By F. Dudley. Virginia University of Lynchburg.
The key to successful hair relaxing is an experienced beautician who can quickly apply and remove the chemicals and determine when the desired degree of disulﬁde bond breaking has occurred buy extra super avana 260 mg mastercard. It is estimated that virgin hair loses about 30% of its tensile strength following a properly performed chemical straightening procedure buy cheap extra super avana 260 mg on line. It also becomes more porous extra super avana 260mg otc, allowing future relaxing procedures to process more quickly (72) purchase extra super avana 260 mg on-line. Hair relaxing is a careful balance between achieving the straighten- ing of kinky hair and minimizing irreversible hair-shaft damage. With continued grooming and chemical manipulation the hair loses it protective lipid coating, cuticular scale, elasticity, and strength. Combing, brushing, and shampooing all inﬂict damage on the hair shaft that is temporarily partially reversed with conditioners. Semipermanent and permanent dyeing proce- dures involve the formation of holes within the hair shaft where the color molecules can either penetrate or undergo chemical formation. Once these holes are created through cuticle swelling, they can never be completely closed. An even more dramatic physical insult is inﬂicted with permanent waving and straightening. Here the strong protein backbone of the hair shaft is broken by dissolving and reforming the disulﬁde bonds. Hair with an altered physical shape can never be returned to its original conﬁguration. Individuals with hair and scalp disease, with or without hair loss, will want to beautify their hair with some of the procedures discussed in this chapter. While the physician may be tempted to tell patients to avoid all hair products and procedures except for the most basic shampoos, it is unlikely that this advice will be heeded. Thus, a basic working knowledge of the formulation and function of these products must be obtained. The use of x-ray ﬂuorescent spectroscopy to study the inﬂuence of cationic polymers on silicone oil deposition from shampoo. The critical determination of ﬁne change in the surface architecture of human hair due to cosmetic treatment. Optical properties of hair: Effect of treatments on luster as quantiﬁed by image analysis. Generation of light-scattering factors in hair cuticles and the inﬂuence on hair shine. Advancements in spectroscopic and microscopic techniques for investigating the adsorption of conditioning polymers onto human hair. Investigations on the penetration of hydrolyzed wheat proteins into human hair by confocal laser-scanning ﬂuorescence microscopy. Hair shine: correlation instrumental and visual methods for measuring the effects of silicones. A curing method for permanent hair straightening using thioglycolic and dithiodiglycolic acids. Within the United States for ﬁscal year 2005/2006 total sales of antidandruff products were between $450 and $500 million dollars. However, scientiﬁc attention has only recently been focused on the causes and treat- ment of dandruff (1). The scalp, like the rest of the skin, is a stratiﬁed squa- mous epithelium continually shedding dead microscopically sized corneocytes from the sur- face. It is estimated that each person sheds about 4 kg of corneocyte squames per year (2). While bloodhounds may detect these shed ﬂakes from normal scalps, we are generally only aware of them when they are large enough to see clumped on the scalp, adherent to the hairs, and visible on clothing. Seborrheic dermatitis of the scalp includes both visible ﬂaking and inﬂammation with erythema and, generally, pruritus. Now that more is known about the pathophysiology of both conditions, it is reasonable to consider that most dandruff is seborrheic dermatitis with a range of inﬂamma- tory severity from inapparent to severe (1). At more severe grades, the ﬂakes are present over more of the scalp, are larger, and accumulate in clumps (Figs. At its most severe, dandruff ﬂaking can form a dense mat over the entire scalp surface. With clinically evident seborrheic dermatitis, the ﬂaking may occur in patches with associ- ated erythema and serous oozing. Seborrheic dermatitis also typically affects other hair-bearing or oily areas such as the eyebrows, sideburns, beard, moustache, alar and nasolabial creases, postauricular creases, glabellar crease, and sternum (Fig. Even the axillae and intertriginous folds in adults and the diaper area of infants may be involved. Patients with seborrheic dermatitis commonly report a positive family history of similar problems, suggesting a genetic predisposition. The tendency to develop seborrheic dermatitis persists life-long but ﬂuctuates in activity. It may appear as “cradle cap” (thick oily ﬂaking at the vertex of the scalp) in infancy, remit during childhood, return during adolescence, and appear episodically thereafter (3). Seborrheic dermatitis may produce hypopigmentation or post-inﬂammatory hyper- pigmentation, especially noticeable on pigmented skin. The primary symptom is pruritus, although the degree of itching does not necessarily correlate directly with the degree of ﬂaking. The Scalpdex and other quality-of-life measurement tools are available to assess these effects (6) There is often a discrepancy between the scalp condition severity and the patient’s aware- ness of it. In studies where subjects are asked to assess their scalp state prior to examination by a trained scalp grader, there is wide variation in the self-reported versus directly observed degree of scalp scale. This may be explained in part by a culturally learned reluctance to admit to “dandruff. In the past, it has been estimated that approximately 50% of the population have dandruff at some point in life, with 2–5% having inﬂammatory seborrheic dermatitis (7). The prevalence of scalp scale is higher in African American subjects, especially women, related in part to the decreased average shampoo frequency common to African American hairstyles. This was conﬁrmed in population screening of 1408 Caucasian, African American, and Chinese adults and teenagers studied in Minnesota, Georgia, and China. The prevalence of noticeable ﬂaking was 81–95% in African Americans, 66–82% in Caucasians, and 30–42% in the Chinese. The Chinese subjects, although they had a lower shampoo frequency, had a much higher prevalence of routine antidandruff shampoo use (10–20% in the United States vs 40–52% in the Chinese) which correlated with their overall lower level of ﬂaking (7,8). Thus, there will usually be increased scale where the scalp creases, under hat bands and eyeglass frames, and under areas where the hair is gathered into a ponytail or twist. Temporary changes in hair care can affect dandruff, such as illness, stroke, or injury to the arm or hand impeding shampooing. There is even a subtle decrease in scale on the side of the dominant hand, presumably because of more effective mechanical scale removal during shampooing and brushing. Systemic Disease Associations Worsening seborrheic dermatitis is an early and prominent sign in Parkinson’s disease and related neurological conditions (9,10). The reason for this association is not clear, though pooling of sweat where the facial muscles are inactive, inability to remove sweat and sebum, or changes in sebum are postulated (11,12). Seborrheic dermatitis in this population has been reported to be more severe, more extensive, and more erythematous and papular than usual in immunocompetent individuals. Diagnosis is facilitated by observation of psoriatic plaques elsewhere on the body or typical nail disease. The therapeutic measures used for dandruff and seborrheic dermatitis are also the ﬁrst line therapy for scalp psoriasis. Irritant dermatitis of the scalp presents with thin, dry, crackling scale plus symptoms of stinging, burning, or itching. It is most often produced by barrier disruption from strong sur- factants in shampoos or chemical treatments for hair styling. Patients with atopic dermatitis are particularly susceptible to such barrier damage. Tinea capitis, particularly Trichophyton tonsurans infection, may mimic dandruff or seb- orrheic dermatitis. Microscopic examination of scale and plucked hairs plus culture should be performed when tinea capitis is a possibility.
Wash the equipment free of residual sodium hypochlorite solution with three rinses of filter-sterilized water; do not de-chlorinate the equipment using sodium thiosulfate buy extra super avana 260 mg low cost. This procedure is best done in the office with dedicated sampling equipment for each site; however cheap extra super avana 260mg without a prescription, it may be done in the field as long as the hypochlorite solution is stored and disposed of properly buy generic extra super avana 260mg on line. The cubitainer is sent in a cardboard box to laboratory for Cryptosporidium analysis order extra super avana 260 mg on line. Sampling and equipment cleaning procedures are more thoroughly described elsewhere (G. Environmental Protection Agency, 1997) into a self-contained box with easy-to-use control valves. Waterborne Diseases ©6/1/2018 216 (866) 557-1746 Groundwater Sample Collection Collecting ground-water samples by use of sterile techniques requires knowledge of the type of well, its use, its construction, and its condition. Because we are interested in the microbial population in the ground water and not in the distribution system, it is best to sample directly from the wellhead using a pump with sterile tubing, if possible. Because this is operationally prohibitive for private domestic wells, a tap that yields water directly from the well and before entering the holding tank is preferred. In addition, if the well can easily be opened for inspection, document the condition of the well, including the sanitary seal (if any) and the amount of debris in the well. Any information on the location of the well, including proximity to septic systems or feedlots, should also be documented in the field at the time of sampling. For wells without in-place pumps, samples should be obtained by use of the following methods (in descending order from most to least desirable): (1) a peristaltic or vacuum pump with autoclavable silicon tubing, (2) a sterile bailer, (3) a chlorine-disinfected pump and tubing, or (4) a detergent-cleaned pump and tubing. Pre-sampling activities, such as purging, must be carried out in such a way as to avoid contaminating the well. All equipment must be properly cleaned and sterilized between sites, using a Liquinox wash and a thorough tap water or deionized-water rinse. If using this last method, collect additional field blanks to evaluate the effectiveness of the cleaning procedure. Refer to Myers and Sylvester (1997) for a detailed discussion of ground-water sampling for microbiological analysis. Because ground water is less prone to microbiological contamination than surface water, larger volumes of ground water are needed than of surface water. In the laboratory, coliphage analysis is done using 1 L for somatic and 1 L for F-specific coliphage. Sample Preservation and Storage Holding times for samples before processing are 6 hours for total coliforms, E. Waterborne Diseases ©6/1/2018 217 (866) 557-1746 • Add sodium thiosulfate to sample bottles for bacterial and viral indicators if the water collected contains residual chlorine. Add ethylene diaminetetracetic acid to sample bottles when water is suspected to contain trace elements such as copper, nickel, and zinc at concentrations greater than 1 mg/L (Britton and Greeson, 1989, p. Analytical Methods Field Analysis Analysis of water samples for total coliforms, E. Other new methods can be added to the monitoring program for field testing as they are developed. Waterborne Diseases ©6/1/2018 218 (866) 557-1746 Laboratory Analysis Samples need to be kept on ice and shipped to a central laboratory for analysis of coliphage, C. Because of contamination by naturally occurring bacteria in streamwater samples, antibiotic- resistant host- culture strains, E. Large sample volumes, such as 1-L volumes or greater, are recommended for detection of coliphage in ground water. After incubation, the plates are exposed to ammonium hydroxide, and all straw-colored colonies that turn dark pink to magenta are counted as C. In the case of a high-flow or high-turbidity streamwater sample, lower sample volumes may be plated. Environmental Protection Agency, 1999c) is recommended for detection of Cryptosporidium oocysts and Giardia cysts in water. The oocysts are concentrated on a capsule filter from a 10-L water sample, eluted from the capsule filter with buffer, and concentrated by centrifugation. Fluorescently labeled antibodies and vital dye are used to make the final microscopic identification of oocysts and cysts. During these steps, the 10-L streamwater sample (or 2,000-L ground- Waterborne Diseases ©6/1/2018 219 (866) 557-1746 water sample) is concentrated down to 40 μL. The enteric viruses detected by use of this method include enterovirus, hepatitis-A, rotavirus, reovirus, and calicivirus. For cell-culture analysis, the sample eluate is added to a monlayer of a continuous cell line derived from African green monkey kidney cells (U. Results are reported as most probable number of infectious units per volume of water. Proper and consistent procedures for counting and identifying target colonies will be followed, as described in Myers and Sylvester (1997). Have a second analyst check calculations of bacterial concentrations in water for errors. For coliphage, Cryptosporidium, Giardia, and enteric virus samples, equipment and field blanks are used to determine sampling and analytical bias. An equipment blank is a blank solution (sterile buffered water) subjected to the same aspects of sample collection, processing, storage, transportation, and laboratory handling as an environmental sample, but it is processed in an office or laboratory. Waterborne Diseases ©6/1/2018 220 (866) 557-1746 Field blanks are the same as equipment blanks except that they are generated under actual field conditions. At a minimum, the number of field blanks should equal 5 percent of the total number of samples collected. Five percent of samples collected for bacterial and viral indicators (total coliforms, E. For streamwater samples, concurrent replicates to estimate sampling variability are collected by alternating subsamples in each vertical between two collection bottles. For ground-water samples, sequential replicates are collected one after another into separate sterile bottles. Concurrent and sequential replicates are then analyzed in duplicate (split replicates) to estimate analytical variability. To assess analytical bias of the sampling and analytical method, 2 to 5 percent of the samples collected for enteric virus should be field matrix spikes. Because of the variability in the performance of Method 1623 for recovery of Cryptosporidium and Giardia, each sample will be collected in duplicate—one will be a regular sample and the other a matrix spike. Quality Assurance and Quality Control in the Laboratory The following criteria may be used to evaluate each production analytical laboratory: (1) appropriate, approved, and published methods, (2) documented standard operating procedures, (3) approved quality-assurance plan, (4) types and amount of quality-control data fully documented and technical defensible, (5) participation in the standard reference sample project (6) scientific capability of personnel, and (7) appropriate laboratory equipment. The microbiology laboratories must follow good laboratory practices—cleanliness, safety practices, procedures for media preparation, specifications for reagent water quality—as set forth by American Public Health Association (1998) and Britton and Greeson (1989). Reference cultures are used by the central laboratory to evaluate the performance of the test procedures, including media and reagents. Waterborne Diseases ©6/1/2018 221 (866) 557-1746 Because contamination of samples from coliphage during the analytical procedure is highly probable (Francy and others, 2000), a negative control of host and sterile buffered water is run concurrently with each batch of samples. In addition, to ensure that the method is being executed properly, a positive-control sewage sample is run with each batch of samples. A laminar flow safety hood is recommended for processing the samples for coliphage analysis. Alternatively, a separate coliphage room may be established to discourage laboratory contamination during the analytical process. An ultraviolet light is installed and operated for 8 hours every night in the safety hood or coliphage room to reduce contamination. Waterborne Diseases ©6/1/2018 222 (866) 557-1746 Disinfection Byproduct Regulations Drinking water chlorination has contributed to a dramatic decline in waterborne disease rates and increased life expectancy in the United States. Largely because of this success, many Americans take it for granted that their tap water will be free of disease-causing organisms. In recent years, regulators and the general public have focused greater attention on potential health risks from chemical contaminants in drinking water. It is now recognized that all chemical disinfectants form some potentially harmful byproducts. Thus, it is important that disinfection not be compromised in attempting to control such byproducts. Most water systems are meeting these new standards by controlling the amount of natural organic matter prior to disinfection, while ensuring that microbial protection remains the top priority. For this reason, The American Academy of Microbiology (Ford and Colwell, 1996) has recommended, the health risks posed by microbial pathogens should be placed as the highest priority in water treatment to protect public health.