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Biomedical subjects

M S Cohn

Publications and source records attributed to M S Cohn.

At least 19 recordsLinked to original sources

Ambulatory phlebectomy using the tumescent technique for local anesthesia.

BACKGROUND: Ambulatory phlebectomy is a cosmetically elegant procedure that provides outpatient office-based surgical removal of large truncal varicose veins. The process of local anesthetic infiltration using traditional means is a time-consuming process that can be painful, and carries with it the inherent risk of accidental intravascular injection. OBJECTIVE: To introduce the tumescent technique for local anesthesia as it relates to the procedure of ambulatory phlebectomy and discuss the benefits of this form of anesthesia. METHODS: A description of the technique utilizing a dilute anesthetic solution, an injection syringe, and blunt-tipped anesthetic probe is provided. RESULTS: Using the tumescent technique for local anesthesia, large areas can be anesthetized quickly, safely, effectively, and relatively painlessly, offering multiple advantages over simple local infiltration, and eliminating the need for regional or general anesthesia. CONCLUSION: The authors consider the tumescent anesthesia technique to be highly effective and an important adjunct to the procedure of ambulatory phlebectomy.

Ambulatory Surgical Procedures↗

Telangiectasia macularis eruptiva perstans.

Telangiectasia macularis eruptiva perstans (TMEP) is a rare form of mastocytosis. It appears most frequently in adults and only occasionally will affect young children or infants. In this disease, multiple brownish-red confluent macules and telangiectasias develop, primarily on the trunk. Pruritus frequently occurs, and may be mild to severe. Most patients have only skin involvement; however, involvement may be systemic as well. Clinical signs and symptoms of systemic mastocytosis are varied and depend on which internal organs are affected. Classic symptoms--such as episodic flushing, gastrointestinal complaints, heart palpitations, and syncope--may be confused with those of other diseases, most notably the carcinoid syndrome. A simple workup can help to differentiate between these two conditions. The authors describe a 48-year old woman who was seen with cutaneous features of TMEP and with multiple symptoms suggesting systemic mastocytosis. They discuss the clinical features, diagnostic workup, and therapeutic options in the management of this relatively rare condition.

Biopsy↗

Apert's syndrome (acrocephalosyndactyly) in a patient with hyperhidrosis.

Apert's syndrome, also known as acrocephalosyndactyly, is a rare type of premature craniofacial synostosis characterized by the clinical triad of cranial and facial malformations along with syndactyly of the hands and feet. Acne vulgaris involving atypical sites such as the upper extremities constitutes the dermatologic hallmark of this rare genodermatosis. We report a patient who demonstrates the classic findings of Apert's syndrome. Our patient also presented with severe hyperhidrosis, which may represent a new clinical finding not previously reported in association with this syndrome.

Acrocephalosyndactylia↗

The sign of Leser-Trélat associated with adenocarcinoma of the rectum.

The authors report a case of the sign of Leser-Trélat occurring in a patient with primary adenocarcinoma of the rectum. The patient demonstrated the sign several months before the internal malignancy was discovered. Although the majority of patients with the sign have an underlying adenocarcinoma of the gastrointestinal tract, relatively few cases have been reported with the rectum as the primary site. This case demonstrates a classic example of the sign of Leser-Trélat and illustrates its importance as a marker of underlying malignancy.

Adenocarcinoma↗

Superficial fungal infections. Topical and oral treatment of common types.

Superficial fungal infections are common dermatologic conditions, and patients often visit primary care physicians for evaluation. Diagnosis can be established with direct microscopic examination, fungal culture, and Wood's light examination. Some infections (eg, tinea corporis, tinea cruris, tinea pedis, pityriasis versicolor) are often successfully treated with a topical antifungal alone. Others (eg, tinea capitis, onychomycosis) require use of a systemic antifungal. Physicians should be familiar with available agents and their adverse effects and closely follow patients receiving long-term antifungal therapy.

Administration, Oral↗

Accidental ingestions of oral prescription drugs: a multicenter survey.

Accidental ingestion of oral prescription drugs by children under age five continues to be a public health problem. A telephone survey of 1,866 ingestion incidents reported to nine poison control centers was conducted in the spring of 1986. Accidental ingestion occurred most often with a two-year-old child (42 per cent) in their own home (82 per cent). Thirty-five per cent of the toxic drugs ingested at home belonged to someone other than the immediate family, most often a grandparent. Toxic drugs were more often out of their usual storage location and in non-child-resistant prescription packaging, a nonprescription container, or in no container. Twenty-two per cent of all child-resistant packages were non-functional. Overall, at least 61 per cent of all medications had no child-resistant barrier at the time of ingestion. Accessible storage locations such as the kitchen counter, table top, or top of a dresser or bedside table greatly increased the risk of accidental ingestion. These results suggest the need for effective child-resistant packaging that is easier for all adults to use.

Administration, Oral↗

Sutureless intraluminal graft for repair of abdominal aortic aneurysm.

A series of seven patients undergoing elective repair of abdominal aortic aneurysms using sutureless intraluminal aortic prostheses for infrarenal tube grafts was reviewed. Follow-up was five to seven months. There was no morbidity related to the graft and one late mortality. In the uncomplicated cases, the average total operative time was two hours 14 minutes with no bank blood transfusions. The overall average operative time was two hours 41 minutes with an average operative transfusion of 0.28 units and total transfusions of 1.70 units of bank blood per case. Based on this experience and the observation that operative time and blood loss are major determinants of mortality with emergency abdominal aortic aneurysm repairs, we believe that use of sutureless intraluminal prostheses in suitable cases of leaking or ruptured abdominal aortic aneurysms has the potential to markedly improve survival.

Aorta, Abdominal↗

An intussuscepted ileal ureter bladder nipple.

We report a case of an intussuscepted bladder nipple following construction of an ileal ureter. The ileal ureter has become a valuable option in reconstructing the urinary system. This complication bears consideration during construction of an ileal ureter and stresses the need for close observation of these patients.

Adult↗

The biochemistry, genetics, and regulation of polyamine biosynthesis in Saccharomyces cerevisiae.

We have studied the enzymes and genes involved in the biosynthesis of putrescine, spermidine, and spermine in Saccharomyces cerevisiae. Mutants have been isolated with defects in the biosynthetic pathway as follows: spe10 mutants, deficient in ornithine decarboxylase, cannot make putrescine, spermidine, or spermine; spe2 mutants, lacking S-adenosylmethionine decarboxylase, cannot make spermidine or spermine; spe3 mutants, lacking putrescine aminopropyltransferase, cannot make spermidine or spermine; and spe4 and spe40 mutants, lacking spermidine aminopropyltransferase, contain no spermine and permit growth of spe10 mutants. Studies with these mutants have shown that in yeast: 1) polyamines are absolutely required for growth; 2) putrescine is formed only by decarboxylation or ornithine; 3) two separate aminopropyltransferases are required for spermidine and spermine synthesis; 4) spermine and spermidine are important in the regulation of ornithine decarboxylase and the amines exert this control by a posttranslational modification of the enzyme; and 5) spermidine or spermine is essential for sporulation of yeast and for the maintenance of the double-stranded RNA killer plasmid. Recent studies in amine-deficient mutants of Escherichia coli have shown an important role of the polyamines in protein synthesis in vivo.

Adenosylmethionine Decarboxylase↗

Streptomycin resistance (rpsL) produces an absolute requirement for polyamines for growth of an Escherichia coli strain unable to synthesize putrescine and spermidine [delta(speA-speB) delta specC].

The presence of certain rpsL (strA) mutations in a strain of Escherichia coli that cannot synthesize putrescine or spermidine because of deletions in ornithine decarboxylase, arginine decarboxylase, and agmatine ureohydrolase, converts a partial requirement for polyamines for growth into an absolute requirement.

Drug Resistance, Microbial↗

Regulatory mutations affecting ornithine decarboxylase activity in Saccharomyces cerevisiae.

We isolated several strains of Saccharomyces cerevisiae containing mutations mapping at a single chromosomal gene (spe10); these strains are defective in the decarboxylation of L-ornithine to form putrescine and consequently do not synthesize spermidine and spermine. The growth of one of these mutants was completely eliminated in a polyamine-deficient medium; the growth rate was restored to normal if putrescine, spermidine, or spermine was added. spe10 is not linked to spe2 (adenosylmethionine decarboxylase) or spe3 (putrescine aminopropyltransferase [spermidine synthease]). spe 10 is probably a regulatory gene rather than the structural gene for ornithine decarboxylase, since we isolated two different mutations which bypassed spe10 mutants; these were spe4, an unliked recessive mutation, and spe40, a dominant mutation linked to spe10. Both spe4 and spe40 mutants exhibited a deficiency of spermidine aminopropyltransferase (spermine synthase), but not of putrescine aminopropyltransferase. This suggests that ornithine decarboxylase activity is negatively controlled by the presence of spermidine aminopropyltransferase.

Carboxy-Lyases↗

Effect of sphincteroplasty on gallbladder function and bile composition.

The effect of sphincteroplasty on bile concentration and composition and on gallbladder function was investigated in the dog. Gallbladder and hepatic bile samples were analyzed for cholesterol, phospholipid (lecithin), bile salt concentration and individual bile salt content. Motor function was studied by cholecystokinin-cholecystography with changes in gallbladder volume computed from the radiographs. All bile samples were cultured and at the conclusion of the experiments, the gallbladders were histologically examined. Sphincteroplasty did not alter biliary cholesterol concentration but the concentration of lecithin and bile salts decreased in gallbladder bile and increased in hepatic bile (p less than .001). These changes depict a trend toward greater lithogenicity for gallbladder bile and lesser lithogenicity for hepatic bile. Postoperative analysis of individual bile salts in gallbladder bile showed an increase in monohydroxy and dihydroxy bile salts and a decrease in trihydroxy bile salts (p less than .001). This tendency has been shown to be conducive to gallstone formation. The concentrating ability of the gallbladder was partially eliminated by sphincteroplasty but gallbladder filling and motor response to stimulation by cholecystokinin was not affected. All gallbladders demonstrated histologic changes of chronic inflammation and all developed a significant bacterial flora following sphincteroplasty. It is concluded that cholecystectomy should always be performed following transduodenal sphincteroplasty not because of any resultant abnormality of motor function, as has previously been held, but because of the resultant abnormality of gallbladder pathophysiology.

Ampulla of Vater↗

Identification of pyruvate in S-adenosylmethionine decarboxylase from rat liver.

S-Adenosylmethionine decarboxylase has been purified to homogeneity (26,000-fold) from rat liver. The enzyme has a molecular weight of 155,000 and a subunit molecular weight of 42,000. One mole of covalently bound pyruvate was found to be present per mole of enzyme subunit. This is the first mammalian enzyme found to contain covalently linked pyruvate.

Adenosylmethionine Decarboxylase↗

Isolation and characterization of Saccharomyces cerevisiae mutants deficient in S-adenosylmethionine decarboxylase, spermidine, and spermine.

Four mutants were isolated from Saccharomyces cerevisiae that are deficient in S-adenosylmethionine decarboxylase (spe2). All four mutants are chromosomal and fall into a single complementation group tightly linked to arg1. Since one of the mutants contained a temperature-sensitive activity, this complementation group defines the structural gene. Mutants totally lacking enzymic activity did not contain spermidine or spermine and had a greatly increased doubling time when grown in the absence of these two polyamines. Addition of 10(-6) M spermidine or 10(-5) M spermine, but not putrescine or cadaverine, restored the doubling time to that of the wild type. Diploids formed from a cross of two mutants completely deficient in spermidine and spermine were unable to sporulate in the absence of added spermidine or spermine. We obtained evidence that arg1 was not located on any of the 17 known chromosomes, and therefore we postulate that arg1 and spe2 are located on a new 18th chromosome.

Adenosylmethionine Decarboxylase↗