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Biomedical subjects

K A Collins

Publications and source records attributed to K A Collins.

At least 37 records · Page 2Linked to original sources

Vascular assessment.

The assessment of the patient with peripheral vascular disease encompasses a thorough history and physical examination with the adjunctive use of the noninvasive vascular laboratory to confirm, localize, and grade lesions. The need for additional vascular testing depends upon the clinical scenario and urgency with which intervention must be undertaken with contrast angiography reserved for planning surgical intervention. While multiple noninvasive and invasive methods are available to assess the peripheral vasculature, it should be obvious that not every patient requires an exhaustive battery of tests in order to evaluate their vascular status. In general, only those tests that are likely to provide information which will alter the course of action should be performed. Differing clinical syndromes mandate the extent of peripheral vascular testing. Table 5 lists distinct clinical syndromes and presentations and the peripheral vascular testing that is likely to yield timely and cost efficient results.

Diagnostic Imaging↗

Suicide: a ten-year retrospective study.

Suicide is a complex phenomenon associated with psychological, biological, and social factors, claiming approximately 30,000 lives each year in the United States. We retrospectively reviewed all cases referred to the Medical Examiners' Office/Forensic Pathology Section at the Medical University of South Carolina from January 1988 to December 1997. The cases of suicide totaled 678. All of the cases were analyzed as to age/race/sex, method of suicide, time of year, and toxicological results. Files were also reviewed to determine if the victim left behind a suicide note. The ages ranged from 12 to 94 years; males comprised 79.5% of the victims, and whites 78.3%. The male to female and white to black ratios were both 3.9:1. The most common methods were gunshot wounds, accounting for 64.6% of the cases. No correlation existed with time of year, and the number of cases was not increased around major holidays. The group of victims 65 years and older and the pediatric group under the age of 18 were also examined separately.

Adolescent↗

Suicide under the age of eighteen: a 10-year retrospective study.

The number of suicides in the pediatric age group is rising, and death investigators need to be aware of the common scenarios, risk factors, and victims as they investigate such cases to properly assign the cause and manner of death. We reviewed all pediatric cases referred to the Medical University of South Carolina, Forensic Section, from January 1988 through January 1998. Thirty-one cases of pediatric suicide were analyzed with regards to age, gender, race, cause of death, surrounding circumstances, and past history. Sixty-eight percent of victims were aged 16 or 17 years, 84% were male, 68% were white, 78% used firearms to commit suicide, 81% were found within close vicinity of their home, and 26% had a documented history of mental illness. Suicide is a manner of death that is often difficult for the public to accept, especially in pediatric cases. We report our findings in this 10-year retrospective study to better understand this entity and work toward the prevention of future cases.

Adolescent↗

A decade of pediatric homicide: a retrospective study at the Medical University of South Carolina.

More than 3 million children are abused and/or neglected each year in the United States. Unfortunately, a significant percentage of these cases result in homicide by child abuse or child neglect. Causes of death range from blunt force trauma and shaking to asphyxia to immolation. We retrospectively reviewed all pediatric forensic cases referred to the Medical University of South Carolina Forensic Pathology Section over the past 10 years, from January 1986 to December 1995. Of these, we looked only at children < or =5 years of age. The majority (342 cases, 69%) of these deaths were classified as natural, 96 (19%) as accident, and 60 (12%) as homicide. Of the homicides, we examined the cause of death; age, gender, and race of the victim; relationship to the perpetrator; time interval between injury and death; and the initial history given as to the cause of the injury. The cause of death fell into nine categories, the number one category being head trauma. Forty-five percent of the homicides were by head trauma, 12% by abdominal or body trauma, 25% by asphyxia (with half of these due to drowning), 10% by carbon monoxide poisoning or thermal injury, and the remaining 8% involving cases of neglect, stabbing, and poisoning. The majority of the homicide victims were male (67%) and black (67%). Forty-six percent were < or =1 year of age. Approximately 25% of the homicide cases were designated as shaken baby syndrome (SBS). In 97% of the cases, the assailant was known to the victim and was a family relative in 77%. Sixty-three percent of the assailants were female and 45% of the assailants were male; in 12%, the assailants were both parents, and in 1 case, the assailant remains unknown. Of the asphyxia deaths, 87% of the assailants were female. The time interval between injury and death ranged from minutes to hours in most cases to months in cases of repeated abuse and chronic injury and sequelae. The time interval between injury and the onset of symptoms remains unknown in most cases due to inconsistencies in the history and lack of credibility of the caretaker. The most common initial history given was "a fall" (20%). We report our findings of a decade of pediatric homicides to increase awareness of the common scenarios and case histories, demographics of the victims, causes of death, and perpetrators of pediatric homicide.

Asphyxia↗

Cost effectiveness of community leg ulcer clinics: randomised controlled trial.

OBJECTIVES: To establish the relative cost effectiveness of community leg ulcer clinics that use four layer compression bandaging versus usual care provided by district nurses. DESIGN: Randomised controlled trial with 1 year of follow up. SETTING: Eight community based research clinics in four trusts in Trent. SUBJECTS: 233 patients with venous leg ulcers allocated at random to intervention (120) or control (113) group. INTERVENTIONS: Weekly treatment with four layer bandaging in a leg ulcer clinic (clinic group) or usual care at home by the district nursing service (control group). MAIN OUTCOME MEASURES: Time to complete ulcer healing, patient health status, and recurrence of ulcers. Satisfaction with care, use of services, and personal costs were also monitored. RESULTS: The ulcers of patients in the clinic group tended to heal sooner than those in the control group over the whole 12 month follow up (log rank P=0.03). At 12 weeks, 34% of patients in the clinic group were healed compared with 24% in the control. The crude initial healing rate of ulcers in intervention compared with control patients was 1.45 (95% confidence interval 1.04 to 2. 03). No significant differences were found between the groups in health status. Mean total NHS costs were 878.06 pounds per year for the clinic group and 859.34 pounds for the control (P=0.89). CONCLUSIONS: Community based leg ulcer clinics with trained nurses using four layer bandaging is more effective than traditional home based treatment. This benefit is achieved at a small additional cost and could be delivered at reduced cost if certain service configurations were used.

Aged↗

Sudden unexpected death resulting from an anomalous hypoplastic left coronary artery.

We present a case of sudden death in a 24-year-old, healthy white female who was physically active and participated in sports, including soccer. Two weeks prior to her death, an insurance physical examination revealed an abnormal electrocardiogram which demonstrated flipped T waves in the anterior leads. There was no other remarkable medical history. At autopsy, only one coronary ostium was demonstrated and it originated from the right aortic sinus. Approximately 0.8 cm from this right coronary artery (RCA) ostium, a left coronary artery (LCA) branched off the RCA at a 90-degree angle. The LCA had luminal diameter of 0.4 m but the LCA had a luminal diameter of only 0.1 cm. The LCA coursed anterior to the base of the pulmonary artery and down the anterior ventricular septum reflecting the usual course of the left anterior descending (LAD) coronary artery. The LCA and RCA paths appeared to merge or terminate at the anterior left ventricular myocardium which was discolored gray, a process that involved the inner and middle thirds of the myocardium. Based on the autopsy findings, we certified the cause of death as a probable arrhythmia due to myocardial fibrosis and dystrophic calcification resulting from complications of an anomalous hypoplastic left coronary artery. Anomalies of coronary arteries have been classified and studied at autopsy and by clinical angiography. Coronary artery anomalies can be divided into minor and major forms with major anomalies often resulting in cardiac dysfunction that may cause failure and death. Minor anomalies, in general, have no pathophysiological significance and are compatible with life. Minor anomalies include variations in number and location of coronary ostia. A single coronary ostia is exceedingly rare in hearts with no other congenital malformations. The prognostic significance can be unpredictable. A single coronary artery has the potential to be dangerous if obstructed at its main stem, or if it branches at an acute angle. Additionally, hypoplasia of one or more coronary arteries has been found to be associated with sudden death.

Adult↗

Speedballing with needle embolization: case study and review of the literature.

Foreign-body embolization is not an uncommon occurrence. However, to our knowledge, there are only ten reported cases of needle embolization associated with intravenous drug use. We report the sudden death of a 49-year-old white male with a known history of crack cocaine abuse. At autopsy, suspicious needle marks were noted on the right lower extremity. The lungs were of increased weight at 1000 and 1090 g and appeared edematous. The heart weighed 520 g and had a normal red-brown myocardium. Upon sectioning, a broken hypodermic needle of very small caliber was identified in the right ventricular myocardium protruding into the right ventricular chamber. This needle apparently traveled from the injection site to the right ventricle. The right ventricle was dilated and hypertrophied, and microscopic examination showed hyperemic myocardium surrounding the needle. Sections of lung showed numerous foreign-body type giant cells containing polarizable foreign material consistent with intravenous drug use. Toxicological analysis revealed the presence of ethanol (36 mg/dL), cocaine (0.098 mg/L), benzoylecgonine (2.16 mg/L), and morphine (0.841 mg/L). Urine and blood were positive for the presence of 6-monoacetylmorphine. Based on the toxicological analysis, the cause of death was determined to be cocaine and heroin toxicity, and the manner accidental. The needle embolus was considered an incidental finding.

Embolism↗

Mouse model of hyperkinesis implicates SNAP-25 in behavioral regulation.

Although hyperkinesis is expressed in several neurological disorders, the biological basis of this phenotype is unknown. The mouse mutant coloboma (Cml+) exhibits profound spontaneous locomotor hyperactivity resulting from a deletion mutation. This deletion encompasses several genes including Snap, which encodes SNAP-25, a nerve terminal protein involved in neurotransmitter release. Administration of amphetamine, a drug that acts presynaptically, markedly reduced the locomotor activity in coloboma mice but increased the activity of control mice implicating presynaptic function in the behavioral abnormality. In contrast, the psychostimulant methylphenidate increased locomotor activity in both coloboma and control mice. When a transgene encoding SNAP-25 was bred into the coloboma strain to complement the Snap deletion, the hyperactivity expressed by these mice was rescued, returning these corrected mice to normal levels of locomotor activity. These results demonstrate that the hyperactivity exhibited by these mice is the result of abnormalities in presynaptic function specifically attributable to deficits in SNAP-25 expression.

Amphetamine↗

Dyadic deaths involving Huntington's disease: a case report.

Huntington's disease is a hereditary neurodegenerative disorder characterized by involuntary choreiform movements and progressive dementia. Although controversy exists regarding the exact risk of suicide in patients with Huntington's chorea, the literature supports an increased risk of suicide, especially in the early stages of this disease. We describe a case of homicide-suicide involving a father and son. The 60-year-old father, the homicide victim, suffered from advanced Huntington's disease; his 30-year-old son, the assailant, had a history of depression but had not been diagnosed with Huntington's disease at the time of his suicide. The psychiatric implications of this dementing disease, including the risk of suicide, are discussed. The gross, histologic, and molecular genetic features of this neurodegenerative disease are also described. The recognition of this autosomal dominantly inherited disorder at autopsy can make a profound impact on the lives of surviving family members.

Adult↗

Pretreatment with pertussis toxin differentially modulates morphine- and beta-endorphin-induced antinociception in the mouse.

The experiments were designed to determine the role of pertussis toxin-(PTX) sensitive G-proteins Gi/Go in the brain and spinal cord in antinociception induced by epsilon-opioid receptor agonist beta-endorphin (beta-EP) and mu-opioid receptor agonist morphine. The effects of intracerebroventricular (i.c.v.) or intrathecal (i.t.) pretreatment with PTX on antinociception induced by morphine, beta-endorphin (beta-EP) and other selective opioid receptor agonists given i.c.v. or i.t. were studied in male ICR mice. Antinociception was assessed by the tail-flick and hot-plate tests. An i.c.v. pretreatment with PTX (0.5 microgram) caused a time- and dose-dependent attenuation of the tail-flick and hot-plate inhibition induced by i.c.v.-challenged morphine-induced antinociception. However, the same pretreatment with PTX did not affect the antinociception induced by i.c.v.-administered beta-EP. The tail-flick and hot-plate inhibition induced by selective mu-, delta- and kappa-opioid receptor agonist, DAMGO, [D-Ala2]deltorphin II and U50,488H, respectively, given i.c.v. was also attenuated by the i.c.v. pretreatment with PTX. An i.t. pretreatment with PTX (0.5 microgram) blocked markedly the tail-flick inhibition induced by morphine and beta-EP given i.c.v. However, the same treatment did not affect the hot-plate inhibition induced by beta-EP and attenuated, to a lesser degree, the hot-plate inhibition induced by morphine given i.c.v. An i.t. pretreatment with PTX blocked the tail-flick inhibition induced by selective delta 2-, alpha 2 and 5-HT receptor agonist [D-Ala2]deltorphin, norepinephrine and 5-HT, respectively, given i.t. Our results indicate that the antinociception induced by mu-, delta-, kappa-opioid receptor agonists given supraspinally is mediated by respectively opioid receptors that are coupled to PTX-sensitive Gi/Go proteins at the supraspinal sites and subsequently mediated by the activation of PTX-sensitive Gi/Go coupled receptors in the spinal cord. However, the antinociception induced by beta-EP given supraspinally is mediated by the PTX-resistant epsilon-opioid receptors at the supraspinal sites and subsequently activation of the delta 2-opioid receptors in the spinal cord that is sensitive to the pretreatment with PTX.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

Pretreatment with pertussis toxin blocks morphine- but not beta-endorphin-induced antinociception in the mouse.

We have previously demonstrated that the antinociception induced by morphine and beta-endorphin given intracerebroventricularly (i.c.v.) is mediated by the stimulation of respective mu- and epsilon-opioid receptors. The effects of i.c.v. pretreatment with pertussis toxin on the antinociception induced by morphine and beta-endorphin given i.c.v. were studied in male ICR mice. Antinociception was assessed by the tail-flick and hot-plate tests. Pretreatment with pertussis toxin (0.5 microgram) given i.c.v. 96 h earlier blocks the antinociception induced by i.c.v. administered morphine in both tail-flick and hot-plate tests. The same pretreatment did not affect the antinociception induced by i.c.v. administered beta-endorphin. Our results indicate that morphine-, but not beta-endorphin-induced antinociception is mediated by pertussis toxin sensitive G-proteins.

Analgesics, Opioid↗

Spinal delta 2-, but not delta 1-, mu-, or kappa-opioid receptors are involved in the tail-flick inhibition induced by beta-endorphin from nucleus raphe obscurus in the pentobarbital-anesthetized rat.

The antinociception induced by beta-endorphin given supraspinally has been previously demonstrated to be mediated by the release of [Met5]enkephalin acting on delta-opioid receptors in the spinal cord. The present study was designed to determine what type of opioid receptors in the spinal cord is involved in beta-endorphin-induced antinociception in the rat. Antinociception was induced by beta-endorphin (0.6 nmol) given into nucleus raphe obscurus and was assessed by the tail-flick test in pentobarbital-anesthesized rats. Naltriben (0.6-6.0 nmol), a selective delta 2-opioid receptor antagonist, given intrathecally dose-dependently attenuated beta-endorphin-induced inhibition of the tail-flick response. On the other hand, 7-benzylidene naltrexone (2.1-64.3 nmol), CTOP (D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2, 0.09-2.8 nmol), or nor-binaltorphimine (1.4-40.8 nmol), selective delta 1-, mu-, and kappa-opioid receptor antagonists, respectively, did not block beta-endorphin-induced antinociception. The results of present study in rats are consistent with previous experiments in mice indicating that spinal delta 2-, but not delta 1-, mu- or kappa-opioid receptors are involved in beta-endorphin-induced inhibition of the tail-flick response.

Amino Acid Sequence↗

Differential ontogenesis of thermal and mechanical antinociception induced by morphine and beta-endorphin.

The antinociceptive effects induced by beta-endorphin and morphine given supraspinally have been previously demonstrated to be mediated by the activation of different neural mechanisms. The present experiments were to examine the effects of intraventricular administration of beta-endorphin and morphine in mechanical paw-withdrawal and thermal tail-flick nociceptive tests in rats of 2-28 days of age. 2-4-day-old neonates were not responsive to i.c.v. injection of beta-endorphin or morphine for the inhibition of the tail-flick response. The thermal antinociceptive responses induced by beta-endorphin and morphine started to develop in 7-14-day-old rats and continued to increase at 21-28 days. The inhibition of the mechanical paw-withdrawal response to beta-endorphin was already present in 2-day-old rats and morphine in 4-day-old rats. The mechanical antinociception progressively increased and reached a plateau at 7 days of age for beta-endorphin and 28 days of age for morphine. beta-Endorphin was found to be more efficacious than morphine in producing mechanical antinociception. The results demonstrate that beta-endorphin- and morphine-induced antinociception to mechanical and thermal stimuli develops differently and are consistent with the hypothesis that two descending pain inhibitory systems activated by beta-endorphin and morphine are differentially developed.

Aging↗

Extragonadal germ cell tumors: a fine-needle aspiration biopsy study.

Germ cell tumors (GCT) are neoplasms that originate predominately in the ovary and testis. Tumors of germ cell origin only very uncommonly arise in extragonadal sites. We have diagnosed ten primary malignant extragonadal GCT arising in the mediastinum, retroperitoneum, liver, and sacrococcygeal region by fine-needle aspiration biopsy (FNAB). Patient ages ranged from 1 to 54 years; the majority were males. Our series included three seminomas, three yolk sac tumors (YST), one choriocarcinoma, one embryonal carcinoma, and two mixed, poorly differentiated GCT. In aspirates, seminomatous elements are dissociated with uniform mononucleate cells having large vesicular nuclei and prominent nucleoli. A tigroid background is produced with Diff-Quik-stained smears. YST yields cohesive clusters of cells with large nuclei, vacuolated cytoplasm, and extracellular hyaline matrix (spheres or hyaline globules). Giant multinucleate tumor cells are seen in choriocarcinoma. Embryonal carcinoma yields cellular smears of hyperchromatic cells with scant cytoplasm arranged predominantly in glandular or papillary formations. Ultrastructural (four cases) and immunocytochemical (seven cases) studies of aspirated material corroborated our cytologic interpretations. Aneuploid tumor cells were found by flow cytometry in aspirated material from a YST. Subsequent histologic examinations were performed on eight, and all were confirmatory. Although extragonadal GCT are relatively uncommon, they need to be considered in FNAB material from midline mass lesions. Ancillary studies were useful in confirming their diagnosis.

Adult↗