMC was apoptosis resistant and expressed CD44v7. Thus, survival of activated T cells in progressive AA patients' PBMC is apparently sustained by downregulation of CD95L and upregulation of CD44v7 which is known to be associated with anti-apoptotic gene expression.

Adolescent↗

Macrophage-stimulating protein promotes hair growth ex vivo and induces anagen from telogen stage hair follicles in vivo.

Hepatocyte growth factor (HGF) is a promoter of hair follicle growth. We examined another HGF family member, macrophage-stimulating protein (MSP), for its hair follicle-modulating properties. Western blotting revealed presence of mature MSP in cultured human dermal papilla (DP) cells and bulbar dermal sheath (DS) cells, but not non-bulbar DS cells. Immunohistology demonstrated expression of MSP receptor RON in the outer and inner root sheaths, hair matrix cells, DP, and bulbar DS whereas non-follicular epithelium and some cells of the sweat glands exhibited low-level receptor expression. Human hair follicles exposed in vitro for 8 d to 0.1, 1, 10, and 100 ng per mL MSP all yielded a mean net increase in hair follicle length in excess of the mean baseline growth observed in controls. MSP was incubated with agarose beads and injected subcutaneously into mice all 70 d old when a uniform telogen state in dorsal skin was apparent. All eight mice receiving 1 microg MSP, and four of eight receiving 100 ng MSP showed induction of anagen hair growth at the site of bead implantation by 16 d whereas eight mice implanted with saline incubated beads had no hair growth. The data identify MSP as a modulator of hair growth.

Adult↗

The progressive state, in contrast to the stable or regressive state of alopecia areata, is reflected in peripheral blood mononuclear cells.

Alopecia areata (AA) is a putative autoimmune disease of the skin with an inflammatory component that can be treated by the local application of contact sensitizers. Here, we explored whether responsiveness toward diphenylcyclopropenone (DPCP) is reflected by the composition and the activation state of peripheral blood mononuclear cells (PBMCs). PBMCs of 43 AA patients, 26 treated and 17 untreated, and of 31 healthy volunteers were tested. AA patients' PBMCs differed from that of healthy donors by a slight increase in CD16- and tumor necrosis factor-alpha (TNF-alpha)-expressing cells. These features were independent of the disease state and treatment. Additional changes in the activation state of PBMCs, upregulation of the costimulatory molecules CD40 and CD80, of the accessory molecule CD154, and of interferon-gamma expression were identified only in AA patients where the disease was advancing, i.e. these changes were independent of the extent of hair loss and were not seen in patients with spontaneous or DPCP treatment-induced, regressing AA. Thus, the progressive state of AA is accompanied by a systemic activation of T cells, and the therapeutic efficacy of treatment can be estimated by restoration of the non-activated state. Furthermore, an increase in CD16(+)- and TNF-alpha-expressing cells may contribute to AA susceptibility.

Adolescent↗

Alopecia areata susceptibility in rodent models.

With our current view of alopecia areata as an autoimmune disease, it is probable that disease development in an individual is dependent on multiple genetic and environmental factors interacting in a complex system. Rodent models afford the opportunity to investigate alopecia areata development and to define the significance of the different factors involved. Recently, rodent model characterization has been conducted using flow cytometry, microarray analysis, and functional studies. From these a pattern of events in alopecia areata development has emerged. Although the preliminary activation events for the onset of alopecia areata remain unknown, the response of the immune system is characterized by antigen presentation and costimulation of lymphocytes in the lymph nodes and skin, a deficiency of CD4+/CD25+ regulatory cells, and an action of activated lymphocytes on hair follicles via Fas/FasL signaling and cytokines. Thus, onset of disease may require appropriate (or inappropriate) expression of stimulatory antigens within the hair follicle, the breakdown of the putative hair follicle immune privilege, the presentation of antigens to the immune system, a failure of immune system regulation, and the ability of the activated immune system to disrupt anagen-stage hair follicles. Once the sequence of events is initiated, it may become a self-perpetuating cycle, with epitope spreading leading to a wider range of targets in chronic alopecia areata. Rodent model studies have provided significant insight into alopecia areata, but much more remains to be explained about the mechanisms of disease development.

Alopecia Areata↗

The pathogenesis of alopecia areata in rodent models.

Rodent models of human disease provide an important tool in the investigation of genetic and environmental activation factors, disease pathogenesis, and the development of new and improved treatments. Up to 20% of aged C3H/HeJ mice and 70% of Dundee Experimental Bald Rats (DEBR) develop alopecia areata (AA), a nonscarring, inflammatory hair loss disease with a suspected autoimmune pathogenesis. These rodent models are currently employed in determining the genetic basis of AA, understanding the mechanisms of disease initiation and progression, and defining potential endogenous and environmental influences. Induction of AA by skin graft transfer between affected and unaffected mice has been employed to examine skin and immune system changes during AA pathogenesis. Manipulation of inflammatory cells in vivo indicates AA is primarily a cell mediated disease with auto-antibody production as a secondary event. Whether the AA activating factors are exogenous or endogenous antigens, or involve normal or aberrant epitope expression remains to be elucidated. However, current research suggests a self contained disease cycle involving four key events: (1) Failure of the putative anagen stage hair follicle immune privilege and exposure of hair follicle located AA inciting epitopes to the immune system; (2) Antigen presentation, costimulation, and activation of responsive lymphocytes by antigen presenting cells; (3) Activated inflammatory cell migration to, and infiltration of, hair follicles; (4) The subsequent disruptive actions of the inflammatory cell infiltrate on the hair follicles. Each of these events is vulnerable to therapeutic intervention, and rodent models will be fundamentally involved in developing new treatments for AA.

Adjuvants, Immunologic↗

Alopecia areata: treatment of today and tomorrow.

It is the aim of this article to review and appraise available data on treatments for alopecia areata (AA) according to the demands of evidence based medicine. Studies evaluating the efficacy of a treatment for AA should include appropriate controls, use cosmetically acceptable hair regrowth as a parameter for treatment success, include patients with AA totalis, universalis or extensive patchy AA, and exclude patients suffering from AA for less than 3 months. Moreover, the treatment must be safe over a prolonged period of time. Among the various therapeutic approaches presently available for AA, only treatment with contact sensitizers such as diphenylcyclopropenone or squaric acid dibutylester has been shown to be effective in studies that fulfill these criteria. Improved future treatments may be immunosuppressive or immunomodulatory targeting of the autoimmune pathogenesis of AA, or they may otherwise protect hair follicles from the injurious effects of inflammation. Such possible future therapeutic approaches include the incorporation of immunomodulatory agents into liposomes as an improved vehicle; inhibition of apoptosis mediated by the Fas-FasL system; inhibition of the lymphocyte homing receptor CD44v10; induction of tolerance.

Adjuvants, Immunologic↗

Fas-deficient C3.MRL-Tnfrsf6(lpr) mice and Fas ligand-deficient C3H/HeJ-Tnfsf6(gld) mice are relatively resistant to the induction of alopecia areata by grafting of alopecia areata-affected skin from C3H/HeJ mice.

Alopecia areata is suspected to be a T cell-mediated autoimmune disease of the hair follicle, where Fas is expressed on hair follicles and Fas ligand on perifollicular infiltrates. To elucidate whether the Fas/Fas ligand pathway is of pathogenetic significance in alopecia areata, we investigated whether alopecia areata can be induced in Fas-deficient and Fas ligand-deficient mice and whether alopecia areata develops in Fas-deficient and Fas ligand-deficient skin. Therefore, we induced alopecia areata by grafting alopecia areata-affected C3H/HeJ mouse skin on to C3H/HeJ mice (control), on to Fas ligand-deficient C3H/HeJ-Tnfsf6(gld) mice or Fas-deficient C3.MRL-Tnfrsf6(lpr) mice. All control mice developed alopecia areata, whereas no Fas-deficient mice showed hair loss and two of seven Fas ligand-deficient mice developed only transitory, limited alopecia areata. Moreover, skin from C3H/HeJ mice (control), C3H/HeJ-Tnfsf6(gld) mice, and C3.MRL-Tnfrsf6(lpr) mice was grafted on to C3H/HeJ mice with extensive alopecia areata. Skin grafts from control mice developed hair loss, whereas Fas-deficient and Fas ligand-deficient skin grafts were spared from alopecia areata. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling and immunofluorescence studies revealed an increased number of apoptotic cells and expression of Fas on hair follicles as well as expression of Fas ligand on cells of the perifollicular infiltrate in C3H/HeJ mice with alopecia areata, whereas in Fas-deficient and Fas ligand-deficient mice apoptotic cells were virtually absent in hair follicles. The results suggest that the Fas/Fas ligand pathway plays an important pathogenetic role in alopecia areata.

Alopecia Areata↗

TrichoScan: a novel tool for the analysis of hair growth in vivo.

Hair loss or hair thinning is a common complaint in clinical dermatology, and patients seeking advice for hair loss are not necessarily bald. Because the effects of treatment attempts are hard to measure, there is need for a sensitive tool to monitor hair loss and treatment responses. Such a method must be able to analyze the biologic parameters of hair growth, which are: (i) hair density (n per cm2); (ii) hair diameter (microm); (iii) hair growth rate (mm per day); and (iv) anagen/telogen ratio. Herein we present the TrichoScan as a method that combines epiluminescence microscopy with automatic digital image analysis for the measurement of human, and potentially animal hair, in situ. The TrichoScan is able to analyze all four parameters of hair growth with a so-called intraclass correlation of approximately 91% within the same TrichoScan operator and an intraclass correlation of approximately 97% for different TrichoScan operators. The application of the technique is demonstrated by comparing the hair parameters in individuals without apparent hair loss, men with untreated androgenetic alopecia, and men after treatment with finasteride (1 mg per day). We were able to detect a significant increase in hair counts and cumulative hair thickness 3 and 6 mo after treatment. Advantages of the TrichoScan are that it can be used for clinical studies to compare placebo versus treatment, to compare different capacities of hair growth promoting substances, to study androgenetic alopecia and other forms of diffuse hair loss, and to study the effects of drugs and laser treatment on hypertrichosis and hirsutism.

Adult↗

Cultured peribulbar dermal sheath cells can induce hair follicle development and contribute to the dermal sheath and dermal papilla.

Green fluorescent protein (GFP)-expressing wild-type, and nontransgenic mouse vibrissa follicle cells were cultured and implanted to mouse ears and footpads. Dermal papiller (DP)-derived cells and cells from the peribulbar dermal sheath "cup" (DSC) induced new hair follicles in both implanted ears and footpads, while nonbulbar dermal sheath cells did not. Confocal microscopy revealed that GFP-expressing DP and DSC cells induced hair growth associated with the formation of DP exclusively comprised of fluorescent cells. In mouse ears, but not footpads, fluorescent DP and DSC cells could also be identified in DP along with nonfluorescent cells. DSC cells were characterized in vivo and in vitro by low alkaline phosphatase activity in contrast to high alkaline phosphatase in DP cells. The results indicate transplanted DP and DSC cells were equally capable of DP formation and hair follicle induction. This suggests the DP and peribulbar DSC may be functionally similar. In addition to observing papillae exclusively composed of GFP-expressing cells, DP and DSC cells may also have combined with resident cells to form papillae composed of implanted GFP-expressing cells and host-derived non-GFP-expressing cells. Alkaline phosphatase expression may be utilized as a simple marker to identify hair follicle mesenchyme derived cells with hair follicle inductive abilities.

Alkaline Phosphatase↗

Steroidogenic isoenzymes in human hair and their potential role in androgenetic alopecia.

Androgenetic alopecia (AGA) is the most common type of hair loss. The relatively strong concordance of the degree of baldness in fathers and sons is not consistent with a simple Mendelian trait, and a polygenic basis is considered to be most likely. So far, the predisposing genes for AGA are unknown and we do not understand the molecular steps involved in androgen-dependent beard growth versus androgen-dependent hair loss, but AGA can be defined as a dihydrotestosterone (DHT)-dependent process with continuous miniaturization of sensitive hair follicles. The type 2 5alpha-reductase plays a central role by the intrafollicular conversion of testosterone to DHT. However, due to the increasing knowledge in this field, we now know that there are many more steroidogenic enzymes involved in the onset and development of AGA, and this article shall provide a critical overview of recent discoveries.

Alopecia↗