Influence of a 70 kilobase virulence plasmid on the ability of Yersinia enterocolitica to survive phagocytosis in vitro. During the course of infection, Yersinia enterocolitica invades tissues where macrophages and polymorphonuclear leucocytes (PMNs) constitute the first line of defence. As expression of virulence in Y. enterocolitica is governed in part by a c. 70 kilobase virulence plasmid (pYV), we investigated the influence of this plasmid on the interaction between Y. enterocolitica and phagocytes in vitro. The results showed that, irrespective of plasmid-carriage, yersiniae survived phagocytosis by macrophages and PMNs. Plasmidless Y. enterocolitica that had grown intracellularly in macrophages, however, were susceptible to killing by PMNs, whereas plasmid-bearing bacteria were resistant. In vitro cultivation of Y. enterocolitica in a Ca(2+)-deficient medium resembling that found within macrophages, did not influence the susceptibility of plasmid-bearing and plasmidless strains to killing by PMNs. These results indicate that passage through macrophages renders plasmidless strains of Y. enterocolitica susceptible to killing by PMNs. This finding may explain some of the differences in the behaviour of plasmid-bearing and plasmidless strains of Yersinia species in vivo.


A 'safe-site' for Salmonella typhimurium is within splenic polymorphonuclear cells. Following oral or systemic infection with Salmonella typhimurium, the focus of infection is in the liver and spleen. The majority of Salmonella surviving in the liver and spleen by 4 h post infection are already in an environment where they are largely protected from subsequent killing. Previous studies have shown that the majority of surviving Salmonella are intracellular. In the present study we sought to determine the cell type containing most of the cell-associated Salmonella liberated from the spleen. We enriched for Salmonella-containing cells by Ficoll-Hypaque separation followed by fluorescence-activated cell sorting. Approximately 85% of the total intracellular Salmonella were found in Mac-1+/J-11d+ cell fractions of the Ficoll-Hypaque band and pellet. By microscopic examination of stained cells from the sorted cell populations, it was evident that virtually all of the Salmonella were in polymorphonuclear cells (PMN). The numbers of Salmonella observed microscopically were similar in numbers to Salmonella colony forming units detected by plating. Salmonella containing PMN in the Ficoll band generally contained a single bacterium, while those from the probably less healthy cells in the Ficoll pellet generally contained several Salmonella.


Effect of Haemophilus somnus on phagocytosis and hydrogen peroxide production by bovine polymorphonuclear leukocytes. The interactions between bovine polymorphonuclear leukocytes (PMNs) and the bacterium Haemophilus somnus are known to be complex. In this paper, we evaluated the effect of H. somnus on PMN function using a flow cytometric (FC) technique that simultaneously determined the extent of phagocytosis and hydrogen peroxide production by PMNs, as well as using conventional techniques, such as the nitroblue tetrazolium (NBT) and chemiluminescence assays, to analyse the PMN respiratory burst. Results from the FC and chemiluminescence assays demonstrated that in vitro exposure of PMNs to logarithmically growing H. somnus reduced the respiratory burst of PMNs obtained from healthy calves. However, this reduction was not detected by the NBT assay. A decrease in phagocytosis by PMNs could also be shown using the FC assay. In addition, PMNs from calves with acute Hemophilosis (i.e. exposed to H. somnus in vivo) showed reduced activity when compared to PMNs from healthy calves. These in vitro and in vivo observations indicate that the modulation of bovine PMN function by H. somnus may contribute significantly towards the pathogenesis of the disease.


The role of Haemophilus ducreyi bacteria, cytotoxin, endotoxin and antibodies in animal models for study of chancroid. Haemophilus ducreyi cytotoxin-positive and -negative strains as well as bacterial sonicates and lipooligosaccharides (LOS) from such strains were evaluated for the capacity to produce dermonecrotic lesions, especially ulcers, after intradermal injections to rabbits and to different mouse strains, including nude mice. Dermonecrotic lesions of the ulcerous type were observed within 4 days and they were developed in both rabbits and mice with about 10(7) colony forming units (cfu) of H. ducreyi. Viable bacteria were isolated from the lesions up to 9 days after inoculation. All lesions healed spontaneously within 2-3 weeks. Bacterial sonicate (heated and unheated) and LOS preparations caused mainly abscess formation in rabbits, while in mice, a superficial, haemorrhagic ulceration was observed. To obtain ulceration at all injection sites, about 200 micrograms of LOS was required. Histological examination of acute, dermonecrotic lesions caused by viable bacteria showed deep necrosis, infiltrate of inflammatory cells, especially granulocytes and dilatation of blood vessels. The same type of inflammatory cells as seen in lesions caused by bacteria, were involved in the mouse lesions caused by bacterial sonicate and LOS preparations. The results indicate that LOS/endotoxin, probably in combination with other bacterial polysaccharides, can play a role in ulceration caused by H. ducreyi in animals; however, a relatively high amount of LOS preparation was necessary to cause dermal ulceration at all injection sites in the mouse model. The development of ulcers correlated with the endotoxin activity in bacterial sonicate and in LOS preparations. The model may therefore be useful to study the role of LOS components in development of ulceration. There was no significant difference in lesions caused by cytotoxin producing, respectively, non-producing H. ducreyi strains and cell-free preparations from such strains. The bacterial sonicates, cytotoxic for human cell lines, failed to kill animal cell lines, indicating that animal models do not adequately reflect the cytotoxin activity in experimental H. ducreyi infection. Antibodies to H. ducreyi sonicate and LOS, tested by means of ELISA, were found in pre-immune sera from both rabbits and mice. There was a significant antibody response to homologous cell sonicate and LOS, after primary and secondary infections with bacteria. Still, there was no clear difference between primary and secondary lesions in animals. Since animal lesions are mainly due to endotoxin activity, this may indicate that antibodies are of minor importance for protection in animal models.


Cloning and nucleotide sequence of a variant Shiga-like toxin II gene from Escherichia coli OX3:H21 isolated from a case of sudden infant death syndrome. Escherichia coli OX3:H21 expressing a toxin related to Shiga-like toxin (SLT) was isolated from the small bowel contents of a case of Sudden Infant Death Syndrome (SIDS). This strain was lysogenic for a lambdoid bacteriophage, but this did not encode the toxin. Southern hybridization analysis of chromosomal DNA revealed that the SLT-related gene was located on a 4.6 kb PstI fragment, which was cloned into E. coli JM109 in both orientations, using the vector pUC19, to generate plasmids pJCP501 and pJCP502. JM109 cells harbouring the recombinant plasmid produced SLT, as judged by cytotoxicity for Vero cells. Nucleotide sequence analysis revealed that the SLT gene was related to, but distinct from, previously reported variants of Shiga-like toxin type II, produced by E. coli from both human and animal sources. The A subunit of the SLT gene from OX3:H21 exhibited 95.9% homology (at both the DNA and derived amino acid sequence level) to the A subunit of the most closely related SLT-II variant. The B subunit was less similar, exhibiting 88.6 and 88.8% homology to the related gene at the DNA and amino acid level, respectively.


Detection of a vascular permeability factor in the extracellular products of Renibacterium salmoninarum. The presence of vascular permeability factors in the extracellular products (ECP) of 10 strains of Renibacterium salmoninarum with different geographical origin and serological characteristics are reported. All the ECP produced haemorrhagic and/or oedematous zones at the injection site with a diameter ranging from 10-30 mm. However, the ECP samples did not display toxic effect in fish at the same dose as inoculated in rabbit (180-400 micrograms protein/0.1 ml). No differences were observed in the production of this dermatotoxic factor between the two antigenic groups found in this microorganism. Whereas heating (80 and 100 degrees C/15 min) the ECP samples resulted in a complete loss of their proteolytic activity, only a decrease (but not total inactivation) of the dermatotoxic effects was detected. Therefore, although proteases could be implicated in the permeability factor, they are not totally responsible for this activity.


The 17 kDa lipoprotein and encoding gene of Francisella tularensis LVS are conserved in strains of Francisella tularensis. A T-cell-stimulating 17 kDa protein of the vaccine strain Francisella tularensis LVS has previously been cloned, sequenced and shown to be a lipoprotein. In the present study, it was investigated whether the protein, denoted TUL4, and its gene are present in various strains of the genus Francisella. By Western blot analysis, it was demonstrated that a TUL4-specific monoclonal antibody bound to a protein present in each of the Francisella strains. The immunoreactive proteins had an M(r) of 17 kDa in all F. tularensis strains and in the strain Francisella novicida, whereas the M(r) in strains of Francisella philomiragia was 20 kDa. When genomic preparations were probed with a radioactive DNA fragment of F. tularensis LVS encoding TUL4, hybridization was demonstrated in all strains of Francisella, although the F. philomiragia strains did not hybridize under conditions of high stringency. The hybridizing chromosomal DNA fragment of the F. philomiragia strains was larger than that of the other Francisella strains. No hybridization or Western blot reactivity was seen when various other Gram-negative and Gram-positive bacteria were probed. In summary, the 17 kDa lipoprotein of F. tularensis LVS appears to be Francisella-specific and present in the species F. tularensis and F. novicida, whereas an immunologically related protein is present in F. philomiragia.


The rebirth of midwifery in Canada: an historical perspective. The history of midwifery in Canada, beginning in the 17th century in New France, is characterised by periods of suppression and rebirth. At present, the long standing dominance of the medical establishment is giving way to the demand of women to assume greater control over the birthing process. Several provinces in Canada are in the process of obtaining midwifery legislation designed to strengthen, support and legalise the practice of midwifery. Lack of supportive legislation has discouraged the practice of midwifery. Though midwifery care has not been readily accessible, women have persisted in their search for care by a midwife. In response, female friends with a variety of educational preparation have found ways to prepare themselves and respond to women's need for an expert in normal birth. From an historical analysis of midwifery in Canada it would appear that a primary factor influencing midwifery's rebirth has been the power and determination of women to demedicalise normal birth and return it to the domain of women.


To stay or not to stay: are fears about shorter postnatal hospital stays justified? Common concerns raised during a Ministerial Review of Birthing Services in Victoria, Australia about the potential detrimental effects of shorter hospital stays after birth were examined in a study of women's actual experiences of and opinions about their hospital stays. Just under one in four women left hospital within five days of the birth, with the greater majority staying five days or more. Satisfaction with length of stay was high in the sample, with 82% of women feeling their stay had been about right, 11% feeling it had been too long and only 7% of women feeling their stay had been too short. A number of the concerns about the consequences of shorter lengths of stay were not borne out. Women who left hospital earlier than the traditional 5-7 day stay were not less likely to breast feed, nor were they more likely to be depressed 8-9 months after the birth. They were also much more likely to feel confident about looking after their baby when they went home than women who stayed five days or more. Implications for further research and for policy development concerning length of stay are considered.


She can lip-read, she'll be all right: improving maternity care for the deaf and hearing-impaired. In the UK a midwife is unlikely to meet many deaf women during her working life. Therefore very few midwives have a wealth of experience in providing care for these women. Postnatal discussion with one woman showed us that despite our good intentions the care we had given her was inadequate for her individual needs. We recognised that other deaf women were possibly receiving inadequate care. We set out to investigate this, and when we discovered that our suspicions were correct, devised a method that we hoped would improve the care we provided. The process of investigating the needs of deaf women is described in this paper together with the development of a teaching package for student and qualified midwives.


The value of clinical experience to a non-clinician: combining midwifery practice with teaching. This paper explores the value of clinical experience to midwives and other health care providers who work in other than clinical situations. The value of this experience may relate to personal or educational goals. Due to the lack of attention to this topic in the midwifery literature, the author recounts her own experience and compares it with the nursing and health visiting literature. Differing expectations feature as an issue. The value of this arrangement, for teaching, research and personal development more than compensate for the difficulties identified.


A simplified form of cardiotocography for antenatal fetal assessment. Antenatal cardiotocography has become the primary method of evaluation of fetal wellbeing, and the relationship between the presence of fetal heart rate accelerations in response to fetal movement and subsequent good fetal outcome has been demonstrated. However, in areas where electronic monitors are few or not available it would be useful if such accelerations could be demonstrated using the Pinard stethoscope. A prospective study involving 200 women with a singleton pregnancy of more than 34 weeks gestation was performed at Harare Maternity Hospital, Harare, Zimbabwe, when a 6 min electronic trace using an external transducer was compared with simultaneously performed 6 min manual record using the Pinard stethoscope. The findings showed that the manual record has a sensitivity of 75% and although traces with excessive base line variability would show an acceleration on the manual record, in no case with a flat trace was an acceleration noted on the manual record. This acceptable degree of sensitivity would allow for a significant decrease in the number of women being referred for electronic tracing and would be a more appropriate use of limited resources in terms of manpower and equipment.


Comparison of the effect of sodium fluoride and calcidiol on the rib cortical-endosteal surface remodeling in dogs receiving prednisone. The effects of sodium fluoride and calcidiol on the remodeling of the rib cortical-endosteal surface were compared in dogs treated with prednisone over long-term periods. In the study histomorphometric and tetracycline-labeling methods were used. It was found that administration of sodium fluoride in combination with calcidiol and calcium carbonate limited the development of prednisone-induced osteoporosis to a higher degree than treatment with calcidiol and calcium. This included less enhancement of the bone resorption surface, an increase in both the bone formation surface and osteoid seam thickness in conjunction with a lower reduction in the mineralization rate. The changes induced by sodium fluoride had a favorable effect on the ratio of the resorption to the formation processes at the basal multicellular units of bone turnover.


Stimulation of renal prostanoid synthesis by potassium loading in the rat. In vitro we measured the urinary excretion and synthesis of prostaglandins (PGE2, 6-keto-PGF1 alpha, thromboxane B2 and PGF2 alpha) by isolated glomeruli, cortical homogenates, medulla and papilla in KCl-loaded rats (KCl+, average K intake: 17 mmol/day for 20 days) and in rats loaded with non-Cl K salts (KCl-, average K intake: 21 mmol/day) as compared with control rats. In 2 separate groups of rats (KCl+ and KCl-) the urinary excretion of prostaglandins was measured after variations of K intake from an average of 4 to 20 mmol/day in 5-day periods. Glomerular PGE2 synthesis tended to decrease in KCl+, whereas it increased in KCl- rats. 6-Keto-PGF1 alpha and TXB2 did not vary, and PGF2 alpha decreased in both K-loaded groups. In the cortex, KCl loading decreased PGE2 synthesis. In KCl-, cortical TXB2 decreased. In the medulla, KCl loading increased the synthesis of TXB2 and PGF2 alpha, but not that of PGE2 and 6-keto-PGF1 alpha. In KCl- rats, TXB2 but not PGF2 alpha increased and PGE2 synthesis was also elevated. In the papilla, TXB2 synthesis increased in both KCl+ and KCl- rats. The urinary excretion of 6-keto-PGF1 alpha and TXB2 increased in both KCl+ and KCl- rats, whereas PGF2 alpha increased only in KCl+ rats. The changes of glomerular prostaglandin synthesis during K loading could dilate the glomerular vasculature, in keeping with the known vasoactive effects of the cation.(ABSTRACT TRUNCATED AT 250 WORDS)


Platelet levels of reduced glutathione, superoxide dismutase, zinc and malondialdehyde in uremic patients. Platelet-reduced glutathione (GSH), superoxide dismutase (SOD) and zinc content as well as malondialdehyde (MDA) formation were studied in 24 healthy volunteers as controls and 25 patients with chronic renal failure. Uremic patients had a significantly lower GSH and SOD content as well as an abnormal MDA formation in platelets. Their plasma zinc levels were sharply below the normal value, but the platelet zinc content was similar to normal controls. The decrease in the platelet GSH level was closely related to plasma zinc in uremic patients. We also found that the platelet zinc levels were positively correlated to the platelet GSH content in normal controls and uremic patients, but not to the platelet SOD level. The results suggest that uremic toxins may influence the content of platelet GSH and SOD, as well as inhibit prostaglandin synthesis. The decreases in platelet GSH may partially be related to the low plasma zinc level.


Acute renal denervation decreases tubular phosphate reabsorption. Acute renal denervation (DNX) has been reported to increase urinary phosphate (Pi) excretion in rats with intact parathyroid glands and also in rats which were thyroparathyroidectomized (TPTX). The present study was performed to determine the effects of acute renal denervation on the tubular transport of Pi in rats in the absence of parathyroid hormone (PTH) and in rats with constant PTH levels. In TPTX rats, the reabsorbed Pi normalized for the glomerular filtration rate (Reab Pi/GFR) was 2.38 +/- 0.16 mumol/ml in the DNX kidney compared to 2.56 +/- 0.16 mumol/ml (p < 0.05) in the contralateral innervated (INN) kidney at endogenous plasma phosphate levels (n = 6). The lower values for the Reab Pi/GFR in the DNX kidney persisted at elevated plasma phosphate concentrations during phosphate infusions. Infusion of PTH resulted in markedly lower Reab Pi/GFR values in the innervated kidney (1.47 +/- 0.21 mumol/ml) at endogenous plasma phosphate levels than in the vehicle-infused group. Furthermore, the Reab Pi/GFR in the DNX kidney was decreased (1.21 +/- 0.14 mumol/ml, n = 6) compared to the contralateral INN kidney. These studies demonstrate that acute renal DNX decreases the tubular transport of Pi both in the absence and in the presence of constant PTH levels.


Hyperparathyroidism: cause or consequence of recurrent calcium nephrolithiasis? Primary hyperparathyroidism (PHP) might be characterized by either prevailing bone or renal stone patterns with different metabolic features. To explore the possibility of different hormonal patterns we studied 129 patients with PHP: 95 stone formers (SF) and 34 nonstone formers (NSF). Females prevailed over males in both groups. Severe and specific bone lesions were more evident in NSF than SF. Parathyroid gland histology displayed a prevalence of adenoma in NSF, whereas isolated hyperplasia prevailed in SF. SF had lower levels of serum Ca, urinary Ca, ALP and serum PTH than NSF. As expected serum 1,25-dihydroxyvitamin D [1,25(OH)2 D] levels were greater in both groups of patients than in controls but we found no difference between the two groups. 25-Hydroxyvitamin D was neither increased with respect to controls nor different between groups. We conclude that patients with PHP may represent well separated metabolic and clinical entities, but we cannot confirm that serum 1,25(OH)2D levels play a key role in discriminating the different clinical features. In addition, the findings of predominant parathyroid hyperplasia in SF and the clinical evidence of recurrent hyperparathyroidism only in these patients suggest the possibility that the endocrine disorder might be the consequence over time rather than the cause of nephrolithiasis.


Severe hypophosphatemia in a patient with anorexia nervosa during oral feeding. We report a case of refeeding-associated hypophosphatemia in a 24-year-old malnourished male patient with anorexia nervosa but no history of alcoholism. He was given tube feeding with a low-calory preparation supplemented with phosphate. During refeeding, a severe hypophosphatemia developed after 5 days, i.e., serum phosphate 0.00-0.01 mmol/l for 2 days, accompanied by a reduction in red-cell ATP and 2,3-diphosphoglycerate, mild hemolytic anemia and transient changes in cardiac repolarization; there was, however, a striking lack of clinical symptomatology. Parenteral replacement with phosphate initially was complicated by an unexpected high urinary phosphate excretion due to an extremely low TmP/GFR (0.02 mmol/l) for over 2 days. Only after an increase of the TmP/GFR to supranormal values, i.e. up to 2.5 mmol/l, unrelated to changes in serum PTH or vitamin D3, the serum phosphate concentration became normal. The case report shows that severe hypophosphatemia can occur in nonalcoholic patients after oral feeding, and may induce reversible changes in renal phosphate handling that complicate replacement therapy.


Effect of ethanol on water and chloride transport in the rat papillary collecting duct. While it is believed that the effect of ethanol on human renal water homeostasis is indirect, amphibian membrane experiments have demonstrated direct effects albeit at high concentrations. To evaluate the direct effect of ethanol, diffusional water and chloride permeability was simultaneously measured in isolated rat papillary collecting ducts with increasing concentrations of ethanol (0, 0.12, 0.24, 0.48, 0.96 and 1.92 g%) both in the presence and absence of arginine vasopressin (AVP). Low concentration of ethanol (0.12 g%) increased basal water permeability by 9%. With increasing concentrations it then fell to control levels (0.48 g%) only to increase again with concentrations of 0.96 and 1.92 g% to a maximum increase of 26%. Similar changes in chloride permeability occurred. Water permeability in the presence of submaximal concentrations of AVP (20 microU/ml) was also significantly increased with lower concentrations of ethanol (0.12, 0.24 and 0.48 g%) but fell to control levels with higher concentrations. With the highest ethanol concentration (1.92 g%), submaximal AVP did not significantly increase water permeability. However water permeability was unaltered by increasing concentrations of ethanol in the presence of supramaximal AVP (2,000 microU/ml). These results demonstrate a direct effect of ethanol upon distal nephron water and chloride transport.


Subdiaphragmatic vagotomy in rats induces systemic hypertension and sodium retention. We examined the acute effects of bilateral subdiaphragmatic vagotomy (BSV) on blood pressure and renal function in female Sprague-Dawley rats. Mean arterial pressure was greater (p < 0.0001) in rats with BSV than in sham-operated rats (SOR). Rats with BSV had a significantly lower effective renal plasma flow (p < 0.01), total sodium excretion (p < 0.005), fractional sodium excretion (p < 0.01), urine flow (p < 0.01), and fractional excretion of water (p < 0.02) than SOR. The glomerular filtration rate was not significantly different between the 2 groups of rats. Plasma potassium was greater in rats with BSV than in SOR (p < 0.02). Pretreatment with an inhibitor of the angiotensin-converting enzyme prevented the above changes in rats with BSV. Changes in renal function and mean arterial pressure could not be attributed to antidiuretic hormone since plasma levels of antidiuretic hormone were lower in rats with BSV than in SOR (p < 0.002). In addition, the activity of the sympathetic system was decreased in rats with BSV, as suggested by the lower plasma levels of epinephrine (p < 0.003) and norepinephrine (p < 0.02) and the significantly lower renal tissue concentrations of norepinephrine (p < 0.03). No significant changes in renal tissue concentrations of acetylcholine or choline, its precursor, were observed in BSV rats when compared to SOR, suggesting a lack of renal parasympathetic innervation. Plasma renin activity was lower in rats with BSV (p < 0.02) than in SOR, but this effect was blunted in rats given an angiotensin-converting enzyme inhibitor prior to BSV.(ABSTRACT TRUNCATED AT 250 WORDS)


Acute effect of parathyroid hormone on Ca2+ ATPase of pancreatic islets. The Vmax of Ca2+ ATPase of pancreatic islets is reduced in states of chronic excess of PTH. This has been attributed to the reduced ATP content of pancreatic islet and to impaired response of the enzyme to calmodulin. It is also possible that excess PTH directly inhibits the activity of islet Ca2+ ATPase. The present study examined this issue. Small doses of 1-84 PTH (0.0625 and 0.125 x 10(-7) M) stimulated while larger doses (0.25, 0.5, 1.0, 2.0 and 4.0 x 10(-7) M) inhibited the activity of Ca2+ ATPase of intact islets. PTH has no effect on Ca2+ ATPase when the hormone was added to preparation of membrane homogenate of islets. Verapamil abolished both the stimulatory as well the inhibitory effects of PTH on Ca2+ ATPase of intact islets. The data indicate that PTH does not have a direct effect on the Vmax of islet Ca2+ ATPase of islet. Its effect on the enzyme activity of intact islet is most likely mediated through the hormone-induced calcium influx.


Luminal membrane potassium conductance of rabbit proximal straight tubules. Potassium channels have been found in the apical and basolateral membranes of renal proximal straight tubules, but the fraction of apical membrane conductance due to or associated with potassium has not been reported. Therefore, the transepithelial conductance of rabbit pars recta was measured and the portion of conductance which was inhibited by barium determined. The mean control transepithelial voltage and conductance were -5.6 +/- 0.7 mV and 106 +/- 10 mS/cm2, respectively. The addition of barium to the luminal perfusing solution decreased transepithelial conductance to 93 +/- 9 mS/cm2. This decrease of 13 +/- 2% from control (p < 0.001, n = 20) cannot be explained solely by inhibition of an apical potassium conductance. It is proposed that the apical potassium channels found in the pars recta facilitate transepithelial conductive transport by sodium and other ions.


Transfusion medicine in the 1990s, why it has changed and how. This paper is intended for physicians not directly responsible for transfusion medicine in their everyday practices. The field has changed dramatically in the last decade. This paper attempts to outline these changes, and detail factors that will be of practical use in general, medical, and surgical practices. Topics include available blood products with indications and risks, education about types of blood donation, possible future products, and a key concept in the field today, "conservation."


Dissociation of somatosensory and motor evoked potentials in a patient with an intramedullary spinal tumor. We describe a patient with an intramedullary spinal tumor who demonstrated postoperative improvement of motor and sensory function despite the lack of somatosensory evoked potentials (SSEPs) before and after intraoperative monitoring. The motor system was evaluated by direct spinal cord stimulation across the tumor bed. The resultant evoked compound muscle action potentials and compound nerve activities were normal. Although there is sufficient clinical evidence that SSEPs are sensitive to posterior and posterolateral ischemic insults of the spinal cord, the technique should be employed with an awareness of its limitations in monitoring the descending tracts which have a different blood supply and occupy more anterior locations in the spinal cord.


Contemporary management of chronic persistent cough. A chronic persistent cough is one that lasts longer than eight weeks in a patient without known chronic pulmonary disease. These patients may experience prolonged frustration, guilt and self-imposed social isolation, besides risking the medical and surgical complications of recurrent coughing episodes, if the cause of their cough is not quickly established and treated. A comprehensive discussion of the management approach to this problem with reference to the recent literature is presented.


The spectrum of opportunistic filamentous fungi present in the CBS culture collection. The mould collection of the Centraalbureau voor Schimmelcultures, Baarn, The Netherlands, was screened for isolates originating from warm-blooded animals. The range of species indicates that distribution of clinically relevant, pathogenic or opportunistic strains over the fungal kingdom is non-random. Some opportunistic fungi possess adaptations to life under hostile environmental conditions, enabling them to survive inside the human body. Presence of melanin or carotene seems to be an important virulence factor. Opportunistic fungi which sporulate in submersion are able to disseminate or cause severe local mycoses when the aspecific immune system of the host is impaired. Mycoses caused by a few dimorphic fungi, mostly in their natural ecological niche living in association with vertebrates, are promoted by specific immune deficiencies.


A retrospective clinical comparison between antifungal treatment with liposomal amphotericin B (AmBisome) and conventional amphotericin B in transplant recipients. Invasive fungal infections are an important cause of morbidity and mortality in immunosuppressed bone marrow and solid organ transplant recipients. Treatment with amphotericin B, the drug of choice for these infections, is however often limited by toxicity. Ten transplant patients receiving a liposomal amphotericin B formulation (AmBisome) were compared to ten retrospective control patients given conventional amphotericin B. Each group included bone marrow (8), kidney (1), and liver transplant (1) recipients. Conventional amphotericin B treatment was instituted due to nine Candida infections, and one Aspergillus fumigatus infection. In the AmBisome group treatment was instituted due to eight Candida infections, one infection caused by Saccharomyces cerevisiae and in one case as prophylactic treatment. In the amphotericin B group, maximal daily doses ranged from 0.1 to 0.65 mg kg-1 and cumulative doses were 21-836 mg kg-1 and were given over 3-32 days. In the AmBisome group, maximal daily doses ranged from 0.9 to 2.3 mg kg-1 and cumulative doses ranged from 225 to 3525 mg kg-1 over 8-28 days. All patients in the amphotericin B group experienced severe toxicity, especially nephrotoxicity which in four cases caused withdrawal of the drug. In contrast, the only adverse reaction in the AmBisome group was cholestasis in one patient. Only three out of ten patients in the amphotericin B group responded to treatment, seven patients died and six patients still had evidence of invasive fungal infection at autopsy. In contrast, eight out of nine patients in the AmBisome group responded to treatment, and the patient that received prophylaxis had a successful course.


Prophylaxis and treatment of fungal infections with fluconazole in bone marrow transplant patients. In an open study 31 patients undergoing bone marrow transplantation for various haematological diseases received fluconazole as prophylaxis or treatment of fungal infections. In 26 of these patients an antecedent oral prophylaxis with polyene antimycotics had failed to prevent infections with Candida species. Five of the 31 patients received fluconazole as primary prophylaxis because of non-compliance for polyene antimycotics. Fluconazole was administered orally at a daily dose of 100 mg and 200 mg, respectively (n = 29), or intravenously at a dose of 100 mg and 400 mg (n = 2). Cure or efficient prophylaxis was achieved in 22/31 patients (71%) after a median of 52 (9 to 493+) treatment days. In three patients (10%) Candida was eradicated but the infection reappeared 14-28 days after cessation of the drug; in 6 patients (20%) the infection was persistent or progressive. Four patients developed lethal Aspergillus infection while on fluconazole medication. A moderate and reversible elevation of liver function tests under therapy was observed in 9 patients and was possibly attributable to fluconazole in three of them (10%). One patient developed tremor which resolved after cessation of fluconazole. No other adverse drug reactions could be noted. We conclude that fluconazole is a relatively safe and effective drug for the prevention and treatment of superficial and, possibly, deep Candida infections in severely immunocompromised patients. However, it is presumably without preventive value in Aspergillus infections.


Fungal infections in surgical patients.

Fungal infections in surgical patients. Deep fungal infection was diagnosed in 42 patients (a rate of four per 1000) treated during a one-year period between 1988 and 1989 at the Surgical Clinic in Würzburg. Most occurred in association with damage to intra-abdominal hollow organs. Diagnosis of deep fungal infections is difficult and only histological identification provides definite proof. However, often the decision to treat has to be made on the basis of the clinical picture and the physician's subjective assessment. Combination treatment with amphotericin B and 5-fluorocytosine is still the current recommendation but the introduction of the azole antifungal agents appears likely to bring about a change. A trial of fluconazole showed it to have clear advantages over combination treatment, being effective, well tolerated and easily administered.


Vaginal yeast flora of pregnant women in the Cusco region of Peru. A study of the vaginal yeast flora in pregnant women living in Cusco and in its region (Peru), located approximately 3000 m above sea level, is reported. We observed 300 pregnant, healthy and non-diabetic women who attended a gynaecological clinic in the Lorena, Regional or IPSS (Instituto Peruano de Seguridad Social) hospitals in Cusco. A comprehensive clinical history was obtained from each patient. It included age, work, parity, time of pregnancy, use of contraceptives or antibiotics, type of vaginal symptoms, type and amount of vaginal secretion. The yeasts were isolated from 44.3% of the cases. The positive cases were more frequently found in the following categories: 20-30 year-old patients (69.2%), ninth month of pregnancy (49.6%), first pregnancy (41.4%), no delivery (58.7%) and no abortion (66.9%). Most women complained of leukorrhea (75.9%) with mucus, scarce without odour (18.8%) or lumpy, regular, without odour (15.8%) secretion. The yeasts isolated were Candida albicans (66.2%), other Candida species (12.8%), Torulopsis glabrata (8.3%) or other Torulopsis species (2.2%), Saccharomyces cerevisiae (7.5%), Rhodotorula sp. (1.5%) and Trichosporon cutaneum (1.5%).


Immunogenic potential of Aspergillus nidulans subcellular fractions and their polypeptide components. Cell-free extracts of the ascomycetous fungus Aspergillus nidulans were separated into three subcellular fractions: cell walls, total membranes and cytosol, and two different immunization protocols were used to raise antibodies against them in 12 New Zealand rabbits. The immune response was followed over time by dot and Western blot analyses to determine the immunogenic potential of each individual fraction and their polypeptide components. The IgG fractions, purified from pools of the best sera, were used to analyze in detail the antigenic composition of A. nidulans mycelium. The fast immunization protocol provided a much earlier response and higher sera titres. Cytosols and membranes were more immunogenic than cell walls and, in most cases, a positive correlation was shown between the titre of each serum and the number of detected antigens. The polypeptides of A. nidulans included six major immunodominant antigens of the molecular weights ranging between 13 and 200 kDa.


Cutaneous phaeohyphomycosis due to Cladosporium cladosporioides. A 54-year-old man, affected by pemphigus vulgaris and severe steroid-induced diabetes, developed seven red-brown, firm, slightly raised 0.1-1 cm papular lesions on the anterior aspect of both knees and thighs. A cutaneous biopsy showed a granulomatous infiltrate with numerous fungal elements scattered in the dermis and also within giant cells. Cultures of cutaneous biopsy fragments on Sabouraud glucose agar in presence of chloramphenicol resulted in the growth of dark-green colonies at 25 degrees C. They were identified as typical Cladosporium cladosporioides. As far as we know, this species was previously isolated only in an HIV-seropositive patient as opportunistic pathogen in the site of skin testing.


Incidence of febrile seizures in The Netherlands. To assess the incidence of febrile seizures in The Netherlands, we analyzed data from a population-based study carried out in 161 Dutch general practices. The overall incidence rate was 4.8/1,000 person-years. Considerable age and seasonal variation was found. The chance of a child suffering a febrile seizure in the course of the relevant age period (3-72 months) is 2.7%. One out of 3 children was referred to hospital. This is considerably less than in other countries. The incidence rates are similar to those found in the United States, England and Sweden, but differ from Asian studies.


Demonstration of antibodies against Candida guilliermondii var. guilliermondii in asymptomatic infertile men. Candida guilliermondii (C.g.) occurs mostly in animals, but it can affect humans too. Using serological screening methods studies have been carried out in 57 (30 normozoospermic and 27 oligozoospermic) asymptomatic infertile men, of whom 15 (26.3%; 9 oligozoospermic and 6 normozoospermic) were found to have responded to Candida guilliermondii var. guilliermondii. Sperm parameters (cell count, motility, morphology) were determined and various tests (hypo-osmotic swelling test, bovine mucus penetration, swim-up and testosterone examinations) were also performed. In the C.g.-infected and non-infected groups no significant difference was observed in any of the parameters. Precipitation was performed with a special antigen and in the positive group agglutination titres ranged from 0 to 1/320. Comparing C.g. titres with sperm parameters, only the swim-up technique showed noticeable alteration (P = 0.003). One month following ketoconazole treatment, the patients showed no precipitation reactions and their agglutination titres were < 1/80. Our results suggest that for the diagnosis of male infertility a serologic screening for C.g. is essential. As C.g. can also be sexually transmitted, both the husband and wife must be treated, if infection occurs.


Correlates of hot water epilepsy in rural south India: a descriptive study. Seizures precipitated by the stimulus of hot water known as 'hot water epilepsy' (HWE) have been commonly reported from South India. The present report outlines certain descriptive epidemiological aspects of 78 cases from two rural satellite clinics of National Institute of Mental Health and Neuro Sciences (NIMHANS), Bangalore, India. Geographical clustering was observed in one of the centres. HWE was common in the age group of 26-35 years with a male to female ratio of 3.6:1. The frequency of seizure occurrence was more than 1-4 attacks/month in 89% of cases. Past history of febrile convulsions and family history of HWE was noticed in 27 and 18% of our cases, respectively. The conversion of reflex to nonreflex epilepsy occurred in 30.8% of cases. Population-based epidemiological studies are essential for further understanding of HWE for developing strategies towards prevention and control.


Outdoor airborne dermatophytes and related fungi: a survey in Turin (Italy). Aerial dispersal of propagules, an important mechanism of fungal spread, has not been sufficiently studied for skin-infecting fungi. Over a period of one year, we have monitored the distribution of dermatophytes in the air of Turin. We have also examined the related aleurioconidic and arthroconidic fungi, which share physiological and morphological characters with dermatophytes and are sometimes considered to cause similar infections. A viable volumetric collector was used. Samples were taken each month; each sample collected 9.6 m3 of air. The medium was Dermasel agar supplemented with cycloheximide and chloramphenicol. Thirty-two species were isolated, within the genera Aphanoascus, Arthrographis, Chrysosporium, Geomyces, Gymnoascus, Malbranchea, Myceliophthora, Myxotrichum, Ovadendron, Trichophyton. The total mycoflora load obtained was rather low throughout the year and particularly in the hottest months. Apart from T. rubrum and T. mentagrophytes, which are dermatophytes very frequently encountered in Turin, many of the species detected have known pathogenic potential and/or keratinolytic activity.


Effects of epilepsy on daily functioning in northern Ecuador: summary of findings of a population-based research project. 215 patients with epilepsy and 125 healthy controls were questioned on the effects of epilepsy on social functioning as part of a population-based study of epilepsy in Northern Ecuador. 144 of these patients and 98 of the controls were followed, over a period of 1 year during an intervention study and their response to treatment assessed. Economic, intellectual and social functioning were examined. In the patient group, function was affected in important areas, most clearly, work. The low opinion the community had of the intellectual and physical abilities of patients might affect a patient's own view of themselves and sometimes diminish their opportunity for development. At 12 months, as a result of treatment, a significantly lower level of patients reported effects on function in some areas, though control individuals' views of their functional impairment had not shifted to any extent. Moreover, despite improvement, more patients at 12 months acknowledged fear of seizures, especially their unpredictability, as a handicapping factor, particularly in working outside or away from home. This seems to indicate that even when seizures are controlled, for many patients, the uncertainties of the condition remain and continue to affect their view of their capabilities.


Stroke subtype is an age-independent predictor of first-year survival. The short-term outcome after acute stroke is known to be strongly dependent on stroke subtype, especially favoring patients having suffered a lacunar stroke. The value of stroke subtypes as long-term predictors of survival has not been firmly established. We therefore examined the 1-year survival from acute stroke in the Klosterneuburg Stroke Data Bank, which since 1988 systematically collects data on acute stroke patients treated in one center in Lower Austria. The cumulative survival of 398 consecutive patients (mean age 67.7 +/- SD 11.6) 1 year after a first-ever stroke was not only adversely related to age but also appeared to be age independent when compared according to stroke subtypes. The cumulative survival rates (CSR) ranged from 88.7 [95% confidence interval (CI): 82-92] for lacunar strokes (n = 107) to 68.1 (CI: 50-79) for atherothrombotic strokes (n = 69). Cardiogenic embolism (n = 68) showed a CSR of 72.1 (CI: 61-83) similar to the group of cryptogenic strokes (n = 121, CSR: 74.4, CI: 67-82). The CSR for primary intracerebral hemorrhage (n = 33) was 68.8 (CI: 53-85). It is concluded that the comparatively favorable prognosis of lacunar strokes must be recognized in trials designed to evaluate efficacy in terms of 1-year mortality. Furthermore, as cryptogenic stroke has an almost identical survival rate when compared to strokes caused by cardiogenic embolism it may be assumed that a considerable number of strokes for which no cause can be found are, in fact, cardiogenic embolic.


Update of trends in mortality from stroke in Italy from 1955 to 1987. Mortality form stroke in Italy over the period 1955-1987 was analysed in terms of age-specific, age-standardised death certification rates, and by means of a log-linear model to separate the effects of age, cohort of birth and calendar period of death. In males the overall age-adjusted rate on the world standard population fell from 118.4/100,000 population in 1955-1959 to 72.0 in 1985-1987 and in females from 94.8 in 1955-1959 to 54.7 in 1985-1987. The overall decline in age-standardised rates over the 3 decades was thus 39% for males (averaging 1.7%/year) and 42% for females (averaging 1.9%/year). The declines were even greater in truncated rates from 35 to 64 years: from 80.4 to 41.2/100,000 for males (49%), and from 63.0 to 24.1/100,000 for females (62%). Inspection of age-specific rates shows comparable falls--in relative terms--in early and later middle age. For instance, male rates declined from 70.4 to 38.1/100,000 (46%) at age 50-54, and from 1,151.1 to 584.2/100,000 (50%) at age 70-74. Only above age 75 were the falls smaller. In females aged 50-54 years the decline was 63%, and for those aged 70-74 years it was 59%. In young adults, no appreciable changes were observed in either sex. Thus, the age, period and cohort model showed downwards trends in both the period and cohort effect, except for the most recent cohorts on account of an age-cohort interaction. These favourable trends are discussed in relation to better control of hypertension and the potential impact of other risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)


Measuring stroke in the population: quality of routine statistics in comparison with a population-based stroke registry. The validity of routine stroke data (official mortality statistics and hospital discharge registries) and a population-based MONICA stroke registry was assessed in a population of 309,806 25- to 74-year-old people in Sweden. The 'true' number of strokes in the population was estimated by screening for non-stroke diagnoses in death certificates and hospital discharge records and by a period of intensified search for otherwise unrecognized non-hospitalized stroke cases. Applying strict stroke criteria, the proportion of false-positive diagnoses was 10% and false-negative 17% in official mortality statistics. Among patients discharged alive from hospital, there were 32% false-positive and 6% false-negative stroke diagnoses. In the MONICA registry, the proportion of false-negative cases was 6% in fatal cases and 4% in non-fatal cases. Diagnostic information for subtyping stroke improved over time in non-fatal cases but remained essentially unchanged in fatal cases. We conclude that official mortality statistics give a reasonably good estimate of fatal stroke cases in Sweden, whereas hospital discharge records reflect poorly the incidence of stroke in the population. The overall quality of the population-based MONICA registry is good, although 4% of all strokes are missed. The proportion of unspecified stroke is substantial and changes over time; this makes longitudinal studies of stroke subtype difficult.


Dietary fat in the epidemiology of multiple sclerosis: has the situation been adequately assessed? Epidemiological studies have demonstrated that environmental influences contribute to determining the risk of multiple sclerosis (MS). The nature of this influence has not been established, although infectious agents have received the most attention with relative neglect of alternative hypotheses. This paper critically reviews the evidence implicating dietary fat in altering susceptibility to MS. It is concluded that a dietary theory accords with current knowledge regarding MS as well as an infective theory and thus should not be dismissed in research examining the aetiology of MS.


Epidemiology of multiple sclerosis in US veterans. 4. Age at onset. Age at onset of multiple sclerosis (MS) symptoms was ascertained for subsets of some 4,400 veterans of World War II who had been adjudged 'service-connected' for this condition. Average age at onset was 27.0 years for white men, 27.7 for white women, and 27.5 for black men. The unexpectedly older age for women is attributed to their older age at entry into service. When the coterminous United States was divided into three horizontal tiers of states, we found a strong effect of geography on age at onset. By state of residence at entry into active duty (EAD), white men had an average age at onset of 26.4 years in the northern tier, 27.3 years in the middle, and 28.8 years in the south. Trends were similar for white women and black men. Migrants, defined as those whose birth and EAD tiers differed, showed increasing ages at onset with southward moves. A statistical model used to discriminate between the influence of birth and EAD tiers on age at onset confirmed the significant effect of EAD alone. These data are compatible with the theses that the cause of MS is less common (or less efficient) in locations where the clinical disease is less common, and that its acquisition therefore occurs at an older age in those locales.


The changing mortality from motor neurone disease and multiple sclerosis in England and Wales and the Republic of Ireland. A study has been undertaken to ascertain the changes in mortality from motor neurone disease (MND) and from multiple sclerosis (MS) in England and Wales and in the Republic of Ireland. During the 20 years 1968-1987, 16,077 deaths were reported as being primarily due to MND in England and Wales with a male/female ratio of 1.22. There has been an increase in MND deaths from 3,185 in 1968-1972 to 5,241 in 1983-1987. The increase occurred in the death rates in both sexes and in all age groups, but particularly over the age of 65. In contrast, there was no increase in MS deaths and the MS death rates fell below the age of 55 but increased over this age, evidence that MS patients are living longer. A similar but more marked increase in MND mortality, and a considerable fall in MS mortality, occurred in the Republic of Ireland. The increase in MND mortality is not due to an increase in the number of neurologists, as there has been little increase in their numbers. The highest MND mortality was in Social Class IIIN males - skilled non-manual workers.


Multiple sclerosis and prostate cancer: what do their similar geographies suggest? Mortality rates from multiple sclerosis show a well-known north-south gradient, both within the United States and internationally. Mortality rates from prostate cancer show a similar gradient and are significantly correlated with multiple sclerosis (MS) mortality and MS prevalence. This finding adds prostate cancer to the set of diseases whose geographic distributions are significantly correlated with MS and whose members include colon cancer, dental caries, and Parkinson's disease. Review of the literature indicates that these clinically dissimilar diseases may share an aberration in vitamin (hormone) D. Recent evidence demonstrating a multi-faceted role for vitamin D in immunoregulation suggests that a vitamin D aberration may also contribute to the etiology of MS. A vitamin D hypothesis can illuminate several unexplained features of the epidemiology of MS and suggests opportunities for epidemiologic, laboratory, and clinical investigation.


Meta-analysis of progestin and estrogen receptors in human meningiomas. Among 301 human meningiomas published in the literature, 69% were progestin receptor (PgR)-positive. Estrogen receptors (ER) were detected in only 13% of the samples. The PgR levels were also elevated (p < 0.001) compared to the ER concentration. No association with sex, age, menstrual status or tumor location was found. Meningiomas with typical histology (75/171), were PgR-positive in significantly greater proportion than the atypical (12/171) or transitional (27/171) tumors. The PgR levels in the typical meningiomas were also increased (p = 0.005) compared to the atypical or transitional meningiomas. The ER levels did not differ by histology. The association of PgR levels with different histologic types is not well documented in the literature. Such an association is important for the understanding of the natural history of this disease as well as in the design and evaluation of therapeutic trials.


The Neuro-Oncology Register.

The Neuro-Oncology Register. In this report we describe the establishment of a Neuro-Oncology Register (NOR) at the University Hospital of Maastricht, The Netherlands. The register includes data on numbers and types of primary central nervous system (CNS) tumours and neurological complications of systemic cancer. One of the objectives of the register is to determine the incidence rate of neuro-oncological complications in systemic tumours and the incidence and prevalence rates of primary CNS tumours in a well-defined population. The catchment area of the NOR was defined with the help of the Dutch Regional Cancer Register. It involves 140,819 inhabitants and will be considered as our catchment population. At present, 1,168 cases have been recorded since the NOR became operational. All neuro-oncological reports in 1988 were chosen for further analysis (n = 276). We diagnosed 79 metastatic complications from systemic cancer. Metastasis of the brain is the most frequent metastatic complication in our population, followed by epidural metastasis. As in other series, the lung and breast are the most frequently encountered tumour sites. The NOR is a clinically based register which, in co-operation with the Dutch Regional Cancer Register, will generate important epidemiological data on CNS complications.


A perceived cluster of amyotrophic lateral sclerosis cases in a Massachusetts community. We investigated a report of a perceived cluster of amyotrophic lateral sclerosis (ALS) in Middleborough, Mass. Although an increase in ALS incidence was observed [2.51 deaths/100,000 person-years (p-y)], relative to the statewide rate over the years 1969-1985 (1.26/100,000 p-y), it was not statistically significant at the 95% confidence level. Problems in evaluating possible neurological disease clusters and their association with environmental exposures are presented.


Elevated ratio of late measles among subacute sclerosing panencephalitis patients in Karachi, Pakistan. Subacute sclerosing panencephalitis (SSPE) in Western countries and Japan is found more often in early- than in late-measles sufferers. Recent SSPE findings in Karachi, however, present a different picture. Age at measles contraction was obtained and analyzed for 44 SSPE patients identified in Karachi between 1983 and 1988. The ratios of early- (< 2 years of age) and late- (> or = 2 years of age) measles sufferers among 36 of these patients who had experienced only one attack of measles were 0.33 and 0.67, respectively. This is in striking contrast to the predominance of early measles in the SSPE histories reported in Japan and an number of Western countries.


Validation of the Hodkinson abbreviated mental test as a screening instrument for dementia in an Italian population. We investigated the accuracy of the Hodkinson abbreviated mental test (AMT) as a screening instrument for dementia in an Italian population. The AMT was administered by nonmedical personnel to 124 subjects > 59 years old. Each subject independently underwent a clinical evaluation for dementia (DSM-III criteria), and scores on the AMT were compared to corresponding clinical diagnoses (standard for comparison). Twenty of the 124 subjects were found to be affected by dementia upon clinical investigation. Although a score of 6 on the AMT showed the best combination of sensitivity (90%) and specificity (89%), only a score of 7 yielded 100% sensitivity (71% specificity). Specificity was higher in men, younger, and more educated subjects.


A new type of epidemiological study: questionnaire administered by medical personnel. Doctors, nurses, and medical and nursing students administered a questionnaire on memory disturbances, tremor and clumsiness in their first-degree relatives who live or lived near them. We obtained data on 1,479 relatives, of whom 805 were alive and 674 had died. Of those alive and older than 65, 8.69% had severe memory disturbances, 1.11% a parkinsonian syndrome and 5.59% essential tremor. Of those who had died, 10.68% had suffered from severe memory disturbances before they died. The results of both groups are similar and in accordance with the data in the literature. In our opinion this new type of epidemiological study can be very useful in diseases which are easily detected by nonspecialists and in areas with hospitals and medical schools.


Correlation between milk and dairy product consumption and multiple sclerosis prevalence: a worldwide study. Multiple sclerosis (MS) epidemiology suggests that different factors are involved in the clinical expression of the disease. Alimentary cofactors have already been considered, but mainly theoretically. We have studied the relationship between MS prevalence and dairy product consumption in 27 countries and 29 populations all over the world, with Spearman's correlation test. A good correlation between liquid cow milk and MS prevalence (rho = 0.836) was found; this correlation was highly significant (p < 0.001). A low but still significant correlation was obtained with cream or butter consumption (rho = 0.619 and rho = 0.504, respectively). No correlation was found for cheese. These results suggest that liquid cow milk could contain factor(s) - no longer present in the processed milk - influencing the clinical appearance of MS. The possible role of some dairy by-products is discussed in the light of a multifactorial etiology of MS.


[Demonstration of cardiac arrhythmias in multi-infarct dementia and ischemic stroke using Holter monitoring]. The occurrence of the cardiac arrhythmias was estimated by using 24-hour ECG Holter monitoring in 30 patients with multi-infarct dementia and in 30 with ischaemic stroke. Holter monitoring revealed pathological cardiac arrhythmias in 36.7% patients with multi-infarct dementia and in 40% with single ischaemic focus in the brain. It also allowed to reveal more frequent occurrence of cardiac arrhythmias in patients with ischaemic stroke (40%), than standard ECG (17%).


[Phenotype characteristics of mononuclears in peripheral blood and csf in multiple sclerosis]. In 48 clinically definite cases of multiple sclerosis the studies were performed of mononuclears phenotypes in CSF and peripheral blood. The results lead to following conclusions: 1. The percentage of cells with dominant reactivity of Anti HLADR, CD14 and CD56 in CSF is markedly lower than in the peripheral blood. 2. There exists a marked difference in the percentage of cells in CSF with reactivity anti-HLADR, CD14 and CD56 between patients in the relapse-remitting and chronic progressive phases of multiple sclerosis.


[Long-term steroid therapy in multiple sclerosis]. Corticosteroids have a firm place in the treatment of ms, but as yet no generally accepted regimen of this therapy exists. It is not known either, how to achieve the greatest effectiveness of these drugs and avoid side effects. Many clinicians advocate high intravenous doses of methylprednisolone in a short time of 5-7 days. This method is more effective and leads to less adverse effects. The studied patients received prednisone (Encorton Polfa) in short course of 3 days every month. The dose of Encorton in each course depended on the clinical condition but never exceeded 200 mg. The regimen was used in 18 patients who were followed up at least one year. Evident improvement or stabilization was obtained in 11 cases. No adverse effects were noted. These results are comparable to those achieved with methylprednisolone. It may be supposed that every regimen of corticoid treatment in ms is usefull if it causes no adverse effects. The treatment by method of long-term pulse therapy with corticoids is applicable in outpatients.


[Hospitalization of patients with central nervous system neoplasms in 1979-1981 and 1986-1988]. The hospitalizations and hospital deaths due to nervous system tumours were analysed on the basis of statistical cards filled in hospitals in a random sample of 10% of patients hospitalized in all Polish hospitals in the years 1979-1981 and 1986-1988. An evident rise was observed in the frequency of these hospitalizations and a less evident rise in the number of hospital deaths with a decrease of the hospital deaths caused by nervous system tumours. In the analysed time periods the greatest number of hospitalizations was in the age group 40-59 years, and deaths in the age group over 60 years. Hospitalization and hospital deaths indices were higher for urban population and males.


[Hospitalization of patients with cerebrovascular diseases in Poland in 1979-1981 and 1986-88]. Hospitalization and death indices of patients admitted with cerebrovascular diseases were analysed on the basis of statistical cards filled by hospitals in a sample of 10% in patients in all Polish hospitals in the years 1979-1981 and 1986-1988. In these years a 40% rise was noted of the hospitalization indices and a 22% rise in the death rated caused by these diseases. On the other hand, the hospital death rate decreased from 32.2% to 27.9%. Higher hospitalization indices were found for males and for the urban population. The death rates and intrahospital mortality were higher for women but the standardized death rates, with the exception of oldest age group, were higher for men. A cause for concern is the rise of hospitalization indices for men and women and death rates in men aged 40-59 years which may indicate lowering of the age of threatening stroke.


[First-hand experiences in trans-sylvian microsurgery of the posterior part of the circulus arteriosus and end-part of the basilar artery]. The authors present the technique and the obtained results of surgical treatment of vascular malformations in the upper part of the basilar artery in 14 patients using a trans-sylvian microsurgical approach. The techniques of subfrontal and subtemporal approaches are compared.


[Treatment of cerebral vein aneurysms in children]. Aneurysms of the vein of Galen are very rare vascular anomalies found mainly in newborns and infants. In the years 1982-1989 five children with these aneurysms were treated. Their age was from 6 weeks to 16 months, all were males. The diagnosis was based on computed tomography (initial examination) and cerebral angiography. Two cases with hydrocephalus were treated with valves. The main procedure was clipping of supplying vessels. One child died during diagnostic procedures. The results in four operated on patients are good.


[Tumor metastases to the brain. Clinical differences]. The authors analysed differences between two types of clinical diseases based on 161 cases of brain metastases. The first type (A) is, when symptoms of brain metastasis appear in different time of recognized malignant disease. In type B brain metastasis is the first symptom of neoplastic disease.


[Usefulness of intracranial pressure measurement by Camino V420 system: preliminary report]. The authors discuss the basis of ICP measurements with Camino V420 system and present the introductory experience of Department of Neurosurgery, Medical Academy of Lódź with it's clinical use. Continuous ICP measurements, lasting from 24h to 15 days were performed in 16 patients. In 13 of them ICP measurements were done in order to establish the dynamics of hydrocephalus and indications for shunt surgery. The other 3 suffered from intracranial hypertension, caused by trauma (1 patient) or spontaneous intracranial haemorrhage (2 patients). Camino system proved to be easy in handling, highly reliable, and infallible, even for successive days.


[Application of physiological data in evaluation of the intracranial volume-pressure interaction. I. An experimental study]. In experimental studies on cats the pressure and volume loadings corresponding to the physiological situations were used. The following tests were applied: central venous pressure increase, postural changes and increase of CO2 percentage in inspired gas mixture. It was found that the central venous pressure increase test is useful in the evaluation of CSF outflow routes, the postural change test examines the intracranial compensation and the elevation of CO2 level in inspired air tests the intracranial volume reserve.


[Changes of visual evoked potentials in experimental occlusion of superior sagittal sinus in the cat]. In the model of experimental occlusion of superior sagittal sinus (SSS) in 6 cats, the authors examined cerebral cortex activity by means of visual evoked potentials (VEP). They found shortening of latency of P2 wave potential in relation to the control by 5.5-13.3 msec, appearing after 4-6 hours following occlusion. Simultaneous cerebrospinal fluid pressure measurement indicated an increase in pressure following SSS occlusion from the control medium value 6.8 mmHg to 12-13 mmHg. Visual cortex in cat (area 17) is situated along the posterior portion of SSS. The occlusion of this vessel results in local haemostasis, which is likely to affect the physico-chemical properties of visual cortex cells, especially in the slow conducting system X (X cells can be found exclusively in area 17). The partial disappearance of this system activity results in reducing the signal and noticeable shortening of latency to peak P2 wave of VEP.


[Gangliosides in neurological pharmacotherapy]. Gangliosides take part in synaptic transmission, neuronal metabolism and development of nervous tissue. They cooperate with nerve growth factor (NGF) and have positive influence on regeneration of the nervous system impairments. There exist many behavioural and biochemical evidences of gangliosides participation in the regeneration of experimentally injured animal nervous system. The therapeutic effectivity of gangliosides in clinical practice is encouraging. Commercial preparates of gangliosides (Cronassial, Sygen) have been successfully used in the therapy of chronic neuropathies, strokes and subarachnoidal haemorrhages. Among the adverse reactions to these drugs are: local irritation, anxiety and possible detrimental effect in immunological system. Ganglioside preparations need further clinical examinations.


[A case of Alzheimer's disease simulating Creutzfeldt-Jakob disease]. A case of Alzheimer's disease simulating Creutzfeldt-Jakob disease--We report here a case of 67-year old man with frank dementia accompanied by extrapyramidal syndrome and myoclonic jerks. The diagnosis of Creutzfeldt-Jakob disease was suggested but the neuropathological examination revealed features most compatible with Alzheimer's disease. The "gray area" between both cerebral amyloidoses was discussed.


[Subacute sclerosing panencephalitis pregnancy]. In a patient aged 16 behaviour at changes, followed by visual agnosia, aphasia, paraparesis and involuntary movements developed about the 24th week of pregnancy. The presence of measles virus antibodies in the cerebrospinal fluid and progressing course of the disease with fever suggested SSPE. Pregnancy was terminated by caesarean section in the 30th week of pregnancy, the male premature baby died after 4 days, his brain was not examined under microscope. The mother died 2 weeks after labour in decerebrate rigidity. In the brain numerous profuse infiltrations composed of lymphocytes and plasma cells were found around blood vessels, the glia was proliferated and hypertrophied, eosinophilic inclusions were demonstrated in the nucleic of cortical neurons. The authors review the very few case, reported as yet, of SSPE in pregnant women. During pregnancy natural immunosuppression occurs, which may lead to activation of dormant infection with measles virus mutant. However, the history of one of the published cases suggests the possibility of other pathogenetic factors active in such cases.


[Diagnostic difficulties in tumours of foramen occipitale magnum]. The reported case was diagnosed formerly as multiple sclerosis. On autopsy it was found that disseminated neurological symptoms were caused by a neurofibroma of the foramen magnum. The diagnostic difficulties in cases of tumours in this location are discussed.


[A case of progressive bulbar paralysis in a child (Fazio-Londe disease)]. The reported case was diagnosed in a girl aged 14, in whom the first signs developed at the age of 6, with progressive involvement of the cranial nerves IX, X, XI and XII, and V with VII. After ruling out other possible causes the diagnosis of the Fazio-Londe disease was established. Electromyographic examination confirming the diagnosis demonstrated also evidence of changes of neurogenic type in the muscles of upper extremities despite absence of demonstrable clinical abnormalities, which, as suggest the authors, may support the hypothesis of the similarity of the disease to other forms of spinal muscular atrophy, such as Werdnig-Hoffman and Kugelberg-Welander diseases.


[Parkinsonism caused by bilateral subdural haematomas]. The authors present a case of 75-year old man with bilateral chronic subdural haematomas presenting as parkinsonism. Surgical removal haematomas was followed by complete recovery of the patient.


[Micropsia in multiple sclerosis].

[Micropsia in multiple sclerosis]. Micropsia is described in a case of remitting multiple sclerosis with left optic neuritis and spastic paraparesis. The damage to small axons in the optic nerve conducting spatial impulses from temporal and lower segments of retina might be responsible for the occurrence of transient micropsia.


[Spontaneous chronic spinal epidural haematoma in a 14-year-old boy. Case report]. An unusual case of a 14-year-old boy with spontaneous chronic spinal epidural haematoma treated surgically with full success is reported. The clinical presentation and aetiology are discussed. The result of treatment depends mainly on the time of duration of neurological deficit. Immediate transfer to neurosurgical department gives a chance of good recovery.


[The electrocardiogram in epidemiology: the Minnesota code]. A correct methodological approach to electrocardiogram interpretation is an important requirement above all as far as epidemiological studies on large case reports are concerned. The Minnesota code represents a pattern of objective classification of the electrocardiogram and it is fit for application to studies on people and consequent statistical analysis. It consists of a series of items which are assembled in nine principal classes, each of them describing with objectivity a figure of the electrocardiogram; moreover it includes several classes for the codification of the electrocardiogram after effort and in sequenced studies. Multiple applications in this sense confirm the validity of this code which gains, in times of automatisation, a new value.


[Physiopathology of venous stasis at the microcirculation level]. The division of the venous circulation in to two sectors, one constituted by the superficial and deep venous trunks (macrocirculation) and the other by the capillaries and precapillary venules (microcirculation), is surely schematical but aids the comprehension of many hemodynamic effects connected to hampered venous return and to the incompetence of the valvular devices. In fact many of the effects of stasis and venous hypertension (oedema, red cell diapedesis, skin dystrophies) cannot be explained merely by hydraulic mechanisms but require a primary alteration of the microvascular wall associated with structural changes of the perivascular connective tissue. The alterations that occur in microcirculation are of the utmost importance in the formation of the venules ulcerations. The passage of fibrinogen through large pores in the venules of the patients affected by venous hypertension derived from venous insufficiency creates a pericapillary fibrin deposition that cannot be removed because of inadequate blood and tissue fibrinolysis. This accumulation acts as a barrier to the diffusion of oxygen and other nutrients, determining a stasis dermatitis that may lead to tissue necrosis and ulceration. The more precise knowledge of the phenomena connected with the venous stasis at the level of microcirculation (pericapillary fibrin deposition, endothelial ischemia, blocked lymphatic drainage) will not only allow a deeper comprehension of the clinical signs but hopefully will lead to a more effective treatment of the postphlebitic syndrome.


[The choice of approach in the surgical therapy of the superior thoracic outlet syndrome]. The symptoms of thoracic outlet syndrome (TOS) may be improved or cured either by physiotherapy or by a surgical operation. The choice of patients to be submitted to surgery must be performed on the basis of clinical picture and of non invasive and invasive assessment. Moreover the surgeon must choose the best procedure to relieve symptoms. The Authors on the basis of their experience and of a literature review refer to the various surgical approaches used in the treatment of TOS.


[Profundaplasty as the only revascularization procedure in ischemia of the leg. Clinical contribution]. The profunda femoris artery is the primary source of collateral flow to the lower extremity in the presence of superficial femoral and/or popliteal occlusion. The arteriosclerotic disease involvement of this segment is relatively less frequent and in the majority of the cases localized on the ostium and reaches to the first branch. Profundaplasty to relieve limb-threatening ischemia is infrequently employed as an isolated procedure. However many Authors reported their experience on this treatment, in case of critical limb ischemia in patients without significative lesions of the aortofemoral district. Our late four year experience concerns of 22 patients (18 male, 3 female). All the patients had severe ischemia of the lower limbs, with serious symptoms, such as invalidating claudicatio (13), rest pain (7) and gangrene (2). Twenty-two profundaplasty were performed as the only reconstructive procedure. There was no postoperative mortality. Two patients had above knee amputations (15 days and 14 months after the revascularization). All of the other patients improved and follow-up extended to 48 months shows a limb salvage rate of 90%. In conclusion, on the basis of our experience, we think that the operation is recommended, whenever possible, in patients with critical ischemia when the possibilities of more extensive revascularization procedures are considered to be poor.


Ten years of surgery of aortic dissections and aneurysms. Clinical experience and original contributions. From January '82 to April '91, 117 patients with aortic disease were operated upon at our University Hospital in Genoa, Italy. Thirty-seven had arch dissections or aneurysms; 66 had acute aortic dissection type A and 14 had aortic dissections or aneurysms type B, acute and chronic. Patients with arch or type B aortic pathology but without surgical indication and cases of post-traumatic aortic transections are not included. There were 84 male and 33 female patients with a mean age of 52 (6 min and 74 max). In the acute patients, the mean interval between clinical onset and surgery was 34 hours (6 min-72 max). All patients with primary arch disease had surgical repair with the aid of deep hypothermia and circulatory arrest (17-96 min). Type A dissections were treated with standard CPBP at 28 degrees C. Surgical techniques included direct suture of intimal tear alone, direct suturing of the two aortic stumps; interposition of Dacron tubular prosthesis; Bentall repair; separated valve and aortic replacement; an original aortic bulb aortoplasty with valve repair; arch replacement with resuturing of one or more aortic trunks. Human fibrin glue (Tissucol) was employed either as haemostatic agent, widely spread over the suture lines or as tissue adhesion agent between dissected aortic layers. Human fibrin glue is adopted because it gathers high glueing capacity and maintenance of the elastic property of the vessel wall. Hospital mortality (30 days) has been 25% in ascending aortic dissections (16/66 patients) and 50% in patients with arch disease (18/37 patients) who needed circulatory arrest. Late mortality 5/83 (6%). Reoperations for aortic valve insufficiency or re-dissection have been 7 (8.4%). Early diagnosis (increasing reliability of 2D-Echo and CT scans), aggressive surgery, meticulous myocardial and cerebral protection and introduction in clinical use of biological glues seem to be the milestones of present and further improvements in surgical results.


[Electrocardiogram ambulatory monitoring: technological evolution and current prospectives]. The value of ambulatory ECG monitoring in the investigation of arrhythmic or ischemic events with paroxysmal patterns is well-known and its use is widespread. More recently, technical advances in informatics and in ECG signal digitizing have rapidly developed the current available ambulatory ECG instruments, reducing the time necessary for pattern analysis meanwhile assuring acceptable accuracy and reliability of the results. ECG recording techniques other than traditional Holter monitoring are now available such as transtelephonic transmission of ECG signal recorded in real time or previously stored in solid state memory by intermittent recorders that can be switched on by the patients himself at the first prodroms or at the end of the event. These "loop recorders" make it possible to indefinitely extend ECG monitoring time, reducing costs and increasing record sensitivity in comparison to conventional Holter monitoring. Moreover, recent technological development of Holter monitoring makes it possible to perform heart rate variability analysis and late potentials research in addition to traditional analysis of cardiac rate and ventricular repolarization. Thus Holter recording may become, combined with other usual risk factors, a polyparametrical non invasive approach to sudden cardiac death risk assessment characterised by low cost/benefit ratio and by large screening capacity.


[Coenzyme Q10: contractile dysfunction of the myocardial cell and metabolic therapy]. Coenzyme Q10, a mitoquinone involved in mitochondrial energy synthesis and the removal of free radicals, may be lacking in a number of cardiac pathologies leading to reduced contractile activity. The administration of exogenous coenzyme Q10 may help to improve contractile activity. In order to assess this hypothesis 63 patients suffering from altered myocardial contractile function (29 dilated cardiopathies, 15 valvular cardiopathies, 19 ischemic cardiopathies) which presented a NYHA class above 2 were selected. The study was open and patients were subdivided into two groups, one of which received conventional therapy alone whereas the other also received exogenous coenzyme Q10. After 4 months of follow-up clinical (NYHA class, effort tolerance) and echocardiographical (ventricular diameter and contraction fraction %) parameters were evaluated. In those patients treated with coenzyme Q10 and suffering from dilated cardiomyopathy a significant reduction in the NYHA class and a marked improvement in echocardiographic parameters were observed at the end of this period. The variations observed in other groups of patients treated were less conspicuous and not always statistically significant. The results of this study confirm that the association of coenzyme Q10 and conventional therapy may lad to a marked improvement in contractile function and correlated clinical conditions.


[Clinical study of the therapeutic efficacy and tolerance of nimesulide in comparison with a sodium diclofenac in the treatment of acute superficial thrombophlebitis]. The efficacy and tolerability of nimesulide were assessed in a randomized study versus diclofenac sodium in the treatment of 50 patients affected with acute superficial thrombophlebitis. Both drugs, administered in a dose of 1 tablet b.i.d. for 10 days, evidenced a prompt and effective analgesic and anti-inflammatory activity. Particularly, the tolerability of nimesulide was excellent.


[Usefulness of temporal bicameral stimulation in the interruption of refractory ventricular tachycardia]. The occurrence of sustained ventricular tachycardia with worsening hemodynamic performance in patients with ischemic heart disease can represent a critical event when the arrhythmia, refractory to antiarrhythmic drugs, recurs after D.C. shock. In this case temporary DDD pacing can be a reliable alternative treatment.


Clinical prosthodontic management of a new implant system. Just prior to the advent of the branemark implant, the Harvard consensus on implantology condemned all maxillary implants. While implant utilization has skyrocketed in the last few years integration of implants in the maxilla is a persistent problem and even the branemark implant enjoys a lower success rate in this bone. These observations underscore the higher failure rate of the maxillary implant and suggest the need for development of a new implant design configuration that would favour long term successful integration despite the attenuated maxillary attributes. Such is the intent of the ostial implant. The basic considerations concerning this device, its bioengineering, experimental performance and clinical trials are discussed elsewhere. The purpose of this paper is to describe clinical prosthodontic applications of this implant system.


Tactile sensibility of sapphire endosseous dental implants. Experiments are described in which the tactile thresholds of sapphire (bioceram) endosseous implants were measured and compared with those of natural teeth. The effects of local anaesthesia were determined in an attempt to localize the mechanoreceptors involved. The thresholds of the implants were higher than those of natural teeth but lower than those of another type of implant (alumina tubingen) examined in another study. The results of local anaesthesia testing indicated that the sensory receptors involved were located in the connective tissues around the implant.


[Case management. The nursing business of care or cost]. Less money spent on health services, cost-effectiveness, better productivity and more efficiency are some of the driving forces of contemporary "neo-liberalism" and political trends. How can nursing services and the profession's human values adapt in this difficult context? The authors describe the newest modality of patient care delivery system: nursing case management. They examine the factors and assumptions that led up to its development and point out the validity of asking some serious questions before embarking on the euphoria of case management.


Combined use of bone graft and Biotes fixtures in the treatment of the severely resorbed upper jaws. Horse-shoe shaped bone grafts from the hip together with biotes self-tapping fixtures were used to rehabilitate patients with extremely resorbed upper jaws. Our experience and results from the 10 first consecutive case have been analyzed to form the base for further use of the method. We have lost eight fixtures out of 57 so far. Surgical complications with exposure of the bone transplant have occurred in three patients. A surprisingly good recovery from the hip has been seen in all of the patients. Certain technical precautions such as construction of a splint in the dentulous or partially dentulous jaw to prevent occlusal trauma towards the transplant have been made to avoid complications such as rupture of the mucosal flap. The method should be used with great care and the case meticulously chosen to avoid individuals who do not have the right motivation for the long-lasting and demanding surgical and prosthetic procedures. The combined use of implants and transplants should not be used routinely until a long-term evaluation of the method has been made to minimize potential drawbacks.


The management of soft tissue defects using the "gingival shaving" technique. A simple, effective technique is described for the correction of unfavourable gingival contour during post-surgical or pre-prosthetic procedures. Termed the "gingival shaving technique", it is conducted with high-speed course diamond burs. Results are relatively rapid and predictable, especially in cases where esthetics are most desirable. The technique can be performed by the periodontist or prosthodontist, and can be repeated until satisfactory gingival contour is achieved. Case selection, careful preparation, and post treatment management and care are essential for success.


Ludwig's angina: a place for steroid therapy in its management? Ludwig's angina is an uncommon but potentially fatal condition which presents as a hard swelling of the floor of the mouth. It spreads rapidly as a gangrenous process that may cause death through local airway obstruction. Ludwig's angina carried a 54% mortality rate in the preantibiotic era which has now been reduced to approximately 4%. Diagnosis is based on history and clinical observation. Currently described treatment involves protecting the airway and managing the infection with antibiotics and surgical drainage when indicated.


The risk of transmission of human immunodeficiency virus in dental practice. After a decade of study of the acquired immunodeficiency syndrome (AIDS) there is evidence to address the concerns of dental staff about possible transmission of human immunodeficiency virus (HIV). This paper reviews that evidence which demonstrates an extremely low risk of transmission of HIV to staff and patients. Only a few isolated cases have implicated transmission during dental practice, however, there are no proven cases where seroconversion has been demonstrated in relation to an exposure during dental treatment.


Immediate placement of osseointegrated dental implants into extraction sockets: advantages and case reports. Osseointegrated dental implants have proven to be predictably successful when appropriate guidelines are followed. The technique as outlined by bränemark includes a post-extraction period of up to 12 months in order to allow for bone healing. This delay, combined with ridge resorption following extraction, may contribute to several problems. Insufficient available bone for ideal implant placement and prolonged treatment time are two common difficulties. Recently, several investigators have reported immediate placement of dental implants into extraction sockets achieving excellent results while, at the same time, minimizing or eliminating the above-mentioned difficulties. This paper will discuss the technique of immediate placement of osseointegrated dental implants into extraction sockets and its potential advantages. A future article will detail surgically-related difficulties with this technique.


Modern concepts in endodontics. Part 1. Diagnosis. Diagnosis is the basic procedure from which further endodontic treatment decisions flow. Although we still use diagnostic tools which differ little from those of 50 years ago, our understanding and interpretation of their results has been slowly changing. As an example, we now believe that the painful responses to hot and cold occur via different a delta and C fibre pathways, involving changes in intra pulpal pressure and neuropeptides such as VIP and SP. As treatment planning is becoming more sophisticated and treatment modalities and options are expanding, correct endodontic diagnosis is even more important in the new age of rising patient expectations and ever-increasing legal complexities. Endodontists are frequently called upon to deal with difficult diagnostic situations, or manage situations of misdiagnosis where treatment has been initiated but the original chief complaint mysteriously persists. In the future, new exciting techniques such as pulse oximetry or laser doppler analysis may be clinically available as endodontic diagnostic aids. This paper will try and cover some of the broader concepts involved in correctly diagnosing a patient's chief complaint.


Functional properties of cloned melanogenic proteins. Several genes critical to the regulation of melanin production in mammals have recently been cloned and characterized. They map to the albino, brown, and slaty loci in mice, and encode proteins with similar structures and features, but with distinct catalytic capacities. The albino locus encodes tyrosinase, an enzyme with three distinct catalytic activities--tyrosine hydroxylase, 3,4-dihydroxyphenylalanine (DOPA) oxidase and DHI (5,6-dihydroxyindole) oxidase. The brown locus encodes TRP-1 (tyrosinase-related protein-1), which has the same, but greatly reduced, catalytic potential. The slaty locus encodes TRP-2, another tyrosinase related-protein, which has DOPAchrome tautomerase activity. In this study we have examined the enzymatic interactions of these proteins, and their regulation by a novel melanogenic inhibitor. We observed that tyrosinase activity is more stable in the presence of TRP-1 and/or TRP-2, but that the catalytic function of TRP-2 is not affected by the presence of TRP-1 or tyrosinase. Other factors also may influence melanogenesis and a unique melanogenic inhibitor suppresses tyrosinase and DOPAchrome tautomerase activities, but does not affect the spontaneous rate of DOPAchrome decarboxylation to DHI. The results demonstrate the catalytic functions of these proteins and how they stably interact within a melanogenic complex in the melanosome to regulate the quantity and quality of melanin synthesized by the melanocyte.


Molecular characterization of the p(un) allele of the mouse pink-eyed dilution locus. The mouse pink-eyed dilution locus, p, located on chromosome 7, mediates coat and eye color. The human correlate of this gene may underlie some forms of tyrosinase-positive oculocutaneous albinism. Mutations at the p locus result in a reduction in pigmentation of the eyes and coat. Although most mutant p alleles (including all spontaneous mutations) affect only pigmentation, several mutant alleles (all radiation induced) are also associated with a variety of other phenotypes. We have focused our attention on the p(un) mutant allele, a spontaneous mutation, exhibiting one of the highest reversion frequencies reported for a mammalian mutation. Using a new technique, genome scanning, we have cloned fragments of genomic DNA from the p locus that are associated with a DNA duplication in p(un) DNA. These fragments can now be used to locate the p gene-encoding sequences and aid in the molecular characterization of complex mutant p alleles.


Analysis of mutations in the copper B binding region associated with type I (tyrosinase-related) oculocutaneous albinism. Mutations of the tyrosinase gene are responsible for type I (tyrosinase-related) oculocutaneous albinism (OCA), an autosomal recessive genetic syndrome with a broad phenotypic spectrum. Mutant tyrosinase alleles can be associated with no melanin synthesis (I-A, tyrosinase-negative OCA), small to moderate amounts of melanin (I-B, yellow OCA) or unusual pigment patterns (I-TS, temperature-sensitive OCA). A total of 26 mutations of this gene have been described in type I OCA. Analysis of all known mis-sense mutations (n = 17) shows that most cluster in three areas of the coding region. Two clusters involve the copper A or copper B binding sites and may disrupt the metal ion-protein interaction necessary for enzyme function and the third cluster is located in exon I. Computer modeling of the secondary structure of the copper binding regions based on homology with the known crystal structure of hemocyanin show that they both consist of two alpha helices containing three histidine ligands that complex to a single copper atom. Mutations in the copper B binding region lie in the region between the two alpha helices that consists of a loop structure. These mutations may affect tyrosinase activity by either altering the position of the alpha helical domains and thus preventing proper copper binding to the histidine ligands, or affecting a catalytic or substrate binding site located between the two alpha helical domains.


Mutations of the tyrosinase gene in oculocutaneous albinism. Since our first report showing that the phenotype of tyrosinase-negative or type IA oculocutaneous albinism (OCA) is a consequence of a mutation in the tyrosinase gene (Tomita et al., Biochem. Biophys. Res. Commun., 164:990-996, 1989), a number of mutations were found in the tyrosinase gene of OCA patients. However, to establish the molecular basis of OCA in each patient, we must carry out several important experiments as summarized here. First, we should confirm that the cloned or amplified genomic DNA segments are not derived from the pseudogene or related gene. It should be noted that the putative tyrosinase pseudogene contains the sequence almost identical to exons 4 and 5, including their exon/intron boundaries of the authentic tyrosinase gene. Thus, the mutations, detected in exon 4 or 5 amplified from genomic DNA, must be carefully analyzed to exclude a possibility that the mutation is located in the pseudogene. Second, it is of significance to confirm the promoter activity of the patients' tyrosinase gene. Accordingly, we established the cell-free transcription system derived from melanoma cells where the cloned tyrosinase gene is faithfully transcribed. Finally, transient expression assay of mutant tyrosinase is invaluable to conclude that OCA phenotypes are associated with the mutant tyrosinase alleles. I also discuss the implications of a cluster of mutation sites in exon 1 coding for the amino-terminus of tyrosinase.


Phylogeny of regulatory regions of vertebrate tyrosinase genes. Highly homologous DNA elements were found to be shared by the upstream regions of the mouse tyrosinase and tyrosinase related protein (TRP-1) genes. Several nuclear proteins were shown to bind to both of these upstream regions. Shared homologous DNA elements were also found in the 5' flanking sequences of Japanese quail and snapping turtle tyrosinase genes. Shared homologous nucleotide sequences were found to be scattered like an archipelago in the 5' upstream regions of mouse and human tyrosinase genes. Comparisons between Japanese quail and snapping turtle tyrosinase genes gave similar results. On the contrary, mammalian (mouse and human) and nonmammalian (quail and snapping turtle) tyrosinase genes did not show significant homology in their 5' upstream regions. In contrast, coding sequences in the first exons of vertebrate tyrosinase genes and their deduced amino acid sequences were found to be highly conserved except for their putative leader sequence-coding regions.


Molecular characterization of the mouse tyrosinase gene: pigment cell-specific expression in transgenic mice. Tyrosinase is the key enzyme in melanin synthesis, and is expressed in the pigment epithelium of the retina, a cell layer derived from the optic cup; and in neural crest-derived melanocytes of skin, hair follicle, choroid, and iris. The tyrosinase gene has been cloned and shown to map to the well-characterized c-locus (albino locus) of the mouse. Subsequent studies demonstrated that a functional tyrosinase minigene was able to rescue the albino phenotype in transgenic mice. The transgene was expressed in a cell type-specific manner in skin and eye. During development of the mouse, the tyrosinase gene is expressed in the pigment epithelium of the retina as early as day 10.5 of gestation. In the hair follicle, tyrosinase gene expression is detected from day 16.5 onwards. This cell-type-specific expression is largely reproduced in transgenic mice. Our results suggest that sequences in the immediate vicinity of the mouse tyrosinase gene are sufficient to provide cell type-specificity and developmental regulation in melanocytes and the pigment epithelium.


Expression of tyrosinase gene in transgenic albino mice: the heritable patterned coat colors. To elucidate the regulatory mechanism for tyrosinase gene expression in vivo, we microinjected a mouse tyrosinase minigene, mg-Tyrs-J, into the fertilized eggs of BALB/c albino mice. As a result, we obtained six pigmented founder mice that exhibited non-standard coat color variations as well as the wild-type phenotype. These founder mice were subsequently crossed with BALB/c albino mice to establish the transgenic lines. As a consequence, two primary lines and five sublines have been obtained from four of the six founder mice. We found that not only uniformly pigmented phenotypes but also patterned phenotypes were inherited by their descendants. The possible underlying mechanism of the patterned phenotypes is discussed.


The expression of mouse tyrosinase in chick cells in vitro and in vivo when controlled by a constitutive promoter. Virally introduced mouse tyrosinase expression was checked both in vitro and in vivo in chicken cells and tissues. The results indicate that a constitutive promoter is able to express mouse tyrosinase in a variety of cells and tissues both in vitro and in vivo. Tyrosinase expression is marked by pigment production in situ, which is visible at macroscopic as well as microscopic levels without the use of substrates. It is concluded that tyrosinase can be a valuable marker for tracking gene insertion since it is spontaneously expressed. The expression of tyrosinase in some cells and tissues has a detrimental effect, however, and should be controlled by tissue-specific promoters.