Antibodies to hair follicles in alopecia areata

Although alopecia areata is suspected to be an autoimmune disease, no direct evidence of an altered immune response to components of the hair follicle has been reported. We studied whether antibodies to normal human anagen scalp hair follicles are present in individuals with alopecia areata. Thirty-nine alopecia areata sera and 27 control sera were tested by Western immunoblotting for antibodies to 6 M urea-extractable proteins of normal anagen scalp hair follicles. At serum diluted 1:80, all alopecia areata subjects (100%), but only 44% of control individuals, had antibodies directed to one or more antigens of approximately 57, 52, 50, 47, or 44 kD. The incidence of antibodies to individual hair follicle antigens in alopecia areata was up to seven times more frequent than in control sera and their level up to 13 times greater and was statistically significant for all five antigens. Tissue specificity analysis indicated that these antigens were selectively expressed in hair follicles. These findings indicate that individuals with alopecia areata have abnormal antibodies directed to hair follicle antigens, and support the hypothesis that alopecia areata is an autoimmune disease.     

Unmyelinated innervation of sinus hair follicles in rats

Unmyelinated nerve fibres comprise approximately one third of the innervation of rodent sinus hair follicles but their function is unknown. They may play a role as high-threshold sensory fibres, or may be autonomic efferents controlling the vascular sinus. In the present experiments capsaicin and surgical sympathectomy were used to establish whether these unmyelinated fibres are afferent fibres or autonomic efferents. The deep vibrissal nerves of mystacial follicles (C1 and C4) and a non-mystacial follicle (the postero-orbital, PO) were assessed in normal adult animals (n = 6) and compared with those treated with neonatal capsaicin (n = 6) or bilateral superior cervical ganglionectomy (n = 7). In capsaicin-treated animals, counts of fibres in the deep vibrissal nerves from all follicles showed normal numbers of myelinated axons, but approximately 80% reduction in unmyelinated fibres (normal mean +/- SD: C1 94 +/- 10, C4 89 +/- 9, PO 85 +/- 6; after neonatal capsaicin: C1 17 +/- 8, C4 16 +/- 6, PO 18 +/- 6; n = 6, P < 0.001 for all follicles). After sympathectomy there was no significant reduction in myelinated or unmyelinated fibre numbers. Labelling of PO follicles with WGA-HRP showed minimal numbers of labelled cells (0-10) within the superior cervical ganglion, also suggesting minimal sympathetic innervation. This sparse sympathetic supply to the follicle was further demonstrated by a lack of tyrosine hydroxylase reactivity within the follicle complex; tissues outside the dermal capsule showed reactivity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Arginine transferase activity in homogenates from guinea-pig hair follicles

A retrospective 10-year experience with the traditional three-stage plan (diverting colostomy, resection, colostomy closure) for perforated diverticulitis of the colon in four urban hospitals was reviewed to accurately assess the mortality rate. Only patients who were admitted in a non-elective manner with signs of an acute abdomen or who were already hospitalized with another illness and developed an acute abdomen were considered. Fecal or generalized purulent peritonitis, or pelvic peritonitis with abscess were observed at laparotomy in all instances. Two hundred and eight patients representing 211 episodes met the above stated criteria for inclusion in the study. A transverse colostomy was performed in 203 instances associated with 16 deaths, and 8 sigmoid colostomies were associated with two deaths. The overall mortality after the first stage was 8.5%. A loop colostomy was constructed most frequently and a completely divided colostomy performed in only 31 of 211 (15%) instances. Of 147 instances in which the diseased sigmoid colon was resected, 44 (30%) had the colostomy ablated at the same operation, resulting in only one death (0.7% mortality). Colostomy closure as a separate procedure in 103 instances resulted in 4 deaths (3.9% mortality). The highest mortality rate occurred in patients in the in the eighth decade. Staged procedures for perforated colonic diverticula can be carried out with a mortality rate of 11%.     

Ageing-associated large-scale deletions of mitochondrial DNA in human hair follicles

Hair follicles plucked from the bi-temporal region of the scalp of 433 Chinese subjects of different ages were used for the examination of ageing-associated mutations of human mitochondrial DNA (mtDNA). By use of PCR techniques, we detected the 4,977 bp and 7,436 bp deletions of mtDNA in hair follicles from aged individuals. The frequencies of occurrence of both mtDNA deletions were found to increase with age of the subject. Moreover, we employed a semi-quantitative PCR method to determine the proportion of the 4,977 bp deleted mtDNA (dmtDNA) in hair follicles. The results showed that the average proportion of the 4,977 bp dmtDNA in hair follicles were 0.05% +/- 0.01%, 0.00%, 0.55% +/- 0.05%, 0.52% +/- 0.24%, 0.65% +/- 0.17%, 1.33 +/- 0.25%, and 1.89% +/- 0.81% for the subjects in the age groups of 21-30, 31-40, 41-50, 51-60, 61-70, 71-80, and 81-99, respectively. Furthermore, we screened all the subjects harboring the 4,977 bp and/or 7,436 bp deletions for tandem duplications in the D-loop region of mtDNA by PCR with back-to-back primers. The results showed that none of the previously reported tandem duplications were present in all the hair follicles examined. This indicates that tandem duplications do not predispose to large-scale deletions of mtDNA. However, the data suggest that mtDNA deletions occur and accumulate in hair follicles during human ageing. As hair follicles can be easily and non-invasively obtained from the human, we suggest that the aged-dependent accumulation of dmtDNAs in hair follicles may be used for the monitoring of human ageing process.     

Different populations of melanocytes are present in hair follicles and epidermis

Melanocytes in human skin reside both in the epidermis and in the matrix and outer root sheath of anagen hair follicles. Comparative study of melanocytes in these different locations has been difficult as hair follicle melanocytes could not be cultured . In this study we used a recently described method of growing hair follicle melanocytes to characterize and compare hair follicle and epidermal melanocytes in the scalp of the same individual. Three morphologically and antigenically distinct types of melanocytes were observed in primary culture. These included (1) moderately pigmented and polydendritic melanocytes derived from epidermis; (2) small, bipolar, amelanotic melanocytes; and (3) large, intensely pigmented melanocytes; the latter two were derived from hair follicles. The three sub-populations of cells all reacted with melanocyte-specific monoclonal antibody. Epidermal and amelanotic hair follicle melanocytes proliferated well in culture, whereas the intensely pigmented hair follicle melanocytes did not. Amelanotic hair follicle melanocytes differed from epidermal melanocytes in being less differentiated, and they expressed less mature melanosome antigens. In addition, hair follicle melanocytes expressed some antigens associated with alopecia areata, but not antigens associated with vitiligo, whereas the reverse was true for epidermal melanocytes. Thus antigenically different populations of melanocytes are present in epidermis and hair follicle. This could account for the preferential destruction of hair follicle melanocytes in alopecia areata and of epidermal melanocytes in vitiligo.     

Measurement of apoptotic fragments in growing hair follicles following gamma-ray irradiation in mice

Feeding ticks are generally spatially distributed in clusters on vertebrate hosts. To test the effect of clustering on transmission of a tick-borne pathogen, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner-infected Ixodes ricinus L. nymphs and uninfected I. ricinus larvae were allowed to feed together in retaining chambers on uninfected AKR/N mice. Engorged infective nymphs dropped off at days 5, 6, and 7, and the 1st infected larvae that fed in the chambers together with the infected nymphs dropped off at day 5. In contrast, ear biopsies and xenodiagnostic larvae placed on the head remained negative during that period. These results suggest that a cofeeding transmission occurred between B. burgdorferi-infected ticks and noninfected ones in the absence of a disseminated infection. Further investigations are being undertaken to determine whether the mechanism responsible for this cofeeding transmission is similar to that described previously with virus-infected ticks.     

The Notch signalling pathway in hair growth

The Notch signalling pathway is an important mediator of cell fate selection whose involvement in epidermal appendage formation is now becoming recognised. Hair follicle development and hair formation involve the co-ordinated differentiation of several different cell types in which Notch appears to have a role. We report intricate expression patterns for the Notch-1 receptor and three ligands, Delta-1, Jagged-1 and Jagged-2 in the hair follicle. Notch-1 is expressed in ectodermal-derived cells of the follicle, in the inner cells of the embryonic placode and the follicle bulb, and in the suprabasal cells of the mature outer root sheath. Delta-1 is only expressed during embryonic follicle development and is exclusive to the mesenchymal cells of the pre-papilla located beneath the follicle placode. Expression of Jagged-1 or Jagged-2 overlaps Notch-1 expression at all stages. In mature follicles, Jagged-1 and Jagged-2 are expressed in complementary patterns in the follicle bulb and outer root sheath, Jagged-1 in suprabasal cells and Jagged-2 predominantly in basal cells. In the follicle bulb, Jagged-2 is localised to the inner (basal) bulb cells next to the dermal papilla which do not express Notch-1, whereas Jagged-1 expression in the upper follicle bulb overlaps Notch-1 expression and correlates with bulb cell differentiation into hair shaft cortical and cuticle keratinocytes.     

Final height in Turner syndrome patients treated with growth hormone

The first treatment trials on patients presenting with Turner syndrome were successful in accelerating growth velocity. It is therefore essential to know the final height of the patients who were treated in order to ascertain whether or not growth hormone treatment increases final height. We are reporting on a group of 117 patients with Turner syndrome whose growth hormone treatment was initiated in 1986. The mean growth hormone dose was 0.74 IU/kg/week for an average period of 4 years. At the start of treatment, the patients' chronological age was 129/12 years, height -3.8 +/- 1.0 standard deviation scores (SDS) and bone age 10.5 +/- 2.1 years. Mean final height was 147.7 +/- 5.6 cm, i.e. a gain of 1.5 SDS. We noted no significant difference due to the type of chromosomal abnormality, nor to oxandrolone or estrogen-associated treatment. A significant correlation was found between final height, mean parental height, the duration of the treatment, height SDS at the start of treatment and growth hormone peak during pharmacological stimulation tests. However, there was no correlation between growth hormone dosage, chronological age and bone age at the start of treatment. These results show that the growth hormone treatment improves the final heights of patients with Turner syndrome.     

Fatigue crack initiation and microcrack growth in 4140 steel

Initiation and growth of fatigue microcracks were studied in vacuum degassed 4140 steel in three conditions: as-quenched, tempered at 400°C, and tempered at 650°C. Micro-scopic examinations were made of specimens with metallographically polished notches using a 400 times long working distance microscope with an x-y micrometer base mounted directly on an MTS machine. Following Barsom and McNicol, the cycles to fatigue crack initiationN _i were plottedvs ΔK/√p and threshhold values of gDK√p were determined. The data of logN _i vs log [ΔK/√p-ΔK/√p|_th] fit on a straight line. Microcracks grew most rapidly in as-quenched specimens and least rapidly in 650°C tempered specimens at the same ΔK/√p. In as-quenched specimens, fatigue cracks initiated at grain boundaries but in the 400 and 650°C tempered specimens they initiated at intrusions-extrusions. They are also associated with Northwestern’s Materials Research Center.     

Mechanical isolation and in vitro growth of preantral and small antral human follicles

OBJECTIVE: To develop a procedure for isolating small human follicles and to determine their growth requirements. DESIGN: Preantral and early antral follicles were isolated manually, allocated randomly to experimental groups, and cultured for a few weeks. SETTING: Patients giving informed consent in hospitals. PATIENT(S): Women undergoing laparotomy or oophorectomy. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Follicular size, E2, histology. RESULT(S): Human FSH (at a dose of 1.5 U/mL) induced antral growth of follicles, and the addition of human LH (2.5 ng/mL) to human FSH stimulated growth and antral development. Histologic studies showed that most of the early antral follicles did not contain an oocyte and already had begun to undergo atresia before culturing. Levels of E2 increased in the incubation medium as the follicles increased in size, but those levels were significantly greater when the follicles contained oocytes. CONCLUSION(S): It is possible to grow small human follicles after they have been isolated manually. To develop successfully, they require a low concentration of human LH in addition to human FSH. The rate of atresia between the preantral and early antral stages in vivo is very high; therefore, it is worthwhile to develop techniques for isolating and culturing the follicles before the antral stages.     

Changing patterns of gap junctional intercellular communication and connexin distribution in mouse epidermis and hair follicles during embryonic development

This paper is concerned with whether transport accident risk tends to peak at particular times, in relation to both time of day and time on task, and with the underlying causes of such peaks. Macro-analyses confirmed the presence of a clear circadian (ca 24 hour) rhythm in road accident risk with a major peak at ca 03:00 but suggested that this rhythm could not be entirely accounted for in terms of drivers falling asleep at the wheel. Sleep propensity clearly shows a pronounced circadian rhythm and performance efficiency in wakeful subjects shows a similar trend implying that the 03:00 road accident peak may simply reflect lowered performance capabilities. However, there are 'residual' peaks in accidents at certain times of day that are difficult to account for in terms of circadian rhythmicity. It is suggested that these may reflect a time on task effect which shows a pronounced, but transient, 2-4 hour peak in risk. Only when individuals had been on duty for 12 hours or more did the risk exceed that found during the 2-4 hour peak. While an explanation for this transient peak is offered, the underlying reason for it is, as yet, uncertain and clearly warrants investigation in view of its practical implications. It is concluded that there are 'black times' when accidents are far more likely and that there is a strong need to investigate possible countermeasures.     

Trypsin-induced follicular papilla apoptosis results in delayed hair growth and pigmentation

Programmed cell death is a controlled process that leads to the elimination of single cells via apoptosis. Programmed cell death is fundamental to development, morphogenesis, and homeostasis. Proteases play a major role in the death process. We have previously shown that a serine protease, secreted by a keratinocyte cell line, can induce apoptosis in numerous cell lines. Here we show that serine proteases can induce cell death in vivo as well. Using a synchronized hair growth mouse model, we show that topical trypsin treatment following depilation induces cell death at the follicular papilla. This results in delaying hair growth and pigmentation. We speculate that trypsin might affect a receptor-mediated signaling pathway that leads to follicular papilla cell death.     

Improvement of doxorubicin induced cardiomyopathy in rats treated with insulin-like growth factor I

OBJECTIVES: This study was designed to assess the effects of treatment with insulin-like growth factor-I (IGF-I) on cardiac function and structure in rats with an established cardiomyopathy. METHODS: Adult male Wistar rats were injected with doxorubicin (2 mg.kg-1 subcutaneously) weekly for 12 weeks and either rhIGF-I (0.8 mg.kg-1.day-1; n = 16, D-I group) or saline (n = 25, D-S group) subcutaneously via an osmotic pump from weeks 9 to 12. A non-doxorubicin injected control group was also studied. After 12 weeks survivors were anaesthetised and cardiac output determined with radiolabelled microspheres. At postmortem pleural effusion and ascitic volumes were measured and the heart was removed for histological examination by light and transmission electron microscopy. RESULTS: Doxorubicin treated animals showed less mean weight gain from week 2 than the untreated control group. Animals treated with IGF-I from week 9 showed a significant (p < 0.05) but non-sustained increase in weight. Survival to 12 weeks was 56% in the D-I group and 44% in the D-S group (p = 0.2). Evidence of cardiac failure was seen in the D-I and the D-S groups, but there was a tendency (p = 0.06) for less ascites in the D-I group (21 (SEM 8) ml) than in the D-S group (46 (10) ml). Cardiac output was significantly higher in the D-I than in the D-S group (132 (7.2) v 91.4 (6.4) ml.min-1, p < 0.01), as was stroke volume (0.323 (0.03) v 0.226 (0.02) ml, p < 0.01). There was focal cardiac damage in both D-I and D-S animals. Scattered groups of myocytes showed prominent vacuolation of the nuclear envelope, sarcoplasmic reticulum, and t tubular system, mild to severe mitochondrial swelling, and loss of orientation and definition of myofibrils. No clear morphological differences were evident between the two groups. CONCLUSIONS: Administration of IGF-I may improve the function of damaged myocardium, although the mechanisms are unclear. Further studies with earlier coadministration of IGF-I, quantitative histological analysis, and with other models of cardiac injury are indicated.     

Fusimotor-free spindles in reinnervated muscles of neonatal rats treated with nerve growth factor

Crushing the nerve to the medial gastrocnemius muscle in newborn rats and administering nerve growth factor afterwards results in a reinnervated muscle containing supernumerary muscle spindles. The structure and innervation of 88 spindles in the reinnervated muscles were reconstructed from serial thick and thin transverse sections at 30-35 days after the nerve crush, and compared to those of five control spindles. The spindles consisted of one to four small-diameter encapsulated fibers with features of nuclear chain intrafusal fibers, or infrequently a nuclear bag intrafusal fiber. Some of the spindles were located within a capsule that also contained an extrafusal fiber. Each spindle was innervated by an afferent with features of the primary afferent. The density of secondary afferents was lower in reinnervated muscles than in controls. Endplates were observed on extrafusal fibers in the experimental muscles, attesting to restoration of skeletomotor (alpha) innervation after the nerve crush. However, 78% of the experimental spindles were entirely devoid of efferent innervation. The remainder received either one or two fusimotor (gamma) axons or a skeletofusimotor (beta) axon, compared to the six to eight motor axons that innervated control spindles. The presence of supernumerary spindles composed of fibers that resemble normal intrafusal fibers in the absence of motor innervation suggests that afferents alone can induce the formation and subsequent differentiation of intrafusal fibers in nerve-crushed muscles of neonatal rats. In addition, the paucity of gamma innervation in nerve-crushed muscles suggests that immature gamma neurons are more susceptible than spindle afferents or alpha efferents to cell death after axotomy at birth.     

Fibroblast growth factor receptor expression in outer hair cells of rat cochlea

Fibroblast growth factors (FGFs) are critical for normal development of the organ of Corti, and may also protect hair cells from ototoxic damage. Four different fibroblast growth factors are known, three of which have different splice variants in the extracellular immunoglobin-like (Ig) III FGF-binding domain, giving different patterns of sensitivity to the different FGFs. Analysis of a cDNA library of rat outer hair cells by the polymerase chain reaction, using isoform specific primers, showed expression only of FGF receptor 3, splice variant IIIc. This allows us to predict the pattern of sensitivity to applied FGFs, which may be useful in targeting outer hair cells selectively during an FGF-based strategy for cochlear therapy.     

Induction of hair growth in ear wounds by cultured dermal papilla cells

In the adult hair follicle the dermal papilla plays a crucial role in the dermal-epidermal interactions that control hair production and events of the growth cycle. It has previously been shown that cultured cells from rat vibrissa follicle dermal papillae can stimulate hair growth when implanted into amputated follicles. This study investigated the effects of implanting low-passage cultured papilla cells into small incisional wounds in the rat ear pinna. The groups of fibers that emerged from wound sites were much larger than local hairs, and often had vibrissa-type characteristics. Later-passage papilla cells or cultured skin fibroblasts failed to elicit the same response. Histology revealed that big follicles were formed when papilla cells were trapped between the cut edges of the epidermis. Abnormally large follicles were seen at wound sites many months post-operatively. Independent of epidermal influence, cultured papilla cells in the wound dermis formed rounded papilla-like aggregates that also persisted until biopsy. A previously described method of wrapping papilla cells in glabrous epidermis was less successful in percentage terms but resulted in the production of one very large vibrissa-type follicle and fiber. These results further illustrate that the inductive powers and developmental information retained by cultured dermal papilla cells parallel the properties of their embryonic precursors; the findings may have implications for human hair growth.     

Targeted expression of activated erbB-2 to the epidermis of transgenic mice elicits striking developmental abnormalities in the epidermis and hair follicles

The erbB-2 proto-oncogene belongs to a receptor tyrosine kinase family that includes the epidermal growth factor receptor, erbB-2, erbB-3, and erbB-4. erbB-2 is expressed in basal cells of the squamous epithelia and the outer root sheath of the hair follicles, but its function in epidermal development has not been well studied. To investigate its role in the skin, we created transgenic mice harboring an activated erbB-2 oncogene under the control of the human keratin 14 promoter. The keratin 14 promoter directed its expression to cells in which erbB-2 is normally expressed, whereas the activated receptor gene ensured increased signaling. All transgenic founder mice exhibited extensive and striking skin phenotype, including epidermal hyperplasia, preneoplasia, papilloma, hyperkeratosis, and dyskeratosis. The majority of the hair follicles were replaced by bizarre hyperproliferative intradermal squamous invaginations, whereas the rest of the follicles exhibited severe hyperplasia and disorganization. All but one of the transgenic mice died before or shortly after birth, probably as a consequence of defects in the skin and esophagus. These observations demonstrate that the skin is sensitive to erbB-2 signaling, suggesting an important role for this receptor tyrosine kinase in epidermal growth, differentiation, and hair follicle morphogenesis.