Clinical Use and Treatment Mechanism of Molecular Hydrogen in the Treatment of Various Kidney Diseases including Diabetic Kidney Disease

As diabetes rates surge globally, there is a corresponding rise in the number of patients suffering from diabetic kidney disease (DKD), a common complication of diabetes. DKD is a significant contributor to chronic kidney disease, often leading to end-stage renal failure. However, the effectiveness of current medical treatments for DKD leaves much to be desired. Molecular hydrogen (H2) is an antioxidant that selectively reduces hydroxyl radicals, a reactive oxygen species with a very potent oxidative capacity. Recent studies have demonstrated that H2 not only possesses antioxidant properties but also exhibits anti-inflammatory effects, regulates cell lethality, and modulates signal transduction. Consequently, it is now being utilized in clinical applications. Many factors contribute to the onset and progression of DKD, with mitochondrial dysfunction, oxidative stress, and inflammation being strongly implicated. Recent preclinical and clinical trials reported that substances with antioxidant properties may slow the progression of DKD. Hence, we undertook a comprehensive review of the literature focusing on animal models and human clinical trials where H2 demonstrated effectiveness against a variety of renal diseases. The collective evidence from this literature review, along with our previous findings, suggests that H2 may have therapeutic benefits for patients with DKD by enhancing mitochondrial function. To substantiate these findings, future large-scale clinical studies are needed.

The overlooked benefits of hydrogen-producing bacteria

Intestinal bacteria can be classified into "beneficial bacteria" and "harmful bacteria." However, it is difficult to explain the mechanisms that make "beneficial bacteria" truly beneficial to human health. This issue can be addressed by focusing on hydrogen-producing bacteria in the intestines. Although it is widely known that molecular hydrogen can react with hydroxyl radicals, generated in the mitochondria, to protect cells from oxidative stress, the beneficial effects of hydrogen are not fully pervasive because it is not generally thought to be metabolized in vivo. In recent years, it has become clear that there is a close relationship between the amount of hydrogen produced by intestinal bacteria and various diseases, and this report discusses this relationship.

Molecular Hydrogen as a Medical Gas for the Treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Possible Efficacy Based on a Literature Review

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disorder that is characterized by fatigue that persists for more than 6 months, weakness, sleep disturbances, and cognitive dysfunction. There are multiple possible etiologies for ME/CFS, among which mitochondrial dysfunction plays a major role in abnormal energy metabolism. The potential of many substances for the treatment of ME/CFS has been examined; however, satisfactory outcomes have not yet been achieved. The development of new substances for curative, not symptomatic, treatments is desired. Molecular hydrogen (H₂) ameliorates mitochondrial dysfunction by scavenging hydroxyl radicals, the most potent oxidant among reactive oxygen species. Animal experiments and clinical trials reported that H₂ exerted ameliorative effects on acute and chronic fatigue. Therefore, we conducted a literature review on the mechanism by which H₂ improves acute and chronic fatigue in animals and healthy people and showed that the attenuation of mitochondrial dysfunction by H₂ may be involved in the ameliorative effects. Although further clinical trials are needed to determine the efficacy and mechanism of H₂ gas in ME/CFS, our literature review suggested that H₂ gas may be an effective medical gas for the treatment of ME/CFS.

Guidelines for the selection of hydrogen gas inhalers based on hydrogen explosion accidents

Despite the fact that we have reported on the dangers of the explosion of hydrogen gas inhalers, hydrogen gas inhalers with explosive hazards are, as a matter of fact, still being sold today. In this study, we investigated past reports of hydrogen gas inhaler explosion accidents to clarify the causes of these explosion incidents. As a result of this investigation, we found that the central cause was the leakage of hydrogen gas inside the hydrogen gas inhaler. Although it is said that the explosive concentration of hydrogen is between 10% and 75%, and that the gas does not explode above 75% due to the lack of oxygen, we confirmed through a series of ignition experiments that explosions can occur even in hydrogen gas inhalers that produce 100% hydrogen gas. Some manufacturers of such highly concentrated hydrogen gas inhalers claim that the high concentration and purity of hydrogen is safe and that there is no risk of explosion. We believe that manufacturing or selling such products that pose a risk of explosion or detonation is a violation of social justice. This paper presents ideas for selecting safe hydrogen gas inhalers based on a survey of past accident cases.

Impact of habitual swimming on the success of lacrimal surgery

PURPOSE

To elucidate how factors associated with swimming affect the lacrimal ducts of swimmers.

STUDY DESIGN

Prospective, interventional cohort study, METHODS: Five hundred seventy four consecutive epiphora patients were surveyed via a questionnaire regarding details of their swimming-pool usage; i.e., frequency, swim-goggles' wear, and type of pool activity (i.e., swimming vs. waist-depth walking). In this cohort, all the swimmers over 20 years old with anatomical lacrimal duct obstruction underwent surgical reconstruction. The surgical success rates at 12-months postoperative were compared using multivariable logistic regression analyses between swimmer/non-swimmer patients, those with a history of high/low frequency of pool usage, and those with high/low amount of conjunctival contact with the swimming-pool water.

RESULTS

Of the patients with anatomical lacrimal duct obstruction, 6.4% were habitual swimmers; nasolacrimal duct obstruction was more common in the swimmers than in the non-swimmers' controls (89.1%/66.7%, P = 0.025). The success rate of lacrimal surgery for the swimmers with anatomical nasolacrimal duct obstruction was lower (60.6%) than of the non-swimmers (83.3%, P = 0.048). A receiver operating characteristic curve analysis of the frequency for the prediction of surgical failure showed that the threshold was 4 days/week. The success rate was statistically lower (26.7%) in the high-frequency swimmers compared to the low-frequency swimmers (88.9%, P = 0.037). However, no statistical difference in the high/low ocular surface contact to the swimming-pool water was observed (71.4%/57.7%, P = 0.56).

CONCLUSION

Habitual swimmers have a high risk of nasolacrimal-duct damage retrogradely from the nasal cavity that lowers lacrimal surgery's success rate.

Molecular Hydrogen as a Novel Protective Agent against Pre-Symptomatic Diseases

Mibyou, or pre-symptomatic diseases, refers to state of health in which a disease is slowly developing within the body yet the symptoms are not apparent. Common examples of mibyou in modern medicine include inflammatory diseases that are caused by chronic inflammation. It is known that chronic inflammation is triggered by the uncontrolled release of proinflammatory cytokines by neutrophils and macrophages in the innate immune system. In a recent study, it was shown that molecular hydrogen (H2) has the ability to treat chronic inflammation by eliminating hydroxyl radicals (·OH), a mitochondrial reactive oxygen species (ROS). In doing so, H2 suppresses oxidative stress, which is implicated in several mechanisms at the root of chronic inflammation, including the activation of NLRP3 inflammasomes. This review explains these mechanisms by which H2 can suppress chronic inflammation and studies its applications as a protective agent against different inflammatory diseases in their pre-symptomatic state. While mibyou cannot be detected nor treated by modern medicine, H2 is able to suppress the pathogenesis of pre-symptomatic diseases, and thus exhibits prospects as a novel protective agent.

[A Case of Advanced Gastric Cancer Treated Effectively with Combination Chemotherapy of Paclitaxel plus Ramucirumab]

A 74-year-old man was referred to our hospital because of a gastric tumor. A Borrmann type 2 gastric tumor was found on upper gastrointestinal endoscopy, but tissue biopsy indicated only necrotic tissue and the preoperative diagnosis was difficult. Contrast CT and FDG-PET revealed lymphadenopathy at multiple sites accompanied by high accumulation of FDG in the perigastric lymph nodes, left upper collarbicular fossa, bilateral hilar ganglia, and longitudinal cauda. Because the tumor was strongly suspected to be gastric cancer or malignant lymphoma, distal gastrectomy was performed. The tumor was finally diagnosed as a poorly differentiated adenocarcinoma with multiple lymph node metastasis. S-1 plus cisplatin therapy was administered as first-line chemotherapy, and paclitaxel(PTX)plus ramucirumab(RAM)therapy was administered as secondline chemotherapy. PTX plus RAM therapy was effective, and the patient achieved complete remission(CR), as observed on imaging. However, because adverse events such as numbness in the periphery of the limbs were noted, PTX plus RAM therapy was discontinued per the patient's request. Currently, 13 months since the interruption of treatment, the CR has been maintained, as determined on imaging.

Convenient methods for ingestion of molecular hydrogen: drinking, injection, and inhalation

Molecular hydrogen (H2) is clinically administered; however, in some hospitals, H2 is given to patients without consideration of its safe use. In the present study, we prepared convenient and safe devices for the drinking of super-saturated H2 water, for intravenous drip infusion of H2-rich saline, and for the inhalation of H2 gas. In order to provide useful information for researchers using these devices, the changes in H2 concentration were studied. Our experimental results should contribute to the advance of non-clinical and clinical research in H2 medicine.

Effect of rebamipide ophthalmic suspension on the success of lacrimal stent intubation

PURPOSE

To evaluate the effect of the postoperative administration of rebamipide ophthalmic suspension on the success rate of lacrimal stent intubation (LSI) for the treatment of primary acquired nasolacrimal duct obstruction (PANDO).

METHODS

This comparative interventional cohort study investigated 110 consecutive patients with PANDO who were treated with LSI and followed up for 12 months postoperatively at one institution. LSI was performed by one surgeon, and all patients received identical postoperative care. Among the total 110 patients, 71 underwent LSI with postoperative administration of rebamipide ophthalmic suspension, and 39 underwent LSI without administration of the suspension. Data related to patient age, gender, laterality, and postoperative administration of rebamipide ophthalmic suspension were collected and used as independent variables, and logistic regression analyses were performed to compare the anatomical success rate at 12 months postoperatively between patients with and without postoperative administration of the suspension.

RESULTS

The anatomical success rate of LSI in patients with and without postoperative administration of rebamipide ophthalmic suspension was 90.1 and 69.2 %, respectively. A comparison of these success rates showed statistical significance, in that the rate of treatment success was higher in PANDO patients who underwent LSI with postoperative administration of the suspension [odds ratio (OR), 3.37; P < 0.05].

CONCLUSIONS

The findings of this study show that postoperative administration of rebamipide ophthalmic suspension increases the rate of anatomical success in patients who undergo LSI for the treatment of PANDO.

A Case of Coats' Disease with Spontaneous Retinal Reattachment after Total Detachment

Purpose

To report a case of Coats’ disease in which spontaneous reattachment occurred after total retinal detachment.

Patient and Methods

A young boy (patient age: 4 years and 11 months) presented with leukocoria in the left eye. Slit-lamp examination revealed total retinal detachment with abnormal retinal blood vessels and subretinal exudation just behind the lens. Computed tomography imaging showed no solid mass lesion in the intraocular space. Secondary total retinal detachment as a complication of Coats’ disease was diagnosed. No light perception was detected, so we determined that surgical treatment was not indicated.

Results

Four months after the initial diagnosis, the retina showed complete reattachment with a large amount of subretinal hard exudate. Visual acuity remained unchanged, with no light perception.

Conclusions

We speculate that the spontaneous retinal reattachment in the present case was caused by the decreased permeability of the abnormal retinal vessels and the good functional effect of the retinal pigment epithelium.

Improvement of psoriasis-associated arthritis and skin lesions by treatment with molecular hydrogen: A report of three cases

Psoriasis, a chronic inflammatory skin disease, is caused by infiltrating lymphocytes and associated cytokines, including tumor necrosis factor (TNF)α, interleukin (IL)-6, and IL-17. Effective treatments, including pathogenesis-based biological agents against psoriasis, are currently under development. Although the role of reactive oxygen species (ROS) in the pathogenesis of psoriasis has been investigated, it remains to be fully elucidated; ROS-targeted therapeutic strategies are also lacking at present. Therefore, the objective of the present study was to assess whether H2, a ROS scavenger, has a therapeutic effect on psoriasis-associated inflammation by reducing hydroxyl radicals or peroxynitrite in the immunogenic psoriasis cascade. Three methods were used to administer H2: Drop infusion of saline containing 1 ppm H2 (H2-saline), inhalation of 3% H2 gas, and drinking of water containing a high concentration (5-7-ppm) of H2 (high-H2 water). Treatment efficacy was estimated using the disease activity score 28 (DAS28) system, based on C-reactive protein levels, and the psoriasis area and severity index (PASI) score, determined at baseline and following each H2 treatment. Furthermore, levels of TNFα, IL-6, and IL-17 were analyzed. The DAS28 and PASI score of the three patients decreased during H2 treatment, regardless of the administration method. The psoriatic skin lesions almost disappeared at the end of the treatment. IL-6 levels decreased during H2 treatment in Case 1 and 2. IL-17, whose concentration was high in Case 1, was reduced following H2 treatment, and TNFα also decreased in Case 1. In conclusion, H2 administration reduced inflammation associated with psoriasis in the three cases examined and it may therefore be considered as a treatment strategy for psoriasis-associated skin lesions and arthritis.

Consumption of water containing over 3.5 mg of dissolved hydrogen could improve vascular endothelial function

BACKGROUND

The redox imbalance between nitric oxide and superoxide generated in the endothelium is thought to play a pivotal role in the development of endothelial dysfunction. A third reactive oxygen species (ROS), H2O2, is known to have both beneficial and detrimental effects on the vasculature. Nonetheless, the influence of the hydroxyl radical, a byproduct of H2O2 decay, is unclear, and there is no direct evidence that the hydroxyl radical impairs endothelial function in conduit arteries. Molecular hydrogen (H2) neutralizes detrimental ROS, especially the hydroxyl radical.

OBJECTIVES

To assess the influence of the hydroxyl radical on the endothelium and to confirm that a gaseous antioxidant, H2, can be a useful modulator of blood vessel function.

METHODS

The efficacy of water containing a high concentration of H2 was tested by measuring flow-mediated dilation (FMD) of the brachial artery (BA). The subjects were randomly divided into two groups: the high-H2 group, who drank high-H2 water containing 7 ppm H2 (3.5 mg H2 in 500 mL water); and the placebo group. Endothelial function was evaluated by measuring the FMD of the BA. After measurement of diameter of the BA and FMD at baseline, volunteers drank the high-H2 water or placebo water immediately and with a 30-minute interval; FMD was compared to baseline.

RESULTS

FMD increased in the high-H2 group (eight males; eight females) from 6.80%±1.96% to 7.64%±1.68% (mean ± standard deviation) and decreased from 8.07%±2.41% to 6.87%±2.94% in the placebo group (ten males; eight females). The ratio to the baseline in the changes of FMD showed significant improvement (P<0.05) in the high-H2 group compared to the placebo group.

CONCLUSION

H2 may protect the vasculature from shear stress-derived detrimental ROS, such as the hydroxyl radical, by maintaining the nitric oxide-mediated vasomotor response.

Therapeutic efficacy of infused molecular hydrogen in saline on rheumatoid arthritis: a randomized, double-blind, placebo-controlled pilot study

The aim of this study was to demonstrate the safety and efficacy of H2-saline infusion for treatment of rheumatoid arthritis (RA). We conducted a randomized, double-blind, placebo-controlled investigation of the infusion of 1 ppm H2-dissolved saline (H2-saline) in 24 RA patients. Patients were randomized 1:1 to receive 500 ml of either H2-saline or placebo-saline, which was drop infused intravenously (DIV) daily for 5 days. The disease activity score in 28 joints (DAS28) was measured at baseline, immediately post infusion, and after 4 weeks. Therapeutic effects of H2-saline on joint inflammation were estimated by measuring serum biomarkers for RA, tumor necrosis factor-α (TNFα), interleukin-6 (IL-6), matrix metalloproteinase-3 (MMP-3), and urinary 8-hydroxydeoxyguanosine (8-OHdG). In the H2-infused group, average DAS28 decreased from 5.18 ± 1.16 to 4.02 ± 1.25 immediately post infusion and reached 3.74 ± 1.22 after 4 weeks. No significant decrease in DAS28 was observed in the placebo group throughout the study. IL-6 levels in the H2 group significantly decreased in 4 weeks by 37.3 ± 62.0% compared to baseline, whereas it increased by 33.6 ± 34.4% in the placebo group. TNFα levels did not change remarkably in the H2 or placebo groups in 4 weeks post-infusion compared to baseline. The relative ratio of 8-OHdG in the H2 group also significantly decreased by 4.7%. After 4 weeks, MMP3 was significantly reduced by 19.2% ± 24.6% in the H2 group, and increased by 16.9% ± 50.2% in the placebo group. Drop infusion of H2 safely and effectively reduced RA disease activity.

Electrolyzed Hydrogen-Saturated Water for Drinking Use Elicits an Antioxidative Effect: A Feeding Test with Rats

A new type of electrolyzed hydrogen-saturated (EHS) water was produced using a water-electrolyzing device equipped with a special cation exchanger. Use of the EHS water for drinking in a feeding test with rats elicited an antioxidative effect. After intraperitoneal injection of 2,2-azobis-amidinopropane dihydrochloride, urinary secretion of 8-hydroxydeoxyguanosine and hepatic formation of peroxidized lipid were significantly lessened in rats which had received the EHS water for one week. These results suggest the possibility that this drinking water shows an effect in reduction of oxidative stress in the body.

Process of spontaneous resolution in the conservative management of congenital dacryocystocele

Purpose

To assess efficacy of the conservative management of patients with congenital dacryocystocele.

Materials and methods

This was a retrospective case series involving six sides of five infants with a dacryocystocele treated at Osaka Kaisei Hospital, Osaka, Japan. The conservative management protocol consisted of the application of warm compresses and massage over the mass, with the addition of antibiotics when dacryocystitis developed. Patient age at the time of resolution, presence of retrograde outflow of contents of dacryocystoceles from the puncta, and development of dacryocystitis were recorded.

Results

The dacryocystocele was unilateral in four patients and bilateral in one patient. A nasal cyst was present in four patients without respiratory distress. The median patient age at the time of the diagnosis was 7 days (range 2–10 days). Conservative management was selected in all patients, and the dacryocystocele was resolved in all patients at a median patient age of 14.5 days (range 11–105 days). Two sides developed dacryocystitis, which resolved in a few days with antibiotic treatment. In those two sides, rupture of the dacryocystoceles to the common canaliculus with retrograde discharge of the contents from the puncta before the dacryocystitis developed was noted. For the other four treated sides, no such discharge or development of dacryocystitis was observed.

Conclusion

The findings of this study show that a dacryocystocele has a good chance of resolving spontaneously with conservative management and careful observation, and that rupture of the dacryocystocele to the common canaliculus might be an important precursor of dacryocystitis.

Transperitoneal administration of dissolved hydrogen for peritoneal dialysis patients: a novel approach to suppress oxidative stress in the peritoneal cavity

Background

Oxidative stress (OS) related to glucose degradation products such as methylglyoxal is reportedly associated with peritoneal deterioration in patients treated with peritoneal dialysis (PD). However, the use of general antioxidant agents is limited due to their harmful effects. This study aimed to clarify the influence of the novel antioxidant molecular hydrogen (H₂) on peritoneal OS using albumin redox state as a marker.

Methods

Effluent and blood samples of 6 regular PD patients were obtained during the peritoneal equilibrium test using standard dialysate and hydrogen-enriched dialysate. The redox state of albumin in effluent and blood was determined using high-performance liquid chromatography.

Results

Mean proportion of reduced albumin (ƒ(HMA)) in effluent was significantly higher in H₂-enriched dialysate (62.31 ± 11.10%) than in standard dialysate (54.70 ± 13.08%). Likewise, serum ƒ(HMA) after administration of hydrogen-enriched dialysate (65.75 ± 7.52%) was significantly higher than that after standard dialysate (62.44 ± 7.66%).

Conclusions

Trans-peritoneal administration of H₂ reduces peritoneal and systemic OS.

Consumption of water containing a high concentration of molecular hydrogen reduces oxidative stress and disease activity in patients with rheumatoid arthritis: an open-label pilot study

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by the destruction of bone and cartilage. Although its etiology is unknown, the hydroxyl radical has been suggested to be involved in the pathogenesis of RA. Recently, molecular hydrogen (H2) was demonstrated to be a selective scavenger for the hydroxyl radical. Also, the method to prepare water containing extremely high concentration of H2 has been developed. We hypothesized that H2 in the water could complement conventional therapy by reducing the oxidative stress in RA.

METHODS

Twenty patients with rheumatoid arthritis (RA) drank 530 ml of water containing 4 to 5 ppm molecular hydrogen (high H2 water) every day for 4 weeks. After a 4-week wash-out period, the patients drank the high H2 water for another 4 weeks. Urinary 8-hydroxydeoxyguanine (8-OHdG) and disease activity (DAS28, using C-reactive protein [CRP] levels) was estimated at the end of each 4-week period.

RESULTS

Drinking high H2 water seems to raise the concentration of H2 more than the H2 saturated (1.6 ppm) water in vivo. Urinary 8-OHdG was significantly reduced by 14.3% (p < 0.01) on average. DAS28 also decreased from 3.83 to 3.02 (p < 0.01) during the same period. After the wash-out period, both the urinary 8-OHdG and the mean DAS28 decreased, compared to the end of the drinking period. During the second drinking period, the mean DAS28 was reduced from 2.83 to 2.26 (p < 0.01). Urinary 8-OHdG was not further reduced but remained below the baseline value. All the 5 patients with early RA (duration < 12 months) who did not show antibodies against cyclic citrullinated peptides (ACPAs) achieved remission, and 4 of them became symptom-free at the end of the study.

CONCLUSIONS

The results suggest that the hydroxyl radical scavenger H2 effectively reduces oxidative stress in patients with this condition. The symptoms of RA were significantly improved with high H2 water.

A convenient method for determining the concentration of hydrogen in water: use of methylene blue with colloidal platinum

A simple titration (oxidimetry) method using a methylene blue-platinum colloid reagent is effective in determining the concentration of hydrogen gas in an aqueous solution. The method performs as effectively as the more complex and expensive electrochemical method.

Relationship between Diabetic Macular Edema and Peripheral Th1/Th2 Balance

<i>Purpose:</i> To determine whether inflammatory reactions are involved in the pathogenesis of diabetic macular edema, we examined the relationship between diabetic macular edema and the ratio of T helper 1 (Th1) to T helper 2 (Th2) cells. <i>Methods:</i> Thirty-nine diabetic patients with diabetic retinopathy were evaluated at our hospital between February 2004 and February 2005. Blood samples were collected from each patient, and the ratio of CD4+ Th1 to Th2 cells (Th1/Th2) was determined by flow cytometry after fluorescent antibody staining for intracellular cytokines. Logistic regression analysis was used to determine the association of macular edema with age, gender, HbA_1c level, interval after retinal photocoagulation and Th1/Th2 ratios. Differences in these parameters were also compared between patients with and without macular edema. <i>Results:</i> Logistic regression analysis showed that the Th1/Th2 ratios were significantly associated with macular edema (odds ratio = 0.838; p = 0.02), while other variables were not. The Th1/Th2 ratio was significantly lower in the patients with diabetic macular edema than in those without (p = 0.02; t test). Higher Th1/Th2 ratios tended to be associated with better visual acuity. <i>Conclusions:</i> Shifts in the balance of Th1/Th2 towards a predominance of Th2 may represent an exacerbating factor for diabetic macular edema, although a causal relationship has still not been definitively determined.

Characterization of ANIT-induced toxicity using precision-cut rat and dog liver slices cultured in a dynamic organ roller system

This article describes the toxicity of alpha-naphthylisothiocyanate (ANIT), a compound known to induce dose-dependent hepatobiliary toxicity in vivo, using the slice model. Liver slices (200 microm thick) from male Sprague-Dawley rats and male beagle dogs were cultured for 7 days while exposed to a range of ANIT concentrations (1- 100 microM for rat and 4-320 microM for dog). Tissues (and medium for dog) were evaluated using a panel of clinically relevant biomarkers for liver and histological endpoints to assess viability and proliferation. ANIT increased slice levels of enzyme biomarkers corresponding to biliary markers. At high concentrations (80-100 microM for rat, 320 microM for dog) a diminution of tissue enzyme levels was observed, corresponding to severe hepatobiliary injury. By days 5 and 7, biochemical markers in the medium of dog slices indicated an elevation of hepatocellular and biliary markers. Histologically for both species, minimal hepatocellular injury was noted, but proliferation of biliary epithelial cells (BEC) was observed using 5-bromo-2-deoxyuridine (BrdU) immunostaining. In rat slices, ANIT increased the expression of inducible nitrous oxide synthase (iNOS) within 12 hrs of exposure. In summary, additional experimentation using slice culture may further demonstrate its value in screening compounds that cause hepatobiliary toxicity.

Possible involvement of endothelin-1 and nitric oxide in the pathogenesis of proliferative diabetic retinopathy

BACKGROUND

Overproduction of endothelin-1 (ET-1) and nitric oxide (NO) in the retina is demonstrated in experimental diabetic animals. To clarify the possible involvement of ET-1 and NO in the pathogenesis of diabetic retinopathy, the authors examined the vitreous levels of these principal endothelium-derived vasoactive substances in patients with proliferative diabetic retinopathy (PDR).

METHODS

Vitreous fluid was taken from patients with PDR (ET-1, n = 12; NO, n = 12) and from patients with macular holes as controls (ET-1, n = 10; NO, n = 10) at vitreous surgery. Endothelin-1 and NO metabolites were measured by radioimmunoassay and high-performance liquid chromatography based on the Griess method, respectively.

RESULTS

Endothelin-1 levels (mean +/- SE) were 21.5 +/- 1.7 pg/mL in the vitreous of patients with PDR and 16.7 +/- 0.7 pg/mL in the vitreous of patients with macular hole. There was a significant difference between patients with PDR and controls (P = 0.009, Mann-Whitney). Nitrate (NO3) was 49.8 +/- 5.0 micromol/L in patients with PDR and 24.2 +/- 2.8 micromol/L in patients with macula hole; it was also significantly elevated in patients with PDR (P = 0.004, Mann-Whitney), whereas nitrite (NO2) was not detected in this study.

CONCLUSION

These results indicate that ET-1 and NO may be related in the pathogenesis of PDR.

The spin temperature of NH3 in Comet C/1999S4 (LINEAR)

A high-dispersion spectrum of Comet C/1999S4 (LINEAR) was obtained in the optical region with the high-dispersion spectrograph on the Subaru telescope when the comet was 0.863 astronomical units from the Sun before its disintegration. We obtained high signal-to-noise ratio emission lines of the cometary NH2 bands from which an ortho-to-para ratio (OPR) of 3.33 +/- 0.07 was derived on the basis of a fluorescence excitation model. Assuming that cometary NH2 mainly originates from ammonia through photodissociation, the derived OPR of NH2 molecules should reflect that of ammonia, which provides information on the environment of molecular formation or condensation and of the thermal history of cometary ices. Assuming that the OPR of ammonia in comets was unchanged in the nucleus, the derived spin temperature of ammonia (28 +/- 2 kelvin) suggests that a formation region of the cometary ammonia ice was between the orbit of Saturn and that of Uranus in the solar nebula.

Immunohematotoxicity studies with combinations of dapsone and zidovudine

We investigated the immunohematoxicities of the antiparasitic drug dapsone (DDS) and the antiretroviral drug zidovudine (ZDV, AZT) given alone or in combination in BALB/c mice. DDS is used for prophylaxis and treatment of Pneumocystis carinii infection in AIDS patients. We examined the impact of concurrent administration of these drugs on the immune and hematopoietic systems because DDS causes hematotoxicity and ZDV therapy results in bone marrow toxicity. Daily oral administration of DDS at 25 and 50 mg/kg for 28 days caused a slight anemia, marked methemoglobinemia, reticulocytosis, and a moderate leukopenia (P < 0.01 for all parameters) but had no discernible effect on platelet count. In DDS-treated mice, the proliferative response of splenic T cells to concanavalin A was > or = 35% higher than that manifested by splenocytes from vehicle-treated control mice. ZDV at 240 and 480 mg/kg was not immunosuppressive but caused low-grade macrocytic anemia, thrombocytosis, and neutropenia; these effects were drug dose-dependent and statistically significant (P < 0.01). Concurrent administration of DDS and ZDV augmented the severity of ZDV-mediated macrocytic anemia, and 7 of 12 (58%) mice did not survive treatment with the high doses of DDS and ZDV (50 and 480 mg/kg, respectively). On the other hand, co-administration of ZDV mitigated DDS-induced methemoglobinemia and the DDS-associated elevation in lymphoproliferative response. These data suggest interaction between DDS and ZDV in mice and indicate a need for caution in using DDS as long-term therapy in AIDS patients receiving ZDV.

Living-related liver transplantation for fulminant hepatic failure in children

Liver transplantation is increasingly accepted as a choice of treatment for fulminant hepatic failure (FHF) since it has been proved to significantly improve the survival rate in these patients compared with other therapeutic modalities. We have successfully performed a total of 76 living related liver transplantations (LRLT) three of which were for FHF. The first case was an 11-year-old boy with FHF due to an unidentified cause. He had required plasmapheresis a total of 24 times and haemofiltration to save his life before LRLT. He was transplanted with a left lobe (420 g) graft, calculated as 1.05% of his weight (40 kg). He recovered hepatic function uneventfully and was discharged from hospital after 7 weeks. The second case was a 13-year-old girl who developed FHF with grade III encephalopathy due to acute Wilson's disease, and was referred to us. She underwent LRLT with a left lobe graft (440 g), estimated as 0.95% of her weight (47 kg), which functioned well after surgery. The third case was a 13-year-old girl with grade II encephalopathy due to acute Wilson's disease. She was 27% obese with a body weight of 58 kg. She underwent LRLT with ABO blood group incompatibility with a left lobe (352 g), estimated as 0.80% of her weight (modified 44 kg). She was discharged with sensorimotor neuropathy due to vitamin B deficiency. The present results suggest that LRLT is feasible for FHF both clinically and ethically, and that a partial liver graft weighing around 1% of the recipient's weight can maintain the recipient's life. We limit the diagnostic indication for LRLT to chronic liver disease, since an urgent situation may affect a voluntary decision for the patient's parents to donate the partial liver. However, LRLT is thought to be an acceptable choice of treatment provided it is requested by the patient and family. Furthermore, it is a potential option for resolving the graft shortage in paediatric liver transplantation, being independent of cadaver donor availability.

FR131535, a novel water-soluble echinocandin-like lipopeptide: synthesis and biological properties

The synthesis and biological properties of a novel water-soluble echinocandin-like lipopeptide, FR131535, are described. This compound displayed potent in vitro and in vivo antifungal activities. The hemolytic activity of FR901379 was reduced by replacing the acyl side chain. This compound showed good water-solubility, comparable to the natural product FR901379.

Reduction of atherosclerosis despite hypercholesterolemia in lyn-deficient mice fed a high-fat diet

Oxidation and other modifications of serum low-density lipoprotein (LDL) are associated with the development of atherosclerosis, and a scavenger receptor and CD40 signalling are also known to play important roles in the process. We previously showed that the Src family protein-tyrosine kinase Lyn is physically and/or functionally associated with macrophage type-I and type-II class-A scavenger receptors (MSR-A) and CD40. In this study, we addressed whether Lyn is involved in the build-up of serum lipid levels and in atherosclerotic changes. When fed a normal diet, lyn-deficient mice had serum lipid levels that were no different from those of wild-type mice. By contrast, lyn-deficient mice fed a high-fat diet showed serum lipid levels that were much higher than those seen in wild-type mice. Curiously, however, the lyn-deficient mice fed either diet showed no increase in incidence of atherosclerotic lesions compared with wild-type mice. This may be partly explained by our data showing suppression of proliferation of peritoneal macrophages in response to oxidized LDL in the absence of Lyn, and failure of stimulation of the CD40 pathway in lyn-deficient macrophages to induce expression of monocytic chemoattractant protein-1 (MCP-1), which is related to atherosclerosis. These results suggest that Lyn plays an important role in the metabolism of serum lipids and in the development of atherosclerotic lesions on high-fat diets.

A new antimitotic substance, FR182877. III. Structure determination

During the course of screening for novel cell cycle inhibitors, FR182877 was isolated from the fermentation broth of Streptomyces sp. No.9885. During the NMR measurements, FR182877 decomposed so much that the structure elucidation of FR182877 itself was difficult. Then, combinations of chemical correlations and spectroscopic methods clarified that FR182877 possesses an unprecedented multi-ring system including the strained double bond, which was unexpectedly epoxidized by molecular oxygen. FR182877 showed broad antitumor activities in vitro and promoted assemblies of tublins in vitro as well as taxol. It is noteworthy that epoxidation of the distorted double bond resulted in significant decrease in antitumor activities.

A new antimitotic substance, FR182877. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities

Using the characteristic morphological changes of mammalian cells, we screened novel antimitotic substances and found that a strain of Streptomyces sp. No.9885 produced FR182877. This substance was isolated from the culture broth by ethyl acetate extraction, silica gel column chromatography and ODS column chromatography. Structural studies on FR182877 suggested that it had a unique hexacyclic structure encompassing its highly strained double bond. FR182877 exhibited potent antitumor activities against murine ascitic tumor and solid tumor in vivo.

Can an autocrine loop explain sex-hormone-dependent tumor growth? A brief overview

Sex hormones and their related compounds have been known to regulate the target cell growth positively or negatively in the receptor-dependent manner. The molecular mechanism of these complicated events, especially sex hormone-dependent growth enhancement, has been studied extensively. In MCF-7 cells, estrogen-induced autocrine loop has been demonstrated to play the important role for estrogen-dependent growth. Androgen has been also found to promote the growth of SC-3 cell through the induction of an autocrine growth factor (FGF 8). The blockade of FGF 8 activity resulted in a complete inhibition of androgen-dependent growth of SC-3 cells, suggesting that FGF 8 acts as an essential component of androgen-dependent growth. However, the constitutional expression of FGF 8 failed to convert SC-3 cells from an androgen-dependent to an androgen-independent phenotype. These observations would suggest that sex hormone-induced autocrine loop is an obligatory but not sufficient component for the growth of sex hormone-dependent tumor.

A case of interleukin-6-producing malignant fibrous histiocytoma originating in the heart

Primary cardiac malignant fibrous histiocytoma is extremely rare and its pathophysiological characteristics remain largely unknown. We treated a female patient with persistent fever and disseminated intravascular coagulation. Since ultrasonic echocardiography revealed the presence of a cardiac tumor and her serum interleukin-6 level was elevated, we speculated she had a cardiac myxoma. Histological examination of the surgically resected specimen, however, revealed that the tumor was malignant fibrous histiocytoma. Although her disseminated intravascular coagulation and heart failure were transiently improved after operation, local recurrence and systemic metastasis occurred and she died 7 weeks after operation. Using the autopsied specimen, we examined whether the malignant fibrous histiocytoma constitutively synthesized interleukin-6. The interleukin-6 content in the tumor was high, consistent with interleukin-6 production by the tumor. This was confirmed by immunohistochemical analysis. To our knowledge, this is the first report demonstrating interleukin-6 production by a cardiac malignant fibrous histiocytoma.

Hypoxia-activated apoptosis of cardiac myocytes requires reoxygenation or a pH shift and is independent of p53

Ischemia and reperfusion activate cardiac myocyte apoptosis, which may be an important feature in the progression of ischemic heart disease. The relative contributions of ischemia and reperfusion to apoptotic signal transduction have not been established. We report here that severe chronic hypoxia alone does not cause apoptosis of cardiac myocytes in culture. When rapidly contracting cardiac myocytes were exposed to chronic hypoxia, apoptosis occurred only when there was a decrease in extracellular pH ([pH](o)). Apoptosis did not occur when [pH](o) was neutralized. Addition of acidic medium from hypoxic cultures or exogenous lactic acid stimulated apoptosis in aerobic myocytes. Hypoxia-acidosis-mediated cell death was independent of p53: equivalent apoptosis occurred in cardiac myocytes isolated from wild-type and p53 knockout mice, and hypoxia caused no detectable change in p53 abundance or p53-dependent transcription. Reoxygenation of hypoxic cardiac myocytes induced apoptosis in 25-30% of the cells and was also independent of p53 by the same criteria. Finally, equivalent levels of apoptosis, as demonstrated by DNA fragmentation, were induced by ischemia-reperfusion, but not by ischemia alone, of Langendorff-perfused hearts from wild-type and p53 knockout mice. We conclude that acidosis, reoxygenation, and reperfusion, but not hypoxia (or ischemia) alone, are strong stimuli for programmed cell death that is substantially independent of p53.

Surgery for cholecystocholedocholithiasis in a patient with asymptomatic essential thrombocythemia: report of a case

Essential thrombocythemia (ET) is a myeloproliferative disorder characterized by a remarkable increase in the platelet count and various clinical symptoms. The perioperative management of patients with ET has yet to be determined, especially when there are no clinical symptoms. We report herein the case of a woman with gallstones whose preoperative hematological data showed remarkable thrombocythemia, but her coagulation studies were normal. The Philadelphia chromosome was negative and bone marrow cytology showed a marked increase in megakaryocytes. Surgery was performed under a diagnosis of cholelithiasis with ET. Considering her severe thrombocythemia and obesity, sufficient heparin was administered to prevent deep vein thrombosis; however, this precipitated postoperative bleeding, necessitating a reoperation. A functional abnormality of the patient's platelets was suspected, and the aggregation by adenosine diphosphate was subsequently found to be significantly inhibited. As patients having ET with no symptoms might have depressed platelet aggregability despite remarkable thrombocythemia, when abdominal surgery is performed, prophylactic therapy for deep vein thrombosis should be avoided. Hence, the preoperative aggregation study of platelets might offer useful information about whether postoperative antithrombotic therapy is indicated.

Hyperlipidemia enhancement of renal preneoplasia but not tumor formation is due to elevated apoptosis in the Eker rat

The influence of a high-fat diet on the appearance of renal tumors was assessed in the Eker rat model of hereditary renal carcinoma. Examination of H&E-stained sections showed a significant increase in the number of microscopic solid adenomas in the high-fat group compared with the low-fat group, whereas there was no significant difference in the number of macroscopic tumors between the two groups. Where had the tumor buds gone? Staining for apoptotic bodies occasionally revealed apoptosis in and around the microscopic adenomas. In addition, an Eker rat renal tumor-derived cell line showed apoptosis when it was cultured with high concentrations of native and acetylated low-density lipoprotein. These findings suggested that tumor buds repeatedly appeared and disappeared in Eker rats on a high-fat diet.

Adenovirus E1A inhibits cardiac myocyte-specific gene expression through its amino terminus

Adenovirus E1A oncoproteins inhibit muscle-specific gene expression and myogenic differentiation by suppressing the transcriptional activating functions of basic helix-loop-helix proteins. As one approach to identifying cardiac-specific gene regulatory proteins, we analyzed the functional regions of E1A proteins that are required for muscle gene repression in cardiac cells. Myocyte-specific promoters, including the alpha-actins and alpha-myosin heavy chain, were selectively and potently inhibited (>90%) by E1A, while the ubiquitously expressed beta-actin promoter was only partially ( approximately 30%) repressed; endogenous gene expression was also affected. Distinct E1A protein binding sites mediated repression of muscle-specific and ubiquitous actin promoters. E1A-mediated inhibition of beta-actin required both an intact binding site for the tumor repressor proteins pRb and p107 and a second E1A domain (residues 15-35). In contrast, cardiac-specific promoter repression required the E1A amino-terminal residues 2-36. The proximal skeletal actin promoter (3' to base pair -153) was a target for repression by E1A. Although E1A binding to p300 was not required for inhibition of either promoter, co-expression of p300 partially reversed E1A-mediated transcriptional repression. We conclude that cardiac-specific and general promoter inhibition by E1A occurs by distinct mechanisms and that cardiac-specific gene expression is modulated by cellular factors interacting with the E1A p300/CBP-binding domain.

Advanced glycation endproducts stimulate interleukin-6 production by human bone-derived cells

Advanced glycation endproducts (AGEs), which result from nonenzymatic reactions of glucose with tissue proteins, have been shown to accumulate on long-lived proteins in advanced aging and diabetes mellitus. Thus, AGEs have been implicated in some of the chronic complications associated with these disorders. In this study, we investigated the effects of the glucose-modified protein on the production of the potent bone resorption factors by cells derived from explants of human bone. AGEs stimulated the release of interleukin-6 (IL-6) in the culture supernatants from the bone-derived cells and increased the levels of IL-6 mRNA in the cells. By contrast, the levels of IL-11 in the culture supernatants were not altered by AGEs, and the other bone resorption factors IL-1 alpha and IL-1 beta were undetectable (< 1.0 pg/ml) either without or with the treatment of AGEs. Electrophoretic mobility-shift assays revealed that the transcription nuclear factor-kappa B, which is critical for the inducible expression of IL-6, was activated in the nuclear extracts from mouse osteoblastic MC3T3-E1 cells treated with AGEs. These results suggest that AGEs are involved in bone remodeling modulation by stimulating IL-6 production in human bone-derived cells.

Detection of herpes simplex DNA in semen and menstrual blood of individuals attending an infertility clinic

OBJECTIVE

To determine a possible link between herpes simplex virus 1 (HSV) and infertility.

METHOD

A specifically designed polymerase chain reaction with nested primers, was developed and used to test for HSV in 153 men and 20 women attending an infertility clinic.

RESULTS

HSV DNA was detected in 37 (24%) out of 153 semen samples and in 11 (55%) out of 20 menstrual blood samples. However, HSV DNA (0%) was not detected in the semen of 16 males with children. A significant association between the evidence for infertility and an HSV positive test was observed in men (Fisher's exact test, p = 0.024), and a stronger effect was found in females after failed in vitro fertilization (Fisher's exact test p = 0.0086).

CONCLUSION

This is the first report of the detection of herpes simplex virus DNA in semen and menstrual blood. Encouraging preliminary results justify antiviral therapy in case of a positive test.

Functional and possible physical association of scavenger receptor with cytoplasmic tyrosine kinase Lyn in monocytic THP-1-derived macrophages

Acetyl LDL (modified low-density lipoprotein), which is thought to be taken up through scavenger receptor A (SR-A), rapidly induced the appearance of phosphotyrosine proteins in monocytic THP-1-derived macrophages in vitro. The two alternative forms of Lyn (p53 and p56) were found to be tyrosine-phosphorylated within 30 s after the stimulation with acetyl LDL. The catalytic activity of Lyn measured by an in vitro kinase assay had also increased in acetyl LDL-stimulated THP-1-derived macrophages. Furthermore, Lyn could be co-immunoprecipitated with SR-A from the cell lysate. These observations suggest a functional and possible physical association of SR-A with Lyn in THP-1-derived macrophages, and also imply a possible involvement of Lyn in SR-A signal transduction.

New antitumor substances, FR901463, FR901464 and FR901465. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities

New antitumor substances, FR901463, FR901464 and FR901465 were isolated from the culture broth of a bacterium of Pseudomonas sp. No.2663. FR901463, FR901464 and FR901465 remarkably enhanced the transcriptional activity of the promoter of SV40 DNA virus. Further, these compounds exhibited potent antitumor activities against murine and human tumor cell lines in vitro.

Analysis of factors affecting the graft oxygenation state in living related liver transplantation

BACKGROUND/AIMS

In liver transplantation, graft dysoxia after reperfusion may lead to graft failure. The aim of this study is to investigate the relationship between the factors, which were supposed to affect the oxygen supply to the graft, and the oxygenation state of the graft in order to determine which factor is important to prevent the graft from dysoxia.

MATERIALS AND METHODS

The relationship between oxygen supply and oxygenation state of the graft was investigated in 56 successful cases of living related liver transplantation. Factors affecting the oxygen supply to the graft were considered as follows; portal venous flow (PVF), mean velocity of the hepatic artery (HA-Vm), hemoglobin concentration in the peripheral blood (Hb), size of the graft liver relative to the recipient body weight (G/R ratio), partial oxygen pressure in the arterial blood (PaO2), and rate-pressure product (BP*PR). Oxygenation state of the graft was estimated by oxygen saturation of hemoglobin in the graft tissue (graft SO2) as measured by tissue near infrared spectroscopy.

RESULTS

1) Graft SO2 was rather independent of PVF and HA-Vm probably due to compensatory interrelation between the portal venous flow and hepatic arterial flow. 2) Significant correlation between G/R ratio and graft SO2 was observed after portal reflow (p < 0.01), but the correlation diminished after hepatic arterial reflow. Positive correlation between G/R ratio and AKBR after portal reflow suggested that the graft with large G/R ratio is likely to suffer dysoxia early after reperfusion. 3) Graft SO2 was positively correlated with Hb (p < 0.05), while there was no significant correlation between graft SO2 and PaO2 or BP*PR.

CONCLUSION

This study clarified the contribution of the factors which were supposed to affect the oxygen supply to the graft and the oxygenation state of the graft, and which factor is important to prevent the graft from dysoxia.

Inhibition of growth and metastasis of ovarian carcinoma by administering a drug capable of interfering with vascular endothelial growth factor activity

The present study investigates the relationship between in vivo growth/metastasis of tumor cells and their capacity to produce the vascular endothelial growth factor (VEGF), as well as the regulation of tumor growth/metastasis using an angiogenesis-inhibitory drug. Two cloned tumor cell lines designated OV-LM and OV-HM were isolated from a murine ovarian carcinoma OV2944. OV-LM and OV-HM cells grew in cultures at comparable rates. However, when transplanted s.c. into syngeneic mice, OV-HM exhibited a faster growth rate and a much higher incidence of metastasis to lymph nodes and lung. Histologically, intense neovascularization was detected in sections of OV-HM but not of OV-LM tumor. OV-HM and OV-LM tumor cells obtained from in vitro cultures expressed high and low levels of VEGF mRNA, respectively. A difference in VEGF mRNA expression was much more clearly observed between RNAs prepared from fresh OV-HM and OV-LM tumor masses: RNA from OV-HM contained larger amounts of VEGF mRNA, whereas RNA from OV-LM exhibited only marginal levels of VEGF mRNA. An angiogenesis-inhibitory drug, FR118487 inhibited the VEGF-mediated in vitro growth of endothelial cells but did not affect the expression in vitro of VEGF mRNA by OV-HM tumor cells. Intraperitoneal injections of FR118487 into mice bearing OV-HM tumors resulted in: (i) a subsequent growth inhibition of primary tumors; (ii) a marked decrease in neovascularization inside tumor masses expressing comparable levels of VEGF mRNA to those detected in control OV-HM masses; and (iii) almost complete inhibition of metastasis to lymph nodes and lung. These results indicate that growth/metastasis of tumor cells correlates with their VEGF-producing capacity and that an angiogenesis inhibitor, FR118487, inhibits tumor growth and metastasis through mechanism(s) including the suppression of VEGF function in vivo.

Fusigenic liposome-mediated DNA transfer into cardiac myocytes

Current methods of gene transfer into cultured cardiac myocytes have serious limitations, including low efficiency, toxicity or constraints on DNA insert size. The present study examined the effectiveness of hemagglutinating virus of Japan (HVJ) in promoting liposome-mediated DNA transfer into cultured neonatal rat cardiac myocytes. Fluorescein isothiocyanate-labeled oligonucleotides (F-ODN) or plasmid expression vectors encoding SV40 large T antigen (pActSVT) and beta-galactosidase (pAct beta-gal) were complexed with liposomes and the viral protein coat of HVJ. Plasmid vectors were complexed with the nuclear localizing protein HMG-1 prior to HVJ-liposome encapsulation. Neonatal myocytes were transfected by incubation with HVJ-liposome/DNA complexes on culture day 3 or 7. Using F-ODN, we were able to demonstrate significant uptake of DNA (transfection efficiencies of 80-90%) 1 h after transfection that persisted for 1 week in culture. Interestingly, F-ODN were concentrated in the myocyte nuclei for the first 4 days after transfection. Immunohistochemistry showed that 25-30% of myocytes transfected with either pActSVT or pAct beta-Gal expressed plasmid-encoded protein at 72 h whether they were transfected at day 3 or day 7 of culture, while cells transfected with blank vectors did not. Quantitative beta-galactosidase assays confirmed that the use of HVJ significantly enhanced liposome-mediated transfection. Cell toxicity was not apparent. Gene transfer via intracoronary injection also demonstrated the capacity of HVJ to mediate transfection of rabbit cardiac myocytes in vivo, with F-ODN-dependent fluorescence persisting for up to 1 week. We conclude that HVJ/liposome-mediated transfer is efficient for the transfection of both oligonucleotides and plasmids into cardiac myocytes both in vitro and in vivo, and may provide a new tool for the investigation of cardiac myocyte biology and disease.

Cold preservation-induced changes in oxygen radical generation between parenchymal and nonparenchymal cells in rat liver

Many of the reports implicating the contribution of oxygen radicals to preservation-reperfusion injury have been based largely on indirect experiments demonstrating the effects or the consumption of various antioxidants. Investigations based on the direct measurement of the amounts of oxygen radicals that are actually formed during reoxygenation after preservation have not given satisfactory results. In this study, we attempted direct measurement of H2O2 from hepatocellular mitochondria and superoxide (O2-) from Kupffer cells, using the HRP method and cytochrome c perfusion method, respectively, for quantitative comparison of the cold preservation-induced changes in radical generation activity between these sources. H2O2 generation in mitochondria isolated after 24 h cold preservation decreased to 8% of non-preserved liver, but in the mitochondria isolated from the livers that were reperfused for 30 min after 24 h preservation H2O2 generation recovered to 60%. The respiratory control ratio also decreased significantly after 24 h preservation, and similarly recovered after an additional 30 min reperfusion. By contrast, O2- from Kupffer cells increased in time-dependent fashion until 12 h preservation and decreased after 24 h preservation. Although 12 h preservation did not cause an increase in LDH release, the lipid peroxide in the perfusate significantly increased after 12 h preservation, which indicated the occurrence of lipid peroxidation in the sinusoidal area. These results suggested that mitochondrial H2O2 was dependent upon the activity of respiratory function and so did not cause hepatocellular injury and that O2- from Kupffer cells contributed to oxidative injury to the sinusoidal lining cells. Our data support reports demonstrating the vulnerability of nonparenchymal cells.

Identification of alternatively spliced messenger ribonucleic acid encoding truncated growth hormone-releasing hormone receptor in human pituitary adenomas

The expression of GHRH receptor (GHRH-R) messenger ribonucleic acid (mRNA) was studied in 22 pituitary adenomas and 2 normal anterior pituitaries. Northern blot analysis revealed that GHRH-R mRNA were expressed in all 14 GH-producing adenomas, 1 of 3 ACTH-producing adenomas, the 1 PRL-producing adenoma, 2 of 4 nonfunctioning adenomas, and the 2 normal anterior pituitaries. Their expression levels varied among GH-producing adenomas and were relatively low in GH-nonproducing adenomas. In addition to the major transcript with a molecular mass of 2.0 kilobases (kb), the transcripts were identified at 2.8 and 4.5 kb in some GH-producing adenomas. To examine the structural variations in GHRH-R mRNA in pituitary adenomas, we amplified the complementary DNA fragment encompassing the region from the third cytoplasmic loop to the sixth transmembrane domain of GHRH-R. This region was selected because this region of the G protein-coupled receptor has been known to interact with G protein. Two amplified fragments with the molecular masses of 250 and 810 base pairs were identified by the reverse transcriptase-polymerase chain reaction method. The nucleotide sequence of a smaller fragment, which was the expected size, revealed that no mutations were found in this region in 10 GH-producing adenomas examined. However, a larger fragment contained the currently unidentified insertion. Compared with the genomic DNA sequence, this insertion was found to be generated through alternative splicing. In addition, this variant form contained the premature stop codon in-frame, indicating that it encodes the truncated GHRH-R. This insertion-specific probe could hybridize with 2.8- and 4.5-kb species of GHRH-R mRNA on Northern blot analysis, and these transcripts were expressed mainly in GH-producing adenomas. Finally, study of cell transfection and cAMP measurement revealed that this truncated GHRH-R was unable to transmit GHRH signals. These results suggest that some GH-producing adenomas preferentially express the truncated GHRH-R as a nonfunctioning receptor through alternative splicing.