Attempted rapid elbow flexion movements in patients with athetosis.

Voluntary rapid elbow flexion movements were studied in 14 patients with athetosis on the basis of cerebral palsy. When the movement was attempted with one arm, other muscles inappropriate for the task, such as muscles in the opposite limb, were also activated. EMG activity of the biceps and triceps was analysed in detail, and the patterns seen in the different patients were divided into six groups: (1) The normal "ballistic" triphasic pattern, with bursts of normal duration, alternating in biceps and triceps, but the triceps might be activated first, causing the limb to extend rather than flex, (2) The triphasic pattern, with bursts of long duration, (3) Repetitive cycles of the triphasic pattern with particularly long antagonist bursts, apparently limiting the movement in each cycle, (4) Long bursts synchronous in agonist and antagonist muscles, (5) Continuous activity of the agonist, with reduction in activity of the antagonist, (6) Failure to be able to do the task. The pathophysiology of athetosis is that voluntary movement is characterised by excessive muscular activity, most prominently in inappropriate muscles, both extraneous to the task and directly antagonistic.     

Sub-populations of smaller diameter trigeminal primary afferent neurons defined by expression of calcitonin gene-related peptide and the cell surface oligosaccharide recognized by monoclonal antibody LA4.

Summary Immunocytochemistry has been used to examine the trigeminal ganglion cell populations in the rat which express calcitonin gene-related peptide (CGRP) and the oligosaccharide antigen recognized by the monoclonal antibody LA4. Calcitonin gene-related peptide and LA4 identify two large but mainly separate populations of trigeminal ganglion cells. Depending on the method of assessment used, CGRP-immunoreactive cells represent 29–37% of trigeminal ganglion cells while LA4 labels 26–40% of the cells, but with only 8% overlap between the two populations. Both CGRP and LA4 label predominantly small diameter cells (mean diameters 23 m and 25 m respectively) but with CGRP cells exhibiting a greater range of diameters than LA4 cells. The cell sizes indicate that small diameter CGRP-immunoreactive cells and most LA4-immunoreactive cells are likely to have unmyelinated axons, and together the two populations can account for the great majority of unmyelinated trigeminal primary afferent neurons. Centrally, CGRP and LA4 show distinct patterns of staining. Thus although both antigens are found in lamina II of subnucleus caudalis of the spinal trigeminal nucleus, CGRP is most abundant in lamina I and lamina II outer while LA4 irnmunoreactivity is most dense in lamina II inner. In addition CGRP-, but not LA4-, immunoreactive fibres occur in the magnocellular portion of caudalis. Previous studies have show that in rat dorsal root ganglion cells CGRP coexists with most other known neuropeptides and can therefore be used as a general marker for peptide-containing primary afferents. In contrast LA4 labels a cell population which is probably largely identical to that identified by the presence of fluoride resistant acid phosphatase or by the binding of lectins such as Griffonia simplidfolia isolectin B4 and this population does not contain neuropeptides. Our results thus provide further evidence that unmyelinated primary afferents can be divided into peptide and non-peptide containing subpopulations and that these populations innervate distinct regions of laminae I and II.     

Dermatosis among the Xavánte from the Pimentel Barbosa Indian Reservation, Mato Grosso, (Brazil)

The authors present the results of a dermatological survey conducted among the Xavánte Indians from the Pimentel Barbosa Reservation, state of Mato Grosso, Brazil Scabies, pediculosis, and pioderma were the most frequent diseases, clearly related to poor hygiene. The finding of perleche indicates the presence of nutritional deficiency. Endemic pemphigus foliaceus (fogo selvagem) was the most serious dermatological affection found in this population.     

Pressure ulcers: critical considerations in prevention and management

Pressure ulcer development is a serious problem occurring predominately among elderly persons, who are confined to bed or chair. Factors associated with pressure ulcer development include: cerebrovascular accident, impaired nutritional intake, fecal incontinence, lymphocytopenia and a high comorbidity score. Implementation of preventative measures, such as: in-depth assessment for mobility, a pressure relieving device combined with adequate repositioning, thorough evaluation for nutritional status and urinary incontinence, significantly reduce pressure ulcer incidence. If the pressure ulcer is a partial thickness (Stage II) wound, the causative factors are probably friction and/or moisture. If the ulcer is full thickness (Stage III, IV) it is secondary to pressure and/or shearing forces. The development of wound infection is the most common complication. Osteomyelitis is not an uncommon occurrence and must be initially ruled out in all full thickness pressure ulcers. Surgical debridement of necrotic tissue is necessary prior to further treatment and /or assessments. Cultures and antibiotic therapy are indicated only upon evidence of infection (erythema, edema, cellulitis, osteomyelitis, leukocytosis, bandemia or fever). Topical pharmacologic agents may be used to prevent or treat infection but must be carefully controlled to avoid such adverse effects as toxicity to the wound, allergic reaction and development of resistant pathogens. Proper use of occlusive dressings increase patient comfort, enhance healing, decrease the possibility of infection, save time and reduce costs. A patient presenting an ulcer which fails to improve, or due to its size will take a great deal of time to heal, should be evaluated for surgical closure.     

Microfluorometry of nuclear acridine orange metachromasia in lymphocytes of thymus, spleen, and blood of AKR and random-bred mice.

Lymphocyte chromatin lability to acid hyrolysis was studied using acridine orange fluorescence metachromasia in a high-lymphocytic-leukemia-susceptibility strain (AKR) and random-bred mice (ICR). Comparisons were made of blood, thymus, and spleen lymphocytes between random-bred, "normal" AKR, and leukemic AKR animals. The leukemic mice were in the stages of the disease characterized by enlarged thymus and spleen but preceding massive elevation of blood lymphocytes. The ranges of the mean chromatin acid lability overlapped and were nearly identical in peripheral blood lymphocytes. However, thymic and splenic lymphocytes showed a marked rise in mean chromatic acid lability in the leukemic animals. The ranges of the mean values of this parameter were also found to be far greater in the lymphopoietic organs of normal AKR than in the random-bred mice. The data indicate that anatomically normal AKR animals of an age in which they are highly susceptible to spontaneous lymphocytic leukemia may contain a greater number of lymphoblasts in both the spleen and the thymus than do comparable random-bred mice. The implications of these findings are discussed in relation to strain differences and the concept of thymic origin of lymphocytic leukemia in mice.     

Molecular basis of cancer and clinical applications

This article attempts to show the vertiginous advances that exist today in the concept of what cancer is. The authors chose some multiple biologic concepts that have enabled the progress in the knowledge of this disease to occur at a speed no one could imagine until recently. Although the areas and biologic problems that remain to be solved are more numerous and complex than they expected, the basic fundamentals already partially understood and the multidisciplinary integration of the various medical specialties with biomolecular research enable physicians to face the next millennium with great optimism about the possibilities of therapeutic success, prevention, and effective early diagnosis.