Biomedical subjects

Hiroyuki Okamoto

Publications and source records attributed to Hiroyuki Okamoto.

42 records · Page 3Linked to original sources

PubMed2002

Treatment of chronic actinic dermatitis with tacrolimus ointment.

BACKGROUND: Chronic actinic dermatitis (CAD) is difficult to treat. Topical corticosteroids induce adverse effects after long-term use, especially on light-exposed skin. OBJECTIVE: Our purpose was to study the effects of tacrolimus ointment in the treatment of elderly patients with CAD. METHODS: In an open trial, 6 male patients between 51 and 80 years old with CAD applied 0.1% tacrolimus ointment twice a day to the face and neck. According to improvements, the frequency of application was reduced. Sunscreen agents were also applied outdoors. RESULTS: Tacrolimus ointment effectively treated cutaneous changes in all patients. Symptoms were moderately improved in 2 weeks, and greatly in 4 weeks. A brief and localized irritating sensation occurred in all patients, but no other adverse events developed throughout the study course from 0.5 to 2.5 years. CONCLUSION: Topical tacrolimus ointment for facial lesions of CAD appears to be effective and well tolerated and may provide long-term benefits.

Administration, Topical↗

PubMed2002

Percutaneous transhepatic lymphography method to image and treat intra-abdominal lymph node metastasis in patients with unresectable hepatobiliary pancreatic cancer.

BACKGROUND: There have been no effective treatments for intra-abdominal lymph node metastasis. One of the main reasons is that we cannot deliver chemotherapeutic agents directly. We evaluated percutaneous transhepatic lymphography (PTL) as a drug delivery system. METHODS: PTL was performed 16 times in 13 patients. PTL was performed by puncture of the intrahepatic periportal area. Immediately after injection of contrast medium, lymphatic flow through the hepatoduodenal ligament to the intra-abdominal lymph nodes was visualized. The chemotherapeutic agent was delivered to the metastatic intra-abdominal lymph nodes by this route. RESULTS: In 10 of 13 patients, intrahepatic and extrahepatic lymphatic vessels and lymph nodes were visualized by PTL. Computed tomography after PTL showed retention of lipiodol in the lymphatic system around the portal vein and in the enlarged metastatic lymph nodes located in the pancreatic and celiac lymph nodes. According to the Response Evaluation Criteria in Solid Tumors, there were 8 patients with progressive disease and 5 with stable disease. CONCLUSIONS: The present study showed that PTL can be used as a drug delivery system specific for intra-abdominal lymph nodes as well as for identification of the lymph tracts.

Aged↗

PubMed2002

Ictal and interictal single photon emission computed tomography in a patient with benign familial infantile convulsions.

Ictal and interictal single photon emission computed tomography (SPECT) and ictal electroencephalography (EEG) were studied in a 3-month-old girl with benign familial infantile convulsions (BFIC) to reveal the epileptic focus. There was bilateral diffuse propagation from a left frontal lobe focus on the ictal EEG. Perfusion in the left frontal region was increased on ictal SPECT and decreased on interictal SPECT. Epileptic foci of BFIC showed the same characteristics as foci of symptomatic partial epilepsy.

Electroencephalography↗

PubMed2002

In-vitro and in-vivo pharmacokinetic interactions of amprenavir, an HIV protease inhibitor, with other current HIV protease inhibitors in rats.

The drug interactions between a new human immune deficiency virus (HIV) protease inhibitor, amprenavir, and four other protease inhibitors which are presently used have been characterized by in-vitro metabolic studies using rat liver microsomal fractions and in-vivo oral administration studies. The metabolic clearance rates (Vmax/Km) of amprenavir, saquinavir, indinavir and nelfinavir in rat liver microsomes were 50.67+/- 3.77, 170.88 +/- 15.34, 73.01 +/- 2.76 and 126.06 +/- 6.23 microLmin(-1) (mg protein)(-1), respectively, and the degree of metabolicclearance was in the order of saquinavir > nelfinavir > indinavir > amprenavir > ritonavir. The inhibition constants (Ki) of ritonavir for amprenavir, indinavir, nelfinavir and saquinavir were 2.29, 0.95, 1.01 and 1.64 microM, respectively, and that of indinavir for amprenavir was 0.67, indicating that amprenavir metabolism in rat liver microsomes was strongly inhibited by indinavir. The Ki values of amprenavir for indinavir, nelfinavir and saquinavir were 7.41, 2.13 and 16.11 microM, respectively, and those of nelfinavirand saquinavirforamprenavirwere 9.15 and 34.57 microM, respectively. The area under the concentration vs time curve (AUC) of amprenavir after oral co-administration with saquinavir, indinavir, nelfinavir or ritonavir (20 mg kg(-1) for each oral dose in rats) was increased by 1.6-, 2.0-, 1.2- and 9.1-fold, respectively. The AUC values of saquinavir, indinavir and nelfinavir by co-administration with amprenavir showed about 7.3-, 1.3-, and 7.9-fold increase, respectively. These observations suggested that the oral bioavailability of amprenavir was not so affected by co-administration with saquinavir, nelfinavir or indinavir, compared with ritonavir, whereas amprenavir markedly affected the oral bioavailability of saquinavir and nelfinavir. In addition, the in-vivo effects after co-administration of two kinds of HIV protease inhibitors cannot always be predicted from in-vitro data, suggesting the presence of other interaction processes besides metabolism in the liver. However, these results provide useful information for the treatment of AIDS patients when they receive a combination therapy with two kinds of HIV protease inhibitor.

Administration, Oral↗

PubMed2002

[Cutaneous sarcoidosis].

The frequency of skin involvement of sarcoidosis is 10-30% of all cases, but the prevalence of a particular type of cutaneous lesion varies among races as well as individual cases. Cutaneous involvement is divided into specific and nonspecific categories. Specific lesions include nodules, plaques, lupus pernio, subcutaneous nodules, and other rare manifestations as well as scar infiltrates. Despite the clinical importance of scar infiltrates in the diagnosis of sarcoidosis, it is often overlooked because the lesions are usually small and asymptomatic. There is some clinical importance of cutaneous sarcoidosis; the ease in obtaining lesional samples which enables a histological diagnosis of sarcoidosis, and the association of a particular type of cutaneous lesion with other organ involvement.

Diagnosis, Differential↗

PubMedDate not supplied

Photobiological information obtained from XPA gene-deficient mice.

The XPA gene-deficient mouse, an animal model of xeroderma pigmentosum (XP), develops enhanced photobiologic reactions including acute inflammation, immunosuppression and skin carcinogenesis, because of the defect in the excision repair of ultraviolet-induced DNA lesions. The results strongly suggest that nuclear DNA is an important chromophore to initiate acute and chronic skin damages. The model mouse is a useful experimental animal not only to investigate the mechanisms of photosensitivity in XP, but also to study physiological photobiology in humans, because photobiologic reactions are greatly intensified in this mouse.

Animals↗