Horizontal transmission of hepatitis B virus amongst British 2nd World War soldiers in South-East Asia

Infection with hepatitis B virus (HBV) is much more common in tropical than in temperate countries. Visitors to the tropics are thus at risk from HBV, though the degree of risk, and the routes of infection involved are uncertain. We report serological markers of HBV in two groups of 2nd World War soldiers, who served in the Thai/Burma jungles. The groups comprised 100 ex-prisoners of the Japanese (POW), and 100 Burma Campaign Veterans (BCV). Surface antigen to HBV (HbsAg) was positive in 0% of POW and 2% of BCV (P = not significant). Surface antibody (anti-HBs) and core antibody (anti-HBc) were both positive in 40% POW and 13% BCV (P less than 0.001). Quoted UK prevalence rates for these markers are 0.1% for HBsAg, 1.5% for anti-HBs and 0.7% for anti-HBc. Both groups thus show very high rates of past HBV infection. For the POW there were many possible reasons, including contaminated surgical instruments and needles, blood transfusions, and multiple beatings with common weapons. None of these factors operated significantly for BCV. Malarial transmission was, however, intense in both groups, though more so in POW. The data thus again raise the possibility of horizontal transmission of HBV by biting insects in tropical countries.

Fatty streak development in the vicinity of aortic coarctations in hypercholesterolemic rabbits

The influence of altered local hemodynamics on fatty streak development in rabbits fed high cholesterol diets was investigated. An aortic coarctation was created in the abdominal aorta of nine rabbits by placing a partially constricting gold or silver band (1.7 mm x 10 mm) around the aorta between the renal arteries and aortic bifurcation. Controls were 20 rabbits; seven sham operated and 13 unoperated rabbits. The abdominal aorta 1-2 cm proximal to the coarctation showed lipid deposition involving 45 +/- 8% (mean +/- SEM) of the luminal surface which was more than occurred within or distal to the obstruction (p less than 0.05) and also more than in controls (p less than 0.05). Within the coarctation, 4 +/- 2% of the luminal surface showed lipid deposition which was less than either proximally or distally (p less than 0.01) and also less than in comparable regions in controls (p less than 0.05). The aorta 1-2 cm distal to the coarctation showed lipid deposition involving 18 +/- 4% of the surface which was similar to control rabbits. Lipid deposition in corresponding regions of the control rabbits was involved in 17 +/- 4%, 19 +/- 5% and 19 +/- 4% of the luminal surface, respectively. Fatty streak development, therefore, appeared to be inhibited within the coarctation and enhanced proximal to it. The results suggest that some early step in the process of lipid accumulation may be affected by local fluid dynamics or modification of the wall of the vessel.

Initial equilibration of albumin and IgG in rabbit hind paw skin and lymph

To determine if the interstitial distribution of plasma proteins influences transport from plasma to lymph, the initial plasma-to-extravascular and plasma-to-lymph equilibrations for 131I-labeled rabbit albumin and 125I-labeled rabbit IgG were compared in hind paw heel skin of anesthetized New Zealand White rabbits. Plasma specific activities were maintained constant with time using continuous infusions. The plasma space in skin samples taken at the end of the experiment was estimated by a 3-min accumulation of 59Fe-labeled bovine transferrin. Albumin and IgG concentrations in plasma, lymph, and skin were determined by rocket electroimmunoassay. The lymph specific activity relative to that of plasma for the larger sized IgG was significantly greater (P less than 0.01) than that for albumin during the initial 8 hr of equilibration. The tissue specific activity relative to that of plasma for IgG was significantly less (P less than 0.01) than that for albumin. The distribution space at lymph concentration for both proteins was 1 ml/g dry skin wt, indicating similar excluded volumes. These data are consistent with the hypothesis that convective movement of plasma proteins through the interstitium affects lymph equilibration while diffusion affects tissue equilibration.

Combined use of cyclosporin A and verapamil in modulating multidrug resistance in human leukemia cell lines

This study describes the synergistic interaction of two biochemical modulators, cyclosporin A (CyA) and verapamil (Vp), in multidrug-resistant cells, the highly resistant and moderately resistant variants (CEM/VLB 1000 and CEM/VLB 100) of the parental drug-sensitive T-cell leukemia cell line CEM/CCRF. In the absence of either modulator, the 50% inhibitory concentration for Adriamycin in these cell lines was 270 +/- 10.6 (SD) micrograms/ml, 96 +/- 8.5 micrograms/ml, and 1.5 +/- 0.1 micrograms/ml, respectively. CyA and Vp dramatically reduced multidrug resistance in CEM/VLB 100 and CEM/VLB 1000 in a dose-dependent manner but had no effect on the sensitivity of the parental line to Adriamycin. At a CyA concentration of 8.3 mumol (10 micrograms/ml), the 50% inhibitory concentration of Adriamycin of CEM/VLB 1000 and CEM/VLB 100 fell to 5.9 +/- 0.9 micrograms/ml and 3.3 +/- 0.6 micrograms/ml, respectively. Similarly at a Vp concentration of 10 mumol the 50% inhibitory concentration of Adriamycin of CEM/VLB 1000 and CEM/VLB 100 fell to 23.7 +/- 3.7 micrograms/ml and 5.7 +/- 0.2 micrograms/ml, respectively. More importantly, CyA and Vp showed significant synergism when tested in combination in the moderately resistant line at concentrations normally seen after the clinical administration of these modulators. Synergy was also present when both drugs were tested in the highly resistant variant. These data indicate the need for in vivo studies, given the potential clinical importance of these observations.

Individualities in post-serotonin attenuation and Na+/K+ pump activity in vascular smooth muscle

Prior treatment with serotonin (10(-8)-10(-7) M for 6 min) attenuated responses of rabbit mesenteric arteries to norepinephrine (NE) by 18-62%, but was without effect on the responses of the rabbit aorta. K+ relaxation responses in the mesenteric arteries were enhanced by serotonin, but in the aortic strips K+ relaxation occurred either before or after treatment with serotonin. Maximum relaxation to monensin was similar in the two tissues. Post-serotonin attenuation and K+ and monensin relaxation were blocked by ouabain, indicating that they depended on Na+/K+ pump stimulation. Intracellular Na+ contents (Nai) were determined in the vessels by the Li substitution method. Nai was greater, and was increased to a greater extent by serotonin and K(+)-free physiological salt solution in the mesenteric artery compared to the aorta, suggesting that the cell membrane of the mesenteric artery is leakier to Na+ than is that of the aorta. We conclude that the absence of post-serotonin attenuation in the aorta results from the failure of serotonin to increase Nai and thereby to stimulate the Na+/K+ pump in this tissue. This study demonstrates that important individualities in vascular smooth muscle reactivity even in the same animal may result from differences in membrane permeability to sodium.

Atypical multidrug resistance in a therapy-induced drug-resistant human leukemia cell line (LALW-2): resistance to Vinca alkaloids independent of P-glycoprotein

Near diploid leukemic T-cells (LALW-2), exposed to cytotoxic drugs only as a consequence of therapy administered to the donor patient, have been maintained by serial xenograft in nude mice. In comparison with the leukemic line CCRF-CEM, using a growth inhibition assay, LALW-2 cells were resistant to Vinca alkaloids and actinomycin D (relative resistance, 200-fold or more), were slightly resistant to Adriamycin (relative resistance, 4-fold), and showed no resistance to daunorubicin or teniposide. By comparison, a vincristine-resistant CEM subline developed in our laboratory (CEM/VCR R) was resistant to all these agents by at least 30-fold. The VCR R subline served as a positive control, confirming the previously reported correlation between multidrug resistance and amplification of the P-glycoprotein gene. Comparison of CEM, CEM/VCR R, and LALW-2 cells establish that the P-glycoprotein gene was not amplified or overexpressed in the LALW-2 cells; neither could the gene product be detected by immunoblotting in extracts from these cells. The LALW-2 cells were further distinguished from CEM/VCR R cells due to the lack of increased vincristine efflux by the xenografted cells, an effect readily demonstrable in the CEM/VCR R cells. However, although LALW-2 cells efflux vincristine at the same rate as CCRF-CEM cells, the xenografted cells exhibited a reduced rate of vincristine accumulation. Uptake of daunorubicin by LALW-2 cells was not distinguished from that by CEM cells, consistent with similar 50% inhibitory dose levels for this drug in both cell populations, and differentiating both from CEM/VCR R cells. Thus, clinical resistance in this case appears to be an "atypical" form of multidrug resistance specifically distinguished by resistance to Vinca alkaloids and actinomycin D occurring in the absence of increased amounts of P-glycoprotein and manifesting decreased drug uptake.

Comparison of western blot analysis and immunocytochemical detection of P-glycoprotein in multidrug resistant cells

A sensitive immunocytochemical technique was developed to detect a 170,000 dalton cell membrane glycoprotein (P-gp) in cell lines resistant to vincristine and vinblastine with varying degrees of resistance. P-gp was shown very clearly using the C219 monoclonal antibody and immunocytochemical detection with either antialkaline phosphate or peroxidase-antiperoxidase with silver gold intensification. There was good correlation between the results obtained with immunocytochemical detection of P-gp in single cells and Western blot analysis. The technique is easily performed and can detect P-gp in relatively small numbers of cells that Western blot analysis could miss and is suitable for clinical application.

Profiles of velocity in coronary arteries of dogs indicate lower shear rate along inner arterial curvature

Multiple-range, gate-pulsed Doppler velocimetry was used to examine the velocity profile within the lumen of the left circumflex and left anterior descending coronary arteries of 10 anesthetized, open-chest dogs at rest and after administration of propranolol and intracoronary adenosine. The peak diastolic and mean profiles of velocity were skewed away from the inner walls of the vessels (p less than 0.01). The extent of skewness was not affected by propranolol or adenosine. The shear rates were significantly lower along the inner wall in comparison to the outer wall under all conditions in both the left circumflex and the left anterior descending coronary arteries (p less than 0.017). Irrespective of the levels of flow, therefore, the velocity profiles were skewed away from the inner wall of the coronary arteries. Consequently, the shear rates were lower along the inner walls of the coronary arteries.

Cisplatin plus VP 16-213 in advanced ovarian carcinoma

Thirty-five patients with advanced epithelial ovarian carcinoma (24 untreated, 11 previously treated with alkylating agents) were treated with a combination of cisplatin and etoposide (VP16-213). Tumor response (i.e., complete response and partial response) was seen in 16 of the 35 patients (i.e., 46%), with 5 complete responses. The response rate in previously untreated patients was 54%, but only 27% in previously treated patients. The median survival was 42 weeks. The toxicity of this regimen was severe. Twelve patients became severely myelosuppressed, including one septic death while severely neutropenic. Treatment with cisplatin and etoposide produces only average tumor response rates and patient survival, but is associated with severe toxicity. There is no evidence of synergy between cisplatin and VP16 in this study.

Identification of a multidrug resistance associated antigen (P-glycoprotein) in normal human tissues

The multidrug resistance (NDR) phenotype describes a pattern of cross-resistance to unrelated compounds observed in mammalian cell lines selected in vitro for resistance to a single agent. Overexpression of a 170,000 dalton cell membrane glycoprotein (P-glycoprotein) is associated consistently with this phenotype in these cell lines. Recently, several human tumours have been shown to contain P-glycoprotein and expression was greatest in tumours exhibiting clinical drug resistance. To explore further the significance of P-glycoprotein, we examined normal human tissues obtained at autopsy by polyacrylamide gel electrophoresis and immunoblotting using a monoclonal antibody directed against P-glycoprotein. We showed expression of P-glycoprotein in normal liver and small bowel mucosa but not in other organs examined. This suggests there may be significant expression of P-glycoprotein in certain normal human tissues and any plan to exploit P-glycoprotein clinically must take these findings into account.

High flow attenuates relaxation by acetylcholine in isolated perfused canine femoral arteries

The effect of changes in flow on endothelial-dependent and -independent dilation of isolated perfused arteries was determined. Femoral arteries from ten dogs were excised and mounted in a vessel bath containing a physiological salt solution (PSS) at 37 degrees C, bubbled with 95% O2-5% CO2. The vessel outer diameter was measured using an ultrasonic crystal dimension system. Arteries were perfused with PSS at a steady flow of 1 ml/s at 90 mmHg. Tone was induced in the arteries by the addition of phenylephrine to the vessel bath. Acetylcholine (six dogs) and sodium nitroprusside (four dogs) were added to the perfusate in a cumulative fashion and changes in vessel diameter were recorded until maximum vasodilation was achieved. Dose-response relationships to the agents were determined with each vessel perfused at 1 and 4 ml/s. Sensitivity to each agent was measured as the ED50 value calculated from the respective dose-response relationships. Sensitivity to acetylcholine, but not sodium nitroprusside, was significantly decreased in arteries perfused at 4 ml/s versus 1 ml/s [acetylcholine ED50: 1 ml/s = (0.79 +/- 0.31) x 10(-8) mol/l, 4 ml/s = (1.55 +/- 0.60) x 10(-8) mol/l, P less than 0.05; sodium nitroprusside ED50: 1 ml/s = (2.57 +/- 0.12) x 10(-7) mol/l, 4 ml/s = (2.69 +/- 0.60) x 10(-7) mol/l, not significant]. We conclude that high flow decreases sensitivity to acetylcholine in canine femoral arteries and suggest that vascular reactivity to this agent may be modified by changes in shear on the vascular endothelium.

External auditory canal stenosis and atresia: dual flap surgery

Surgical correction of the severely stenosed or atretic external canal still remains a difficult surgical challenge. As more and more techniques are described, it is apparent that the main thrust and emphasis is to prevent late cicatrization or stenosis. The essential principles are to create a wide canal and cover as much raw surface as possible with skin, preferably full-thickness and with an intact blood supply. The following technique, using dual flaps, has been used successfully in 10 consecutive problem ears with unusual underlying pathologies. With follow-up ranging from seven months to four years, there have been no cases of restenosis to date.

Initial equilibration of albumin in rabbit hindpaw skin and lymph

We compared initial plasma to extravascular and plasma to lymph equilibrations of 125I-labeled rabbit albumin in hindpaw heelskin of anesthetized rabbits during control conditions, increased venous pressure (IVP), and intra-arterial infusions of papaverine or bradykinin. Plasma tracer concentrations were maintained constant during the experiments. Control prenodal lymph specific activity relative to plasma specific activity (L*/P*) was significantly greater (P less than 0.01) than extravascular specific activity relative to plasma specific activity (M/P) following 3, 5.5, and 11 h of tracer infusion. Papaverine increased lymph flow and lymph albumin flux (LCL) 2.4-fold, without significantly changing the extravascular albumin mass (MA). IVP increased LCL 2.5-fold and decreased MA 25%. L*/P* at 3 h was twice control following papaverine. M*/P* at 3 h was not significantly affected by papaverine or IVP. Bradykinin increased LCL 10-fold and MA 2.3-fold. L*/P* and M*/P* were 3.1 and 4.3 times control, respectively. The data are consistent with extravascular albumin distributing into two pools that equilibrate with plasma at different rates. Papaverine and IVP affect the faster pool, whereas bradykinin affects both pools.

The chemotherapy of onchocerciasis. XII. The prediction of microfilarial loads in patients with onchocerciasis after treatment with diethylcarbamazine in northern Ghana

This paper presents some statistical problems of analysing changes in patterns of microfilarial loads in onchocerciasis patients after chemotherapeutic treatment. Analyses are made of a pooled set of data from ten separate studies of diethylcarbamazine (DEC) conducted at the Onchocerciasis Chemotherapeutic Research Centre, Tamale, between 1978 and 1983. Regression models of microfilarial load at different intervals post-treatment are fitted with initial microfilarial load, total dose of DEC, duration of treatment and age of the patient as the independent variables. Appropriate transformations of the variables are chosen by examination of plots of residuals for violations of the assumptions underlying the regression models. A dose response curve for DEC is produced.

A prospective randomized trial of single-agent versus combination chemotherapy in meningeal carcinomatosis

Forty-four patients with documented meningeal carcinomatosis (small-cell lung carcinoma [SCLC], 29%; breast carcinoma, 25%) were treated in a prospective randomized trial with intrathecal methotrexate (MTX) 15 mg or MTX plus cytosine arabinoside (Ara-C) 50 mg/m2. Most patients received intrathecal hydrocortisone (HC) each treatment to minimize arachnoiditis. Overall response was 55%. Seven patients achieved complete response. Response to MTX was superior to combined MTX/Ara-C, but not significantly so (61% v 45%; P greater than .10). Response was more frequent if drugs were administered via Ommaya reservoir than by lumbar puncture (65% v 48%; P greater than .10). Concurrent radiotherapy to the CNS was associated with significantly better response (73% v 35%; P less than .05). Small-cell lung carcinoma patients showed the best response (69%). Overall median survival for the whole group was 8 weeks, but responders fared better than nonresponders (median survival, 18 v 7 weeks; P less than .05). Nausea and vomiting were the most common toxicities encountered (45%), but rarely proved limiting. An unusual, previously undocumented reaction to intrathecal HC was noted. MTX is moderately effective in nonleukemic meningeal carcinomatosis, but the addition of Ara-C does not appear to improve results. Pretreatment factors did not predict outcome in this trial.

P-glycoprotein in human sarcoma: evidence for multidrug resistance

Overexpression of an immunologically conserved, cell-surface glycoprotein (P-glycoprotein) is consistently associated with multidrug resistance in cell lines in vitro. A preliminary survey of specimens from 12 solid tumor types in our laboratories indicates significant overexpression of P-glycoprotein in some sarcomas. When tested by immunoblotting with monoclonal antibodies directed against P-glycoprotein; tumors from six of 25 sarcoma patients displayed elevated levels of P-glycoprotein. Three of the sarcoma patients exhibiting P-glycoprotein had not previously been exposed to chemotherapy, implying that overexpression of this marker and possible concomitant multidrug resistance may not depend only on selection during prior drug treatments. The P-glycoprotein overexpression in the sarcoma specimens is evidence for the presence of multidrug resistant cells in these tumors; thus, our data suggest that this mode of resistance may have clinical significance in sarcoma patients.

Decreased intraocular pressure in dogs with one-kidney, one wrapped hypertension

We examined the relationship of intraocular pressure and the development of one-kidney, one wrapped (perinephritic) hypertension in the dog. Conscious femoral arterial pressure (direct arterial puncture) and intraocular pressure (Schiotz tonometer) were measured weekly before and after the surgical induction of hypertension in 11 healthy male mongrel dogs and before and after unilateral nephrectomy in 15 normotensive control dogs. Preoperative mean arterial pressure (102 +/- 5 vs 99 +/- 8 [SD] mm Hg, hypertensive vs control dogs) and intraocular pressure (18.1 +/- 2.5 vs 17.7 +/- 2.1 mm Hg, hypertensive vs control dogs) were similar in both groups. In normotensive control dogs, mean arterial pressure and intraocular pressure averaged over the postoperative period (4-8 weeks) did not differ significantly from preoperative values. In contrast, during the same period arterial pressure significantly increased and intraocular pressure significantly decreased in hypertensive dogs (arterial pressure, 163 +/- 8 mm Hg; intraocular pressure, 11.9 +/- 4.0 mm Hg; p less than 0.001 for both values compared with corresponding values in control dogs). Intraocular pressure was inversely related to arterial pressure in hypertensive dogs (r = 0.56, p less than 0.01). These observations indicate that intraocular pressure decreases with the development of canine one-kidney, one wrapped hypertension. The mechanism of this decrease may be related to abnormalities in Na+,K+-adenosine triphosphatase activity found in this form of hypertension.

Strongyloides stercoralis infection in Burma Star veterans

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Chromosomal location of human P-glycoprotein gene sequences

Nonresponse to chemotherapy may result from the acquisition of multidrug resistance by malignant cells. Overexpression of the 170,000 dalton cell surface P-glycoprotein is associated with this phenotype and this appears to result from amplification of a multigene family coding for this protein. A cDNA encoding a conserved portion of P-glycoprotein has been cloned from hamster cells, and this was used in the present study to localize human P-glycoprotein gene sequences to chromosome 7q36.

Angiosarcoma of the heart

The case of a woman with angiosarcoma of the right atrium is reported. The tumor was inoperable, and the patient was treated with chemotherapy. There was no response to treatment.