Fine structure of the merozoite of a haemogregarine from the testis of a lizard

In the course of our studies on the fine structure ofKaryolysus sp. of the rock lizardsLacerta saxicola nairensis from Armenia, we observed that the host was simulataneously infected by another apicomplexan organism. A large meront, about 31.09 μm in diameter, containing more than 40 merozoites was found in the testis of the lizard. Of special interest was the presence of crystalloid bodies in the majority of the merozoites examined. Analysis of the fine structure of the merozoites enabled us to conclude that we were dealing with merozoites of an unknown haemogregarine.     

Kinetics of the reaction of a glycol with a diisocyanate

The reaction between poly(ethylene oxide) glycol (α-hydro-ω-hydroxypoly(oxyethylene)) and methylenebis(1,4-cyclohexylene) diisocyanate was studied at 70, 80 and 90°C. The course of the reaction was followed by determining the isocyanate content of the reaction mixture at appropriate time intervals. The data thus obtained were analyzed by taking into consideration the glycol- and urethane-catalyzed reactions separately. It was found that although the urethane-catalyzed reaction was faster in the temperature range studied, its relative importance decreased with increasing temperature.     

Multicentric reticulohistiocytosis: a report of a case and a review of the pathology

A case of multicentric reticulohistiocytosis (MR) in a 24-yr-old woman is presented. MR is a rare disorder characterized by progressive polyarthropathy and a papulo-nodular skin rash. The diagnosis was established by histological examination of biopsies of erythematous nodules on the fingers which showed circumscribed collections of large mononuclear cells and multinucleate giant cells in the reticular dermis. These were embedded in a fine network of mature fibrous tissue with a scanty lymphocytic infiltrate. Histochemical, immunopathological and ultrastructural investigations confirmed that the large mononuclear cells had the properties of macrophages. The histopathological features of MR are reviewed in the light of current knowledge of macrophage physiology, and evidence for lymphocyte-histiocyte interactions in the pathogenesis of this bizarre granulomatous disorder is presented.     

Creation of a defense dominant during the functioning of a blink dominant in the rabbit

The possibility of creating (through serial electrodermal stimulation of the limb) a defense dominant during the formation and functioning of a blink dominant was investigated in chronic experiments in rabbits. The formation of a motor dominant against the background of a blink dominant was difficult. Sequential, but not simultaneous, manifestation of the dominants under investigation was observed when the motor defense dominant was created against the background of a formed blink dominant. Difficulty in the formation of the motor dominant was also observed in the presence of transition to an inhibitory state, as a result of the repeated summation of the initial dominant focus, created via the reflex route, and in the presence of induction activation of a secondary dominant focus in symmetrical structures. Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow. Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 45, No. 3, pp. 464–471, April–May–June, 1995.     

Abscess of the caudate lobe of the liver,a rare disease with a challenging management: a case report

We reported a rare case of abscess of the caudate lobe of the liver in a 60-year old man. We first tried computed tomography (CT) guided percutaneous drainage of the abscess but failed to eradicate the infection. Deterioration of the general condition of the patient necessitated open surgical drainage, which resulted in cure of the abscess. The peculiar anatomical location of caudate lobe abscess introduces a great challenge for the surgeon in planning the appropriate management and paucity of patients with caudate lobe abscess has led to lack of guidelines for management. The non-operative interventional radiology approach has become the therapeutic choice for pyo?genic liver abscess, but is it applicable also for caudate lobe abscess?     

Transformation of the kinematic characteristics of a precise movement after a change in a spatial task

The central mechanism of motor programming was studied using a model of precise horizontal flexion of the arm at the elbow joint. Training was performed in the dark to ensure that formation of the motor program was based predominantly on the use of proprioceptive afferentation. The target was not demonstrated before training: subjects determined the angle of arm flexion during training, the moment at which the target position was reached being identified by a brief LED flash. Subjects had to perform the movement as quickly and accurately as possible. The amplitude, speed, and accuracy of the movement were measured in real time. The ten subjects were divided into two groups for initial training to precise movements, using two different protocols: flexion of the elbow to 70° and to 55°. At the second stage of the experiment, each subject’s initial target position was suddenly changed (from 70° to 55° and vice versa). Training was continued until a stable accuracy in the new conditions was achieved (with errors of no more than 5% of the specified amplitude). The nature of the transformation in the kinematics of the precise movement in response to the change in the single task parameter illuminated the fundamental principle of organization of the supraspinal motor command for movements of this type. For both specified flexion amplitudes, the ratio between the acceleration and deceleration phases of the movement were identical during the period of skill fixation. On average, 70% of the total amplitude of flexion was accounted for by the acceleration phase and 30% by the deceleration phase. Adaptation of the precise movement to changes in the specified horizontal elbow flexion angle (i.e., re-achievement of the required movement accuracy in the changed conditions) during rearrangement was completed by inversion of these values. According to the results of previous studies, the most informative measure for analysis of the dynamics of the controlling central command was the acceleration of the movement. In terms of current concepts of the mechanism of motor control, the acceleration plateau can be regarded as mirroring long-term depression-the voltage plateau in Purkinje cells and motoneurons. Data processing involved calculation of the integral acceleration in both phases of the movement in relation to the angle of flexion (phase plots). These data underlie our understanding of the mechanism of transformation of movement kinematics responsible for the formation of a new central command. __________ Translated from Zhurnal Vysshei Nervnoi Deyatel’nosti imeni I. P. Pavlova, Vol. 56, No. 5, pp. 618–628, September–October, 2006.     

Malakoplakia of the prostate: a report of two cases and a review of the literature.

Two cases of malakoplakia of the prostate are documented, bringing the total described in the world literature to 15. This literature is reviewed, and typical features of the condition are established. The majority of the cases have had proven previous episodes of Escherichia coli infection of the urinary tract, but bacilliform organisms have yet to be demonstrated in the diseased prostatic tissue. Five of the reported cases have also had important additional disease, including three instances of malignant lung tumour. Finally, it is emphasised that recognition of prostatic malakoplakia as an entity will prevent its confusion with prostatic carcinoma.     

Generation of a rapid step in the temperature of a papillary muscle

A fast temperature jump method is described for the study of electromechanical properties of an isolated papillary muscle of the rabbit heart. Arguments are given that such a temperature jump can be best obtained by joule heating using an alternating current with a frequency in the shortwave region. For the measurement of the fast increasing temperature and the achieved temperature distribution two types of thermometer are used with a response time shorter than a few ms and a high spatial resolution. No self heating of the thermometers due to induced currents was detected. Electrical disturbance in the signals representing temperature, Transmembrane potential and force of contraction were negligible immediately after the fast temperature increase as well as during the following steady-state temperature elevation. The inhomogeneity of the temperature increase in the muscle appeared to be about 30 per cent. In response to a temperature increase of 4°C in 30 ms the action potential shortens in about 3 s and the force of contraction decreases within one beat. From the results it can be concluded that fast changes in electromechanical properties of heart muscle after a fast temperature increase induced by a high-frequency alternating current are measurable and have physiological relevance.     

Acinar cystic transformation of the pancreas: Report of a case and a review of the literature

Acinar cystic transformation (ACT) is a rare cystic lesion of the pancreas lately reclassified as a non-neoplastic entity. This is a presentation of a case of ACT and a review of the literature. A systematic PubMed search was conducted, yielding a result of 24 publications. Including our case report, 75 cases of ACT have been reported in the literature. The patients are mainly females with initial symptoms of abdominal pain. The cysts are primarily located in the head of the pancreas and are often multilocular on cross section and have a mean size of 53.2 mm. Microscopically, the cysts are lined by an acinar epithelium with abortive acinar formations. The cells are immunohistochemically positive in stains for trypsin, chymotrypsin and CK7. The Ki67-index is low; 1–2 %. No genetic alterations indicative of a neoplastic pathogenesis have been found. The mean follow up time is 37.4 months and no malignant transformation has been observed. A preoperative diagnosis is difficult to establish, but microbiopsies seem a promising tool. The indication for surgical intervention should be founded on the symptoms of the patients since no malignant transformation has ever been reported.     

Inactivation of a centromere during the formation of a translocation in maize

Fluorescence in situ hybridization analysis of a reciprocal translocation in maize between chromosomes 1 and 5 that has been used extensively in maize genetics revealed the presence of an inactive centromere at or near the breakpoints of the two chromosomes. This centromere contains both the satellite repeat, CentC, and the centromeric retrotransposon family, CRM, that are typical of centromere regions in maize. This site does not exhibit any of the tested biochemical features of active centromeres such as association with CENP-C and phosphorylation of serine-10 on histone H3. The most likely scenario for this chromosome arrangement is that a centromere was included in the repair process that formed the translocation but became inactive and has been inherited in this state for several decades. The documentation of an inactive A chromosome centromere in maize extends the evidence for an epigenetic component to centromere function in plants. This case provides an experimental example of how karyotype evolution might proceed via changes in centromere inactivation.     

Myolipoma of the round ligament: report of a case with a review of the English literature

Tumours consisting of a mixture of mature adipose and smooth muscle tissues, including those designated lipoleiomyomas, fibrolipoleiomyomas and myolipomas, are exceedingly rare, but most often occur in the uterine corpus. We describe here a case of such a tumour arising in the right round ligament of a 44-year-old woman. The tumour, which measured approximately 20×15×10 cm, was well encapsulated and did not involve the intrapelvic organs. Intricate mixtures of adult adipose tissue and bland smooth muscle exhibited no cellular atypia or nuclear mitotic figures, and there was little vascular proliferation. We diagnosed the lesion as a myolipoma of soft tissue with dual differentiation, and have found only 13 cases of this tumour including our own in the English literature. The present tumour is the first reported in the round ligament. Although this tumour is rare, its recognition is important for the avoidance of erroneous diagnoses.     

Leiomyoma of the urinary bladder: a cytogenetic study of a case

We report the first case of a leiomyoma of the urinary bladder studied by cytogenetics. In comparison with cytogenetic changes of leiomyomas of other sites, the karyotype of the tumor was unusual: 47,XX,+7/89 approximately 93,XXXX,-1,+7,+7,add(12)(q23.4),+add(12)(q23.4),-18,-21,+idic(21)(p11.2),-22.     

Isolated metastasis to the gallbladder of a malignant melanoma of the skin. Report of a case

A case of single, polypoid metastatic malignant melanoma of the gallbladder is described. The differential diagnosis with primary malignant melanoma and undifferentiated carcinoma is discussed.     

Reinnervation of a segment of the pancreas

Central Research Laboratory, Department of Pathological Physiology and Department of Normal Anatomy, Medical Faculty, Patrice Lumumba Peoples' Friendship University. (Presented by Academician of the Academy of Medical Sciences of the USSR T. T. Beresov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 109, No. 5, pp. 468–470, May, 1990.