ABSTRACT
Loss of PKC-epsilon limits the magnitude of acute hypoxic pulmonary vasoconstriction (HPV) in the mouse. Therefore, we hypothesized that loss of PKC-epsilon would decrease the contractile and/or structural response of the murine pulmonary circulation to chronic hypoxia (Hx). However, the pattern of lung vascular responses to chronic Hx may or may not be predicted by the acute HPV response. Adult PKC-epsilon wild-type (PKC-epsilon(+/+)), heterozygous null, and homozygous null (PKC-epsilon(-/-)) mice were exposed to normoxia or Hx for 5 wk. PKC-epsilon(-/-) mice actually had a greater increase in right ventricular (RV) systolic pressure, RV mass, and hematocrit in response to chronic Hx than PKC-epsilon(+/+) mice. In contrast to the augmented PA pressure and RV hypertrophy, pulmonary vascular remodeling was increased less than expected (i.e., equal to PKC-epsilon(+/+) mice) in both the proximal and distal PKC-epsilon(-/-) pulmonary vasculature. The contribution of increased vascular tone to this pulmonary hypertension (PHTN) was assessed by measuring the acute vasodilator response to nitric oxide (NO). Acute inhalation of NO reversed the increased PA pressure in hypoxic PKC-epsilon(-/-) mice, implying that the exaggerated PHTN may be due to a relative deficiency in nitric oxide synthase (NOS). Despite the higher PA pressure, chronic Hx stimulated less of an increase in lung endothelial (e) and inducible (i) NOS expression in PKC-epsilon(-/-) than PKC-epsilon(+/+) mice. In contrast, expression of nNOS in PKC-epsilon(+/+) mice decreased in response to chronic Hx, while lung levels in PKC-epsilon(-/-) mice remained unchanged. In summary, loss of PKC-epsilon results in increased vascular tone, but not pulmonary vascular remodeling in response to chronic Hx. Blunting of Hx-induced eNOS and iNOS expression may contribute to the increased vascular tone. PKC-epsilon appears to be an important signaling intermediate in the hypoxic regulation of each NOS isoform.
Subject(s)
Hypoxia/enzymology , Lung/blood supply , Lung/enzymology , Protein Kinase C-epsilon/metabolism , Pulmonary Circulation , Animals , Blood Pressure/drug effects , Blood Pressure/genetics , Female , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Enzymologic/genetics , Hypertension, Pulmonary/enzymology , Hypertension, Pulmonary/genetics , Hypertension, Pulmonary/pathology , Hypoxia/genetics , Hypoxia/pathology , Lung/pathology , Male , Mice , Mice, Knockout , Nitric Oxide/administration & dosage , Nitric Oxide/metabolism , Nitric Oxide Synthase Type II/biosynthesis , Nitric Oxide Synthase Type III , Protein Kinase C-epsilon/deficiency , Protein Kinase C-epsilon/genetics , Pulmonary Circulation/drug effects , Pulmonary Circulation/genetics , Signal Transduction/drug effects , Signal Transduction/geneticsABSTRACT
BACKGROUND AND OBJECTIVE: The study of hair removal is a slow, tedious process. Efficacy evaluations require test-site observation for at least one complete hair cycle, a minimum of 6-8 months. In addition, tracking and counting individual hairs is extremely labor intensive. The objective of this study was to develop and evaluate a mathematical model for hair removal that could significantly speed the entire process. STUDY DESIGN/MATERIALS AND METHODS: Generally accepted kinetic and statistical modeling methods were used to develop a mathematical description of hair growth. The anagen and telogen percentages and decay times were the variables used to predict the kinetics of untreated hair. In the case that the follicles were treated, it was necessary to additionally consider the possible outcomes after treatment, making the calculations much too complicated for simple mathematical formulations. Therefore, a computerized statistical model was developed that considered the probabilities of no, partial, or complete follicular damage in addition to the untreated model variables. These models were then evaluated by comparing them to data derived from the literature and a study center. RESULTS: Values derived from the mathematical model were capable of closely approximating the experimental results of untreated (shaving) and treated (plucking, electrolysis, ruby laser, Q-switched Nd:YAG laser) hair growth kinetics. The model was also shown to be useful for optimizing the number and interval of Q-switched Nd:YAG laser treatments. CONCLUSIONS: A mathematical model can be used to reliably predict results from a variety of hair removal techniques. It also appears to be useful for optimizing a particular treatment protocol. In addition, the development of new hair removal products may be aided by using this method.
Subject(s)
Hair Follicle/physiology , Hair Removal/methods , Hair/growth & development , Laser Therapy/methods , Models, Theoretical , Computer Simulation , Hair Follicle/growth & development , Humans , Laser Therapy/instrumentation , Models, Biological , Models, StatisticalABSTRACT
BACKGROUND AND OBJECTIVE: Laser hair removal is believed to affect only anagen hairs. However, proof of this belief in humans is lacking. The objective of this study was to determine the influence of the anagen: telogen ratio on the results of Q-switched Nd:YAG laser hair removal. STUDY DESIGN/MATERIALS AND METHODS: Fifteen subjects had four test sites delineated in one body area. The test sites were chosen by trimming the hair and evaluating the area in 2 weeks. At that time, the anagen hairs were at least twice as long as the nongrowing telogen hairs and, therefore, could be differentiated and counted. Two sites with a low anagen number and two with a high number were chosen for comparison. All sites were then treated with a Q-switched Nd:YAG laser. Follow-up examination was in 1 month. RESULTS: Test sites with a low anagen number demonstrated a low level of hair loss compared with those sites with a high anagen number. A significantly higher percentage of hair loss was noted when comparing the anagen-only with total hair loss. In addition, lasing plus shaving demonstrated more hair loss than lasing alone. These findings indicated that anagen hairs were clearly affected, but the immediate clinical effect on telogen hairs was minimal. CONCLUSION: Q-switched Nd:YAG laser treatment of anagen hairs results in a rapid switch to telogen and a subsequent clinically obvious shedding of the hair shaft. This process causes a greater percentage hair loss at sites with high anagen number. Telogen hairs demonstrate no such effect and remain in their pretreatment phase after lasing.
Subject(s)
Hair Removal/methods , Hair/growth & development , Lasers , Adult , Humans , Time FactorsABSTRACT
Laser emission from neodymium-doped glass was first produced nearly 40 years ago. Later, a crystal of yttrium, aluminum, and garnet (YAG) was discovered to be a better lasing host for neodymium. The Nd:YAG laser has since been used for a variety of medical applications, more recently, this instrument has been used for the purpose of damaging hair follicles to epilate unwanted hair. This article reviews the background of the Nd:YAG laser with particular application to hair removal, summarizing the clinical and histologic studies presently available. Its current clinical use and possible future modification for elimination of excess hair are discussed.
Subject(s)
Hair Follicle/surgery , Hair Removal , Laser Therapy , Hair Follicle/anatomy & histology , Hair Follicle/pathology , Hair Removal/instrumentation , Hair Removal/methods , Hirsutism/pathology , Hirsutism/surgery , Humans , Hypertrichosis/pathology , Hypertrichosis/surgery , Laser Therapy/instrumentation , Laser Therapy/methods , NeodymiumABSTRACT
BACKGROUND: Many individuals seek to decrease facial and body hair density. Although a variety of epilating methods are available, improved techniques would be of interest to patients and physicians alike. OBJECTIVE: To determine the safety and clinical efficacy of a new laser-based method of hair removal. METHODS: A Q-switched Nd:YAG laser was used to scan skin with increased hair after applying a topical carbon-based solution. Thirty-five healthy, adult volunteers were treated with a single treatment to selected facial, neck, and axillary sites. RESULTS: Twelve weeks after a single treatment, integrated site scores revealed that the majority of patients had over 25% fewer hairs. The 12-week mean percentage of hair reduction, based on anatomic sites, ranged up to 66% and 44% as judged by physicians and subjects, respectively. Adverse events were minimal and temporary. CONCLUSION: Topical suspension-assisted Q-switched Nd:YAG laser therapy reduces hair density after a single treatment. Advantages include its speed, technical ease, and minimal adverse effects.
Subject(s)
Hair Removal/methods , Laser Therapy , Administration, Topical , Adult , Aged , Carbon/administration & dosage , Hair Removal/instrumentation , Humans , Middle Aged , Mineral Oil/administration & dosage , SuspensionsABSTRACT
BACKGROUND: Hypertrichosis lanuginosa congenita (HLC) is a cutaneous disorder marked by diffuse lanugo-like hair present at birth. Although affected individuals are usually healthy, the excessive hair creates an extraordinary appearance. Permanent eradication of their superfluous hair is therefore a priority. However, a procedure that would achieve this objective is not currently available. OBJECTIVE: To evaluate the efficacy of a new laser technique for hair reduction in a patient with HLC. METHODS: Selected sites were repeatedly treated with a neodymium:YAG (Nd:YAG) laser subsequent to application of a topical carbon-based solution. RESULTS: Forty to eighty percent hair reduction was noted in the sites treated. CONCLUSION: Topical solution-assisted Q-switched Nd:YAG laser hair removal is a safe and effective method for reducing hair density in cases of extensive hypertrichosis. It is an attractive method for children because the low fluences used minimize the associated pain.
Subject(s)
Hair Removal/methods , Hypertrichosis/congenital , Laser Therapy , Administration, Cutaneous , Aluminum Silicates , Anesthetics, Local/administration & dosage , Carbon/administration & dosage , Carbon/therapeutic use , Child , Drug Combinations , Female , Follow-Up Studies , Humans , Hypertrichosis/surgery , Lidocaine/administration & dosage , Lidocaine, Prilocaine Drug Combination , Neodymium , Ointments , Prilocaine/administration & dosage , Solutions , YttriumSubject(s)
Delusions/drug therapy , Hypochondriasis/drug therapy , Pimozide/therapeutic use , Adult , Female , HumansABSTRACT
A newborn female infant suddenly developed a generalized gray-brown discoloration of her skin while receiving phototherapy for hyperbilirubinemia. The discoloration waned over the succeeding weeks. Her serum contained an unknown pigment that had a characteristic absorbance on spectrophotometry. The distinctive findings and some possible causes of the bronze baby syndrome are discussed. The findings are compared to other causes of dusky-hued skin in the neonate. The bronze baby syndrome is usually innocuous but can signal life-threatening disease.
