Transcranial Doppler ultrasound: present status

Summary and critique. Advantages of method. TCD is a noninvasive test effective in monitoring blood velocities in large intracranial arteries. It uses small, potentially portable, relatively inexpensive equipment. The test can be repeated and therefore allows the detection of changes over time and after various physiologic studies or pharmacologie intervention, and during various postural and positional changes. TCD can also be used to monitor changes during surgery or other interventions.

Evaluation of pediatric cadaver kidneys transplanted into adult recipients receiving cyclosporine

The major problem in clinical transplantation is the imbalance between the need for cadaveric organs and the available numbers of donors. If pediatric kidneys were transplanted into adult recipients when no pediatric recipient was available, the potential number of renal donors would be increased by 15 to 20%. Some centers are reluctant to use pediatric kidneys for adult recipients because of recent reports indicating poorer patient and allograft survival, increased delayed graft function, increased post-transplant hypertension and increased technical complication. (There also has been concern that the nephrotoxic effect of cyclosporine A would retard the organ growth that is necessary to provide normal renal function in adults.) A retrospective analysis was performed on 18 adult recipients who received kidneys from cadaver donors 14 months to 12 years old (group 1). These patients were compared to 106 adult recipients who received kidneys from donors greater than 12 years old (group 2). Actuarial patient survival at 1 year was 85% for group 1 and 95.8% for group 2 (p equals 0.13), while 1-year actuarial allograft survival was 83.1% for group 1 and 81.1% for group 2 (p equals 0.87). There was no significant difference between groups 1 and 2 in the frequency of delayed graft function, serum creatinine at 1, 3 and 6 months after transplantation, incidence of post-transplant hypertension or frequency of surgical complications. It is of interest that the pediatric kidneys had significant growth during the initial post-transplant month. Sonographic examination at postoperative days 1 and 30 demonstrated a mean increase in size from 80.7 to 143.5 cm. (p less than 0.001). In this series pediatric kidneys were safe and effective donor organs in adult recipients, and increased the available number of organs by 15%.

Physostigmine treatment of progressive supranuclear palsy

Cognitive and extrapyramidal effects of cholinomimetic therapy were evaluated in 8 patients with progressive supranuclear palsy. Each was randomized to a 10-day double-blind crossover trial of physostigmine and placebo. Physostigmine treatment was associated with marginal and inconsistent changes in long-term memory, suggesting that cholinergic therapy alone is insufficient to restore cognitive function. Motor scores remained unchanged.

Memory impairment in patients with progressive supranuclear palsy

Verbal memory was compared in 12 patients with progressive supranuclear palsy and 12 healthy control subjects matched for age, sex, and education. Learning, consolidation, and retrieval were significantly impaired in patients with progressive supranuclear palsy. Information scanning, which requires the use of short-term memory processes, remained intact. Duration of symptoms and degree of motor dysfunction correlated with intrusions during learning. No relation between central dopamine metabolism and memory dysfunction could be established.

Alkaloids from Rauwolfia cubana Stem Bark

Six indole alkaloids, tetrahydroalstonine, aricine, 16- EPI-affinine, ajmaline, amerovolfine, and amerovolficine have been isolated from the ethanolic extract of the stem bark of RAUWOLFIA CUBANA A. DC. Amerovolfine ( N(alpha)-demethylaccedine) and amerovolficine (16-demethoxy-carbonylpagicerine) are new alkaloids related to 16- EPI-affinine, and their structures have been determined by spectroscopic analysis.

In vitro evaluation of lomefloxacin activity in Colombia

As part of the worldwide in vitro program to determine the antimicrobial activity of lomefloxacin, our study tested susceptibility of bacterial isolates from hospitals in Medellin, Colombia. A total of 504 bacterial isolates were obtained from patients at three different centers. For Enterobacteriaceae, 0.5 micrograms/ml inhibited 100% of the indole-positive Proteus and Salmonella spp.; 1 microgram/ml inhibited 100% of Shigella and Citrobacter, 2 microgram/ml inhibited 100% of Enterobacter spp., E. coli, Proteus mirabilis, and Serratia marcescens isolates tested. The MIC90 for Klebsiella spp. and Pseudomonas spp. was 4 micrograms/ml. The MIC90 was 4 micrograms/ml for S. aureus and 2 micrograms/ml for S. epidermidis and S. saprophyticus. The MIC90 of Streptococcus spp. were less than or equal to 4 micrograms/ml for all isolates tested. Considering that 97.8% were susceptible to concentrations of less than or equal to 4 micrograms/ml of lomefloxacin, this new quinolone offers potential in the therapy of a variety of systemic infections, especially in patients with multiply resistant pathogens.

Restricted use of T cell receptor V genes in murine autoimmune encephalomyelitis raises possibilities for antibody therapy

Experimental allergic encephalomyelitis (EAE) is a paralytic autoimmune disease induced in susceptible animals by active immunization with myelin basic protein (MBP) or by passive transfer of MBP-specific T helper (TH) lymphocytes. We have analyzed the T cell receptor genes of 33 clonally distinct TH cells specific for a nonapeptide of MBP inducing EAE in B10.PL (H-2u) mice. All 33 TH cells used two alpha variable gene segments (V alpha 2.3, 61%; V alpha 4.2, 39%), the same alpha joining gene segment (J alpha 39), and two V beta and J beta gene segments (V beta 8.2-J beta 2.6, 79%; V beta 13-J beta 2.2, 21%). The anti-V beta 8 monoclonal antibody F23.1 was found to block completely recognition of the nonapeptide by V beta 8 TH cells in vitro and to reduce significantly the susceptibility of B10.PL mice to peptide-induced EAE.

Scanning electron microscopy and electron probe microanalyses of the crystalline components of human and animal dental calculi

A review of the use of scanning electron microscopy (SEM) and electron probe microanalyses in the study of dental calculus showed that such studies provided confirmatory and supplementary data on the morphological features of human dental calculi but gave only limited information on the identity of the crystalline or inorganic components. This study aimed to explore the potential of combined SEM and microanalyses in the identification of the crystalline components of the human and animal dental calculi. Human and animal calculi were analyzed. Identification of the crystalline components were made based on the combined information of the morphology (SEM) and Ca/P molar ratios of the crystals with the morphology and Ca/P molar ratio of synthetic calcium phosphates (brushite or DCPD; octacalcium phosphate, OCP; Mg-substituted whitlockite, beta-TCMP; CO3-substituted apatite, (CHA); and calcite. SEM showed similarities in morphological features of human and animal dental calculi but differences in the forms of crystals present. Microanalyses and crystal morphology data suggested the presence of CaCO3 (calcite) and CHA in the animal (cat, dog, tiger) and of OCP, beta-TCMP and CHA in human dental calculi. X-ray diffraction and infrared (IR) absorption analyses confirmed these results. This exploratory study demonstrated that by taking into consideration what is known about the crystalline components of human and animal dental calculi, combined SEM and microanalyses can provide qualitative identification.

Xyloside inhibits synthesis of the class II-associated chondroitin sulfate proteoglycan and antigen presentation events

An alternative form of the human invariant chain exists as a chondroitin sulfate proteoglycan (CSPG) with invariant chain as the core protein. The selective inhibitor of proteoglycan synthesis, p-nitrophenyl beta-D-xyloside was used to study the role of this CSPG in class II biology. At xyloside concentrations of 2.5 and 5.0 mM, CSPG synthesis was completely inhibited with marginal inhibition of protein synthesis. The inhibitory effect on CSPG synthesis was completely reversible. The number of class II molecules on the cell surface was not affected by xyloside, but biosynthesis and appearance of newly synthesized class II molecules at the cell surface were both decreased by xyloside. Recognition of influenza virus-infected cells by class II-restricted, virus-specific cytotoxic T lymphocytes was not diminished by the presence of xyloside in the effector phase of the cytotoxicity assay. However, sensitization of target cells was markedly inhibited when target cells were exposed to virus in the presence of xyloside. These results are consistent with the hypothesis that the CSPG form of invariant chain has a role in antigen processing.

Xyloside inhibits synthesis of the class II-associated chondroitin sulfate proteoglycan and antigen presentation events

An alternative form of the human invariant chain exists as a chondroitin sulfate proteoglycan (CSPG) with invariant chain as the core protein. The selective inhibitor of proteoglycan synthesis, p-nitrophenyl beta-D-xyloside was used to study the role of this CSPG in class II biology. At xyloside concentrations of 2.5 and 5.0 mM, CSPG synthesis was completely inhibited with marginal inhibition of protein synthesis. The inhibitory effect on CSPG synthesis was completely reversible. The number of class II molecules on the cell surface was not affected by xyloside, but biosynthesis and appearance of newly synthesized class II molecules at the cell surface were both decreased by xyloside. Recognition of influenza virus-infected cells by class II-restricted, virus-specific cytotoxic T lymphocytes was not diminished by the presence of xyloside in the effector phase of the cytotoxicity assay. However, sensitization of target cells was markedly inhibited when target cells were exposed to virus in the presence of xyloside. These results are consistent with the hypothesis that the CSPG form of invariant chain has a role in antigen processing.

Calcium and calcitonin responses to calcium infusion in type I diabetes mellitus

We studied calcium and calcium and calcitonin responses to intravenous calcium infusion (3 mg of elemental calcium/kg of body weight in 10 minutes) in 21 type I diabetic males and 17 age-matched normal males. Baseline total calcium, parathyroid hormone and calcitonin levels were normal in the diabetic group, but ionized calcium was lowered. Cortical bone status and osteocalcin levels were normal, suggesting a normal osteoblastic function. Total calcium and ionized calcium responses to calcium infusion were lowered in the diabetic group. Despite these lowered calcaemic responses, calcitonin secretion was normal.

AB variant GM2 gangliosidosis: cerebrospinal fluid and neuropathologic characteristics

A child with AB variant GM2 gangliosidosis who had progressive intellectual deterioration and seizures commencing at the age of 12 months is described. Neuronal loss, and neuronal and astrocytic inclusions characteristic of the gangliosidoses, were seen on cortical biopsy. GM2 ganglioside was detected in the CSF. As CNS ganglioside accumulation in this condition occurs in the presence of normal leukocyte hexosaminidase A and B levels, spinal fluid assay for GM2 ganglioside may serve as a valuable aid in diagnosis.

A comparative analysis of the development of the primary somatosensory cortex: interspecies similarities during barrel and laminar development

The development of the barrels and layers II-V was examined in Nissl-stained preparations of the primary somatosensory cortex in six species--hamster, mouse, rat, gerbil, rabbit, and guinea pig--that have increasingly longer gestation periods. The barrels and layers II-V begin to differentiate postnatally during the first week postpartum in the hamster, mouse, rat and gerbil; perinatally in the rabbit; and approximately 4 weeks prenatally in the guinea pig. The structure of the barrels and layers II-V is similar at the onset of their differentiation in each species, even though there are interspecies differences in the mature structure of the barrels and layer V. The rate of the initial differentiation of the barrels and layers II-V is also similar in each species, even though there are considerable interspecies differences in the duration of the preceding period of development. In each species, layer V begins to differentiate first from the cortical plate and, within 1 or 2 days, contains sublayers that eventually disappear in the rabbit and guinea pig. About 3 days after the initial differentiation of layer V, layers II-IV begin to differentiate, seemingly simultaneously, causing the cortical plate to have a trilaminar appearance. Barrels are first evident just before the appearance of the trilaminar plate in hamsters; concomitant with the trilaminar plate in mice, rats, and guinea pigs; and just after the trilaminar plate in gerbils and rabbits. Septa appear 1 or 2 days after the barrels except in rabbits, which never have septa. Barrel maturation proceeds rapidly after the initial appearance in all species except the hamster, in which continued maturation seems to be delayed until the appearance of the trilaminar plate. The barrels in immature rats and rabbits become more prominent than they will eventually be in the adults. Our results indicate a close and rapid developmental affiliation between layers II-V, especially layers II-IV, that seems quite separate from the development of layers I and VI. However, barrel development and differentiation of layers II-IV seem to be closely, but independently initiated. Secondary remodeling occurs in layer V and the barrels of some species.

Hypersomnia, bithalamic lesions, and altered sleep architecture in Kearns-Sayre syndrome

An 11-year-old boy with Kearns-Sayre syndrome developed hypersomnia associated with bithalamic lesions and had complete absence of sleep spindles on a nocturnal polysomnogram.

No influence of number of donor CFU-GM on granulocyte recovery in bone marrow transplantation for acute leukemia

The possible interrelation between infused bone marrow CFU-GM and peripheral granulocyte recovery was studied in 16 patients transplanted for acute leukemia. The influence of several clinical events that could modify the graft fate were also analysed. Our results show that: 1) There was no correlation between the number of infused nucleated cells and granulocyte recovery. 2) There was no correlation between the number of infused CFU-GM and granulocyte regeneration. 3) There were significant differences between the day of engraftment in patients with clinically documented HSV infection compared to patients without infection.