Cyclic guanosine 3'3' monophosphate concentrations in pre-eclampsia: effects of hydralazine

Objective To elucidate the role of the L-arginine: nitric oxide pathway in pregnancy and pre-eclampsia.
Participants Pregnant women (nulliparous, age < 25 years). Normotensive pregnancy (   n = 22  ) was defined when blood pressure remained at levels of < 120/80 mmHg and there was no proteinuria. Women with pre-eclampsia (   n = 22  ) had blood pressure measurements of > 140/90 mmHg and proteinuria of > 300 mg/l. Nonpregnant normotensive women (   n = 22  ) were studied as controls.
Study Design Blood samples were taken for measurements of ionised calcium, atrial natriuretic factor, cyclic guanosine 3'5'monophophate (GMP), arginine and asymmetric dimethylarginine. Urine samples were collected for determination of cyclic GMP excretion. Cyclic GMP concentrations were also determined in 12 women with severe pre-eclampsia before and after treatment with hydralazine.
Results L-arginine, asymmetric dimethylarginine and atrial natriuretic factor were not different in any group. Cyclic GMP concentrations in plasma [0.94 (SD 0.23) nM] as well as in urine [50.1 (SD15.7)μM] were increased significantly (   P < 0.05  ) in normal pregnancy compared to nonpregnant controls [plasma mean 0.46 (SD 0.12) nM and urine mean 18.4 (SD 10.3) μM], but not in the pre-eclampsia group [plasma mean 0.48 (SD 0.10) nM and urine mean 24.1 (SD 14.5) μM]. Concentrations of cyclic GMP in plasma and urine increased significantly (   P < 0.05  ) in women treated with hydralazine.
Conclusions The differences in cyclic GMP concentrations may reflect differences in nitric oxide production. Hydralazine increases cyclic GMP concentrations in severely pre-eclamptic women. This action could explain the antihypertensive effect of hydralazine.     

Heterotopic ossification in the anterior maxilla: a case report and review of the literature

A 13-year-old boy had complained of an asymptomatic swelling in the anterior maxilla for approximately 4 years. The patient reported no local trauma. The intra-oral examination revealed an exophytic lesion in the incisive papilla between the maxillary central and lateral incisor teeth. The radiographies detected no significant findings. Histopathologically, the lesion showed a dense fibrous tissue above the overlying mucosa. Bone ossification lay beneath a partially hypertrophic cartilage showing occasionally pleomorphic chondrocytes. Because of its microscopic aspects, heterotopic ossification may be mistaken for chondrosarcoma or other conditions involving periosteum, such as parosteal osteosarcoma. A case of heterotopic ossification in the anterior maxilla is presented, and clinicopathologic similarities with other osteochondromatous lesions are discussed.     

Use of the microorganism Bacillus stearothermophilus as a model to evaluate toxicity of the lipophilic environmental pollutant endosulfan

Microorganisms are very powerful tools for the supply of information about the toxic effects of lipophilic compounds, since an impairment of cell growth usually occurs as a result of perturbations related, in most cases, with the partition of toxicants in membranes. The thermophilic eubacterium Bacillus stearothermophilus has been used as a model system to identify α- and β-endosulfan interactions with the membrane possibly related with the insecticide toxicity. Two approaches have been pursued: (a) bacterial growth is followed and the effects of endosulfan isomers determined; (b) biophysical studies with the fluorescent fluidity probe 1,6-diphenyl-1,3,5-hexatriene (DPH) were performed to assess the effects of α- and β-endosulfan on the organization of the membrane lipid bilayer. The effects on growth were quantitatively evaluated by determination of growth parameters, namely the lag phase, the specific growth rate and the cell density reached by cultures in the stationary phase. Growth inhibition by α and β-endosulfan dependent on the concentration is diminished or removed by the addition of 2.5 m Ca²⁺ to bacterial cultures. Fluorescence DPH polarization consistently showed opposite effects of Ca²⁺ and α- and β-endosulfan on the physical state of bacterial polar lipid dispersions.     

Tamoxifen induces ultrastructural alterations in membranes of Bacillus Stearothermophilus

Tamoxifen (TAM), a non-steroid antiestrogen, is the mostly used drug for chemotherapy and chemoprevention of breast cancer. However, the mechanisms by which TAM inhibits cell proliferation in breast cancer are not fully understood. TAM strongly incorporates in biomembranes and a variety of effects have been assigned to biophysical and biochemical interactions with membranes. Therefore, a better understanding of the physicochemical basis of interaction of TAM with biomembranes is essential to elucidate the molecular mechanisms of action. A strain of Bacillus stearothermophilus has been used as a model to clarify the interaction of TAM with the cell membrane. TAM effects on the ultrastructure of membranes of this bacterium were evaluated by electron microscopy. Important ultrastructural alterations were observed in B. stearothermophilus treated with TAM, namely change in the geometry of the membrane profile from asymmetric to symmetric, disaggregation of ribosomes, coagulation of the cytoplasmic matrix, occurrence of mesossomes, appearance of fractures in membranes and the alteration of the ultrastructure of cell wall. These ultrastructural alterations confirm that TAM is a membrane-active drug and that membrane damage may be involved in molecular mechanisms of cell death induced by this drug.     

Tamoxifen induces ultrastructural alterations in membranes of Bacillus Stearothermophilus.

Tamoxifen (TAM), a non-steroid antiestrogen, is the mostly used drug for chemotherapy and chemoprevention of breast cancer. However, the mechanisms by which TAM inhibits cell proliferation in breast cancer are not fully understood. TAM strongly incorporates in biomembranes and a variety of effects have been assigned to biophysical and biochemical interactions with membranes. Therefore, a better understanding of the physicochemical basis of interaction of TAM with biomembranes is essential to elucidate the molecular mechanisms of action. A strain of Bacillus stearothermophilus has been used as a model to clarify the interaction of TAM with the cell membrane. TAM effects on the ultrastructure of membranes of this bacterium were evaluated by electron microscopy. Important ultrastructural alterations were observed in B. stearothermophilus treated with TAM, namely change in the geometry of the membrane profile from asymmetric to symmetric, disaggregation of ribosomes, coagulation of the cytoplasmic matrix, occurrence of mesossomes, appearance of fractures in membranes and the alteration of the ultrastructure of cell wall. These ultrastructural alterations confirm that TAM is a membrane-active drug and that membrane damage may be involved in molecular mechanisms of cell death induced by this drug.     

Attachment loss and serum antibody levels against autologous and reference strains of Actinobacillus actinomycetemcomitans in untreated localized juvenile periodontitis patients

Abstract Immunological data have been suggested to be a potential tool in the diagnosis, classification and monitoring of periodontal diseases. However, the role of circulating antibodies in periodontal patients is poorly understood. Patients suffering from localized juvenile periodontitis (LJP) are often reported to show high titers of serum IgG antibodies against Aetinobaeillus actinomycetemcomitans (A. actinomycetemcotnitans), but several affected patients do not. Most studies use well-known reference strains of the bacterium for testing against the patients' sera. The aim of the present investigation was to study the relationship between serum IgG antibody levels to autologous A. actinomycetemcomitans strains and clinical attachment loss (CAL). In addition, we wanted to assess the patients’serum titers against 4 well-known reference strains of the bacterium as well as their general potential immunoglobulin response. Intravenous blood samples were taken from 23 LJP patients and 10 healthy individuals, and autologous A. actinomycetemcomitans strains were cultured from 18 of the L.JP patients. CAL was measured at 4 different sites around ail present teeth and assessed as a % of teeth with at least 1 site moderately ≥2<5 mm) or severely (≥5 mm) involved. An enzyme-linked immunosorbent assay (ELISA) was performed to evaluate the serum titers of IgG antibodies to A. actinomycetemcomitans antigens. No significant correlation was found between serum IgG antibody titers to autologous strains and CAL. However, there was a trend that low responders had more moderately affected teeth than had high responders and patients with undetectable A. actinomycetemcomitans levels, which is in agreement with a hypothetically protective role of the antibodies. The total counts of immunoglobulin assessed in all participants showed that the predominant class was IgG and the reference group displayed significantly less (p<0.05) IgG and IgG1 counts than the LJP patients. Both the reaction pattern against reference and autologous strains varied widely. We conclude that the specific antibody response against A. actinomycetemcomitans shows a weak correlation to clinical attachment levels in LJP patients.     

Role of DAT‐SPECT in the diagnostic work up of Parkinsonism

The diagnosis of idiopathic Parkinson's disease (PD) can be achieved with high degrees of accuracy in cases with full expression of classical clinical features. However, diagnostic uncertainty remains in early disease with subtle or ambiguous signs. Functional imaging has been suggested to increase the diagnostic yield in parkinsonian syndromes with uncertain clinical classification. Loss of striatal dopamine nerve terminal function, a hallmark of neurodegenerative Parkinsonism, is strongly related to decreases of dopamine transporter (DAT) density, which can be measured by single photon emission computed tomography (SPECT). The use of DAT‐SPECT facilitates the differential diagnosis in patients with isolated tremor symptoms not fulfilling PD or essential tremor criteria, drug‐induced, psychogenic and vascular Parkinsonism as well as dementia when associated with Parkinsonism. This review addresses the value of DAT‐SPECT in early differential diagnosis, and its potential as a screening tool for subjects at risk of developing PD as well as issues around the assessment of disease progression. © 2007 Movement Disorder Society     

Lower Lip Hypertrophy Secondary to Port-Wine Stain: Combined Surgical and Carbon Dioxide Laser Treatment

Background. Port-wine stains (PWSs) are capillary malformations that usually show progressive stasis of the vascular channels and cause slow hyperplasia of the soft and hard tissues. When these lesions involve the lower lip, macrocheilia may be developed along the time. Vascular-specific lasers are not adequate to correct these three-dimensional tissue deformities, and surgical management becomes necessary, resulting in considerable morbidity and aesthetic disturbances.
Objective. To report a case of macrocheilia secondary to PWS treated by combination of surgery and carbon dioxide laser.
Methods. A 51-year-old man with macrocheilia of the lower lip and severe functional impairment, secondary to long evolution PWS, received treatment with carbon dioxide laser vaporization and minimal surgical correction, resulting in significant improvement of the lower lip hypertrophy, good aesthetic and functional status, and preservation of the muscular function.
Conclusions. Combined carbon dioxide laser and surgery treatment may constitute a valuable alternative in treatment of macrocheilia secondary to PWS because bleeding risk is minimized and improves the preservation of muscular function and aesthetic results in relationship to conventional surgical approaches.