Biomedical subjects

A M Harding

Publications and source records attributed to A M Harding.

5 recordsLinked to original sources

PubMed1995

Traumatic injuries in the preschool child.

The dental management of traumatic injuries in the preschool child demands a careful and methodical approach to the clinical patient care. Insurance claims and litigation possibilities require detailed documentation of the accident, the nature and extent of the injury and all treatment rendered, follow-up care, and verbal instructions given to the parent. The prognosis of the treatment and the damage to the permanent teeth depend upon the nature and extent of the injury and, in part, upon the treatment rendered and the follow-up care received by the patient. The dental records must be retained until the permanent teeth erupt to fully assess the extent of the damage to the developing dentition.

Child Abuse↗

PubMed1994

Calcium fluoride formation on sound enamel using fluoride solutions with and without lactate.

The formation of calcium (Ca) fluoride (CaF2) on bovine enamel blocks during clinically relevant treatment times using neutral fluoride (F) solutions (0.26 mol/l F) with and without 0.1 mol/l lactate was investigated. Uncoated and pellicle-coated blocks were evaluated for alkali-soluble (1 mol/l KOH, three consecutive 24-hour treatments) Ca, PO4, and F after treatment by the F solutions for 0, 5, 15, 30, and 60 min. There was an overall time-related increase in F recovery, while Ca tended to remain at baseline levels. Less F was recovered from the pellicle-coated blocks. The addition of lactate to the F treatment solution did not result in an overall increase in alkali-soluble F recovery, but did result in the formation of cuboidal shaped crystals which closely approached the morphology of pure CaF2. A 1:2 stoichiometric ratio Ca:2F (mol:mol) was not established based on chemical analyses. The ultrastructural and elemental composition of surface deposits on the samples, as determined using scanning electron microscopy, X-ray diffraction, and energy-dispersive spectroscopy, established the presence of CaF2 after 24-hour F treatments; however, it was not possible to directly demonstrate the formation of CaF2 after clinically relevant treatment times.

Animals↗

PubMed1994

Pharmacologic considerations in pediatric dentistry.

The unique physical, emotional, and developmental characteristics of the growing child make dental care particularly challenging for the practitioner. Children are not simply small adults, and the principles of adult pharmacotherapeutics are not easily extrapolated to "fit" the profile and needs of the child. Unfortunately, there is a paucity of literature concerning the use of pharmacologic agents in pediatric dentistry. This has been attributed largely to the fears and difficulties associated with working with children. In the literature available, comparison of studies and compilation of information are frequently impossible because of differences in selection criteria, study populations, and drug regimens used. Despite these difficulties, when young patients appear with pain, anxiety and infection, they must depend on the skills and knowledge of the practitioner to resolve their problem. Children have difficulties in locating or expressing pain, and fear may prevent any communication at all. The diagnosis and prevention of pain, anxiety, and infection are within the jurisdiction of the dentist and the parents. A working knowledge of the current trends in pharmacologic management of pain, infection, and anxiety enables the dentist to better treat and educate the parents in effective prevention, treatments, and therapy. The use of pharmacotherapeutic agents in unskilled hands can be potentially disastrous in children. Practitioners should use only those drugs in which they have been well trained to avoid excessive risk to the patient. The manufacturer's recommended dose should be followed carefully; if in doubt, consultation with the child's pediatrician is appropriate.

Analgesics↗

PubMed1991

A comparison of swim-down and swim-up methods for the extraction of high motility sperm.

High quality motile sperm are essential for the success of the in vitro fertilization-embryo transfer program and related procedures, for the performance of sperm antibody assays, and other in vitro tests of sperm function. Two methods for the extraction of high motility sperm, swim-down and swim-up, were compared on 30 ejaculates, and sperm motility was assessed at intervals up to 18 hours. The swim-down method was simpler, shorter, and provided a significantly better recovery of sperm with sustained high motility than did the swim-up method.

Analysis of Variance↗

PubMed1983

Systolic anterior motion of the posterior mitral leaflet: a previously unrecognized cause of dynamic subaortic obstruction in patients with hypertrophic cardiomyopathy.

Dynamic obstruction to left ventricular outflow in patients with hypertrophic cardiomyopathy usually occurs when the anterior mitral leaflet moves forward in systole and approaches or contacts the ventricular septum. However, we have recently identified, by M mode and two-dimensional echocardiography, 21 patients with hypertrophic cardiomyopathy who had a unique pattern of mitral valve motion characterized by abnormal mitral valve coaptation and systolic anterior motion of the posterior mitral leaflet. This abnormality of mitral valve motion was most reliably identified with two-dimensional echocardiography in views of the left ventricle obtained from the apex. At end-diastole the anterior and posterior mitral leaflets did not appear to coapt at their distal free margins. Rather, at mitral valve closure, the anterior mitral leaflet contacted the basal portion of posterior mitral leaflet. Subsequently, during systole the "residual" distal portion of posterior mitral leaflet approached or contacted the ventricular septum. Morphologic observations in nine other patients with hypertrophic cardiomyopathy suggested that systolic anterior motion of the posterior mitral leaflet is due to elongation of the middle scallop of the posterior leaflet, which probably comes into apposition with the ventricular septum during systole by passing through the space created by the normal pattern of chordal attachments onto the anterior mitral leaflet. Of the 16 patients who underwent cardiac catheterization, nine had basal subaortic gradients of 20 to 85 mm Hg, which were apparently due to moderate or marked systolic anterior motion of the posterior mitral leaflet. Ventricular septal myotomy-myectomies were performed in two patients and resulted in markedly diminished systolic anterior motion of the posterior mitral leaflet in each and abolition of subaortic gradient in the one patient who underwent postoperative cardiac catheterization. Hence, in patients with hypertrophic cardiomyopathy, systolic anterior motion of the posterior mitral leaflet (1) is not uncommon (identifiable in about 10% of a consecutively studied series of patients), (2) constitutes a previously undescribed mechanism for dynamic subaortic obstruction, and (3) is due to a malformation of the posterior mitral leaflet.

Adolescent↗