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Biomedical subjects

M Levinson

Publications and source records attributed to M Levinson.

At least 19 recordsLinked to original sources
PubMed1998

ACL reconstruction in children with open physes.

Nine male patients with wide open physes who underwent intra-articular anterior cruciate ligament (ACL) reconstruction using semitendinosus and gracilis tendon grafts passed through the tibial physis and over the top of the femoral condyles were retrospectively reviewed at an average follow-up of 39 months (range: 24 to 72 months). Five patients underwent reconstruction < 6 weeks following injury (range: 11 days to 41 days); the other four underwent reconstruction 2, 3, 5, and 24 months following injury. Seven patients had excellent results and fully returned to their sport. Mean Lysholm score in these patients was 99 (range: 95 to 100), and the mean maximum KT-1000 difference (available for six patients) was 2.8 mm (range: 0 to 5.5 mm). Four of six intact grafts had a mean maximum KT-1000 difference < or = 3.5 mm. Two grafts ruptured and were considered failures (one complete rupture at 10 months and one partial rupture at 3 years). Postoperative height increase averaged 10.7 cm (range: 4 to 22.9 cm). No patient had a clinically significant leg-length discrepancy, angular deformity, or radiographic evidence of physeal injury.

Adolescent↗
PubMed1997

Increased expression of decorin in experimental hydronephrosis.

Transforming growth factor (TGF)-beta1 is a potential mediator of tubulointerstitial (TI) fibrosis in the rat unilateral ureteral obstruction (UUO) model. Decorin is a protein composed of a core protein and a chondroitin sulfate side chain and is capable of inactivating TGF-beta. Since TGF-beta strongly induces the synthesis of decorin in experimental glomerulonephritis, it was our intent to investigate whether altered decorin expression is operant in the rat UUO model. Renal cortical decorin mRNA levels initially became elevated (2.5-fold) in obstructed kidney (OBK) versus contralateral unobstructed kidney (CUK) 24 hours post-UUO and remained greater in the OBK specimens at 48 (2.3-fold), 96 (2.2-fold), and 168 (1.9-fold) hours post-ureteral ligation. Whole-body X-irradiation 11 days prior to UUO significantly reduced decorin mRNA at 24 and 96 hours post-UUO. On immunolabeling, decorin was only evident in the adventitia of blood vessels in CUK specimens at any time point after UUO. In contrast, OBK specimens initially demonstrated periglomerular and peritubular interstitial localization of decorin at 96 hours post-ureteral ligation, which became even more intense and diffuse in the tubulointerstitium at 168 hours post-UUO. On Western analysis, there were highly significant increases in decorin protein expression in the OBK versus the CUK specimens at 96 and 168 hours post-UUO. Levels of active TGF-beta1 in the renal cortex of OBK were 1.9- and 3.6-fold higher than CUK at 48 and 96 hours post-UUO. In summary, we demonstrated that post-UUO, decorin mRNA and protein expression is up-regulated in the renal cortex of OBK, but not CUK, specimens in a temporal parallel with active TGF-beta1 levels and macrophage infiltration. We postulate that the development of TI fibrosis in this model may be related to only a physiologic induction of decorin by TGF-beta, and that pharmacologic levels may be required to retard or prevent scarring via TGF-beta inhibition.

Animals↗
PubMed1997

Adenylyl cyclase inhibitory pathway is differentially modified in rat white and brown fat by high-energy diets.

Incubation of white adipose tissue (WAT) adipocytes from rats fed a high-energy diet (Exp group) with antilipolytic Gi-coupled adenylyl cyclase inhibitory agonists, nicotinic acid (Nic) and N8-(L-2-phenylisopropyl)adenosine (PIA), resulted in lower cellular adenosine 3',5'-cyclic monophosphate (cAMP) levels than in stimulated adipocytes from rats fed a nutritionally balanced diet (Con group). In contrast to WAT, incubation of brown adipose tissue (BAT) adipocytes with Nic yielded higher cAMP levels in the Exp vs. Con rats. In both WAT and BAT adipocytes, pertussis toxin treatment abolished the differences in Nic- and PIA-inhibited cAMP formation between Exp and Con animals. Immunoblotting of adipocyte membranes indicated a lower content of Gi alpha but not Gs alpha in BAT membranes of Exp vs. Con animals after 6 and 10 wk of feeding. No such differences were found in the Gs alpha or Gi alpha contents of WAT membranes. Thus the inhibitory pathway of adenylyl cyclase is proposed to be sensitized in WAT and desensitized in BAT of rats fed high-energy diets. These modifications in sensitivity are in line with reduced cAMP and lipolysis in WAT and increased cAMP and thermogenesis in BAT during obesity.

Adenylyl Cyclase Inhibitors↗
PubMed1995

Cerebral artery stenoses in Williams syndrome cause strokes in childhood.

Extensive narrowing of lumens of many cerebral arteries caused strokes with brain damage and chronic hemipareses in two children with Williams syndrome. Increased irritability, loss of consciousness, and seizures were initial signs. Arterial stenoses are not limited to the supravalvular aorta and pulmonary arteries in patients with Williams syndrome.

Adult↗
PubMed1995

The conservative management of the unstable shoulder including rehabilitation.

The conservative management of shoulder instability depends on a well-defined program that emphasizes early diminution in the patient's symptoms, appropriate immobilization, and a well-defined precise rehabilitation program that can be individually tailored to meet the patient's needs. Immobilization should be considered in younger patients less than 20 years of age for between 3 to 4 weeks in order to enhance capsulolabral complex healing. Older patients may be immobilized for a shorter period of time. Analgesic medication and local physical therapeutic modalities may be used to decrease the patient's symptomatic complaints. Once the immobilization period has ended, a precise and specific rehabilitation program tailored for the individual needs of the patient should be undertaken. The rehabilitation program should emphasize early and safe regaining of normal ROM, strengthening of the dynamic stabilizers of the shoulder, and strengthening of the scapular stabilizing muscles of the shoulder. Finally, rehabilitation programs that enhance the patient's neuromuscular control over the glenohumeral joint should be considered in the conservative management of the unstable shoulder.

Arm Injuries↗
PubMed1993

Enteral feeding, gastric colonisation and diarrhoea in the critically ill patient: is there a relationship?

In this prospective study we aimed to determine whether there is any relationship between enteral feeding, gastric colonisation and diarrhoea in the critically ill patient. Sixty-two critically ill patients from an intensive care unit of a major teaching hospital, who satisfied the usual criteria for enteral feeding, were randomised to receive enteral feeding or not for three days followed by a second randomisation to enterally feed or not for three days. Diarrhoea was recorded and cultures taken of both gastric aspirates and stool. There was no significant difference in the incidence of diarrhoea between the groups. Gastric colonisation was unrelated to feeding practice and to the development of diarrhoea. We conclude that in the critically ill patient, enteral feeding does not cause or promote diarrhoea.

Bacteria↗
PubMed1992

Daisybank 1983-1989. An audit of a residential home preparing adolescents for permanent placements.

This paper describes the evaluation of a small children's home, Daisybank, set up to prepare adolescents, who had been in care for several years, to live in permanent placements. The home seemed largely to fail in this explicit task, but appear to succeed in helping a majority of its residents make substantial progress in coming to terms with their deprived and disrupted lives. It provided them with genuine care and commitment, which they acknowledged and appreciated. We believe that the success of the home needs to be judged by these criteria, since for young people in mid- to late adolescence the search for new permanent parental homes probably conflicted with other psychosocial tasks relating to adolescence. On the other hand, Daisybank seemed unable adequately to resolve the problems of a subgroup of adolescent males with serious conduct problems who were responsible for the not infrequent physical abuse of several female staff.

Adolescent↗
PubMed1992

Differential post-receptor responses of adenylate cyclase in white and brown adipose tissue membranes of rats fed high-energy diets.

1. Adenylate cyclase activity was determined in membranes of white and brown adipose tissue (WAT and BAT, respectively) from rats fed a high-energy diet (EXP group) vs those fed a nutritionally balanced one (CON group). 2. The isoproterenol- and guanine nucleotide-induced adenylate cyclase activity in WAT membranes of EXP rats was lower than that in CON rats. 3. Relative adenylate cyclase activity in like treated BAT membranes was higher in EXP than in CON rats. 4. It is concluded that feeding high-energy diets to rats induces similar post-receptor modifications of adenylate cyclase as found in genetic obese rodents.

Adenylyl Cyclases↗
PubMed1991

Interaction of MSG taste with nutrition: perspectives in consummatory behavior and digestion.

Studies in the taste system of mammals indicate that monosodium glutamate (MSG) produces a unique taste sensation termed umami. As a derivative of glutamic acid, MSG is a naturally occurring nutrient in many foods; its commercial use to improve food palatability for humans is well documented. Behavioral studies with experimental animals have revealed that preference for MSG in solutions and selection of MSG-flavored diets can be explained by sensory means with no appreciable effects on preference by postingestive consequences. However, preference for umami-flavored fluids is reduced by feeding rats low-protein diets or low quality protein. MSG-flavored diets, initially unpreferred, were subsequently highly selected. However, the adulteration of diets by MSG either did not or only slightly increased food intake. In light of the significant contribution of MSG to diet taste, apparently as a signal coupled to dietary proteins, physiological studies have been initiated to reveal its role as a stimulator of the cephalic phase of pancreatic exocrine secretion. Modified sham-feeding experiments with dogs have shown that oral stimulation by MSG produced significant stimulation of both pancreatic flow and protein output in conscious dogs.

Amino Acids↗
PubMed1991

Adenylate cyclase responses to sucrose stimulation in membranes of pig circumvallate taste papillae.

1. Typical adenylate cyclase (AC) responses to guanine nucleotides were found in membranes of pig circumvallate (CV) taste papillae. 2. Sucrose stimulated AC activity in the CV membranes and this stimulation was GTP dependent and tissue specific. 3. The stimulatory effect of sucrose in the CV membranes was dependent on the concentration of membranes used in the AC assay. 4. This study provides the first biochemical data on cellular transduction of taste in the pig, compares positively to preliminary results in cattle and supports recent suggestions for a role of cAMP in sweet taste transduction.

Adenylyl Cyclases↗
PubMed1990

Serum factors influencing cultured hepatocyte exogenous and endogenous triglyceride.

Rat hepatocyte monolayer triglyceride content was increased modestly by incubations with apolipoprotein E-containing triglyceride emulsions or chylomicrons (exogenous) and was increased substantially by increasing media free fatty acid concentrations (endogenous). The secretion of both endogenous and exogenous triglyceride into media was enhanced by additions of serum and serum components. These additions not only enhanced hepatocyte triglyceride secretion but also, because of the absence of media lipolysis, more triglyceride was recovered in the system. Lipoprotein-free serum replicated the effect of whole serum. Lipoprotein produced a more modest secretory response. The apolipoprotein C components were the only ones that enhanced hepatic triglyceride secretion. Both lipoprotein-free plasma and lipoprotein enhanced the in vitro transfer of hepatocyte exogenous triglyceride to fibroblast.

Animals↗
PubMed1989

Gastrointestinal complications after human transplantation and mechanical heart replacement.

One hundred fifty-three patients underwent 159 heart transplants; 7 of these patients received 8 artificial hearts used as a bridge before implantation. The 1-year survival rate was 81 percent. One hundred forty gastrointestinal complications developed in 70 patients. Thirty-eight operations were required. Twenty-nine were intraabdominal operations. Of these, 22 were elective and 7 were emergency procedures. Five of the seven patients who underwent emergency procedures died, for an overall total mortality rate of 17 percent for major intraabdominal interventions. There were no complications or deaths in patients who underwent elective procedures. Major elective intraabdominal surgical interventions can be safely carried out in heart transplant patients. Repeated physical examination, aggressive use of endoscopy and imaging techniques, sound surgical judgement and a mutual relationship of trust and respect between cardiac and general surgeons are keys to a successful outcome.

Emergencies↗
PubMed1984

Amebic appendicitis associated with hepatic abscess.

We have described a case of primary amebic appendicitis with liver abscess, and we suggest that this diagnosis be considered in patients with appendicitis after returning from endemic areas. Careful histologic preparation will establish the diagnosis and dictate appropriate therapy.

Amebiasis↗
PubMed1979

Serum gamma-glutamyl transpeptidase: its specificity and clinical value.

The clinical import of the serum gamma-glutamyl transpeptidase (GGTP) level was evaluted in 162 prospectively studied patients. GGTP is helpful in determining the origin of alkaline phosphatase (AP); it clearly separates increased AP of bone and placental origin from that of liver origin. The GGTP level closely parallels the AP level in most instances, but it may be more sensitive in detecting liver disease in anicteric patients. The finding of significantly increased GGTP in patients with chronic aggressive hepatitis as compared to normal levels found in chronic persistent hepatitis may provide a prognostic clue in cases of unresolved hepatitis. The apparent specificity and sensitivity of the GGTP test, combined with ease of performance and low expense, make it a valuable addition to the evaluation of a patient with hepatic disease.

Adolescent↗