Fractional CO2 laser and adjunctive therapies in skin of color melasma patients

Background

Ablative lasers have long been considered an unfavorable option for melasma in patients with skin of color and continue to be underutilized.

Objective

To evaluate the safety and outcomes of ablative fractional CO₂ lasers on refractory melasma in patients with skin of color.

Methods

A retrospective chart review of 12 patients from a single-center dermatology clinic. The study included refractory melasma patients receiving ablative fractional CO₂ laser therapy alone or with laser toning and/or tranexamic acid (TXA). A validated modified Melasma Area and Severity Index (mMASI) scoring scale was used to assess disease severity at baseline and approximately 1 month after each treatment session.

Results

Among the 12 patients, 41.7% patients showed >50% reduction in mMASI scores with 33.3% of patients showing statistical significance (P < .05). The CO₂ laser therapy with the TXA cohort showed the largest decrease in the mean mMASI scores and the CO₂ laser with laser toning showed the lowest decrease in scores. Patients who started on oral TXA earlier, after their initial ablative laser session, showed better clinical improvement.

Limitations

Retrospective study design with short follow-up period and a small sample size.

Conclusion

Ablative CO₂ laser treatment may be a reasonable option for refractory melasma in patients with skin of color, though future research is needed.

Representation of Fitzpatrick skin type in dermatology textbooks compared with national percentiles

As time progresses, more patients with skin of color will be seen by dermatologists. To meet the needs of the ever-changing population, medical education needs to analyze how residents are trained in recognizing dermatological disorders in patients with skin of color. The aim of this study was to analyze dermatology textbooks to evaluate how well skin of color patients are represented compared to the current national distributions. The most common skin types depicted in the textbooks were Fitzpatrick skin types II and III, whereas the least common skin types depicted were skin types V and VI. There was a significant difference between a national distribution of skin types when compared to photographs in each of the textbooks (P&lt;0.001). These findings emphasize the need to better represent patients with skin of color in medical textbooks.

Effect of an anti-depressant on mouse hippocampus protein turnover using MIMS

Although antidepressants have been used in the treatment of affective disorders for over fifty years, the precise mechanism of their action remains unknown. Treatment regimens are based by and large on empirical parameters and characterized by a trial and error scheme. A better understanding of the mechanisms involved in antidepressant drug response is of fundamental importance for the development of new compounds that have a higher success rate and specificity. In order to elucidate the molecular pathways involved in the action of antidepressants, we wish to identify brain areas, cell types, and organelles that are targeted by antidepressant treatment in mice. Multi-isotope Imaging Mass Spectrometry (MIMS) allows a quantitative approach to this analysis, allowing us to delineate antidepressant effect on protein synthesis in the brain at single cell and organelle resolution. In these experiments, we obtained a global analysis of protein turnover in the hippocampus dentate gyrus (DG) and in the Cornu Ammonis (CA) regions, together with a subcellular analysis in the granular cells and others.

Study of protein and RNA in dendritic spines using multi-isotope imaging mass spectrometry (MIMS)

The classical view of neuronal protein synthesis is that proteins are made in the cell body and then transported to their functional sites in the dendrites and the dendritic spines. Indirect evidence, however, suggests that protein synthesis can directly occur in the distal dendrites, far from the cell body. We are developing protocols for dual labeling of RNA and proteins using 15N-uridine and 18O- or 13C-leucine pulse chase in cultured neurons to identify and localize both protein synthesis and fate of newly synthesized proteins. Pilot experiments show discrete localization of both RNA and newly synthesized proteins in dendrites, close to dendritic spines. We have for the first time directly imaged and measured the production of proteins at the subcellular level in the neuronal dendrites, close to the functional sites, the dendritic spines. This will open a powerful way to study neural growth and synapse plasticity in health and disease.

Classifying client goals in community-based ABI rehabilitation: a taxonomy for profiling service delivery and conceptualizing outcomes

PURPOSE

To develop, confirm and trial a framework for analysing the content of goals set within community-based rehabilitation. This framework (taxonomy) is proposed as a tool to assist in service evaluation and outcome exploration.

METHOD

Qualitative thematic analysis and categorization of 1765 rehabilitation goal statements in a four phase process of synthesis, refinement, verification and application.

RESULTS

A taxonomy of goal content was developed comprising 21 categories within five domains, utilizing 125 descriptors. The taxonomy demonstrated good inter-rater consistency and was able to discriminate between similar but related data sets comprising goal statements.

CONCLUSION

Structured analysis of the content of goal setting (particularly in community rehabilitation) utilizing a framework such as the proposed taxonomy has considerable potential as a 'window' into service delivery to broaden the parameters of existing service evaluation and to more clearly link outcome exploration to intervention.

Confirmation of translocated gastrointestinal bacteria in a neonatal model

PURPOSE

The hypothesis that enteric bacteria translocate from the gastrointestinal (GI) tract to extraintestinal sites has been extensively studied. However, definitive evidence that spontaneous bacterial translocation and dissemination from the GI tract to extraintestinal sites occur in a neonatal model has been lacking. The aim of this study was to confirm this phenomenon by tracking enterally administered, plasmid-labeled bacteria to extraintestinal sites.

MATERIALS AND METHODS

Escherichia coli 07:K1 (E. coli K1) with and without a nontransferable, ampicillin resistance plasmid (pGEM-7) were used in this study. Newborn New Zealand white rabbit pups were separated into three treatment groups: transformed E. coli K1 (E. coli K1 + pGEM-7, n = 20), nontransformed E. coli K1 (n = 12), and control pups (no bacteria, n = 7). Pups were enterally fed 10% Formulac solution supplemented with a suspension of bacteria respective to their group. After the pups fed twice daily for 2 days, representative tissue specimens from the small bowel (SB), mesenteric lymph nodes (MLNs), spleen (SPL), and liver (LIV) were aseptically harvested and tested for culture growth in ampicillin-supplemented medium.

RESULTS

Positive growths of plasmid-induced ampicillin-resistant bacteria were detected in tissue specimens harvested from rabbits fed transformed E. coli K1, but were not detected in the other groups.

CONCLUSION

This experiment demonstrated conclusively that transformed E. coli K1 fed to healthy rabbit pups spontaneously translocated from the intestinal lumen and subsequently disseminated to the mesenteric lymph nodes, spleen, and liver.

Skin response to ultraviolet B light in patients infected with human immunodeficiency virus

Photosensitivity disorders have been reported in human immunodeficiency virus (HIV)-infected patients, often as the initial manifestation of the disease. The objective of this study was to evaluate whether the HIV-infected population demonstrates increased sensitivity to ultraviolet B (UVB) radiation. Minimal erythema dose values to UVB (MED-B) of 57 consecutive HIV-infected patients were compared to those of a control group of 57 consecutive patients with skin diseases, who were otherwise healthy and had no risk factors for HIV infection. MED-B determinations were performed in all individuals prior to the initiation of phototherapy for treatment of skin disease. None of the patients had a history of photosensitivity. Furthermore, the mean levels of the highest UVB doses received by each group during the treatment courses were compared. The mean age of the HIV-infected cohort was 43 years (range 26-61 years). The mean MED-B for this group was 82.8 +/- 3.8 (SEM) mJ/cm2. The mean age of the control group was 45 years (range 24-77 years), and their mean MED-B was 81.0 +/- 3.8 (SEM) mJ/cm2. After 12 weeks of treatment, one HIV-infected patient developed photosensitivity associated with a decreased MED-B value. The mean level of the highest UVB doses received by the HIV-infected group [427.5 +/- 67.2 (SEM) mJ/cm2] was lower than that received by the control group [640.8 +/- 65.9 (SEM) mJ/cm2], since HIV-infected patients received fewer treatments (mean: 34.7 treatments per patient) than the patients in the control group (mean: 65.6 treatments per patient). These data indicate that the HIV-infected patient population, without history of photosensitivity, does not show increased sensitivity to UVB light as determined by MED-B values.

Efficacy of ultraviolet B phototherapy for psoriasis in patients infected with human immunodeficiency virus

To evaluate the efficacy of ultraviolet B (UVB) phototherapy for the treatment of psoriasis in patients infected with human immunodeficiency virus (HIV), the response of 14 patients was compared to that of matched seronegative control individuals. All patients were evaluated prior to treatment (baseline) and after 21 treatments for the extent of total body surface area (TBSA) involvement and the quantification of scale, erythema, and thickness of plaques using a scale of 0 (absent) to 4 (severe). The only concomitant medication allowed was salicylic acid in petrolatum. The cumulative score for scale, erythema, and thickness improved 1.9 +/- 0.5 [mean +/- standard error of mean (SEM)] in the HIV group and 2.4 +/- 0.3 in controls. There was 40.9 +/- 7.3% reduction of TBSA involvement in the former and 38.4 +/- 7.6% reduction in the latter group. None of the differences was statistically significant. There was no statistically significant difference in the response to therapy among various stages of immunosuppression in the HIV group. There was also no deterioration of immune status in this group. UVB phototherapy is an effective treatment for psoriasis in patients infected with HIV. The response is identical to that of matched control individuals.

Determinant of bacterial translocation in the newborn: small bowel versus large bowel colonization

This study investigated the relationship between bacterial translocation (BT) and small and large bowel bacterial colonization in the neonatal rabbit. The authors have previously shown that spontaneous BT occurs in rabbits during the first week of life, but is less frequent before the third day of life. The authors have also shown that bacterial colonization of the small bowel, is delayed until 3 to 5 days of age, and is preceded by colonization of the large bowel. Therefore, the authors hypothesizes that BT is dependent on small bowel, not large bowel, colonization. New Zealand White rabbit pups (n = 255) were divided into four groups, formula-fed (FF), formula-fed plus antibiotic (FFAB), breast-fed (BF) and unfed controls (UC). Animals from each group were killed on day 1 to 4 of life. Small bowel (SB) and large bowel (LB) specimens, mesenteric lymph nodes (MLN), spleen (SPL), and liver (LIV) were obtained from each rabbit, incubated for 24 hours in thioglycolate broth, and plated on both MacConkey and Colistin Naladixic Acid media in an aerobic environment. After 24 hours, growth on either plate was recorded. Bacterial colonization was significantly greater in FF versus UC, BF, and FFAB rabbit groups. In addition, large bowel colonization was significantly increased compared with small bowel colonization in all feeding groups (P < .05). Bacterial translocation to MLN, SPL, and LIV ranged from 10% to 27% in all groups. Gram-negative bacteria predominated over gram-positive bacteria in translocation to the various tissues sampled.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduction in reperfusion-induced myocardial necrosis in dogs by RheothRx injection (poloxamer 188 N.F.), a hemorheological agent that alters neutrophil function

BACKGROUND

Reperfusion after prolonged coronary artery occlusion may be followed by additional myocardial necrosis persisting for hours to days. Potential mechanisms include neutrophil-mediated injury and compromised flow within the microcirculation of the reperfused myocardium. Poloxamer 188 is a nonionic surfactant with beneficial hemorheological and neutrophil-inhibitory properties. The purpose of the present study was to determine if poloxamer 188 is capable of reducing the myocardial injury associated with sustained reperfusion and to examine the effect of treatment duration.

METHODS AND RESULTS

Three groups of closed-chest dogs underwent 90 minutes of left anterior descending coronary artery occlusion (angioplasty balloon) and 72 hours of reperfusion. Poloxamer 188, formulated as RheothRx Injection (Burroughs Wellcome Co), was given as a 75 mg/kg IV bolus 15 minutes before reperfusion followed by a 150 mg.kg-1.h-1 continuous IV infusion for 4 hours (n = 13) or 48 hours (n = 13); control dogs (n = 12) received saline for 48 hours. The 48-hour infusion of poloxamer 188 resulted in a 42% reduction in infarct size (as a percent of the area at risk) compared with the control group (25.0 +/- 4.2% versus 43.3 +/- 4.3%, P D .01), whereas the 4-hour group demonstrated a 25% reduction in infarct size compared with the control group (32.4 +/- 4.3%, P = .08). ANCOVA demonstrated that the 48-hour infusion of poloxamer 188 reduced myocardial infarct size independent of differences in collateral blood flow (P = .002 versus control). A trend toward infarct size reduction was observed in the 4-hour infusion group (P = .098 versus control by ANCOVA). Plasma creatine phosphokinase concentration was lower in both poloxamer 188-treated groups (P < .05 versus control). Global left ventricular ejection fraction at 72 hours of reperfusion was improved in the 48-hour infusion group compared with the control group (43 +/- 3.1% versus 33 +/- 2.0%, P < .05), whereas ejection fraction in the 4-hour group was 37 +/- 1.3% (P = NS versus control). Regional ventricular function was also significantly better in the 48-hour infusion group compared with the control group. In vitro studies demonstrated that at concentrations comparable to those achieved in vivo, poloxamer 188 inhibited neutrophil chemotaxis. This finding may represent a beneficial mechanism of action.

CONCLUSIONS

A 48-hour infusion of poloxamer 188 reduced myocardial infarct size and improved left ventricular function in this dog model of 90 minutes of coronary artery occlusion and 72 hours of reperfusion. The finding that the 4-hour infusion of poloxamer 188 did not result in similar benefits suggests that additional reperfusion injury occurred between 4 and 48 hours.

Primary lymphocutaneous nocardiosis caused by an unusual species of Nocardia: Nocardia transvalensis

We present the first case of lymphocutaneous nocardiosis caused by Nocardia transvalensis and the seventh report of infection caused by this microorganism. The patient was allergic to sulfonamides but responded to amikacin and cefotaxime and later to erythromycin. The treatment and criteria for differentiation of cutaneous Nocardia species infection are discussed.

Temporal effects of estradiol and diethylstilbestrol on pituitary and plasma prolactin levels in ovariectomized Fischer 344 and Holtzman rats: a comparison of radioimmunoassay and Nb2 lymphoma cell bioassay

An Nb2 lymphoma cell bioassay (Nb2BA) and a radioimmunoassay (RIA) were used to compare plasma and pituitary levels of prolactin in ovariectomized Fischer 344 (F344) and Holtzman rats treated with either diethylstilbestrol (DES) or estradiol for up to 8 weeks. The objectives were to determine whether there were temporal differences in prolactin responses in strains with different genetic predispositions to estrogen-induced pituitary tumor formation and to determine whether the results of the two assay methods were equivalent. All rats were ovariectomized for 7 days and all except controls received subcutaneous Silastic implants of DES or 17 beta-estradiol and were sacrificed at intervals from 2 days to 8 weeks later. Pituitary content and plasma levels of prolactin were determined by Nb2BA and RIA and the ratio of these measurements was calculated. DES induced a significant increase in pituitary prolactin in F344 rats by 2 days of treatment, as measured by RIA. Pituitary content increased to a peak by Day 4, after which a gradual decline occurred until the end of the experiment. Nb2BA measurements were similar to those obtained by RIA, except at 8 weeks, when the content determined by Nb2BA was significantly higher than the content determined by RIA. When estradiol was given to F344 rats a pattern of increase and subsequent decrease in pituitary content similar to that seen with DES was observed and levels measured by Nb2BA and RIA were essentially equivalent. Plasma levels of prolactin in DES-treated F344 rats increased exponentially through the 8 weeks, and the Nb2BA measurements were significantly greater than levels determined by RIA throughout the treatment period. Estradiol treatment produced a pattern of change in plasma levels of prolactin similar to that observed with DES, except that RIA and Nb2BA measurements were not different. Comparable results were obtained in Holtzman rats, except plasma levels were not increased to the same degree as seen in F344 rats. From these results, we conclude that DES, but not estradiol, can selectively increase the secretion of prolactin that is more bioactive than immunoreactive and that this effect of DES is observed in F344 and Holtzman rats, although F344 rats released more prolactin in response to estrogens than did Holtzman females.

Staphylococcal sepsis in HIV antibody seropositive psoriasis patients

The cases of three HIV-positive men with generalized psoriasis and staphylococcal sepsis are reported. In each case the skin appeared to be the source of infection. While the patients received antibiotic therapy, the psoriatic plaques resolved despite minimal or no topical treatment.

The effects of exercise and weight loss on plasma lipids in young obese men

We studied the independent and combined effects of exercise training and weight loss on blood lipids under fixed diet and exercise conditions. Twenty-one obese sedentary men were randomly allocated to one of four treatment groups: (1) inactive and constant weight (control), (2) exercise training and constant weight, (3) inactive and weight loss, and (4) exercise training and weight loss. There were three study periods: a 3 week baseline period inactive and on an isocaloric diet, a 12 week treatment period, and a 3 week weight stabilization period. Exercise consisted of treadmill walking at an energy cost of 3500 kcal/wk for groups 2 and 4 with replacement caloric intake only in group 2. Group 3 reduced caloric intake by 3500 kcal/wk during the treatment period. Weight loss for groups 3 and 4 were 13.4 pounds and 13.7 pounds, respectively. Maximal oxygen uptake (mL/min) increased 6% in both exercise groups (2 and 4), and percent body fat decreased only in these groups. Regression analysis by group assignment on HDL cholesterol (HDL-C) showed that the inactivity-weight loss modality (group 3) and the exercise-constant weight modality (group 2) each significantly increased HDL-C, with an additive effect of exercise and weight loss (group 4). The rate of HDL-C change differed significantly between groups (P = 0.01). HDL-C increased 0.63, 0.61, and 1.89 mg/dL per 3 weeks or 2%, 2.4%, and 5.5% above baseline levels in groups 2, 3, and 4, respectively, while the control group decreased 0.11 mg/dL. Plasma triglycerides and very low-density lipoprotein (VLDL) cholesterol increased with exercise at constant weight (group 2) and decreased with exercise associated with weight loss (group 4). In conclusion, exercise and weight loss separately and independently increase HDL-C, and their effects are additive.

Lymphotoxin-induced loss of plasma-membrane protein

Lymphotoxin-sensitive L cells were prelabeled with isotopically marked leucine and exposed either to human alpha-lymphotoxin (alpha-LT) or control buffer. Plasma membranes were then isolated from these cells, and TCA-precipitable leucine was determined as a measure of membrane protein. Human alpha-LT caused a marked reduction of plasmalemmal protein in LT-sensitive target cells. This loss of protein was general, not restricted to specific fractions, as assessed by sodium dodecyl sulfate (SDS)--polyacrylamide gel electrophoresis. Since purified alpha-LT had no detectable proteolytic activity, the effect of the lymphokine is not readily explained by direct enzymatic action on plasma-membrane protein. In contrast, there was no plasma--membrane protein loss in LT-resistant target cells on exposure to alpha-lymphotoxin.