Avaliação e comparação entre métodos de mensuração de pressão arterial sistólica em gatos hígidos conscientes / Evaluation and comparison between methods of measurement of systolic blood pressure in healthy conscious cats

Após validação de dois diferentes métodos de mensuração de pressão arterial sistólica (PAS) não invasivos ou indiretos (oscilométrico e Doppler vascular) com o invasivo ou direto (cateterização arterial - padrão ouro) em 12 gatos hígidos anestesiados de mesma faixa etária, os métodos não invasivos foram avaliados e comparados em 24 gatos hígidos e conscientes, divididos em quatro grupos de idade. Em cada animal, procedeu-se à mensuração da pressão pelos métodos Doppler e oscilométrico. O método oscilométrico foi o primeiro a ser realizado, e, logo em seguida, o método Doppler. Os valores considerados foram obtidos das médias de sete medidas consecutivas para cada método, com intervalo de 30 segundos entre elas. A primeira medida e as medidas discrepantes (variação ˃ 20% PAS), obtidas com sinais óbvios de estresse e/ou com movimentação do animal, foram descartadas. Os métodos de mensuração oscilométrico e Doppler, embora tenham apresentado médias estatisticamente diferentes em todos os grupos, quando comparados em cada grupo, apresentaram uma correlação significativa, alta e positiva. Ou seja, sempre que for obtido um valor elevado por um método, o mesmo fato ocorrerá com o outro método e vice-versa. Clinicamente, a diferença observada não é relevante, uma vez que a diferença média dos valores obtida pelos dois métodos, em cada grupo, foi menor que 1,1%.(AU)

After two different validation systolic blood pressure measurement methods (PAS), not invasive or indirect (oscillometric and doppler vascular) with invasive or direct (arterial catheterization - Gold Standard) in 12 anesthetized healthy cats of the same age group, not invasive methods were evaluated and compared in 24 healthy conscious cats, divided into four age groups. In each animal, we proceeded to measure the pressure by Doppler and oscillometric methods. The oscillometric method was the first to be performed, and, shortly thereafter, the doppler method. The values considered were obtained from averages from seven consecutive measurements for each method with an interval of thirty seconds between them. The first measurement and disparate measurements (range ˃ 20% PAS) obtained with obvious signs of stress and / or animal movement were discarded. Methods of oscillometric and doppler measurement, although statistically different averages were shown in all groups when compared, each group showed a significant high positive correlation, meaning that when a high value is obtained by a method, the same occurs with the other method, and vice versa. Clinically, the observed difference is not relevant since the mean difference values obtained by the two methods, in each group was lower than 1.1%.(AU)

Profiling of promoter occupancy by PPARalpha in human hepatoma cells via ChIP-chip analysis.

The transcription factor peroxisome proliferator-activated receptor alpha (PPARalpha) is an important regulator of hepatic lipid metabolism. While PPARalpha is known to activate transcription of numerous genes, no comprehensive picture of PPARalpha binding to endogenous genes has yet been reported. To fill this gap, we performed Chromatin immunoprecipitation (ChIP)-chip in combination with transcriptional profiling on HepG2 human hepatoma cells treated with the PPARalpha agonist GW7647. We found that GW7647 increased PPARalpha binding to 4220 binding regions. GW7647-induced binding regions showed a bias around the transcription start site and most contained a predicted PPAR binding motif. Several genes known to be regulated by PPARalpha, such as ACOX1, SULT2A1, ACADL, CD36, IGFBP1 and G0S2, showed GW7647-induced PPARalpha binding to their promoter. A GW7647-induced PPARalpha-binding region was also assigned to SREBP-targets HMGCS1, HMGCR, FDFT1, SC4MOL, and LPIN1, expression of which was induced by GW7647, suggesting cross-talk between PPARalpha and SREBP signaling. Our data furthermore demonstrate interaction between PPARalpha and STAT transcription factors in PPARalpha-mediated transcriptional repression, and suggest interaction between PPARalpha and TBP, and PPARalpha and C/EBPalpha in PPARalpha-mediated transcriptional activation. Overall, our analysis leads to important new insights into the mechanisms and impact of transcriptional regulation by PPARalpha in human liver and highlight the importance of cross-talk with other transcription factors.

Gene expression profiling of the long-term adaptive response to hypoxia in the gills of adult zebrafish.

Low oxygen levels (hypoxia) play a role in clinical conditions such as stroke, chronic ischemia, and cancer. To better understand these diseases, it is crucial to study the responses of vertebrates to hypoxia. Among vertebrates, some teleosts have developed the ability to adapt to extremely low oxygen levels. We have studied long-term adaptive responses to hypoxia in adult zebrafish. We used zebrafish that survived severe hypoxic conditions for 3 wk and showed adaptive behavioral and phenotypic changes. We used cDNA microarrays to investigate hypoxia-induced changes in expression of 15,532 genes in the respiratory organs (the gills). We have identified 367 differentially expressed genes of which 117 showed hypoxia-induced and 250 hypoxia-reduced expressions. Metabolic depression was indicated by repression of genes in the TCA cycle in the electron transport chain and of genes involved in protein biosynthesis. We observed enhanced expression of the monocarboxylate transporter and of the oxygen transporter myoglobin. The hypoxia-induced group further included the genes for Niemann-Pick C disease and for Wolman disease [lysosomal acid lipase (LAL)]. Both diseases lead to a similar intra- and extracellular accumulation of cholesterol and glycolipids. The Niemann-Pick C protein binds to cholesterol from internal lysosomal membranes and is involved in cholesterol trafficking. LAL is responsible for lysosomal cholesterol degradation. Our data suggest a novel adaptive mechanism to hypoxia, the induction of genes for lysosomal lipid trafficking and degradation. Studying physiological responses to hypoxia in species tolerant for extremely low oxygen levels can help identify novel regulatory genes, which may have important clinical implications.

Laser resurfacing: a safe and predictable method of skin resurfacing.

Skin resurfacing with lasers for skin restoration has been the most exciting advance in cosmetic surgery in the past 2 years. This method has effectively replaced chemical peel and dermabrasion as modes for skin rejuvenation, yet surprisingly, very little has been published on its effectiveness. Our aim is to delineate clear indications, methods and results of laser skin resurfacing. Laser resurfacing has evolved over the past 13 years and our current method has emerged from this experience. This method has been employed on 258 consecutive patients treated over the past 2 years. A total of 201 patients were treated for photodamaged skin, 53 for facial acne scarring and four for post-surgical scars. Each of these conditions has in common the pathological finding of contour irregularity of the involved abnormal skin. The CO2 Ultrapulse laser's advantage is the predictable ability to vaporize the upper layer of elevated skin, tighten collagen bundles and induce a local inflammatory reaction with epithelial proliferation. This paper presents a clear, concise, and conservatively oriented technique, including pre- and post-operative care of laser skin resurfacing. The technique presented is conceived to correct precisely the underlying pathological condition and can be used in conjunction with other cosmetic procedures. A total of 200 patients underwent full face resurfacing, 41 periorbital, 13 perioral and four for facial scars. Of the patients, 78% were female and 22% were male. The results of each patient were judged by an independent observer. Some 92% were found to have either an excellent or very good result; 2% were judged to be satisfactory; and 6% were from outside the region or were lost to follow-up. Minor complications included 12% transient post-inflammatory hyperpigmentation, 3% acute acne and 1% herpes type 1. There were no major complications, including hypertrophic scarring. A total of 15% required some type of secondary touch-up resurfacing. Our method of laser skin resurfacing offers a consistent method for dramatic improvement of facial skin quality for those patients with photodamage and acne scarring, while minimizing risk.

Penetration depth of Ultrapulse carbon dioxide laser in human skin.

BACKGROUND: Recent technological advances have dramatically increased the use of lasers in skin resurfacing. The first high-power short-pulse laser, Ultrapulse, has found extensive use in dermatology and plastic surgery for skin resurfacing. Reports for penetration depth are at best anecdotal. To our knowledge this is the first report of histological effects of the Ultrapulse in human skin. OBJECTIVE: To determine the effect of single and repeated (two or three) Ultrapulse laser impacts on volar forearm skin. METHOD: The volar surface of the arm in four patients received in adjacent areas either one, two, or three pulses, after anesthesia. The treated areas were immediately biopsied, hematoxylin & eosin prepared, and examined. RESULTS: Increasing the number of passes correlates with increased depth of penetration and thermal ablation. No significant propagation of destructive thermal energy to adjacent tissue was noted. CONCLUSION: One impact at the tested parameters ablated most of the epidermis. Two impacts superimposed ablated the entire epidermis and the superficial papillary dermis. Three superimposed impacts penetrated to the reticular dermis.

Rapid laser scanning for facial resurfacing.

BACKGROUND: Laser skin resurfacing is growing in popularity in both the professional as well as lay populations. Freehand delivery of impacts is relatively time consuming. Accurate and precise placement of impacts to avoid unwanted overlapping and the superimposing of multiple impacts is difficult. OBJECTIVE: To evaluate a new computerized scanning device, the computerized pattern generator (CPG), and to compare it with freehand delivery of multiple laser impacts over large areas. METHODS: Sixty-one patients were treated using the CPG by surgeons who are experienced with freehand laser resurfacing. RESULTS: CPG delivery provides more rapid resurfacing with more uniform, accurate, and precise distribution of impacts. CONCLUSION: Combining the CPG with the Ultrapulse laser is a valuable addition making the procedure faster and more controllable.

Laser-assisted rhytidectomy. A preliminary report.

BACKGROUND: The carbon dioxide (CO2) laser is a surgical tool recognized for its capacity of combined simultaneous tissue transection and hemostasis without unwanted distant transmission of energy. OBJECTIVE: To determine the potential of laser-assisted rhytidectomy. METHODS: A preliminary group of 18 patients were treated for facial rejuvenation by a technique of laser-assisted rhytidectomy with excellent results. RESULTS: No major complications including hematoma were seen. CONCLUSION: Based on these initial findings, we conclude that laser-assisted rhytidectomy shows great promise for better results with diminished risks.

Laser hair transplantation.

BACKGROUND: A new ultrapulse CO2 laser has been investigated for its possible use in hair transplanting. This laser, because of its ultrashort high energy pulses, produces far less thermal damage to adjacent tissues, including hair follicles, than earlier types of CO2 lasers. The potential advantages of using such a laser in minigrafting are reviewed and include less bleeding, greater density, and absence of "compression." OBJECTIVE: The purpose of this study was to see if hair survival in grafts placed into laser-prepared sites would be as good or better than that seen with scalpel slits. METHOD: Hair counts were used in 10 patients to compare hair survival in grafts placed into laser-prepared sites and into scalpel-prepared sites in a comparable but contralateral location. RESULTS: Average graft hair counts were greater in laser-prepared sites in four of 10 patients, equal to grafts in scalpel-prepared sites in five, and fewer in one. Hair growth occurred earlier in laser-prepared sites in five of the 10 patients. CONCLUSION: The authors are optimistic that the ultrapulse laser will become an important tool in hair transplanting.

Aging hands: a technique of hand rejuvenation by laser resurfacing and autologous fat transfer.

Hands are a primary target for actinic damage and premature aging. Until recently, very little could be done to successfully erase the various signs of photoaging. This article presents a simple technique, combining fat transfer and laser resurfacing, to safely and effectively rejuvenate hands and erase the signs of aging.

Laser abrasion for cosmetic and medical treatment of facial actinic damage.

Previous studies have shown the carbon dioxide (CO2) laser to be effective in the treatment of actinic cheilitis. After CO2 laser abrasion, normal skin and marked cosmetic improvement of the lip were noted. In our study, twenty-three patients were treated with CO2 laser abrasions for cosmetic improvement of facial lines and actinic changes. Pre- and postoperative histopathologic examinations were made on two patients. Preoperative examination of specimens from actinically damaged skin showed atypical keratinocytes in the basal layer of the epidermis, with overlying dense compact orthokeratosis and parakeratosis. Abundant solar elastosis was seen in the papillary dermis. Postoperative histologic specimens showed a normal-appearing epidermis with fibrosis in the papillary dermis and minimal solar elastosis (about four weeks after laser treatment). At present, various modalities are available for the regeneration of the aged skin, including chemical peels and dermabrasion. Significantly fewer complications were noted with CO2 laser abrasion than with these methods. Thus, CO2 laser abrasion can be useful in the cosmetic and medical treatment of the aged skin. Marked clinical and histologic improvement has been demonstrated.

Carbon dioxide laser blepharoplasty: conjunctival temperature during surgery.

Eight patients underwent carbon dioxide (CO2) laser blepharoplasty. The temperature of the upper eyelid conjunctiva was monitored and recorded during laser surgery. A minimal increase in temperature was noted. This study confirms the absence of thermal injury at a distal site from the laser application and the safety of the laser procedure.

The laser approach to blepharoplasty.

A new technique for upper and lower eyelid blepharoplasty, combining the advantages of the transconjunctival approach with those of the CO2 laser, is described. The use of the CO2 laser as the only cutting tool eliminates many of the most common and the most serious complications of blepharoplasty attributable to hemorrhage and hematoma. The transconjunctival approach yields superior cosmetic results to those of the more commonly performed traditional techniques, which sometimes results in unacceptable lower eyelid scars and/or lower eyelid retraction. Patient rehabilitation to normal activity is rapid because of decreased bruising and swelling. The laser procedure is well suited to the office-based laser surgical practice, but requires a high degree of skill in CO2 laser excisional surgery. In the hands of the inexperienced operator, new and serious complications may occur.

Laser treatment of juvenile hemangioma.

Capillary hemangioma in the infant may result in amblyopia, refractive error, or strabismus, and is often disfiguring. Treatment is challenging with respect to maintaining vision, as well as preserving function of the eyelids and ocular adnexa and obtaining the best possible cosmetic outcome. Neodymium-YAG laser photocoagulation may be a useful modality for the treatment of these lesions. We review the characteristics of the three types of lasers currently in wide use in skin surgery, with particular emphasis on their applicability for treatment of juvenile hemangioma. A possible role for the Nd-YAG laser in the management of these tumors is suggested.

Neodymium-YAG laser photocoagulation of hemangiomas of the head and neck.

Hemangiomas of the head and neck region can be a therapeutic challenge depending on their size, flow rate, and location. The neodymium-yttrium aluminum garnet (Nd-YAG) laser was used to treat 16 pediatric and adult patients with cavernous, capillary, and mixed hemangiomas as well as hypertrophic port-wine stains of the head and neck. Low-power energy and intermittent short exposure accomplished photocoagulation with minimal damage to surrounding tissue. Follow-up study in these patients has ranged from 1 to 3 years with excellent results in 14 of 16 patients. Few complications and no major morbidity or mortality occurred. Photocoagulation of hemangiomas of the head and neck using the Nd-YAG laser appears to be an exciting new therapeutic option for this difficult problem. Further clinical study and follow-up appear to be warranted.

CO2 laser blepharoplasty: a comparison to cold steel and electrocautery.

Thirteen patients underwent blepharoplasty in a paired comparison study. A carbon dioxide laser was employed for one side while standard cold steel surgery and electrocautery was used on the contralateral side. In addition to reduced intraoperative time and bleeding, we found less postoperative ecchymosis and edema on the laser-treated side. Long-term follow-up showed no difference between the two sides when cosmetic end result and scars were compared.