Monoclonal anti-human prostatic acid phosphatase antibodies

Hybrid cell lines producing monoclonal antibodies against human prostatic acid phosphatase (E. C. 3.1.3.2) were prepared by the fusion of mouse myeloma cells with the spleen cells of BALB/c mice and Lewis rats immunized with prostatic acid phosphatase (PAP). Approximately 14% of the hybrid cell microcultures which produced specific antibodies were cloned, and 6 eventually yielded stable cell lines. The monoclonal antibodies produced by these 6 hybridomas were characterized for their isotypes, isoelectric points, concentrations and affinities. The specificity of these monoclonal antibodies was further investigated by radioimmunoassay and immunohistochemical methods. All of the 6 monoclonal antibodies exhibited strict specificity for prostatic acid phosphatase.     

Microcystic adenomas of the pancreas. Report of three cases with two of multicentric origin

Three cases of microcystic adenomas of the pancreas with special reference to multicentric origin are described. The gross features and light microscopic findings were consistent with those described as being microcystic adenomas, but in two cases the gross examination and gelatin-embedded giant slices revealed multiple, isolated development of tumors ranging from submacroscopic nodules to tumors 4.5 cm in diameter. The larger tumors often showed ragged margins with small satellite nodules around the masses. A central fibrolamellar stellate core with centrifugally radiating septation was found in most of the tumor masses, even in the smaller ones. Ultrastructural and immunohistochemical findings revealed a single row of glycogen-rich epithelial cells, but participation of myoepithelial cells was not confirmed. Instead, vimentin-positive cells (pericytes) within the interstitial space incorporated closely with the basal lamina of the cyst wall. This study suggests that a small percentage of microcystic adenomas of the pancreas develop in multiple tumors, and some appear as a single tumor by their confluence.     

Cloning and expression of the gene involved in Sanfilippo B syndrome (mucopolysaccharidosis III B)

Sanfilippo B syndrome is caused by a deficiency of alpha-N- acetylglucosaminidase, a lysosomal enzyme involved in the degradation of heparan sulphate. Accumulation of the substrate in lysosomes results in degeneration of the central nervous system with progressive dementia often combined with hyperactivity and aggressive behaviour. In order to clone the deficient gene, we purified the enzyme from human placenta and obtained amino acid sequence information. Alignment of one of the CNBr generated internal peptides to sequence from the database revealed the chromosomal location of the gene in the 5' upstream flanking region of the gene for 17-beta-hydroxysteroid-dehydrogenase at 17q21.1. The available DNA sequence was used to clone the cDNA coding for alpha-N- acetylglucosaminidase and analyse its gene structure. The gene is fully contained in the 5' upstream flanking region of the gene for 17-beta- hydroxysteroid-dehydrogenase and interrupted by five introns. The cDNA clone has a length of 2575 bp and encodes a protein of 743 amino acids. Chinese hamster ovary cells transfected with the cDNA construct show alpha-N-acetylglucosaminidase activity about 17-fold over background. This will allow correction studies with NAG deficient Sanfilippo B cell lines and facilitate the development of enzyme replacement therapy for these patients.      

Hyperreactio luteinalis despite the absence of a corpus luteum and suppressed serum follicle stimulating concentrations in a triplet pregnancy

Hyperreactio luteinalis is characterized by moderate to marked cystic enlargement of the ovaries related to multiple theca lutein cysts and is associated with very high sex steroid concentrations. It is a rare condition especially in the first trimester. The case described below is believed to be the only case of hyperreactio luteinalis reported following frozen embryo transfer. This case provides an opportunity to gain further insight into the mechanism responsible for this unusual condition. The 30 year old woman demonstrated a slightly elevated LH/FSH ratio (5 and 3 mIU/ml respectively) and normal baseline androgen concentrations. Two years following oocyte retrieval she had a second frozen embryo transfer. The ovaries were normal size when the embryos were transferred and androgens were still normal. The ovaries did not begin to enlarge until 51 days from transfer. A dichorionic intrauterine pregnancy with monozygotic twins in the left gestational sac was seen. Eventually, 86 days from transfer, the ovaries enlarged to 145x103x116 mm right; and 83x95x117 mm left. Serum oestradiol was 30 078 pg/ml, beta-human chorionic gonadotrophin (HCG) 239 920 mIU/ml, serum progesterone >160 ng/ml, total testosterone 2254 ng/dl, free testosterone 42.3 pg/ml and androstenedione 7328 ng/dl. Throughout the first trimester, serum FSH was <1 mIU/ml. Thus, neither FSH nor a corpus luteum is necessary to initiate this syndrome.     

Localized form of colitis cystica profunda--a case of occurrence in the descending colon.

An unusual localization of localized colitis cystica profunda in a 31-year-old man is described. The patient presented as anal bleeding and a protruding mass at the descending colon; the mass was polypoid and was made up of papillary epithelial hyperplasia with downward herniation of glands into the submucosa. Only one similar case involving a descending colon has been reported in the world literature.     

Waning Antibody Responses in Asymptomatic and Symptomatic SARS-CoV-2 Infection

We investigated the kinetics of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies in 7 asymptomatic persons and 11 patients with pneumonia. The geometric mean titer of neutralizing antibodies declined from 219.4 at 2 months to 143.7 at 5 months after infection, indicating a waning antibody response.     

Surveillance of COVID-19–Associated Multisystem Inflammatory Syndrome in Children,South Korea

A concerning development during the coronavirus disease pandemic has been multisystem inflammatory syndrome in children. Reports of this condition in East Asia have been limited. In South Korea, 3 cases were reported to the national surveillance system for multisystem inflammatory syndrome in children. All case-patients were hospitalized and survived with no major disease sequelae.