Non-invasive assessment of skin hydration and sensation with diffuse reflectance spectroscopy

The skin is a vital organ in the human body, providing essential functions such as protection, sensation, and metabolism. Skin hydration is one of the crucial factors in maintaining normal skin function. Insufficient skin hydration can lead to dryness, shedding of the stratum corneum, a decrease in skin barrier function, and may cause skin inflammation. Therefore, maintaining or improving skin hydration is critical in promoting healthy skin. Currently, the commonly used method for measuring skin hydration is bioelectrical capacitance analysis, which is often affected by environmental humidity and can only provide limited information. To overcome these limitations, this study used diffuse reflectance spectroscopy (DRS) in the wavelength range of 400-1000 nm to quantify skin absorption and scattering modulation caused by changes in skin hydration states. The advantages of this technique include rapid measurements, non-invasiveness, a straightforward optical setup, and suitability for prolonged skin monitoring. We found that DRS-derived skin absorption coefficients had a correlation coefficient of 0.93 with the skin capacitance at various skin hydration states. In addition, our findings reveal that absorption and scattering coefficients may be useful in discerning skin hydration enhancement induced by applying soaked cotton pads or cosmeceutical facial masks, as well as evaluating skin sensation. This study verifies that the DRS method could be a convenient and effective tool for evaluating skin hydration related information.

Handheld diffuse reflectance spectroscopy system for noninvasive quantification of neonatal bilirubin and hemoglobin concentrations: a pilot study

The prevalence rate of neonatal jaundice can reach 80%, of which 5% may develop dangerous hemolytic jaundice. The blood test for obtaining bilirubin and hemoglobin concentration is the gold standard for diagnosing hemolytic jaundice; however, frequently drawing blood from jaundice neonates for the screening purpose is not practical. We have developed a handheld diffuse reflectance spectroscopy system to noninvasively determine the bilirubin and hemoglobin levels in neonates. Our study showed that the correlation coefficients were 0.95 and 0.80 for bilirubin and hemoglobin between the results from the blood tests and our handheld system, respectively. This handheld system could be an effective tool for screening hemolytic jaundice.

Investigation of water bonding status of normal and psoriatic skin in vivo using diffuse reflectance spectroscopy

Psoriasis affects more than 125 million people worldwide, and the diagnosis and treatment efficacy evaluation of the disease mainly rely on clinical assessments that could be subjective. Our previous study showed that the skin erythema level could be quantified using diffuse reflectance spectroscopy (DRS), and the hemoglobin concentration of most psoriatic lesion was higher than that of its adjacent uninvolved skin. While the compromised epidermal barrier function has been taken as the major cause of clinical manifestation of skin dryness and inflammation of psoriasis, very few methods can be used to effectively evaluate this function. In this study, we investigate the near infrared spectroscopic features of psoriatic (n = 21) and normal (n = 21) skin that could link to the epidermal barrier function. From the DRS measurements, it was found that the water bonding status and light scattering properties of psoriasis are significantly different from those of uninvolved or normal skin. The connection between these parameters to the epidermal barrier function and morphology will be discussed. Our results suggest that objective evaluation of epidermal barrier function of psoriasis could be achieved using a simple DRS system.

Noninvasive transcutaneous bilirubin assessment of neonates with hyperbilirubinemia using a photon diffusion theory-based method

Transcutaneous bilirubinometers are widely used to screen neonatal jaundice. However, it was reported that their accuracy is compromised at low and high bilirubin levels. We used a photon diffusion theory-based method valid in the 450-600 nm wavelength region to overcome this obstacle. Our clinical study results showed that our system could properly determine the transcutaneous bilirubin concentrations at total serum bilirubin levels higher than 14 mg/dL, where a commercial bilirubinometer failed to provide proper results in several cases. These findings suggested that photon diffusion theory could be employed to improve the core algorithm of modern bilirubinometers and enhance their applicability.

A linear gradient line source facilitates the use of diffusion models with high order approximation for efficient, accurate turbid sample optical properties recovery

In this paper, we demonstrate that a scanning MEMS mirror can be employed to create a linear gradient line source that is equivalent to a planar source. This light source setup facilitates the use of diffusion models of increased orders of approximation having closed form solution, and thus enhance the efficiency and accuracy in sample optical properties recovery. In addition, compared with a regular planar light source, the linear gradient line source occupies much less source area and has an elevated measurement efficiency. We employed a δ-P1 diffusion equation with a closed form solution and carried out a phantom study to understand the performance of this new method in determining the absorption and scattering properties of turbid samples. Moreover, our Monte Carlo simulation results indicated that this geometry had probing depths comparable to those of the conventional diffuse reflectance measurement geometry with a source-detector separation of 3 mm. We expect that this new source setup would facilitate the investigating of superficial volumes of turbid samples in the wavelength regions where tissue absorption coefficients are comparable to scattering coefficients.

Anticardiolipin antibody-related Budd-Chiari syndrome: report of a case

We report a case of a 37-year-old female who suffered from upper abdominal pain, progressive abdominal distention, shortness of breath, palpitation and pitting edema of lower legs for more than one month. Abdominal sonography showed small caliber of hepatic veins, mild hepatosplenomegaly and moderate ascites. Computed tomography of abdomen disclosed extensive thrombi in bilateral femoral veins, ovarian veins and inferior vena cava. Ascites was transudate with normal cell count. Laboratory data showed hypoalbuminemia, mild elevation of total bilirubin and iron deficiency anemia. Anti-cardiolipin antibody was positive and antinuclear antibody was negative. The histopathological features, including sinusoidal dilatation with atrophic change of adjacent hepatocytes, slight congestion and hemosiderin-like material within the cytoplasm of Kupffer cells, were compatible with the criteria of Budd-Chiari syndrome. Heparin was intravenously administered immediately to prevent further progression of thrombosis. The ascites was successfully controlled with diuretics (spironolactone and furosemide). After a two-week course of treatment, she was discharged in good condition and on warfarin anti-coagulant medication.

Clinical experience of esophageal ulcers and esophagitis in AIDS patients

In Taiwan, numbers of patients with the acquired immunodeficiency syndrome (AIDS) have been increasing in recent years. We present esophageal disease of different causes in 5(16%) heterosexual men among 31 AIDS patients over a 5-year period. Major symptoms included mild dysphagia in 4 (80%) patients and odynophagia in 3 (60%) patients. The duration of symptoms varied from 3 days to 6 months. The symptoms occurred before the diagnosis of AIDS in 3 patients. At esophagogastroduodenoscopy (endoscopy), all 5 patients had esophagitis and/or esophageal ulcers proved by histopathologic evaluation. Four had Candida esophagitis, 3 had cytomegalovirus esophagitis/ulcers and 2 had idiopathic esophageal ulcerations (IEU). Three patients had different esophagitis/ulcers at the same time or during follow-up. The median CD4 lymphocyte count at the time of diagnosis of esophageal disease was 12.2 cells/mm3 (range, 3 to 35 cells/mm3). The endoscopic pictures of the different causes of esophagitis/ ulcers lack uniformity in number, size and appearance. These observations make a conclusion that all AIDS patients with an esophageal disease should undergo endoscopy with biopsy to obtain a definitive diagnosis.

Drug-induced liver disease--a review of 14 cases

The clinical and pathological features of 14 cases of acute drug-induced liver disease (DILD) were analyzed using the French group method for drug reaction assessment. Among them, 8 were of the cytotoxic type, 4 were of the cholestatic type and 2 were of the mixed type. Serum alkaline phosphatase (ALP) levels of the cytotoxic type DILD were all < 1.8 times the normal value, while those of the cholestatic type DILD > 1.8 times (P < 0.05). The alanine aminotransaminase and aspartate aminotransaminase (ALT and AST) levels of the cholestatic type were all < 13.1 times the normal value, while those of the cytotoxic type varied from 2.2 to 118 times the normal value. We found that steatosis was the major feature in the cytotoxic type with ALT and AST < 2.5 times the normal value. Piecemeal necrosis was noted only in all the cases with ALT and AST > 20 times the normal value. In the cholestatic type, the pathological features of the oral contraceptive-related DILD showed mainly cholestasis, whereas chlorpromazine-related DILD revealed additional portal inflammation. Meticulous taking of patient history and clinical assessment are mandatory for the diagnosis of DILD. The ALP levels were helpful in distinguishing different types of DILD. There are some correlations between biochemical changes and pathological features, and both are helpful in distinguishing different etiologies of DILD when the inciting drug is in doubt.