Myopathies of the lower extremities

The myopathies that can manifest themselves within the lower extremity are reported here and can serve as a guideline for clinicians in the early diagnosis of these disabling conditions. The classification of these disease entities based on signs and symptoms is significant if correlated with the age of the patient at the time of onset, the evolution and course, and the type of familial inheritance. This article can also aid the practitioner in assessing and planning the course of treatment for a particular patient.     

Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography

The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study.     

Pharmacological analysis of the interaction between Bay K 8644 and 5-HT in rabbit aorta

Bay K 8644 potentiated and augmented 5-hydroxytryptamine (5-HT)-induced contractions in the rabbit, isolated aorta preparation, as manifested in leftward shift and increase in the asymptote of 5-HT E/[A] (effect vs concentration) curves. The operational model of agonism (Black & Leff, 1983) was used to analyse this interaction and the concomitant effects of irreversible receptor alkylation by phenoxybenzamine. The competitive effects of spiperone in the presence and absence of Bay K 8644 were also examined. From these analyses it is concluded that Bay K 8644 elicits its potentiating effects by increasing the efficacy of 5-HT at the 5-HT2 receptor with no alteration in affinity. This is consistent with the known effect of Bay K 8644 of causing an increase in the functional concentration of plasmalemmal calcium channels coupled to the 5-HT2 receptors in this preparation. The positively co-operative shape of the 5-HT E/[A] curves obtained in the aorta and the quantitative nature of their potentiation by Bay K 8644 indicated that the coupling of 5-HT2 receptor occupancy to intracellular calcium concentration is linear and that the co-operativity resides in the subsequent relation between intracellular calcium and pharmacological effect. Bay K 8644 may serve as a probe for differentiating between the types of calcium channels that transduce 5-HT receptor-mediated effects in different systems. Such information would be useful in the classification of agonist interactions with 5-HT receptors.     

Primary lymphoma of prostate: transrectal ultrasonic appearance

In the case presented, primary lymphoma of the prostate was diagnosed by ultrasonically guided transrectal biopsy. Primary lymphoma of the prostate should be included in the differential diagnosis of a hypoechoic lesion found on ultrasonic evaluation of the prostate in a young adult.     

Drugs and the bone marrow

Some drugs have a predictable suppressive effect upon the bone marrow and are used in the treatment of malignant disease. Others are unpredictable and may cause unanticipated side effects to bone marrow during the treatment of non-malignant pathologies. In this article, bone marrow maturation is discussed and both the defined and potential effects of drugs upon the bone marrow are considered.     

Immunosuppressive agents in current use

The use of immunosuppressants has increased as clinical applications for such therapy have become more widespread. Immunosuppressive therapy is now particularly relevant in the field of organ transplantation, a practice that has only developed over the last 20 years. Drugs used as immunosuppressants are discussed in relation to disease category, where they are of value, mode of action, and potential side effects. Future prospects concerning the development and use of immunosuppressants are considered.     

Paediatric dacryocystorhinostomy

Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease.