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Lymphatic filariasis is a chronic disease characterized by a pronounced Th2 bias in the immune response and impaired antigen (Ag)-specific Th1 responses. We have used a mouse model of filariasis to investigate the role of the infective form (the third-stage larvae [L3]) in modulating the immune response. Subcutaneous infection of BALB/c mice with L3 of Brugia pahangi has a profound effect on Th cell function. By day 12 post-infection, spleen cells from these mice exhibited a dramatic reduction in concanavalin A-driven proliferation and interleukin-2 (IL-2) and gamma interferon (IFN-gamma) secretion in comparison with uninfected controls. However, exposure to L3 did not render the mice completely unresponsive; these animals mounted a strong Th2 response to the parasite, characterized by elevated levels of IL-4, IL-5, and IL-10 and parasite-specific serum immunoglobulin G (IgG), IgG1, and IgE. Treatment of spleen cells from L3-infected mice with neutralizing anti-IL-4 or recombinant IL-2 resulted in a dramatic increase in concanavalin A-induced proliferation and IL-2 and IFN-gamma production. Despite their defective polyclonal Th1 response, cells from L3 infected mice proliferated when stimulated with Ag, and this response was blocked by anti-IL-4. However, anti-IL-4 treatment failed to induce Ag-specific IL-2 or IFN-gamma production, indicating that B.pahangi-primed Th1 cells do not appear to be present or are still unable to respond even in the absence of IL-4.

We describe a case of recurrent hypoglycaemia associated with a hepatoma. During hypoglycaemia serum insulin was undetectable. Plasma insulin-like growth factor II (IGF-II) was not elevated although 71% of plasma IGF-II was present as big IGF-II (molecular weight 11 kDa) which probably represents a non-glycated form of pro-IGF-II. The GH response to hypoglycaemia was impaired and plasma levels of both IGF-I and the GH-dependent IGF binding protein (IGFBP-3) were low. A recently described unextracted assay directed against the first 21 amino acids of the E-domain (E-21) of proinsulin-like growth factor-II (pro-IGF-II) allows direct plasma estimation (plasma E-21) of larger molecular forms of IGF-II without interference from normal IGF-II and IGF binding proteins. Basal values were grossly elevated (23.7 and 23.8 nmol/l). Treatment with GH led to an increase in the mean plasma glucose across 24 hours (4.25 +/- 0.21 mol/l (mean +/- SEM) before treatment, compared with 4.86 mmol/l +/- 0.17 following GH (P < 0.01)) and a reduction in hypoglycaemic attacks. The treatment was associated with a rise in IGFBP-3 and small increases in insulin like growth factors. Subsequent treatment with the somatostatin analogue octreotide did not produce a significant change in plasma glucose levels or insulin-like growth factors. Two courses of intrahepatic adriamycin restored elevated levels of E-21 to normal. Total IGF-II remained normal and IGF-I increased. GH treatment was successfully withdrawn with no effect on plasma glucose or growth factor levels. The patient remained free from hypoglycaemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary malignant melanoma is a very rare tumour of the oesophagus, and although this is the first case reported in a black patient in South Africa, the clinical, radiographic and histopathological features were characteristic of this malignancy. Primary oesophageal melanoma is a highly lethal tumour--fewer than 2% of patients are surviving 5 years after diagnosis. Flow cytometric DNA analysis of the resected specimen in this case revealed two populations of malignant cells, one of which had grossly abnormal DNA. Existence of two clones of malignant melanoma cells supports the observations that this tumour is biologically aggressive, radioresistant and almost always incurable.

Prognosis in oesophageal cancer is directly related to depth of invasion and lymph node metastases. However, without surgical exploration, assessment of the spread of oesophageal cancer is notoriously inaccurate and there is a need for another objective measurement of prognosis. In this study, the relationship of DNA-ploidy status to tumour length, histological appearance, extra-oesophageal spread and survival was examined in 42 patients with squamous oesophageal cancer. No correlation was found between DNA-ploidy status and tumour length or histological appearance. But the DNA-aneuploidy rate in cancers with extra-oesophageal spread was significantly greater than the rate in tumours localised to the oesophagus (P = 0.038). Short-term survival was poorer in patients with DNA-aneuploid cancers than in those with a DNA-diploid pattern. DNA analysis may prove to be a more accurate guide to prognosis in oesophageal cancer than either clinical or operative staging.

In a single-blind, randomised trial, 50 consecutive adult patients for inguinal herniorrhaphy under general anaesthesia received either an inguinal field block or bupivacaine instilled into the wound to provide postoperative analgesia. Bupivacaine instillation was found to be simple, safe and effective. The method is particularly appropriate for day-case surgery.

Summary A double-blind, randomised clinical study was undertaken to compare the effect of temperature on the incidence and severity of the pain experienced on injection of propofol. The number of patients who experienced pain and the severity of the pain were reduced significantly when propofol was administered at a temperature of 4°C. The efficacy of propofol as an induction agent appeared to remain unaltered.

The optically detected magnetic resonance (ODMR) spectrum of phosphorus activated potassium chloride crystals obtained at 2 K in zero and weak applied external magnetic fields is reported and analyzed. A theoretical fit to the observed field and angular dependence ofthe ODMR spectrum is obtained using a phenomenological spin hamiltonian, assuming the center to be the paramagnetic photoexcited 3B1 state of the C2v ion PO2−. The components of the phosphorus nuclear hyperfine structure tensor are obtained from the theoretical analysis and compared with those of other AB2 ions and radicals. Optical polarization measurements and weak field ODMR spectra are used to determine the orientation of the PO2− chemical impurity center in the cubic KCl lattice and the orientation is compared with those of other isostructural impurities in KCl. The PO2− chemical impurity center exhibits a dramatic photo-orientation effect at 2 K and is shown to be in thermal equilibrium between twelve crystallographically equivalent orientations at temperatures above 45 K.

The small molecular anion PO − 2 has been incorporated at chloride ion vacancies in the potassium chloride lattice, where the relatively high symmetry of the crystal field permits a variety of crystallographically equivalent orientations of the ion within the vacancy site. Electronic excitation to the first excited singlet state of PO − 2 ( 1 B 2 ) is followed by rapid radiationless relaxation and intersystem crossing to the phosphorescent 3 B 1 state. Subsequent electronic relaxation to the ground state is found to proceed with a reorientation of the ion in the multi-minimum crystal potential. At temperatures sufficiently low that competitive thermal reorientation of the ions is quenched, it is possible to prepare photo-oriented arrays of PO − 2 ions in the anion vacancies by irradiation with plane polarized light at special angles. The temperature dependence of the rate of photo-orientation has been determined and it has been found possible to describe the observed kinetics in terms of a simple phenomenological rate equation. Photo-orientation-evidently results from an extraordinarily strong linear electron—phonon coupling and may be used for a detailed study of this type of interaction. The potential barrier for conversion between crystallographically equivalent sites is found to be 783 cm −1 .

The modulation of low temperature (2°K) molecular crystal phosphorescence by submicrosecond duration heat pulses is discussed in connection with the study of rates of triplet energy transfer and trap thermalization. A phenomenological discussion of the dynamics of heat pulse propagation in molecular solids is presented and estimates of the thermal relaxation time of the lattice are obtained. It is suggested that these times are sufficiently short to permit investigation of the dynamics of exciton energy transport in molecular crystals. The details of the technique are discussed and results from several experiments are presented. Additionally, heat pulse modulation of the electron paramagnetic spin distribution of radiative triplet states is discussed and some preliminary results presented.

The phosphorescence and phosphorescence excitation spectra of phosphorus activated single crystals of potassium chloride have been examined at 4.2 K. The “color center” responsible for the blue emission in these samples is identified as PO 2 − by isotopic substitution and optically detected magnetic resonance measurements. The observed vibrational frequencies of the PO 2 − ion have been used to compute the normal coordinates of the ground state totally symmetric modes as well as the valuence angle in the valence force approximation. The vibrational analysis of the phosphorescence spectrum has been used together with the computed ground state normal coordinate description to compute the geometrical changes associated with excitation to the lowest triplet state of PO 2 − . The results for PO 2 − are compared with the results of similar calculations and measurements for other 18-electron AB 2 type molecules of the isoelectronic sequence PO 2 − , SO 2 , NO 2 − and O 3 .

Optically detected zero field magnetic resonance (ODMR) has been utilized to obtain the time structure parameters IDi and IEI of the phosphorescent color center in phosphorous activated potassium chloride and bromide single crystals. The dipole activity of the zero field spin-orbital states, the Franck-Condon analysis of the vibronic structure of the phosphorescence spectrum and the fine structure parameters are ah consistent with the proposed identification of the impurity center as PO; ion.

A continuous tissue culture line (SH-4) derived from pleural effusion cells of a patient with metastatic melanoma is described. The cells became established after five passages lasting a period of 5 months of slow growth. Doubling time of the continuous culture was 20 hr in passage 51. The cell line is now in passage 60. The cells of all passages examined appear spindle-shaped or oligodendritic as seen by light microscopy. Pigment deposition in the cells is light and incomplete, but more marked than in cells of the original pleural effusion as shown by electron microscopy. Chromosome complement shows a single peak with a modal number of 51.

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We investigated the effects of calcitonin (CT) and parathyroid hormone (PTH) on the distribution of actin, tubulin, vimentin, and on cell size in cultured chick osteoclasts. In addition, we studied the effects of colchicine on intracellular acidity. Osteoclasts were isolated from the endosteum of 2-3-week chick tibias and were maintained under culture conditions for 5 days. The cells were treated with CT for 30 min or PTH for 60 min and were observed after immunocytochemical staining of cytoskeletal proteins. In untreated cells, actin was found in both a filamentous and a punctate staining pattern, with indented or invaginated regions free of punctate spots. The tubulin distribution in untreated cells was characterized by a pattern of microtubules radiating from the cell center and running parallel to the cell edge. Vimentin staining was usually localized to the perinuclear area. There were no changes in cytoskeletal element distribution or morphology attributable to PTH treatment. Osteoclasts treated with CT were more irregularly shaped, contained more retraction fibers, and were more rounded, with a denser array of cytoskeletal elements in the cell center. In addition, the mean area of the CT-treated cells was significantly less than that of the untreated cells. The actin distribution after CT treatment was still characterized by both a filamentous and a punctate pattern. After CT treatment, vimentin staining appeared more centrally localized than in untreated cells and tubulin staining revealed microtubules which now extended to the retracted cell margin. These results indicate that isolated osteoclasts respond to CT by significant morphological changes which are reflected in the distribution of the major cytoskeletal elements. Disruption of the microtubular system by colchicine treatment also resulted in an initial increase in intracellular acidity, suggesting the involvement of microtubules in the movement of acid-laden vesicles to the exterior.

Summary The induction, maintenance and recovery characteristics of propofol anaesthesia were compared with thiopentone induction and halothane maintenance in 51 spontaneously breathing, intubated patients who underwent dental surgery. Induction with thiopentone produced fewer side effects than propofol, notably pain on injection. Control of the depth of anaesthesia was better in patients who breathed halothane than in those who received intermittent bolus doses of propofol. Recovery characteristics of the two groups were similar.

Spontaneous emergence of fast-growing cells in prolonged culture of pleural effusion cells obtained from a patient with breast cancer has led to the establishment of a cell line designated as SH-3. By morphological criteria, as revealed by light and electron microscopy, SH-3 cells are epithelial and resumble the poorly differentiated cells of a series of established human tumor cell lines. Their karyotype is hypotetraploid and different from that of HeLa cells. Isoenzyme analysis has shown the presence in the cells of a bone-type alkaline phosphatase and of the fast (A) band of G6PD. The line is free of mycoplasma.

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For more than 200 years the etiology of pellagra has been a subject of serious inquiry. This problem, formerly an Old World question, now concerns us, and it still awaits solution. Though the disease is positively known to have existed in this country for less than thirty years, it is now found in almost one-half the states of the Union, becoming in the South a grave disorder. Briefly, it may be said that the causation of pellagra is purely conjectural. Since 1776, when the Patriotic Society of Milan offered a prize for the determination of the cause, an immense amount of work has been done by worthy investigators, but as yet its real cause is unknown. We do not know whether the disease is toxico-chemical, toxico-infectious or due to a specific infection by molds, bacteria, or protozoa. The solution of this problem has at various times been proclaimed, but sub'.T'eni