A semiautomated isolation procedure for selecting low-serum-requiring animal cell population

Isolation of low-serum-requiring mouse-mouse hybridoma and human hybridoma cell population was done in a simple, gradual, and semiautomated selection system. It involved the addition of medium containing a lower serum level than that of the culture vessel. The rate of addition was determined by the rate of acidification of the culture medium in the vessel. Therefore, the whole population was subjected to a gradual and continuous reduction of serum level. Dilution rate was determined by the genetic potential of individual cells. Thus, the lowest-serum-requiring cells could be isolated within the shortest possible time, without the labor of repeating subculturing.

The Beri-Beri Hospital, Singapore (1907-1925)

The high incidence of Beri-beri in the 1890s and 1900s coupled with the ignorance of its causation led to many forms of treatment, culminating in the establishment of a "specialised hospital" in Singapore. However, the "anti-beri-beri" factor in unpolished rice soon made this hospital redundant.

Transient cold shock induces the heat shock response upon recovery at 37 degrees C in human cells

We evaluated the effects of a transient cold shock followed by recovery and incubation at 37 degrees C on the regulation of heat shock gene expression in the IMR-90 human diploid fibroblasts and HeLa cells in tissue culture. We showed that preincubation of cells at 4 degrees C induced the synthesis and accumulation of the heat shock proteins (HSPs) upon recovery at 37 degrees C, and the degree of this induction was directly related to the time that the cells spent at 4 degrees C. Assays on the abundance of the hsp 70 transcript, the hsp 70 gene promoter activity, and the trimerization and activation of heat shock factor (HSF) to bind to its consensus heat shock element (HSE) provided evidence that this induction of the heat shock response in cells recovering from a transient cold shock is attributable to a transcriptional event mediated by the activation of HSF. Further, the induction was a response to the temperature upshift from 4 to 37 degrees C as opposed to the 4 degrees C treatment itself; quantitation of the HSE-binding activity of cells incubated at 4 degrees C without recovery and incubation at 37 degrees C gave no evidence of an activated response. Analysis of the effects of protein synthesis inhibitors demonstrated that neither cycloheximide nor puromycin was effective in blocking the induction of HSE-binding activity in cells recovering from a transient cold shock. Experiments on the time course and temperature dependence of this induction of HSE-binding activity showed that the onset, magnitude, and duration of this induction were directly proportional to the severity of the cold stress (measured by time and temperature). We discuss the possible mechanism(s) involved in this induction of the heat shock genes at 37 degrees C by a transient cold shock and the biological implications of this observation.

Pyogenic vertebral osteomyelitis: treatment by anterior spinal debridement and fusion

Forty-three patients with pathologically proven vertebral osteomyelitis were studied between 1957 and 1990. Thirty-nine underwent anterior debridement and fusion, and four underwent anterior debridement only. The indications for surgery were uncertain diagnosis, persistent pain, failed conservative treatment with uncontrolled sepsis, and neurological involvement. Thirty patients were followed-up for an average period of 5 years, with a minimum of 2 years and the longest for 15 years. All their symptoms improved after surgery; only one patient subsequently deteriorated due to multiple level recurrence. All patients with neurological deficit improved. Bony fusion occurred in 93% of cases (average time to fusion, 6.8 months), and 90% of the patients were able to return to their original work 4-20 months after surgery. We feel that anterior debridement and spinal fusion allow for reliable microbiological and histological diagnosis, and rapid relief of symptoms and return to work. Primary bone grafting is successful despite the presence of infection.

Early years of the out-patient services, Singapore (1880-1946)

This article traces the history of the Out-patient Services from its humble beginnings in the late 19th Century to just after World War II. The class of patients catered for, the disease pattern, the work done and benefits accrued are recorded.

Effects of pre-conditioning and microbial composition on the sensing efficacy of a BOD biosensor

Sensitivity and the linear range of BOD measurement of a microbial BOD sensor using a mixed cell population of Bacillus subtilis and Bacillus licheniformis 7B depend significantly on the proportion of the two microorganisms and on the cell population immobilized on the biofilm. Optimum characteristics were obtained with equal proportion of the two microorganisms and an immobilized cell population of not less than 10(8) in the biofilm. Pre-conditioning of newly installed biofilm was best carried out in high BOD solutions and the time required to fully activate the microbial system decreased with increasing cell population. Fully activated biofilm remained stable and gave reproducible results for over 200 measurements covering a time period of more than 2 months. The technique of cell immobilization used in the present study provided a close control of the population and composition of the two microorganisms in the biofilm. Consistent and reproducible quality biofilms can therefore be produced for the preparation of the microbial BOD sensor.

Invariant pattern recognition using angular signature functions

A new concept for invariant pattern recognition is presented that uses object contour information. First, an angular signature of the object contour is obtained by a nonlinear operation applied to two-dimensional directional convolutions with a long, narrow kernel. The angular signature function is normalized by either its area or its energy to achieve quasi-invariance to scale. The resulting signature is then compared with template signatures for the invariant recognition for which an angular similarity measure is obtained from a one-dimensional correlation between the two signatures. Numerical experiments demonstrate that the method discussed exhibits invariance to shift and angular orientation and quasi-invariance to scale.

NMDA receptor antagonist decreases the progesterone-induced increase in GnRH gene expression in the rat hypothalamus

We previously reported that GnRH gene expression was enhanced by progesterone (P) in the hypothalamus from ovariectomized and estrogen (OVX+E) treated immature rats. Recent studies indicate that excitatory amino acids may play an important role in the regulation of GnRH secretion and gene expression by steroids. Therefore the present study attempts to examine whether excitatory amino acids are involved in the P-induced GnRH gene expression and release in vitro. MK-801, an NMDA receptor antagonist or CNQX, a non-NMDA receptor antagonist, was administered to OVX+E+P-treated prepubertal female rats. GnRH mRNA was determined by Northern blot hybridization using 32P-labeled antisense RNA, and GnRH release in vitro from the hypothalamic fragments was monitored by GnRH radioimmunoassay. The administration of MK-801 (0.2 mg/kg) for 2 h significantly reduced the P-induced GnRH gene expression and release, whereas CNQX (0.4 mg/kg) had no effect. These results clearly indicate that excitatory amino acids by way of NMDA receptor are involved in the transsynaptic regulation of GnRH gene expression.

The Mental Diseases Hospital, Singapore (1st 100 years)--Part IV

This article (in four parts) traces the history of the first four Mental Hospitals built in Singapore, which were occupied in 1840, 1861, 1887 and 1928. The management of the patients is described; also their lives and deaths. Mention is also made of the doctors and others who looked after them.

The mental diseases hospital, Singapore (the first 100 years)--a short history (Part III)

This article (in four parts) traces the history of the first four Mental Hospitals built in Singapore, which were occupied in 1840, 1861, 1887 and 1928. The management of the patients is described; also their lives and deaths. Mention is also made of the doctors and others who looked after them.

The mental diseases hospital, Singapore (1st 100 years)--a short history (Part II)

This article (in four parts) traces the history of the first four Mental Hospitals built in Singapore, which were occupied in 1840, 1861, 1887 and 1928. The management of the patients is described; also their lives and deaths. Mention is also made of the doctors and others who looked after them.

The mental diseases hospital, Singapore (the first 100 years)--a short history (Part I)

This article (in four parts) traces the history of the first four Mental Hospitals built in Singapore, which were occupied in 1840, 1861, 1887 and 1928. The management of the patients is described; also their lives and deaths. Mention is also made of the doctors and others who looked after them.

Renal salt wasting in patients treated with high-dose cisplatin, etoposide, and mitomycin in patients with advanced non-small cell lung cancer

Cisplatin has many toxic effects; emesis, impairment of renal function, myelosuppression, peripheral neuropathy, ototoxicity and renal tubular wasting. We used MVP regimen (Mitomycin C, Vp-16, and Cisplatin) in advanced Non-Small Cell Lung Cancer (NSCLC). Using hydration and prophylactic supplementation of sodium and potassium before and during chemotherapy, we have observed the development of hyponatremia in 48 courses (43%), hypokalemia in 23 courses and hypomagnesemia in 11 courses. Some patients showed abnormalities of renal function in 16 courses. All the electrolyte depletion and renal problem was corrected before next courses by hydration and replacement of the wasting. Frequent measurement of serum cation and appropriate replacement are recommended when high dose Cisplatin containing regimen is used in chemotherapy of neoplasms.

Comparison of 26- and 27-G needles for spinal anesthesia for ambulatory surgery patients

Seven hundred thirty ambulatory surgery patients, randomly assigned to receive spinal anesthesia with a 26- or 27-G needle, were studied for the incidence of post-dural puncture headache (PDPH), postoperative back pain, and patient acceptance. The incidence of PDPH following the use of 26- and 27-G needles was 9.6% and 1.5%, respectively (P less than 0.05). The incidence of PDPH was 5.7% among men and 13.4% among women following the use of 26-G needles (P less than 0.05), whereas no difference between men and women was noted after the use of 27-G needles. Of the patients who were 40 yr of age or younger, the overall incidence of PDPH was 11.9%, with a 7.5% incidence among men and a 16.4% among women following the use of 26-G needles (P less than 0.05) and a 1.8% incidence of PDPH following the use of 27-G needles, with no statistical difference between genders. Postoperative back pain was experienced in 18.3% of the patients in the 26-G group and 20.2% in the 27-G group (difference not significant). Favorable acceptance of spinal anesthesia was reported in 89.4% of patients in the 26-G group and 98.2% in the 27-G group (P less than 0.01). Results from this study demonstrate that, in patients who received spinal anesthesia for ambulatory surgery, the use of 27-G needles resulted in a significantly lower incidence of PDPH and greater patient acceptance compared with the use of 26-G needles. The incidence of postoperative back pain was not significantly different between the two groups.

Molecular events involved in transcriptional activation of heat shock genes become progressively refractory to heat stimulation during aging of human diploid fibroblasts

We examined the induction, by heat shock, of heat shock transcription factor (HSTF) DNA-binding and hsp 70 gene promoter activities during aging of the IMR-90 human diploid fibroblasts. Cells with population doubling level (PDL) ranging from 15-48 were heat shocked at temperatures of 39, 42, and 45 degrees C for various time periods; the binding of HSTF to its consensus DNA was determined by gel retardation assay and the promoter activity of the human hsp 70 gene was analyzed by transient expression of reporter gene activity. We observed that the induction of HSE-binding activity was inversely related to the PDL of the cells used. Importantly, as cells progress through their life span, a higher temperature and a longer period of heat shock were needed to evoke an optimal increase in HSE-binding activity. A substantial and rapid (within 30 min) increase in HSE-binding activity was observed when PDL 20 cells were heat shocked at 39, 42, or 45 degrees C. However, PDL 35 cells did not respond to 39 degrees C, and PDL 48 cells responded slowly to heat shock at 45 degrees C, but not 39 or 42 degrees C. Experiments on the heat induced increase in hsp 70 promoter driven reporter gene expression provided similar information on the age-dependent decrease in transcriptional activation of hsps. These results were further corroborated by quantitation of the abundance of mRNA of hsp 70. Analysis of the cAMP induced expression of the rat somatostatin promoter driven CAT gene provided evidence that the decrease in transcriptional activation of hsps in aging diploid cells was not a reflection of a generalized dysfunction of signal transduction. We conclude that functional changes in the heat shock response occur before cells lose their capacity to replicate, and we suggest that these changes are likely to have a central role in the expression of the aging phenotype.

A short history of Kandang Kerbau Hospital and the maternity services of Singapore

This article traces the history of Kandang Kerbau Hospital ("the hospital beside the Bukit Timah Canal") and the maternity and infant welfare services of Singapore from 1858 to the present. This includes the development of teaching of Obstetrics and Gynaecology to medical undergraduates and postgraduates, and the training and registration of midwives, and the resulting saving of maternal and infant lives. Why was Kandang Kerbau Hospital converted into a Maternity Hospital in 1924?

Nonlinear image processing by a rotating kernel transformation

We present a new method for nonlinear image processing that is well suited for hybrid optical-electronic implementation. An input image is convolved with a long, narrow two-dimensional kernel that is rotated, either continuously or discretely, through 360 deg. During rotation the convolution output is monitored, and the maximum and minimum values measured at each point are stored. The processed image is given by an application-dependent function of Max(x, y) and Min(x, y). Setting the output equal to [Max(x, y) - Min(x, y)] enhances straight-line features in noisy, low-contrast images. Better results can be obtained by cascading a Max and a [Max - Min] operation. Numerically calculated examples illustrate the method and compare it with linear filtering.

Low-nicotine regenerated smoke aerosol reduces desire for cigarettes

We have developed a method of producing an aerosol with many of the sensory qualities of cigarette smoke, but with only 3% of the tar and nicotine and none of the carbon monoxide of a typical commercial cigarette. The aerosol was generated from a suspension of 1% cigarette smoke condensate in 10% ethanol. The aerosol, generated with an ultrasonic nebulizer, resembled smoke visually but had a larger particle size than cigarette smoke (3.5 microns vs. 0.5 micron mass median diameter). Twelve smokers rated blocks of 10 puffs of aerosolized smoke solution, a popular commercial cigarette, and an unlit cigarette (control). The blocks of puffs were evaluated for sensory qualities and smoking satisfaction obtained. The rated strength of the smoke aerosol was comparable to that of the commercial cigarette. The aerosol was rated significantly more desirable and more satisfying than the control, though not as desirable as the commercial cigarette. Surprisingly, the smoke aerosol reduced self-reported desire for cigarettes as much as the commercial cigarette. This new method is a promising approach for evaluating the role of sensory cues in smoking, and it may also be useful as a clinical tool for smoking cessation.

Four-wave theory of electrooptic gratings with a simple expansion for use in design

A four-wave theory of phase gratings electrooptically induced in dielectric waveguides is analyzed and solutions to the coupled-wave equation are derived for incidence at the first Bragg angle. These solutions are compared with the solutions for the two-wave theory of Kogelnik, and expansions for the differences are obtained in reciprocal powers of the Nath parameter rho. The leading terms in the expansion can be used to estimate the errors committed in designs using the simpler two-wave theory.

Endoscopic extraction of a perforating wire from the stomach

A Report on the succesful endoscopic removal of a wire 3.8 cm long which perforated the gastric wall.

Clinical experience in 200 renal transplants at Catholic Medical Center

Between March, 1969, and April, 1986, two hundred of renal allograft recipients were treated with either cyclosporine (CsA) + prednisone (n=53) or azathioprine (Aza) + prednisone (n = 147). On October 31, 1986, the actuarial patient survival rate at two years was 75% for all patient group. The corresponding graft survival rate at two years was 68 % for all patients. The actuarial patient survival rate at two years was 71% in the Aza group, and 94% in the CsA group including recipients converted from CsA to Aza (3 cases), which was statistically significant (p<.001), and the corresponding graft survival rate was 65% and 80%: the difference was not statistically significant. In the CsA-treated group, excluding converter from CsA to Aza (3 cases), however, the graft survival rate at two years was 91%, which was statistically significant (p = .0056). There was no significant difference of graft survival rate between the recipients who received DST vs non-DST in CsA-treated group. It was difficult to evaluate the recipients who were given DST due to a small number of cases and short follow-up period. In either, the Aza-or the CsA-treated group, the graft survival rates were higher in HLA identical LRD group than in either haplo-identical or mismatched LRD group. Total of 63 patients, who received kidney transplantation expired. The most frequent cause of death in 17.5% of cases was uremia per se due to graft failure, followed by infection (14.7%), vascular (14.3%), and cardiac (11.1%). The most commonly encountered posttransplant complications in order of frequency were as follows: erythrocytosis (18.0%), pneumonia (15.0%), urinary tract infections (14.0%), herpetic infections (12.0%), fungal infection (11.5%), posttransplant diabetes (8.5%), technical (5.0%) and others.

Spinal tuberculosis presenting with abdominal symptoms--a report of two cases

We present two unusual cases of tuberculosis of the spine presenting with abdominal symptoms; both patients underwent exploratory laparotomy before the true nature of the diagnosis became known. The diagnosis of spinal tuberculosis was evident on the pre-operative abdominal radiographs but this was overlooked.

Antibodies to Actinobacillus actinomycetemcomitans in a Korean population

Previous studies demonstrated that serum antibodies to Actinobacillus actinomycetemcomitans strain Y4 are significantly elevated in sera from localized juvenile periodontitis (LJP) and postlocalized juvenile periodontitis (P-LJP) patients compared to normal controls in United States populations. This study examined the age of subjects in relation to the antibody levels to A. actinomycetemcomitans in a Korean population. Seven groups were investigated including sera from newborns, infants, children, periodontally normal puberty and adult groups and LJP and P-LJP groups. Antibody levels were determined by an enzyme-linked immunosorbent assay (ELISA) to A. actinomycetemcomitans strain SNUDC 10-1 (serotype C) isolated from a Korean LJP patient. In the healthy non-LJP and non-P-LJP subjects, IgG levels decreased from the newborn group to the 5-month-old group and then gradually increased through the adult group. The IgM levels in these groups continuously increased from birth until a plateau was reached in the 2- to 6-year group. Serum IgA levels to strain SNUDC 10-1 were too low to be measured by this assay.

A clinical trial with cefoperazone in pneumonia and pyelonephritis

15 cases of pneumonia and 15 cases of pyelonephritis were included in a clinical trial of parenteral cefoperazone. The organisms isolated from patients with bacterial pneumonia were: Staphylococcus aureus (6), Klebsiella pneumoniae (5), Diplococcus pneumoniae (3), Pseudomonas species (2), and 6 others. Amongst those with pyelonephritis, Escherichia coli (12), Enterobacter (1), and 3 other pathogens, were isolated. All were sensitive to cefoperazone. The efficacy of cefoperazone in patients with pneumonia was: good in 11 (73%), fair in 3, and poor in 1. In pyelonephritis, 12 (80%) responded well and in the other 3 response was fair. There were no significant side effects or hypersensitivity reactions.