Seroprevalence of antibodies to the human immunodeficiency virus in dialysis workers: results of a multi-center study.

The Center for Devices and Radiological Health, in collaboration with the Department of Veterans Affairs Medical Center, Brooklyn, N.Y., conducted a multi-center, multi-institutional study of the seroprevalence of antibodies to the human immunodeficiency virus (HIV) among dialysis workers. Seven dialysis units and 112 dialysis workers participated in the study over a period of 2 years. Participation was limited to dialysis workers who, by questionnaire, denied non-occupational risk factors for HIV infection. The vast majority of the study participants were drawn from areas where the prevalence of HIV infection and AIDS cases are substantially greater than the national average. Study participants received the ELISA test for HIV antibodies. All 112 of the participants tested negative for HIV antibodies. These results are encouraging, as they failed to reveal unrecognized occupational transmission of HIV infection among dialysis workers.


Effect of eicosapentaenoic acid on the progression of chronic renal failure in rats.

Eicosapentaenoic acid (EPA) can induce a shift in prostaglandin and leukotriene synthesis. The effects of EPA supplementation of the diet on the progression of chronic renal failure (CRF) were evaluated in a model of 5/6 renal mass ablation in rats. After 30 or 60 days of CRF, elevation in single-nephron glomerular filtration rate due to an increase in glomerular plasma flow and hydraulic pressure was observed. These hemodynamic alterations were followed by a rise in proteinuria and glomerular sclerosis. EPA treatment for 30 or 60 days did not substantially modify the hemodynamic or morphological profiles induced by renal mass ablation. In the present non-immune model of CRF, preglomerular vasodilation with glomerular hyperperfusion and hypertension were responsible, at least in part, for the presence of proteinuria and glomerular sclerosis. No additional vasodilation was observed in the present model of CRF, and, thus, hemodynamic effects induced by EPA did not modify renal damage, in contrast to the EPA effects observed in immune-mediated models of CRF.


Enhanced urinary excretion of eicosanoids in fawn-hooded rats.

Compared to Wistar (WAG) rats, rats of the fawn-hooded (FH) strain have a high level of glomerular filtration rate (GFR) and urinary protein excretion (UpV). To investigate the possible role of vasoactive eicosanoids in this spontaneous model of hyperfiltration and proteinuria, we compared the urinary excretion of thromboxane-B2 (TxB2), 6-keto-prostaglandin (Pg)F1 alpha and PgE2 in male FH and WAG rats during normal ageing. All measurements were performed sequentially in the same animals 12, 24, 36, 48 and 60 weeks after weaning. Throughout the study, GFR was higher in FH rats as were the filtration fraction and UpV. From week 24, UpV in FH rats increased progressively. No elevations in UpV were observed in WAG rats. At weeks 12 and 24, the urinary excretion of TxB2, 6-keto-PgF1 alpha and PgE2 was 2-4 times higher in FH rats compared to WAG rats. With time, a shift in the urinary excretion from vasodilator to vasoconstrictor eicosanoids was observed, i.e., the excretion of PgE2 declined and that of TxB2 increased. Proteinuria in FH rats was positively correlated with TxB2 excretion and negatively correlated with PgE2 excretion. We conclude that in FH rats, early hyperfiltration coincides with enhanced urinary excretion of all eicosanoids. Subsequent progressive proteinuria is associated with an increase in TxB2 and a decrease in PgE2 excretion.


Double monoclonal cryoglobulinemia, glomerulonephritis and lymphoma.

We present a case of monoclonal cryoglobulinemia with double monoclonal component IgA lambda-IgG lambda, without complement activation, membranoproliferative glomerulonephritis (MPGN) with deposits of IgA, IgG and lambda chains and lymphocytic IgA-lambda-chain-secreting lymphoma. This case emphasizes the possibility that double monoclonal cryoglobulins could behave differently compared to type I cryoglobulins, determining a MPGN-like type II cryoglobulins do, but without activating the complement cascade.


[Physical basis of therapeutic uses of lasers].

Therapeutic applications of lasers usually require different mechanisms of laser tissue interaction: the thermal interaction mechanism where light energy is converted into heat, the photochemical interaction mechanism where light induces chemical reactions, the mechanical interaction mechanism where light produces shock wave and the photoablative interaction mechanism where light energy produces desorption of tissue. The interaction mechanism depends on the choice of the laser parameters.


[Carbon dioxide laser and stereotaxic craniotomy].

This article describes the development and contemporary clinical applications for a computer interactive volumetric stereotactic system in CT and/or MRI-based resection of superficial and deep seated intracranial lesions. The carbon dioxide laser was found to be particularly useful in the resection of deep seated lesions by this volumetric stereotactic method for three reasons: 1) the CO2 laser is a convenient tool for removing tissue from the depths of a deep cavity, 2) it is relatively hemostatic, and 3) the precision provided by the CO2 laser renders it safer than other methods for dissecting tumors from important brain tissue, e.g. the internal capsule. The specific clinical methods of the technique: data acquisition, computer based surgical planning, and interactive stereotactic open surgery are discussed. The clinical experience in 500 consecutive cases in the resection of various lesions from specific anatomical areas is presented. Total overall morbidity was 7% and mortality 1%. We have found the technique of most benefit in the resection of histologically circumscribed intra-axial lesions.


[Laser microsurgery of meningioma. An analysis of a consecutive series of 164 cases treated surgically by using different lasers].

Over a six years period, 224 laser procedures were performed in our clinic, of these 164 (72%) involved meningiomas of various intracranial and spinal locations; 82 (50%) tumors were located in the posterior fossa, 36 (32%) were suprasellar or parasellar meningiomas: a carbon dioxide laser was used in 56 cases, a double wave length YAG laser in 101 cases, and recently a simultaneous Nd YAG and CO2 combolaser in 7 cases. Complete tumor removal was accomplished in 83% of cases and overall mortality was 3%. We think that microscope guided laser techniques represents a significant advancement in the ability to remove deep situated meningiomas that might prove difficult to extirpate by conventional microsurgery. The advantages of these methods include: 1. reduced brain retraction; 2. the ability to operate with smaller and different exposures; 3. a reduced amount of mechanical manipulation by vaporizing in first the dural attachment; 4. improved operative precision and 5. decreased intra operative blood loss.


[Statistical comparison of surgical results with or without laser in neurosurgery].

In the literature, no significant statistical studies have been published on the effectiveness of laser compared with traditional procedures in neurosurgery; we have decided to study a series of 198 gliomas and 220 meningiomas operated upon either with a laser or with conventional techniques. We considered the post-operative morbidity, the duration and the quality of survival. These data have been clearly influenced by the type of surgery. On the contrary, no significative difference was observed concerning the survival rate of gliomas whatever their grading. In the laser-group, morbidity and quality of life are improved (36 months follow-up); but the mortality rate (3 years) is equal in both groups. Concerning meningiomas, patients of both groups (with and without laser) were clinically improved during the post-operative period. A significative difference appears only for meningiomas located in functional areas and operated with a laser.


[YAG laser in neurosurgery].

The authors try to answer to some practical questions concerning Yag Lasers in neurosurgery. The aim of this work is to determine the main data useful for the choice of a YAG-Laser. Are considered: the wavelengths which can be bought on the international market (1.06 microns or 1.32 microns for instance), the peripherics at disposal, the tissular effects due to the different lasers, the surgical applications and indications. The Laser unit which will be chosen should be a compromise between the different advantages and inconveniences of a particular laser, its tissular effects, its price. The multi-wavelengths units appear to be, at the present time, interesting compromises (such as 1.32 + 1.06 microns, CO2 + 1.06 microns).


[Combined CO2 and Nd-YAG laser in neurosurgical practice. A 1st experience apropos of 40 intracranial procedures].

The authors present their experience concerning the use of Combolaser (Lasermatic, Finland), in neurosurgery. This laser-unit combines two wavelengths (CO2 and 1.06 Nd-YAG) which are emitted simultaneously and coaxially. During the last 12 months, 40 patients harbouring an intracranial tumor were operated upon with such a combolaser unit: 8 infra-tentorial, 32 supra-tentorial, 17 were meningiomas. The mean output power used during the procedures was 3-5 w for both CO2 and Nd-YAG beams. The authors discuss the advantages and inconveniences of such a laser; and they compare it with the other laser-units they have been using for the last 10 years: CO2-Laser, 1.06 Nd-YAG and 1.32 Nd-YAG laser. The main inconvenience of this unit is linked to the utilization of the articulated arm which conducts the CO2 laser beam. This drawback should be avoided or limited by the use of a fiber microguide, which will conduct both CO2 and Nd-YAG beams simultaneously. The principal contribution of a combined-laser unit is the quality of the haemostasis associated to a very good vaporization and cutting effect. When both wavelengths are synchronized, the combined laser beams penetrate into the nervous parenchyma more deeply than the only CO2 laser beam would with the same parameters. The vaporization effect is identical to that obtained with the isolated CO2 laser; the quality of haemostasis is limited to the effects of the Nd-YAG laser. Another advantage must be emphasized: the possibility of utilizing separately the CO2 laser and the 1.06 Nd-YAG.


[Stereotaxic laser interstitial thermotherapy. A new alternative in the therapeutic management of some brain tumors].

Laser Interstitial Thermo Therapy (ITT) is a new procedure which has been performed only a few times in our department as well as in foreign services. The aim of an ITT is to increase the temperature of a tumoral target which has been perfectly determined stereotactically. In the center of the target, i-e at the extremity of the laser fibre, temperature reaches 80 degrees 90 degrees C and creates a coagulation necrosis. At the periphery of the target, temperature must be 41 degrees-43 degrees C so as to create a selective lesion of the pathological tissue due to proteinic and enzymatic denaturation. The authors present their experience based on 8 patients who underwent an ITT between June 1990 and October 1991. A stereotactic determination of the tumor is first performed; then two routes are determined for the laser-fibre (Nd-YAG 1.06 microns, fiber diameter: 400 mu) and for the thermic electrode. The ITT itself is performed a few days later (P = 3-5w, time: 800-1200 seconds). Laser heat effects are monitored with MRI controls (H5, H24, D8 then monthly). The authors insist on the importance of a long follow-up so as to be sure of the complete inocuity of such a treatment. It is the only way to broaden and develop laser-ITT procedures as therapeutic alternatives for certain deep-seated intracerebral tumors.


[Use of Nd-YAG laser in intracranial endoscopy. An initial experience in stereotaxy].

The authors report on four cases of intra-ventricular lesions surgically treated by endoscopic laser-therapy in stereotactic conditions. Two colloid cysts of the third ventricle, one arachnoidal cyst responsible for with an intracranial hypertension and an intraventricular meningioma were treated with such a procedure. The laser beam was used as a surgical knife on cystic lesions and to vaporize the meningioma. The laser coupled with an endoscope add to the comfort given by direct visualization the precision of surgical instrument the effects of which are perfectly controllable in areas where surgical traumatism must be avoided as much as possible.


[Future of medical lasers].

Whatever the medical field of application of lasers, their future is linked to research and to the realization of systems of automatization which will allow the development of "smart lasers". It will be linked to the improvement of imaging techniques and of medical computers, as well as to the development of new feedback systems; the wavelength and the laser beam dosimetry could then be automatically chosen depending on the aimed tissue and on the biophysical effect desired on the target (coagulation, vaporization, cutting, hyperthermia, photo-ablation). Practically, the future of lasers also depends on the elaboration of new peripheric systems and a better conception of new laser equipment. At last, clinical evaluation of such new surgical technologies with well adapted procedures, formation and information through specific teaching courses and seminars will help to the development of all new laser-technologies.


[Popliteal entrapment syndrome with distal embolization. Description of a clinical case].

External compression of the popliteal artery is probably still underdiagnosed. Repeated minor trauma to the popliteal artery as it passes through anomalous fibrous bands, due to developmental defects, may lead to stenosis and occlusion, with consequent chronic or acute ischaemic symptoms, usually in young males without cardiovascular risk factors. Distal embolization to the tibial arteries, to the foot arch and digital vessels is common but is not emphasized in the literature. This distal embolization may compromise the results of surgical repair. Early repair of the anomaly fibrous band is advocated even in a still asymptomatic lower limb. One patient with bilateral popliteal artery entrapment, causing unilateral occlusion, with distal embolization, is reported.


[Arterial hypertension and macroangiopathic complications in a group of diabetic out-patients].

We have retrospectively studied 814 diabetic outpatients, 407 hypertensives and 407 normotensives. The aim of the study was to investigate on possible associations between macroangiopathic complications (coronary heart disease, peripheral and cerebral arteriopathy) and well recognized risk factors for atherosclerosis. Macroangiopathy was present in 27% of males and 24% of females (p = NS), and in 32% of hypertensives and 18% of normotensives (p < 0.0001). Macroangiopathy associated, in both sexes, with age and duration of diabetes, but did not correlate, instead, with metabolic control, obesity, serum cholesterol and triglycerides. High triglyceride levels were associated strictly with arterial hypertension, in both sexes, but are more elevated in men. Risk factors for atherosclerosis seem not to be simply considered in the same way in diabetic and non diabetic populations.


[Arterial hypertension secondary to Conn's disease: an infrequent pathology in nephrology. Report of a clinical case].

In this work we describe a case of Conn's syndrome caused by a suprarenal adenoma in a sixty-one year female. The patient had come to our observation because of severe hypertension and hypokalemia. Primary aldosteronism resulting from the secretion of excessive amounts of aldosterone caused by autonomous hyperfunction of the adrenal cortex usually by a solitary adenoma. In most series of unselected patients, it is found in fewer than 0.5% of hypertensives. In our study we demonstrated the circadian changes of arterial blood pressure but we failed to demonstrate the presence of hypertrophic cardiomyopathy as recently emphasized in the literature. Regardless of its rarity, primary aldosteronism is a fascinating disease, protean in its manifestations, logical in its pathophysiology.


[Chronic hepatitis. Histologic and epidemiologic findings. A 4-year retrospective study of a caseload].

We evaluated 108 liver biopsies--performed over a four year period (1986-1990) at the Ospedale degli Infermi di Biella--with histologic signs of chronic hepatitis. Histological and epidemiological aspects are here reported.


[Prevention of hepatitis B infection in the neonatal care section of the Biella Hospital during a 5-year period from 1986 to 1991. Results and conclusions].

The paper reports the passive and/or active prophylaxis against hepatitis B virus infection carried out in the Neonatal Section of Biella Hospital during the 5-year period 1986-1991. All neonates and non-neonatal subjects at risk of vertical and/or horizontal contagion were vaccinated. The aim of this study was to compare the levels of compliance in relation to serum controls during pregnancy, acceptance of vaccination, percentages of seroconversion and collateral effects. In conclusion, the author underlines the good compliance both during screening in pregnancy and in accepting vaccination. The percentages of seroconversion were similar to those reported in the literature, as was the incidence of HBsAg-positive pregnant women in the local population. Complications were virtually nil both in relation to incidence and severity.


[Intrauterine torsion of the spermatic cord].

Description of a clinical case diagnosed in the first hours of life in apparently well newborn. Diagnostic suspicion by palpation and transillumination. Absence of any subjective sign. Inspective symptom the light scrotal swelling. The neonate received an immediate surgical exploration with subsequent orchiectomy.


[Meniscal suture through the arthroscopic route. 3 years' experience].

Meniscal suture using an arthroscopic route is a safe method with an extremely low percentage of failure and complications. The two techniques most commonly used (from inside to outside and from outside to inside) are similar. The introduction of the needle as far as possible from neurovascular structures makes the outside-inside technique less risky. In the event of associated rupture of LCA ligament reconstruction must always be performed as well as the repair of the meniscus. Isokinetic evaluation has confirmed the rapidity of functional recovery times.


[Microdiscectomy in the treatment of lumbar slipped disk].

The paper describes the surgical technique of microdiscectomy used in lumbar slipped disk and its clinical indications. A total of 113 patients were treated with microdiscectomy over a period of 4 years with positive results in 90% of cases.


[Percutaneous needle aspiration in the treatment of contained lumbar herniated disk].

The authors describe the technique of percutaneous fine needle aspiration in contained lumbar slipped disk and its clinical indications. The paper reports a series of 20 patients treated two years with positive results in 75% of cases.


[Microsurgical treatment of carpal tunnel syndrome].

The paper examines a microsurgical technique of neurolysis and epineurotomy in the treatment of the carpal tunnel syndrome. The cases reported comprise an homogeneous group of 61 "idiopathic" syndromes (slight chronic tenovaginitis of the flexors) at the irritative or sensitive stage. A complete recovery was obtained in 70% of cases and patient assessment was good is 90% of cases. From the authors' point of view, the most interesting findings was the complete absence of problems relating to the palm of the hand following renewed activity.


[Mitochondrial disease and complete heart block. Kearns-Sayre syndrome. Description of a case].

Defects of the mitochondrial respiratory chain form a clinically and biochemically heterogeneous group of diseases. Mitochondrial diseases include myopathies and multisystem disorders that are defined either by biochemical abnormalities of the mitochondria or by the presence of "ragged red fibers" in muscle-biopsy specimens stained with modified Gomori's trichrome stain. Several syndromes have been identified. Typical Kearns-Sayre syndrome is a sporadic condition that is characterized by an onset before the age of 20, progressive external ophthalmoplegia, pigmentary retinopathy and cardiac disorders. Mitochondrial DNA deletions were found in patient with Kearns-Sayre syndrome. We report the case of a 33 year-old woman, with neuromuscular syndrome of the Kearns-Sayre type, insulin-sensitive diabetes and complete heart block, who was implanted a pacemaker.


[Primary malignant lymphoma of the heart. Description of a case and review of the literature].

Primary cardiac tumors are rare. Approximately 25% of primary cardiac tumors are malignant, with the majority of these being sarcomas. Primary lymphoma of the heart is a very rare malignancy, usually recognized at autopsy or fatal within a few weeks of diagnosis. we report the case of a patient with diffuse large uncleaved cell lymphoma of the heart who had dyspnea, distention of the neck veins, edema of the face and arms. The diagnosis in this patient was aided by 2D-echocardiography, CT scan of the chest and superior vena caval angiography. The diagnosis was confirmed at operation and by histological examination. Surgical procedures were only palliative and aimed at prolonging life. However, prognosis remained severe and unchanged.


[Halo-vest in the treatment of fractures of the upper cervical spine. Fractures of the epistropheus].

The authors examine the use of a halo-vest brace in the treatment of fractures of the upper cervical spine. This brace forms a valid alternative to the classic plaster cast in that it is easily positioned, well tolerated by the patient and has a high restrictive capacity for the centre of the fracture. In the cases treated by the authors no complications were reported during treatment, and consolidation time was shortened by 30 days in relation to traditional plaster cast treatment.


1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced astrogliosis does not require activation of ornithine decarboxylase.

Mechanical injury to the brain results in enhanced immunostaining for glial fibrillary acidic protein (GFAP) that is markedly inhibited by difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase. In the current study, systemic exposure of mice to the dopaminergic neurotoxicant, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), also increased GFAP but, unlike mechanical injury, this increase was not prevented by DFMO pretreatment. These results indicate that de novo polyamine biosynthesis is not obligatory for the MPTP-induced increase in GFAP. MPTP administration, unlike mechanical injury, does not disrupt the blood-brain barrier; thus, a role for polyamine biosynthesis in the astrocyte response to injury may be restricted to insults involving a compromised blood-brain barrier.


Selective inhibition of homosynaptic depression in a tetanized pathway by an adenosine A1 blocker in the CA1 region of rat hippocampal slice.

The involvement of adenosine A1 receptors in post-tetanic depression (PTD) of CA1, induced by 5 Hz, 20 s stimulation to the Schaffer collateral/commissural fibers was studied in the rat hippocampal slice. The tetanic stimulation induced post-tetanic depression (PTD) lasting for 5-10 min in the excitatory postsynaptic potentials (EPSP) and the population spike (PS) of the tetanized pathway (homosynaptic PTD), and of a non-tetanized pathway (heterosynaptic PTD). 8-Cyclopentyltheophylline (an adenosine A1 antagonist) blocked the induction of homosynaptic PTD, but not of heterosynaptic PTD. These results indicate that adenosine released during tetanic stimulation acts on the A1 receptor to induce the homosynaptic PTD.


Microglia in the mature and developing quail brain as revealed by a monoclonal antibody recognizing hemopoietic cells.

The monoclonal antibody QH1, which recognizes quail endothelial and hemopoietic cells, was found to label microglia in the developing and mature brain of the quail. Forms of microglia similar to those described in mammals were labelled. Ameboid microglia predominated at embryonic stages, became less numerous in late embryonic development, and disappeared completely by day 10 post-hatch (P10). Poorly ramified microglia were present as early as day 5 of incubation (E5), and were progressively replaced by mature ramified microglia from E14 onwards. From P10 onwards, ramified microglia were the only microglial form seen in the quail brain.


Distribution of NADPH-diaphorase positive somata in the brainstem of the monitor lizard Varanus exanthematicus.

The distribution and size of presumptive cholinergic somata in the brainstem of the Savanna monitor lizard Varanus exanthematicus were determined using the enzyme histochemical marker NADPH-diaphorase. Numerous neurons were labelled in the lizard brainstem with this technique. A three dimensional computer reconstruction of this population revealed that it shows marked similarity to the laterodorsal tegmental/pedunculopontine tegmental cholinergic cell column, an NADPH-diaphorase positive population in the mesopontine tegmentum of the mammalian brainstem.


Immunohistochemical evidence for a crossed cholecystokinin corticostriatal pathway in the rat.

Using the indirect immunofluorescence technique, the effects of decortication and callosotomy on the pattern of cholecystokinin (CCK)-like immunoreactivity were studied in the striatum of the rat. Decortication plus callosotomy, but not decortication alone, caused a strong decrease in the immunoreactivity on the side ipsilateral to the lesion. An almost complete disappearance of CCK immunoreactive patches in the medial-dorsal aspects of the striatum was observed. These results indicate that part of the striatal CCK immunoreactive fibres are of cortical origin, to a considerable extent from the contralateral side.


Recombinant human tumor necrosis factor alpha constricts pial arterioles and increases blood-brain barrier permeability in newborn piglets.

Tumor necrosis factor alpha (TNF alpha) plays a significant role in the pathogenesis of central nervous system infections. We investigated the effect of intracisternal injection of recombinant human TNF alpha (50-50,000 IU) on pial vasoreactivity and blood-brain barrier permeability in newborn piglets. The cytokine administration resulted in arterial vasoconstrictions, blood-brain barrier opening for Na-fluorescein (mol. wt. 376 Da) and increased Na-fluorescein uptake in brain regions examined (parietal and occipital cortex, cerebellum, pons/medulla, periventricular white matter) in a dose-dependent manner. TNF alpha may be involved in the pathophysiology of neonatal brain injuries.


Developmental changes in the hypoxia tolerance of the in vitro respiratory network of rats.

The functional relation between respiratory activity, extracellular potassium activity (aKe) and tissue oxygen pressure (pO2) was analyzed in vitro in the ventral respiratory group (VRG) of the neonatal brainstem-spinal cord (NB) and the perfused adult brainstem (AB) of rats. In the AB, an aKe increase of up to 35 mM and a reversible blockade of respiratory activity occurred during anoxia periods of 5-10 min. In the NB, respiratory activity persisted during a 60 min anoxia in CO2/HCO3(-)-buffered solutions and aKe increased by less than 1.5 mM. In both preparations, inhibition of glycolysis by iodoacetate led to an irreversible blockade of respiratory rhythm and a delayed increase of aKe by more than 15 mM. We conclude that anaerobic metabolism is sufficient for the maintenance of respiratory activity and potassium homeostasis in the brainstem of the neonatal rat, but not of the adult.


Adenosine A2 receptor antagonist facilitates the reversal of long-term potentiation (depotentiation) of evoked postsynaptic potentials but inhibits that of population spikes in hippocampal CA1 neurons.

The effects of the adenosine A2 receptor antagonist CP-66713 on the reversal of long-term potentiation (LTP) were studied in CA1 neurons of guinea pig hippocampal slices. Reduction of LTP (depotentiation, DP) was effected by delivering a train of low-frequency afferent stimuli (depotentiation stimulation, DPS) which was given 20 min after tetanus (100 Hz, 100 pulses). DPS (1 Hz, 1000 pulses) was applied during perfusion of CP-66713 (10 microM). In the presence of CP-66713, DPS reduced the potentiated component of the slope of the field EPSP (S-EPSP) and the amplitude of the population spike (A-PS) by 101.7% and 19.1% of the potentiated amount, respectively (mean, n = 8). The reduction of LTP of the S-EPSP was significantly larger than the control (68.5% (mean, n = 6)) while that of the A-PS was significantly smaller than the control (80.1% (mean, n = 6)). Based on these results, we conclude that the inhibition of DP in the EPSP, the facilitation of DP in the PS, and the consequent attenuation in the EPSP-PS relationship follow from activation of adenosine A2 receptors.


Evidence for G protein modulation of experimental-generalized absence seizures in rat.

Pertussis toxin is known to inhibit G proteins via ADP-ribosylation, and a response to pertussis toxin is presumptive evidence of G protein modulation of the activity being studied. Therefore, in order to test the hypothesis that G protein-mediated mechanisms are involved in the pathogenesis of generalized absence seizures, the effect of pertussis toxin in two pharmacological models of generalized absence seizures in rat was investigated. The experimental absence seizure models used were the gamma-hydroxybutyrate (GHB) model and low dose pentylenetetrazole (PTZ) model in rat. Pretreatment with pertussis toxin administered intracerebroventricularly (i.c.v.) resulted in a significant decrease in duration of seizure in both models. These data suggest that G-protein-mediated mechanisms may be involved in the pathogenesis of the bilaterally synchronous spike wave discharges (SWD) that characterize experimental absence seizures.


Multiple projection of vagal non-myelinated afferents to the anterior insular cortex in rats.

Projection of the vagal C-afferent to the insular cortex was examined in rats. Electrical activation of the C-afferent resulted in two cortical field potentials in the anterior insula. They were independent of each other and neither of them was attributed to the specific thalamic projection. These results imply that vagal information is conveyed to the cerebral cortex by more than one pathways.


Tonic suppression of baroreceptor reflex response by endogenous neuropeptide Y at the nucleus tractus solitarius of the rat.

We evaluated the potential participation of endogenous brain neuropeptide Y (NPY) in central cardiovascular regulation, using adult male Sprague-Dawley rats anesthetized with pentobarbital sodium (40 mg/kg, i.p.). Bilateral microinjection of NPY (4.65 pmol) into the caudal one-third level of the nucleus tractus solitarius (NTS), the terminal site for baroreceptor afferent fibers, promoted a significant suppression of the baroreceptor reflex (BRR) response. The maximal inhibition occurred at 30-40 min postinjection, and amounted to -42.7 +/- 8.6% (mean +/- S.E.M., n = 9). The same treatment, however, only caused transient (approximately 5 min) hypotension and bradycardia. Blocking the endogenous NPY activity at the NTS with its antiserum appreciably enhanced the sensitivity of BRR response (+ 59.2 +/- 18.8%, mean +/- S.E.M., n = 6), but had no appreciable effect on systemic arterial pressure or heart rate. These results suggest that neurons that contain NPY may participate in central cardiovascular regulation by tonically suppressing the BRR response, possibly by exerting an influence on the baroreceptive neurons at the NTS.


Localization of cannabinoid receptor in the human developing and adult basal ganglia. Higher levels in the striatonigral neurons.

In the infant and adult human basal ganglia, the finding of mRNA exclusively in the striatal medium-sized neurons together with the detection of [3H]CP55,940 binding sites in the caudate-putamen, accumbens, substantia nigra pars reticulata and globus pallidus suggests cannabinoid receptor localization on the striatal intrinsic enkephalinergic and substance P-projecting neurons and on their nigral and pallidal terminals. However, the consistent finding of higher binding in the substantia nigra pars reticulata and medial part of the globus pallidus over its lateral segment suggests cannabinoid receptor enrichment on the striatal substance P neurons which express selectively the dopamine D1 receptor.


Effects of reducing plantar support on anticipatory postural and intentional activities associated with flexion of the lower limb.

This study examines the anticipatory dynamics of the center of gravity and the EMG activity of ipsi- and contralateral (to the moving leg) soleus (SOL) and tibialis anterior (TA) in flexion of the lower limb executed from different plantar support surfaces. Subjects were standing initially on a plane surface or a surface reduced to two narrow rods under the moving or stance foot. Reduction of the plantar support surface under the moving limb induced a decrease in the anticipatory activity of both TA and in the intentional ipsilateral SOL EMG activity, but the anticipatory activity of SOL did not change. The lateral and vertical accelerations of the center of gravity decreased. When the reduction was under the stance limb, the biomechanical traces did not change markedly and the EMG activity was similar to that of the control situation. The differential effects in EMG activity, depending on whether the reduced plantar surface was under the moving or the stance side, suggest that tonic plantar stimulation induces complex reflex actions on muscles involved in the preparation and execution of voluntary movement. The functional demand could explain the gating from one motor organization to another.


Stimulation of the hamster ventral lateral geniculate nucleus induces Fos-like immunoreactivity in suprachiasmatic nucleus cells.

The suprachiasmatic nucleus (SCN) functions as a pacemaker for circadian rhythms in rodents. Its activity and, therefore, circadian rhythms, are synchronized by light information from both a direct retinal projection and an indirect projection from the thalamic intergeniculate leaflet (IGL) and ventral lateral geniculate nucleus (vLGN) (geniculohypothalamic tract; GHT). The GHT also appears to be important for synchronizing circadian rhythms to non-photic cues. Light can activate expression of several immediate-early genes in the SCN, including c-fos. We examined whether electrical stimulation of the IGL/vLGN region would induce Fos-like immunoreactivity (lir) in the hamster SCN. Electrical stimulation was given for one hour during the dark period of the lighting cycle. Stimulation at night of the IGL and adjacent LGN regions induced Fos-lir in cells in the SCN. Labeled cells were found in the dorsolateral part of the caudal SCN, and not in rostral or central regions of the SCN, nor in the ventral part of the caudal SCN. These results indicate that activation of cells contributing to the hamster GHT can induce Fos-lir in a restricted region of the caudal SCN.


Responses of neurons in the rat anterior hypothalamic periventricular zone to osmotic stimulation and angiotensin II in vitro.

Extracellular recordings were made in vitro from neurons in slices of the rat periventricular zone surrounding the anterior portion of the third ventricle. Spontaneous unit activity of these neurons was decreased in 39.5% of the neurons tested, increased in 32.9%, and biphasically changed (i.e., excitation-inhibition) in 10.5%, in response to bath application of hypertonic artificial cerebrospinal fluid (aCSF) containing elevated levels of NaCl (330 mOsm). Similar responses were observed following bath application of hypertonic aCSF prepared with additional mannitol. Angiotensin II in the perfusion medium dramatically increased spontaneous unit activity in 73.7% of neurons tested, while, unexpectedly, 5.3% were inhibited. These results suggest that some neurons in the periventricular zone are themselves osmosensitive, and may be involved in the regulation of water balance.


A high concentration of NPY (Y1)-receptor mRNA-expressing cells in the rat arcuate nucleus.

The Y1 neuropeptide Y (NPY) receptor cDNA was recently cloned from a rat brain library. In situ hybridization histochemistry using a synthetic oligonucleotide probe complimentary to bases 716-764 of the Y1 receptor cDNA was used to localize the corresponding mRNA in the rat brain with special reference to the hypothalamic arcuate-paraventricular axis, because these areas are considered to play a key role in eating behavior. Quantification of the hybridization signals by a computerized image analyzing system revealed that the arcuate nucleus together with the granular cell layer in the gyrus dentatus contained a high concentration of Y1 mRNA. In emulsion-dipped sections, the neurons containing Y1 mRNA transcripts were found particularly in the ventromedial part of the arcuate nucleus. These data indicate that NPY or NPY-related peptides via a Y1 receptor on neurons of the arcuate nucleus may influence the homeostasis.


Phorbol esters and K+ up-regulate alpha-bungarotoxin binding sites in cultured chromaffin cells through a related mechanism.

Nicotinic alpha-bungarotoxin (alpha-BGT) receptors in cultured chromaffin cells are up-regulated in response to long term (days) exposure to nicotinic antagonists, elevated K+, and activators of protein kinase C (PKC), such as the phorbol ester, 4 beta-phorbol 12-myristate 13-acetate (PMA). The present experiments were done to determine whether their was any interaction in the ability of PMA and K+ to up-regulate the alpha-BGT receptors. Chromaffin cells were treated for 3 days with both 100 nM PMA and 20 mM K+, concentrations which produce maximal responses on their own. The increase in alpha-BGT binding after the combined treatment was the same as that seen with K+ alone suggesting that K+ inhibited the PMA-mediated effect. The K(+)-induced increase in toxin binding was partially prevented by polymyxin B, an agent which completely inhibited the PMA induced increase. The time courses of the increases in binding induced by both K+ and PMA were similar in that the most marked increases in binding were observed at the later time points. The PMA-induced up-regulation was partially inhibited by an activator of adenylate cyclase, a result similar to that previously seen with K+. The present studies suggest that the up-regulation of alpha-BGT receptors induced by K+ shares similarities with that induced by phorbol esters. The observations that K+ inhibited the PMA induced increase and that a PKC inhibitor partially blocked the K+ response suggest that the K+ and PMA mediated induction of the alpha-BGT sites may be linked with the effects of K+ preceding those of PMA.


Distribution of amyloid in the brainstem of patients with Alzheimer disease.

A4 protein (beta-protein, beta-amyloid) deposits were identified with silver stains in postmortem brainstem sections from 13 patients with Alzheimer disease (AD), 6 patients with mixed Alzheimer disease and Parkinson disease (AD-PD), 5 disease controls, and 2 elderly controls. A rostro-caudal gradient of A4 was found in patients with AD and AD-PD, such that A4 was most prevalent in the midbrain and least prevalent in the medulla. The brainstem of the controls contained little or no A4. The midbrain tectum and tegmentum contained the greatest densities of A4, but the red nucleus and substantia nigra pars reticulata were largely spared. This distribution of A4 suggests that A4 deposition is a function of synaptic connectivity rather than passive diffusion from vascular sources.


Age-dependent effects of lead on [3H]MK-801 binding to the NMDA receptor-gated ionophore: in vitro and in vivo studies.

Lead (Pb2+) is a more potent inhibitor of [3H]MK-801 binding to rat neuronal membranes than Zn2+ and Mg2+. The inhibitory effects of Pb2+ appeared to be age-dependent since the IC50 was significantly lower in cortical membranes prepared from neonatal than from adult rats. The results also indicate that the hippocampus is more sensitive than the cerebral cortex since the Pb2+ IC50 was significantly lower in the hippocampus. These findings suggest developmental and regional brain heterogeneity to the inhibitory action of lead on [3H]MK-801 binding. Chronic in vivo exposure to Pb2+ resulted in the loss of [3H]MK-801 binding sites in the cerebral cortex of neonatal but not of adult rats. These lead-induced changes may influence developmental processes requiring NMDA receptor activation.


Neuroprotective effects of carvedilol, a new antihypertensive, at the N-methyl-D-aspartate receptor.

Carvedilol's potent antioxidant activity could explain its protective action in brain ischemia, but may not apply to glutamate-induced excitotoxicity in cultured cerebellar granule cells, since glutamate neurotoxicity was not associated with the formation of lipid peroxidative products. Rather, carvedilol diminished the N-methyl-D-aspartate (NMDA)/glycine-induced increase in intracellular calcium ([Ca2+]i), lowering [Ca2+]i by a maximum of 66 +/- 5% (n = 8) with a 50% inhibitory concentration of 0.8 microM. Prior addition of 5 microM dihydropyridines did not shift the dose-response of carvedilol, but did significantly lower the NMDA/glycine-stimulated response to 64% of untreated (n = 8, P = 0.014). Inclusion of 5 microM carvedilol before the additions of NMDA/glycine prevented 85% of the increase in [Ca2+]i. Furthermore, carvedilol displaced 3[H]MK-801 binding to rat brain cortical membranes with a Kd of 29.4 +/- 2.2 microM (n = 6) and no selectively for the glutamate or glycine binding sites. These data therefore suggest that, in addition to its antihypertensive and anti-lipid peroxidative functions, carvedilol has neuroprotective activity as a calcium channel blocker and as a non-competitive inhibitor at the NMDA receptor.


Co-release of neuropeptide Y (NPY) and noradrenaline from the sympathetic nerve terminals supplying the rat vas deferens; influence of calcium and the stimulation intensity.

Epididymal (E) and prostatic (P) segments of the rat vas deferens were incubated with tritium-labeled noradrenaline (NA); upon transmural electrical stimulation for 20 or 60 s (70 V, 1 ms, 3-35 Hz), the outflow of immunoreactive neuropeptide Y (ir-NPY) and NA was detected in the superfusion media. Ir-NPY was detected only following trains of 35 Hz for 60 s in both E and P. In contrast, tritium was released in a graded fashion following trains of 3, 15 or 35 Hz stimulation for 60 s in E, whereas in P it reached a plateau at frequencies larger than 15 Hz. The outflow of tritium, under present conditions, was dependent on the duration of the stimuli, while the release of ir-NPY was only evoked with stimuli of 60 s duration. In the absence of external Ca2+, neurotransmission was blocked and co-release of ir-NPY and NA was prevented.


Resetting from low threshold afferents of N-methyl-D-aspartate-induced locomotor rhythm in the isolated spinal cord-hindlimb preparation from newborn rats.

In this study we have investigated the effects of low threshold afferent stimulation on the centrally generated locomotor rhythm in an isolated spinal cord-hindlimb preparation from newborn (0-3 days old) rats. Locomotor activity was induced by bath application of N-methyl-D-aspartate (NMDA). Stimulation of low threshold afferents (below 2 times threshold (x T) for the incoming volley) in L2 and L3, but not L4 and L5 dorsal roots resets the ongoing rhythm. This is due to an abrupt excitation of the L2 and L3 ventral root bursts and an inhibition of the L5 ventral root burst on the ipsilateral side followed by reciprocal effects on the contralateral side. Similar effects were seen after stimulation of the quadriceps nerve with weak intensity (below 1.8 x T). We conclude that low threshold muscle afferents, possible group I afferents, have access to central pattern generators early in postnatal life and suggest that these findings may give an important opening in ontogenetic studies of how neural networks are assembled.


Hippocampal kindling increases the expression of glutamate receptor-A Flip and -B Flip mRNA in dentate granule cells.

The level of the mRNAs encoding the AMPA-selective glutamate receptors-A and -B, alternatively splice variants, Flip and Flop, was studied by in situ hybridization in the brains of rats kindled by Schaffer collateral/commissural-fiber stimulation. In comparison to control animals, the expression level of the Flip variant of both GluR-A and GluR-B mRNAs was bilaterally enhanced in the dentate granule neurons of kindled animals 24 h after last-generalized seizure, whereas no obvious alterations were observed in the GluR-A Flop and GluR-B Flop mRNA variants. In kindled animals, studied 1 month after the last seizure, GluR-A Flip and GluR-B Flip mRNA had returned to control levels. We suggest that these changes may result in an enhanced glutamate receptor sensitivity in the fascia dentata during kindling.


Differential increases of neurokinin B- and enkephalin-like immunoreactivities and their mRNAs after chronic haloperidol treatment in the rat.

Changes in neurokinin B-like immunoreactivity (NKB-IR) and neurokinin B mRNA were investigated after daily injection of haloperidol for 10 days on adjacent sections by means of immunocytochemistry and in situ hybridization in the caudate putamen of the rat. In the dorsal striatum the number of NKB immunoreactive perikarya and the staining intensity of striatal efferents increased. The number of NKB mRNA-expressing cells (45%) and the grain density over single positive cells (37%) were significantly higher after the neuroleptic treatment. The levels for enkephalin mRNA were uniformly increased throughout the rostrocaudal extent of the caudate putamen (85%). A main difference to the enkephalin system was that the dorsal pallidum was nearly devoid of NKB-IR in untreated as well as in haloperidol-treated animals. The present data for the first time provide evidence for the regulation of the biosynthesis of NKB after pharmacological intervention.


Perisomatic sprouts immunoreactive for nerve growth factor receptor and neurofibrillary degeneration affect different neuronal populations in the basal nucleus in patients with Alzheimer's disease.

Aberrant morphological profiles, most likely reflecting a process of perisomatic sprouting, have been detected in Alzheimer's disease (AD) on neurons of the basal nucleus of Meynert by means of Golgi impregnation. Using the mouse monoclonal antibody, ME 20.4., perisomatic profiles were shown to be immunoreactive for nerve growth factor receptor (NGFR). Double label studies using either thioflavin S or anti-neurofibrillary tangle (NFT) antibody B5 in combination with ME 20.4 demonstrated that neurons with aberrant growth profiles failed to express neurofibrillary tangle-bearing material, which otherwise could be detected in large amounts throughout the basal forebrain. The results indicate that in AD, neurons in the basal forebrain, not affected by neurofibrillary degeneration, respond to an increased trophic influence. Dendritic sprouting in AD might, therefore, more likely be regarded as an attempt by the nervous system to repair itself following damage rather than as an abnormal process with primary pathologic significance leading to cellular degeneration.


Distribution of c-fos expression in brainstem neurons associated with conditioning and pseudo-conditioning of the rabbit nictitating membrane reflex.

Experiments were performed to test the hypothesis that there is a characteristic distribution of neuronal c-fos expression associated with the classical conditioning of the rabbit nictitating membrane reflex (NMR). Rabbits were divided into two groups: a conditioning group that received paired tone and airpuff stimuli in a traditional delay NMR conditioning paradigm and a pseudo-conditioning group in which the same number of tone and airpuff stimuli were applied but without being paired. Labeling was present in similar brainstem nuclei in both groups of animals. The labeled sites included trigeminal and auditory nuclei in the classical pathway for the nictitating membrane reflex as well as other nuclei such as the raphe nuclei and those in the ventrolateral medulla (VLM). However, there were quantitative differences in the labeling between the two groups. There were significantly more labeled nuclear profiles in the trigeminal nucleus of the pseudoconditioned rabbits, but more labeled nuclear profiles in the raphe nuclei in the conditioned animals. Interestingly, the ratio of the labeling in the raphe versus the VLM strongly differed between the two groups.


Central effects of tumor necrosis factor alpha and interleukin-1 alpha on nociceptive thresholds and spontaneous locomotor activity.

To extend the knowledge on the central effects of cytokines, we studied the effects of tumor necrosis factor alpha and interleukin-1 alpha on nociceptive thresholds and spontaneous locomotor activity in rats. After central administration, both tumor necrosis factor alpha and interleukin-1 alpha significantly (P < 0.001) increase the nociceptive thresholds as measured by the hot-plate test. Tumor necrosis factor alpha, but not interleukin-1 alpha decreases spontaneous locomotor activity evaluated by the Animex test. The increase in nociceptive thresholds induced by tumor necrosis factor alpha or interleukin-1 alpha is not affected by the opiate receptor antagonist naloxone, or antisera against the endogenous opioids beta-endorphin, met-enkephalin or dynorphin. The analgesic effect of tumor necrosis factor alpha is completely antagonized by anti-IL-1 antibodies. Moreover, the cyclooxygenase inhibitor indomethacin does not antagonize the increase of nociceptive thresholds induced by either cytokine.


Regional and temporal glycerol changes induced by forebrain ischemia in gerbils.

Temporal ischemic changes in glycerol and energy metabolites were studied in the striatum, hippocampus and cortex of gerbils subjected to 15 min of bilateral carotid artery occlusion alone or with various periods of recirculation. The same tissue sample served for the determination of glycerol and energy reserve by a simple enzymatic fluoro- and spectrometric assay after perchloric acid extraction. Cerebral ischemia increased the levels of glycerol (8- to 10-fold) and depleted the energy stores. During the first hour of recirculation, the glycerol content decreased and thereafter (at 2 h), normalized in all structures. However, the glycerol content was still twice as high in the striatum and hippocampus as compared to their respective controls. At the same time, an incomplete restoration of energy reserves was observed in these structures. The findings indicate that glycerol is not a stable postischemic indicator of the ischemia-induced membrane damage.


In vitro and in vivo effects of ammonia on glucose metabolism in the astrocytes of rat cerebral cortex.

Effects of 1 and 5 mM ammonium acetate on glucose metabolism were studied in astrocytes. But for an elevation in the levels of fructose-6-phosphate, phosphoenol pyruvate, and pyruvate, glucose metabolism was unaltered in the presence of 1 mM ammonium acetate. With 5 mM ammonium acetate, but for unaltered lactate, ADP, ATP and decreased aspartate, levels of several intermediates were elevated. Similar results were obtained when astrocytes isolated from hyperammonemic rats were incubated with glucose except for an enhanced production of 14CO2 from [U-14C]glucose. It is suggested that glucose metabolism of astrocytes may not be severely affected in astrocytes of cerebral cortex in acute hyperammonemic states.


Circadian rhythms of pineal melatonin release in the pigeon measured by in vivo microdialysis.

Circadian rhythms of pineal melatonin release were measured in freely moving pigeons (Columba livia) by in vivo microdialysis. The birds were placed in light-dark cycles with 12 h of light and 12 h of darkness (LD 12:12) or continuous dim light (LLdim) after LD 12:12. Although the level of melatonin was various, daily changes of melatonin with higher levels during the dark and lower levels during the light were observed in all of the birds examined. The daily changes of melatonin persisted in LLdim, indicating circadian nature of pineal melatonin release. Moreover pineal melatonin release was inhibited by acute exposure of light during the dark. These results indicate that microdialysis is useful for studying circadian pineal melatonin rhythms of birds.


Specific binding of 3N-(2'-[18F]fluoroethyl)benperidol to primate cerebral dopaminergic D2 receptors demonstrated in vivo by PET.

3N-(2'-[18F]Fluoroethyl)benperidol ([18F]FEB) an 18F-labeled analogue of the D2 antagonist benperidol, was evaluated as a tracer for positron emission tomography (PET). PET imaging of a living baboon showed that the fluorinated ligand rapidly localized in vivo within D2 receptor-rich brain tissue, with selective retention lasting over 2 h after tracer injection. Pretreatment of the animal with unlabeled D2-specific antagonist eticlopride (4 mg/kg, i.v.) 1 h before [18F]FEB completely abolished the selective disposition of the radioligand, whereas the regional cerebral blood flow, blood volume and peripheral metabolism/protein binding of [18F]FEB were not changed. Tracer localization when the baboon was pretreated with unlabeled ketanserin (0.55 mg/kg, i.v.) or SCH 23390 (1.1 mg/kg, i.v.) was identical to that for the control case, indicating that the [18F]FEB did not bind to S2 of D1 receptors in vivo. [18F]FEB has advantages compared to previously used PET tracers, and may be an excellent radioligand for non-invasive study of D2 receptor binding.


Dynamic visual acuity and contrast sensitivity for static and flickered gratings in a college sample.

For a sample of college observers, visual performance was assessed with three types of measures: (1) contrast sensitivity for a range of spatial frequency gratings with 4-Hz flicker, (2) contrast sensitivity for a range of stationary wallchart gratings, and (3) dynamic visual acuity (DVA) for a range of target velocities. Within each of these three performance measures, mean results were generally consistent with previous reports. However, across-test comparisons revealed little commonality of processes between either of the contrast sensitivity scores and the dynamic acuity scores. These findings are discussed in terms of the separate contributions to overall visual performance made by the increasingly popular contrast sensitivity function (CSF) and DVA.


Prevalence of disabled stereopsis in a class of optometry students.

Stereopsis is said to be disabled when the third dimension (3-D) cannot be perceived during everyday life but can be when viewing conditions are appropriately arranged. To discover a test suitable for detecting disabled stereopsis, I measured stereoacuity, stereolatency, and the subjective difference in depth perception between monocular and binocular vision of a group of 41 optometry students. Only 2 students showed no sign of this disability. A predictive value for each test was calculated from the results of 14 students whose disability was confirmed by another means. Stereoacuity had the worst predictive value (43%) and stereolatency the best (100%). The prevalence of disabled stereopsis in this group was no less than 34% and might have been as great as 95%.


Stereolatency: a stereopsis test for everyday depth perception.

An instrument is described which tests for the use of stereopsis by measuring how long it takes for depth perception to begin (its latency) after a transition from monocular to binocular vision. Starting at 1 s, the duration of binocular vision is reduced progressively toward a limit of 16 ms (or increased to a limit of 4 s) until the latency of stereopsis is found. The preliminary period of monocular vision acts as a probe for suppression of either eye and allows time for accommodation and vergence to stabilize before binocular vision begins. Typical results are presented.


Influence of polarographic cathode diameter on measured oxygen transmissibility of hydrogel contact lenses with optical power.

The oxygen transmissibility of a contact lens is defined as its oxygen permeability (Dk) divided by its thickness (L). Transmissibility can be obtained from separate measurements of Dk and L, or from a single measurement of oxygen flux through the lens (as for example by the polarographic method). Dk/L of hydrogel contact lenses with optical power measured by the polarographic method was compared with Dk/L calculated from separate measurements of Dk and L. Polarographic sensors of different cathode diameters were used to show the effect of the area over which the flux is measured on the observed Dk/L. Dk/L from oxygen flux measured by the polarographic sensor was found to be a function of the optical power of the lens and cathode diameter. Dk/L calculated from separately determined Dk and L for optically powered lenses was found to be a function of Dk and the choice of L (central or average).


Computerized Moiré analysis of progressive addition lenses.

A computerized image capture and analysis system capable of 256-level intensity resolution was used to digitize and store images as a 512 by 512 pixel array. The system was used to record a standard square-wave grating (0.80 lines/mm) located 1 m from the camera. Subsequently, an ophthalmic lens was interposed between the camera and the grating. Nonzero lens powers induced magnification and thus altered the spatial frequency of the grating image. Subtractive-type Moiré analysis was performed to compare the intensity distributions of the magnified and the unmagnified (reference) gratings. The Moiré patterns created using digital, pixel-by-pixel subtraction of the two images showed graphically the power distributions of the lenses studied. These patterns varied noticeably between different brands of progressive-addition lenses (PAL's) of the same nominal power. Using only commercially available components, this method of analysis was both fast and repeatable, and may be of value to manufacturers and large-volume finishers of progressive-addition lenses.


Twelve-month success rates with a hydrogel diffractive bifocal contact lens.

In this study we assessed success rates over 12 months with a hydrogel diffractive bifocal contact lens. A total of 108 presbyopes were fitted with lenses, and after 12 months 46% were still wearing the lenses. Subjects with previous presbyopic lens-wearing experience achieved greater success (58% of those fitted) than neophyte lens wearers (33% of those fitted, and 17% of all neophyte presbyopes initially expressing an interest in contact lenses before screening). More neophytes failed for nonvision-related reasons than experienced subjects (31% vs. 12% of those fitted). Consequently, when nonvision-related failures were excluded from the calculation of success rates, 59% of those fitted with lenses (49% of neophytes and 66% of experienced subjects) were still wearing the lenses at 12 months. Most discontinuations from lens wear occurred in the first month of the study, the major reason for discontinuation being poor near vision (blur and/or ghosting; 47% of discontinuations).


Quantitative analysis of visual acuity through amber discolored lenses.

Discoloration of hydrogel contact lenses is frequently encountered in clinical practice and often precipitates lens replacement. This investigation sought to determine if lens discoloration was associated with a compromise in low or high contrast, high illumination visual acuity. This association would lead to a more scientific rationale for lens replacement. Amber lens discoloration was achieved using human-worn 55% water hydrophilic contact lenses (Methafilcon-A) heated in a 1% potassium sorbate, low pH saline solution. A spectrum of 6 discolored lenses was obtained with a peak absorbance at 320 nm. Fifteen subjects, between the ages of 22 and 38 years, were tested wearing each of the discolored lenses. None of the differences in high or low contrast acuity between our discolored and nondiscolored lenses were found to be statistically significant using a paired t-test at the 99% significance level.


Effect of rigid gas permeable lens flexure on vision.

The flexure of spherical rigid lenses (various materials) and a soft lens was measured using automated over-keratometry on 6 adapted rigid lens wearers (12 eyes) whose corneal toricity ranged from 1.37 to 3.87 D. The results showed: (1) that there was no significant difference in flexure between polymethyl methacrylate (PMMA), silicone acrylate, and the fluorosilicone acrylate lenses (whose Dks ranged from 0 to 115). However, Advent (fluoropolymer) did flex significantly more than the other rigid lenses, and significantly less than the soft lens (Bausch & Lomb U4) and (2) that lens flexure of the rigid lenses did not alter over a 2-h period. We also measured high and low contrast visual acuity (HCVA and LCVA), and the results from subjects wearing Advent and the soft lens were significantly worse than with the other rigid lenses. Finally, the results of this study showed no correlation between rigid lens flexure and permeability and between rigid lens flexure and visual acuity when Advent was excluded from the linear regression analysis.


Trajectories of changing refractive status.

Refractive status can be represented as a point plotted on a three-dimensional graph. As the refractive status changes a curve is traced out on the graph. Trajectories of changing refractive status are illustrated in a number of representative ideal cases. The three-dimensional graphs are shown by means of stereo-pairs. Trajectories are constructed from clinical data and interpreted with reference to the ideal examples. They show changing refractive status with age, after cataract extraction, and after radial keratotomy. The trajectories may prove to be a useful tool for both clinician and researcher. They show overall trends and allow prediction of future changes. Certain types of trajectories could prove to be characteristic of certain conditions and thus be useful for diagnosis. Trajectories allow monitoring of change after intervention.


Relative strength of central and peripheral fusion as a function of stimulus parameters.

We investigated the role of various stimulus parameters that influence motor fusion responses for peripheral as compared to central fusional stimuli. Results from the initial experiment indicated that a central stimulus equal in size to a peripheral fusion stimulus dominated the response independent of the amount of retinal eccentricity of the peripheral target. A second experiment indicated that the central stimulus dominated even when the peripheral stimulus was larger. However, when the peripheral stimulus was changed in shape so that it became an annulus surrounding the central stimulus, the peripheral stimulus was always stronger. In another phase of the experiment, we found that the extent to which a peripheral stimulus surrounded the central one determined which controlled the response. We concluded that the surrounding perceptual gestalt produced by the peripheral stimulus was the most significant variable determining the relative strengths of central and peripheral fusion stimuli. Clinical implications are discussed.


Tear film bubble formation after decompression.

Decompression disorders can occur after a reduction in environmental pressure due to dissolved gases forming bubbles in affected tissues. The objective of this study was to evaluate the use of tear film bubble formation as an indicator of decompression. Eleven subjects were exposed to a simulated dive to 30.48 m (100 ft) (in sea water) for 15 min. There was a significant (p < 0.001) increase in tear film bubble formation post-dive. This noninvasive technique may be of value in both research and clinical environments for monitoring decompression.


Variation of congenital nystagmus with viewing distance.

Involuntary oscillations of the eyes in persons with congenital nystagmus often dampen in intensity (amplitude x frequency) with near viewing. This study examined how changes in viewing distance affect the duration and position variability of foveation periods (intervals of low eye velocity when the target's image is at or near the fovea), as these parameters generally correlate better with acuity than nystagmus intensity. To do so, the horizontal positions of both eyes were recorded by infrared limbal tracking in 4 subjects with congenital nystagmus and 4 normals during monocular and binocular fixation at 200, 40, and 20 cm. At nearer distances, position variability (the standard deviation of horizontal eye position) increased in normal subjects, as well as during foveation periods in the subjects with nystagmus. Other parameters of the nystagmus varied idiosyncratically with viewing distance. In none of the subjects with nystagmus was visual acuity (measured psychometrically) better at 40 cm than at distance. The results show that characteristics of congenital nystagmus do not necessarily improve and, in some instances worsen, with near viewing.


Oral fluorescein angiography and fluoroscopy: determination of plasma fluorescein levels and clinical application.

One hundred oral fluorescein angiographic explorations were performed in 85 patients of both sexes, mean age 55.57 years, and range 8 to 77 years. Fluorescein was administered as one 250-mg (15 patients) or 500-mg (70 patients) capsule per 15 kg of body weight. In 15 fasting and 15 postprandial patients administered 500-mg capsules, no significant differences by group were found between fluorescein plasma levels. Fundus fluorescence under slitlamp illumination was poor for patients receiving the lower dosage of fluorescein, whereas at the higher dosage it was visible in all but one patient. The best filters were found to be a Kodak-Wratten 47A for the excitation filter and Kodak-Wratten 8 for the barrier filter. With a conventional fundus camera and fluorescein angiography filters, good photographs were achieved in all cases. The integrity of the blood-retina barriers was explored for various chorioretinal pathologies.


What kinds of leaders are entering optometry schools?

The purpose of this study was to determine the parameters of leadership of students entering one optometry school, assess the relation between personality types and leadership during optometry school, and forecast potential for leadership beyond school. Personality inventories of 269 students entering University of Houston College of Optometry (UHCO) from 1988 through 1990 were analyzed for personality type according to Gough's two-vector system (V1 = extroversion/introversion; V2 = norm-favoring/norm-doubting) which results in four types or life styles: Alpha, Beta, Gamma, and Delta. Although some sex and ethnic differences were found, most (71%) optometry students were Alphas (extroverted/norm-favoring), accepted leaders who strive to maintain and advance consensual values. Alphas achieved well in classroom and clinic and were student leaders. A lesser number (10%), mostly women, were Gammas; extroverted but norm-questioning, Gammas can provide creative and progressive leadership. Remaining types were Betas (15%) and Deltas (4%), both introverted types who avoid leadership positions. In sum, traditional and, to a lesser degree, innovative leadership potential appears strong among optometry students; they should serve the profession well.


[Clinical and prognostic usefulness of Ki67 determination in breast carcinoma].

We studied the correlation between tumor size, nodal status, menopausal status, nuclear oestrogen receptors, disease free survival and Ki67 (proliferation rate) measured by mean of immunohistochemical analysis with monoclonal antibody. Median value was 10%. From December 1986 to October 1989 we studied 236 consecutive patients (pts). Median follow up was 34 months (range 7-51 months). Median age was 56 years (r. 26-82). We observed: 1) lower levels in smaller tumors; 2) poor correlation with nodes involvement; 3) lower levels when nuclear oestrogen receptors were positive. Preliminary data seem to suggest longer disease free survival when Ki67 is low.


Direct thrombin inhibitors.

Thrombin not only plays an important role in thrombosis and haemostasis but may also be involved in other pathological situations such as the progression of atherosclerotic plaque formation, inflammatory response and neurodegenerescence. It is therefore important to be able to control the action and/or the generation of this enzyme. With this aim in view, a great number of synthetic or recombinant direct thrombin inhibitors have recently been made. They block either the thrombin catalytic site or an anion-binding exosite which is a recognition site for some of its substrates (fibrinogen, thrombin receptor, thrombomodulin, heparin cofactor II) or act on both sites. Some of these inhibitors have revealed a number of advantages over heparin in experimental animal models of thrombosis and haemorrhagic risk. On-going clinical studies with some candidates will establish their real interest for patients.


Immunophenotypic characterisation of human peritoneal and alveolar macrophages and of human blood monocytes differentiated in the presence of either GM-CSF or M-CSF or a combination of GM-CSF/M-CSF.

In vivo, circulating blood monocytes (Mo) migrate into the various tissues where they undergo terminal maturation into macrophages (M phi) with morphological and sometimes functional properties that are characteristic for the tissue in which they reside. This tissue-specific M phi heterogeneity results from the immediate microenvironment, but may also originate from genetically distinct Mo subpopulations. The in vitro transformation of Mo to M phi is thought to reflect the events of the in vivo maturation and thus is widely used as a model to analyse M phi development. To study the heterogeneity within the mononuclear phagocyte system, we have investigated the phenotypic characterisation of mature tissue M phi, blood Mo and Mo-derived M phi cultured in medium with either GM-CSF, M-CSF or a combination of both cytokines. Tissue peritoneal and alveolar M phi showed different antigenic specificities, particularly concerning the transferrin receptor and CD68 and CD14 antigens. M-CSF-derived M phi when compared to the other M ø populations also exhibited a significantly increased expression of transferrin receptor and CD68 antigen. In contrast, GM-CSF treated cells which exhibited a better long term survival, showed notably more positivity for CD11b and CD32 antigens. These results show that the phenotypic heterogeneity of the different M phi populations is limited and appears to result from discrepancies in the differentiation and/or activation of the cells. The location of the CD68 antigen, which is generally considered to be an intracellular protein, was investigated at the ultrastructural level and found to be exclusively situated at the outer cell membrane.


Macrophage activation syndromes.

The clinical and laboratory features of 47 cases of macrophage activation syndrome (MAS) were reviewed in a workshop within the Groupe Français d'Hématologie cellulaire. There was no predilection for a particular age group, while common symptoms at presentation included fever, hepatic and splenic enlargement and profound depression of blood count. Examination of bone marrow aspirates allowed diagnosis to be established in almost all cases. The most characteristic sign of MAS was the presence of well differentiated macrophages without notable cytologic abnormalities but shown to be actively ingesting haematopoietic elements. Haemophagocytic syndromes generally occur in patients who develop infections in the context of preexisting immunologic abnormalities or neoplasms. In the majority of patients evolution of the disease was regressive, once spontaneously but often after antibiotic, antiparasitic and/or antiviral treatment accompanied or not by corticotherapy and/or chemotherapy. Some regressive phases were followed by more or less long term relapse, especially in the case of associated systemic lupus erythematosus. There exists at present no explanation for the occurrence of MAS, although one may remark its association with other pathologies, in particular congenital or acquired immune deficiencies and haemopathies. Several hypotheses have been proposed to explain the appearance and evolution of the disease and at present two pathways of investigation of MAS seen to merit attention: exploration of macrophages themselves and their secretion products and exploration of lymphocytes and NK cells. The current possibilities for these investigations should lead to a greater understanding of the physiopathology of MAS and it is to be hoped that a better application of appropriate therapy will enable control of its evolution.


Erythropoiesis in long term cultures of foetal liver cells is transiently obtained on adult but not on foetal adherent cell layers.

We have previously reported long term erythroid differentiation of adult bone marrow cells seeded onto adherent cells derived from adult bone marrow. In this paper, we show that the adherent cells obtained from foetal liver do not support the erythroid differentiation of either adult bone marrow cells or foetal liver cells. Adherent layers derived from bone marrow of adult W/Wv mice supported differentiation of adult bone marrow precursors, but foetal liver progenitors only produced erythrocytes for a few weeks and the foetal origin of these red cells was confirmed by haemoglobin typing. The duration and extent of erythropoiesis was generally inversely proportional to the cell dose. Foetal progenitors were as sensitive to erythropoietin as adult cells, but were optimally stimulated at a lower plateau concentration. These results suggest that inhibitory cells present in foetal liver may block erythropoiesis and their growing importance with age may provide an explanation for the arrest of erythropoiesis in the liver at late developmental stages.


Haematopoietic microenvironmental status of the 13-day mouse embryonal liver.

The haematopoietic microenvironment which is provided by the stromal cells and extracellular matrix elements has been shown to influence the growth and differentiation of haematopoietic cells. However, most of the information thus far available has been derived from experiments performed using Long Term Bone Marrow Cultures and there is as yet no information regarding the haematopoietic microenvironmental status of the developing liver. Stroma were therefore established using 13-day embryonal liver cells, at a point in time when the liver shows peak haematopoietic activity. These stroma when compared to bone marrow stroma showed differences in histochemical staining. 2M NaCl extracts from 13-day embryonal liver were capable of binding pluripotent stem cells and on SDS-PAGE showed a 14 kDa band of increased intensity. The extracts could also induce erythroid colonies in a semisolid medium. However, 13-day embryonal liver stroma were unable to maintain bone marrow stem cells in culture and overall results would suggest differences between the stromal components of bone marrow and embryonal liver.


[Primary prostaglandins PGE2, PGF2, prostacyclin and thromboxane in patients with myocardial infarction].

In 47 patients with acute myocardial infarction and in 17 healthy volunteers blood concentration and urinary excretion of PGE2, PGF2 alpha, 6-keto-PGF1 alpha--hydrolysis product of prostacyclin--and TXB2 were determined using RIA. Myocardial infarction patients were found to have significantly higher blood level and urinary excretion of 6-keto-PGF1 alpha, higher blood level of PGF2 and higher urinary excretion of TXB2 than controls, PGE2 urinary excretion was significantly lower. Increased excretion of 6-keto-PGF1 alpha was observed in patients with ventricular arrhythmias. Excretion of all determined prostaglandins was increased in patients with myocardial infarction complicated by atrioventricular block as compared to the other patients. The results suggest, that increase of prostacyclin synthesis in the acute phase of myocardial infarction may provide protection mechanism against heart muscle damage and improve coronary blood flow.


[Effect of lovastatin on platelet function in hypercholesterolemic patients].

18 patients were studied with primary hypercholesterolemia (type II according to Fredricksen) and fasting cholesterol level during low fat diet above 250 mg/dl. Blood samples were taken: I--before lovastatin administration on diet, II--after 4 weeks administration of 20 mg, III--after 4 weeks of 80 mg and IV--4 weeks after the drug discontinued. The following tests were performed: platelets aggregation induced by ADP and adrenaline, PF3 and PF4, platelet MDA, serum triglycerides, total cholesterol, HDL-cholesterol and LDL-cholesterol. Before treatment patients showed significant platelets hyperaggregation and MDA concentration comparing to the control group. During the drug administration significant lowering of platelets MDA concentration, was observed small but significant HDL cholesterol level increase which correlated with platelet MDA concentration. Availability of PF3 and release of PF4 did not change during study.


[Influence of treating hypothyroidism and hyperthyroidism upon psychical reaction time].

The aim of the study was answering the question whether determination of psychical reaction time may be useful for the monitoring of treatment of hypothyreosis and hyperthyreosis. The correlation of disease symptoms (diagnostic index for hypothyroidism after Murray and for hypothyroidism according to Crooks), concentration of triiodothyronine, thyroxine, index of free thyroxine in blood serum and Achilles tendon reflex--with the simple reaction time (srt) as well as with the choice reaction time (chrt) before and during treatment was investigated in 18 patients with primary hypothyroidism and in 24 with hyperthyroidism caused by Graves-Basedow's disease. Two control groups comprised 84 healthy persons. Either in hypothyroidism or in hyperthyroidism the srt and chrt was significantly prolonged. The substitution therapy in hypothyroidism resulted in a normalization of both parameters. On the other hand, administration of thiamazole, especially in the early period of treatment of hyperthyroidism, further prolonged the srt and chrt. A shortening of the time of each of the two reactions occurred, however, when the restoration of euthyroidism was achieved, which was accompanied by reduction of thiamazole dosage. The obtained data point to the usefulness of srt and chrt determination for the diagnosis and therapy monitoring of functional disturbances of the thyroid gland.


[Value of plasma testosterone, carcinoembryonic antigen and CA 19-9 in the differential diagnosis of pancreatic carcinoma and chronic pancreatitis].

Diagnostic value was assessed of serum testosterone concentration and compared with that of serum assay of CEA and CA 19-9 in the differential diagnosis of pancreatic cancer (PC) and chronic pancreatitis (CP). Thirty-six patients with PC were compared with thirty-two CP patients. The sensitivity of CA 19-9 (76.9%) in detecting PC was greater than that of testosterone and CEA (30.6% and 30.8%, respectively). The specificity of testosterone and CA 19-9 were comparable (93.7% and 96.4%, respectively). The combination of tests did not enhance the sensitivity and specificity of each test when used alone. The serum CA 19-9 concentration in PC patients was significantly higher then in patients with colon cancer, gastric cancer and benign gastrointestinal diseases.


[Treatment of anemia with erythropoietin (rhuEPO) in patients with chronic kidney failure who are not yet in need of dialysis therapy].

Eleven uraemic predialysis patients have been selected for the treatment of anaemia with rhuEPO. Administration of rhuEPO was followed by a significant increase of the Hct value and haemoglobin concentration as well as an improvement of well being. The main adverse effects of rhuEPO therapy were the following: increase of blood pressure, reduction of the residual renal function and increase of serum potassium and phosphorous concentration. Monitoring of the iron status in uraemic predialysis patients on rhuEPO therapy seems to be mandatory.


[Effect of opioid receptor blockade with naloxone on plasma renin activity and aldosterone levels in patients with kidney transplantation].

Function of the renin-angiotensin-aldosterone (RAA) system in kidney transplant patients (KTP) is often abnormal as in patients with chronic renal failure. On the other hand the importance of opioids in the regulation of function of endocrine organs is well established. These facts were the background of studies presented in this paper. They aimed to assess the role of opioid receptors in the regulation of the RAA in KTP. 12 patients with a stabilized renal graft function and on cyclosporin A + prednisone therapy and 15 healthy subjects were examined. In all subjects plasma renin activity (PRA), plasma aldosterone level (Ald) and blood pressure were assessed during a 4 hr bed-rest test. In each subject two tests were performed: the first one without naloxone administration, and the second one--after opioid receptor blockade. In KTP significantly elevated PRA and blood pressure and moderately elevated plasma Ald levels were found as compared with normals. After a 4 hr bed rest without naloxone no significant changes of the above mentioned parameters were noticed both in the patients and the controls. After opioid receptors blockade by naloxone a significant decrease of PRA and plasma Ald was observed in both examined groups. This decrease was significantly more marked in KTP than in controls. In addition only in KTP 4 hrs after naloxone administration a significant increase of systolic and diastolic blood pressure was found. Results obtained in this study suggest, that opioid receptors are involved in the regulation of the activity of the RAA system and of blood pressure more markedly in KTP than in healthy subjects.


[Prognostic value of an early peak CK-MB in plasma of patients treated with streptokinase for acute myocardial infarction].

111 patients below 70 years old, with the first acute myocardial infarctions, 6 hours since the pain occurred--have been treated with streptokinase i.v. In 102 patients we obtained full curve of CK-MB activity. Early peak of CK-MB activity < 15 hours after onset of symptoms we have observed in 59 patients, and late peak of CK-MB activity > 15 hours in 43 patients. There was not any significant statistics differences between early and late groups in frequency of: early ventricular fibrillation (< 48 hours), complex ventricular arrhythmia (in 21 day), heart failure and in-hospital mortality. 1 patient died in hospital in early group and in late group also died 1 patient. The follow-up period was from 10 to 48 months (av. 26 +/- 13). 100 patients left the hospital and the full informations we have obtained in 97 cases. No one died in that time. In the group with early peak CK-MB activity we observed more often the unstable angina and the new myocardial infarction (21%) than in the group with late peak of CK-MB activity (15%), but these differences were nonsignificant. In conclusion our results don't confirm that the early peak of CK-MB activity is the positive risk factor of unstable angina and the new myocardial infarction.


[Influence of long-term hemodialysis treatment on total and free thyroxine serum concentration in patients with chronic renal failure].

Many disturbances in functioning of pituitary-thyroid axis in patients with advanced chronic renal failure are well documented. The present paper aimed to assess the influence of duration of haemodialysis treatment on basal and after stimulating TT4 and fT4 serum concentration in uraemic patients. 17 nondialyzed uraemic patients, 15 dialysed up to 50 months, 11 dialysed for 51-100 months, 11 dialysed for more than 100 months and 14 control subjects were examined. In all subjects TT4 and fT4 levels were assessed before and after TRH administration (400 micrograms/i.v.). 1. The patients, independently if the duration of dialysis therapy, did not show any significant differences in basal TT4 from the normal subjects. 2. Nondialyzed and patients dialysed up to 50 months showed significantly lower basal values of fT4 as compared with the patients dialysed longer and with normal subjects. 3. Areas over basal values of TT4 did not show any significant differences in all examined groups. 4. Areas over basal fT4 values were significantly higher in the patients dialysed over 50 months than in the remaining groups. 5. Positive significant correlations were found between the duration of dialysis therapy and basal fT4 as well as area over basal fT4 values. Duration of haemodialysis treatment significantly influences the fT4 serum concentration in chronic renal failure.


[Influence of long term hemodialysis treatment on total, free and reverse triiodothyronine serum concentration in patients with chronic renal failure].

Many disturbances is functioning of pituitary-thyroid axis in patients with advanced chronic renal failure are well documented. The present paper aimed to assess the influence of duration of haemodialysis treatment on the basal and after TRH stimulation TT3, fT3 and rT3 serum concentration in uremic patients. 17 nondialyzed uraemic patients, 15 dialysed up to 50 months, 11 dialysed for 51-100 months, 11 dialysed for more than 100 months and 14 control subjects were examined. In all subjects TT3, fT3, and rT3 levels were assessed before and after TRH administration (400 micrograms i.v.). 1. All patients showed significantly lower basal TT3 in comparison with normal subjects. 2. Nondialyzed and dialysed patients up to 50 months showed significantly lower basal values of fT3 as compared with the patients dialysed longer and with normal subjects. 3. The basal rT3 in the patients dialysed over 50 months were significantly higher then in nondialyzed, dialyzed up to 50 months and in the control group. 4. Areas over basal values of TT3 and fT3 were distinctly lower in all patients as compared with control group and significantly higher in patients dialysed from 51-100 months than in patients dialysed up to 50 months. 5. Areas over basal rT3 values did not show any significant differences in all examined groups. 6. Positive significant correlations were found between the duration of dialysis therapy and basal TT3, fT3 and rT3. Duration of haemodialysis treatment is a important factor influencing serum TT3, fT3 and rT3 concentration. This effect is observed in partial normalisation of: a) basal TT3 and fT3, b) reactivity of TT3 and fT3 after THR administration.


[Influence of long term hemodialysis treatment on TSH secretion in patients with chronic renal failure].

In patients with advanced chronic renal failure many disturbances in functioning of pituitary-thyroid axis are well documented. The present paper aimed to assess the influence of duration of haemodialysis treatment on the basal and stimulated TSH secretion. 17 nondialyzed uraemic patients, 15 dialysed up to 50 months, 11 dialysed for 51-100 months, 11 dialysed for more than 100 months and 14 control subjects were examined. In all subjects TSH levels were assessed before and 15, 30, 45, 60 and 120 minutes after TRH administration (400 micrograms i.v.). 1. Nondialyzed and dialysed patients up to 50 months showed significantly lower basal values of TSH as compared with the patients dialysed longer and with normal subjects. 2. Areas over basal values of TSH were distinctly lower in all patients as compared with control group. 3. Negative significant correlation between the duration of dialysis therapy and area over basal TSH values was found. Duration of haemodialysis treatment influences markedly secretion of TSH in chronic renal failure.


[Prognostic value of selected hemodynamic parameters featuring left ventricular systolic and diastolic function in patients with dilated cardiomyopathy].

The goal of the study was the choice of hemodynamic parameters most useful in prognosing the survival of the patients with dilated cardiomyopathy (DCM). The investigated group comprised 40 patients, who underwent left and right cardiac catheterization with left ventricular (LV) quantitative angiography. The day of catheterization was the starting point of the observation, which was performed by means of follow-up regular examinations and information from questionnaires sent to and returned by the patients or their families. The follow-up spanned from 1 to 120 months (means = 43). The hemodynamic parameters of LV systole, ejection, isovolumic relaxation and filling were assessed. The patients were divided into two subgroups featuring survival of less and more than 3 years, respectively. In these two subgroups the following parameters were compared: LVEADP, T constant of relaxation, LVEDP, LVEDVI,+dp/dt max, EF, LV mass/volume ratio, MCSD (midwall circumferential LV stress in early diastole), -dp/dt min. They were also correlated with survival and analyzed in Cutler-Ederer survival tables. 1. 32% of patients survived more than 5 years. 2. The prognostically most valuable parameters seem to be: -dp/dt min, LVEADP, LVEDVI, EF, LVEDP, MCSD, +dp/dt max. 3. The prognosing of survival in patients with DCM should be based on a multifactorial analysis because of lack of domination of any single factor.


[Evaluation of thrombotic risk in young men after myocardial infarction during a period of clinical stability].

The study was aimed at an evaluation of individualized indications for antithrombotic therapy for secondary prevention in a group of 40 young survivors (aged 30-40 years) of myocardial infarction, presenting a stable phase of coronary disease. The control group consisted of 19 healthy men, of approximately similar age distribution. The determinations concerned the following: in vitro ADP and collagen induced platelet aggregation, plasma fibrinogen concentration, factor VII, VIII and antithrombin III activity, protein C concentration, spontaneous fibrinolytic activity and fibrinolytic activity after venostasis, plasminogen and alpha-2 antiplasmin activity. Moreover, to determine correlations with hemostatic parameters lipids, apolipoproteins, glucose, uric acid plasma concentration as well as percentages of lipoproteins and glycolyzed hemoglobin were also studied. In the study group various hemostasis disturbances were found: an increased platelet aggregation induced by low concentrations of ADP, increased plasma fibrinogen concentration and factor VII activity, decreased protein C concentration and impaired plasma fibrinolytic activity after venostasis. Some correlations between hemostatic and lipids parameters were also observed. Results of the study have suggested necessity for the individualized antithrombotic prevention in young survivors of myocardial infarction with antiplatelet and/or anticoagulant drugs.


[The role of erythropoietin in blood pressure regulation in patients with arteritis].

Renal erythropoietin production is dependent on local oxygen content of blood which activates so called "oxygen sensors". Taking into consideration altered local renal blood supply in patients with arterial hypertension in the course of arteritis (HA) and from the other side contribution of the renin-angiotensin system in both pathogenesis of hypertension and regulation of erythropoietin production it seemed plausible to undertake this study. The aim of the study was to determine whether and in what extent patients with HA and healthy subjects differ in EPO secretion and whether EPO serum level is related in this patients to renin response to dietary sodium restriction and upright position of the body. 18 patients with HA and 12 healthy subjects were investigated. In all subjects haematocrit value, haemoglobin concentration, erythrocyte count, sodium, potassium, creatinine, iron, ferritin serum levels, total iron binding capacity, plasma renin activity (PRA), erythropoietin serum level and mean arterial blood pressure (MAP) were measured in basic conditions (normal sodium diet). Additionally PRA, EPO and MAP were measured after dietary sodium restriction to 10-20 mmol Na/24 hrs for three days and upright position of the body for three hours. Patients with HA had insignificantly lower serum EPO concentrations than healthy subjects and both studied groups did not differ in haematocrit value and determinants of iron metabolism except of significantly higher ferritin concentration in HA. After dietary sodium restriction and upright position of the body significant rise in PRA and no significant changes in EPO level were found in studied groups.(ABSTRACT TRUNCATED AT 250 WORDS)


[Treatment of chronic hepatitis B with interferon alpha (Wellferon) with and without previous corticosteroid therapy -- results of a multicenter, double blind study].

The present study was aimed to test the efficacy and safety of interferon alpha (Wellferon-Wellcome Foundation Ltd.) either alone, or in combination with short-term corticosteroid pretreatment in the therapy of chronic hepatitis B. 44 patients with documented chronic hepatitis type B (12 women and 32 men; mean age 37.5 years, range 23-59 years) and satisfying the entry criteria were subjects of the study. 30 patients had chronic active hepatitis on liver biopsy, while 14 had chronic persistent hepatitis. Consecutive patients were given either placebo or prednisone in a double-blinded manner for 4 weeks (0.6 mg/kg/day in the first two weeks, 0.45 mg/kg/day in the third week and 0.25 mg/kg/day in the last week), and then, after a 2 week pause, therapy with interferon was instituted for a total of 12 weeks. Interferon was given by intramuscular injection in a single daily dose of 10 x 10(6) IU for 5 days and three times weekly thereafter. However, because of side effects, the dose of interferon was occasionally reduced to 5 x 10(6) IU in most patients. Interferon induced a sustained cessation of HBV replication as judged by loss of DNA-polymerase activity in 26 (59%) patients, 20 (45%) patients seroconverted to anti-HBe. Additionally, 6 (14%) cases lost HBsAg and seroconverted to anti-HBs. Prednisone pretreatment did not seem to improve the efficacy of interferon therapy. The outcome of the treatment was unrelated to gender and pretreatment activity of transaminases, however, patients with low activity of HBV replication were more likely to respond to therapy than patients with high HBV replication.


[Personal experiences in the treatment of peritonitis with a complicated extended program of peritoneal dialysis].

In 37 pts treated with peritoneal dialysis (PD) in years 1980-1990 results of peritonitis (P) treatment were compared between years 1986-90 (cycle II) and years 1980-85 (cycle I). In I cycle 47 episodes of P occurred in 9 of 21 pts treated with PD, and in cycle II 15 episodes of P in 7 of 16 dialysed pts. Treatment of P was as follows: in cycle I, daily standard PD with gentamicin and cephradine added to 2.01 dialysing exchanges; in cycle II, after initial lavage of peritoneum with a few litres of dialysing solution, 1.0 g vancomycin was given iv and continuous PD started using 1.0 litre prolonged exchanges and aminoglycosides added to dialysis solution. Treatment protocol used in cycle II was more effective than the first one: all episodes of P were immediately cured (only 32 of 47 in cycle I), there was only 1 relapse (in cycle I 6/32 cured P), duration of P was shorter (mean 6.5 days/9.8 days in cycle I) and morphological changes of peritoneum were less expressed than in cycle I. Practically important indicator of cure was decline of polynuclear cells in smear of peritoneal effluent sediment (less than 50% of cells). All 9 pts suffering from P in cycle I had to be transferred to HD (43% of all dialysed pts) and only 2 in cycle II (12% of all dialysed pts).


[Efficacy of recombinant human erythropoietin (rhuEPO) in treatment of anemia in patients with myelodysplastic syndrome].

This paper summarizes results of rhuEPO--treatment obtained by different authors in 27 patients with a myelodysplastic syndrome (MDS). Only 1/3 of all patients with a MDS were responsive to rhuEPO treatment, while in 2/3 of these subjects no amelioration of anaemia was noticed, even after extremely high doses of this hormone. A detailed description of a patient with MDS, which was observed by the authors, is presented. In this patient the anaemia was refractive even after very high doses of rhuEPO administered for 10 weeks.


[Unusually large thrombus in the left cardiac ventricle in a patient with a history of anterior wall infarction].

The giant size thrombus like a swallow's nest in the left cardiac ventricle in the patient with a history of anterior infarction was reported. In the autopsy a significant narrowing of the left coronary artery and two critical narrowings of the anterior interventricular artery were revealed. The relation between the localization of the pathological changes in the coronary arteries and the thrombi occurring during cardiac infarction was discussed.


[Non-invasive evaluation of function in both cardiac ventricles and arrhythmias in patients with dilated cardiomyopathy].

Resting echocardiography with M-mode technique under the control of bidimensional picture and pulsating Doppler ultra sound and a 24-hour ECG with Holter technique were performed in 19 patients with dilated cardiomyopathy (6 females and 13 males; mean age 46 years, mean duration of the disease 23 months). A group of 7 patients with electrocardiographic features of the left ventricle hypertrophy, according to Sokolov index, was distinguished and compared with a group of patients without ventricular hypertrophy. The symptoms of pulmonary hypertension with progressing dilatation and failure of the right cardiac ventricle were found in patients with dilated cardiomyopathy without coexisting hypertrophy, despite of significant deterioration of the contractive function. Cardiac arrhythmias and thrombotic disorders which are hazardous for life were significantly more frequent (78% and 22%, respectively) in this group. Percentage of sudden deaths in these patients was high (56%).