Classical Hodgkin and Reed-Sternberg cells demonstrate a non-clonal immature B lymphoid lineage: evidence from a single cell assay and in situ hybridization

Hodgkin and Reed-Sternberg (H & RS) cells are generally considered to be the neoplastic cells of Hodgkin's disease (HD), however such cells are only found in a minority of the lesions. Recently in a few studies on HD, the clonality of H & RS cells was examined, using a single-cell polymerase chain reaction (PCR) examination. To clarify the lineage and clonality of H & RS cells, we performed single cell PCR and in situ hybridization (ISH), and nine cases of classical HD were thus studied. By ISH, the immunoglobulin J chain, and the kappa and lambda light chain were rarely expressed in the H & RS cells, however, no T-cell markers could be detected. The expression of the recombination activating genes (RAG-1, 2) could be determined in the H & RS cells. We isolated CD30+ H & RS cells, CD3 + T cells and CD20 + B cells from suspended materials using a mechanical sorter. We performed single cell PCR in a sorted individual cell, to amplify the complementarity determining region of the Ig heavy chain (IgH) gene and T-cell receptor gamma chain (TCR gamma) gene. In all cases, TCR gamma could be frequently amplified in the T cells, but was only rarely amplified in the H & RS and B cells. In contrast, the IgH was frequently amplified in the H & RS and B cells, but not in the T cells. In addition, the PCR production of the H & RS cells all showed different lengths. The results therefore support the polyclonal nature and immature B lymphoid cell origin of H & RS cells.

Umbilical vein endothelial cells are an important source of c-kit and stem cell factor which regulate the proliferation of haemopoietic progenitor cells

The expression and production of c-kit and its ligand, stem cell factor (SCF), in cord blood and neonates were studied. Serum SCF levels were significantly higher in cord blood, neonates aged 1-30 d, and in 4-month-old infants than in the maternal serum (P < 0.01). SCF levels decreased in children from 7 months to 15 years of age (P < 0.01). The serum soluble c-kit levels were significantly higher in cord (P < 0.01) and neonatal blood (P < 0.05) than in the maternal blood. SCF and c-kit levels in placental tissue homogenates and the culture media of decidual cells and trophoblasts were low. To determine the sites of high SCF and c-kit production in cord blood and in early neonates. SCF and c-kit mRNA expression was analysed in various tissues by polymerase chain reaction. High SCF mRNA expression was observed in human umbilical vein endothelial cells (HUVEC). Moderate c-kit mRNA expression was detected in HUVEC, the bone marrow, and cord blood. These findings suggest that endothelial cells mainly produce the SCF in cord blood and in early neonates. To confirm the role of endothelial cells in haemopoiesis, colony-forming assays were performed in the presence of HUVEC culture media, which induced the formation of high numbers of granulocyte and erythroid colonies in cord blood. IL-3, IL-6 and SCF levels were elevated in the media. Our findings suggest that endothelial cells have an important role in the maintenance and proliferation of progenitor cells in neonatal blood via the interaction of c-kit and SCF with other factors. The ex vivo expansion of cord progenitor cells in the presence of endothelial cells needs to be investigated further.

[A case of acute disseminated encephalomyelitis (ADEM) associated with demyelinating peripheral neuropathy]

A 41-year-old man had common cold on April 10, 1991. Five days after this illness he developed fever, dysarthria, visual field impairment, gait disturbance and consciousness disturbance followed. On admission in another hospital, cerebrospinal fluid showed 341/mm3 cells (303 mononuclear cells, 33 polynuclear cells, 5 red cells), protein of 238 mg/dl, and sugar of 59 mg/dl. One month later, the neurological examinations revealed flaccid paraparesis, decreased deep tendon reflexes in the lower extremities, bilateral positive Babinski and Chaddock reflexes, positive Beevor sign, stocking type superficial sensory disturbance, diminished vibration sense in the lower extremities and neurogenic bladder. Eight months later, he improved to be able to walk by himself, but decreased Achilles tendon reflexes, bilateral positive Babinski and Chaddock reflexes and paresthesia over both feet were noted neurologically. Nerve conduction study revealed reduced conduction velocities at tibialis anterior nerves, sural nerves and no response on both deep peroneal nerves. A 1 micron thick epon section of a biopsied sural nerve with toluidine blue stain showed a decreased number of myelinated fibers (6394/mm2) with many thinly myelinated fibers and Renaut bodies. There was no edema nor cell infiltration. Electronmicroscopical findings of their ultrathin sections showed many collagen pockets, denervated Schwann cell clustering and a few onion bulb formations. Teased fiber preparations suggested segmental demyelination and remyelination in many fibers. This case could be regarded as a case of ADEM associated with demyelinating peripheral neuropathy, and the possibility of the simultaneous demyelinating process in the central and peripheral nervous system was discussed.

Nodular lymphoid hyperplasia in the lung

We describe an immunocompetent adult patient presenting with cough and hemoptysis who was found to have a pulmonary mass localized to the right upper lobe. Lobectomy was performed and pathological examination revealed nodular lymphoid hyperplasia (pseudolymphoma) of the bronchus-associated lymphoid tissue.

Antineutrophil cytoplasmic antibodies and the optic-spinal form of multiple sclerosis in Japan

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Maternal and zygotic expression of mRNA for S-adenosylmethionine decarboxylase and its relevance to the unique polyamine composition in Xenopus oocytes and embryos

From Xenopus tailbud cDNA library, we isolated the cDNA for S-adenosylmethionine decarboxylase (SAMDC), an enzyme which provides putrescine and spermidine with the aminopropyl group to form spermidine and spermine, respectively. The cDNA coded for 335 amino acids whose sequence had high homology (ca. 83%) to other vertebrate SAMDCs, preserving the sequences reportedly essential for enzyme activity, proenzyme processing, and putrescine stimulation of the enzyme activity. Northern blot analysis showed one major mRNA signal of ca. 3.5 kb, with a minor signal of ca 2.0 kb which may probably be due to cross-hybridization. In oocytes the SAMDC mRNA occurred from stage I, and its amount peaked at stage II, then gradually decreased from stage III to VI. The decreased level of the mRNA was maintained during oocyte maturation, further decreased from the cleavage to early neurula stage, and then increased greatly due to the zygotic expression during late neurula stages (stage 21-25), reaching a plateau level at the late tailbud stage (stage 28). Enzyme assays showed that the changing level of the SAMDC mRNA was reflected in the level of the functional enzyme, suggesting strongly that the zygotic expression of the mRNA leads to a large increase in the amount of SAMDC, albeit in the pre-neurula embryo the amount of the enzyme is very small. We found that the relative composition of polyamines is the eukaryote-type (high-level spermine) at the beginning of oogenesis, but it changes to the prokaryote-type, or more appropriately Escherichia coli-type (high-level putrescine but background level spermine) during oocyte maturation, and remains E. coli-type throughout embryogenesis. We assume that the E. coli-type polyamine composition is a necessary factor for the normal embryogenic development in Xenopus and its maintenance, especially that in pre-neurula stages, can be explained by the low level of both SAMDC mRNA and SAMDC.

[MRI changes in spontaneous intracranial hypotension]

We report MRI changes in a spontaneous intracranial hypotension(SIH). The patient was 29-year-old woman, who developed headaches in upright position, nausea, and vomiting preceded by pressure feeling of ears. Neurological examination was unremarkable except for hyperreflexia in the lower extremities. Lumbar punctures revealed very low opening pressure, a mild elevated CSF protein and a mild pleocytosis. No evidence of underlying systemic or neoplastic diseases was noted. The brain and cervical MRI showed diffuse and continuous pachymeningeal enhancement with gadolinium. Her symptoms gradually improved within two months without any treatment, and follow-up MRI showed resolution of the abnormalities within five months. The dural enhancement with gadolinium seen in the SIH should be kept in mind in case of hypertrophic pachymeningitis of unknown etiology, and be differentiated from such diseases as hypertrophic pachymeningitis associated with infectious, neoplastic diseases or sarcoidosis.

[Clinical study on urinary cytology in renal pelvic and ureteral tumors]

We analyzed the urinary cytology of 126 patients with renal pelvic and ureteral cancer who were initially treated during the last 10 years. Cytological specimens were stained by the Papanicolaou techniques. Urinary cytology was classified according to the Papanicolaou's classification. Classes IV and V were defined as positive. The cytologic findings were compared with the grade, shape, size, number and stage of tumors. The positive rates were 49.2% in renal pelvic and ureteral cancers. Higher positive rates were observed in high grade, non-papillary and large (> or = 3 cm) tumors. No correlation existed among the positive rates and number or stage of the tumor.

Identification of a cDNA encoding a thiazide-sensitive sodium-chloride cotransporter from the human and its mRNA expression in various tissues

We report here the identification of a cDNA encoding a human thiazide-sensitive sodium-chloride cotransporter (hTSC) using a PCR-based method. The homology of the hTSC with rat TSC (rTSC) and rat bumetanide-sensitive sodium-potassium-chloride cotransporter (rBSC) was 86% and 64%, respectively, at the nucleotide level, and 92% and 61%, respectively, at the amino acid level. Using fluorescence in situ hybridization (FISH), the hTSC gene has been mapped to chromosome 16q13. Northern blot analysis using polyA+RNA from various human tissues, revealed a major 4.5 kb transcript and a minor 6.5 kb specifically in the kidney, but low level of expression was also observed in small intestine, placenta, prostate, colon, and spleen.

Syringomyelia as a cause of body hypertrophy

BACKGROUND

Among 26 patients with communicating syringomyelia who came to our out-patient clinic from April, 1989, to March, 1995, three (11.5%) had hypertrophy in limbs, hands, or feet. One had crossed hypertrophy. We considered the possibility that syringomyelia caused body hypertrophy.

METHODS

We searched MEDLINE for articles which mention body asymmetry or hypertrophy, and examined the findings in our own patients.

FINDINGS

The site of hypertrophy in our three patients coincided with the site of the neurological and magnetic resonance imaging findings. In addition, the horizontal and vertical location of the syrinx corresponded with the site of all four hypertrophic limbs. We located ten articles in which a diagnosis of syringomyelia was made, and five in which other diagnoses were made.

INTERPRETATION

From studying our patients as well as those previously reported, we speculate that some types of body hypertrophy are due to damage, accompanied by stimulation, of the sympathetic neurons in the ipsilateral lateral horn of the spinal cord. Although there are many causes of hypertrophy, we suggest that the possibility of syringomyelia be investigated in patients with body hypertrophy, especially in those with any accompanying neurological abnormality.

[A case of chronic bromvalerylurea intoxication with episodic neurological manifestations such as optic neuropathy ophthalmoplegia and ataxia]

A 28-year-old man presented with a bilateral visual loss of acute onset, and was diagnosed as having optic neuropathy by an ophthalmologist. It disappeared spontaneously within 2 months. A visual loss at the left side relapsed ten months later, followed by a dysarthria, horizontal defective saccade, ataxia, and mild weakness of four extremities, which also subsided within one month only by multi-vitamin therapy. These signs recurred episodically with characteristic clinical features of dysarthria, horizontal ophthalmoplegia, defective saccade, ataxia, and weakness, during the next year. Clinical features mimicked those of various neurological disorders, especially multiple sclerosis, Wernicke encephalopathy, brainstem encephalitis, Fisher syndrome, disorders of amino acid metabolism and episodic ataxia. Tablets of bromvalerylurea were incidentally found at the bedside and bromides were detected in his sera. Drugs containing bromides are now easily available without prescription, so we should keep the intoxications of those drugs in mind in facing undiagnosed patients with various episodic neurological symptoms.

Random suppression of T cells that bear specific T cell receptor V beta sequences in adult T cell leukemia/lymphoma (ATLL) patients at each clinical stage: carrier, smoldering, chronic, and acute

Human T cell leukemia virus type I (HTLV-I) is associated with adult T cell leukemia/lymphoma (ATLL), which is well known as a T cell malignancy. In order to clarify whether HTLV-I plays a role as a virus-encoded superantigen in the neoplastic process, we examined the TCR V beta families in the peripheral blood at four different clinical stages: carrier, smoldering leukemia, chronic leukemia, and acute leukemia. An increased number of CD4 T cells was found in each of the four clinical stages. However, we found neither uniform specific losses nor uniform clonal expansion of particular TCR V beta gene families in any case from the four clinical stages. However, a suppression of the random TCR V beta families was found. Our data did not therefore directly suggest the existence of a common superantigen model of HTLV-I which induces an increase in CD4 T cells. The random suppression in the TCR V beta repertoire is most likely caused by the influence of HTLV-I neoplastic pathogenesis rather than by virus-encoded superantigens. In the patients with acute leukemia, one or two families of the V beta repertoires were very strongly expressed, while in chronic leukemia, no such repertoire of strong expression was observed. The immunological reaction of the hosts might thus be different between the above described groups.

Local increase in polymorphonuclear leukocyte elastase is associated with tumor invasiveness in non-small cell lung cancer

The production of tumor cell proteases is implicated in tumor cell invasion and metastasis. To determine whether lung cancer cells can produce polymorphonuclear leukocyte elastase (PMN-E), we measured the concentration of immunoreactive (ir)-PMN-E in the conditioned medium of seven lines of non-small cell lung cancer cells, EBC-1, LC-1sq, LK-2, A-549, PC-3, RERF-LC-MS, and RERF-LC-OK, and three normal lung epithelial cell lines, CCD-8Lu, WI-1003, and LL-24, by using a recently developed enzyme immunoassay (EIA). We measured the concentration of ir-PMN-E in extracts of 40 non-small cell lung cancers, and evaluated its association with the clinicopathologic findings in these patients. The ir-PMN-E level in the culture medium increased with time in six of the seven lines of lung cancer cells; the exception was PC-3. No detectable ir-PMN-E was secreted into the culture medium of the three lines of normal lung epithelial cells. The ir-PMN-E was detected in tissue extracts from 34 to 40 specimens at concentrations ranging from 0.11 to 15.5 micrograms/100 mg of protein. When 40 specimens of lung cancer were categorized by clinical stage of disease, the ir-PMN-E concentration was significantly higher in stage IIIB vs stages I, II, or IIIA. Similarly, the ir-PMN-E concentration was significantly higher in stage IIIA than in stage I. Evaluation of correlations between the ir-PMN-E concentration and patient characteristics showed that the ir-PMN-E level was significantly higher in T3 and T4 tumors than in T1 or T2 tumors. Analysis of prognostic factors in a group of 101 patients with non-small cell lung cancer demonstrated that those with high ir-PMN-E had a significantly shorter overall survival vs those with a low ir-PMN-E at the cutoff point of 3.5 micrograms/100 mg of protein. Multivariate analysis showed that ir-PMN-E was a significant porgnostic factor for early death (hazard ratio, 4.04; 95% confidence interval, 1.65 to 9.95) (p = 0.005), suggesting it was an independent marker for prognosis. Results suggest that the local production of PMN-E may be involved in the tumor invasion associated with a poor prognosis in patients with non-small cell lung cancer.

[What is brain's senility?]

Japan is the nation of the highest longevity in the world, average length of life being 76.57 years old for man and 82.98 for woman in 1994, according to the Ministry of Health and Welfare of Japan. How to cope with normal or abnormal senility is the matter of utmost interest at present time. Therefore, this symposium was very important, and was open not only for physicians, but for citizens. The five expert lecturers made the excellent presentations on these difficult topics from basic to clinical standpoints. The participants were all impressed by these up-to-date talks and discussions throughout the sessions.

A 1.6-Mb P1-based physical map of the Down syndrome region on chromosome 21

The Down syndrome (DS) region on chromosome 21, which is responsible for the main features of DS such as characteristic facial features, a congenital heart defect, and mental retardation, has been defined by molecular analysis of DS patients with partial trisomy 21. The 2. 5-Mb region around the marker D21S55 between D21S17 and ERG in 21q22 is thought to be important, although contributions of other regions cannot be excluded. In this region, we focused on a 1.6-Mb region between a NotI site, LA68 (D21S396, which is mapped distal to D21S17) and ERG, because analysis of a Japanese DS family with partial trisomy 21 revealed that the proximal border of its triplicated region was distal to LA68. We constructed P1 contigs with 46 P1 clones covering more than 95% of the 1.6-Mb region. A high-resolution restriction map using BamHI was also constructed for more detailed analysis. Our P1 contig map supplements other physical maps previously reported and provides useful materials for further analysis including gene isolation and sequencing of the DS region.

Prevalence of Parkinson's disease in Hokkaido, the northernmost island of Japan

The prevalence of Parkinson's disease (PD) was investigated in Hokkaido, the northernmost island of Japan. A pilot case-finding study was carried out to estimate the prevalence in the entire island of Hokkaido (population = 5,643,647) initially, then we surveyed the prevalence at one of the smaller cities, Iwamizawa City (population = 80,417). We ascertained 5,342 cases with PD in Hokkaido and 77 cases in Iwamizawa City, estimating the crude prevalence of 94.7/100,000 in Hokkaido (June 30, 1993) and 95.8/100,000 in Iwamizawa City (April 1, 1994), respectively. We calculated that the crude prevalence rate of PD in Japan in currently close to 100/100,000, but the age-adjusted prevalence is still low, compared with those in Europe and North America.

Detection of human T-lymphotropic virus type-I DNA and mRNA in the lymph nodes; using polymerase chain reaction in situ hybridization (PCR/ISH) and reverse transcription (RT-PCR/ISH)

To examine the relationship between human T-lymphotrophic virus type I (HTLV-I) proviral DNA and its expression in the lymph nodes, HTLV-I DNA and tax/rex mRDA were directly amplified by polymerase chain reaction in situ hybridization (PCR/ISH), and reverse transcription (RT)-PCR/ISH [RT-PCR/ISH]. We studied 24 lymph nodes from patients with adult T-cell leukemia/lymphoma (ATLL), incipient ATLL (I-ATLL), and HTLV-I associated lymphadenitis dermatopathic type (HAL-D) and enlarged paracortical type (HAL-EP). In ATLL, 40-60% of the nucleated cells were positive for for HTLV-I proviral DNA by PCR/ISH, while in I-ATLL and HAL, respectively 5-20% and less than 1-5% of cells were positive. The number of mRNA expressing cells was smaller than that of the proviral DNA-positive cells. The mRNA-expressing cells varied in number among the ATLL and I-ATLL cases, while they were only rarely observed in HAL-D and HAL-EP. These results show that HTLV-I infection and activation might increase with malignant transformation of the target T helper cells.

Aerosolized and instilled surfactant therapies for acute lung injury caused by intratracheal endotoxin in rats

OBJECTIVE

To compare the effects of surfactant replacement by aerosol inhalation and bolus instillation on acute lung injury caused by the intratracheal injection of endotoxin in rats.

DESIGN

Prospective, randomized study.

SETTING

University Laboratory.

SUBJECTS

Male Wistar rats weighing 368 +/- 31 (SD) g.

INTERVENTIONS

Escherichia coli endotoxin (57 +/- 20 mg/kg) was injected into the tracheas of 36 anesthetized and mechanically ventilated rats (FIO of 1.0). When the PaO2 had decreased to <200 torr (<26.7 kPa), the rats were randomly assigned to one of three groups: a control group (n=12)given no material; a bolus group (n=12) given a modified natural surfactant suspension (100 mg/kg in 2.0 mL/kg saline) by bolus instillation into the trachea; and an aerosol group (n=12) given surfactant aerosolized with an ultra-sonic nebulizer for 60 mins.

MEASUREMENTS AND MAIN RESULTS

Bolus instillation transiently decreased the mean blood pressure by approximately 30%. However, aerosol inhalation did not. The PaO2 values of the control group remained <90 torr (<12.0 kPa) until the end of the experiment (180 mins). In contrast, the PaO2 of the bolus group increased to 387 +/- 134 torr (51.6 +/- 17.9 kPa; p<.05 vs. other groups) 15 mins after surfactant replacement, and remained at approximately 400 torr (approximately 53.3 kPa) throughout the experiment. The PaO2 values of the aerosol group increased slowly, peaked at 240 +/- 109 torr (32.0 +/- 14.5 kPa; p<.05 vs. the control group) 60 mins after the start of surfactant replacement, and remained at approximately 200 torr (approximately 26.7 kPa).

CONCLUSIONS

Bolus instillation was superior to aerosol inhalation concerning maximum efficacy, the rapid onset of therapeutic effects, and the necessary dose of surfactant. However, aerosol that does not cause hypotension may be of use in the treatment of adult respiratory distress syndrome in patients with circulatory instability.

Complementary DNA cloning and sequencing of rat enteropeptidase and tissue distribution of its mRNA

A cDNA clone encoding enteropeptidase (EC 3.4.21.9), a key enzyme for the conversion of trypsinogen to trypsin, was isolated from a rat duodenal mucosa cDNA library. Sequences of the 3585 base pair clone predicted that enteropeptidase is synthesized as a single-chain precursor form, proenteropeptidase, consisting of 1058 amino acid residues with an internal signal sequence (51 residues) and is then processed into the mature enzyme consisting of three different peptide chains, i.e., mini, light and heavy chains, not the previously reported two-chain enzyme. The structure of enteropeptidase is relatively conserved among different species and the rat enteropeptidase is 24 and 39 amino acids longer than the porcine and human ones, respectively. Northern blot analysis of rNAs from normal rat tissues revealed that the enteropeptidase mRNA of around 4.4 kb in size was expressed only in the duodenal mucosa, and high proteolytic activity of the enzyme was detected in the proximal small intestine. Additional analysis of the RNAs by RT-PCR revealed that a low level of the mRNA was also expressed in the other parts of the small intestine, i.e., jejunum and ileum. These results indicate that the biosynthesis of enteropeptidase takes place mainly in the proximal small intestine, the duodenum, and the importance of the region in the physiology of intestinal protein digestion regulated by the enzyme is suggested. Furthermore a faint signal of the mRNA was also detected in the stomach, colon and brain in which the existence of trypsin-like serine proteases were reported. The significance of the low level expression of the gene is unclear, but the potential peptide-processing function of the enzyme in these tissues is also suggested.

Cloning and expression studies of cDNA for a novel Xenopus cadherin (XmN-cadherin), expressed maternally and later neural-specifically in embryogenesis

From a Xenopus tailbud cDNA library, we obtained the cDNA for a novel cadherin which was named as XmN-cadherin (Xenopus maternally expressed neural cadherin). The cDNA consisted of 3690 bp and encoded 922 amino acid residues. XmN-cadherin preserved five extracellular cadherin motifs, a single transmembrane domain, and a cytoplasmic domain, and was closely related by its sequence to R- and N-cadherin. In the adult frog, XmN-cadherin mRNA was detected strongly in ovary, testis, brain, eye, and kidney, and weakly in stomach, and intestine. In the egg, the mRNA occurred as a maternal mRNA at a relatively high level, and its level became very low by the neurula stage, then increased steadily thereafter. Dissection experiments with 8-cell stage and neurula stage embryos revealed that the maternally inherited mRNA was relatively uniformly distributed within the embryo. By a sharp contrast, whole mount in situ hybridization revealed that the zygotically expressed mRNA occurred almost exclusively in neural tissues such as brain, the anterior part of spinal cord, and the optic and otic vesicles. Thus, XmN-cadherin appears to have at least triple functions; it probably contributes in early embryos to cell-type non-specific cell adhesion, but in post-neurula embryos may be responsible for the development and/or maintenance of anterior neural tissues, and may be used in adult frog for the development and/or maintenance of neural, endodermal and reproductive organs.

Clinical features and natural history of spinocerebellar ataxia type 1

SCA1 is a dominant spinocerebellar ataxia (SCA) and a multi-systemic syndrome caused by abnormal expansion of unstable CAG repeat in a novel gene located on chromosome 6p22-p23. We clinically studied 35 Japanese SCA1 patients who were assumed to have come from a common origin. The age at onset ranged from 15-63 years, and significantly correlated with CAG repeat units of mutant alleles. Ataxia was the initial symptom, and the majority of patients had a similar history of signs and symptoms. Nystagmus was at first minimal, later attenuated, and a slow saccade followed. Limb tendon reflexes were mostly hyperactive and depressed with the development of diffuse amyotrophy. The cardinal feature was ataxia-hyperreflexia-late slow saccade syndrome with terminal amyotrophy. Although the phenotype of SCA1 overlaps with those of other dominant SCAs, some facets of the neurological events differ from either SCA2 with ataxia-hyporeflexia-slow saccade syndrome, or early-onset Machado-Joseph disease with dystonia-bradykinesia-spasticity syndrome.

Eight-year follow-up study of bromocriptine monotherapy for Parkinson's disease

An 8-year nationwide study of bromocriptine monotherapy and combination therapy with bromocriptine and levodopa in Parkinson's disease is reported. Fifteen patients were on bromocriptine monotherapy, and 44 patients on bromocriptine combined with levodopa for a certain time during an 8-year period. By judging from Hoehn and Yahr's grading, 4 of the 15 patients in the monotherapy group were in a better condition than before treatment, while 7 cases remained in the same grading, and only 4 showed deterioration. On the other hand, 26 of 44 patients on combination therapy showed more advanced grading at the end of 8 years compared to the stage at the onset of the trial. Maintenance doses of bromocriptine in the two groups were 12-13 mg per day, and levodopa doses were kept at a relatively low level (310-370 mg per day) during this study period. Whether dopamine receptor agonists have neuroprotective effect or not is extremely difficult to prove in human subjects, but this type of long-term follow-up study might give some clues as to these important questions.