Tumor necrosis factor receptors in neuroblastoma SKNBE cells and their regulation by retinoic acid

The human neuroblastoma cell line SKNBE can be differentiated either by serum removal or by adding to the culture medium different morphogens, for instance, retinoic acid (RA), cyclic AMP derivatives, and phorbol esters. Both the differentiated and undifferentiated cells express the two types of membrane tumor necrosis factor (TNF) receptors (TNFRs) of 55 and 75 kDa (p55 and p75 TNFR, respectively) and also their soluble forms. After RA addition the number of the surface TNFRs per cell is increased approximately twofold, but the kinetics of expression are different, depending on the receptor type. The level of the mRNAs of 2.4 and 4.2 kb, which, respectively, encode the p55 and p75 TNFRs, is also increased during the time course of differentiation, and the kinetics of their expression are biphasic. In contrast, the number of TNFRs and the level of their encoding mRNAs remain unchanged after exposure of the cells to both a phorbol and a cyclic AMP derivative.     

How accurate is size measurement of pancreas cancer masses by computed axial tomography (CT) scanning?

With the advent of preoperative radiotherapy for pancreas cancers, their measurement by imaging is rendered more important, so that outcome data from various treatment programs may be compared. Two radiologists have examined tumor size measurements from 29 patients by CT scans obtained within a week of measurement in the Pathology Department after resection. The radiologists assessed these scans independently from one another and blinded from the pathologic measurement. The largest diameter of their readings was compared to the largest diameter of the tumor measured by the Pathology technician. The correlation between radiologists (P < 3 x 10(-8) was excellent. Correlation between the average of the two radiologic estimates of greatest tumor diameter and actual tissue measurement is excellent for tumors (n = 21) greater than 2 and less than 5 cm in diameter (P < 0.03), but of four specimens measured in the Pathology laboratory as less than 2 cm, all were measured by the radiologists as being at least 1.5 cm larger. Twenty of the 29 cancers (69%) were measured by two radiologists to be within 1 cm of the actual diameter. The nine specimens producing the greatest errors were two with diffuse mucinous tumors throughout the gland (radiologists undercalled by 2.5 cm), one 7 cm mass with a cystic center composed of necrotic cells (overcalled by 2.5 cm, perhaps because of deformity or release of fluid in Pathology), four small masses (1, 1.5, 1.5, and 1.5 cm in diameter), smaller than the normal diameter of the pancreas head, and two tumors with inexplicably inaccurate size estimates.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preparation and use of fibrin glue in surgery

Fibrin glue (FG) is used to control bleeding, to adhere tissues together, and to seal tissue defects. FG is prepared from platelet-rich plasma or by mixing concentrated fibrinogen solutions with thrombin. Concentrated fibrinogen solutions are produced by cryoprecipitation or by chemical precipitation of plasma. The literature on FG preparation is reviewed in order to compare the advantages and disadvantages of the different products reported and to summarize the clinical applications. It is concluded that additional studies are needed to fully evaluate the advantages and disadvantages of fibrinogen concentrated using cryoprecipitation and chemical precipitation and that specific advantages exist for use of both pooled homologous and autologous blood.     

Scanning electron microscopic study of the surface finish of the round sections of preformed arches of NiTi (orthodontic wires made of nickel/titanium

The authors indicate the advantageous characteristics of NiTi wire, focusing the attention on finishing surface accuracy. Every surface damage can become the start of a fracture.     

Kinetics and mechanism of the interaction between human serum albumin and monomeric haemin

Previous studies showed hyperre-sponsiveness to human growth hormone (hGH) in men with myotonic or limb girdle dystrophies (MMD or LGD). Because polyamines may mediate some actions of hGH, we have now investigated polyamine metabolism in these and other dystrophies. Under metabolic balance study conditions, serum and urine levels of putrescine (Pu), spermidine (Sd), spermine (Sm), and cadaverine (Cd) were measured in six normal men (36-44 yr), four men with MMD (38-44 yr), and three men with LGD (30-36 yr), before and during treatment with 0.532 U/kg body wt ((3/4)/d) of hGH. Daily balances of N, P, and K were also monitored. In the normal subjects, hGH did not influence elemental balances or serum and urine polyamines. In MMD, hGH caused significant retention of N, P, and K (P < 0.005). Basal levels of Sm and Cd were significantly elevated above normal (P < 0.005), and Pu, Sm, and Cd increased two- to fourfold above basal during hGH treatment (P < 0.005). In LGD, hGH also caused retention of N, P, and K. Basal levels of nearly all the polyamines (not serum Pu) were significantly above normal in serum and urine (P < 0.05). During hGH treatment, all four polyamines rose significantly above basal (P < 0.005). Serum and urine polyamine levels in five boys with Duchenne muscular dystrophy, age 8-13, did not differ from those in five age-matched normal boys. Skeletal muscle polyamines were measured in five men (31-40 yr) without muscle disease and in three men with LGD (30-38 yr). Average concentrations of Pu, Sd, Sm, and Cd were 46, 306, 548, and 61 nmol/g wet wt in LGD and 1, 121, 245, and 14 in the normal subjects, respectively (P < 0.05 in each instance). Polyamines were determined in skeletal muscle, liver, kidney, and brain of male mice with hereditary muscular dystrophy and in age- and sex-matched normal controls. Pu, Sd, Sm, and Cd levels were two to three times higher than normal in muscle, but did not differ in liver, kidney, and brain. Similar findings were made in male hamsters with hereditary dystrophy and in their controls. The abnormality in hamster muscle polyamines appeared between 1 and 6 wk of age and persisted or intensified until 30 wk. These data reveal abnormalities of polyamine metabolism in men with MMD, in men with LGD, and in mice or hamsters with hereditary muscular dystrophy. The polyamine disorder could be related to dystrophic patients' hyperresponsiveness to hGH.     

Socio-familial characteristics of black male heroin addicts and their nonaddicted friends

To determine whether family, peer, and school variables are associated with divergent heroin-use patterns or career outcomes, we interviewed 183 black male heroin addicts, experimenters, and non-heroin users from Chicago's south side. While subgroup differences on socio-familial variables generally were not statistically significant, we did observe a number of trends in the expected direction. For example, addicts were more likely than experimenters or nonusers to come from broken homes, to have friends who were involved in serious types of drug use and other illegal activities, and to drop out of high school. At the same time, the pervasiveness of some of our measures of "social disharmony" across the sample suggest that, at least in some inner-city black neighborhoods, these patterns are perhaps becoming the norm.     

Clozapine in the treatment of a young adolescent with schizophrenia

Although recent reports have suggested that clozapine may be efficacious in the treatment of adolescents with schizophrenia, few studies have examined the use of clozapine in patients younger than 17 years of age. We describe highly successful trials of clozapine conducted in a 13-year-old girl and her cousin, both of whom developed severe symptoms of schizophrenia, which were refractory to neuroleptic medication, at the ages of 11 and 13 years, respectively. The pharmacology of and clinical experience with clozapine are reviewed.     

Adult vaccination

Experience with a urological waiting list initiative is presented, wherein a list of 231 non-urgent cases was cleared over a 5 month period by a single operator. Some patients had waited 10 years for surgery. Following a postal request, the waiting list was validated; 31.2% of patients wished to be removed. The remaining 68.8% desired surgery and consisted of 51 requiring minor surgical procedures and 108 who needed more major surgery mostly for the relief of bladder outflow obstruction. Minor cases received dates for surgery; however, only 68.2% of this group attended despite being given more than one date for admission. Major cases were reviewed in a pre-admission clinic. General and urological condition was assessed, improved where necessary and surgery booked or delayed accordingly. A small number of patients did not attend or only attended to be reassured that surgery was not needed. Following clinical review, 18.5% of this group did not require operation. The long urological waiting list is a unique situation where patients listed may no longer require surgery. Reviewing these patients not only reduces numbers but also markedly increases percentage attendance for surgery.