Case report: in utero diagnosis of a vein of Galen aneurysm using colour flow Doppler

We report the ante-natal diagnosis of a vein of Galen aneurysm using colour flow Doppler at 33 weeks gestation. Ultrasound demonstrated a midline, tubular, echo-free structure superior to the thalamus extending posteriorly. Venous flow was demonstrated within the structure using colour flow Doppler. The diagnosis was confirmed by post-natal sonography. We believe this to be the first ante-natal diagnosis of this condition using colour flow Doppler.

An apolipoprotein CII mutation, CIILys19----Thr' identified in patients with hyperlipidemia

Five hyperlipidemic patients (one with Type III, three with Type IV, and one with Type V hyperlipoproteinemia) were found on isoelectric focusing to have both the normal isoform of apolipoprotein CII and a second isoform whose isoelectric point was consistent with a single charge change. The structure of the apolipoprotein CII variant was determined to be the same as normal apolipoprotein CII except for replacement of the normal Lys at amino acid residue 19 by Thr (C2K19T). The mutation was absent from 160 apoCII alleles screened from normolipemic subjects. The C2K19T substitution occurs in a domain of apolipoprotein CII postulated to contain a lipid-binding amphipathic alpha-helix. The presence of C2K19T in unrelated hyperlipidemic patients of various racial backgrounds suggests that, in combination with other factors such as mutations in apolipoprotein E, it plays a role in the development of hyperlipoproteinemias.

Cholesterol accumulation in J774 macrophages induced by triglyceride-rich lipoproteins. Comparison of very low density lipoprotein from subjects with type III, IV, and V hyperlipoproteinemias

The capacity of human triglyceride-rich lipoproteins to induce cholesterol accumulation in the murine J774 macrophage cell line was investigated with large very low density lipoprotein (VLDL, Sf 60-400) obtained from subjects with type III, IV, and V hyperlipoproteinemias. After incubation for 24 hours, VLDLs from type IV and type V subjects were similar in their ability to raise cellular cholesterol deposition threefold to fourfold and cellular triglyceride 16-fold. The increase in cholesterol was entirely due to the dramatic increase in cholesterol ester, from less than 1 to greater than 50 micrograms/mg cell protein. Total cholesterol accumulation was fourfold to fivefold greater than the cholesterol accumulation observed for VLDL or low density lipoprotein (LDL) from normal subjects. Cholesterol esterification (acyl coenzyme A: cholesterol acyltransferase [ACAT] activity) paralleled the rate of cholesterol accumulation in these cells. Treating the macrophages with the ACAT inhibitor 58035, which is known to downregulate the LDL receptor in these cells, diminished cholesterol accumulation by 40% for type IV VLDL and by 23% for normal LDL. Since hypertriglyceridemic VLDL carries excess apoprotein (apo) E molecules, we investigated the role of normal and abnormal apo E. An anti-apo E monoclonal antibody, known to block the binding of apo E to the LDL receptor, blocked type IV VLDL-induced cholesterol ester accumulation by approximately 70%. In contrast to type IV subjects, VLDL from type III subjects (homozygous for apo E2) when incubated with J774 macrophages (which do not secrete apo E) caused only a modest 1.5-2-fold increase in cellular cholesterol. Pre-beta- and beta-migrating VLDL subfractions from type III subjects were equally ineffective in causing cholesterol accumulation. By contrast, beta-VLDL from cholesterol-fed rabbits caused a sevenfold to eightfold increase in cellular cholesterol content. These results indicate that triglyceride-rich lipoproteins from type IV and type V subjects can cause substantial cholesterol ester accumulation and enhanced cholesterol esterification in J774 cells. The lower cholesterol accumulation with type IV VLDL in the presence of apo E antibodies and VLDL from type III subjects demonstrates the importance of functional apo E in this process.

Rapid MR imaging of blood flow with a phase-sensitive, limited-flip-angle, gradient recalled pulse sequence: preliminary experience

To assess blood flow rapidly, a limited-flip-angle, gradient recalled pulse sequence was modified to acquire two views at the same phase-encoding step in successive repetitions. One view is obtained with first-moment flow compensation, while the second view is obtained with selectable flow encoding (non-zero first moment) along one direction. Blood flowing along the encoded direction acquires a phase difference between the two views, resulting in signal dependent on both direction and speed of flow. Stationary tissues undergo no phase change. Therefore, the phase shift between the two views produces an image that spatially renders flow direction and velocity. With a 24-msec repetition time, a 256 X 128 matrix, and two excitations, data acquisition is completed in 13 seconds per location (both a magnitude image and a flow image are produced at each location). Images generated with flow phantoms confirmed the accuracy of this method. Preliminary clinical evidence in 23 human subjects suggests that this method is useful in evaluating portal hypertension, distinguishing arterial from venous flow, distinguishing between slow flow and clot, and confirming the presence of clot. This method appears to be a fast, easy way to assess blood flow in large vessels.

Identification and metabolic characteristics of an apolipoprotein C-II variant isolated from a hypertriglyceridemic subject

The very low density lipoprotein (VLDL) apolipoproteins from a Type IV hypertriglyceridemic Caucasian subject (plasma TG: 645 mg/dl) and his brother (plasma TG: 328 mg/dl) were separated by isoelectric focusing gel electrophoresis (IEF) and found to contain two isoforms of apoC-II, identified by immunoblot. These corresponded to normal apoC-II-1 (isoelectric point: pI 4.88) and a variant isoform (apoC-II-v, pI 4.74). The pI of C-II-v was not altered by neuraminidase treatment, indicating that it was not sialylated. The concentration of total immunoreactive C-II in VLDL was elevated (18 mg/dl vs normal; 5.0 +/- 2 mg/dl) but similar to that in other Type IV subjects. In VLDL, which contained 90% of the plasma immunoreactive apoC-II, the ratio (by IEF) of C-II-1:C-II-v was 2:1, whereas in high density lipoproteins (HDL) the ratio was 1:1. VLDL apoB turnover was measured after the pulse injection of 125I-labeled VLDL. VLDL apoB kinetic parameters for the proband and four Type IV subjects were similar: production rate, 28 mg/kg per day versus 30 mg/kg per day; fractional catabolic rate, 1.62.day-1 versus 1.96.day-1; and pool size, 17 mg/kg versus 18 mg/kg. The decline in VLDL triglyceride (TG) after the infusion of heparin (9,000 IU over 4 h) was also similar to that observed in Type IV subjects. In VLDL, the fractional catabolic rates of apoC-II-1 and C-II-v were similar (C-II-1: 0.31.day-1, C-II-v: 0.29.day-1) whereas in HDL, although similar to each other, the rates were greater than in VLDL (C-II-1: 0.48.day-1, C-II-v: 0.44.day-1). VLDL and HDL from the proband were normal in their ability to activate bovine skim milk lipase, compared to Type IV VLDL and HDL without C-II-v. Purified apoC-II-1 and apoC-II-v activated the milk lipase to a similar extent (at 1 microgram of C-II; C-II-1: 34 units/h, C-II-v: 35 units/h). Thus, apoC-II-v is a newly recognized isoform of apoC-II-1. It remains to be determined whether this mutation plays a role in the genesis of hypertriglyceridemia.

Urinary growth hormone excretion as a screening test for growth hormone deficiency

Overnight urinary growth hormone secretion was measured by an immunoradiometric assay incorporating commercially available reagents, in 41 normal prepubertal school-children from three age groups: 3-5 years, 6-7 years, and 9-10 years. There was no significant difference between the groups expressing the results as total microU/specimen and so they have been combined to provide a prepubertal reference range of 2.25-10.50 microU/night. Prepubertal children with growth hormone deficiency who had not been receiving growth hormone treatment for two days had overnight urinary growth hormone concentrations well below this range. Urinary growth hormone was assayed in 49 children undergoing investigation for short stature with conventional provocative testing, and those shown to have growth hormone deficiency had correspondingly low overnight urinary growth hormone concentrations. There was, in addition, a strong correlation between overnight urinary growth hormone concentrations and peak serum response to provocation. This simple urine assay may provide a useful screening test for growth hormone deficiency.

Accumulation of an apoE-poor subfraction of very low density lipoprotein in hypertriglyceridemic men

Studies were undertaken to investigate the mechanism of the marked accumulation of an apoE-poor very low density lipoprotein (VLDL) subfraction in untreated Type IV and IIb hypertriglyceridemic subjects. Heparin-Sepharose chromatography was used to separate large VLDL (Sf 60-400) from fasted subjects, into an apoE-poor, unbound fraction and an apoE-rich, bound fraction. As a percent of total VLDL protein, the apoE-poor fraction comprised 40 +/- 4% of total VLDL in hypertriglyceridemic subjects versus 25% in normal subjects. Compared to the apoE-rich, bound fraction, this apoE-poor material was found to have a 5-fold lower ratio of apoE to apoC (0.20 +/- 0.06 vs 0.91 +/- 0.18, P less than 0.005), but a 1.5-fold higher ratio of triglyceride to protein (11.41 +/- 0.85 vs 7.97 +/- 0.77, P less than 0.01). In addition, the apoE-poor fraction was found to be enriched 2-fold in apoB-48 (10.30 +/- 2.41% vs 5.73 +/- 1.59% of total apoB, P less than 0.005) compared to the apoE-rich fraction, suggesting that the apoE-poor fraction contains more chylomicron remnants. The amount of this apoE-poor VLDL was markedly reduced following a reduction in VLDL triglyceride levels (a decrease from 40 +/- 4% to 21 +/- 2% of VLDL protein following a 50% reduction in VLDL triglyceride levels). The large VLDL from Type I, III, and V hyperlipoproteinemic subjects subfractionated using heparin-Sepharose showed an equal distribution of apoE between the two fractions in contrast with the Type IV and IIb subjects. The separation of VLDL from Type I, III, and V subjects using heparin-Sepharose involves a mechanism other than apoE binding. Separation in the latter likely results from apoB-100 binding to heparin, as opposed to apoE binding of VLDL from Type IV and IIb subjects.

Development of an assay for human growth hormone in urine using commercially available reagents

An assay for the measurement of human growth hormone in urine (u-HGH) has been developed using commercially available reagents and its analytical variables have been investigated. The procedure is sensitive to 0.50 muU/L urine, has an interassay precision of 6.2-7.5 (CV%) over the standard curve, and shows good parallelism and recovery. Urine samples for the assay can be collected in plain plastic bottles, stored at room temperature for up to 24 h and, after adding preservative, at -20 C before assay for three months. There was a good correlation between the responses of HGH in serum and in urine during clonidine and insulin stimulation tests.

Infection following caesarean section

In a prospective clinical study of post-operative infection in 124 patients undergoing Caesarean section, 39 (31.5%) patients developed a total of 45 infections. There was no significant difference in infection rates between elective and emergency procedures. Five patients (4%) developed endometritis, wound infection was found in 14 (11.3%) and 18 patients (14.5%) developed a post-operative urinary tract infection. Pre-operative C-reactive protein levels and intraoperative swabs of the uterine cavity were not helpful in the early detection of endometritis. The risk factors predisposing to post-caesarean infection were obesity and low socioeconomic status.

Evaluation of flow through simulated vascular stenoses with gradient echo magnetic resonance imaging

Magnetic resonance imaging using gradient echo sequences can quickly generate dynamic images of the cardiovascular system. We used a gradient echo sequence (repetition time = 21 milliseconds, echo time = 12 milliseconds, flip angle = 30 degrees) to evaluate how a simulated vascular stenoses affects the signal intensity of flowing fluid. Axial slices were obtained at regular intervals along a plastic tube containing a circular constriction (25%, 51%, or 73% reduction of cross-sectional area). Image data collected at each slice level were used to reconstruct 32 images evenly spaced in time over one cycle of pulsatile flow. Contrast ratios were calculated between signal intensities from tube lumen and surrounding stationary water jacket. Upstream from each stenosis, signal intensity increased during systole and decreased during diastole, paralleling the changes in velocity we measured with a flow probe. However, within the 51% and 73% stenoses and just beyond them, there were consistent decreases in systolic signal intensity. Flow through the 25% constriction had little effect on the signal intensity pattern. These results suggest that the gradient echo pulse sequence may be useful in evaluating disturbed flow associated with vascular stenoses.

A cardiac phantom and pulsatile flow pump for magnetic resonance imaging studies

Fast scan magnetic resonance imaging (MRI) acquisitions are a rapid noninvasive means of evaluating the cardiovascular system. Because the appearance of flowing blood is highly variable, the interpretation of these images is sometimes difficult. A nonferromagnetic phantom that could generate lifelike pulsatile flow and also simulate the motions of the beating heart would facilitate image interpretation. This paper describes an MRI-compatible cardiovascular phantom that mimics the motions of the heart and also creates physiologic pulsatile flow. The phantom consists of a ventricle and an air pump that drives it. The pump is connected to the ventricle with seven meters of air hose so that the pump (which has ferromagnetic parts) can be placed outside the magnet room. The ventricle is placed in an airtight Plexiglas cylinder and the pump alternately pressurizes and depressurizes the cylinder, driving fluid in and out of the ventricle. The motions of the ventricular wall simulate the motions of the heart, and the pulsatile flow generated is of physiologic velocities and volumes. This phantom also can be used with other methods of evaluating cardiovascular function, such as MUGAS, angiography, and Doppler, allowing correlation between MRI and other modalities. Finally, the phantom can be used to study almost any aspect of cardiovascular function from pulsatile flow velocity to ventricular studies (ejection fractions, cardiac output, wall motion) and even studies of stenotic or regurgitant valves.

Effects of turbulence on signal intensity in gradient echo images

Although the appearance of laminar vascular flow in magnetic resonance (MR) images has been characterized, there is no general agreement about the effect of turbulent flow on MR signal intensity. This study uses a fast scan gradient echo pulse sequence to evaluate nonpulsatile turbulent flow in two different models. The first model simulated flow in normal vascular structure. It generated nonpulsatile, laminar and turbulent flow in straight, smooth-walled Plexiglas tubes. The second model simulated flow through a vascular stenosis. It generated nonpulsatile, laminar, and turbulent flow through an orifice. Velocities and flow rates ranged from low physiologic to well above the physiologic range (velocity = .3 to 280 cm/second, flow rate from .15 to 40 L/minute). Transition from laminar to turbulent flow was observed with dye streams. Turbulent flow in straight, smooth-walled vessels was not associated with a decrease in MR signal intensity even at the highest velocities and flow rates studied. The transition from laminar to turbulent flow through an orifice is not associated with a decrease in gradient echo signal intensity. As the intensity of the turbulent flow increases, however, there is a threshold above which signal intensity decreases linearly as turbulence increases (r = .97). This study suggests that flow in normal vascular structures should not be associated with decreased signal intensity in gradient echo images. Turbulent flow through areas such as valves, valvular lesions or vascular stenoses, may be associated with a decrease in gradient echo signal intensity.

Proteolysis of apoprotein B during the transfer of very low density lipoprotein from hens' blood to egg yolk

We report an example of the enzymic cleavage of an apoprotein B (apoB), the main apoprotein in the very low density lipoprotein (VLDL) of laying hens' blood, in a normal biological process, the formation of egg yolk. Plasma VLDL was labeled in vivo with 3H-amino acids, isolated by centrifuging, and injected into another laying hen. Yolk VLDL was isolated and its apoproteins were separated. ApoB was not detected in this lipoprotein. Most of the label originally in apoB was distributed among four smaller yolk apoproteins, apovitellenins III to VI, which are a large proportion of the apoproteins of VLDL in yolk. This distribution of 3H suggested that 80% of apoB was cleaved at three places. One yolk apoprotein, apovitellenin II, was not labeled, indicating that it did not originate from an apoprotein in plasma VLDL. The site for cleavage of apoB in the ovarian tissue has not been determined, but cleavage may occur during receptor-mediated endocytosis. The pattern of cleavage of apoB during transfer to yolk was not imitated by some known proteolytic enzymes.

Evaluation of steady and pulsatile flow with dynamic MRI using limited flip angles and gradient refocused echoes

Magnetic resonance imaging sequences utilizing limited flip angles and gradient echoes yield rapid (less than 2 min) dynamic images of the cardiovascular system. These images contain both accurate anatomical and functional information. Using a gradient refocused acquisition in the steady state (GRASS) in the CINE mode, we studied the relationship between gradient echo signal intensity and velocity of steady and pulsatile flow in a phantom simulating medium to large vessels. Images were acquired on a 1.5 Tesla system (repetition time = 21 ms, echo time = 12 ms, flip angle = 30 degrees). Data from each pulse interval were sorted in 16 images. Signal intensities from flow tube lumina and surrounding stationary water jacket were used to calculate contrast ratios which were compared to velocity measurements made with electromagnetic (EM) flow probes outside the magnet room. During steady flow, signal intensity contrast ratios increased with increasing flow and in a 10 mm thick slice, reached a peak at 48 cm/s, and declined for velocities up to 90 cm/s. Changes in instantaneous velocity during pulsatile flow correlated well (r greater than .88) with signal intensity changes up to a maximum mean velocity of 17 cm/s. Total signal intensity from the lumen for an "R to R" interval correlated extremely well (r greater than .97) with mean pulsatile flow velocities up to 30 cm/s. The excellent correlation between gradient echo signal intensity and actual flow velocities suggests that this imaging sequence might be useful for evaluating normal and pathologic flow phenomena.

Secretion of neuron-specific enolase, prolactin, growth hormone, luteinising hormone and follicle stimulating hormone by "functionless" and endocrine-active pituitary tumours in vitro

Secretion of the neuroendocrine marker neuron-specific enolase by 24 pituitary tumours was measured in maintenance tissue culture. Eleven endocrine-active and 13 "functionless" tumours were defined by measurement of prolactin, growth hormone, luteinising hormone (LH) and follicle stimulating hormone (FSH) secretion rates in vitro and the corresponding plasma hormone levels. Measurement of prolactin secretion provided a clear distinction between true prolactinomas and "functionless" tumours causing hyperprolactinaemia by stalk compression (pseudoprolactinomas). A previous report of LH and/or FSH secretion by the majority of "functionless" tumours was confirmed, but plasma levels of LH and FSH were usually normal. It is argued that LH and FSH are not the major hormones secreted by "functionless" tumours. A high production rate of neuron-specific enolase appears to be characteristic of the cell type from which most "functionless" tumours derive.

Dopaminergic inhibition of growth hormone and prolactin release during continuous in vitro perifusion of normal and adenomatous human pituitary

An in vitro technique for continuous perifusion of human pituitary has been developed to study the effect of dopamine on hormone release. Pituitary tissue was obtained from 2 patients with prolactinomas, 3 patients with acromegaly and 2 patients with disseminated malignancy whose pituitaries were normal. During perifusion prolactin release was reversibly inhibited from both normal and adenomatous glands, confirming the direct effect of dopamine on the pituitary. Rebound secretion following inhibition suggested that dopamine acted upon hormone release rather than synthesis under these conditions. Growth hormone (GH) release in vivo is stimulated by levodopa in normal subjects but inhibited in acromegaly. In vitro, however, we have demonstrated inhibition of GH release by dopamine, regardless of whether the pituitary was normal or adenomatous. This finding does not support the view that dopamine receptors are acquired by tumour cells as a result of adenomatous dedifferentiation. It is suggested that the paradoxical GH response to levodopa in acromegaly can be explained by a dual action of dopamine at hypothalamic and pituitary levels. According to this hypothesis GH release is stimulated by a hypothalamic effect, whereas inhibition occurs at pituitary level. The net effect of these opposing stimuli in vivo may depend upon the sensitivity of dopamine receptors at the prevailing concentration of GH.

Cefuroxime compared with penicillin for the treatment of gonorrhea

One hundred seventy-eight men and women with acute gonorrhea were treated by intramuscular administration of cefuroxime. Use of 1 g of cefuroxime plus 1 g of probenecid gave a cure rate of 95.5%, which compared well with that of a standard treatment of 5 x 10(6) units of intramuscularly administered benzyl penicillin plus 1 g of probenecid. The latter gave a cure rate of 97.2% in a concurrent series of 178 patients. A subsequent comparison of 163 patients who received 750 mg of cefuroxime plus 1 g of probenecid with 145 patients who received 1.5 g of cefuroxime alone showed cure rates of 95.1% and 97.2%, respectively. Only two cases of possible hypersensitivity to cefuroxime were found. It is concluded that cefuroxime is a valuable drug for single-session treatment of acute gonorrhea in both men and women.

Prolonged use of the Greenland method of treatment of gonorrhoea

Of 1081 patients with gonorrhoea treated with probenecid 1 g orally and benzyl penicillin 5 megaunits intramuscularly, 96.7% were cured and no complications were encountered. This treatment regimen was associated with a pronounced reduction in the proportion of gonococcal strains showing diminished sensitivity to penicillin, from 51% to between 4% and 14% over a period of four years. When this treatment method was abandoned, however, the percentage of less sensitive strains rose to 33% over the following 18 months.

The demonstration of very low density lipoprotein in the basal lamina of the granulosa layer in the hen's ovarian follicle

The isolated basal lamina from the granulosa layer in ovarian follicles of the domestic fowl contains an abundance of spherical particles with a modal cross-sectional diameter of 25-30 nm. The lipid in this basal lamina is predominantly triacylglycerol and its total fatty acid composition resembles that of plasma very low density lipoprotein (VLDL). Immunodiffusion studies and immunoelectrophoresis indicated that this basal lamina contains diffusible antigen identifiable with plasma VLDL. Perfusion with an alkaline buffer displaced the particles from the basal lamina and subsequent perfusion with plasma VLDL in an acidic buffer resulted in the reappearance of particles of similar size and form. Alternatively, when the perfused basal lamina was subsequently perfused with VLDL-free serum, few particulate structures were observed. Measurements of total and VLDL triacylglycerol together with electron microscope studies of the untreated and of the perfused basal lamina provided further evidence for the identification of the majority of particles with plasma VLDL. Other particulate lipoprotein is most probably plasma low density lipoprotein (LDL). These studies demonstrated that this basal lamina is permeable to the circulating VLDL of the laying fowl.

Rebuilding the burned face

Many of the methods and techniques used throughout the whole field of reconstructive plastic surgery owe their origins to problems first encountered in the severely burned patient. Gillies first used the tubed pedicle flap in reconstructing the face of a naval seaman burned in World War I. Axial pattern flaps such as the deltopectoral are widely used in the treatment of head and neck cancer and the one-stage free flap obviously has an exciting future. In many burned patients such flaps cannot be utilised owing to the non-availability of suitable vessels in either donor or recipient areas. Random pattern flaps such as the tube pedicle must therefore continue to play an important role in treating these cases. The plastic surgeon who undertakes the repair of the burned face must have wide experience of all methods of tissue replacement, whether by free graft or flap transfer. In resurfacing the nose the author has used Wolfe grafts when the cartilages are not involved or a tubed flap from the arm if this is not so. A long tubed pedicle flap from the back is preferred for resurfacing the chin and upper neck providing contour as well as excellent skin cover. Some extremely deep burns such as occur in epileptics or alcoholics may need bone-grafting, and the help of a good prosthetics department will be needed when the orbit has been destroyed.

The structure of the germinal disc region of the hen's ovarian follicle during the rapid growth phase

The structure of the ovarian follicle in the region of the germinal disc, which appears as a white plaque at the surface of the oocyte, was examined by electron microscopy and compared with the non-disc region which overlies the yellow yolk mass of the oocyte in the final growth phase. The main differences concerned the granulosa cell layer and the surface layer of the oocyte. In the disc the granulosa cells were less regularly arranged and the spaces between them varied in width. Their mitotic rate was higher than that in the non-disc region, where cell division was seldom observed at maturity. The perivitelline layer was comparatively poorly developed at the periphery of the germinal vesicle in 15 mm follicles, but eventually attained a uniform thickness throughout the follicle. In the intercellular and perivitelline spaces there were smaller amounts of granular material. Marked differences were observed in the ooxyte surface layer. In 15 mm follicles the surface of the germinal disc was thrown into numerous microvilli and some narrow indentations containing macrovilli from the granulosa cells. Coated vesicles, 120 nm diameter, appeared to be invaginating from the oolemma, whereas 70 nm coated vesicles were present in the deeper cytoplasm. In follicles of more than 25 nm diameter these structural conformations were evident only at the periphery of the disc; for the most part the 120 nm coated vesicles were absent, and over the germinal vesicle microvilli were of rare occurrence. On the other hand, the bulk of the oocyte surface was highly convoluted throughout this period of growth, numerous granulosa cell macrovilli extended into deep pouches associated with 300 nm coated vesicles, and the oolemma possessed a coating of fuzzy material. These observations suggest that there is a restricted passage of yolk precursors to the surface of the germinal disc, and that the inability to transport yellow yolk into the disc is related to differences in the oolemmal surface coat and the population of coated vesicles. The surface modifications, as well as the proliferation of the granulosa cells, are likely to be influenced by the presence of the germinal vesicle.

A survey of the effectiveness of a telephone-answering service

A survey was carried out over a two-year period in Exeter to find out what source of information led patients to attend the local clinic for venereal diseases and to evaluate the effectiveness of a tape-recorded telephone message advertising clinic times. Based on the response from patients it seems difficult to justify the cost of installing a telephone-answering service.

Electron microscope observations on the ovarian follicle of the domestic fowl during the rapid growth phase

A survey has been made of the ultrastructural features of the oocyte surface and its enveloping layers, comprising the theca, the granulosa and the perivitelline layer, during the final growth phase of 'yellow yolk' deposition. The following observations suggest that many macromolecular components of the blood plasma have free access from the vasculature to the oolemma: the fenestrated structure of the endothelium of the thecal capillaries, the intercellular spaces containing several erythrocytes in the theca interna, the 20-30 nm particles in the granulosa basal lamina, the wide spaces between the granulosa cells, and the open meshwork of fibres in the perivitelline layer. Numerous coated pits and vesicles, of 0.25-0.35 micron diameter, in the highly convoluted surface layer of the oocyte provide a mechanism for the incorporation of yolk precursors by pinocytosis. Such large coated vesicles and wide spaces between the granulosa cells are lacking in follicles in the preceding growth phase, which is concerned with the deposition of 'white yolk'. Considerable metabolic activity of the granulosa cells is indicated by their prominent Golgi elements, diverse granules, vesicles and villus processes. Cell junctions at the tips of the macrovilli anchor the granulosa to the oocyte. The theca externa, which provides mechanical support for the oocyte and its vascular and nervous elements, consists of sheets of collagen fibrils and fibroblast-like cells. Microfilaments in these cells may contribute to the contractility of the theca. Groups of interstitial cells associated with nerve fibres are present in the theca interna.

Changes in plasma lipid and glucose levels during the onset of fatty liver and kidney syndrome in chics

Plasma glucose, free fatty acid and triglyceride levels were measured during the onset of fatty liver and kidney syndrome in chicks. Intial studies indicated that behavioural and clinical changes characteristically associated with the syndrome were observed only during the 24 h preceding death. A more detailed examination of the blood changes was made on fasted birds. Typically, affected birds could be distinguished from healthy fasted birds by a hypoglycaemia which developed within 2.5 h of the removal of food, and a slightly higher and more sustained elevation of free fatty acid levels. Triglyceride values were not generally different from those found in normal birds. Although moderate to large amounts of lipid were occasionally observed in the kidneys of healthy fasted birds, only in affected birds was significant lipid infiltration of the kidneys associated with a similar level of lipid infiltration of the liver. In extreme cases death from fatty liver and kidney syndrome could occur within 4 h of the removal of food.

Lecithin--cholesterol--acyltransferase activity in the plasma of immature, oestrogenised and laying fowl (Gallus domesticus)

A study was made of the role of the lecithin-cholesterol-acyltransferase (LCAT) enzyme in the changes in the concentrations and fatty acid composition of the plasma cholesteryl esters of the fowl associated with oestrogen treatment and sexual maturity. Although there was a considerable increase in the concentration of free cholesterol in the plasma of oestrogen treated and laying birds, only in the oestrogen treated birds was it associated with an increased rate of cholesterol esterification. In both laying and oestrogen treated birds, changes in the fatty acid composition of the plasma cholesterol esters could be attributed to related changes in the fatty acid specificity of the LCAT enzyme. Evidence is provided to indicate that the cholesterol esters in the plasma of the fowl are synthesised mainly by the plasma LCAT system. The changes in the rates and fatty acid specificity of the LCAT system in the plasma of the fowl associated with sexual maturity or oestrogen treatment are discussed in relation to the extensive alterations shown to occur in the lipoprotein pattern of the plasma.

The involvement of biotin in preventing the fatty liver and kidney syndrome in chicks

Three experiments were carried out to investigate the involvement of vitamins in the fatty liver and kidney syndrome. The compounds studied, singly and in combination, were thiamin, riboflavin, nicotinic acid, pyridoxine, pantothenic acid, biotin, folic acid vitamin B12, ascorbic acid, choline and inositol and of these, only biotin prevented the syndrome. The minimum levels of supplemental dietary biotin required to prevent mortality varied from 0-05 to 0-15 mg/kg, depending on the diet. These levels were higher than the amounts required for maximum liveweight.

Biotin deficiency and fatty liver and kidney syndrome in chicks given purified diets containing different fat and protein levels

1. The occurence of biotin deficiency and fatty liver and kidney syndrome (FLKS) in chicks was studied using a 2x2x2x2 factorial-design experiment in which the variables were dietary biotin, fat and protein, and starvation. 2. The severity of biotin deficiency, using growth retardation and severity of dermal lesions as criteria, was least when the low-biotin diet also contained low levels of fat and protein. Addition of fat or protein increased the severity of the deficiency. Tissue fatty acid composition was affected by biotin deficiency only in those birds given the low-protein, low-fat diet. The main change was an increase in the ratio, 16:1 fatty acids :18:0 fatty acids. Plasma glucose and free fatty acid levels in non-fasted birds were unaffected by the dietary variables. 3. Mortality from FLKS with the diet containing low biotin, fat and protein levels was 52% at 28d, but was reduced or eliminated when the dietary level of any of these ingredients was increased. 4. Starvation considerably increased the incidnece of FLKS in the period immediately after fasting, and also affected plasma glucose and free fatty acid concentrations. Liver fatty acid composition, indicated an increase in the proportion of 18:0 at the expense of 16:1 and concentrations increased in proportion, at the expense of 18:0. 5. The relationship between biotin deficiency and FLKS, and a possible mechanism for the induction of FLKS by starvation are discussed.

Carbohydrate absorption by chicks affected with the fatty liver and kidney syndrome

Chicks with fatty liver and kidney syndrome (FLKS) were given oral doses of one of the following test solutions: water, glucose, maltose, starch. Plasma glucose concentration was measured during the four subsequent hours. All FLKS-affected chicks were hypoglycaemic before treatment. Although in some cases plasma glucose concentration increased slightly in the FLSK-chicks given water alone, significantly greater increases were invariably observed following the administration of carbohydrate to sick birds. Results obtained from dietary experiments in which starch was replaced by glucose in a ration causing high mortality from the syndrome revealed no beneficial effect due to the substitution. It was concluded that FLKS does not involve any major impairmant of carbohydrate digestion or absorption.

Evidence for a lesion in carbohydrate metabolism in fatty liver and kidney syndrome in chicks

Liver and kidney slices from chicks affected with fatty liver and kidney syndrome (FLKS) were incubated in vitro with a variety of non-carbohydrate precursors and their ability to form glucose was studied. The results show that the affected liver was unable to form significant quantities of glucose from the precursors (gluconeogenesis). Glycogen breakdown was also drastically reduced because the tissue was almost devoid of this carbohydrate store. Blood chemistry revealed no evidence of overall liver malfunction but reflected the consequences of lack of gluconeogenesis. In contrast, kidney gluconeogenic activity was significantly higher than in the controls, suggesting an attempt by this organ to offset the reduced hepatic capability. Attempts to restore activity in vitro were made by adding known cofactors of gluconeogenesis. Asmall but significant improvement resulted from addition of biotin to liver slices.

Some aspects of lipid metabolism in fatty liver and kidney syndrome in chicks

Various aspects of lipid metabolism were examined in broiler chicks affected with fatty liver and kidney syndrome (FLKS). Plasma free fatty acid concentrations were invariably elevated. Plasma triglyceride concentrations were increased amounts of triglyceride-rich lipoproteins. Lipoprotein lipase activity in adipose tissue was considerably reduced, but in heart tissue the enzyme activity was increased. Hepatic lipogenesis was reduced. Rates of oxidation of palmitic and succinic acids by liver, heart and kidney were normal. The increased oxidation rate of palmitic acid following the addition of carnitine was also normal. These findings indicate that elevated blood lipid levels are likely to be an important factor contributing to the development of fatty deposition, particularly in extrahepatic tissues.

The involvement of dietary fat and vitamins, stress, litter and starvation on the incidence of the fatty liver and kidney syndrome in chicks

Dietary and environmental factors involved in the fatty liver and kidney syndrome (FLKS) were studied. Addition of maize oil, tallow or olive oil isoenergetically at the expense of starch to the standard highmortality diet reduced mortality from 19 to 7 per cent. Supplementation of the standard diet with a mixture of vitamins reduced mortality to 1 per cent whereas supplementation with thiamin alone reduced it to 11 per cent. Mortality was 53 per cent higher among females than males. At 25 days of age mortality was 94 per cent higher among birds that had been subjected to repeated stressing. Withdrawal of food on day 36 resulted in a marked increase in mortality.