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Biomedical subjects

M M Carr

Publications and source records attributed to M M Carr.

At least 37 records · Page 2Linked to original sources

Nodular fasciitis in the parotid region of a child.

BACKGROUND: Nodular fasciitis is a common pathologic entity in the limbs of adults but rare in the head and neck of children. It is defined by the World Health Organization as a benign and probably reactive fibroblastic growth extending as a solitary nodule from superficial fascia into subcutaneous tissue. Treatment is local excision, and recurrence is rare. METHOD: Case Report RESULTS: A 3.5-year-old boy was initially seen with a 1-year history of gradually enlarging but otherwise asymptomatic right facial mass. On examination, a firm nodule was palpable anterior to the right ear, and facial movement was symmetrical. Computed tomography showed a rounded, well-defined solid mass continuous with the parotid fascia. The patient underwent superficial parotidectomy without complication. The pathology was reported as nodular fasciitis, and the child has had no clinical recurrence over 2 years. CONCLUSION: Benign lesions in this region in children may present similarly to malignancies but require much more-conservative treatment.

Child, Preschool↗

Ichthyosiform erythroderma associated with generalized pustulosis.

Two unrelated boys are described who were born as collodion babies and subsequently developed non-bullous ichthyosiform erythroderma and flares of generalized sterile pustulosis, similar to generalized pustular psoriasis. Both patients had a good response to treatment with oral retinoids.

Acute Disease↗

Disturbances of loudness perception.

This article reviews information on some auditory disorders that have in common a disturbance in loudness perception. The perceptual disturbances in these disorders have interchangeably been labeled "hyperacusis," "dysacusis," or "phonophobia." Our question concerns whether the loudness disturbances associated with these auditory disorders are sufficiently different as not to justify the equivalence implied by the labelling. Emphasis is placed on those articles that have given clear accounts of the phenomenology of the disturbed perceptual experience and have offered testable hypotheses about the mechanisms underlying it. Hypotheses about the origins of disturbed loudness perception are compared with independent experimental and clinical evidence on those mechanisms. The disturbances of loudness perception that occur in cochlear hearing loss, facial nerve paralysis and stapedectomy, and in more "central" disorders are phenomenologically different, have different underlying mechanisms, and merit different labels that most of them do not currently receive.

Facial Paralysis↗

Detection of silent intervals between noises activating different perceptual channels: some properties of "central" auditory gap detection.

This article describes four experiments on gap detection by normal listeners, with the general goal being to examine the consequences of using noises in different perceptual channels to delimit a silent temporal gap to be detected. In experiment 1, subjects were presented with pairs of narrow-band noise sequences. The leading element in each pair had a center frequency of 2 kHz and the trailing element's center frequency was parametrically varied. Gap detection thresholds became increasingly poor, sometimes by up to an order of magnitude, as the spectral disparity was increased between the noise bursts that marked the gap. These data suggested that gap-detection performance is impoverished when the underlying perceptual timing operation requires a comparison of activity in different perceptual channels rather than a discontinuity detection within a given channel. In experiment 2, we assessed the effect of leading-element duration in within-channel and between-channel gap detection tasks. Gap detection thresholds rose when the duration of the leading element was less than about 30 ms, but only in the between-channel case. In experiment 3, the gap-detection stimulus was redesigned so that we could probe the perceptual mechanisms that might be involved in stop consonant discrimination. The leading element was a wideband noise burst, and the trailing element was a 300-ms bandpassed noise centered on 1.0 kHz. The independent variable was the duration of the leading element, and the dependent variable was the smallest detectable gap between the elements. When the leading element was short in duration (5-10 ms), gap thresholds were close to 30 ms, which is close to the voice onset time that parses some voiced from unvoiced stop consonants. In experiment 4, the generality of the leading-element duration effect in between-channel gap detection was examined. Spectrally identical noises defining the leading and trailing edges of the gap were presented to the same or to different ears. There was a leading-element duration effect only for the between channel case. The mean gap threshold was again close to 30 ms for short leading-element durations. Taken together, the data suggest that gap detection requiring a temporal correlation of activity in different perceptual channels is a fundamentally different task to the discontinuity detection used to execute gap detection performance in the traditional, within-channel paradigm.

Adult↗

Cranial nerve defects in congenital facial palsy.

METHODS: Cranial nerve defects were enumerated in 29 children with congenital facial palsy presenting for reanimation via chart review with a view to determining unaffected donor nerves. The literature was searched via Medline to reveal 186 additional case reports that were complete enough in their description to allow assessment of cranial nerve defects. RESULTS: The group presenting for reanimation comprised 24 females and 5 males. All of the males had unilateral isolated facial nerve paralysis. Of the females, 9 had isolated unilateral palsy and 14 had bilateral palsy, and half of these were isolated. Six had bilateral abducens nerve palsy, fulfilling the original definition of Möbius syndrome. Of these, 3 had a right-sided hypoglossal weakness, one had a bilateral oculomotor palsy, and one had a bilateral trochlear palsy. One girl had bilateral facial and auditory involvement. The literature review revealed a group that was 60% male, with 85% having bilateral facial palsy. Abducens palsy was present in 68%, glossopharyngeal in 28%, hypoglossal in 26%, and oculomotor in 20%. The group was very heterogeneous in many ways. CONCLUSIONS: There are many theories of pathogenesis of this syndrome. Isolated facial palsy is in concordance with previous findings of nerve lesions within the temporal bone. Multiple cranial nerve defects are more likely to have brainstem lesions, related to prenatal ischemic events. The cranial nerve least likely to be involved was the accessory nerve, suggesting that this may be a reliable donor for reanimation procedures.

Child↗

Tonsillectomy: indications for referral by family physicians versus indications for surgery by otolaryngologists.

OBJECTIVE: The purpose of this study was to compare reasons for family physician (FP) referral of children for tonsillectomy to the indications for this surgery used by otolaryngologists practising in the same region. METHOD: A checklist-type survey was sent to a random sample of 300 FPs and all of the practising otolaryngologists in Nova Scotia in the spring of 1995. RESULTS: There were significant differences between reasons for referral and indications for treatment in many areas, the most important of which was that over 60% of FPs referred cases because of parental insistence, while no surgeons operated for this reason. If inappropriate referrals are taken to be those for which no specialist intervention occurs, it appears that there is a significant number of referrals. CONCLUSION: These results suggest that both FPs and parents require information about these common paediatric problems.

Adolescent↗

Congenital teratomas of the head and neck.

OBJECTIVE: This article reviews teratomas, neoplasms composed of the three germinal layers of the embryo that form tissues foreign to the part in which they arise. These are most common in the sacrococcygeal region and are rare in the head and neck. In this region, major concerns are airway obstruction and cosmesis. METHOD: Pathology records at two tertiary care paediatric hospitals were reviewed for diagnoses of head and neck teratomas. This revealed nine cases between 1983 and 1993, five males and four females. Two males were stillborn. Five were cervical, two were in the nasopharynx, and two were facial. The lesions were immature in two cases and mature in the remainder. All of the liveborn children underwent surgery within the first year of life, and only one required tracheotomy. RESULTS: One child had recurrence of teratomatous tissue diagnosed with CT, which was treated surgically. The child has remained free of tumour for over 3 years. Pathogenesis, clinical appearance, diagnostic work-up, and currently accepted modes of therapy are reviewed.

Female↗

Extremity gangrene in utero.

A neonate with extremity gangrene resulting from intrauterine embolization of infarcted placental substances is discussed. This rare clinical entity is thought to be most commonly a manifestation of embolic phenomenon during maturation of the neonatal circulatory system. Management of neonatal gangrene is conservative, delaying amputation as long as possible since the line of demarcation tends to migrate distally. Evidence of multiple emboli should be carefully sought prior to definitive treatment.

Arm↗

Blue rubber bleb nevus syndrome.

Blue rubber bleb nevus syndrome, an uncommon condition, is manifested by gastrointestinal and skin hemangiomas and gastrointestinal hemorrhage causing anemia. The authors report a unique case of the syndrome in association with a congenital cardiac malformation. A 26-year-old woman presented with iron-deficiency anemia after the birth of her first child. She had a history of skin and gastrointestinal hemangiomas and tetralogy of Fallot. Endoscopy revealed multiple new intestinal hemangiomas, which were removed through enterotomies with resolution of the anemia. Iron therapy was prescribed, and her condition was stable at follow-up 5 years later.

Adult↗

Delayed rupture of the spleen and streptokinase therapy.

Delayed rupture of the spleen is a rare but serious complication of blunt abdominal trauma. A 47-year-old woman with a history of fractured pelvis from a motor vehicle accident 6 months earlier presented with evidence of a myocardial infarction. Subsequent streptokinase administration was complicated by splenic rupture, which was managed by evacuation of the clotted blood and splenectomy. The patient made a complete recovery. The risk of splenic rupture and bleeding complications resulting from thrombolytic therapy for myocardial infarction is discussed, as are the controversy over whether delayed splenic rupture is a true diagnosis, the mechanism of rupture and the clues to impending rupture.

Abdominal Injuries↗

Gracilis donor site morbidity.

Donor site morbidity in 104 cases of gracilis free tissue transfer was examined through a retrospective chart review and mail survey. Fifty-one females and 53 males with an average age of 23 years comprised the study group. Forty-three were under age 18. In-hospital donor site complications occurred in 10 patients. There was excessive pain in 4, wound infections in 3, hemorrhage in 2, and temporary nerve palsy in 1. Early complications were more common in the pediatric group. Sixty-two surveys were returned from patients detailing late complications where they graded parameters between 0 and 10 where 0 was "none" and 10 was "worst imaginable." The highest average score was 5.12 reported for noticeability of the scar. There was a significant difference between adults and children for sensitivity, tightness, notice-ability, and ugliness of the scar. More than half the respondents had no complaints about their donor site scar. Fifteen percent of patients reported temporary reduction of leg strength with a men duration of 6 months.

Adolescent↗

The behaviour of monoclonal antibodies in the First International Pig CD Workshop reacting with gamma delta/Null T lymphocytes in the blood of SLAb/b line pigs.

Further studies were carried out on the monoclonal antibodies (mAbs) from the First International Swine CD Workshop which react with gamma delta Null T-lymphocytes, defined by the binding of mAb w020/141 (MAC320) as Swine Workshop Cluster number SWC6. Studies were also carried out on several other mAbs from the same workshop which identify other CD antigens, but whose binding is not restricted exclusively to gamma delta Null T-lymphocytes. The first group consists of 11 mAbs (w021, w022, w059-w065, w105 and w117) and the second group of 18 mAbs (w008, w026, w056, w067-w071, w080, w091-w094, w110, w111, w118, w119 and w121). All mAbs were characterised by binding to peripheral blood lymphocytes (PBL) from normal, sham-thymectomized (STx) and thymectomized (Tx) pigs of the Babraham SLAb/b line and by their overlap, using two-colour immunofluorescence with biotinylated mAb MAC320 (w020/141), which identifies all gamma delta Null cell T-lymphocytes and the Null cell subpopulation identified by MAC319 (w021). The Null cell-specific mAbs were also used in inhibition studies of MAC319 and MAC320 binding and by staining PBL with pairs of mAbs together with either MAC319 or MAC320. Based on these data we suggest a putative relationship of the Null cell subsets defined by these mAbs with each other.

Animals↗

Sporotrichosis of the hand: an urban experience.

Sporotrichosis is uncommon in Canadian urban centers. Lymphocutaneous and fixed cutaneous are the most common cutaneous forms of the disease, typically seen in the upper extremity in adult patients. History usually reveals a puncture injury contaminated with soil. Lesions are refractory to commonly used antibiotics. Cultures of biopsy specimens reliably grow the fungus Sporothrix schenkii. First line treatment is oral potassium iodide. We have reviewed a series of 7 cases from various Toronto teaching hospitals and compared them to the world literature.

Adult↗

The foot in ballet dancers: the importance of second toe length.

Ballet dancers are prone to foot injuries. Our hypothesis was that the length of the second toe in relation to the big toe affected the distribution of stresses on the foot, correlating with calluses, injuries, and pain. Fifty-nine ballet dancers were examined for second toe length with respect to great toe, calluses, and metatarsophalangeal inflammation. Daily foot pain, limitation of work hours because of this, injuries, age, sex, and rank in the company were considered. The dancers' feet had an incidence of shorter, equal, or longer second toes which was comparable to a non-ballet-dancing cohort (N = 60). In female dancers (N = 34), total callus counts and pain scores were significantly lower in the group with shorter second toes versus those with equal or longer second toes. Counts were unrelated to age or rank. Longer second toes were related to hallux rigidus. Limitation of practice hours, ankle sprains, and foot/ankle fractures and sprains were comparable across the groups. The male dancers (N = 25) had significantly fewer calluses than did the women, but had equal pain scores and number of injuries. There were no significant differences among the males in total callus counts, pain scores, limitation of practice hours, or injuries between groups based on toe length, age, or rank. We conclude that there is no significantly more ideal pattern of toe lengths for male ballet dancers, but females with shorter second toes have fewer calluses and less daily foot pain. Those with a longer second toe had a higher incidence of hallux rigidus and correspondingly increased pain scores.

Adult↗

Human bites to the hand.

Human bites to the hand or penetrating injuries contaminated with saliva can be a source of aggressive infection and debilitating injury. These types of injuries may also be a mode for the transmission of disease, notably hepatitis B. Dental personnel have an increased risk of experiencing bite injuries and should understand the general principles of appropriate management. Staphylococcal or streptococcal species are often associated with infected bite injuries, and amoxicillin and clavulanate are currently advised for prophylaxis. Wound cleansing and careful monitoring, combined with appropriate prophylaxis, are the mainstays of treatment.

Amoxicillin↗

Summary of first round cluster analysis: complete antibody panel.

The reactivities of 141 monoclonal antibodies (mAbs) with 60 target cell types or lines were analysed by flow cytometry and the data subjected to statistical clustering. mAbs were assigned to 23 clusters by statistical similarity and information on specificity supplied by the contributor. Clustered mAbs were examined in more detail in the second round of workshop analyses.

Animals↗