TGF-beta- and angiotensin-II-induced mesangial matrix protein secretion is mediated by protein kinase C

BACKGROUND

Glomerulonephritis is characterized by the accumulation of extracellular matrix protein within the glomerulus. This process, when allowed to proceed unimpeded, leads to glomerulosclerosis and eventually to cessation of glomerular filtration. There is evidence that protein kinase C (PKC) activation plays an important role in mediating at least some of the effects of TGF-beta in vascular smooth-muscle cells. The current study was undertaken to determine whether PKC activity is required for both TGF-beta and angiotensin II (Ang II) to induce mesangial cell matrix protein secretion.

METHODS

PKC was inhibited by two separate methods, and [3H]thymidine incorporation was assessed in both the presence and the absence of PKC inhibition. Conditioned medium from cells stimulated with TGF-beta or Ang II was collected and analysed for secreted matrix proteins and sulphated proteins by SDS-polyacrylamide gel electrophoresis and western blotting.

RESULTS

Twenty-four-hour incubation of rat mesangial cells with phorbol-12-myristate-13-acetate (PMA) reduced total PKC activity to basal levels. Both TGF-beta and Ang II were mitogenic in mesangial cells, and chronic PMA pre-incubation inhibited this DNA synthesis. TGF-beta-and Ang-II-induced sulphated protein secretion into conditioned medium was markedly attenuated in PKC-downregulated cells. Secretion of the specific matrix proteins laminin and fibronectin by mesangial cells stimulated with either TGF-beta or Ang II was also diminished in PKC-downregulated cells and in cells pre-incubated with the specific PKC inhibitor, chelerythrine. There was no evidence of generalized cell toxicity or decreased non-specific protein synthesis caused by these PKC inhibitors.

CONCLUSIONS

PKC is a key intermediary in the process by which TGF-beta and Ang II cause DNA synthesis and mesangial cell matrix protein production. Thus, PKC inhibitors deserve further study as potential therapeutic agents for a variety of glomerular diseases.

Nursing case management in the NICU: enhanced coordination for discharge planning

A primary goal of health care today is finding alternative ways to provide high-quality, cost-effective care. A model of care that addresses these issues is nursing case management. This article describes the development and implementation of nursing case management in a Level III regional center with the primary goal of enhancing coordination for discharge planning. The model involves development of clinical pathways and utilization of nurse practitioners as case managers. Decreased length of stay, charge per case, and readmission rates are demonstrated following implementation of this program.

MEK inhibition augments Raf activity, but has variable effects on mitogenesis, in vascular smooth muscle cells

Proteins comprising the mitogen-activated protein (MAP) kinase signaling cascade are activated by a variety of growth factors, but the precise role of this series of kinase reactions, especially Raf kinase and MAP kinase kinase (MEK), in vascular smooth muscle (VSM) cell mitogenesis is not known. In this study, a specific and selective inhibitor of MEK, PD-98059, was used to examine the role of MEK in DNA synthesis and Raf-1 activity in VSM cells stimulated with serum as well as with growth factors encompassing both tyrosine kinase and G protein-coupled receptor classes. Although significant increases in DNA synthesis are seen after stimulation of VSM cells with either 10% serum,platelet-derived growth factor (PDGF)-BB, or alpha-thrombin, preincubation of the cells with 50 microM PD-98059 for 1 h inhibits stimulation by PDGF and thrombin, but not by serum. There is a dose-dependent inhibition of the mitogenic effect by PD-98059 in all cases; these results are not affected when PD-98059 is added at times ranging from 4 h before to 2 h after growth factor addition (times at which PD-98059 exerts its inhibitory effect). In the presence of PD-98059, stimulated MAP kinase activity is attenuated when growth factors are added between 10 min and 4 h, times which correspond to both early and sustained phases of MAP kinase activity. In addition, Raf-1 activity is markedly increased by incubation of the cells with PD-98059,despite attenuation of hyperphosphorylation of this kinase. Thus growth factors coupled to both tyrosine kinase and G protein receptors require components of the MAP kinase cascade (MEK and/or MAP kinase) for VSM cell mitogenesis, whereas serum is capable of stimulatory effects in the absence of active MEK and MAP kinase. Furthermore, there exists a functional feedback stimulatory effect of inhibited MEK on its upstream activator Raf-1 in the case of serum as well as growth factors coupled to tyrosine kinase and G protein receptors.

Effects of pimozide on the psychopathology of delusional disorder

1. The effects of pimozide on the psychopathology of delusional disorder were studied. 2. After six weeks, pimozide (2-12 mg/day) administration had no effect on the Brief Psychiatric Rating Scale, or in the psychological, social and occupational functioning, as measured by the Global Assessment of Functioning Scale. 3. When the different dimensions of the delusional experience were looked upon, no modifications were observed in any of them after six weeks of pimozide treatment. 4. These data failed to support the therapeutic role of pimozide in the treatment of delusional disorder and may suggest, when compared to other disorders with prominent delusions such as schizophrenia, a different neurobiology for the illness.

The effect of ultrasound on collagen synthesis and fibroblast proliferation in vitro

Ultrasound has been applied therapeutically to accelerate connective tissue healing although there is little direct scientific evidence to support its use. This investigation was conducted to determine the effects of ultrasound on the rate of collagen synthesis and cell proliferation using cultured fibroblasts derived from Achilles tendons of neonatal rats. Ultrasound (intensity = 0.4 W.cm-2; frequency = 1 MHz) was applied to experimental cells growing as monolayers in culture flasks. Ultrasound had no effect on the rate of collagen synthesis by control fibroblasts over a period of 9 d. The addition of vitamin C to culture media stimulated collagen synthesis to the same extent in both control and ultrasound-treated cultures. Partial digestion of cell matrices with collagenase (used to simulate injury) resulted in an approximately 20% increase in the rate of collagen synthesis. Synthesis was further increased with ultrasound treatment (50-67%). For example, after a single ultrasound treatment, the rate of collagen synthesis was 3.0 +/- 0.4 pg.micrograms-1 DNA.h-1 in cultures treated with collagenase, compared with 1.8 +/- 0.3 pg.micrograms-1 DNA.h-1 in collagenase-treated cultures not treated with ultrasound and 1.4 +/- 0.3 pg.micrograms-1 DNA.h-1 in controls. Ultrasound applied to preconfluent cultures resulted in significant increases in the rate of thymidine incorporation and DNA content. Three daily ultrasound treatments caused a 100% increase in the rate of thymidine incorporation and a 28% increase in DNA content. The results indicate that ultrasound stimulates collagen synthesis in tendon fibroblasts in response to an injury of the connective tissue matrix and that ultrasound stimulates cell division during periods of rapid cell proliferation.

Comparison of manual and automatic CPAP titration in patients with sleep apnea/hypopnea syndrome

Automatic CPAP (auto-CPAP) is engineered to automatically provide a positive pressure to the upper airway in response to apnea, hypopnea, airflow limitation, or snoring in patients with the sleep apnea/ hypopnea syndrome (SAHS). Self-adjusted CPAP has theoretical advantages over traditional fixed CPAP. We investigated the value of auto-CPAP regulation in 20 patients with SAHS in order to predict future fixed-level CPAP needs, as an alternative method to conventional polysomnographically (PSG)-controlled CPAP titration. This was accomplished through comparison of the optimal CPAP level obtained with PSG with that obtained with auto-CPAP. There were no significant differences between the optimal CPAP level achieved with full PSG or with auto-CPAP. As a secondary analysis, we analyzed auto-CPAP performance with regard to sleep-stage distribution and arousals in a group of nine male patients, and compared it with the previous group of 20 patients in which manually CPAP titration was guided by PSG. After adequate CPAP was reached, upward and downward fluctuations in the CPAP level had no significant effect on sleep architecture or fragmentation. We conclude that auto-CPAP permits the prediction of future fixed-level CPAP needs, and does so without sleep disruption.

Increased use of mammography among Hispanic women: baseline results from the NCI Cooperative Group on Cancer Prevention in Hispanic Communities

BACKGROUND

The Healthy People 2000 report set the objective of increasing the percentage of women 40 or older who had ever received a mammogram and clinical breast examination to 80% by the year 2000. The report used a baseline of 36% for all American women and 20% for Hispanic women. The purpose of this study was to compare baseline estimates with data obtained in five Hispanic communities.

METHODS

Common survey measures were administered in five studies participating in a National Cancer Institute Cooperative agreement. The surveys evaluated history of mammography in five Hispanic communities in the southwestern Unites States.

RESULTS

Across the five communities, the rates of mammography use were significantly higher than the national baseline. Among women 40-49 years of age, 55% had completed mammography (95% confidence interval [CI] = 52%, 57%). Among women 50 years of age or older, 64% had received a mammogram (95% CI = 62%, 66%). Older women (above age 50) were significantly more likely to have completed the test than younger women (younger than age 50), and mammography was obtained less often among women who were uninsured and those who had lower levels of acculturation.

CONCLUSIONS

We conclude that the rate of mammography use among Hispanic women has increased significantly over the last few years and that we are on track to reach the goal of 80% mammography compliance for Hispanic women 40 years and older by the year 2000.

Demonstration of hypoperfusion surrounding intracerebral hematoma in humans

We undertook this study to determine whether ischemic regions are present that may contribute to poor outcome after intracerebral hemorrhage (ICH) in humans. Hypoperfusion around an ICH has not been reported in humans. Brain computed tomography (CT) and (99m)Tc-HMPAO brain single photon emission computed tomography (SPECT) perfusion studies were carried out 51 +/- 12 hours after supratentorial ICH in seven patients selected from a referral hospital over an 8-month period. The widest diameters of the hematoma on CT and of reduced perfusion on SPECT were measured and compared. The diameters of reduced perfusion were measured at the 40% and 20% reduced count levels compared with the contralateral side. Reduced perfusion in and around the hematoma was seen in all seven cases. The diameters of ICH on CT (mean, 53 +/- 12 mm) were comparable to the diameters of 40% reduction of counts (mean, 61 +/- 14 mm) measured by SPECT. The mean diameter of brain demonstrating 20% reduction in counts was 76+/-19 mm, which was 43% greater than the hematoma diameter on CT (p = .004). In conclusion, substantial regions of reduced perfusion surround ICH in humans, which might contribute to poor outcome and be amenable to anti-ischemic therapy.

Clinical and epidemiological evaluation of a live, cold-adapted influenza vaccine for 3-14-year-olds

Reported is a study of live, cold-adapted (CA) reassortant mono-, di-, and trivalent influenza type A and B vaccines in a series of controlled clinical and epidemiological investigations involving nearly 130 000 children aged 3-15 years. The results of clinical, immunological, and morbidity investigations of the vaccinees and a control group over 6-months' follow-up indicated that the vaccines were completely attenuated by the children. Transient febrile reactions occurred in < 1% of the children after vaccination, including double seronegative individuals with low antibody titres. The type A reisolates examined were genetically stable. The reassortants did not suppress each other after simultaneous inoculation of children and stimulated antibody response to influenza virus strains A1, A3, and B. The incidence of influenza-like diseases was approximately 30-40% lower among the vaccinated group than among the control group. The study demonstrates, for the first time, the efficacy of CA vaccine against infections caused by influenza B virus.

Detection of salivary and seric IgG and IgA antipooled pigeon sera activities in patients with pigeon breeder's disease

Pigeon breeder's disease (PBD) is an interstitial lung disease induced by exposure to pigeon antigens. Search of antipigeon antigen antibodies (APSA) in serum or bronchoalveolar lavage is generally used for auxiliary diagnostic purposes. However, APSA can be present in a number of exposed but asymptomatic individuals as well as in patients with other interstitial lung diseases who live in areas where keeping pigeons is a common domestic habit. In this study, saliva was evaluated as an alternative means to serum for APSA detection by ELISA using pooled pigeon sera as antigen. Serum and saliva samples obtained from 17 patients with PBD, 14 with idiopathic pulmonary fibrosis (IPF), 19 asymptomatic relatives (AR) exposed to pigeon antigens, and 27 clinical healthy voluntary subjects (CHVS) were tested for IgG and IgA APSA. Our results showed that both fluids obtained from PBD patients exhibited a significantly higher specific IgG antibody activity compared to the other groups. Serum optical density (O.D.) values for PBD were 1.187 +/- 0.738 vs. 0.024 +/- 0.033, 0.255 +/- 0.471, and 0.204 +/- 0.346 for CHVS, AR and IPF, respectively (P < 0.05). Salivary O.D. for PBD were 0.801 +/- 0.447 vs 0.010 +/- 0.011, 0.104 +/- 0.151, and 0.22 +/- 0.447 (P < 0.05). In contrast, serum specific IgA did not discriminate between PBD and IPF patients. In addition, although the PBD group exhibited the highest values of IgA salivary APSA, high levels were also observed in saliva specimens from CHVS, a group of normal individuals who deny pigeon exposure. These findings suggest that measurement of IgG salivary APSA can play a role in the evaluation process of patients with pigeon breeder's disease.

Prevalence of antibodies against Entamoeba histolytica in Mexico measured by ELISA

The prevalence of antibodies against Entamoeba histolytica was studied in the Mexican population using an immunoenzyme assay in solid phase (ELISA) and semiautomatic equipment. The antigen was a mixture of membrane proteins obtained by Triton X-100 extraction from an axenic culture of Entamoeba histolytica HM1-IMSS. The method was standardized by comparing serum samples from amoebic liver abscess patients with healthy volunteers. From the 60,538 samples supplied by the National Seroepidemiology Survey, antibodies were found in 4.49% (4.32-4.65% at 95% confidence limit). More significant titres occurred in the central region of the country. The ratio female to male was 1.25:1. The population living in metropolitan areas had probably been infected at a younger age than those living in the country. Important differences were found in the seroprevalence obtained by ELISA compared with a study which used indirect haemagglutination (IHA) in the same sample frame.

Elective intubation for neurologic deterioration after stroke

OBJECTIVE

To provide data to guide physicians and family when deciding whether a patient should be electively intubated after ischemic stroke.

DESIGN

Chart review and patient interview. Clinical course, neurologic outcome, and financial and psychosocial effect of the decision to intubate were determined.

SETTING

Neurology/Neurosurgery critical care unit.

PATIENTS

Of our last 250 acute carotid territory ischemic stroke cases, we found 20 patients (8%) who were electively intubated, after CT and neurologic assessment, for neurologic deterioration.

INTERVENTIONS

All patients received standard medical therapy.

RESULTS

Intubation occurred 3 hours to 7 days (mean, 41 hours) after the onset of symptoms; six of 20 patients required intubation within the first 6 hours. Once clinical deterioration began, 10 of 20 patients required intubation within 1 hour. Six of 20 patients were discharged alive; two subsequently died, one is mostly dependent, two became mostly independent (one of these had a hemicraniectomy and is still improving, and the other died of an intercurrent illness 4 years after her stroke), and one is totally independent. The four "good" outcome survivors were distinguished by higher Glasgow Coma Scale scores (9.2 versus 5.9), and extubation was usually possible within 72 hours. For nonsurvivors, mean hospitalization after intubation was 6.4 days. In survivors, the monthly uninsured cost was $0 to $2,000, and caregivers experienced moderate stress. The same decision would be repeated by 76% of caregivers; 53% of caregivers would want intubation for themselves.

CONCLUSIONS

Satisfactory outcome is possible in the 8% of ischemic stroke patients requiring elective intubation. Possible predictors of good outcome include less severe depression of consciousness at the time of intubation, extubation within 3 days, and hemicraniectomy. In retrospect, most families would repeat the decision to intubate. Further study in more patients of the cost/benefit of cerebral resuscitation after stroke is greatly needed.

Observations on the birth of goats

The parturient behavior of 90 Murciano-Granadina goats was analyzed. Hourly frequencies of births showed a unimodal distribution with a maximum number of births between 10:00 and 18:00 h (74.45%). Twenty-four births (26.66%) took place with the goat standing, and sixty-six births (73.33%) took place with the goat recumbent. Fetuses were presented head-first (80.95%), breech (14.97%) and forelegs first (4.08%). Length of labor was 19.49 min for single birth and 30.36 min for twins (first born and second born, 14.52 and 15.84 min, respectively). Time for complete expulsion of placental tissue for goats with single and twin births was 86.58 ± 4.93 and 106.57 ± 4.80 min, respectively. Finally, placentophagy for goats with single or twin births was: total ingestion (0%; 0%), partial ingestion (33.33%; 52%), licking (46.67%; 36%), and no contact (20%; 12%), respectively. Key words: Goat, parturition, placentophagy

[The immunogenic properties and prophylactic efficacy of a live polyvalent influenza vaccine in children 5 to 14 years old]

Production lots of a live influenza vaccine made of strains A/47/T (N1H1), A/47/6/2 (H3N2), and B/60/32 were used for vaccination of 3663 children aged from 5 to 14 years inoculated twice with monovaccines, a trivaccine made of the above strains, or placebo. Both mono- and polyvaccine were practically areactogenic. An average per cent of subjects with a significant rise in antibody titres to the respective three antigens was 60%. The efficacy of the vaccination was 31.0-42.8% for monopreparations and 36.3% for the trivaccine. The studies showed the possibility and expedience of using for children the live influenza vaccine in the form of a polyvalent preparation including current influenza type A and B viruses.

Pressure diuresis and natriuresis in cirrhotic rats

Arterial hypotension in liver cirrhosis has been proposed as a major mechanism contributing to renal sodium and water retention. To evaluate kidney excretory responses at different levels of arterial pressure (AP), we have characterized the relationships between renal perfusion pressure (RPP) and sodium and water excretion in carbon tetrachloride cirrhotic rats. Experiments were performed in anesthetized control (n = 9) and cirrhotic rats with (Asc, n = 6) and without ascites (Cir, n = 6) by mechanically adjusting vascular resistance in animals with renal denervation and infused with main systemic hormones. Control and Cir animals showed similar glomerular filtration rates (GFR), renal blood flows, hematocrits (Hct), and plasma proteins (PP). However, Hct, PP, and GFR were significantly lower in the Asc rats. For the same level of RPP, both cirrhotic groups excreted significantly less water and sodium than controls. Then, the pressure diuresis and natriuresis relationships of the Cir animals were significantly depressed, but those of the Asc animals were more reduced than those of the Cir rats. These results indicate that the cirrhotic kidney is not able to normally increase the sodium and water excretion in response to changes in AP. Intrarenal mechanisms, and not mainly RPP, are likely mediators of the renal alterations of liver cirrhosis.

Specific expression in adult mice and post-implantation embryos of a transgene carrying the histone H1(0) regulatory region

Histone H1(0), a variant of the H1 group, has been found associated with the repressed state of chromatin and its content is increased in terminally differentiated cells. We have cloned a mouse H1(0) histone gene and introduced the promoter region, ligated to the beta-galactosidase reporter gene, into transgenic mice. By histochemistry we demonstrated a strong expression of the transgene in adult kidney, testis and brain. Intestine, uterus and ovarium were also positive. This expression followed the same pattern as that of the endogenous H1(0) gene, as demonstrated by in situ hybridization with a non-coding fragment of the mRNA, by Northern analysis, and by immunofluorescence with specific antibodies. In post-implantation embryos, the expression was very low up to day ten p.c. At this time, most of the X-Gal staining was found in the brain, retina and some of the large blood vessels. Hence, expression of the transgene as well as of the endogenous H1(0) gene is not exclusively linked to a differentiated phenotype or to a reduced cell proliferation capacity.

[Mechanical reperfusion in acute myocardial infarction after failure of thrombolysis with intravenous streptokinase]

AIM

to report the clinical evolution of four patients with acute myocardial infarction that were subjected to immediate coronary angioplasty due to the failure of reperfusion with streptokinase.

BACKGROUND

the limitations for the use of thrombolytic agents, an accepted treatment of acute myocardial infarction, or their uncertain results in selected groups of patients has prompted the search for mechanical revascularization infarction subjected to thrombolytic therapy with streptokinase (1.500.000 U i.v.) after administration of hydrocortisone (100 mg i.v.) and acetyl salicylic acid (500 mg od). After 60 min thrombolytic therapy and due to hemodynamic depression with requirement of inotropic agents or the absence of clinical signs of reperfusion, the patients were subjected to coronary angiography. In view of a total occlusion or severe stenosis of the artery responsible for the infarction, an immediate transluminal angiography was performed to improve coronary flow.

RESULTS

transluminal coronary angioplasty revascularized arteries with total occlusion or increased the lumen of those with severe residual stenosis. This was accompanied by reduction in pain and hemodynamic improvement. In one patient with complete AV block, conduction was improved and sinus rhythm was recovered. Echocardiographic controls showed preservation of ventricular function with persistence of segmental motility alterations.

CONCLUSIONS

transluminal coronary angioplasty can be a revascularization alternative in patients with acute myocardial infarction and failure of reperfusion with systemic streptokinase.

The reproducibility of the 50-g, 1-hour glucose screen for diabetes in pregnancy

OBJECTIVE

To explore the day-to-day reproducibility of the 50-g, 1-hour glucose screening test performed on 2 consecutive days in the same women.

METHODS

Eight women at 12-23.6 weeks' gestation (early subjects) and 80 women at 24-28 weeks (late subjects) without known diabetes mellitus were studied. The glucose screening test was performed in the morning on 2 consecutive days in the same women, under an identical or opposite sequence of fasting and fed conditions. The women were thus divided into four subgroups: fast-fast, fed-fed, fast-fed, and fed-fast. Duplicate serum glucose concentrations were measured by the glucose oxidase method. Paired Student t test was used to analyze day-1 versus day-2 glucose levels in each woman of each subgroup.

RESULTS

The serum glucose concentrations were higher on day 1 than on day 2 in the subgroups fast-fast and fast-fed (P < .05) in both early and late patients, whereas the opposite was seen in the subgroups fed-fast (P < .05). No significant differences were observed in the subgroups of fed-fed. At three different glucose thresholds (130, 135, and 140 mg/dL), there was more than 90% daily reproducibility for normal results in both groups, and nearly 50 and 83% daily reproducibility for abnormal results in the early and late patients, respectively.

CONCLUSIONS

Up to 28 weeks of pregnancy, the screening test had a high reproducibility for normal results. For abnormal results, daily reproducibility was better after than before 24 weeks' gestation, regardless of prior testing conditions. Depending on the pre-testing conditions, the use of a different serum glucose threshold seems warranted.

Health promotion and disease prevention strategies

The rapid growth and relative youth of the Latino population of the United States, soon to become the largest ethnic-racial group in the country, presents numerous opportunities and a special challenge to those concerned with the health and well-being of this segment of people. The challenge is to develop and implement efficacious strategies for improving Latino health at a time when the overall socioeconomic profile of this population is in striking contrast to that of the rest of the American people. Much can be done to improve Latino health by implementing health promotion and disease prevention interventions designed to achieve Latino parity in reaching year 2000 national health care objectives. The problems encountered by Latinos in obtaining health promotion and disease prevention services, previous recommendations on how these problems could be addressed, and new strategies for implementing more effective services for Latinos are summarized.

Pseudomonas vesicularis bacteraemia

A case of repeated episodes of Pseudomonas vesicularis bacteraemia, in a 54-year-old woman with a past history including systemic lupus erythematosus and chronic active autoimmune hepatitis is reported. She was treated with tobramycin and ceftazidime but bacteraemia persisted until surgical resection of the infected tissue was performed.

Inhibition of the transepithelial potential difference and short circuit current in the isolated frog skin by alloxan

1. Electrical parameters: short circuit current (SCC), transepithelial potential difference (PD) and electrical resistance (R) were measured in isolated frog skin (Rana pipiens) in the presence and in the absence of alloxan. 2. Alloxan decreased SCC and PD in a concentration-dependent pattern, while R remained unchanged. 3. The effect on SCC and PD was observed after 25 min of exposure to the drug. Maximal average effect was 20% in SCC and 17.5% in PD. 4. These results suggest that alloxan decreased epithelial sodium transport, through interference with the activity of the Na(+)-K(+)-ATPase.

Effects of cyclic AMP and butyrate on cell cycle, DNA, RNA, and purine synthesis of cultured astrocytes

Dibutyryl cyclic monophosphate (dBcAMP) has been shown to inhibit growth, and alter the morphology of astrocytes. However, the potential contribution of its hydrolytic product, butyrate, in inducing some of the changes that have been attributed to dBcAMP, is not clear. DNA, RNA, and purine synthesis were therefore studied in primary astrocyte cultures after 24 hours of exposure to varying concentrations of butyrate, dBcAMP, and agents that increase intracellular cAMP levels. Progression of cells through cell cycle was also studied by flow cytometry. Dibutyryl cAMP partially arrested cells in Go/G1 phase of cell cycle while sodium butyrate increased the percentage population of cells in G2/M phase. DNA synthesis and de novo purine synthesis were inhibited after treatment with dBcAMP, sodium butyrate, and various drugs that increase intracellular cAMP levels. RNA synthesis was increased with cAMP but was not affected by sodium butyrate. Our study shows that at millimolar concentrations, butyrate is capable of altering the cell cycle and inhibiting DNA synthesis in primary astrocyte cultures, in a manner that is similar although not identical to the effects of dBcAMP.

Effects of methotrexate on RNA and purine synthesis of astrocytes in primary culture

There is increasing evidence to indicate that astrocytes are primary targets for methotrexate (MTX) neurotoxicity. However, the mechanism by which MTX exerts its deleterious effect on astroglial cells is not known. Methotrexate acts by inhibiting dihydrofolate reductase and in other cell systems has been reported to inhibit thymidylate synthesis, purine synthesis or both. To determine the mechanism involved in MTX-induced toxicity to the nervous system, RNA synthesis was studied in two week-old primary astrocyte cultures by measuring [3H]Uridine (Urd) incorporation 24 hours after exposure to varying concentrations of MTX. De novo purine synthesis was also studied by measuring incorporation of [14C]glycine and [14C]formate in cultured astrocytes. The radioactivity level of incorporated Urd in culture decreased to 48%, 53% and 43% after exposure to 1, 10 and 100 microM MTX. Total [14C]glycine incorporation was not affected while incorporation of [14C]formate was almost completely inhibited by MTX. The MTX-induced inhibition of [3H]Urd incorporation was not reversed by concomitant addition of exogenous purine bases (1 and 10 microM adenine, guanine and hypoxanthine) or nucleosides (1 and 10 microM adenosine, guanosine and inosine) to the MTX-treated cultures. On the other hand, addition of formyl-tetrahydrofolate reversed the MTX-induced reduction in [3H]Urd incorporation, indicating that the RNA inhibition was due to depletion of folate-dependent substrates for purine synthesis. Our results provide evidence that inhibition of purine and RNA synthesis may be the underlying mechanism involved in MTX-induced injury to the astrocytes, and may be important in the pathogenesis of MTX encephalopathy.

Experimental glaucoma significantly decreases atrial natriuretic factor (ANF) receptors in the ciliary processes of the rabbit eye

ANF binding sites were analysed in the ciliary processes of rabbits with unilateral experimental glaucoma which had been induced by injecting alpha-chymotrypsin into the posterior chamber of the right eyes. The intraocular pressure (IOP) of glaucomatous eyes was significantly greater (28.4 +/- 4 mmHg) than that of normotensive control eyes (13.1 +/- 1.4 mmHg, mean +/- S.E.M., n = 23, P less than 0.05). ANF concentrations in aqueous humour and the ciliary processes were significantly higher in glaucomatous eyes (91 +/- 2 pg ml-1 and 30.4 +/- 4.2 pg g-1 wet weight) than in normal eyes (3.1 +/- 2.2 pg ml-1 and 10.2 +/- 2.7 pg g-1 wet weight, respectively, n = 6, P less than 0.01). The number of ANF-binding sites (Bmax) in the ciliary processes of glaucomatous rabbit eyes was significantly decreased in comparison to the controls (24 +/- 4 vs. 13 +/- 3 fmol mg-1 protein, n = 10, P less than 0.05). These data suggest that ANF receptors in the ciliary processes are down-regulated and that ANF may play an important role in the pathophysiology of experimental glaucoma.

[The inoculation properties of live recombinant influenza vaccine types A and B used separately and jointly in children 3 to 14]

The reactogenicity and immunizing activity of vaccine influenza virus A (H1N1) and B strains used as mono- and bi-preparations in children of 3 to 14 years was studied. No increased reactogenicity after the use of bivaccine was observed in the children. Febrile reactions as well as 9 other clinical symptoms which could indicate the reactogenicity of the vaccines were identical for mono- and bivaccine and corresponded to the requirements of the technical documents for the vaccine. The optimal conditions for the evaluation of the immunogenicity of the B component by HI test were developed, and the necessity of using additionally the enzyme immunoassay for this purpose is substantiated. The above method demonstrated that the immunogenicity of the live influenza type A and B vaccine was high in children. No significant inhibition of immunological parameters was observed when the two viruses were combined in the bivaccine.

HIV infection of human gastrointestinal submucosal cells: an in vitro model that mimics Kaposi's sarcoma

Infection of human gastrointestinal submucosal mesenchymal cells with HIV-1 led to cell populations with abnormal growth properties, increased synthesis of endothelial cell and angioblast markers, and release of angiogenic factors. This system may be the first in vitro model for HIV-induced Kaposi's sarcoma.

Infection of human gastrointestinal cells by HIV-1

Human immunodeficiency virus (HIV-1) infected and replicated in primary cultures of normal human ileal and colonic epithelial cells. Monocyte-tropic strains (ADA, 24, and 36) were better able to replicate in the gastrointestinal (GI) cells than the T-cell-tropic HIV strain HTLV-IIIB. In some cultures, virus replication persisted through several months. Intestinal epithelium may be an initial target and reservoir for HIV and a vector for virus dissemination and transmission.

Spinal cord ischemia after resection of thoracoabdominal aortic aneurysms: MR findings in 24 patients

MR images of the thoracic spinal cord were made in 24 patients who developed signs and symptoms of spinal cord ischemia or infarction following surgery for a thoracoabdominal aortic aneurysm. Findings consisted primarily of four different patterns of signal abnormalities in the distribution of the anterior spinal artery. These abnormalities were identified as types A-D, depending on the degree of involvement of the gray matter and surrounding white matter. We found good correlation between the distribution of the signal abnormalities in the cord, the severity of the neurologic deficits, and the clinical outcome. MR is the imaging method of choice for diagnosing spinal cord ischemia or infarction. A thorough knowledge of the spinal cord arterial territories is crucial for characterizing ischemic MR signal abnormalities and for differentiating them from other causes of myelopathy.

Inhibition of gamma-glutamyl transpeptidase decreases amino acid uptake in human keratinocytes in culture

Acivicin inhibits gamma-glutamyl transpeptidase activity in human keratinocytes in culture. Treatment of these cells with acivicin produces a decrease in the uptake of L-[U-14C]alanine, 2-amino-[1-14C]-isobutyrate, L-[U-14C]leucine and 1-aminocyclopentane-1-[14C]carboxylate. D-[U-14C]glucose uptake is not affected by the presence of acivicin. These results support, for the first time in vitro, the hypothesis that the gamma-glutamyl cycle may be involved in amino acid uptake by human cells.

Decreased lymphokine-activated killer cells in kidney transplant recipients. Correlation with a diminished number of CD3-/NKH1+ cells

The activity of lymphokine-activated killer cells, measured either by a clonal or polyclonal technique, was assessed in 30 kidney transplant recipients (TX), in 13 hemodialyzed patients (HD-CRI), and in 18 normal (N) controls. A highly significant decrease of the LAK activity in TX in comparison with HD-CRI or N (P = 0.0001) was observed. Moreover, the percentage of CD3-/NKH1+ cells was decreased in TX in comparison with N (P = 0.01). LAK activity was strongly correlated (r = 0.72; P = 0.0001) with the percentage of CD3-/NKH1+ cells and not with that of double-positive CD3+/NKH1+ cells. Multivariate analysis showed that the sole independent variable that determined the LAK activity was the percentage of CD3-/NKH1+ cells: the pathological status (TX, HD-CRI, and N) variable was statistically not significant. On the other hand, two T cell-specific functions (IL-2 secretion and specific cytotoxic activity) were, on the whole, preserved in TX. Altogether, these results suggest that TX are LAK deficient predominantly because they have a decreased number of CD3-/NKH1+ cells. The normality of T cell functions suggests that the high rate of malignancies seen in TX is related to this LAK deficiency. Moreover, our study indicates that, in vivo, CD3+ cells do not significantly contribute to the LAK precursors.

Enhanced spatial discrimination learning in rats following 5,7-DHT-induced serotonergic deafferentation of the hippocampus

Learning in rats trained in the Stone 14-unit T-maze, a complex, positively reinforced spatial discrimination task was assessed following cytotoxic (5,7-dihydroxytryptamine; 5,7-DHT) deafferentation of the serotonergic inputs to the hippocampus. Serotonergic deafferentation was accomplished by infusing the cytotoxin in to the fornix-fimbria/cingulum bundle. Lesioned rats reached criterion (i.e. learned) in significantly fewer trials and made significantly fewer errors throughout training than either vehicle-injected or sham-operated controls. This represents the first time that the effects of selective chronic destruction of serotonergic inputs to the hippocampus have been investigated. The present results provide, therefore, evidence in support of a neuromodulatory role for serotonin (5-HT) within the rat hippocampus in the mediation of the processes underlying learning and memory for this task. Other studies are, therefore, warranted in order to determine whether hippocampal 5-HT also plays a role in the mediation of the processes underlying learning and memory in other types of tasks.

Immunoreactive atrial natriuretic factor in aqueous humor: its concentration is increased with high intraocular pressure in rabbit eyes

Atrial natriuretic factor (ANF) concentration in the aqueous humor (AH) was studied in rabbits with experimental glaucoma induced by injecting alpha-chymotrypsin into the posterior chamber. In normal rabbit eyes, the ANF concentration in AH was 3.1 +/- 1.2 pg/ml (mean +/- SEM; n = 12), ranging from 0 to 5.8 pg/ml, whereas it was significantly higher in AH from glaucomatous rabbit eyes, being 81.0 +/- 9.8 pg/ml (n = 12). These findings were correlated with intraocular pressure (IOP), which was 13.0 +/- 2.4 mmHg (n = 12) in normal rabbit eyes and significantly greater in glaucomatous eyes: 24.4 +/- 3.0 mmHg (n = 12). Our data indicate that enhanced ANF release in AH during experimental glaucoma may play an important physiological role in modulating IOP.

Spinal cord ischemia after resection of thoracoabdominal aortic aneurysms: MR findings in 24 patients

MR images of the thoracic spinal cord were made in 24 patients who developed signs and symptoms of spinal cord ischemia or infarction following surgery for a thoracoabdominal aortic aneurysm. Findings consisted primarily of four different patterns of signal abnormalities in the distribution of the anterior spinal artery. These abnormalities were identified as types A-D, depending on the degree of involvement of the gray matter and surrounding white matter. We found good correlation between the distribution of the signal abnormalities in the cord, the severity of the neurologic deficits, and the clinical outcome. MR is the imaging method of choice for diagnosing spinal cord ischemia or infarction. A thorough knowledge of the spinal cord arterial territories is crucial for characterizing ischemic MR signal abnormalities and for differentiating them from other causes of myelopathy.

Distribution of epithelial antigens in the human uterine cervix: a review

Epithelial antigen immunostaining in the uterine cervix has been claimed to be helpful in the identification and classification of rare lesions, evaluation of basement membrane integrity, study of atypical condylomas, immunodetection of proliferating processes and early diagnosis of malignant transformation. The present review attempts to demonstrate the potential value of immunohistological techniques as a means of identifying normal and abnormal patterns of antigenic expression in cervical epithelium.

Role of vitamin D-dependent and vitamin D-independent mechanisms in absorption of food calcium

We measured net calcium absorption and the calcium content of the digestive glands secretions in people with widely different serum concentrations of 1,25 dihydroxy vitamin D (hereafter referred to a 1,25-D). Patients with end stage renal disease on hemodialysis served as a model of human 1,25-D deficiency; they were also studied when they had abnormally high serum 1,25-D concentrations as a result of short periods of treatment with exogenous 1,25-D. Normal subjects were studied for comparison. The amount of calcium secreted into the duodenum by the digestive glands was found to be trivial compared to the calcium content of normal or even low calcium meals; therefore, values for net and true net calcium absorption differed only slightly. There was a linear correlation between true net calcium absorption and serum 1,25-D concentration. By extrapolating the short distance to a zero value for serum 1,25-D, D-independent true net calcium absorption was estimated. By subtracting D independent from true net calcium absorption, values for D-dependent absorption were obtained. For a given level of meal calcium intake, D-dependent calcium absorption was found to be directly proportional to serum 1,25-D concentration. At any given value for serum 1,25-D, absorption via the D-dependent mechanism was approximately the same with a low (120 mg) calcium meal as it was when meal calcium intake was increased to 300 mg. We interpret this to mean that the D-dependent mechanism is saturated or nearly saturated by low calcium meals. The D-independent absorption/secretion mechanism resulted in secretion (a loss of body calcium in the feces) when intake was low (120 mg per meal) and absorption when intake was normal. All of the increment in calcium absorption that occurs when low or normal calcium meals are supplemented with extra calcium is mediated by the D-independent mechanism.