Antitumor effect of CPT-11, a camptothecin derivative, on human testicular tumor xenografts in nude mice

OBJECTIVE

The antitumor effect of CPT-11, a camptothecin derivative, on two human testicular embryonal carcinomas (TTSC-2 and TTSC-3) heterotransplanted into-nude mice was studied.

MATERIALS AND METHODS

Tumor-bearing nude mice were given daily intraperitoneal injections of the anticancer drugs in 0.1 ml saline 3 times at 3-day intervals. At the end of the experiments tumors were resected and subjected to light-microscopic observation.

RESULTS

When 10, 30 and 50 mg/kg of CPT-11 was administered to tumor-bearing mice intraperitoneally, the antitumor effect of CPT-11 was observed dose-dependently in both TTSC-2 and TTSC-3. When 30 mg/kg of CPT-11 was administered in combination with CDDP, complete tumor regression was observed in both TTSC-2 and TTSC-3 tumors. Histological findings correlated well with the decrease in tumor volume of treated tumors. No mice died after treatment with CPT-11 in a single-agent and combination chemotherapy.

CONCLUSION

Chemotherapy with CPT-11 was an effective and safe method against human testicular tumors heterotransplanted in nude mice.

Secondary acute monocytic leukemia occurring during the treatment of a testicular germ cell tumor. A case report and review of the literature

Secondary leukemia following chemotherapy or radiotherapy for mediastinal germ cell tumors is a well-described entity. It also may occur in patients with testicular germ cell tumors. We report a case of acute monocytic leukemia occurring in a 44-year-old man who received etoposide-based chemotherapy and radiotherapy for a recurrent, metastatic testicular germ cell tumor. The patient received 14 cycles of systemic chemotherapy for pulmonary and para-aortic lymph node metastases following his initial orchiectomy. The total amount of etoposide this patient received was 6,400 mg/m2. Leukemia occurred 11 years after orchiectomy. A literature review revealed 25 other reported cases of secondary leukemias after treatment for testicular carcinoma. It is not clear whether chemotherapy, radiotherapy or both are responsible for the secondary leukemias seen in these patients.

Fas/APO-1-mediated apoptosis of human renal cell carcinoma

We have investigated the Fas-mediated apoptosis of cultured human renal cell carcinoma OUR-10. OUR-10 cells express Fas antigen on their cell surface and showed apoptotic cell death by stimulation with anti-Fas agonistic antibody. Cell proliferation of OUR-10 was reduced to 62% by the addition of anti-Fas antibody. The cytotoxic effect of anti-Fas antibody on OUR-10 was augmented by the pretreatment of these cells with interferon-gamma, not with interferon-alpha or with interleukin-2. Flow cytometry demonstrated that preculture of Our-10 cells with interferon-gamma increased the cell surface Fas antigen. Immunohistochemical analysis of resected tissues from the patients with renal cancer revealed stronger expression of Fas antigen on the surface of cancer cells than that of normal cells. These data suggest that Fas may be one of the possible targets for a novel approach to human kidney cancer, and the efficiency of this Fas-mediated treatment for kidney cancer could be augmented by the treatment with interferon-gamma.

Independent self-assembly of cadmium-binding alpha-fragment of metallothionein in Escherichia coli without participation of beta-fragment

We examined the independent self-assembly of the alpha- and beta-fragments of human metallothionein (MT) into cadmium-binding conformation in an Escherichia coli expression system, in addition to wild-type MT expression. The expressed alpha-fragment formed independently the structure of a metal-binding cluster without the aid of the beta-fragment. The alpha-fragment and wild-type MT expressed in E.coli were purified and analyzed for their biochemical and spectroscopic properties. The apparent cadmium binding of the alpha-fragment was approximately 12-fold greater than that for the wild-type MT, whereas in other respects the studied biochemical properties were similar. In contrast, we were unable to obtain any independently expressed beta-fragment as the cadmium-binding form in this study. Possible explanations for this phenomenon are discussed.

[An investigation of the factors influencing serum pepsinogen levels--sex, age, smoking, drinking]

BACKGROUND

Until now, the influence of sex, age, smoking, drinking on serum pepsinogen levels has been assessed by single regression analysis. However, the influence of those factors on pepsinogen levels should be assessed exactly by multiple regression analyses.

SUBJECTS AND METHODS

891 subjects were collected from by questionnaire and serum tests. Analyses were done with serum pepsinogen I (PG I), pepsinogen II (PG II) and pepsinogen I/II ratio (PG I/II) as a criterion variable and as categorized explanatory variables, sex, age, current or past smoking habit, and current drinking habit. And analyses are done by Mann-Whitney U test, correlation coefficient, single regression method, multiple regression method.

RESULTS

PG I level is significantly higher in men than in women by Mann-Whitney U test. But the effect of sex factor is not remarkable by multiple regression analyses. PG II level increased and PG I/II level decreased with progression of age by all analyses methods. Current or past smoking elevates PG I level by Mann-Whitney U test, but current smoking dose and past smoking amount showed no dose-dependent associations with PG I level. Current drinking elevates PG I level by Mann-Whitney U test, but current drinking dose showed no dose-dependent associations with PG I. However, the effects of current smoking and current drinking to serum PG levels is not so large by multiple regression analyses.

CONCLUSION

The effects of sex, current smoking and current drinking to serum PG levels are not remarkable by multiple regression analyses. Significantly, PG II level increased and PG I/II level decreased with progression of age. Therefore it may not be necessary to consider the effects of sex, smoking habit and drinking habit when serum pepsinogen levels are used as markers for gastric cancer.

Effect of photic conditioning on blink reflex recovery function in blepharospasm

Patients with blepharospasm may have selective sensitivity to photic stimuli, for their symptoms are often aggravated after exposure to brightness. To investigate the pathophysiology underlying this phenomenon, we compared the effects of electric and photic conditioning on electrically-evoked blink reflex in 21 patients with blepharospasm and 11 age-matched control subjects. With electric conditioning, R1 was facilitated at inter-stimulus intervals (ISIs) of up to 100 ms in both groups. R2 was inhibited at all ISIs longer than 20 ms in the normals, but to a much lesser extent in the patients, suggesting increased excitability of the multi-synaptic reflex pathway. Compared to electric conditioning, photic conditioning was less potent in inhibiting R2 in the normals. In contrast, photic conditioning in the patients produced R2 inhibition as powerful as electric conditioning. These findings indicate that, in patients with blepharospasm, photic input has a relatively more profound inhibitory effect on the test blink reflex than electric conditioning as compared with normal subjects. The greater susceptibility of the brainstem interneurons to photic conditioning in blepharospasm may be related to the clinically-observed light sensitivity.

Binding sites for blood coagulation factor Xa and protein S involving residues 493-506 in factor Va

Inactivation due to cleavage of Factor Va (FVa) at Arg 506 by activated protein C (APC) helps to downregulate blood coagulation. To identify potential functional roles of amino acids near Arg 506, synthetic overlapping pentadecapeptides comprising FVa heavy chain residues 481-525 were tested for their ability to inhibit prothrombin activation by prothrombinase complexes [Factor Xa (FXa):FVa:phospholipids:Ca2+]. The most potent inhibition was observed for peptide VP493 (residues 493-506), with 50% inhibition at 2.5 microM. VP493 also inhibited FXa in plasma in FXa-1-stage clotting assays by 50% at 3 microM. When the C-terminal carboxamide group of VP493 was replaced by a carboxyl group, most prothrombinase inhibitory activity was lost. VP493 preincubated with FXa inhibited prothrombinase with a pattern of mixed inhibition. Homologous peptides from Factor VIII sequences did not inhibit prothrombinase. Affinity-purified antibodies to VP493 inhibited prothrombinase activity and prolonged FXa-1-stage clotting times. VP493 also blocked the ability of protein S to inhibit prothrombinase independently of APC. Immobilized VP493 bound specifically with similar affinity to both FXa and protein S (Kd approximately 40 nM), but did not measurably bind prothrombin or APC. These studies suggest that FVa residues 493-506 contribute to binding sites for both FXa and protein S, providing a rationale for the ability of protein S to negate the protective effect of FXa toward APC cleavage of FVa. Possible loss of this FVa binding site for FXa due to cleavage at Arg 506 by APC may help explain why this cleavage causes 40% decrease in FVa activity and facilitates inactivation of FVa.

Epidermoid cyst of the scrotum: a case report

A 44-year-old male was admitted with the chief complaint of a huge mass in the right scrotum. Computed tomography (CT), magnetic resonance imaging (MRI) and ultrasonography demonstrated a homogeneous lesion in the right testis. Under the diagnosis of right testicular tumor, surgical resection was performed and the right testis itself was found to be essentially normal. The mass contained 500 ml of liquid. The pathologic diagnosis was an epidermoid cyst of the scrotum, a rare disease with only 11 cases reported in Japan.

Papillary carcinoma of the thyroid originating in a thyroglossal cyst. Report of a case and diagnostic criteria

A 34-year-old female with papillary carcinoma of the thyroid originating in a thyroglossal cyst is described. The patient's chief complaint was a submental mass. The mass was 6 x 4 cm, elastic, soft, and smooth-surfaced. CT examination showed high-density areas in part of the interior of the mass. Resection of the mass was attempted with a diagnosis of thyroglossal cyst. Since papillary carcinoma of the thyroid was noted in the cyst by intraoperative frozen section pathological examination, primary carcinoma of the thyroid was suspected, and the thyroid and surrounding areas were examined. Since no abnormalities were noted in the thyroid, the thyroid was preserved. According to the following reasons, the tumor was considered to be primary papillary carcinoma of the thyroid arising in the thyroglossal cyst: (1) Scar formation was noted in the center of the tumor; (2) tumor cells partly infiltrated into the surrounding tissues, and (3) no tumor was noted in the thyroid. A definitive diagnosis of carcinoma arising in the thyroglossal cyst has required confirmation of the absence of carcinoma in the thyroid by total thyroidectomy. In the present case, however, total thyroidectomy was avoided, because no gross pathological changes were observed in the thyroid during the operation. This decision may be controversial both diagnostically and therapeutically, but we consider from our observation of the course that total thyroidectomy is not always necessary.

Case report: portal-systemic encephalopathy due to a congenital extrahepatic portosystemic shunt

We present a case of portal-systemic encephalopathy due to a congenital splenorenal shunt. A 69 year old woman was admitted to hospital because of recurrent episodes of disturbed consciousness. The present episode had begun 3 months prior to admission. Although the patient demonstrated mildly slurred speech, the remainder of her neurological examination was unremarkable. She showed no clinical signs of portal hypertension and her liver function, except for a serum hepaplastin test of 58% and an ICG retention rate of 28% at 15 min, was normal. Her serum ammonium level was 210 micrograms/dL. The venous phase of a superior mesenteric arteriogram revealed a splenorenal shunt and narrowing of the portal vein, which was 4 mm in diameter. The histological findings, demonstrated by a needle liver biopsy specimen, were consistent with mild fibrosis and lymphocytic infiltration. Following the diagnosis of a splenorenal shunt in the absence of liver cirrhosis, ligature of the shunt was performed with a splenectomy. The portal vein pressure after ligature of the shunt rose from 12.5 to 18.8 mmHg. This shunt was thought to be of congenital origin. The high preoperative serum ammonia concentration decreased to the normal range postoperatively and the serum hepaplastin test and ICG retention rate similarly improved postoperatively. A follow-up superior mesenteric arteriogram was performed during the venous phase, demonstrating resolution of the shunt and decreased portal vein narrowing. The patient has suffered no further episodes of disturbed consciousness postoperatively.

[Particle numbers in classified sizes of roadside dust caused by studded tires in the air at different heights from the pavement surface]

Increased use of motor vehicles has produced various risks to human health due to air pollution by noxious gases, heavy metals and roadside dust. Since the late 1970s, the wide spread use of studded tires for cars has caused pavement wear, resulting in not only economic losses, but also roadside air pollution in cold and snowy regions in Japan. The most serious environmental problem in Sapporo, a city with heavy snowfall, in the 1980s, was roadside dust derived from studded tires. The inhabitants suffered from this dust in the early winter and in the early spring when the streets were not covered with snow. To investigate the influence of such roadside dust upon human health, particle numbers in classified sizes of roadside dust were counted after the roadside dust in the air was collected with a device we constructed at 30, 60, 90, 120, 150, and 180 cm above the pavement surface. The results indicated that the concentration of roadside dust in the air did not greatly vary according to the height from the pavement surface. The results also suggested that xenogranuloma, reported in lungs of stray dogs, under roadside dust-pollution conditions such as those examined here, may occur in humans in the future.

Roles of the conserved serines of metallothionein in cadmium binding

The sequence of six amino acid residues -Ser-Cys-Cys-Ser-Cys-Cys- is present in all mammalian metallothionein sequences and has been highly conserved during evolution, although the metallothioneins have divergent primary sequences. To determine whether two serines in the sequence play a crucial role in metal-binding of metallothioneins, a mutant metallothionein with these two serines replaced by leucines was obtained using an Escherichia coli expression system. The expressed protein was analyzed for its chemical and spectroscopic properties. It was confirmed that the mutant metallothionein (MT) bound cadmium through a metal-thiolate complex and that there was no strong difference between the mutant and the wild-type MTs in retaining the metal-binding cluster. However, the metal-binding cluster of the mutant metallothionein was more unstable than that of the wild-type metallothionein. The two conservative serines could play a role in the stability of metal-binding ligands.

Low molecular weight copper-binding protein in the liver of rats given a single and repeated injections of copper

Whether Cu-metallothionein is the sole low molecular weight Cu-binding protein induced in Cu-loaded rat tissues or not is hotly debated, because several investigators reported that Cu-metallothionein did not exist and other Cu-binding proteins were induced in the Cu-loaded rat liver. Investigation by using rats given a single and repeated injections of Cu led us to settle the problem. Cu-metallothionein was identified in the liver of both groups of rats by the purification procedure established in this study. Moreover in the final purification step of Cu-metallothionein, an additional unknown protein which did not belong to the metallothionein group was found only in the rats given repeated Cu injections, and not in the rats given a single Cu injection. The confusion on Cu-metallothionein and other Cu-binding proteins was shown to be caused by inadequate purification of Cu-metallothionein.

Copper replacement of cadmium-binding alpha-fragment of metallothionein expressed in Escherichia coli

Titration studies of Cd-binding alpha-fragment, the carboxyl-terminal half of human metallothionein-2, which was independently expressed in Escherichia coli as a Cd-binding form, with Cu were performed. The Cu saturated alpha-fragment was not obtained when the alpha-fragment incubated with Cu (I), although completely saturated MT with Cu (I) was successfully obtained in the same conditions. The stoichiometry of the alpha-fragment replaced with Cu (I) was Cu 4 and Cd 1. It is considered that the Cu-binding alpha-fragment required the presence of Cd (II) to form a stable structure. Our results could suggest that each fragment was independent in the metal binding processes, e.g. alpha-fragment for Cd-binding.

Relative gold-binding capacity of metallothionein: studies in renal cytosols of gold-injected rats

To determine the gold-binding capacity of metallothionein (MT) in cytosols of gold-injected rats, we examined the relationship between gold contents in cytosols and in MT fraction in rat kidneys. Each rat was injected intraperitoneally once with 0.9% NaCl or gold (5, 10 or 20 mg gold/kg b.w.). The gold contents in kidneys and in MT fraction increased following the injected amount of gold. The distribution profiles of the renal cytosols of gold-injected rats on a Sephadex G-75 column showed that the amount of the increased gold was attributable to the high molecular weight proteins (HP) and the MT fractions. There were close relationships between the gold contents in cytosol and in MT fractions, and between the gold contents in cytosol and in HP fractions. These results demonstrate that 14% of the increased gold in the renal cytosols of gold-injected rats was bound to MT and that 79% of the increased gold was bound to HP. Our results suggest that the role of metallothionein in gold accumulation in kidneys is different from that in zinc accumulation in kidneys.

Structure-activity relationships of dermorphin analogues containing chiral piperazin-2-one and piperazine derivatives

The amide and ester carbonyl groups of four piperazin-2-one derivatives (N,N'-ethylene-bridged dipeptide ethyl esters) constructed from (R)- or (S)-phenylalanine and glycine were reduced with borane-tetrahydrofuran complex to produce the corresponding piperazine derivatives in 70-80% yields. These piperazin-2-one or piperazine derivatives were used as the carboxyl-terminal residues of eight dermorphin analogues (H-tyrosyl-D-alanyl-piperazine derivatives were used as the carboxyl-terminal residues of eight dermorphin analogues (H-tyrosyl-D-alanyl-piperazin-2-one or piperazine derivatives) whose opiate activities were examined in vitro by use of the guinea pig ileum and the mouse vas deferens assays. It was found in the guinea pig ileum assay that the configuration of pheylalanine and the replacement of the piperazin-2-one ring with a piperazine ring are important for enhancing or reducing the opiate activities of these analogues.

Impaired intracellular signal transduction in gastric smooth muscle of diabetic BB/W rats

The pathophysiological mechanisms responsible for diabetic gastroparesis remain unclear. Diabetes mellitus occurs spontaneously in 90% of a partially inbred colony of BB/W rats. This animal model resembles human insulin-dependent diabetes and is suitable for investigating the mechanism of diabetic gastroparesis. Diabetic BB/W rats were killed 6 mo after the onset of diabetes. Muscle contraction experiments and [3H]acetylcholine release studies were performed with muscle strips of the gastric body. Biochemical measurements of inositol trisphosphate (IP3) and protein kinase C (PKC) in gastric muscle were performed to characterize abnormalities of the intracellular signal transduction system in gastric myocytes. Circular muscle contractions in response to direct myogenic stimulants, carbachol (10(-7) - 10 (-3)M) or substance P (10(-7) - 10(-5)M), were significantly impaired in diabetic BB/W rats compared with controls. Similarly, muscle contractions in response to NaF (10 mM), a direct stimulant of G proteins, were also impaired in diabetic BB/W rats. In contrast, muscle contractions in response to KCl (25-75 mM) were similar between control and diabetic BB/W rats, indicating normal voltage-dependent Ca2+ entry in muscle strips obtained from diabetics BB/W rats. [3H]acetylcholine release from gastric myenteric plexus in response to electrical transmural stimulation remained intact in diabetic BB/W rats. In separate studies, we demonstrated that carbachol (10(-6) - 10(-4)M) -induced IP3 responses were significantly reduced in diabetic rats compared with control. In addition, there was also impairment of translocation of PKC in diabetic BB/W rats. These observations indicate that myogenic impairment occurred in diabetic BB/W rats. This resulted from altered intracellular signal transduction involving abnormal IP3 production and PKC translocation.

Metallothionein in the ovaries of laying hens exposed to cadmium

The presence of metallothionein (MT) and its mRNA in the ovaries of laying hens is reported. In laying hens injected with cadmium (Cd), Cd accumulated in the follicle walls of the ovaries not in the follicle yolks. In the follicle walls, (Cd, Zn)-MT and its mRNA were found. This indicates that MT bound to Cd is biosynthesized in the follicle walls. We suggest that MT might play a role in sequestering Cd. On the other hand, zinc (Zn) was found in the follicle walls and yolks in the Cd-treated laying hens. The relationship between Zn and (Cd, Zn)-MT is also discussed.

Disaccharide analysis of human skin glycosaminoglycans in sun-exposed and sun-protected skin of aged people

The total amount of main disaccharide units of skin glycosaminoglycans was compared between sun-exposed (n = 12) and sun-protected skin (n = 14) of aged people using high performance liquid chromatography after labeling with 1-phenyl-3-methyl-5-pyrazolone. The total amount of main disaccharide units in sun-exposed skin was comparable to sun-protected skin presumably due to the diversity of individuals. Consequently, we compared sun-exposed skin with sun-protected skin in identical individuals (n = 6). The total amount of main disaccharide units in sun-exposed skin was significantly greater than that in sun-protected skin (P < 0.05). In addition, the ratio of delta Di-HA (hyaluronic acid, HA)/delta Di-4S (dermatan sulfate, DS) in sun-exposed skin showed a decreasing trend as compared with sun-protected skin in four of six individuals. These results are in agreement with our previous results obtained in animal experiments of photoaging, i.e., hairless mouse skin exposed to repeated UV irradiation showed an increase in total amount of main disaccharide units and a decrease in the ratio of delta Di-HA(HA)/delta Di-4S(DS). We could confirm similar changes in skin glycosaminoglycans both in human and murine photoaging supporting the appropriate rationale for using the hairless mouse as an animal model for photoaging. Again, disaccharide analysis should provide a useful method to examine the biochemical changes of skin glycosaminoglycans in human photoaging.

[A case of pulmonary dirofilariasis]

A 41-year-old man was admitted to the hospital for detailed evaluation of chronic hepatitis C. A nodular shadow (15 x 15 mm) was detected in the left middle lung field on a chest X-ray film. Roentgenologic, cytologic, and bronchial endoscopic examinations resulted in no definitive diagnosis. To rule out a malignant tumor the left lung was partially resected (S6). Histological examination of the resected specimen revealed Dirofilaria worms in a necrotic mass. In most cases of pulmonary dirofilariasis, thoracotomy is done to confirm the diagnosis. Recently, however, antibodies against Dirofilaria have been detected by immunologic methods and have been used to help make the diagnosis in some cases. A less invasive procedure, such as a reliable immunologic test or a technique for thoracoscopic resection, would be very useful in cases of this benign condition.

Abnormal excitability of the corticospinal pathway in patients with amyotrophic lateral sclerosis: a single motor unit study using transcranial magnetic stimulation

The pathophysiology of corticospinal tract degeneration in amyotrophic lateral sclerosis (ALS) was investigated by studying the effect of transcranial magnetic stimulation on discharge characteristics of single motor units during voluntary activation. The motor units were recorded from the first dorsal interosseus muscles of 12 patients with ALS, 14 healthy subjects, 12 patients with upper motor neuron lesions and 9 with pure lower motor neuron diseases. More than 100 magnetic stimuli were delivered over the scalp during minimal muscle contraction. The occurrence of motor unit discharges was plotted in a peristimulus time histogram. An increase in discharge probability at latencies of 20-30 msec, that represents monosynaptic activation (primary peak) was found in normal units. Motor units from ALS patients with short disease durations had significantly increased discharge probabilities in the primary peak (P < 0.001). Motor units from 4 ALS patients with upper motor neuron signs showed double primary peaks: an initial synchronized peak followed by a dispersed peak. The latter was ascribed to a slow corticospinal pathway, which remains undetected or is functionally insignificant in healthy subjects. We conclude that the excitabilities of the surviving corticospinal tract pathways are abnormally increased in ALS, especially in the early stage.