Temperature and myogenesis in embryos of the Atlantic herring Clupea harengus

The development of axial muscles has been investigated in spring-spawning Atlantic herring (Clupea harengus L.) reared at 5, 8, 12 and 15 °C. In 1994, around 90 % of embryos hatched after 28 days at 5 °C, 16 days at 8 °C, 9 days at 12 °C and 8 days at 15 °C. The somites were formed from cells of the paraxial mesoderm in a rostral to caudal direction, starting at the neural plate stage. Somites were added at rates ranging from one every 3 h at 5 °C to one every 52 min at 15 °C. A small number of myoblasts, located adjacent and lateral to the notochord, elongated to span the somite to form mononuclear myotubes. The majority of muscle fibres were formed by the fusion of 2­5 myoblasts to produce multinucleated myotubes that subsequently differentiated into either superficial or inner fibre types. The timing of myogenesis with respect to somite stage and the initial appearance of the gut, pectoral fin buds and pronephric tubules was found to vary with development temperature. For rostral myotomes, the synthesis of contractile filaments and myofibril assembly were first observed at the 42-, 38- and 27-somite stages at 5, 8 and 12 °C, respectively. The differentiation of myotubes into morphologically recognisable muscle fibre types first occurred at the 62-somite stage at 5 °C, at the 48-somite stage at 8 °C and as early as the 40-somite stage at 12 °C. Cell proliferation experiments with 5-bromo-2'-deoxyuridine showed that another population of myoblasts was activated on the surface of muscle fibres just prior to hatching. Development temperature also affected muscle cellularity; there were 43 % more inner muscle fibres in the myotomes of 1-day-old larvae reared at 12 °C than at 5 °C (P<0.02).

High fertilization rate with intracytoplasmic sperm injection in mosaic Klinefelter's syndrome

With the introduction of intracytoplasmic sperm injection (ICSI) as a practical successful treatment for male infertility, we are able to offer the procedure to a group of patients who probably could never father a child of their own. From a patient with mosaic Klinefelter's syndrome, sufficient motile sperm for intracytoplasmic sperm injection were obtained from a fresh ejaculate estimated to contain < 100 motile sperm. In the first IVF-ICSI attempt, out of seven oocytes that were collected from the wife, four were mature and were injected by ICSI. Fertilization occurred in all four oocytes but only one cleaved and was transferred to the uterus. Pregnancy test was negative 16 days after ET. In the second treatment cycle four out of eight oocytes were selected for ICSI. All four fertilized, three cleaved at the right time, and two were transferred into the wife's uterus. One embryo was frozen. Pregnancy test 16 days after ET was negative. The high fertilization rate achieved in this case indicates the potential of ICSI to treat extreme male infertility. Its use offers hope to those patients with conditions previously considered to be untreatable.

Are theophyllines being prescribed effectively and safely in general practice?

To investigate the attitudes and practices of GPs towards the use and monitoring of theophyllines, a questionnaire was mailed to all 479 GP principals in Nottinghamshire with one reminder to non-responders. Valid responses were obtained from 49% (236). Theophyllines were regarded as first-line or frequent second-line bronchodilators by 40% (94 of 234) of GPs in chronic bronchitis, 24% (56 of 234) in nocturnal asthma, and by 6% (15 of 234) in chronic stable asthma, although only 1% (2 of 234) of GPs regarded theophylline as strictly first-line therapy in chronic stable asthma. Theophylline levels were never checked by 76% (172 of 225) of practitioners at the start of therapy, or by 48% (110 of 231) during long-term therapy; half (110 of 217) could identify only up to 50% of a series of common factors affecting theophylline levels. There was no relationship between a score of theophylline knowledge and prescribing habits in chronic bronchitis, but doctors who checked levels scored significantly higher. Although theophyllines are being used in general practice for broadly sensible indications, this survey highlights aspects of prescribing that may be compromising both safety and effectiveness. Patients are likely to benefit if the need to check levels and the factors affecting levels become better known.

Swimming kinematics of fast starts are altered by temperature acclimation in the marine fish Myoxocephalus scorpius

The swimming kinematics of prey capture was studied in short-horned sculpin (Myoxocephalus scorpius L.) acclimated for 6&shy;8 weeks to either 5 &deg;C or 15 &deg;C (12 h:12 h light:dark) using 15 &deg;C-acclimated shrimps as prey. Fish acclimated to 5 &deg;C remained interested in feeding following an acute rise in temperature to 15 &deg;C over 12 h. Prey capture was a stereotyped behaviour consisting of stalking and stationary phases, followed by an S-shaped fast-start (stage 1), a propulsive stroke (stage 2) and a glide of variable duration during which the mouth was expanded and protruded to suck in the prey (stage 3). The duration of the preparatory stroke (half tail-beat, stage 1) was significantly shorter at 15 &deg;C (48.8 ms) than at 5 &deg;C (108.3 ms) in the 5 &deg;C-acclimated sculpin (Q10=2.2). For 5 &deg;C-acclimated fish, at 5 &deg;C, the maximum values for acceleration and velocity along the path travelled by the fish were 16.2 m s-2 and 0.8 m s-1 respectively. Both variables were relatively independent of acute temperature change (Q10=1.1&shy;1.2; P&gt;0.1). At 15 &deg;C, the maximum velocity was 33 % higher and the tail-beat duration of the propulsive stroke was 37 % shorter in 15 &deg;C-acclimated than in 5 &deg;C-acclimated fish. Both stride length and tail-beat amplitude were significantly higher (28 and 23 % respectively) in 15 &deg;C- compared with 5 &deg;C-acclimated sculpin at 15 &deg;C. The results demonstrate plasticity in the major kinematic variables of fast-starts following warm acclimation sufficient to increase the percentage of successful attacks during prey capture from 23.2 to 73.4 %.

Plasticity of muscle contractile properties following temperature acclimation in the marine fish Myoxocephalus scorpius

Live fibre bundles were isolated from the fast myotomal muscle of short-horned sculpin (Myoxocephalus scorpius L.) and isometric contractile properties and the force&shy;velocity (P&shy;V) relationship determined at 5, 10 and 15 &deg;C. Experiments were carried out on winter- and summer-caught sculpins and on individuals acclimated for 6&shy;8 weeks to either 5 or 15 &deg;C (12 h:12 h light:dark). Maximum tetanic tension (P0) in fibres from 15 &deg;C-acclimated fish increased from 125 kN m-2 at 5 &deg;C to 282 kN m-2 at 15 &deg;C (R10=2.3). For 5 &deg;C-acclimated fish, P0 was 139 kN m-2 at 5 &deg;C, but fell to 78 kN m-2 at 15 &deg;C, consistent with a partial failure of excitation&shy;contraction coupling at high temperatures. Peak force at 15 &deg;C was increased 2.2 times following depolarisation with a high-K+ solution, but was unaffected by the addition of caffeine and/or eserine to the Ringer's solution. The results from winter- and summer-caught fish were similar to those from 5 &deg;C- and 15 &deg;C-acclimated sculpins respectively. In 15 &deg;C-acclimated fish, the power output of muscle fibres calculated from the P&shy;V relationship was 55 W kg-1 at 5 &deg;C and 206 W kg-1 at 15 &deg;C. The P&shy;V relationship at 5 &deg;C was significantly less curved in muscle fibres from 5 &deg;C- than from 15 &deg;C-acclimated fish. After normalizing the curves for P0 and Vmax, it was found that the change in curvature was sufficient to produce a 40 % increase in relative power output at 5 &deg;C in cold-acclimated fish. The maximum contraction speed of muscle fibres at 15 &deg;C was 2.4 times higher in 15 &deg;C- than in 5 &deg;C-acclimated fish. It was concluded that acclimation modifies the contractile properties of fast muscle fibres at both low and high temperatures.

An improved diagnostic assay for Lambert-Eaton myasthenic syndrome

A new immunoprecipitation assay has been established for detecting antibodies to voltage-gated calcium channels (VGCCs) in Lambert-Eaton myasthenic syndrome (LEMS), using 125I-omega-conotoxin MVIIC, which binds to P-type VGCCs, to label extracts of human cerebellum. Fifty six of 66 serum samples (85%) from patients with clinically and electrophysiologically definite LEMS were positive for the presence of VGCC antibodies, defined as a titre > 3 SD above the mean for the healthy controls (n = 10). All disease controls (n = 40) were negative. This sensitive immunoassay should prove valuable in the diagnosis of LEMS.

ARE MITOCHONDRIA SUBJECT TO EVOLUTIONARY TEMPERATURE ADAPTATION?

Thermal tolerance and the respiratory properties of isolated red muscle mitochondria were investigated in Oreochromis alcalicus grahami from the alkaline hot-springs, Lake Magadi, Kenya. Populations of O. a. grahami were resident in pools at 42.8 &deg;C and migrated into water reaching temperatures of 44.8 &deg;C for short periods. The maximum respiration rates of mitochondria with pyruvate as substrate were 217 and 284 natom O mg-1 mitochondrial protein min-1 at 37 &deg;C and 42 &deg;C, respectively (Q10=1.71). Fatty acyl carnitines (chain lengths C8, C12 and C16), malate and glutamate were oxidised at 70&shy;80 % of the rate for pyruvate. In order to assess evolutionary temperature adaptation of maximum mitochondrial oxidative capacities, the rates of pyruvate and palmitoyl carnitine utilisation in red muscle mitochondria were measured from species living at other temperatures: Notothenia coriiceps from Antarctica (-1.5 to +1 &deg;C); summer-caught Myoxocephalus scorpius from the North Sea (10&shy;15 &deg;C); and Oreochromis andersoni from African lakes and rivers (22&shy;30 &deg;C). State 3 respiration rates had Q10 values in the range 1.8&shy;2.7. At the lower lethal temperature of O. andersoni (12.5 &deg;C), isolated mitochondria utilised pyruvate at a similar rate to mitochondria from N. coriiceps at 2.5 &deg;C (30 natom O mg-1 mitochondrial protein min-1). Rates of pyruvate oxidation by mitochondria from M. scorpius and N. coriiceps were similar and were higher at a given temperature than for O. andersoni. At their normal body temperature (-1.2 &deg;C), mitochondria from the Antarctic fish oxidised pyruvate at 5.5 % and palmitoyl-dl-carnitine at 8.8 % of the rates of mitochondria from the hot-spring species at 42 &deg;C. The results indicate only modest evolutionary adjustments in the maximal rates of mitochondrial respiration in fish living at different temperatures.

Subacute cerebellar degeneration and Lambert-Eaton myasthenic syndrome associated with antibodies to voltage-gated calcium channels: differential effect of immunosuppressive therapy on central and peripheral defects

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Atopy as a risk factor for cryptogenic fibrosing alveolitis

In a case-control study of occupational and environmental causes of cryptogenic fibrosing alveolitis we recently observed a higher prevalence of self-reported symptoms of wheeze, rhinitis or conjunctivitis in cases than in controls. To determine objectively whether this was due to a higher prevalence of atopy amongst cases of CFA, we have measured skin sensitivity to common allergens (D. Pteronyssinus, grass pollen, and cat fur), eosinophil counts and total Immunoglobulin E (IgE) in venous blood in the 22 surviving CFA cases from that study who were willing to provide a blood sample, and in one matched control per case. At least one positive skin test was recorded in 13 cases and six controls, the matched odds of one or more positive test being significantly increased in cases by a ratio of 8.0 (95% confidence interval 1.01-64, P = 0.05). Geometric mean eosinophil counts and IgE levels were also increased amongst cases by factors of 1.6 (95% CI 0.96-2.6) and 1.9 (0.9-3.8) respectively, although these differences were not significant. Differences in skin sensitivity, eosinophil counts, and IgE levels all tended to be more obvious in the 13 case control pairs in which the case was not taking steroids or other immunosuppressive treatment. We conclude that cases of CFA showed increased skin sensitivity to common allergens, and had evidence of increased IgE and eosinophilia in peripheral blood. These findings suggest that atopy may be an important determinant of susceptibility to CFA.

Hydrocephalus and pseudotumour cerebri in the mucopolysaccharidoses

This paper reports two cases of cerebrospinal fluid circulation disorder in children with mucopolysaccharidosis. One patient developed pseudotumour cerebri and the other communicating hydrocephalus. It is suggested that both have a similar underlying abnormality of cerebrospinal fluid absorption with different modes of presentation.

Heterogeneity of calcium channel autoantibodies detected using a small-cell lung cancer line derived from a Lambert-Eaton myasthenic syndrome patient

We investigated the heterogeneity of anti-voltage-gated calcium channel (VGCC) antibodies in the Lambert-Eaton myasthenic syndrome (LEMS) using a small-cell lung carcinoma line (MB) derived from an LEMS patient. Four of 13 LEMS patients had raised titers of anti-125I-omega-conotoxin-labeled (N-type) VGCCs, measured by radioimmunoassay using line MB as the source of antigen. Antagonists for L-type (nitrendipine and nifedipine) and N-type (omega-conotoxin) VGCCs inhibited K(+)-stimulated (voltage-dependent) Ca2+ flux into this line--by 22% for L-type and 2% for N-type at maximum concentration. Inhibition by the LEMS IgGs, by contrast, ranged from 46 to 78% at a concentration of 2 mg/ml. These differing effects on Ca2+ flux inhibition by LEMS IgGs on the one hand and by L- and N-type channel antagonists on the other, taken together with the observation that many of the sera failed to react with omega-conotoxin-labeled (N-type) channels in the immunoprecipitation assay, suggest that in many LEMS patients the autoantibodies target other VGCC subtypes besides L- or N-types, and that these are important in inducing the myasthenic disorder.

Cross-linking of presynaptic calcium channels: a mechanism of action for Lambert-Eaton myasthenic syndrome antibodies at the mouse neuromuscular junction

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder of neuromuscular transmission. Immunoglobulin G (IgG) autoantibodies act presynaptically to cause functional loss of Ca2+ channels by down-regulation. This in turn causes reduced release of acetylcholine in response to nerve stimulation (i.e. reduced quantal content). We show here that in vitro application of LEMS IgG for 24 h was as effective in causing reduced quantal content in mice as injecting animals with the antibody for 2 days. Furthermore, incubation with divalent (F(ab')2) fragments also significantly reduced quantal content. However, monovalent (Fab) fragments were without significant effect. No antibody or antibody fragment preparation affected spontaneous release. Whole LEMS IgG and F(ab')2 (but not Fab) fragments also inhibited K(+)-evoked 45Ca2+ flux in a small cell carcinoma cell line. These findings present functional evidence that LEMS IgG-induced down-regulation of nerve terminal Ca2+ channels arises due to antibody cross-linking of these channels.

SCM4, a gene that suppresses mutant cdc4 function in budding yeast

The gene SCM4 encodes a protein which suppresses a temperature-sensitive allele of the cell division cycle gene CDC4 in Saccharomyces cerevisiae. SCM4 was cloned on a 1.8 kb BamHI fragment of yeast genomic DNA in the high copy-number vector pJDB207, which results in a 50- to 100-fold increase in the level of the 700 nucleotide SCM4 transcript in vivo. The SCM4 gene encodes a 20.2 kDa protein of 187 amino-acids with a clear tripartite domain structure in which a region rich in charged residues separates two domains of largely uncharged amino acids. Although the apparent allele specificity of cdc4 suppression suggests that the CDC4 and SCM4 proteins interact, disruption of SCM4 demonstrates that the gene product is not essential for mitosis or meiosis; however, it may be a member of a family of related, functionally redundant proteins.

Paraneoplastic cerebellar degeneration. III. Cerebellar degeneration, cancer, and the Lambert-Eaton myasthenic syndrome

We studied nine patients with a subacute onset of a pancerebellar syndrome. Six had known cancer (three small-cell carcinoma of the lung [SCLC], one metastatic small-cell carcinoma, one small-cell carcinoma of the prostate, and one non-Hodgkin's lymphoma). Six of eight who had neurophysiologic testing, including the three patients without detectable cancer, had coexistent Lambert-Eaton myasthenic syndrome (LEMS). In two of the patients, LEMS was discovered only by neurophysiologic testing. We looked for anti-Purkinje cell autoantibodies in all patient's sera and in four patients' CSF. We also looked for autoantibodies to voltage-gated calcium channels (VGCCs) in seven patients' sera and two patients' CSF, using the 125I-omega-conotoxin radioimmunoassay. We were unable to detect anti-Purkinje cell autoantibodies in any patients' serum or CSF. However, there were raised titers of anti-VGCC autoantibodies in five of seven patients' serum, including one patient with SCLC who did not have LEMS, and in the CSF of one of two patients. We conclude that the frequency of presentation of a pancerebellar syndrome with LEMS is higher than expected by chance and is usually associated with cancer. In some of these patients, LEMS may be clinically occult. The presence of LEMS and raised titers of anti-VGCC autoantibodies in some patients with subacute cerebellar degeneration is suggestive of an autoimmune etiology even though anti-Purkinje cell antibodies could not be detected. Anti-VGCC autoantibodies are not confined to LEMS. They may be found at high titer in CSF as well as serum.

Pituitary gigantism

A case of pituitary gigantism resulting from a pituitary adenoma which secreted growth hormone is described. The patient was successfully treated by surgery, which led to the normalisation of endogenous growth hormone secretion. An acceptable final height was achieved with high dose intramuscular testosterone treatment.

Heterotopic pregnancy associated with gamete intra-fallopian transfer

Recent reports in the literature have focused on the increased risk of heterotopic pregnancy after the transfer of multiple concepti or oocytes. In an international collaborative patient registry between 1985 and 1989, 601 clinical pregnancies resulted from 2092 gamete intra-Fallopian transfer (GIFT) retrieval cycles. Five of the pregnancies were heterotopic (0.83%). After surgical intervention, all five cases of combined gestation resulted in live birth from intrauterine pregnancies. Routine vaginal ultrasonographic examination of the adnexa in patients who conceive after GIFT may help early diagnosis of heterotopic pregnancy. If the diagnosis is made early, conservative treatment may preserve the future fecundity of the patient and more intrauterine pregnancies may be salvaged.

Seronegative myasthenia gravis: a plasma factor inhibiting agonist-induced acetylcholine receptor function copurifies with IgM

Anti-acetylcholine receptor antibodies cannot be detected by standard radioimmunoassay in 10 to 15% of patients with generalized myasthenia gravis (seronegative myasthenia gravis). We investigated the effect of seronegative myasthenia gravis plasma on 22Na+ flux through acetylcholine receptors and voltage-gated sodium channels in the human rhabdomyosarcoma cell line, TE671. Fourteen of 19 seronegative MG plasmas inhibited acetylcholine receptor 22Na+ flux; none inhibited voltage-gated sodium channel flux. The inhibitory activity was found in the IgG-depleted fraction, and copurified with IgM after gel-filtration chromatography. Inhibitory activity was absent from the plasma of 8 healthy control subjects and of 6 patients with the Lambert-Eaton myasthenic syndrome, but was present in the IgG-depleted plasma fraction of 4 of 6 seropositive patients with myasthenia gravis and all 5 patients with demyelinating polyneuropathy. We conclude that a low-affinity serum factor, probably an IgM antibody, found in a high proportion in patients with seronegative and those with seropositive myasthenia gravis may contribute to the muscle weakness in myasthenia gravis, but its role in these and other neuroimmunological disorders requires further investigation.

Benign intracranial hypertension in childhood: a review of 23 patients

Twenty-three patients with benign intracranial hypertension (BIH) were seen at the Royal Alexandra Hospital for Children, Sydney over an 18 year period to 1988. Age at presentation ranged from 6 months to 13 years and 5 months. The female to male ratio was 2.3:1. The aetiological factors (sometimes multiple) included: chronic middle ear infection, 30%; dural sinus thrombosis, 22%; head injury, 13%; Vitamin A overdosage, 4%; tetracycline exposure, 4%; and no apparent cause, 43%. Headache was the most common presenting symptom occurring in 91% of patients, followed by vomiting in 65% and blurred or double vision in 57%. Papilloedema occurred in 96% of patients, abducens palsy was noted in 48% and visual impairment in 45%. All patients improved clinically after treatment, one with lumbar puncture only. Of 17 patients treated with steroids, 10 patients recovered and seven patients went on to lumboperitoneal shunt. Two patients recovered with steroid and diuretic treatment. Of two patients initially treated with diuretics only, one recovered and one subsequently required a shunt. Only one patient was initially treated with a lumboperitoneal shunt. Three of the shunted patients had shunt block requiring revision. None had permanent visual loss or other significant sequelae. The visual prognosis of BIH in childhood is good. In view of the relatively high complication rate of steroids and shunting, a controlled comparison of steroid vs acetazolamide/diuretic therapy should be undertaken.

The pseudotumor syndrome. Disorders of cerebrospinal fluid circulation causing intracranial hypertension without ventriculomegaly

We report a series of eight cases that show a close resemblance to, but are not identical with, pseudotumor cerebri (PTC) as normally defined. The majority of these cases are characterized by raised intracranial pressure without ventriculomegaly. They include two cases of cranial venous outflow obstruction in which clinical or radiologic abnormalities precluded the diagnosis of PTC proper (cases 1 and 2); one case of chronic meningitis in which an abnormal cerebrospinal fluid (CSF) composition precluded the diagnosis of PTC (case 3); two cases without either papilledema or a measured increase of CSF pressure, which in other respects, particularly in response to treatment, resembled PTC (cases 4 and 5); and three cases of what is thought to represent an infantile form of PTC (cases 6 through 8). The purpose of the analysis of these cases is twofold. First, it is argued that these cases throw light on the mechanism of PTC itself, supporting a concept of a disturbance of CSF circulation in this condition, and that they are themselves illuminated by considerations of typical PTC. Second, the cases are used to frame a proposed classification of the pseudotumor syndrome aimed at broadening the diagnostic criteria applied currently to PTC. It is suggested that the pseudotumor syndrome has a single underlying mechanism (disturbed CSF circulation) and that recognition of this mechanism not only clarifies the pathophysiologic processes of PTC but also has important diagnostic and therapeutic implications.

A familial coincidence of pseudotumor cerebri and communicating hydrocephalus

A family in which the mother and two of four daughters had a diagnosis of pseudotumor cerebri and one son developed communicating hydrocephalus is described. The other two daughters both have a long history of headaches but no signs of intracranial hypertension. The argument is advanced that there exists a defect of cerebrospinal fluid absorption common to pseudotumor cerebri and communicating hydrocephalus.

Calcium channel autoantibodies in the Lambert-Eaton myasthenic syndrome

We have tested 36 patients with the Lambert-Eaton myasthenic syndrome for serum antibodies to voltage-gated calcium channels by using an immunoprecipitation assay with [125I] omega-conotoxin-labeled voltage-gated calcium channels extracted from a human neuroblastoma cell line, SKN-SH. Forty-four percent of these patients had significant levels of antibody (30-1,466 pM) compared with healthy control individuals (less than 15 pM). The incidence of positive sera in patients without associated small cell lung carcinoma (61%) was greater than in those patients with small cell lung carcinoma (28%). Results correlated strongly with results obtained using voltage-gated calcium channels extracted from the small cell lung carcinoma line, MAR5. Anti-voltage-gated calcium channel antibody titers did not correlate with disease severity across individuals, but longitudinal studies in 2 patients receiving immunosuppressive therapy showed a clear inverse relation between antibody titer and an electromyographic index of disease severity. The incidence of positive sera among patients with other neurological disorders was not significant, but 8 of 12 patients with rheumatoid arthritis or systemic lupus erythematosus had raised titers (30-82 pM). We conclude that the antibodies detected in this assay are heterogeneous and that some of them are likely to be implicated in this disorder of neuromuscular transmission. The assay should prove useful as an additional diagnostic aid in patients with Lambert-Eaton myasthenic syndrome.

The embryo comes of age: the first decade of the Fertility Society of Australia

The Fertility Society of Australia was conceived in 1980 and born in 1982. After 10 years its history and achievements are reviewed.

What causes cryptogenic fibrosing alveolitis? A case-control study of environmental exposure to dust

OBJECTIVE

To investigate the role of occupational and domestic exposure to dust in the aetiology of cryptogenic fibrosing alveolitis.

DESIGN

Matched case-control study.

SUBJECTS

40 Patients with cryptogenic fibrosing alveolitis and 106 community controls matched for age and sex who responded to a questionnaire.

MAIN OUTCOME MEASURE

Responses to self administered questionnaire asking about lifetime exposure to dust, animals, and smoke at home and at work.

RESULTS

The patients with cryptogenic fibrosing alveolitis were more likely to report occupational exposure to metal dust (matched odds ratio 10.97 (95% confidence interval 2.30 to 52.4), p less than 0.001) or wood dust (2.94 (0.87 to 9.90), p = 0.08), to have worked with cattle (10.89 (1.24 to 96.0), p = 0.01), and to have lived in a house heated by a wood fire (12.55 (1.04 to 114), p = 0.009). A history of smoking and social class based on occupation were not significantly related to disease state.

CONCLUSION

Environmental exposure to dust may be an important factor in the aetiology of cryptogenic fibrosing alveolitis.

Rising mortality from cryptogenic fibrosing alveolitis

OBJECTIVE

To determine the pattern of mortality ascribed to cryptogenic fibrosing alveolitis and to identify factors that might be important in the aetiology of the disease; and to assess the validity of death certification of the disease.

DESIGN

A retrospective examination of mortality ascribed to cryptogenic fibrosing alveolitis in England and Wales between 1979 and 1988 with analysis, by multiple logistic regression, of independent effects of age, sex, region of residence, and social class as indicated by occupation on data for 1979-87; also a retrospective review of hospital records of patients certified as having died of cryptogenic fibrosing alveolitis in Nottingham and of the certified cause of death of patients known to have had the disease.

MAIN OUTCOME MEASURES

Time trends in mortality nationally; effects on mortality of age, sex, and region of residence; validity of death certification in Nottingham.

RESULTS

The annual number of deaths ascribed to cryptogenic fibrosing alveolitis doubled from 336 in 1979 to 702 in 1988, the increase occurring mainly at ages over 65. Mortality standardised for age for both sexes likewise increased steadily over the period. Deaths due to cryptogenic fibrosing alveolitis were commoner in men (odds ratio 2.24, 95% confidence interval 2.11 to 2.33) and increased substantially with age, being 7.84 (7.24 to 8.49) times higher in subjects aged much greater than 75 than those aged 45-64. Odds ratios of death due to cryptogenic fibrosing alveolitis adjusted for age and sex were increased in the traditionally industrialised central areas of England and Wales (p less than 0.02, maximum odds ratio between regions 1.25), but no significant increase in odds of death was found for manual occupations. Of 23 people whose deaths were registered in Nottingham as having been due to cryptogenic fibrosing alveolitis, 19 were ascertained from clinical records to have had the disease. Only 17 of 45 patients known to have had cryptogenic fibrosing alveolitis in life were recorded as having died from the disease.

CONCLUSIONS

The diagnostic accuracy of death certification of cryptogenic fibrosing alveolitis is high, but the number of deaths recorded as being due to the disease may underestimate the number of patients dying with the disease by up to half. Mortality due to the disease is increasing, and the male predominance and regional differences in mortality suggest that environmental factors are important in its aetiology.

Increasing the human menopausal gonadotropin dose--does the response really improve?

This study assesses the effects of attempts to optimize human menopausal gonadotropin (hMG) dosage in 271 patients who had at least two hyperstimulation cycles for in vitro fertilization or gamete intrafallopian transfer. In the first cycle, all patients received clomiphene citrate and hMG 150 IU/d. In the second cycle, the hMG dose was increased in 45% of patients to try to increase the egg yield. In spite of the increase, the population response was practically identical in both cycles. Median numbers of eggs retrieved (6 versus 6), no eggs retrieved (0.4% versus 1%), only one or two eggs retrieved (10% versus 10%), and canceled cycles (10% versus 10.7%). This suggests that increasing the hMG dosage above 150 IU does not increase the number of eggs retrieved. A poor response may be due to inherent differences in follicular development that cannot be overcome by increases in hMG dosage.

Human chorionic gonadotropin to oocyte retrieval interval in in vitro fertilization--how critical is it ?

This study shows that modification of the hCG-oocyte retrieval interval from 34 1/2 hours to 37 hours in patients having IVF had no significant effect on the number or quality of oocytes retrieved or on the ultimate pregnancy rate. More consideration can therefore be given to other factors such as patient convenience when scheduling the timing of hCG administration.

Cerebrospinal fluid diversion in the treatment of benign intracranial hypertension

Thirty-six patients from a consecutive series of 41 patients with benign intracranial hypertension (BIH) were treated by cerebrospinal fluid shunting. In 12 patients this was selected as the primary treatment due to the severe deterioration of vision or concern regarding the possible adverse effects of steroids; all 12 patients showed rapid and complete resolution of the disease, although eight patients still have a shunt in place. In 24 patients a shunt was inserted when other forms of treatment failed; all of these patients showed rapid resolution of the condition, although 20 patients still have a shunt in place. Three patients had the shunt removed without sequelae, and one patient in whom the shunt was removed because of low-pressure symptoms remains symptomatic with persistent papilledema (over 6 years). The percutaneous lumboperitoneal (LP) shunt was associated with the lowest revision and complication rates. Cisternal shunting to either the atrium or pleural cavity was next most effective, whereas valved LP shunts inserted via a laminectomy were least effective; ventricular shunts were used in only two cases. Shunting is therefore very effective in the treatment of BIH, but the significant complication rate and the possibility of inducing shunt dependence must be recognized.

Intracranial arteriovenous malformations: an 11-year experience

A consecutive series of 107 patients with an intracranial arteriovenous malformation who were considered for surgical treatment over the 11-year period between 1974 and 1985 is analysed. In 71 (66.4%) patients complete obliteration (which in some cases was combined with pre- or peroperative embolization) by surgery was attempted and was achieved in all but two patients. Five patients were treated by embolization alone and three patients by radiotherapy alone. Twenty-eight patients were managed conservatively for one of four reasons: an expectation of a good outcome without treatment (six patients); the refusal of recommended surgical treatment (five patients); poor condition at presentation (eight patients); or the risks of operative treatment were thought to be too great (nine patients). There was a 9.9% mortality in the surgically-treated series and significant morbidity in 16 (22.3%) patients. In all but two of these 16 patients, morbidity was related directly to the initial intracerebral haemorrhage. The one-year mortality in the group that did not undergo operation was significantly higher than in those patients who were treated surgically. Some general guide-lines for the management of intracranial arteriovenous malformations are proposed.

Cerebral arteriovenous malformations, steal, and the hypertensive breakthrough threshold. An experimental study in rats

An experiment was designed to investigate the effects of arteriovenous (AV) fistula occlusion on cerebral autoregulation. A right carotid-jugular fistula was created in 63 rats in such a way as to produce an intracranial AV fistula with a loop extension into the neck. The fistula was occluded after an 8-week interval with the rats under both normotension and metaraminol-induced hypertension, and evidence of blood-brain barrier disruption was investigated with an Evans blue dye technique. The results indicate that an intracranial AV fistula may cause cerebral steal which is responsible for a reduction in the threshold for hypertensive breakthrough following fistula occlusion.

Intracranial carotid artery injury in closed head trauma

Six patients with trauma to the intracranial internal carotid artery are reported. One patient died and two are permanently disabled due to ischemic sequelae. The incidence of this complication of trauma is unknown because of the infrequent use of angiography in head-injured patients. The pathology, clinical course, and management of this condition are discussed with reference to the 25 previously reported cases in addition to the six in this series.

A laparoscopic approach to a program of gamete intrafallopian transfer

Gamete intrafallopian transfer (GIFT) provides an effective method of achieving pregnancy in infertile women with normal fallopian tubes. Laparoscopic approach to ovum pickup and tubal catheterization provides a simple and rapid means of performing the operation. Equipment used to facilitate this process is described, and techniques of tubal catheterization are discussed. A clinical pregnancy rate of 27% is reported in a series of 71 treatment cycles. The application of GIFT in conjunction with in vitro fertilization is discussed, especially the use of excess gametes to provide embryos for freezing. The use of GIFT as a research and investigative tool may provide further insight into the causes for idiopathic infertility.

Spinal arteriovenous malformation presenting at birth: case report

A newborn with paraplegia and evidence of a subarachnoid hemorrhage was found to have a spinal arteriovenous malformation. The arteriovenous malformation was managed by direct surgical obliteration. This patient is the youngest ever reported to have this disorder and the youngest so treated.

Cross-over trial of superovulation protocols from two major in vitro fertilization centers

A study was undertaken as a controlled comparison of two different superovulation induction protocols currently in use in major Australian in vitro fertilization (IVF) clinics. Thirty patients each from the Monash University and the Royal Women's Hospital (RWH) IVF programs were stimulated for ovulation induction by the other program. Once timing for oocyte retrieval was scheduled, all care reverted to the program from which the patient first came. Results given as pregnancies per patient commencing stimulation were: RWH patients on Monash protocol, 27%; RWH control patients, 15%; Monash patients on RWH protocol, 7%; Monash control patients, 13%. In the year preceding the trial pregnancy rates were 16.9% at Monash and 10.6% at RWH. Stimulation protocols were also compared with respect to each of administration, cost, and patient stress. The results of this cross-over trial demonstrated major differences between the two ovulation induction protocols studied, although it was not possible to conclude that differences in pregnancy rate were due to stimulation alone.

A radionuclide method of evaluating shunt function and CSF circulation in hydrocephalus. Technical note

A simple technique for the evaluation of shunt function and cerebrospinal fluid (CSF) circulation in hydrocephalic patients is described. The method utilizes clearance rates of a radionuclide tracer injected into the lateral ventricle via an indwelling frontal catheter which is separate from the shunt apparatus. This permits an accurate assessment of drainage of ventricular CSF via the shunt, or the patency of normal or alternative CSF pathways where the shunt is malfunctioning.

Variability of peak flow in wheezy children

A study of peak flow variability was carried out among a population sample of 63 wheezy children aged 9-11 years. Recordings were made over 12 days at three times during the day--first thing in the morning, on returning home from school and at bedtime. Eighty nine per cent of the children had symptoms during the diary period. The mean amplitude (difference between the highest and lowest daily peak flow values) was 17% of the mean daily value (range 4-48%). By cosinor analysis the amplitude was 12% of the mean value (range 1-53%). In 65% of the children the lowest point of the daily rhythm as determined by cosinor analysis lay between midnight and 8am; the rhythm was, however, statistically significant in only fourteen individuals (22%). These levels of variability are considerably lower than those previously reported in hospital based studies of adult asthmatics. As a method of demonstrating variable airflow obstruction, which is the defining physiological characteristic of asthma, the use of a peak flow diary alone appears to be of limited value in children.

A technique for enrichment of motile spermatozoa from oligozoospermic and asthenozoospermic patients

A system for rapid selection of normal motile spermatozoa from poor semen samples is described. Analysis of the selected samples shows that there are significant improvements in the percentage motility, velocity and morphology. The final spermatozoa suspension of 0.5 ml is sufficient for the purpose of intrauterine AIH and IVF.

Pregnancy after percutaneous transvesical ultrasound-guided follicle aspiration for in-vitro fertilization

A case, in which pregnancy (unfortunately ectopic) followed oocyte collection by an ultrasound technique, is reported. Nevertheless, the procedure is less invasive than laparoscopic follicular aspiration, does not require general or major regional anaesthesia, and is suitable for patients in whom access to the ovaries by means of laparoscopy is either not possible or severely restricted.

Serum supplement in human in vitro fertilization and embryo development

The effects of maternal preovulatory serum and human fetal cord serum supplement in culture medium in human in vitro fertilization and embryo development were compared in 208 cases over an 8-month period when there were no significant changes in other variables. A significantly higher pregnancy rate was observed in the fetal cord serum group despite no significant difference being found in fertilization and embryo cleavage rates. This suggests a difference in the health of the embryo cultured in different serum supplements.