Xenon-enhanced CT CBF measurements in cerebral AVM's before and after excision. Contribution to pathogenesis and treatment

Unlike neurological deficits resulting from intracranial hemorrhage in patients with cerebral arteriovenous malformation (AVM), which have well defined etiology, the pathogenesis and treatment of progressive and/or fluctuating non-hemorrhagic neurological and psychological deficits require clarification. Values for local cerebral blood flow (LCBF) and local partition coefficients (L lambda) were measured by the method using stable xenon (Xe)-computerized tomography (CT-CBF) scanning, and were compared to 133Xe inhalation values using external probes in 16 patients with cerebral AVM's. Values were measured by both methods before and after total excision of AVM's in five cases. Neurological and mental status assessments were compared with LCBF results. Clinical improvement was most evident after total excision of AVM's. Other procedures, such as clipping of vessels, partial excision, and ventriculoperitoneal shunting for hydrocephalus, were associated with frequent complications. Embolization carried risks of cerebral infarction and was not efficacious unless combined with excision. Medical treatment resulted in poor or unsuccessful seizure control, with neurological deterioration despite anticonvulsant therapy. Compared with age-matched normal individuals, LCBF values in patients with AVM's were significantly reduced, particularly adjacent to the AVM's. Mean L lambda values for gray and white matter were normal. After excision, LCBF values in gray and white matter increased significantly up to normal. Due to overestimation of CBF by shunt flow with the 133Xe method of measurement, no correlation was found with results of the CT-CBF method before AVM excision, but significant correlation of the two methods resulted after excision. If accurate LCBF values are obtained by high resolution, direct measurement of tracer clearance from brain tissue, progressive and/or fluctuating neuropsychological deficits correlate with the degree of cerebral steal.

Prolactin binding sites in the uterus of the mink

The present study was conducted to determine if specific binding sites for prolactin (PRL) are present in the uterus of the mink. Uteri of anestrous mink were homogenized and subjected to differential centrifugation into three particulate fractions, 1500, 15 000 and 50 000 X g. Binding of [125I]oPRL to membranes in an aliquot (200-400 micrograms protein) of the 50 000 X g particulate fraction was quantified. Time and temperature for optimal binding were 18 h at 25 degrees C. Scatchard plot analysis revealed a single set of binding sites for PRL with a Kd of 8.25 X 10(-11) +/- 0.68 M. The maximum amount of [125I]oPRL bound was 28 fmoles/mg protein. Prolactin binding sites were detected in both the uterus and kidney of mink, but not in skeletal muscle, spleen, diaphragm or lung. These data indicate that uterine cell membranes of the mink contain sites that bind prolactin with high affinity.

Effects of prednisolone and medroxyprogesterone on corneal wound healing, ulceration, and neovascularization

Albino rabbits were treated four or six times daily with 1% prednisolone acetate, 1% medroxyprogesterone acetate, or a control vehicle, after one of three conditions. First, after 3-mm linear perforating stromal incisions; drugs were given for seven days, and wound bursting strength was determined. Prednisolone suppressed wound tensile strength by 20%; medroxyprogesterone suppressed it by 11%. Second, after trephination, drug administration for 14 days decreased collagen formation in the scar buttons by 43% in the prednisolone-treated group and 39% in the medroxy-progesterone-treated group. Third, after thermal burns; when drug application followed the burn immediately, deep ulceration or perforation developed in 85% of the controls, in none of the prednisolone-treated group, and in 17% of the medroxyprogesterone-treated group. When drug delivery was withheld until day 6, severe ulceration developed in 44% of both groups. In both experiments, stromal neovascularization was markedly suppressed by prednisolone, but only moderately decreased by medroxyprogesterone.

The metabolism of tertiary amines

The metabolism of tertiary amines is mediated primarily by cytochrome P-450 and MFAO, leading to alpha-C oxidation and N-oxidation, respectively. We have discussed how lipophilicity, basicity, steric hindrance, and stereochemistry can effect the outcome of metabolism as well as species, sex, and age. The proposed oxidation of tertiary amines to iminium ions by cytochrome P-450 may explain the isolation of various intramolecular and cyanide-trapped metabolites. N-oxides may represent a smaller percentage of the overall in vitro metabolism of tertiary amines due to the postmortem inactivation of MFAO. In addition N-oxide reducing enzymes present in vivo and in vitro may influence the extent of N-oxide formation. In general, definite conclusions about substrate requirements have been difficult to formulate because of the numerous biological and physical parameters affecting the outcome of metabolism. More singularly directed research on a single species of animal and a wide variety of substrates or vice versa would greatly increase our understanding of the potential metabolism of tertiary amine xenobiotics.

Redistribution of cerebral blood flow following STA-MCA by-pass in patients with hemispheric ischemia

Regional cerebral blood flow and vasomotor reactivity were measured in 33 patients with surgically remediable hemispheric ischemia by the 133Xe inhalation method prior to superficial temporal to middle cerebral artery (STA-MCA) by-pass. Thirteen patients also underwent LCBF and L lambda measurements by the stable xenon CT method for comparison. Twenty-four had proximal occlusion of one or both internal carotid arteries, 9 had intracranial occlusive disease (4 internal carotid, 5 middle cerebral). Measurements were repeated at intervals up to 30 months following surgery and compared to measurements in a similar group (N = 13) treated medically. In the surgically treated group 22 patients had recurrent TIAs, of whom 12 also had minor residual neurological deficits from recent small cerebral infarctions with potential for recovery (RINDs) while the remaining 11 had RINDs without TIAs. After surgery 28 improved with cessation of TIAs and/or neurological recovery, 3 remained unchanged, 2 cases worsened. Compared to age-matched normal hemispheric F1 (gray matter) values, pre-operative F1 values in the STA-MCA group were reduced in both ischemic and opposite hemispheres. Ischemic regions showed imparied vasomotor reactivity to 5% CO2 or 100% O2 inhalation. After surgery, mean hemispheric F1 values increased + 12.8% on the by-pass side and + 10.5% on the contralateral side. Mean F1 increases reached a maximum 3 months after by-pass, most evident in ipsilateral frontal regions (+ 24.2%). Vasomotor reactivity did not significantly improve. Medically treated cases did not show similar F1 increases. Thirteen with carotid occlusive disease (8 with TIAs, 5 with small recent infarcts) underwent CT LCBF and L lambda measurements before and after STA-MCA by-pass. Cases with recent infarcts showed reduced LCBF and L lambda values which increased significantly after STA-MCA by-pass, however the total group operated upon showed only trends for CBF increases, probably due to large standard deviations encountered in serial measurements.

Plasminogen activator (urokinase) causes vascularization of the cornea

The presence of a peripheral zone of (presumed intracellular) plasminogen activator in the normal rabbit cornea has suggested that activator, once released, might regulate the permeability of limbal vessels and angiogenesis, by plasmin-dependent pathways. Plasminogen activator (urokinase [UK]) in rabbit serum albumin (RSA) was injected once (20 microliter, 3.7 CTA U) into the corneal stroma, 2 mm from the limbus. Sprouts arose from the engorged circumlimbal vessels (16 of 20 corneas) beginning on the third day and grew into the cornea over the next several days. Histologically, PMNs were observed in association with growing vessels. Contralateral corneas injected with UK (in RSA) previously inactivated by 99.7% with the specific active site inhibitor, Phe-Ala-Arg-chloromethyl ketone showed minimal vessel engorgement or stromal edema and no vascularization (0 to 20 corneas). Injuries to the so-called (plasminogen activator-containing)"critical zone" of the cornea which elicit neovascularization possibly do so by causing extracellular release of endogenous plasminogen activator. Thus, in addition to initiating the destructive events of ulceration, activator might initiate increases in vessel permeability and also neovascularization, which would result in the eventual arrest of ulceration.

Medroxyprogesterone on corneal ulceration. Its effects after alkali burns on rabbits

The effect of medroxyprogesterone acetate treatment in preventing or retarding corneal ulceration after alkali burns was studied in rabbits in an attempt to correlate dose and response. The eyes were treated for 21 days with a 0.01% or 1% suspension administered topically four times a day or medroxyprogesterone acetate, 4 mg or 30 mg, given subconjunctivally on alternate days. None of these regimens was noticeably effective, although at times there was a trend toward retarding ulceration. Thus, it was not possible to confirm earlier reports of substantial efficacy of medroxyprogesterone. Corneal stroma with epithelial defects and/or ulcers persistently showed infiltration with neutrophils in the superficial stroma within the epithelial defect, implicating the tears as the source of the inflammatory cells.

Heart rate response of fetal and adult sheep to hemorrhage stress

The responses of heart rate and blood pressure to hemorrhage of 15% of estimated blood volume were studied in 24 chronically instrumented fetal lambs of gestational ages 81-144 days (0.55-0.98 gestation) and 6 conscious adult nonpregnant ewes. A transient tachycardia of 25 +/- 3 beats/min (+ 15 +/- 2%) was noted in the fetuses after removal of about 5% blood volume and reduction of mean arterial pressure of 2 +/- 1 mmHg (8 +/- 2%). With 15% reduction of blood volume fetal mean arterial pressure fell 12 +/- 1 mmHg (27 +/- 2%), venous pressure fell from 3.5 +/- 0.5 to 2.0 +/- 0.5 mmHg, and heart rate dropped by 39 +/- 8 beats/min (22 +/- 4%). The fetal bradycardia during the hemorrhage period was reversed by atropine administration. In adult ewes, mean arterial pressure decreased 12 +/- 3 mmHg, venous pressure was unchanged but heart rate increased by 25 +/- 6 beats/min (29 +/- 8%). These studies indicate the presence of a functional baroreflex by 81 days (0.55 gestation).

A parents' group in the management of anorexia nervosa

Recent reports have suggested that family therapy is useful in the treatment of anorexia nervosa. There are, however, recognized contraindications to family therapy. As we were seeing patients with anorexia nervosa for whom family therapy was not possible, we predicted that the formation of a group for the parents would provide benefit through education, support and insight. The present study was designed to develop and evaluate such a group. We selected parents of ten anorectic patients for whom family therapy was contraindicated. There were two therapists, the unit social worker and a former patient who had successfully overcome the symptoms of anorexia nervosa. After an 18-month period, the ten couples were sent anonymous questionnaires assessing the group's value. Six indicated positive feelings about the group and felt they had benefited. One couple reported dissatisfaction. Most perceived the group as an important part of the overall treatment.

Diagnosis of haemobilia by duodenoscopy

A case of haemobilia due to liver abscess presenting as haematemesis and melaena is described. Duodenoscopy in the acute phase can distinguish haemobilia from other causes of upper gastrointestinal bleeding and is the first step towards accurate localization of the lesion by hepatic arteriography.

Prevention of stromal ulceration in the alkali-burned rabbit cornea by glued-on contact lens. Evidence for the role of polymorphonuclear leukocytes in collagen degradation

Stromal ulceration of the alkali-burned rabbit cornea was found to be associated invariably with phagocytically active polymorphonuclear leukocytes (PMNs). A glued-on methylmethacrylate lens applied to corneas soon after burning, however, prevented re-epithelialization and also prevented PMN infiltration of the stroma and stromal ulceration. Subsequent partial detachment or complete removal of the lens resulted in epithelial resurfacing of the stroma, PMN infiltration, and stromal ulceration. Glued-on lenses applied to already ulcerating corneas arrested further ulceration by prohibiting additional PMN infiltration. Either surface debridement or glued-on methylmethacrylate rings also prevented re-epithelialization and ulceration in stromas not infiltrated by PMNs, but neither treatment was sufficient to prevent ulceration in corneas already containing numerous PMNs. The data suggest the possibility that the epithelium stimulates infiltration of the stroma by PMNs which then participate in stromal matrix degradation. Although no claim is made that only PMNs mediate matrix destruction in corneal ulceration, the efficacy of the lens would seem to be due to exclusion of the epithelium and the consequent prevention of stromal infiltration by PMNs.

Effect of topical corticosteroids on ulceration in alkali-burned corneas

Dexamethasone sodium phosphate was administered topically to one eye of rabbits with bilateral alkali corneal burns, and saline solution was administered to the contralateral eye. Topical steroids were also administered in animals with moderate corneal ulcers and were found to enhance the severity of ulceration when given during the second and third weeks following the burn. If the corticosteroids were given daily in the first six days or in the fourth and fifth weeks following the burn, they did not have an adverse effect on the cornea. Corticosteroids can be used intensively during the first week following an alkali burn, without increasing the risk of corneal melting. The mechanism for the enhancement of corneal ulceration is not a direct augmentation of collagenase activity, but probably involves the inhibition of repair processes.

Trisomy 8 mosaicism syndrome. Report of monozygotic twins

Monozygotic twins were born with the phenotypical appearance of the trisomy 8 syndrome. The first twin, a stillborn, had autopsy findings suggestive of trisomy 8 syndrome. Cultured lymphocytes and skin fibroblasts of the second, liveborn twin, showed trisomy 8. While the lymphocyte culture showed 46/47, +8 mosaicism, with normal cells predominating, skin fibroblasts yielded only cells with trisomy 8. Bone marrow preparation showed only normal cells, 46,XY. Repeat lymphocyte culture at age 14 months, showed a reduced number of trisomy 8 cells. We would like to emphasize the importance of cytogenetic studies in early infancy, using both peripheral lymphocyte and skin fibroblast cultures, to increase the chance of detecting chromosomal abnormalities.

Ultrasonography of adrenal masses: usual features

Gray-scale B-scan was successful in delineating adrenal masses in 40 patients, all confirmed pathologically. Two patients with extra-adrenal pheochromocytomas, two calcified cysts, and two patients with bilateral adrenal hyperplasia are demonstrated. The usual ultrasonographic features are presented in this paper; they correlated well with urographic, angiographic, CT, and pathological findings. The smallest mass demonstrated was an aldosteronoma (1.3 cm in size).

Ultrasonography of adrenal masses: unusual manifestations

Forty patients with pathologically-proved adrenal masses, and two patients with extra-adrenal pheochromocytomas, were examined with gray scale B-scan. The authors describe unusual echo patterns of adrenal masses due to necrosis or hemorrhage, variations in the effects of large adrenal masses on surrounding organs and vessels, and the differential diagnosis. The complementary role of computed tomography is also discussed.

An evaluation of the role of the Doppler stethoscope and the testicular scan in the diagnosis of torsion of the spermatic cord

The spermatic cord of five dogs were twisted 720 degrees. The animals then underwent both Doppler and isotope evaluations of their scrotums. Both modalities proved highly accurate in diagnosing acute testicular ischemia.

Avoidable factors contributing to death after head injury

We reviewed 116 patients, known to have talked before dying after head injury, to discover factors which had contributed to death but which might have been avoided. All the patients were admitted to a neurosurgical unit and had a neuropathological post-mortem examination. One or more avoidable factors were identified in 86 patients (74%); an avoidable factor was judged certainly to have contributed to death in 63 patients (54%). The most common avoidable factor was delay in the treatment of an intracranial haematoma; others included poorly controlled epilepsy, meningitis, hypoxia, and hypotension. Changes in the management of patients with head injuries which reduce the incidence of avoidable factors should decrease mortality from this condition.

Regional categorization and quality of care in major trauma

A statewide evaluation of major inpatient trauma treatment was completed demonstrating the relationship of emergency medical service categorization and quality of trauma care. Demographic and organ injury data provided guidelines for preventive and medical education emphasizing the need for more practical sessions. The differences between the review process of primary care physicians and specialists was also discussed.

Long-term prognosis of mitral-valve prolapse

We examined the natural history of mitral-valve prolapse in 53 patients who had had a midsystolic click or late systolic murmur (or both) documented phonocardiographically a mean of 13.7 years earlier. Thirty-eight patients were alive without serious complications, and seven had died of unrelated causes. In two patients prolapse was implicated in the cause of death. Other complications were ventricular fibrillation in one patient and bacterial endocarditis in three. Progressive mitral regurgitation developed in five patients, requiring valve replacement in two. These complications occurred in a total of eight patients (15 per cent), and were significantly (P = 0.15) associated with a late systolic murmur rather than an isolated midsystolic click. Thus it appears that the diagnosis of mitral-valve prolapse should not be regarded as ominous; however, patients in whom this diagnosis is associated with a late systolic murmur should be followed carefully.

A double-blind comparison of meptazinol with placebo in postoperative pain

In a double-blind clinical trial, meptazinol (400-mg capsules) was shown to be significantly better than placebo in relieving postoperative pain in patients who had under gone total abdominal hysterectomy operations. Analgesic activity was assessed by patients rating their pain before and 1 hour after the administration of each treatment, by sequential analysis of patient and investigator preference for treatment, and by calculating the time interval between doses of the two treatments.

Evaluation of the quality of hospital care for major trauma

A retrospective analysis of trauma care in five hospitals was undertaken. Eight hundred twenty-three charts met criteria for major trauma. A panel of surgeons reviewing 237 selected charts found the quality of care unacceptable in 16%. Unacceptability rates between hospitals ranged from 7 to 58%. Injury severity score rather than length of stay appears to be a better method for selecting patients at greater risk for poor care.

Isolation and partial characterization of single-stranded adenoviral DNA produced during synthesis of adenovirus type 2 DNA

Single-stranded fragments of adenovirus type 2 DNA were isolated from infected KB cells under conditions which retarded reassociation of complementary sequences but did not denature native viral DNA. Of the total intracellular, virus-specific DNA labeled during a 1-h pulse with tritiated thymidine begining 15 h after infection, about 20% was single stranded when fractionated on hydroxylapatite. This DNA shifted predominantly to the double-stranded fraction on hydroxylapatite during an extended chase incubation, suggesting that it may represent single-stranded DNA in replicating intermediates. Furthermore, the single-stranded DNA annealed nearly equally to both strands of the adenovirus genome. These findings indicate that at least portions of both complementary strands of adenovirus type 2 DNA are exposed as single strands during the period of viral DNA synthesis.