The natural history of aortic dilatation in Marfan syndrome

OBJECTIVES

To determine the relationship between age and aortic dilatation in patients with Marfan syndrome and to define the rate of progression of aortic dilatation in these patients.

DESIGN

All patients were evaluated in a multidisciplinary clinic to establish a firm diagnosis of Marfan syndrome. Aortic dimensions were measured by echocardiography and patients with Marfan syndrome were followed up with annual physical and echocardiographic examinations to detect any change in aortic diameter over the subsequent four years.

PATIENTS

One hundred and fifty-seven patients were referred to the clinic for assessment, of whom 40 exhibited diagnostic features of Marfan syndrome. Only 24 of these patients had previously been diagnosed with Marfan syndrome, while 17 other patients, previously diagnosed with Marfan syndrome, had insufficient clinical features to justify the diagnosis.

RESULTS

Among the 40 patients (19 male, 21 female) with Marfan syndrome (mean age, 28 +/- 15 years), the prevalence of cardiovascular abnormalities was 90%. Aortic root dilatation was present in 78% of patients, aortic regurgitation in 28%, mitral valve prolapse in 65% and mitral regurgitation in 35%. Mean aortic root diameter in the Marfan patients (21.4 +/- 4.0 mm/m2 body surface area) markedly exceeded that of age and sex matched controls without Marfan syndrome (14.9 +/- 2.2 mm/m2) and that of first-degree relatives without Marfan syndrome (15.3 +/- 2.9 mm/m2). The occurrence of aortic dilatation in Marfan syndrome was variable, with patients as young as 20 years exhibiting severe dilatation. All patients with Marfan syndrome exhibiting aortic dilatation were advised to take beta-adrenergic blocking drugs, unless contraindicated, in an effort to retard the rate of aortic dilatation. Among 33 patients followed up for at least one year, 14 (42%) exhibited an increase in aortic diameter of at least 2 mm, while 16 of 23 patients (70%) followed up for at least three years exhibited similar progression of aortic dilatation. The overall mean rate of dilatation in the Marfan patients was 1.9 mm per year. Nine patients developed aortic dilatation of more than 50 mm diameter during four years' follow-up and required surgical repair of the aorta. Each of these patients is well at between three months' and four years' follow-up.

CONCLUSIONS

Aneurysmal dilatation of the aorta is a common complication of Marfan syndrome and may become manifest at an early age. Furthermore, aortic dilatation can progress rapidly, even in the absence of symptoms. Individuals with Marfan syndrome should have annual echocardiographic examinations to monitor aortic root dimensions, and those exhibiting rapid progression of aortic dilatation or an aortic root diameter in excess of 50 mm, should be considered for elective composite graft repair of the aorta.

The effects of CRF and α-helical CRF on anxiety in normal and hypophysectomized rats

The effect of corticotrophin-releasing factor (CRF) on anxiety in normal and hypophysectomized (HYPOX) rats was investigated. Intracerebroventricular injection (i.c.v.) of 2 μg of CRF increased anxiety in the elevated plus maze test in normal and HYPOX rats. Anxiety was measured as the ratio of time spent in the open arms of the maze to total time spent in all arms of the maze. CRF also reduced head dipping and rearing in the hole board, and the number of entries into the arms of the plus maze. These latter changes in behavior were independent of the changes in anxiety. All behavioral effects of CRF in HYPOX rats were blocked completely by the CRF receptor blocker, α-helical CRF (50 μg). Completeness of hypophysectomy was assessed by measuring plasma corticosterone (CORT) level changes 20 min after i.c.v. CRF (2 μg). CORT levels of all HYPOX rats given CRF were well below (< 1/10th) resting baseline levels of normal rats. Moreover, i.c.v. injection of saline vehicle nearly tripled CORT levels over resting baseline in normal rats, and CRF increased CORT levels 2-fold over vehicle. Taken together, these findings replicate the observation that CRF administered i.c.v. to rats is selectively anxiogenic in the elevated plus maze. They also indicate that the anxiety produced by CRF does not involve activation of the pituitary-adrenal axis. Rather, CRF-induced anxiety depends on the binding of CRF to central nervous system CRF receptors. Finally, the plasma CORT data indicate that i.c.v. injection of saline vehicle is stressful, as is injection of CRF.

Simultaneous measurement of cholecystokinin-stimulated amylase release and cholecystokinin receptor binding in rat pancreatic acini

In the past, isolated-dispersed pancreatic acini have been used to examine either cholecystokinin-stimulated amylase release or pancreatic acinar cholecystokinin receptors. We have developed and validated a method for simultaneous measurement of synthetic cholecystokinin octapeptide-stimulated (CCK8-stimulated) pancreatic amylase release and cholecystokinin receptors. After an 18-hour fast, rats were killed and their pancreatic acini isolated. Three-milliliter aliquots of acinar suspension were incubated for 60 minutes in N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-Ringer buffer containing graded doses of CCK8 and a constant amount (7 pmol/L) of iodine 125-labeled CCK8 (by the Bolton-Hunter method) ([125I]BH-CCK8). A 1 ml sample was removed from each flask for determination of amylase release, and the remaining 2 ml were used to determine cholecystokinin receptor capacities and affinities. The median effective dose for amylase release was 16 pmol/L, and release was maximal at 100 pmol/L CCK8 plus 7 pmol/L [125I]BH-CCK8, a dose that released 28% +/- 3% of total cellular amylase content. High affinity (equilibrium dissociation constant of high-affinity receptors = 58 +/- 8 pmol/L, receptor density of high-affinity receptors = 4 +/- 1 fmol/mg protein) and low affinity (equilibrium dissociation constant of low-affinity receptors = 7 +/- 2 nmol/L, receptor density of low-affinity receptors = 313 +/- 108 fmol/mg protein) cholecystokinin receptors were measured. The results demonstrate that CCK8-stimulated amylase release and cholecystokinin receptor binding in pancreatic acini can be measured concurrently and that the parameters of amylase release and cholecystokinin receptor binding are strikingly similar to those previously observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Rat liver mitochondrial malate dehydrogenase: purification, kinetic properties, and role in ethanol metabolism

Malate dehydrogenase was purified from the mitochondrial fraction of rat liver by ion-exchange chromatography with affinity elution. The kinetic parameters for the enzyme were determined at pH 7.4 and 37 degrees C, yielding the following values (microM): Ka, 72; Kia, 11; Kb, 110; Kp, 1600; Kip, 7100; Kq, 170; Kiq, 1100, where a = NADH, b = oxalacetate, p = malate, and q = NAD+. Kib was estimated to be about 100 microM. The maximum velocities for mitochondrial malate dehydrogenase in rat liver homogenates, at pH 7.4 and 37 degrees C, were 380 +/- 40 mumol/min per gram of liver, wet weight, for oxalacetate reduction and 39 +/- 3 mumol/min per gram of liver, wet weight, for malate oxidation. Rates of the reaction catalyzed by mitochondrial malate dehydrogenase under conditions similar to those in vivo were calculated using these kinetic parameters and were much lower than the maximum velocity of the enzyme. Since mitochondrial malate dehydrogenase is not saturated with malate at physiological concentrations, its kinetic parameters are probably important in the regulation of mitochondrial malate concentration during ethanol metabolism. For the mitochondrial enzyme to operate at a rate comparable to the flux through cytosolic malate dehydrogenase during ethanol metabolism (about 4 mumol min-1 per gram liver), the mitochondrial [malate] would need to be about 2 mM and the mitochondrial [oxalacetate] would need to be less than 1 microM.

An epoxygenase metabolite of arachidonic acid mediates angiotensin II-induced rises in cytosolic calcium in rabbit proximal tubule epithelial cells

Previous studies from this and other laboratories have shown that angiotensin II (AII) induces [Ca2+]i transients in proximal tubular epithelium independent of phospholipase C. AII also stimulates formation of 5,6-epoxyeicosatrienoic acid (5,6-EET) from arachidonic acid by a cytochrome P450 epoxygenase and decreases Na+ transport in the same concentration range. Because 5,6-EET mimics AII with regard to Na+ transport, it effects on calcium mobilization were evaluated. [Ca2+]i was measured by video microscopy with the fluorescent indicator fura-2 employing cultured rabbit proximal tubule. AII-induced [Ca2+]i transients were enhanced by arachidonic acid and attenuated by ketoconazole, an inhibitor of cytochrome P450 epoxygenases. Arachidonic acid also elicited a [Ca2+]i transient that was attenuated by ketoconazole. 5,6-EET augmented [Ca2+]i similar to that seen with AII, but was unaffected by ketoconazole. By contrast, the other regioisomers (8,9-, 11,12-, and 14,15-EET) were much less potent. [Ca2+]i transients resulted from influx through verapamil- and nifedipine-sensitive channels. These results suggest a novel mechanism for AII-induced Ca mobilization in proximal tubule involving cytochrome P450-dependent arachidonic acid metabolism and Ca influx through voltage-sensitive channels.

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Lymphomatoid granulomatosis presenting as sudden blindness

Lymphomatoid granulomatosis is an uncommon clinical problem and even more rarely presents to the ophthalmologist. A case is described in which a 60-year-old Fijian woman presented with sudden, sequential, complete visual loss in association with signs of scleritis. Direct eyewall biopsy and nasal mucosal biopsy confirmed the diagnosis of lymphomatoid granulomatosis. Despite intensive high-dose oral prednisone therapy her vision remained at no light perception and she developed recrudescence of disease necessitating the use of radiotherapy. All systemic investigations failed to show any other organ involvement by the disease process and she remains well. This is the first report of lymphomatoid granulomatosis presenting as sudden blindness.

Phase I and pharmacology study of intravesical mitoxantrone for recurrent superficial bladder tumors

A phase 1 study of intravesical mitoxantrone was done in patients with superficial bladder tumors recurrent after previous intravesical therapy. Mitoxantrone (5 to 10.5 mg.) was instilled in the bladder via catheter and was left in situ for 2 hours. Each patient received 6 treatments at 1-week intervals. Pharmacology studies were conducted in a subset of consenting patients. Dysuria, urinary frequency and hematuria were dose-limiting at 10 to 10.5 mg., the dose recommended for our phase 2 studies. One patient treated with 7.5 mg. mitoxantrone had bladder contracture after severe bladder injury caused by the drug. The interval free of recurrence increased in 5 of 8 patients treated with 10 to 10.5 mg. mitoxantrone and in 6 of 19 treated at lower dose levels. One patient who had residual evaluable tumor in the bladder at treatment experienced a complete remission for 16 months. Only 1 of 18 patients who underwent pharmacology studies had any mitoxantrone detectable in the blood after intravesical administration. This patient had severe irritative symptoms at treatment. No systemic toxicity was noted in any patient. Of the mitoxantrone instilled into the bladder 33 to 100% (mean 75%) was recovered in the specimen voided at the end of treatment. In summary, intravesical mitoxantrone is reasonably well tolerated and should be studied further at a dose of 10 mg. per week for 6 weeks. Caution should be exercised, since bladder contracture was seen in 1 patient. Systemic absorption and toxicity are negligible.

Differential processing of the neurotensin/neuromedin N precursor in the mouse

Posttranslational processing of the neurotensin/neuromedin N (NT/NN) precursor has been investigated in mouse brain and small intestine by means of region-specific radioimmunoassays coupled to chromatographic fractionations. In brain, total NT/NN immunoreactivity measured with a common C-terminal antiserum was 15.72 pmol/g. NT measured with an N-terminal antiserum was 9.74 pmol/g and NN measured with an N-terminal antiserum was 5.98 pmol/g. In small intestine, combined NT/NN immunoreactivity was 108.55 pmol/g, consisting of 66.37 pmol/g NT but only 0.96 pmol/g NN. Gel permeation chromatography and reverse phase HPLC revealed that the large discrepancy in the NT and NN values obtained in small intestinal extracts was due to the presence of a high molecular weight, hydrophobic peptide, which was reactive only with the common C-terminally directed antiserum. Pepsinization of this generated an immunoreactive peptide with similar chromatographic characteristics to NN. In mouse intestine, NN is only partially cleaved from the common NT/NN precursor, resulting in the presence of an N-terminally extended molecular species. This novel molecular species of neuromedin N may be the physiological mediator of certain peripheral biological effects hitherto attributed to neurotensin or neuromedin N.

Effect of L-364,718 on GRP-stimulated pancreatic and gastric secretions and GI peptides in conscious dogs

The effect of L-364,718, a cholecystokinin (CCK) receptor antagonist, on exocrine pancreatic secretion, gastric secretion, and plasma levels of gastrointestinal (GI) peptides stimulated by gastrin-releasing peptide (GRP) was examined in five conscious dogs. Intravenous infusion of graded doses of synthetic porcine GRP (18, 36, and 178 pmol/kg/h) caused significant and dose-dependent increases in pancreatic and gastric juice secretion and in plasma levels of pancreatic polypeptide (PP), CCK, and gastrin. Intravenous injection of L-364,718 (20 nmol/kg) significantly inhibited GRP-stimulated pancreatic outputs of juice volume, protein, and amylase and plasma PP release. L-364,718, however, did not affect gastric juice volume and plasma levels of CCK and gastrin. The results suggest that endogenously released CCK is, at least in part, responsible for GRP-stimulated pancreatic protein and enzyme secretions and PP release in dogs. The results further suggest that GRP-stimulated pancreatic secretion might be, in part, a direct response of GRP to exocrine pancreas.

Mechanism of action of nicotine on amylase release by isolated pancreatic acini

The effects of nicotine on the pH of acinar suspension, amylase release and on amylase response stimulated by carbachol were examined in isolated rat pancreatic acini. Additions of nicotine at concentrations ranging from 10 microM to 30 mM caused dose-dependent increases in pH of acinar suspension with simultaneous amylase release (p less than 0.05). There was no increase in amylase release when acinar cells were incubated with nicotine adjusted to pH 7.40. Carbachol alone released amylase whereas nicotine (pH 7.40) at a concentration of 10 mM caused a significant and nonparallel inhibition of amylase release in response to graded doses of carbachol. At concentrations ranges between 3 microM and 10 mM, nicotine at pH 7.40 inhibited amylase release stimulated by 1 microM carbachol, with a half maximal inhibition at 0.8 +/- 0.2 mM. These results indicate that in isolated rat pancreatic acini nicotine at pH 7.40 has no effect on basal nonstimulated amylase release but it inhibits carbachol-stimulated amylase response in a noncompetitive manner. These observations may have direct implications in underlying mechanism of pancreatic disorders.

Total small bowel resection inhibited bombesin-stimulated release of cholecystokinin and pancreatic polypeptide in anesthetized cats

In anesthetized cats, immunoreactive cholecystokinin (CCK), pancreatic polypeptide (PP), and gastrin were released in response to bombesin both before and after small bowel resection. Total small bowel resection significantly decreased bombesin-stimulated release of cholecystokinin and pancreatic polypeptide without affecting the release of gastrin. Integrated analysis showed that CCK, pancreatic polypeptide, and gastrin were released in significant quantities after small bowel resection. The results show that total small bowel resection caused significant inhibition of bombesin-stimulated release of cholecystokinin and pancreatic polypeptide; in contrast, gastrin release remained unaffected. The data further indicate that extra bowel sources of cholecystokinin exist in cats and the release of CCK from those sources occurred following bombesin stimulation.

Flexor tendon ruptures in patients with rheumatoid arthritis

One hundred fifteen flexor tendon ruptures were reviewed in 43 hands with rheumatoid arthritis, one hand with psoriatic arthritis, and one hand with lupus erythematosis. Ninety-one tendons were ruptured at the wrist, four ruptures occurred at the palm, and 20 ruptures occurred within the digits. At the wrist level, 61 ruptures were caused by attrition on a bone spur and 30 were caused by direct invasion of the tendon by tenosynovium. All ruptures distal to the wrist were caused by invasion of the tendon by tenosynovium. Patients whose ruptures were caused by attrition regained better motion than those whose ruptures were caused by invasion by tenosynovitis; however, motion overall was poor. Patients with isolated ruptures in the palm or at the wrist had the best functional results. Those patients with multiple ruptures within the carpal canal had a worse prognosis. Ruptures of both tendons within the fibro-osseous canal had the worst prognosis. The severity of the patient's disease and the degree of articular involvement had a great effect on the outcome of surgery. Prevention of tendon ruptures by early tenosynovectomy and removal of bone spurs should be the cornerstone of treatment.

Effect of L364718, a new CCK antagonist, on amylase secretion in isolated rat pancreatic acini

We examined the effect of L364718, a new cholecystokinin (CCK) receptor antagonist, on amylase release stimulated by CCK or different secretagogues in isolated rat pancreatic acini. L364718 caused a parallel rightward shift of the dose-response curve of CCK8. Schild plots showed a slope of 1.05 +/- 0.15 and a pA2 value of 10.01 +/- 0.31. L364718 inhibited maximally stimulated amylase release by CCK in a dose-dependent manner, with half maximal inhibition (ID50) at 1.7 nM and complete inhibition at 30 nM. Asperlicin, a prototype compound of L364718, also caused dose-dependent inhibition, but L364718 was approximately 400 times more potent than asperlicin (ID50 = 761 nM). L364718 significantly inhibited amylase release in response to CCK33 and CCK8 but had no effect on amylase release stimulated by other receptor secretagogues or agents by passing receptors. The results indicate that L364718 acts as an extremely potent, competitive, and specific antagonist of CCK's action on pancreatic acini.

L364718, a new CCK antagonist, inhibits biological actions of CCK in conscious dogs

The effects of L364718, a new CCK receptor antagonist, on CCK-8 stimulated pancreatic secretion and PP release were examined in three conscious dogs with pancreatic fistulas. L364718 (20 nmol/kg) caused a potent inhibition of CCK-8 stimulated pancreatic protein, amylase and trypsin secretion but not of volume and bicarbonate secretion. Release of PP by CCK was also significantly suppressed by L364718. The degree of inhibition by L364718 was dependent upon the amount of CCK-8 infused. This study demonstrates that L364718 acts as a potent antagonist of CCK's action on pancreatic enzyme secretion and PP release in dogs and suggests that this agent might be a useful tool for studying the physiological role of CCK in conscious animals.

Acquired immune deficiency syndrome presenting as bone marrow and mediastinal cryptococcosis

Disseminated cryptococcosis developed as the first manifestation of the acquired immune deficiency syndrome in a previously healthy Haitian man. Following presentation with a febrile illness that included massive mediastinal and peripheral lymphadenopathy, the patient died of overwhelming pulmonary, visceral, and meningeal cryptococcosis.

Intra-arterial cisplatin treatment of unresectable or medically inoperable invasive carcinoma of the bladder

Five patients between 72 and 82 years old received 5 to 6 treatments of 50 to 75 mg. per m.2 cisplatin by bilateral internal iliac artery infusion for unirradiated invasive transitional cell carcinoma of the bladder. Of the patients 3 also were diabetics and 1 had congestive heart failure. Treatment was tolerated extremely well, although most courses were associated with moderate to severe nausea and vomiting lasting several hours. Of 4 evaluable patients 3 achieved complete remission and 1 achieved a good partial remission. An additional 55-year-old woman with a large invasive bladder carcinoma fixed to surrounding structures was treated with 4 courses of 100 mg. per m.2 intra-arterial cisplatin. This patient had a marked decrease in tumor size, permitting surgical resection of all known residual tumor. A 49-year-old patient with large pelvic lymph node metastases from a squamous cell carcinoma of the bladder achieved only minimal decrease in tumor size after 3 courses of 100 mg. per m.2 intra-arterial cisplatin. We conclude that intra-arterial cisplatin can be highly effective for localized invasive bladder cancer even when relatively low doses are used. With proper care the regimen can be used safely and effectively in elderly patients with medical contraindications to an operation.

Effect of synthetic porcine gastrin-releasing peptide on plasma levels of immunoreactive cholecystokinin pancreatic polypeptide and gastrin in dogs

This study was conducted to determine if synthetic porcine gastrin-releasing peptide (GRP) stimulates the release of immunoreactive cholecystokinin (CCK), pancreatic polypeptide (PP) and gastrin in dogs. Three doses (0.01, 0.1 and 0.5 micrograms/kg-hr) of synthetic porcine GRP were administered intravenously to six conscious dogs. Synthetic porcine GRP stimulated the release of each hormone in a dose-related manner. The effect of GRP on the response of gastrin was greater than its effect on CCK and PP responses. This study indicates that the biological action of synthetic porcine GRP is similar to the bombesin, an amphibian peptide shown previously to stimulate the release of gastrointestinal peptides.

High pressure liquid chromatographic determination of mono- and disaccharides in presweetened cereals: Collaborative study

A collaborative study was conducted using a modified AOAC method (sugars in chocolate) for the determination of fructose, glucose, sucrose, and maltose in presweetened cereals by high pressure liquid chromatography (HPLC). Eight samples consisting of 6 products were analyzed in duplicate by the HPLC method and the AOAC Lane-Eynon method. The AOAC method was modified to use water-alcohol (1 + 1) and Sep-Pak C18 cartridges for sample cleanup. The HPLC results indicate precision comparable to the lane-Eynon method and the chocolate method. The modified HPLC method has been adopted official first action.

Carbon monoxide effect on alveolar epithelial permeability

A carbon monoxide (CO)-intoxicated patient developed increased permeability-type pulmonary edema demonstrated by a normal capillary wedge pressure and production of protein-rich edema fluid. To investigate the effect of CO on alveolar-epithelial permeability, a radio-active labelled isotope, 51Cr-EDTA (MW 377), was instilled into the airways of rabbits. Subsequent egress of the marker from the lungs into arterial blood was determined in serial arterial blood samples. The 51Cr-EDTA counts increased significantly within 15 minutes in the CO-exposed animals, compared with the control animals, while dynamic lung compliance fell, airways resistance rose, and arterial blood pressure decreased. Ultrastructural study of the lungs of CO-exposed animals revealed epithelial and endothelial cell swelling, in terstitial edema, and alveolar type II cells depleted of lamellar bodies. These findings support the possibility that carbon monoxide intoxication is associated with increased alveolar-epithelial permeability.

Congenital absence of the radius

We review the experience in treating congenital absence of the radius at Shriners Hospital in Shreveport. The prognosis for hand function in patients treated nonoperatively is poor to fair, while a minority of patients have good function after operative treatment.

Clindamycin in the treatment of osteomyelitis in children: a report of 29 cases

Clindamycin phosphate was used in the treatment of 29 children with osteomyelitis of whom 25 had an acute and four a chronic type of infection. The usual dose was 50 mg/kg/day intravenously for approximately three weeks followed by oral clindamycin palmitate at home in a dose of 30 mg/kg/day for an additional six weeks. Staphylococcus aureus was isolated in 22 of 29 cases: 96% of strains were penicillin resistant. The clinical and bacteriologic results in the present series were good to excellent. There was prompt clinical and bacteriologic response shortly after initiation of clindamycin therapy. Good bone penetration of the drug was observed. Long-term evaluation revealed satisfactory clinical and roentgenographic progress in all patients. No diarrhea or manifestations of enterocolitis appeared in any patient in spite of high doses of the drug for intervals up to nine weeks.

Immunity in the invertebrates. II. Adaptive immunity in the crayfish (Parachaeraps bicarinatus)

Studies have been made on the resistance of the crayfish (Parachaeraps bicarinatus) to a bacterial pathogen following immunization. The development of immunity is dependent on the dose of vaccine given, and the temperature at which the animals are maintained. The implications of these findings in relationship to the immune response in vertebrates is discussed.