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Biomedical subjects

M Mayes

Publications and source records attributed to M Mayes.

At least 19 recordsLinked to original sources
PubMed2004

Digital ulcers in systemic sclerosis: prevention by treatment with bosentan, an oral endothelin receptor antagonist.

OBJECTIVE: Recurrent digital ulcers are a manifestation of vascular disease in patients with systemic sclerosis (SSc; scleroderma) and lead to pain, impaired function, and tissue loss. We investigated whether treatment with the endothelin receptor antagonist, bosentan, decreased the development of new digital ulcers in patients with SSc. METHODS: This was a randomized, prospective, placebo-controlled, double-blind study of 122 patients at 17 centers in Europe and North America, evaluating the effect of treatment on prevention of digital ulcers. The primary outcome variable was the number of new digital ulcers developing during the 16-week study period. Secondary assessments included healing of existing digital ulcers and evaluation of hand function using the Scleroderma Health Assessment Questionnaire. RESULTS: Patients receiving bosentan had a 48% reduction in the mean number of new ulcers during the treatment period (1.4 versus 2.7 new ulcers; P = 0.0083). Patients who had digital ulcers at the time of entry in the study were at higher risk for the development of new ulcers; in this subgroup the mean number of new ulcers was reduced from 3.6 to 1.8 (P = 0.0075). In patients receiving bosentan, a statistically significant improvement in hand function was observed. There was no difference between treatment groups in the healing of existing ulcers. Serum transaminase levels were elevated to >3-fold the upper limit of normal in bosentan-treated patients; this elevation is comparable with that observed in previous studies of this agent. Other side effects were similar in the 2 treatment groups. CONCLUSION: Endothelins may play an important role in the pathogenesis of vascular disease in patients with SSc. Treatment with the endothelin receptor antagonist bosentan may be effective in preventing new digital ulcers and improving hand function in patients with SSc.

Activities of Daily Living↗
PubMed2002

The effects of spinosad, a naturally derived insect control agent, to the honeybee (Apis melifera).

Spinosad is a novel insect control agent derived by fermentation of the Actinomycete bacterium, Saccharopolyspora spinosa. Spinosad controls many caterpillar pests in vines, pome fruit and vegetables (including tomatoes and peppers), thrips in tomatoes, peppers and ornamental cultivation and dipterous leafminers in vegetables and ornamentals. Application rates vary between 25 to 100 g of active substance per hectare (g as/ha) and 4.8 to 36 g of active substance per hectolitre (g as/hL) depending on the crop and target pest. It is important that plant protection products are authorized for use only in ways that do not pose an unacceptable risk of harm to honeybees. For this purpose testing was performed to enable the safety of spinosad to be evaluated. The effects of spinosad to honeybees have been extensively researched. Testing has been performed under a variety of conditions in a range of countries globally. Studies to determine the acute toxicity of spinosad under laboratory conditions were conducted to generate LD50 or LC50 values for oral and contact routes of administration. These demonstrated that spinosad was highly toxic to worker honeybees under worst case laboratory conditions and that the oral route of exposure provided the greater risk. Residue tests conducted under laboratory, semi-field and field conditions on worker honeybees foraging on treated foliage indicated that dry product residues were harmless. Therefore the effects seen in the laboratory acute toxicity tests did not translate to a more realistic exposure scenario indicating that safe use patterns for the product can be developed. Semi-field cage studies have also demonstrated that spinosad was safe to bees when applied to flowering crops during periods of bee activity. The majority of studies conducted have indicated that spinosad does not adversely affect honeybee behaviour, brood or queen. It can be concluded that spinosad when used according to the approved product label recommendations, would be safe to foraging worker bees, queen and brood. Additional levels of safety could be achieved by avoiding situations where bees would forage primarily on aphid honey dew.

Animals↗
PubMed2001

The Disability Index of the Health Assessment Questionnaire is a predictor and correlate of outcome in the high-dose versus low-dose penicillamine in systemic sclerosis trial.

OBJECTIVE: To explore the clinical implications of a score of > or =1.0 on the Disability Index of the Health Assessment Questionnaire (HAQ DI) at the first patient visit, and to examine the implications of improvement in HAQ DI score over 2 years in a cohort of systemic sclerosis (SSc) patients with diffuse cutaneous scleroderma. METHODS: SSc skin and visceral involvement was assessed in 134 SSc patients with diffuse scleroderma (mean +/- SD disease duration of 10 +/- 4 months) when they entered a multicenter drug trial and again 2 years later. Mortality and the occurrence of scleroderma renal crisis were assessed for a mean +/- SD of 4.0 +/- 1.1 years. Logistic and linear regression analyses were used to examine the relationship of the baseline HAQ DI score to morbidity, mortality, and visceral involvement, as well as the relationship of changes in the HAQ DI score to changes in physical examination, laboratory, and functional variables over 2 years. RESULTS: A baseline HAQ DI score of > or =1.0 was predictive of mortality (odds ratio 3.22, 95% confidence interval 1.097-9.468) over 4 years. Multivariate linear regression demonstrated that a model which included the erythrocyte sedimentation rate at baseline (P = 0.005) and changes at 2 years in the swollen joint count (P = 0.002), total skin score (P = 0.005), and white blood cell count (P = 0.005) best explained the change in HAQ DI score over 2 years (R2 = 0.528). The HAQ DI score and total skin score at baseline were highly correlated (correlation coefficient 0.368), as were changes in the HAQ DI score and the total skin score over 2 years (correlation coefficient 0.492). Although the HAQ DI score was heavily influenced by hand dysfunction at baseline and at 2 years, improvement (reduction) in the HAQ DI score over 2 years was related to factors other than hand dysfunction. CONCLUSION: A baseline HAQ DI score of > or =1.0 predicted mortality over 4 years. Improvement in the HAQ DI score in these patients with diffuse scleroderma was associated with improvement in skin thickening, hand function, oral aperture, lung function, signs of arthritis, serum creatinine level, and the investigator's global assessment of improvement. The HAQ DI is a self-administered questionnaire that SSc patients can complete easily and rapidly and that gives the practicing physician important information about prognosis, patient status, and changes in disease course over time.

Disability Evaluation↗
PubMed2001

Nuclear ultrastructure in bovine oocytes after inhibition of meiosis by chemical and biological inhibitors.

Various components of the ovarian follicle as well as different chemicals can suppress the resumption of meiosis in cumulus-oocyte complexes (COCs). In this study the nuclear ultrastructure of bovine COCs was assessed after 8 h of meiotic inhibition with 50 microM roscovitine (ROSC), 50 microM butyrolactone (BL-I), 2 mM 6-DMAP, 2 microM cycloheximide (CX), or a theca cell monolayer (TC). COCs were recovered according to standard in vitro methods, cultured in a simple and defined medium, and processed for transmission electron microscopy. Control COCs were processed before onset of culture and multiple oocytes were evaluated for each treatment. In all groups, the oocyte nucleus presented a dense fibrillar nucleolus consisting of a fibrillar sphere with a fibrillar center. In TC and 6-DMAP inhibited COCs condensed chromatin adhered to the nucleolus while in all other groups the perinuclear chromatin was separated from the nucleolus. In ROSC inhibited COCs, the nuclear envelope presented only slight small amplitude undulation. The BL-I-inhibited COCs presented an intermediate level of low amplitude undulation of the NE. In CX, 6-DMAP, and TC inhibited COCs the nuclear envelope presented extensively low amplitude undulations. In ROSC inhibited COCs, electron-dense granules formed ring-shaped structures. In some of the BL-I inhibited COCs multiple stellate crystal-like structures were found, and in these COCs the nuclear envelope and the perinuclear cisternae appeared less distinct than in the other BL-I inhibited COCs. In 6-DMAP inhibited COCs interchromatin-like granule clusters were present. In conclusion, the oocyte nuclei in all COCs presented a dense fibrillar nucleolus resembling that in control COCs. However, variations were observed in 1) the nuclear envelope morphology; 2) the chromatin location in relation to the nucleolus; and 3) the presence of different populations of intranuclear granules. Although all treatments inhibited oocyte nucleus breakdown, the mechanisms underlying these effects are different and require further characterization. Mol. Reprod. Dev. 59: 459-467, 2001.

4-Butyrolactone↗
PubMed2000

Skin thickness score as a predictor and correlate of outcome in systemic sclerosis: high-dose versus low-dose penicillamine trial.

OBJECTIVE: To study the clinical implications of a skin thickness score > or =20 at first visit and of softening of sclerodermatous skin in a cohort of systemic sclerosis (SSc) patients with diffuse cutaneous scleroderma. METHODS: Skin and visceral involvement were assessed in 134 SSc patients with diffuse scleroderma (mean +/- SD duration of SSc 10 +/- 4 months) as they entered a multicenter drug trial and again at 2 years of followup. Advent of mortality and scleroderma renal crisis (SRC) were assessed during a followup of 4.0 +/- 1.1 years (mean +/- SD). Logistic and linear regression were used to examine the relationship of baseline skin score to morbidity, mortality, and visceral involvement and the relationship of changes in skin score to changes in physical examination, laboratory, and functional variables over 2 years. RESULTS: A baseline skin score > or =20 was associated with heart involvement at baseline (odds ratio [OR] 3.10, 95% confidence interval [95% CI] 1.25-7.70) and was predictive of mortality (OR 3.59, 95% CI 1.23-10.55) and SRC (OR 10.00, 95% CI 2.21-45.91) over 4 years. Multivariate linear regression demonstrated that a model with skin score at baseline (P = 0.0078) and changes in large joint contractures (P = 0.0072), tender joint counts (P = 0.0119), handspread (P = 0.0242), and Health Assessment Questionnaire disability index (HAQ-DI) (P = 0.0244) explained the change in skin score over 2 years (R2 = 0.567). Multivariate logistic regression demonstrated that the investigator's global assessment of improvement was best explained by a model with skin score and HAQ-DI (R2 = 0.455). CONCLUSION: A baseline skin score > or =20 was associated with heart involvement at baseline and predicted mortality and SRC over the subsequent 4 years. Improvement in skin score in these patients with diffuse cutaneous scleroderma was associated with improvement in hand function, inflammatory indices, joint contractures, arthritis signs, overall functional ability, and the examining investigator's global assessment of improvement.

Adult↗
PubMed2000

The effects of pregnancy and smooth muscle contractility on cervical distensibility in the rat.

OBJECTIVE: We sought to compare distensibility of the isolated rat cervix from nonpregnant rats (n = 6), rats at midgestation (n = 5), and rats at term gestation (n = 4). STUDY DESIGN: The cervix was excised, and one cervical channel was cannulated from both ends and positioned in the organ chamber for perfusion-superfusion by a peristaltic pump at an intraluminal pressure of 30 mm Hg for 30 minutes. After the equilibration period, perfusion was stopped, the outlet was closed, and the cervix was inflated with a syringe pump. The volume was increased at a rate of 3.33 microL/s until intraluminal pressure reached approximately 120 mm Hg. The outlet was then opened, and the cervix was perfused at 30 mm Hg of intraluminal pressure for another 30 minutes. The volume-pressure relationships were obtained 3 times without any agent present and in the presence of 60-mmol/L potassium chloride or 10(-4)-mol/L 3-morpholinosydnonimine hydrochloride (also known as SIN-1). RESULTS: The volume-pressure relationship was shifted to the right during progression of pregnancy, demonstrating increased compliance of the cervix. The nonspecific depolarizing agent potassium chloride or the nitric oxide donor 3-morpholinosydnonimine did not affect volume-pressure relationships in cervices from nonpregnant rats, rats at midgestation, or rats at term gestation. CONCLUSION: The volume-pressure relationship in the isolated cannulated rat cervix reflects the resistance of the organ to increased intraluminal pressure. The compliance of the cervix is increased as pregnancy progresses, demonstrating decreased resistance to stretch. Activation or inhibition of cervical smooth muscle does not contribute to the physical properties of the cervix, which controls compliance-resistance.

Animals↗
PubMed2000

Management of the older person with diabetes in the community.

As the incidence of diabetes increases in the UK, community nurses will have increasingly larger caseloads of elderly patients with diabetes. It is important that nurses assess the patient's understanding of the disease and its treatment. The aim of good diabetic control is to reduce morbidity from the complications of the disease. Factors that affect the patients' quality of life; the patients' ability to manage their condition; and the importance of providing education and support for both the patients and their carers are discussed. The importance of diet, blood glucose monitoring and taking diabetic medication appropriately are explained.

Aged↗
PubMed1999

High-dose versus low-dose D-penicillamine in early diffuse systemic sclerosis: analysis of a two-year, double-blind, randomized, controlled clinical trial.

OBJECTIVE: To test the hypothesis that systemic sclerosis (SSc) patients taking high-dose D-penicillamine (D-Pen) would have greater softening of skin, lower frequency of renal crisis, and better survival than patients taking low-dose D-Pen. METHODS: Seventeen centers enrolled 134 SSc patients with early (< or =18 months) diffuse cutaneous scleroderma into a 2-year, double-blind, randomized comparison of high-dose D-Pen (750-1,000 mg/day) versus low-dose D-Pen (125 mg every other day). All 134 patients were followed up for a mean+/-SD of 4.0+/-1.1 years to assess the frequencies of new-onset scleroderma renal crisis (SRC) and mortality. RESULTS: Sixty-eight patients completed 24 months of drug treatment. The course of the modified Rodnan skin thickness score in the 32 high-dose and the 36 low-dose D-Pen completers was not different at 24 months: the skin score dropped 4.8+/-10.3 (mean+/-SD) units in the high-dose group and 6.9+/-8.4 units in the low-dose group (P = 0.384 by t-test; favoring low-dose D-Pen) from 20.4+/-10.3 in the high-dose and 19.9+/-6.6 in the low-dose D-Pen group at study entry. The incidences of SRC and mortality were not different (P > 0.38 by Cox proportional hazards and by chi-square test) in the 66 high-dose patients (8 developed SRC and 8 died) compared with the 68 low-dose patients (10 developed SRC and 12 died). Of the 20 adverse event-related withdrawals, 80% occurred in the high-dose D-Pen group. CONCLUSION: The course of the skin score and the frequencies of SRC and mortality in the high-dose D-Pen group were not different from those in the low-dose D-Pen group. Eighty percent of the adverse event-related withdrawals occurred in the high-dose D-Pen patients. Although this study cannot answer the question of whether low-dose D-Pen is effective, it does suggest that there is no advantage to using D-Pen in doses higher than 125 every other day.

Adult↗
PubMed1999

Correlates of the disability index of the health assessment questionnaire: a measure of functional impairment in systemic sclerosis.

OBJECTIVE: To evaluate functional impairment in systemic sclerosis (SSc) patients with diffuse cutaneous scleroderma at the time of entry into a trial of a therapeutic intervention (D-penicillamine). METHODS: The 20-item Disability Index of the Health Assessment Questionnaire (HAQ-DI) was administered to 134 patients as they entered a multicenter trial of high-dose versus low-dose D-penicillamine. All patients had diffuse SSc of < 18 months' duration. SSc patients who had severe organ system involvement and recent renal crisis and who were receiving prednisone > 10 mg/day were excluded from entry. Logistic regression modeling was used to examine the relationship of HAQ-DI scores to SSc skin and organ system involvement. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to estimate effects. RESULTS: The mean (+/-SD) HAQ-DI score at entry was 1.04 +/- 0.67. Fifty-three percent of patients had HAQ-DI scores > or = 1.0 (signifying moderate-to-severe functional impairment). Multivariate logistic regression demonstrated that impaired fist closure > or = 23 mm (OR 4.24, 95% CI 1.68-10.70), reduced handspread < or = 175 mm (OR 4.5, 95% CI 1.80-11.24), joint tenderness count > or = 1.0 (OR 2.93, 95% CI 1.16-7.40), age > or = 43 years (OR 2.44, 95% CI 1.01-5.95), platelet count > or = 330,000/mm3 (OR 2.30, 95% CI 0.96-5.57), and female sex (OR 2.43, 95% CI 0.77-7.73) were the most important correlates of HAQ-DI scores > or = 1.0. CONCLUSION: Increased HAQ-DI scores at baseline were correlated with reduced fist closure, reduced hand-spread, elevated platelet count, presence of tender joints, older age, and female sex. The most important contributor to functional impairment was hand dysfunction. Even within the first 18 months after SSc onset, moderate-severe functional impairment (HAQ-DI scores > or = 1.0) was frequent (53%) in this group of diffuse SSc patients. In early diffuse SSc, the self-administered HAQ-DI is therefore a valuable assessment of function that correlates with objective physical and laboratory measures of SSc disease involvement. Abnormal HAQ-DI scores may support patient claims of functional impairment, help to focus physician attention on implementing measures to reduce functional impairment, and be useful in reflecting the disease course over time.

Adolescent↗
PubMed1999

A randomized double-blind study comparing the fetal effects of sulindac to terbutaline during the management of preterm labor.

OBJECTIVE: The object of this study was to compare the fetal effects of sulindac and terbutaline used in the management of preterm labor on the ductus arteriosus, middle cerebral artery, renal artery, umbilical artery, fetal urine production, and amniotic fluid index. STUDY DESIGN: In a randomized, double-blind study 20 patients with preterm labor and no evidence of fetal structural anomalies or intra-amniotic infection received either sulindac (200 mg orally every 12 hours for 6 doses) or terbutaline (5 mg orally every 4 hours) for 72 hours of therapy. All medications were administered from identical blister packs. Opaque glucose base tablets were given at 4-hour intervals in the sulindac treatment arm to mimic the dosing interval in the terbutaline arm of the study. The Doppler pulsatility indices for the ductus arteriosus, middle cerebral artery, renal artery and umbilical artery and also the fetal urinary output were obtained at baseline and 5, 12, 24, 48, and 72 hours after the medication was started. Doppler data were analyzed within each group with raw data and between groups with the change in pulsatility indices from baseline. Statistical analysis was performed with the Kolmogorov-Smirnov test for normality, repeated measures analysis of variance, Mann-Whitney rank sum test, and Student t test as appropriate. P <.05 (2-tailed) was used to denote statistical significance. RESULTS: There were 10 patients in each group, with no difference in gestational age between the 2 groups (32.3 vs 31.7 weeks). Sulindac was stopped in 2 patients after severe ductal constriction was noted, in 1 at 12 hours and in the other at 24 hours. One patient at 33 weeks' gestation was delivered because of fetal distress after 46 hours of sulindac therapy. When analyzed across time within groups, the pulsatility index in the ductus arteriosus decreased significantly at 12 and 24 hours in the sulindac group but not the terbutaline group. No significant differences were noted in the middle cerebral artery, umbilical artery, renal artery, or fetal urinary output within either group over time. Significant differences in the change from baseline in pulsatility index of the ductus arteriosus between the sulindac and terbutaline groups were noted at 5, 12, 24, and 48 hours. A similar effect was noted in the change from baseline in pulsatility index of the middle cerebral artery at 48 and 72 hours. There was a significant decrease in the amniotic fluid index in both groups at 24, 48, and 72 hours. The amniotic fluid index in the sulindac group was significantly lower than that in the terbutaline group at 48 and 72 hours of therapy. CONCLUSIONS: Sulindac constricted the fetal ductus arteriosus, with an effect noted within 5 hours of starting therapy. The constriction, which resolved in all cases within 48 hours of discontinuing therapy, had minimal effects on the pulsatility index of the middle cerebral artery, renal artery, and umbilical artery. Sulindac and terbutaline both resulted in a significant reduction in the amniotic fluid index, with sulindac having a greater effect.

Amniotic Fluid↗
PubMed1999

Toughen up.

PROBLEM: Within six months, AHS needed to integrate three recently merged hospitals running on disparate hardware and software systems into one unified system. SOLUTION: AHS partnered with DataStudy Inc., Parsippany, N.J., and formed a team to address the specific enterprise resource planning needs of this healthcare organization. RESULTS: The implementation team completed the project within the six-month time frame and incorporated functionality that went beyond the initial specifications for the project. KEYS TO SUCCESS: "To maximize the return on the always substantial ERP investment, healthcare executives must be aware of the many pitfalls waiting to derail every well-intentioned implementation."

Consultants↗
PubMed1996

A study of prescribing patterns in the community.

Qualified nurse practitioners working in the community prescribe from a wide formulary. Despite degree level education, their prescriptions still have to be signed by a GP. This study describes the prescribing patterns of 41 nurse practitioners over one month. The medications prescribed were categorised and their frequency of prescription noted. The author notes the amount of time wasted by nurses waiting for a doctor's signature due to legal restrictions and states the case for autonomy in prescribing for nurse practitioners. The types of medication and situations where they are being prescribed are also discussed.

Community Health Nursing↗
PubMed1996

Endothelial isoform of nitric oxide synthase in rat heart increases during development.

BACKGROUND: Although nitric oxide seems important to cardiovascular function, the ontogenesis of this chemical messenger in the heart is unknown. To investigate this issue, we determined the distribution of nitric oxide synthase (NOS) in the rat heart at different stages during development. METHODS: Immunohistochemistry and the NADPH-diaphorase reaction were used to localize NOS activity-specifically, the endothelial isoform (eNOS) and neuronal isoform (bNOS)-in fetal (14- and 18-day gestation), neonatal (0-, 3-, and 6-day gestation), 12-day-old, 1-month-old, and mature adult Fischer 344 rat hearts. RESULTS: There was sparse eNOS immunoreactivity in the endocardium of the youngest fetal hearts; antibody to eNOS did not localize any vessels within the noncompact myocardium at this stage. By the eighteenth day of embryonic development (e18), eNOS was present not only in endocardium but also in the intima of numerous small vessels within the compact myocardium. In the neonatal rat heart, vascular eNOS predominated, with extensive reaction product in arteries, veins, and numerous capillary size vessels within the myocardium; the endocardium also contained eNOS immunoreactivity. A similar distribution was maintained throughout the remainder of development. Only rare bNOS-immunoreactive neurons were detected in hearts at the three oldest ages. CONCLUSIONS: (1) At e14, eNOS is confined to the endocardium of the developing rat heart; (2) as the myocardium becomes compact, vascular eNOS predominates over endocardial eNOS; (3) at birth, there is extensive eNOS in a distribution similar to the mature pattern; and (4) there is very little bNOS-immunoreactive neural tissue in the rat heart at any stage.

Aging↗
PubMed1995

Placental transfer of sulindac and its active sulfide metabolite in humans.

OBJECTIVE: Our aim was to investigate whether the human placenta is permeable to sulindac or its active sulfide metabolite. STUDY DESIGN: Nine pregnant patients (median gestational age [range]: 31.8 [24.3 to 36.4] weeks) were given a 200 mg oral dose of sulindac 5.5 (4.4 to 6.7) hours before 18 intravascular transfusions for rhesus or Kell alloimmunization. At each procedure maternal and fetal serum levels of sulindac and the active sulfide metabolite were measured by high-performance liquid chromatography. RESULTS: The maternal sulfide level was significantly higher than the fetal sulfide levels, but no significant difference was noted between maternal and fetal sulindac levels. The sulfide fetal/maternal ratio was significantly lower than the sulindac fetal/maternal ratio. The sulfide/sulindac ratio was significantly higher in maternal serum versus fetal serum. The sulfide/sulindac ratio correlated with time from drug ingestion to sampling on the maternal side only. In patients studied on more than one occasion no consistent relationship between fetal sulindac, fetal sulfide, or fetal sulfide/sulindac ratio, and gestational age could be demonstrated. CONCLUSION: The placenta is permeable to sulindac but less so to its active sulfide metabolite. The reduction of sulindac to its active sulfide metabolite is decreased in the human fetus.

Female↗
PubMed1995

An animal model for hemolytic disease of the fetus and newborn. II. Fetal effects in New Zealand rabbits.

OBJECTIVE: The addition of ultrasonography and ultrasonographically directed fetal blood sampling was attempted in an effort to study the fetal effects of red blood cell alloimmunization in a rabbit model. STUDY DESIGN: Nineteen New Zealand does were alloimmunized to incompatible red blood cells. Sensitized does were bred twice, once with a homozygous buck of incompatible blood type and once with a homozygous buck of compatible blood type. Ultrasonographic examinations were performed on days 20 and 27 of gestation (term 28 to 31 days). Fetal blood sampling was undertaken on day 27 of gestation, and hematologic data were compared between compatible and incompatible litters. RESULTS: A total of 41 pregnancies occurred in 19 does. Fetal hemoglobin was higher in the compatible litters (9.7 gm/dl vs 5.8 gm/dl, p < 0.001), whereas no difference could be detected between the respective reticulocyte counts (31.9 vs 36.0/100 red blood cells, p = 0.2). Hydrops fetalis was noted in none of 18 compatible litters versus 12 of 19 incompatible litters (p < 0.01). CONCLUSION: A disease analogous to human hemolytic disease of the newborn can be induced in the rabbit fetus.

Animals↗
PubMed1995

Anatomic distribution of nitric oxide synthase in the heart.

Nitric oxide synthase is a useful maker for nitric oxide's scope. Localized by either NADPH-diaphorase histochemistry or immunohistochemical methods, most nitric oxide synthase activity in the normal heart is present in endothelium along the extensive network of arteries, veins and capillaries within myocardium. This endothelial isoform of nitric oxide synthase also exists in the endocardium lining the cavities. Neuronal nitric oxide synthase appears much less prominent, although the exact amount of this isoform in the heart is uncertain. Scattered nerves and ganglion cells are localized by the histochemical methods. While there is no inducible nitric oxide synthase in the normal heart, macrophages associated with repair following various forms of cardiac damage contain this isoform. For all nitric oxide synthases, however, species variation and variability among models underscore the importance of correlative studies of structure and function.

Animals↗