Cell growth in a pinned soap froth

Experimental kinetic data on soap froth cell growth in a random array of fixed pinning centers is reported. The scaling of our two-dimensional data is analyzed and compared with pinning-free growth. The obtained data agree fairly well with a proposed cell growth law. We also discuss the relationship between the pin concentration and the final cell size.

Detection of growth factor receptor RNA in individual hematopoietic cells by in situ RT-PCR; comparison with RT-PCR

The ability to detect changes in RNA expression in single cells would greatly enhance understanding of the molecular basis of biological responses to positive and negative growth regulators. To this end, we compared expression of RNA encoding the receptors for interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, leukemia inhibitory factor (LIF) and stem cell factor (SCF) in populations of primitive hematopoietic progenitors (lineage marker negative, Lin(-), and Lin(-) c-Kit(+)) by RT-PCR and in situ RT-PCR. Both Lin(-) and Lin(-) c-Kit(+) progenitors expressed all receptors by RT-PCR. However, RT-PCR could not distinguish between the possibility that all cells expressed growth factor receptor RNA, or the possibility that only a proportion of cells expressed RNA. Therefore, we used in situ RT-PCR to examine growth factor receptor mRNA expression in individual cells. In contrast to RT-PCR, we observed that only 40-80% of Lin(-) cells and 75-100% of Lin(-) c-Kit(+) cells were positive for expression of the growth factor receptor subunits, demonstrating that not all cells were receptor positive. We found that in situ RT-PCR could also be used to measure induction or repression of receptor RNA expression in these cell populations. Specifically, the percentage of cells expressing IL-6alpha receptor RNA decreased from 88% positive in freshly harvested cells to 9% in Lin(-) c-Kit(+) cells cultured in IL-3 for 18 h. Thus, in situ RT-PCR can be used to detect and quantify the number of individual cells that express growth factor receptor mRNA, and may also be useful to measure changes in expression of other endogenous genes or genes introduced by transfection and gene therapy vectors.

Inflammation, not hyperhomocysteinemia, is related to oxidative stress and hemostatic and endothelial dysfunction in uremia

BACKGROUND

Several cardiovascular risk factors are present in patients with chronic renal failure (CRF), among which are systemic inflammation and hyperhomocysteinemia. Increased oxidative stress, endothelial activation/dysfunction, and coagulation activation are considered integral components of the inflammatory response, but have also been proposed as mediators of plasma homocysteine (tHcy)-induced cell damage. Using correlation analysis, we assessed the relative contributions of inflammation and hyperhomocysteinemia in the abnormal oxidative stress, endothelial activation/dysfunction, and hemostasis activation in patients with CRF.

METHODS

The relationships of inflammatory proteins and tHcy with plasma markers of these processes were studied in 64 patients with CRF (serum creatinine 526 +/- 319 micromol/L) on conservative treatment, comparing the results with healthy controls (N = 15 to 40, depending on the measured variable) of similar sex and age.

RESULTS

Patients had significant increases in inflammatory cytokines (TNF-alpha and IL-8) and acute-phase proteins (C-reactive protein, fibrinogen and alpha1-antitrypsin). tHcy was increased in 87.5% of patients (mean = 27.1 micromol/L, range 6.5 to 118). Patients had significant increases in (1) indices of oxidative stress: TBARS (thiobarbituric acid-reactive species), a marker of lipid peroxidation and AOPP (advanced oxidation protein products), a marker of protein oxidation; (2) endothelial cell markers such as von Willebrand factor (vWF:Ag), soluble ICAM-1 and soluble thrombomodulin (sTM); (3) markers of intravascular thrombin generation: thrombin-antithrombin complexes (TAT) and prothrombin fragment F(1+2) (PF(1+2)); and (4) indices of activation of fibrinolysis: plasmin-antiplasmin complexes (PAP), fibrin degradation products (FnDP) and fibrinogen degradation products (FgDP). tHcy was significantly correlated with plasma creatinine (r = 0.29, P < 0.018) and with serum folate (r = -0.38, P < 0.002). However, no significant correlations were observed between tHcy and TBARS, AOPP, vWF:Ag, sICAM-1, sTM, TAT, F(1+2), sTF, PAP, FnDP, and FgDP. Conversely, acute-phase proteins showed significant, positive correlations with most markers of oxidative stress, endothelial dysfunction and hemostatic activation.

CONCLUSIONS

Systemic inflammation, which is closely associated with augmented oxidative stress, endothelial cell dysfunction and hemostatic activation, emerges as a major cardiovascular risk factor in CRF. tHcy is unrelated to these events. Thus, alternative mechanisms through which hyperhomocysteinemia could predispose to vascular lesion and thrombotic events in CRF needs to be investigated.

[Tumors diagnosed in 65 patients with type I neurofibromatosis]

BACKGROUND

Type 1 neurofibromatosis patients develop malignant neoplasm more frequently than general population.

PATIENTS AND METHOD

We have studied 65 patients with neurofibromatosis type 1 because we intend to know the kind of neoplasms that they have presented.

RESULTS

65 patients (48 men and 17 women) fulfilling type 1 neurofibromatosis criteria have been studied. Globally 67 tumors appeared, from which 47 (70%) were benign and 20 (30%) were malignant. Benign tumors included 25 neurofibromas, 11 central nervous system tumors and 11 extraneurological tumors. Malignant tumors accounted for 6 soft tissue sarcomas, 6 carcinomas, 3 malignant CNS tumors and 2 acute lymphoblastic leukemias.

CONCLUSION

Presentation of neoplasms is frequent in type 1 neurofibromatosis and constitutes main death and morbility cause.

HIV type 1 non-B subtype prevalence in Spain, 1997-1998

We have evaluated the prevalence of HIV-1 non-B subtypes in Spain by means of an enzyme immunoassay (EIA) for discrimination between B and non-B subtypes. Samples were obtained from newly diagnosed patients attended at internal medicine outpatient clinics between October 1997 and October 1998. Discrimination between HIV-1 B and non-B subtypes was carried out by means of the EIA, with V3 synthetic peptides specific to the different subtypes. Non-B-serotyped samples were genetically analyzed in the gp41 region from the original sera. During the study period, 909 samples were collected from 21 medical units located in various Spanish geographical regions. Serotyping was possible in 885 cases, of which 791 were assigned as B serotype (89.38%), 70 showed no reactivity to any of the peptides (7.91%), and the remaining samples displayed other reaction patterns (2.72%). Of the 94 non-B-assigned samples, 65 were genetically characterized in the gp41 region of the env gene: 55 were B subtype, 5 were A subtype (4 clustered with CRF02AG reference strains), 3 were C subtype, and 2 were G subtype. The prevalence rate for non-B subtypes in Spain was established at 1.13% (95% CI, 0.59-2.21). Although the B subtype is predominant in the Spanish population, other subtypes have been detected.

[A new species of amphipod crustacean of the genus Amphilochus (Crustacea, Amphipoda, Amphilochidae) from Venezuela]

A new species of amphipod Crustacea (Gammaridea, Amphilochidae) of the genus Amphilochus Bate, 1862, is described. The species was collected in Phallusia nigra (Savigny, 1816) at depths between 0 and 2 m, in the pier piles of the Marina El Ancla and Los Manglares gas station in Morrocoy National Park (Falcón State, Venezuela), during the months of June and July 1998. The main differences between A. ascidicola new species and all others species of the genus recorded from the Gulf of Mexico and the Caribbean Sea, are given.

Histological evaluation of immune organs in chicken embryos inoculated with Marek's disease virus and lymphokines

The aim of the present study was to evaluate the presence of lymphocytes and granulocytes in different stages of embryonic development and on the first posthatching day. The lymphocytes present in the bursa of Fabricius and thymus were evaluated by histological analysis of the yolk sac, bursa of Fabricius, thymus, liver and bone marrow of 100 chicken embryos divided into groups and treated with: (I) Marek's disease vaccine as viral antigen, (II) Marek's disease vaccine plus lymphokines, (III) lymphokines, and (IV) vaccine diluent. Group V was not treated. Samples were taken on days 14, 17 and 20 of incubation and on the first posthatching day. An increase in the number of epithelial matrix as precursors of lymphoid follicles was observed in the bursa of Fabricius of embryos inoculated with lymphokines compared to embryos in all the other groups (p < 0.05). In addition, a higher amount of granulocytes was found in the yolk sac and liver of embryos inoculated with lymphokines than in the embryos of all other groups (p < 0.05). In the bone marrow, no significant difference was observed among the treated groups concerning the amount of granulocytes. The results suggest that administration of antigens or protein molecules at an early stage of embryonic development increases the presence of granulocytes in the liver and granulopoiesis in the yolk sac, and also increases the number of epithelial matrixs in the bursa of Fabricius.

Panic disorder in a Spanish sample of 89 patients with pure alcohol dependence

High rates of anxiety disorders, including panic disorder (PD), have been found in patients suffering from alcohol dependence (AD). It has been suggested that alcoholic subjects with PD represent a more severe subgroup of patients. Eighty-nine patients with 'pure' AD (without abuse of other drugs) were examined and compared for the presence of PD. Several clinical scales were administered to assess symptomatology and severity. Twenty-three patients (25.8%) met the criteria for PD. The mean age at onset for alcohol use was 18.7 versus 28.5 years for PD onset. Our finding of an earlier onset for alcoholism than for PD in a sample of Spanish patients illustrates the potential importance of transcultural factors. These patients were more likely to be women and to have first-degree relatives with PD. Overall, alcoholic patients with comorbid PD showed greater clinical severity. They were found to have more comorbidity with axis I disorders (major depression and dysthymia), greater clinical severity, and a history of more suicide attempts.

Molecular epidemiology of HIV type 1 subtypes in equatorial guinea

Equatorial Guinea is endemic for HIV-1. This country borders to the north with Cameroon, where different subtypes belonging to group M, as well as group O strains, are circulating simultaneously. To assess the molecular epidemiology of HIV-1 in Equatorial Guinea we analyzed 76 plasma samples collected throughout 1999 from seropositive individuals. Phylogenetic analysis of the gp41 region revealed that 53 were of subtype A, with 64% of these sequences clustering with CRF02_AG reference strains; 11 were of subtype C; 4 were of subtype D; 2 (closely related to subtype F2) were of subtype F; 3 were of subtype G, two of them forming a separate cluster with the recombinant circulating forms CRF06_cpx; 1 was of subtype H; and 2 were unclassifiable. Although subtype A is predominant, the presence of 14% of subtype C is also noteworthy. This work represents the first HIV-1 subtype distribution study in Equatorial Guinea.

Determinants of inducibility of ventricular tachycardia

We analyzed the incidence and predictive factors for induction of clinical ventricular tachycardia (VT) during an electrophysiologic study in 127 patients with structural heart disease and spontaneous VT documented by 12-lead electrocardiography. Eighty-five patients had coronary artery disease (CAD), 24 had idiopathic dilated cardiomyopathy (IDC), and 18 had right ventricular dysplasia (RVD). Clinical variables were age, gender, electrocardiographic patterns of spontaneous arrhythmia, cardiac diagnosis, left ventricular (LV) ejection fraction (EF), infarct location, and presence of LV aneurysm. Clinical VT was induced in 76 patients (60%, group 1) and was not induced in 51 patients (group 2). Clinical VT was induced in 83% of patients with RVD, 58% of patients with CAD, and 50% of patients with IDC (p = 0.07). LVEF tended to be significantly higher in group 1 than in group 2 (p = 0.06). The presence of left QRS axis in the frontal plane during spontaneous VT was significantly associated with a higher inducibility both in the general group (69% vs 46%, p <0.02) and in patients with CAD (70% vs 44%, p <0.02). In patients with CAD, only the presence of a left QRS axis was significantly associated with a higher inducibility. A multivariate analysis identified only the left QRS axis as a significant and independent predictor of induction of clinical VT. The association of a leftward axis with inducibility suggests that vectorial factors in the depolarization wavefronts may be related to inducibility since conventional stimulation is performed from the right ventricle, producing a leftward axis in most cases.

Usefulness of unipolar electrograms to detect isthmus block after radiofrequency ablation of typical atrial flutter

BACKGROUND

RS morphology of the unipolar electrogram is associated with propagation of the wave front through the exploring electrode, whereas positive uniphasic (R) unipolar electrograms are characteristic of the end of activation.

METHODS AND RESULTS

Unipolar electrograms were recorded in 45 consecutive patients with atrial flutter who were undergoing radiofrequency ablation (RFA). Bidirectional cavotricuspid isthmus (CTI) block was achieved in 44 patients. The unipolar electrogram obtained before RFA at the low anterolateral right atrium during coronary sinus pacing changed from RS, rS, or QS to R or Rs in all patients after clockwise CTI block was obtained. The morphology of unipolar electrograms recorded close to the coronary sinus during pacing from the low anterolateral right atrium changed from RS or rS to R or Rs in all but 4 patients after counterclockwise CTI block. In the patient in whom CTI block was not achieved, the RS morphology of the unipolar electrogram remained unchanged. In 18 patients, the results of the RFA were assessed with only the unipolar electrogram. The unipolar electrogram correctly predicted 100% and 89% of the cases of clockwise and counterclockwise CTI block, respectively.

CONCLUSIONS

The creation of CTI block is associated with an easily detectable loss of negative components and development of an R or Rs pattern of the unipolar electrogram recorded close to the ablation line while pacing at the opposite side of the CTI.

Molecular characterization of non-B HIV type 1 subtypes from Africa in Spain

All of the known HIV-1 subtypes are present in sub-Saharan Africa. The B subtype is predominant in the United States and Europe, but previous studies have revealed that other subtypes are also in circulation. We report here on the genetic characterization of eight non-B subtype VIH-1 virus strains detected during 1999 in patients living in Spain and having epidemiological relationships with African countries. Five isolates clustering with recombinant form CRF02-AG came from West and Central Africa. One isolate was characterized as being of the D subtype in the gp41 region, and clustered with subtype A outside the CRF02-AG recombinant form, in regions C2V3 and p17. Another isolate was a G subtype, and the remaining isolate was an O subtype. In Spain, the B subtype is the most frequently detected HIV-1 subtype, although in more recent years non-B subtypes have been introduced through immigrant HIV-1-infected individuals coming from African countries, or through infected persons having relationships with endemically affected areas.

[Diagnostic and clinical course features of lupus membranous glomerulonephritis]

BACKGROUND

Lupus membranous glomerulonephritis (LMG) is sometimes difficult to distinguish from idiopathic membranous glomerulonephritis (IMG) and little is known about its natural history.

METHODS

We have performed a retrospective study of 16 patients with LMG, types Va ("pure" LMG) (8 patients) and Vb (mesangial proliferation) (8 patients). Analytical and clinical characteristics were analyzed in each case at the onset of the disease and during follow-up.

RESULTS

At the time of diagnosis, 7 patients (43%) did not present any extrarenal manifestations of systemic lupus erythematosus (SLE). Nephrotic syndrome was the most common clinical presentation (81%). 14 patients (87%) showed positive antinuclear antibodies (ANA), but at low titres (< 1/300); anti-DNA antibodies were positive only in 3 cases (18%) and hypocomplementemia was observed in 2 (12%). The most relevant histological findings were the presence of Clq deposits (83%) and subendothelial and mesangial deposits. Treatment consisted of corticosteroids, adding immunosuppression when no response was obtained in 2-3 months. In recent years, an angiotensin-converting enzyme inhibitor (ACEI) was added before immunosuppression. At the end of the study, 6 patients (42%) developed chronic renal insufficiency and 8 (58%) renainea with normal renal function. Actuarial renal survival was 100% at 5 years and 75% at 10 years. The evolution towards a non-nephrotic range proteinuria throughout the follow-up was the only parameter significantly associated with a good prognosis.

CONCLUSIONS

LMG can present without extra-renal symptoms of SLE and even with very poor expression of its serological markers. Almost half of the patients (42%) developed chronic renal insufficiency. The evolution towards a non-nephrotic range proteinuria correlated with the maintenance of a normal renal function.

Moderate alcohol intake is associated with survival in the elderly: the Dubbo Study

OBJECTIVE

To examine the relationship between alcohol intake and survival in elderly people.

DESIGN AND SETTING

A prospective study over 116 months of non-institutionalised subjects living in Dubbo, a rural town (population, 34,000) in New South Wales.

PARTICIPANTS

1235 men and 1570 women aged 60 years and over who were first examined in 1988-89.

MAIN OUTCOME MEASURES

All-causes mortality; gross cost of alcohol per life-year gained.

RESULTS

Death occurred in 450 men and 392 women. Intake of alcohol was generally moderate (i.e., less than 14 drinks/week). Any intake of alcohol was associated with reduced mortality in men up to 75 years and in women over 64 years. In a proportional hazards model, the hazard ratio for mortality in men taking any alcohol was 0.63 (95% CI, 0.47-0.84) and in women was 0.75 (95% CI, 0.60-0.94). Cardiovascular deaths in men were reduced from 20/100 (95% CI, 14-26) to 11/100 (95% CI, 9-13) and in women from 16/100 (95% CI, 13-19) to 8/100 (95% CI, 6-10). The reduction in mortality occurred in men and women taking only 1-7 drinks/week--hazard ratios, 0.68 (95% CI, 0.49-0.94) and 0.78 (95% CI, 0.61-0.99), respectively, with a similar protective effect from intake of beer or other forms of alcohol. After almost 10 years' follow-up, men taking any alcohol lived on average 7.6 months longer, and women on average 2.7 months longer, compared with non-drinkers. The gross cost for alcohol per life-year gained if consuming 1-7 drinks/week was $5700 in men, and $19,000 in women.

CONCLUSIONS

Moderate alcohol intake in the elderly appears to be associated with significantly longer survival in men 60-74 years and in all elderly women.

Prevalence of dermographism in children

The prevalence of dermographism in our pediatric population was studied in 238 children of both sexes (128 boys and 110 girls) aged 2-14 years, randomly selected from a health care center. Skin reaction was evaluated after 5 min pressure (3,200 g/cm2) applied with a dermatographometer on a 5-cm length of dorsal skin. The reaction was considered positive when a wheal of more than 2 mm was observed. The prevalence of dermographism was found to be 24%, with a significant female predominance (33%) over males (16%). Forty-one percent of the children with dermographism reported exanthema in response to friction and pressure, which was compatible with symptomatic dermographism, compared with only 5% of those who yielded negative reactions. In order to assess the prevalence of dermographism in the atopic population, 100 patients in the 4-14 age range with respiratory disease (perennial allergic rhinitis and/or bronchial asthma) involving sensitization to aeroallergens (house dust mites and/or Alternaria) were studied. A positive response to the application of pressure (3,200 g/cm2) was observed in 47% of cases, this figure being significantly higher than in the general pediatric population.

Depersonalization in panic disorder: a clinical study

Panic disorder (PD) has been hypothesized to be a heterogeneous entity, with distinct clinical subgroups. The presence of depersonalization during panic attacks may distinguish a specific subgroup of PD. We sought to analyze the differential features of a subgroup of PD patients with depersonalization. A total of 274 patients with PD were assessed and divided into 2 groups according to the presence or absence of depersonalization. The Structured Clinical Interview for DSM-III-R (SCID-UP-R) was used to assess PD and comorbid disorders. The clinical scales administered included the Hamilton Anxiety and Depression Rating Scale (HARS and HDRS), the Marks and Mathews Fears and Phobia Scale, Panic-Associated Symptom Scale (PASS), and a panic attack symptoms inventory. A total of 66 patients (24.1%) exhibited depersonalization during the attacks. Patients with depersonalization appeared to be younger and had an earlier age at onset. PD was more severe in the depersonalization group (greater number of attacks, worse level of functioning, and higher scores on most self-rating scales). Also, depersonalization patients showed more comorbidity with specific phobia. Our results support the view that PD with depersonalization may be considered a distinct and more severe subcategory of PD.