Bilateral herpetic keratitis presenting with unilateral neurotrophic keratitis in pemphigus foliaceus: a case report.

INTRODUCTION: We report a case of bilateral herpetic keratitis developing after rapid oral corticosteroid tapering in a patient with pemphigus foliaceus, which was followed by unilateral neurotrophic keratitis that was treated with amniotic membrane transplantation. CASE PRESENTATION: A 71-year-old Korean man developed bilateral herpetic keratitis one week after rapid tapering of systemic corticosteroid. He had been on high-dose oral corticosteroid and azathioprine therapy for six months for treatment of pemphigus foliaceus. Topical acyclovir ointment was prescribed. A week later, our patient's right eye had healed, but his left eye showed increased stromal edema with enlarged epithelial defects. He was prescribed oral acyclovir with topical broad-spectrum antibiotics applied to his left eye. The stromal edema cleared within a week but the epithelial defect remained unchanged. An amniotic membrane transplantation was performed on our patient's left eye, and his epithelial defect had totally healed three weeks later. CONCLUSIONS: Patients with autoimmune disease or who are on immunosuppressive therapy have a higher chance of developing bilateral herpetic keratitis. Although rare, the condition may be followed by unilateral neurotrophic keratitis. Rapid corticosteroid tapering may act as a triggering factor for viral infection or reactivation of herpes.

Xenocorneal transplantation.

PURPOSE OF REVIEW: Donor shortage in corneal transplantation is a significant problem in Asian countries and is an emerging issue worldwide. This review will discuss current knowledge of the pathogenesis of the rejection mechanism, recent advances in xenocorneal transplantation, and feasibility of porcine xenocorneal graft. RECENT FINDINGS: α-Gal epitopes which are expressed on the porcine cornea, however less than in other vascularized organs. A small animal model provided evidence of complement-mediated or antibody-mediated rejection in porcine xenocorneal transplantation. Recent progress in genetic engineering of the pig or biomedical engineering for removal of the α-Gal epitope appears to have resulted in reduction of antibody-mediated rejection. Porcine corneal xenograft is not rejected hyperacutely in all animal models. T cells predominantly mediate xenocorneal rejection through various animal models. Survival of lamellar fresh porcine grafts is longer than that of full-thickness fresh porcine grafts. Decellularized porcine grafts also demonstrate significantly longer survival than fresh grafts do. SUMMARY: Recent studies have documented the potential of the porcine corneal graft as a substitute for use in human allograft and have highlighted the mechanisms of rejection of xenocorneal transplantation. Antibody-mediated or complement-mediated xenogeneic rejection should be further explored in a large animal model.

Trends in the prevalence of type 2 diabetes in Asians versus whites: results from the United States National Health Interview Survey, 1997-2008.

OBJECTIVE: To examine trends in the prevalence of type 2 diabetes and related conditions in Asian Americans compared with non-Hispanic whites. RESEARCH DESIGN AND METHODS: We analyzed data from the National Health Interview Survey (NHIS) from 1997 to 2008 to construct a nationally representative sample of 230,503 U.S. adults aged ≥ 18 years. Of these adults, 11,056 identified themselves as Asian Americans and 219,447 as non-Hispanic whites. RESULTS: The age- and sex-adjusted prevalence of type 2 diabetes was higher in Asian Americans than in whites throughout the study period (4.3-8.2% vs. 3.8-6.0%), and there was a significant upward trend in both ethnic groups (P < 0.01). BMI also was increased in both groups, but age- and sex-adjusted BMI was consistently lower in Asian Americans. In fully adjusted logistic regression models, Asian Americans remained 30-50% more likely to have diabetes than their white counterparts. In addition, Asian Indians had the highest odds of prevalent type 2 diabetes, followed by Filipinos, other Asians, and Chinese. CONCLUSIONS: Compared with their white counterparts, Asian Americans have a significantly higher risk for type 2 diabetes, despite having substantially lower BMI. Additional investigation of this disparity is warranted, with the aim of tailoring optimal diabetes prevention strategies to Asian Americans.

A radio controller using speech for the blind.

This article describes a low-cost, portable real-time DSP-based speech controller system to provide radio interface control command applications for the blind. The system recognizes spoken Mandarin Chinese words on a DSP chip (TMS320C31) using a hidden Markov model. The function of the radio set, which includes a tuner, tape, and compact disc, were evaluated under both noisy and noiseless environments. Four subjects took part in the experiment and achieved 83 and 90% mean recognition rates under noisy and noiseless conditions, respectively. In addition, because this system is based on a DSP chip, it can easily be programmed to execute speaker-independent algorithms.

Role of different peripheral components in the expression of neuropathic pain syndrome.

Peripheral nerve injury frequently leads to neuropathic pain like hyperalgesia, spontaneous pain, mechanical allodynia, thermal allodynia. It is uncertain where the neuropathic pain originates and how it is transmitted to the central nervous system. This study was performed in order to determine which peripheral component may lead to the symptoms of neuropathic pain. Under halothane anesthesia, male Sprague-Dawley rats were subjected to neuropathic surgery by tightly ligating and cutting the tibial and sural nerves and leaving the common peroneal nerve intact. Behavioral tests for mechanical allodynia, thermal allodynia, and spontaneous pain were performed for 2 weeks postoperatively. Subsequently, second operation was performed as follows: in experiment 1, the neuroma was removed; in experiment 2, the dorsal roots of the L4-L6 spinal segments were cut; in experiment 3, the dorsal roots of the L2-L6 spinal segments were cut. Behavioral tests were performed for 4 weeks after the second operation. Following the removal of the neuroma, neuropathic pain remained in experiment 1. After the cutting of the L4-L6 or L2-L6 dorsal roots, neuropathic pain was reduced in experiments 2 and 3. The most remarkable relief was seen after the cutting of the L2-L6 dorsal roots in experiment 3. According to the fact that the sciatic nerve is composed of the L4-L6 spinal nerves and the femoral nerve is composed of the L2-L4 spinal nerves, neuropathic pain is transmitted to the central nervous system via not only the injured nerves but also adjacent intact nerves. These results also suggest that the dorsal root ganglion is very important in the development of neuropathic pain syndrome.

Antiallodynic effects produced by stimulation of the periaqueductal gray matter in a rat model of neuropathic pain.

It has been well documented that there is opioid resistance in neuropathic pain. This indicates that the endogenous opioid system may not be involved effectively in modulating neuropathic pain. The present study sought to determine if activation of the descending pain inhibition system might produce analgesia in the animal neuropathic model we developed. Under ketamine anesthesia, male Sprague-Dawley rats were chronically implanted with stimulating electrodes in the ventral periaqueductal gray matter (PAG) and both the tibial and sural nerves of the sciatic nerve branches were severed. Pain sensitivity was measured with a von Frey filament and acetone applied to the sensitive area for 1 week postoperatively. Rats with neuropathic pain syndrome after transection of the tibial and sural nerves were tested as to the analgesic effects of ventral PAG stimulation for an additional two weeks. Electrical stimulation of the ventral PAG turned out to be highly effective in alleviating neuropathic pain. Mechanical allodynia and cold allodynia were reduced by PAG stimulation. Naloxone reversed the antiallodynic effects of ventral PAG stimulation. These results suggest that activation of the descending pain inhibition system including the ventral PAG reduces neuropathic pain syndrome and that opiates are involved in this system.

An animal model of neuropathic pain employing injury to the sciatic nerve branches.

The present study was conducted to develop a new animal model of neuropathic pain employing injury to the distal sciatic nerve branches. Under halothane anesthesia, the tibial, sural, and/or common peroneal nerves were injured and neuropathic pain behaviors were compared among different groups of rats. Different types of injury produced different levels of neuropathic pain. Rats with injury to the tibial and sural nerves showed the most vigorous mechanical allodynia, cold allodynia, and spontaneous pain. These neuropathic pain behaviors were not relieved by functional sympathectomy using guanethidine. The results suggested that injury to the tibial and sural nerves, while leaving the common peroneal nerve intact, can be used as a new animal model of neuropathic pain and that this model represents sympathetically independent pain (SIP). The present animal model is very simple to produce injury and can produce profound and reliable pain behaviors. These features enable the new animal model to be a useful tool in elucidating the mechanisms of neuropathic pain, especially SIP.

Estudo experimental da eficácia clínica e microbiológica da associaçäo do diclofenaco sódico e sulfato de gentamicina no tratamento da ceratite por Pseudomonas aeruginosa / Clinical and microbiological effect of sodium diclofenac on gentamicin treatment of experimental Pseudomonas aeruginosa keratitis

Objetivo comparar o efeito da associaçäo de diclofenaco sódico 0,1 ppor cento, mais sulfato de gentamicina 0,3 por cento em olhos de coelhos infectados por meio de injeçäo intra-estromal de Pseudomonas aeruginosa, após remoçäo do epitélio da regiäo central da córnea. Métodos: os animais foram tratados com soluçöes tópicas contendo diferentes drogas. Grupo I: associaçäo de diclofenaco sódico 0,1 por cento, mais sulfato de gentamicina 0,3 por cento. Grupo II: veículo da associaçäo de diclofenaco sódico 0,1 por cento, mais sulfato de gentamicina 0,3 por cento. Grupo III: apenas diclofenaco sódico 0,1 por cento. Grupo IV: sulfato de gentamicina 0,3 poe cento isoladamente. Grupo V: BSS. Grupo VI: näo recebeu nenhuma medicaçäo. Os animais do grupo VI foram sacrificados no primeiro dia ..

Role of the "helix clamp" in HIV-1 reverse transcriptase catalytic cycling as revealed by alanine-scanning mutagenesis.

Residues 259-284 of HIV-1 reverse transcriptase exhibit sequence homology with other nucleic acid polymerases and have been termed the "helix clamp" (Hermann, T., Meier, T., Gotte, M., and Heumann, H. (1994) Nucleic Acids Res. 22, 4625-4633), since crystallographic evidence indicates these residues are part of two alpha-helices (alpha H and alpha I) that interact with DNA. Alanine-scanning mutagenesis has previously demonstrated that several residues in alpha H make important interactions with nucleic acid and influence frameshift fidelity. To define the role of alpha I (residues 278-286) during catalytic cycling, we performed systematic site-directed mutagenesis from position 277 through position 287 by changing each residue, one by one, to alanine. Each mutant protein was expressed and, except for L283A and T286A, was soluble. The soluble mutant enzymes were purified and characterized. In contrast to alanine mutants of alpha H, alanine substitution in alpha I did not have a significant effect on template.primer (T.P) binding as revealed by a lack of an effect on Km, T.P, Ki for 3'-azido-2',3'-dideoxythymidine 5'-triphosphate, koff, T.P and processivity. Consistent with these observations, the fidelity of the mutant enzymes was not influenced. However, alanine mutagenesis of alpha I lowered the apparent activity of every mutant relative to wild-type enzyme. Titration of two mutants exhibiting the lowest activity with T.P (L282A and R284A) demonstrated that these mutant enzymes could bind T.P stoichiometrically and tightly. In contrast, active site concentrations determined from "burst" experiments suggest that the lower activity is due to a smaller populations of enzyme bound productively to T.P. The putative electrostatic interactions between the basic side chains of the helix clamp and the DNA backbone are either very weak or kinetically silent. In contrast, interactions between several residues of alpha H and the DNA minor groove, 3-5 nucleotides from the 3'-primer terminus, are suggested to be critical for DNA binding and fidelity.