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Biomedical subjects

D O Morris

Publications and source records attributed to D O Morris.

At least 19 recordsLinked to original sources
PubMed2005

Humoral measurement of type-1 hypersensitivity reactions to a commercial Malassezia allergen.

Malassezia pachydermatis is considered to be a contributing factor to canine atopic dermatitis (AD). The purpose of this study was to investigate the humoral response to a commercially produced M. pachydermatis extract. Fifteen atopic dogs with Malassezia overgrowth on the skin (MD), 16 atopic dogs without MD, three atopic dogs with overgrowth of Malassezia in the ears only (MO), and 12 normal dogs were intradermally tested with M. pachydermatis extract at 50, 100, 250, 500, 1000, 2000 and 4000 PNU mL(-1). All dogs were evaluated cytologically by cutaneous tape strip and bilateral ear exudate sampling to determine presence of MD or MO. Each had serum evaluated for anti-Malassezia IgE using three Malassezia extracts with an ELISA assay. The irritant threshold concentration at which healthy nonatopic dogs ceased to react was 1000 PNU mL(-1). There was a significant difference in intradermal test reactivity between the atopic groups. At this dilution, 93% (14/15) of the atopic MD group, 31% (5/16) of the atopic group without MD or MO, and 100% (3/3) of the atopic MO only group reacted. There were no significant differences in the serum IgE levels as measured by the Greer ELISA assay, between any groups using any of the three extracts. These results support that Greer's M. pachydermatis extract is useful for intradermal testing of dogs with an allergic phenotype, and that atopics with MD are more likely to have a type-1 Malassezia hypersensitivity than those without. The ELISA assay may require further development in order to be useful for the diagnosis of Malassezia hypersensitivity.

Allergens↗
PubMed2003

Orthodontic preparation for orthognathic surgery: how long does it take and why? A retrospective study.

We investigated the duration of pre-operative orthodontic treatment of patients who had combined orthodontic and orthognathic treatment and examined the variables that influenced this. Records of patients who had undergone such treatment in the past 5 years were collected (n=65) from three consultant orthodontists and one Senior Specialist Registrar/Fixed Term Training Appointment (FTTA). The number of days from placement of the first active orthodontic component to the day that final planning impressions were taken was used to calculate the duration of treatment before the patient was ready for operation. The variables investigated were: sex, age, malocclusion, extractions (excluding third molars), and the clinician. The median duration of pre-operative treatment was 17 months (range 7-47). Only the orthodontist appeared to affect this duration, but this requires further investigation as it may merely reflect variation in other factors such as compliance. We conclude that patients should be informed that the pre-operative phase may last 12-24 months.

Adolescent↗
PubMed2003

Forestadent Young Specialist Prize (1999).

This paper describes the clinical orthodontic treatment of the three cases that were awarded the 1999 Forestadent Young Specialist Prize. There are two Class II division 1 cases treated by different treatment modalities and a Class II division 2 case complicated by a palatally ectopic maxillary canine. These case reports demonstrate the three main treatment modalities available to the orthodontist for treating skeletally-based malocclusions, i.e. growth modification, orthodontic camouflage, and a combined surgical-orthodontic approach.

Adolescent↗
PubMed2001

Dermatologic disorders in dogs with diabetes mellitus: 45 cases (1986-2000).

OBJECTIVE: To characterize skin lesions and causative infections in diabetic dogs and evaluate other potential causes of dermatologic disorders, including concurrent endocrinopathies, allergic skin disease, and long-term corticosteroid administration. DESIGN: Retrospective study. ANIMALS: 45 dogs with diabetes mellitus (DM) that were examined by dermatologists. PROCEDURE: Medical records were reviewed for signalment; allergic conditions prior to development of DM; prior corticosteroid administration; and results of dermatologic examinations, ear and skin cytologic examinations, skin scrapings for parasites, bacteriologic and fungal culturing of ear and skin specimens, histologic examinations, and endocrine testing. RESULTS: Bacterial skin infection was the most common dermatologic disorder (n = 38 [84%]), followed by otitis (26 [58%]) and Malassezia-induced dermatitis (19 [42%]). Twenty-two (49%) dogs had pruritic skin disease consistent with allergic dermatitis, which preceded diagnosis of DM. Prior corticosteroid administration was reported in 21 (47%) dogs. Concurrent hyperadrenocorticism was diagnosed in 13 (29%) dogs, and concurrent hypothyroidism was diagnosed in 5 (11%) dogs. Iatrogenic hyperadrenocorticism was diagnosed in 1 additional dog. Only 10 (22%) dogs did not have a documented concurrent endocrinopathy or allergic disease that could have caused the dermatitis. CONCLUSIONS AND CLINICAL RELEVANCE: Bacterial and yeast-induced dermatitis and otitis develop in dogs with DM. Many diabetic dogs with dermatologic problems have a preexisting allergic condition, history of prior corticosteroid administration, or concurrent endocrinopathy that may be a more likely cause of dermatologic problems than DM alone.

Animals↗
PubMed2001

A retrospective study of canine and feline cutaneous vasculitis.

Twenty-one cases of cutaneous vasculitis in small animals (dogs and cats) were reviewed, and cases were divided by clinical signs into five groups. An attempt was made to correlate clinical types of vasculitis with histological inflammatory patterns, response to therapeutic drugs and prognosis. Greater than 50% of the cases were idiopathic, whereas five were induced by rabies vaccine, two were associated with hypersensitivity to beef, one was associated with lymphosarcoma and two were associated with the administration of oral drugs (ivermectin and itraconazole). Only the cases of rabies vaccine-induced vasculitis in dogs had a consistent histological inflammatory pattern (mononuclear/nonleukocytoclastic) and were responsive to combination therapy with prednisone and pentoxifylline, or to prednisone alone. Most cases with neutrophilic or neutrophilic/eosinophilic inflammatory patterns histologically did not respond to pentoxifylline, but responded to sulfone/sulfonamide drugs, prednisone, or a combination of the two.

Animals↗
PubMed2000

Personality types of dental school applicants.

A questionnaire-based prospective study was carried out to measure the personality styles of students being interviewed for a place on the 1997/98 dental undergraduate course in Leeds, England. A total of 334 applicants attended for interview between November 1997 and March 1998, of which 311 anonymously and voluntarily completed a personality questionnaire. The Keirsey Temperament Sorter was used to measure the strength and nature of preferences along four dimensions: extroversion-introversion (E-I), sensing-intuition (S-N), thinking-feeling (T-F) and judging-perceiving (J-P). 4 personality types accounted for 79% of the students, 21% were divided among nine personality types with no type comprising more than 6.7% of the students. The remaining 3 possible personality types were not represented in this student population. Further comparisons revealed significant differences between this student sample and the general population in the judging-perceiving preference and also an intra-group gender difference with regard to the thinking-feeling (T-F) preference. A predominance of the S-J (sensing with judging) temperament type was also confirmed. Personality questionnaires may be a useful adjunct in the selection process of dental school applicants. The identification of a student's working and learning style preference has implications for both the dental undergraduate curriculum and the teaching methods employed by dental school staff.

Adolescent↗
PubMed2000

Dental arch relationships in Yorkshire children with unilateral cleft lip and palate.

OBJECTIVE: To assess the dental arch relationships of children with a complete unilateral cleft lip and palate (UCLP), born consecutively between 1983 and 1987, who had undergone primary cleft repair in the West Yorkshire region of the United Kingdom. The treatment outcome of this UCLP sample was then compared with the results of a previously published intercenter European study. DESIGN: A retrospective study with standardized record collection and blind assessment. SETTING: Regional dental hospital providing secondary and tertiary health care to the local population. PATIENTS: 35 UCLP patients whose primary repair had been performed within West Yorkshire. INTERVENTIONS: Dental casts obtained for each subject within 12 months of their 10th birthday. MAIN OUTCOME MEASURES: The West Yorkshire models were randomly mixed with an anonymous sample of 115 UCLP cases from other cleft centers in the U.K. The dental arch relationships of the 10-year-old models were assessed by applying the Goslon Yardstick. RESULTS: One-third of the West Yorkshire cleft sample were rated as belonging to Goslon group 2 (good result), another third to group 3 (fair result), and the remaining third to groups 4 and 5 (poor/very poor result). Numerically, the results were of a slightly higher standard than that previously published for other U.K. and European cleft centers but were inferior to the treatment outcome of two European centers. No statistically significant differences were found between the outcome results of the West Yorkshire group and the other cleft centers. CONCLUSIONS: These results provide useful baseline data against which progress in achieving improved treatment outcome for West Yorkshire UCLP children can be determined by future research.

Analysis of Variance↗
PubMed1999

Eosinophilic dermatitis with edema in nine dogs, compared with eosinophilic cellulitis in humans.

A unique eosinophilic dermatitis with edema in dogs is characterized by extremely erythematous coalescing macules and plaques with associated edema, and is similar to eosinophilic cellulitis (Wells' syndrome) in humans. Histopathologic features include a profound eosinophilic dermal infiltrate, focal areas of collagen fiber degeneration surrounded by eosinophils (flame figures), dilated vessels, and dermal edema. Etiopathogenesis is unknown, but a hypersensitivity reaction to medications, arthropod bites, or other foreign antigens is suspected.

Animals↗
PubMed1999

Malassezia dermatitis and otitis.

The incidence of dermatitis and otitis resulting from overgrowth of M. pachydermatis is great enough that cytological sampling techniques should be considered a routine part of the dermatological examination. Because most cases of MD and Malassezia otitis cannot be grossly distinguished from bacterial pyoderma and otitis, respectively, efficiency in performing cytology testing of skin and ear canal exudate is essential to the successful diagnosis and management of pruritic skin diseases and otitis. Although Malassezia infections are rarely primary, therapy can be instituted to remove the yeast as a confounding factor while a differential diagnosis is pursued in evaluating the underlying disease process.

Animals↗
PubMed1999

Cutaneous vasculitis and vasculopathy.

Although uncommon to rare in occurrence, cutaneous vasculitides and vasculopathies are becoming better recognized entities in veterinary medicine. The heterogeneity in their clinical presentations can be confusing, and the diagnostic evaluation of suspected cases can be clinically and financially challenging. The most important step is confirming a vasculitic/vasculopathic process histologically and then searching for an underlying cause. As many cases are diagnosed as idiopathic by exclusion, a familiarity with treatment options is important and may be guided in some cases by the histological inflammatory pattern. Because of the frequent temporal association with drug administration, any case of vasculitis requires a thorough drug history and physical examination for systemic complications. Familiarity with breed-associated vasculopathies is also key in properly diagnosing and managing these problems.

Animals↗
PubMed1998

A prospective evaluation of Bass, Bionator and Twin Block appliances. Part I--The hard tissues.

A prospective clinical study with a random allocation of 47 adolescent patients to three different functional appliance groups was established and compared with an untreated control group over a 9-month period. Treatment was undertaken with either a Bionator, Twin Block, or Bass appliance. Pre- and post-treatment cephalograms were used to quantify the skeletal and dentoalveolar changes produced by the appliances and compared with those observed in the control group as a result of growth. Both the Bionator and Twin Block appliances demonstrated a statistically significant increase in mandibular length (3.9 +/- 2.7 mm; 3.7 +/- 2.1 mm, respectively) compared with the control group (P < 0.05), with an anterior movement of pogonion and point B. Highly statistically significant increases (P < 0.01) were seen in lower face heights for all the appliance groups compared with the control group. The Twin Block group showed the least forward movement of point A due to a change in the inclination of the maxillary plane. The Bionator and Twin Block groups showed statistically significant reductions in the inclination of the upper incisors to the maxillary plane (P < 0.05). The Bass group showed minimal change in the inclination of the lower labial segment to the mandibular plane. The Bionator group demonstrated the greatest proclination of the lower labial segment (4.0 +/- 3.6 degrees). Clinically important changes were measured in all the appliance groups when compared with the control group. Differences were also identified between the functional appliance groups. The Twin Block appliance and, to a lesser extent, the Bionator appeared the most effective in producing sagittal and vertical changes.

Activator Appliances↗
PubMed1998

A prospective evaluation of Bass, Bionator and Twin Block appliances. Part II--The soft tissues.

A prospective clinical study with a random allocation of 47 patients to three different functional appliance groups was established and compared with a slightly younger control group over a 9-month period. The cephalometric hard tissue changes were assessed in relation to the soft tissue changes produced and the patients were also assessed by three-dimensional (3D) laser scanning of the facial soft tissues. Each 'averaged' appliance group scan was compared with the 'averaged' control group face. Statistically and clinically significant changes occurred in the group treated with the Twin Block appliance, and to a lesser extent in the group treated with the Bionator appliance. No statistically significant facial soft tissue changes could be demonstrated in the Bass appliance group. Upper lip position remained stable despite the significant overjet reduction attained in the three appliance groups. Lower lip protrusion (up to 3.8 mm), lower lip length (up to 4.0 mm), and soft tissue lower and total face height increased significantly in all appliance groups by varying amounts. The long-term effect of these changes needs to be fully evaluated. The laser scanning system was found to be a sensitive and accurate method of quantitatively assessing small changes in the soft tissue facial form. Significant changes of the facial tissues in the transverse plane were highlighted by this technique.

Activator Appliances↗
PubMed1998

Type-1 hypersensitivity reactions to Malassezia pachydermatis extracts in atopic dogs.

OBJECTIVE: To investigate the potential allergenic role of the yeast Malassezia pachydermatis in dogs with clinical diagnosis of atopic dermatitis. ANIMALS: 5 clinically normal nonatopic dogs, 10 atopic dogs with cytologic evidence of Malassezia dermatitis, and 12 atopic dogs without cytologic evidence of Malassezia dermatitis. PROCEDURE: A crude yeast extract was produced by disrupting the cell wall of M pachydermatis. The crude extract and 8 of its fractions, which were generated by fractionation in a high-performance liquid chromatography column, were injected along with 46 commercial allergens for intradermal allergy testing of normal and atopic sample populations. Significant difference between atopic populations was evaluated, using a threshold concentration of crude yeast extract that failed to induce wheal-and-flare responses in normal nonatopic dogs. RESULTS: Atopic dogs with cytologic evidence of Malassezia dermatitis had significantly greater wheal-and-flare reactions to intradermal injection of crude extract of M pachydermatis than did atopic dogs without cytologic evidence of Malassezia dermatitis. CONCLUSIONS: It is concluded that M pachydermatis is capable of promoting type-1 hypersensitivity reactions in dogs with an atopic dermatitis phenotype. CLINICAL RELEVANCE: Currently, Malassezia dermatitis is principally managed by use of antifungal chemotherapy. Because the yeast appears to be a contributing allergen in dogs with atopic dermatitis, hyposensitization with M pachydermatis extracts may offer a future alternative to extended or repeated episodic administration of antifungals for extended control of recurrent infections.

Allergens↗
PubMed1992

Fusion of mandibular third and supernumerary fourth molars.

Fusion of the permanent molars is a relatively uncommon dental anomaly. In this article, a case of fusion of a symptomatic mandibular third molar with a supernumerary fourth molar is reported. The differentiation with other forms of 'double teeth' is explained and the possibility of the initial panoramic radiograph view being misinterpreted as an artefact is discussed.

Adult↗