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Biomedical subjects

J L Frost

Publications and source records attributed to J L Frost.

13 recordsLinked to original sources

Ethanol level differential between postmortem blood and subdural hematoma.

Alcohol use is a major risk factor for accidental injury and death. However, when death occurs several hours after injury, ethanol in the blood may be absent or low. Ethanol in sequestered hematomas has been used to retrospectively implicate alcohol as a contributing factor at the time of injury. A 69-year-old man died from a large acute subdural hematoma. He had been seen in a hospital emergency department 8 to 12 hours before his death for treatment of two lacerations (one on the head) that occurred during a fall. Postmortem blood ethanol was 0.07%, and subdural hematoma ethanol was 0.04%. This ethanol level differential between the postmortem blood and the subdural hematoma indicates that this man had consumed alcohol after being released from the hospital.

Accidental Falls↗

Ethical and legal responsibilities of the neurosurgeon: selected topics.

There are many ethical and legal implications in a variety of activities in the neurosurgeon's day-to-day practice. Awareness of and proper attention to these issues are a professional responsibility that should be attended to, to ensure that the practice of medicine is carried out efficiently and effectively, to maintain public confidence, and to try to avoid micromanagement by third parties. The authors discuss four such subjects of particular interest to them, namely: 1) reporting of certain diseases and conditions to authorities and third parties; 2) acting without the consent of the patient to prevent harm to him or her and/or others; 3) reporting problems with drugs and devices; and 4) the detection and treatment of colleagues impaired by alcohol, drugs, or mental or physical illness.

Confidentiality↗

The effect of ouabain on tension in isolated respiratory tract smooth muscle of humans and other species.

1. The Na+,K+-pump has been implicated in animal models of airway hyperreactivity. We examined the effects of inhibiting the Na+,K+-pump and Na+,Ca2+-exchange on isometric tone of isolated trachealis from humans and other species. 2. In preparations from 5 out of 9 humans, strong spontaneous contractions (36-48 h-1; up to 1.8 g) developed within 25 min. 3. Ouabain (10(-7)-10(-5) M) caused an immediate and sustained contraction. This response was not blocked by atropine, diphenhydramine, or cimetidine. 4. Contractions were also elicited when the normal physiological solution was changed to a K+-free solution, a procedure which inhibits the Na+,K+-pump, and in reduced (15 mM) Na+ solution, which inhibits Na+,Ca2+ exchange. 5. In preparations of dog and guinea-pig isolated trachea, ouabain (10(-5) M) caused a multiphasic response; in the rabbit, ouabain was without effect. K+-free solution was without effect in the dog preparations and produced relaxation of the guinea-pig trachea. Guinea-pig tracheae responded to a low Na+ solution with a strong contraction. 6. Our findings indicate that: (a) human airway smooth muscle may be a spontaneously contracting muscle, at least in vitro, (b) a prolonged contraction to ouabain is unique for the human airway smooth muscle among the animals tested, as is the contraction in a K+-free medium, and (c) the contractile response does not involve acetylcholine or histamine release, but may involve a Na+,Ca2+-exchange mechanism. These results suggest that the level of Na+,K+-pump activity could play a role in determining the degree of bronchomotor tone in humans.

Adult↗

Posttraumatic syringomyelia with paroxysmal episodes of unconsciousness.

A 41-year-old man survived 23 years with quadriplegia following a C-5 fracture dislocation. During the last four months of his life he had paroxysmal episodes of unconsciousness. Necropsy disclosed a posttraumatic syrinx. The cyst extended caudally to the midlumbar region and rostrally into the midline of the medulla without communication into the fourth ventricle. Central apnea due to expansion of the cyst in the medullary respiratory centers is postulated as the possible cause of his paroxysmal episodes of unresponsiveness.

Adolescent↗

Perfusion nephropathy in human transplants.

To determine whether perfusion preservation affected the structure and survival of kidney transplants, we correlated clinical and histologic data in 77 kidneys biopsied one hour after transplantation. Twenty-one of 36 perfusion-preserved kidneys had a glomerular capillary lesion suggestive of intravascular coagulation. None of 41 kidneys preserved by hypothermia alone had this lesion. Presence of the lesion did not correlate with donor or recipient characteristics, warm or cold ischemia time, HLA match, percentage of preformed lymphocytotoxic antibody titers or perfusion characteristics. Of 21 transplants with the lesion, nine required nephrectomy by one month, and one-month serum creatinine was less than 2.0 mg per deciliter in only three of the remaining 12 transplants. We conclude that perfusion preservation may cause pathologic changes that may adversely affect kidney-transplant function. The causes of the pathologic process remain unclear.

Cadaver↗

Neonatal pancreatic beta-cell hyperplasia: report of a case with failure of diazoxide and benefit of early subtotal pancreatectomy.

A newborn infant with pancreatic beta-cell hyperplasia had persistent hypoglycemia due to hyperinsulinism. After medical management, including the use of diazoxide and constant glucose infusions had proved ineffective, a subtotal pancreatectomy was curative. Cumulative experience seems to indicate that there should be little delay in performing a subtotal pancreatectomy when aggressive medical management cannot maintain normoglycemia in a neonate.

Diazoxide↗

Early detection of acute rejection in renal allografts using radioiodinated autologous fibrinogen.

131I-labeled autologous fibrinogen was used to detect acute renal allograft rejection in the early postoperative period. Ratios of radioactive counts over transplanted kidneys to those over the heart increased with deposition of radioactive fibrinogen in kidneys undergoing rejection. The test was positive in all instances of acute rejection twelve to twenty-four hours prior to clinical ro biochemical changes. False-positive test results were noted in instances of perinephric hematoma, seroma, and wound abscess and in one patient with urinary tract infection. The test was negative in cases of renal failure secondary to acute tubular necrosis, uric acid nephropathy (in the absence of acute rejection), and chronic rejection. This test is simple, rapid, and practical. It can be performed at the bedside and is free from complications, particularly serum hepatitis.

Acute Disease↗

Unsuspected cerebral Toxocara infection in a fire victim.

This report documents cerebral involvement by Toxocara in a child who died in a fire. Although visceral larval migrans caused by Toxocara canis is relatively common, especially in the southern states, cerebral involvement rarely has been documented histologically. Foci of inflammation, consistent with visceral larva migrans, were present in the liver.

Animals↗

Persistent olfactory bulb ventricle.

A large cystic olfactory bulb was discovered incidentally at autopsy. There was no evidence of central nervous system trauma or infection. Hemispheric malformations did not exist except for a dorsal displacement of the overlying gyrus rectus. We interpreted the cyst to be a persistent olfactory bulb ventricle.

Adult↗