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Biomedical subjects

K Gross

Publications and source records attributed to K Gross.

At least 19 recordsLinked to original sources

Prostate adenocarcinoma using Gleason scores correlates with prostate-specific antigen and prostate acid phosphatase measurements.

To evaluate a relationship between Gleason scores of histopathology of prostate carcinoma and concurrent serum prostate-specific antigen (PSA) and prostate acid phosphatase (PAP) values, 65 men with prostate carcinoma were studied. These patients' cumulative Gleason scores were obtained by totaling the primary and secondary patterns, resulting in two groups: 42 patients received high (6-10) and 23 received low (2-5) Gleason scores. Serum PSA and PAP values were measured by radioimmunometric assay 1 to 7 days before surgical procedures or biopsy for prostate carcinoma. Mean serum PSA for patients in the high Gleason score group was 134.39 ng/mL (normal range: 0 to 4), and the mean serum PSA for patients in the low Gleason score group was 23.62 ng/mL. Mean serum PAP for patients with high scores was 28.08 ng/mL (normal range: 0 to 5), and the mean serum PAP for patients with low scores was 18.19 ng/mL. Patients with high Gleason scores showed significantly greater elevation of serum PSA than those with low Gleason scores (P = .047), using two samples to test for groups having unequal variants. Prostate acid phosphatase levels of patients with high scores were not significantly higher than the levels in patients with low scores (P = .60). These results indicate that PSA levels but not PAP levels correlate with Gleason scores.

Acid Phosphatase

Enlisting the eccentric photoscreener in a public hospital eye department.

We analysed retrospectively non-acute new referrals of children to Waikato Hospital over one year. It was found that children were required to wait unacceptably long to be seen. Almost half the children with established amblyopia were not seen until after the age of five years (42% were not referred until after that age). On the other hand, half the children seen had no significant pathology, and the high level of non-attendance also wasted clinic time. An attempt was made to address these problems by holding regular screening clinics using a photoscreener, assessing all children within three weeks of referral so that children with pathology could be examined and treated promptly. Preliminary investigations into mass community photoscreening produced an average recall rate of 11% (54% of whom fell into our definition of pathological). We feel that enlisting the photoscreener has provided a much more efficient paediatric service, which it is hoped will lead to a reduction in visual loss due to amblyopia.

Adolescent

Malignant acrospiroma.

A 76-year-old woman was referred after results of the biopsy of an ulcerated mass of the right long finger suggested poorly differentiated squamous cell carcinoma. Excision and skin grafting were done and a diagnosis of malignant acrospiroma was established. These tumors are aggressive and 5-year survival rate may be as low as 30%. A ray amputation was subsequently done and the specimen was without residual tumor. At 14 months follow-up, the patient remains free of disease.

Adenoma, Sweat Gland

The effectiveness of two sonic and two ultrasonic scaler tips in furcations.

This study compared the effectiveness of two sonic and two ultrasonic scaler tips on artificial calculus removal from the furcations of mandibular first and second molars. Twenty-four extracted mandibular molars were cleaned and randomly assigned to one of four treatment groups. Teeth were split buccal lingually, artificial calculus was placed in the furcation areas, and the teeth were photographed with a stereo camera. Teeth were reconnected with bonding material and mounted in a typodont with simulated gingiva and attached to a dental chair. Teeth were instrumented with either a Cavitron TFI10 tip, Cavitron EWPP tip, Titan-S Universal tip, or Titan-S Sickle tip by a licensed dental hygienist until each tooth was judged calculus free to the touch with a CH3 explorer. Time for each instrumentation period was recorded. Following instrumentation, the teeth were again split and photographed. Stereophotogrammetry was used to produce tracings of the teeth with initial calculus and remaining calculus. Pre-instrumentation and post-instrumentation amounts of calculus on the surface area were computed using the Bioquant system. A two factor analysis of variance was conducted followed with a Newman-Keuls Multiple Comparison Technique to test for within and between differences. Significant differences (P less than or equal to 0.01) were found between pre- and post-amounts of calculus for all tips. No significant differences (P less than or equal to 0.05) were found between the four instrument tips with respect to percentage of furcation surface with calculus remaining. No differences were found between tips with regard to the time required to clean the test surfaces.

Dental Calculus

Electrophysiology and metallosis: support for an oxidative (free radical) mechanism in the human eye.

Nine cases of metal intraocular foreign body are presented. This study investigates the use of electrodiagnostic techniques in the diagnosis of metallosis and as a prognostic indicator. The electro-oculogram (EOG) and the electoretinogram (ERG) indicate that there are two mechanisms of metallosis, one of which involves cytotoxic damage by siderosomes, and the other lipid peroxidation of photoreceptor outer segments and retinal pigment epithelium. The evidence suggests that the location of the foreign body in the eye determines whether either or both of these mechanisms occur. We propose that these tests can help the ophthalmologist decide when a foreign body has to be removed and give information as to the mechanism of the pathological process.

Biomechanical Phenomena

Bacterial clearance in the intact and regenerating liver.

The Kupffer cells in the liver play an important role in reticuloendothelial system (RES) function by clearing particulate matter and bacteria from the blood stream. While hepatocyte regeneration and function have been extensively studied following partial hepatectomy, little information is available concerning RES function in the regenerating liver. This study investigates hepatic RES function by evaluating bacterial clearance (live E. coli) in the intact and regenerating liver. Thirty-four young male Sprague Dawley rats were studied. Twenty-two animals underwent a standard 70% partial hepatectomy using ligature technique and 12 had a sham operation. Both groups of rats received 10(9) organism of S35 labeled E coli, intravenously at 24 hours, 72 hours, 2 1/2 weeks, and 6 weeks postoperatively. Rats were killed 10 minutes following injection and liver, lung, spleen, and kidney harvested, fixed, and radioactivity was determined using a scintillation spectrometer interfaced with a micro-computer counting the S35 radiolabel. The total organ count of trapped bacteria in liver in partially hepatectomized rats was lower than intact controls at 24 hours (22.0% v 46.4%, P less than .01), but was similar at 72 hours, 2 1/2 weeks, and 6 weeks. Partial hepatectomy increased the amount of bacterial trapping in the lung at 24 hours (11.3% v 1.7%, P less than .01) and 72 hours (10.1% v 1.7%, P less than .05) and returned to normal at 2 1/2 weeks and 6 weeks. Splenic activity was increased following hepatectomy at 2 1/2 weeks. Renal clearance was increased at 72 hours and 2 1/2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Intra-abdominal complications of cystic fibrosis.

In recent years patients with cystic fibrosis (CF) have experienced longterm survival and have demonstrated a number of intra-abdominal complications. This report evaluates the intra-abdominal complications seen in 69 of 189 children with cystic fibrosis from 1972 to 1983. Forty-one patients were boys and twenty-eight girls. Complications occurred in 36 neonates, with meconium ileus (MI) noted in 33 and giant cystic meconium peritonitis (GCMP) in 3. Meconium ileus equivalent occurred in seven older children presenting with bowel obstruction. In addition, rectal prolapse occurred in 12, inguinal hernia in 10, intussusception in 3, cholelithiasis in 3, GE reflux in 4, stress ulcer in 1 and appendicitis in 1. Three infants with GCMP survived resection and enterostomy. Infants with MI were divided into simple (15) or complicated (18) cases. Nonoperative therapy using gastrografin enema was successful in three of eight with simple MI. Operative enterotomy and irrigation was successful in three cases while resection and enterostomy was done in nine. MI was complicated by atresia, volvulus and/or perforation in 18 cases requiring resection and anastomosis or enterostomy. Survival for MI was 86% compared to 36% in 25 MI patients treated in the previous two decades. Meconium ileus equivalent was successfully managed using gastrografin enema in five of seven children. Only 3 of 12 children with rectal prolapse required repair. Two cases of intussusception were reduced while one required resection. Three of 10 children had hernia recurrence due to chronic pulmonary problems.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen

Performance differences between addicts and non-addicts.

Methadone addicts and non-addict controls were tested before and after receiving up to 10 mg of methadone on simple visual reaction time tests and on a vigilance type visual attention test. Addicts were faster than controls on pre-drug testing, although there were no pre-drug differences between groups on the attention task. Addicts maintained faster reaction times than controls even when money was offered as an incentive for speed. Additional methadone did not affect addict performance on any of the tasks. Methadone slowed control reaction times in a dose-related fashion. No significant attention decrements were seen after methadone in controls. Visual reaction time differences between addicts and controls cannot be attributed to group differences in motivation or ability to attend. Slowing of reaction time with acute dose of methadone in controls cannot be attributed to the effect of the drug on attention. An hypothesized drug-induced decrease in visual sensitivity with acute dose in controls and a drug-induced increase in visual sensitivity with chronic dose in addicts can account for the presented data.

Adult

Molecular analysis of the histone gene cluster of Psammechinus miliaris: I. Fractionation and identification of five individual histone mRNAs.

The electrophoretic separation of labeled "9S" histone mRNAs obtained from cleaving sea urchin polysomes was found at first to be highly unreproducible. It became evident that the secondary structure of the individual mRNAs had a greater effect on their relative electrophoretic mobilities than did their molecular weight differentials. We determined the parameters affecting electrophoretic mobility by the novel method of running the labeled polysomal RNA in slab gels across polyacrylamide and urea gradients. The initially complex and species-specific electrophoretic pattern could then, by a judicious choice of denaturing conditions, be simplified to yield five well defined classes of labeled mRNAs. Using optimal conditions for the separation of the RNA components, five messengers were isolated from Psammechinus embryos by preparative disc electrophoresis, four of which, after two electrophoretic separations, exhibited a unimodal distribution. Each of the mRNAs was translated in vitro, four of the five fractions promoting the synthesis of one major protein. The in vitro products were characterized by comparison of their electrophoretic mobilities with those of known sea urchin histones. It was thus possible to correlate individual mRNAs with specific histones. We propose that the five mRNAs designated a-e in order of decreasing electrophoretic mobility code for the histones H4, H2A, H2B, H3, and H1.

Animals

Molecular analysis of the histone gene cluster of psammechinus miliaris: II. The arrangement of the five histone-coding and spacer sequences.

Histone DNA of Psammechinus miliaris was obtained in an enriched form by buoyant density gradient centrifugation and was cleaved into 6 kb repeat units (Birnstiel et al., 1975a) by the action of the specific endonucleases EcoRI and HindIII. Since it was suspected that the 6 kb unit harbored all five histone-coding sequences, the histone DNA unit was subdivided into five segments with the aim of providing five fragments carrying just one coding sequence each. This was achieved by the combined use of EcoRI Hindll, Hindlll, and Hpa I. A physical map was constructed from the overlaps arising in these restriction experiments. Each of the five segments was shown to hybridize uniquely with just one of the five highly purified histone mRNAs (Gross et al., 1976a). By this procedure, the order of the mRNA sequences on the histone DNA was found to be a, c, d, b, e (Gross et al., 1976a), and hence of the protein coding sequences H4, H2B, H3, H2A, and H1. Further evidence is presented that the 6 kb repeat unit, amplified by means of a Murray lambda vector phage, contains AT-rich DNA sequences which would be expected not to code for histone proteins.

Adenine

Molecular analysis of the histone gene cluster of Psammechinus miliaris: III. Polarity and asymmetry of the histone-coding sequences.

Fragments of histone DNA produced by restriction endonucleases contain 5' and 3' termini with defined topologies relative to the histone-coding sequences. After limited resection with lambda-exonuclease, the 6 kb Hindlll histone DNA fragment (see Schaffner et al., 1976) hybridizes to H4 histone mRNA whether or not the DNA has been denatured. This shown that the coding sequence for the histone H4 is proximal to the 3' terminus of the Hindlll restriction fragment. By contrast, lambda-exonuclease digestion of the 6 kb EcoRI histone DNA fragment drastically reduces hybridization of the H4 mRNA. Hence in this molecule, the H4 DNA sequence is near a 5' terminus of the EcoRI restriction fragment. From these results and those described in the preceding paper (Schaffner et al., 1976), the polarity of the H4 gene is therefore 5' H2B leads to H4 leads to H1 3'. Cloned Psammechinus histone DNA (S. G. Clarkson, H. Smith, W. Schaffner, K. Gross, and M. Birnstiel, manuscript submitted for publication) may be strand-separated by electrophoresis. Highly purified histone mRNAs (Gross et al., 1976) all hybridize almost exclusively to the strand of lesser electrophoretic mobility. It follows that all coding sequences are arranged in tandem within the same DNA strand, and that hence they share the same polarity as the H4 DNA sequences. Transcription therefore proceeds in the gene cluster in the direction H4 leads to H2B leads to H3 leads to H2A leads to H1.

Animals