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Biomedical subjects

R Kay

Publications and source records attributed to R Kay.

At least 127 records · Page 7Linked to original sources
PubMed1994

Neonatal testis tumors: a review of the Prepubertal Testis Tumor Registry.

Since 1980, 338 testis tumors have been registered in the Prepubertal Testis Tumor Registry of the American Academy of Pediatrics, Section on Urology. Of these tumors 22 occurred in neonates less than 1 month old, of which 7 (31%) were diagnosed at birth. The distribution of lesions in this group revealed 6 yolk sac tumors, 6 gonadal stromal tumors, 6 juvenile granulosa cell tumors, 2 gonadoblastomas, 1 teratoma and 1 hamartoma. Preoperative serum alpha-fetoprotein levels were available for 10 patients and ranged from 23 to 61,700 ng/ml., which is within normal limits. No patient had evidence of metastatic disease at presentation. Of the 18 children in whom follow up is available 17 have no evidence of disease and 1, who was diagnosed with a yolk sac tumor before the advent of chemotherapy, died of metastatic disease before reaching age 1 year. Although neonatal testis tumors are rare, they should be considered in the differential diagnosis and management of a newborn with a scrotal mass.

Follow-Up Studies↗
PubMed1994

Long-term results of renal transplantation into the valve bladder.

Between 1970 and 1990 renal transplantation was performed in 16 patients with a history of posterior urethral valves. While 10 patients had undergone supravesical urinary diversion before the development of end stage renal disease, all but 1 transplant were drained to the unaugmented native bladder. The 2 and 5-year graft survival rates were 70% and 59%, respectively. Of the 15 surviving patients 11 have allografts that are functioning at a mean of 86 months after transplantation with a mean serum creatinine of 2.0 mg./dl. Urological complications occurred in 19% of the transplants. No detrimental effect of the valve bladder on long-term allograft survival or function was apparent. With appropriate treatment of vesical dysfunction, these patients can be expected to have graft function comparable to the general transplant population despite use of the unaugmented native bladder.

Adolescent↗
PubMed1994

Pilot study of low-molecular-weight heparin in the treatment of acute ischemic stroke.

BACKGROUND: Our purpose was to assess the feasibility and risk of performing a double-blind placebo-controlled study of low-molecular-weight heparin in the treatment of acute ischemic stroke. SUMMARY OF REPORT: Fifty-five patients were treated within 48 hours of stroke onset. Pretreatment computed tomography was performed to rule out cerebral hemorrhage. Fraxiparine (6000 IU per day) was given subcutaneously for 7 days. No adverse reaction was encountered during the treatment period. At 3 months, 26 patients were independent, 21 moderately disabled, 4 severely disabled, and 4 dead. CONCLUSIONS: It would be safe and practical to conduct a clinical trial on the use of Fraxiparine in the treatment of acute ischemic stroke.

Acute Disease↗
PubMed1993

Expression of Thy-1 on human hematopoietic progenitor cells.

Expression of Thy-1 on hematopoietic cells from human fetal liver (FL), cord blood (CB), and bone marrow (BM) was studied with a novel anti-Thy-1 antibody, 5E10. Specificity of 5E10 for human Thy-1 was demonstrated by immunoprecipitation of a 25-35-kD molecule, and the sequence of a cDNA that was cloned by immunoselection of COS cells transfected with a cDNA library derived from a 5E10+ cell line. Two- and three-color immunofluorescence staining experiments revealed that the Thy-1 expression is restricted to, an average, 1-4% of FL, CB, and BM cells, and binding to these cell types is essentially restricted to a very small subset of lymphoid cells and approximately 25% of CD34+ cells. Thy-1+ CD34+ cells were further characterized as CD38lo/CD45RO+/CD45RA-/CD71lo/c-kit(lo) and rhodamine 123dull. When CD34+ cells were sorted on the basis of Thy-1 expression, the majority of clonogenic cells were recovered in the CD34+Thy-1- fraction, whereas the majority of cells capable of producing myeloid colonies after 5-8 wk of long-term culture (long-term culture initiating cells) were recovered in the Thy-1+CD34+ fraction. In addition to CD34+ cells, Thy-1 was found to be expressed on a variable, very small number (< 1%) of CD34- mononuclear cells in BM, CB, and peripheral blood that were further characterized as CD3+ CD4+ lymphocytes. The restricted expression of Thy-1 on primitive hematopoietic cells is in agreement with a previous report (Baum et al., 1992. Proc. Natl. Acad. Sci. USA. 89:2804) in which Thy-1 expression was used to enrich for primitive hematopoietic cells from fetal tissue. Compared with those previous studies, we found Thy-1 expression on a larger proportion of CD34+ cells (25% in our study vs. 5% in Baum et al.) and furthermore performed studies on Thy-1 expression on CD34+ cells from CB, FL, and BM in relation to markers that are known to be differentially expressed on hematopoietic cells. Taken together our results indicate that Thy-1-specific antibody 5E10 is an attractive tool for further studies on the biology and purification of human stem cells.

Adult↗
PubMed1993

Reoperation for cryptorchid testis in prepubertal child.

Twenty-two prepubertal patients with cryptorchid testes after having previous inguinal surgery were referred. These included 17 patients in whom orchidopexy had been unsuccessful. Five patients had prior surgery for hernia and/or hydrocele resulting in surgical entrapment of the testis. Five patients had bilateral disease. In 1 patient the testis was involved in Marlex mesh, 1 had had two prior orchidopexies, and 1 had prune belly syndrome. Postoperatively the testes were in good position in the scrotum in all 22 cases, with mean follow-up of 8.9 months. All testes were of normal size, and no atrophic testes ensued following the procedures. Principle factors for success in re-exploration included initial retrograde dissection of the testis and cord, intraperitoneal exposure, and subsequent dissection and adequate lengthening of the cord with protection of the spermatic vessels.

Child↗
PubMed1993

Successful treatment of amoebic meningoencephalitis in a Chinese living in Hong Kong.

Primary amoebic meningoencephalitis due to Naegleria fowleri was found in a 38-year-old Chinese man living in Hong Kong who presumably acquired the infection from swimming in a hot spring in neighbouring China. Amoebic cysts were identified in tissue taken from a brain abscess. The patient responded to surgical drainage and a 6-week course of amphotericin B, rifampicin and chloramphenicol. This is one of 6 cases of successful treatment of primary amoebic meningoencephalitis documented in the medical literature.

Adult↗
PubMed1993

Prepubertal Testicular Tumor Registry.

The Prepubertal Testicular Tumor Registry has been in existence for 12 years. Information on 327 patients was collected and registered in the database. Demographic data have been analyzed, leading to a better understanding of these rare tumors. Information regarding the natural history and behavior of the tumors has also evolved from a retrospective review of the tumors. The registry will continue in an effort to collect centrally information on these unusual tumors and to attempt to aid in developing a better understanding of the natural history and behavior of the tumors to provide early detection, consistent treatment and improved survival.

Child↗
PubMed1993

Testis sparing surgery for pediatric epidermoid cysts of the testis.

Epidermoid cyst of the testis is a rare, benign intratesticular tumor in children. Four patients 4 to 15 years old with epidermoid cysts were managed by tumor excision with salvage of the testis. Preoperative ultrasound, tumor marker status and intraoperative findings were suggestive of a benign neoplasm. Under these circumstances epidermoid cysts may be safely treated by excision in prepubertal patients.

Adolescent↗
PubMed1993

Effect of intravenous ketanserin on arterial and intracranial pressures in patients with systemic hypertension following intracerebral haemorrhage.

The response of arterial BP and intracranial pressure to an intravenous injection of the serotonin antagonist, ketanserin, was recorded in ten patients with hypertension following intracerebral haemorrhage. Five minutes after ketanserin administration, arterial pressure had fallen by 40/21 mmHg from a baseline level of 213/113 mmHg, and remained below pre-treatment levels for two hours. Intracranial pressure was steady throughout the two hour observation period. Although calculated cerebral perfusion pressures declined and whereas it is not known if cerebral perfusion might have been compromised in zones of borderline ischaemia, the present data suggest that ketanserin might be preferred to drugs known to raise intracranial pressure or agents requiring infusion and intensive haemodynamic monitoring for patients with severe hypertension complicating intracerebral haemorrhage.

Blood Pressure↗
PubMed1993

Prepubertal testicular tumor registry.

There are 327 patients in the Prepubertal Testicular Tumor Registry, and demographic data and a better understanding of the natural history and behavior of the tumors have evolved. Information on these rare tumors should be collected centrally and treatment using national protocols followed closely. Continuation of the Registry is important to help clarify the knowledge of these unusual tumors and to aid in the management of these patients through information from a large database.

Child↗
PubMed1992

Hypertension as a complication of multicystic dysplastic kidney.

The detection of multicystic dysplastic kidney in utero using prenatal ultrasound is becoming a more frequent occurrence. An accurate diagnosis of multicystic dysplastic kidney usually can be made radiographically, and therefore the main indication for surgery in the asymptomatic patient may be the potential risk of complications developing later in life. We report hypertension as a complication of multicystic dysplastic kidney and review the literature.

Child, Preschool↗
PubMed1992

Biodegradable pericardial implants for bladder augmentation: a 2.5-year study in dogs.

Bladder augmentation using biodegradable pericardial tissue was evaluated in canine bladders. Acetic acid and acetic anhydride treated pericardial tissue grafts were stored in 75% ethanol for 18 to 27 months before implant. Ten dogs weighing 20 to 25 kg. were subjected to a 50% partial cystectomy. After careful separation of the mucosa, bladder muscle and adventitial layers a pericardial graft volumetrically equivalent to the portion of the bladder removed was sutured to the bladder remnant in 2 layers. In 1 control dog the bladder was opened, 50% of the bladder was removed and the bladder was closed primarily. In another control dog the excised bladder was replaced with fresh chemically treated patch material that was never subjected to ethanol storage. Excretory urography and cystography were performed on all dogs. Urodynamics with filling pressures and bladder volumes measured before and after the operation at intervals of up to 36 months confirmed that adequate bladder capacity was achieved. There were no operative complications. Postmortem histological evaluations revealed a smooth epithelialized inner surface with no traces of any surface irregularities or suture lines. The bladder apex showed an intact epithelium and the absence of a smooth muscle layer. The biodegradable acetylated tissue provides an intact structural reservoir for urine and serves as a template for epithelial regeneration. This permits volumetric bladder enlargement while the graft is progressively reabsorbed with time.

Animals↗
PubMed1992

Soluble CD23 levels are elevated in the serum of patients with primary Sjögren's syndrome and systemic lupus erythematosus.

The low affinity IgE receptor Fc epsilon RII (CD23) is important in several aspects of T and B cell function. In this study serum levels of soluble CD23 (sCD23) were measured in three groups: 26 female patients with systemic lupus erythematosus (SLE), 21 females with primary Sjögren's syndrome (pSS) and 25 normal healthy females. The concentration of sCD23 was determined using an enhanced chemiluminescent sandwich ELISA developed in this laboratory. Increased levels of sCD23 were observed in pSS and in SLE patients compared with controls (median 23.0 versus 8.6, P less than 0.0002 and 18.1 versus 8.6, P less than 0.002 respectively). While the median level of sCD23 was found to be higher in pSS than in SLE the difference was not statistically significant. Patients with SLE and pSS on glucocorticoid treatment had significantly lower levels of sCD23 than patients not on this treatment (median 28.9 versus 14.4, P less than 0.05). Amongst the control patients sCD23 was inexplicably lower in the female members relative to the males (median 8.5 versus 12.3, P less than 0.05). Although serum IgG and IgA levels were significantly elevated in pSS and SLE patients relative to controls there was no direct correlation between sCD23 and the serum levels of these immunoglobulins. We conclude that B cell hyperactivity which occurs in both pSS and SLE is associated with raised levels of sCD23.

Adult↗
PubMed1992

Elderly subjects aged 70 years and above have different risk factors for ischemic and hemorrhagic strokes compared to younger subjects.

OBJECTIVE: To compare risk factors for ischemic and hemorrhagic strokes in subjects aged 70 years and above with those in younger subjects. DESIGN: Case control study, with controls matched for age and sex in 5-year age groups. SETTING: A general district hospital in Hong Kong with a catchment population of over 1 million. PATIENTS: All patients admitted consecutively over a 6-month period. Classification of stroke was by neurological examination and CT scan, or autopsy if death occurred before CT scanning could be performed. EXCLUSION CRITERIA: onset of ictus greater than 48 hours before admission, those with previous stroke, subarachnoid hemorrhage, or embolic stroke from rheumatic heart disease, and those with liver, renal, biliary, or thyroid diseases. For ischemic strokes, 78 pairs less than 70 years and 121 pairs greater than or equal to 70 years were recruited. For hemorrhagic strokes, the numbers were 40 and 39, respectively. RESULTS: For ischemic strokes, atrial fibrillation and the presence of ischemic heart disease were risk factors only for those aged 70 years and above, while smoking and left ventricular hypertrophy were risk factors only for those below 70 years. Hypertension and glucose intolerance were risk factors for both age groups, although the effect of glucose intolerance was less marked in the older group. No marked difference in serum lipids and lipoproteins as risk factors was observed between the two age groups. Hypertension was the only demonstrable risk factor for hemorrhagic stroke in the younger, but not in the older, group. CONCLUSION: Risk factors for ischemic and hemorrhagic strokes are different in elderly compared with younger subjects, with the possibility that certain risk factors for ischemic strokes, in contrast to those for hemorrhagic strokes, may be modifiable even in subjects aged 70 years or above.

Age Factors↗
PubMed1992

Hospital arrival time after onset of stroke.

To estimate the proportion of patients with stroke likely to be eligible for a trial of anticoagulant treatment for acute ischaemic stroke, the interval between onset of symptoms and arrival at hospital was analysed prospectively. Of 773 patients with stroke admitted in one year, 63% arrived at hospital within 12 hours, 76% within 24 hours, and 85% within 48 hours of ictus. The arrival time varied significantly with stroke subtype. Patients with intracerebral haemorrhage tended to arrive earlier than those with cerebral infarct, who arrived sooner than those with lacunar infarct. The results suggest that about half of all patients with ischaemic stroke in Hong Kong would present within 12 hours of ictus, in time for inclusion in a therapeutic trial.

Aged↗
PubMed1992

Factors influencing long-term survival and disability among three-month stroke survivors.

216 survivors of acute stroke were studied 3 months postictus to determine predictors of long-term survival and disability 20 months after the initial stroke. Factors predicting mortality were, in order of importance, old age, a history of ischaemic heart disease, low mental-test score, low serum cholesterol concentration, low Glasgow Coma Score on admission, and the presence of left ventricular hypertrophy. 73% of subjects were correctly classified by discriminant function analysis using these variables. Factors predicting poor functional outcome (Barthel Index 15) were a low Barthel Index at 3 months, old age, low mental-test score at 3 months and a low Glasgow Coma Score on admission. 70% of subjects were correctly classified into 3 functional-outcome groups using these variables. Stroke subtype and size, position, and the territory of the lesion on brain CT did not influence long-term outcome. We conclude that factors affecting long-term survival and disability are different from those affecting outcome immediately after stroke.

Aged↗