Search PubMed⌕ Search

Biomedical subjects

C Wallis

Publications and source records attributed to C Wallis.

At least 73 records · Page 4Linked to original sources
PubMed1987

Familial rhizomelic dysplasia: phenotypic variation or heterogeneity?

In a consanguineous kindred of mixed ancestry in Cape Town we observed a boy with severe shortness of stature and an unusual skeletal dysplasia with marked shortness of the humeri. A male one-half second cousin had gross abnormalities of the lower limbs, which were worst in the femora, but his skeleton was otherwise virtually normal. A brother and sister of this latter individual had been similarly affected and their parents were consanguineous. The question arises as to whether two similar but separate disorders are present in this family or whether the condition in these two persons represents extreme phenotypic variability of the same autosomal recessive entity.

Bone Diseases, Developmental↗
PubMed1987

Heterozygous manifestations of Langer mesomelic dysplasia.

The mesomelic dysplasias are a heterogeneous group of genetic disorders with predominant skeletal manifestations in the forearms and shanks. We have documented, over a thirteen-year period, the clinical and radiographic course of the condition in a boy with the Langer type of mesomelic dysplasia. It has been suggested that dyschondrosteosis or the Madelung deformity are the phenotypic manifestations of the gene which causes Langer mesomelic dysplasia in the homozygote. Several relatives on both sides of the family which we studied had malformations of their forearms, in keeping with this concept. However, these anomalies differed from those of dyschondrosteosis and the classical Madelung deformity; the exact syndromic status of the heterozygous phenotype remains unsettled.

Adolescent↗
PubMed1987

Linkage analysis of British and Indian families with Von Recklinghausen neurofibromatosis.

Linkage analysis has been undertaken in two British and three South African Indian families with Von Recklinghausen neurofibromatosis. Eleven polymorphic DNA probes were studied, including both random DNA sequences and candidate oncogenes. Although no evidence for linkage of these probes to the disease was detected, substantial exclusion regions were established on six of the chromosomes studied.

Genetic Linkage↗
PubMed1987

A new hypospadias-mental retardation syndrome in three brothers.

Three brothers had a syndrome of hypospadias and mental retardation in association with microcephaly, craniofacial dysmorphism, joint laxity, and beaked nails. No other family members were affected, and this previously undelineated condition appears to be inherited in either an autosomal recessive or X-linked recessive mode.

Child↗
PubMed1986

5-Methyltryptamine decreases net accumulation of 32P into the polyphosphoinositides from [gamma-32P]ATP in a cell-free system from blowfly salivary glands. Activation of breakdown of the newly synthesized [32P]polyphosphoinositides.

Incubation of blowfly salivary gland homogenates with 30 microM [gamma-32P]ATP resulted in a rapid, Mg2+-dependent, synthesis of [32P]polyphosphoinositides and [32P]phosphatidic acid. 5-Methyltryptamine, in the presence of 10 microM guanosine 5'-(3-O-thio)trisphosphate, reduced the net accumulation of 32P label into phosphatidylinositol-4,5-P2 and phosphatidylinositol-4-P by 35 and 20%, respectively. 5-Methyltryptamine did not affect synthesis of [32P]phosphatidic acid. Phosphorylation of polyphosphoinositides was not affected by 5-methyltryptamine. In membranes labeled in vitro with [gamma-32P]ATP, 5-methyltryptamine stimulated a rapid breakdown of the [32P]polyphosphoinositides. These results indicate that in blowfly salivary gland homogenates, hormone stimulates breakdown of the newly synthesized polyphosphoinositides. In the presence of hormone, the rate of polyphosphoinositide synthesis does not compensate for the rate of polyphosphoinositide degradation.

Adenosine Triphosphate↗
PubMed1985

5-Hydroxytryptamine stimulates inositol phosphate production in a cell-free system from blowfly salivary glands. Evidence for a role of GTP in coupling receptor activation to phosphoinositide breakdown.

Phosphoinositide breakdown has been linked to the receptor mechanism involved in the elevation of cytosolic Ca2+. In a cell-free system prepared from [3H] inositol-labeled blowfly salivary glands, 5-hydroxytryptamine stimulated the rapid production of inositol phosphates. Within 30 s of hormone addition, there was a 100% increase in inositol trisphosphate formation, a 70% increase in inositol bisphosphate formation, and a 90% increase in inositol monophosphate formation as compared to control homogenates incubated for the same length of time. 5-Hydroxytryptamine did not stimulate inositol or glycerol phosphoinositol formation. Half-maximal activation of inositol phosphate production was obtained with 0.33 microM 5-hydroxytryptamine. Ethylene glycol bis(beta-aminoethyl ether)-N',N',N',N'-tetraacetic acid, (EGTA) (0.3 mM) inhibited the basal formation of inositol phosphates and decreased the net accumulation of inositol bisphosphate and inositol trisphosphate due to hormone as compared to homogenates incubated in the absence of added Ca2+. EGTA, however, had little effect on the per cent stimulation of inositol phosphate production due to hormone. In homogenates, ATP, GTP or guanyl-5'-yl imidodiphosphate (Gpp(NH)p) was required for a hormone effect. Gpp(NH)p, unlike ATP or GTP, increased the basal formation of inositol phosphates. In membranes, GTP, Gpp(NH)p, or guanosine 5'-(3-O-thio)trisphosphate (GTP gamma S) sustained a hormone effect whereas ATP was ineffective. GTP did not affect production while Gpp(NH)p and GTP gamma S increased inositol phosphate production. Half-maximal effects of Gpp(NH)p and GTP gamma S on hormone-stimulated inositol phosphate formation occurred at 10 microM and 100 nM, respectively. In the presence of 1 microM GTP gamma S, 5-methyltryptamine stimulated inositol phosphate formation within 2 s in membranes. These results indicate that in a cell-free system, GTP is involved in mediating the effects of Ca2+-mobilizing hormones on phosphoinositide breakdown.

Animals↗
PubMed1985

An instrument for the immediate quantification of bacteria in potable waters.

A new semiautomated instrument is described which quantifies the number of bacteria in potable waters within 3 min, providing a permanent colorimetric record of the results. The bacteria detection device can measure as few as 100 CFU/ml in potable waters. In brief, a 100- to 1,000-ml sample of tap water is drawn through a large surface, customized filter housed in the device, and bacteria, rust, and humic acid in the water are concentrated thereon. A reducing agent is used to remove the rust and humic acid from the filter. The filter is inverted and backflushed to elute the bacteria which are collected and reconcentrated onto a 7-mm-diameter filter surface. The reconcentrated bacteria are stained, and the filter fibers are preferentially decolorized without removing the dye from the bacteria. The color intensity of the filter surface is compared with a color guide to determine the amount of bacteria in the test water.

Bacteria↗
PubMed1985

Method for detecting viruses in aerosols.

A simple method with poliovirus as the model was developed for recovering human enteric viruses from aerosols. Filterite filters (pore size, 0.45 micron; Filterite Corp., Timonium, Md.) moistened with glycine buffer (pH 3.5) were used for adsorbing the aerosolized virus. No virus passed the filter, even with air flow rates of 100 liters/min. Virus recovery from the filter was achieved by rapid elution with 800 ml of glycine buffer, pH 10. The virus in the primary eluate was reconcentrated by adjusting the pH to 3.5, adding AlCl3 to 0.0005 M, collecting the virus on a 0.25-micron-pore Filerite disk (diameter, 25 mm) and and eluting with 6 ml of buffer, pH 10. With this method, virus could be detected regularly in aerosols produced by flushing when 3 X 10(8) PFU of poliovirus were present in the toilet bowl. Poliovirus-containing fecal material from two of four infants who had recently received oral polio vaccine also yielded virus in the aerosols when feces containing 2.4 X 10(7) to 4.5 X 10(7) PFU of virus had been added to the toilet bowl. Persons infected with a variety of natural enteric viruses are known to excrete this amount of virus in their daily stools.

Aerosols↗
PubMed1985

Rapid, colorimetric method for the detection of microorganisms in blood culture.

A semiautomated instrument (Septi-Screen) and method are described that semiquantify bacteria colorimetrically in blood-inoculated cultures in 2 to 8 h. If the blood culture is positive, concentrates (of viable bacteria) are obtained free of blood cells. In pediatric cases and in septicemia attributed to indwelling catheters where bacteremia is often manifested by high bacterial counts, the total time required to obtain bacterial concentrates is only 2 to 3 h. In brief, at various intervals after inoculation of 10 ml of blood into 100 ml of culture fluid, 25-ml blood culture samples are passed through the Septi-Filter. Erythrocytes and leukocytes pass into the filtrate and are discarded, but bacteria are electrostatically retained on the filter surface. The entrapped bacteria are backflushed and recovered as a concentrate that is processed through a second filter (Septi-Count) for colorimetric quantitation. The bacteria are stained, and the filter fibers are decolorized. The color intensity of the filter surface is proportional to the number of bacteria in the concentrate processed. The total Septi-Screen processing time is 3 to 5 min.

Bacteria↗
PubMed1984

Reverse-flow apparatus for enhanced colorimetric detection of bacteriuria.

The reverse-flow apparatus is a new device for enhancing the detection of bacteria in urine. Bacteria are trapped onto a customized filter, and the pigments, crystals, and other interfering substances in the urine pass through the filter and are discarded. The bacteria are backflushed and are recovered as a concentrate, and the concentrate is then processed through the previously described colorimetric bacteriuria detection device. A total of 1,000 urine samples were obtained from randomly selected patients and were cultured on agar. Upon enumeration of the colonies, 160 urine samples were shown to contain more than 10(5) CFU/ml. In the bacteriuria detection device, 150 urine samples could not be processed (pigmenters and cloggers), and of the 850 urine samples processed, 127 were culture positive for 10(5) CFU/ml or greater, and 150 urine samples contained between 10(4) and 10(5) CFU/ml. At 10(5) CFU/ml, there were 140 false-positives and 14 false-negatives. When duplicate urine samples were processed through and concentrated by our new reverse-flow apparatus, all samples, including the above pigmenters and cloggers, could be tested in the bacteriuria detection device. The 150 unprocessable samples described above yielded 33 additional bacteria-positive urines, 23 at the 10(5)-CFU/ml cutoff and 10 at the 10(4)-to-10(5)-CFU/ml cutoff. There were 105 false-positives at 10(5) CFU/ml and only 2 false-negatives at the same level of bacteria. At 10(4) to 10(5) CFU/ml there was only 1% false-positive and 4% false-negative. The reverse-flow apparatus allows greater specificity and sensitivity in the rapid bacteriuria test. Urine containing 10(4) CFU/ml or more can now be detected with a 96% sensitivity in a total processing time of less than 2 min.

Bacteriological Techniques↗