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P H Rees

Publications and source records attributed to P H Rees.

At least 37 records · Page 2Linked to original sources
PubMed1989

Research policy and review 30. How to add value to migration data from the 1991 census.

"The form in which migration information is likely to be provided from the 1991 Census [of the United Kingdom] is reviewed, and suggestions are made about how this provision can be improved for the academic research community, building on the experience of the 1981 Census. The recommendations add considerable value to the information at relatively low cost."

Censuses↗
PubMed1988

Human mast cell heterogeneity: histamine release from mast cells dispersed from skin, lung, adenoids, tonsils, and colon in response to IgE-dependent and nonimmunologic stimuli.

We have compared the ability of anti-IgE, calcium ionophore A23187, substance P, compound 48/80, poly-L-lysine, and morphine to release histamine from mast cells of human skin, lung, adenoids, tonsils, and colon. Use of a single collagenase/hyaluronidase dispersion technique for all tissues has allowed comparisons of reactivity to be made that are free from methodological variations. Mast cells from all tissues examined secreted histamine in response to anti-IgE and calcium ionophore A23187. However, only skin mast cells were responsive to substance P, compound 48/80, poly-L-lysine, and morphine. Activation of human skin mast cells by these nonimmunologic stimuli clearly distinguishes them from the mast cells of human lung, adenoids, tonsils, and colon and is indicative of functional heterogeneity within the human mast cells population. We propose that the presence of functional receptor sites for neuropeptides and basic compounds on skin mast cells that are not present in mast cell populations from mucosal or lymphoid sources reflects a specialized role for these cells in vascular homeostasis.

Adenoids↗
PubMed1988

The secretory characteristics of mast cells isolated from the human large intestinal mucosa and muscle.

The use of a collagenase dispersion technique has allowed us to compare size, histamine content and the secretory characteristics of mast cells from the mucosal and muscle layers of the human large intestine. Mast cells from the mucosa, which constituted 1.8% of the total nucleated cells, contained approximately equal numbers of formalin-sensitive and -insensitive mast cells. Those dispersed from the muscle layer constituted 3.2% of the total nucleated cells and were almost all formalin insensitive. The cells from both layers were similar with respect to size and mean cell histamine content. Anti-IgE released up to 15.1% and 16.5% of total cell histamine in the mucosa and muscle, respectively, with similar concentration-response characteristics. The kinetics of anti-IgE-induced release, however, were different, mucosal mast cells releasing histamine 55 seconds (P less than 0.05) faster than cells dispersed from intestinal muscle. Cells from both layers also released histamine in response to A23187 in a similar concentration-related fashion. Neither mucosal or muscle mast cells released significant amounts of histamine in response to compound 48/80, substance P, morphine, poly-L-lysine or f-met-leu-phe. Our results show intestinal mast cells possess secretory characteristics similar to those of human lung, adenoids and tonsils, but are different from human skin mast cells. The absence of significant histamine release in response to basic secretagogues from either layer of the human intestine contrasts with studies in the rodent intestine. Furthermore it suggests that in human mast cells, histochemical properties, protease content and secretory characteristics may not be closely associated.

Cell Count↗
PubMed1987

Portable ultrasound scanner versus serology in screening for hydatid cysts in a nomadic population.

3553 nomads in Turkana, a remote area of north-west Kenya, were screened for hydatid cysts by a portable ultrasound scanner and by serology. 198 (5.6%) proved to have liver or upper abdominal cysts. In the group screened by both techniques (2644) 174 (6.6%) cases of hydatidosis were detected by ultrasonography and 76 (2.9%) by serology. Ultrasonography gave immediate results and was less expensive and more acceptable and educationally valuable to the people. This non-invasive rapid technique also provided important clinical information about the cysts. The prevalence data thus obtained will contribute to the surveillance of a hydatid control programme.

Abdomen↗
PubMed1987

The effects of medullary reaming on the torsional strength of the femur.

The authors have investigated the effect on the torsional strength of the bone of reaming the medulla of the femur from 12 to 16 mm in steps of 1 mm. Five groups of femurs, with 10 pairs in each, were tested comparatively in torsional loading and the torque required to cause fracture and the angle through which the bone had twisted at fracture were directly recorded for each pair. The results of maximum torque at failure (expressed as a proportion of the same parameter for the unreamed femur) plotted against the ratio of bone shaft diameter to reamed diameter showed a good correlation. The proportional maximum torque was found to range from 0.63 (at 12 mm) to 0.36 (at 16 mm) with a sharp transition between 14 and 15 mm. This drastic reduction was felt to be important for both the surgeon and the patient.

Biomechanical Phenomena↗
PubMed1987

Chronic splenomegaly in Nairobi, Kenya. I. Epidemiology, malarial antibody and immunoglobulin levels.

Chronic splenomegaly in 131 Kenyan patients was investigated at Kenyatta National Hospital, Nairobi. Patients were allocated to diagnostic groups on the basis of clinical, haematological, parasitological, histological, radiological and endoscopic data. The major diagnostic groups were hyper-reactive malarial splenomegaly, our preferred name for tropical splenomegaly syndrome, (31%), hepatosplenic schistosomiasis (18%), visceral leishmaniasis (5%) and "indeterminate splenomegaly", where no diagnosis could be reached (12%). Another 20% of patients were suffering from various non-schistosomal forms of portal hypertension. A number of specific and rarer causes accounted for the rest of the cases. The tribal and geographical distribution of patients with chronic splenomegaly was compared with the pattern of general medical admissions. Splenomegaly was more frequent than expected in Kamba and Luo patients. Hyper-reactive malarial splenomegaly and hepatosplenic schistosomiasis were common in both groups, whereas visceral leishmaniasis was almost restricted to the Kamba and indeterminate splenomegaly was especially prevalent in the Luo. Malarial antibody and immunoglobulin levels differed significantly between the various diagnostic categories of patients and controls. Malarial serology can be diagnostically useful for chronic splenomegaly, provided results are interpreted in their geographical context.

Antibodies, Protozoan↗
PubMed1987

Chronic splenomegaly in Nairobi, Kenya. II. Portal hypertension.

Eighty-five patients with chronic splenomegaly and proven oesophageal varices were studied at Kenyatta National Hospital, Nairobi. The major defined groups were hepatosplenic schistosomiasis (24%), cirrhosis (20%) and portal vein occlusion (11%). Hyper-reactive malarial splenomegaly (tropical splenomegaly syndrome) was considered as the cause of oesophageal varices in only one patient. In 26% of cases liver biopsy was non-diagnostic and the extrahepatic portal vein was demonstrated radiologically to be patent. Such patients were thought to be suffering from idiopathic portal hypertension, not previously described elsewhere in Africa. Hepatitis B surface antigen was detected in 12% of controls and in 58% of patients with cirrhosis (p less than 0.001). Some serological marker of previous hepatitis B virus infection was present in 92% of patients with cirrhosis and in 79% of controls. Kamba patients from Machakos and Kitui Districts were significantly more prevalent than expected among these 85 cases of portal hypertension.

Esophageal and Gastric Varices↗
PubMed1987

Cutaneous leishmaniasis caused by Leishmania tropica in Kenya.

9 leishmanial strains, isolated from cutaneous papulonodular lesions on 3 patients, were characterized by cellulose acetate electrophoresis using 7 enzymes. The patterns obtained were indistinguishable from those of a Leishmania tropica reference strain and these 9 strains were similar to L. tropica in failing to infect mice. Although these 3 patients were Americans, their only potential exposure to sandflies was in Kenya, and thus they are believed to be the first cases of cutaneous leishmaniasis due to L. tropica in Kenya.

Animals↗
PubMed1987

Derby intramedullary nail: further biomechanical comparison.

This paper is the second part of a study into the mechanical effectiveness of a new intramedullary femoral nail (the Derby nail). The results of three point bending tests have shown that the Derby nail is stronger and stiffer than both the K and Zickel nails and offers advantages over the AO plate, despite the latter's higher load carrying ability when used on the compressively loaded bone face. Previous work by the authors has shown the Derby nail to be superior in torsional loading and it is felt that this intramedullary device offers sound clinical advantages over the other designs, this being confirmed by extensive clinical trials.

Biomechanical Phenomena↗
PubMed1986

Assessment of some shock absorbing insoles.

Due to the increase in prescription of insoles to relieve symptoms due to skeletal shocks at heel strike a pilot study was initiated to look at some materials used for this purpose. Five materials were examined (Plastazote, Spenco, Sorbothane, Poron (PPT) and Viscolas) by two methods. The first method used an accelerometer mounted between the teeth of one of the authors (PR) to record skeletal shock. The second method used a force plate to record the shock produced by dropping a ball-bearing onto the insoles from a standard height. The results showed that Plastazote is poor at absorbing shock with Spenco and Sorbothane being quite good. The best insole materials tested were Poron (PPT) and Viscolas with the latter being marginally superior. No account was taken of degradation of the materials in use except that Plastazote worn for 72 hours was also used in the study, this producing the worst results.

Evaluation Studies as Topic↗
PubMed1986

Immunoglobin M and malarial antibody levels in hyper-reactive malarial splenomegaly.

In a study of chronic splenomegaly in Kenya, hyper-reactive malarial splenomegaly, our preferred name for tropical splenomegaly syndrome, was diagnosed in 38 patients. This diagnosis was based on exclusion of other conditions and observations of hepatic sinusoidal lymphocytosis on liver biopsy. To assess the previously recommended diagnostic criterion of elevation of serum IgM, to two standard deviations (s.d.) above the local mean, serum IgM levels were measured in patients and in 90 geographically matched controls. Patients with IgM levels 2 s.d. above the local mean were compared with those with lower levels. No differences were found other than higher malarial antibody titres in the group with higher IgM levels. Agreement is required concerning diagnostic criteria for hyper-reactive malarial splenomegaly; other features of the syndrome may occur in the absence of marked IgM elevation.

Adult↗
PubMed1986

Haematological investigations in visceral leishmaniasis.

Various haematological parameters were followed in a group of 47 Kenyan patients with visceral leishmaniasis during treatment and follow up. The WBC and platelet numbers were normal by the time of cure, the Hb level took longer to become normal. Red cells were microcytic and hypochromic. MCV and MCH increased during follow up but microcytosis persisted up to a year after cure. Low serum iron and transferrin concentration, low total iron binding capacity and normal to high serum ferritin levels were found in 10 patients and are consistent with 'anaemia of chronic inflammation'. Bone marrows of 15 patients before treatment were normo- to hypercellular with increased erythropoietic activity. Low haemosiderin content of the bone marrow was consistent with iron deficiency, but normalization of Hb without iron suppletion would argue against a major role of iron deficiency. Coagulation studies did not indicate diffuse intravascular coagulation. Splenomegaly seems the most important factor in the causation of the pancytopenia. Further studies of contributing factors and of the cause and mechanism of 'hypersplenism' are needed.

Adolescent↗
PubMed1985

Derby intramedullary nail--a biomechanical comparison.

This paper describes the design and function of the Derby intramedullary nail and its biomechanical testing, comparing it with the K nail and reamed unfractured femurs. The Derby nail is designed to transmit torsional loads and apply compression to the fracture site using a sliding proximal collar and distal extendable 'wings'. Femurs fixed with Derby, K and Zickel nails and AO plates were tested in torsion and the rotation and torsional load at failure recorded and compared with unfractured control femurs. The results show that the strength of the Derby nail in torsion is approximately equal to 4 times and the energy to failure 2.3 times that of the K nail.

Biomechanical Phenomena↗