A digital master hearing aid

The use of computer simulation in evaluating conventional and experimental hearing aids is described. Two illustrative examples are provided. The first involves the simulation of a conventional master hearing aid and its application in evaluating different adaptive strategies in the prescriptive fitting of hearing aids. The second example involves the simulation of an experimental hearing aid embodying modern digital signal-processing techniques for the reduction of background noise. A high-speed array processor is used in order to accomplish these simulations in real time.

A history of acute suppurative otitis media and allergic symptomatology in children with chronic secretory otitis media and controls

The parents of children with secretory otitis media and the parents of healthy children attending for routine school or community medical examinations have been questioned about previous acute otitis media, aural discharge, chronic nasal symptoms and allergic disorders. Eighty-nine pairs of children, matched for age and sex, were available for analysis. There was a significantly higher incidence of acute otitis media, aural discharge and chronic nasal symptoms in the secretory otitis group (P = less than 0.001). Amongst the allergic symptoms and disorders, the only significant differences demonstrated were for drug allergy, eye itching and eye running (P = less than 0.05). The results confirm that a relationship exists between acute otitis media and secretory otitis media and also support the conventional image of the child with secretory otitis as a mouth breather with nasal symptoms. They do not lend support to the view that allergy is an important factor in the pathogenesis of secretory otitis.

Relationship between acute suppurative otitis media and chronic secretory otitis media: role of antibiotics

A total of 204 chronic middle ear effusions from 122 children have been studied. Bacteria were isolated from 30 effusions. The commonest species found were Strep. pneumoniae and H. influenzae. These are also the commonest organisms causing acute otitis media (AOM). A similar pattern of serotypes was also demonstrated. In vitro sensitivity testing showed that most of the organisms isolated were sensitive to most commonly-used antibiotics. The main exception was resistance to penicillin amongst strains of H. influenzae and Staph. aureus. It is suggested that some cases of chronic secretory otitis media (SOM) may arise as a result of incomplete resolution of AOM and that the use of penicillin to treat AOM may be one factor in this process.

Isolation and Identification of Piperacillin Amide as an Impurity in Piperacillin

Piperacillin amide (IV) was successfully identified as the predominant impurity in commercial lots of piperacillin monohydrate (III). The impurity was isolated via a preparative liquid chromatographic scheme utilizing Florisil as the adsorbent and a mobile phase of water-acetonitrile (4:96, v/v). The isolated component had nearly the same reverse-phase HPLC properties as piperacillin and was chemically and thermally unstable. This labile impurity was spectroscopically identified by field desorption (FD), fast atom bombardment (FAB) with collision activation decomposition (CAD), and desorption chemical ionization (DCI) mass spectrometries , and NMR and IR spectrometries . Identity was confirmed on comparison of the chromatographic and spectrometric data of the impurity with an independently synthesized sample of piperacillin amide.

Hexosaminidase: a biochemical marker for necrotizing enterocolitis in the preterm infant

To evaluate hexosaminidase as a biochemical marker for the early detection of necrotizing enterocolitis in preterm infants, 33 preterm infants without necrotizing enterocolitis and 18 preterm infants with necrotizing enterocolitis had hexosaminidase activity measured during the course of their hospitalization. Although hexosaminidase activity could not identify those preterm infants with necrotizing enterocolitis who had impending perforation, the data strongly suggest that measurements of serum hexosaminidase activity may provide an early biochemical indication of the presence of necrotizing enterocolitis in the preterm infant. Hopefully, early detection of necrotizing enterocolitis in these infants will reduce the morbidity and mortality of this disease.

Comparison of synthetic adhesive moisture vapor permeable and fine mesh gauze dressings for split-thickness skin graft donor sites

SAM and fine mesh gauze dressings were compared on 60 consecutive skin graft donor sites. SAM dressings are significantly better than fine mesh gauze dressings for healing of split-thickness skin graft donor sites; healing occurs much more rapidly with much less pain. In patients known to be colonized with Pseudomonas, care should be taken when using SAM dressings, although it is not an absolute contraindication. There were no clinically significant differences between Tegaderm and Op-Site.

Scalp as skin graft donor site: rapid reuse with synthetic adhesive moisture vapor permeable dressings

Synthetic Adhesive Moisture vapor permeable (S.A.M.) dressings, Op-Site and Tegaderm, are compared to Fine Mesh Gauze (F.M.G.), as a dressing for split-thickness skin graft donor sites. Scalp as a donor site is compared to nonscalp donor sites. The combination of S.A.M. dressings and scalp as a donor site allows for rapid reuse of a donor site. Pain is substantially decreased and rate of healing is increased when this combination is used. The scalp, because of its availability, accessibility, excellent color match for facial grafting, and rapid healing, is recommended as a donor site.

Chronic blockade of sciatic nerve transmission by tetrodotoxin does not produce central changes in the dorsal horn of the spinal cord of the rat

Rat sciatic nerves were treated with tetrodotoxin (TTX) for 4--10 days, by implanting a glass capillary tube filled with TTX into the nerve through the epineurium. Following this treatment the somatotopic organization of receptive fields in the L4 dorsal horn, an area of cord normally responding only to foot stimulation. The map was normal in animals treated with TTX. Dorsal horn levels of fluoride-resistant acid phosphatase, substance P, somatostatin, cholecystokinin-like peptide, neurotensin and neurophysin were also normal as assessed from density of staining. These results are discussed in the light of the positive changes that are seen following chronic sciatic nerve section.

Mutual diffusion, intradiffusion and viscosity coefficients for mixtures of cyclopentane and cyclooctane at 298.15 K

Mutual diffusion, intradiffusion and viscosity coefficients have been measured at 298.15 K for the system cyclopentane (1)+cyclooctane (2). The mutual diffusion coefficient extrapolates to Do21 2.361×10-9 m s-1 for pure cyclopentane and to D°12 0.793x 10-9 m s-1 for pure cyclooctane and these values are in good agreement with the corresponding tracer-diffusion ones. The viscosity and intradiffusion coefficients vary from 0.415 × 10-3 kg m-1 s-1 and 3.114 × 10-9 m2 s-1 for pure cyclopentane to 2.250 × 10-3 kg m-1 s-1 and 0.546 × 10-9 m2 s-1 for pure cyclooctane. ��� It is shown that the intradiffusion and viscosity coefficients can be related through the Stokes-Einstein equation. The diffusion measurements have been transformed to velocity cross-correlation coefficients and it is found that there appear to be no special associative effects or structural features in this system.

An anatomy of hope

This paper speaks of hope as a state of being that originates in conditions of despair and is transformed as a function of its participation in transcendent relationships. In transcendence of self, one establishes the dynamic awareness of that peace which enlarges the self to accommodate life's anguish.

Acute visual loss during pregnancy after bromocriptine-induced ovulation. The elusive tumor

The evaluation of patients complaining of amenorrhea with or without galactorrhea has been greatly enhanced by the availability of serum prolactin determinations and advances in diagnostic radiology. Likewise, the treatment of these patients with ergot derivative has resulted in the return of normal menses, and many pregnancies have been reported. The present report is of a patient with hyperprolactinemic amenorrhea-galactorrhea successfully treated with bromocriptine. A pregnancy followed resumption of menses, and a suprasellar cromophobeadenoma became manifest by producing blindness of the patient. The case is presented with recommendations for diagnosis and treatment.

Gluteus maximus myocutaneous flaps for repair of pressure sores

Myocutaneous flaps based on the gluteus maximus muscle, and its blood supply, have many advantages for the surgical repair of pressure sores in paraplegics. These are described, as well as the techniques used in various areas.